JP2006301045A - Display panel, image display device, and display method for image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display panel or the like capable of displaying half-tone of high quality when the pixels of the display panel are segmentalized by a plurality of pixel pieces. <P>SOLUTION: In the display panel 10, each pixel 1 for example is segmentalized in stripes by a plurality of pixel pieces 1a-1c which can perform ON/OFF control of display. The pixel piece 1a-1c comprises a unit pixel piece 1a which is approximately at the center of the pixel 1, and a plurality of pixel piece pairs 1b, 1c arranged sequentially so as to sandwich the unit pixel piece 1a. The area of each pixel piece forming a pair is nearly equal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display panel composed of a plurality of pixels, an image display device including the display panel, and a display method thereof. In particular, the present invention relates to a display panel, an image display apparatus, and a display method thereof in which one pixel is subdivided by a plurality of pixel pieces.

  When displaying a halftone image on a flat image display device such as a liquid crystal display device or a plasma display device, the following two methods have been conventionally employed.

  The first method is a method for controlling the voltage value applied to the pixel. The second method is a method for controlling the ON time width of a pixel by controlling ON / OFF of the pixel at high speed. However, when halftones are displayed by the above methods, there are the following problems.

  For example, assume that the first method is adopted for the liquid crystal display device. In this case, by changing the applied voltage value, the amount of light transmitted or reflected by the pixel (optical characteristics of the liquid crystal) is changed.

  However, the optical characteristics change with temperature. Therefore, when displaying a certain halftone, even if the same voltage value is applied, there is a problem that the actually displayed halftone changes depending on the temperature during operation.

  Further, when displaying a halftone by the second method, there are the following problems.

  In order for the human eye not to perceive the pixel ON / OFF control and to perceive an appropriate halftone, it is necessary to perform the ON / OFF control at a high speed in addition to the ON time width control. there were.

  The display device to which the second method can be applied for the high-speed ON / OFF control has a problem that it is limited to a display device with a high response speed. Further, even in a display device with high responsiveness, the number of pixels constituting the display panel must be limited in consideration of processing speed (that is, the number of pixels cannot be increased to a predetermined number or more). There was a problem.

  In view of such a problem, in recent years, a technique (method) according to Patent Document 1 has been developed as a new halftone display method.

  In the technique according to Patent Document 1, one pixel is divided into a plurality of pixel pieces. An appropriate halftone is displayed by changing the integrated area of the pixel pieces to be lit (ON state). In this technique, there is no need to change the voltage in an analog manner as in the first method, and the voltage control is simple binary control of ON / OFF. The voltage application time can also be constant.

Japanese Patent Publication No. 3-5724

  The technique according to Patent Document 1 does not particularly refer to the display method of each pixel piece. However, it is assumed that, as a result of displaying a predetermined pixel piece in order to display a predetermined halftone in one pixel, the center of gravity of the luminance distribution in the one pixel is shifted from the center of the one pixel.

  In this case, the shift of the center of gravity is perceived by human eyes like noise. In particular, when the viewing distance is short, the contour portion is roughly recognized in the pixel.

  In addition, when the center of gravity shift occurs in one or both of adjacent pixels, the image displayed as a result is perceived to be different from the actual display image by human eyes. There is also a possibility.

  As described above, in the technique according to Patent Document 1, when the pixel subdivision structure and the display method of each pixel piece are not appropriate, a low-quality halftone is displayed.

  Accordingly, an object of the present invention is to provide a display panel, an image display device, and a display method thereof capable of displaying a high-quality halftone in a display panel in which pixels are subdivided by a plurality of pixel pieces. To do.

  In order to achieve the above object, the display panel according to claim 1 of the present invention is a display panel having a plurality of pixels arranged according to a predetermined arrangement, wherein each of the pixels is turned on / off of display. The pixel pieces are subdivided into stripes by a plurality of controllable pixel pieces, and the pixel pieces are sequentially arranged so as to sandwich the unit pixel pieces located substantially at the center of the pixels. A plurality of pixel piece pairs are provided, and the areas of both pixel pieces forming the pair are substantially the same.

  According to a third aspect of the present invention, in the display panel having a plurality of pixels arranged according to a predetermined arrangement, each of the pixels is a plurality of pixels capable of display ON / OFF control. The pixel pieces are subdivided into pieces, and the pixel pieces include a unit pixel piece existing at a substantially center of the pixel, and a plurality of annular pixel pieces arranged in a nested manner so as to surround the unit pixel piece. Is provided.

  An image display device according to a sixth aspect of the present invention includes the display panel according to any one of the first to fifth aspects.

  A display method for an image display device according to a twelfth aspect of the present invention is the display method for an image display device including a display panel having a plurality of pixels arranged according to a predetermined arrangement. The pixels are subdivided by a plurality of pixel pieces capable of ON / OFF control of display, and the center of the luminance distribution of the one pixel is positioned at the center of the one pixel. By displaying the predetermined pixel piece of the pixel, a predetermined halftone is displayed in each pixel.

  The display panel according to claim 1 of the present invention is a display panel having a plurality of pixels arranged according to a predetermined arrangement, wherein each of the pixels is composed of a plurality of pixel pieces capable of ON / OFF control of display. The pixel piece is subdivided into stripes, and the pixel piece includes a unit pixel piece existing at the approximate center of the pixel and a plurality of pixel piece pairs sequentially arranged so as to sandwich the unit pixel piece. Since the areas of the two pixel pieces forming the pair are substantially the same, a halftone can be displayed in the pixel so that the center of gravity of the luminance distribution is located at the approximate center of the pixel. Therefore, it is possible to prevent image degradation due to uneven luminance of pixels.

  According to a third aspect of the present invention, in the display panel having a plurality of pixels arranged according to a predetermined arrangement, each of the pixels is a plurality of pixel pieces capable of ON / OFF control of display. The pixel piece includes a unit pixel piece existing substantially at the center of the pixel and a plurality of annular pixel pieces arranged in a nested manner so as to surround the unit pixel piece. Therefore, it is possible to display halftones in the pixel so that the center of gravity of the luminance distribution is located at the approximate center of the pixel. Therefore, it is possible to prevent image degradation due to uneven luminance of pixels.

  Moreover, since the image display apparatus according to claim 6 of the present invention includes the display panel according to any one of claims 1 to 5, the image display apparatus displays a high-quality halftone. It is possible to provide an image display device that can be used.

  A display method for an image display device according to a twelfth aspect of the present invention is the display method for an image display device including a display panel having a plurality of pixels arranged according to a predetermined arrangement. The pixels are subdivided by a plurality of pixel pieces capable of ON / OFF control of display, and the center of the luminance distribution of the one pixel is positioned at the center of the one pixel. By displaying the predetermined pixel piece of the pixel, the predetermined halftone is displayed in each pixel, so that it is possible to prevent image deterioration due to the luminance unevenness of the pixel. Therefore, a high-quality halftone can be displayed on the image display device.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.

<Embodiment 1>
FIG. 1 is a plan view showing an overall view of a display panel of an image display apparatus according to the present invention.

  As shown in FIG. 1, the display panel 10 has a plurality of pixels 1 arranged according to a predetermined arrangement. Here, in FIG. 1, the display panel 10 has a plurality of pixels 1 arranged in a matrix (that is, at equal intervals in the vertical and horizontal directions). Further, as shown in FIG. 1, an electrode lead portion is formed on one short side and one long side of the display panel 10.

  Here, although not shown in FIG. 1, each pixel 1 is subdivided into a plurality of pixel pieces.

  FIG. 2 is a diagram showing a typical configuration of one enlarged pixel 1.

  As shown in FIG. 2, the pixel 1 is subdivided into stripes by a plurality of pixel pieces 1a, 1b, and 1c.

  Here, the display panel 10 has a configuration capable of independently controlling the display of the pixel pieces 1a to 1c. For example, as disclosed in Patent Document 1, each pixel piece 1a, 1b, 1c is a device having a function of holding ON / OFF display information for each pixel piece (MOS-type FET, signal storage capacitor). Etc.) may be configured. The display control of the pixel pieces 1a to 1c is simple ON / OFF control.

  Now, specifically, the arrangement and total area of the pixel pieces 1a to 1c are configured as follows.

  That is, as shown in FIG. 2, the pixel piece is composed of a unit pixel 1a and a pair of pixel pieces 1b and 1c. The unit pixel piece 1a exists at the approximate center of the pixel 1 and has the smallest area among the pixel pieces. The pixel piece pairs 1b and 1c are sequentially arranged from the inside of the pixel to the outer peripheral portion so as to sandwich the unit pixel piece 1a.

  Specifically, the pixel piece pair 1b is arranged so as to directly sandwich the unit pixel piece 1a. Further, the pixel piece pair 1c is arranged so as to sandwich the unit pixel piece 1a and the pixel piece pair 1b. Here, the area of both pixel pieces constituting one pixel piece pair is substantially the same.

  The total area (the area of the pair) of each pixel piece pair 1b, 1c is a predetermined ratio (in this embodiment, doubled with reference to the unit pixel piece 1a as the distance from the unit pixel piece 1a increases. However, in the present invention, the predetermined ratio is not limited to 2).

That is, in this embodiment, as shown in FIG. 1, the total area (area of the pair) of the pixel piece pair is increased by 2 ⁿ . Here, n increases by 1 as the distance from the unit pixel piece 1a increases. Specifically, the area of the unit pixel piece 1a is “1 (= 2 ⁰ )”. In this case, the total area of the pixel piece pair 1b is “2 (= 2 ¹ )”. The total area of the pixel piece pair 1c is “4 (= 2 ² )”.

In addition to the pixel pair 1b and 1c, a pair of pixel pieces is formed so as to sandwich the pixel pair 1b and 1c (that is, the pixel 1 is further subdivided than shown in FIG. 1). In other words, the total area of the other pixel piece pairs increases as “8 (= 2 ³ )”, “16 (= 2 ⁴ )”... “2 ⁿ ”. Here, “2 ⁿ ” is the total area of the pixel piece pair arranged n-th with respect to the unit pixel piece 1a.

  Next, a display method of the image display apparatus having the display panel 10 configured as described above will be described.

  FIG. 3 is a diagram illustrating an image display state of 8 gradations including halftones in one pixel 1. In FIG. 3, 1 to 6 display halftones.

  As shown in FIG. 3, the display of each image piece 1a to 1c is controlled in accordance with the density of the image to be displayed (that is, the degree of each gradation). FIG. 3 shows a total of eight gradation display states of complete lighting (seventh gradation), complete extinction (zero gradation), and halftone (first to sixth gradation).

  Here, the display control of each of the pixel pieces 1a to 1c is simple ON / OFF control. Accordingly, the luminance distribution when each pixel piece 1a to 1c is lit (during display) is substantially uniform both within one pixel piece and between each pixel piece.

  When displaying halftone in one pixel 1, the predetermined pixel pieces 1 a to 1 c are displayed (lighted) so that the center of gravity of the luminance distribution of the pixel 1 is always located substantially at the center of the pixel. .

  Specifically, in the case of the zeroth gradation, all the image pieces 1a to 1c are not turned on. In the case of the first gradation, only the unit pixel piece 1a is turned on. In the case of the second gradation, only the pixel piece pair 1b is turned on. In the case of the third gradation, the unit pixel piece 1a and the pixel piece pair 1b are turned on. In the case of the fourth gradation, only the pixel piece pair 1c is turned on. In the case of the fifth gradation, the unit pixel piece 1a and the pixel piece pair 1c are turned on. In the case of the sixth gradation, the pixel pair 1b, 1c is turned on. In the case of the seventh gradation, all the image pieces 1a to 1c are turned on.

  As can be seen from FIG. 3, as the gray level of the halftone increases, the total area of the pixel pieces to be lit increases in the area unit of the unit pixel. In any halftone, the center of gravity of the luminance is located at the approximate center of the pixel 1. That is, by displaying the predetermined pixel pieces 1a to 1c of the one pixel so that the center of gravity of the luminance distribution of the one pixel 1 is located at the center of the one pixel, a predetermined intermediate point is obtained in each pixel 1. Key is displayed.

  As described above, in the display panel 10 (or the image display device including the display panel) according to the present embodiment, each pixel 1 is configured as described above and is displayed as described above. Have the following effects.

  For example, as shown in FIGS. 4 and 5, when the halftone is displayed in a state where the center of gravity of the luminance is not always at the approximate center of the pixel 1, the following problems occur. Here, in FIG. 4, as in the present embodiment, the pixel 1 is subdivided into a unit pixel piece and a pair of pixel pieces. However, in a halftone display, the center of gravity of the luminance distribution is the center of the pixel 1. This is the case. FIG. 5 shows a case where the subdivision configuration of the pixel 1 by the pixel piece is different from the present embodiment, and the center of the luminance distribution is not at the center of the pixel 1 in the halftone display. .

  In other words, in this case, the local luminance perception of the local pixel is perceived as noise, and particularly when the viewing distance is close, the roughness of the contour of the image is noticeable. It becomes.

  However, in the case of the present embodiment, even when halftones are displayed, the center of brightness always exists at the center of the pixel, so that it is possible to prevent image degradation due to the uneven luminance of the pixel. it can.

  In the case of the first method of the prior art, halftones are displayed by controlling the voltage applied to the pixels in an analog manner (see FIG. 6). In this case, display variations due to voltage deviation occurred.

  However, in the present embodiment, lighting of each of the pixel pieces 1a to 1c is controlled by a digital voltage (that is, a simple ON / OFF voltage). Therefore, in the first conventional method, it is possible to suppress display variations that have occurred when displaying halftones.

  In the present embodiment, the ON time width of the pixel is not controlled as in the second method of the prior art described above. Therefore, the speed of the control operation is increased by the conventional second method. It is not required than when it is adopted.

  Further, when each pixel 1 is subdivided, as shown in FIG. 7, the pixel 1 may be subdivided by a plurality of pixel pieces 1t having the same area. In this configuration, when each gradation is displayed so that the center of gravity of the luminance distribution of the pixel 1 exists at the center of the pixel 1, the display is as shown in FIG. The pixel 1 is divided into five by the pixel piece 1t as in the present embodiment.

  In this case, the change in each gradation is six as shown in FIG.

  However, when the pixel 1 is subdivided by the unit pixel piece 1a and the pair of pixel pieces 1b and 1c that increase in area at a predetermined rate as in the present embodiment, it is shown in FIG. As described above, eight kinds of gradation changes are possible. That is, as in the present embodiment, the pixel 1 is divided into the unit pixel piece 1a and the pixel piece pair 1b, 1c whose area is increased at a predetermined rate, so that the halftone is displayed more finely. can do.

  Further, in the present embodiment, a case where the total area (the area of the pair) of each pixel piece pair 1b, 1c increases by a factor of 2 with respect to the unit pixel piece 1a as the distance from the unit pixel piece 1a increases. did. However, the total area (the area of the pair) of each pixel piece pair 1b, 1c only needs to increase at a predetermined rate as the distance from the unit pixel piece 1a increases, and increases by a factor of 2 with respect to the unit pixel piece 1a. It is not necessary to limit to a case.

  However, as described above, when the total area (area of the pair) of each pixel piece pair 1b and 1c increases from the unit pixel piece 1a by a factor of 2 as the distance from the unit pixel piece 1a increases, The following effects are exhibited.

  That is, the change of each gradation can be changed in the area unit of the unit pixel piece 1a. Specifically, as shown in FIG. 3, when increasing every gradation from the zeroth gradation, the luminance can be increased by the luminance unit of the unit pixel piece 1a.

  In the present embodiment, the pixel 1 is subdivided into stripes in the “lateral direction” by the pixel pieces 1a to 1c. However, as shown in FIG. 9, the pixel 1 may be subdivided into stripes in the “vertical direction” by the pixel pieces 1a to 1c.

<Embodiment 2>
Also in the present embodiment, the display panel 10 includes a plurality of pixels 1 arranged in a matrix (that is, at equal intervals in the vertical and horizontal directions), for example. However, in the present embodiment, the subdivision method for each pixel 1 is different from that in the first embodiment. FIG. 10 is a diagram showing a subdivision method for each pixel 1 according to the present embodiment.

  As shown in FIG. 10, the pixel piece includes a unit pixel piece 1a and annular pixel pieces 1r and 1s. The unit pixel piece 1a is located substantially at the center of the pixel 1, and has the smallest area among the pixel pieces 1a, 1r, and 1s. The annular pixel pieces 1r and 1s are arranged in a nested manner so as to surround the unit pixel piece 1a.

Further, the area of the annular pixel pieces 1r and 1s increases in a geometric sequence of 2 (in ²ⁿ ) as the distance from the unit pixel piece 1a increases.

Specifically, the area of the unit pixel piece 1a is “1 (= 2 ⁰ )”. In this case, the area of the annular pixel piece 1r is “2 (= 2 ¹ )”. The area of the annular pixel piece 1s is “4 (= 2 ² )”.

If an annular pixel piece surrounding the annular pixel piece 1r, 1s is formed in addition to the annular pixel piece 1r, 1s, the area of the other annular pixel piece is “8 (= 2 ³ ) ”,“ 16 (= 2 ⁴ ) ”...“ 2 ⁿ ”. Here, “2 ⁿ ” is the area of the annular pixel piece arranged n-th with respect to the unit pixel piece 1a.

  In the present embodiment, the display control of the pixel pieces 1a, 1r, and 1s is simple ON / OFF control.

  Next, a halftone display method for the subdivided pixel 1 as shown in FIG. 10 will be described.

  FIG. 11 is a diagram illustrating an image display state of 8 gradations including halftones in one pixel 1. In FIG. 11, 1 to 6 display halftones.

  As shown in FIG. 11, the display of each image piece 1a, 1r, 1s is controlled corresponding to the shade of the image to be displayed (that is, the degree of each gradation). FIG. 11 illustrates a state of eight gradation display of complete lighting (seventh gradation), complete extinction (zero gradation), and halftone (first to sixth gradation).

  Here, the display control of each pixel piece 1a, 1r, 1s is simple ON / OFF control. Therefore, the luminance distribution when each pixel piece 1a, 1r, 1s is lit (during display) is substantially uniform both within one pixel piece and between each pixel piece.

  When displaying halftone in one pixel 1, predetermined pixel pieces 1a, 1r, and 1s are displayed (lighted) so that the center of gravity of the luminance distribution of the pixel 1 is always located at the center of the pixel. Yes.

  Specifically, in the case of the zeroth gradation, all the image pieces 1a, 1r, and 1s are not lit. In the case of the first gradation, only the unit pixel piece 1a is turned on. In the case of the second gradation, only the annular pixel piece 1r is turned on. In the case of the third gradation, the unit pixel piece 1a and the annular pixel piece 1r are turned on. In the case of the fourth gradation, only the annular pixel piece pair 1s is turned on. In the case of the fifth gradation, the unit pixel piece 1a and the annular pixel piece 1s are turned on. In the case of the sixth gradation, the annular pixel pieces 1r and 1s are turned on. In the case of the seventh gradation, all the image pieces 1a, 1r, and 1s are turned on.

  As can be seen from FIG. 11, as the gradation increases, the total area of the pixel pieces to be lit increases in the area unit of the unit pixel 1a. In any halftone, the center of gravity of the luminance is located at the approximate center of the pixel 1.

  As described above, in the display panel 10 according to the present embodiment (or the image display device including the display panel 10), each pixel 1 is configured as described above and is displayed as described above. Therefore, it has the same effect as the first embodiment.

  In addition, when subdividing each pixel 1, the pixel 1 may be subdivided by a plurality of annular pixel pieces having the same area.

  However, when the pixel 1 is subdivided by the unit pixel piece 1a and the annular pixel piece pair 1b, 1c that increases in area at a predetermined rate, as described in the first embodiment, Fine halftones can be displayed.

  Further, in the present embodiment, the case where the area of each annular pixel piece 1r, 1s increases by a factor of 2 with respect to the unit pixel piece 1a as it moves away from the unit pixel piece 1a has been mentioned. However, the area of each annular pixel piece 1s, 1r may be increased at a predetermined rate as it moves away from the unit pixel piece 1a, and is not limited to a case where the area is increased by a factor of 2 with respect to the unit pixel piece 1a. Also good.

  However, as described above, when the area of each annular pixel piece 1s, 1r increases by a factor of 2 with respect to the unit pixel piece 1a as the distance from the unit pixel piece 1a increases, the following effects are obtained. .

  That is, the change of each gradation can be changed in the area unit of the unit pixel piece 1a. Specifically, as shown in the figure, in the case where the gradation is increased from the zeroth gradation, the luminance can be increased by the luminance unit of the unit pixel piece 1a.

<Embodiment 3>
The present embodiment relates to an electrode structure that is applied to the pixel structure according to the first embodiment and can light (display) each pixel piece. FIG. 12 is a plan view showing the configuration of the electrode structure. FIG. 13 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 12, the row electrodes 11 are arranged in stripes in the horizontal direction of the drawing. The column electrodes 12 are arranged in stripes in the vertical direction of the drawing. As shown in FIG. 13, the column electrode 12 is disposed on the back glass substrate 13. A row electrode 11 is disposed on the surface glass substrate 14. Here, both the row electrode 11 and the column electrode 12 are transparent electrodes.

  Here, the row electrode 11 and the column electrode 12 intersect with each other in plan view, and each pixel 1 is formed at the intersecting portion. As shown in FIG. 13, the row electrode 11 and the column electrode 12 are disposed with a predetermined distance therebetween, and a display layer 15 such as a liquid crystal is provided between the row electrode 11 and the column electrode 12. Is formed.

  Furthermore, as shown in FIGS. 12 and 13, in the electrode structure according to the present embodiment, the column electrode 12 is subdivided by the electrode pieces 12a, 12b, and 12c corresponding to the pixel pieces 1a to 1c shown in FIG. It has become.

  That is, the pixel piece 1a is formed in a region where the row electrode 11 and the electrode piece 12a overlap. Further, the pixel piece 1b is formed in a region where the row electrode 11 and the electrode piece 12b overlap. Further, the pixel piece 1c is formed in a region where the row electrode 11 and the electrode piece 12c overlap.

  Here, the case where the column electrode 12 is subdivided by the electrode pieces 12a, 12b, and 12c is mentioned. However, as shown in FIG. 14, the row electrode 11 may be subdivided by electrode pieces 11a, 11b, and 11c corresponding to the pixel pieces 1a to 1c shown in FIG.

  That is, one of the row electrode 11 and the column electrode 12 is subdivided by the electrode pieces 11a, 11b, 11c (or 12a, 12b, 12c) corresponding to the pixel pieces 1a to 1c shown in FIG. It only has to be done.

  Although not shown, an insulating film is formed or a slight space is formed between the electrode pieces 12a to 12c (or 11a to 11c).

  In the electrode structures shown in FIGS. 12 and 13, for example, a scanning signal voltage is applied to a predetermined row electrode 11, and a data signal voltage is applied to predetermined electrode pieces 12a to 12c. Then, the display layer 15 at a portion where the row electrode 11 through which the scanning signal voltage flows and the electrode pieces 12a to 12c through which the data signal voltage flows intersects to emit light based on each signal voltage. That is, the predetermined pixel pieces 1a to 1c are turned on (displayed).

  In other words, the scanning signal voltage is sequentially applied to the row electrode 11, and the data signal voltage is applied to the electrode pieces 12a to 12c in a period in which each scanning signal voltage is valid. Thereby, the predetermined pixel pieces 1a to 1c are sequentially displayed, and as a result, the entire image is displayed.

  In the image display device according to the present embodiment, as described above, in the electrode structure, either the row electrode 11 or the column electrode 12 corresponds to the pixel pieces 1a to 1c, and the electrode pieces 12a to 12c (or 11a to 11c).

  Therefore, compared with the technique related to Japanese Patent Publication No. 3-5724 (that is, an electrode structure for individually controlling each pixel piece), the predetermined pixel pieces 1a to 1c are turned on (displayed) with a simple electrode structure. be able to.

  Further, with the simplification of the electrode structure, the display method of each pixel piece 1a to 1c can be easily performed.

  In the present embodiment, the electrode structure that is applied to the pixel structure according to the first embodiment and can turn on (display) each of the pixel pieces 1a to 1c has been described.

  However, the concept of the present embodiment can also be applied to an electrode structure that is applied to the pixel structure according to the second embodiment and can light (display) each pixel piece 1a, 1r, and 1s. That is, one of the row electrode 11 and the column electrode 12 is subdivided by a plurality of electrode pieces corresponding to the pixel pieces 1a, 1r, and 1s. However, in this case, the electrode pieces are arranged in multiple layers (that is, a multilayer electrode piece structure).

<Embodiment 4>
In the image display device according to each of the above embodiments, in order to increase the resolution, it is necessary to increase the number of pixels. Then, the number of row electrodes and column electrodes increases, and the necessity of applying the scanning signal voltage at a higher speed arises due to the limitation of the voltage signal scanning time. Therefore, the lighting time of each pixel (each pixel piece) is shortened and the contrast is lowered.

  Therefore, in order to solve the problem of lowering the contrast that occurs when the resolution is improved, the image display device according to the present embodiment is arranged in the display panel corresponding to each pixel (each pixel piece). A display device having a display holding function is employed as the display device.

  As a display device having the display holding function, for example, there are a device composed of a MOS type FET, a signal storage capacitor, or the like, or a device using a cholesteric liquid crystal for a display layer.

  Thus, by applying a device having a display holding function, the following effects are obtained.

  For example, in the electrode configuration shown in FIG. 12, the scanning signal voltage is sequentially applied to the row electrode 11, and the data signal voltage is applied to the electrode pieces 12a to 12c in a period in which each scanning signal voltage is valid. Thereby, the display of the predetermined pixel pieces 1a to 1c is sequentially determined, and the display state is maintained until a signal voltage is applied next.

  Therefore, the display time is longer than when a display device having a display holding function is not applied, and even if the resolution is improved, high-contrast image display can be performed.

  In particular, when a cholesteric liquid crystal is adopted as a display device having a display holding function (that is, when a cholesteric liquid crystal is adopted as the display layer 15 in the structure shown in FIG. 13), for example, a MOS type FET or a signal There is also an effect that the electrode structure and wiring can be simplified as compared with the case where a display holding function device including a storage capacitor or the like is employed.

<Embodiment 5>
It is assumed that halftone is displayed on the display panel 10 of the image display device according to the first and second embodiments. In this case, as described above, in each pixel 1 displaying a halftone, the center of gravity of the luminance distribution is substantially at the center of the pixel 1. Therefore, image quality deterioration due to the uneven luminance distribution is reduced, and a good image can be viewed when the display panel 10 displaying the halftone is viewed from a long distance.

  However, when the display panel 10 displaying the halftone is viewed from a short distance, the pixel pieces 1a to 1c, 1r, and 1s are directly observed. Therefore, when the display panel 10 is viewed from a short distance, it may be felt that the image quality is deteriorated.

  Therefore, in order to solve the problem that occurs in the short distance viewing, in the image display device according to the present embodiment, a light diffusing unit is provided on the front surface of the display panel 10 according to each of the above embodiments.

  As the light diffusion portion, for example, a frosted glass or a non-glare sheet subjected to a non-glare process can be considered. The ground glass subjected to the non-glare treatment is formed by corroding the surface of the glass with a chemical and roughening the surface. Further, when a non-glare sheet is employed as the light diffusion portion, it is only necessary to attach the non-glare sheet to the front surface of the display panel 10.

  FIG. 15 is a diagram illustrating a state in which the light diffusing unit 20 is disposed on the front surface of the display panel 10.

  As described above, in the image display device according to the present embodiment, the light diffusion unit 20 is provided on the front surface of the display panel 10. Therefore, even if the display panel 10 is observed from a short distance, the pixel pieces 1a to 1c, 1r, and 1s are not clearly recognized. Thereby, it is possible to alleviate the deterioration of the image quality caused by clearly viewing the pixel pieces 1a to 1c, 1r, and 1s.

  In addition, when non-glare processing is performed, it is possible to reduce the reflection (glare) of lighting and the like, and this has the effect of making the display easier to see and reducing eye fatigue.

  Therefore, as described above, when the light diffusing unit 20 that has been subjected to the non-glare process is installed in the image display device, the image display device can also exhibit the effects resulting from the non-glare process.

<Embodiment 6>
The present embodiment is characterized in that the display panel 10 according to each of the above-described embodiments is arranged in a matrix to constitute one large display.

  An image display device (large display) according to the present embodiment is shown in FIG. As shown in FIG. 16, a large number of display panels 10 according to each embodiment are arranged vertically and horizontally. And as a whole, the large display 100 which displays the one image is comprised.

  As described above, in the present embodiment, since a large number of display panels 10 according to each embodiment are arranged to form one large display 100, the following effects are obtained.

  That is, as described in the fourth embodiment, when the pixel 1 is subdivided into a plurality of pixel pieces 1a to 1c, 1r, and 1s, an image displayed on the display panel having the pixel is visually recognized from a long distance. Is preferable. This is because when viewed from a short distance, the pixel pieces 1a to 1c, 1r, and 1s are visually recognized, and the image quality is deteriorated.

  However, as described above, when used as a large display 100, the large display 100 is intended for visual recognition from a long distance, and therefore, even if the light diffusing unit 20 is not provided, the image quality is deteriorated. Will disappear.

  Further, it is assumed that one large display is configured by arranging a plurality of display panels according to the first method of the related art that display halftones by controlling voltage values.

  In this case, since the luminance change characteristics (hereinafter referred to as display characteristics) due to the voltage value of each display panel are usually different, even if the same voltage value is applied to display the same halftone, each display panel As a result, different halftones are displayed. That is, unevenness occurs in the image.

  Further, when the temperature of the use environment rises, the display characteristics differ more significantly between the display panels. Therefore, the image unevenness becomes more obvious.

  By the way, since the brightness | luminance displayed is saturated when it becomes more than a predetermined voltage, when the said predetermined voltage value is applied, the dispersion | variation in the display characteristic between each display panel does not arise. That is, the variation in display characteristics occurs at an intermediate value from zero voltage (OFF) to saturation voltage (fully ON) voltage.

  Here, in the image display apparatus (large display 100) according to the present embodiment, each of the pixel pieces 1a to 1c, 1r, and 1s is controlled by simple ON / OFF even when halftone is displayed.

  Therefore, the image display apparatus (large display 100) according to the present embodiment hardly causes variations in display characteristics between the display panels 10 and can suppress unevenness in the image.

It is a top view which shows the structure of a display panel. It is a top view which shows the mode of the pixel subdivided by the pixel piece. It is a figure which shows a mode that the display of each gradation is performed by lighting a predetermined pixel piece (display). It is a figure for demonstrating the effect of the invention which concerns on Embodiment 1. FIG. It is a figure for demonstrating the effect of the invention which concerns on Embodiment 1. FIG. It is a figure which shows a mode that the display of each gradation is performed by changing a voltage value. It is a figure which shows a mode that one pixel is subdivided into stripe form by the pixel piece which has an equivalent area and the same shape. It is a figure which shows a mode that the display of each gradation is performed by lighting a predetermined pixel piece (display). It is a figure which shows a mode that one pixel is subdivided by the pixel piece in stripe form in the vertical direction. It is a figure which shows a mode that one pixel is subdivided into the nested form by cyclic | annular pixel change. It is a figure which shows a mode that the display of each gradation is performed in the pixel which concerns on Embodiment 2 by lighting (displaying) the predetermined | prescribed pixel piece. It is a top view which shows a mode that the column electrode is subdivided by the electrode piece. It is a figure which shows the cross-section of a display panel. It is a top view which shows a mode that the row electrode is subdivided by the electrode piece. It is a perspective view which shows a mode that the light-diffusion part is arrange | positioned in the front surface of the display panel. It is a figure which shows one large sized display comprised by arrange | positioning a some display panel in matrix form.

Explanation of symbols

1 pixel, 1a unit pixel piece, 1b, 1c pixel piece pair, 1r, 1s annular pixel piece, 2 extraction electrode, 10 display panel, 11 row electrode, 12 column electrode, 12a, 12b, 12c electrode piece, 20 light diffusion part , 100 Large display.

Claims (12)

In a display panel having a plurality of pixels arranged according to a predetermined arrangement,
Each of the pixels is subdivided into stripes by a plurality of pixel pieces capable of display ON / OFF control,
The pixel piece is
A unit pixel piece located substantially at the center of the pixel;
A plurality of pixel piece pairs sequentially arranged so as to sandwich the unit pixel piece,
The areas of both pixel pieces forming the pair are substantially the same.
A display panel characterized by that. The unit pixel piece is
The pixel piece has a minimum area;
The total area of each pixel piece pair is:
As the distance from the unit pixel piece increases, the unit pixel piece increases at a predetermined rate.
The display panel according to claim 1. In a display panel having a plurality of pixels arranged according to a predetermined arrangement,
Each of the pixels is subdivided into a plurality of pixel pieces capable of ON / OFF control of display,
The pixel piece is
A unit pixel piece located substantially at the center of the pixel;
A plurality of annular pixel pieces arranged in a nested manner so as to surround the unit pixel piece,
A display panel characterized by that. The unit pixel piece is
The pixel piece has a minimum area;
The area of the annular pixel piece is:
As the distance from the unit pixel piece increases, the unit pixel piece increases at a predetermined rate.
The display panel according to claim 3. The predetermined ratio is:
2 times with respect to the unit pixel,
The display panel according to claim 2, wherein the display panel is a display panel. A display panel according to any one of claims 1 to 5 is provided and configured.
An image display device characterized by that. A first electrode;
A second electrode that intersects the first electrode in plan view, and
Each pixel is formed in a portion where the first electrode and the second electrode intersect,
Corresponding to the pixel piece, either the first electrode or the second electrode is subdivided by the electrode piece,
Applying a predetermined signal to the predetermined electrode piece and the non-subdivided electrode to light the predetermined pixel piece;
The image display device according to claim 6. A display device disposed in the display panel corresponding to each of the pixel pieces and having a display holding function is further provided.
The image display device according to claim 6. The display device is:
It is a device that uses cholesteric liquid crystal for the display layer.
The image display apparatus according to claim 8. A light diffusing unit disposed on the front surface of the display panel and having a light diffusing function;
The image display device according to claim 6. By disposing the display panel according to any one of claims 1 to 5 according to a predetermined arrangement, a large display is configured.
An image display device characterized by that. In a display method of an image display device configured to include a display panel having a plurality of pixels arranged according to a predetermined arrangement,
Each of the pixels is subdivided by a plurality of pixel pieces capable of ON / OFF control of display,
By displaying the predetermined pixel piece of the one pixel so that the center of gravity of the luminance distribution of the one pixel is located at the center of the one pixel, a predetermined halftone is displayed in each pixel. ,
A display method for an image display device.

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