CN1126982C - Front-illuminating device and reflection-type liquid crystal display using such device - Google Patents

Abstract

The present invention relates to a front lighting device and a reflection type liquid crystal display device equipped with the device. The first radiating surface for radiating light and the second radiating surface for radiating reflected light from the object to be illuminated, the second radiating surface is formed in a stepped shape by alternately connecting inclined parts and flat parts, and the first radiating surface radiates light from the light source to the object to be illuminated Reflected by the illuminated object, the reflected light reaches the observer side through the flat part, and the light parallel to the flat part of the light source light is reflected by the inclined part and irradiated to the illuminated object, which has the advantages of high light utilization efficiency of the light source.

Description

Front lighting device and reflective liquid crystal display device having the same

technical field

The present invention relates to a front lighting device, which is arranged between an object to be illuminated and an observer, irradiates light to the object to be illuminated, and at the same time must allow reflected light to pass through, so that the observer can recognize the reflected light of the object to be illuminated, and has The front lighting device is a reflective liquid crystal display device as an auxiliary light source.

Background technique

Unlike other displays called cathode ray tubes (CRT: Cathode Ray Tube), plasma display panels (PDP: Plasma Display Panel) or electroluminescent devices (EL: Electro Luminescence), liquid crystal displays do not emit light by themselves. The amount of transmitted light from a specific light source is used to display text or images.

Conventional liquid crystal display devices (hereinafter referred to as LCDs) can be broadly classified into transmissive LCDs and reflective LCDs. In a transmissive LCD, a surface emitting light source such as a fluorescent tube or EL is arranged as a light source (back light) on the back of a liquid crystal tube.

In addition, reflective LCDs have the advantage of less power consumption because they use ambient light for display and do not require backlighting. In addition, in a very bright place such as direct sunlight, the display on the reflective LCD is more vivid than that of the light-emitting display or the display of the transmissive LCD, which is almost invisible. Therefore, reflective LCDs are suitable for portable information terminals and mobile computers, which are increasingly in demand in recent years.

However, reflective LCDs have the following problems. Since reflective LCDs utilize ambient light, the display brightness is highly dependent on the surrounding environment. Therefore, especially at night, it may also appear completely unrecognizable. Especially in reflective LCDs that use color filters for colorization and reflective LCDs that use polarizers, the above-mentioned problems are more prominent, and auxiliary lighting is necessary when the ambient light is insufficient.

However, since the reflective LCD has a reflector on the back of the liquid crystal tube, it does not use backlighting like the transmissive LCD. A device known as a transflective LCD using a half mirror as a reflector was also proposed, but its display characteristics were neither transmissive nor reflective, and it was considered difficult to put it into practical use.

Therefore, in places where the surroundings are not bright, it has been proposed in the past to arrange a front lighting system in front of the liquid crystal tube as an auxiliary lighting for reflective LCDs. Previous lighting systems generally have a light guide and light sources arranged laterally to the light guide. The light from the light source incident from the side of the photoconductor passes through the interior of the photoconductor, is reflected by the shape of the photoconductor surface, and is radiated toward the liquid crystal cell side. The radiated light is adjusted according to the display information while passing through the liquid crystal cell, and then reflected by the reflector arranged on the back side of the liquid crystal cell. The reflected light is again transmitted through the photoconductor and radiated toward the viewer. Therefore, even when the amount of ambient light is not sufficient, the viewer can recognize the display.

In addition, such front lighting is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-158034, SID Digest P.375 (1995) and the like.

Now, with reference to FIG. 51 described later, the working principle of the front lighting system disclosed in SID abstract P.375 (1995) will be briefly explained. In the front lighting system described above, one side surface of the photoconductor 104 having the interface 101 formed by the flat portion 101 a and the inclined portion 101 b is used as the incident surface 105 of the incident light of the light source 106 . That is, the light source 106 is arranged at a position facing the incident surface 105 of the photoconductor 104 .

Among the light incident on the photoconductor 104 from the light source 106 through the incident surface 105 , a part travels in a straight line and a part enters the interfaces 101 and 108 between the photoconductor 104 and its surrounding medium. When the surrounding medium of the photoconductor 104 is air, and the refractive index of the photoconductor 104 is about 1.5, it can be seen from Snell's law (Formula 1), that the light with an incident angle of about 41.8° or more relative to the interfaces 101 and 108 is in the Total reflection occurs at the interface 101,108.

n ₁ ·sinθ ₁ ＝n ₂ ·sinθ ₂

θc＝arc sin(n ₂ /n ₁ )...(Formula 1)

In the formula, n ₁ - the refractive index of the first medium (photoconductor 104),

n ₂ - the refractive index of the second medium (air),

θ ₁ - the incident angle from the photoconductor 104 to the interface 101,

θ ₂ -radiation angle from the interface 101 to the second medium,

θc - critical angle.

Of the light incident on the interfaces 101 and 108, the light totally reflected on the inclined portion 101b as the reflection surface and the light reflected on the inclined portion 101b of the interface 101 after being totally reflected on the interface 108 are incident on the liquid crystal tube 110. enter. The light incident on the liquid crystal tube 110 is dimmed by the liquid crystal layer (not shown), reflected by the reflector 111 provided on the back of the liquid crystal tube 110, enters the photoconductor 104 again, passes through the flat portion 101a, and radiates toward the observer 109 side.

In addition, the light from the light source 106 that passes through the incident surface 105 and enters the flat portion 101a without passing through the inclined portion 101b propagates through repeated total reflection between the interface 101 and the interface 108 until reaching the inclined portion 101b. In addition, the area of the inclined portion viewed from the side of the observer 109 is formed to be sufficiently smaller than the area of the flat portion 101a.

The above-mentioned conventional front lighting system has the following problems in its structure.

(1) As shown in FIG. 52 , there is light that cannot reach the inclined portion 101 b even through repeated total reflection, and light that is approximately perpendicular to the incident surface 105 is directed toward the outside of the photoconductor 104 from the surface 107 facing the incident surface 105 . The emitted light 114 cannot be used for display. That is, the utilization efficiency of light decreases.

(2) The shape of the interface 101 composed of the inclined portion 101b and the flat portion 101a is similar to the shape of flattening the apex of the prism plate, as shown in FIG. reduce.

These problems are substantially the same as those present in conventional front lighting systems. Therefore, even if such a front lighting system is used, it is not possible to illuminate an object to be illuminated (such as a reflective LCD) with a sufficient amount of light. Therefore, it is required to improve the utilization efficiency of the light source light of the front lighting system.

Contents of the invention

In view of the above problems, the present invention aims to provide a front lighting device capable of improving the utilization efficiency of light from a light source and uniformly and brightly illuminating an object to be illuminated, and a reflective liquid crystal display device provided with the front lighting device.

In order to solve the above-mentioned problems, the front lighting device of the present invention has a light source and a photoconductor arranged in front of the object to be illuminated. The first radiating surface emits the second radiating surface of the light reflected by the illuminated object, and the above-mentioned second radiating surface is alternately composed of inclined surfaces mainly reflecting light from the light source to the first radiating surface and flat parts mainly passing the reflected light of the illuminated object. Connected to form a ladder.

In the above structure, the illumination light is radiated from the first radiation surface to the object to be illuminated, and the reflected light of the object to be illuminated returns from the first radiation surface to the inside of the photoconductor again, passes through the flat portion of the second radiation surface, and reaches the observer side. . The second radiating surface of the photoconductor facing the first radiating surface is formed into a stepped shape in which inclined parts and flat parts are alternately connected to each other, and furthermore, since the inclined part located between the flat parts and the flat parts mainly directs light from the light source to the first radiating surface. 1 Radiation surface reflection means that among the incident light from the light source, all of the light parallel to the flat portion is reflected by the inclined surface and then irradiates the object to be illuminated from the first radiation surface. Accordingly, in the front lighting device of the present invention, light traveling parallel to the flat portion is irradiated to the object to be illuminated without leaking out of the photoconductor, as compared with a conventional structure having a substantially flat photoconductor. Therefore, it is possible to provide a brighter front lighting device with high utilization efficiency of light from the light source.

A front lighting device for solving the above-mentioned problems. Furthermore, the photoconductor is used as a first photoconductor and a second photoconductor for uniformizing the luminance distribution of the radiated light from the first radiating surface.

In the above structure, since the first photoconductor is formed in steps, the distance from the inclined portion of the second radiation surface to the first radiation surface is reduced in proportion to the distance from the light source. Therefore, the luminance distribution of the light radiated from the first radiating surface is not uniform. In the above configuration, the luminance distribution of the radiated light to the object to be illuminated can be averaged by having the second photoconductor. As a result, it is possible to provide a front lighting device that is a surface light source with uniform brightness.

In order to solve the above-mentioned problems, the front lighting device further includes an optical compensation plate for aligning the radiation directions of the light emitted from the flat portion and the light emitted from the inclined portion of the second radiation surface.

In the above structure, since the second radiating surface is formed into a stepped shape in which flat portions and inclined portions are alternately connected to each other, the light incident on the light guide from the first radiating surface and reflected by the object to be illuminated respectively passes from the second radiating surface. The flat part and the oblique direction radiate in different directions, which may cause blurring of the image of the illuminated object. Therefore, a clear image of the object to be illuminated can be obtained by having an optical compensation plate that aligns the radiation directions of the light emitted from the flat portion and the light emitted from the inclined portion of the second radiation surface.

In order to solve the above-mentioned problem, the front lighting device further has a prism plate and a diffuser plate etc. between the light source and the incident surface to limit light scattering from the light source.

In the above structure, the light from the light source is mainly reflected by the inclined portion of the second radiation surface. However, since the inclined portion is not totally reflected, in order to reduce components leaking to the outside of the photoconductor, it is preferable to make the light from the light source have a certain degree of directionality. , so that the components incident on the inclined portion at an angle smaller than the critical angle are reduced. Therefore, in the above-mentioned structure, by having the prism plate and the diffuser plate that limit the light scattering of the light source, the leakage light from the inclined portion is reduced, the light utilization efficiency can be further improved, and the image of the object to be illuminated can be prevented from being blurred. As a result, it is possible to realize a front lighting device as a surface light source capable of obtaining a bright and clear image of an object to be illuminated.

In order to solve the above problems, the reflective liquid crystal display device of the present invention has a reflective liquid crystal tube with a reflective plate, and a front illuminator having the above-mentioned structure is disposed on the front of the reflective liquid crystal tube.

With the above configuration, the front lighting device can be used with the lights off when the ambient light is sufficient, for example, outdoors during the daytime, and can be used with the front lighting device turned on when sufficient ambient light cannot be obtained. As a result, it is possible to provide a reflective liquid crystal display device capable of realizing always bright and high-level display regardless of the surrounding environment.

In order to solve the above problems, another reflective liquid crystal display device of the present invention has a front illuminating device with the above-mentioned optical compensation plate on the front of the reflective liquid crystal tube with a reflector.

The optical compensation plate is flexible to a predetermined pressure, and a pair of transparent electrodes for detecting the pressure applied position by mutual contact are provided on the optical compensation plate and the second radiation surface, respectively.

In the above structure, the front lighting device has a so-called touch panel function. That is to say, for example, when a certain position on the surface of the optical compensation plate is pressed with a pen or the like, the pair of transparent electrodes respectively provided on the optical compensation plate and the second radiating surface will be positioned on the above-mentioned position due to the deflection of the optical compensation plate. touch each other. If the position can be identified as a coordinate, a reflective liquid crystal display device can be realized that uses a pen to input the content displayed on the liquid crystal tube.

Other objects, features, and advantages of the present invention can be more fully understood through the following description. In addition, the advantages of the present invention will be more clearly described below with reference to the accompanying drawings.

Description of drawings.

1 is a cross-sectional view showing the structure of a reflective LCD according to an embodiment of the present invention,

Fig. 2 (a)-(c) is the figure that shows that reflective LCD shown in Fig. 1 has the shape of front lighting photoconductor, and Fig. 2 (a) is the plan view that sees photoconductor from the top of flat part normal direction, and Fig. 2 (b ) is a side view of the photoconductor viewed from the normal direction of the incident surface, and Fig. 2 (c) is a cross-sectional view of the photoconductor with the longitudinal direction of the light source as the normal section.

3( a )-( c ) are diagrams explaining how the light from the light source behaves in the photoconductor.

FIG. 4 is a diagram illustrating the behavior of light reflected by a reflector of a reflective LCD.

Fig. 5 is an explanatory diagram of the front lighting light intensity measuring system shown in Fig. 2(a)-(c).

Fig. 6 is a graph showing the measurement results of the front lighting light intensity shown in Figs. 2(a)-(c).

7( a ) is an explanatory diagram showing the relationship between radiated light and ambient light of a light-emitting display, and FIG. 7( b ) is an explanatory diagram showing the relationship between radiated light and ambient light of a reflective LCD.

Fig. 8 is a cross-sectional view showing the structure of a reflective LCD according to another embodiment of the present invention.

Fig. 9 (a) is a cross-sectional view showing that the distance from the inclined portion of the photoconductor to the radiation surface of the front lighting system in the front lighting system of the reflective LCD shown in Fig. 8 is uniform, and Fig. 9 (b) is For comparison, it is a cross-sectional view showing a case where the distance from the inclined portion to the radiation surface serving as the front light is not uniform in the front light of the reflective LCD shown in FIG. 1 .

Fig. 10(a) and Fig. 10(b) are diagrams illustrating measurement systems for measuring the luminance distribution of the headlights shown in Fig. 9(a) and Fig. 9(b), respectively,

Fig. 11 (a) and Fig. 11 (b) are graphs showing the measurement results of the luminance distribution of the headlights shown in Fig. 9 (a) and Fig. 9 (b), respectively,

12 is a cross-sectional view showing the structure of a reflective LCD according to another embodiment of the present invention,

FIG. 13 is a schematic diagram showing the behavior of light in the front lighting system of the reflective LCD shown in FIG. 12,

14 is a graph showing the measurement results of the luminance distribution of the irradiated light of the front lighting system of the reflective LCD shown in FIG. 12,

Fig. 15 is an explanatory view showing the principle of image blurring in the reflective LCD according to Embodiment 4 of the present invention.

16 is a partially enlarged cross-sectional view of the inclined portion of the photoconductor of the reflective LCD, showing a structure in which a metal reflective film is provided on the inclined portion,

Fig. 17 (a)-(e) is the cross-sectional view showing the process of forming the above-mentioned metal reflective film,

FIG. 18 is a schematic diagram showing the behavior of light when no metal reflective film is provided in the photoconductor shown in FIG. 16 .

Fig. 19 is a sectional view showing a modification of the structure shown in Fig. 16,

20 is a cross-sectional view showing the structure of a reflective LCD according to another embodiment of the present invention,

Fig. 21 is a schematic diagram showing the performance of light between the photoconductor and the optical compensation plate in the above-mentioned reflective LCD,

Figure 22 (a)-(c) is a figure showing the reflective LCD structure as a modification of the structure shown in Figure 20, Figure 22 (a) is a sectional view of the reflective LCD, Figure 22 (b) and Figure 22 (c ) are cross-sectional views each showing an example of the structure of the optical compensation plate of the reflective LCD,

23 is a cross-sectional view showing the structure of the contact plate of the reflective LCD according to other embodiments of the present invention,

FIG. 24 is an explanatory view showing the structure of a reflective electrode provided on the contact plate,

Fig. 25 is a top view showing the structure on the above-mentioned touch plate for detecting the coordinates of the position pressed by the pen,

Fig. 26 is a cross-sectional view showing a state in which part of the contact plate is pressed with a pen,

27 is a cross-sectional view showing the structure of a reflective LCD in another embodiment of the present invention,

FIG. 28 is a diagram illustrating conditions for total reflection of light incident from an incident surface on an inclined surface in the photoconductor of the reflective LCD shown in FIG. 27,

FIG. 29 is a graph showing the condensing characteristics of the prism sheet included in the reflective LCD shown in FIG. 27,

30( a ) and FIG. 30( b ) are explanatory diagrams showing other structural examples applicable to the reflective LCD shown in FIG. 27 in order to limit scattering of incident light.

Fig. 31 (a)-(c) shows the photoconductor structure that reflective LCD of other embodiment of the present invention has above, shows the sectional view of the performance of the light in this photoconductor at the same time,

32 is a cross-sectional view showing the structure of a reflective LCD in another embodiment of the present invention,

FIG. 33 is an explanatory diagram for explaining the inclination angle condition of the front illumination incident surface of the reflective LCD shown in FIG. 32,

34 is a perspective view showing the structure of a reflective LCD in another embodiment of the present invention,

Fig. 35 is a perspective view showing an example of use of a lighting device according to another embodiment of the present invention,

Fig. 36 is a plan view showing an example of use of the lighting device shown in Fig. 35,

37 is a cross-sectional view showing the structure of a reflective LCD in another embodiment of the present invention,

Figure 38 (a)-(c) shows the photoconductor shape of the headlight that reflective LCD has shown in Figure 37, and Fig. 38 (a) is the plan view that sees photoconductor from the top of flat part normal direction, and Fig. 38 (b ) is a sectional view of the photoconductor viewed from the normal direction of the incident surface, and Fig. 38(c) is a sectional view of the photoconductor with the longitudinal direction of the light source as the normal section,

Fig. 39 is an explanatory diagram of the structure of the flat part and the inclined part in the photoconductor shown in Fig. 38,

40(a)-(c) are explanatory diagrams showing how the light from the light source behaves in the photoconductor,

Fig. 41 is a graph showing the relationship between the distance from the light source and the brightness in the headlight of the reflective LCD shown in Fig. 37,

FIG. 42 is a graph showing the angular characteristics of light emitted from the headlight of the reflective LCD shown in FIG. 37,

Fig. 43 is a sectional view showing the structure of the reflective liquid crystal tube of the reflective LCD shown in Fig. 37,

44(a)-44(e) are process diagrams showing the formation method of the reflective electrode in the reflective liquid crystal tube shown in FIG. 43,

Fig. 45 is a graph showing the relationship between the scattering intensity and the scattering angle of the reflective electrode in the reflective liquid crystal tube shown in Fig. 43,

Fig. 46 is a cross-sectional view showing another example of the reflective liquid crystal tube shown in Fig. 43 .

Fig. 47 is a top view showing the structure of pixels, scanning lines and signal lines of the reflective liquid crystal tube shown in Fig. 43,

Fig. 48 is a graph showing the luminance and luminance distribution characteristics of the radiated light in the headlight of the reflective LCD shown in Fig. 37,

49 is a cross-sectional view showing the structure of a reflective LCD according to another embodiment of the present invention,

50(a)-(b) are graphs showing the measurement results of the illumination luminance distribution of the headlights of the reflective LCD shown in FIG. 49 and the conventional headlights, respectively,

51 is a cross-sectional view schematically showing the structure of a conventional reflective LCD with auxiliary lighting and the behavior of light in the reflective LCD,

Fig. 52 is a cross-sectional view showing the behavior of light in the above-mentioned conventional reflective LCD.

Detailed ways

Example 1

Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the reflective LCD of this embodiment has a front light 20 (front lighting device) on the front of a reflective liquid crystal tube 10 (reflective liquid crystal tube).

The headlight 20 is essentially formed from a light source 26 and a light guide 24 . The light source 26 is, for example, a linear light source such as a fluorescent lamp, and may be arranged along a side surface of the photoconductor 24 (incident surface 25 ). The interface 28 (first radiation surface) of the photoconductor 24 facing the liquid crystal cell 10 is formed as a flat surface. In addition, the interface 23 (second radiation surface) where the photoconductor 24 and the above-mentioned interface 28 face each other is formed of a multi-stage flat portion 21 that is approximately parallel to the interface 28 and an inclined portion 22 that is inclined at a certain angle in the same direction relative to the flat portion. , and are configured alternately. That is, as can be seen from FIG. 1 , the photoconductor 24 is formed on a cross-section with the longitudinal direction of the light source 26 as the normal line, and is formed in a stepped shape that becomes lower as it is farther away from the light source 26 .

The inclined portion 22 mainly functions as a surface that reflects light from the light source 26 toward the interface 28 . The flat portion 21 is mainly a surface that transmits the reflected light toward the observer when the illumination light from the headlight 20 returns as reflected light from the liquid crystal tube 10 .

The shape of the photoconductor 24 will now be described in more detail with reference to FIGS. 2(a)-(c). Fig. 2 (a) is the plan view that sees photoconductor 24 from above the normal direction of flat part 21, and Fig. 2 (b) is the side view that sees photoconductor 24 from the normal direction of incident surface 25, and Fig. 2 (c) is A cross-sectional view of the light guide 24 taken along a plane perpendicular to both the incident surface 25 and the interface 28 .

The photoconductor 24 can be formed, for example, by injection molding of PMMA (polymethyl methacrylate). The photoconductor 24 in this embodiment has a width W=110 mm, a length L=80 mm, a thickness h ₁ of the incident surface 25 =2 mm, and a width W ₁ of the flat portion 21 =1.9 mm. In addition, the step difference h ₂ of the inclined portion 22 = 50 μm, the inclined angle α of the inclined portion 22 relative to the flat portion 21 = 30°, and the width W ₂ of the inclined portion 22 was about 87 μm.

Forming the light guide 24 into a stepped headlight 20 has the following advantages. First, as shown in FIG. 2( b), when viewed from the normal direction of the incident surface 25, if the flat portion 21 is formed to be parallel to the interface 28, the flat portion 21 cannot be recognized, and only the inclined portion 22 can be seen. . That is, the sum of the projections of the inclined portion 22 onto the incident surface 25 is equal to the incident surface 25 .

In this way, of the light source light incident from the incident surface 25 , the components perpendicular to the incident surface 25 are all directly incident on the inclined surface 22 and then reflected to the interface 28 . Therefore, the problem that a large amount of light is radiated from the outside of the light guide body facing the incident surface as seen in the aforementioned conventional front lighting system does not occur. That is to say, by making the front lighting 20 have a stepped light conductor 24, the utilization rate of light is greatly improved compared with the conventional structure.

The structure of the liquid crystal tube 10 and its manufacturing method will now be described.

As shown in FIG. 1, the liquid crystal tube 10 basically has a structure in which a liquid crystal layer 12 is sandwiched between a pair of electrode substrates 11a and 11b. The electrode substrate 11a is constituted by providing a transparent electrode 15a (scanning line) on a light-transmitting glass substrate 14a, and a liquid crystal alignment film 16a covering the transparent electrode 15a.

The above-mentioned glass substrate 14a can be manufactured using, for example, a glass substrate (trade name: 7059) manufactured by a Japanese company (Conning Corporation). The transparent electrode 15a is made of, for example, ITO (Indium Tin Oxide). On the glass substrate 14a on which the transparent electrode 15a is formed, for example, an alignment material (trade name: AL-4552) manufactured by Nippon Synthetic Rubber Co., Ltd. is coated with a spin coater, and a rubbing treatment is applied as an alignment treatment to form a liquid crystal alignment film. 16a.

The electrode substrate 11b is also formed by sequentially laminating a glass substrate 14b, a transparent electrode 15b, and a liquid crystal alignment film 16b, similarly to the above-mentioned electrode substrate 11a. In addition, an insulating film or the like may be formed on the electrode substrates 11a and 11b as necessary.

The liquid crystal alignment films 16a, 16b of the electrode substrates 11a, 11b are arranged to face each other, and the direction of the rubbing treatment is arranged in parallel and opposite directions (so-called antiparallel), and they are bonded together with an adhesive. At this time, gaps at uniform intervals were formed between the electrode substrates 11a and 11b by sprinkling a glass bead spacer (not shown) with a particle diameter of 4.5 μm in advance.

The liquid crystal layer 12 is formed by introducing liquid crystal into the gap by vacuum pumping. As the material of the liquid crystal layer 12 , for example, a liquid crystal material (trade name: ZLI-3926) manufactured by a Japanese company (Melk Corporation) can be used. Δn of this liquid crystal material is 0.2030. The liquid crystal material is not limited thereto, and various liquid crystals can be used.

In addition, for example, a hairline-finished aluminum plate is bonded to the outer surface of the glass substrate 14b as the reflection plate 17 with an epoxy resin-based adhesive. On the other hand, on the outer surface of the glass substrate 14a, a polarizing plate 18 with a polarization axis set therein is provided so that the liquid crystal alignment direction with respect to the liquid crystal layer 12 becomes 45°.

The reflective liquid crystal tube 10 is manufactured through the above steps. A reflective LCD with a front lighting device is produced by combining the front lighting 20 with the liquid crystal tube 10 as follows. First, the photoconductor 24 is laminated on the polarizing plate 18 of the liquid crystal cell 10 . And between the polarizing plate 18 and the photoconductor 24 of the liquid crystal tube 10, a granular spacer (not shown) with a particle diameter of 50 μm is sprinkled in advance. Accordingly, voids 29 having a uniform thickness approximately equal to the particle diameter of the granular liner are formed. That is, the interface 28 of the light guide 24 is optically equivalent to the interface between PMMA and the air layer. In addition, since the thickness of the space 29 corresponds to only about 100 times the wavelength of light, it is possible to suppress interference or the like caused by the space 29 .

Next, a fluorescent tube as a light source 26 is provided facing the incident surface 25 of the photoconductor 24, and the light source 26 and the incident surface 25 are surrounded by a reflector 27 (light collecting means). The reflection mirror 27 condenses the light from the light source 26 only on the incident surface 25 . In addition, as the reflection mirror 27, for example, an aluminum tape or the like can be used. Through the above steps, a reflective LCD having the headlight 20 as an auxiliary light is manufactured.

This reflective LCD can be used in an illumination mode of turning on the front lighting 20 when the surrounding light is insufficient, and in a reflection mode of turning off the front lighting 20 when sufficient surrounding light is available.

The working principle of the headlight 20 will now be described with reference to FIGS. 3(a)-(c).

As mentioned above, the sum of the projections of the inclined portions 22 of the light guide 24 onto the incident surface 25 is equal to the incident surface 25 . Therefore, as shown in FIG. 3( a), the part perpendicular to the incident surface 25 in the incident light of the light source 26 is reflected by the inclined portion 22, and is directed from the interface 28 to the liquid crystal tube not shown in FIG. 3( a). 10 outputs.

In addition, as shown in FIG. 3( b ), among the incident light from the light source 26 , the light that first enters the interface 23 is divided into two parts by its behavior in the guide body 24 . A part is the light 31a as shown in FIG. The other part is the light 32a shown in FIG. 3( b ), which propagates in the photoconductor 24 while being totally reflected between the flat surface 21 and the interface 28 , and finally reaches the inclined portion 22 and is reflected to become the output light 32b.

In addition, as shown in FIG. 3( c), among the incident light of the light source 26, the light that first enters the interface 28 undergoes total reflection between the interface 28 and the flat portion 21 of the interface 23, propagates in the photoconductor, and finally reaches It is reflected by the inclined portion 22 and output to the liquid crystal tube 10 from the interface 28 .

As can be seen from the above description, almost all of the light incident on the photoconductor 24 from the light source 26 is reflected on the inclined portion 22 and radiated toward the liquid crystal tube 10 through the interface 28 . That is to say, since the headlight 20 of this embodiment is equipped with the photoconductor 24 having the stepped interface 23, the light loss of the light source 26 is extremely small, and the utilization rate of the light source can be improved.

Now, the conditions 1-3 of the inclined portion 22 or the flat portion 21 for improving the light utilization efficiency of the light source will be further described.

1. About the inclined part 22

In the photoconductor 24 , the inclined portion 22 of the interface 23 mainly functions as a reflection surface that reflects incident light from the light source 26 . In addition, the flat surface 21 of the interface 23 is mainly used as a transmission surface for transmitting light reflected by the reflector 17 provided on the back surface of the liquid crystal cell 10 and ambient light.

In order to totally reflect incident light from the light source 26 by the inclined portion 22, the following conditions must be satisfied. That is, light incident on a contact surface (interface) of materials with different refractive indices is totally reflected at the interface when the incident angle is larger than the critical angle. Therefore, the light incident on the inclined portion 22 is totally reflected by the inclined portion 22 .

θ ₁ ≥ θc=arc Sin(n ₂ /n ₁ )……(Formula 2)

In the above formula 2,

θ ₁ -incident angle to the inclined portion 22,

n ₁ - the refractive index of the light guide 24,

n ₂ - the refractive index of the substance in contact with the photoconductor 24 on the inclined portion 22,

θc—the critical angle of the inclined portion 22 .

It suffices to incident the inclined portion ₂₂ at the incident angle θ1 represented by Equation 2.

As described above, by forming the inclined portion 22 according to the condition of Equation 2, the leakage of light from the inclined portion 22 to the outside of the photoconductor 24 can be suppressed, and the utilization efficiency of light can be further improved.

2. About the flat part 21

The flat part 21 is mainly used as the transmitted light region and has been described above, however, the light transmitted from the flat part 21 includes:

(1) Reflected light from the liquid crystal tube 10,

(2) Ambient light when used in reflective mode.

The output light of the above (1) is to be dimmed with the liquid crystal layer 12 of the liquid crystal tube 10, reflected by the reflector 17, radiated to the photoconductor 24 again, and then radiated from the interface 23 to the viewer's side. However, at this time, it is mainly from the flat Section 21 outputs. In addition, the light reflected by the reflection plate 17 is scattered light. In order to transmit the scattered light on the flat portion 21 with little reflection, it is preferable to enter the flat portion 21 at an angle smaller than the critical angle. The critical angle varies depending on the refractive index of the light guide 24, but when PMMA is used as the material of the light guide 24, it is about 42°. That is, it is preferable that the output light from the liquid crystal element 10 is incident on the flat portion 21 of the photoconductor 24 at an angle of less than about 40°.

In addition, the flat portion 21 does not have to be parallel to the interface 28 . The incident angle to the flat portion 21 is also related to the light scattering range of the reflector 17 . Therefore, if the characteristics of the reflection plate 17 are also considered, as shown in FIG. If the inclination angle δ of 17 is within approximately ±10°, the component 33 of light reflected on the flat portion 21 can be made extremely small. In addition, in FIG. 4 , in order to understand the inclination of the flat portion 21 relative to the interface 28 , the inclination angle δ is shown to be larger than the above-mentioned appropriate range.

In this way, if the flat portion 21 is formed parallel to the interface 28 or inclined less than ±10°, the incident light from the light source 26 enters the flat portion 21 at a larger incident angle than the incident angle to the inclined portion 22 . Therefore, the light incident on the flat portion 21 from the light source 26 is less likely to leak to the outside, and the amount of light reflected on the flat portion 21 is large, so that loss of light from the light source can be suppressed.

In addition, it is considered that this reflective LCD is used as a reflective mode when the light is turned off. At this time, considering the ambient light when used in the reflection mode of (2) above, in order to allow sufficient ambient light to enter the liquid crystal tube 10 , it is better to make the area of the flat portion 21 as large as possible.

3. Arrangement of the inclined part 22 and the flat part 21 of the interface 23

Regarding the arrangement of the inclined portion 22 and the flat portion 21 of the interface 23, the following two conditions are important.

(a) When the user looks at the reflective LCD from the side of the interface 23, the area of the inclined portion 22 is small and the area of the flat portion 21 is large,

(b) The sum of the projections of the inclined portion 22 to the incident surface 25 is large, and the sum of the projections of the flat portion 21 is small.

The above condition (a) means that the sum of the projections of the flat portion 21 onto the interface 28 is greater than the sum of the projections of the inclined portions 22 . The size of the projection of the inclined portion 22 onto the interface 28 is determined by the inclination angle α of the inclined portion 22 relative to the interface 28 as shown in FIG. 2( c ). Therefore, by adjusting the magnitude of the inclination angle α, it is possible to make the area of the inclined portion 22 seen from the user extremely smaller than the area of the flat portion 21 .

In addition, by making the pitch of the inclined portion 22 and the flat portion 21 consistent with the extraction or bus line of the scanning line of the liquid crystal tube 10, the flat portion 21 can be arranged on the entire area where the liquid crystal tube 10 is actually displayed, and the light can be further improved. utilization rate.

The above condition (b) means that, as mentioned above, in order to effectively utilize the incident light of the light source 26, it is preferable that only the inclined portion 22 of the interface 23 can be seen when the incident surface 25 is viewed from the normal direction.

Next, the measurement results of the illumination light intensity of the headlights 20 will be described. In order to measure the illumination light intensity of the headlight 20, a measurement system as shown in FIG. 5 is used. That is, with the normal direction of the interface 28 of the headlight 20 being 0°, the light intensity in the range from 0° to ±90° is measured by the detector 34 .

Its measurement result is as shown in Figure 6, and Figure 6 shows clearly, from the light source 26 of headlight 20 by incident surface 25 the light that injects photoconductor 24, due to the effect of photoconductor 24, approximately to the normal direction of interface 28 radiation. . That is to say, the headlight 20 can make the light from the light source 26 disposed on the side of the photoconductor 24 enter the liquid crystal tube 10 approximately vertically, and fully exert the auxiliary lighting function.

In addition, the reflective LCD of this embodiment has the advantage of brighter display compared with self-luminous displays such as transmissive LCDs, CRTs, and PDDs.

That is, as shown in FIG. 7( a ), the traveling direction of the light 36 a from the self-luminous display 35 is reversed with respect to the ambient light 37 . Thus, what the observer sees is component 36b from light 36a after subtracting ambient light 37 .

In this regard, the reflective LCD of the present embodiment is used in the lighting mode as shown in FIG. (shown) reflection, the observer can see the component 39b corresponding to the sum of the auxiliary light 39a and the ambient light 37. Therefore, a clearer display can be realized not only in a dark place but also in a bright place such as outdoors during the daytime.

Therefore, in the structure of the present embodiment, the utilization efficiency of the light emitted from the light source 26 can be improved by the headlight 20 having the stepped photoconductor 24 . Accordingly, sufficient illumination light can be irradiated to the liquid crystal tube 10 when the surrounding light is not sufficient, and a reflective LCD that can always display clearly regardless of the surrounding environment can be provided.

As mentioned above, the present invention is arranged in front of the object to be illuminated, and has a light source and a light guide. a first radiating surface, a second radiating surface that radiates reflected light from the object to be illuminated, the second radiating surface is composed of an inclined portion that mainly reflects the light from the light source to the first radiating surface and a flat portion that mainly passes the light reflected from the object to be illuminated, By arranging the inclined portions and the flat portions alternately, the photoconductor is formed into a stepped shape.

Therefore, in the above structure, the illumination light is radiated from the first radiation surface to the object to be illuminated, and the reflected light from the object to be illuminated returns to the inside of the light guide again from the first radiation surface, and reaches the observer through the flat part of the second radiation surface. side. The second radiation surface facing the first radiation surface of the photoconductor with the above structure is formed into a stepped shape formed by alternately arranging the inclined surfaces and flat surfaces. The light from the light source is reflected toward the first radiating surface, so that all components parallel to the flat portion of the incident light from the light source are reflected by the inclined portion and irradiated to the illuminated object from the first radiating surface. Therefore, compared with the conventional structure having a substantially flat photoconductor, in the front lighting device of the present invention, the light traveling parallel to the flat portion can be irradiated to the object to be illuminated without leaking out of the photoconductor. Therefore, the utilization efficiency of light from the light source can be improved, and a brighter front lighting device can be provided.

In addition, a front lighting device arranged in front of the object to be illuminated has a light source and a photoconductor. The photoconductor has a planar bottom surface, a surface facing the bottom surface, and an incident surface for making light from the light source incident. The above surface can also be formed by The flat portion substantially parallel to the bottom surface and the inclined portion inclined in the same direction relative to the flat portion are alternately arranged in a stepped shape.

In the above-mentioned structure of the front lighting device of the present invention, the above-mentioned incident surface is located on the side surface of the photoconductor. Therefore, by allowing light to enter from the side of the light guide, there is an advantage that the observer does not directly see the light source. Accordingly, the light from the light source does not directly affect the image of the object to be illuminated, and a front lighting device that obtains a clear image of the object to be illuminated can be realized.

In the above configuration of the front lighting device of the present invention, the sum of the projections of the inclined portion on a plane perpendicular to the first radiation surface is substantially equal to the projection of the incidence plane on the above-mentioned plane. Therefore, all of the light incident from the incident surface of the photoconductor is incident on the portion parallel to the first radiation surface, and is reflected on the first radiation surface. Therefore, the utilization efficiency of the light from the light source can be further improved, and a brighter front lighting device can be provided.

In the above-mentioned structure of the front lighting device of the present invention, there is further provided a light-collecting means for making the light from the light source incident only on the above-mentioned incident surface. Therefore, the loss of the light source light can be further reduced, the utilization rate of the light source light can be improved, and a brighter surface light source front lighting device can be obtained.

In the above configuration of the front lighting device according to the present invention, the sum of the projected areas of the inclined portions on the first emitting surface is smaller than the sum of the projected areas of the flat portions on the first emitting surface. Since the light incident on the first radiating surface and reflected by the illuminated object passes through the flat part on the second radiating surface and radiates to the observer, in order to obtain a bright and clear image, it is better to make the projection sum of the inclined part as much as possible than the flat part. The sum of the projections of the parts is small. Therefore, according to the above structure, it is common that the area of the flat portion which mainly contributes to displaying the image of the object to be illuminated increases. As a result, a front lighting device capable of obtaining bright and clear images can be realized.

In the above configuration of the front lighting device of the present invention, the flat portion does not have to be parallel to the first radiation surface, and may have an inclination angle of 10° or less with respect to the first radiation surface. Especially considering the influence on the display level of the image of the object to be illuminated, the inclination angle of the flat portion on the second radiation surface relative to the first radiation surface is preferably 0-10°.

The above structure of the front lighting device of the present invention satisfies the above formula 2. This preferably makes the incident light of the light source to the inclined portion of the second radiation surface be totally reflected by the inclined portion. If the incident angle θ ₁ to the inclined portion satisfies the above-mentioned conditions, the incident light to the inclined portion can be totally reflected. Therefore, it is possible to prevent light from the light source from leaking from the inclined portion to the observation side, and it is possible to further improve the utilization efficiency of light. As a result, a front lighting device having what is known as a bright surface light source can be obtained.

The reflective liquid crystal display device of the present invention includes a reflective liquid crystal tube having a reflector, and a front lighting device having the above-mentioned structure is disposed on the front of the reflective liquid crystal tube.

Therefore, on the one hand, there are situations where the front lighting device is turned off when there is sufficient ambient light such as outdoors during the day, and the front lighting device is turned on when sufficient ambient light cannot be obtained. As a result, it is possible to provide a reflective liquid crystal display device that can always achieve bright and high-level display regardless of the ambient lighting environment.

In addition, in the above-mentioned structure of the reflective liquid crystal display device of the present invention, the reflective liquid crystal tube has scanning lines, and it is preferable that the pitch of the scanning lines is equal to the pitch of the flat portion of the second radiation surface of the front illuminator. approximately equal, the flat portion is arranged above the scanning line. Therefore, the flat portion can be arranged on the pixel area where display is actually performed by the liquid crystal tube. As a result, since the reflected light from the pixel area enters the flat portion efficiently, the utilization efficiency of light can be further improved, and a reflective liquid crystal display device capable of realizing high-quality display can be provided.

Example 2

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the parts having the same functions as those described in the first embodiment are given the same reference numerals and their descriptions are omitted.

Present embodiment reflective LCD as shown in Figure 8, it is characterized in that in the front of liquid crystal tube 10, has the 2nd photoconductor by the front illuminator 20 (the 1st light guide) that explained in embodiment 1 and wedge-shaped 40 constitutes the front lighting system 51.

The second photoconductor 40 is disposed between the photoconductor 24 of the headlight 20 and the liquid crystal tube 10, and has a slope 41 parallel to the interface 28 of the photoconductor 24 and a bottom surface 42 parallel to the surface of the liquid crystal tube 10. The angle of inclination of the inclined surface 41 relative to the bottom surface 42 is as shown in Figure 9 (a), preferably designed to make each inclined portion 22 of the interface 23 of the photoconductor 24 connected to the flat portion 21, and the connecting line 49 connected to each apex of the mountain shape is parallel to the bottom surface 42 .

In addition, it is preferable to form the second photoconductor 40 from a material having a refractive index equal to that of the photoconductor 24 serving as the first photoconductor as much as possible. Needless to say, the second photoconductor 40 can also be formed of exactly the same material as the photoconductor 24 . In addition, the photoconductor 24 and the second photoconductor 40 can be integrally formed by, for example, injection molding, and the manufacturing process can be simplified.

In the gap between the photoconductor 24 and the second photoconductor 40, a granular spacer (not shown) having a particle diameter of 50 μm may be sprinkled in advance. Accordingly, a gap 43 substantially equal to the particle diameter of the spacer is formed between the photoconductor 24 and the second photoconductor 40 .

Between the bottom surface of the second photoconductor 40 and the polarizing plate 18 of the liquid crystal cell 10, a filler (not shown) having the same refractive index as both is filled. Therefore, the attenuation of reflected light due to the interface between the second photoconductor 40 and the polarizing plate 18 can be prevented, and the loss of light from the light source can be further suppressed. In addition, as the above-mentioned filler, for example, an ultraviolet (UV) curable resin, methyl salicylate, or the like can be used.

Here, the effect of providing the second photoconductor 40 between the photoconductor 24 and the liquid crystal tube 10 will be described.

As shown in Figure 9 (b), in the structure without the second photoconductor 40 (embodiment 1), the distance 1n from the inclined portion 22 to the interface 28 as the radiation surface to the liquid crystal tube 10 increases as the distance from the light source increases. The distance Xn of 26 becomes smaller. In this regard, in the front lighting system 51 of the present embodiment, as shown in FIG. The distance Ln from the bottom surface 42 is substantially equal regardless of the distance Xn from the light source 26 .

That is to say, by making the second photoconductor 40 have the effect of keeping the distance from the inclined portion 22 of the headlight 20 to the liquid crystal tube 10 constant, the front lighting system 51 can be fixed at a constant distance regardless of the distance from the light source 26. Luminosity The role of glowing surface light sources.

Here, in order to find out the effect of using the second photoconductor 40, as shown in FIG. Brightness distribution. Then, the vicinity of the incident surface 25 is defined as the measurement start position Ps, and the position on the bottom surface 42 farthest from the light source 26 is defined as the final measurement position _PE . The measurement results are shown in Fig. 11(a).

Similarly, for comparison, in order to measure the luminance distribution of the output light of the structure (Example 1) without the second photoconductor 40, as shown in FIG. Measure while moving. Then, the vicinity of the incident surface 25 is set as the measurement start position Ps, and the position farthest from the light source 26 on the interface 28 is set as the final measurement position _PE . The results of the measurement are shown in Fig. 11(b).

From the comparison of Fig. 11(a) and Fig. 11(b), it can be seen that for the occasion without the second photoconductor 40, as shown in Fig. 11(b), the closer the pitch P of the brightness peak value is to the light source 26, the larger, the more The smaller the distance from the light source 26, the front lighting system 51 of this embodiment is shown in Figure 11(a), the pitch P of the brightness peaks is approximately equal along the entire bottom surface 42 of the second guide body 40, and the brightness peaks are also the same.

In this way, the reflective LCD of the present embodiment has a front lighting system 51 in front of the liquid crystal tube 10, and the front lighting system 51 has a structure between the photoconductor 24 and the liquid crystal tube 10 as the first photoconductor. The distance from the inclined part 22 of 24 to the liquid crystal tube 10 is the second photoconductor 40, so that the front lighting system 51 can uniformly illuminate the liquid crystal tube 10, even if it cannot obtain enough ambient light, it can also realize lighting. The effect of a uniform high level display.

As described above, the front lighting device of the present invention is further composed of the photoconductor in the first embodiment as the first photoconductor and the second photoconductor for uniformizing the luminance distribution of the light emitted from the first radiation surface.

In the front lighting device of the present invention, the first photoconductor is formed in steps, and the distance from the inclined portion of the second radiation surface to the first radiation surface becomes smaller in proportion to the distance from the light source. Therefore, there is non-uniform luminance distribution of the light emitted from the first radiation surface. In the above configuration, the luminance distribution of the radiated light to the object to be illuminated is made uniform by having the second photoconductor. As a result, it is possible to provide a front lighting device as a surface light source that eliminates brightness unevenness.

In the above-mentioned structure of the front lighting device of the present invention, the second photoconductor has a first surface facing the first radiation surface of the first photoconductor, faces the first surface, and passes through the first photoconductor from the first photoconductor. The incident light on the first surface is radiated to the second surface to be illuminated, so that the distances from the slopes on the second radiation surface of the first photoconductor to the second surface are substantially equal. .

Therefore, in the above-mentioned structure, by having the second photoconductor, in the first photoconductor, the distance from each inclined portion of the second radiation surface that reflects the light from the light source to the second photoconductor that becomes the radiation surface to the object to be illuminated is adjusted. The distance of the second surface is made uniform, and the luminance distribution of the emitted light from the second surface is made uniform. As a result, a front lighting device that is a surface light source with uniform brightness can be realized.

In the above configuration of the front lighting device of the present invention, it is preferable that the refractive index of the first photoconductor is substantially equal to the refractive index of the second photoconductor. With this structure, since the refractive index of the first photoconductor is approximately equal to that of the second photoconductor, the light reflected by the second inclined portion on the first photoconductor is radiated to the object to be illuminated at its original angle. . As a result, there is no need to consider the change of the light trajectory due to refraction when it enters the first photoconductor or when it radiates from the second photoconductor, and there is an advantage that the design becomes easy.

In the above structure of the front lighting device of the present invention, the first photoconductor and the second photoconductor may be integrally formed. With this structure, since the first photoconductor and the second photoconductor are integrally formed, there is an advantage that manufacture is easy.

In the above structure of the front lighting device of the present invention, a filler is introduced between the first photoconductor and the second photoconductor to alleviate the difference in refractive index caused at the optical interface between these photoconductors.

According to the above-mentioned structure, compared with the case where there is an air layer between the first photoconductor and the second photoconductor, the light caused by the refraction caused by the optical interface between the first photoconductor and the second photoconductor can be suppressed. attenuation. As a result, the utilization efficiency of light from the light source can be further improved, and a brighter surface light source can be realized as a front lighting device. In addition, if the refractive index of at least one of the first photoconductor and the second photoconductor is equal to the refractive index of the filler, the number of optical interfaces between the first photoconductor and the second photoconductor can be reduced, so that Better results.

Example 3

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same symbols are assigned to the structures having the same functions as those described in the above-mentioned embodiments, and their descriptions are omitted.

In the reflective LCD of this embodiment, as shown in FIG.

The above-mentioned second photoconductor 45, as shown in FIG. 13 , has a forward scattering plate that scatters the incident light from the photoconductor 24 only to one side of the light advancing direction, and also has a function of scattering only light incident from a predetermined angle range. , and an anisotropic scattering plate that transmits incident light from outside the above-mentioned specified angle range. As the second photoconductor 45 satisfying such conditions, for example, a commercially available viewing angle control plate (trade name: lumisty) of Sumitomo Chemical Co., Ltd. is used.

In addition, it is preferable that the angle range in which the second photoconductor 45 scatters the incident light completely includes the angle range in which the radiated light from the photoconductor 24 enters. Accordingly, the radiated light from the photoconductor 24 can be scattered without waste, and the utilization rate of the light from the light source can be improved. In addition, by making the second photoconductor 45 to scatter only the incident light from the predetermined angle range, the anisotropic scattering of the incident light transmission property outside the above-mentioned predetermined angle range, due to the incident light outside the above-mentioned predetermined angle range, the second photoconductor 45 The photoconductor 45 does not act on it, and it is possible to prevent the problem of lowering of the display level due to unnecessary scattered light.

In the gap between the photoconductor 24 and the second photoconductor 45, a granular spacer (not shown) having a particle diameter of 50 μm was sprinkled in advance. Accordingly, as shown in FIG. 12 , a void 46 approximately equal to the particle size of the spacer is formed in the gap between the photoconductor 24 and the second photoconductor 45 .

Between the second photoconductor 45 and the polarizing plate (not shown) of the liquid crystal cell 10 is filled with a filler that makes the refractive index of both equal. Therefore, attenuation of light due to refraction at the interface between the second photoconductor 45 and the liquid crystal tube 10 can be prevented, and loss of light from the light source can be further suppressed.

The measurement results of the illumination light intensity of the front illumination system 52 will now be described. In order to measure the illumination light intensity of the front lighting system 52, the same measurement system as that used in the aforementioned Example 1 (see FIG. 5 ) was used. Taking the normal direction of the second photoconductor 45 of the front lighting system 52 as 0°, the range from 0° to ±90° was measured with the detector 34, from the surface on the side of the liquid crystal tube 10 of the second photoconductor 45 coming light intensity. The results of the measurement are shown in Fig. 14 .

As can be seen from FIG. 14, the front lighting system 52 of this embodiment has a flattened angle characteristic compared with the first embodiment by using the second photoconductor 45 to scatter the radiated light from the photoconductor 24 as the first photoconductor.

In this way, the structure described in this embodiment has the second photoconductor 45 that scatters the radiated light of the photoconductor 24, so that the brightness distribution of the light emitted to the liquid crystal tube 10 is uniformized, and the liquid crystal tube 10 can be uniformly distributed. Irradiate.

In addition, as the above-mentioned second photoconductor 45, a hologram or the like may be used in addition to the anisotropic scattering plate.

As described above, in the front lighting device of the present invention described above, the second photoconductor shown in the second embodiment may be configured as a light scatterer for scattering radiated light from the first radiation surface of the first photoconductor.

In the above configuration, the light scatterer as the second photoconductor scatters the radiated light from the first photoconductor, so that the luminance distribution of the radiated light to the object to be illuminated is made uniform. As a result, a front lighting device can be realized as a surface light source with uniform brightness.

In the above structure of the front lighting device of the present invention, since the light scatterer is an anisotropic scatterer that scatters only incident light from a predetermined angle range, the radiated light from the first photoconductor is incident on the second photoconductor. At least a part of the angle range is included in the above-mentioned predetermined angle range.

Therefore, according to the above-mentioned structure, since the incident light outside the above-mentioned predetermined range, for example, the light output in the direction of the observer/the anisotropic scatterer as the above-mentioned light scatterer does not act on it, it can be suppressed due to no fdmj The scattered light causes deterioration of the image of the illuminated object. Furthermore, the incident light can be efficiently scattered by the light scatterer as the second photoconductor making the radiated light from the first photoconductor incident within the angular range of the scattered incident light. As a result, a bright surface light source with uniform luminance and a front lighting device capable of obtaining a clear image of an object to be illuminated can be realized.

In the above configuration of the front lighting device of the present invention, the light scatterer is also a forward scatterer. Also, the light scatterer serving as the second photoconductor is a forward scatterer that scatters the incident light of the first photoconductor only to one side in the traveling direction of the light, so that the incident light of the first photoconductor is not scattered backward. Therefore, the utilization efficiency of light can be further improved, and at the same time, deterioration of the image of the illuminated object caused by backscattered light can be prevented. As a result, it is possible to realize a front lighting device which can obtain a clear image of an object to be illuminated as a bright surface light source with uniform brightness.

Example 4

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same reference numerals are assigned to components having the same functions as those described in the above-mentioned embodiments, and description thereof will be omitted.

As described in the foregoing embodiments, when the interface 23 on the viewer side of the photoconductor 24 is formed by the inclined portion 22 and the flat portion 21, the light reflected by the liquid crystal tube 10 and incident on the photoconductor 24 passes through the interface again. 23, the image will be blurred.

That is, as shown in FIG. 15 , the output light 48 a of the liquid crystal tube 10 does not necessarily transmit only from the flat portion 21 but also from the inclined portion 22 toward the viewer. At this time, the radiated light 48b from the inclined portion 22 and the radiated light 48c from the flat portion 21 intersect each other due to the different radiation directions, thereby blurring the image to be displayed.

In order to solve such a problem, the reflective LCD of this embodiment, as shown in FIG. The metal reflective film 47 reflects all the light incident on the inclined portion 22 regardless of the incident angle thereof, as shown in FIG. 16 . Therefore, the light emitted from the interface 23 toward the viewer passes only through the flat portion 21 . As a result, clear images without blurring can be obtained.

Hereinafter, as a method of manufacturing the above-mentioned metal reflective film 47, an aluminum material will be described as an example. In addition, the material of the metal reflective film 47 is not limited to aluminum, and silver or the like may be used, for example.

First, as shown in FIG. 17(a), an aluminum film 61 is formed on the entire surface of the interface 23 of the photoconductor 24 by sputtering or the like. Further, as shown in FIG. 17( b ), a photoresist 62 is coated on the surface of the aluminum film 61 . Next, through an exposure step, as shown in FIG. 17(c), the photoresist 62 is patterned. Then, as shown in FIG. 17( d ), the aluminum film 61 is etched using the formed photoresist 62 as a mask. Thereafter, by peeling off the photoresist 62, a metal reflective film 47 made of aluminum is formed on the surface of the inclined portion 22 of the interface 23 as shown in FIG. 17(e).

As described above, by providing the metal reflective film 47 on the surface of the inclined portion 22, as shown in FIG. 16, the inclination angle α of the inclined portion 22 with respect to the flat portion 21 can be increased. For example, as shown in FIG. 18 , in a structure in which no metal reflection film is provided on the inclined portion 22, when the inclined angle α is approximately 60°, the light incident on the inclined portion 22 at an incident angle smaller than the critical angle θc 49a becomes light 49b which passes through the inclined part 22 and transmits toward the observer. Since such light 49b deteriorates the display level, it is not desirable.

In contrast, in the structure of this embodiment, by forming the metal reflective film 47 on the inclined portion 22, even if the inclined angle α is large, the light transmitted through the inclined portion 22 such as the above-mentioned light 49b does not exist. All light is reflected on the inclined portion 22 .

Thus, by making the inclination angle α of the inclined portion 22 large, the inclined portion 22 becomes difficult to be seen when viewed from the normal direction of the flat portion 21 , and there is an advantage that the display level can be improved.

In addition, as shown in FIG. 19, if a matrix 47b (shielding member) for preventing ambient light reflection is laminated on the surface of the metal reflective film 47, ambient light can be prevented from being reflected toward the viewer. Therefore, it is better because deterioration of display level due to reflection of ambient light toward the viewer can be prevented.

The feature of the headlight 20 according to this embodiment is that the metal reflection film 47 is formed on the inclined portion 22 so as not to transmit light from the inclined portion 22 to the viewer side. Therefore, since the light radiated from the interface 23 to the viewer side is only the radiated light of the flat portion 21, in an emission type LCD having the headlight 20 in front of the liquid crystal tube 10, a clear and clear image without blurring can be obtained. Display the image.

As described above, in the front lighting device of the present invention, the reflective member for reflecting light is provided on the surface of the inclined portion of the first photoconductor. Preferably, the light incident from the light source on the inclined portion of the second radiation surface is totally reflected by the inclined portion. Therefore, by providing the reflecting member on the above-mentioned inclined portion, incident light to the inclined portion is totally reflected regardless of the incident angle. Therefore, light from the light source does not leak from the inclined portion to the viewer's side, and the utilization efficiency of light is further improved. As a result, a front lighting device as a bright surface light source can be realized.

In the above configuration of the front lighting device of the present invention, a light shielding member is provided on a surface of the reflection member. Therefore, the reflective member is used to reflect ambient light into the viewer's eyes, thereby preventing degradation of the image display level of the object to be illuminated and obtaining a clear image of the object to be illuminated.

In the inclined portion of the front lighting device of the present invention, in the above-mentioned structure, when the refractive index of the photoconductor is n ₂ and the refractive index of the external medium in contact with the inclined portion is n ₁ , then the ratio of light incident on the inclined portion by the light source is The incident angle θ also works effectively in the range of the following inequalities.

θ＜arc sin(n ₁ /n ₂ )

The incident angle θ at which the light source enters the inclined portion decreases as the inclination angle relative to the flat portion increases. If the reflective member is provided on the inclined portion of the second radiation surface, the light incident on the inclined portion is totally reflected regardless of the incident angle, and is not radiated toward the observer through the inclined portion. Therefore, within the range where the incident angle θ of light from the light source incident on the inclined portion satisfies the above inequality, the inclination angle of the inclined portion relative to the flat portion can be designed to be larger. As a result, when viewed from the normal direction of the flat portion, it becomes difficult to recognize the inclined portion which does not contribute to the display of the image of the object to be illuminated, and it is possible to improve the display level of the image of the object to be illuminated.

Example 5

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same reference numerals are assigned to components having the same functions as those described in the above-mentioned embodiments, and description thereof will be omitted.

The characteristics of the reflective LCD of the present embodiment are as shown in FIG. The front lighting system 53 formed by the optical compensation plate 64 (compensation device) on the top.

In the above-mentioned optical compensation plate 64, as shown in FIG. That is, the position of the bottom surface 64 a facing the inclined portion 22 of the photoconductor 24 forms an inclined portion 65 parallel to the inclined portion 22 , and the position facing the flat portion 21 of the photoconductor 24 forms a flat portion 66 parallel to the flat portion 21 . Further, a surface 64 b of the optical compensation plate 64 on the observer side is formed parallel to the interface 28 of the photoconductor 24 .

The optical compensation plate 64 , like the light guide 24 , can be produced, for example, from PMMA by injection molding. As described above, the inclined portion and the flat portion of the optical compensation plate 64 and the photoconductor 24 are arranged to face each other and contacted by a granular spacer (not shown) having a particle diameter of about 20 μm. Accordingly, the air layer 67 having a substantially uniform thickness is formed between the bottom surface 64 a of the optical compensation plate 64 and the interface 23 of the photoconductor 24 .

Thus, by providing the optical compensation plate 64 in front of the photoconductor 24 and the presence of the air layer 67 between the photoconductor 24 and the optical compensation plate 64, the following effects can be obtained.

That is to say, as described in the description of the foregoing embodiment 4 with reference to the accompanying drawings, even if the light 48a·48a incident on the photoconductor 24 from the liquid crystal tube 10 advances in the same direction inside the photoconductor 24, the The inclined portion 22 or the flat portion 21 of the interface 23 passes through and radiates from the interface 23 of the photoconductor in different directions, thus causing blurring of the image.

In contrast, in the front lighting system 53 of this embodiment, as shown in FIG. The refraction with the bottom surface 64a which is the interface of the optical compensation plate 64 becomes light that travels in the same direction again, that is, radiates from the surface 64b of the optical compensation plate 64 in the same direction as shown by light 68b·69b. Therefore, a sharp image without blurring can be obtained when viewed from the viewer's side.

In addition, in addition to the above-mentioned optical compensation plate 64, as shown in FIG. In this case, as shown in FIG. 22( b), by making the incident region 71a of light radiated from the inclined portion 22 of the photoconductor 24 and the incident region 71b of light radiated from the flat portion 21 of the photoconductor 24 have different refractive indices, , the radiation angles θa·θb at which light is radiated from the surface of the regions 71a·71b to the observer side are approximately equal. Alternatively, the region 71a may be formed by a member having a diffraction function (for example, a diffraction element) so that the light passing through the region 71a and the light passing through the region 71b are diffracted in the same direction.

Alternatively, as shown in FIG. 22(c), the region where the light radiated from the inclined portion 22 of the photoconductor 24 is incident in the optical compensation plate 71 may be formed with a light-shielding black mask 71c, so that the light from the inclined portion 22 The emitted light cannot reach the viewer's side.

Therefore, according to the structure of this embodiment, by using the optical compensation plate 64 (or the optical compensation plate 71) to make the radiation directions of the light radiated from the inclined portion 22 and the flat portion 21 of the interface 23 of the photoconductor 24 consistent, it is possible to provide different Reflective LCD for blurry clear display.

As described above, in the above configuration of the front lighting device of the present invention, a compensating device is further provided for aligning the radiation directions of the light emitted from the flat portion of the second radiation surface and the light emitted from the inclined portion.

Since the second radiating surface is formed into a stepped shape in which flat portions and inclined portions are alternately arranged, the light incident from the first radiating surface into the photoconductor and reflected by the object to be illuminated will flow from the flat portion and the inclined portion of the second radiating surface, respectively. Parts radiate in different directions, thus blurring the image of the illuminated object. Therefore, as shown in the above configuration, by providing compensation means for aligning the radiation directions of the light emitted from the flat portion of the second radiation surface and the light emitted from the inclined portion, a clear illuminated image can be obtained.

In the above-mentioned structure of the front lighting device of the present invention, the above-mentioned compensating device has a first surface facing the second radiation surface of the photoconductor and a second surface facing the above-mentioned first surface, and the first surface as the compensating device is arranged In order to make the inclined surface substantially parallel to the inclined part of the second radiation surface of the photoconductor and the flat surface substantially parallel to the flat part of the second radiation surface alternately connected to form a stepped shape complementary to the second radiation surface, the above-mentioned The second surface of the compensating device is arranged substantially parallel to the first radiation surface of the photoconductor.

Therefore, according to the above-mentioned structure, the light radiated from the first radiating surface of the photoconductor is reflected by the object to be illuminated, and returns to the inside of the photoconductor from the first radiating surface. The flat portion 21 and the inclined portion 22 of the surface radiate in different directions. However, by forming the first surface 64a of the compensating device 64 disposed facing the above-mentioned second radiating surface into a stepped shape complementary to the second radiating surface of the photoconductor, the light 69a radiated from the flat portion 21 is directed toward the first surface 64a of the compensating device. Light 68a emitted from the inclined portion 22 incident on the flat surface of the surface enters the inclined surface of the first surface, and becomes light 68b·69b radiated in substantially the same direction from the second surface. In this way, by aligning the radiation direction of the light emitted from the flat portion with the radiation direction of the light emitted from the inclined portion, a clear image of the object to be illuminated without blurring can be obtained.

In the above-mentioned structure of the front lighting device of the present invention, the incident area of the above-mentioned compensating device that mainly radiates light from the inclined portion of the second radiation surface and the incident area that mainly radiates light from the flat portion of the second radiation surface have different refraction. Rate.

Therefore, in the above configuration, the directions of light emission from the inclined portion and the flat portion are aligned with each other by compensating means for making the incident area mainly radiating light from the inclined portion and the incident area mainly emitting light from the flat portion have different refractive indices. As a result, it is possible to provide a front lighting device capable of obtaining a clear image of an illuminated object without blurring.

In the above configuration of the front lighting device according to the present invention, a diffractive member may be provided in the incident area of the compensating device where the light is mainly radiated from the inclined portion of the second radiating surface. In this configuration, by providing a diffractive member in the incident region where light is mainly radiated from the inclined portion, the radiation directions from the inclined portion and the flat portion are aligned. As a result, a front lighting device capable of obtaining a clear image of an illuminated object without blurring can be realized.

In the above configuration of the front lighting device according to the present invention, a light shielding member may be provided on the incidence area of the compensation device where the light is mainly radiated from the second radiation surface. In this configuration, by providing a light shielding member that does not transmit light in the incident region where light is mainly radiated from the inclined portion, light radiated from the second light emitting surface of the photoconductor is radiated only from the flat portion. Therefore, it is possible to realize a front lighting device capable of obtaining a clear image of an illuminated object without blurring.

Example 6

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same symbols are assigned to the structures having the same functions as those described in the foregoing embodiments, and their descriptions are omitted.

The reflective LCD of this embodiment has a structure in which a touch function board is added to the front lighting system 53 (see FIG. 20 ) of the reflective LCD described in the fifth embodiment.

In order to realize the above-mentioned function of the touch panel, the reflective LCD of this embodiment, as shown in FIG. A reflective electrode 73 that can reflect light and has conductivity and is made of, for example, aluminum is provided on the inclined portion 22 of the 24 . The above-mentioned transparent electrode 72 and reflective electrode 73 constitute position detection means.

The figure shown in the lower part of FIG. 24 shows the plan view shape of the above-mentioned reflective electrode 73 seen from the normal direction of the flat portion 21 of the photoconductor 24 . As shown in FIG. 24 , since the reflective electrode 73 is provided on the entire surface of the inclined portion 22 of the photoconductor 23 , it has a strip shape when viewed from the normal direction of the flat portion 21 of the photoconductor 24 . Furthermore, as shown in FIG. 25 , the transparent electrodes 72 formed on the optical compensation plate 64 are also formed in a strip shape, and the reflective electrodes 73 and the transparent electrodes 72 intersect perpendicularly to form a matrix.

In addition, a plastic granular spacer (not shown) with a particle diameter of about 10 μm is sprinkled between the reflective electrode 73 of the photoconductor 24 and the transparent electrode 72 of the optical compensation plate 64 to form a space approximately equal to the particle diameter.

The optical compensation plate 64 is flexible, and as shown in FIG. 26 , the transparent electrode 72 is brought into contact with the reflective electrode 73 by pressing with a pen 74 . Coordinate recognition after pressing with the pen 74 is performed as follows. As shown in Figure 25, by performing signal scanning on the transparent electrode 72 and the reflective electrode 73 in a line-sequential manner respectively, the X coordinate and the Y coordinate of the contact point 75 are measured, and in the plane of the contact plate, it is possible to determine the 74 Position coordinates of the press.

In addition, the structure in which the belt-shaped transparent electrode 72 is formed on the optical compensation plate 64 has been exemplified here, however, the transparent electrode may be formed on the entire bottom surface 64 a of the optical compensation plate 64 . However, as described above, forming the transparent electrode 72 into a strip shape has the advantage of high light utilization efficiency.

Therefore, according to the structure of the present embodiment, since the optical compensation plate 64 functions as a touch panel, it is possible to provide a reflective LCD that can input the content displayed by the liquid crystal tube 10 with a pen.

As mentioned above, the reflective liquid crystal display device of the present invention has the front lighting device shown in the foregoing embodiment 5 in front of the reflective liquid crystal tube having a reflector, and the above-mentioned compensating device has flexibility with respect to a predetermined pressure. A pair of position detection mechanisms are provided on the second radial surface to detect the position where pressure is applied by contacting each other.

Therefore, the above structure has the function of making the front lighting device a so-called touch panel. That is to say, for example, when a certain position on the surface of the compensating device is pressed with a pen, etc., the deflection of the compensating device is made, and a pair of position detection devices respectively arranged on the compensating device and the second radial surface are mutually aligned on the above-mentioned position. touch. If the position detecting means recognizes the position as a coordinate, a reflective liquid crystal display device capable of inputting with a pen relative to the content displayed on the liquid crystal tube can be realized.

In addition, in the above structure of the reflective liquid crystal display device of the present invention, the reflective liquid crystal tube has scanning lines, the position detection means includes transparent electrodes formed on the flat portion of the second radiation surface, and the pitch of the scanning lines is the same as that of the transparent electrodes. The pitches are approximately equal, and the transparent electrodes are arranged above the scanning lines.

Therefore, in the above structure, the transparent electrode of the position detecting means can be arranged on the area where the image is actually displayed by the liquid crystal tube. As a result, the resolution of the touch panel is approximately equal to the resolution of the liquid crystal tube. Therefore, there is an effect of improving the sense of unity between the input image and the display image when input is performed using the touch panel.

Example 7

Other embodiments of the present invention are described as follows in conjunction with the accompanying drawings. In addition, the same symbols are assigned to the structures having the same functions as those described in the above-mentioned embodiments, and their descriptions are omitted.

The front lighting lamp that the reflective LCD of the present embodiment has, as shown in Figure 27, is characterized in that in the structure described in the aforementioned embodiment 1, between the light source 26 and the incident surface 25 of the photoconductor 24, further increase as The prism plate 81 and the diffusion plate 82 of the light control mechanism control the scattering angle of the incident light from the light source 26 to the incident surface 25 . In addition, the prism apex angle of the prism plate 81 was set to 100°. Between the photoconductor 24 and the polarizing plate 18 of the liquid crystal cell 10, a filler 84 for reducing the difference in refractive index is introduced.

As the light source 26, for example, a fluorescent tube can be used, but the light output from the fluorescent tube is of course not directional and occurs randomly. Therefore, there is light that enters the inclined portion 22 of the photoconductor 24 at an angle larger than the critical angle, and becomes light leaking from the inclined portion 22 to degrade the display level.

Considering that PMMA having a refractive index of about 1.5 is preferably used as the material of the photoconductor 24, the incident light to the inclined portion 22 whose incident angle is below the critical angle (about 42°) becomes leakage light. In order to prevent such leaked light from occurring, the scattering angle of the output light from the light source 26 may be controlled in advance so that the incident light that becomes the leaked light does not enter the photoconductor 24 .

In addition, as shown in FIG. 28 , let the inclination angle of the inclined portion 22 with respect to the interface 28 be α. For convenience of explanation, FIG. 28 is a diagram showing the positional relationship of the inclined portion 22, the interface 28, and the incident surface 25 of the photoconductor 24 alone. Actually, the photoconductor 24 is of course not formed in such a shape.

If the scattering angle of the incident light on the incident surface 25 of the photoconductor 24 is ±β, and the critical angle of the inclined portion 22 is θc, the incident angle θ of the above-mentioned light to the inclined portion 22 can be expressed as:

                                                                       

Therefore, the condition for preventing the incident light from the incident surface 25 toward the inclined portion 22 from passing through the inclined portion 22 is

       θc<θ＝90°-α-β

Or β<90°-(θc+α)...(Formula 3)

Also, in this embodiment, the inclination angle α of the inclined portion 22 is set to 10°. Using this and using the critical angle θc as 42°, according to the above formula 3, it can be derived that β<38°.

The output light from the light source 26 is once scattered by the diffusion plate 82 and enters the prism plate 81 . The prism plate 81 has the function of concentrating scattered light to a specific angle range. When the prism apex angle is 100°, as shown in FIG. When the concentrated light in the angle range of about ±40° is incident on the photoconductor 24, the light is further concentrated by the refraction of the incident surface 25, and becomes scattered light gathered into a range of about ±25.4°, that is to say, the incident surface can be The incident light at 25 degrees is sufficiently contained in the above-mentioned range of β<38° at the scattering angle. From this, it can be seen that light leakage from the inclined portion 22 naturally does not occur.

Therefore, in the reflective LCD of this example, in order to control the scattering of light from the light source, the prism plate 81 is provided between the light source 26 and the incident surface 25 of the photoconductor 24, so that the leakage light of the inclined portion 22 can not be generated, and the display level can be further improved. .

Furthermore, in the present embodiment, the apex angle of the prism plate 81 has been set to 100°, however, it is not necessarily limited to this angle. In addition, the prism plate 81 is used as the light control device for restricting light scattering from the light source, but it is not limited to this, as long as the same effect can be obtained, it may be used, for example, a collimator or the like. In addition, as shown in FIG. 30( a ), the periphery of the light source 26 is covered with an ellipsoidal mirror 98 , and the same effect can be obtained by disposing the light source 26 at the focus of the ellipsoidal mirror 98 . In addition, as described in the abstract SID P.375 (1995), the light pipe 99 shown in FIG. 30( b) is used to control the scattering of the irradiation light from the light source 26.

As described above, the front lighting device of the present invention further has a light control device for limiting light scattering of the light source between the light source and the incident surface.

The light from the light source is mainly reflected by the inclined portion of the second radiation surface. However, since the inclined portion is not total reflection, in order to reduce the components leaked from the outside of the photoconductor, it is preferable to make the light from the light source have a certain degree of directionality, so that the light on the above-mentioned inclined portion Components incident at angles less than the critical angle are reduced. Therefore, the above structure has a light control mechanism that limits the light scattering of the light source, so that the leaked light from the inclined portion is reduced, the utilization rate of light is further improved, and at the same time, blurring of the image of the object to be illuminated can be prevented. As a result, a front lighting device can be realized as a surface light source capable of obtaining a bright and clear image of an illuminated object.

In the above configuration of the front lighting device of the present invention, the light control means restricts scattering of light from the light source that directly enters the inclined portion of the second radiation surface from the incident surface at an incident angle greater than the critical angle.

Therefore, according to the above configuration, the scattering of light from the light source is restricted by the light control means, so that no light entering at an incident angle smaller than the critical angle exists among the light directly incident on the inclined portion from the incident surface. Therefore, the leakage light from the inclined portion is reduced, the utilization rate of light is further improved, and blurring of the image of the object to be illuminated can be prevented at the same time. As a result, it is possible to realize a front lighting device as a surface light source capable of obtaining a bright and clear image of an object to be illuminated.

In addition, the front lighting device of the present invention is further provided between the light source and the incident surface, and in the range where there is almost no direct incident light from the first radiation surface on the incident surface on the first photoconductor, the light control device that limits the scattering of light from the light source is provided. mechanism.

In the above structure, by introducing a filler between the first photoconductor and the second photoconductor to relax the refractive index difference existing on the optical interface, an air layer exists between the first photoconductor and the second photoconductor. Compared with the case where the light source is directly incident on the first radiation surface from the light source, the components incident on the second photoconductor through the first radiation surface are increased. Among these components, there are components that enter the second photoconductor at a relatively large incident angle and do not contribute to illumination of the object to be illuminated. Therefore, in the above configuration, the scattering of the light from the light source is restricted by the light control device, and the component directly incident on the first radiation surface of the light incident from the incident surface on the light guide can be almost eliminated. Therefore, it is possible to reduce the components incident on the second photoconductor at a relatively large incident angle from the first radiation surface. As a result, the utilization efficiency of light can be further improved, and a bright front lighting device can be realized.

Example 8

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same reference numerals are assigned to components having the same functions as those described in the above-mentioned embodiments, and description thereof will be omitted.

The reflective LCD of this embodiment is the adjustment of filling between the front lighting (or front lighting system) and the liquid crystal tube 10 to prevent light attenuation caused by the difference in refractive index in the reflection LCD that has been described in the foregoing embodiments. Filling agent (matching agent).

Now, the structure using the above-mentioned filler in the reflective LCD described in Embodiment 1 will be described as an example. As described with reference to FIG. 1 in Embodiment 1, the photoconductor 24 of the headlight 20 is laminated on the polarizing plate 18 of the liquid crystal tube 10 to form a granular spacer with a particle diameter of about 50 μm. Therefore, between the liquid crystal tube 10 and the photoconductor 24, a space 29 having a uniform thickness substantially equal to the particle diameter of the spacer is formed.

In the reflective LCD of this embodiment, as shown in FIG. 32, the above-mentioned gap 29 is filled with a filler 84. As shown in FIG. In addition, as the filler 84, ultraviolet (UV) curable resin, methyl salicylic acid, etc. can be used, for example. Therefore, the photoconductor 24 comes into contact not with air but with a filler 84 having a higher refractive index than air. Preferably, the filler 84 has a refractive index substantially equal to that of the photoconductor 24 .

Thus, where the interface 28 of the photoconductor 24 is in contact with the filler 84, the behavior of light at the interface 28 is different from where the interface 28 of the photoconductor 24 is in contact with air as in the previous embodiments.

As shown in FIG. 31( a), among the incident light of the light source 26, the light that is approximately perpendicular to the incident surface 25 is directly incident and reflected from the incident surface 25 to the inclined portion 22, and then passes through the interface 28 and the filler 84, Incident to the liquid crystal tube 10 . At this time, the behavior of light on the interface 28 is the same as when the interface 28 is in contact with air (see FIG. 3( a )).

In addition, as shown in FIG. 31( b ), among the incident light from the light source 26 , among the light that first enters the interface 23 from the incident surface 25 , there is also light such as light 85 a incident on the interface 28 after being reflected by the flat portion 21 . Since the interface 28 is in contact with the filler 84 having approximately the same refractive index as the photoconductor 24, such light 85, or as shown in FIG. The incident light passes through the interface 28 without any effect.

These lights become incident with a very large incident angle relative to the liquid crystal layer 12 of the liquid crystal tube 10. However, due to reflection by the reflector, the interface 28 relative to the photoconductor 24 is incident with the above-mentioned large incident angle again, and will not reach the observer.

However, in order to improve the utilization efficiency of light from the light source, it is preferable to prevent the light directly incident on the interface 28 from the light source 26 . Therefore, as shown in FIG. 32 , by forming the incident surface 25 so that the incident surface 25 and the interface 28 are inclined at an obtuse angle, light directly incident on the interface 28 from the incident surface 25 can be eliminated.

In addition, as shown in FIG. 33 , the angle γ formed between the incident surface 25 and the interface 28 is preferably

γ≥90°+β.

According to this, almost all of the light from the light source incident on the incident surface 25 is incident on the direction of the interface 23, and the utilization efficiency of the light from the light source can be further improved.

As described above, in the front lighting device of the present invention, the gap between the first photoconductor and the second photoconductor is filled with a filler for reducing the difference in refractive index at the optical interface existing between these photoconductors. Therefore, in the above structure, compared with the case where there is an air layer between the first photoconductor and the second photoconductor, it is possible to suppress the reflection caused by the optical interface existing between the first photoconductor and the second photoconductor. attenuation of light. As a result, the utilization efficiency of light from the light source can be further improved, and a front lighting device as a brighter surface light source can be realized. In addition, as mentioned above, if the refractive index of one of the first photoconductor and the second photoconductor is equal to the refractive index of the filler, the optical interface between the first photoconductor and the second photoconductor can be made The smaller the number, the better the effect.

Furthermore, the front illuminating device of the present invention is configured in the above-mentioned configuration such that an obtuse angle is formed between the above-mentioned incident surface and the first radiating surface. Therefore, according to the above configuration, by forming an obtuse angle between the incident surface and the first radiating surface, light directly incident on the first radiating surface among light from the light source incident from the incident surface is reduced. Therefore, the utilization efficiency of light from the light source can be further improved, and a brighter front lighting device can be realized.

Example 9

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. Components having the same functions as those described in the foregoing embodiments are given the same reference numerals, and their descriptions are omitted.

The reflective LCD of this embodiment is characterized in that the headlight 20 is formed into a cover shape that can be freely opened and closed relative to the liquid crystal tube 10 .

In each of the above-mentioned embodiments, various forms of the front lighting or the front lighting system as the front lighting device have been described, however, especially in the structure described in Embodiment 4, the inclination of the light guide When the reflective film 47 is provided on the portion 22, the metal reflective film 47 prevents ambient light from entering the photoconductor 24. Therefore, the surrounding environment does not appear so dark when it is necessary to use the reflective LCD in the lighting mode, but in the case of using the reflective mode and cannot obtain a sufficient amount of ambient light, there are occasions where the display becomes dark especially in the reflective mode.

Therefore, as shown in FIG. 34, the reflective LCD 91 of the present embodiment is provided so that the headlight 20 can be freely opened and closed relative to the liquid crystal tube 10 by fixing one side thereof, for example, with a hinge (not shown). That is, the front light 20 is formed to have an inner cover 92 that can be opened and closed independently to cover the liquid crystal tube 10 and the front light 20 .

Therefore, it is possible to use the reflective LCD 91 in the lighting mode, the front light 20 is covered on the surface of the liquid crystal tube 10, that is, it can be used in the state where only the cover 92 is opened, and the reflective LCD 91 is used in the reflective mode. It can be used with the headlight 20 turned on relative to the liquid crystal tube 10 .

Therefore, when used in reflective mode, no loss of light occurs due to the headlight 20, and it is possible to realize a reflective LCD in which bright display can always be obtained.

In addition, the structure of fixing at least a part of the front lighting 20 relative to the liquid crystal display has been described above. However, the front lighting 20 can also be formed as a complete unit structure that can be freely attached to and detached from the liquid crystal tube 10 . However, in this case, it is necessary to consider how to store the headlight 20 after detaching it from the liquid crystal tube 10 .

In addition, the reflective LCD having the headlight 20 in the inner cover has been described, however, it is also possible to configure the front lighting system described in the above-mentioned embodiments to be provided in the inner cover.

As mentioned above, in the reflective liquid crystal display device of the present invention, the front illuminator shown in the foregoing embodiments is arranged so that it can be opened and closed freely relative to the reflective liquid crystal element. Therefore, according to the above structure, when the reflective liquid crystal display device is used in the state where the front lighting device is turned on, the front lighting device is covered with the liquid crystal tube for use. Use with lighting turned on. Therefore, when the front lighting device is unnecessary, it is possible to provide a reflective liquid crystal display device capable of always bright display without hindering the incidence of ambient light by the front lighting device.

Example 10

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same reference numerals are assigned to components having the same functions as those described in the above-mentioned embodiments, and description thereof will be omitted.

In the foregoing embodiments, the description has been given of the reflective LCD having a combined structure of the headlight as the front lighting device or the front lighting system and the reflective liquid crystal tube as the object to be illuminated. However, the headlights or the front lighting system as the front lighting device of the present invention are not limited to be used in combination with reflective liquid crystal tubes. For example, as shown in FIG. 35, the lighting device 95 of this embodiment is formed by using the front lighting or the front lighting system in the above-mentioned embodiments as an independent unit, and can illuminate various objects.

For example, the above-mentioned lighting device 95 can be arranged on a book 96 as shown in FIG. 35 . Therefore, as shown in FIG. 36 , since the lighting device 95 can illuminate only the area substantially directly below, for example, when reading a book in a bedroom or the like, there is an effect of not disturbing people around.

In addition, the present invention is not limited to the above-mentioned embodiments, and various changes are possible within the gist of the present invention. For example, as the material of the light guide, specifically PMMA is used as an example, but as long as it can conduct light uniformly and without attenuation, any material with a suitable refractive index can be used, such as glass, polycarbonate, polyvinyl chloride or polyester. In addition, the dimensions of the inclined portion and the flat portion of the photoconductor described above are merely examples, and can be freely designed as long as equivalent effects can be obtained.

In addition, as the liquid crystal tube, various LCDs such as unipolar matrix LCD and active matrix LCD can be used. In addition, in the above, a liquid crystal cell of ECB mode (single polarizing plate mode) using a polarizing plate having both a polarizer and an analyzer is used, however, PDLCs or PC-GHs etc. which do not use a polarizing plate can also be used other liquid crystal tubes.

As mentioned above, the front lighting device of the present invention is not limited to being illuminated as shown in the above embodiments and is not limited to reflective liquid crystal display elements, but can also be generally used in display media for illumination and identification display by external light. Therefore, for example, by making the above-mentioned front lighting device detachable from the reflective liquid crystal display device, when the liquid crystal display device is not used, the front lighting device can be detached and used for other display media as appropriate.

Example 11

Other embodiments of the present invention are described below with reference to the accompanying drawings, and the same symbols are assigned to structures having the same functions as those described in the foregoing embodiments, and their descriptions are omitted.

The reflective LCD of this embodiment, as shown in FIG. 37 , has the same structure as that of Embodiment 1 in that the reflective liquid crystal tube 10a has a front light 20a in front of it. The anti-reflection film 13 as the second photoconductor (optical device) is arranged between the illumination 20a, and the width (pitch) of the flat part 21 and the inclined part 22 formed on the photoconductor 24 are different, and the reflective liquid crystal tube 10a is different from the foregoing Embodiment 1 in that a reflective electrode (reflective plate) is formed inside.

First, the front lighting lamp 20a is specifically described. The front lighting lamp 20a is the same as the aforementioned embodiment 1, and is mainly composed of a light source 26 and a photoconductor 24, and is covered with a reflector 27 connected to the incident surface 25 of the photoconductor 24 as a line light source. The light source 26.

The interface (the first radiation surface) 28 on the side of the liquid crystal tube 10a of the photoconductor 24 is formed into a flat surface, and the interface (the second radiation surface) 23 facing the interface is composed of a flat portion 21 parallel or substantially parallel to the interface 28 and an opposite surface. The inclined portions 22 inclined at a constant angle in the same direction in which the flat portions are inclined are alternately arranged in succession.

In this way, as in the first embodiment, as shown in FIG. 37 , the photoconductor 24 is formed in a stepped shape on a cross-section normal to the longitudinal direction of the light source 26 and decreases as the distance from the light source 26 increases.

Now, the shape of the photoconductor 24 will be described in detail with reference to FIGS. 38(a)-(c). Fig. 38(a) is a top view of the photoconductor viewed from above the normal direction of the flat portion, Fig. 38(b) is a side view of the photoconductor viewed from the normal direction of the incident surface, and Fig. 38(c) is a view perpendicular to the A cross-sectional view of the plane of incidence and the interface cut through the light guide.

As a material of the photoconductor 24, an acrylic sheet is used in this embodiment, and the photoconductor 24 can be processed into a stepped shape by molding with a metal mold. In this embodiment, the width W of the photoconductor 24 is 75 mm, the length L is 170 mm, the thickness h ₁ of the incident surface 25 is 2.0 mm, and the width W ₁ of the flat portion 21 is 0.2 mm. In addition, the width W 2 of the inclined portion is made approximately 10 μm by setting the level difference h ₂ of the inclined portion 22 to 10 μm and the angle of inclination α to the flat portion ₂₁ to 45°.

In addition, in this embodiment, the photoconductor 24 is configured along the direction away from the incident surface 25, that is, away from the light source 26, such that the sum of the width W ₁ of the flat portion 21 and the width W ₂ of the inclined portion 22 gradually becomes W ₃ =0.21 mm. smaller structure. The structures of the flat portion 21 and the inclined portion 22 will be further specifically described with reference to FIGS. 38( a )-( c ) and FIG. 39 . In addition, in the photoconductor 24, the direction which takes the longitudinal direction of the light source 26 on the side away from the light source 26 as a normal line is hereinafter referred to as a first direction, and is indicated by an arrow A in the figure.

As shown in FIG. 39 , each flat portion 21 and each inclined portion 22 are combined into one group, and the block consisting of 100 sets of flat portions 21 and inclined portions 22 closest to the light source 26 is taken as the first block B ₁ . Also, the distance W ₄ in the direction along the first direction in the first block B ₁ is 21 mm.

The above-mentioned interval W ₄ of the second block B ₂ of the next block consisting of 100 sets is 20 mm. Furthermore, the interval _W4 of the next _third block B3 is 19 mm, the interval _W4 of the fourth block B4 is 18 mm, and the interval _W4 of the _fifth block B5 is 17 _mm .

Therefore, in the photoconductor 24 of the present embodiment, the distance W4 between the blocks is sequentially reduced by 1 mm for each block from the end face on the light source side along the first direction to the end face on the side where the light source 26 is not disposed. Just become along with leaving light source 26, every 100 groups that are made up of flat portion 21 and inclined portion 22, the pitch sum of the pitch of its flat portion 21 and inclined portion 22 (width W ₁ of flat portion 21 and inclined portion The sum of the widths W ₂ and W ₃ of 22 has been reduced by 10 μm (0.01 mm) in this way. In addition, for the convenience of illustration, in Fig. Not pictured.

In the photoconductor 24 , the inclined portion 22 mainly functions as a minute light source portion serving as a surface that reflects light from the light source 26 toward the interface 28 . In addition, the flat portion 21 mainly functions as a surface for letting the reflected light of the headlight 20 return as reflected light of the liquid crystal tube 10 a to the viewer side. The effects of these parts are the same as in the aforementioned embodiment 1.

In addition, the photoconductor 24 in the above-mentioned headlight 20a, in addition to forming it into a stepped shape, also has 100 sets of flat parts 21 and inclined parts 22, and the pitch of each set is reduced by, for example, 10 μm. That is, the pitch of the steps decreases with distance from the light source 26 . Therefore, as shown in FIG. 40( a ), the number of inclined portions 22 per unit area is increased as the distance from the light source 26 increases.

Light source 26 enters incident surface 25 and is reflected due to the inclined portion 22 that acts as a small light source portion. Since the number of inclined portions 22 per area increases away from light source 26, it is illuminated as front light 20a. The brightness of the reflective liquid crystal tube 10a of the object to be illuminated increases as it leaves the light source 26 . Usually, since there is a tendency that the luminance decreases as the light source is separated from it, if the structure of the photoconductor 24 of this embodiment is used, on the interface 28 (the first radiation surface), the decrease of the luminance along with the distance from the light source is offset, so that the light source can be The high-quality light illuminates the entire object to be illuminated at a high angle and with high efficiency. As a result, the luminance distribution on the interface 28 side that is the interface (first radiation surface) on the object side can be made uniform.

On the other hand, in the conventional front lighting 120 in which the photoconductor 124 is formed into a wedge-shaped flat plate as shown in FIG. Therefore, the luminance on the first radiation surface (the interface 128 on the lamp 120 for the front lighting) decreases as the distance from the light source 26 increases.

In addition, the luminance distribution state on the first radiation surface is shown in FIG. 41. Compared with the graph F showing the luminance distribution of the conventional headlight 120, the luminance distribution of the headlight 20a according to this embodiment is represented by the curve E, It is substantially unchanged even at a distance from the light source 26 . It can be seen from this that the headlight 20a of this embodiment has the advantage of being able to make the brightness distribution on the first radiation surface (interface 28) uniform.

In addition, in the photoconductor 24 of the above-mentioned structure, since the pitch of the steps is 0.21mm, the pitch of the black body (matrix) formed around the image of the reflective liquid crystal tube 10a corresponding to the photoconductor 24 and the above-mentioned inclined portion 22 grooves have different pitches. As a result, since the occurrence of moire due to the interference between the black body and the inclined portion 22 can be suppressed, the display level of the reflective LCD can be improved. This point will be described later.

The results concerning the radiation angle characteristics of the photoconductor 24 described above are shown in FIG. 42, and the graph G for the reflective LCD side (the interface 28 side) as the object to be irradiated is in the period from -10° to -5° when the light receiving angle is from -10° to -5°. , The luminance rises to 2000cd/m ₂ as a peak value. On the other hand, for the curve H on the viewer side (the interface 23 side), the luminance is about 5000cd/ _m2 at the maximum when the light receiving angle is -60°, and the luminance is 100cd near the viewing angle of 0° for the reflective LCD. / _m2 or less.

In this way, the light from the light source 26 arranged on the end surface of the photoconductor 24 can be radiated from the interface 28 to the object to be illuminated (reflective LCD) at a substantially perpendicular angle. At the same time, there is almost no light leakage on the observer side which is the interface 23 side, and light from the light source can be efficiently guided to the object to be illuminated at a high angle.

In addition, in the present embodiment, a fluorescent tube is used as the light source, however, the light source is not limited thereto, for example, an LED (Light Emitting Diode), an EL element, or a tungsten lamp may be used.

Next, the liquid crystal tube 10a will be described. As shown in FIG. 37, the liquid crystal tube 10a has the same basic structure as the liquid crystal tube 10 of the first embodiment, except that a reflection plate is formed inside the liquid crystal tube 10a.

This liquid crystal tube 10a, also shown in FIG. 43, has a liquid crystal layer 12 sandwiched between a pair of electrode substrates 11a and 11c, and has a retardation plate 49 and a polarizer 18 on the side of the electrode substrate 11a that is the display side. Although there is only one retardation plate 49 (not shown in FIG. 37 ) in FIG. 43 , there may be two retardation plates or none.

In the electrode substrate 11a, a color filter member 38 is provided on a translucent glass substrate 14a, and a transparent electrode 15a (scanning line) is provided thereon to form a liquid crystal alignment film 16a covering the transparent electrode 15a. In addition, an insulating film or the like may be formed on the electrode substrate as needed. In addition, the color filter member 38 is not shown in FIG. 37 .

Further, in the electrode substrate 11c, an insulating film 19 is formed on a glass substrate 14b, a reflective electrode (reflector) 17a is formed thereon, and a liquid crystal alignment film 16b is formed to cover the reflective electrode 17a. A plurality of irregularities are formed on the surface of the insulating film 19 , and a plurality of irregularities are also formed on the surface of the reflective electrode 17 a covering the insulating film 19 .

The reflective electrode 17a also serves as a liquid crystal drive electrode for driving the liquid crystal monster 12 and as a reflector. An aluminum (Al) reflective electrode having excellent reflective properties can be used as the reflective electrode 17a. And the above-mentioned insulating film 19 is formed using an organic resist. The contact holes and uneven portions on the insulating film 19 are formed by the photolithography method described later. The materials and forming methods of the glass substrates 14a·14b, the transparent electrodes 15a·15b, and the liquid crystal alignment films 16a·16b are the same as those in the first embodiment.

Now, the method of forming the above-mentioned electrode substrate 11c will be described in detail with reference to FIGS. 44(a)-(e).

First, as shown in FIG. 44(a), an organic resist is coated on the entire surface of the glass substrate 14, and an insulating film 19 is formed by baking. Thereafter, as shown in FIG. 44(b), the insulating film 19 is irradiated with ultraviolet rays 30a through a sandwiched mask (mask) 30, and then, as shown in FIG. 44(c), the irradiated portion of the ultraviolet rays 30a is removed, and the A predetermined pattern is formed on the irradiated portion of 30a.

Next, as shown in FIG. 44(d), the insulating film 19 formed in a predetermined pattern is fired by performing a heat treatment at 180°. A thermal sag is generated on the organic resist, and the concavo-convex portion 19 a is formed by the thermal sag.

Finally, as shown in FIG. 44( e ), vacuum deposition of aluminum is performed to cover the concavo-convex portion 19 a. Accordingly, the reflective electrode 17a having concavo-convex portions is formed on its surface along the concavo-convex portions 19a.

The electrode substrate 11c obtained in this way and the above-mentioned electrode substrate 11a were arranged so that the liquid crystal alignment films 16a and 16b faced each other, and the directions of the rubbing treatment were antiparallel to each other, and were bonded together with an adhesive. Furthermore, between the electrode substrates 11a and 11c, hollow glass bead spacers (not shown) with a particle size of 4.5 μm were sprinkled in advance in order to make the space between the electrode substrates 11a and 11c uniform. Further, liquid crystal is introduced into the gap by vacuum pumping method to form the liquid crystal layer 12 . In addition, the material of the liquid crystal layer 12 is also the same as that of the first embodiment.

The reflective liquid crystal tube 10a of this embodiment is manufactured as described above, and the unexplained manufacturing process and manufacturing conditions are the same as those of the reflective liquid crystal tube 10 of the first embodiment, so they are omitted.

The pattern of the concave-convex portion formed on the reflective electrode 17a of the above-mentioned electrode substrate 11c (that is, the pattern of the concave-convex portion 19a of the insulating film 19) is irregularly formed so as to direct the incident light incident on the reflective liquid crystal tube 10a in a specific direction. Scattered reflections.

As for the concave-convex portion on the insulating film 19, it is preferable that the difference between the apex of the convex portion and the bottom surface of the concave portion is 0.1 μm to 2 μm. If the difference between the apex of the convex portion and the bottom surface of the concave portion on the concave-convex portion is within this range, incident light can be scattered without being affected by the orientation of the liquid crystal molecules and the tube thickness of the liquid crystal tube.

A comparison of the reflective characteristics of the reflective electrode 17a formed in this way with that of a standard white board (MGO) showing substantially the same scattering reflective characteristics as paper will now be described with reference to FIG. 45 . The aforementioned MGO (Japanese paper, etc.) exhibits non-directional reflection characteristics as shown by a dotted curve M in the figure. In contrast, the above-mentioned reflective electrode 17a (MRS) has directional scattering reflection characteristics in the angular range of ±30° as shown by the solid line curve N in the figure.

In the reflective liquid crystal cell 10a having such a reflective electrode 17a, images can be observed even when light is incident from directions other than the front and back. In addition, the reflective characteristics of the above-mentioned reflective electrode 17a are not limited to those shown in FIG. 45, and the design of the reflective electrode 17a can be appropriately changed to correspond to the characteristics of reflective LCDs used in various devices.

In addition, since the reflective electrode 17a is formed adjacent to the liquid crystal layer 12 in the reflective liquid crystal tube 10a, and the reflective plate is formed on the back side of the reflective liquid crystal tube 10a (the surface facing the side in contact with the photoconductor 24 ) can eliminate the parallax caused by the glass substrate 14b. Therefore, image replay can be suppressed in the obtained reflective LCD. In addition, the components of the reflective liquid crystal tube 10a can be simplified.

In addition, as shown in FIG. 37 and FIG. 43 , the reflective electrode 17 a of this embodiment, the display mode of the reflective liquid crystal tube 10 a may also be a polarizing mode with a polarizing plate 18 . In addition, as shown in FIG. 46, a reflective liquid crystal tube of a guest-host mode (without a polarizing plate) may be used. In addition, the basic structure of the reflective liquid crystal tube is substantially the same as that of the reflective liquid crystal tube 10a, so detailed description is omitted.

Hereinafter, the pixel structure configured on the above-mentioned liquid crystal tube 10a will be described. As shown in FIG. 47, the above-mentioned reflective element 10a forms a plurality of scanning lines 54 ... A plurality of signal lines 55... are formed in the direction in which the scanning lines 54... are formed. Then, a plurality of pixels 56 are formed corresponding to the grid pattern formed by the scanning lines 54... and the signal lines 55....

One pixel 56 is composed of pixel electrodes 56a corresponding to three color filter members of red (R), green (G) and blue (B). These pixel electrodes 56a are arranged in the order of R·G·B along the direction in which the scanning lines 54... are formed.

As the shape of the above-mentioned reflective liquid crystal tube 10a, in the present embodiment, it becomes a diagonal 6.5 size (longitudinal W _L =58 mm, lateral L _L =154.5 mm), the number Xm of scanning lines 54 = 240, and the number of signal lines 55 The number Yn=640 pieces. In addition, the pitch _PL of the pixels 56 arranged on the reflective liquid crystal cell 10a is 0.24 mm (R·G·B). An unillustrated black body (hereinafter, abbreviated as BM) having a width of 8 μm is formed on the periphery of the above-mentioned pixels 56 . . .

In the reflective LCD of this embodiment, the above-mentioned reflective liquid crystal tube 10a and front light 20a are combined. Here, in the headlight 20a, the pitch of the flat portion 21 and the inclined portion 22 of the photoconductor 24 is 0.21 mm as described above, which is smaller than the pitch of the scanning lines 54 . . . , BM. Therefore, the pitch of the BM of the reflective liquid crystal tube 10 a and the pitch of the grooves of the inclined portion 22 can be made different. If the respective pitches are staggered, the occurrence of moiré fringes due to the interference between the BM and the inclined portion 22 can be suppressed. Therefore, the display level of the obtained reflective LCD can be improved.

In the structure of the photoconductor 24 described above, the pitch of the flat portion 21 and the inclined portion 22 is smaller than the pitch of the scanning lines 54 . . . . That is, in order to suppress the occurrence of the Famoire fringes, it is only necessary to make the pitch of the grooves of the inclined portion 22 different from the pitch of the BM.

Here, _the sum W 3 of the width W ₁ of the flat portion 21 and the width W ₂ of the inclined portion 22 is the pitch of the grooves of the inclined portion 22 . Also, the above-mentioned BM shields the scanning lines 54... and the signal lines 55..., however, since the scanning lines 54... are parallel to the grooves of the inclined portion 22, the pitch _P1 of the scanning lines 54 is the pitch of the BM.

In order to make the groove pitch of the inclined portion 22 different from the pitch of BM, it is sufficient as long as the above-mentioned W ₃ and P ₁ are inconsistent (W ₃ ≠ P ₁ ). For the relationship between W ₃ and P ₁ , the width of W ₃ is particularly desirable. Greater than 2 times of P ₁ (W ₃ >2P ₁ ) or the width of W ₃ is less than half of P ₁ (W ₃ <1/2P ₁ )

When the above-mentioned relationship between _W3 and _P1 is not in the above-mentioned range, even if the groove pitch of the inclined part 22 is different from the pitch of the BM, it can be considered to be approximately the same from an optical point of view. Therefore, since the occurrence of moiré fringes cannot be effectively suppressed, it is not preferable.

In addition, the width _W1 of the flat part 21 in this embodiment, the width _W2 of the inclined part 22, the sum _W3 of _W1 and _W2 , and the angle of the inclined part 22 are not limited by the above numerical values, as long as they are formed and used. It is sufficient that the pixels of the reflective liquid crystal tube 10a are consistent.

In addition, in this embodiment, the pitch of the flat portion 21 is reduced along the direction (first direction) away from the light source 26 in order to make the luminance distribution uniform. However, it is also possible to change the angle of the inclined portion 22 instead The sum of the pitches of the flat portion 21 and the inclined portion 22 is reduced. For example, by reducing the flat portion 21 and at the same time reducing the angle α formed by the flat portion 21 and the inclined portion 22 in a direction (first direction) that is farther away from the light source 26, the distance between the flat portion 21 and the inclined portion 22 can be reduced. The sum of the pitches decreases. Even in this case, since the incident light incident on the inclined portion can be efficiently radiated in the direction (first direction) as it gets away from the light source 26, the luminance distribution can be averaged.

In addition, the reflective LCD of this embodiment is in the headlight 20a of the above-mentioned structure and the reflective liquid crystal tube 10a of the above-mentioned structure, and is arranged between the headlight 20a and the reflective liquid crystal tube 10a as the second photoconductor. anti-reflection film.

The anti-reflection film will now be described. In the above-mentioned reflective LCD, the polarizing plate 18 disposed on the reflective liquid crystal tube 10 and the interface (the first radiation surface) of the photoconductor 24 are bonded as the above-mentioned anti-reflection film. anti-reflection sheet 13.

As the anti-reflection sheet 13, an anti-reflection sheet (TAC-HC/AR) manufactured by Nitto Denko Co., Ltd. was used in this embodiment. This antireflection sheet 13 is a multilayer film having a four-layer structure. Specifically, triacetyl cellulose (TAC) is used as the base material, and the antireflection layer as the first layer of MgF ₂ , the second layer of CeF ₃ , the third layer of TiO ₂ , and the fourth layer of MgF ₂ are respectively formed thereon. film13.

The above-mentioned TAC sheet had a refractive index n ₁ =1.51 and a thickness of 100 μm. The first layer of _MgF2 has a refractive index n _m = 1.33 and a thickness of about 100 nm, the second layer of _CeF3 has a refractive index n _c = 1.63 and a thickness of about 120 nm, and the third layer of _TiO2 has a refractive index n _ti = 2.30 and a thickness of about 120 nm , The fourth layer of MgF ₂ has a refractive index n=1.38 and a thickness of about 100 nm. The first to fourth layers are sequentially formed on the TAC sheet of the base material by vacuum evaporation.

In addition, when bonding to the headlight 20a, an acrylate _- based adhesive layer having a refractive index n1 substantially the same as the refractive index _n2 of the acrylate material used for the photoconductor 24 is formed. Therefore, the light input and output conditions in the photoconductor 24 can be substantially unchanged, the anti-reflection effect can be improved, and uneven brightness distribution and rainbow light splitting can be prevented at the same time.

In addition, the above-mentioned TAC sheet of the first layer is not an essential member in the structure of the anti-reflection sheet 13 , for example, the first layer may be removed and the second to fourth layers may be directly laminated on the photoconductor 24 . However, in this case, the manufacturing cost may slightly increase.

The anti-reflection sheet 13 of the above-mentioned multilayer structure film has a structure of a λ/4-λ/2-λ/4-λ/4 wavelength plate for incident light having a wavelength of λ=550 nm. Therefore, the anti-reflection sheet 13 can function as the anti-reflection sheet 13 in a wide wavelength band.

In the photoconductor 24, the inclined portion 22 formed on the surface (interface 23) of the photoconductor 24 functions as a minute light source portion for the reflective liquid crystal tube 10a. Therefore, the light from the inclined portion 22 irradiates the reflective liquid crystal tube 10a, and on the interface 28 serving as the facing interface 23, the light from the inclined portion 22 About 4% of that is reflected as reflected light.

Due to the generation of this reflected light, a reflected image from the interface 28 to the interface 23 side is formed. Therefore, the reflected image interferes with or diffracts with the image on the inclined portion 22, and from the viewer's point of view, uneven brightness distribution and rainbow splitting occur on the surface of the reflective LCD.

However, in the reflective LCD of the present embodiment, an anti-reflection film (anti-reflection sheet 13) is arranged between the reflective liquid crystal tube 10a and the headlight 20a, that is, on the side of the interface 28 of the photoconductor 24, so that Reflected light generated by reflecting incident light on the inclined portion 22 on the interface 28 .

Therefore, interference or diffraction of the image on the inclined portion 22 as the minute light source portion and the reflected image reflected on the interface 28 side can be prevented. Therefore, uneven luminance distribution and rainbow light splitting in the display direction observed on the observer's side can be prevented from occurring.

Comparing the display luminance distribution between the case where the anti-reflection sheet 13 is arranged and the case where the anti-reflection sheet 13 is not arranged in the reflective LCD of this embodiment, as shown in FIG. 48 , the graph C when the anti-reflection sheet 13 is arranged The brightness distribution of the LED display is constant, there is no unevenness, and the brightness is higher than it, that is, the brightness is improved.

Furthermore, since the anti-reflection sheet 13 having the above-mentioned structure can be used as it is, a commercially available material can be used, so that the increase in the manufacturing cost of the headlight 20a can be suppressed. Therefore, an inexpensive front light 20a and a reflective LCD having the same can be obtained.

In addition, since the above-mentioned anti-reflection sheet 13 can be bonded with an adhesive _having a refractive index n1 approximately equal to the refractive index _n2 of the photoconductor 24 as the first photoconductor, the input of light in the photoconductor can be substantially unchanged. The anti-reflection effect is improved according to output conditions.

In addition, regarding the structure and material of the above-mentioned anti-reflection sheet 13, it is not limited to the above-mentioned structure and material. For example, as the structure of the wave plate, a λ/4-λ/2-λ/2-λ/2-λ/4-configuration can also be adopted. By constituting such a wavelength plate, it is possible to obtain a further antireflection effect over a wide wavelength band. Also, an anti-reflection sheet with a single-layer structure of a λ/4 wavelength plate can also be used. However, in this case, the wavelength band in which the antireflection effect is obtained is narrow.

In this way, by forming the pitch of the flat portion 21 and the inclined portion 22 formed on the surface (interface 23) of the photoconductor 24 to become smaller along the direction (first direction) away from the light source 26, the pitch from the inclined portion 22 The amount of reflected light increases with distance from the light source compared to conventional structures. Therefore, the luminance distribution on the interface 23 (first radiation surface) of the photoconductor 24 can be averaged.

And, by forming the pitch of the flat portion 21 and the inclined portion 22 on the interface 23 of the photoconductor 24 on the headlight 20a to be smaller than the pitch of the reflective liquid crystal tube 10a, it is possible to suppress the loss of Moiré fringes generated by interference of light caused by the BM formed around and the grooves of the above-mentioned inclined portion 22 . Therefore, a decrease in the display level of the reflective LCD can be prevented.

In addition, by providing an anti-reflection film (anti-reflection sheet 13) between the reflective liquid crystal tube 10a and the front lighting 20a, uneven brightness distribution and rainbow light splitting at the interface 23 of the photoconductor 24 can be prevented. Therefore, a brighter reflective liquid crystal LCD with a higher display level can be obtained.

In addition, by forming concavo-convex portions on the reflective electrode 17a of the reflective liquid crystal cell 10a, incident light can be scattered without being affected by the alignment of the liquid crystal molecules and the thickness of the liquid crystal cell. Therefore, an image can be observed even when light from outside the regular reflection direction enters the reflective liquid crystal cell 10a.

As mentioned above, in the front lighting device of the present invention, the second photoconductor is configured as an optical device for suppressing reflection of light from the second radiating surface of the first photoconductor on the first radiating surface of the first photoconductor. structure.

Usually, the first radiation surface of the first photoconductor reflects light from the inclined portion formed on the second radiation surface as reflected light. By the generation of this reflected light, a reflected image from the first radiation surface and the second radiation surface of the first photoconductor is formed. As a result, since the reflected image interferes with or diffracts with the image on the above-mentioned inclined portion, uneven luminance distribution and rainbow splitting occur on the surface of the object to be illuminated as viewed by the observer.

However, according to the above configuration, since the front illuminating device has the above-mentioned optical device as the second photoconductor, it is possible to suppress the reflected light generated by the incident light from the inclined portion being reflected on the first radiation surface. Therefore, it is possible to prevent mutual interference or diffraction between the image of the inclined portion which is the minute light source portion and the reflected image caused by the reflected light. Therefore, it is possible to prevent occurrence of luminance unevenness and rainbow splitting in the display observed on the viewer side (second radiation surface).

In the front lighting device of the present invention, the optical device is an antireflection film. Since a commercially available antireflection film can be directly used as the optical device, an increase in the manufacturing cost of the front lighting device can be suppressed. As a result, an inexpensive front lighting device can be provided.

In the front lighting device of the present invention, the optical device is bonded to the first photoconductor with an adhesive having a refractive index substantially equal to that of the first photoconductor. Therefore, the anti-reflection effect can be improved without changing the light input and output conditions in the first photoconductor.

In the front lighting device according to the present invention, the sum of the pitch of the flat portion and the pitch of the inclined portion formed on the photoconductor is made smaller as the distance from the incident surface increases. Therefore, the number of the above-mentioned inclined portions per unit area increases as the distance from the light source increases. As the slope increases, the brightness on the surface of the object to be illuminated increases as it moves away from the light source. Generally, since there is a tendency for the brightness to decrease with distance from the light source, in the above-mentioned structure, the increase of the inclined portion offsets the decrease in the brightness of the illuminated object caused by the distance from the light source, and the light from the light source can be guided to the entire area at a high angle and high efficiency. to be illuminated. As a result, the luminance distribution on the surface of the object to be illuminated can be averaged.

The reflective liquid crystal display device of the present invention has the front illuminating device of above-mentioned structure, and further reflective liquid crystal tube has scanning line, makes the pitch of the flat part and the pitch of the inclined part on the 2nd radiation surface of the front illuminating device sum ratio The above scanning lines have a small pitch.

Therefore, according to the above-mentioned structure, since the sum of the pitches of the above-mentioned flat portion and the inclined portion is smaller than the sum of the pitches of the scanning lines, the pitch of the inclined portion that becomes the front illuminator and the surrounding pixels of the reflective liquid crystal tube are smaller than the sum of the pitches of the scanning lines. The pitch of the formed blackbody is different. As a result, generation of moiré fringes due to interference between the black body and the inclined portion can be suppressed. The display level of the obtained reflective liquid crystal display device can be provided.

In the reflective liquid crystal display device of the present invention, in the above configuration, the sum of the pitch of the flat portion and the pitch of the inclined portion on the second radiation surface of the front illuminator is larger than the pitch of the scanning lines. Even with this configuration, the pitch of the inclined portion of the front illuminator can be made different from the pitch of the black bodies formed around the pixels of the reflective liquid crystal tube. As a result, since the generation of moiré fringes due to the interference between the black body and the inclined portion can be suppressed, the display level of the obtained reflective liquid crystal display device can be improved.

In the reflective liquid crystal display device of the present invention, in the above-mentioned configuration, the reflective liquid crystal cell has a reflector having a surface having concavo-convex portions that do not affect the thickness of the device. Therefore, the reflection plate can scatter incident light without giving influence to the orientation of the liquid crystal molecules and the thickness of the liquid crystal tube. Therefore, an image can be observed even if light is incident from a direction other than the regular reflection direction.

In the reflective liquid crystal display device of the present invention, in the above configuration, the reflective plate is a reflective electrode serving also as a liquid crystal drive electrode for driving a liquid crystal layer of a reflective liquid crystal tube, and is provided adjacent to the liquid crystal layer. Therefore, compared with the case where the reflection plate is not provided adjacent to the liquid crystal layer, the occurrence of parallax due to the electrode substrate constituting the reflection type liquid crystal tube can be eliminated. As a result, image reappearance can be suppressed in the obtained reflective liquid crystal display device. Furthermore, since the reflector doubles as the liquid crystal driving electrode, the structure of the reflective liquid crystal display device can also be simplified.

Example 12

Other embodiments of the present invention are described below in conjunction with the accompanying drawings. In addition, the same reference numerals are assigned to components having the same functions as those described in the above-mentioned embodiments, and description thereof will be omitted.

The reflective LCD of this embodiment, as shown in Figure 49, has the same basic structure as that of the aforementioned embodiment 2, but the difference is that it is arranged between the reflective liquid crystal tube 10 and the front lighting system 51 as the 3rd photoconductor (optical device). ) anti-reflection sheet (anti-reflection film) 13.

The above-mentioned anti-reflection sheet 13 is the same member as that used in Embodiment 11 described above. Furthermore, since the descriptions of the anti-reflection sheet 13, the reflective liquid crystal tube 10, and the front lighting system 51 have already been carried out in the above-mentioned Embodiment 2 and Embodiment 11, they are omitted.

In this embodiment, the above-mentioned anti-reflection mold 13 has a function as a third photoconductor added to the photoconductor 24 serving as the first photoconductor and the photoconductor 40 serving as the second photoconductor.

In the case where the anti-reflection sheet 13 is not formed, the light from the inclined portion formed on the interface 23 (the second radiation surface) of the first light guide 24 is placed on the bottom surface (second surface) 42 of the second light guide 40. , About 4% is reflected and becomes reflected light. The image of the inclined portion 22 formed by the reflected light interferes with the inclined portion 22 on the photoconductor 24, resulting in uneven brightness distribution on the interface 28 (first radiation surface) of the photoconductor 24.

Therefore, in the reflective LCD of the present embodiment, an anti-reflection sheet having the same structure as that in Embodiment 11 is disposed between the bottom surface 42 of the second photoconductor 40 and the surface on the display side of the reflective liquid crystal tube 10. 13. By arranging the anti-reflection 13, the occurrence of the above-mentioned reflected light can be effectively suppressed. Therefore, uneven brightness distribution on the interface 28 can be suppressed, and a reflective LCD with high-level display can be realized.

Comparing the situation where the above-mentioned anti-reflection sheet 13 is arranged in the reflective LCD with the situation where it is not arranged, as shown in FIG. In contrast, the pitch P of the luminance peaks in the luminance distribution diagram 50(a) shown in the case where the above-mentioned anti-reflection sheet 13 is arranged is approximately equal along the entire bottom surface 42 of the second photoconductor 40, and the luminance peaks are gentle and the luminance distribution is uneven. reduce. Therefore, the luminance state is improved.

Furthermore, the above-mentioned antireflection sheet 13 is bonded with an adhesive having a refractive index _n1 substantially equal to the refractive index _n2 of the second photoconductor 40 . Therefore, the anti-reflection effect can be provided substantially without changing the light input and output conditions in the second photoconductor 40 .

In addition, since the antireflection sheet 13 having the above-mentioned structure can be used as it is, a commercially available item can be used, so that the increase in the manufacturing cost of the front lighting system 51 can be suppressed. Therefore, an inexpensive front lighting system 51 and a reflective LCD having the front lighting system can be obtained.

As described above, the front lighting device of the present invention has a third photoconductor on the second surface of the second photoconductor, and the light from the second radiation surface on the first photoconductor is reflected by the second surface. The structure of the suppressed optics.

Usually, part of the light from the inclined portion formed on the second radiation surface of the first photoconductor is reflected on the second surface of the second photoconductor as reflected light. Owing to the generation of this reflected light, a reflected image from the first radiation surface on the first photoconductor to the second radiation surface is formed. As a result, the reflected image interferes with or diffracts with the image on the above-mentioned inclined portion, and uneven brightness distribution and rainbow light splitting occur on the surface of the object to be illuminated as viewed by the observer.

However, according to the above configuration, since the front illuminating device has the above-mentioned optical device as the third photoconductor, it is possible to suppress the reflected light generated by the incident light of the inclined portion being reflected on the second surface. Therefore, interference or diffraction of the image on the inclined portion functioning as the micro light source portion and the reflected image caused by the reflected light can be prevented. Therefore, it is possible to prevent occurrence of unevenness in luminance distribution and rainbow splitting on the display observed on the observer side (second radiation surface).

The above-mentioned optical device in the front lighting device of the present invention is an antireflection film. Therefore, since a commercially available anti-reflection film (anti-reflection sheet) can be directly used as an optical device, an increase in the manufacturing cost of the front lighting device can be suppressed. Therefore, an inexpensive front lighting device can be provided.

In the front lighting device of the present invention, the optical device is bonded to the second photoconductor with an adhesive having a refractive index substantially equal to that of the second photoconductor. Therefore, the anti-reflection effect can be improved substantially without changing the light input/output conditions in the photoconductor.

The above specific implementation forms or examples in detail are for the purpose of clearly introducing the technical content of the present invention, but it should not be narrowly understood that the present invention is only limited to these examples, and various implementation changes can be made under the spirit of the present invention.

Claims (42)

1. A front lighting device having a light source and a photoconductor arranged in front of an object to be illuminated, wherein the photoconductor has an incident surface on which the light from the light source is incident, radiates light to the object to be illuminated, and transmits light from the object to be illuminated. The first radiating surface on which the reflected light is incident faces the first radiating surface, and the second radiating surface radiates the reflected light from the object to be illuminated. The flat parts and the flat parts that mainly transmit the reflected light from the object to be illuminated are alternately connected to each other in a stepped shape. 2. The front lighting device according to claim 1, wherein said photoconductor is used as a first photoconductor, and further includes a second photoconductor for uniformizing the luminance distribution of the radiated light from said first radiating surface. 3. The front lighting device according to claim 2, wherein the second photoconductor has a first surface facing the first radiating surface of the first photoconductor and a light passing through the first photoconductor facing the first surface. The light incident on the above-mentioned first surface is radiated to the second surface of the object to be illuminated, and the above-mentioned first surface and the second surface are formed such that the distance from each inclined portion of the second radiation surface of the first photoconductor to the above-mentioned second surface is uniform. 4. The front lighting device according to claim 3, wherein the refractive index of the first photoconductor is equal to the refractive index of the second photoconductor. 5. The front lighting device according to claim 3, wherein the first photoconductor and the second photoconductor are integrally formed. 6. The front lighting device according to claim 3, characterized in that on the second surface of the second photoconductor, there is a third photoconductor for light from the second radiation surface of the first photoconductor. 2 Optics for surface reflection suppression. 7. The front lighting device according to claim 6, wherein the optical device is an anti-reflection film. 8. The front lighting device according to claim 6, wherein the optical device is bonded to the second photoconductor with an adhesive having a refractive index equal to that of the second photoconductor. 9. The front lighting device according to claim 2, wherein the second photoconductor is a light scatterer for scattering radiated light from the first radiation surface of the first photoconductor. 10. The front lighting device according to claim 9, wherein the light scatterer is a front light scatterer. 11. The front lighting device according to claim 2, wherein the second photoconductor suppresses light from the second radiation surface of the first photoconductor from being reflected by the first radiation surface of the first photoconductor. optical device. 12. The front lighting device according to claim 11, wherein the optical device is an anti-reflection film. 13. The front lighting device according to claim 11, wherein the optical device is bonded to the second photoconductor with an adhesive having a refractive index equal to that of the second guide body. 14. The front lighting device according to claim 2, characterized in that filling between the first photoconductor and the second photoconductor alleviates the refractive index difference caused by the optical interface between these photoconductors. agent. 15. The front lighting device according to claim 14, characterized in that between the light source and the incident surface, there is further control of the scattering of light from the light source so that there is no component directly incident on the first radiation surface of the first photoconductor from the incident surface. range of light control devices. 16. The front lighting device according to claim 1, wherein the incident surface is located on the side of the photoconductor. 17. The square lighting device according to claim 16, wherein the sum of the projections of the inclined portion perpendicular to the first radiation plane is equal to the projection of the incidence plane to the plane. 18. The front lighting device according to claim 16, wherein the incident surface forms an obtuse angle with the first radiating surface. 19. The front lighting device according to claim 1, further comprising a light collecting means for making the light from the light source incident only on the incident surface. 20. The front lighting device according to claim 1, wherein the sum of projections of said inclined portions onto said first radiation surface is smaller than the sum of projections of said flat portions onto said first radiation surface. 21. The front lighting device according to claim 1, wherein the flat portion is parallel to the first radiating surface or is inclined at an angle of 10° or less with respect to the first radiating surface. 22. The front lighting device according to claim 1, wherein the refractive index of the photoconductor is n ₂ , the refractive index of the external medium in contact with the inclined portion is n ₁ , and the incidence of light incident on the inclined portion by the light source is The angle θ satisfies the following inequality: θ≥arc sin(n ₁ /n ₂ ) 23. The front lighting device according to claim 1, wherein a reflection member for reflecting light is provided on the surface of the inclined portion. 24. The front lighting device according to claim 23, wherein the refractive index of the photoconductor is n ₂ , the refractive index of the external medium in contact with the inclined portion is n ₁ , and the incidence of light incident on the inclined portion by the light source is The angle θ satisfies the following inequality: θ＜arc sin(n ₁ /n ₂ ) 25. The front lighting device according to claim 23, wherein a light shielding member is provided on a surface of the reflecting member. 26. The front lighting device according to claim 1, further comprising compensating means for aligning the radiation directions of the light emitted from the flat portion of the second radiation surface and the light emitted from the inclined portion. 27. The front lighting device according to claim 26, wherein the compensating device has a first surface facing the second radiation surface of the photoconductor and a second surface facing the first surface, and the compensating device's first surface 1. The surface is formed in a stepped shape complementary to the second radiating surface by alternately connecting inclined surfaces parallel to the slanted portion of the second radiating surface of the photoconductor and flat surfaces parallel to the flat portion of the second radiating surface. 28. The front lighting device according to claim 26, wherein in the compensating means, the area mainly allowing the radiated light of the inclined portion of the second radiating surface to enter is the same as the area mainly allowing the radiated light of the flat portion of the second radiating surface to be incident. The regions where light is incident have different refractive indices. 29. The front lighting device according to claim 26, wherein in the compensating means, a diffractive element is provided in a region where the radiated light from the inclined portion of the second radiating surface mainly enters. 30. The front lighting device according to claim 26, wherein in the compensating device, a light shielding member is provided in a region where the radiated light from the inclined portion of the second radiating surface mainly enters. 31. The front lighting device according to claim 1, characterized in that between the light source and the incident surface, there is a light control device for limiting light scattering of the light source. 32. The front lighting device according to claim 31, characterized in that in the light control, the incident angle of the light directly incident on the inclined portion of the second radiation surface from the incident surface limits the scattering of light from the light source in a range larger than the critical angle. . 33. The front lighting device according to claim 1, wherein the sum of the pitch of the flat portion and the pitch of the inclined portion formed on the photoconductor becomes smaller as the distance from the incident surface increases. 34. A reflective liquid crystal display device, comprising a reflective liquid crystal tube having a reflector, a front lighting device disposed in front of the reflective liquid crystal tube, the front lighting device having a light source and a photoconductor disposed in front of an illuminated object, It is characterized in that the photoconductor has an incident surface for making light from the light source incident, a first radiation surface for radiating light to an object to be illuminated and for incident light reflected from the object to be illuminated, facing the first radiation surface, and receiving light from the object to be illuminated. The second radiating surface where the reflected light of the object radiates, the above-mentioned 2nd radiating surface is formed by alternately connecting the inclined part that mainly reflects the light source light to the first radiating surface and the flat part that mainly transmits the reflected light from the object to be illuminated. shape. 35. The reflective liquid crystal display device according to claim 34, wherein the reflective liquid crystal tube has scanning lines, and the pitch of the scanning lines is equal to the pitch of the flat portion on the second radiation surface of the front illuminator. Equivalently, the flat portion is arranged above the scan line. 36. The reflective liquid crystal display device according to claim 34, wherein the reflective liquid crystal tube has scanning lines, and the distance between the pitch of the flat portion and the pitch of the inclined portion on the second radiation surface of the front illuminator is and smaller than the pitch of the above scan lines. 37. The reflective liquid crystal display device according to claim 34, wherein the reflective liquid crystal tube has scanning lines, and the distance between the pitch of the flat portion and the pitch of the inclined portion on the second radiation surface of the front illuminator is and larger than the pitch of the above scan lines. 38. The reflective liquid crystal display device according to claim 34, wherein the reflective liquid crystal cell includes a reflector having concavo-convex portions on its surface. 39. The reflective liquid crystal display device according to claim 38, wherein the reflective plate is a reflective electrode also serving as a liquid crystal driving electrode for driving a liquid crystal layer of a reflective liquid crystal tube, and is provided adjacent to the liquid crystal layer. 40. The reflective liquid crystal display device according to claim 34, characterized in that the front lighting device is arranged to be freely openable and closed relative to the reflective liquid crystal tube. 41. A reflective liquid crystal display device, which has a front lighting device in front of a reflective liquid crystal tube with a reflector, and the front lighting device has a light source and a photoconductor arranged in front of the object to be illuminated, characterized in that the photoconductor It has an incident surface on which the light from the light source is incident, a first radiation surface that radiates light toward the object to be illuminated and receives reflected light from the object to be illuminated, and a first radiation surface that faces the first radiation surface and radiates reflected light from the object to be illuminated. 2 radiating surfaces, the above-mentioned 2nd radiating surface is alternately connected to each other by inclined portions mainly reflecting the light from the light source to the 1st radiating surface and flat portions mainly allowing the reflected light from the object to be illuminated to A compensating device in which the radiation direction of the light emitted from the flat part of the radiation surface is consistent with the radiation direction of the light emitted from the inclined part. The compensation device is flexible to a predetermined pressure. Out position detection mechanism by applying pressure position by mutual contact. 42. The reflective liquid crystal display device according to claim 41, wherein said reflective liquid crystal tube has a scanning line, said position detection means includes a transparent electrode formed on a flat portion of said second radiation surface, said The pitch of the scanning lines is equal to the pitch of the above-mentioned transparent electrodes, and the transparent electrodes are arranged above the scanning lines.

Images