JP2010078795A - Liquid crystal display device - Google Patents

Abstract

Laser light having a polarization direction is efficiently incident on each of RGB pixels of a liquid crystal panel, and the laser light is diffused in directions orthogonal to each other by a pair of optical sheets sandwiching a liquid crystal portion of the liquid crystal panel. The present invention provides a liquid crystal display device that is thin, has low power consumption, and has a uniform and uniform display on a large screen.
A liquid crystal display device of the present invention includes a laser light source that emits a laser beam and a laser beam that is incident from a side surface and holds the polarization direction of the laser beam from one main surface. A set of light guide plate 13 that emits, a liquid crystal panel that modulates laser light 11 emitted from light guide plate 13, and a liquid crystal unit 14 a of liquid crystal panel 14, and which diffuses laser light 11 in directions orthogonal to each other And an optical sheet 15.
[Selection] Figure 1

Description

  The present invention relates to a high-brightness and thin liquid crystal display device using a laser light source.

  A liquid crystal display device is a method of displaying an image by controlling the amount of transmitted light irradiated from the back using an electro-optic effect due to the orientation of liquid crystal molecules, and is generally composed of a fluorescent display tube or the like. A planar illumination device called a backlight unit is required. In recent years, such a liquid crystal display device has been increased in screen size and has been put into practical use even for a display device for a television of 50-inch size or more. However, since power consumption has increased with the increase in size, there is a need for technology development that achieves uniform and consistent screen display and low power consumption throughout the large screen display, and in the installation room Thinning is also strongly desired in order to reduce the occupied space of the space as much as possible.

  In order to cope with low power consumption and thinning among these demands, light is emitted as a light source in a thin configuration called an edge light system in which light is incident from the side surface of a so-called light guide plate and light is emitted from one main surface. The use of efficient light-emitting diodes (hereinafter referred to as LEDs) and lasers has been studied, and planar illumination devices using LEDs as light sources and liquid crystal display devices using the same have already been put into practical use.

  In addition, in order to realize low power consumption, studies are being made to improve the light utilization efficiency of liquid crystal panels, and methods using polarization and wavelength are being studied.

  As a configuration using polarized light, a polarizing reflection sheet is inserted between the liquid crystal panel and the backlight unit to transmit the necessary polarization component, reflect the unnecessary polarization component, and rotate the polarization of the reflected light. A configuration in which it is converted into a polarized light component and recycled is put into practical use.

  In addition, a configuration that realizes higher light utilization efficiency by making laser light incident on the light guide plate and converting the laser light into planar illumination while being linearly polarized has been studied.

  In addition, as a configuration using a wavelength, a liquid crystal display device that efficiently collects irradiation light separated by wavelength separation means such as a diffraction grating onto a predetermined pixel of a liquid crystal panel has been proposed (for example, Patent Document 1, 2 and 3).

Further, as a configuration using wavelengths, a configuration in which a wavelength other than a predetermined wavelength incident on each pixel is reflected and recycled can be considered. As such a reflective color filter, a dielectric multilayer film can be used (see, for example, Patent Document 4).
JP 2000-241812 A JP-A-10-253955 JP-A-9-113903 JP 2008-170979 A

  However, the above-described configuration for improving the light use efficiency of the liquid crystal panel has a problem that a configuration for securing the viewing angle of the liquid crystal display device has not been sufficiently studied.

  In the configuration in which polarized light is aligned and emitted from the light guide plate, there is a problem in that if a diffusing element for widening the viewing angle is inserted between the light guide plate and the liquid crystal panel, the polarization is disturbed and the efficiency decreases. It is difficult to achieve both viewing angles. In addition, even in the configuration using the prior art disclosed in Patent Documents 1, 2, and 3 and the reflective color filter, in order to condense the wavelength-separated light on each pixel of the liquid crystal panel efficiently, The viewing angle cannot be expanded by diffusing the irradiated light on the light side.

  Therefore, in such a configuration using the conventional technique, it is conceivable to dispose a diffusion sheet having a high haze on the exit surface of the liquid crystal panel to widen the viewing angle. There arises a problem of whitening that is reflected on the surface and inside of the diffusion sheet to reduce the contrast of the bright place, and that light from each pixel overlapped on the exit surface of the liquid crystal panel is further diffused and mixed to blur the image.

  The present invention solves the above-mentioned conventional problems, and it effectively improves the light utilization efficiency of the liquid crystal panel by effectively using the polarization or wavelength of the light source, realizes a wide viewing angle, and further suppresses whitening and image blurring. The present invention provides a liquid crystal display device that is thin, has low power consumption, and has a uniform large screen display.

  In order to achieve the above object, a liquid crystal display device of the present invention has a light source that emits light of at least three different wavelengths, a planar illumination device that irradiates light emitted from the light source from a planar region, and the planar A liquid crystal panel that modulates light emitted from the illuminating device; and a diffusing element that is disposed so as to sandwich at least the liquid crystal part of the liquid crystal panel. The diffusing element is closer to the planar illuminating device than the liquid crystal part of the liquid crystal panel. And the second diffusion element disposed on the image display side of the liquid crystal panel from the liquid crystal portion of the liquid crystal panel, and the first diffusion element and the second diffusion element Is configured to diffuse the irradiation light in a one-dimensional direction orthogonal to each other.

  With such a configuration, the incident angle of the irradiated light to the liquid crystal portion can be reduced, so that the contrast viewed from an oblique direction can be improved. In addition, compared with a configuration in which the liquid crystal panel is diffused in all directions on the exit surface side, a wide viewing angle can be realized while suppressing whitening due to reflection of external light. Thereby, an image with a wide viewing angle can be displayed, and a liquid crystal display device having a wide range and good contrast can be realized.

  At this time, it is desirable that the planar illumination device has a light guide plate that allows light emitted from the light source to enter from a side surface and exit from one main surface.

  With such a configuration, a thin liquid crystal display device can be realized.

  The first diffusing element is configured such that linearly polarized irradiation light is incident thereon, and the polarization direction of the irradiation light is the direction in which the irradiation light is incident on the first diffusing element and the first It is desirable to be configured to be parallel or perpendicular to a virtual plane including the direction diffused by the diffusing element, and to coincide with the transmission axis of the polarizing plate on the surface illumination device side of the liquid crystal panel. .

  With such a configuration, the polarized light can be diffused and incident on the liquid crystal panel, so that a wide viewing angle can be realized while suppressing the polarization loss at the polarizing plate of the liquid crystal panel. Thereby, it is possible to realize a liquid crystal display device capable of displaying an image with lower power consumption, higher luminance, and a wide viewing angle.

  At this time, a light reflected by the polarization reflection sheet is further provided between the planar illumination device and the first diffusion element, further including a polarization reflection sheet that transmits a predetermined polarization component and reflects a polarization component orthogonal thereto. Is preferably reflected by the planar illumination device and returned to the polarizing reflection sheet again.

  By adopting such a configuration, it is possible to realize a planar illumination device that emits light with uniform polarization with a simple configuration.

  Alternatively, the planar illumination device further includes a light guide plate that emits light emitted from the light source from a side surface and exits from one main surface, and the light guide plate is configured to receive linearly polarized light. It is preferable that linearly polarized light is emitted from the light guide plate.

  By adopting such a configuration, in the planar illumination device that emits light with the polarized light aligned, loss of efficiency in the process of aligning the polarized light can be reduced, so that it can be realized with higher light utilization efficiency.

  The light source is composed of an RGB light source that emits at least red light, green light, and blue light, and the first diffusion element is configured so that irradiation light spatially separated for each wavelength is incident thereon, The diffusion direction of the first diffusion element is preferably configured to be orthogonal to the direction in which the RGB pixels of the liquid crystal panel are repeatedly arranged.

  By adopting such a configuration, spatially separated RGB light can be diffused while being separated and efficiently led to each pixel, thus realizing a wide viewing angle while suppressing loss in the color filter of the liquid crystal panel. it can. Thereby, it is possible to realize a liquid crystal display device capable of displaying an image with lower power consumption, higher luminance, and a wide viewing angle.

  At this time, a reflective color filter is further provided between the planar illumination device and the first diffusing element, and the reflective color filter reflects green light and blue light and transmits red light. A region, a G region that reflects red light and blue light and transmits green light, and a B region that reflects red light and green light and transmits blue light are formed. The R region, G region, and B region are It is desirable that the liquid crystal panel is arranged so as to correspond to the RGB pixels, and the light reflected by the reflective color filter is reflected by the planar illumination device and returns to the reflective color filter again.

  With this configuration, a light guide plate that efficiently separates RGB light can be realized.

  Alternatively, a wavelength separation element that is disposed between the light source and the first diffusion element and separates a traveling direction for each wavelength using diffraction or refraction, and is disposed between the wavelength separation element and the liquid crystal panel. A cylindrical lens, wherein the wavelength separation element is configured to separate an emission angle for each wavelength in a direction in which RGB pixels of the liquid crystal panel are repeatedly arranged, and the cylindrical lens includes the liquid crystal It is desirable to have a curvature in the direction in which the RGB pixels of the panel are repeatedly arranged.

  Even if comprised in this way, the light-guide plate which isolate | separates RGB light efficiently is realizable.

  The light guide plate is configured such that the irradiation light is diffused and emitted only in a one-dimensional direction, and the direction in which the irradiation light is incident on the light guide plate and the light emitted from the light guide plate are diffused. It is desirable that the direction and the direction diffused by the first diffusion element are in the same virtual plane.

  By adopting such a configuration, it is possible to increase the parallelism in a direction in which the light is diffused in a one-dimensional direction and in a direction in which it is not diffused. When combined with a light guide plate, the efficiency can be further increased. As a result, a liquid crystal display device with lower power consumption and higher luminance can be realized.

  Here, the light guide plate has a groove formed in parallel to the side surface on the opposing surface facing the one main surface, and the cross-sectional shape of the bottom surface and the side surface of the groove is a curved surface, and is incident from the side surface. A part of the irradiated light may be emitted from the one main surface after being diffused in a one-dimensional direction using the groove as a reflection surface.

  By adopting such a configuration, a liquid crystal display device that can diffuse laser light incident on the light guide plate only in a one-dimensional direction by the reflecting surface of the groove, can realize a wide viewing angle, and has improved uniformity. realizable.

  In addition, a transflective filter that transmits part of incident light and reflects part of the incident light is further provided between the liquid crystal part of the liquid crystal panel and the light guide plate, and the first diffusion element is the one of the light guide plates. In order to diffuse in a one-dimensional direction by repeating reflection between the plurality of inclined surfaces and the semi-transmissive filter. It may be configured.

  By adopting such a configuration, it is not necessary to separately use an optical sheet as the first diffusion element, so that the cost can be reduced.

  At this time, the transflective filter may be formed of a polarization reflection sheet that transmits a predetermined polarization component and reflects a polarization component orthogonal thereto.

  Alternatively, the transflective filter reflects an R region that reflects green light and blue light and transmits red light, a G region that reflects red light and blue light and transmits green light, and reflects red light and green light. You may be comprised with the reflection type color filter which has B area | region which permeate | transmits blue light.

  With such a configuration, the efficiency can be improved and the cost can be reduced.

  The first and second diffusing elements may be constituted by an optical sheet in which a lenticular lens or an unequal pitch diffraction grating is formed on one side or both sides.

  By setting it as such a structure, the one-dimensional diffusion element which suppressed white floating compared with the diffusion sheet containing a diffusion bead etc. is realizable.

  The second diffusing element has a lens array structure including a plurality of lenses in a corresponding region corresponding to at least one of R, G, and B pixels constituting the RGB pixels of the liquid crystal panel. It is desirable to have a configuration having

  With such a configuration, the angular distribution of the luminance of the laser light can be made more uniform.

  The second diffusing element is preferably arranged between the glass substrate on the image display side of the liquid crystal panel and the polarizing plate.

  With such a configuration, about half of the external light is absorbed by the polarizing plate before the external light is incident on the second diffusing element, so that the whitening seen from the front direction can be reduced.

  The second diffusing element may have a configuration in which a black stripe is disposed on the image display side and above the boundary region between adjacent RGB pixels.

  Alternatively, the second diffusion element may have a configuration in which black stripes are arranged along the image display side and the direction in which the RGB pixels are repeatedly arranged.

  With such a configuration, since external light is absorbed by the black stripes, it is possible to further reduce white floating as viewed from the front.

  The first diffusing element has a lenticular lens or an unequal pitch diffraction grating formed on one surface, and diffuses transmitted light in a one-dimensional direction, and the other surface has a direction to diffuse in a one-dimensional direction. You may comprise with the optical sheet in which the light distribution pattern condensed in the orthogonal | vertical direction in the vicinity of the output surface of a liquid crystal panel was formed.

  With such a configuration, light emitted from the liquid crystal panel can be realized with high efficiency without being absorbed by the black stripe. Thereby, it is possible to realize a liquid crystal display device with further improved bright place contrast.

  The liquid crystal display device according to the present invention is a planar illumination device that uses a planar illumination device that emits illumination light with the same polarization, or a liquid crystal display device that uses a planar illumination device that emits illumination light separately for each wavelength. The light emitted from the light can be guided efficiently so as to pass through the polarizing plate of the liquid crystal panel or the color filter of each pixel, and can be diffused greatly in two orthogonal directions. As a result, a liquid crystal display device with extremely low power consumption, high brightness, and a wide viewing angle can be realized. Furthermore, the contrast when viewed from an oblique direction is high, and a thin and large screen display can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same element and description may be abbreviate | omitted.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of a liquid crystal display device according to Embodiment 1 of the present invention, where (a) is a perspective view of the entire liquid crystal display device, and (b) is a plan view of the entire liquid crystal display device. ing. In FIGS. 1A and 1B, each part of the liquid crystal display device is illustrated as being separated for easy understanding of the configuration, but in the actual configuration, it is illustrated. It is installed on the base plate and in the edge frame, etc., and fixed as a whole.

  As shown in FIGS. 1A and 1B, the liquid crystal display device 10 according to the first embodiment is a red laser light source (hereinafter referred to as R light source) that emits red laser light (hereinafter referred to as R light). ) 11a, a green laser light source (hereinafter referred to as G light source) 11b that emits green laser light (hereinafter referred to as G light), and a blue laser light source (hereinafter referred to as B light) that emits blue laser light (hereinafter referred to as G light). (Hereinafter referred to as “B light source”) 11 c, a laser light source 11 composed of three light sources 11 c, a dichroic mirror 13 that combines R light, G light, and B light emitted from the laser light source 11 into laser light 12, and a mirror 14 Then, the laser light 12 is converted into parallel light arranged in a line by a plurality of half mirrors 15a and emitted, and the laser light 12 emitted from the linear light guide 15 is emitted from the side surface 16a. Incident, on the other hand The light guide plate 16 emitted from the main surface 16b, the liquid crystal panel 17 that modulates the laser light 12 emitted from the light guide plate 16, and the liquid crystal portion 17a of the liquid crystal panel 17 are arranged so as to sandwich the laser light 12 in directions orthogonal to each other. A set of optical sheets 18 to be diffused and a control unit 19 connected to the laser light source 11 through a wiring 19a are provided.

  Here, each of the light sources 11a, 11b, and 11c includes a collimating lens, and is configured to emit parallel light. The R light source 11a and the B light source 11c include, for example, R light having a wavelength of 640 nm and a wavelength of 445 nm. And a high-power semiconductor laser that emits B light, and a high-power SHG laser pumped by a semiconductor laser that emits G light having a wavelength of 535 nm is used as the G light source 12b.

  The R light, G light, and B light emitted from the laser light source 11 are configured so that their polarization directions are aligned, and are incident on the light guide plate 16 with polarized light parallel or perpendicular to the main surface 16b of the light guide plate 16. It is configured.

  2 is a cross-sectional view showing a schematic configuration of the liquid crystal display device 10 according to the first embodiment, and FIG. 2A is a cross-sectional view of the liquid crystal display device 10 shown in FIG. FIG. 2B shows a cross-sectional view taken along line 2B-2B.

  In FIG. 2, a liquid crystal panel 17 includes a liquid crystal unit 17a having a configuration in which a liquid crystal layer 17b and a color filter 17c are sandwiched between glass substrates 17d and 17e on the incident side and the emission side, and a polarizing plate sandwiching the liquid crystal portion 17a from the incident side and the emission side. The polarization direction 12 a of the laser light 12 incident on the light guide plate 16 is configured to be parallel to the main surface 16 b of the light guide plate 16.

  Here, on the opposing surface 16c of the main surface 16b of the light guide plate 16, a large number of polarizing grooves for deflecting the laser light 12 incident on the light guide plate 16 toward the main surface 16b are formed in parallel to the side surface 16a. The laser beam 12 incident perpendicularly to the side surface 16a is emitted in parallel to a virtual surface (hereinafter referred to as a propagation surface) perpendicular to the side surface 16a and the main surface 16b.

  Further, as shown in FIG. 1A, for example, the set of optical sheets 18 includes a one-dimensional diffusing element including lenticular lenses 18a and 18b. The lenticular lens 18a on the light guide plate 16 side is The laser beam 12 is diffused in parallel directions. The one-dimensional diffusion element may have a configuration other than the lenticular lens as long as it has a function of diffusing only in one direction, such as an unequal pitch diffraction grating.

  Further, in this configuration, the polarization direction of the laser light 12 emitted from the light guide plate 16 and incident on the liquid crystal panel 17 is perpendicular to the propagation surface, and the transmission axis of the polarizing plate 17 f of the liquid crystal panel 17 is the light guide plate 16. It is comprised so that it may correspond with the polarization direction of the laser beam 12 radiate | emitted from.

  Next, the operation of the liquid crystal display device 10 of the first embodiment configured as described above will be specifically described.

  As shown in FIGS. 1A and 1B, the R light, G light, and B light emitted from the R light source 11a, the G light source 11b, and the B light source 11c with the same polarization are collimated for each light source, and the dichroic mirror 13 is collimated. Are combined as laser light 12, enter the linear light guide 15 via the mirror 14, and are emitted perpendicularly to the side surface 16 a of the light guide plate 16 by the plurality of half mirrors 15 a while maintaining the polarization.

  As shown in FIGS. 2A and 2B, the laser light 12 emitted from the linear light guide unit 15 enters from the side surface 16 a of the light guide plate 16 and is not deflected by the facing surface 16 c of the light guide plate 16. The light is reflected by the groove, travels toward the main surface 16b, and exits from the main surface 16b. The laser beam 12 emitted from the light guide plate 16 is diffused in the one-dimensional direction 18c by the lenticular lens 18a, which is a one-dimensional diffusion element, and enters the liquid crystal panel 17.

  At this time, as shown in FIG. 2A, the reflection of the laser light 12 on the facing surface 16c of the light guide plate 16 and the diffusion on the lenticular lens 18b are performed in the same plane (propagation surface), and Since the polarization direction 12a of the laser beam 12 is always orthogonal to this surface, the polarization of the laser beam 12 is maintained. Accordingly, the laser beam 12 is incident on the liquid crystal panel 17 in a state of uniform polarization, and the polarization direction 12a and the transmission axis of the polarizing plate 17f are configured to coincide with each other. Therefore, most of the laser beam 12 is polarized. High light utilization efficiency is obtained through the plate 17f.

  The laser light 12 incident with high efficiency from the polarizing plate 17f of the liquid crystal panel 17 is modulated by the liquid crystal layer 17b, and a predetermined light of the R light, G light, and B light is transmitted through the color filter 17c for each region. After traveling, the light is emitted from the polarizing plate 17g on the emission side, and is diffused in the one-dimensional direction 18d by the sheet-like lenticular lens 18b.

  Here, since the lenticular lenses 18a and 18b are configured to diffuse the laser beam 12 in directions orthogonal to each other, a wide viewing angle can be realized.

  At this time, as shown in FIG. 2B, the laser light 12 emitted from the light guide plate 16 is substantially parallel to the propagation surface, and the light transmitted through different pixels in the one-dimensional direction 18d is on the lenticular lens 18b. Since there is almost no overlap, there is no deterioration in image quality such that images appear to overlap in the one-dimensional direction 18d.

  Further, as shown in FIG. 2A, since the laser light 12 is diffused in the propagation plane by the lenticular lens 18a, light transmitted through different pixels in the one-dimensional direction 18c overlaps on the lenticular lens 18b. Since the lens 18b does not diffuse in the same direction as the lenticular lens 18a, the light overlapped on the lenticular lens 18b does not exit in the same direction, and image quality deterioration such that images appear to overlap in this direction does not occur.

  With such a configuration, in the liquid crystal display device 10 of the present embodiment, the polarized light of the laser light 12 can be held and efficiently incident on the liquid crystal panel 17, so that the liquid crystal with high brightness and low power consumption can be obtained. A display device can be realized. At the same time, the laser light 12 is sufficiently diffused in directions orthogonal to each other, so that an image with a wide viewing angle can be displayed, image quality deterioration such as blurring is small, and incident when passing through the liquid crystal layer 17b. Since the corner can be made smaller than usual, even when viewed from an oblique direction, a high contrast equivalent to that viewed from the front direction can be realized.

  In addition, when a diffusion sheet with a high haze containing diffusing beads or the like is arranged on the exit side of the liquid crystal panel, whitening becomes a problem. However, since the lenticular lens has few reflecting surfaces and AR coating is possible, whitening is caused. Can be suppressed.

  Further, as shown in FIG. 2B, the lenticular lens 18b is a lens composed of a plurality of lenses in one pixel for each of the R pixel 21r, G pixel 21g, and B pixel 21b constituting the RGB pixel 21. It is configured to have an array structure. In this example, a single bar-shaped lenticular lens corresponding to one pixel is arranged in units of 2 to 3 bars.

  By adopting such a configuration, the angular distribution of the luminance of the laser beam 12 can be made more uniform, so that a liquid crystal display device having a wider viewing angle and a uniform and uniform display can be realized. Can do.

  In the present embodiment, the polarization direction 12a of the laser beam 12 incident on the light guide plate 16 is parallel to the main surface 16b of the light guide plate 16, but it is also perpendicular to the main surface 16b, that is, as the polarization direction in the propagation plane. Since the light can be diffused while maintaining the polarization, if the transmission axis of the polarizing plate 17f is set to this polarization direction, high light utilization efficiency can be obtained.

  Further, although the laser beam 12 incident on the light guide plate 16 is perpendicular to the side surface 16a, even if it is diffused in the thickness direction of the light guide plate 16, that is, in the propagation plane, the polarization is similarly maintained, and the high light use efficiency. Is obtained.

  Further, a general television display device is configured such that the direction along the direction 18e in which the RGB pixels 21 are repeatedly arranged is a horizontal direction, but the liquid crystal display device 10 of the present invention has the direction 18e. It may be horizontal or vertical.

  3A and 3B are diagrams showing a schematic configuration of another liquid crystal display device 20 according to the first embodiment of the present invention. FIG. 3A is a cross-sectional view of the liquid crystal display device 20, and FIG. The perspective view which showed the surface 26c typically is shown.

  The liquid crystal display device 20 of the first embodiment is different from the liquid crystal display device 10 shown in FIGS. 1 and 2 only in the structure of the light guide plate 26, and the other configuration is the same.

  As shown in FIGS. 3A and 3B, the light guide plate 26 has a deflection groove 26d formed in parallel to the side surface 26a on the facing surface 26c facing the one main surface 26b. The shape of the bottom surface and the side surface is a curved surface.

  In the liquid crystal display device 20 configured as described above, when the laser beam 12 is incident from the side surface 26a of the light guide plate 26, the laser beam 12 is diffused and reflected in the one-dimensional direction 18c with the deflection groove 26d as a reflecting surface, and is reflected on the main surface. Outgoing from 26b in one-dimensional direction 18c.

  By adopting such a configuration, high light utilization efficiency and a wide viewing angle can be realized as in the liquid crystal display device 10, and a more uniform and non-uniform liquid crystal display device can be realized.

  In FIGS. 2A and 3A, the lenticular lens 18a is disposed slightly apart from the light guide plates 16 and 26. However, the lenticular lens 18a is disposed on the main surfaces 16b and 26b of the light guide plates 16 and 26. You may arrange | position adjacently and you may form the lenticular lens 18a integrally on the main surfaces 16b and 26b.

  By adopting such a configuration, the lenticular lens 18a and the light guide plates 16 and 26 can be integrally molded, so that the cost can be reduced.

  In this embodiment, a laser light source is used, but an LED can be used as the light source. FIG. 9 is a diagram illustrating a schematic configuration of another liquid crystal display device according to the first embodiment of the present invention, where (a) is a perspective view of the entire liquid crystal display device, and (b) is a plan view of the entire liquid crystal display device. Is shown.

  As shown in FIGS. 9A and 9B, the liquid crystal display device 70 includes an LED light source 71 composed of a red LED 71 a, a green LED 71 b, and a blue LED 71 c, and R light and G light emitted from the LED light source 71. And a collimating lens 72 for collimating the B light, an incident light 73 from the side surface 16a, a light guide plate 16 that exits from the main surface 16b, and a polarized light reflection that transmits a specific polarization component and reflects a polarization component orthogonal thereto. The liquid crystal panel 17 which modulates the irradiation light 73 which permeate | transmits the sheet | seat 74 and this polarized light reflection sheet 74 is provided, and the liquid crystal panel 17 is arrange | positioned on both sides of the liquid crystal part 17a at least, and diffuses the irradiation light 73 in the direction orthogonal to each other. A set of optical sheets 18 is further provided.

  Here, the polarization reflection sheet 74 is configured to transmit polarized light in the same direction as the transmission axis of the polarizing plate on the light guide plate side of the liquid crystal panel 17.

  Although not shown, a reflection sheet is disposed adjacent to the facing surface 16 c of the light guide plate 16. In addition, a phase difference sheet that rotates the polarization of the reflected light is disposed on the surface of the polarization reflection sheet 74 on the light guide plate side.

  In the liquid crystal display device 70 configured as described above, the irradiation light 72 emitted from the red LED 71a, the green LED 71b, and the blue LED 71c is collimated for each LED, is incident from the side surface 16a of the light guide plate 16, and is opposed to the light guide plate 16. The light is reflected by a deflection groove (not shown) at 16 c and emitted from the main surface 16 b to reach the polarization reflection sheet 74. Here, a specific polarization component is transmitted, and a polarization component in a direction orthogonal thereto is reflected. The light reflected by the polarization reflection sheet 74 is rotated by the phase difference sheet, passes through the light guide plate 16, is reflected by the reflection sheet adjacent to the opposing surface 16 c of the light guide plate 16, and reaches the polarization reflection sheet 74 again. To do. Thus, the light reflected by the polarization reflection sheet 74 is recycled and eventually passes through the polarization reflection sheet.

  Irradiation light 73 transmitted through the polarization reflection sheet 74 is diffused in a one-dimensional direction while being polarized by the lenticular lens 18 a and enters the liquid crystal panel 17. At this time, since the polarization direction of the irradiation light 73 coincides with the transmission axis of the polarizing plate on the light guide plate side of the liquid crystal panel 17, most of the irradiation light 73 is incident on the liquid crystal panel 17 without being absorbed by the polarizing plate. Light utilization efficiency can be obtained.

  Irradiation light 73 incident on the liquid crystal panel 17 with high efficiency is modulated by the liquid crystal layer, emitted from the polarizing plate on the emission side, and diffused in a one-dimensional direction by the sheet-like lenticular lens 18b.

  Here, since the lenticular lenses 18a and 18b are configured to diffuse the irradiation light 73 in directions orthogonal to each other, a wide viewing angle can be realized.

  At this time, as in the configuration shown in FIGS. 1, 2, and 3, image quality deterioration due to image blur and whitening are sufficiently suppressed.

  With such a configuration, the liquid crystal display device 70 of the present embodiment can also realize a liquid crystal display device with high brightness and low power consumption, and at the same time, an image with a wide viewing angle can be displayed and the image is blurred. Image quality degradation is small, and high contrast can be realized.

  Moreover, in this Embodiment, cost reduction can be achieved by simplifying the optical system of a linear light source part.

  In addition, as another configuration using the LED light source, a configuration may be adopted in which a large number of LEDs are arranged on a plane to form a planar illumination device. With this configuration, so-called local dimming technology can be used, so that the light use efficiency can be further improved.

(Embodiment 2)
4A and 4B are schematic configuration diagrams showing a liquid crystal display device according to a second embodiment of the present invention. FIG. 4A is a cross-sectional view showing the entire configuration of the liquid crystal display device, and FIG. 4B is a sectional view taken along line 4B-4B in FIG. A cross-sectional view of the liquid crystal display device seen, (c) shows a plan view of only the light guide plate seen from the arrow 4C of (a). 4 (a) and 4 (b), the respective parts of the planar lighting device are shown as being separated for easy understanding of the configuration, but in the actual configuration, It is installed on a base plate (not shown) or in an edge frame, and the whole is fixed integrally.

  The liquid crystal display device 30 according to the second embodiment shown in FIG. 4 is different from the liquid crystal display devices 10 and 20 shown in the first embodiment in that a reflective color filter 31 is disposed between the light guide plate 16 and the liquid crystal panel 17. And where the reflective sheet 32 is provided are different.

  That is, the liquid crystal display device 30 causes at least the laser light source 11 shown in FIGS. 1A and 1B that emits the laser light 12 and the laser light 12 to enter from the side surface 16a, and maintains the polarization direction of the laser light 12. The light guide plate 16 that emits light from the main surface 16b and the liquid crystal panel 17 that modulates the laser light 12 emitted from the light guide plate 16 are provided. The liquid crystal panel 17 is disposed with at least the liquid crystal portion 17a interposed therebetween, and is orthogonal to each other. A set of optical sheets 18 for diffusing the laser beam 12 in the direction is further provided.

  The reflective color filter 31 has three regions having different spectral characteristics, each of which includes an R light filter 31r, a G light filter 31g, and a B light filter 31b. As shown in FIG. Arranged in a shape. Each filter is disposed corresponding to the R pixel 21r, G pixel 21g, and B pixel 21b of the liquid crystal panel 17.

  Further, the longitudinal direction of each filter of the reflective color filter 31 is configured to be the same as the one-dimensional direction 18c in which the laser light 12 is diffused by the lenticular lens 18a.

  8A and 8B are explanatory views showing the structure and characteristics of the reflective color filter 31, wherein FIG. 8A is a schematic structural diagram of the reflective color filter, and FIG. 8B is a diagram showing the spectral characteristics of the reflective color filter. Yes.

  8A, the reflective color filter 31 includes, for example, high refractive materials 82, 84, 86, 88, 90, 92 such as TiO 2 and low refractive materials 81, 83, 85, 87, 89, 91, such as SiO 2. No. 93 is laminated, and a film structure having different spectral characteristics is formed for each filter region.

  In FIG. 8B, 95 indicates the spectral characteristic of the R optical filter 31r, 96 indicates the spectral characteristic of the G optical filter 31g, 97 indicates the spectral characteristic of the B optical filter 31b, and the R optical filter 31r transmits the R light. Transmits and reflects G light and B light, G light filter 31g transmits G light, reflects R light and B light, and B light filter 31b transmits B light and reflects R light and G light It is configured.

  In the liquid crystal display device 30 configured as described above, the laser light 12 incident on the light guide plate 16 propagates through the light guide plate 16 and is reflected by a deflection groove (not shown) on the opposing surface 16c of the light guide plate 16 to be the main surface. It is deflected toward 16b and exits from the main surface 16b. At this time, since the laser beam 12 is incident perpendicularly to the side surface 16a of the light guide plate 16, and the deflection groove of the light guide plate 16 is provided in parallel to the side surface 16a, the laser beam 12 is incident on the side surface 16a and the main surface 16b. Propagate parallel to the vertical propagation plane.

  The laser light 12 emitted from the light guide plate 16 in parallel to the propagation surface enters the reflective color filter 31, and is R light by the R light filter 31r, G light by the G light filter 31g, and B light by the B light filter 31b. Are transmitted, and the other light is reflected.

  The R light, G light, and B light reflected by the reflective color filter 31 pass through the light guide plate 16, are reflected by the reflective sheet 32, pass through the light guide plate 16 again, return to the reflective color filter 31, and again predetermined. Only predetermined light incident on the filter is transmitted, and other light is reflected. The light reflected again by the reflection type color filter 31 is repeatedly reflected between the reflection type color filter 31 and the reflection sheet 32, and becomes a predetermined filter among the R light filter 31r, the G light filter 31g, and the B light filter 31b. Transmits when incident.

  The laser light 12 transmitted through the reflective color filter 31 and separated into R light, G light, and B light for each region and emitted from the light guide plate 16 is obtained in a one-dimensional direction 18c by a lenticular lens 18a that is a one-dimensional diffusion element. And is incident on the liquid crystal panel 17 toward the RGB pixel 21.

  At this time, since the laser light 12 emitted from the light guide plate 16 travels parallel to the propagation surface, the R light, G light, and B light separated for each region are emitted from the RGB pixels 21 configured in a stripe shape. It efficiently enters each pixel, and most of the light is transmitted through the color filter 17c.

  The laser beam 12 that has passed through the color filter 17c is emitted from the polarizing plate 17g on the emission side, and is diffused in the one-dimensional direction 18d by the sheet-like lenticular lens 18b.

  With this configuration, the liquid crystal display device 30 of the present embodiment can display an image with a wide viewing angle, has little image quality deterioration such as blurring, and realizes high contrast even when viewed from an oblique direction. it can.

  Furthermore, R light, G light, and B light can be efficiently incident on each pixel of the liquid crystal panel 17, and the light reflected by the reflective color filter 31 can be recycled and used. Thus, a liquid crystal display device with lower power consumption can be realized.

  Although the reflective color filter of this embodiment has a structure as shown in FIG. 8, it may have another structure as long as the same spectral characteristics can be realized. The reflective color filter can also be realized with a two-dimensional or three-dimensional photonic crystal structure, and may be, for example, a sub-wavelength grating having a fine periodic structure of a wavelength or less. The sub-wavelength grating can also be formed on the main surface 16b of the light guide plate or the back surface of the lenticular lens 18a using nanoimprinting, and is excellent in mass productivity and cost reduction.

  FIG. 5: is a schematic block diagram which shows the other liquid crystal display device concerning Embodiment 2 of this invention, (a) is sectional drawing which shows the whole structure of a liquid crystal display device, (b) is 5B-5B of (a). FIG. 3 shows a cross-sectional view of the liquid crystal display device as viewed from the line.

  The liquid crystal display device 40 shown in FIG. 5 is different from the liquid crystal display device 30 shown in FIG. 4 in that a reflective color filter 41 is formed and disposed below the glass substrate 17d. Further, the light guide plate 46 is composed of a combination of a plurality of inclined surfaces having different opposing surfaces 46c, and a reflective coat is formed on the entire surface of the opposing surface 46c. The laser light 12 incident on the light guide plate 46 is configured to be diffused and incident in the thickness direction of the light guide plate 46. In the liquid crystal display device 40, the reflection sheet 32, the lenticular lens 18a, and the polarizing plate 17f included in the liquid crystal display device 30 are not used.

  In the liquid crystal display device 40 configured as described above, the laser light 12 incident on the light guide plate 36 while being diffused in the thickness direction of the light guide plate 36 has a traveling direction in the propagation surface every time it is reflected by the facing surface 46c. In contrast, when the incident angle on the main surface 46b becomes equal to or smaller than the critical angle, the light guide plate 46 exits and enters the reflective color filter 41. Here, the R light filter 41r transmits the R light, the G light filter 41g transmits the G light, the B light filter 41b transmits the B light, and the other light is reflected. The reflected R light, G light, and B light are diffused in the direction of the one-dimensional direction 18c while being repeatedly reflected between the reflective color filter 41 and the facing surface 46c of the light guide plate 46, and the R light filter 41r, G light is diffused. The light passes through a predetermined filter out of the filter 41g and the B light filter 41b.

  The laser light 12 transmitted through the reflective color filter 41 and separated into R light, G light, and B light for each region efficiently enters each pixel of the RGB pixel 21, and most of the light is color filter 17c. , And is diffused in the one-dimensional direction 18d by the sheet-like lenticular lens 18b.

  With this configuration, the laser light 12 incident on the liquid crystal panel 17 can be diffused in a one-dimensional direction without separately providing a one-dimensional diffusion element such as a lenticular lens, so that the cost can be reduced. In addition, since the polarized light is retained by the reflection at the facing surface 46c and the reflective color filter 41, the polarizing plate on the incident side of the liquid crystal panel 17 can be made unnecessary, and the cost can be further reduced.

  In the present embodiment shown in FIG. 5, the reflection type color filter 41 is configured to diffuse in a one-dimensional direction by repeating reflection between the reflection color filter 41 and the facing surface 46 c of the light guide plate 46. Instead of 41, a semi-transmissive filter that partially transmits and reflects a part or a polarizing reflection sheet may be combined with the light guide plate 46 of the present embodiment.

  For example, the surface of the lenticular lens 18a on the light guide plate side in the configuration of FIG. 2 is a semi-transmissive surface and combined with the light guide plate 46 shown in FIG. 5 can provide a wide viewing angle and improve uniformity. it can. Further, if the light guide plate is the light guide plate 46 of the present embodiment in the configuration of FIG. 9 using the polarization reflection sheet, the lenticular lens 18a is not necessary, and the cost can be reduced.

  In the present embodiment shown in FIGS. 4 and 5, an LED can be used as the light source as shown in FIG. Moreover, it can also be set as the structure which arranges LED on a plane instead of using a light-guide plate.

  In this embodiment, a reflective color filter is used to spatially separate R light, G light, and B light. However, instead of the reflective color filter, a diffraction element, hologram, prism, or the like is used. A configured wavelength separation element may be used. 10A and 10B are diagrams showing a schematic configuration of another liquid crystal display device according to the second exemplary embodiment of the present invention. FIG. 10A is a cross-sectional view showing the entire configuration of the liquid crystal display device, and FIG. A cross-sectional view of the liquid crystal display device viewed from line 10B is shown.

  The liquid crystal display device 80 shown in FIG. 10 has substantially the same configuration as the liquid crystal display device 30 shown in FIG. 4, but the direction in which the laser light 12 is incident on the light guide plate 16 and the wavelength separation element 101 instead of the reflective color filter. The difference is that the lenticular lens 102 is provided between the wavelength separation element 101 and the liquid crystal panel 17.

  Here, the wavelength separation element 101 is configured to separate the traveling direction for each wavelength in the one-dimensional direction 18d using, for example, wavelength dispersion of the diffraction angle, and the lenticular lens 102 is also in the direction of the one-dimensional direction 18d. It is configured to have a curvature.

  With this configuration, R light, G light, and B light separated for each wavelength by the wavelength separation element 101 can be efficiently incident on the pixels according to the incident angle by the lenticular lens 102, and high light Use efficiency is obtained.

  Even in this configuration, the lenticular lens 18a diffuses only in the direction orthogonal to the direction of wavelength separation, so that high efficiency is achieved and a wide viewing angle is obtained.

(Embodiment 3)
FIG. 6: is a schematic block diagram which shows the liquid crystal display device concerning Embodiment 3 of this invention, (a) is sectional drawing which shows the whole structure of a liquid crystal display device, (b) is from the 6B-6B line | wire of (a). FIG. 3 shows a cross-sectional view of the liquid crystal display device as viewed. The liquid crystal display device 50 shown in FIG. 6 has substantially the same configuration as the liquid crystal display device 10 shown in FIG. 2 of the first embodiment, but forms a light distribution pattern on the back side of the surface on which the lenticular lens of the optical sheet 18a is formed. In other words, the black stripe 51 is provided on the optical sheet 18b, and the positional relationship between the optical sheet 18b and the polarizing plate 17g is different.

  That is, the liquid crystal display device 50 makes at least the laser light source 11 shown in FIGS. 1A and 1B that emits the laser light 12 and the laser light 12 incident from the side surface 16a, and maintains the polarization direction of the laser light 12. The light guide plate 16 that emits light from the main surface 16b and the liquid crystal panel 17 that modulates the laser light 12 emitted from the light guide plate 16 are provided. The liquid crystal panel 17 is disposed with at least the liquid crystal portion 17a interposed therebetween, and is orthogonal to each other. A set of optical sheets 18 for diffusing the laser beam 12 in the direction is further provided.

  Here, for example, the optical sheet 18b made of a lenticular lens is disposed at least between the glass substrate 17e on the emission side of the liquid crystal panel 17 and the polarizing plate 17g, and a black stripe 51 corresponding to RGB pixels is provided on the polarizing plate 17g side. It has been.

  Further, on the back side of the surface on which the lenticular lens of the optical sheet 18a is formed, as shown in FIG. 6B, the light transmitted through each pixel of the RGB pixel 21 gathers for each RGB pixel on the optical sheet 18b. A light distribution pattern that deflects in this manner is formed.

  In the liquid crystal display device 50 configured as described above, the laser light 12 incident on the light guide plate 16 propagates in the light guide plate 16 and is reflected by a deflection groove (not shown) on the opposing surface 16c of the light guide plate 16 to be the main surface. It is deflected toward 16b and exits from the main surface 16b in parallel with the propagation surface.

  The laser beam 12 emitted from the light guide plate 16 enters the optical sheet 18a, is deflected in a virtual plane orthogonal to the propagation surface by the light distribution pattern formed on the incident surface, and is one-dimensionally 18c by the lenticular lens on the emission surface. Is incident on the liquid crystal panel 17 and reaches the optical sheet 18 b via the RGB pixels 21. At this time, as shown in FIG. 6B, the laser light 12 that has passed through each of the RGB pixels 21 is condensed for each RGB pixel.

  The laser beam 12 incident on the optical sheet 18b is diffused in the one-dimensional direction 18d by the lenticular lens, passes through the polarizing plate 17g, and is emitted from the liquid crystal panel 17.

  Further, in the liquid crystal display device 50 configured as described above, external light incident on the liquid crystal panel 17 from the image display side is absorbed by the polarizing plate 17 g and the black stripe 51.

  With such a configuration, the liquid crystal display device of this embodiment can realize a liquid crystal display device that can display an image with low power consumption, high luminance, and a wide viewing angle, as in the first embodiment.

  Furthermore, in the present embodiment, the optical sheet 18b is disposed between the polarizing plate 17g and the glass substrate 17e, and further black stripes are provided, whereby reflection of external light can be suppressed and whitening can be reduced. At this time, as shown in FIG. 6B, since the laser beam 12 is condensed for each RGB pixel on the optical sheet 18b on the emission side, the laser beam 12 is blocked by the black stripe 51 to reduce the efficiency. There is nothing. Thereby, it is possible to realize a liquid crystal display device with improved bright place contrast without reducing the efficiency of emitted light.

  In this embodiment, black stripes are provided along the boundaries of the RGB pixels. However, black stripes may be provided along the direction in which the RGB pixels are repeatedly arranged as shown in FIG.

  FIG. 7: is a schematic block diagram which shows the other liquid crystal display device concerning Embodiment 3 of this invention, (a) is sectional drawing which shows the whole structure of a liquid crystal display device, (b) is 7B-7B of (a). FIG. 3 shows a cross-sectional view of the liquid crystal display device as viewed from the line. The liquid crystal display device 60 shown in FIG. 7 has substantially the same configuration as the liquid crystal display device 50 shown in FIG. 6, but the incident direction of the laser light 12 to the light guide plate 16, the diffusion direction of the lenticular lenses of the optical sheets 18a and 18b, The condensing direction of the light distribution pattern on the back side of the optical sheet 18a and the direction of the black stripe are rotated by 90 ° compared to the configuration shown in FIG.

  With such a configuration, high light utilization efficiency similar to that of the first embodiment can be obtained, and furthermore, whitening can be significantly suppressed.

  The liquid crystal display device of the present invention can efficiently cause the laser beam of the light source to reach the liquid crystal portion of the liquid crystal panel, and can realize a uniform and wide viewing angle, suppressing deterioration of bright place contrast which is a concern for the configuration, It can also be made thinner. As a result, a thin, high-brightness, low power consumption, large-screen display can be realized, and a uniform, non-uniform liquid crystal display device with a wide viewing angle can be realized, which is useful.

(A) It is a figure which shows schematic structure of the liquid crystal display device concerning Embodiment 1 of this invention, and is a perspective view of the whole liquid crystal display device, (b) The top view of the whole liquid crystal display device (A) It is sectional drawing which shows schematic structure of the liquid crystal display device concerning Embodiment 1 of this Embodiment, sectional drawing seen from the 2A-2A line | wire of the liquid crystal display device shown in FIG.1 (b) (b) 2B- Sectional view seen from line 2B (A) It is a figure which shows schematic structure of the other liquid crystal display device concerning Embodiment 1 of this invention, It is sectional drawing of a liquid crystal display device, (b) The perspective view which showed typically the side surface and opposing surface of a light-guide plate (A) It is a schematic block diagram which shows the liquid crystal display device concerning Embodiment 2 of this invention, It is sectional drawing which shows the whole structure of a liquid crystal display device, (b) The liquid crystal display device seen from the 4B-4B line of (a) Sectional view (c) Plan view of only the light guide plate seen from arrow 4C in (a) (A) It is a schematic block diagram which shows the other liquid crystal display device concerning Embodiment 2 of this invention, It is sectional drawing which shows the whole structure of a liquid crystal display device, (b) The liquid crystal display seen from the 5B-5B line | wire of (a) Cross section of the device (A) It is a schematic block diagram which shows the liquid crystal display device concerning Embodiment 3 of this invention, It is sectional drawing which shows the whole structure of a liquid crystal display device, (b) The liquid crystal display device seen from the 6B-6B line of (a) Cross section (A) It is a schematic block diagram which shows the other liquid crystal display device concerning Embodiment 3 of this invention, It is sectional drawing which shows the whole structure of a liquid crystal display device, (b) The liquid crystal display seen from the 7B-7B line | wire of (a) Cross section of the device (A) It is explanatory drawing which showed the structure and characteristic of the reflection type color filter concerning Embodiment 2 of this invention, The schematic structure figure of a reflection type color filter (b) The figure which showed the spectral characteristic of the reflection type color filter (A) It is a figure which shows schematic structure of the other liquid crystal display device concerning Embodiment 1 of this invention, and is a perspective view of the whole liquid crystal display device, (b) The top view of the whole liquid crystal display device (A) It is a figure which shows schematic structure of the other liquid crystal display device concerning Embodiment 2 of this invention, and is sectional drawing which shows the whole structure of a liquid crystal display device, (b) The liquid crystal seen from the 10B-10B line | wire of (a) Cross section of display device

Explanation of symbols

10, 20, 30, 40, 50, 60, 70, 80 Liquid crystal display device 11 Laser light source 11a R light source (red laser light source)
11b G light source (green laser light source)
11c B light source (blue laser light source)
DESCRIPTION OF SYMBOLS 12 Laser beam 12a Direction of deflection 13 Dichroic mirror 14 Mirror 15 Linear light guide part 15a Half mirror 16, 26, 46 Light guide plate 16a, 26a, 46a Side surface 16b, 26b, 46b Main surface 16c, 26c, 46c Opposing surface 17 Liquid crystal panel 17a Liquid crystal part 17b Liquid crystal layer 17c Color filter 17d, 17e Glass substrate 17f, 17g Polarizing plate 18 Optical sheet 18a, 18b Lenticular lens (optical sheet)
18c, 18d One-dimensional direction 18e direction 19 Control unit 19a Wiring 21 RGB pixel 21r R pixel 21g G pixel 21b B pixel 31, 41 Reflective color filter 31r, 41r R optical filter 31g, 41g G optical filter 31b, 41b B optical filter 32 Reflective sheet 51 Black stripe 71 LED light source 71a Red LED
71b Green LED
71c Blue LED
72 Collimating lens 73 Irradiation light 74 Polarization reflection sheet 81, 83, 85, 87, 89, 91, 93 Low refraction material 82, 84, 86, 88, 90, 92 High refraction material 95 Spectral characteristics of R light filter 96 G light Spectral characteristics of filter 97 Spectral characteristics of B optical filter 101 Wavelength separation element 102 Lenticular lens

Claims (19)

A planar illumination device having a light source that emits light of at least three different wavelengths, and irradiating light emitted from the light source from a planar region;
A liquid crystal panel for modulating light emitted from the planar illumination device;
A diffusing element arranged with at least the liquid crystal part of the liquid crystal panel interposed therebetween,
The diffusion element includes a first diffusion element disposed on the planar illumination device side from the liquid crystal part of the liquid crystal panel, and a second diffusion element disposed on the image display side of the liquid crystal panel from the liquid crystal part of the liquid crystal panel. A liquid crystal display device comprising: an element, wherein the first diffusion element and the second diffusion element diffuse the irradiation light in a one-dimensional direction orthogonal to each other. The liquid crystal display device according to claim 1, wherein the planar illumination device includes a light guide plate that allows light emitted from the light source to enter from a side surface and exit from one main surface. The first diffusion element is configured such that linearly polarized irradiation light is incident thereon,
The polarization direction of the irradiation light is configured to be parallel or perpendicular to a virtual plane including a direction in which the irradiation light is incident on the first diffusion element and a direction in which the irradiation light is diffused by the first diffusion element. The liquid crystal display device according to claim 1, wherein the liquid crystal display device coincides with a transmission axis of a polarizing plate on the surface illumination device side of the liquid crystal panel. Between the planar illumination device and the first diffusing element, there is further provided a polarization reflection sheet that transmits a predetermined polarization component and reflects a polarization component orthogonal thereto, and the light reflected by the polarization reflection sheet is the surface. The liquid crystal display device according to claim 3, wherein the liquid crystal display device is configured to be reflected by the illuminating device and return to the polarization reflection sheet again. The planar illumination device further includes a light guide plate that enters light emitted from the light source from a side surface and exits from one main surface, and the light guide plate is configured to receive linearly polarized light, 4. The liquid crystal display device according to claim 3, wherein linearly polarized light is emitted from the light guide plate. The light source comprises an RGB light source that emits at least red light, green light, and blue light,
The first diffusing element is configured such that irradiation light spatially separated for each wavelength enters,
The liquid crystal display device according to claim 1, wherein a diffusion direction of the first diffusion element is configured to be orthogonal to a direction in which RGB pixels of the liquid crystal panel are repeatedly arranged. A reflective color filter is further provided between the planar illumination device and the first diffusion element,
The reflective color filter reflects an R region that reflects green light and blue light and transmits red light, a G region that reflects red light and blue light and transmits green light, and reflects red light and green light. B region that transmits blue light is formed,
The R region, the G region, and the B region are arranged so as to correspond to the RGB pixels of the liquid crystal panel, and the light reflected by the reflective color filter is reflected by the planar illumination device, and again the reflective color filter The liquid crystal display device according to claim 6, wherein the liquid crystal display device is configured to return to step (a). A wavelength separation element that is disposed between the light source and the first diffusion element and that separates a traveling direction for each wavelength using diffraction or refraction, and is disposed between the wavelength separation element and the liquid crystal panel; A cylindrical lens, and
The wavelength separation element is configured to separate an emission angle for each wavelength in a direction in which RGB pixels of the liquid crystal panel are repeatedly arranged,
The liquid crystal display device according to claim 6, wherein the cylindrical lens has a curvature in a direction in which RGB pixels of the liquid crystal panel are repeatedly arranged. The light guide plate is configured so that the irradiation light is diffused and emitted only in a one-dimensional direction,
The direction in which the irradiation light is incident on the light guide plate, the direction in which the emitted light from the light guide plate is diffused, and the direction in which the light is diffused by the first diffusion element are in the same virtual plane. The liquid crystal display device according to claim 2. The light guide plate has a groove formed in parallel to the side surface on a facing surface facing the one main surface,
The cross-sectional shape of the bottom surface and the side surface of the groove is a curved surface, and a part of the irradiation light incident from the side surface is diffused in a one-dimensional direction using the groove as a reflection surface and emitted from the one main surface. The liquid crystal display device according to claim 9. Between the liquid crystal part of the liquid crystal panel and the light guide plate, further comprising a transflective filter that transmits a part of incident light and reflects a part thereof,
The first diffusion element is composed of a plurality of inclined surfaces having different inclinations formed on an opposing surface facing the one main surface of the light guide plate,
The liquid crystal display device according to claim 2, wherein the liquid crystal display device is configured to diffuse in a one-dimensional direction by repeating reflection between the plurality of inclined surfaces and the semi-transmissive filter. The liquid crystal display device according to claim 11, wherein the transflective filter is a polarization reflection sheet that transmits a predetermined polarization component and reflects a polarization component orthogonal thereto. The semi-transmissive filter includes an R region that reflects green light and blue light and transmits red light, a G region that reflects red light and blue light and transmits green light, and a red region that reflects red light and green light and blue light. The liquid crystal display device according to claim 11, wherein the liquid crystal display device is a reflective color filter having a B region that transmits light. 2. The liquid crystal display device according to claim 1, wherein the first and second diffusing elements are optical sheets in which a lenticular lens or an unequal pitch diffraction grating is formed on one side or both sides. The second diffusing element has a lens array structure including a plurality of lenses in a corresponding region corresponding to at least one of the R pixel, the G pixel, and the B pixel constituting the RGB pixel of the liquid crystal panel. The liquid crystal display device according to claim 14. The liquid crystal display device according to claim 14, wherein the second diffusing element is disposed between a glass substrate on the image display side of the liquid crystal panel and a polarizing plate. 15. The liquid crystal display device according to claim 14, wherein the second diffusing element has a black stripe disposed on the image display side and above a boundary region between adjacent RGB pixels. 15. The liquid crystal display device according to claim 14, wherein the second diffusing element has a black stripe disposed along an image display side and a direction in which RGB pixels are repeatedly arranged. The first diffusing element has a lenticular lens or an unequal pitch diffraction grating formed on one side thereof, and diffuses transmitted light in a one-dimensional direction, and is orthogonal to the direction in which the other surface is diffused in a one-dimensional direction. The liquid crystal display device according to claim 17, wherein the liquid crystal display device is an optical sheet in which a light distribution pattern for condensing light in the direction near the exit surface of the liquid crystal panel is formed.

Images