JP4885300B2 - Autostereoscopic display device - Google Patents

Description

  The present invention includes means for making a display comprising an array of display pixels arranged in columns and rows, and extending parallel to each other over the display pixel array and through which the display pixels are observed. The present invention relates to an autostereoscopic display device comprising an existing array of elongated lenticular elements.

  Examples of such autostereoscopic display devices are SPIE Proceedings, volume 2653, pages 32-39, published 1996, by C. van Berkel et al., Titled “Multiview 3D-LCD”, and the UK This is described in Japanese Patent Application Publication No. GB-A-2196166. In these devices, a matrix display device having a column and row array of display elements and comprising a liquid crystal (LC) display panel acting as a spatial light modulator produces the display. Said lenticular element is provided by a lenticular sheet, the lenticular sheet of lenticular comprising an elongate (semi) cylindrical lens element overlying each group of two or more adjacent rows of display elements With each lenticular, it extends in the row direction of the display panel in parallel with the display element row. Typically in such devices, liquid crystal matrix display panels are customary, with regularly spaced columns and rows of display elements, such as those used in other types of display applications, such as computer display screens. It ’s a good shape. European Patent Application EP-A-0625861 describes another example of an autostereoscopic display device, which includes several display elements in groups arranged so as to be substantially in contact with each other in the row direction. A liquid crystal matrix display panel having a non-standard display element layout in which adjacent display elements are arranged in such a group is used. This specification also describes an example of a projection apparatus using a panel in which an image of a display element array is amplified and projected onto a screen, and a lenticular sheet is associated with the screen.

  Considering a direct observation type device, a display pixel that forms a display at that time is constituted by a display element of the display panel. For example, in an apparatus where each lenticular is associated with two rows of display elements, the display elements in each row provide a vertical slice of the respective two-dimensional (auxiliary) image. The lenticular lamina displays these two lamellae and the corresponding lamina from the row of display elements associated with the other lenticular so that the observer recognizes a single stereoscopic image. Point to the left and right eyes respectively. Each lenticular is associated with a group of four or more adjacent display elements in the column direction and the corresponding row of display elements within each group is suitable for providing vertical flakes from a respective two-dimensional (auxiliary) image. In other multi-view devices that are in place, as the observer's head is then moved, a series of different stereoscopic views are recognized, for example, creating an impression of looking around. In this case, a similar three-dimensional effect is obtained by the projection apparatus, except that the display pixels that form the display on the screen are constituted by the projected image of the display element.

  The use of a matrix display panel with a lenticular screen in which the lenticular extends parallel to the display element rows provides a simple and effective way to achieve a three-dimensional display. However, for a standard display panel having a predetermined number of display elements in a row, then the horizontal display resolution is necessarily sacrificed to provide multiple views in the three-dimensional display. For example, a display panel having an array of 800 rows and 600 columns of display elements (if a full color display is required, each of these display elements may comprise a color triplet) For a four-view system that gives a stereo pair of, the resulting display has a resolution of only 200 in the horizontal, column direction and a resolution of 600 in the vertical, row direction for each view. Thus, each stereoscopic image as seen by an observer has a relatively high vertical resolution, but only a relatively small horizontal resolution. Of course, significant differences between vertical and horizontal resolution capabilities are undesirable.

  It is an object of the present invention to provide an improved autostereoscopic display device.

  According to the invention, there is provided an autostereoscopic display device of the kind described at the beginning, characterized in that the lenticular elements are tilted at an angle with respect to the display pixel rows. With this device, the number of views to be obtained need not involve trading for the horizontal resolution capability alone. By tilting the lenticular element, some of the reduction in horizontal resolution that would otherwise be required is converted to vertical resolution and shared between horizontal and vertical resolution rather than simply being held by horizontal resolution. Both vertical and horizontal resolution can be used to increase the number of views displayed due to the disadvantage of obtaining multiple views. Thus, a conventional type of display panel with a standard column and row display element layout, which results in a limited number of views obtained when adequate horizontal resolution is maintained, and a lenticular extending parallel to that row. Compared to known examples of devices using elements, the degree of horizontal resolution reduction required to provide a fixed number of views is reduced at the expense of some vertical resolution.

  This apparatus may be a direct observation type display apparatus or an image projection type display apparatus in which an amplified image is projected onto a display screen by a projection lens. In a preferred embodiment, the means for making the display comprises a matrix display panel, preferably a liquid crystal matrix display panel having a column and row array of display elements, each of which comprises a display pixel. In a direct viewing device, the display pixels that form the display to be viewed are thus constituted by the display elements of the panel, and in this case an array of lenticular elements is placed on the output side of the display panel. . In a projection display device, the display pixels that form the display to be viewed comprise the projected image of the display elements of the matrix display panel, and the array of lenticular elements in this case is on the viewing side of the display screen. It has been placed. In the projection device, the display pixels may instead comprise an image projected from another type of display device, for example a cathode ray tube.

  An important advantage of the present invention is that it allows a conventional shaped liquid crystal matrix display panel with regularly spaced columns of aligned display elements and rows to be used. In particular, no changes to the display element layout are required. EP-A-0625861 describes an example device in which the number of two-dimensional views for a three-dimensional frame is increased at the expense of vertical resolution, This is accomplished using a display panel in which adjacent display elements in the group are swung vertically, i.e. in the row direction. The display element layout is thus unusual and therefore a standard display panel, as used for other applications, cannot be used. Furthermore, the display element layout method results in an insufficient use of panel area with only a small amount of light processing.

  Another important advantage of the present invention is that the degree of unwanted display artifacts due to the presence of black matrix material extending into the gaps between display elements in the matrix display panel is reduced. Such a black matrix material that borders the display element is used to enhance contrast, and in the case of an active matrix panel, a liquid crystal display panel for shielding a switch element, for example a thin film transistor (TFT). Used within. Since it extends vertically between adjacent rows of display elements, this material is imaged by a lenticular screen in conventional devices and the viewer recognizes it as a black band between adjacent two-dimensional views. . In the apparatus of the present invention, the visibility of the black mask in the perceived display is then since the lenticular elements do not extend parallel to the rows of display elements and hence parallel to the vertical strips of black matrix material between the rows. Reduced.

  Although the matrix display panel preferably comprises a liquid crystal display panel, it is anticipated that other types of display panels may be used, such as electroluminescent or plasma display panels.

Preferably, the lenticular elements are tilted with respect to the row of display pixels so as to create a repeating group of display elements, each of these groups being constituted by adjacent display pixels in r adjacent columns. Where r is a number greater than one. In a particularly preferred embodiment, r is equal to 2. The degree of overlap between views is then minimized. The tilt angle of the lenticular element may be approximately equal to tan ⁻¹ (H _p / (V _p × r)), where H _p and V _p are the display pixel pitch in the column and row directions, respectively.

  The pitch of the lenticular elements need not correspond to the total number of display pixels in the column direction. The pitch of the lenticular elements should preferably be at least 11/2 times the pitch of the display pixels in the column direction in order to obtain 3 or more views. In a particularly preferred embodiment, the pitch of the lenticular elements is equal to 2 1/2 or 3 1/2 times the pitch of the display pixels in the column direction, providing a 5 view and 7 view system, respectively. In these, a better balance between horizontal and vertical resolution is achieved with a reasonable number of views.

  The lenticular element may have a cross section with a part of a circle. Such a lenticular element is easy to make. Alternative forms of lenticular elements can be used. For example, the lenticular element can be formed of adjacent straight portions.

  The autostereoscopic display device may be a color display device in which different display pixels give different colors. In the case of a liquid crystal matrix display panel, for example, a color display is usually achieved by an array of color, red, green and blue filters on top and aligned with the array of display elements. Typically, the color filter is arranged as a strip that extends parallel to the display element rows such that three adjacent rows of display elements are associated with the red, green and blue filters, respectively. Is repeated across the array so that every third row displays the same color, eg, red. However, the use of such a color pixel layout can result in undesirable display artifacts in the form of visible horizontal or diagonal color strips. Preferably, therefore, to reduce the visibility of such strips, the color pixels are arranged to have a Δ contour, each creating a color pixel triplet comprising red, green and blue display pixels. Has been. In one preferred embodiment of a color display device using a color matrix display panel, all display pixels in a column are arranged to display the same color, and each of three adjacent columns of display pixels is each Display one color red, green and blue. Thus, for example, a continuous row of pixels displays red, green, blue, red, green, blue, etc. As a result, the aforementioned problems with visible color strips are reduced. In a liquid crystal color display panel, this is simply achieved by arranging the color filters in strips that extend in the column direction rather than the normal row direction.

  In another preferred embodiment of a color display device using a color matrix display panel, the display pixels under each lenticular element are all of the same color and under each of three adjacent lenticular elements. Each display pixel is arranged to display one color red, green and blue. Thus, for example, each column of display pixels comprises a continuous group of red, green and blue display pixels, with the display pixels in each group below the respective lenticular element. Due to the tilt of the lenticular elements with respect to the pixel rows, a group of color display pixels in a certain column, eg every third column, is offset in the column direction with respect to the group in the adjacent column. This type of color pixel layout provides two other advantages. Initially, the color triplets, each consisting of red, green and blue display pixels in adjacent views, are meshed, so that the color triplet pitch is effectively halved where the eye sees two views simultaneously due to crosstalk. Secondly, the installation of the color filter device in the liquid crystal matrix display panel allows display elements of the same color to be grouped together, and this classification is necessary for the required alignment accuracy between the black mask and the color filter array. Allow relaxation, which improves product manufacturing without reducing display element openings.

  An embodiment of an autostereoscopic display device according to the present invention will be described below by way of example with reference to the drawings.

  It should be understood that the figures are merely schematic and are not drawn to scale. In particular, certain dimensions have been exaggerated while other dimensions have been reduced. It should also be understood that the same reference numerals are used throughout the drawings to denote the same or similar parts.

  Referring to FIG. 1, an apparatus that is directly observable in this embodiment is similar to a conventional liquid crystal matrix display panel 10 comprising a flat array that can be used as a spatial light modulator and individually addressed. And display elements 12 arranged in columns and rows vertically aligned with each other in size. This display element is shown schematically with relatively little in each column and row. In practice, however, there can be about 800 rows (or 2400 rows if color red, green, blue triplets are used to provide a full color display) and 600 columns of display elements. Such panels are known and will not be described in detail here. In simple terms, however, a liquid crystal panel has a transparent plate, for example between two pieces of glass, between which a twisted nematic or other liquid crystal material is placed, and they are On the opposing surfaces, for example, supporting the transparent electrode pattern of ITO (indium tin oxide) that determines the layout and shape of the display elements, each element is an electrode facing the two plates having intervening liquid crystal material It has. A polarizing layer is normally provided on the outer surface of the plate. Display elements 12 are substantially rectangular in shape and extend in rows, i.e. in two adjacent rows separated by vertically extending gaps, and in columns, i.e. horizontally. Regularly spaced from each other by display elements in two adjacent rows separated by an air gap. Preferably, the liquid crystal matrix display panel 10 comprises an active matrix in which each display element is associated with a switching element comprising, for example, a thin film transistor (TFT) or thin film diode (TFD) placed adjacent to the display element. Of the type. In order to accommodate these devices, their display elements cannot be perfectly rectangular. As usual, the air gap between the display elements is covered by a black mask comprising a matrix of light absorbing material supported on one or both plates separating the display elements.

  The liquid crystal matrix display panel 10 is illuminated by a light source 14, which in this example comprises a flat backlight extending over the area of the display element array. Other types of light sources can be used instead. Light from the light source 14 is directed through a panel having individual display elements that are driven by appropriate application of drive voltages to modulate this light in a conventional manner to create a display output. The array of display pixels that make up the display thus produced corresponds to a display element array, each display element providing a respective display pixel.

  On the output side of the liquid crystal matrix display panel 10, extending substantially parallel to the plane of the display panel, and elongated, parallel lenticular elements, that is, for the observer facing the side of the thin plate 15 far from the liquid crystal matrix display panel 10 In order to create a stereoscopic display, a lenticular sheet 15 is placed comprising an array of lenticulars that serve as optical detector means for providing separate images to the observer's eyes. The lenticular of the thin plate 15 includes a lenticular that is formed, for example, as a convex cylindrical lens or a gradient index cylindrical lens and condenses optically in a cylindrical shape. Autostereoscopic display devices that use lenticular sheets together with a matrix display panel are well known and it is not considered necessary to describe in detail the manner of their operation here. Examples of such devices and their operation of creating stereo images are described in the aforementioned paper by C. van Berkel et al., In GB-A-2196166, and in EP-A-2196166. EP-A-0625 861, the disclosures of which are hereby incorporated herein by reference. Preferably, the lenticular array is provided directly on the outer surface of the output side plate of the liquid crystal matrix display panel 10. Unlike known lenticulars in the device that extend parallel to the display pixel rows (corresponding to the display element rows), the lenticulars in the device of FIG. 1 are tilted with respect to the rows of display pixels. That is, their main longitudinal axis is at a certain angle with respect to the row direction of the display element array.

  The pitch of the lenticulars is selected in relation to the pitch of the display elements in the horizontal direction according to the number of views required, as will be described later, and away from them on the side of the display element array. Extends from the top to the bottom of the display element array. FIG. 2 illustrates an exemplary arrangement of lenticular 16 in combination with the display panel for a typical portion of the display panel. The vertical axis L of the lenticular 16 is tilted at an angle α with respect to the row direction Y. In this example, the vertical axes of the parallel lenticulars are wide enough to provide a 6 view system for the pitch of the display elements in the column and to provide a 6 view system for the rows of display elements. It is tilted at an angle. The display element 12 is again shown by a simple rectangle representing the display element and thus the effective aperture of the display pixel, and the area between the display elements is covered by a black mask material 18 in a grid pattern. The size of the gap between adjacent display elements shown in FIG. 1 is shown very exaggerated. The display elements 12 are numbered (1-6) according to the view number to which they belong. The lenticulars 16 of the individual and substantially the same lenticular sheet 15 each have a width approximately corresponding to three adjacent display elements in the row, ie, the width of the three display elements and their intervening gaps. is doing. The six view display elements are thus placed three in each row in a group comprising display elements from two adjacent rows.

  Individually operable display elements are driven by the application of display information in a suitable manner such that a narrow slice of a two-dimensional image is displayed by a selected display element under the associated lenticular. The display produced by this panel comprises six interleaved two-dimensional auxiliary images composed of outputs from the respective display elements. Each lenticular 16 receives six output beams from an associated underlying display element having view numbers 1-6, each having an optical axis in a different direction and extending angularly about the longitudinal axis of the lenticular. give. The 3D image is then recognized by the appropriate 2D image information applied to the display element and by the observer's eye at an appropriate distance to receive a different one of the output beams. As the observer's head moves in the row direction, then five stereoscopic images can be observed in succession. Thus, the observer's two eyes will each see, for example, an image consisting of all display elements “1” and an image consisting of all display elements “2”. As the observer's head moves, an image consisting of all display elements “2” and all display elements “3” can be seen by each eye, and then all display elements “3” and all display elements “4”. And so on, and so on. At another viewing distance, closer to the panel, the observer can, for example, view “1” and “2” together with one eye and views “3” and “4” together with the other eye. You will see.

  The plane of the display element 12 coincides with the focal plane of the lenticular 16, these lenticulars are properly designed and spaced for this purpose, and therefore the position in the display element plane corresponds to the viewing angle is doing. Therefore, under a particular horizontal (column direction) viewing angle, all points on the dashed line A in FIG. 2 are all points on the broken line B in FIG. 2 from different viewing angles. Seen simultaneously by an observer. A line A represents a monochromatic observation position where only the display element can be seen from the view “2”. Line B represents the monochromatic viewing position where the display elements can be viewed together from both view “2” and view “3”. Line C now represents the position where only display elements can be seen from view “3”. Thus, a stepwise transformation from view “2” to view “3” as the observer's head moves with one eye closed from the position corresponding to line A to line B and then to line C. Is experienced. Therefore, when the observer's eyes move, the recognized image does not suddenly bounce or skip to the next, but instead has a blending effect to give a smooth transition at the transition between the two images. If the autostereoscopic display contains enough views, this effect increases the recognition of the “solid” object display rather than just a collection of “popping” views. For the observer, the gradual change in successive views experienced gives an impression of enhanced continuous parallax. The conversion from one view to another depends on the actual display element layout and the aperture ratio between the open display element area and the black mask area. Since the lenticular 16 is spaced from the plane of the display element 12, the underlying display elements are some display elements such as the view 6 that they comprise between the two lenticulars. Even if it appears to be on the boundary, it is visible through the lenticular.

  It can be seen that this tilted lenticular device thus provides many different views without sacrificing the horizontal resolution exclusively as in known devices where the lenticular extends parallel to the display element rows. Instead, the inevitable reduction in resolution is distributed more evenly between both horizontal and vertical resolution. For example, in the 6-view device of FIG. 2 that produces a monochrome display output, the horizontal resolution is reduced to one-third and the vertical resolution is halved. According to conventional equipment, the 6-view system then reduces the horizontal resolution by a factor of 6, while the vertical resolution is not affected. This advantage is achieved without resorting to custom-made display panels having unusual display element formations, and this display panel 10 is a display screen for other commonly observed network computers and the like. The standard type can be used for display applications and can be used for off-the-shelf products.

  An additional advantage of this device is that the visibility of these strips to the viewer is reduced because the lenticular does not extend parallel to the continuous vertical strips of black mask material 18 between adjacent rows of display elements, And avoids the kind of problems experienced by conventional devices, such as those imaged by the lenticular so that such strips appear as black bands separating different successive views as the observer's head moves. It is.

  The tilted lenticular device can be applied to both monochromatic and color displays. For example, a color microfilter array is associated with a display element array and a color filter that becomes a horizontal red, green, and blue row triplet (ie, three consecutive rows of display elements that display red, green, and blue, respectively). ) Considering the 6 view plan of FIG. 2 applied to the installed LCD panel, then if the view “1” display element in the second column is red, then the view “1” in the fourth column. “The display element turns green. Similar situations occur for other views. Each view can therefore have a colored column, which means that for a color display, the vertical resolution is one third of the vertical resolution of a monochrome display.

In one embodiment of this apparatus, a color liquid crystal display panel having a resolution of 2400 display elements (800 × 3 color triplets) horizontally and 600 display elements vertically was used. The horizontal triplet pitch was 288 μm (96 μm per display element) and the display element vertical pitch was 288 μm. The width and tilt angle of the lenticular 16 are determined by the size and pitch of the display elements and the number of views required. For a 6 view plan as shown in FIG. 2, the lenticular tilt angle α, ie, the angle between the vertical axis and the vertical of the lenticular is α = tan ⁻¹ (96 / (2 × 288) ) = 9.46 °. Normally, the lateral magnification of a lenticular lens is determined by the requirement that display elements corresponding to adjacent views are projected into the left and right eyes of the viewer. Assuming an interocular distance of 65 mm, the required lateral magnification m is 1354. However, there is a minimum separation distance L between the lenticular and the display element determined by the thickness t of the glass plate (including the polarizing layer) of the panel. Assuming this distance is about 1.5 mm and the refractive index n of the glass plate is 1.52, the distance of the observer's eye from the lenticular sheet and the working distance D given by m × t / n is Undesirably large, about 1.34m. For this reason, the requirement that only the next most recent adjacent view is magnified with respect to the interocular distance was chosen, reducing the lateral magnification from 1354 to 677 by half. As a result, the operating distance D was reduced to 67 cm. The lenticular pitch μp perpendicular to the lenticular vertical axis, ie, the pitch at which the mold must be cut, will eventually be μp = 283.66 μm. This lens focal length f (given by D / (m + 1)) is then 0.99 mm, and (in paraxial approximation) its radius of curvature R given by R = f (n-1) is a refractive index of 1.383. To 0.48mm.

  The resolution obtained for each view in this 6 view plan using an 800 (triplet) x 600 display element array is 800 horizontally and 100 vertically. This is comparable to the horizontal and vertical resolutions of 133 and 600 per view obtained in a conventional device using the same display panel with lenticulars extending parallel to the display element rows.

  In another example embodiment, in the case of an 8-view system and using the same display panel, the lenticular is tilted at the same angle as before (ie 9.46 °), but with a 33 1/3% longer pitch. And four display elements on each row. Eight-view display elements are thus placed from two adjacent columns into a group with four display elements in each column. Each lenticular 16 in this case provides eight output beams from the underlying display elements whose optical axes are in different directions and angularly spread around the lenticular longitudinal axis. The resolution for each view obtained in this 8-view device is now 400 horizontally and 150 vertically, comparable to 100 horizontally and 600 vertically in conventional devices.

  In 6 and 8 view devices, the horizontal resolution is greatly increased, whereas the vertical resolution is rather poor. However, this situation can be greatly improved in the following way. Each lenticular lies on the total number of adjacent display elements in the row and need not cooperate optically. In another preferred embodiment, again using the same display panel, rather than the lenticular covering 3 or 4 display elements on each row as in the device described above, instead they are 2 1/2 or Designed to cover 3 1/2 display elements, ie, the pitch of the lenticular elements is 2 1/2 and 3 1 / of the pitch of the display elements in the column direction to give a 5 view and 7 view system respectively. Designed to accommodate twice. In these, the output beam 5 or 7 provided by each lenticular from the underlying display element has optical axes that are in different directions and angularly extend around the longitudinal axis of the lenticular. A device for a 7 view system is shown in FIG. As mentioned above, the display elements are numbered according to the view number to which they belong and indicate that the dashed lines A, B and C are observed simultaneously for different horizontal viewing angles. As can be seen, the observation number under each lenticular 16 is not repeated along the display row (as was the case in the FIG. 2 device) but is offset by one row between adjacent lenticulars. . This type of device provides an improved balance between the resulting horizontal and vertical resolution. This principle can be extended, for example, to a lenticular covering 2 1/3 or 2 1/4 display elements and down to the lowest 1 1/2 display elements giving 3 views.

  Using the 800 × 600 display panel with display elements arranged in aligned columns and rows again, the resolution obtained per view in the 5 and 7 view plans described above is 480 × 200 and 342 × 200, respectively. Become. These use the same panels, but are comparable to 160 × 600 and 114 × 600, respectively, with lenticulars conventionally arranged parallel to the rows. Thus, a significant improvement in horizontal resolution is achieved while still maintaining a reasonably high vertical resolution.

  In all the above examples, the lenticular tilt angle α is the same, ie 9.46 °, and the number r of display element rows used in each group of display elements is two. However, the tilt angle can be changed. This angle is the formula

α = arctan (H _p / (V _p × r))
Where V _p and H _p are the vertical and horizontal pitches of the display elements in the display panel, respectively. Assuming that these values are as described above, then the angle of inclination α is 6.34 ° and 4.76 ° for r equal to 3 or 4, respectively. However, as the tilt angle decreases, the overlap between views increases.

  A color liquid crystal display panel for data graphic display applications, where each color pixel has three (red R, green G, and blue B) adjacent (auxiliary) pixels in a row forming a horizontal RGB triplet. The provided color pixel layout is normally used. Such a color pixel layout is formed using vertical color filter strips so that the display elements of the panel are arranged in R, G and B rows, respectively, in a repetitive manner. In this way, when using a tilted lenticular device with a color display in which the pixels are arranged, the layout of the color pixel triplets recognized by the eye in each view is unidirectional, eg horizontal The pixel pitch in the direction can be perpendicular, i.e. much larger than the pixel pitch in the vertical direction, and this runs diagonally, for example in the case of 5 or 7 view systems, or in the case of 6 view systems Can result in a visible color strip running horizontally across the display.

  FIG. 4A shows a seven view similar to the system of FIG. 3 using this ordinary type of color liquid crystal display panel in which display (auxiliary) elements 12 and thus display pixels are arranged in each color row. Illustrates the system. As before, the slanted lines indicate the boundaries between adjacent lenticulars 16. Individual pixels, represented as rectangles, are arranged on a square grid in a horizontal triplet, and each such square triplet consists of three adjacent red r, green g, And blue b (auxiliary) pixels. Those numbers (1-7) and the characters r, g, b represent the view number and color for each pixel. An array of lenticulars is placed approximately 1.5mm above the LCD cell panel. As an example, assuming that an SVGA 11.4 inch (29 cm) liquid crystal color display panel is used, the horizontal pixel pitch is about 96 μm and the vertical pitch is about 288 μm.

FIG. 4B illustrates what an observer's eye sees with this device, for example in a position corresponding to view 4, for a typical portion of the display. From this position, the pixels labeled “4” in FIG. 4A appear to fill all of the lenticulars 16 above each of them, and even numbered (0, 2, 4, 6) views The lenticular portion on the group of pixels for appears black or dim. As can be seen from FIG. 4B, each auxiliary pixel in view “4” comprises three such separately colored triplet of auxiliary pixels running diagonally across the green, two such triplets. Is indicated by a broken line. FIG. 4C is a vector diagram showing various pitches as given to the eye in this case. The color pixel (triplet) pitch perpendicular to the color filter strip indicated by P⊥ in FIG. 4C is 1440 μm, and the color pixel pitch parallel to the color strip indicated by P‖ in FIG. 4C is 403 μm. The color pixel pitches P _h and P _v in the horizontal and vertical directions are 672 μm and 864 μm, respectively, giving a reasonable total number of pixels of 343 × 200 in each view. However, the appearance of the display is relatively large pitch P⊥, or its dominated by a relatively small pitch P‖ contrary, the product of P _v and P _h is equal to the product of the P‖ and P⊥ is Attention. This pitch difference manifests itself as a color strip extending diagonally. A similar effect appears for example in a 5-view system, while for a 6-view system, a relatively large vertical pitch manifests itself as a color strip running horizontally.

  This problem can be avoided by rearranging the color filters and thus the color auxiliary pixel layout. An example of a device with appropriately rearranged color filters will be described again in connection with the 7 view system embodiment as described above. However, it will be appreciated that the principle can be applied analogously to embodiments having different numbers of views.

A simple attempt to avoid the above problems is to rearrange the color filter strips so that the color filter strips extend in the column direction rather than the row direction. The shape and total number of individual auxiliary pixels need not be changed. All of the display elements in one row of the array of liquid crystal display panels are then displayed the same color by three adjacent display element rows, each displaying red, green and blue. Iterate over successive groups. A display panel with color pixels rearranged in this way is illustrated in FIG. 5A in the case of a 7 view system, similar to the display panel of FIG. 4A. FIG. 5B shows, for comparison with FIG. 4B, what the observer perceives with one eye when in the position to view view “4”. As can be seen, the column-by-column contour of the color filter gives a full color pixel triplet with a Δ-shaped contour in its view and organized vertically. Three such color pixel triplets in the column are shown in dashed outline in the upper half of FIG. 5B. The horizontal and vertical pitches P _h and P _v shown by FIG. 5C are again 672 μm and 864 μm, giving a 343 × 200 resolution for each view. In this embodiment, since the triplets are of Δ contour rather than elongated, the color components of the red, green and blue triplets are placed closer together and form a tighter group. Thus, the individual pixels are only slightly distinguishable and unwanted visible display artifacts in the form of diagonal color strips are reduced.

  The appearance of a pixel in view “5” is indicated in the lower half of FIG. 5B by the dashes r ′, g ′ and b ′. At positions where both views are viewed simultaneously by one eye due to optical crosstalk, color pixel triplets are made up of r, g, and b auxiliary pixels that are directly below each other in the row direction (one such triplet is The horizontal pitch is then effectively halved from 672 μm to 336 μm (shown in the outer half of the dashed line in the lower half of FIG. 5B).

  The situation for the other views obtained is similar.

  For example, the use of such a color pixel layout in the 6-view device of FIG. 2 will generally have a similar effect in removing unwanted color strips.

  A different method of color filter rearrangement to avoid the aforementioned problems with color strips is illustrated in FIG. 6, again using a 7-view system as an example. In this embodiment, the display elements, either completely below each lenticular 16, or at least most of it below, are all made of the same color and are three adjacent. Each lenticular is associated with a different color element (red, green and blue), and the pattern is repeated for other groups across the array. Thus, each row of display elements consists of a series of groups of adjacent display elements of the same color, and the number in each group yields 7 views, in this case two adjacent groups corresponding to the number of views. It alternates between 3 and 4 depending on the number of elements inside. FIG. 6B shows, for comparison with both FIG. 4B and FIG. 5B, the color pixels seen by the viewer's eye when in position to view view “4”. As in FIG. 5B, a Δ shape color triplet is created, in which case the Δ shape triplet appearing in view “4” is rotated compared to the triplet of FIG. 5B, and this triplet is now rather than vertical. Triplets that are knitted horizontally and are adjacent in the row direction are inverted with respect to each other. Four such triplets are shown in dashed outline in FIG. 6B. Also as in FIG. 5B, the appearance of a pixel in view “5” is indicated in the lower half of the figure by r ′, g ′ and b ′.

  The horizontal and vertical pitches of the color triplets in this embodiment are 1008 μm and 576 μm, respectively, and the view resolution is 228 (horizontal) × 300 (vertical). For example, at the crosstalk position between views 4 and 5, the vertical pitch is halved to 288 μm.

  As in the previous embodiment, the triplets are then Δ contours with their color components forming a tighter group, so that individual pixels are only slightly distinguishable and the visibility of the color strip in the display is reduced Is done.

  Crosstalk, as in the case of the embodiments of FIGS. 5A and 5B and FIGS. 6A and 6B, thanks to color filters that are appropriately arranged so that the color triplets in adjacent views are then meshed at those positions. By halving the color triplet pitch at the position where the eye sees two views simultaneously, the visibility of the red, green and blue color components is further reduced, so that the observation runs across the display diagonally or horizontally The problem of color strips appearing to the person is further alleviated.

  Another advantage of properly arranging the color filters in the manner shown in FIGS. 5A and 6A is that the red, green and blue auxiliary elements in the liquid crystal display panel are arranged together in groups. The rearrangement is performed in the way that is done. If a larger spacing is provided between adjacent groups, this grouping will not reduce the opening of the individual display (auxiliary) elements, and the black mask used in this liquid crystal display panel; Allows relaxation of alignment accuracy with the color filter array providing better product manufacturing.

  Although the matrix display panel in the above embodiment comprises a liquid crystal display panel, flat panel display devices such as electro-optic spatial light modulation and electroluminescent or plasma display panels can be used. Is expected.

  It is also anticipated that although the lenticular elements associated with the display elements are in the form of lenticular sheets, they can be provided in any way. For example, these elements can be formed in the glass plate of the display panel itself.

  The embodiment described above provides a direct observation display. However, the autostereoscopic display device may instead comprise a projection display device. An embodiment of such a device comprising a rear projection device is shown in FIG. In this apparatus, the generated image is projected by the projection lens 30 onto the rear part of the diffuser projection screen 32. On the front side of the screen 32, ie on the side facing the viewer, a lenticular sheet 35 comprising a parallel, elongated array of lenticular elements is placed. The image projected onto the screen is generated by a matrix liquid crystal display panel 10 similar to the previously described display panel, which in this example is illuminated by light from the light source 33 via a condenser lens. Since the projection lens projects an image of the display element of the display panel 10 onto the screen 32, the column and row display element array consisting of display pixels comprising an enlarged image of the display element in the corresponding array is amplified. An image is created on the screen. This display image, which consists of display pixels each composed of a projected image of the display element, is observed through a lenticular sheet 35. The lenticular elements of the lenticular sheet 35 are in a tilted relationship to the display pixels, i.e. the rows of display element images on the screen, for example on the screen as described above, as shown in FIGS. The lenticular block in FIGS. 2 and 3 now of course represents the image of the display element on the screen.

  A display device other than a liquid crystal display panel, such as a cathode ray tube, can alternatively be used to provide a projected display image comprising columns and rows of display pixels on the screen.

  In summary, therefore, means for making a display consisting of display pixels in columns and rows, such as a liquid crystal matrix display panel having a column and row array of display elements, and an array of parallel lenticular elements above the display. An autostereoscopic display device is described, in which the lenticular elements are tilted with respect to the display pixel rows. The reduction in display resolution experienced in such devices, especially in the case of multi-view displays, is then shared between both horizontal and vertical resolution.

  Reading this disclosure will reveal other modifications to those skilled in the art. Such modifications may involve other features that are already known in the field of autostereoscopic display devices and components thereof and may be used in place of or in addition to the features already described herein.

1 is a schematic perspective view of an embodiment of an autostereoscopic display device according to the present invention using a matrix display panel. FIG. FIG. 6 is a schematic plan view of an exemplary portion of a display element array of a display panel illustrating an example arrangement of lenticular elements associated with display elements for providing six view outputs. FIG. 3 illustrates the arrangement of lenticular elements similar to FIG. 2 but related to display elements to provide seven view outputs. FIG. 4A is a plan view schematically illustrating the relationship between display elements and lenticular elements for a portion of a display element array in one embodiment of an apparatus for producing seven view display outputs of all colors; FIG. 4B shows the color pixels seen by one eye of the observer in the embodiment of FIG. 4A when in a position corresponding to a particular view, and FIG. 4C is recognized by the eyes present in the arrangement of FIGS. 4A and 4B. FIG. 6 is a vector diagram showing various color pixel pitches. FIG. 5A illustrates the relationship between display elements and lenticular elements in a manner similar to that of FIG. 4A in another embodiment of an all color display device, and FIGS. 5B and 5C are for the embodiment of FIG. 5A. 4B is a drawing corresponding to FIGS. 4B and 4C. FIG. 6A illustrates the relationship between display elements and lenticular elements in another embodiment of an all-color display device, and FIG. 6B illustrates the observer's eye in the embodiment of FIG. 6A for comparison with FIGS. 4B and 5B. An example of a color pixel that can be seen in FIG. FIG. 6 is a schematic plan view of another embodiment of the present invention that provides a projected display.

10 LCD matrix display panel
12 Display element
14 Light source
15 sheet
16 Lenticular
18 Black mask material
30 Projection lens
32 Diffuser projection screen
33 Light source
35 Lenticular thin plate A, B, C Dash line H _P Display element horizontal pitch V _p Display element vertical pitch P ⊥ Color filter strip and vertical color pixel (triplet) pitch P 平行 Color pixel pitch parallel to color strip L Minimum separation Distance Y Row direction α Lenticular tilt angle

Claims (4)

A plurality of elongated shaped display pixel arrays arranged in rows and columns bordered by a mask material; and an array of elongated lenticular elements disposed on the array of display pixels and extending parallel to each other;
The lenticular element causes an observer to recognize a three-dimensional image by providing an output beam of each of a plurality of views from the array of display pixels in different directions around the longitudinal axis of the lenticular element;
The longitudinal direction of the elongated display pixels and the longitudinal direction of the elongated lenticular elements are inclined with respect to each other, the array of display pixels is a color display array, and the display pixels adjacent in the lateral direction display the same color, An autostereoscopic display device in which the display pixels adjacent in the vertical direction display different colors.   The autostereoscopic display device according to claim 1, wherein the array of display pixels is a liquid crystal display panel. The pitch of the lenticular elements, Ru 2 1/3 or 2 1/4 Baidea of the display elements in the horizontal direction, autostereoscopic display device according to claim 1 or claim 2.   The autostereoscopic display device according to any one of claims 1 to 3, wherein an angle formed between a longitudinal direction of the display pixel and a longitudinal direction of the lenticular element is 9.46 °.

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