JPH1152374A - Liquid crystal display device with light condensing mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a lighting quantity and to obtain a bright display screen by forming first and second backlighting parts to a wedge shape, superposing these parts on each other in the form of compensating their thicknesses with each other and providing plate the lighting part of the first backlighting part in the form projecting from their superposition structure. SOLUTION: The lighting part 2d of the first backlighting part 2 consists of the end of a light transmission plate 2a and is exposed outside from a lighting window 4a opened in a frame 4 to take the external light. Particularly the lighting part 2d is projected from a main body part housed in the frame 4 and, therefore, the lighting quantity is large. The lighting part 2d is formed by working an acrylic resin to a lens shape, by which the lighting efficiency is further enhanced. In addition, the backlighting part is formed to the wedge shape so as to be thickest near the lighting part 2d and the light source 5 and to be gradually thinner the more distant therefrom. The first backlighting part 2 and the second backlighting part 3 are superposed on each other so as to constitute a rectangular parallelepiped by flatly and corresopondingly compensate the thicknesses with each other. As a result, the liquid crystal display device which is of a thin type, is reduced in electric power consumption and is made lighter in weight may be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD) for performing display utilizing the electro-optical anisotropy of liquid crystal.
In particular, the present invention relates to a liquid crystal display device with a light-collecting mechanism, which has a light-collecting mechanism to reduce power consumption of a backlight.

[0002]

2. Description of the Related Art An LCD is constructed by sealing liquid crystal between electrode substrates having transparent electrodes formed on a transparent substrate. Since the liquid crystal has electro-optical anisotropy, by applying a desired voltage between the electrodes to form an electric field in the liquid crystal, the liquid crystal exhibits optical characteristics according to the electric field intensity. Therefore, by controlling the voltage for each pixel, a display image is created as an aggregate of pixels exhibiting a desired luminance. As described above, in the LCD, a display image is created by voltage control, and the LCD is small-sized,
It has advantages such as thinness and low power consumption, and has been put to practical use in fields such as OA equipment and AV equipment.

FIG. 4 shows a configuration diagram of an LCD with a light condensing mechanism.
(10) is an LCD panel, (11) is a first illumination unit,
(12) is a second illumination unit. These are the frames (1
3) is stored inside. The first illuminating unit (11) is a light collecting mechanism, and is a light guide plate (11a) made of acrylic resin or the like.
It comprises a first diffusion plate (11b) provided on the back and side surfaces of the light guide plate (11a), and a second diffusion plate (11c) provided on the front surface of the light guide plate (11a). The second illumination unit (12) includes a light source (14) such as a fluorescent lamp, and includes a light guide plate (12a) made of acrylic resin or the like and a light guide plate (1).
Reflectors (12b) provided on the back and side surfaces of 2a);
And it is constituted by a third diffusion plate (12c) provided on the front surface of the light guide plate (12a). Diffusion plate (11b, 1
1c and 12c) are obtained by subjecting a polyester (PET) plate to diffusion processing using beads or the like, and the diffusivity is controlled by changing the distribution density of the diffused substance. In addition, the reflection plate (12
b) is obtained by irregularly reflecting a PET plate with Al, Ag, white paint, or the like. The reflectivity is controlled by changing the distribution density of these reflectors.

The first illuminating section (11) includes a light guide plate (11).
The end of a) is exposed as a lighting part (11d), and external light is taken in from a lighting window (13a) opened in the frame (13). The light introduced into the light guide plate (11a) is diffusely diffused upward and downward by the first diffusion plate (11b), and the upward light is converted into uniform parallel light by the second diffusion plate (11c). LCD (1
0). On the other hand, light directed downward enters the second illuminator, is reflected by the reflector (12c), and is again diffused by the second diffuser (11b) of the first illuminator (11).

The second illuminating section (12) has a light source (1) at an end.
4), the light emitted from the light source (14) is introduced into the light guide plate (12a), reflected by the reflection plate (12b), converted into uniform parallel light by the diffusion plate (12c).
Is transmitted to the LCD (10) through the illuminating section (11). First diffuser (11b) and third diffuser (12c)
Can also be used in common.

In this LCD with a light condensing mechanism, the second illuminating section (12) is operated as required. That is, in an environment where the outside light is abundant, such as a sunny outdoors or a brightly lit indoor, the second illuminator (12) is turned off and the first illuminator (1) is turned off.
The observation of the LCD monitor is performed alone in 1). On the other hand, the second illuminating unit (12) is turned on outdoors in rain or cloudy or indoors with dark lighting. For this reason, a sufficiently bright screen can be obtained even if the amount of irradiation of the first illuminating unit (11) is small, and the second illuminating unit (12) only replenishes the amount of light of the first illuminating unit (11). Therefore, power consumption can be reduced.

[0007]

As described above, the LCD with the light condensing mechanism shown in FIG. 4 has both a high luminance screen and low power consumption, but the backlight is the first illuminating section (11).
In addition, since the second illuminating section (12) has a double structure, there is a problem in that the advantage of the LCD (10) that it is thin and lightweight is impaired.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and a liquid crystal is sealed between a pair of electrode substrates each having a predetermined electrode formed on a transparent substrate. A liquid crystal display panel whose distribution is controlled so that the display screen is in a recognizable front state, a first illuminating unit that takes in external light and irradiates the liquid crystal display panel, and light from a light emitting source is supplied to the liquid crystal display. A second illuminating unit for irradiating the panel with the first and / or second illuminating unit, and a display screen in a front state recognizable by the liquid crystal display panel is visualized by the illumination from the first and / or second illuminating unit. In the liquid crystal display device with a light mechanism, the first illuminating section is the thickest in the lighting section for taking in external light, and the light guide section for integrating the light path and illuminating the liquid crystal display panel is separated from the lighting section. Progressively thinner according to the 2 of illumination unit, a light guide unit for performing illumination to connect the optical path the liquid crystal display panel is progressively thinner with increasing distance from the light source to the light emitting source, first and second
Of the liquid crystal display panel, and the first illuminating portion is mostly located behind the liquid crystal display panel, and the lighting unit is provided on the liquid crystal display panel. It is a configuration that protrudes from behind.

Accordingly, the thickness of the first illuminated portion and the second illuminated portion superimposed on each other is greater than the thickness of the maximum thickness of the first illuminated portion and the maximum thickness of the second illuminated portion. And the entire device is reduced in size and weight. Further, since the lighting portion of the first illuminating portion slightly protrudes from these overlapping structures, the lighting efficiency is improved and a bright display screen is obtained.

[0010] In particular, the daylighting section is configured to be processed into a lens shape. Thereby, the lighting efficiency is further improved, and a brighter display screen is obtained. Also, a liquid crystal display panel in which liquid crystal is sealed between a pair of electrode substrates each having a predetermined electrode formed on a transparent substrate, the transmittance distribution of the liquid crystal is controlled, and the display screen is brought to a recognizable front state, A first illuminating unit that irradiates the liquid crystal display panel with external light and a second illuminating unit that illuminates the liquid crystal display panel with light from a light emitting source are overlapped with each other, and the first and / or In the liquid crystal display device with a light-collecting mechanism in which the display screen brought into a recognizable front state is visualized by the illumination from the illumination unit 2, the first illumination unit takes in external light. The light-collecting air space is the thickest, and the air-light guiding layer that illuminates the liquid crystal display panel by integrating the space with the light-collecting air space becomes progressively thinner as the distance from the light-collecting air space increases, and the second lighting unit connects an optical path to a light emitting source. To the liquid crystal display panel Light guiding unit that performs illumination can be thinned progressively as the distance from the light source, the first and second illuminating section has a configuration which is arranged to form a planar correspondingly thickness complementary relationship.

Accordingly, the thickness of the first illuminated portion and the second illuminated portion superimposed on each other is larger than the thickness of the maximum thickness of the first illuminated portion and the maximum thickness of the second illuminated portion. And the first illuminating section is simple, so that the entire apparatus can be reduced in size, weight, and cost. Especially,
The air light guide layer is located behind the liquid crystal display panel,
At an end thereof, a lighting part for connecting an optical path is provided, and is projected from behind the liquid crystal display panel.

[0012] Thus, since the lighting portion of the first illuminating portion slightly protrudes from these overlapping structures, the lighting efficiency is improved and a bright display screen is obtained.

[0013]

FIG. 1 is a side sectional view of an LCD with a light collecting mechanism according to a first embodiment of the present invention. (1)
Is the LCD panel, (2) is the first illuminator, and (3) is the second illuminator.
Illumination part. These are accommodated in the frame (4). The first illuminating section (2) is a light collecting mechanism section, and includes a light guide plate (2a) made of acrylic resin or the like, a first diffusion plate (2b) provided on the back and side surfaces of the light guide plate (2a), and A second diffusion plate (2c) provided on the front surface of the light guide plate (2a)
It consists of. The second illuminating section (3) includes a light source (5) such as a fluorescent lamp at an end, and a light guide plate (3a) made of acrylic resin or the like, and a reflection plate (3) provided on the back and side surfaces of the light guide plate (3a). 3b) and a third diffusion plate (3c) provided on the front surface of the light guide plate (3a).

The first illuminating section (2) has a light guide section (2d) at the end of the light guide plate (2a), and a frame (4).
The light is exposed to the outside through a lighting window (4a) opened therein so that external light can be taken in. In particular, the lighting section (2
Since d) is protruded from the main body housed in the frame (4), the amount of collected light is large. In addition, the daylighting section (2d) further improves the daylighting efficiency by processing the acrylic resin into a lens shape.

The light introduced into the light guide plate (2a) from the daylighting section (2d) is diffused by the first diffusion plate (2b) and scattered upward or downward. The light going upward is the second
Is made into uniform parallel light by the diffusion plate (2c), and is irradiated onto the LCD panel (1). In particular, the first diffusion plate (2b)
Are arranged in an inclined manner toward the light-collecting unit (2d), so that the efficiency of capturing light introduced from the light-collecting unit (2d) is increased, and the light use efficiency is improved. On the other hand, the light traveling downward enters the second illuminator (12), is reflected by the reflector (3b), and is diffused again by the first diffuser (2b).

The second illuminator (3) has a light source (5) at an end.
And the light emitted from the light source (5) is used as the light guide plate (3a).
Is reflected by the reflection plate (3b), is converted into uniform parallel light by the diffusion plate (3c), passes through the first illuminating section (3), and is emitted to the LCD panel (1). Further, since the reflector (3b) is arranged in a form inclined toward the light source (5), the light capture rate is increased, and the light use efficiency is improved. Here, the first illuminating section (2)
And the third diffuser plate (3c) of the second illuminator (3) may be common.

The first illuminating portion (11) and the second illuminating portion (12) are wedge-shaped portions which are thickest in the vicinity of the light-collecting portion (2d) and the light source (5), and are thinned away from the portions. . Then, these first illumination units (1
1) and the second illuminating section (12) are overlapped so as to form a rectangular parallelepiped by complementing each other in a planar manner. Therefore, the thickness of the backlight portion is reduced to almost half that of the conventional LCD with a light condensing mechanism shown in FIG.
Thinning is realized.

FIG. 2 is a side sectional view of an LCD with a light collecting mechanism according to a second embodiment of the present invention. In the present embodiment, the first illuminating unit (6) is provided with the LCD panel (1) and the second illuminating unit.
Air guide layer (6) utilizing the space between the illuminator (7)
a) and an upper part thereof, that is, a first diffusion plate (6b) provided at a lower part of the LCD panel (1), and the air light guide layer (6a) is spatially provided as a lighting window of the frame (4). The end connected to (4a) is a lighting airspace (6c). The second illuminator (7) includes a light guide plate (7a) having a light source (5) at an end, a reflector (7b) provided on the back and side surfaces of the light guide plate (7a), and a light guide plate (7b). It is constituted by a second diffusion plate (7c) provided on the front surface of the light plate (7a).

In this configuration, external light is naturally introduced into the air light guide layer (6a) from the daylighting window (4a) and diffused by the second diffusion plate (7c) on the second illuminating section (7) side. And a part thereof is converted into parallel light through the first diffusion plate (6b).
The light is irradiated to the panel (1). In the present embodiment, the amount of collected light cannot be increased so much, but the cost is low due to the simple structure. Further, since the second diffusion plate (7c) is inclined toward the daylighting window (4a), the light capture rate is increased.

Here, in the present embodiment, the light taken in from the daylighting air space (6c) of the first illuminating section (6) is transmitted to the second diffuser (7c) on the second illuminating section (7) side. ). That is, the second diffuser plate (7) of the second illuminator (7)
c) both captures light from the light source (5) and captures light from the daylighting window (4a). However, by providing a diffusion plate exclusively for capturing light from the daylighting window (4a) on the side of the first illuminating section (6) and arranging the diffusion plate so as to overlap with the second diffusion plate (7c), the light source is provided. The diffusing ability of light from (5) and the diffusing ability (transmittance) of light from the daylighting window (4a) should be different, and the specifications should be such that the light source (5) or external light is emphasized depending on the application. Can be.

FIG. 3 is a side sectional view of an LCD with a light collecting mechanism according to a third embodiment of the present invention. In the present embodiment, the first illuminating unit is an air light guiding layer (6a) using a space between the LCD panel (1) and the second illuminating unit, and an upper part thereof, that is, the LCD panel (1). The first provided at the bottom of
Of the air light guide layer (6a), and a light collecting part (8) as a condensing lens at the end of the air light guide layer (6a).
This daylighting section (8) is the daylighting section (2d) of the first embodiment.
Similarly to the above, the light is projected outside from a lighting window (4a) opened in the frame (4) to increase the amount of light. Also in the present embodiment, the lighting window (4) is provided on the first illuminating section (6) side.
By providing a diffusion plate exclusively for capturing the light from a) and arranging it so as to overlap with the second diffusion plate (7c), the diffusing ability of the light from the light source (5) and the lighting window (4a) The light source (5) or the external light can be designated as important depending on the application by making the diffusing ability (transmittance) of the light from the light source different.

In this configuration, external light is transmitted from the daylighting section (8).
The light is condensed and introduced into the air light guide layer (6a), and the second diffuser plate (7
The light is diffused in (c), and a part of the light is made parallel by the first diffusion plate (6b) and irradiated on the LCD panel (1). In this embodiment, since the air light guide layer is used, the cost is lower than that of the first embodiment, and more external light is introduced by the daylighting section (8) including the condenser lens. Therefore, a brighter display screen can be obtained as compared with the second embodiment.

[0023]

As is apparent from the above description, a liquid crystal display device with a light condensing mechanism comprising a first illuminating section for taking in and irradiating external light and a second illuminating section for irradiating light from a light source. In the above, the first and second illuminating portions are overlapped in a wedge shape so as to complement each other, so that a thin and small size is realized, and the lighting portion of the first illuminating portion protrudes from these overlapping structures. With such a shape, the amount of light collected is increased, a bright display screen is obtained, and the power consumption of the light source is reduced.

Thus, brightness, low power consumption, thinness,
A liquid crystal display device that satisfies all of the requirements for miniaturization and weight reduction was obtained. In particular, the light guide layer of the first illuminating section was formed as an air guide layer, thereby achieving further weight reduction.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an LCD with a light collecting mechanism according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of an LCD with a light collecting mechanism according to a second embodiment of the present invention.

FIG. 3 is a side sectional view of an LCD with a light collecting mechanism according to a third embodiment of the present invention.

FIG. 4 is a side sectional view of a conventional LCD with a light collecting mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LCD panel 2, 6 First illuminating part 3, 7 Second illuminating part 4 Frame 5 Light source 6 Lighting part 8 Condensing lens

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Makoto Shimizu 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Yoshinori Kurahashi 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5-5 in Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. A liquid crystal display in which a liquid crystal is sealed between a pair of electrode substrates each having a predetermined electrode formed on a transparent substrate, the transmittance distribution of the liquid crystal is controlled, and the display screen is brought to a recognizable front state. The panel, a first illuminating unit that takes in external light and irradiates the liquid crystal display panel with the liquid crystal display panel, and a second illuminating unit that irradiates light from a light emitting source to the liquid crystal display panel are overlapped with each other, and And / or in the liquid crystal display device with the light condensing mechanism in which a display screen brought into a recognizable front state is visualized by the illumination from the second illumination unit, the first illumination unit is an external device. The light-collecting unit that takes in light is the thickest, and the light-guide unit that illuminates the liquid crystal display panel with the light path integrated with it is gradually thinner as it goes away from the light-collecting unit. To the LCD panel Light guide section that performs illumination can be thinned progressively as the distance from the light source, the first and second illuminating portion is arranged to form a planar correspondingly thickness complementary relationship,
A liquid crystal display device with a light-collecting mechanism, wherein the first illuminating section is mostly located behind the liquid crystal display panel, and the lighting section protrudes from behind the liquid crystal display panel. 2. The liquid crystal display device with a light-collecting mechanism according to claim 1, wherein the lighting unit is processed into a lens shape. 3. A liquid crystal display in which a liquid crystal is sealed between a pair of electrode substrates each having a predetermined electrode formed on a transparent substrate, and the transmittance distribution of the liquid crystal is controlled so that the display screen is in a recognizable front state. The panel, a first illuminating unit that takes in external light and irradiates the liquid crystal display panel with the liquid crystal display panel, and a second illuminating unit that irradiates light from a light emitting source to the liquid crystal display panel are overlapped with each other, and And / or in the liquid crystal display device with the light condensing mechanism in which a display screen brought into a recognizable front state is visualized by the illumination from the second illumination unit, the first illumination unit is an external device. The light-collecting air space that takes in light is the thickest, and the air-light guide layer that illuminates the liquid crystal display panel by integrating this with the space becomes progressively thinner as the light-guiding layer moves away from the light-collecting air space. Connect the optical path to the liquid crystal display Light guide section that performs illumination of the panel is progressively thinner with increasing distance from the light source, the first and second
Wherein the illuminating section is arranged so that the thicknesses thereof complement each other in a planar manner. 4. The air light guide layer is located behind the liquid crystal display panel, and at one end thereof is provided a lighting part for connecting an optical path, and protrudes from the back of the liquid crystal display panel. The liquid crystal display device with a light collecting mechanism according to claim 3.