This application claims priority from and the benefit of Korean Patent Application No. 10-2011-0075919, filed on Jul. 29, 2011, which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field
Exemplary embodiments of the present invention relate to a display apparatus having an autostereoscopic 3D or 2D/3D switchable pixel arrangement and, more particularly, to a display apparatus having a pixel arrangement for an autostereoscopic 3D or 2D/3D switchable display which can compensate for luminance degradation.
2. Discussion of the Background
3D (three-dimensional) display technology is classified into stereoscopic display technology, which requires that the observer wear special glasses, such as shutter glasses, to watch 3D images, and autostereoscopic display technology, which requires no special glasses. The stereoscopic display technology requires glasses, which may consist of shutter glasses having liquid crystals for left and right eyes alternately transmitting and blocking light with a predetermined period, respectively, and a device for driving the shutter glasses. That is, images for left and right eyes are separately provided to create the illusion of 3D images. However, stereoscopic display technology has a drawback in that it requires additional devices, including the liquid crystal shutter glasses and their driving device.
The autostereoscopic display technology has an advantage in that it can display 3D images without requiring inconvenient shutter glasses. The autostereoscopic display technology can include a parallax barrier 3D display device and a lenticular 3D display device. The parallax barrier 3D display device includes a display panel, which has pixels arranged in rows and columns, and a parallax barrier having openings of a vertical lattice shape installed in front of the display panel. The parallax barrier separates left and right images for left and right eyes of the observer, respectively, and generates binocular disparity of different images on the display panel. This type of display device has a drawback in that diffraction interference occurs through the lattice openings. Therefore, an autostereoscopic display device employs a lenticular 3D display device or a lenticular 3D system. Instead of the vertical lattice-shaped parallax barrier, the lenticular 3D system commonly uses a lenticular lens sheet, which has column-direction arrangement of semi-cylindrical lenses placed on the display panel, for 3D display. A 2D/3D switchable lenticular 3D system includes a lenticular lens sheet, a flat-surfaced plate facing it, liquid crystals filling the space between them, and electrodes formed inside the lenticular lens sheet and the flat-surfaced plate.
The lenticular device is installed in front of the display panel and is adapted to switch between 2D and 3D display modes according to turning on and off of the voltage applied between the electrodes.
In the 2D display mode, according to whether a voltage is applied across the liquid crystal materials, the refractive index of the liquid crystals in the viewing direction is substantially identical to that of the material used for the sheet, so that the lens action of the lenticular device ceases, and the lenticular system acts as a light transmitter on the display panel (i.e., having no effect on the path of light coming from the display panel).
In the 3D display mode, according to whether a voltage is applied across the liquid crystal materials, the orientation of liquid crystals makes the refractive index of the liquid crystals different from that of the material used for the sheet, so that the lenticular device acts as a lens, thereby providing the observer's left and right eyes with different images (i.e., creating the illusion of 3D images).
The resolution of liquid crystal display panels is increasing over time and in proportion to developments in relevant technology. In the case of a liquid crystal display panel upgraded by reducing the horizontal and vertical sizes of each pixel by half, the area of each pixel becomes a quarter of that before the upgrade. Such an upgrade of resolution of a liquid crystal display panel degrades the pixel aperture ratio, resulting in degradation of the display panel's luminance.
In an attempt to compensate for such degradation of luminance, the luminance of a backlight source, which illuminates the rear surface of the display panel, may be increased. This approach, however, increases power consumption and is thereby undesirable.
In the case of an autostereoscopic 3D or 2D/3D display device, the observer's viewpoint of watching 3D images may be fixed, making it crucial to increasing it to multiple viewpoints.
Therefore, there is a need for a pixel arrangement of a display panel used for a lenticular system employing, instead of sub-pixels of basic colors of red, green, and blue, basic sub-pixels of red, green, blue, and white (i.e. four sub-pixels), in order to compensate for luminance degradation.
There is also a need for a multi-viewpoint 3D display device adopting a pixel arrangement using four basic sub-pixels in line with technological developments that increase of the resolution of the display panel.
Exemplary embodiments of the present invention provide a display device having a pixel arrangement for a 3D or a 2D/3D display which can compensate for luminance degradation without increasing power consumption.
Exemplary embodiments of the present invention also provide pixel arrangement capable of increasing the number of multiple viewpoints.
Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.
An exemplary embodiment of the present invention discloses an autostereoscopic 3D display apparatus including a display panel having an array of pixels arranged in rows and columns, the pixels including basic pixels having four basic colors; and a lenticular device positioned above the display panel, the lenticular device including an array of a plurality of lenticular components extending in parallel with a slant line slanted at an angle of tan−1(a/mb) with regard to columns of the pixels, where m refers to the number of adjacent rows before an identical viewpoint on the same slant line appears, and a and b refer to horizontal and vertical lengths of each pixel. When n is 0 or a natural number, the number of viewpoints is 2m(2n+1), and pixels corresponding to the given viewpoints are repeated at every m rows in each lenticular component, the number of parallel lines extending through centers of pixels in parallel with the slant line inside each lenticular component is identical to the number of viewpoints, and each of the parallel lines lies on the repeated basic pixels.
An exemplary embodiment of the present invention also discloses an autostereoscopic 3D display apparatus including a display panel having an array of pixels arranged in rows and columns, the pixels arranged at the odd-numbered rows being basic pixels of four colors arranged repeatedly, the pixels arranged at the even-numbered rows being aligned under the pixels arranged at each odd-numbered row starting from the third pixel; and a lenticular device positioned above the display panel, the lenticular device including an array of a plurality of lenticular components extending in parallel with a slant line slanted at an angle of tan−1(a/mb) with regard to columns of the pixels, where m refers to the number of adjacent rows before an identical viewpoint on the same slant line appears, and a and b refer to horizontal and vertical lengths of each pixel. When n is 0 or a natural number, the number of viewpoints is 2m(2n+1), pixels corresponding to the given viewpoints are repeated at every m rows in each lenticular component, the number of parallel lines extending through centers of pixels in parallel with the slant line inside each lenticular component is identical to the number of viewpoints, and each of the parallel lines lies on the repeated basic pixels.
An exemplary embodiment of the present invention further discloses an autostereoscopic 3D display apparatus including a display panel having an array of pixels arranged in rows and columns, the pixels arranged at the rows being repeatedly arranged basic pixels of four colors; and a lenticular device positioned above the display panel, the lenticular device comprising an array of a plurality of lenticular components extending in parallel with a slant line slanted at an angle of tan−1(a/mb) with regard to columns of the pixels, where m refers to the number of adjacent rows before an identical viewpoint on the same slant line appears, and a and b refer to horizontal and vertical lengths of each pixel. When n is 0 or a natural number, the number of viewpoints is 2m(2n+1), pixels corresponding to the given viewpoints are repeated at every m rows in each lenticular component, the number of parallel lines extending through centers of pixels in parallel with the slant line inside each lenticular component is identical to the number of viewpoints, and each of the parallel lines lies on the repeated basic pixels.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.
The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of pixels and the arrangement of pixels may be exaggerated for clarity. Like reference numerals in the drawings denote like elements.
It will be understood that the term “basic colors” refers to red, green, blue, and white, but the color of white can be replaced with one of yellow, cyan, and magenta. Pixels generally include sub-pixels of basic colors, but it will be assumed for convenience of description of the present invention that red, green, blue, and white sub-pixels are defined as pixels, respectively. It will be understood that for the purposes of this disclosure, “at least one of X, Y, and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ).
Referring to
When a display device 10 capable of switching from 3D to 2D is needed, the lenticular device 16 may include a lenticular lens sheet, a flat-surfaced plate facing it, liquid crystals filling the space between them, and electrodes formed within the lenticular lens sheet 16 and the flat-surfaced plate 162.
The display panel 14 receives light from the backlight source 12; the light is incident through a rear plate (not shown) of the display panel 14; and images modulated by pixels driven by signals on gate and data lines are outputted through the display panel 14. The images outputted through the lenticular device 16, which is fastened to the display panel 14, are provided as different images for the left and right eyes of the observer such that, in the case of 3D, autostereoscopic 3D display is possible.
Referring to
The gap 22 between the lenticular device 16 and the display panel 14 may be filled with an adhesive for fastening them together. The adhesive may be optically transparent so that the refractive index of the adhesive does not differ from that of the material of the adhesive layers of the lenticular device 16 and the display panel 14, i.e., glass layers. The gap 24 between the backlight source 12 and the rear surface of the display panel 14 may also be filled with an optically transparent adhesive.
The distance between the surface of the lenticular device 16 and the observer's eyes, i.e., the distance of distinct vision D, can be determined by the designer. The distance between the minimums and the surface of the lenticular device 16, i.e., the stack thickness t, can be the sum of thicknesses of the front glass plate of the display device 14, the adhesive layer of the gap 22, and the lenticular device 16. The stack thickness is typically given: t=n·(D/g), where g refers to the magnification of lenticular components. As described above, the refractive indices of the front glass plate of the display device 14, the adhesive of the gap 22, and the lenticular device 16 may be the same as the refractive index of glass, 1.52. Therefore, the stack thickness t is inversely proportional to the magnification g of lenticular components, and the larger the magnification g becomes, the smaller the stack thickness t becomes. When ES is the interpupillary distance of the observer, and HP is a pixel horizontal period between pixels, the magnification g is given as ES/HP. Considering that the interpupillary distance ES is typically set in the range of 62-65 mm, the pixel horizontal period HP may need to be reduced to increase the magnification. The HP can be reduced by increasing the number of viewpoints according to characteristics of the present invention, as will be described later.
Referring to
The slant line SL extends through upper left vertices of a pixel at the first row and the first column, a pixel at the (m+1)th row and the second column, a pixel at the (2m+1)th row and the third column, and a pixel at the (3m+1)th row and the fourth column, respectively, and all of these pixels correspond to the first viewpoint (labeled “1”). Pixels at rows right next to the rows of pixels having viewpoint 1 and the same columns correspond to the last viewpoint, i.e., 2m(2n+1). That is, at the same column, a pixel at a row next to a pixel having viewpoint 1 has viewpoint 2m(2n+1); and, as the number of rows increases, the viewpoint decreases by 1 until a pixel of viewpoint 1 appears. Therefore, at the same column, pixels at rows above a pixel having viewpoint 1 are increased by 1. In addition, at the same row, pixels successively increasing in the column direction from a pixel having viewpoint 1 increase by m until 4mn+m+1, which is the viewpoint of a pixel at a column right before the next pixel of viewpoint 1. Appearance of the next pixel of viewpoint 1 means, as will be described later, appearance of the next lenticular component.
As shown in
It is clear from
In order to display 3D colors, in the case of pixels having the same viewpoints, red, green, blue, and white pixels may be arranged repeatedly. However, red, green, blue, and white pixels need not be arranged repeatedly in that order.
Within respective lenticular components, the number of pixels in each row is 2m(2n+1).
FIGS. 5A-8Ee schematically magnify the arrangement of pixels, with regard to various values of m and n, within respective lenticular components for a 3D or 2D-3D switchable color display.
Therefore, improvement of resolution and reduction of the stack thickness can be advantageously achieved by applying suitable values of m and n and increased numbers of viewpoints. In addition, when all RGB pixels are turned on they produce a white color and, together with W pixels, compensate for luminance degradation.
When m doubles, the number of viewpoints also doubles, and the magnification doubles accordingly, as described above. This makes it possible to reduce the stack thickness to half, thereby resulting in the manufacture of a thin and light display panel.
It will be obvious to those skilled in the art that, although the present invention has been described with regard to a LCD display panel, the present invention is also applicable to other types of display panels, such as CRT, PDP, OLED, and FED.
The present invention produces the following advantage: on a display panel having an array of rows and columns of pixels having basic PenTile colors, the lenticular device has an array of a plurality of lenticular components extending in parallel with a slant line having an angle of tan−1(a/mb) with regard to the columns, and the number of viewpoints is 2m(2n+1), so that an increase of the number of viewpoints can be adjusted properly according to increase of resolution of pixels of display panels in line with the demands of the time and development of relevant technologies. Furthermore, it is possible to obtain high luminance of display panels, as the pixel aperture ratio decreases, without a resulting increase in the power consumption of the backlight source.
In this case, a and b refer to the horizontal and vertical sizes of each pixel, m refers to the number of adjacent rows, and n is 0 or a natural number. Proper selection of m can reduce the stack thickness, including the thickness of the lenticular device, and thus realize a thin and light 3D display device.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Number | Date | Country | Kind |
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10-2011-0075919 | Jul 2011 | KR | national |