JP2005078092A - Multi-view directional display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that the movement of the head performed by an observer observing one of a plurality of images on a display is restricted in the existing multi-view display. <P>SOLUTION: The multi-view directional display is equipped with an image display device having the set of pixels, and a parallax optical element having the array of color filters. Some or all of the filters can transmit a plurality of primary color light beams. The respective color filters are aligned with the respective sets of pixels. The color filter is constituted in an aperture on the parallactic optical element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multi-view directional display. This displays two or more images, so that each image can be viewed from different directions, so two or more viewers viewing the display from different directions see different images from each other. Such a display can be used, for example, as an autostereoscopic display device or a dual view display device.

  Conventional display devices have been designed for many years to be viewed by multiple users simultaneously. The display characteristics of the display device enabled multiple observers to see the same good image from different angles with respect to the display. This is effective when multiple users may need the same information from a display such as, for example, display of departure information at airports and stations. However, there are multiple applications where it is desired that individual users can see different information from the same display. For example, in the case of a car, the driver may desire to watch satellite navigation data while the passenger may desire to watch a movie. This conflicting requirement can be met by providing two separate displays, but this occupies extra space and is costly. Further, if two separate displays are used in this example, the driver can move his head to see the passenger's display, but will distract the driver. As a further example, each player playing a computer game for two or more players may desire to view the game from his / her perspective. This is currently done by each player watching the game on a separate display screen so that each player sees his own unique perspective on a separate screen. However, providing a separate display screen for each player takes up a lot of space, is costly and is not practical 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 as a “dual view display”, which can display two or more different images simultaneously, each image only visible in a specific direction, ie 1 An observer looking at the display device from one direction sees one image, whereas an observer looking at the display device from another different direction sees a different image. A display that can show different images to two or more users provides significant space and cost savings compared to using two or more separate displays.

  While possible applications of multi-view directional display devices have been described so far, there are many other applications. For example, multi-view directional display devices are used in airplanes and each passenger is provided with a separate in-flight entertainment program. Currently, each passenger is typically provided with a separate display device on the back of the front row of seats. By using a multi-view directional display, significant cost, space and weight savings can be provided. This is because one display can serve two or more passengers, while each passenger can further select a unique movie according to their preference.

  A further advantage of multi-view directional displays is the ability to make it impossible for users to see each other's screen displays. This is desirable, for example, in applications that require security, such as banking or trading transactions using an automated teller machine (ATM), and in the example computer game described above.

  A further use for multi-view directional displays is in the generation of 3D displays. In normal vision, the two human eyes perceive an external view from different perspectives because they are at different positions on the head. Therefore, these two perspectives are used by the brain to evaluate the distance to various visual objects in a scene. In order to produce a display that effectively displays a three-dimensional image, this state is reproduced and a so-called “stereoscopic pair” of images, ie one image for each eye of the observer. It is necessary to.

  Three-dimensional displays are classified into two types depending on the method used to provide different views to the eye. A stereoscopic display typically displays two images of a pair of stereoscopic images over a wide viewing area. Each view is coded, for example, by display color, polarization state, or time. The user needs to wear eyeglasses of a filter system that separates the views and causes each eye to see only the view for that eye.

  The autostereoscopic display displays the right-eye view and the left-eye view in different directions so that each view can only be viewed from a respective predetermined area of space. The area of space in which the image can be seen throughout the display active area is called the “display window”. If the observer is positioned so that the viewer's left eye is in the display window for the left-eye view of the stereoscopic pair, and the viewer's right eye is in the display window for the right-eye image of the pair Each eye sees a view and perceives a three-dimensional image. Autostereoscopic displays do not require the observer to wear an observation aid.

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

  In the case of a flat panel autostereoscopic display, the display window is typically a combination of an optical element called a parallax optical element and a pixel (or “pixel”) structure of an image display unit of the autostereoscopic display. It is formed. 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 opaque areas. This screen can be set in front of or behind a spatial light modulator (SLM) with a two-dimensional array of pixels to produce an autostereoscopic display.

  FIG. 1 is a plan view of a conventional multi-view directional display, in this case, an autostereoscopic display. The directional display 1 includes a spatial light modulator (SLM) 4 and a parallax barrier 5 that constitute an image display device. The SLM of FIG. 1 is in the form of a liquid crystal display (LCD) device having an active matrix thin film transistor (TFT) substrate 6, a counter substrate 7, and a liquid crystal layer 8 disposed between the substrate and the counter substrate. The SLM is provided with an addressing electrode (not shown) defining a plurality of independently addressable pixels, and further provided with an alignment layer (not shown) for aligning the liquid crystal layer. . A viewing angle widening film 9 and a linear polarizer 10 are provided on the outer surface of each substrate 6, 7. Illumination 11 is supplied by a backlight (not shown).

  The parallax barrier 5 includes a substrate 12 on which a parallax barrier aperture array 13 is formed on a surface adjacent to the SLM 4. The aperture array comprises a transparent aperture 15 that extends vertically (ie, extends toward the plane of FIG. 1) separated by an opaque portion 14. An anti-reflection (AR) coating 16 (which forms the output surface of the display 1) is formed on the opposite surface of the parallax barrier substrate 12.

  The pixels of the SLM 4 are composed of rows and columns, and the columns extend toward the paper surface of FIG. The row or horizontal pixel pitch (distance from the center of one pixel to the center of an adjacent pixel) is p. The width of the transmissive slits 15 extending vertically in the aperture array 13 is 2w, and the horizontal pitch of the transmissive slits 15 is b. The plane of the barrier aperture array 13 is spaced from the plane of the liquid crystal layer 8 by a distance s.

During use, the display device 1 forms a left eye image and a right eye image, and the left eye and the right eye are aligned with the left eye display window 2 and the right eye display window 3, respectively. The observer who has positioned the 3D image. The left-eye display window 2 and the right-eye display window 3 are formed on the window plane 17 having a predetermined viewing distance from the display. Window plane spaced minute interval distance r _o from the plane of the aperture array 13. The windows 2 and 3 are adjacent in the window plane and have a pitch e corresponding to the average distance between the two human eyes. Byte from the normal direction of the axis of the display relative to the center of each window 10, 11 is alpha _s.

  The pitch of the slits 15 in the parallax barrier 5 is selected to approximate an integer multiple of the pixel pitch of the SLM 4, so that a group of pixel columns is associated with a particular slit in the parallax barrier. FIG. 1 shows a display device in which two pixel columns of the SLM 4 are associated with each transmissive slit 15 of the parallax barrier.

  FIG. 2 shows the angular area of light generated from the SLM 4 and the parallax barrier 5, where the parallax barrier has a pitch that is an exact integer multiple of the pixel column pitch. In this case, the angular areas coming from different positions across the display panel surface are mixed and the pure area of the view of image 1 or image 2 (where “image 1” and “image 2” are displayed by the SLM 4 Does not exist). To address this, the pitch of the parallax barrier is preferably reduced slightly, such that it is slightly less than an integer multiple of the pixel column pitch. As a result, the angular area converges in a predetermined plane (“window plane”) in front of the display. This is known as viewpoint correction and is shown in FIG. 3 of the accompanying drawings showing the image area generated by the SLM 4 and the modified parallax barrier 5 '. When the viewing zone is generated by this method, the plan view has an approximately kite shape.

  FIG. 4 is a plan view of another conventional multi-view directional display device 1 ′. This generally corresponds to the display device 1 of FIG. 1 except that the parallax barrier 5 is located behind the SLM 4 so as to be between the backlight and the SLM 4. This device may have the advantage that the parallax barrier is hardly visible to the viewer and the pixels of the display appear relatively near the front of the device. Further, FIGS. 1 and 4 each show a transmissive display device illuminated by a backlight, but reflective devices using ambient light (in a bright state) are known. In the case of an anti-transmissive device, the rear parallax barrier of FIG. 4 does not absorb ambient illumination. This is advantageous when the display using reflected light is in 2D mode.

  In the display devices of FIGS. 1 and 4, the parallax barrier is used as a parallax optical element. Other types of parallax optical elements are known. For example, a lenticular lens array can be used to direct interlaced images in different directions to form stereoscopic image pairs, or to form two or more images that are each viewed in different directions. .

  Although holographic methods of image segmentation are known, in fact, these methods have problems with viewing angle, false vision area, and lack of simple control of the image.

  Another type of parallax optic is a micropolarizer display, which uses a polarized directional light source and a patterned precision micropolarizer element that is aligned with the pixels of the SLM. Such a display offers the possibility of high quality window images, compact devices and the ability to switch between 2D and 3D display modes. A dominant requirement when using a micropolarizer display as the parallax optical element is the need to avoid parallax problems when the micropolarizer element is incorporated into an SLM.

  When a color display is required, each pixel of the SLM 4 is generally provided with a filter associated with one of the three primary colors. By controlling a group of three pixels, each having a different color filter, multiple visible colors can be generated. In an autostereoscopic display, each of the stereoscopic image channels must fully contain a color filter with a balanced color output. As useful to manufacturers, multiple SLMs have color filters organized in vertical columns, and all pixels in a given column have the same color filter associated with them. When the parallax optic is placed in such an SLM having three pixel columns associated with each slit or lenslet of the parallax optic, each viewing zone sees only one color pixel. In order to avoid this situation, care must be taken with the color filter layout. Further details of a suitable color filter layout are given in US Pat.

  The function of the parallax optic in directional display devices such as those shown in FIGS. 1 and 4 is to limit the light transmitted through the pixels of the SLM 4 to a specific output angle. This limitation defines the viewing angle of each of the pixel columns behind a given element of a parallax optical element (eg, a transmissive slit). The angular range of view of each pixel is the pixel pitch p, the separation s between the plane of the pixel and the plane of the parallax optic, and the plane of the pixel and the plane of the parallax optic (this plane in the display of FIG. Determined by the refractive index n of the material between it and the substrate 7. Non-Patent Document 1 shows that the separation angle between images in an autostereoscopic display depends on the distance between the display pixel and the parallax barrier.

The half angle α in FIG. 1 or FIG.
sin α = n · sin (arctan (p / 2s)) (1)
Sought by.

  One problem with multiple existing multi-view directional displays is that the angular separation between the two images is too small. Basically, the angle 2α between the display windows is increased by increasing the pixel pitch p, decreasing the separation s between the parallax optic and the pixel, or increasing the refractive index n of the substrate. obtain.

  Co-pending U.S. Patent No. 6,057,836 proposes increasing the angle of the distance between viewing windows of a multi-view directional display by increasing the effective pitch of the pixels. This can be accomplished by grouping the pixels so that two or more adjacent pixels show the same image. If the color subpixels alternate between image 1 and image 2, this is called NP1. If the pair of color sub-pixels shows image 1 and image 2 alternately, this is called NP2. If a group of three color subpixels alternates between image 1 and image 2, this is called NP3. This has the disadvantage that the parallax barrier pitch must be increased as the effective pixel pitch increases, which results in improved visibility of the parallax barrier to the viewer.

  FIG. 5 shows a dual view display attached to an automobile. The dual view display 18 is attached to the dashboard 19 of the automobile. One image displayed on the dual view display is a map that may also indicate the position of the vehicle if the vehicle is compatible with a GPS location system. This view is made visible to the vehicle driver. Another image displayed by the dual view display 19 is an entertainment program such as a movie, which is made visible to a passenger in a front seat in the vehicle, for example. Use in vehicles, particularly automobiles, is becoming increasingly important as a dual view display application.

  FIG. 6 illustrates a problem that arises in a dual view display having a conventional parallax barrier 13 composed of an array of opaque portions 14 and transparent portions 15. As shown in FIG. 6 a, if the observer is located at the exact position 20 for observing the image 1, he can see only the pixel 21 through the slit 15. However, if the viewer moves to a different position 22, the viewer can see two adjacent pixels 21, 23 that display different images. Thus, the viewer can see both images simultaneously from that position. FIG. 6b shows the angular regions 24, 25 where the viewer views image 1 and image 2, respectively. In the central area 26, the viewer can see both images simultaneously. This is known as “crosstalk”.

  One solution to this problem is to reduce the width of the transparent portion 15, as shown in FIG. 6c. Here, the observer views the pixel 21 displaying the image 1 from various positions 20 and 22 in a state where the adjacent pixel 23 cannot be seen. As shown in FIG. 6d, the area 26 where the viewer can see both images is reduced, and the areas 24, 25 where only image 1 or only image 2 is visible are enlarged. Unfortunately, reducing the width of the transparent slit 15 reduces the brightness of the image seen by the viewer. In order to create enough freedom for the observer to move the head, the width of the transparent slit 15 must be about half the width of the pixel, so that the panel is of the brightness of a non-multiview panel. About a quarter.

  Non-Patent Document 2 describes the use of two parallax barriers in an autostereoscopic display. Depending on the slit width of the barrier, the two barriers prevent the viewer from seeing a crosstalk area (one per eye) between the two views or as the viewer moves across the panel. The resulting intensity variation can be eliminated.

  U.S. Patent No. 6,057,031 discloses an LCD in which pixels are grouped together into three sets. A group of pixels alternates between left and right image slices (NP3 interlace). It is proposed that the color filter parallax barrier allows light from a group of pixels to emit in different directions. The color filter barrier and LCD color filter use the same three primary colors.

  Patent Document 4 proposes a design similar to Patent Document 3. Each slit in the color filter barrier allows light to pass through only one LCD color filter.

  U.S. Patent No. 6,057,031 discloses another color filter barrier design for LCDs in which pixels are grouped into three sets. Each color filter barrier slit is the same color as the corresponding pixel.

  U.S. Patent No. 6,057,051 discloses a color filter barrier design for an LCD in which the left image and the right image are interlaced pixel by pixel (NP1 interlace). The color filter barrier is used to send the left and right images in the appropriate direction. Each portion of the color on the color filter barrier is about twice the width of the pixel.

  Patent Document 7 relates to a color filter barrier associated with two or more views (multi-view).

Patent document 8 discloses an NP1 parallax barrier having a colored slit. This means that both the color filter and the barrier can be in the same plane. Only one layer of color filter is required (ie there is no parallax effect between the two sets of color filters).
European Patent Application No. 0756610 British Patent Application No. 0315170.1 Japanese Patent No. 8146346 Japanese Patent No. 8146347 Japanese Patent No. 8163605 US Pat. No. 5,751,479 US Patent Application Publication No. 2003/0067539 US Pat. No. 6,392,690 H. Yamamoto et al., “Optimum parameters and viewing areas of stereoscopic full-color LED display using parallax barrier”, IEICE Trans. Electron. , Vol. E83-C, no. 10, 1632 (2000) G. Hamagishi et al., "A display System with 2-D / 3-D Compatibility" SID 98 Digest, 1998, page 915.

  Existing multi-view displays have limited head movement that is possible for an observer observing one of the images on the display. A further problem is that crosstalk occurs in the area between the two viewers of the display.

  The multi-view directional display according to the present invention is a multi-view directional display, and achieves the above object by including an image display device including a set of pixels and a parallax optical element including an array of color filters.

  Each color filter may be aligned with a respective set of the pixels.

  The color filter may be configured in an aperture in the parallax optical element.

  Each pixel may be configured to emit primary color light, and at least one of the color filters may be configured to transmit a plurality of primary color lights.

  The parallax optic may comprise at least one substantially transparent region for transmitting all three primary color lights.

  All of the color filters may be secondary color filters configured to transmit two primary colors.

  The pixels may alternately show portions of two images.

  The color filter may include a pattern that repeats periodically.

  The pixels may be configured to emit colored light in a pattern that periodically repeats, and the pattern of the color filter and the pixels may be different.

  One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of the second primary color and the third primary color, and only the third primary color And a fourth filter configured to transmit the light.

  One period of the color filter pattern includes a first filter configured to transmit light of only the first primary color and a first filter configured to transmit light of only the second primary color. A second filter, a third filter configured to transmit light of the first primary color and the third primary color, and a configuration of transmitting light of the second primary color The fourth filter may be provided, and a fifth filter configured to transmit only the light of the third primary color.

  One period of the color filter pattern includes a first filter configured to transmit light of the first primary color and a second configured to transmit light of the second primary color only. A third filter configured to transmit only the light of the third primary color, a fourth filter configured to transmit the light of the second primary color, And a fifth filter configured to transmit the light of the first primary color.

  The pixel pattern may include elements configured to emit a primary color in a first, second, third, third, second, first order.

  The third primary color may be green.

  The first period of the color filter pattern transmits the first filter configured to transmit the light of the first primary color and the second primary color, and the light of the third primary color only. A second filter configured as described above, and a third filter configured to transmit light of the first and second primary colors.

  The pixel pattern may include elements configured to emit a primary color in a first, third, second, second, third, first order.

  The first period of the color filter pattern transmits the first filter configured to transmit the first primary color light and the first primary color light and the second primary color light. A second filter configured to transmit light of the second primary color and the third primary color, and the third and first primary colors. A fourth filter configured to transmit the first light, and a fifth filter configured to transmit only the light of the first primary color.

  The pixels may be composed of three groups, whereby three adjacent pixels may show the same image.

  The width of each color filter may be substantially the same as the interval between the pixels.

  One period of the color filter pattern may further include an opaque mask.

  The color filter may have various widths.

  One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of only the second primary color, a first opaque mask, and the second primary color A fourth filter configured to transmit only the light, a fifth filter configured to transmit the light of the second primary color and the third primary color, and the third filter A sixth filter configured to transmit the primary color light, a second opaque mask, and a seventh filter configured to transmit only the third primary color light; An eighth filter configured to transmit light of the third and first primary colors, and transmit light of only the first primary color A ninth filter configured to so that may be a third opaque mask.

  The second, fifth, and eighth filters may be wider than the first, third, fourth, sixth, seventh, and ninth filters.

  One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of only the second primary color, and the second primary color and the third primary color A fourth filter configured to transmit light of the first color, a fifth filter configured to transmit light of only the third primary color, and the third and first primary colors And a sixth filter configured to transmit the light.

  The first, third, and fifth filters may be wider than the second, fourth, and sixth filters.

  The parallax optical element may not include an opaque portion.

  One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit light, a transparent portion configured to transmit all three primary color lights, and the second primary color light and the third primary color light. You may provide the 3rd filter comprised so that it might permeate | transmit, and the 4th filter comprised so that the light of only this 3rd primary color might be permeate | transmitted.

  The transparent portion may be narrower than the color filter.

  The color filter may be composed of a pattern that repeats periodically, and the number of the color filters in one period of the pattern may be larger than three.

  The pixels may be configured in a pattern that repeats periodically, and the number of pixels in one period of the pattern may be greater than three.

  The color filter may have various widths.

  Some or all of the color filters may be switchable.

  The display may be a dual view display.

  The color filter may be configured to create a 90 ° region with respect to the display that appears dark to the viewer.

  A multi-view directional display according to the present invention comprises an image display device comprising a set of pixels illuminated by an array of light sources, wherein at least one of the light sources achieves the above objective by emitting light of a secondary color. To do.

  In the parallax optical element including the array of color filters according to the present invention, at least one of the color filters achieves the above object by transmitting a plurality of primary colors.

  In a first aspect of the invention, there is a multi-view directional display comprising an image display device that includes a set of pixels and a parallax optical element that includes an array of color filters.

  The display according to the present invention can be viewed from a wider variety of angles than previously possible. Thus, the user's head freedom is increased without compromising display brightness. Furthermore, an area of approximately 90 ° with respect to the display where crosstalk occurs can be reduced. This may prevent a dual display device viewer from seeing both images simultaneously.

  Each color filter is preferably aligned with a respective set of pixels. The color filter may be disposed in an aperture in the parallax optical element.

  In a preferred embodiment, each pixel is configured to emit primary color light, and at least one of the color filters is configured to transmit a plurality of primary color light. The use of color filters that transmit secondary colors allows much greater freedom in designing parallax optical elements. This further allows the optical element to be placed closer to the image display device. This further provides a “black” central window to facilitate the reduction of the appearance of crosstalk.

  Furthermore, the parallax optic may comprise at least one substantially transparent region for transmitting three primary colors of light. Alternatively, all of the color filters can be secondary colors that are configured to transmit only two primary colors.

  A pixel may alternately represent two image portions (known as NP1 interlaces). Alternatively, the pixels may be grouped into pairs or three representing each image (NP2 and NP3 interlace). Although a relatively large number of pixels may be grouped to show each image, it is clear that the design of the color filter becomes more difficult.

  The color filter is preferably configured in a pattern that repeats periodically. The pixels may be further configured to emit colored light in a periodically repeating pattern, and the color filter and pixel patterns may be different. The number of color filters in one cycle of the pattern is preferably larger than 3.

  In a preferred embodiment, one period of the color filter pattern includes a first filter configured to transmit light of only the first primary color, and the first primary color and the second primary color. A second filter configured to transmit light, a third filter configured to transmit light of the second primary color and the third primary color, and a third primary color. And a fourth filter configured to transmit only the light.

  One period of the color filter pattern instead is configured to transmit the first filter configured to transmit the light of the first primary color and the light of the second primary color only. A second filter, a third filter configured to transmit light of the first primary color and the third primary color, and configured to transmit light of the second primary color. And a fourth filter and a fifth filter configured to transmit light of only the third primary color.

  As a further alternative, one period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color and a light of only the second primary color. A second filter configured to transmit light of only the third primary color, and a second filter configured to transmit light of the second primary color. 4 filters and a fifth filter configured to transmit light of the first primary color.

  In the above-described embodiment, it is preferable that the third primary color is green. This makes it possible to place the green (third) color filter in the center of the pattern. This has the advantage that the green color filter has little effect if it leaks some red and blue. This is useful for crosstalk problems caused by leakage through the color filter.

  The number of elements in one period of the pixel pattern may be more than three. For example, the pixel pattern may include elements configured to emit a primary color in a first, second, third, third, second, first order.

  In another embodiment, one period of the color filter pattern includes only a first filter configured to transmit light of a first primary color and a second primary color, and a third primary color. A second filter configured to transmit the first light, and a third filter configured to transmit the first and second primary color light. In this case, one period of the pixel pattern may include elements configured to emit the primary color in the first, third, second, second, third, first order.

  In yet another embodiment, one period of the color filter pattern includes a first filter configured to transmit only the light of the first primary color, the first primary color, and the second primary. A second filter configured to transmit color light; a third filter configured to transmit light of the second primary color and the third primary color; A fourth filter configured to transmit light of one primary color and a fifth filter configured to transmit light of only the first primary color.

  The width of each color filter is preferably substantially the same as the pixel interval. One period of the color filter pattern may further include an opaque mask. However, an opaque mask is not always required.

  In some embodiments, the color filter is variable in width and may allow fine control of the behavior of light emanating from the pixel.

  In a further embodiment, a period of the color filter pattern includes a first filter configured to transmit light of only the eleventh color, and light of the first primary color and the second primary color. A second filter configured to transmit; a third filter configured to transmit light of only the second primary color; a first opaque mask; and only the second primary color. A fourth filter configured to transmit the first light, a fifth filter configured to transmit the light of the second primary color and the third primary color, and a third primary. A sixth filter configured to transmit only color light, a second opaque mask, a seventh filter configured to transmit only light of the third primary color, and a third filter And an eighth filter configured to transmit light of the first primary color and light of only the first primary color. Including a ninth filter configured to, a structure and a third opaque mask.

  In this embodiment, the second, fifth, and eighth filters can be wider than the first, third, fourth, fifth, sixth, seventh, and ninth filters.

  In yet another embodiment, one period of the color filter pattern includes a first filter configured to transmit only the light of the first primary color, the first primary color, and the second primary. A second filter configured to transmit color light, a third filter configured to transmit only light of the second primary color, a second primary color and a third filter A fourth filter configured to transmit primary color light, a fifth filter configured to transmit only light of the third primary color, and third and first primarys And a sixth filter configured to transmit color light. The first, third, and fifth filters are preferably wider than the second, fourth, and sixth filters.

  In an alternative embodiment, one period of the color filter pattern includes a first filter configured to transmit only the light of the first primary color, the first primary color and the second primary. A second filter configured to transmit color light, a transparent portion configured to transmit light of all three primary colors, a second primary color and a third primary. A third filter configured to transmit color light; and a fourth filter configured to transmit only light of the third primary color. The transparent portion is preferably narrower than the color filter.

  The color filter can be switchable, allowing the position of the image window to be adjusted in response to observer movement, or between use as a dual view display and use as a single view display. Allows to be switched between.

  The display is preferably a dual view display.

  The color filter is preferably configured to be in a 90 ° region with respect to a display that appears dark to the viewer.

  According to a second aspect of the present invention, there is provided a parallax optical element comprising an array of color filters, at least one of which transmits one or more primary colors.

  In another embodiment, the backlight emits light of a different color, which eliminates the need for additional color filters. Thus, according to a third aspect of the present invention, there is provided a multi-view directional display comprising an image display device comprising a set of pixels, at least one of which is illuminated by an array of light sources emitting secondary color light.

  Existing multi-view displays have limited head movement that is possible for an observer observing one of the images on the display. A further problem is that crosstalk occurs in the area between the two viewers of the display. Embodiments of the present invention make it possible to expand the range in which the head can move without compromising the brightness of the display. Some embodiments further allow for the provision of a central black window that reduces or eliminates crosstalk.

  Some preferred embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings in which:

  The display according to the present invention can be viewed from a wider variety of angles than previously possible. Thus, the user's head freedom is increased without compromising display brightness. Furthermore, an area of approximately 90 ° with respect to the display where crosstalk occurs can be reduced. This may prevent a dual display device viewer from seeing both images simultaneously.

  Like reference numerals refer to like components throughout the drawings.

  FIG. 7 a shows in front view a dual view display 1 according to an embodiment of the invention with an LCD array 8 of pixels and a parallax barrier 13. The pixels are constructed using an NP3 interlace system so that the first three pixels 27, 28, 29 emit red, green, and blue light corresponding to image 2, and the next three pixels 30, 31 and 32 emit red, green, and blue light corresponding to the image 1, and the next three pixels 33, 34, and 35 emit red, green, and blue light corresponding to the image 2.

  The parallax barrier 13 includes an opaque region 14 and a slit 15 in a manner similar to the barrier shown in FIG. A series of color filters 36, 37, 38, 39 are disposed in each slit 15. The color filters have substantially the same spacing as the pixels, and in the embodiment shown, there are four filters colored in red, yellow, cyan, and blue in each slit. The red filter transmits only red light. The yellow filter transmits red light and green light. The cyan filter transmits green light and blue light, and the blue filter transmits only blue light. In this and subsequent figures, the filter is labeled with its color. That is, red is “R”, blue is “B”, green is “G”, yellow is “Y”, cyan is “C”, and magenta is “M”.

  The pitch of the filters 36, 37, 38, 39 in the slit is substantially the same as the pixel pitch. The red filter 36 is aligned with the green pixel 31 at the center of the three pixels that transmit the image 1. The yellow filter 37 is aligned with the blue pixel 32 at the edge of the image 1 group. The cyan filter 38 is aligned with the red pixel 33 at the start of the adjacent image 2 group, and the blue filter 39 is aligned with the green pixel at the center of the image 2 group.

  It is clear from FIG. 7a that the range of angles 20, 22 where only the image 1 is visible to the observer is magnified by comparison with the configuration shown in FIG. 6a. Furthermore, the slit width is much larger than the slit width shown in FIG. 6c, which results in significantly increased brightness. Therefore, the loss of brightness of the image is much smaller when the freedom of movement of the observer's head is much greater.

  Further advantages of the configuration of FIG. 7a are apparent from FIG. 7b. When the display is viewed at 90 °, the filters 36, 37, 38, 39 are aligned with the pixels 31, 32, 33, 34 so that light from the pixels cannot pass through the filter. Therefore, if the observer looks at the display at 90 °, the observer does not see the light emitted from the display. This substantially reduces or even eliminates image mixing (crosstalk) that occurs using conventional opaque / transparent parallax barriers.

  This behavior is shown in FIG. In the region 24 on the right side of the figure, the observer 20 sees only the image 1. In the region 25 on the left side of the figure, the observer sees only the image 2. The narrow area 26 between these two areas does not emit light and the device appears black to the viewer.

  FIG. 8 shows the most important design parameters of a parallax barrier with a color filter. As shown in FIG. 8, the pixels are configured to emit light alternately to the “left” and “right” images using the interlace system NP1. The parallax barrier comprising the color filter can be any interlace system NP1, NP2, NP3,. . . It is understood that it can be designed for use with the like.

In FIG. 8 and the next figure, both of these pixels are labeled with an image where these pixels are the portion and color of emitted light. For example, L _B and labeled pixel is the pixel that emits blue light for the left image. The pixel labeled _RG emits green light for the right image.

  In FIG. 8, the distance between the pixel 8 and the parallax barrier 13 is labeled “d”. By using an appropriate configuration of color filters in the parallax barrier, it is possible to use a wide range of different distances to achieve the same angular distance between images. For example, the barrier 13 shown in FIG. 14 is three times away from the pixel 8 than the barrier shown in FIG. 18, but in both cases the angular distance of the image is the same.

  The width of the slit in the barrier 13 is labeled “s” in FIG. Although FIG. 8 shows a slit that includes only a red filter, this is merely an example. The slit width substantially controls the angular range β in which the left or right pixel can be seen. This angular range is required to be large in order to obtain sufficient head freedom. An example of this can be seen in FIGS. In FIG. 15, the slit width is narrow and the pixels can only be seen over a small range of angles. In FIG. 16, the slit width is larger and the pixels can be seen over a larger angular range.

  FIG. 9 shows a known autostereoscopic display in which the parallax barrier 13 has an opaque portion 14 and a transparent slit 15 but no color filter. The interlace system is NP3. The distance between the barrier and the pixel is large, and the width of the slit is equivalent to the width of a set of three pixels (ie, three adjacent pixels forming part of the left image, for example). The light of the viewer's right eye 40 travels from the right pixels 30, 31, 32 through the slit 15. Similarly, the light of the left eye 41 travels from the left pixels 27, 28, 29 through the slit 15.

  The angular range defined by the slits in each of the pixels 29, 30, 31 of the right image is indicated by dotted lines. It is clear that the left eye 41 of the observer can also see some light from at least one of the red pixels 30 in the right image. Therefore, although the brightness of each image is high, the crosstalk between the images is very large, the observer can see color artifacts, and has little freedom of head movement.

  FIG. 10 shows a similar autostereoscopic display, where pixel 8 is constructed using the NP1 interlace system and the distance between the barrier and the pixel is small. The width of each slit 15 is similar to the width of each individual pixel. The angular range delimited by the slit in each of the right pixels 48, 50, 52 is also indicated by a dotted line. In this case, there is no crosstalk or color artifact, but the brightness and head freedom are small.

  FIG. 11 illustrates the use of color filters in an autostereoscopic display. The distance between the barrier and the pixel is large, and the slit is again equivalent to the pixel width configured for the NP1 interlace. Compared to a similar display with an empty slit instead of a color filter, this display shows sufficient head freedom and brightness, and no color artifacts are seen.

  FIG. 12 shows a configuration similar to FIG. 9, but in this case, red, green, and blue color filters 55, 56, 57 are inserted into the slit 15. This reduces the appearance of color artifacts.

  FIG. 13 shows an autostereoscopic display whose color filter configuration can completely remove opaque regions from the parallax barrier 13. As a result, the head is sufficiently freed without causing a color artifact problem, and sufficient luminance is possible.

  FIGS. 14, 15, and 16 are similar in design to the displays shown in FIGS. 11, 12, and 13 except that in each case the barrier is moved closer to the pixel. This enlarges the angular distance between the two images and allows this type of display to be used as a dual view display in addition to an autostereoscopic display. All of these displays have a black central “window” when fully head free and when viewed at 90 ° to the display. “Left” and “right” in FIGS. 14 to 16 are not the left eye or the right eye of the observer, but the left observation position and the right observation position.

  The black center window is particularly important for dual view displays. The central area of the autostereoscopic display is between the user's eyes and therefore cannot be seen. Therefore, crosstalk in this region cannot be a problem. However, returning to the example shown in FIG. 5 of a dual view display in a car, a centrally located observer (eg, in the rear seat) views the display 18 at 90 °. Therefore, it is important that such a display has a black central region rather than a crosstalk region.

  All of the displays shown in FIGS. 11-13 and 14-16 use color filters that each allow a single primary color to pass through. By using a filter, a plurality of primary colors can be passed, and the flexibility in designing a parallax barrier is increased.

  FIG. 17a shows the requirement of a barrier 13 having a large slit and a large angle delimited by each color filter for each pixel. The display shows regions 58, 59, 60 that use NP3 interlace and must allow red, green, and blue light to pass through, respectively. These regions overlap each other so that the angle can be changed sufficiently. Note that the region 58 that transmits red light is much larger than the red pixels 27, 30 through which light passes. These large areas that transmit light from each pixel increase the brightness and make the viewer's head much free.

  FIG. 17b shows how such a barrier can actually be fabricated. If both green and red light must be transmitted, a yellow filter 61 is used. If green and blue light must be transmitted, a cyan filter 62 is used. In other words, some of the color filters may be secondary colors rather than primary colors. The width of each filter is substantially the same as the width of the pixel, but as shown in FIG. 17a, the regions 58, 59, 60 that transmit each primary color are much larger than the width of the corresponding pixel. Note that it is big. The display has sufficient brightness and sufficient angle range for each image, and there is no crosstalk.

  FIG. 18 shows a display similar to that shown in FIG. 10 with a secondary color filter inserted into the slit 15. The use of color filters in such a barrier eliminates crosstalk when the barrier is viewed from a tilt angle, i.e. from outside the normal left and right viewing areas.

  FIG. 19a shows an NP3 display with a further enlarged slit. This display can be used as an autostereoscopic display or a dual view display. The color filters are “reconstructed” so that no longer follow a simple red, green, blue pattern, and there are five filters 63-67 in each slit 15. FIG. 19b shows a similar configuration using only the primary color filters 63-67, but it has five filters in each slit. In FIG. 19b, the order of the pixels is also changed. That is, the order of the left pixels is a mirror image of the order of the right pixels.

  Reconfiguring the color filter allows the barrier to be closer to the panel. This further allows the green color filter (as shown in FIG. 19b) to be located in the center of the slit. If the green color filter leaks some red and blue, it has little effect. This helps to mitigate crosstalk problems caused by color filter leakage.

  FIG. 20a shows a further possible embodiment of the present invention. In this embodiment, the filter is not uniform in width. Each slit 15 includes a secondary color filter 68 having a narrower primary color filter 69 adjacent to either side. This allows further control over the direction of transmitted light.

  FIG. 20b is a similar design to FIG. 20a but with the opaque regions 14 removed. The primary color filter on each side of the opaque area extends to fill this area. The angular range of each pixel, and thus the freedom of head movement, is very large here, but still has little crosstalk and high brightness.

  FIG. 21 shows a further embodiment of the present invention. FIG. 21a shows regions 58 ', 59', 60 'similar to regions 58-60 of FIG. 17a through which red, green and blue light respectively pass. In the middle of the slit where all three regions overlap, all light of all three primary colors is transmitted. A barrier 13 that makes this practical is shown in FIG. 21b. The central region 70 is substantially transparent, which allows all three primary color lights to pass through and the secondary color filters 71, 72 are adjacent.

  FIG. 22 provides a further example of a possible configuration according to the present invention. Both use NP3 interlace, and in both cases the pixel order is different between the left and right images.

  FIG. 23 may allow the use of a secondary color filter to move the barrier 13 closer to the pixel 8 and achieve the same angular distance between the images. In FIG. 23a, the filter is a primary color filter, and the distance between the barrier and the pixel is large. In FIG. 23b, secondary color filters and transparent portions 70 are used, allowing the barrier to be placed very close to the pixel. In fact, the area through each primary color is larger in FIG. 23a than in FIG. 23b.

  It is also understood that the configuration of FIG. 23b has much greater head freedom than that of FIG. 23a. This is because, in FIG. 23a, each color filter that transmits a single primary color is equivalent to the pixel width. In FIG. 23b, the area that transmits a single primary color is much larger, more than twice the width of the pixel.

  The present invention comprises a multi-view directional display comprising a display device and a parallax optic having an array of color filters. It will be appreciated by those skilled in the art that various modifications can be made to the above-described embodiments without departing from the scope of the invention.

  For example, the above embodiments are all illustrated with respect to a multi-view display of the type shown in FIG. 1 having a parallax barrier 5 in front of the spatial light modulator 4. It will be appreciated that the present invention can be equally well applied to displays of the type shown in FIG. 4, where the parallax barrier 5 is located between the backlight 11 and the SLM 4. As a further alternative, the parallax barrier aperture array 13 can all be removed and the backlight itself is configured to emit various colors of light. For example, the backlight may comprise an array of LEDs, some or all of which emit secondary color light.

  In a further refinement, the color filter or backlight color array may be switchable. Thereby, the positions of the left and right observation windows can be changed. This can be useful, for example, in autostereoscopic displays. If the viewer's head moves, the display can be dynamically reconfigured so that the left and right images are still directed toward the viewer's eyes. Or, for example, by switching all the color filters and opaque areas in the parallax barrier so that these filters and areas are completely transparent, the dual view display is reconfigured for use as a single view display. obtain.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

(wrap up)
The multi-view directional display includes an image display device having a set of pixels and a parallax optical element having an array of color filters. Some or all of the filters may transmit multiple primary colors of light.

FIG. 1 is a schematic plan view of a conventional autostereoscopic display device. FIG. 2 is a schematic view of an observation window provided by a conventional multi-view display device. FIG. 3 is a schematic plan view of an observation window generated by another conventional multi-view directional display device. FIG. 4 is a schematic plan view of another conventional autostereoscopic display device. FIG. 5 shows a conventional dual view device installed in an automobile. FIG. 6a shows a known method of reducing crosstalk between images of a dual view display. FIG. 6b shows a known method of reducing crosstalk between images of a dual view display. FIG. 6c shows a known method of reducing crosstalk between images of a dual view display. FIG. 6d shows a known method of reducing crosstalk between images of a dual view display. FIG. 7a illustrates a method for enlarging the angle of each image and reducing crosstalk according to the present invention. FIG. 7b illustrates a method for enlarging the angle of each image and reducing crosstalk according to the present invention. FIG. 7c illustrates a method for enlarging the angle of each image and reducing crosstalk according to the present invention. FIG. 8 shows design parameters of the color filter parallax barrier. FIG. 9 shows an autostereoscopic display in which the distance between the barrier and the pixel is large and is an NP3 interlace system but is not a color filter. FIG. 10 shows an NP1 interlaced autostereoscopic display with a small distance between the barrier and the pixel. FIG. 11 shows an NP1 interlaced autostereoscopic display with a large distance between the barrier and the pixel. FIG. 12 shows an autostereoscopic display of an NP3 interlace system in which the distance between the barrier and the pixel is large. FIG. 13 shows an autostereoscopic display in which the distance between the barrier and the pixel is large, is an NP1 interlace method, and the barrier has no opaque portion. FIG. 14 shows a NP1 interlaced dual view display with a large distance between the barrier and the pixel. FIG. 15 shows an NP3 interlaced dual view display with a large distance between the barrier and the pixel. FIG. 16 shows a dual view display where the distance between the barrier and the pixel is large, is NP1 interlaced, but has no opaque part in the barrier. FIG. 17a illustrates the principle of operation of an embodiment of the present invention. FIG. 17b illustrates the principle of operation of an embodiment of the present invention. FIG. 18 shows a dual view display having color filters that transmit secondary colors. FIG. 19a shows two displays with repeating patterns of four or more color filters. FIG. 19b shows two displays with repeating patterns of four or more color filters. FIG. 20a shows two displays with variable color filter widths. FIG. 20b shows two displays with variable color filter widths. FIG. 21a shows a display with a color filter and a transparent part in the parallax barrier. FIG. 21b shows a display with a color filter and a transparent part in the parallax barrier. FIG. 22a shows a display in which the order of the pixels has been changed. FIG. 22b shows the display with the pixel order changed. FIG. 23a illustrates how an embodiment of the present invention allows a reduction in the distance between the barrier and the display. FIG. 23b illustrates how certain embodiments of the present invention allow a reduction in the distance between the barrier and the display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Directional display 2 Left observation window 3 Right observation window 6 Active substrate 7 Opposite substrate 9 Viewing angle enhancement film 10 Polarizer 11 Backlight 12 Parallax barrier substrate 13 Parallax barrier aperture array 15 Transparent portion 16 AR coating 17 Window plane

Claims (36)

  A multi-view directional display comprising an image display device including a set of pixels and a parallax optic including an array of color filters.   The display of claim 1, wherein each color filter is aligned with a respective set of pixels.   The display according to claim 1, wherein the color filter is configured in an aperture of the parallax optical element.   4. Each pixel is configured to emit primary color light, and at least one of the color filters is configured to transmit a plurality of primary color lights. Display.   5. A display as claimed in any one of the preceding claims, wherein the parallax optic comprises at least one substantially transparent region for transmitting all three primary colors of light.   The display of claim 4, wherein all of the color filters are secondary color filters configured to transmit two primary colors.   The display of claim 6, wherein the pixels alternately show portions of two images.   The display according to claim 1, wherein the color filter is configured in a pattern that repeats periodically.   9. The display of claim 8, wherein the pixels are configured to emit colored light in a pattern that periodically repeats, and the pattern of the color filters and the pixels are different.   One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of the second primary color and the third primary color, and only the third primary color 10. A display according to claim 8 or 9, comprising a fourth filter configured to transmit the light.   One period of the color filter pattern includes a first filter configured to transmit light of only the first primary color and a first filter configured to transmit light of only the second primary color. A second filter, a third filter configured to transmit light of the first primary color and the third primary color, and a configuration of transmitting light of the second primary color 10. A display according to claim 8 or 9, comprising a fourth filter arranged and a fifth filter configured to transmit light of only the third primary color.   One period of the color filter pattern includes a first filter configured to transmit light of the first primary color and a second configured to transmit light of the second primary color only. A third filter configured to transmit only the light of the third primary color, a fourth filter configured to transmit the light of the second primary color, 10. A display according to claim 8 or 9, comprising a fifth filter configured to transmit light of the first primary color.   The display of claim 12, wherein the pixel pattern comprises elements configured to emit a primary color in a first, second, third, third, second, first order.   14. A display according to claim 12 or 13, wherein the third primary color is green.   The first period of the color filter pattern transmits the first filter configured to transmit the light of the first primary color and the second primary color, and the light of the third primary color only. 10. A display according to claim 8 or 9, comprising a second filter configured as described above and a third filter configured to transmit light of the first and second primary colors.   16. The display of claim 15, wherein the pixel pattern comprises elements configured to emit a primary color in a first, third, second, second, third, first order.   The first period of the color filter pattern transmits the first filter configured to transmit the first primary color light and the first primary color light and the second primary color light. A second filter configured to transmit light of the second primary color and the third primary color, and the third and first primary colors. 10. A fourth filter configured to transmit the first light and a fifth filter configured to transmit only the light of the first primary color. 10. display.   18. A display according to any of claims 10 to 17, wherein the pixels are composed of three groups, whereby three adjacent pixels show the same image.   The display according to claim 10, wherein the width of each color filter is substantially the same as the interval between the pixels.   The display according to claim 10, wherein one period of the color filter pattern further includes an opaque mask.   The display according to claim 8 or 9, wherein the color filter has various widths.   One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of only the second primary color, a first opaque mask, and the second primary color A fourth filter configured to transmit only the light, a fifth filter configured to transmit the light of the second primary color and the third primary color, and the third filter A sixth filter configured to transmit the primary color light, a second opaque mask, and a seventh filter configured to transmit only the third primary color light; An eighth filter configured to transmit light of the third and first primary colors, and transmit light of only the first primary color Comprising a ninth filter configured to so that, the third opaque mask display according to any one of claims 8, 9 or 21.   23. The display of claim 22, wherein the second, fifth, and eighth filters are wider than the first, third, fourth, sixth, seventh, and ninth filters.   One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit, a third filter configured to transmit light of only the second primary color, and the second primary color and the third primary color A fourth filter configured to transmit light of the first color, a fifth filter configured to transmit light of only the third primary color, and the third and first primary colors 22. A display according to any of claims 8, 9 or 21, comprising a sixth filter configured to transmit the light.   25. The display of claim 24, wherein the first, third, and fifth filters are wider than the second, fourth, and sixth filters.   The display according to claim 24 or 25, wherein the parallax optical element does not include an opaque part.   One period of the color filter pattern transmits a first filter configured to transmit only the light of the first primary color, and the light of the first primary color and the second primary color. A second filter configured to transmit light, a transparent portion configured to transmit all three primary color lights, and the second primary color light and the third primary color light. 22. A third filter configured to transmit and a fourth filter configured to transmit only the light of the third primary color, according to claim 8, 9, or 21. display.   The display according to claim 27, wherein the transparent portion is narrower than the color filter.   The display according to any one of claims 1 to 7, wherein the color filter includes a pattern that repeats periodically, and the number of the color filters in one period of the pattern is greater than three.   The display according to claim 1, wherein the pixels are configured in a pattern that repeats periodically, and the number of pixels in one period of the pattern is greater than three.   The display according to claim 1, wherein the color filters have various widths.   32. A display according to any of claims 1 to 31, wherein some or all of the color filters are switchable.   The display according to claim 1, wherein the display is a dual view display.   34. The dual view display of claim 33, wherein the color filter is configured to create a 90 [deg.] Region relative to the display that appears dark to the viewer.   A multi-view directional display comprising an image display device including a set of pixels illuminated by an array of light sources, wherein at least one of the light sources emits secondary color light.   A parallax optical element comprising an array of color filters, wherein at least one of the color filters transmits a plurality of primary colors.