Three-dimensional image display device

Abstract

To provide a three-dimensional video display device capable of displaying a three-dimensional video of an integral system with high display quality by suppressing unnecessary light generated on both surfaces of a lens array with a simple configuration without substantially changing the thickness of a conventional three-dimensional video display device of the integral system.SOLUTION: A three-dimensional image display device 1 includes: an elemental image group display part 10 for displaying an elemental image group in which elemental images are two dimensionally arranged; a first circularly polarizing plate 12A arranged on the display surface side of the elemental image group display part 10; a lens array 11 which is arranged on the light exit surface side of the circularly polarizing plate 12A and in which elemental lenses are two dimensionally arranged opposite to a display position of an elemental image; and a second circularly polarizing plate 12B which is arranged on the light exit surface side of the lens array 11 and whose rotation direction of the circularly polarized light is the same as that of the circularly polarizing plate 12A.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional image display device that displays three-dimensional images. [Background technology]

[0002] Conventionally, a wide variety of three-dimensional image display devices have been proposed, primarily the binocular system using 3D glasses. In particular, integral-type three-dimensional image display devices, which display a group of elemental images on a display device and place a lens array in front of it to display a three-dimensional image, do not require special glasses and can display natural three-dimensional images with parallax in the horizontal and vertical directions. However, in this method, unwanted light such as multiple reflections between the lens array and the display device, and reflections of ambient light on the surface of the lens array, are superimposed on the displayed three-dimensional image, degrading the display quality such as the contrast of the three-dimensional image.

[0003] As a conventional technique for blocking such unwanted light, a method has been proposed for a binocular type naked-eye three-dimensional image display device using lenticular lenses, in which an anti-reflective film is formed between the lenticular lens and the display device to prevent multiple reflections of light rays occurring between the lenticular lens and the display device (see Patent Document 1). Furthermore, a technique for blocking reflected ambient light from the surface of a display device is known, which involves placing a circular polarizing plate on the front of the display device (see Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 6611956 [Patent Document 2] Japanese Patent Publication No. 2021-015271 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The method described in Patent Document 1 can also be applied to integral-type display devices using lens arrays. However, anti-reflective coatings are generally formed by coating both sides of the element whose reflection is to be prevented with a predetermined thickness of a material such as magnesium fluoride. Therefore, forming an anti-reflective coating requires specialized coating equipment, which presents a problem as it cannot be easily implemented. Furthermore, the method described in Patent Document 2 has the problem that, when applied to an integral-type three-dimensional image display device, it is not possible to prevent multiple reflected light from occurring between the lens array and the display device. Furthermore, in conventional integral-type three-dimensional image display devices, no technology has been proposed to block reflected light generated on both sides of the lens array with a simple configuration that does not require anti-reflective coatings or the like.

[0006] This invention has been made in view of the problems of the prior art, and aims to provide a three-dimensional image display device that, compared to conventional integral-type three-dimensional image display devices, suppresses unwanted light generated on both sides of the lens array with a simple configuration and is capable of displaying integral-type three-dimensional images with high display quality. [Means for solving the problem]

[0007] To solve the aforementioned problems, the three-dimensional image display device according to the present invention is an integral type three-dimensional image display device comprising an element image group display unit, a first circular polarizer, a lens array, and a second circular polarizer, wherein the first and second circular polarizers have the same direction of rotation of circular polarization, and are configured to consist of a quarter-wave plate and a linear polarizer, respectively, in order from the one closest to the lens array.

[0008] In this configuration, the three-dimensional image display device displays an element image group in which integral element images are arranged in a two-dimensional array using an element image group display unit. The three-dimensional image display device then converts the light rays of the elemental image group into circularly polarized light rays using the linear polarizer and quarter-wave plate of the first circular polarizer, which is positioned on the display surface side of the elemental image group display unit. Then, the three-dimensional video display device displays an integral three-dimensional video from the light rays of the elemental image group by means of a lens array arranged on the light-emitting surface side of the first circular polarizing plate.

[0009] Also, the three-dimensional video display device converts the circularly polarized light rays emitted from the lens array into linearly polarized light rays by means of a quarter-wave plate of a second circular polarizing plate having the same rotation direction as the first circular polarizing plate and a linear polarizing plate, which are arranged on the light-emitting surface side of the lens array. That is, the three-dimensional video display device displays an integral three-dimensional video as linearly polarized light rays.

[0010] At this time, when a part of the circularly polarized light rays displayed by the elemental image group display unit is reflected by the lens array toward the elemental image group display unit side, the three-dimensional video display device blocks the reflected light with the first circular polarizing plate because the reflected light becomes circularly polarized light rays having different rotation directions.

[0011] Also, when external light of random polarization is incident, the three-dimensional video display device converts the external light into circularly polarized light rays with the second circular polarizing plate. When the circularly polarized external light is reflected by the lens array toward the second circular polarizing plate side, the three-dimensional video display device blocks the reflected light with the second circular polarizing plate because the reflected light becomes circularly polarized external light having different rotation directions. In this way, the three-dimensional video display device suppresses the thickness of the entire device with the first circular polarizing plate and the second circular polarizing plate that can be mounted with a thin circular polarizing filter, and suppresses unnecessary light generated on both sides of the lens array with a simple configuration that does not require an antireflection film.

Advantages of the Invention

[0012] According to the present invention, it is possible to suppress unnecessary light generated on both sides of the lens array with a simple configuration, with almost no change in thickness compared to a conventional integral three-dimensional video display device, and display an integral three-dimensional video with high display quality.

Brief Description of the Drawings

[0013] [Figure 1]This is a schematic perspective view showing a three-dimensional image display device according to an embodiment of the present invention. [Figure 2] This is a plan view showing the configuration of a three-dimensional image display device according to the first embodiment of the present invention. [Figure 3A] This is an explanatory diagram illustrating an example of the configuration of a right-handed circular polarizer when a right-handed circular polarizer is used as the circular polarizer in Figure 2. [Figure 3B] This is an explanatory diagram illustrating an example of the configuration of a left-hand circular polarizer when a left-hand circular polarizer is used as the circular polarizer in Figure 2. [Figure 4A] This is an explanatory diagram illustrating the principle of blocking light rays from a group of elemental images reflected by a lens array in a three-dimensional image display device according to the first embodiment of the present invention. [Figure 4B] This is an explanatory diagram illustrating the principle of blocking ambient light reflected by the lens array in a three-dimensional image display device according to the first embodiment of the present invention. [Figure 5] This is a plan view showing the configuration of a three-dimensional image display device according to a second embodiment of the present invention. [Figure 6] This is an explanatory diagram to illustrate stray light that occurs at the lens boundaries of a lens array. [Figure 7A] This is an explanatory diagram illustrating an example of a pattern (square grid arrangement) of a circular polarizing plate (patterned circular polarizing plate) used in a three-dimensional image display device according to the second embodiment of the present invention. [Figure 7B] This is an explanatory diagram illustrating an example of a pattern (honeycomb arrangement) of a circular polarizing plate (patterned circular polarizing plate) used in a three-dimensional image display device according to the second embodiment of the present invention. [Figure 8A] This is a plan view showing an example of the configuration of a circular polarizing plate (pattern circular polarizing plate) used in a three-dimensional image display device according to the second embodiment of the present invention. [Figure 8B] This is a plan view showing another example of the configuration of a circular polarizing plate (pattern circular polarizing plate) used in a three-dimensional image display device according to the second embodiment of the present invention. [Figure 9A] This is an explanatory diagram illustrating the principle of blocking unwanted light from the light rays of an element image group in a three-dimensional image display device according to a second embodiment of the present invention. [Figure 9B] This is an explanatory diagram illustrating the principle of blocking ambient light (unwanted light) in a three-dimensional image display device according to a second embodiment of the present invention. [Figure 10] This is a plan view showing the configuration of a three-dimensional image display device according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. ≪First Embodiment≫ <Configuration of a 3D video display device> First, with reference to Figures 1 and 2, the configuration of the three-dimensional image display device 1 according to the first embodiment of the present invention will be described.

[0015] The three-dimensional image display device 1 displays a three-dimensional image T using the integral method. The integral method uses the principle of a stereoscopic photography technique called integral photography (IP) to display a stereoscopic image by passing a quadratic array of elemental images (group of elemental images) through elemental lenses (lens arrays) facing each individual elemental image.

[0016] As shown in Figure 2, the three-dimensional image display device 1 comprises an elemental image group display unit 10, a lens array 11, and circular polarizers 12 (12A, 12B) positioned before and after the lens array 11. The distance between the elemental image group display unit 10 and the circular polarizer 12A, the distance between the circular polarizer 12A and the lens array 11, and the distance between the lens array 11 and the circular polarizer 12B can each be any distance. However, in order to display an integral three-dimensional image T, the elemental image group display unit 10 and the lens array 11 must be spaced apart and not in close proximity. For example, the distance between the elemental image group display unit 10 and the lens array 11 can be the focal length of the lens array 11. Furthermore, in order to make the three-dimensional image display device 1 thinner, the distance between the lens array 11 and the circular polarizer 12B should be short, and even more preferably, they should be in contact.

[0017] The element image group display unit 10 displays an element image group in which integral element images are arranged in a two-dimensional array. The element image group display unit 10 displays the element images I at the same interval D as the element lenses 110 of the lens array 11. This element image group display unit 10 can use common display devices such as liquid crystal displays, organic EL displays, and projectors. The element image group display unit 10 illuminates the lens array 11 from the back with light rays from the element image group via the circular polarizing plate 12A.

[0018] The lens array 11 is configured with tiny element lenses 110 arranged in a two-dimensional array on the light-emitting surface side of the circular polarizer 12A, facing the display position of the element image I, and forms a three-dimensional image (stereoscopic image) of the light rays of the element image group displayed on the element image group display unit 10. The lens array 11 is positioned between the circular polarizer 12A and the circular polarizer 12B. Note that the element lenses 110 shown in Figure 2 are illustrated individually for the sake of simplicity. Furthermore, the size and number of element lenses 110 can be freely designed according to the specifications of the three-dimensional image T to be displayed. The arrangement of the element lenses 110 that make up the lens array 11 can also be freely designed according to the specifications of the three-dimensional image T to be displayed, such as a square grid arrangement, a honeycomb arrangement, or a delta (stacked) arrangement. The lens array 11 illuminates the element image group, which has been back-illuminated via the circular polarizer 12A, onto the circular polarizer 12B positioned in front.

[0019] The circular polarizer 12 converts the polarization of transmitted light. A thin circular polarizer filter can be used for this circular polarizer 12. In this configuration, the circular polarizer 12 is configured to have a first circular polarizer 12A on the back side (towards the element image group display unit 10) and a second circular polarizer 12B on the front side (towards the observer), with the lens array 11 in between. The circular polarizer 12A is positioned between the element image group display unit 10 and the lens array 11. The circular polarizer 12 can be configured by superimposing a linear polarizer 120 and a quarter-wave plate 121.

[0020] The linear polarizer 120 is a polarizer having a transmission axis that aligns the vibration direction of incident light in a specific direction. When a display device that emits linearly polarized light is used as the element image group display unit 10, the circular polarizer 12A has a transmission axis through which light rays are transmitted that is in the same direction as the linearly polarized light rays emitted by the element image group display unit 10. The quarter-wave plate 121 is a wave plate that emits incident light with a phase difference of λ / 4 on the polarization plane. As a result, the circular polarizer 12 can convert light rays incident from the linear polarizer 120 side into circularly polarized light rays, and convert circularly polarized light rays incident from the quarter-wave plate 121 side into linearly polarized light rays.

[0021] Here, circular polarizers 12A and 12B are assumed to be circular polarizers with the same direction of rotation for circular polarization. For example, if circular polarizer 12A is a right-handed circular polarizer, then circular polarizer 12B is also a right-handed circular polarizer. Also, for example, if circular polarizer 12A is a left-handed circular polarizer, then circular polarizer 12B is also a left-handed circular polarizer. However, the circular polarizers 12A and 12B are each composed of a quarter-wave plate 121 and a linear polarizer 120, arranged in order from the side closest to the lens array 11, such that the quarter-wave plates 121 face each other.

[0022] Here, with reference to Figures 3A and 3B, the direction of circular polarization of the circular polarizer 12 will be explained. As shown in Figure 3A, the circular polarizer 12 has a transmission axis A of the linear polarizer 120. T In contrast, the high-speed axis A of the quarter-wave plate 121 H By tilting it 45 degrees clockwise, the right circular polarizing plate 12 R It can be configured as follows. Right circular polarizing plate 12 R Light incident from the linear polarizer 120 side passes through the transmission axis A of the linear polarizer 120. T By passing through it, it becomes linearly polarized light that vibrates in a certain direction, and furthermore, the high-speed axis A of the quarter-wave plate 121 HBy being given a phase difference of λ / 4, it becomes right circularly polarized light. Also, for the right circular polarizing plate 12 R The right circularly polarized light incident from the side of the quarter-wave plate 121 on the right circular polarizing plate 12 becomes linearly polarized light by being given a phase difference of λ / 4 at the fast axis A H of the quarter-wave plate 121, and passes through the transmission axis A T of the linear polarizing plate 120 while remaining linearly polarized.

[0023] Also, as shown in FIG. 3B, the circular polarizing plate 12 is formed as a left circular polarizing plate 12 T by tilting the fast axis A <00,00011>of the quarter-wave plate 121 clockwise by -45 degrees with respect to the transmission axis A L of the linear polarizing plate 120. For the left circular polarizing plate 12 L The light incident on the left circular polarizing plate 12 from the side of the linear polarizing plate 120 becomes linearly polarized light vibrating in a certain direction by passing through the transmission axis A T of the linear polarizing plate 120, and further becomes left circularly polarized light by being given a phase difference of λ / 4 at the fast axis A H of the quarter-wave plate 121. Also, for the left circular polarizing plate 12 L The left circularly polarized light incident on the left circular polarizing plate 12 from the side of the quarter-wave plate 121 becomes linearly polarized light by being given a phase difference of λ / 4 at the fast axis A H of the quarter-wave plate 121, and passes through the transmission axis A T of the linear polarizing plate 120 while remaining linearly polarized. With the configuration described above, the three-dimensional video display device 1 can block unnecessary reflected light reflected by the lens array 11. The principle of blocking this reflected light will be described below.

[0024] <Principle of blocking reflected light in a three-dimensional video display device> Referring to FIGS. 4A and 4B, the principle of blocking reflected light in the three-dimensional video display device 1 will be described. Hereinafter, an example using the right circular polarizing plate 12 R (FIG. 3A) will be described.

[0025] <00,00198> First, referring to Figure 4A, we will explain the principle of blocking the light rays of the elemental image group reflected by the lens array 11. In the case where the element image group display unit 10 is a typical liquid crystal display, organic EL display, etc., the light rays emitted from each pixel of the displayed element image are divergent light. For the sake of simplicity, only one light ray traveling perpendicular to the plane from the element image group display unit 10 is shown in this diagram.

[0026] Furthermore, the light rays displayed by the element image group display unit 10 may be linearly polarized, circularly polarized, randomly polarized, etc., depending on the specifications. For the sake of simplicity, here we will assume that the light rays displayed by the element image group display unit 10 are linearly polarized in the same direction as the transmission axis of the linear polarizer 120 that constitutes the circular polarizer 12A.

[0027] The element image group display unit 10 illuminates the circular polarizer 12A with the linearly polarized light ray P1, which is the light ray of the element image group. Then, the circular polarizer 12A converts the linearly polarized light P1 ray irradiated from the element image group display unit 10 into a right circularly polarized light P2 ray, and irradiates the circular polarizer 12B via the lens array 11.

[0028] At this time, a portion of the right-circularly polarized light P2 is reflected towards the circular polarizer 12A by Fresnel reflection from both the incident and exit surfaces of the lens array 11, becoming the reflected light of left-circularly polarized light P3. The reflectivity of the lens array 11 depends on the material, but for example, if the lens array 11 is made of a transparent resin such as acrylic, it is about 4% on one side. Since this reflected light is left-circularly polarized light P3, it is blocked by the circular polarizer 12A of the right-circular polarizer.

[0029] Then, the circular polarizer 12B converts the right-circularly polarized light P2 ray irradiated through the lens array 11 into a linearly polarized light ray P4. As a result, observer M perceives the three-dimensional image as a linearly polarized P4 ray. In this way, the three-dimensional image display device 1 can prevent the generation of multiple reflected light between the element image group display unit 10 and the lens array 11 by blocking the light rays that would otherwise be reflected towards the element image group display unit 10 with the lens array 11.

[0030] Next, with reference to Figure 4B, the principle of blocking ambient light reflected by the lens array 11 will be explained. The circular polarizer 12B is illuminated with randomly polarized ambient light P5 from the outside. Here, the circular polarizer 12B converts the randomly polarized light P5 into right-circularly polarized light P6. At this time, the circular polarizer 12B can attenuate the brightness of the ambient light to half.

[0031] Then, the circular polarizer 12B irradiates the circular polarizer 12A with the converted right-circularly polarized light P6 ray via the lens array 11. At this time, a portion of the right-circularly polarized light P6 is reflected by Fresnel reflection towards the circular polarizer 12B on both the incident and exit surfaces of the lens array 11, becoming left-circularly polarized light P7. As explained in Figure 4A, the reflectivity of the lens array 11 depends on the material, but for example, if the lens array 11 is made of a transparent resin such as acrylic, it is about 4% on one side. Since this reflected light is left-circularly polarized P7, it is blocked by the circular polarizer 12B of the right-circular polarizer. The circular polarizer 12A converts the right-circularly polarized light P6 irradiated through the lens array 11 into linearly polarized light P8 and irradiates the element image group display unit 10 with it.

[0032] The degree to which light rays of a certain brightness are reflected by the surface of the element image group display unit 10 depends on the design specifications. For example, if the element image group display unit 10 is a liquid crystal display or an organic EL display, generally about 4% of the light rays are reflected from one side of the glass substrate attached to the display surface, and about 8% from both sides. Also, if an anti-reflective coating is attached to the glass substrate, the reflectivity depends on the thickness and material of the anti-reflective coating, and is generally about 0.1% to 2% on one side.

[0033] Thus, even when reflected from the surface of the element image group display unit 10, the brightness of this reflected light is attenuated to half by the circular polarizer 12B, and the lens array 11 acts as a diffuser, averaging out the brightness distribution. Therefore, the three-dimensional image display device 1 can minimize the impact on the display quality of the three-dimensional image even if reflected light is present on the surface of the element image group display unit 10.

[0034] The principle by which the three-dimensional image display device 1 blocks reflected light using only light rays traveling perpendicular to the surface has been explained above with reference to Figures 4A and 4B. However, reflected light can be similarly blocked for light rays at other angles as well.

[0035] Furthermore, if the light emitted by the element image group display unit 10, as explained in Figure 4A, is not linearly polarized but circularly polarized or randomly polarized, the brightness of the light rays will be attenuated by half by the circular polarizer 12A, and the brightness of the displayed three-dimensional image will be halved. Therefore, if you want to display a bright three-dimensional image, you should use a display device that emits linearly polarized light, such as a liquid crystal display, in the element image group display unit 10.

[0036] As explained above, the three-dimensional image display device 1 can block reflected light (unwanted light) reflected from both sides of the lens array 11 and display integral-type three-dimensional images with high display quality. Furthermore, since the three-dimensional image display device 1 is configured to have circular polarizing plates 12, which can be realized with polarizing filters, on the front and back sides of the lens array 11, it is possible to block reflected light with a simple configuration without changing the thickness almost compared to conventional integral-type three-dimensional image display devices.

[0037] ≪Second Embodiment≫ <Configuration of a 3D video display device> Next, with reference to Figures 1 and 5, the configuration of the three-dimensional image display device 1B according to the second embodiment of the present invention will be described.

[0038] The three-dimensional image display device 1B, like the three-dimensional image display device 1, displays a three-dimensional image T using the integral method. The three-dimensional image display device 1 blocked reflected light generated on both sides of the lens array 11. The three-dimensional image display device 1B blocked not only reflected light generated on both sides of the lens array 11, but also stray light generated at the boundaries (lens boundaries) between the lenses (element lenses 110) of the lens array 11.

[0039] Now, with reference to Figure 6, we will explain the stray light that occurs at the boundaries between the lenses of the lens array 11. For the sake of simplicity, Figure 6 shows an example where parallel light is incident on the lens array 11. As shown in Figure 6, when parallel light is incident on the lens array 11, the incident light is focused at the focal length f of each element lens 110, as shown by the dotted line, and then diverges to become refracted light Lr.

[0040] On the other hand, when parallel light is incident on the boundary between the element lenses 110 of the lens array 11, the incident light does not refract but becomes stray light Ls that travels in a straight line or diffuses. This stray light Ls does not contribute to the reproduction of three-dimensional images and is superimposed on the three-dimensional image as unwanted light, thus causing a decrease in the display quality of the three-dimensional image. Returning to Figure 5, we will continue our explanation of the configuration of the three-dimensional image display device 1B.

[0041] The three-dimensional image display device 1B comprises an element image group display unit 10, a lens array 11, and circular polarizing plates 12 (12A, 12C) arranged in front of and behind the lens array 11. The configuration of the three-dimensional image display device 1B differs from that of the three-dimensional image display device 1 only in that it includes a circular polarizing plate 12C on either the front or back of the lens array 11, in which a right circular polarizing plate and a left circular polarizing plate are patterned. The element image group display unit 10, the circular polarizer 12A, and the lens array 11 are the same as those described in Figure 2 for the three-dimensional image display device 1, so their description is omitted. Here, the circular polarizer 12A is a right-handed circular polarizer.

[0042] The distance between the element image group display unit 10 and the circular polarizer 12A, and the distance between the circular polarizer 12A and the lens array 11 can be any distance. However, in order to display an integral three-dimensional image T, the element image group display unit 10 and the lens array 11 must be spaced apart and not in close proximity. Furthermore, it is desirable that the lens array 11 and the circular polarizer 12C be placed in close proximity so that the light rays reflected by the lens array 11 towards the circular polarizer 12C illuminate the desired right-circular polarizer or left-circular polarizer.

[0043] The circular polarizer (patterned circular polarizer) 12C is a circular polarizer (patterned circular polarizer) in which a left circular polarizer is formed in the region facing the lens boundary region of the lens array 11, and right circular polarizers are formed in the regions facing the other element lenses. If a left circular polarizer is used for the circular polarizer 12A, then the circular polarizer 12C will be a circular polarizer in which a right circular polarizer is formed in the region facing the lens boundary region of the lens array 11, and left circular polarizers are formed in the regions facing the other element lenses. The circular polarizer 12C can be constructed by superimposing a linear polarizer 120 and a quarter-wave plate 121B.

[0044] The linear polarizer 120 has the same configuration as the circular polarizer 12B described in Figure 2. The quarter-wave plate 121B is a wave plate in which the high-speed axis and low-speed axis for giving a phase difference to the incident light are formed in different directions in the region that becomes a right-circular polarizer and the region that becomes a left-circular polarizer. For example, the quarter-wave plate 121B can be formed by patterning in which the high-speed axis is tilted at +45 degrees or -45 degrees relative to the transmission axis of the linear polarizer 120, for each region that becomes a right-circular polarizer and the region that becomes a left-circular polarizer (see Figures 3A and 3B). As a result, the circular polarizer 12C becomes a patterned circular polarizer in which a right circular polarizer and a left circular polarizer are formed in a pattern.

[0045] The pattern of this circular polarizer 12C corresponds to the arrangement pattern of the element lenses 110 of the lens array 11. For example, if the element lenses 110 of the lens array 11 are arranged in a square grid, the circular polarizer 12C will, as shown in Figure 7A, polarize the region including the lens boundary B as the left circular polarizer 12 L And in the other region, the region corresponding to the element lens 110 is the right circular polarizer 12 R Let's assume that. Furthermore, for example, if the element lenses 110 of the lens array 11 are arranged in a honeycomb pattern, the circular polarizer 12C will, as shown in Figure 7B, polarize the region including the lens boundary B as the left circular polarizer 12 L In the remaining region, the hexagonal region corresponding to the element lens 110 is the right circular polarizer 12 R Let's assume that.

[0046] Furthermore, as shown in Figure 8A, the circular polarizer 12C is a general linear polarizer 120 and the right circular polarizer 12 R The region and the left circular polarizer 12 L It is composed of a quarter-wave plate 121B that has been patterned by separating it from the region that will be used, and However, as shown in Figure 8B, the circular polarizer 12C is a combination of a general quarter-wave plate 121 and a right-hand circular polarizer 12 R The region and the left circular polarizer 12 L It may also be composed of a linear polarizing plate 120B formed by separating the region into a right circular polarizing plate 12. R The region and the left circular polarizer 12 L In this region, the transmission axis can be formed by patterning that differs between the horizontal and vertical directions.

[0047] Furthermore, in this case, the three-dimensional image display device 1B is configured by replacing the circular polarizing plate 12B of the three-dimensional image display device 1 with a circular polarizing plate 12C, which is a patterned circular polarizing plate. However, the three-dimensional image display device 1B may be configured by replacing the circular polarizer 12A of the three-dimensional image display device 1 with a circular polarizer 12C, which is a patterned circular polarizer. In that case, the circular polarizer 12C shall be positioned with the quarter-wave plate 121 (121B) facing the lens array 11. With the configuration described above, the three-dimensional image display device 1B can block unwanted reflected light reflected by the lens array 11, as well as stray light generated at the boundaries between the lenses of the lens array 11. The principle of blocking this reflected light and stray light will be explained below.

[0048] <Principles of blocking reflected and stray light in three-dimensional image display devices> Referring to Figures 9A and 9B, the principle of blocking reflected light and stray light in the three-dimensional image display device 1B will be explained below. R Using (Figure 3A), the circular polarizer 12C is configured as a patterned circular polarizer with the right circular polarizer 12 in the region corresponding to the element lens. R , left circular polarizer 12 in the region of the lens boundary L Let's explain using an example.

[0049] First, with reference to Figure 9A, the principle of blocking the light rays of the elemental image group reflected by the lens array 11 will be explained. For the sake of simplicity, only two rays of light traveling perpendicular to the plane from the element image group display unit 10 are shown in this diagram.

[0050] Furthermore, the light rays displayed by the element image group display unit 10 are linearly polarized in the same direction as the transmission axis of the linear polarizer 120 that constitutes the circular polarizer 12A. The upper linearly polarized light ray P1 traveling perpendicular to the plane from the element image group display unit 10 is defined as a light ray that passes through the center of the lens of the lens array 11. Furthermore, the lower linearly polarized light ray P10 traveling perpendicular to the plane from the element image group display unit 10 is defined as a light ray that passes through the boundary between the lenses of the lens array 11.

[0051] The element image group display unit 10 illuminates the circular polarizer 12A with the linearly polarized light ray P1, which is the light ray of the element image group. Then, the circular polarizer 12A converts the linearly polarized light P1 emitted from the element image group display unit 10 into a right circularly polarized light P2, and illuminates the circular polarizer 12C via the lens array 11.

[0052] At this time, a portion of the right-circularly polarized light P2 rays on the surface of the lens array 11 are reflected as left-circularly polarized light P3 due to Fresnel reflection. Since this reflected light is left-circularly polarized light P3, it is blocked by the right-circular polarizer 12A. Then, the circular polarizer 12C receives the right circular polarized light P2 ray irradiated through the lens array 11, and the right circular polarizer 12 R This converts it into a linearly polarized P4 ray. As a result, observer M perceives the three-dimensional image as a linearly polarized P4 ray.

[0053] In this way, the three-dimensional image display device 1B can prevent the generation of multiple reflected light between the element image group display unit 10 and the lens array 11 by blocking the light rays of the element image group that are reflected towards the element image group display unit 10 with the lens array 11.

[0054] Furthermore, the element image group display unit 10 illuminates the circular polarizer 12A with linearly polarized light rays P10, which are light rays of the element image group. Then, the circular polarizer 12A converts the linearly polarized light P10 ray irradiated from the element image group display unit 10 into a right circularly polarized light P11 ray, which passes through the lens boundary of the lens array 11 and irradiates the circular polarizer 12C.

[0055] At this time, at the boundary of the lenses in the lens array 11, a portion of the right-circularly polarized light P11 is reflected as left-circularly polarized light P12 by Fresnel reflection. Since this reflected light is left-circularly polarized light P12, it is blocked by the circular polarizer 12A of the right-circular polarizer. Then, the circular polarizer 12C receives the right circular polarized light P11 that has been irradiated through the boundary of the lenses of the lens array 11, and the left circular polarizer 12 L It is blocked by this.

[0056] In this way, the three-dimensional image display device 1B can prevent the generation of multiple reflected light between the element image group display unit 10 and the lens array 11 by blocking the light rays of the element image group that are reflected towards the element image group display unit 10 with the lens array 11. Furthermore, the three-dimensional image display device 1B can block stray light from the elemental image group that passes through the boundaries of the lenses of the lens array 11.

[0057] Next, with reference to Figure 9B, the principle of blocking ambient light reflected by the lens array 11 will be explained. For simplicity, only two rays of light are shown in this diagram for ambient light. The upper randomly polarized light ray P5 incident as ambient light is defined as a ray that passes through the center of the lens in the lens array 11. The lower randomly polarized light ray P13 incident as ambient light is defined as a ray that passes through the boundary between the lenses in the lens array 11.

[0058] The circular polarizer 12C filters randomly polarized P5 ambient light from the outside into the right circular polarizer 12 R It is irradiated. Here, the circular polarizer 12C is the right circular polarizer 12 R This converts randomly polarized light P5 into right-circularly polarized light P6. At this time, the circular polarizer 12C can reduce the brightness of ambient light by half. Then, the circular polarizer 12C irradiates the circular polarizer 12A with the converted right-circularly polarized P6 light ray via the lens array 11.

[0059] At this time, a portion of the light rays of right-circularly polarized P6 on the surface of the lens array 11 are reflected as left-circularly polarized P7 light by Fresnel reflection. Since this reflected light is left-circularly polarized P7, the right-circularly polarized plate 12C R It will be blocked by this. The circular polarizer 12A converts the right-circularly polarized light P6 irradiated through the lens array 11 into linearly polarized light P8 and irradiates the element image group display unit 10 with it.

[0060] Even if ambient light is reflected from the surface of the element image group display unit 10, the brightness of this reflected light is attenuated to half by the circular polarizer 12C, and the lens array 11 acts as a diffuser, averaging out the brightness distribution. Therefore, the three-dimensional image display device 1B can minimize the impact on the display quality of the three-dimensional image even if reflected light is present on the surface of the element image group display unit 10.

[0061] Furthermore, the circular polarizer 12C receives randomly polarized P13 ambient light from the outside, and the left circular polarizer 12 L It is irradiated. Here, the circular polarizer 12C is the left circular polarizer 12 L This converts randomly polarized P13 light into left-circularly polarized P14 light. Then, the circular polarizer 12C irradiates the converted left circular polarized light P14 onto the circular polarizer 12A from the boundary between the lenses of the lens array 11.

[0062] At this time, at the boundary of the lenses of the lens array 11, a portion of the light rays of left circularly polarized P14 are reflected as right circularly polarized P15 by Fresnel reflection. Since this reflected light is right circularly polarized P15, the left circular polarizer 12 of the circular polarizer 12C L It will be blocked by this. Then, the circular polarizer 12A blocks the left circular polarized light P14 that is irradiated through the boundary of the lenses of the lens array 11 by the circular polarizer 12A of the right circular polarizer. This allows the three-dimensional image display device 1B to block stray light from the ambient light that is reflected at the boundaries of the lenses in the lens array 11.

[0063] ≪Third Embodiment≫ <Configuration of a 3D video display device> Next, with reference to Figures 1 and 10, the configuration of the three-dimensional image display device 1C according to the third embodiment of the present invention will be described.

[0064] The three-dimensional image display device 1C, like the three-dimensional image display device 1, displays a three-dimensional image T using the integral method. The three-dimensional image display device 1C comprises an element image group display unit 10B, a lens array 11, and circular polarizing plates 12 (12A, 12B) arranged in front of and behind the lens array 11.

[0065] The element image group display unit 10B displays an integral-type element image group and is composed of a liquid crystal display. The element image group display unit 10B includes a backlight 100, a linear polarizing plate 101, and a liquid crystal panel 102.

[0066] The backlight 100 is a surface light source that illuminates the LCD panel 102 from behind. The linear polarizer 101 is a polarizer having a transmission axis that aligns the vibration direction of incident light in a specific direction. The linear polarizing plate 101 converts randomly polarized light emitted from the backlight 100 into linearly polarized light and irradiates the liquid crystal panel 102 with it.

[0067] The liquid crystal panel 102 includes a color filter substrate, a liquid crystal layer, an array substrate, etc. (not shown), and in the liquid crystal layer, the orientation of the molecules is changed by applying a voltage, thereby transmitting or blocking light on a sub-pixel basis. Here, the liquid crystal panel 102 displays a group of elemental images by external voltage control, and the light rays from the elemental image group are shone onto the circular polarizer 12A.

[0068] The lens array 11 and circular polarizers 12 (12A, 12B) have the same configuration as the three-dimensional image display device 1 described in Figure 2, so their description is omitted. However, the transmission axis of the circular polarizer 12A that transmits light rays from the linear polarizer 120 is tilted to be perpendicular to the transmission axis of the linear polarizer 101.

[0069] In a typical liquid crystal display, linear polarizers with transmission axes perpendicular to the light incident and exit surfaces of the liquid crystal panel are placed on either side. Here, the element image group display unit 10B shares the linear polarizer on the light-emitting side of the liquid crystal panel 102 with the linear polarizer 120 of the circular polarizer 12A. In this example, the liquid crystal panel 102 of the element image group display unit 10B and the circular polarizer 12A are spaced apart, but they may be placed close together. As a result, the three-dimensional image display device 1C can reduce the number of linear polarizing plates by one compared to when a general liquid crystal display is used as the elemental image group display unit, and can suppress the decrease in brightness of the three-dimensional image T due to transmission through the linear polarizing plates.

[0070] Furthermore, similar to the three-dimensional image display device 1 (Figure 2), the three-dimensional image display device 1C can block reflected light (unwanted light) reflected from both sides of the lens array 11, enabling it to display high-quality integral-type three-dimensional images.

[0071] In this three-dimensional image display device 1C, either the circular polarizer 12A or 12B may be the circular polarizer (patterned circular polarizer) 12C described in Figure 5. Furthermore, in order to display an integral three-dimensional image T, the element image group display unit 10B and the lens array 11 must be positioned at a distance from each other, not in close proximity. For example, the distance between the element image group display unit 10B and the lens array 11 should be the focal length of the lens array 11. Therefore, when the circular polarizer 12A is to be in close contact with the element image group display unit 10B, it is desirable to use a circular polarizer (pattern circular polarizer) 12C instead of the circular polarizer 12B, and to configure the lens array 11 and the circular polarizer 12C to be in close contact. This allows the light rays reflected by the lens array 11 towards the circular polarizer 12C to be directed onto the desired right-hand or left-hand circular polarizer.

[0072] In this way, by making either the circular polarizer 12A or 12B of the three-dimensional image display device 1C a circular polarizer (patterned circular polarizer) 12C, the three-dimensional image display device 1C can block stray light generated at the boundaries between the lenses of the lens array 11, just like the three-dimensional image display device 1B.

[0073] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Here, the circular polarizers 12A and 12B, positioned before and after the lens array 11, are designated as right-hand circular polarizers. Furthermore, a patterned circular polarizer is created in which the region corresponding to the element lens of the circular polarizer 12C is designated as a right-hand circular polarizer, and the region corresponding to the lens boundary is designated as a left-hand circular polarizer.

[0074] However, both circular polarizers 12A and 12B may be left-hand circular polarizers. Also, if both circular polarizers 12A and 12B are left-hand circular polarizers, and one of them is designated as circular polarizer 12C of the patterned circular polarizer, then the region corresponding to the element lens may be designated as a left-hand circular polarizer, and the region corresponding to the lens boundary may be designated as a right-hand circular polarizer. Thus, even if the right-circular polarizer and the left-circular polarizer are replaced, only the polarization direction is different, and the operation and effect are the same as those of the three-dimensional image display devices 1, 1B, and 1C according to the embodiment of the present invention. [Explanation of Symbols]

[0075] 1,1B,1C Three-dimensional image display device 10,10B Element image group display section 100 Backlight 101 Linear polarizing plate 102 LCD panel 11 Lens Array 110-element lens 12A Circular Polarizer (First Circular Polarizer) 12B Circular Polarizer (Second Circular Polarizer) 12C Circular Polarizing Plate (Pattern Circular Polarizing Plate) 120 Linear polarizing plate 121 1 / 4 wave plate

Claims

1. An integral type three-dimensional image display device, An element image group display unit that displays an element image group in which the integral-type element images are arranged in a two-dimensional array, A first circular polarizer is positioned on the display surface side of the element image group display unit and converts the light rays of the element image group into circularly polarized light rays, A lens array is provided, which is arranged on the light emission side of the first circular polarizer, with element lenses arranged in a two-dimensional array facing the display position of the element image, The lens array comprises a second circular polarizer positioned on the light-emitting side of the lens array, which converts circularly polarized light rays emitted from the lens array into linearly polarized light rays, The first circular polarizer and the second circular polarizer have the same direction of rotation of circular polarization, and each is composed of a quarter-wave plate and a linear polarizer, in order from the one closest to the lens array. A three-dimensional image display device characterized in that either the first circular polarizer or the second circular polarizer is a patterned circular polarizer composed of circular polarizers in which the rotation direction of circular polarization in the region opposite to the lens boundary region of the element lenses constituting the lens array is opposite to that of the region opposite to the element lenses.

2. The three-dimensional image display device according to claim 1, characterized in that the patterned circular polarizer is patterned such that the high-speed axis of the quarter-wave plate differs from the transmission axis of the linear polarizer by +45 degrees and -45 degrees, corresponding to the rotation direction of the circular polarization.

3. The three-dimensional image display device according to claim 1, characterized in that the patterned circular polarizer is patterned such that the transmission axis of the linear polarizer is different in the horizontal and vertical directions, corresponding to the rotation direction of the circular polarization.

4. The aforementioned element image group display unit is a liquid crystal display, The three-dimensional image display device according to claim 1, characterized in that the linear polarizing plates provided on the light incident surface and the light exit surface of the liquid crystal panel of the liquid crystal display are shared with the linear polarizing plate of the first circular polarizing plate on the exit surface side.

Images