JP2008083411A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display in which an image can be simultaneously observed by transmitting the light on the back and the texture of a display can be improved. <P>SOLUTION: A pair of polarizing plates 14, 16 are disposed on the front and the back of a liquid crystal cell 12 and further, a light transmission plate 18 is disposed on the back side of the light transmission plate 14 on the back side. A plate-like transparent spacer 24 is interposed in order to open the prescribed spacing between the polarizing plate 14 on the back side and the liquid crystal cell 12, and the light transmission plate 18 is comprised of a diffusion section 20 and a transmission section 22. The image is observed by the light from the diffusion section 20 and the background can be observed by the light from the transmission section 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device capable of displaying a two-dimensional image or a three-dimensional image.

  Currently, various three-dimensional image display devices have been proposed in order to increase the presence of image display. A three-dimensional image display device using a backlight has been proposed (see, for example, Patent Document 1). A three-dimensional image display device using a combination of a light beam control element and an image element array has also been proposed (see, for example, Patent Document 2).

  In the conventional three-dimensional image display device, the two-dimensional image display device such as a liquid crystal display device has been devised to give the image a sense of reality. However, in conventional displays, there are frames around the screen, and backgrounds and objects in the real space are visible around them, so the difference between what is displayed on the screen and the background and objects in the real space. There were times when I couldn't feel a sense of reality. This is called a frame effect. In addition, if the background and objects in the real space can be observed together, it can be observed while comparing with the display image, and the sense of reality can be increased. This is called mixed reality.

  In other words, if a transparent and transparent display can be performed on the 3D image display device, the frame effect can be reduced, and mixed reality can be obtained, resulting in increased floating, realism, and 3D image. A feeling can be heightened.

Further, even in a normal two-dimensional image display device, a sense of reality can be increased even without a three-dimensional image feeling by obtaining a mixed reality with a background and an object in real space with transparency.
Japanese Patent No. 3425572 JP 2004-40722 A

  Therefore, the present invention provides a liquid crystal display device that can be observed simultaneously with an image by transmitting light on the back surface of the two-dimensional image display device or the three-dimensional image display device, and can improve the display texture.

  The present invention includes a liquid crystal cell, a polarizing plate disposed on the front side of the liquid crystal cell, a light guide plate disposed on the back side of the liquid crystal cell, a polarizing plate disposed on the back side of the liquid crystal cell, or In the liquid crystal display device having a plurality of deflectors, the light guide plate is composed of a plurality of transmission portions that transmit light from the back side of the light guide plate, and a plurality of diffusion portions that diffuse light, The transmissive part and the diffusing part are alternately formed along at least one direction, displaying a background on the back side of the light guide plate by light from each transmissive part, and by the light from each diffusing part The liquid crystal display device displays an image of a liquid crystal cell.

  According to the present invention, it is possible to observe the image at the same time by transmitting the light on the back surface of the liquid crystal display device, and to give a sense of unity between the background and the display.

(Principle with transparent background)
Before explaining the liquid crystal display device according to the embodiment of the present invention, the principle of the present embodiment through which the background can be seen will be described with reference to FIG.

  When a human observes an object, even if it is partially displayed, it can be recognized by interpolating with the brain.

  FIG. 1 shows an example in which a perspective view of a cube is partially displayed. Although the cube can be observed in a lattice shape, the outline of the cube is difficult to feel as a broken line. When two objects are presented, the human selectively recognizes one or both of the brightness, the presence / absence of movement, the presence / absence of texture, and the like.

  Therefore, in this embodiment, by forming transmissive portions on the light guide plate of the liquid crystal display device, the background behind the liquid crystal display device can be seen through these transmissive portions, and images are observed in other portions. Provide what you can see through the background.

  In the following description, the liquid crystal display device in which the background of the present embodiment can be seen through is referred to as “transparent liquid crystal display device”, and the conventional liquid crystal display device in which the background cannot be seen through is referred to as “transparent liquid crystal display device”.

  Hereinafter, in the first to third embodiments, the liquid crystal display device 10 through which two-dimensional image display is transparent will be described. In the fourth and fifth embodiments, the liquid crystal display device 10 through which three-dimensional image display (stereoscopic display) is transparent will be described.

(Embodiment 1)
A liquid crystal display device 10 through which a two-dimensional image display of Embodiment 1 of the present invention is transparent will be described with reference to FIG. FIG. 2 is a longitudinal sectional view of the transparent liquid crystal display device 10 according to the first embodiment.

(1) Configuration of Transparent Liquid Crystal Display Device 10 The transparent liquid crystal display device 10 includes a pair of polarizing plates 14 and 16 disposed on the front and back surfaces of a liquid crystal cell 12, and a light guide plate 18 on the back side of the polarizing plate 14 on the back side. Is arranged. A plate-like transparent spacer 24 is interposed between the back-side polarizing plate 14 and the liquid crystal cell 12 so as to provide a predetermined interval. Note that an image is displayed on the liquid crystal cell 12 as in the conventional case, and in FIG. 2, the image is observed from below the transparent liquid crystal display device 10.

  The light guide plate 18 includes a diffusion part 20 and a transmission part 22. Specifically, the diffusing portions 20 are formed at arbitrary intervals in the plate-like light transmitting portion 22.

  The light from the light source is reflected at the interface of the light guide plate 18 and is irradiated only from the diffusion portion 20, passes through the polarizing plate 14 on the back side, the spacer 24, the liquid crystal cell 12, and the polarizing plate 16 on the front side, Observed from the human eye. That is, when an image is displayed by switching the polarization state of the liquid crystal in the liquid crystal cell 12, it is observed by the light from the diffusion unit 20. However, in these diffusers 20, the background light diffuses and the background cannot be seen like ground glass. On the other hand, the transmissive part 22 can be observed as it is because the background light is transmitted.

(2) Effect Thereby, the image displayed on the liquid crystal cell 12 and the background can be observed simultaneously. That is, when the background light is transmitted, the viewer can feel as if the light is floating in the real space. FIG. 3 shows an example applied to a mobile display terminal. You can observe the displayed cube image and your hand in the background at the same time. Since the transmitted real space and the image can be observed at the same time, a cube can pop out and be displayed in the hand, and an effect of increasing the sense of reality can be obtained.

  FIG. 4 is a diagram illustrating what appears to be transparent. When a part of FIG. 3 is enlarged, display portions and transmission portions are alternately formed. Since the display portion includes the diffusing portion 20 of the light guide plate 18 and the polarizing plate 16, the light from the light source is supplied and the polarization state is in order, so that the liquid crystal cell 12 can be switched and displayed. However, the background is diffused and cannot be observed. Since the transmissive part 22 does not have the diffusing part 20 of the light guide plate 18, light from the light source is not supplied, and what is displayed cannot be observed, and the background can be seen through. As a whole, there are a display portion and a transmission portion alternately at fine intervals, and the displayed image and the background can be seen at the same time.

(Modification of Embodiment 1)
A liquid crystal display device 10 with a transparent two-dimensional image display according to a modification of the first embodiment will be described.

  In the transparent liquid crystal display device 10 according to the first embodiment, the light in the background portion is also affected by the displayed image because the polarization state is aligned by the polarizing plate 14 on the back surface.

  Therefore, as a method for displaying an image in the liquid crystal cell 12, the background can be more easily seen by increasing the transmittance of a portion other than the object to be displayed.

(Embodiment 2)
A liquid crystal display device 10 through which a two-dimensional image is displayed according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view of the transparent liquid crystal display device 10 according to the second embodiment.

  The difference between this embodiment and Embodiment 1 is that a spacer 24 having a deflector 26 is provided instead of the polarizing plate 14 and the spacer 24 on the back surface side. In the spacer 24 of the present embodiment, polarizers 26 are arranged at the same interval as the diffusion portion 20 of the light guide plate 18.

  As a result, the background light transmitted through the transparent portion of the spacer 24 is not easily affected by the liquid crystal cell 12 and the transmittance is also increased. Since the light of the diffusing unit 20 that displays an image has the polarizer 26, the polarization state is uniform, and the image can be displayed according to the state of the liquid crystal cell 12.

(Modification 1 of Embodiment 2)
A liquid crystal display device 10 that can display a two-dimensional image according to the first modification of the second embodiment will be described with reference to FIG. FIG. 6 is a longitudinal sectional view of the transparent liquid crystal display device 10 according to the first modification of the second embodiment.

  In the transparent liquid crystal display device 10 of this modification, the color filter 28 is inserted between the liquid crystal cell 12 and the polarizing plate 16 on the surface side in the transparent liquid crystal display device 10 of the second embodiment. Thereby, the image can be colored.

  Even when the color filter 28 is inserted, the light in the transparent portion is selectively transmitted from the color filter 28, so that a portion of the light is colored, and the whole can be observed without a sense of incongruity.

  The pattern of the light guide plate 18 will be described with reference to FIGS.

  Various patterns can be considered for the diffusing section 20 of the light guide plate 18 that make it difficult to perceive color moire depending on the arrangement of the color filter 28 and the resolution characteristics to be displayed.

  First, as shown in FIG. 7, a linear transmission part 22 and a diffusion part 20 are arranged in the vertical direction like a vertical grid, and the same color as the color filter 28 is arranged in the vertical direction. If it exists, it will become easy to observe the image (color moire) of the same color selectively. Therefore, it is desirable that the pattern of the color filter 28 and the pattern of the diffusion portion 20 of the light guide plate 18 are different.

  Therefore, in FIGS. 8 and 9, the linear transmission portions 22 and the diffusion portions 20 are alternately arranged in an oblique direction like an oblique lattice, and the same color of the color filter 28 is arranged in the oblique direction. This makes it difficult to observe color moire. The vertical direction refers to the vertical direction of the screen, and the horizontal direction refers to the horizontal direction of the screen.

  Moreover, the space | interval of the spreading | diffusion part 20 is greatly related to the observation position and the feeling of depth at the time of the three-dimensional image display mentioned later. That is, when the repeating component of the transmission unit 22 and the diffusion unit 20 is strongly provided in the horizontal direction, those having a small inclination as shown in FIGS. 7, 8, and 9 have a strong parallax in the horizontal direction. Therefore, a person with eyes on the left and right can obtain a three-dimensional image feeling with only the parallax in the horizontal direction.

  As shown in FIG. 10, when the circular diffusing portion 20 is formed in the vertical direction in the form of dots in the planar transmission portion 22, it has alternating repetitive components in the vertical direction and parallax is obtained in the vertical direction.

(Modification 2 of Embodiment 2)
A liquid crystal display device 10 having a transparent two-dimensional image display according to the second modification of the second embodiment will be described with reference to FIG. FIG. 11 is a longitudinal sectional view of the transparent liquid crystal display device 10 according to the second modification of the second embodiment.

  In this modified example, color expression is performed in a time division manner as shown in FIG. The color filter 28 of the first modification is removed, the color of the light source is changed with time, and the pixel value corresponding to the color is displayed on the liquid crystal cell 12.

  An LED 30 is used as the light source. The LED 30 has a fast response speed and can express colors without flickering that humans feel. By arranging LEDs 30 of three primary colors (R: red, G: green, B: blue) on the side surface of the light guide plate 18, the color information can be expressed in a time-sharing manner by motivating the timing and color information of the pixels to be displayed.

  Thereby, there is no absorption of the color filter 28, color display can be performed, and the transmittance of the transmission part can be increased.

(Embodiment 3)
A liquid crystal display device 10 that can display a two-dimensional image according to the third embodiment will be described.

  In the present embodiment, instead of the light guide plate 18, another second liquid crystal cell 12 is disposed, and the polarization state of each pixel of the second liquid crystal cell 12 is electronically controlled, so that the diffusion unit 20 and the transmission unit are provided. 22 can be made variable.

  For example, as a characteristic of the liquid crystal, light can be diffused and transmitted depending on the voltage. By inserting the liquid crystal cell 12 having this diffusion characteristic in place of the light guide plate 18 of the first and second embodiments, the transparent liquid crystal display device 10 can be realized.

  Moreover, in this embodiment, it can also be used as a liquid crystal display device which is not transparent by making all the transmission parts 22 of this 2nd liquid crystal cell 12 into the diffusion part 20. FIG.

  In this embodiment, it is also possible to switch between a 3D image display and a 2D image display, which will be described later.

  In the present embodiment, the number of parallaxes and the parallax formation pattern in the three-dimensional image display can be made variable. By changing the number of parallaxes and the parallax formation pattern of the three-dimensional image display, it is possible to change the resolution and the pop-up amount, which are trade-offs, depending on the image and the display object. For example, in the case of content centered on characters, the pop-up is eliminated and the resolution is increased, and in the case of a game or video that gives a surprise, the pop-up can be increased even if the resolution is somewhat reduced.

  In the present embodiment, the transparent liquid crystal display device 10 can be partially changed, and the pattern can be changed only in a portion having a large depth amount (protrusion amount).

(Embodiment 4)
A liquid crystal display device 10 with a transparent three-dimensional image display according to the fourth embodiment will be described.

  The structure of the liquid crystal display device 10 through which three-dimensional image display is transparent in the present embodiment is the same as that of the first embodiment, and the light guide plate 18 shows an example in which the diffusion unit 20 shown in FIG.

(1) Description of 3D Image Display First, the principle of 3D image display will be described with reference to FIGS.

  As shown in FIG. 12, when observed at a certain observation position, the transparent image of the liquid crystal display device 10 looks like a grid as shown in the upper left of FIG. This is because, as shown on the right in FIG. 12, only the image of the liquid crystal cell 12 in a straight line connecting the eye and the diffusing portion 20 of the light guide plate 18 can be observed, and otherwise, the background becomes the transmissive portion 22 and can be observed. is there.

  As shown in FIG. 13, when the observation position is changed, the liquid crystal cell 12 in which the straight line connecting the eye, the diffusion slit, and the liquid crystal cell 12 can be observed changes, so that different images can be observed depending on the observation position.

  As shown in FIG. 14, it can also be designed so that different images are observed with the right and left eyes of the observer. Since human eyes are divided into left and right, different images are observed with the left and right eyes. If the diffusion portions 20 arranged in the vertical direction are used for the light guide plate 18, different images can be displayed in the horizontal direction depending on the observation position. A stereoscopic image can be observed if different images of the right eye and the left eye are given in the same manner as when viewing the real space, and each is an image corresponding to the parallax of the 3D object.

  FIG. 15 shows an example of displaying a stereoscopic image as a set of light rays.

  As described above, different images can be observed for the right eye and the left eye, and if a corresponding image can be displayed, a stereoscopic image is obtained. However, there is another way of displaying a 3D object of a stereoscopic image as a set of light rays.

  In this method, the light emitted from the diffusing unit 20 can be displayed with directivity in different directions of the liquid crystal cells 12. It can be considered as a light beam having each directivity, and a 3D object can be expressed by a set of the light beams. The pixel value of the 3D object may be displayed on the liquid crystal cell 12 by tracing back from the intersection of the straight line extending from the diffusion unit 20 and the 3D object to be displayed. In this way, each pixel can represent a light beam having directivity from the positional relationship between the liquid crystal cell 12 and the diffusing unit 20, and a 3D object having a depth can be represented by a set of light beams.

The directivity of each pixel is determined by the geometrical relationship between the liquid crystal cell 12 and the diffusing unit 20. The repetition rule is determined by the number of parallaxes (the directivity is the number of divisions) and the pixel pitch (the interval between the pixels of the liquid crystal cell 12). When the repetition rule is an interval obtained by multiplying the number of parallaxes and the pixel pitch, the distance between the liquid crystal cell 12 from the polarizing plate 16 and the diffusion surface can define a displayable light range. If the ray angle range is θ, equation (1) holds when the distance d from the diffusion unit 20 to the liquid crystal cell 12, _PP is the pixel pitch, and n is the number of parallaxes.

θ = 2 tan ⁻¹ (nP _P / 2d) Equation (1)

As described above, the frame effect can be reduced in the three-dimensional image display with a transparent background, and the mixed reality can be obtained, thereby increasing the floating feeling, the real feeling, and the three-dimensional image feeling, thereby further enhancing the sense of reality.

(2) Image Generation Method A method for displaying a three-dimensional image on the transparent liquid crystal display device 10 will be described.

  In the liquid crystal cell 12 of Embodiment 1, parallax image information necessary for displaying a three-dimensional image is displayed on each pixel. Then, as shown in FIG. 20, element images P <b> 1 to Pn composed of a plurality of parallax images that are slightly different depending on the viewing angle are displayed on the liquid crystal cell 12.

  Each of the element images P1 to Pn is displayed on a plurality of pixels, that is, a pixel group as an image pattern corresponding to each of the diffusion portions 20 of the light guide plate 18. Light rays emitted from a large number of patterns corresponding to the element images become light rays R emitted in front of the liquid crystal display device 10 that are transmitted through the diffusion portions 20 of the corresponding light guide plates 18. The three-dimensional real image is periodically traversed by the transmission part 22 and the diffusion part 20 by the group of element image light rays that form an image on the front surface of the light guide plate 18 having the transmission part 22 and the diffusion part 20. A three-dimensional virtual image is observed by the group of element image light rays that form an image on the back surface of the light guide plate 18 that is held. That is, an element image light beam group composed of light rays R traveling from the observer toward the pattern on the liquid crystal cell 12 through the light transmitting plate 18 having the diffusing portion 20 and the light transmitting plate 18 having the diffusing portion 20 periodically. A three-dimensional virtual image is observed, and an elemental image ray group R traveling toward the observer through a light guide plate 18 having a transmission part 22 and a diffusion part 20 periodically of pinholes or microlenses from the pattern on the liquid crystal cell 12. As a result, a three-dimensional real image is formed.

  As shown in FIG. 20, in the transparent liquid crystal display device 10, a viewing distance L serving as a reference when the element image is arranged on the liquid crystal cell 12 is determined, and a viewing zone reference plane 32 at the viewing distance L is determined. It is done. In FIG. 20, the width of the viewing zone in the horizontal direction on the viewing zone reference plane 32 is indicated by hva, and the center of the viewing zone is indicated by V0. The element image is periodically transmitted as described later so that the trajectory of the light ray R from the element image is incident on the viewing zone on the viewing zone reference plane, and in the horizontal direction, speaking within the viewing zone width hva. And the corresponding light transmission region of the light guide plate 18 having the diffusing portion 20, that is, the light diffusing portion 20 of the light guide plate 18. Here, the viewing zone is a region where only a three-dimensional positive image is observed, and corresponds to a region excluding a mixed region where a false image is observed together with a positive image as a three-dimensional image and a false image region where a false image is generated. ing. Thus, by changing the arrangement of the element images P1 to Pn corresponding to the light transmission region, that is, the center of the diffusion portion 20 of the light guide plate 18, the light guide plates 18 are emitted from the element images P1 to Pn. The total transmitted rays Rx passing through the diffusing portion 20 substantially overlap in the region at the viewing distance L, and the width hva of the viewing zone is substantially maximized. In FIG. 20, at the end of the viewing zone reference plane 32 within the viewing zone width hva, the transmitted light rays Rx are drawn so as to intersect with each other at one point. Passing through a region having a certain width. In FIG. 20, it should be noted that an area having the width of the end of the viewing zone reference plane 32 is drawn as one point on the drawing.

  Next, a method for maximizing the viewing zone width hva at the viewing distance will be described with reference to FIG. The following describes the horizontal direction, but the same method can be applied to the vertical viewing area. In FIG. 21, the left end of the screen of the liquid crystal cell 12 is set to 0, and the right side is set to a positive value.

  FIG. 21 illustrates a specific pixel group in which element images facing or substantially facing each other are arranged at the center of the viewing zone, and the liquid crystal cell 12 has a dimension determined by the illustrated parameters. In the liquid crystal cell 12, as is generally the case with existing displays, the pixels of the pixel unit having the number of horizontal pixel units (the size H) are arranged at a constant pixel pitch hp throughout the screen. Here, the pixel unit corresponds to a set of three pixels, red (R), green (G), and blue (B) pixels (sub-pixels), and this pixel pitch hp is the pixel width hp of each pixel. These pixels display a minimum unit of parallax images constituting a three-dimensional image. FIG. 21 shows a specific pixel group confronting or substantially confronting the center of the viewing zone. Therefore, the diffusing portion of the light guide plate 18 having a transparent portion and a diffusing portion 20 that are emitted from each pixel and regularly arranged repeatedly. A light beam traveling toward the viewing zone width hva at the viewing distance L via 20 passes through the center of the diffusion portion 20 of the light guide plate 18 and is symmetric with respect to the opening center axis Op perpendicular to the liquid crystal cell 12. Inject within the range of. In this way, a set of parallax images that form a group of light rays that travel toward the viewing zone width hva through the diffusion unit 20 of a certain light guide plate 18 is referred to as an element image Px, and a three-dimensional stereoscopic image is formed by the element image Px. .

  Further, the light guide plate 18 having the transmissive portions 22 and the diffusing portions 20 that are regularly and repeatedly arranged as shown in FIG. 21 has a vertically long shape that has a horizontal width equivalent to the pixel width hp of the display unit and is continuous in the vertical direction. The diffusing portion 20 of the light plate 18 is a slit plate provided with an interval (hsp) that is an integral multiple of the pixel pitch hp, and the distance hsp of the diffusing portion 20 of the light guide plate 18 is equal to the width of the element image Px. Hereinafter, for simplicity, the description will be limited to this example. In this case, the number of basic parallax images Nvs, that is, the number of pixels constituting this elemental image is represented by Nvs = hsp / hp (interval of the diffusion portion 20 of the light guide plate 18 / pixel width). That is, in the element image Px that faces or substantially faces the center of the viewing zone, the element image on the liquid crystal cell 12 is composed of parallax images having the number of basic parallax images Nvs. The distance hs from the opening center axis Op to the center of the pixel located at the outermost end of the element image Px is represented by hs = hp (Nvs−1) / 2.

  Thus, in the region facing or substantially facing the center of the viewing zone of the liquid crystal cell 12, as shown in FIG. 21, the opening center axis Op passes through the center of the element image Px, and the pixels constituting the element image Px Are arranged substantially symmetrically geometrically with respect to the opening center axis Op. In addition, as will be described later, as the distance from the element image Px facing or substantially facing the center of the viewing zone increases, the pixel groups constituting the element image on the display unit respectively correspond to the diffusion portions 20 of the corresponding light guide plate 18. It is gradually deviated from the central axis Op, and as a result, it is arranged symmetrically with respect to an orthogonal line passing through the center V0 of the viewing zone and orthogonal to the liquid crystal cell 12.

  Here, 3 · hp indicates the width of a pixel unit composed of three pixels (R, G, B pixels), and it is effective to multiply the width of the pixel unit by the total number of pixel units (the size H). A screen width H is calculated. When Nvs is a common divisor of the total number of pixels of the display unit (= 3 · the size H), the number Ns of slits from this screen width is Ns = H / hsp (screen width / diffusing portion 20 of the light guide plate 18). (Interval). Further, the gap (gap) g between the diffusion portion 20 of the light guide plate 18 and the liquid crystal cell 12 is represented by g = hs / tan θ0. θ0 can be determined from an arbitrary viewing zone and viewing zone width hva. In the present embodiment, since the light guide plate 18 is provided on the back surface side of the liquid crystal cell 12, g <0.

  In this description, in order to simplify the description, the four intervals hsp of the diffusion portions 20 (slits) of the light guide plate 18 are constant. Since the interval between the diffusing portions 20 of the light guide plate 18 is the interval between the light rays constituting the three-dimensional image, it is a natural operation to make hsp constant in order to make the resolution as the three-dimensional image constant. It can be said. Furthermore, it is assumed that the interval hsp between the diffusion portions 20 of the light guide plate 18 of the light guide plate 18 having the transmission portion 22 and the diffusion portion 20 periodically is an integral multiple of the pixel pitch hp. If the algorithm described below is used in this premise, the lines connecting the centers of the pixels constituting the parallax images and the centers of the diffusion portions 20 of the light guide plate 18 (light ray trajectories) are parallel to each other with the same parallax number. It becomes a relationship. That is, a parallax image can be formed from images that are parallel-projected from a certain direction. The vertical parallax along the vertical direction can also be given to the pixels as necessary, similarly to the horizontal parallax along the horizontal direction described here. Therefore, the description of vertical parallax is omitted here for the sake of simplicity.

The pixel center position Xp and the center position Xs of the diffusion portion 20 of the light guide plate 18 are determined by the following equations (2) and (3). The pixel center position Xp is indicated by the distance from one end (Xp = 0; FIG. 4) of the liquid crystal cell 12 to the center position of the pixel. If the pixel number vp corresponding to the first pixel is 0, When the pixel width hp is ½ (Xp = hp / 2) and the pixel number is 1, the pixel center position Xp is (1 + ½) hp. Similarly, if the pixel number is vp, the pixel center position Xp is

Xp = (vp + 1/2) xhp (2)

However, vp = 0, 1, 2,... Indicates a pixel number, and 0 ≦ vp ≦ 3 · the size H−1.

  Here, since the pixel numbers are assigned from the leftmost pixel to the rightmost pixel, the maximum pixel number vp is the total number of pixels (3 · the size H) as shown in the equation (2). No. 0 from (3 · the size H-1).

Further, the center position Xs of the diffusing portion 20 of the light guide plate 18 is arranged at equal intervals hsp from one end X0 of the liquid crystal cell 12 to the opposite end, and the number vs of the diffusing portion 20 of the light guide plate 18 is 0. If the slit width hsp is 1/2 (Xs = hsp / 2) and the number of the diffusion portion 20 of the light guide plate 18 is 1, the position Xs of the diffusion portion 20 of the light guide plate 18 is (1 + 1/2). ) Hsp. Similarly, if the number of the diffusion portion 20 of the light guide plate 18 is vs, the position Xs of the diffusion portion 20 of the light guide plate 18,

Xs = (vs + 1/2) xhsp (3)

However, it is vs = 0, 1, 2, ..., shows the number of the spreading | diffusion part 20 of the light-guide plate 18, and is 0 <= vs <= Ns-1.

  The number vs of the diffusion portion 20 of the light guide plate 18 is numbered so as to increase sequentially from the diffusion portion 20a of the light guide plate 18 adjacent to one outermost end of the light guide plate 18 to the opposite end. The number of the diffusing unit 20 is (Ns−1) number obtained by removing the number 0 from the number Ns of diffusing units 20 of the total light guide plate 18.

  Next, the viewing zone width hva at the viewing distance L will be described based on the above-mentioned assumptions and formulas (2) and (3).

  In general, in the IP system, unlike a multi-view display device, light beams carrying a parallax image are not collected at one point in the viewing zone reference plane 32. In the multi-lens system, since the points where the light rays from each parallax image are collected at the viewing distance L are generated by the number of parallax images constituting each parallax image, the region where the light rays are incident at the viewing distance L, that is, The viewing zone width is completely the same, but in the case of the IP system, the trajectory of the light beam carrying each parallax image is dispersed. In particular, as described in the present description, when the light beams carrying each parallax image are composed of parallel light, the trajectory of the parallel light rays determined from the pixel pitch hps, the slit pitch hsp, the viewing area θ0, or the gap g is substantially uniform. It can be considered that the viewing area is satisfied. Thus, when designing an IP display device, it is necessary to consider the dispersion of light rays.

(3) Repetition rule of diffusion part 20 of light guide plate 18 The repetition rule of diffusion part 20 of light guide plate 18 will be described with reference to Japanese Patent Application Laid-Open No. 2004-191570.

  As a transparent liquid crystal display device 10 for displaying a three-dimensional image, a liquid crystal display device having a horizontal parallax number of 4 and a vertical parallax number of 1 was manufactured. Here, XGA: number of pixels = 1024 × 768 was used as the liquid crystal cell 12 of the two-dimensional image. The liquid crystal cell 12 includes a color filter 28 in which vertically long colored layers of red, green, and blue are repeatedly arranged in the horizontal direction.

  The vertical and horizontal dimensions of the red, green, and blue subpixels of the liquid crystal cell 12 were 150 μm × 50 μm, and the pitch P was 150 μm.

  The mask device was fabricated by sequentially forming a chromium film and a chromium oxide film on a glass plate and patterning them. Note that the removed portions of the chromium film and the chromium oxide film correspond to the respective window portions. Here, the vertical and horizontal dimensions of the window portions are 150 μm × 75 μm, and the distance between the window portions is 200 μm.

  By setting various dimensions as described above, the number of 3D image display pixels in the vertical direction is 256 (= 768/3) and the number of horizontal arrays is 768 (= 1024 × 3/4). It was.

  Display was actually performed with the transparent liquid crystal display device 10, and the image was observed with the line connecting both eyes substantially parallel to the horizontal direction. As a result, moire did not appear and good display was possible.

(Embodiment 5)
The transparent liquid crystal display device 10 of the above embodiment can be combined to display on a plurality of display surfaces.

  This is because the display area of a single transparent liquid crystal display device 10 is limited, and the liquid crystal display device 10 is inevitably bound to a reference flat surface. When a plurality of transparent liquid crystal display devices 10 are combined, the display surface (reference surface) becomes a plurality of surfaces. When the same 3D object is displayed on the plurality of display surfaces, the 3D object can be displayed without being tied to one plane. By doing so, the effect of increasing the presence and the three-dimensional image feeling can be obtained.

  Further, as shown in FIG. 16, the liquid crystal display device 10 that is transparent and the liquid crystal display device 42 that is not transparent can be combined. In other words, the liquid crystal display device 42 that is not transparent can be combined with the transparent liquid crystal display device 10 that can display a three-dimensional image using a lenticular sheet or a parallax barrier.

  In this way, the bottom surface of the 3D object can be given, and a sense of stability can be given to the 3D object.

  Moreover, the effect which makes 3D object easy to see by making part non-transparent is also acquired. At this time, the display screens of the two transparent liquid crystal display devices 10 can be connected continuously without a gap, and observation can be performed without worrying about the seam. In some cases, the display angle can be efficiently expanded by setting the angle between the transparent liquid crystal display device 10 and the transparent liquid crystal display device 42 to about 90 degrees. That is, the display angle can be efficiently expanded by making the normal line of the display screen a right angle.

  Note that a plasma display or an organic EL display device may be used instead of the liquid crystal display device 42 that is not transparent.

(Modification 1 of Embodiment 5)
In the display when combining the screens of two liquid crystal display devices, the design observation position is specified, or the observation position is sensed with a camera or the like, and the image is deformed in advance to eliminate distortion from the viewpoint. You can also.

  FIG. 18 is a diagram for explaining distortion correction of an image to be displayed when it is desired that the liquid crystal display device 10 that is transparent to the viewpoint position is directly opposed. When an image that looks rectangular when facing directly is observed from an oblique direction, the image is distorted as shown in FIG.

  Therefore, if an inverse distortion is given to the image in advance, an image without distortion can be observed when observed obliquely. FIG. 19 is a diagram illustrating distortion correction when two screens are combined.

  When two screens are combined, it is possible to create an image that eliminates both distortions by assuming the viewpoint position for each plane and calculating the distortion from the viewpoint position on each plane. Since the display can be performed without distortion by performing the display in this way, it is possible to give a presence with little discomfort with the real object. Further, by displaying a stereoscopic image in which distortion is corrected, it is possible to further increase the sense of reality. That is, the background real object that appears to be transparent and the displayed stereoscopic image are similarly changed, and the image is observed with a sense of depth without distortion.

(Modification 2 of Embodiment 5)
FIG. 16 shows a side view of the liquid crystal display device 42 that is not transparent and the liquid crystal display device 10 that is transparent. There are two liquid crystal display devices, and the light guide plate 18 and the liquid crystal cell 12 are bonded together. As shown in FIG. 16, it is conceivable to provide a common display by providing a common light source 34 and a reflecting plate 36 for supplying light to each light guide plate 18.

  However, the transparent liquid crystal display device 10 is worse than the liquid crystal display device 42 in which light escapes from the back surface and the light efficiency is not transparent. If the light efficiency of the transparent liquid crystal display device 10 is changed using the same light source 34, the image of the liquid crystal display device 42 in which the brightness of the stereoscopic image is not transparent is different.

  Therefore, the luminance can be matched by inserting a filter 38 that absorbs light into the light intake port of the light guide plate 18 of the liquid crystal display device 42 that does not transmit this difference in light efficiency, and matching the absorption rate to the rate of change in luminance. .

(Modification 3 of Embodiment 5)
As shown in FIG. 17, the transparent liquid crystal display device 10 and the non-transparent liquid crystal display device 42 can be combined with a hinge 38 to be opened and closed.

  However, if there is a gap in the transparent liquid crystal display device 10, the display image is lost and the sense of discomfort increases. In particular, in the case of a three-dimensional image that protrudes from the transparent liquid crystal display device 10, the sense of depth of the three-dimensional image is greatly lost due to the frame effect caused by the gap.

  Therefore, the hinge 38 is made movable so as to be housed inside. In other words, in order to slide the hinge 38 inside, it is composed of a coupling lot 40 and a hinge 38 that can be accommodated, and the hinge 38 is housed inside in a rotated open state. By inserting the lower part of the liquid crystal display device 10 that is transparent after being opened, the two liquid crystal display devices can be combined with no gap.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

It is a figure explaining the principle through which the background of embodiment of this invention can be seen through. 1 is a longitudinal sectional view of a transparent liquid crystal display device according to Embodiment 1. FIG. It is a figure of the state holding the transparent liquid crystal display device in the hand. FIG. 4 is a partially enlarged view of FIG. 3. It is a longitudinal cross-sectional view of the transparent liquid crystal display device of Embodiment 2. It is a longitudinal cross-sectional view of the transparent liquid crystal display device of the modification 1 of Embodiment 3. It is a top view of the 1st example which shows the pattern of a light-guide plate. It is a top view of the 2nd example which shows the pattern of a light-guide plate. It is a top view of the 3rd example showing a pattern of a light guide plate. It is a top view of the 4th example showing a pattern of a light guide plate. It is a longitudinal cross-sectional view of the transparent liquid crystal display device of Embodiment 3. It is the 1st figure explaining that it looks solid. It is the 2nd figure explaining that it looks solid. It is a 3rd figure explaining what looks solid. It is the 4th figure explaining that it looks solid. It is a side view of the state which combined two liquid crystal display devices in Embodiment 5. It is a side view of the state which combined two liquid crystal display devices with the hinge. It is explanatory drawing in the case of correct | amending distortion in 1 screen. It is explanatory drawing in the case of correct | amending distortion in 2 screens. FIG. 10 is a first diagram illustrating an image generation method according to a fourth embodiment. It is the 2nd figure explaining an image generation method similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transparent liquid crystal display device 12 Liquid crystal cell 14 Polarizing plate 16 Polarizing plate 18 Light guide plate 20 Diffusion part 22 Transmission part 24 Spacer

Claims (17)

A liquid crystal cell;
A polarizing plate disposed on the surface side of the liquid crystal cell;
A light guide plate disposed on the back side of the liquid crystal cell;
A polarizing plate disposed on the back side of the liquid crystal cell, or a plurality of deflectors;
In a liquid crystal display device having
The light guide plate is composed of a plurality of transmission parts that transmit light from the back side of the light guide plate and a plurality of diffusion parts that diffuse light.
The transmission part and the diffusion part are alternately formed along at least one direction,
A liquid crystal display device, wherein a background on the back side of the light guide plate is displayed by light from each of the transmission parts, and an image of the liquid crystal cell is displayed by light from each of the diffusion parts. The liquid crystal display device according to claim 1, wherein the transmittance of the liquid crystal cell is increased in a range other than the object displayed on the screen of the liquid crystal cell. The liquid crystal display device according to claim 1, wherein the plurality of deflectors are arranged at the same position as the diffusion unit. The liquid crystal display device according to claim 1, wherein the diffusion portions and the transmission portions are alternately formed only in a horizontal direction. The liquid crystal display device according to claim 1, wherein the diffusion portions and the transmission portions are alternately formed in a vertical direction and a horizontal direction. The liquid crystal display device according to claim 1, wherein the liquid crystal cell further includes a color filter. The light guide plate further includes a light source that supplies light whose color tone periodically changes in a time-sharing manner,
The liquid crystal display device according to claim 1, wherein the liquid crystal cell displays pixel information corresponding to the periodically changing color tone. The light guide plate comprises a second liquid crystal cell;
The liquid crystal display device according to claim 1, wherein the transmissive portion and the diffusing portion are formed for each pixel of the second liquid crystal cell. The liquid crystal display device according to claim 1, wherein the liquid crystal cell displays a two-dimensional image. The liquid crystal display device according to claim 1, wherein the liquid crystal cell displays a three-dimensional image. The distance from the diffusion part to the liquid crystal cell corresponds to the horizontal angle of the light beam to be displayed,
The liquid crystal display device according to claim 10, wherein each pixel information of the liquid crystal cell is light ray information of a three-dimensional image corresponding to the diffusion portion and the position of the liquid crystal cell. A combination of the liquid crystal display device and at least one image display device;
The liquid crystal display device according to claim 1, wherein the same object is displayed on the display screen of the liquid crystal display device and the display screen of the image display device. The liquid crystal display device according to claim 12, wherein the display screen of the liquid crystal display device and the display screen of the image display device are continuous. The liquid crystal display device according to claim 12, wherein a normal line of the display screen of the liquid crystal display device and a normal line of the display screen of the image display device intersect at a right angle. The liquid crystal display device according to claim 12, wherein a light source of the liquid crystal display device and a light source of the image display device are common. The image display device displays only the image displayed in the liquid crystal cell;
The liquid crystal display device according to claim 15, wherein a filter is provided on a light guide plate of a liquid crystal display device that displays only an image displayed by the liquid crystal cell. The liquid crystal display device according to claim 12, wherein the liquid crystal display device and the image display device are hinge-coupled to be freely opened and closed.

Images