JP2007155780A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which displays a vivid image having interference fringes reduced. <P>SOLUTION: In the display device wherein a superposition image is displayed by at least two LCDs 14 and 15, a vivid image having interference fringes reduced can be displayed by such configuration that distances (pitches) between pixels are different between a rear display panel 141 and a front display panel 151. As an example of making pitches of pixels different, the same display area is given to the display panels 141 and 151 and the different numbers of pixels are given to the display panels 141 and 151 to make pitches of pixels different, different display areas are given to the display panels 141 and 151 while giving the same number of pixels to them, or a pitch of pixels on one display panel 141 (151) is made uniform while that on the other display panel 151 (141) is made random. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device configured to display one image by at least two sets of display panels.

  As a conventional technique, two liquid crystal panels that display RGB in a time-sharing manner are used, and the pixels of the first liquid crystal panel and the pixels of the second liquid crystal panel are arranged so as to be arranged in a grid pattern to display an image. There is a color display device that performs the above (for example, Patent Document 1 below).

Further, among the projection images projected by the three display panels that control light transmission of the three primary colors, only the projection image of the green pixel is arranged at a predetermined interval with respect to the projection image of the other color pixels. (For example, the following patent document 2).
JP 2002-116717 A JP-A-5-323271

  However, the above prior art displays a high-resolution image by alternately arranging the pixels in two liquid crystals. When an image is displayed with such a configuration, interference fringes are generated between the upper and lower liquid crystal display elements due to pixel pitch interference.

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a display device that displays a clear image with reduced interference fringes.

  In order to achieve the above-mentioned object, the present invention at least first and second display panels are overlapped with each other, a first image is displayed from the first display panel, and a second image is displayed from the second display panel. In the display device that displays an image and displays a superimposed image, a distance between each pixel of the first display panel and a distance between each pixel of the second display panel are different.

  Further, according to the present invention, in the display device, the screen display areas of the first display panel and the second display panel are the same, and the number of pixels of the first display panel and the second display panel is different. It is characterized in that the distance between the pixels is made different by configuring the above.

  Further, according to the present invention, in the display device, the first display panel and the second display panel have the same number of pixels, but the screen display areas of the first display panel and the second display panel are different. It is characterized in that the distance between the pixels is made different by configuring the above.

  Furthermore, in the display device, the distance between the pixels of the first display panel may be equal, and the distance between the pixels of the second display panel may be randomly configured. It is characterized in that the distances are different.

  Furthermore, in the display device according to the present invention, each of the first and second display panels includes a transparent plate in which liquid crystal is sealed, and further includes a backlight that illuminates the transparent plate, and the transparent plate. And a polarizing plate for controlling input / output of light from the backlight.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which displays the clear image | video which reduced the interference fringe can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a multiple liquid crystal display device (hereinafter referred to as “display device”) 1 according to the present invention.

  The display device 1 includes a fluorescent tube 10, a light guide plate 11, a reflection plate 12, two polarizing plates 13 and 16, a rear LCD (Liquid Crystal Display) 14, and a front LCD 15.

  The fluorescent tube 10 is disposed on the side surface of the display device 1. In the present display device 1, two fluorescent tubes 10 are arranged substantially parallel to each other.

  The light guide plate 11 is disposed between the two fluorescent tubes 10, emits light emitted linearly from the fluorescent tubes 10 toward the LCDs 14 and 15, and uniformly irradiates the entire LCDs 14 and 15.

  The reflection plate 12 is located below the light guide plate 11. The light from the fluorescent tube 10 is directed to the LCDs 14 and 15 by the light guide plate 11, but part of the light is reflected and directed to the reflection plate 12. The reflection plate 12 reflects the light from the light guide plate 11 toward the LCDs 14 and 15.

  The fluorescent tube 10, the light guide plate 11, and the reflection plate 12 constitute a so-called backlight.

  The polarizing plate 13 and the polarizing plate 16 are disposed so as to sandwich the LCDs 14 and 15, and the polarization directions are orthogonal to each other. This is to control the input and output of light to the LCDs 14 and 15. The polarizing plate 13 is disposed on the light guide plate 11 side, and the polarizing plate 16 is disposed on the viewpoint position side.

  The rear LCD 14 is disposed on the polarizing plate 13 side, and is configured by two transparent plates each enclosing a liquid crystal. In each transparent plate, liquid crystal molecules are arranged so as to be substantially perpendicular to each other.

  The front LCD 15 is disposed on the polarizing plate 16 side, and is composed of two transparent plates in the same manner as the rear LCD 14.

  In this way, a pair of LCDs 14 and 15 is constituted by two transparent plates, and each LCD 14 and 15 is irradiated with a backlight such as a fluorescent tube 10 to display an image respectively. From the viewpoint position at the top of the drawing, one superimposed image can be seen.

  FIG. 2 is an example of an electrical configuration diagram of the display device 1. As a whole, the display device 1 includes a rear display unit 140, a front display unit 150, a rear display control unit 24, a front display control unit 25, and a CPU 30.

  The front display unit 150 includes a front display panel unit 151, a scanning line driving circuit 152, and a data line driving circuit 153.

  The front display panel unit 151 has gate lines in the horizontal direction and data lines in the vertical direction, and a pixel electrode for applying a voltage to the liquid crystal layer of the front LCD 15 and a TFT (Thin Film Transistor) for switching the pixel electrodes at the intersection. Device.

  The scanning line driving circuit 152 selectively scans the TFT elements by applying a voltage to the gate lines in the front display unit 150 based on the scanning line drive control signal d1 from the timing controller 253.

  The data line drive circuit 153 controls the pixel electrodes in the front display unit 150 by applying a voltage to the data lines based on the data line drive control signal d2 from the timing controller 253.

  The rear display unit 140 has the same configuration as the front display unit 150. In FIG. 2, a part of the configuration in the rear display unit 140 is omitted for convenience of explanation.

  The front display control unit 25 is connected to the front display unit 150 and also to the CPU 30. The front display control unit 25 includes a drawing circuit 252 and a timing controller 253.

  The drawing circuit 252 receives a video signal corresponding to the video displayed on the front LCD 15 from the outside, and outputs the video signal to the timing controller 253 based on the control of the CPU 30.

  The timing controller 253, based on the video signal from the drawing circuit 252, for example, synchronizes with the horizontal synchronization signal included in the video signal, and sends the scanning line drive control signal d1 to the scanning line drive circuit 152 and the data line, respectively. The data line drive control signal d2 is output to the drive circuit 153.

  Similar to the front display control unit 25, the rear display control unit 24 includes a drawing circuit 242 and a timing controller 243. The drawing circuit 242 and the timing controller 243 of the rear display control unit 24 have substantially the same configuration as the drawing circuit 252 and the timing controller 253 of the front display control unit 25, respectively.

  The operation of the display device 1 configured as described above is as follows. When a video signal for front display is input from the outside to the drawing circuit 252 and the scanning line drive control signal d1 is output from the timing controller 253, the scanning line drive circuit 152 outputs a timing signal for scanning each scanning line. Output. A voltage is applied to each gate line by this timing signal.

  On the other hand, the data line drive circuit 153 applies a data voltage corresponding to the image data of each pixel to each data line based on the data line drive control signal d2.

  As a result, a front image is displayed from the front LCD 15. Further, the rear display unit 140 operates in the same manner, and a rear image is displayed from the rear LCD 14. A stereoscopic image is displayed on the two LCDs 14 and 15.

  FIG. 3 shows an example of video display. An image by the front LCD 15 is displayed at the approximate center of the screen, and an image by the rear LCD 14 is displayed as a background image.

  As described in the prior art, when the pixel pitch (distance) between the liquid crystal display elements of the two LCDs 14 and 15 is the same, interference fringes are generated between the upper and lower LCDs 14 and 15 due to interference of the pixel pitch. For example, there is a possibility that interference fringes also occur in the image displayed in FIG. 3 and a clear image cannot be displayed.

  Therefore, in the present embodiment, the rear display panel 141 and the front display panel 151 are configured so that the pixel pitch between the liquid crystal display elements of the upper and lower LCDs 14 and 15 is different, thereby reducing interference fringes and clear images. Is displayed.

  FIG. 4 is an example in which the pixel pitch is made different by changing the number of pixels between the rear display panel 141 and the front display panel 151 with the same display area size.

  FIG. 4A shows an example in which the front display panel 151 has a larger number of pixels than the rear display panel 141 and has a different pixel pitch with the same display area size. On the other hand, FIG. 4B shows an example in which the front display panel 151 has a smaller pixel pitch than the rear display panel 141 with the same display area size and a different pixel pitch.

  By making a difference in pixel pitch between the upper and lower liquid crystal display elements, the possibility of occurrence of interference fringes between the upper and lower pixels is reduced, and as a result, the interference fringes can be reduced.

  FIG. 5 is an example in which the pixel pitch is made different by configuring the display area size to be different between the upper and lower display panels 141 and 151 with the same number of pixels.

  FIG. 5A shows an example in which the front display panel 151 has a smaller display area size than the rear display panel 141 (the number of pixels is the same), and the pixel pitch on the front side is smaller than that on the rear side. It is. On the other hand, FIG. 5B shows an example in which the display area size is smaller on the rear side than on the front side (the number of pixels is the same).

  By changing the display area size with the same number of pixels, there is a difference in pixel pitch between the upper and lower liquid crystal display elements, so that interference fringes due to interference of the pixel pitch can be reduced.

  The example of FIG. 6 is an example in which the pixel pitch of one display panel 14, 15 is configured at equal intervals, and the pixel pitch of the other display panel 14, 15 is random.

  That is, FIG. 6A shows an example in which the pixel pitch of the front display panel 151 is configured at equal intervals and the pixel pitch of the rear display panel 141 is random. FIG. 6B shows an example in which the pixel pitch of the rear display panel 141 is configured at equal intervals, and the pixel pitch of the front display panel 151 is random.

  As an example of the random pitch, it is desirable to randomly arrange within a predetermined range in the vertical and horizontal directions with respect to the equally spaced reference positions. This is because even if the pixel pitch is random, an image may not be displayed with pixels that are too far apart.

  FIG. 7 shows an example. Pixels 50 are arranged at equal intervals on one display panel 141 (151), and pixels 60 are arranged at a random pitch on the other display panel 151 (141). The pixel 60 is disposed within a predetermined range (a range indicated by a dotted line) having a distance that is ½ of the adjacent pixel 50 in the vertical and horizontal directions. Of course, this is only an example, and any distance may be used as long as the pixel 60 is disposed within a predetermined range with respect to the reference pixel 50 position.

  Since one display panel 141 (151) is equally spaced and the other display panel 151 (141) is set to a random pitch, the pixel pitch between the upper and lower display panels 141 and 151 is different. Interference fringes due to interference can be reduced.

  FIG. 8 is a display example of actual video. As shown in FIG. 8A, interference fringes are reduced when one is set to a random pitch, but as shown in FIG. 8B, interference fringes are generated at equal intervals. Therefore, a clear video can be displayed when one of them is set to a random pitch.

  In the example described above, two LCDs are combined into one set, and the display device 1 is configured with two sets of LCDs 14 and 15. In addition to this, the display device 1 may be configured by three or more sets of LCDs such as three sets, four sets, or the like. By configuring at least the pixel pitch between the liquid crystal display elements of two sets of LCDs, a clear image with reduced interference fringes can be displayed. Of course, a clear image with further reduced interference fringes can be displayed by changing the pixel pitch among all the sets of liquid crystal display elements.

  In the above-described example, the LCDs 14 and 15 are displayed by a so-called transmissive type using a backlight, but other than that, a reflective type that displays by reflecting external light, and a transmissive type and a reflective type are also available. You may make it display by the so-called transflective type which united.

  The display device 1 according to the present embodiment is used for, for example, a car navigation device, a mobile phone, and a display device for displaying vehicle instruments.

It is a figure which shows the structural example of the display apparatus concerning this invention. It is a figure which shows the electrical structural example of the display apparatus which concerns on this invention. It is a figure which shows the example of the image | video displayed on the display apparatus. 4A and 4B are diagrams showing examples of LCDs having the same display area size and different number of pixels. FIG. 5A and FIG. 5B are diagrams showing examples of LCDs having the same number of pixels and different display area sizes. FIG. 6A and FIG. 6B are diagrams showing examples of LCDs with one random pitch. It is a figure which shows the example of arrangement | positioning of a pixel when it is set as a random pitch. FIG. 8A shows an actual video example when one LCD is set to a random pitch, and FIG. 8B shows an actual video example when both are equally spaced.

Explanation of symbols

1: multiple liquid crystal display device (display device), 14: rear LCD, 15: front LCD, 24: rear display control unit, 25: front display control unit, 30: CPU, 50: pixels with equal pitch, 60: Random pitch pixels, 140: rear display unit, 141: rear display panel, 150: front display unit, 151: front display panel, 152: scanning line driving circuit, 153: data line driving circuit, 242: drawing circuit, 243: Timing controller, 252: drawing circuit, 253: timing controller

Claims (5)

At least the first and second display panels are overlapped with each other, the first video is displayed from the first display panel, the second video is displayed from the second display panel, and the superimposed video is displayed. In the display device
The distance between the pixels of the first display panel is different from the distance between the pixels of the second display panel.   The screen display areas of the first display panel and the second display panel are the same, and the number of pixels of the first display panel and the second display panel is configured to be different from each other. 2. The display device according to claim 1, wherein the display devices are different from each other.   The first display panel and the second display panel have the same number of pixels, and the screen display areas of the first display panel and the second display panel are configured to be different from each other. 2. The display device according to claim 1, wherein the display devices are different from each other.   The distance between the pixels of the first display panel is equal, and the distance between the pixels of the second display panel is randomly configured so that the distance between the pixels is different. The display device according to claim 1.   Each of the first and second display panels is composed of a transparent plate in which liquid crystal is sealed, and further controls a backlight for illuminating the transparent plate, and input / output of light from the backlight to the transparent plate. The display device according to claim 1, further comprising a polarizing plate.

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