JP2005321754A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve contrast by attenuating reflected light on one end of a light guide plate in the case of displaying a stereoscopic image or two different images. <P>SOLUTION: The display device is equipped with: a light guide plate 2 having a light extracting part 2a provided in a part of the surface; a pair of light sources 1a, 1b disposed outside the either end face of the light guide plate; and a synchronous driving means 4 to alternately turn on the pair of light sources and display images synchronizing above on a transmissive liquid crystal panel 3. The end face of the light guide plate is composed of a light transmitting part 21 in a portion near the pair of light sources and an antireflection part 22 in the rest portion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device, and more particularly to a display device that can be used for information equipment terminals and capable of displaying two different images at the same time in different angular directions.

  In a conventional display device capable of stereoscopic display or two-screen display (displaying two different images simultaneously in different angular directions), a light extraction unit having directivity in the light emission angle by roughening the surface or the like A pair of light sources are arranged close to both end faces of the light guide plate formed, and further provided with a double-sided prism sheet and a transmissive liquid crystal panel on the light extraction portion, and the pair of light sources are alternately lit and synchronized with this. Two different images are displayed on the transmissive liquid crystal panel to perform stereoscopic display or two-image display (for example, see Non-Patent Document 1).

T. Sasagawa et al, “Dual Directional Backlight for Stereoscopic LCD”, P1-P3, Society for Information Display '03 DIGEST (2003)

  Since the light guide plate of the conventional stereoscopic display device or the display device that displays two images in different angle directions has the above-described configuration, the light emitted from one light source is accompanied by the light guide. Other than the direct light emitted from the light extraction portion with one image light distribution, the reflected light reaches the other end and is reflected and guided in the opposite direction. When this reflected light is emitted from the light extraction portion, it becomes a light distribution for one other image, so that two images are overlapped and observed. As a result, there is a problem that the contrast of the stereoscopic image or two different images is lowered.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a display device capable of improving the contrast of a stereoscopic image or two different images while maintaining a uniform luminance distribution. Is.

  In the display device according to the present invention, a light guide plate having a light transmission part and an antireflection part on both end faces and a light extraction part on a part of the surface, and a pair of light sources arranged outside the both end faces And a transmissive liquid crystal panel disposed adjacent to the light extraction section, and a synchronous driving means for alternately lighting a pair of light sources and displaying an image synchronized with the light source on the transmissive liquid crystal panel.

  In addition, a light guide plate having antireflection portions on both end faces, hole rows inside the both end faces, and a light extraction portion on a part of the surface, a pair of light sources inserted into the hole rows, and light extraction A transmissive liquid crystal panel disposed adjacent to the unit, and a synchronous driving means for alternately lighting a pair of light sources and displaying an image synchronized with the light source on the transmissive liquid crystal panel.

  Also, two transparent plates with one end face being a light transmitting portion and the other being an antireflection portion and having a light extracting portion on a part of the surface are light transmitting with the light extracting portion in the same direction. The light guide plate stacked so that the parts face each other, the light source arranged outside the light transmission part, the transmissive liquid crystal panel arranged adjacent to the light extraction part, and a pair of light sources are alternately lit, Synchronous drive means for displaying a synchronized image on a transmissive liquid crystal panel.

  Furthermore, a light guide plate having a light extraction portion provided on a part of the surface, a pair of light sources disposed outside both end faces of the light guide plate, and a surface facing the surface provided with the light extraction portion. The light reflection member disposed with a gap serving as an antireflection portion between the both end faces, the transmissive liquid crystal panel disposed adjacent to the light extraction portion, and a pair of light sources are alternately lit, Synchronous driving means for displaying a synchronized image on the transmissive liquid crystal panel.

  In the present invention, by providing an antireflection portion in a portion other than the light transmission portion, it is possible to reduce the reflected light that is reflected from the other end and travels in the reverse direction, thereby reducing the contrast of the display image. Can be improved.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The inventors have found from the operation principle of two-screen display that preventing reflection of the end face of the light guide plate is an effective means as will be described below.

  When light is incident on the light guide plate from one light source, the luminance distribution of the light emitted from the light extraction unit can be calculated as follows from the state of the light propagating through the light guide plate. FIG. 1 is an explanatory diagram for explaining the propagation of light in the light guide plate in a configuration in which a pair of light sources are arranged outside both end faces of the light guide plate 2. In FIG. 1, it is assumed that only the light source 1b is turned on among the pair of light sources 1a and 1b. The light propagation intensity in the vicinity of the light incident end viewed from the light source 1b of the light guide plate 2 is I1, the light propagation intensity in the center is I2, and the light propagation intensity in the vicinity of the reflection end is I3. Let R be the average reflectance at the reflection end. Regarding the light extraction efficiency of the light extraction portion 2a provided on the light guide plate 2, the light extraction efficiency in the vicinity of the light incident end of the light guide plate is t1, the light extraction efficiency in the center is t2, and the light extraction efficiency in the vicinity of the reflection end is t3. . Regarding the luminance by the light beam extracted from the light extraction portion 2a by the direct light propagating in the light guide plate 2 from the light source 1b in the left direction, the luminance near the light incident end of the light guide plate is φ1, and the luminance at the center is φ2. Let the luminance near the edge be φ3. As for the propagation light intensity when the reflected light reflected at the reflection end of the light guide plate propagates in the right direction, the light intensity near the light incident end is I′1, the light intensity at the center is I′2, and the light intensity near the reflection end is The light intensity is I′3. Further, regarding the luminance due to the light flux from which the reflected light is extracted from the light extraction portion 2a, the luminance near the light incident end of the light guide plate is φ′1, the luminance at the center is φ′2, and the luminance near the reflection end is φ′3. To do.

Of the light extracted from the light extraction section 2a, the ratio of the luminance by the direct light and the luminance by the reflected light is defined as the contrast of the light guide plate, the contrast at the light entrance end is C1, the contrast at the center is C2, and the contrast at the light exit end. Is C3.
The luminance of direct light is φn = tn × In n = 1, 2, 3
The brightness of the reflected light is φ'n = tn × I'n
The propagation intensity of the reflected light is I'3 = R × I3
In addition, the propagation intensity at both ends of the light guide plate is based on the symmetry of light travel / reverse,
I'1 = I'3 * I3 / I1 = R * I3 * I3 / I1
I'2 = I'3 * I3 / I2 = R * I3 * I3 / I2
Is calculated. Contrast is
Cn = φn / φ′n = tn × In / (tn × I′n)
= In / I'n
That is,
C1 = (I1 / I3) ² / R (1)
C2 = (I2 / I3) ² / R (2)
C3 = 1 / R (3)
Is calculated. Or in terms of light extraction efficiency,
C1 = ((φ1 / φ3) (t3 / t1)) ² / R (4)
C2 = ((φ2 / φ3) (t3 / t2)) ² / R (5)
C3 = 1 / R (6)
It becomes.

  From the above formulas, it can be seen that the contrast Cn and the reflectance R at the reflection end of the light guide plate are in inverse proportion to each other on the light guide plate, and the reflectance R must be reduced to improve the contrast. . On the other hand, in the formulas (4) to (6), t3> t1 and t3> t2 are conditions for improving the contrast over the entire surface of the light guide plate without reducing the reflectance R. In the case of the light guide plate of the stereoscopic display device using the light source, it is necessary to have optical characteristics that are symmetric with respect to the respective lights from the pair of light sources, that is, t3 = t1, and therefore t3> t1 and The condition t3> t2 cannot be adopted.

  Further, φ3 <φ1 or φ3 <φ2 is also a condition for improving the contrast over the entire surface of the light guide plate regardless of the reduction of the reflectance R, but under this condition, the luminance distribution becomes non-uniform and φ3 = φ1 It cannot be adopted because it does not satisfy the symmetry condition. From the above, it is necessary to reduce the reflectance R in order to improve the contrast.

FIG. 2 is a schematic diagram for explaining the display device according to the first embodiment for carrying out the present invention. In FIG. 2, the pair of light sources 1 a and 1 b are disposed close to both end faces of the light guide plate 2. The light emitted from the light source 1a or 1b propagates through the light guide plate 2 and is extracted from the light extraction portion 2a provided on the surface of the light guide plate 2 to the transmissive liquid crystal panel 3 side. The light extraction portion 2a is obtained by roughening the surface of the light guide plate 2 so that the light passing therethrough has directivity. FIG. 3A shows a light distribution of light emitted from the light extraction portion 2a when only the light source 1a is turned on. In FIG. 3A, the horizontal axis represents the normal direction of the light guide plate 2 as 0 degree and the angle tilted to the right with the + direction, and the vertical axis represents luminance (unit: cd / m ² ). . The light exiting the light extraction portion 2a passes through the transmissive liquid crystal panel 5 and becomes image information while maintaining the light distribution shown in FIG. On the other hand, the light distribution when the light source 1b is turned on is a light distribution obtained by reversing the light distribution shown in FIG. When the light sources 1a and 1b are alternately lit by the synchronous driving means 4 and two different images are displayed on the transmissive liquid crystal panel 3 in synchronization with each other, the two different images can be observed simultaneously from different angles. . FIG. 4 is a perspective view showing the arrangement of the light sources 1a and 1b, the light guide plate 2, and the transmissive liquid crystal panel 3 in the present embodiment. FIG. 5 is a top view of the light guide plate 2 and the light sources 1a and 1b in the present embodiment as viewed from the display surface side. The end surface of the light guide plate 2 is a light transmitting portion 21 where the light sources 1a and 1b are close to each other. The other parts are constituted by an antireflection part 22. As the antireflection portion, for example, a dielectric multilayer film functioning as an antireflection film may be formed outside the end face of the light guide plate 2. As an example of the dielectric multilayer film, a tantalum dioxide film as a high refractive index film and a silicon dioxide film as a low refractive index film are alternately multilayered.

  The effect of improving the contrast in this case is calculated as follows. In FIG. 5, the ratio of the area of the light guide plate end face where the antireflection part is provided is α, the ratio of the area of the light transmission part is 1−α, and the antireflection part is not provided on a part of the end face If the reflectance of the entire end face is R0, and the reflectance of the entire end face when a reflection preventing portion is provided on a part of the end face is Re, the relationship of the following equation is established.

Re = (1−α) × R0, (0 <α <1)
In the present embodiment, if the area of the antireflection portion is, for example, half of the end face of the light guide plate, α = 0.5 and Re = 0.5 × R0.
The contrasts C1, C2, and C3 in this case are substituted into the expressions (1), (2), and (3) using the contrasts C10, C20, and C30 when the antireflection portion is not provided on the end face.
C1 = 2 × C10
C2 = 2 x C20
C3 = 2 × C30
It becomes. That is, according to the present invention, the contrast can be improved twice as compared with the case where the antireflection portion is not provided over the entire surface of the light guide plate.

  As described above, in the present embodiment, as shown in FIG. 5, the portion of the end face of the light guide plate that is not close to the light source is an antireflection portion, so that each of the two different images displayed simultaneously. With respect to the light, the light reaching the antireflection portion on the reflection end surface facing the incident end surface is attenuated in reflection, and a display device capable of high-contrast two-screen display can be realized.

  In this embodiment, an example of a dielectric multilayer film that functions as an antireflection film as an antireflection part is shown. However, another antireflection film, for example, a film coated with fine particles of silicon dioxide, which is a low refractive index material, is used. But you can. Alternatively, since reflection can also be prevented by providing the antireflection part with light absorption, a method of sticking a sheet with high light absorption to the antireflection part or a method of applying a paint with high light absorption may be used.

Embodiment 2. FIG.
FIG. 6 is a schematic diagram for explaining a display device according to Embodiment 2 for carrying out the present invention. In FIG. 6, both end surfaces of the light guide plate 2 are antireflection portions 22, and hole rows 23a and 23b are provided inside the both end surfaces. The pair of light sources 1a and 1b are light emitting diodes (LEDs) embedded in hole arrays 23a and 23b. The light emitted from the light source 1a or 1b propagates through the light guide plate 2 and is extracted from the light extraction portion 2a provided on the surface of the light guide plate 2 to the transmissive liquid crystal panel 3 side. The light extraction portion 2a has a surface roughened so that the light passing therethrough has directivity, and when only the light source 1a is lit, the arrangement shown in FIG. When only the light source 1b is turned on, the light distribution shown in FIG. 3A becomes a light distribution that is symmetrically reversed left and right around 0 degree. The light exiting the light extraction portion 2a passes through the transmissive liquid crystal panel 3 while maintaining the light distribution as described above, and becomes image information. When the light sources 1a and 1b are alternately lit by the synchronous drive means 4 and two different images are displayed on the transmission type liquid crystal panel 3 in synchronization with each other, the two observers simultaneously observing from different angles are different from each other. The image can be recognized.

  FIG. 7 is a schematic diagram of the LEDs constituting the light sources 1a and 1b in the present embodiment. The LED chip 33 that emits light of a single wavelength is emitted into the LED case 32 having the reflective film 31 formed on the inner surface. Has been placed. The LED chip 33 is filled with a light emitting member 34 that converts single-wavelength light emitted from the LED chip 33 into white light. As the light emitting member 34, for example, there is a material obtained by dispersing and mixing phosphors in resin. The LED case 32 is made of a material having high light absorption. The reflection film 31 is for preventing the light emitted from the LED chip 33 from being absorbed by the LED case 32 and, at the same time, imparting directivity in order to emit a large amount of light to the inside of the light guide plate 2.

  FIG. 8 is a top view of the light guide plate 2 and the light sources 1a and 1b in the present embodiment as viewed from the display surface side, and both end surfaces of the light guide plate 2 are antireflection portions 22. FIG. The antireflection part 22 is obtained by attaching a black light-absorbing sheet, for example, to the end face of the light guide plate 2. Of the light emitted from the light source 1a or 1b, the light reaching the end face of the opposite light guide plate is attenuated by the reflection preventing portion. Furthermore, the light reaching the LED case of the light source 1a or 1b is also absorbed by the LED case made of a material having high light absorption, and the reflected light can be attenuated. As a result, unnecessary reflected light is reduced and contrast can be improved.

  In this embodiment, a sheet having a high light absorption property is used as the antireflection portion, but a paint having a high light absorption property may be applied. Alternatively, a dielectric multilayer film functioning as an antireflection film or a film coated with silicon dioxide fine particles as a low refractive index material may be used. Further, although the LED case is made of a material having a high light absorption property, a structure in which a light absorption paint is applied to the outer surface of the LED case having a low light absorption property may be used. In the present embodiment, an example in which white light is converted by a combination of an LED that emits light of a single wavelength and a light emitting member is shown, but an LED that emits white light may be used. In this case, the light emitting member is unnecessary.

Embodiment 3 FIG.
FIG. 9 is a schematic diagram for explaining a display device according to Embodiment 3 for carrying out the present invention. The light guide plate 2 in the present embodiment is composed of two transparent plates 43 and 44 as shown in FIG. 9, and each of the transparent plates has one end face that is a light transmission portion 45 and the other one. Is the antireflection part 46. The two transparent plates 43 and 44 are overlapped so that the light extraction portions 43a and 44a are in the same direction and the light transmission portion 45 is opposed. The pair of light sources 1 a and 1 b are disposed outside the light transmission part 45. In the light extraction portion 43a, the surface of the transparent plate 43 is roughened so that the light emitted from the light source 1a and guided through the transparent plate 43 has a light distribution as shown in FIG. Is. Similarly, the light extraction section 44a is arranged such that the light emitted from the light source 1b and guided through the transparent plate 44 has a light distribution distribution as shown in FIG. The surface of the transparent plate 44 is roughened so as to obtain a light distribution. Light emitted from the light source 1a or 1b and emitted from the light extraction portion 43a or 44a passes through the transmissive liquid crystal panel 3 while maintaining the light distribution as described above, and becomes image information. The synchronous driving means 4 alternately turns on the light sources 1a and 1b, and displays two different images on the transmissive liquid crystal panel 3 in synchronization therewith. Two observers can recognize different images by observing from different angles.

  In the present embodiment, since the reflection preventing portion 46 between the transparent plates 43 and 44 can be formed on the entire end surface, α () used when the contrast improvement effect is calculated in the first embodiment described above. Since the ratio of the area of the portion where the antireflection portion is provided can be set to 1, Re = 0, and the contrast is theoretically infinite, which is actually improved by 10 times or more. In the present embodiment, since the light guide plate 2 is divided into transparent plates 43 and 44 for the respective light sources, the distribution of the extraction ratio of the light extraction means in the equations (4), (5), and (6) is respectively shown. Since it can be designed so that t3> t2> t1 independently with respect to the light source, contrast is further improved.

  The antireflection portion 46 is a dielectric multilayer film functioning as an antireflection film, a film coated with silicon dioxide fine particles as a low refractive index material, a light absorbing sheet or a light absorbing sheet having a light absorbing property. High coating film of paint can be used.

Embodiment 4 FIG.
FIG. 10 is a schematic diagram of a display device according to Embodiment 4. In FIG. 10, a light reflecting member 51 is provided in the vicinity of the surface of the light guide plate 2 opposite to the surface on which the light extraction portion 2 a is provided. The light reflecting member 51 is formed from the width of the light guide plate 2. A gap 52 is provided between the light reflecting member 51 and both end faces, having a small width. The gap 52 functions as an antireflection portion because the light reflectance is lower than that of the light reflecting member 51.

  By configuring in this way, when a part of the light emitted from the light source 1a arranged at one end reaches the other end, it is reflected at this end and propagates to the light source 1a side. A part of the light is emitted from the gap 52 to the outside of the light guide plate 2. That is, the gap 52 functions as an antireflection portion because the light reflection is lower than that of the light reflecting member 51. FIG. 11 shows the result of the relationship between the width A from the end of the gap 52 and the contrast obtained by simulation when the thickness of the light guide plate 2 is 1 mm, and the contrast improves as A increases. . If the width A increases and the light reflecting member 51 becomes narrower than the region of the light extraction portion 2a, the amount of light flux for image display emitted from the light extraction portion 2a decreases, so the width A cannot be increased so much. .

  In this embodiment, the surface of the gap 52 is not subjected to any particular treatment, but the contrast is further improved by forming an antireflection film or a light absorption film on the surface of the gap 52.

Embodiment 5 FIG.
FIG. 12 is a schematic diagram of a display device in the fifth embodiment. In FIG. 12, a region where the light sources 1 a and 1 b are not installed is formed in a wedge shape on the end surface of the light guide plate 2, and an antireflection film 62 is provided on the surface facing the inclined surface of the wedge-shaped portion 61. FIG. 13 is a top view of the light guide plate 2 and the light sources 1a and 1b according to the present embodiment as viewed from the display surface side, and the portions of the light guide plate 2 where the light sources are not installed are shown in an enlarged perspective view. The antireflection film 62 is provided at a position facing the slope.

  In the present embodiment, most of the light emitted from the light source 1a or 1b that has reached the opposite light guide plate end surface is emitted from the wedge-shaped portion 61 to the outside, but part of the light is emitted from the wedge-shaped portion. The light is reflected downward from the light guide plate at the sloped portion 61, and the reflected light is further attenuated by the antireflection film 62. As a result, unnecessary reflected light can be reduced, and the contrast of the two-screen display can be improved. Assuming that the angle between the wedge-shaped portion 61 and the surface of the wedge-shaped portion facing the inclined surface is B, B is preferably approximately 45 °. If B is greater than 45 °, the probability that unwanted reflected light will return toward the light guide plate increases. Conversely, if B is less than 45 °, the slope of the wedge-shaped portion becomes longer, and the area of the light extraction portion of the light guide plate is reduced. There may be a need.

  The antireflection film 62 may be another antireflection film, for example, a film coated with silicon dioxide fine particles as a low refractive index material. Further, since the antireflection film 62 only needs to have an effect of reducing the reflection of light, it may be changed to a light absorption film. Examples of the light absorbing film include a sheet having high light absorption and a coating film having high light absorption.

  12 shows a configuration in which the light sources 1a and 1b face each other, the light sources 1a and 1b may be configured to face the wedge-shaped portion 61 at the end portion of the opposite light guide plate.

Embodiment 6 FIG.
In the fifth embodiment, since the slope portion of the wedge-shaped portion is formed in a rectangular shape, the light spreading from the light source arranged in the vicinity of the wedge-shaped portion may be blocked. Therefore, the light between the light sources is not sufficiently mixed, and there is a risk that streaky luminance unevenness occurs from the position where the wedge-shaped portion is disposed. FIG. 14 is a partially enlarged perspective view of a light guide plate used in the display device in the sixth embodiment. In the present embodiment, a light guide plate having an antireflection portion shown in FIG. 14 is used in the same configuration as in the fifth embodiment. In FIG. 14, the wedge-shaped portion 63 is configured such that the slope becomes smaller as it goes toward the center of the light guide plate, and an antireflection film 64 is provided at a position facing the slope.

  With this configuration, most of the light emitted from the light source that reaches the opposite light guide plate end face is emitted from the wedge-shaped portion 63 to the outside. And reflected light is attenuated by the antireflection film 64. As a result, unnecessary reflected light can be reduced, and the contrast of the two-screen display can be improved. Further, the light spreading in the lateral direction from the light source arranged in the vicinity of the wedge-shaped portion 63 is not blocked by the wedge-shaped portion 63, and the uniformity of luminance is improved.

Embodiment 7 FIG.
FIG. 15 is a top view of the light guide plate 2 used in the display device in the seventh embodiment. In the present embodiment, the triangular light absorbing portion 65a, at the position where the light from the light source 1a or the light source 1b at the end of the light guide plate on the surface where the light extraction portion 2a on the surface of the light guide plate 2 is provided does not reach directly. 65b is provided.

  With this configuration, the light emitted from the light source 1a arranged at one end is absorbed by the light absorbing portion 65b provided at the other end, and the light emitted from the light source 1b is Since it is not absorbed by the light absorbing portion 65b, the contrast is improved without lowering the luminance.

  In the present embodiment, the light absorption portions 65a and 65b are formed on the surface where the light extraction portion 2a is provided, but may be formed on the surface opposite to the surface where the light extraction portion 2a is formed. Furthermore, it may be formed on both surfaces. Further, by combining the present embodiment with the configuration of the first embodiment, the contrast is further improved.

Embodiment 8 FIG.
FIG. 16 is a schematic diagram of a display device according to the eighth embodiment. In FIG. 16, a wedge-shaped recess 71 is formed between the light extraction portion 2a on the surface of the light guide plate 2 and the end portion of the light guide plate. FIG. 17 is a cross-sectional view of the light guide plate 2 in the present embodiment. The recess 71 having a wedge-shaped cross section has a length D from the end of the light guide plate 2 and an angle formed by the wedge-shaped slope and the surface of the light guide plate 2 is E.

  With this configuration, when a part of the light emitted from the light source 1a arranged at one end reaches the recess 71 provided at the other end, the recess 71 is connected to the outside of the light guide plate 2. Is emitted. For this reason, the reflection of the light which reached the opposite light guide plate end surface among the light emitted from one light source is reduced, and the contrast can be improved.

  In FIG. 18, when the thickness of the light guide plate 2 is 1 mm and the length D of the recess 71 is 3 mm, the light extraction when the angle E formed by the wedge-shaped slope and the surface of the light guide plate 2 is changed is shown. The result of having calculated | required E dependence of the amount of relative luminous flux from a part and contrast is shown. The contrast improvement effect is large in the region where E is 2 to 6 degrees, but when E is 5 degrees or more, the amount of light flux decreases, so that E is desirably 4 degrees or less.

  In the present embodiment, the recess 71 is formed only on the surface side of the light guide plate 2 where the light extraction portion 2a is provided, but is provided on the surface opposite to the surface where the light extraction portion 2a is provided. It may also be provided on both surfaces. Further, in the present embodiment, the cross section is formed in a shape having one inclined surface of the wedge-shaped recess 71, but the recess 71 is configured by forming a plurality of wedge-shaped small recesses as shown in FIG. May be.

  Furthermore, by providing a light absorption film on the inclined surface and the vertical surface of the recess 71, a phenomenon in which light emitted to the outside from the light guide plate 2 is reflected by another member or the like and enters the light guide plate 2 again is prevented. Therefore, the contrast is further improved.

Embodiment 9 FIG.
The operation principle of the ninth embodiment will be described with reference to FIG. In the display device according to the embodiment of the present invention, a prism sheet 5 is disposed between the light extraction portion 2 a and the transmissive liquid crystal panel 3. As shown in FIG. 20, a prism row having a triangular cross section is formed on the surface of the prism sheet 5 facing the light extraction portion 2 a, and a cylindrical lens row is formed on the surface facing the transmissive liquid crystal panel 3. Is formed. The configuration other than the arrangement of the prism sheet 5 is the same as that of the display device described in the first embodiment. The light having a light distribution as shown in FIG. 3A emitted from the light extraction means when only the light source 1a is turned on is shown by refraction and reflection in the prism sheet 5 when passing through the prism sheet 5. Orientation distribution as shown in 3 (b), that is, strong intensity in the range from 0 degrees to about -15 degrees on the left side from the front direction, and almost no light in the range from 0 degrees to about 15 degrees on the right side Is a light distribution that does not emit light. In FIG. 3B, the horizontal axis represents the normal direction of the surface of the prism sheet 5 facing the transmissive liquid crystal panel 3 as 0 degree, and the angle tilted to the right is the + direction, and the vertical axis represents the luminance. (Unit is cd / m ² ). Light having this light distribution passes through the transmissive liquid crystal panel 3 while maintaining the light distribution. If the observer is located at a distance of about 300 mm in front of the panel and the distance between the right eye 6a and the left eye 6b of the observer is 65 mm, a straight line connecting the center of the transmissive liquid crystal panel 3 and the right eye 6a The angle formed with the normal direction of the transmissive liquid crystal panel 3 is about 6 degrees. At this time, if the image has an orientation distribution as shown in FIG. 3B, the image can be recognized by the right eye 6a of the observer as shown in FIG. The light does not reach and the image is not recognized. On the other hand, when only the light source 1b is turned on, an image of the light distribution distribution in which the orientation distribution shown in FIG. In this case, as shown in FIG. 20B, only the left eye 6b can recognize the image, and the right eye 6a does not recognize the image. Therefore, if the left and right parallax images are displayed on the transmissive liquid crystal panel 3 in synchronization with the light sources 1a and 1b being alternately turned on by a synchronous driving means (not shown), the observers are different for the left and right eyes, respectively. A parallax image can be recognized, and stereoscopic viewing by parallax is possible.

  In the display device configured as described above, the light that has reached the end surface of the opposite light guide plate among the light emitted from the respective light sources that display the left and right parallax images is attenuated by the reflection preventing unit. The contrast of the image can be improved, and a clear stereoscopic image can be obtained.

  In the present embodiment, the configuration other than the arrangement of the prism sheet is the same as that of the first embodiment, but any one of the second to fourth embodiments is used instead of the configuration similar to the first embodiment. It may be replaced with a similar configuration.

It is explanatory drawing explaining propagation of the light within the light-guide plate concerning this invention. It is a schematic diagram of the display device in Embodiment 1 of the present invention. It is a figure which shows the light distribution from the light extraction part and prism sheet concerning this invention. It is a perspective view of the display apparatus in Embodiment 1 of this invention. It is a top view of the light-guide plate in Embodiment 1 of this invention. It is a schematic diagram of the display apparatus in Embodiment 2 of this invention. It is a schematic diagram of the light emitting diode in Embodiment 2 of this invention. It is a top view of the light-guide plate in Embodiment 2 of this invention. It is a schematic diagram of the display apparatus in Embodiment 3 of this invention. It is a schematic diagram of the display apparatus in Embodiment 4 of this invention. It is a characteristic view in Embodiment 4 of this invention. It is a schematic diagram of the display apparatus in Embodiment 5 of this invention. It is a top view of the light-guide plate in Embodiment 5 of this invention. It is a partial expansion perspective view of the light-guide plate in Embodiment 6 of this invention. It is a top view of the light-guide plate in Embodiment 7 of this invention. It is a schematic diagram of the display apparatus in Embodiment 8 of this invention. It is a schematic diagram of the light-guide plate in Embodiment 8 of this invention. It is a characteristic view in Embodiment 8 of this invention. It is a fragmentary sectional view of the light-guide plate in Embodiment 8 of this invention. It is explanatory drawing in Embodiment 9 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Light source, 2 Light guide plate, 2a Light extraction part 3 Transmission type liquid crystal panel, 4 Synchronous drive means, 5 Prism sheet 6a Right eye, 6b Left eye 21 Light transmission part, 22 Antireflection part, 23a, 23b Hole row 31 Reflective film, 32 LED case, 33 LED chip 34 Light emitting member, 43, 44 Transparent plate, 43a, 44a Light extraction part 45 Light transmission part, 46 Antireflection part, 51 Light reflection member 52 Gap, 61 Wedge type part, 62 Reflection Prevention film 63 Wedge mold part, 64 Antireflection film, 65a, 65b Light absorption part 71 Recess

Claims (16)

A light guide plate having a light transmission part and an antireflection part on both end faces and having a light extraction part on a part of the surface, a pair of light sources arranged outside the both end faces, and the light extraction part A display device comprising: a transmissive liquid crystal panel disposed adjacently; and a synchronous drive unit that alternately turns on the pair of light sources and displays an image synchronized with the pair of light sources on the transmissive liquid crystal panel. A light guide plate provided with antireflection portions on both end surfaces, provided with hole rows on the inner side of the both end surfaces, and provided with a light extraction portion on a part of the surface, a pair of light sources inserted into the hole rows, A display device comprising: a transmissive liquid crystal panel disposed adjacent to the light extraction unit; and synchronous driving means for alternately lighting the pair of light sources and displaying an image synchronized with the light source on the transmissive liquid crystal panel. Two transparent plates, one of which is a light transmitting portion and the other is an antireflection portion, and a light extraction portion is provided on a part of the surface, are arranged with the light extraction portion in the same direction and the light A light guide plate stacked so that the transmissive portions face each other, a pair of light sources disposed outside the light transmissive portion, a transmissive liquid crystal panel disposed adjacent to the light extraction portion, and the pair of light sources A display device comprising: synchronous driving means for alternately lighting and displaying an image synchronized with the light on the transmissive liquid crystal panel. A light guide plate provided with a light extraction portion on a part of the surface, a pair of light sources arranged outside both end faces of the light guide plate,
A light reflecting member disposed close to the surface opposite to the surface provided with the light extraction portion and provided with a gap serving as an antireflection portion between the both end faces;
A display device comprising: a transmissive liquid crystal panel disposed adjacent to the light extraction unit; and synchronous driving means for alternately lighting the pair of light sources and displaying an image synchronized with the light source on the transmissive liquid crystal panel. The display device according to claim 1, wherein the antireflection portion includes an antireflection film. The display device according to claim 1, wherein the antireflection portion includes a light absorption film. 4. The display device according to claim 1, wherein the antireflection portion has a wedge-shaped cross-sectional shape and has an antireflection film on a surface facing the wedge-shaped inclined surface. . 4. The display device according to claim 1, wherein the antireflection portion has a wedge-shaped cross-sectional shape and has a light absorption film on a surface facing the wedge-shaped slope. . The antireflection portion is formed in contact with both end faces of at least one of the surface of the light guide plate where the light extraction portion is provided or the surface facing the light extraction portion, and is a concave wedge-shaped recess inclined toward the center of the light guide plate. The display device according to claim 1, wherein: The display device according to claim 9, wherein an angle formed by the inclined cross section and the surface of the light guide plate is 4 degrees or less. The display device according to claim 9, wherein a light absorption film is provided on the surface of the inclined section. 8. The display device according to claim 5, wherein the antireflection film is formed of a dielectric multilayer film. 9. The display device according to claim 6, wherein the light absorption film is formed of either a light absorbing sheet or a light absorbing paint. 5. A display device according to claim 1, wherein a prism sheet is disposed between the light extraction portion and the transmissive liquid crystal panel. A prism sheet having a prism array with a triangular cross section on one surface and a cylindrical lens array in the same direction as the prism array on the other surface, the end surface of the light guide plate on which the antireflection portion is formed, and the above The display device according to claim 14, wherein the longitudinal direction of the prism rows is the same direction, and the prism rows are arranged to face the light extraction portion. The display device according to claim 1, wherein the light source includes a plurality of light emitting diodes.

Images