JP5059051B2 - Parallax image display device - Google Patents

Description

The present invention relates to a parallax image display device used for stereoscopic display.

  In general, the stereoscopic display device provides a parallax image from each viewpoint to the left and right eyes of an observer, and there are a method using special glasses and a method not using glasses.

  FIG. 9 shows a first conventional stereoscopic display device that does not use glasses (see Patent Document 1).

The stereoscopic display device of FIG. 9 includes two overlapping light guide plates 101a and 101b, two light sources 102a and 102b provided on the incident surfaces S _ina and S _inb of the wedge light guide plates 101a and 101b, _Single- sided triangular prism sheet 103 provided on the exit surface _{Sout1 of the} wedge-shaped light guide plates 101a and 101b, a transmissive liquid crystal display panel 104 provided on the exit surface _Sout3 of the single-sided triangular prism sheet 103, and transmissive liquid crystal The display panel 104 includes a synchronous drive circuit 105 that synchronizes two light sources 102a and 102b and displays a parallax image. As a result, a stereoscopic image having the same number of pixels as that of the transmissive liquid crystal display panel 104 can be displayed.

  FIG. 10 shows a second conventional stereoscopic display device that does not use glasses (see Patent Document 2).

The stereoscopic display device of FIG. 10 includes a flat light guide plate 201 having a light extraction portion 201a for reflection printing, roughening, and the like, and 2 provided on two opposing incident surfaces S _ina and S _inb of the flat light guide plate 201. Two light source 202a, 202b, a double-sided prism sheet 203 provided on the output surface _{Sout1 of} the flat light guide plate 201 and having a triangular prism row 2031 facing the flat light guide plate 201 and a cylindrical lens row 2032 on its reflection surface A transmissive liquid crystal display panel 204 provided on the emission surface S _out3 of the double-sided prism sheet 203, and a synchronous driving circuit 205 for displaying the parallax image by synchronizing the two light sources 202a and 202b on the transmissive liquid crystal display panel 204. And is composed of. As a result, a stereoscopic image having the same number of pixels as that of the transmissive liquid crystal display panel 204 can be displayed.

JP 2001-66547 A WO2004 / 027492A1 JP 2009-81094 A

  However, in the first conventional stereoscopic display device of FIG. 9, the light from the lower wedge-shaped light guide plate 101b is affected by the pattern of the upper wedge-shaped light guide plate 101a, so the upper wedge-shaped light guide plate 101a. Has a complicated structure, and as a result, there is a problem that the manufacturing cost increases.

  In the second conventional stereoscopic display device of FIG. 10, the flat light guide plate 201 does not have any structure that solves the problem caused by the two wedge-shaped light guide plates 101a and 101b of the stereoscopic display device of FIG.

  Furthermore, the second conventional stereoscopic display device of FIG. 10 requires the double-sided prism sheet 203 when the light distribution of the flat light guide plate 201 is sharp, and the triangular prism row 2031 and the cylindrical lens row 2032 are made of gold. There is a problem in that the manufacturing cost must be increased as a result, because it must be manufactured in a precise dimension using a mold or the like.

In order to solve the above-described problems, a parallax image display device according to the present invention includes a light guide plate having an emission surface that is vertically opposed, a light distribution control surface, and first and second incident surfaces that are opposed to both sides, and a light guide plate. First and second light sources provided on the first and second incident surfaces of the light plate, a single-sided prism sheet provided on the output surface of the light guide plate, and a transmission provided on the output surface of the single-sided prism sheet Type display panel and a synchronous drive circuit for displaying a parallax image by synchronizing the first and second light sources on the transmissive display panel, and the first and second light guide plates on the light distribution control surface of the light guide plate. A plurality of flat mirror surface portions extending in the direction between the incident surfaces of the light guide plate are formed and viewed from the direction between the first and second incident surfaces of the light guide plate in a region where the flat mirror surface portions on the light distribution control surface are not formed. A triangular prism array composed of a plurality of equally spaced triangular prisms is formed, and each of the first and second entrances of the light guide plate is formed. A portion of the incident surface where the first and second light sources are not provided is subjected to a textured process. Thereby, return light is suppressed.
FIG. 6 of Patent Document 3 discloses a light guide plate in which a plurality of flat mirror surface portions are formed on a light distribution control surface and a plurality of triangular prisms are formed in a region where the flat mirror surface portions are not formed. However, this light guide plate is for a surface light source device and is not intended for a stereoscopic display device. Therefore, there is no need to suppress the return light.

Further, the width of the light guide plate of each flat mirror surface portion in the direction perpendicular to the direction between the first and second incident surfaces is constant. Alternatively, the first light guide plate of the flat mirror surface, the width of the second incidence plane between the direction perpendicular to the direction is changed.

  Furthermore, the single-sided prism sheet is composed of a plurality of multi-stage triangular prisms. Thereby, even if the light distribution of the light guide plate is sharp, the light distribution of the single-sided prism sheet can be matched with the parallax image of the stereoscopic image.

  According to the present invention, since a complicated structure is not required, the manufacturing cost can be reduced.

It is a figure which shows embodiment of the parallax image display apparatus which concerns on this invention. It is a top view which shows the 1st example of the light-guide plate of FIG. It is a top view which shows the 2nd example of the light-guide plate of FIG. It is the III-III sectional view taken on the line of FIG. 2A and FIG. 2B. It is a graph which shows the light distribution for left eyes of the light from the light-guide plate of FIG. It is a figure which shows one prism of the single-sided irregular triangular prism sheet | seat of FIG. It is a figure explaining the optical path in the single-sided irregular triangular prism sheet | seat of FIG. It is a figure which shows the optical path in the single-sided irregular triangular prism sheet in case the light from the light-guide plate of FIG. 1 is 50 degrees, 60 degrees, 70 degrees, and 80 degrees. It is a graph which shows the light distribution for left eyes of the light from the single-sided irregular triangular prism sheet | seat of FIG. It is a figure which shows the 1st conventional three-dimensional display apparatus. It is a figure which shows the 2nd conventional stereoscopic display device.

FIG. 1 is a diagram showing an embodiment of a parallax image display device according to the present invention.

The parallax image display device of FIG. 1 is provided on the light guide plate 1, two light sources 2 a and 2 b provided on the two incident surfaces S _ina and S _inb of the light guide plate 1, and the exit surface S _out1 side of the light guide plate 1. The single-sided irregular triangular prism sheet 3, the transmissive liquid crystal display panel 4 provided on the output surface _{Sout3 of the} single-sided irregular triangular prism sheet 3, and the two light sources 2a and 2b are synchronized with the transmissive liquid crystal display panel 4. And a synchronous drive circuit 5 for displaying a parallax image. As a result, a stereoscopic image having the same number of pixels as the transmissive liquid crystal display panel 4 can be displayed.

  FIG. 2A is a plan view showing a first example of the light guide plate 1 of FIG. The light guide plate 1 is made of a translucent material such as acrylic resin or polycarbonate resin.

As shown in FIG. 2A, the light guide plate 1 is symmetrical with respect to the incident surfaces S _ina and S _inb . Further, a plurality of flat mirror surface portions 11 extending in the direction between the incident surfaces S _ina and S _inb are formed on the light distribution control surface opposite to the emission surface S _out1 of the light guide plate 1. The flat mirror surface portion 11 is for making the light uniform to the back. Further, a triangular prism row 12 is formed in a region where the flat mirror surface portion 11 is not formed, for raising light composed of a plurality of triangularly spaced prisms. Furthermore, the incident surface S _ina incident surface S _ina of S _inb particularly flat mirror surface portion 11, the S _inb, for the return light inhibiting, triangular, by processing the embossed surface 13, such as a circular arc shape and the microlens array is there. As shown in FIG. 2A, each of the light sources 2a and 2b can be a plurality of light emitting diodes (LEDs).

  In FIG. 2A, the widths of the light sources 2a and 2b are the same as the width of the triangular prism row 12. In this case, much light totally reflected by the prism surfaces of the triangular prism row 12 is emitted from the vicinity of the light sources 2a and 2b, and the uniformity is reduced. In general, the number of triangular prism rows 12 with respect to the width of the light sources 2a and 2b varies depending on the size of the product and the required uniformity of the surface luminance. Therefore, as shown in FIG. 2B showing a second example of the light guide plate 1 of FIG. 1, a plurality of flat mirror surface portions 11 and triangular prism rows 12 (three in FIG. 2B) are arranged with respect to the width of the light sources 2a and 2b. When the light sources 2a and 2b are alternately arranged, the uniformity increases.

In FIG. 2A, the light sources 2 a and 2 b are arranged symmetrically with respect to the triangular prism row 12. In this case, there is a problem that the opposite side surfaces of the light guide plates, that is, the incident surfaces S _ina and S _inb are flat surfaces, and return light is generated from the flat surfaces. On the other hand, in FIG. 2B, since the opposite side surface of the light sources 2a and 2b is a textured surface, the return light is suppressed.

  3 is a cross-sectional view taken along line III-III in FIGS. 2A and 2B. As shown in FIG. 3A, the triangular prism row 12 may be protruded downward from the flat mirror surface portion 11, and on the other hand, as shown in FIG. The flat mirror surface portion 11 may protrude downward. 3A and 3B, the case where only the light source 2a is operated is illustrated. Since the light sources 2a and 2b are provided symmetrically, the operation of the light source 2b is the same.

3A and 3B, the light R1 from the light source 2a enters from the incident surface _Sina and is directly totally reflected by the triangular prisms of the triangular prism row 12 to become outgoing light. The light R2 from the light source 2a enters from the incident surface _Sina and is totally reflected by the flat mirror surface portion 11 and then totally reflected by the triangular prisms of the triangular prism row 12 to become emitted light. On the other hand, when the textured surface 13 does not exist, the light R3 from the light source 2a indicated by the dotted line is incident from the incident surface _Sinb and is totally reflected by the flat mirror surface portion 11 and becomes return light at the incident surface _Sin2 . Further, the light is totally reflected by the triangular prisms in the triangular prism row 12 to become emitted light. That is, if the light source 2a displays a parallax image for the left eye, the light R1 and R2 in the angle + direction are useful for the parallax image for the left eye, but the return light R3 in the angle-direction is unnecessary outgoing light. This adversely affects the right-eye parallax image. In the present invention, the return light R3 is irregularly reflected and suppressed by the embossed surface 13, so that it does not become outgoing light.

  Since the triangular prisms in the triangular prism array 12 require symmetrically emitted light from the light sources 2a and 2b, they are isosceles triangles and are arranged at equal intervals. Further, the apex angle is large, for example, 164 °, and the rising amount of light is reduced by the amount of returning light.

  FIG. 4 shows a left eye light distribution of light from the light guide plate 1 of FIG. 1 when the left eye light source 2a is turned on. In FIG. 4, the dotted line is the light distribution of the light from the light guide plate 1 when the textured surface 13 does not exist and the return light R3 in FIG. 3 is not suppressed.

As shown in FIG. 4, since the return light R3 in FIG. 3 is suppressed, only light having a weak intensity is emitted in the angle 0 ° to −90 ° direction. Therefore, the right-eye parallax image is not adversely affected, and the left and right crosstalk is small. In FIG. 4, the intensity of light emission is large in the + 50 ° to + 80 ° direction, and is maximum at + 64 ° .

  When the light source 2b for the right eye is turned on, the light distribution is symmetric with respect to 0 ° as in the case of FIG. 4, and only weak intensity light is emitted in the angle 0 to + 90 ° direction. Therefore, the left-eye parallax image is not adversely affected, and the left and right crosstalk is small.

  FIG. 5 is a view showing one prism of the single-sided irregular triangular prism sheet 3 of FIG.

  As shown in FIG. 5, one prism of the single-sided irregular triangular prism sheet 3 is an irregular triangular prism, for example, a three-stage triangular prism. Angle 81 °, side E2, F2 (distance from ridge to 9μm to 39μm) is apex angle 71 °, side E3, F3 (distance from ridge to 39μm to 63μm) is apex The angle is 65 °. Such a single-sided irregular triangular prism sheet 3 can be accurately formed at a desired inclination angle by a molding stamper.

  FIG. 6 is a view for explaining an optical path in the single-sided irregular triangular prism sheet 3 of FIG.

As shown in FIG. 6, the light emitted from the exit surface _Sout1 of the light guide plate 1 is refracted at the side portions E1, E2, and E3, is totally reflected at the side portions F1, F2, and F3, and is emitted to the upper surface. Since the light distribution for the left eye from the light guide plate 1 shown in FIG. 4 is strong in 50 ° to 80 °, one surface deformed triangular prism sheet 3 is 50 ° to 80 also + direction with the light of any angle of emergence of ° in Figure 1 It is acting so that it may be emitted. Hereinafter, the optical path of the single-sided irregular triangular prism sheet 3 will be described in detail when the light from the light guide plate 1 has a light distribution angle of 50 °, 60 °, 70 °, and 80 °.

  FIG. 7A shows an optical path when the light emission angle from the light guide plate 1 is + 50 °. As shown in FIG. 7A, the light from the light guide plate 1 passes through the side portions E1, E2, and E3 of the prism and is totally reflected by the side portions F1, F2, and F3. As a result, the emission angle of the single-sided irregular triangular prism sheet 3 is emitted in the + 22 ° to + 50 ° direction.

  FIG. 7B shows an optical path when the light emission angle from the light guide plate 1 is + 60 °. As shown in FIG. 7B, the light from the light guide plate 1 is transmitted through the side portions E1 and E2 of the prism and totally reflected by the side portions F1, F2, and F3. As a result, the emission angle of the single-sided irregular triangular prism sheet 3 is emitted in the + 10 ° to + 39 ° direction.

  FIG. 7C shows an optical path when the light emission angle from the light guide plate 1 is + 70 °. As shown in FIG. 7C, the light from the light guide plate 1 passes through the sides E1 and E2 of the prism and is totally reflected by the sides F1, F2, and F3. As a result, the emission angle of the single-sided irregular triangular prism sheet 3 is emitted in the direction of + 1 ° to + 28 °.

  FIG. 7D shows an optical path when the light emission angle from the light guide plate 1 is + 80 °. As shown in FIG. 7D, the light from the light guide plate 1 is transmitted through the side E1 of the prism and totally reflected by the side F1. As a result, the emission angle of the single-sided irregular triangular prism sheet 3 is emitted in the direction of + 1 ° to + 17.5 °.

  In addition, when the light emission angle from the light guide plate 1 is 0 ° (vertical) to 50 °, the incident angle to the prism of the single-sided irregular triangular prism sheet 3 and the angle exceeding the critical angle on the upper surface of the prism Incident components increase, and as a result, it is difficult to emit light from the upper surface of the prism.

  FIG. 8 shows a light distribution for the left eye of light from the single-sided irregular triangular prism sheet 3 when the light source 2a for the left eye is turned on. In FIG. 8, the dotted line is the light distribution of light from the single-sided irregular triangular prism sheet 3 when the textured surface 13 does not exist and the return light R <b> 3 in FIG. 3 is not suppressed.

  As shown in FIG. 8, since the return light R3 in FIG. 3 is suppressed, only light having a weak intensity is emitted in the angle 0 ° to −90 ° direction. Therefore, the right-eye parallax image is not adversely affected, and the left and right crosstalk is small. In FIG. 8, the light emission intensity is large in the 0 ° to + 30 ° direction, and hardly emits light in the 0 ° to −30 ° direction.

  When the light source 2b for the right eye is turned on, the light distribution is symmetric with respect to 0 ° as in the case of FIG. 8, and only weak intensity light is emitted in the angle 0 to + 30 ° direction. Therefore, the left-eye parallax image is not adversely affected, and the left and right crosstalk is small.

In the above-described embodiment, the width of the flat mirror surface portion is constant, but the width of the flat mirror surface portion can also be changed. Even in this case, the incident surfaces S _ina and S _inb are symmetric.

  Furthermore, the single-sided irregular triangular prism sheet 3 is not limited to one member, and at least two types of members having different refractive indexes may be bonded together. The prism of the single-sided irregularly shaped triangular prism sheet 3 is a three-stage triangular prism, but it may be a two-stage or four-stage multi-stage triangular prism according to the light distribution.

1: Light guide plate 2a, 2b: Light source 3: Single-sided irregular triangular prism sheet 4: Transmission type liquid crystal display panel 5: Synchronous drive circuit 11: Flat mirror surface portion 12: Triangular prism row 13: Textured surface 101a, 101b: Wedge shaped light guide plate 102a, 102b: Light source 103: Prism sheet 104: Transmission type liquid crystal display panel 105: Synchronous drive circuit 201: Flat plate light guide plate 202a, 202b: Light source 203: Double-sided prism sheet 204: Transmission type liquid crystal display panel 205: Synchronous drive circuit

Claims (6)

A light guide plate having an emission surface facing up and down, a light distribution control surface, and first and second incidence surfaces facing both sides ;
First and second light sources provided on the respective first and second incident surfaces of the light guide plate;
A one-sided prism sheet provided on the exit surface of the light guide plate,
A transmissive display panel provided on the exit surface of the single-sided prism sheet;
A synchronous drive circuit for displaying a parallax image by synchronizing the first and second light sources on the transmissive display panel;
The first light guide plate to the light distribution control surface of the light guide plate, a plurality of flat mirror surface portion extending between the second incidence plane direction to form, the flat mirror surface portion of the light distribution control surface Forming a triangular prism row composed of a plurality of triangular prisms at equal intervals when viewed from the direction between the first and second incident surfaces of the light guide plate in a region not formed;
The parallax image display apparatus which carried out the embossing of the part in which the said 1st, 2nd light source of each said 1st, 2nd incident surface of the said light-guide plate is not provided . The portions of the first and second incident surfaces of the textured light guide plate where the first and second light sources are not provided are the first and second incident surfaces of the flat mirror surface portion. The parallax image display device according to claim 1. The parallax image display device according to claim 1, wherein the first and second light sources are alternately arranged on the left and right sides for each of a plurality of flat mirror surface portions and a plurality of triangular prism rows. The parallax image display device according to claim 1, wherein a width of each of the flat mirror surface portions in a direction perpendicular to the direction between the first and second incident surfaces of the light guide plate is constant. 2. The parallax image display device according to claim 1, wherein a width of each of the flat mirror surface portions in a direction perpendicular to the direction between the first and second incident surfaces of the light guide plate is changed. The parallax image display device according to claim 1, wherein the single-sided prism sheet includes a plurality of multi-stage triangular prisms.

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