JP2006018282A - 3-dimensional display capable of performing vertical display or horizontal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display which a user can properly look without changing a viewpoint when direction of the display is changed. <P>SOLUTION: The display can act as a multi-view directional display in a 1st direction and can act as the multi-view directional display in a 2nd direction different from the 1st direction. For example, the display can act in a sideway mode or in a vertical mode. Looking distance of the display in the 1st direction and looking distance of the display in the 2nd direction are substantially equal. Further a separation angle between a 1st image and a 2nd image displayed by the display in the 1st direction and a separation angle between the 1st image and the 2nd image displayed by the display in the 2nd direction are substantially equal. Accordingly when direction of the display is changed, it is unnecessary for the user to change his viewpoint toward the display. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multi-view directional display, which displays two or more images, each image being viewed from a different direction. Thus, two observers viewing the display from different directions see different images. Such a display can be used, for example, in an autostereoscopic 3-D display device or a dual display device.

  For many years, conventional displays have been designed to be viewed by multiple users simultaneously. Display characteristics of the display are created so that the viewer can see the same good image quality from different angles with respect to the display. This is effective in applications where many users require the same information from the display, for example, display of departure information at airports and railway stations. However, there are many applications that desire individual users to be able to see different information from the same display. For example, in a car, the driver may want to see satellite navigation data, but the passenger may want to watch a movie. These conflicting needs can be met by providing two separate displays, but this requires extra space and increases costs. In addition, if two separate displays are used in this example, the driver can see the passenger's display, distracting the driver. As a further example, in a computer game for two or more players, each player may wish to view the game from his or her own view. This is recently gained by allowing each player to see the game on a separate display screen, allowing each player to see their own unique field of view on the individual screen. However, providing each player with a separate display screen takes up a lot of space and is not realistic for portable games.

  In order to solve these problems, multi-view directional displays have been developed. One application of a multi-view directional display is like a “dual view display”, which displays two or more different images simultaneously, each image being viewable only in a particular direction. Thus, an observer looking at the display device from one direction sees one image, whereas an observer looking at the display device from the other direction or a different direction sees a different image. A display that can show different images to two or more users is a significant space and cost saving compared to using two or more separate displays.

  A further use of multi-view directional displays is to create 3D images. In the case of normal vision, the two human eyes perceive the world scene from different views. This is because the two eyes are in different positions in the head. The brain uses these two views to determine the distance of various objects in the scene. In order to create a display that efficiently shows a three-dimensional image, it is necessary to reproduce this situation and supply a so-called “stereoscopic pair” of images, ie, one image to each eye of the observer.

  Three-dimensional displays are categorized into two types depending on the method used to deliver different scenes to the eye. A stereoscopic display typically displays two images of a stereoscopic image pair over a wide display screen. The user needs to wear filter system glasses that separate the scene and cause each eye to see only the scene directed to that eye.

  The autostereoscopic display displays a right eye view and a left eye view in different directions, so that each view can only be viewed from its respective defined spatial region. A spatial region where an image can be viewed from the entire display active area is called a “viewing window”. If the viewer is positioned so that the viewer's left eye is in the view window for the left eye of the stereoscopic pair and the viewer's right eye is in the view window for the right eye of the pair An accurate scene can be seen in each eye of the observer, and a three-dimensional image can be perceived. The autostereoscopic display does not require the viewer to wear a visual aid.

  The principle of autostereoscopic display is similar to that of dual view display. However, the two images displayed on the autostereoscopic display are the left-eye image and the right-eye image of the stereoscopic image pair, and thus are not independent of each other. In addition, two images are displayed to be visible to one observer, and one image is visible to each eye of the observer.

  For flat panel autostereoscopic displays, the viewing window is usually formed by a combination of the picture element (or “pixel”) structure of an autostereoscopic display image display and an optical element, generally parallax optics. Called an element. An example of a parallax optic is a parallax barrier, which is a screen having transmissive areas (often in the form of slits) separated by non-transmissive areas. This screen can be placed before or after a spatial light modulator (SLM) with a two-dimensional array of pixels to create an autostereoscopic display.

  FIG. 16 is a plan view of a conventional multi-view directional device (in this case, an autostereoscopic display). The directional display 100 includes a spatial light modulator (SLM) 104 and a parallax barrier 105 that constitute an image display device. The SLM of FIG. 16 is in the form of a liquid crystal display (LCD) device having an active matrix thin film transistor (TFT) substrate 106, a counter substrate 107, and a liquid volume layer 108 disposed between the substrate and the counter substrate. . The SLM is provided with addressing electrodes (not shown) that define a plurality of independently addressable pixels, and also with an alignment layer (not shown) that aligns the liquid crystal layer. A viewing angle expansion film 109 and a linear polarizing plate 110 are provided on the outer surfaces of the substrates 106 and 107. The illumination 111 is supplied from a backlight (not shown).

  The parallax barrier 105 includes a substrate 112 on which a parallax barrier opening array 113 is formed on a surface adjacent to the SLM 104. The aperture array comprises a transmissive aperture 115 that extends vertically (ie, extends in the plane of FIG. 16) and is separated from a non-transmissive portion 114. An antireflection (AR) film 116 is formed on the opposite surface of the parallax barrier substrate 112 (which forms the outer surface of the display 100).

  The pixels of the SLM 104 are composed of columns and rows extending in the plane of FIG. The pixel pitch in the row or horizontal direction (the distance from the center of one pixel to the center of an adjacent pixel) is p. The plane of the barrier opening array 113 is spaced from the plane of the liquid crystal layer 108 by a distance s.

In use, the display device 100 forms a left-eye image in the left-eye viewing window 102 and a right-eye image in the right-eye viewing window 103, and the viewer's left eye and right eye are respectively in the left-eye viewing window. An observer who puts his head so as to coincide with 102 and the right eye viewing window 103 can see a three-dimensional image. The left and right viewing windows 102, 103 are formed on the window surface 117 at a desired viewing distance from the display. The window surface is spaced a distance r ₀ minutes from the plane of the aperture array 113. The intended viewing distance of the display is measured perpendicularly from the front of the display and is equal to r ₀ minus the thickness of the parallax barrier substrate 112. The windows 102 and 103 are close to the window surface. The viewing distance of the display is the distance from the display, where the lateral separation e between the viewing window for the right eye image and the viewing window for the left eye image is the average between the two human eyes Equal to separation.

  The pitch of the slits 115 in the parallax barrier 105 is selected to be close to an integer multiple of the pixel pitch of the SLM 104, so that a group of pixel columns is associated with a particular slit in the parallax barrier. FIG. 16 shows a display device in which two pixel columns of the SLM 104 are associated with each transmissive slit 115 of the parallax barrier.

  FIG. 16 shows an autostereoscopic 3D display. The principle of a dual view (or multiview) display is similar to an autostereoscopic display, but displays two (or more) different images to two (or more) different viewers. Thus, the image display layer is facilitated to display two (or more) independent images that are interlaced with each other. The image viewing window is configured to be large enough to accommodate the viewer's eyes at the intended viewing distance. The separation between viewing windows is created so that the viewer sees only one of the displayed images.

  Many conventional 2D displays are designed to be used in one or more directions. Thereby, depending on whether the image is stopped or moving, the observer can display the image better in the landscape orientation as shown in FIG. 1 (a) or in the portrait orientation as shown in FIG. 1 (b). You can have the freedom to choose what is in One example of such a display is the SLC-760 & C750 Zaurus® Personal Digital Assistant (PDA) from Sharp Corporation, which can be used in landscape or portrait mode (May 16, 2003). (See press release available at http://sharp-world.com/corporate/news/030516.html). Also, depending on the application, the ability to use a display in one or more directions in a particular mobile device handset can reduce the number of displays required for that device, and the display can be Increase the degree of freedom in the direction of integration into functionality.

  Multi-view directional displays, such as autostereoscopic 3D displays and dual-view displays or multi-view displays, have so far been designed to operate in only one direction of the display. Many directional displays have images that are distributed only in one plane, and while rotating such displays, the image resolution effect does not rotate and in many cases the desired effect is not achieved.

  FIG. 2 is a schematic diagram of a multi-view display, such as the conventional display 100 of FIG. 16, having parallax optics disposed in front of a pixelated image display layer. The parallax optic is a simple parallax barrier aperture array having opaque strips 114 separated by transmissive apertures 115. The barrier impervious strip 114 extends vertically as shown in FIG. Two interlaced images are displayed on the image display layer. One image (for example, a left-eye image in the case of an autostereoscopic display) has pixel columns C1, C3, C5. . . The other images (in the case of an autostereoscopic display, the right eye image) are displayed on the pixel columns C2, C4, C6. . . Displayed above. (FIG. 2 shows a full color display, where pixel columns C1, C4, C7 ... display red images, pixel columns C2, C5, C8 ... display green images, and pixels Columns C3, C6, C9 ... display a blue image, but this is not important for the general principle of display operation.) The vertical opaque strip 114 of the parallax barrier is displayed on the image display layer. Provides a horizontal separation of the two images, so that the left and right eyes of the viewer see different images. It is due to the opaque strip 114 of the parallax barrier that obscures different parts of the display for each eye. This can be used to create a 3D image.

  The display shown in FIG. 2 is intended to be viewed sideways, where the horizontal width w of the display is greater than its vertical height h. When the display is rotated about an axis perpendicular to the front (or display surface) of the display and is in the longitudinal mode, it is as shown in FIG. The image display layer can be re-addressed to display two interlaced images, one image being on pixel column C′1, C′3 and the other image being pixel column C′2, C′4 (the vertical mode pixel columns C′1, C′2,... Are not the same as the pixel columns C1, C2,. However, the parallax barrier cannot provide horizontal separation of the two images in portrait mode. This is because in this direction of the display, the opaque strip 114 of the parallax barrier is now horizontal. Thus, the viewer's two eyes are now looking at the same part of the display, and the viewer no longer perceives the 3D image because the same part of the display is opaque to both eyes.

  In certain displays that have a lens-shaped barrier as a parallax optic, there are 3D displays that are designed to generate multiple horizontal views and multiple vertical views. Examples of such displays are for example S. S. Kim et al. Described in “Super-multiview three dimensional display system”, SID 02 Digest, p1422-1423, which describes a 3D display that generates 8 views in the horizontal direction and 3 views in the vertical direction. Has been. Another such display is described in US Pat. No. 6,373,637. In general, these displays provide multiple views in the vertical direction to increase the viewer's freedom of viewing, and these displays are optimized to do this for displays in a particular direction The When such a display rotates, for example, when the display rotates from landscape to portrait, the viewing distance of the display changes substantially.

  In a similar manner, by combining a simple parallax barrier designed with a vertical opaque strip 114 and a vertical transmissive aperture 115 as shown in FIG. 2 with a simple horizontal parallax barrier, FIG. The parallax barrier 3 shown is obtained. In FIG. 4B, rectangular transmission openings 4 are arranged in a matrix of rows and columns. The rest of the parallax barrier is impervious to light. A suitable pixelated image display layer 1 for use with the parallax barrier 3 of FIG. 4 (b) is shown in FIG. 4 (a), which is arranged in a matrix of columns and rows. Pixel P is included. (In this example, the image display layer is again a full color display layer, so that the pixels in the pixel columns C1, C4 ... are red pixels and the pixels in the pixel columns C2, C5 ... are green). And the pixels in the pixel columns C3, C6 ... are blue pixels.) The parallax barrier 3 provides horizontal separation of the two interlaced images displayed on the image display layer and displays The orientation is set to either the vertical mode as shown in FIG. 4C or the horizontal mode as shown in FIG.

  As shown in FIG. 4A, when the horizontal pixel pitch in the vertical mode is denoted by p1, and the horizontal pixel pitch in the horizontal mode is denoted by p2, FIGS. 4A to 4D. The viewing distance of the display can be calculated as follows using the distance and angle noted in FIG.

If the refractive index in the panel is n and the refractive index outside the panel is 1 (corresponding to air), according to Snell's law:
n sin (x) = sin (y) (1)
However, since the angle is small, the eye separation is e, the horizontal pixel pitch is p, the viewing distance is r, and the pixel barrier separation is s, equation (1) is An approximate value can be obtained.

np / 2s = e / 2r (2)
The following is obtained from (2).

r = es / np (3)
In the case of an LCD panel, p2 is significantly larger than p1 and is usually about 3 times larger. Therefore, from equation (3), the viewing distance of the display in the vertical mode (when p1 is the pixel pitch in the horizontal direction) is obtained. Usually, the viewing distance in the horizontal mode (when p2 is the pixel pitch in the horizontal direction) is usually about three times longer. This means that if the viewer is positioned at the proper viewing distance to see the display when the display is in landscape orientation, the viewer will no longer be at the proper viewing distance from the display when the display is rotated vertically. The viewer experiences discomfort when viewing the display. For large displays, observers must physically move toward or away from the display as the display rotates to place themselves at the proper viewing distance for the new mode. This is inconvenient and may not be possible. Alternatively, in the case of a small mobile display, the viewer needs to move the display further away from the viewer's eyes or to change the way the display is held so that it is closer. However, the limit to which the observer can move the display is ergonomics such as the length of the observer's arm or the maximum distance from the observer's eye to the display that the observer can resolve the displayed image. Limited by the problem.

  Although the above discussion relates to multi-view displays having a parallax barrier as a parallax optic, the same relationship between horizontal pixel pitch and viewing distance applies to displays having a lens-shaped barrier. Therefore, the problem described above also occurs in the case of a display having a lens-shaped barrier.

  DE 20022456U discloses a multi-view directional display intended for use in two different directions. This specification discloses a display having a pixelated image display layer in which the individual color pixels (ie, red pixels, blue pixels and green pixels) are square. However, in standard image display devices, the color pixels are asymmetric, so the red, blue and green pixels are combined to form a square hybrid pixel (and the color pixels usually have an aspect ratio of approximately 1: 3). Thus DE 20022456U does not apply to displays having such a standard image display device.

  US 2003/0058335 discloses a display having a biconvex lens located in front of the image. The display can be arranged in two different directions, one placed at 90 ° relative to the other. In one direction where the biconvex lens is vertical, if the 3D display is placed and the display is placed in the other direction, the biconvex lens moves horizontally, the observer moving his head in the vertical direction will see a “moving image”. As a result, the observer sees a series of different images.

  EP-A-1 191 384 likewise relates to a display having a biconvex lens array with lenses extending diagonally. Thereby, the observer can perceive the stereoscopic effect or the moving image effect by appropriately moving the head with respect to the display.

  JP-A-2000-281-526 relates to a stereoscopic display in which the position of two displayed images varies as the display rotates. Thereby, even if the display is rotated from the target direction, it is possible to obtain a 3D effect.

  US 6 023 263, WO 2004/042452 and C.I. van Berkel et al., SPIE Conference Proceedings Vol. "Stereoscopic Displays and Virtual Reality Systems III: Multiview 3D LCD" pp 32-39 (April 1996) in 2653 each disclose four view display devices. The pixels of the device's image display layer are divided into four different sources so that there is one image at each of the four viewing positions spaced along the four sides and four separate images are displayed. It is driven from.

  In a first aspect of the present invention, a pixelated image display layer is provided, can operate as a multi-view directional display in a first direction, and is multi-view in a second direction different from the first direction. A display operable as a directional display, wherein the viewing distance of the display in the first direction is substantially equal to the viewing distance of the display in the second direction and is displayed by the device in the first direction. The separation angle between the first image and the second image is substantially equal to the separation angle between the first image and the second image displayed by the device in the second direction, and the image display layer has an aspect ratio of 1. Provide a display with non-color pixels.

  The present invention can also be applied to a display having a standard image display panel having asymmetric color pixels. For example, the present invention may be applied to a display in which an image display panel has color pixels with an aspect ratio of about 1: 3, whereby a red, green pixel, and blue pixel are combined into a square composite pixel. It is formed.

  According to the present invention, the direction of the display can be changed to fit the display image. For example, one image can be displayed horizontally using the display. The display is then used, for example, if it is desired to display another image that is best viewed in portrait orientation (for example, when the aspect ratio of the new image is different from the previous image) Can be rotated in a new direction to display a new image.

  By referring to the case of substantially the same viewing distance, it is shown that the viewing distance in one direction and the viewing distance in another direction need not be exactly the same. This is because the view window created by the multi-view directional display has a finite size in the normal direction of the display. This is true, for example, when using a “view correction” technique in which the parallax barrier is slightly smaller than an integer multiple of the pixel row pitch. If the view window generated by the display in one direction overlaps the view window generated by the display in another direction (in the normal direction of the display), the observer will generate his eyes with the display in both directions Can find a position within the specified view window. In this case, it can be said that the viewing distance in one direction of the display is substantially equal to the viewing distance in another direction. The maximum tolerable difference in viewing distance of the display in one mode and another depends on the exact shape of the view window and the position of the viewer within the view window.

  The separation angle between the first image and the second image displayed by the device in the first direction is substantially the same as the separation angle between the first image and the second image displayed by the device in the second direction. be equivalent to. The separation angle may be a separation angle in a given plane, for example a plane with the viewer's eyes. In the two directions of the display, there is no significant difference between the separation angle of the two images in the plane of the viewer's eyes and the viewing distance of the display, so there is no discomfort, for example, whether the display is oriented horizontally Regardless of whether they are oriented (giving landscape mode) or vertically (giving portrait mode), the viewer can see the display of the present invention from the same viewing distance. When the display orientation is changed, the user does not need to change the viewing position. This makes it more convenient to observe the display in both large and fixed displays and portable displays. For example, in the case of an autostereoscopic three-dimensional display, the distance between the left eye window and the right eye window at the viewing distance of the display does not change when the direction of the display is changed. Thus, for example, an observer who is in the correct position to view a 3D image on the display in the portrait mode direction (ie, the left eye is in the left eye image view window and the right eye is in the right eye image view). It remains in the correct position to perceive a 3D image even if the display is changed to the landscape mode orientation. To switch the display from one display mode to another, simply rotate the display in a new direction and re-address the image display to the new direction (see the implementation described below). In the case of form) it is necessary to reset the parallax optic to match the new direction of the display. In some cases, for example, when an image is displayed in both modes (if the image aspect ratio and the display aspect ratio are different, it may be necessary to reformat all images supplied to the display). The image must be reformatted to match the changed display aspect ratio. Generally, regardless of the aspect ratio of the display, the interlace pattern of the image is changed by switching between the portrait mode and the landscape mode (due to driving of the TFT panel).

  The display may include a parallax optical element disposed in an optical path through the image display layer.

  The pitch of the image display layer along the first direction and the effective pitch of the image display layer along the second direction orthogonal to the first direction are such that the viewing distance of the display in the first direction is the second direction. Can be selected to be substantially equal to the viewing distance of the display. Moreover, it may be necessary to properly select other parameters of the display so that the viewing distance for each direction of the display and the separation angle of the two images are indeed substantially equal. The relationship between the viewing distance and the visual interval in an actual display is generally more complicated than the relationship shown in Equation (3). The parallax barrier in the actual barrier includes a large number of openings, and the pitch of the parallax barrier needs to be selected so that the observer can accurately see each pixel. In the “view correction method”, by setting the pitch of the parallax optical elements so as not to be an integral multiple of the pixel pitch, formation of overlapping image areas is prevented. In an actual display, the pixel pitch p and the refractive index n are fixed, and the ratio r / e of the viewing distance to the visual interval is determined by the interval s between the image display layer and the parallax optical element. The specific value of the viewing distance r is determined by view correction applied to the visual optical element.

  The image display layer may comprise at least a first pixel of a first color and a second pixel of a second color, and the width of the first pixel along the first direction is along the second direction. The width of the second pixel along the first direction is substantially equal to the width of the second pixel along the second direction.

  The image display layer may comprise at least a first pixel of a first color and a second pixel of a second color arranged to form a composite pixel, each composite pixel having at least one first Having a pixel and at least one second pixel, the width of the composite pixel along the first direction is substantially equal to the width of the composite pixel along the second direction.

  The pitch of the parallax optical elements along the first direction may be substantially equal to the pitch of the parallax optical elements along the second direction.

  The parallax optical element may include a plurality of transmissive openings.

  The transmissive openings can be arranged in rows along a first direction, and the openings in one row are arranged in a first direction with respect to the openings in adjacent rows.

  The parallax optical element is a color filter barrier, whereby each opening includes at least first and second regions having different light transmission characteristics.

  The parallax optical element may be a fixed parallax optical element.

  Alternatively, the parallax optical element may be switchable between an OFF state and an ON state.

  The parallax optical element may be resettable between a first ON state and a second ON state.

  The parallax optical element may be further switchable to an OFF state.

  The display includes a first parallax optical element in which the parallax optical element can be switched between an OFF state and a first ON state, and a second parallax optical in which the parallax optical element can be switched between an OFF state and a second ON state. And an element.

  The display may include a first parallax optical element and a second parallax optical element, wherein the first and second parallax optical elements are arranged in an optical path through the image display layer, and the first parallax optical element is The first parallax optical element has a finite pitch in the first direction, the second parallax optical element has a finite pitch in the second direction orthogonal to the first direction, and the pitch of the image display layer along the first direction The ratio of the distance between the first parallax optical element and the image display layer to the ratio of the distance between the second parallax optical element and the image display layer to the pitch of the image display layer along the second direction is Substantially equal.

  The first parallax optical element and the second parallax optical element may be disposed on the opposing surfaces of the image display layer.

  The first parallax optical element and the second parallax optical element may be disposed on the same surface of the image display layer.

  Each of the parallax optical elements may include a liquid crystal material.

  Each of the parallax optical elements may comprise a liquid crystal layer and a patterned retarder disposed in an optical path through the display.

  Each of the parallax optical elements may comprise a first patterned retarder, a liquid crystal layer, and a second patterned retarder, wherein the first patterned retarder, the liquid crystal layer, and the second Patterned retarders are arranged in this order in the optical path through the display.

  Each of the patterned retarders can comprise a reactive mesogen layer.

  Each of the parallax optical elements may include a plurality of addressable liquid crystal regions arranged alternately with regions having certain optical characteristics.

  Each of the parallax optical elements may include an addressable liquid crystal layer having alternating regions having a first alignment characteristic and regions having a second alignment characteristic.

  The parallax optical element includes an addressable layer, a first addressing device that defines a first parallax optical element of the addressable layer, and a second addressing that defines a second parallax optical element of the addressable layer Apparatus.

  The first addressing device may comprise a first electrode set defining a first parallax optic and the display may further comprise an electrode having a shape substantially complementary to the shape of the first electrode set. .

  The second addressing device may comprise a second electrode set defining a second parallax optic, and the display may further comprise an electrode having a shape substantially complementary to the shape of the second electrode set. .

  By rotating the display about the normal of the display surface of the display, the display can be changed from the first direction to the second direction.

  The first direction may be substantially 90 ° with respect to the second direction.

  The first direction can be a horizontal direction and the second direction can be a vertical direction.

  In a second aspect of the invention, a multi-view directional display adapted to display four views, each view being in use in each of four different directions that are not coplanar. And the display includes an image display layer, and at least one of the views is assigned to the image display layer, thereby having a first direction in the image display layer and at least another of the views. Is assigned to the image display layer, thereby providing a multi-view directional display having a second direction different from the first direction in the image display layer.

  The display can display an image to, for example, two or more observers around the desk. By assigning the two images to the image display layer, they have different directions in the image display layer. As a result, each image is accurately reflected on each observer.

  The first to fourth views can be assigned to the image display layer so that the first to fourth views have different directions in the image display layer.

  The display includes a plurality of first areas for displaying the first view, a plurality of second areas for displaying the second view, a plurality of third areas for displaying the third view, and a fourth area An image display layer having a plurality of fourth regions for displaying views and a parallax optical element for displaying each view along each of four different directions that are not on the same plane when used.

  The elements of the parallax optical element include one of the first region of the image display layer, one of the second region of the image display layer, one of the third region of the image display layer, and the fourth of the image display layer. Can be associated with one of the regions.

  The image display layer can be a pixelated image display layer, wherein each first region, each second region, each third region, and each fourth region includes one or more pixels. Prepare.

  The first region and the second region may be disposed laterally adjacent to each other, the third region is disposed above the first region and the second region, and the fourth region The region is disposed below the first region and the second region, and is disposed vertically below the third region.

  In 3rd aspect of this invention, the dual view display apparatus provided with the display in 1st or 2nd aspect is provided.

  In a fourth aspect of the present invention, an autostereoscopic display device provided with the display in the first or second aspect is provided.

(Item 1)
It has a pixelated image display layer, can operate as a multi-view directional display in the first direction, and can operate as a multi-view directional display in a second direction different from the first direction. A first image displayed by the display in the first direction, wherein the viewing distance of the display in the first direction is substantially equal to the viewing distance of the display in the second direction; The separation angle with the second image is substantially equal to the separation angle between the first image and the second image displayed by the device in the second direction, and the image display layer has an aspect ratio of 1. Display with non-color pixels.

(Item 2)
Item 4. The display according to item 1, comprising a parallax optical element disposed in an optical path through the image display layer.

(Item 3)
The effective pitch of the image display layer along the first direction and the effective pitch of the image display layer along the second direction orthogonal to the first direction are the view of the display in the first direction. Item 3. The display of item 2, wherein the distance is selected to be substantially equal to the viewing distance of the display in the second direction.

(Item 4)
The image display layer includes at least a first pixel of a first color and a second pixel of a second color, and a width of the first pixel along the first direction is the second pixel. The width of the first pixel along the direction is substantially equal to the width of the second pixel along the first direction is substantially equal to the width of the second pixel along the second direction 4. The display according to any one of items 1, 2, or 3.

(Item 5)
The image display layer includes at least a first pixel of a first color and a second pixel of a second color arranged to form a composite pixel, each composite pixel having at least one first pixel. Item 1, comprising one pixel and at least one second pixel, wherein the width of the composite pixel along the first direction is substantially equal to the width of the composite pixel along the second direction, The display according to any one of 2 and 3.

(Item 6)
Item 6. The display according to item 4 or 5, wherein a pitch of the parallax optical elements along the first direction is substantially equal to a pitch of the parallax optical elements along the second direction.

(Item 7)
Item 7. The display according to Item 6, wherein the parallax optical element includes a plurality of transmissive openings.

(Item 8)
Item 8. The display according to Item 7, wherein the parallax optical element is a color filter barrier, whereby each opening includes at least first and second regions having different light transmission characteristics.

(Item 9)
Item 9. The display according to any one of items 2 to 8, which is a parallax optical element to which the parallax optical element is fixed.

(Item 10)
Item 9. The display according to any one of items 2 to 8, wherein the parallax optical element is switchable between an OFF state and an ON state.

(Item 11)
Item 10. The display according to any one of Items 2 to 9, wherein the parallax optical element is resettable between a first ON state and a second ON state.

(Item 12)
Item 12. The display according to Item 11, wherein the parallax optical element is further switchable to an OFF state.

(Item 13)
A first parallax optical element and a second parallax optical element, wherein the first and second parallax optical elements are disposed in an optical path through the image display layer, and the first parallax optical element The element has a finite pitch in the first direction, the second parallax optical element has a finite pitch in a second direction orthogonal to the first direction, and the first parallax optical element The ratio between the distance between the image display layer and the distance between the first parallax optical element and the image display layer with respect to the pitch of the image display layer along the first direction is along the second direction. The display according to item 1, wherein the display is substantially equal to a ratio of a distance between the second parallax optical element and the image display layer with respect to a pitch of the image display layer.

(Item 14)
The display includes a first parallax optical element that can be switched between an OFF state and a first ON state, and a second parallax optical element that can be switched between an OFF state and a second ON state. Item 14. The display according to item 11 or 13.

(Item 15)
Item 15. The display according to Item 14, wherein the first parallax optical element and the second parallax optical element are disposed on opposing surfaces of the image display layer.

(Item 16)
Item 15. The display according to Item 14, wherein the first parallax optical element and the second parallax optical element are arranged on the same surface of the image display layer.

(Item 17)
Item 17. The display according to any one of items 11 to 16, wherein each of the parallax optical elements includes a liquid crystal material.

(Item 18)
Item 18. The display of item 17, wherein each of the parallax optical elements comprises a liquid crystal layer and a patterned retarder arranged in an optical path through the display.

(Item 19)
Each of the parallax optical elements comprises a first patterned retarder, a liquid crystal layer, and a second patterned retarder, wherein the first patterned retarder, the liquid crystal layer, Item 18. The display of item 17, wherein the second patterned retarder is arranged in the order described in the optical path through the display.

(Item 20)
20. A display according to item 18 or 19, wherein each patterned retarder comprises a reactive mesogen layer.

(Item 21)
Item 18. The display of item 17, wherein each of the parallax optical elements comprises a plurality of addressable liquid crystal regions arranged alternately with regions having certain optical properties.

(Item 22)
Item 18. The display of item 17, wherein each of the parallax optical elements comprises an addressable liquid crystal layer having alternating regions having a first alignment characteristic and regions having a second alignment characteristic.

(Item 23)
The parallax optical element includes an addressable layer, a first addressing device that defines a first parallax optical element of the addressable layer, and a second that defines a second parallax optical element of the addressable layer 21. A display according to any one of items 12, 13 or items 17-20 when directly or indirectly subordinate to item 13, comprising:

(Item 24)
The first addressing device comprises a first electrode set defining the first parallax optic, and the display has a shape substantially complementary to the shape of the first electrode set. 24. A display according to item 23, further comprising an electrode.

(Item 25)
The second addressing device comprises a second electrode set defining the second parallax optic, and the display has a shape substantially complementary to the shape of the second electrode set. 25. A display according to item 23 or 24, further comprising an electrode.

(Item 26)
26. The item according to any one of items 1 to 25, wherein the display is changed from the first direction to the second direction by rotating the display about the normal line of the display surface of the display. display.

(Item 27)
27. A display according to any one of items 1 to 26, wherein the first direction is substantially 90 ° with respect to the second direction.

(Item 28)
28. A display according to item 27, wherein the first direction is a horizontal direction and the second direction is a vertical direction.

(Item 29)
A multi-view directional display adapted to display four views, each view being displayed along each of four different directions that are not coplanar when used, An image display layer, wherein at least one of the views is assigned to the image display layer and has a first direction in the image display layer, and at least another one of the views A multi-view directional display having a second different direction in the image display layer by being assigned to the image display layer.

(Item 30)
30. The display according to item 29, wherein the first to fourth views are assigned to the image display layer so that the first to fourth views have different directions in the image display layer.

(Item 31)
A plurality of first areas for displaying the first view, a plurality of second areas for displaying the second view, a plurality of third areas for displaying the third view, and a fourth view are displayed. Item 30 comprising: an image display layer having a plurality of fourth regions, and a parallax optical element that displays each view along each of four different directions that are not on the same plane when used. Display as described.

(Item 32)
The parallax optical element includes one of the first region of the image display layer, one of the second region of the image display layer, one of the third region of the image display layer, and the image display. 32. A display according to item 31, associated with one of the fourth regions of the layer.

(Item 33)
The image display layer is a pixelized image display layer, and each first region, each second region, each third region, and each fourth region includes one or more pixels. Item 33. The display according to item 31 or 32.

(Item 34)
The first region and the second region are disposed adjacent to each other in the lateral direction, the third region is disposed above the first region and the second region, and the fourth region 34. The item according to any one of items 31, 31, or 33, wherein the region is disposed below the first region and the second region, and is disposed vertically below the third region. Display.

(Item 35)
35. A dual view display device comprising a display defined as described in any one of items 1-34.

(Item 36)
An autostereoscopic display device including a display defined as described in any one of items 1 to 34.

  Like reference numbers refer to like elements throughout the figures.

  Embodiments of the present invention are described with reference to a display that can operate in a horizontal (or horizontal) direction or a vertical (or vertical) direction. This display transforms from one direction to the other by rotating an axis that is perpendicular to the normal (display) plane of the display approximately 90 degrees.

  6 (a) and 6 (b) show an image display (display) layer 10 and a parallax optic 12 of the display according to an embodiment of the present invention. The image display layer 10 of this embodiment includes pixels 11, 11 ′, 11 ″ arranged in a matrix of rows and columns. For convenience, the space between adjacent pixels is omitted from FIG. 6 (a). The pixel is a color pixel, the pixel 11 is a red pixel, the pixel 11 ′ is a green pixel, and the pixel 11 ″ is a blue pixel.

  The aspect ratio of each color pixel 11, 11 ′, 11 ″ is not equal to 1. That is, the width of the pixel along the horizontal direction in FIG. 6A is equal to the height of the vertical pixel in FIG. The image display layer 10 of the present embodiment is arranged to provide white pixels that are substantially square, a “white pixel” is a composite pixel, which is three color pixels, one It consists of a red pixel, one blue pixel, and one green pixel. The “white pixel” is bordered by a thick line at the upper right corner of FIG. In order for the “white pixel” 14 to be substantially square, each color pixel 11, 11 ′, 11 ″ is rectangular, one direction is approximately three times the length in the vertical direction, Allows the generation of complex white pixels 14 in which adjacent color pixels are substantially square.

  The efficient pitch of the pixels used in equation (3) is the pitch of the composite white pixel. The effective pixel pitch in the vertical direction is 3 × P1, whereas the (effective) pixel pitch in the horizontal direction is P2. By selecting the shape and pixel arrangement of P2 = 3P1, the efficient pixel pitch in the horizontal direction is the same as the efficient pixel pitch in the vertical direction.

  Considering equation (3), the pixel barrier s and the refractive index n of the panel are independent of the orientation of the display. If the parallax barrier provides substantially the same angular separation between the two views in the two directions, and the visual separation at the intended viewing distance does not vary significantly between the two directions of the display, the display will be horizontal in FIG. The viewing distance of the display 10 when providing the vertical image shown in c) is substantially the same as the viewing distance of the display 9 when the display provides the vertical image shown in FIG. 6D in the vertical direction. Are equal. This embodiment of the present invention thus provides a multi-directional directional display. This can be done in either the horizontal or vertical direction and has substantially the same viewing distance in both directions. Therefore, the user of the present display does not need to change position relative to the display as the display rotates from horizontal to vertical or vice versa. In addition, the angular separation between two sights (measured at the intended viewing distance) in the plane of the observer's eye is substantially the same in one direction as in the other direction, and the viewer is equipped with a display. For example, if the display is positioned accurately to view a 3-D image (ie, using the left and right eyes, the left eye captures the view window image and the right eye captures the view window image). When it is in the horizontal direction, the vertical direction is accurately positioned so that the 3-D image is recognized.

  In this way, the orientation of the display can change to suit the displayed image. One image provided with a display is displayed like the image of the horizontal direction of FIG.6 (c), for example. If it is substantially desired to display the different images that are best displayed using the display in the horizontal direction of FIG. 6 (d), the display may rotate vertically to display a new image.

FIG. 6 (b) shows a suitable vertical optical element for the display. The vertical optical element is shown as a vertical barrier 12 having a transmissive aperture that is substantially square. The barrier pitch in the horizontal direction (having the barrier direction as shown in FIG. 6B) is indicated as p _L because it is the barrier pitch when the display is in the horizontal direction, and the barrier pitch in the vertical direction (FIG. 6 (Having a barrier direction as shown in (b)) is indicated as p _P because it is the barrier pitch when the display is in the vertical direction. In the present embodiment, p _L by approximately 6-fold greater than the barrier pitch p1 is substantially equal to p _P, the pitch of the lateral color sub-pixels is equal to approximately twice the p2. The relationship between the size and shape of the aperture and the pixel pitch and the parallax barrier is not related to the general concept of the present invention and is not described here (although it may be related to the crosstalk of the display).

  This embodiment is not defined as a parallax barrier as a parallax optical element of a display. For example, it may alternatively be achieved by using a lenticular barrier having a square bottom lens or a hemispherical lens. In such a parallax barrier, the lenses are arranged in rows and columns in the same manner as the transmissive apertures 13 of the parallax barrier 12 of FIG.

  When this embodiment is implemented using a lens-like parallax optical element, the respective lenses are in contrast in focus characteristics, that is, the focus force in the vertical direction shown in FIG. It is preferred that it is substantially equal to the horizontal focal force shown in b). If the lens is asymmetric in focus characteristics and the viewing distance of the display in the horizontal direction is equal to the viewing distance of the display in the vertical direction, the separation between the view windows is different between the horizontal direction of the display and the vertical direction of the display. A dual view display will affect the viewer. When the display is rotated, the viewer needs to move parallel to the plane of the display in order to remain in the view window for the particular image. In the case of an autostereoscopic 3-D display, the separation between the left-eye view window and the right-eye view changes, and the 3-D effect may disappear as the display rotates. If any 3-D effect remains, the observer's eyes are not correctly positioned in the left-eye right eye view window, and any 3-D effect may not be comfortable.

  6C and 6D illustrate the operation of the display 10 in the horizontal direction and the vertical direction, respectively, and FIG. 6E illustrates the direction of the observer. In the horizontal direction, the two images are combined in rows instead of pixels. For example, in the case of an autostereoscopic 3-D display, the right eye image is displayed in the pixel columns C1, C3, and the left eye image is displayed in the pixel columns C2, C4, and the like. In the vertical direction, the image is displayed in alternating rows of white pixels 14, with each row of white pixels corresponding to three rows of color pixels. Thus, the right eye image is displayed in the color pixel columns CR1, CG1, and CB1 (constituting the first column of white pixels), and the left eye image is composed of the color pixel columns CR2, CG2, and CB2 (constituting the white pixel column C2). To be displayed).

  The display described above with reference to FIGS. 6 (a) -6 (d) can be varied in a known manner. For example, according to the technology disclosed in co-pending UK Patent Application No. 0315171.9, the image display layer may include four or more color subpixels in each white pixel. The combination of left-eye and right-eye images is replaced with one pixel from one row to the next to provide a larger viewing angle, as presented in co-pending UK Patent Application No. 0315170.1 Can do. The color subpixels of the left eye image and the right eye image may be divided across two rows of pixels as presented in British Patent Application No. 0228644.1. The pitch of the parallax optic may be slightly larger than the color pixel pitch of the image display layer, as disclosed in UK Patent Application No. 0306516.6. The contents of these applications are incorporated herein by reference.

  When the parallax optic of the display is embodied as a parallax barrier, the parallax barrier may be embodied as a fixed parallax barrier, for example by selectively exposing photographic emulsion material to define a transmissive aperture. Such parallax barriers are suitable mainly for displays designed to operate in three-dimensional mode or dual view display mode. This is because the parallax barrier cannot be switched off to provide a conventional 2-D display. If it is desired to operate a display having a fixed parallax barrier or other fixed parallax optic in a conventional 2-D mode, the image display layer can be facilitated to display two identical images, Make both visuals provided by the display the same. An alternative method of obtaining a 2-D display mode with a fixed parallax barrier provides a switchable scatterer, such as a polymer distributed liquid crystal material, in the optical path of light from the parallax optic to the viewer. That is. The effect of the parallax optical element is removed when the scatterer switch is turned on and the 2-D display mode is acquired. When the scatterer is switched off, a directional display mode is obtained.

  The above embodiments can instead be embodied using a lenticular parallax barrier such as a microlens array. The microlens array can be a fixed microlens array or can be a microlens array that is switched to provide a 2-D mode of operation. As disclosed in WO 03/015424, a switchable microlens array can be provided using a switchable liquid crystal layer in conjunction with a microlens array processed using a polar sensitive material such as a liquid crystal material.

  Alternatively, the display can be implemented using a color filter barrier as a parallax optic. An example of the color filter barrier 15 is shown in FIG. The color filter barrier includes a plurality of transmission openings 16a, 16b, 16c, and the rest of the color filter barrier is opaque. Compared with the above-described parallax barrier in which the opening 13 is transmissive to all visible light wavelengths, the openings 16a, 16b, and 16c of the color filter barrier in FIG. 7A are transmissive only in a narrow range of the visible spectrum. Opening 16a is transparent to the red portion of the spectrum, opening 16b is transparent to the blue portion of the spectrum, and opening 16c is transparent to the green portion of the spectrum, “r” to indicate the opening of the color filter barrier 15; The letters “b” and “g” are shown. The openings 16a, 16b, 16c are arranged in groups of three openings, each group including one “red” opening 16a, one “blue” opening 16b, and one “green” opening 16c. The color filter barrier 15 of FIG. 7 (a) is suitable for use with the image display layer shown in FIG. 6 (a).

  A display 9 having the image display layer 10 shown in FIG. 6 (a) as a color filter barrier parallax optical element of FIG. 7 (a) is shown in the horizontal direction in FIG. 7 (b). FIG. 7B shows the present embodiment adapted to an autostereoscopic display, and the color subpixels in FIG. 7B are labeled with R or L, and whether the right eye image is displayed or the left eye image is displayed. Indicates whether it is displayed. The lower letters in FIG. 7B indicate the transmission range of the color filter barrier opening.

  The use of a color filter barrier provides a brighter 3-D display and lower crosstalk. ("Crosstalk" occurs when the viewer's left eye recognizes an image intended for the right eye and vice versa.) Details of the use of the color filter barrier are described in co-pending UK Patent Application No. 0320367. No. 6, which is hereby incorporated by reference.

  It is noted that in the display shown in FIG. 7 (b), the right eye image and the left eye image are not displayed in the pixel column. The image is displayed such that the combination is offset by one white pixel changing from one column to the next (ie, by three columns of color pixels). The openings in the color filter barrier 15 are therefore not arranged in columns, but the openings in one row are offset laterally relative to the upper and lower columns, corresponding to the offset of the image combination. However, the color filter barrier is applied to a display device in which images of the left eye and the right eye are displayed in a pixel column, as shown in the embodiments of FIGS. 6 (a) to 6 (d), for example.

  The color filter barrier is generally embodied as a fixed barrier and is suitable for use in displays that require operation in a heavily directional display mode. When it is desired to operate a display with a color filter barrier as a parallax optic in 2-D display mode, a switchable scatterer such as a polymer distributed liquid crystal cell is present in the optical path from the display to the viewer. To remove the effect of the parallax barrier. Instead, the two images displayed on the image display layer of the display can be the same so that the same image is displayed on both eyes and the device is operated in 2-D mode.

  FIG. 8 is a basic conceptual diagram of a display 9 according to a further embodiment of the present invention. The display 9 includes an image display layer 10 and a parallax optical element 12 arranged in an optical path that passes through the image display layer 10. The image display layer may be formed of a conventional liquid crystal layer 18 disposed between the first and second linear polarizers 17, 19, as shown in FIG. An additional linear polarizer 22 is placed in front of the parallax optic 12 (in use, the display 9 is illuminated by a backlight that is placed so that the backlight and image display layer are opposite the parallax optic. In other words, the light from the backlight enters the display via the polarizing plate). For example, other components such as a counter electrode for coping with the liquid crystal layer 18, an alignment layer for aligning the liquid crystal material, and a color filter in the case of a color display do not form part of the present invention and are not shown.

  In the present embodiment, the parallax optical element 12 is a switchable parallax optical element, and is switched between an OFF state and an ON state in which the parallax optical element is not substantially defined. The figure shows one way in which such a switchable parallax optic can be defined. In this embodiment, a switchable parallax optical element is formed by a retarder 20 patterned with a switchable liquid crystal layer. The patterned retarder is patterned such that one or more first portions 23 correspond to the desired transmission apertures of the parallax barrier and one or more second portions 24 correspond to the desired opaque portions of the parallax barrier. Can be done. The liquid crystal layer 21 can be switched between the first states. In the first state, both parts 23, 24 of the patterned retarder have the same optical effect on the light, making the image display layer 10 undefined by the parallax barrier. In another state of the liquid crystal layer, the transmissive part of the first part 23 parallax barrier is defined and the second part defines the opaque part of the parallax barrier.

  The patterned retarder 20 of the parallax barrier 12 is a half-wave retarder plate having a patterned optical axis. The optical axis in one part 23 of the patterned retarder is 45 ° with respect to the optical axis in another part 24 of the patterned retarder. The patterned retarder portions 23 and 24 are transparent to the light of one input (from the switch LCD 21) electrode. The parallax barrier in the patterned retarder is not defined and the display operates in 2-D mode. When the light incident electrode in the patterned retarder 20 rotates at 45 °, by switching the switch LCD 21, one part of the patterned retarder is aligned with the transmission axis of the input polarizer 19 of the image display layer 10. While transmitting parallel polarized light, another portion of the patterned retarder transmits polarized light perpendicular to the transmission axis of the input polarizer 19 of the image display layer. Thus, light from one part of the patterned retarder is blocked while light from the other part of the patterned retarder is transmitted. A parallax barrier is defined and the display operates in a directional display mode, such as a 3-D display mode. The general principle of the patterned retarder 20 of FIG. 8 is described in UK patent application No. 015059.7.

  The embodiment of FIG. 8 can be used to provide any desirable parallax barrier. For example, the first portion 23 and the second portion 24 of the patterned retarder 20 are used in a display in which the color pixels 11, 11 ′, 11 ″ have an aspect ratio that is not equal to 1, FIG. b) may be arranged to provide a parallax barrier, so this embodiment is used in a horizontal or vertical direction, and multiple display orientations having substantially the same visual direction in either direction. Furthermore, using a switchable parallax optic means that the display can be switched between 2-D mode operation and directional mode operation. .

  FIG. 9 is a basic conceptual diagram of a display 9 according to a further embodiment of the present invention. The display according to the present embodiment also includes an image display layer 10 and a parallax optical element 12 arranged in an optical path passing through the image display layer 10. The parallax optical element in the present embodiment is a switchable parallax barrier.

  The image display layer 10 includes a liquid crystal layer 18 disposed between the first substrate 23 and the second substrate 25. Red, green and blue filters 24R, 24G and 24B are disposed between the liquid crystal layer 18 and one of the substrates. For example, other components such as a processing electrode for processing the liquid crystal layer 18, an alignment layer for aligning the liquid crystal material, a polarizing plate, etc. do not form part of the present invention and are not shown. FIG. 9 shows an active matrix image display layer. In an active matrix image display layer, one of the processing electrodes is constituted by a plurality of pixel electrodes, each pixel electrode being controlled by an associated switching element such as a thin film transistor (TFT), so that the image display layer 10 is “TFT”. It may be called a “panel”. In use, the display is illuminated by light provided from above the image display layer (as the display is shown in FIG. 9). Polarizers (not shown) are provided at the input to the image display layer, the output from the image display layer (which also forms the input to the active parallax barrier), and the output from the active parallax barrier.

  The parallax barrier 12 is formed from a strip 28 of material having fixed optical properties, for example resin. These strips extend on the page of FIG. The strips 28 extend so as to be parallel to each other and leave a space between them. A strip of liquid crystal material 21 is disposed between adjacent strips 28 of fixed optical property material. A strip 21 of liquid crystal material and a strip 28 of material with fixed optical properties are arranged between two light-transmitting substrates 26, 27. In use, the strip 21 of liquid crystal material is processed by suitable processing means (not shown). Suitable processing means include, for example, a first uniform electrode (not shown) disposed on one of the layers of resin 28 and one of the layers of resin 28 and liquid crystal material 21 and second disposed on liquid crystal material 21. It consists of two uniform electrodes (not shown). By applying a voltage between the two electrodes, the voltage is applied simultaneously across all liquid crystal portions 21.

  In order to operate the display 9 in 2-D mode, the strip 21 of liquid crystal material is switched so that the refractive index of the liquid crystal material matches the refractive index of the strip 28. There is no difference in the optical properties between the strip 21 and the strip 28 of liquid crystal material, and no parallax barrier is formed. In order to obtain a directional display mode, the strip 21 of liquid crystal material is switched to act as a birefringent part and form a light shielding part of the parallax barrier. The strip of fixed optical material 28 remains transparent.

  The embodiment of FIG. 9 can be applied to any of the above-described displays with reference to FIGS. 6 (a) -6 (d). This embodiment can therefore be used to provide a multi-display directional display. Multi-display directional displays are used in the horizontal or vertical direction and have substantially the same view direction in either direction. Furthermore, using a switchable parallax optical element means that the display can be switched between 2-D mode of operation and 3-D mode of operation.

  In the above embodiment, the exact size and shape of the opening of the parallax barrier are not described in detail because they are not directly related to the principle of the present invention. However, the size and shape of the opening of the parallax barrier do not affect the operation of the display in different directions, but do affect the characteristics of the display such as the degree of display crosstalk. Parameters such as the barrier opening width can be adjusted, indicating that display features such as the center portion of the view window are the least changed in rotation between directions.

  When the parallax barrier shown in FIG. 6B is compared with the conventional parallax barrier as shown in FIG. 2, the conventional parallax in which the ratio of these parallax barrier portions that are light transmissive is light transmissive. It can be seen that it is smaller than the ratio of the part of the barrier. Efficiently, the display of the above invention has a lateral parallax barrier and a longitudinal parallax barrier. The weakened brightness is particularly noticeable in the display. The display has a barrier that is switchable between directional display mode and 2-D display mode.

  To compensate for the reduced brightness in directional display mode, the power supplied to the backlight is increased when the display operates in directional display mode, providing greater light intensity and weakening the parallax barrier It is possible to compensate for the transmitted part. Therefore, in the present embodiment, switching from the 2-D display mode to the directional display mode includes turning on the parallax barrier and increasing the power supplied to the display backlight. Alternatively, the attenuated light in the directional display mode can be compensated by adjusting the drive of the image display layer to provide a brighter gray level when the device is operating in the directional display mode.

  For displays that operate only in the directional display mode, the backlight intensity can be adjusted to provide any desired display brightness.

  FIGS. 10 (a) -10 (d) illustrate additional switchable parallax barriers suitable for use in the display of the present invention. 10 (b) and 10 (d) are schematic cross-sectional views of the parallax barrier in the directional display mode (in this case, 3-D mode) and 2-D display mode, respectively.

  As shown in FIGS. 10 (b) and 10 (d), the parallax barrier 12 includes a liquid crystal layer 21 disposed between substrates 26, 27 provided with a uniform electrode (not shown). The liquid crystal layer 21 and the substrates 26 and 27 are disposed between the first polarizing plate 17 and the second polarizing plate 19. When no voltage is applied to the liquid crystal layer, the one or more first portions 28 of the liquid crystal layer have a first orientation and the one or more second portions 29 have a second orientation. In the embodiment of FIG. 10 (b), the first portion 28 has a vertical orientation, and when one linearly polarizing plate 17 is arranged perpendicular to the transmission axis of the other linearly polarizing plate 19, The part appears dark when the parallax optic is illuminated later. Portion 28 thus defines the opaque portion of the parallax barrier.

  As a result of the first portion 28 of liquid crystal material extending into the strip, the opaque strip 1 separated by the transmissive strip 5 is shown in FIG. 10 (a), which is a front view of the parallax barrier in 3-D mode. It becomes a conventional parallax barrier. However, by selecting a size, shape, and position suitable for the first portion 28 of the liquid crystal material, this embodiment can generate a parallax barrier as shown in FIG. 6B.

  When a voltage is applied to the liquid crystal layer, the liquid crystal alignment in the first portion 28 switches and the same alignment as that in the second liquid crystal portion 29 is applied. As a result, as shown in FIG. 10 (d), all the liquid crystal layers have a uniform alignment. In this embodiment, all the liquid crystal layers have a planar liquid crystal alignment. The parallax barrier is not defined, and the entire part of the parallax barrier is transparent as shown in FIG. 10C which is a front view of the parallax barrier in the present embodiment.

  The patterned orientation of the liquid crystal layer can be obtained in any convenient way, and many ways to obtain a patterned and oriented liquid crystal layer are well known. For example, patterned orientation can be achieved by applying a photographic orientation process to a suitable orientation layer (not shown). The photographic alignment process can be bond breakage, bond formation, or redirection of an alignment layer such as an azo alignment layer. Alternatively, methods such as lattice orientation or multi-rubbing of suitable alignment layers can be used.

As a further alternative, screen printing techniques can be used, in which an alignment layer is deposited on a selected portion of one of the substrates 26,27. The selected part is determined by the screen. A second screen covering different parts of the substrate can then be adapted and the second alignment layer is deposited on different parts of the substrate. The alignment layer is then cured and rubbed to provide a patterned alignment layer that produces the desired alignment of the liquid crystal layer.

  As a further example, a first alignment layer can be disposed on one of the substrates 26, 27 and is cured and rubbed to define the alignment direction. A second photo-imaginable alignment layer can then be placed on the first alignment layer. The second alignment layer can then be rubbed along an alignment direction that is different from the alignment direction of the first alignment layer. The photodrawable alignment layer can then be selectively exposed and developed using appropriate development conditions, while maintaining the photodrawable alignment layer in some parts while allowing photodrawing in other parts. The alignment layer is removed so that the lower first alignment layer is exposed. This provides an alignment layer having portions with different alignment directions, which are used to produce the desired liquid crystal alignment.

  As mentioned above, the use of a parallax barrier of the type shown in FIG. 6 (b) has the potential disadvantage of weakening light in the device due to the low transmission part of the parallax barrier. Therefore, a further preferred embodiment of the present invention provides a display having a parallax optic configured in the first or second ON state. One ON state provides an appropriate parallax barrier when the display is in one direction, and a second ON state provides an appropriate parallax barrier when the display is in the other direction. Thus, when the device is in one direction (eg, lateral direction), the parallax barrier enters a first ON state and when the display is rotated in another direction (eg, vertical direction), the parallax barrier Switches to the second ON state and provides an appropriate parallax barrier in the vertical direction. In this embodiment, the display only has a horizontal parallax barrier or a vertical parallax barrier appropriate for the direction of the display at a time, and the transmission part of the parallax barrier in either the vertical direction or the horizontal direction is shown in FIG. ) Larger than the transmission part of the parallax barrier.

  In certain preferred embodiments, the parallax barrier is not only reconfigured between the first ON state and the second ON state, but also switches to an OFF state in which the parallax optical element is not substantially defined. This switches the display to the 2-D display mode.

  FIG. 11A is a basic conceptual diagram of the display 9 according to this embodiment of the present invention. The display 9 comprises an image display layer 10 and two parallax optical elements 12, 12 '. Each parallax optical element 12, 12 'is provided to the optical path via the image display layer. The image display layer includes a liquid crystal layer 18 disposed between the first and second substrates 23, 25. This embodiment is a full color display and the image display layer thus further comprises red, green and blue color filters 24R, 24G, 24B. For example, other components such as an address electrode that addresses the liquid crystal layer 18, an alignment layer that aligns the liquid crystal material, and a polarizing plate do not form part of the present invention and are not shown.

  In this embodiment, each parallax optical element 12, 12 'is embodied as a switchable parallax barrier. Each parallax optical element 12, 12 'can be switched between OFF states. In the OFF state, the entire portion is non-uniformly transmitted, the parallax barrier is not defined, and the ON state is not set.

  The parallax optical elements 12, 12 'provide a single parallax barrier for use in the ON state when the parallax barrier 12 is in one direction (eg, lateral direction). Another parallax optic 12 'provides one parallax barrier suitable for use in the ON state when the device is in another direction (eg, longitudinal).

  FIG. 11 (b) is a schematic assembly view of the display 9 of FIG. 11 (a), showing two parallax optical elements 12, 12 'and an image display layer 10. FIG. They are separated from each other for clarity of explanation. Both parallax optical elements 12 and 12 'are shown in an ON state in FIG. Again, it is a diagram for clarity explaining how the opaque and transmissive portions of each parallax optical element are arranged. As shown in FIG. 11 (b), the respective parallax optical elements 12, 12 ′ are strip-shaped and generally extend so as to have a parallax in each ON state, and the opaque portions 1, 1 ′. With light transmissive portions 5, 5 'separated by. However, the opaque portion 1 and the transmissive portion 5 of one parallax optical element 12 are substantially perpendicular to the opaque portion 1 'and the transmissive portion 5' of the other parallax optical element 12 '.

  The display 9 is shown in FIG. 11 (b) in the vertical direction. In this direction, the first parallax barrier 12 is switched off and the second parallax barrier 12 'is switched on to define a vertical opaque strip 1'. When the device rotates in the lateral direction, the second parallax barrier switches to ON, and due to the rotation of the device, the opaque strip of this parallax barrier is in the vertical direction. The second parallax barrier 12 'switches to OFF when the device rotates in the lateral direction.

  When both parallax optical elements 12, 12 'are switched off, the display 9 acts as a conventional 2-D display, regardless of whether it is vertical or horizontal.

  In FIG. 11B, both parallax optical elements 12, 12 'are shown in their respective ON states for clarity of explanation. However, it is preferred that the device does not operate with both parallax optical elements switched on simultaneously. It is possible for both parallax optical elements to be switched on at the same time, but then the display will encounter the low intensity problem in the 3-D mode as already explained. It is preferable that only one of the parallax optical elements is switched ON at a time.

  11 (a) and 11 (b), one parallax optical element 12 is installed behind the image display layer 10, and the other parallax optical element 12 ′ is installed in front of the image display layer 10. Yes. (The concepts “back” and “front” relate to a display perceived by the viewer.) Although this embodiment does not prescribe this arrangement, both parallax optical elements 12, 12 ′ are on the same side as the display. It is possible to be installed. For example, both parallax optical elements 12, 12 'can be placed behind the image display layer as shown in the basic structure diagram of FIG. Alternatively, both parallax optical elements 12, 12 ′ can be provided in front of the image display layer 10.

  Any suitable switchable parallax optic may be used in this embodiment. For example, the switchable parallax optic shown in FIGS. 8, 9, 10 (a) -10 (d) may be used.

Further advantages of the embodiments of FIGS. 11 (a) -11 (c) are not defined for image display layers having square pixels or square composite pixels. If the parallax optic is a parallax barrier, for example, the pixel barrier separation of one barrier is not equal to the pixel barrier separation of the second barrier so that the term “s” in equation (3) is not a constant. In addition, two parallax barriers can be arranged. The embodiment of FIGS. 11 (a) -11 (c) provides a constant viewing distance when S _P / P _P -S ₁ / P ₁ . In this case, S _P is the parallax barrier pixel isolation barrier to be used in the vertical direction, with P _P is vertical pixel pitch, S _l in the parallax barrier of pixel isolation barrier to be used in the vertical direction, P _l is The pixel pitch in the horizontal direction (when the separation e between views in one direction is almost the same as in the other direction). (If the two parallax barriers are placed at the same distance, but are placed on the opposite side of the image display layer such that S _P = S ₁ , the image display layer is either a square pixel or (Note that we need to have a square composite pixel.)
The parallax barrier of the type shown in FIG. 6 (b) can be embodied as a parallax barrier that can be switched using any method shown in FIGS. 8, 9, 10 (a) to 10 (d), for example. Should be noted. This has the advantage that the embodiment of FIGS. 6 (a) -6 (d) can be embodied as a display that is switched to provide a 2-D display. However, when operating in the directional display mode, low-intensity problems can occur as described above.

  In the embodiment of FIGS. 11 (a) to 11 (c), each parallax optic 12, 12 ′ and image display layer 10 are provided with a separate pair of substrates. However, when both parallax optical elements are arranged on the same side of the image display layer so that the substrate is common to both parallax optical elements, for example, the substrate is one of the image display layer 10 and the parallax optical element. Can be common.

  In a further embodiment of the invention, two switchable parallax optical elements are defined in a single addressable layer. This embodiment is described with reference to FIGS. 12 (a) -12 (d). In the described example, the addressable layer is a liquid crystal layer, but embodiments are not necessarily defined therein.

  As shown in FIG. 12 (a), an addressable layer is provided with a set of two independent addressable electrodes 28,29. One set of electrodes 28 defines a parallax barrier in the addressable layer. The parallax barrier is suitable for use when the display is in one direction (eg, in the horizontal direction). The second set of electrodes 29 defines a parallax barrier suitable for use when the display is in another direction (eg, the vertical direction). As shown in FIG. 12A, each set of electrodes 28 and 29 is composed of a set of stripe electrodes 28a, 28b and 28c; 29a, 29b and 29c. These stripes extend parallel to each other so that one set of electrodes is substantially perpendicular to the other set of electrodes.

  The parallax optical element of this embodiment can be embodied by arranging one set of electrodes. For example, “transverse electrodes” 28a, 28b, 28c. . . It is. This is shown in FIG.

  Then, the electrically insulating layer 31 is formed with the lateral electrodes 28a, 28b, 28c. . . Place on top so that the lateral electrodes are completely covered. The top surface of the barrier layer is deposited or made substantially flat as shown in FIG. 12 (c).

  A second set of electrodes, in this example "longitudinal electrodes" 29a, 29b, 29c. . . Is deposited on the barrier layer. They are insulated from the lateral electrodes 28a, 28b, 28c by an insulating barrier layer 31. This is shown in FIG.

  A second substrate having two independent addressable sets of crossed electrodes shown in FIG. 12 (a) is similarly prepared. The two substrates are then assembled with a layer of addressable material, such as a liquid crystal material, disposed between one substrate and the other. When this parallax barrier is incorporated into a multi-view directional display, the addressable layer is addressed using either the transverse electrode 28 or the longitudinal electrode 29, whichever is appropriate. When the display is in the horizontal direction, for example, the horizontal electrode 28 is activated, defining a parallax barrier suitable for the horizontal direction of the device in the addressable layer, and the vertical electrode 29 is turned off. When the device rotates in the vertical direction, the lateral electrode 28 is switched off and the vertical electrode 29 is activated to define a parallax barrier suitable for use in the vertical direction of the display.

  In this embodiment, the parallax barrier is defined in the layer 31 in both directions, so the pixel barrier separation does not change between the vertical and horizontal directions. Therefore, to obtain the same viewing distance in one direction as in the other direction, the image display layer needs to have square pixels or square composite pixels.

  The parallax barriers in FIGS. 12A to 12D can be switched in the two ON modes, and can also be switched to the OFF mode in which the parallax barrier is not defined in the addressable layer. The parallax barrier is therefore suitable for incorporation in displays where it is desirable to be able to switch between directional mode and 2-D mode operation.

  Figures 13 (a) to 13 (d) show further embodiments of the present invention. Two switchable parallax optical elements are again defined in a single addressable layer. In the example described, it is an addressable liquid crystal layer, but embodiments are not necessarily limited to this.

  As shown in FIGS. 13 (a) and 13 (b), an addressable layer is again provided with an addressable set of two independent electrodes 28,29. One electrode 28, 29 is arranged on each side of the addressable layer. One set of electrodes 28 defines an appropriate parallax barrier for use when the display is in one direction (eg, lateral direction) in the addressable layer, and a second set of electrodes 29 is the other in the display. Define a parallax barrier suitable for use when in one direction (eg, longitudinal). As in the embodiment of FIG. 12 (a), each set of electrodes 28, 29 consists of a pair of stripe electrodes 28a, 28b, 28c; 29a, 29b, 29c. These striped electrodes extend parallel to each other and one set of electrodes is substantially perpendicular to the other set of electrodes. The stripe electrodes 28a, 28b, 28c; 29a, 29b, 29c are generally similar to the stripe electrodes of the embodiment of FIG.

  In the embodiment of FIGS. 13 (a) and 13 (b), the first set of electrodes 28 includes an additional electrode 28w. Electrode 28w is complementary to the shape of electrodes 28a-28c of the first set of electrodes. In the embodiment of FIG. 13 (a), the complementary electrode 28w comprises a set of stripe electrodes 28x, 28y, 28z. The stripe electrodes 28x, 28y, and 28z have finger-like projections mutually with the stripe electrodes 28a to 28c. The width of one of the stripe electrodes 28x, 28y, 28z of the complementary electrode 28w is slightly smaller than the gap between two adjacent stripe electrodes 28a-28c of the first set of electrodes. Thus, each stripe electrode 28x, 28y, 28z of the complementary electrode 28w substantially fills the gap between two adjacent stripe electrodes 28a-28c of the first set of electrodes, resulting in a small gap 130 ( Electrical insulation between the first set of electrodes 28 and the complementary electrodes 28w is provided, leaving typically 10 μm wide). Similarly, the second set of electrodes 29 includes an additional electrode 29w. Electrode 29w generally has a complementary shape to that of electrodes 29a-29c of the first set of electrodes. In the embodiment of FIG. 13B, the complementary electrode 29w is composed of a set of stripe electrodes 29x, 29y, and 29z. The stripe electrodes 29x, 29y, and 29z project finger-like projections from the stripe electrodes 29a to 29c. The width of one of the stripe electrodes 29x, 29y, 29z of the complementary electrode 29w is slightly smaller than the gap between two adjacent stripe electrodes 29w of the second set of electrodes, so that the stripe electrode 29x of the complementary electrode 29w , 29y, 29z substantially fill the gap between two adjacent stripe electrodes 29a-29c of the second set of electrodes and provide electrical isolation leaving a small gap 130 (typically 10 μm).

  The complementary electrodes 28w, 29w are preferably at the same level as the first or second set of electrodes 28, 29, as shown in FIG. 13 (d) which is a cross-sectional view showing addressable layers and electrodes. . A metal layer is placed on the substrate 30 and the metal layer is etched to define a first set of electrodes 28 and a complementary electrode 28w as shown in FIG. 13 (c), and a second set of electrodes 29 and By correspondingly forming complementary electrodes 29, the electrodes can be advantageously processed. The metal layer can be, for example, an ITO (indium tin oxide) layer.

  The substrate 30 can then be subjected to further processing steps such as deposition and rubbing of an alignment layer (not shown). The substrate 30 is combined to define a cell 131, which is then filled with an addressable material, which in this example is a layer of liquid crystal material 21.

In this embodiment, the first set of electrodes 28 defines a parallax barrier in one direction of the display, for example, in the horizontal direction, and the second set of electrodes 29, for example, parallax in the other direction of the vertical display, for example. Define barriers. Compared to the embodiment of FIGS. 12 (a) -12 (c), one set of electrodes 28, 29 and the corresponding complementary electrodes 28w, 29w, as a counter electrode, apart from the narrow gap 130 between them, Defines the basic continuous electrode part that acts. Thus, to obtain a lateral parallax barrier, a first voltage is applied to the first set of stripe electrodes 28a-28c while a second different voltage is applied to the first set of stripes 29a. Applied to .about.29c and corresponding complementary electrode 29w, basically produces a counter electrode with a uniform potential over the whole addressable part. Defining the opaque portion of the parallax barrier by selecting the first and second voltages such that the portion of the addressable layer under the first set of stripe electrodes 28a-28c is substantially non-transmissive. To do. (In practice, the second voltage can also be applied to the upper complementary electrode 28 so that the potential between the upper complementary electrode 28 and the lower stripe electrodes 29a-29c or the lower complementary electrode 29 is zero. To be.)
Similarly, to obtain a parallax barrier in the vertical direction, a first voltage is applied to the stripe electrodes 29a-29c of the second set 29, while a second different voltage is applied to the second set of stripe electrodes. Applied to 28a-28c and corresponding complementary electrode 28w, essentially produces a counter electrode with a uniform potential across the entire portion of the addressable layer. The opaque portion of the parallax barrier is defined by selecting the first and second voltages such that portions of the addressable layer of the second set of striped electrodes 29a-29c of the electrodes are substantially non-transmissive. To do.

  By applying a first voltage to the first set of stripe electrodes 28a-28c and the corresponding complementary electrode 28w and applying to the first set of stripe electrodes 29a-29c and the corresponding complementary electrode 29w, 2 A dimensional display mode may be acquired. This produces essentially two uniform electrodes, one on each side of the addressable layer. The first and second voltages are selected such that the addressable layer applies a transparent state over the entire portion (depending on the nature of the addressable layer, the first voltage may be equal to the second voltage). Or may be different from the second voltage).

  The operation of the present invention can be summarized by the following table:

本実施形態の視差バリアは、電極の第１（または第２）のセットおよび対応する補完的電極が金属層を単純にエッチングすることによって規定され得るので、製造するのに安価であるという有利性を有する。さらに、一度に１つの視差バリアのみが規定されるので、ディスプレイは比較的狭い非透過部分を有し、明るい画像が獲得される。

The parallax barrier of this embodiment has the advantage that it is inexpensive to manufacture because the first (or second) set of electrodes and the corresponding complementary electrodes can be defined by simply etching the metal layer. Have Furthermore, since only one parallax barrier is defined at a time, the display has a relatively narrow non-transmissive part and a bright image is obtained.

  FIG. 14 (a) shows a further parallax barrier 12 configured in one or the other of two different ON states.

The parallax optical element in FIG. 14A is again a parallax barrier. A first linear polarizing plate 31 having a transmission axis disposed at 45 ° with respect to the reference direction is provided. The next layer is a patterned reactive mesogen layer 32, followed by a Frederick type liquid crystal layer 33 having a thickness of λ / 2, where λ is the designed wavelength of the display. Since 550 nm is approximately the center of the visible wavelength range, typically λ = 550 nm. (A Frederick type liquid crystal layer or a FRED liquid crystal layer is a simple flat type non-twisted liquid crystal layer.)
The liquid crystal layer 33 follows the second patterned reactive mesogen layer 34 and then the second linear polarizer 35 having a 45 ° transmission axis in the reference direction. Finally, the parallax barrier 12 includes a switchable scattering layer 36.

  A switchable scattering layer 36 is provided on the output surface of the parallax barrier 12. That is, in use, light enters the parallax barrier via the first polarizing plate 31 and exits via the switchable scattering layer 36. As a result, when the switch of the switchable scattering layer 36 is turned on and the light exiting the parallax barrier 12 is scattered, any parallax barrier defined in the liquid crystal layer 33 is also removed by the scattering layer 36. Therefore, when the switch of the scattering layer 36 is switched ON, the parallax barrier 12 is switched OFF and has a non-uniform transmittance in the whole part.

  Each RM layer 32, 34 is patterned into four different parts. The optical axis of the reactive mesogen layer varies between parts. In the first RM layer, the first part 32 has an optical axis of 67.5 ° with respect to the reference direction, the second part has an optical axis of 0 ° with respect to the reference direction, The third part has 22.5 ° with respect to the reference direction and the fourth part has an optical axis of 45 ° with respect to the reference direction. In the second RM layer 34, the first portion has an optical axis of 22.5 ° with respect to the reference direction, the second portion has an optical axis of 135 ° with respect to the reference direction, and the third portion This part has an optical axis of 22.5 ° with respect to the reference direction, and the fourth part has an optical axis of 45 ° with respect to the reference direction.

  The liquid crystal layer 33 is switchable and has an optical axis arranged at 45 ° with respect to the reference direction. The liquid crystal layer 33 used switches between a state acting as a half-wave plate and a vertical state. The RM layer acts as a phase retarder.

  When the scattering layer 36 is switched off, the liquid crystal layer includes one set of portions that are always opaque (portion 4) and one set of portions that are always transparent (portion 2). In addition, the liquid crystal layer includes one set of portions (portion 1) that is transparent when the liquid crystal layer is switched on but becomes opaque when the liquid crystal layer 33 is switched off. Finally, it includes one set of portions (portion 3) that becomes opaque when the liquid crystal layer 33 is switched on and transmissive when the liquid crystal layer 33 is switched off. Therefore, it is possible to define a longitudinal mode parallax barrier or a lateral mode parallax barrier in the liquid crystal layer 33.

  FIG. 15 (a) shows one of the respective portions arranged in 1-4 in a 2 × 2 matrix. When the switchable scatterer is OFF but the liquid crystal layer 33 is ON, parts 3 and 4 are opaque and parts 1 and 2 are transmissive. Thereby, a first parallax barrier having a vertically extending opaque and transmissive strip is defined as schematically shown in FIG. 15 (b). However, when the liquid crystal layer 33 is switched OFF, the parts 1 and 4 become opaque and the parts 2 and 3 become transmissive. Accordingly, a parallax barrier having a horizontally extending opaque portion and a horizontally extending transmissive portion is defined as shown in FIG. As described above, the parallax barrier of the present embodiment can be configured again between the first ON state and the second ON state.

  When the switchable scatterer layer 36 is switched ON, all portions of the liquid crystal layer 33 become light transmissive as shown in FIG. This switches the display to a 2-D display.

  FIG. 15 (d) shows one possible arrangement of the parts 1, 2, 3, 4 in the liquid crystal layer. Parts 1 and 2 are arranged in a row, and parts 3 and 4 are also arranged in a row. Like parts 2 and 3, parts 1 and 4 are arranged in rows. When the liquid crystal layer is switched and the portions 3 and 4 are black and the portions 1 and 2 are transmissive, the vertical opaque portion and the vertical transmissive portion (the vertical is related to the direction shown in FIG. 15D) A parallax barrier having is obtained. If the liquid crystal layer is switched so that parts 1 and 2 are black and parts 3 and 4 are transmissive, horizontal opaque and horizontal transmissive parts (horizontal is again shown in FIG. 15 (d). A parallax barrier with a reference to the direction is obtained. In this way, the liquid crystal is switched to provide a parallax barrier having horizontally transmissive and opaque portions, or providing a parallax barrier having vertically transmissive and opaque portions.

  Finally, FIG. 15E shows a necessary state of the portion 1-4 of the liquid crystal layer 33 in the 2-D mode, the vertical mode, and the horizontal mode.

  The switchable scattering layer 36 can be omitted from the parallax barrier of this embodiment. If the scattering layer 36 is omitted, the parallax barrier can be switched to provide 2-D mode operation (two identical images are displayed and the display is operated in 2-D mode so that one eye of the viewer To be able to see the same image).

  In this embodiment, the two parallax barriers defined in the addressable layer may have a width and pitch selected independently of each other. The parallax barrier of this embodiment can therefore be used by appropriately configuring two parallax barriers using any image display layer, where the viewing distance of the display in the horizontal direction is the viewing distance of the display in the vertical direction. It is possible to ensure that they are substantially the same. Using portions 1 to 4 of the dimensions as shown in FIG. 15 (d), for example, one parallax barrier has a pitch approximately three times that of the other parallax barrier.

  The switchable scattering layer 36 can be, for example, a polymer-scattered liquid crystal layer.

  The above display can be provided with other well-known features such as "observer tracking". It is well known to monitor the position of the viewer's eyes and adjust the data allocation to the pixels of the image display layer 10 to take into account viewer movement. This can be done especially if the viewer starts moving to a place where it can otherwise receive crosstalk or secondary images. Monitoring the position of the viewer's eyes and thus adjusting the data allocation to the image display layer can also be performed using any suitable observer tracking technique.

  Alternatively, in an embodiment where the parallax barrier is defined in an addressable layer, rather than adjusting the data allocation to the pixels of the image display layer 10 to take into account the observer's movement, the observer's movement It is possible to adjust the parallax barrier to take into account. In this embodiment, the parallax barrier is adjusted to change the position of the viewing windows of the two images displayed on the image display layer 10 to track the position of the viewer's eyes. For example, the position of the parallax barrier can be adjusted if the electrode strips defining the barrier in the addressable layer are each formed from a plurality of independent addressable electrode strips. For example, it is possible to switch off one strip on the left side of the opaque part of the parallax barrier while switching on one electrode strip on the right side of the opaque part of the parallax barrier. This is repeated for each opaque strip of parallax barrier, and the position of the effective parallax barrier moves to the right, thus changing the position of the visual portion of the two images displayed on the image display layer.

  If the display is rotated from one direction to the other, for example from the horizontal mode to the vertical mode, the viewing angle characteristics of the display may change. If the display used has uniform viewing angle characteristics, the quality of the displayed image is hardly affected by the rotation of the display from one direction to the other. However, if the viewing angle characteristics are non-uniform, the quality of the displayed image is a factor in the display operation, as may be the case with a simple twisted nematic liquid crystal display that does not have a complex viewing angle compensation film. It can vary greatly between directional and longitudinal modes. This can be a problem, especially for dual view displays, because dual view displays tend to be operated at larger viewing angles than autostereoscopic displays. One way that this disadvantage can be overcome is to use a different gray scale mapping for the display in each direction. This allows for the best use of the display's transmission voltage characteristics for each direction of the display.

  In the above embodiment, the parallax barrier is outside the image display device. This limits the minimum separation between the parallax barrier and the image display layer, and the maximum angular separation between the two viewing windows may be too low. If it is desired to increase the angular separation between the two viewing windows, a parallax barrier is placed in one of the substrates of the image display layer in accordance with the teachings of co-pending UK patent application No. 0320358.5. It is possible.

  In the above embodiment, the image display apparatus includes a liquid crystal layer. However, the invention is not limited to displays having a liquid crystal image display layer. Any suitable image display layer can be used. The image display layer can be a transmissive layer illuminated by a suitable backlight, or it can be a radiating layer such as an OLED layer, a plasma panel layer, a cathode ray tube.

  The invention can be applied to front barrier displays and rear barrier displays.

  The invention has been described by reference to a display that is intended to operate in a landscape or portrait mode. However, the present invention is not defined in two specific display modes. The present invention may also be applied to any display that is intended to be viewed in two or more different directions.

  FIG. 17 is a schematic plan view of a further multi-view directional display 120 of the present invention. Display 120 may display four independent views, each view being displayed along a respective one of four different non-coplanar directions. Each view is displayed in a direction inclined with respect to the display surface of the display 120. As a result, each viewer 122a to 122d can see each view. When the direction in which the view is displayed is projected onto the display surface of the display 120, each projected direction is approximately 90 ° with respect to the adjacent projected direction. FIG. 17 shows the viewing window of each view having an angle range of approximately 90 ° as seen in the front view, but the embodiment is not limited to this, and the viewing windows have different angle ranges from each other. Can do. The viewing direction of an image is defined as the center direction of the viewing window for that image. Each of the images has substantially the same viewing distance as the other images.

  As described below, the views are not all displayed in the same orientation. For example, views 2 and 3 can be displayed in one orientation (eg, portrait orientation), and views 1 and 4 can be displayed in different orientations (eg, landscape orientation). When the display is rotated 90 ° about the vertical axis, a view displayed in portrait mode in one orientation of the display is displayed in landscape mode in the new orientation, and vice versa.

  The display 120 of FIG. 17 can be used, for example, in a horizontal desktop interactive game in which the display is arranged on the table 121 such that its display surface is horizontal. Each observer 122a-122d may be a game participant, with different participants being provided with different information about the game situation. Other uses of the display 120 of FIG. 17 can be used in class. One of the observers 122a can be a teacher and the remaining observers 122b-122d can be students. The display 120 can also be used in business meetings or conferences. In these applications, the display operates as a “dual view” display, where each viewer sees a view that can be controlled independently of the view displayed to other viewers.

  A display of the type shown in FIG. 17 can also be used as a three-dimensional multi-view display, in which case the display surface can be used vertically like a conventional display, or the display surface can be used horizontally. . In this case, the positions 122a to 122d shown in FIG. 17 represent the positions of the eyes of the observer rather than the positions of the observer. Thus, for example, view 2 and view 1 can each be a right-eye view and a left-eye view displayed to the viewer from the first view, and views 4 and 3 can each be a view above the first view. The right eye view and the left eye view displayed from Accordingly, the display 120 may display an autostereoscopic 3D image that is independent of two separate views. This can give a vertical “look around” effect, where one observer can change the first 3D view or the second 3D view from above or below the first 3D view. May be in the eyes. (For this application, the orientation of the display needs to be changed from the orientation shown in FIG. 17. The display is in one of the lower corners (eg, the lower right corner for the view assignments that came out earlier). As a result, the two images of each stereoscopic image pair were displayed at the same vertical height, or the pixel assignment shown in Fig. 18 (a) needs to be changed. As a result, two of the images were displayed at one height and the other two of the images were displayed at different heights.) Or (for example, two observers opposite the table) View 1 and 2 can provide a 3D view to each other, and views 3 and 4 can provide a 3D view to a second observer, thus combined 3D, dual viewing mode To provide.

  The embodiment of FIG. 17 is described below with respect to a display that displays exactly four views. However, this embodiment can be applied to displays that can display more than four views.

  FIGS. 18 (a) -18 (c) illustrate one way in which the display 120 may display four views along four separate directions. FIG. 18A shows how an image is displayed on the image display layer 125. The image display layer is displayed from the first area displaying the first view to the fourth view. It can be seen that it has four regions. In the embodiment of FIG. 18 (a), the image display layer is a pixelated image display layer, and FIG. 18 (a) shows how four views are assigned to pixels. In the embodiment of FIG. 18 (a), each view is displayed on two pixels 124a-124h, each pixel being numbered "1", "2", "3" or "4" Indicates which of View 1 to View 4 is displayed at that pixel. As can be seen from FIG. 18 (a), the two views (views 2 and 3) are displayed side by side on one row of pixels. One view (view 1) is displayed on the pixel row above the row of pixels on which views 2 and 3 are displayed, and the fourth view (view 4) is displayed on views 2 and 3. Displayed on the pixel row below the pixel row. Views 1 and 4 are displayed on the same pixel column. In addition, the pixel column in which views 1 and 4 are displayed displays the left column in which view 3 is displayed and view 2 so as to produce the “cross” group of pixels shown in FIG. 18 (a). With the right column.

  The image display layer can be any suitable pixelated image display layer. It can be a liquid crystal transmissive display layer, such as a pixelated display layer illuminated by a suitable backlight, an emissive display layer, such as an OLED (Organic Electroluminescent Device) or a PDP array, or other having a normal suitable pixel structure It can be a display.

  FIG. 18 (a) shows each view displayed on only a single row of pixels and on two columns of pixels. The present invention is not limited to this, and each view may be on more than one pixel row and / or more than two, provided that the “cross” group of FIG. 18 (a) is provided. It can be displayed on a pixel column.

  In the case of a full-color display, each pixel 124a to 124h shown in FIG. 18A is made up of a red sub-pixel 124R, a green sub-pixel 124G, and a blue sub-pixel 124B, as shown in the inset to FIG. It can be done.

  FIG. 18 (b) shows a suitable parallax optic 126 for use with the image display layer 125 of FIG. 18 (a). In this embodiment, the parallax optical element is a parallax barrier with a transmissive aperture 127. The transmissive aperture 127 of the parallax barrier is substantially the same shape as adjacent pixels along the two sides of the image display layer 125, but is slightly smaller. The parallax barrier is generally similar to, for example, the parallax barrier of FIG. 6 (b), with one parallax barrier having impermeable strips extending horizontally in FIG. 18 (b) and in FIG. 18 (b). It can be said to be an overlap with another parallax barrier having a non-transparent strip extending in the vertical direction.

  FIG. 18 (c) shows the parallax barrier 126 of FIG. 18 (b) overlaid on the image display layer 125 of FIG. 18 (a). The opening 127 of the parallax barrier 126 has an area for displaying a first view (ie, having two pixels 124a and 124b) and an area for displaying a second view (ie, having two pixels 124c and 124d). And a region displaying a third view (ie, having two pixels 124e, 124f) and a region displaying a fourth view (ie, having two pixels 124g, 124h). The opening 127 of the parallax barrier is arranged substantially at the center on the cross-shaped group of pixels shown in FIG. When the parallax barrier 126 is placed between the image display layer 125 and the viewer, an observer looking at the display from the left (such as the display shown in FIG. 18 (c)) Since 4 is blocked by the opaque region of the parallax barrier, view 3 is perceived, but views 1, 2 or 4 are not viewed. On the contrary, the observer who is looking at the display from the right hand side perceives only the image 2. Similarly, an observer looking at the display from the upper end perceives only image 4, while an observer looking at the display from the lower end perceives only image 1.

  Note that views 1 and 4 are viewed in landscape mode because the two pixels in which views 1 and 4 are displayed are arranged laterally with respect to their respective viewers. However, views 2 and 3 are arranged so that the two pixels on which image 2 or image 3 is displayed are one on top of the other when viewed by the viewer to whom view 2 or view 3 is directed. So it is displayed in portrait mode. Accordingly, the display 120 of this embodiment displays images simultaneously in two different modes.

  FIG. 18 (a) shows one element of the image display layer 125 of the display 120. FIG. 19 (a) illustrates one way in which pixels of the image display layer can be assigned to four views to define the plurality of cross-shaped pixel groups of FIG. 18 (a). The structure of FIG. 19 (a) is such that the two pixels assigned to view 1 of one element are adjacent in the same row as the pixels assigned to view 4 of the other element. It can be said that it is obtained by interlacing the cross-shaped pixel group. Thus, every other row of pixels in FIG. 19 (a) is assigned to views 2 and 3, and an interlaced row of pixels is assigned to views 1 and 4.

  FIG. 19 (b) illustrates a suitable parallax barrier 126 disposed in front of the image display layer 125 of FIG. 19 (a). The parallax barrier comprises an array of openings 127. When the parallax barrier is arranged on the image display layer 125, the openings are arranged so that each opening 127 is arranged on the center of one of the cross-shaped pixel groups defined in the pixel structure of FIG. Is positioned.

  Comparing FIG. 19 (b) with FIG. 17, when four views are shown to four viewers placed in a tabletop orientation, in the same way that view 1 is displayed on the image display layer, It can be seen that View 1 is displayed to the viewer 122a. That is, the pixel of image 1 shown at the bottom of the image display layer in FIG. 19B is at the bottom of the image viewed by the viewer 122a. However, the pixel of image 4 shown at the bottom of the image display layer in FIG. 19 (b) is at the top of the image viewed by the viewer 122d. This is because the viewer 122d who views the view 4 is on the opposite side of the table 121 with respect to the viewer 122a who views the view 1 (the viewer 122d faces the viewer 122a). In order to ensure that both observers properly view their respective images, the two images are assigned to pixels of each of the two images of the image display in different first and second ways, and As a result, it is preferred that the views have different orientations on the image display layer. That is, view 1 preferably has label 1 of the image display layer so that the top and bottom of the image are at the top and bottom of the image display layer as shown in FIG. 19 (b), respectively. Assigned to numbered pixels. However, view 4 preferably has the numbered pixels of label 4 so that the top and bottom of the image are at the bottom and top of the image display layer, respectively, as shown in FIG. 19 (b). Assigned.

  Similarly, the observers 122b and 122c face each other over the table 121. Therefore, view 2 is assigned to each pixel in a different way than view 3, so that the views need to have different orientations on the image display layer. The viewer is positioned as shown in FIG. 17, and view 2 is preferably such that the top and bottom of the image are respectively to the left and right of the image display layer as shown in FIG. 19 (b). Are assigned to the numbered pixels of label 2. However, view 3 is assigned to the numbered pixels of label 3 so that the top and bottom of the image are respectively to the right and left of the image display layer as shown in FIG. 19 (b).

  The display in FIG. 17 displays stereoscopic images to two different observers, views 1 and 2 form a stereoscopic image pair for one observer, and views 3 and 4 to other observers. Where a stereoscopic image pair is formed, views 1 and 2 must be assigned to respective pixels of the image display layer in the same manner, and views 3 and 4 can also be assigned to the image display layer in the same manner. Must be assigned to each of the pixels. As a result, each observer can see an appropriate stereoscopic image. However, since the two observers are facing each other across the table, the method in which views 1 and 2 are assigned to each pixel of the image display layer is that views 3 and 4 are assigned to each pixel of the image display layer. Different from the method used. For example, views 1 and 2 may be assigned to the image display layer such that the top and bottom of the image move along the upper left and lower right diagonal edges of the image display layer in FIG. Can be assigned to the image display layer such that the top and bottom of the image move along the lower right and upper left diagonal edges of the image display layer in FIG. 19 (b).

  FIG. 20 (a) shows another way in which the pixels 124 of the image display 125 can be assigned to four views. In this structure, each row of pixels displays all four of the views. This structure interlaces the cross pixel group of FIG. 18 (a) so that the row above one pixel group is defined on the same pixel row as the second row of pixels of the adjacent cross pixel group. Can be thought of as doing. One of the cross-shaped pixel groups in FIG. 18A is highlighted in FIG.

  FIG. 20B shows the image display layer 125 of FIG. 20A, on which a parallax barrier is disposed. When the position of the opening 127 of the parallax barrier is selected again and the parallax barrier is disposed on the image display layer 125, the center of each opening of the parallax barrier is one of the cross-shaped pixel structures of FIG. Coincides with the center.

  FIGS. 19 (a) to 20 (b) show two possible assignments of image display layer pixels and corresponding parallax barriers from among the four images that incorporate the “unit cell” of FIG. 18 (a). However, the present invention is not limited to these cross-shaped interlaces. Other cruciform interlaces can be used.

  The allocation of pixels between images can be selected depending on the particular intended use of the display. For example, if barrier visibility is a problem, the pixel structure shown in FIG. 20 (a) is better. This is because the barrier opening 127 is not arranged on a vertical line or a horizontal line as can be seen from FIG. In FIG. 20 (b), the opening 127 of the parallax barrier is arranged in a line inclined in the horizontal direction or the vertical direction, and the human eye has the same degree as the vertical line and the horizontal line in FIG. 19 (b). There is no tendency to see such a line. Another possible assignment of pixels in the image display layer is the “unit cell” random or semi-random structure of FIG. 18 (a), which can further reduce the visibility of the parallax barrier, Also, privacy between views can be improved (since the secondary viewing window shows all pixel blends in different parts of the display, the view is only visible at its intended viewing distance. is there). Privacy is useful in applications such as playing games.

  In FIG. 19 (a) and FIG. 20 (a), each pixel 124 is composed of a red pixel, a blue pixel, and a green pixel as shown in the inset to FIG. 18 (a) in the case of a full color display. obtain. Further, as previously described with reference to FIG. 18 (a), FIGS. 19 (a) and 20 (a) show each view located only in a single row of pixels, but the present invention It is not limited to this.

  Both FIG. 19 (b) and FIG. 20 (b) show that a viewer viewing the display along a right angle to the display surface will see a mixture of views 2 and 3.

  Display 120 can be used as a dual view display where case views 1, 2, 3, and 4 can be independent of each other, as previously described. Alternatively, as previously described, it can be used to provide two 3D autostereoscopic views in the case of four views that include a left eye image and a right eye image of two independent stereoscopic image pairs. Two image pairs may represent one image from two different views and may represent two different images to provide a combined 3D and dual view mode.

  The present invention is not limited to use with a parallax barrier as a parallax optical element. The display according to this embodiment of the invention may comprise other types of parallax optical elements, for example a biconvex lens array. The display of this embodiment may use a multi-parallax barrier system, where two or more parallax barriers are provided, for example as described for the embodiment of FIG. 12 (a).

  The parallax optical element may be a fixed parallax optical element. Alternatively, the parallax optical element can be an active parallax optical element and can switch between an ON state and an OFF state. For example, when the parallax optical element is a parallax barrier, this is because the array of transmissive apertures is defined in the liquid crystal layer, the rest of the liquid crystal layer is non-transmissive, and the liquid crystal layer is uniformly transmissive It can be embodied as a liquid crystal layer that can be switched between OFF states. This allows the display to switch to the conventional 2D display mode by switching the parallax barrier off and re-addressing the display to display a single image in a conventional manner.

  The display 120 of this embodiment may be addressed in chronological order to improve the resolution of the display and / or the brightness of the displayed view.

  As can be seen from FIGS. 18 (a), 19 (a) and 20 (a), the display of the present invention may use a conventional pixelated image display layer in which rectangular pixels are arranged in rows and columns. . Thus, these embodiments of the present invention can be used with any conventional liquid crystal display panel and do not require a spatial display panel. Similarly, a conventional parallax barrier (or other suitable conventional parallax optic) including a regular array of rectangular apertures may be used, and the present invention does not require specialized parallax optic. A further advantage is that the interlaced pattern of the four views is relatively easy to reproduce.

  The view interlacing shown in FIGS. 18 (a), 19 (a) and 20 (a) does not require that any pixel of the image display layer be kept permanently dark. Each pixel in the image display layer is assigned to one of four views. This maximizes the brightness of the display and ensures that a quarter of the display's possible output intensity is input to each of the four views.

Further, as described above, the side edges of the display are vertical and the top and bottom edges of the display are horizontal, so that the panel 120 has a natural orientation with respect to the viewer 122 shown in FIG. ing. Two of the observers are looking at the landscape mode view and the two observers are looking at the portrait mode view. By rotating the display 90 °, the view that appears in the eyes of one observer changes from portrait mode to landscape mode (and vice versa).

  FIG. 21 (a) further illustrates an image display layer 125 suitable for use with the display 120 in this embodiment of the invention. The image display layer 125 is a pixelated image display layer as before, and four images are assigned to the pixels. As shown in FIG. 21 (a), the four images are assigned to groups of four pixels located at the ends of the four arms of the cross (+). In FIG. 21 (a), the pixels are shaded, thereby indicating the image to which the pixels are assigned. Each of the four images is represented by a uniform shadow, a diagonal shadow, a vertical shadow, and a dotted shadow. Thus, by making this assignment to the pixels again, a cross-shaped group of pixels is produced, the group including the pixels assigned to each image. This assignment of pixels is repeated throughout the image display layer, as shown in FIG.

  One parallax optical element suitable for use with the image display layer 125 of FIG. 21 (a) is shown in the figure. In the present embodiment, the parallax optical element is a parallax barrier, and the parallax barrier includes a first set of opaque regions 126a extending in one direction (lateral direction in FIG. 21A), a first set, And an intersecting second opaque region 126b. The first set of opaque regions is outlined in FIG. 21 (a) using a solid line, and the second set of opaque regions 126 (b) is shown in FIG. 21 (a) using a dotted line. Yes. This parallax barrier is similar to the parallax barrier of FIG. 6B, for example, and can be regarded as a superposition of two conventional parallax barriers spreading in a direction in which opaque regions intersect each other.

  FIG. 21 (b) shows the parallax barrier 126 generated by two sets of opaque regions 126 a and 126 b superimposed over the entire image display layer 125. As shown in the figure, the two sets of opaque regions generate a plurality of transmission openings 127, and the shape of the openings 127 is usually rectangular. The widths of the opaque regions 126a and 126b are selected so that the interval between adjacent transmission openings 127 substantially matches the interval between the cross groups of pixels 124. As a result, each transmissive opening 127 of the parallax barrier is associated with one of the cross-shaped groups of pixels, so that, as described above, four images are displayed in four different directions, Each of 21 (b) observers 122 sees one of the four images differently. In FIG. 21 (b), the image seen by each observer 122 is shown by an appropriate shaded area adjacent to the observer.

  In this embodiment, the image display layer region 128 in the middle of the cross-shaped group of pixels is not assigned to display an image. As a result, a black display is observed by an observer who observes the display along the normal line of the display. As a result, two images may be unintentionally observed at the same time, or in the case of an autostereoscopic display, an image for the left eye may be unintentionally seen by the right eye, or The possibility that an image for the right eye is seen is reduced. The black display also provides privacy. This is because it becomes more difficult for an observer to see an image that is not directed at the observer.

  This embodiment of the present invention is implemented in a conventional liquid crystal display panel or another pixelated display device. To that end, the middle pixel of the cross-shaped group needs to be driven invariably to produce a black display, providing a non-display area 128. Alternatively, this embodiment is implemented in a custom liquid crystal panel or another custom image display device in which no addressable pixels are provided in the middle of the cross-shaped group.

  In FIGS. 21 (a) and 21 (b), each image has been shown to be assigned to a single pixel. Thereby, the cross-shaped group of pixels contains exactly four pixels. To obtain a full color display, each pixel shown in FIG. 21 (a) may include three color sub-pixels. The sub-pixels are a red sub-pixel, a blue sub-pixel, a green sub-pixel, and the like as shown in the inset of FIG. Moreover, each image can be displayed on more than one pixel, and each image is not limited to be displayed on only one pixel.

  FIG. 22 shows a further embodiment of the display 120 of FIG. In the present embodiment, four images are assigned to pixels of the image display layer 125 according to the mode shown in FIG. In the present embodiment, the image display layer is a full-color image display layer, and thus the pixel is either a red pixel 124R, a blue pixel 124B, or a green pixel 124G. Each image is assigned to a composite pixel 124 generated by red, blue, and green pixels. For simplicity, each image has been shown to be assigned to only one composite pixel, but the assignment of images to pixels is similar to the assignment shown in FIG. Two images are assigned to two horizontally adjacent pixels, one image is assigned to the upper row, and the remaining one image is assigned to the lower row. The color subpixels of FIG. 22 are numbered “1”, “2”, “3”, or “4”, thereby indicating the image assigned to that subpixel. In FIG. 22, each color sub-pixel is shaded so that the sub-pixel is either a red sub-pixel (hatched shade), a blue sub-pixel (uniform shade), or a green sub-pixel (vertical shade). ).

  In the present embodiment, the parallax optical element is a color filter barrier. Normally, the color filter barrier includes an opening 127 arranged as shown in the parallax barrier in the embodiment of FIG. However, as shown in the inset of FIG. 22, each opening 127 includes regions having different light transmission characteristics. In the present embodiment, each opening 127 in the color filter barrier includes a first region 127r, a region 127b, and a region 127g. The region 127r transmits red light and substantially transmits blue light and green light. The region 127b transmits blue light while substantially blocking red light and green light, and the region 127g transmits green light while substantially blocking red light and blue light. Only the outline of the position of the opening of the color filter barrier is shown in FIG.

  It can be seen that the embodiment of FIG. 22 operates in the manner described above in connection with FIG. 18C for red light, green light, and blue light. The red transparent portion 127r of the opening 127 in the color filter barrier is arranged between the red pixel assigned to the view 2 and the red pixel assigned to the view 3 in the horizontal direction, and assigned to the view 4 in the vertical direction. Between the assigned red pixel and the red pixel assigned to image 1. Similarly, the portion 127B of the opening in the color filter that transmits only blue light is arranged between the blue pixel assigned to view 2 and the blue pixel assigned to view 3 in the horizontal direction, and in the vertical direction. , Between the blue pixel assigned to view 4 and the blue pixel assigned to view 1. The portion of the color filter that transmits the spectrum in the green region is located between the green pixel assigned to view 2 and the green pixel assigned to view 3 in the horizontal direction and assigned to view 1 in the vertical direction. Between the green pixel and the green pixel assigned to view 4. Thus, as in the embodiment of FIG. 18 (c), views 1, 2, 3 and 4 are oriented in four different directions.

  Compared to the embodiment of FIGS. 18 (c), 19 (b) and 20 (b), the embodiment of FIG. 22 perceives a dark display by an observer viewing the display along a right angle to the display surface. Has the potential advantage of This is because each portion of the aperture of the color filter barrier is not placed directly on a pixel that emits light transmitted by that portion of the aperture. The portion of the color filter that transmits red light is, for example, arranged so that it is partially adjacent to the blue pixel and partially adjacent to the green pixel, so that it is perpendicularly incident on the opening of the color filter barrier. All the incident light is blocked. Therefore, this embodiment provides a display that provides a dark display without the need to keep the pixels permanently black when viewed along the display vertically and without the need for a custom image display layer. Is done.

  Further details of color filter barriers are included in noted co-pending UK Patent Application No. 0320367.6.

Figures 23 (a) to 23 (c) show further embodiments of the present invention. In this embodiment, as shown in FIG. 23 (a), four images are assigned to pixels using simple horizontal and vertical interlaces. The parallax optical element in this embodiment is a parallax barrier having a rectangular transmission opening 127. This display is easy to implement, but has the potential disadvantage that the four views are directed to the corners of the display rather than the edges of the display. Since the embodiment of FIG. 23 (a) uses a simple interlace of four images, the display requires an easy and well-known addressing technique. (As in other embodiments, each pixel shown in FIG. 23 (a) may consist of three color sub-pixels as shown in the inset to FIG. 23 (a) to provide a full color display. .)
In order to retain the advantages of simple addressing provided by the simple horizontal and vertical interlaces of FIG. 23 (a), this embodiment is used with an image display layer in which the pixel columns are tilted with respect to the edge of the display. It is possible to execute. This image display layer is shown in FIG. 23 (b), in which a pixel column 128 and a non-display area 129 between adjacent pixel columns 128 are shown. This pixel column extends obliquely to the side edges of the image display layer 125 and to the top and bottom edges. When this image display layer is captured in a display using a parallax barrier in which the side edge of the opening 127 of the parallax barrier extends horizontally or vertically with respect to the pixel column, as shown in FIG. Directed to the center of the four edges of the display. Thereby, the observer does not have to look at the display from the corner, but can observe the display from a right angle shown in FIG. However, this embodiment generally requires a custom image display panel in which the pixel columns extend at an angle with respect to the edge of the image display panel.

  20 (a) and FIG. 20 (b), FIG. 21 (a) and FIG. 21 (b), FIG. 22 and FIG. 23 (a) to FIG. 23 (c), and FIG. As discussed above with respect to, images are preferably assigned to the image display layer in a different manner so that each view is viewed by a respective viewer in the proper orientation.

  The invention has been described above with particular reference to a parallax barrier having a rectangular opening. However, when a parallax barrier is used as a parallax optic, the aperture is not limited to a rectangle, but may be circular, square or any useful specific shape. A non-rectangular opening may be particularly preferred for a display of the type of FIG. 17 that displays five or more views.

  The edge of the opening in the parallax barrier can be further “softened” (apodized) to further reduce crosstalk, as described in UK patent application 9616281.3 and UK patent application 9917318.9. .

24 (a) to 24 (c) are basic conceptual diagrams of a parallax barrier 70 for a display according to a further embodiment of the present invention. The parallax barrier comprises four different types of regions 72 (in this example nine regions are shown, although a practical barrier includes ten or more regions) indicated by numerals 1-4 in the figure. Type 1, 2 and 3 regions are made from liquid crystal material. Once the liquid crystal material has exceeded the appropriate threshold voltage, it can select either opaque type 1 and type 3 regions, or opaque type 2 and type 3 regions, respectively, in the horizontal or vertical direction. It is switched so that a parallax barrier can be generated. Type 1 and type 2 regions can be made of materials that transmit light only under certain conditions. Type 3 regions consist of materials that need to transmit light in 2D mode. Type 4 regions are always required to transmit light and can consist of clear polymers or resins. The resin used in the Type 4 region can be a birefringent photoresist such as a reactive mesogen. (Type 4 regions are always required to transmit light, so the display polarizers must be positioned to allow this. Can the same polarizer configuration be used across the entire display area? Or alternatively, a patterned polarizer may be used.)
FIG. 24 (a) shows the orientation of the viewer and shows a parallax barrier suitable for a display operating in the portrait mode. FIG. 24 (b) again shows the orientation of the viewer, but shows a parallax barrier suitable for a display operating in the landscape mode. The dark strip 71 shows the opaque area of the parallax barrier. It is noted that the dark strip 71 of the barrier is always vertical when viewed by the viewer to provide proper horizontal separation of the two images. Thus, when the display is rotated from horizontal to vertical by appropriately selecting opaque type 1 and type 3 regions, or by selecting opaque type 2 and type 3 regions. The parallax barrier is reconfigured.

  FIG. 24 (c) shows all four different types of parallax barrier regions that transmit light. This figure provides a 2D display mode in which no parallax barrier is required.

  25 (a) and 25 (b) show examples of required threshold characteristics of the regions 1 to 3 of the barrier 70 shown in FIG. FIG. 25 (a) shows the corresponding region when the 2D display mode is required to be the active mode of the device, that is, when a voltage must be supplied to enable the 2D mode. Show properties. While regions of types 2 and 4 transmit light at low voltages, this is not the case for regions 1 and 3. Therefore, the type 1 and 3 regions form a longitudinal mode parallax barrier at low voltage. As the voltage increases above the voltage threshold T1, the type 2 region no longer transmits light and the region type 1 begins to transmit light. Type 3 and 4 regions remain opaque and transparent, respectively. Therefore, the parallax barrier changes from the vertical configuration to the horizontal configuration at the threshold T1. As shown at approximately T2, as the voltage further increases above the voltage threshold, all regions including the Type 3 region become transparent, providing an activated two-dimensional display mode.

  The characteristics of the region in FIG. 25B are similar to those in FIG. 25A except for the following points. That is, the presence of the two-dimensional mode in the zero or low voltage range allows the display to operate in the two-dimensional mode when no power is applied to the parallax barrier. All types below the voltage threshold T3 region are transparent. The transmission of light is stopped in the region above the voltage threshold T3 of type 3 and the region between the voltage thresholds T4 and T5 of type 2 is stopped. Between the only areas of type 1 and 4, which are thresholds T4 and T5, transmit light, thereby providing a lateral parallax barrier mode of operation. The Type 1 region threshold T5 and higher stops light transmission and the Type 2 region becomes transmissive, thereby providing a longitudinal mode of operation. The characteristic of FIG. 25 (b) has the advantage that 2-D mode is acquired with low or zero applied voltage and little or no extra power is required when the display is used in 2-D mode.

  Regions of different thickness of the liquid crystal can be provided to define type 1, 2, 3 regions. The thickness of the liquid crystal can be varied by providing steps or lamps. Steps or lamps can be generated using a polymer such as a photoresist in a liquid crystal cell. Region 4 which is always transmissive is formed entirely of polymer. Such structures are well known and can be processed, for example, by photolithography. The step structure can be fabricated on a substrate on which a uniform electrode is provided. The opposing substrate is also provided with a uniform electrode. The gap between the polymer step and the counter substrate is filled with a suitable liquid crystal. Alignment surfaces can be formed on each substrate to provide the ability to align the liquid crystal and change the director configuration between regions in the case of nematic liquid crystals.

  Instead, an electrode having a non-uniform thickness, such as ITO (Indium Tin Oxide) having different thickness regions, for example, is used, simultaneously providing different thicknesses and liquid crystal regions of the electrode.

  The parallax barrier shown in FIGS. 24A to 24C may be embedded using a ferroelectric liquid crystal as a switchable medium. As is well known, application of voltage pulses in the electrodes allows switching of specific regions of the FLC layer of the parallax barrier according to the applied pulse parameters (including pulse voltage and pulse width). FIG. 26 is a graph of pulse duration versus pulse voltage that defines a plane known as the pulse duration voltage plane. The graph of FIG. 26 shows three curve pairs, 79, 80; 79 ', 80'; 79 ", 80". Considering the first pair of these curves, the region 81 between the curves 79 and 80 shows the pulse width and pulse voltage state at which the regional switching occurs. The liquid crystal material below the curve 79 is not switched. Material over curve 80 switches completely. The arrows indicate the effect of increasing thickness, with curves 79 ′, 80 ′ showing the response to pulses in the region of the parallax barrier having a liquid crystal material thicker than the first curves 79, 80, and curves 79 ″, 80 ″ further It is possible to show a response to a pulse in the region of the parallax barrier having a thick liquid crystal material. The switching threshold is changed by the increased thickness. This effect changes the response of the curve to higher pulse voltages. At low voltages, the width of the regional switching regions 81, 81 ′, 81 ″ is only 2-3 volts, and the curve pair varies by approximately 20 volts per micrometer change in thickness. In order to switch the thickness, the pulse voltage may be changed, thereby changing the position of the parallax barrier.As an example, if the position marked A in FIG. For curve 79, 80 showing the switching behavior for a thickness of 1, position A is above curve 80, so the material is completely switched, but for the larger thickness represented in curves 79 ', 80'. The material cannot be switched.

  As shown in FIG. 26, the two positions indicated by B and C are in a pair of curves, and it is possible to drive the two thicknesses simultaneously to generate either a lateral or longitudinal barrier.

  The pair of intermediate curves 79 ′, 80 ′ in FIG. 26 corresponds to the type 3 region. Type 1 and 2 regions may correspond to either a pair of curves 79, 80 or a pair of curves 79 ", 80".

  Other bistable liquid crystal modes also exist. This can be used in the parallax barriers of FIGS. 24 (a) -24 (c), corresponding to the switching threshold changes for the FLC material as well. These include BTN (bistable twisted nematic) liquid crystals, ZBD (zenithal bistable mode), binem 180 nematic mode (another filling of BTN) having several different types (ie 180 ° or 360 ° twist). In general, nematic materials have the advantage of being about twice the cell thickness required for the FLC mode described above.

  Different dielectric materials can be used in each region to control the voltage dropped on the LC layer. It should be noted that the effective dielectric constant of the liquid crystal changes as the voltage is applied to switch. This is illustrated in FIG. FIG. 27 shows the effective dielectric constant of a 3.7 μm thick layer of negative del type silon nematic liquid crystal as a function of applied voltage.

  FIG. 28 shows a model of the transmission response at voltage for a 7 μm thick layer of liquid crystal, which is used for the type 2 region of FIG. The voltage indicated on the scale is a voltage dropped on the liquid crystal layer. A bright state of approximately 3.2V is used in the longitudinal mode of FIG. 24 (a), a dark state of 4.1V is used in the lateral mode of FIG. 24 (b), and a brighter state of 6.5V is illustrated in FIG. This is used for the two-dimensional display mode 25 (c).

  FIG. 29 is a further model of the transmission voltage response for a 3.7 μm thick layer of liquid crystal, which can be applied to either region type 1 or 3 in FIGS. 24 (a) -24 (c). There is a dark state below about 2.6V and a bright state about 4.0V.

  When the thick steps between the type 1 and 3 regions are produced using materials with different dielectric constants, the barrier of FIG. 24 (a) is a 3.7 μm thick layer and region of liquid crystal for regions 1 and 3 It can be obtained using a 7 μm thick layer of liquid crystal for type 2. Region type 4 is always transparent. This arrangement is shown in FIG. FIG. 30 is a schematic cross-sectional view through the parallax barrier of FIGS. 24 (a) to 24 (c).

  The parallax barrier has two substrates 82 and 83 between which a liquid crystal 84 and a resin 85 are arranged. The resin 85 is arranged with a stepped thickness and defines the regions of types 1 to 4 as described above. Region type 4 is always transparent and therefore contains pure resin. Type 1 and 3 regions have a 3.7 μm thick layer of liquid crystal and a depth equal to the resin. However, the dielectric constant of the resin in the region of type 1 (ε fixed to 1) is not equal to the dielectric constant of the resin in the region of type 3 (ε fixed to 2). Type 2 regions contain a 7 μm thick layer of liquid crystal and a corresponding thin resin. The dielectric constant of the resin in the type 2 and 4 regions can be the same. The dielectric constants of the type 1 and 3 regions are different from those of the type 2 and 4 regions (different from each other as noted).

  The substrate 83 on which the resin 85 is installed can be rubbed uniformly. The substrate 82 on which the liquid crystal 84 is placed can be rubbed to provide different liquid crystal director configurations in different areas. This is because it is required during the production of the liquid crystal cell.

  Other components such as address electrodes and alignment films are omitted from FIG.

  Type 1-3 regions that transmit light in the vertical, horizontal, and 2D modes transmit light that matches the color and brightness (always transmitted) of region type 4, sufficient 2D and 3D images and consistency Is displayed.

1 (a) and 1 (b) show a horizontal display mode and a vertical display mode of the display. 1 is a schematic diagram of a conventional multiple view. The display of FIG. 2 after being rotated 90 ° from the landscape mode shows that it is a basic concept of a view window generated by another conventional multiple view directional display device. 4 (a) and 4 (b) show the image display layer and parallax barrier of another multiple view display. 4 (c), 4 (d), and 4 (e) illustrate the operation of the display of FIGS. 4 (a) and 4 (b) in the vertical and horizontal modes. Indicates the viewing distance of the multiple view display. 6 (a) and 6 (b) show the image display layer and the parallax barrier of the multiple view display of the present invention. 6 (c), 6 (d) and 6 (e) show the operation of the display of FIGS. 6 (a) and 6 (b) in the vertical and horizontal modes. FIG. 7 (a) shows the parallax barrier of another multiple view display of the invention, and 7 (b) shows the operation of the display in the horizontal mode. FIG. 6 is a cross-sectional schematic view of a display according to a further embodiment of the present invention. FIG. 6 is a cross-sectional schematic view of a display according to a further embodiment of the present invention. FIGS. 10 (a) and 10 (b) show the operation of the display according to a further embodiment of the invention in 3-D mode, and FIGS. 10 (c) and 10 (d) show the operation of the display in 2-D mode. Indicates. Figures 11 (a), 11 (b), 11 (c) are cross-sectional schematic views of a display according to a further embodiment of the present invention. FIG. 12 (a) shows a parallax barrier of a display according to a further embodiment of the invention. 12 (b), 12 (c) and 12 (d) show the manufacture of the parallax barrier of FIG. 12 (a). Fig. 4 shows a parallax barrier of a display according to a further embodiment of the invention. Fig. 4 shows a parallax barrier of a display according to a further embodiment of the invention. FIG. 14 shows the manufacture of the parallax barrier of FIG. FIG. 14 shows the manufacture of the parallax barrier of FIG. FIG. 14 (a) is a schematic cross-sectional view of a parallax barrier of a display according to a further embodiment of the present invention, and FIG. 14 (b) shows the operation of the parallax barrier. FIGS. 15A, 15B, 15C, 15D, and 15E show the operation of the parallax barrier shown in FIG. It is a schematic plan view of a conventional multiple view directional display. FIG. 6 is a schematic plan view showing a display according to a further embodiment of the present invention. 18 (a), 18 (b), and 18 (c) show the image display layer, the parallax barrier, and its overlay of one embodiment of the display of FIG. FIG. 19 (a) shows another image display layer for the display of FIG. 17, and FIG. 19 (b) shows a suitable parallax barrier above that of FIG. 19 (a). FIG. 20 (a) shows a further image display layer suitable for the display of FIG. 17, and FIG. 20 (b) shows a suitable parallax barrier above that of FIG. 20 (a). FIG. 21 (a) shows a further image display layer suitable for the display of FIG. 17, and FIG. 21 (b) shows a suitable parallax barrier above that of FIG. 21 (a). Fig. 18 shows a display according to Fig. 17 embodied using a color filter barrier as a parallax optic. FIG. 23 (a) shows a further display according to FIG. 17, FIG. 23 (b) shows the image display layer of the further display of FIG. 17, and FIG. 23 (c) shows the appropriate display above FIG. A parallax barrier is shown. Figures 24 (a), 24 (b), 25 (a) show a rotatable parallax barrier region for a display according to a further embodiment of the invention. FIGS. 25 (a) and 25 (b) are graphs showing threshold characteristics required for a rotatable parallax barrier according to FIGS. 24 (a) to 24 (c). The switching characteristics of a ferroelectric liquid crystal material are shown. FIG. 25 is a graph showing an effective dielectric constant of a liquid crystal region in a parallax barrier according to FIGS. 24 (a) to 24 (c). FIG. FIG. 25 is a graph showing an effective dielectric constant of a liquid crystal region in a parallax barrier according to FIGS. 24 (a) to 24 (c). FIG. FIG. 25 is a graph showing an effective dielectric constant of a liquid crystal region in a parallax barrier according to FIGS. 24 (a) to 24 (c). FIG. FIG. 25 is a cross-sectional view of a diagram of a parallax barrier according to FIGS.

Explanation of symbols

9 Display 10, 125 Image display (display) layer 11, 11 ′, 11 ″ Color pixel 12, 12 ′, 126 Parallax optical element (parallax barrier)
13, 127 opening 14 pixels 18, 21 liquid crystal layer 20 retarder 23 first part of retarder 24 second part of retarder

Claims (36)

  It has a pixelated image display layer, can operate as a multi-view directional display in the first direction, and can operate as a multi-view directional display in a second direction different from the first direction. A first image displayed by the display in the first direction, wherein the viewing distance of the display in the first direction is substantially equal to the viewing distance of the display in the second direction; The separation angle with the second image is substantially equal to the separation angle between the first image and the second image displayed by the device in the second direction, and the image display layer has an aspect ratio of 1. Display with non-color pixels.   The display according to claim 1, further comprising a parallax optical element disposed in an optical path through the image display layer.   The effective pitch of the image display layer along the first direction and the effective pitch of the image display layer along the second direction orthogonal to the first direction are the view of the display in the first direction. The display according to claim 2, wherein the distance is selected to be substantially equal to the viewing distance of the display in the second direction.   The image display layer includes at least a first pixel of a first color and a second pixel of a second color, and the width of the first pixel along the first direction is the second The width of the first pixel along the direction is substantially equal to the width of the second pixel along the first direction is substantially equal to the width of the second pixel along the second direction The display according to any one of claims 1, 2, and 3.   The image display layer includes at least a first pixel of a first color and a second pixel of a second color arranged to form a composite pixel, each composite pixel having at least one first pixel. 2. Having a pixel and at least one second pixel, wherein a width of the composite pixel along the first direction is substantially equal to a width of the composite pixel along the second direction. The display according to any one of 2 and 3.   The display according to claim 4 or 5, wherein a pitch of the parallax optical elements along the first direction is substantially equal to a pitch of the parallax optical elements along the second direction.   The display according to claim 6, wherein the parallax optical element includes a plurality of transparent openings.   The display according to claim 7, wherein the parallax optical element is a color filter barrier, whereby each opening includes at least first and second regions having different light transmission characteristics.   The display according to claim 2, wherein the parallax optical element is a fixed parallax optical element.   The display according to any one of claims 2 to 8, wherein the parallax optical element is switchable between an OFF state and an ON state.   The display according to any one of claims 2 to 9, wherein the parallax optical element is resettable between a first ON state and a second ON state.   The display according to claim 11, wherein the parallax optical element is further switchable to an OFF state.   A first parallax optical element and a second parallax optical element, wherein the first and second parallax optical elements are disposed in an optical path through the image display layer, and the first parallax optical element The element has a finite pitch in the first direction, the second parallax optical element has a finite pitch in a second direction orthogonal to the first direction, and the first parallax optical element The ratio between the distance between the image display layer and the distance between the first parallax optical element and the image display layer with respect to the pitch of the image display layer along the first direction is along the second direction. The display according to claim 1, wherein the display is substantially equal to a ratio of a distance between the second parallax optical element and the image display layer with respect to a pitch of the image display layer.   The display includes a first parallax optical element that can be switched between an OFF state and a first ON state, and a second parallax optical element that can be switched between an OFF state and a second ON state. The display according to claim 11 or 13.   The display according to claim 14, wherein the first parallax optical element and the second parallax optical element are arranged on opposing surfaces of the image display layer.   The display according to claim 14, wherein the first parallax optical element and the second parallax optical element are arranged on the same surface of the image display layer.   17. A display according to any one of claims 11 to 16, wherein each of the parallax optical elements comprises a liquid crystal material.   18. A display according to claim 17, wherein each of the parallax optical elements comprises a liquid crystal layer and a patterned retarder disposed in an optical path through the display.   Each of the parallax optical elements comprises a first patterned retarder, a liquid crystal layer, and a second patterned retarder, wherein the first patterned retarder, the liquid crystal layer, 18. The display of claim 17, wherein the second patterned retarder is arranged in the order described in the optical path through the display.   20. A display according to claim 18 or 19, wherein each patterned retarder comprises a reactive mesogenic layer.   18. A display according to claim 17, wherein each of the parallax optical elements comprises a plurality of addressable liquid crystal regions arranged alternately with regions having constant optical properties.   18. A display according to claim 17, wherein each of the parallax optical elements comprises an addressable liquid crystal layer having alternating regions having first alignment characteristics and regions having second alignment characteristics.   The parallax optical element defines an addressable layer, a first addressing device that defines a first parallax optical element of the addressable layer, and a second that defines a second parallax optical element of the addressable layer 21. A display according to claim 12, 13 or any one of claims 17 to 20 when directly or indirectly dependent on claim 13.   The first addressing device includes a first electrode set defining the first parallax optic, and the display has a shape substantially complementary to the shape of the first electrode set. The display of claim 23, further comprising an electrode.   The second addressing device comprises a second electrode set defining the second parallax optic, and the display has a shape substantially complementary to the shape of the second electrode set. The display according to claim 23 or 24, further comprising an electrode.   26. The display according to any one of claims 1 to 25, wherein the display is changed from the first direction to the second direction by rotating the display about the normal line of the display surface of the display. Display.   27. A display as claimed in any preceding claim, wherein the first direction is substantially 90 [deg.] With respect to the second direction.   28. The display of claim 27, wherein the first direction is a horizontal direction and the second direction is a vertical direction.   A multi-view directional display adapted to display four views, each view being displayed along each of four different directions that are not coplanar when used, An image display layer, wherein at least one of the views is assigned to the image display layer and has a first direction in the image display layer, and at least another one of the views A multi-view directional display having a second different direction in the image display layer by being assigned to the image display layer.   30. The display according to claim 29, wherein the first to fourth views are assigned to the image display layer so that the first to fourth views have different directions in the image display layer.   A plurality of first areas for displaying the first view, a plurality of second areas for displaying the second view, a plurality of third areas for displaying the third view, and a fourth view are displayed. 31. An image display layer having a plurality of fourth regions, and a parallax optical element that displays each view along each of four different directions that are not on the same plane when used. Display as described in.   The parallax optical element includes one of the first region of the image display layer, one of the second region of the image display layer, one of the third region of the image display layer, and the image display. 32. A display according to claim 31, associated with one of the fourth regions of the layer.   The image display layer is a pixelized image display layer, and each first region, each second region, each third region, and each fourth region includes one or more pixels. A display according to claim 31 or 32, comprising:   The first region and the second region are disposed adjacent to each other in the lateral direction, the third region is disposed above the first region and the second region, and the fourth region The region is arranged below the first region and the second region, and vertically below the third region, according to any one of claims 31, 31 and 33. Display as described.   A dual view display device comprising a display as defined in any one of claims 1-34.   The autostereoscopic display apparatus provided with the display defined as described in any one of Claims 1-34.

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