JP2010097170A - Image display device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device which can specify a data conversion expression close to the original color by using the CMY system, and can display brighter than the CMY system, and also provide a method of manufacturing the same. <P>SOLUTION: A liquid crystal or electronic paper display is reflective or semi-transmissive by using pixels each consisting of four color sub-pixels in cyan (C), magenta (M), yellow (Y), and white (W) and has a color display mode, white emphasizing color display mode, and black and white display mode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image display device and a method for manufacturing the same, and more particularly to a reflective image display device that is easy to see even in a dim surrounding and a method for manufacturing the same.

  As an image display device using three primary colors of light, red (R), green (G), and blue (B) as subpixels, a liquid crystal display device using a backlight, an electroluminescence (EL) display device, and the like Is popular. These are bright and easy to see, but consume a lot of power.

In recent years, a reflective image display device such as a reflective liquid crystal that does not use a backlight has been developed and attracts attention in terms of energy saving. In the reflection type image display devices described in Patent Documents 1 and 2, when red (R), green (G), and blue (B) are used, light use efficiency is poor and only dark display can be performed. Therefore, cyan (C), Magenta (M) and yellow (Y) as subpixels are disclosed. However, there is no description of the conversion formula in Patent Document 1, and the following formula is described in Patent Document 2 (see Patent Documents 1 and 2).
C = (G + B) / 2 Formula 8.1
M = (B + R) / 2 Formula 8.2
Y = (R + G) / 2 Formula 8.3

Expressions 8.1 to 8.3 described above are simple. For example, when G and B are increased, not only C but also M and Y are necessarily increased, so that the overall display is always “whiter”. For example, even when R = 0 and G = B = 1 (cyan), C = 1 and M = Y = 1/2, resulting in a whiter display than cyan. This is disadvantageous when the color looks good, such as when using a reflective image display device in a bright environment. Alternatively, the following formula is described. In Patent Document 2, R, G, and B are described as 0 to 255, but are described as 0 to 1 here.
^{C = (G + B + G} 2 + B 2 -RG-GB-2BR + 2RGB) / 2 Equation 9.1
^{M = (R + B + R} 2 + B 2 -RG-2GB-BR + 2RGB) / 2 Equation 9.2
Y = (R + G + R ² + G ² −2RG−GB−BR + 2RGB) / 2 Equation 9.3
These expressions 9.1 to 9.3 are probably incorrect, and the following expressions are assumed.
^{C = (G + B + G} 2 + B 2 -RG-2GB-BR + 2RGB) / 2 Equation 9.4
^{M = (R + B + R} 2 + B 2 -RG-GB-2BR + 2RGB) / 2 Equation 9.5
Y = (R + G + R ² + G ² −2RG−GB−BR + 2RGB) / 2 Equation 9.6
However, the expressions 9.4 to 9.6 are complicated, and the display is always whitish like the expressions 8.1 to 8.3. For example, even when R = 0 and G = B = 1 (cyan), C = 1 and M = Y = 1/2, resulting in a whiter display than cyan. This is disadvantageous when the color looks good, for example using a reflective display device in a bright environment.

  On the other hand, when a reflective display device is used in a dark environment, whitish display is advantageous in that it is bright, but CMY alone has a maximum light utilization efficiency of only 2/3.

JP-A-5-241143 JP 11-272244 A

  An object of the present invention is to provide an image display apparatus capable of defining a data conversion formula close to the primary color in the CMY system and capable of performing brighter display than the CMY system, and a manufacturing method thereof.

  The invention according to claim 1 of the present invention is characterized in that one pixel is composed of sub-pixels of four colors of cyan (C), magenta (M), yellow (Y), and white (W). It is what.

  The invention according to claim 2 of the present invention includes color display and color display in which white component is emphasized, color display and color display in which white component is emphasized, or color display and monochrome display in which color display and white component are emphasized. The image display device according to claim 1 having a display mode.

  According to a third aspect of the present invention, there is provided a substrate, a color filter formed on the substrate, a thin film transistor array formed on the color filter, a display medium formed on the thin film transistor array, and a display medium An image display device comprising: the counter electrode formed, wherein the image display device is a reflective display device or a transflective display device. Is.

  The invention according to claim 4 of the present invention is the image display device according to claim 3, wherein the display medium is a liquid crystal or an electrophoretic material.

  The invention according to claim 5 of the present invention is the image display device according to claim 3 or 4, wherein the substrate and the thin film transistor array are substantially transparent, and display is performed on the substrate side. .

  The invention according to claim 6 of the present invention is characterized in that the color filter is composed of sub-pixels of four colors of cyan (C), magenta (M), yellow (Y), and white (W). The image display device according to any one of 5 to 5 is provided.

  According to the seventh aspect of the present invention, from the color data of red (R), green (G), and blue (B), C = max ((G + B−R) / 2, 0), M = max (( 2. A data conversion means for obtaining color display CMYW color data by B + R−G) / 2, 0), Y = max ((R + GB) / 2, 0), and W = 0. The image display device according to any one of claims 1 to 5 is provided.

  According to the eighth aspect of the present invention, from the color data of red (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0), M0 = max ((B + RG) / 2,0), Y0 = max ((R + GB) / 2,0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0) ), C = C0 × (MIN / MAX) + C0, M = M0 × (MIN / MAX) + M0, Y = Y0 × (MIN / MAX) + Y0, W = 0, R = G = B = 0, 6. The image display apparatus according to claim 1, further comprising a data conversion unit that obtains color data of CMYW for color display when = M = Y = W = 0.

  According to the ninth aspect of the present invention, from the color data of red (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0), M0 = max ((B + RG) / 2,0), Y0 = max ((R + GB) / 2,0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0) ), C = C0 × (MIN / MAX) + C0−X, M = M0 × (MIN / MAX) + M0−X, Y = Y0 × (MIN / MAX) + Y0−X, W = X × 2, where X Has a data conversion means for obtaining CMYW data for color display by C = M = Y = W = 0 when an arbitrary value of 0 ≦ X ≦ MIN and R = G = B = 0. The image display device according to any one of claims 1 to 5 is provided.

  The invention of claim 10 of the present invention can be selected from a plurality of conversion formulas as conversion formulas for obtaining CMYW data for monochrome display from the original data of red (R), green (G), and blue (B). The image display device according to any one of claims 1 to 5 is provided.

  According to the eleventh aspect of the present invention, from the color data of red (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0) , M0 = max ((B + RG) / 2, 0), Y0 = max ((R + GB) / 2, 0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0), C = C0 × (MIN / MAX) + C0, M = M0 × (MIN / MAX) + M0, Y = Y0 × (MIN / MAX) + Y0, W = MIN × 2, R = G = B = 0 6. The image display according to claim 1, further comprising data conversion means for obtaining CMYW data for color display in which a white component is emphasized by C = M = Y = W = 0. It is a device.

  In the invention according to claim 12 of the present invention, from the color data of red (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0) , M0 = max ((B + RG) / 2, 0), Y0 = max ((R + GB) / 2, 0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0), C = C0 × (MIN / MAX) + C0, M = M0 × (MIN / MAX) + M0, Y = Y0 × (MIN / MAX) + Y0, W = 0.2R + 0.7G + 0.1B, R = G = 6. The apparatus according to claim 1, further comprising data conversion means for obtaining CMYW data for color display in which white components are emphasized by C = M = Y = W = 0 when B = 0. This is the image display device described.

  According to the thirteenth aspect of the present invention, from the color data of red (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0) , M0 = max ((B + RG) / 2, 0), Y0 = max ((R + GB) / 2, 0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0), C = C0 × (MIN / MAX) + C0, M = M0 × (MIN / MAX) + M0, Y = Y0 × (MIN / MAX) + Y0, W = (R + G + B) / 3, R = G = B = 6. A data conversion means for obtaining CMYW data for color display in which white components are emphasized by C = M = Y = W = 0 in the case of 0. This is an image display device.

  The invention according to claim 14 of the present invention is an image display device characterized in that one pixel is composed of three sub-pixels of cyan (C), magenta (M), and yellow (Y). From the color data of (R), green (G), and blue (B), when R + G + B> 0, C0 = max ((G + B−R) / 2, 0), M0 = max ((B + R−G) / 2 , 0), Y0 = max ((R + GB) / 2,0), MIN = min (C0, M0, Y0), MAX = max (C0, M0, Y0), C = C0 × (MIN / MAX) When + C0, M = M0 × (MIN / MAX) + M0, Y = Y0 × (MIN / MAX) + Y0, R = G = B = 0, C = M = Y = 0 and CMY color data for color display is obtained. An image display device characterized by having data conversion means for obtaining It is.

  According to the fifteenth aspect of the present invention, the image display device further includes an illuminance sensor, and automatically switches between color display, color display with white components emphasized, and monochrome display according to the external illuminance. 15. The image display device according to claim 1, wherein the image display device is performed.

  According to the sixteenth aspect of the present invention, a substrate is prepared, and one pixel is formed with four sub-pixels of cyan (C), magenta (M), yellow (Y), and white (W) on the substrate. Then, a thin film transistor array including a capacitor electrode and a pixel electrode is formed on the sub-pixel, and the display medium is sandwiched between the thin film transistor array and a counter electrode formed on the separate substrate by bonding the thin film transistor array and the separate substrate. This is a method for manufacturing an image display device.

  The invention according to claim 17 of the present invention is the method for manufacturing an image display device according to claim 16, wherein the display medium is a liquid crystal or an electrophoretic material.

  ADVANTAGE OF THE INVENTION According to this invention, while providing the data conversion type | formula close | similar to a primary color with a CMY system, the image display apparatus which can perform a brighter display than a CMY system, and its manufacturing method can be provided.

(A)-(j) is the schematic plan view and chromaticity diagram which show the example of arrangement | positioning of the color filter of the image display apparatus which concerns on embodiment of this invention. (A) And (b) is a schematic sectional drawing which shows an electronic paper as an example of the image display apparatus which concerns on embodiment of this invention. (A) And (b) is a schematic sectional drawing which shows a reflection type liquid crystal display device as an example of the image display apparatus which concerns on embodiment of this invention. (A) And (b) is a schematic sectional drawing which shows a transflective liquid crystal display device as an example of the image display apparatus which concerns on embodiment of this invention. (A)-(e) is a schematic sectional drawing and schematic plan view which show an example of the manufacturing process of the image display apparatus concerning embodiment of this invention. (A)-(e) is a schematic sectional drawing and schematic plan view which show the other example of the manufacturing process of the image display apparatus which concerns on embodiment of this invention. It is a perspective view which shows an example of the image display apparatus which concerns on embodiment of this invention. (A) And (b) is a schematic plan view which shows the example of arrangement | positioning of the color filter of the image display apparatus which concerns on the past or embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIGS. 1A to 1J are a schematic plan view and a chromaticity diagram showing an example of the arrangement of color filters of the image display device according to the embodiment of the present invention. As shown in FIGS. 1A to 1I, the image display device according to the embodiment of the present invention includes cyan (C), magenta (M), yellow (Y), and white (W) sub-pixels. Have. As shown in FIGS. 1A to 1D, the top and bottom of the subpixels may be interchanged in the adjacent pixels, the left and right may be interchanged, and the top, bottom, left and right may be interchanged. Further, as shown in FIGS. 1E to 1I, the arrangement in the sub-pixel is also arbitrary.

  In addition, although there is usually a slight gap between the sub-pixels of the color filter 11 shown in FIGS. 1A to 1I, only the overcoat layer 11OC may be attached to the portion to make a white W state. Alternatively, a black state may be obtained using Cr or a black resist.

  Here, when one pixel is made of red (R), green (G), and blue (B), the light use efficiency in the color filter is ideally 1/3 each, and the overall average is 1/3. It is. When one pixel is CMY, the light use efficiency in the color filter is 2/3 each, and the overall average is also 2/3. The CMY shown in FIG. 8 has the disadvantage that it cannot display pure red (R), green (G), and blue (B), but has the advantage of being bright. In addition, it was found that if the calculation formula was devised, there would be no sense of incongruity when displaying a normal image.

  Further, when one pixel in FIGS. 1A to 1I is CMYW, the light use efficiency in the color filter is 2/3 for CMY and 1 for W (white). On average, it can be further improved to 3/4.

In order to display the color given by the RGB data in color with CMYW, for example, the following equation can be used. However, R, G, and B shall take the value of 0-1.
C = max ((G + B−R) / 2,0) Formula 1.1
M = max ((B + RG) / 2, 0) Equation 1.2
Y = max ((R + GB) / 2, 0) Equation 1.3
W = 0 Formula 1.4
However, max (A, B,...) Is a function having the largest value among A, B,. In addition, after the expressions 1.1 to 1.3, values obtained by multiplying C, M, and Y by (R + G + B) / (2 × (C + M + Y)) are used as new C, M, and Y, respectively. Also good.

  In Formula 1.1 to Formula 1.4, when close to pure R, G + B−R becomes negative and C = 0. When close to pure G, B + R−G becomes negative and M = 0. When close to pure B, R + GB becomes negative and Y = 0. However, the other colors are kept as they are, and the normal image display is hardly affected. For example, when R = 0 and G = B = 1 (cyan), C = 1 and M = Y = 0, resulting in a pure cyan color. For example, when R = G = B = 1 (white), C = M = Y = 1/2 and W = 0, and the light utilization efficiency = ((2/3) × (1/2) × 3 + 1 × 0) / 4 = 1/4. Note that other than W in this equation may be applied to CMY color display. In the case of CMY color display and R = G = B = 1 (white), the light use efficiency = ((2/3) × (1/2) × 3) / 3 = 1/3.

Alternatively, the color given by the RGB data can be displayed in color by CMYW using, for example, the following equation. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Formula 2.1
M0 = max ((B + RG) / 2, 0) Formula 2.2
Y0 = max ((R + GB) / 2, 0) Formula 2.3
MIN = min (C0, M0, Y0) Equation 2.4
MAX = max (C0, M0, Y0) Equation 2.5
C = C0 × (MIN / MAX) + C0 Formula 2.6
M = M0 × (MIN / MAX) + M0 Formula 2.7
Y = Y0 × (MIN / MAX) + Y0 Formula 2.8
W = 0 Formula 2.9
When R = G = B = 0 C = M = Y = W = 0 Equation 2.10
However, min (A, B,...) Is a function having the smallest value among A, B,..., And max (A, B,...) Is the most among A, B,. It is a function that takes a large value. Further, after Expressions 2.1 to 2.3, values obtained by multiplying C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)) are defined as new C0, M0, and Y0. .4 or later may be used.

  In Expressions 2.1 to 2.10, C, M, and Y are brighter by (MIN / MAX) than C0, M0, and Y0. For example, when R = 0 and G = B = 1 (cyan), C = 1 and M = Y = W = 0, resulting in a pure cyan color. For example, in the case of R = G = B = 1 (white), C = M = Y = 1, W = 0, and light utilization efficiency = ((2/3) × 1 × 3 + 1 × 0) / 4 = 1/2. Note that other than W in this equation may be applied to CMY color display. In the case of CMY color display and R = G = B = 1 (white), the light use efficiency = ((2/3) × 1 × 3) / 3 = 2/3.

Alternatively, the color given by the RGB data can be displayed in color by CMYW using, for example, the following equation. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Formula 3.1
M0 = max ((B + RG) / 2, 0) Equation 3.2
Y0 = max ((R + GB) / 2, 0) Formula 3.3
MIN = min (C0, M0, Y0) Equation 3.4
MAX = max (C0, M0, Y0) Equation 3.5
C = C0 × (MIN / MAX) + C0−MIN Formula 3.6
M = M0 × (MIN / MAX) + M0−MIN Equation 3.7
Y = Y0 × (MIN / MAX) + Y0−MIN Formula 3.8
W = MIN × 2 Formula 3.9
When R = G = B = 0 C = M = Y = W = 0 Equation 3.10
However, min (A, B,...) Is a function having the smallest value among A, B,..., And max (A, B,...) Is the most among A, B,. It is a function that takes a large value. Further, after Expressions 3.1 to 3.3, values obtained by performing correction by multiplying C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)) are defined as new C0, M0, and Y0. .4 or later may be used.

  In Equations 3.1 to 3.10, C, M, and Y are brighter by (MIN / MAX) than C0, M0, and Y0, but darker by the amount of the white component, and W takes charge of the white component. For example, in the case of R = 0 and G = B = 1 (cyan), C = 1 and M = Y = W = 0 and a pure cyan color is obtained as in the above-described formula. For example, in the case of R = G = B = 1 (white), C = M = Y = 1/2 and W = 1, and the light use efficiency = ((2/3) × (1/2) × 3 + 1 × 1) / 4 = 1/2.

The difference between Formula 2.1 to Formula 2.10 and Formula 3.1 to Formula 3.10 is whether the CMY is responsible for the white component or W is responsible for the white component. it can. That is, the color given by RGB data can be displayed in color by CMYW using, for example, the following equation. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Equation 4.1
M0 = max ((B + RG) / 2, 0) Equation 4.2
Y0 = max ((R + GB) / 2, 0) Equation 4.3
MIN = min (C0, M0, Y0) Equation 4.4
MAX = max (C0, M0, Y0) Equation 4.5
C = C0 × (MIN / MAX) + C0−X Formula 4.6
M = M0 × (MIN / MAX) + M0−X Formula 4.7
Y = Y0 × (MIN / MAX) + Y0−X Formula 4.8
W = X × 2 Equation 4.9
When R = G = B = 0 C = M = Y = W = 0 Equation 4.10
However, X is an arbitrary value satisfying 0 ≦ X ≦ MIN. Min (A, B,...) Is a function that takes the smallest value among A, B,..., And max (A, B,...) Is the largest of A, B,. It is a function that takes a large value. Further, after Expressions 4.1 to 4.3, values obtained by multiplying C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)) are set as new C0, M0, and Y0. .4 or later may be used.

  In Equation 4.1 to Equation 4.10, C, M, and Y are brighter by (MIN / MAX) than C0, M0, and Y0, but darker by X and W is responsible for X. . For example, in the case of R = 0 and G = B = 1 (cyan), C = 1 and M = Y = W = 0 and a pure cyan color is obtained as in the above-described formula. For example, when R = G = B = 1 (white), C = M = Y = 1−X, W = X × 2, and the light utilization efficiency = ((2/3) × (1-X ) × 3 + 1 × X × 2) / 4 = 1/2.

  When CMYW or CMY is used as described above, the displayable chromaticity region is inside the CMY triangle of FIG. 1 (j). Colors close to R, colors close to G, and colors close to B cannot be produced, but colors close to C, colors close to M, and colors close to Y can be displayed more clearly than RGB. For example, when the chromaticity (x, y) is R (0.42, 0.29), G (0.30, 0.44), and B (0.20, 0.26), C (0.17) , 0.31), M (0.40, 0.21), and Y (0.40, 0.49) are outside. In this case, the display with C, M, and Y pixels rather than displaying C with G and B pixels, displaying M with B and R pixels, and displaying Y with R and G pixels Can be displayed more vividly.

Alternatively, in order to display a color given by RGB data in monochrome using CMYW, for example, the following equation can be used. However, R, G, and B shall take the value of 0-1.
C = M = Y = W = 0.2R + 0.7G + 0.1B Formula 5.1
In Equation 5.1, when R = G = B = 1 (white), C = M = Y = W = 1, and light utilization efficiency = ((2/3) × 1 × 3 + 1 × 1) / 4 = 3/4. This equation is suitable for displaying an image such as a photograph.

Alternatively, in order to display a color given by RGB data in monochrome using CMYW, for example, the following equation can be used. However, R, G, and B shall take the value of 0-1.
C = M = Y = W = (R + G + B) / 3 Formula 6.1
In Formula 6.1, when R = G = B = 1 (white), C = M = Y = W = 1, and the light utilization efficiency = ((2/3) × 1 × 3 + 1 × 1) / 4 = 3/4. This formula may be suitable for displaying images such as tables and graphs.

  By switching these conversion formulas or other conversion formulas by switching a switch or the like, an image that is difficult to see with one formula can be easily viewed with another formula. In the case of the liquid crystal display device, since the rewriting is always performed, the display mode changes immediately following the switching of the switch. In the case of electronic paper, since rewriting is generally performed only when the screen is changed, it is preferable that the current screen is rewritten even when the switch is switched.

Alternatively, for example, the following formula can be used to display a color given by RGB data with CMYW highlighting the white component. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Formula 7.1
M0 = max ((B + RG) / 2, 0) Equation 7.2
Y0 = max ((R + GB) / 2, 0) Equation 7.3
MIN = min (C0, M0, Y0) Equation 7.4
MAX = max (C0, M0, Y0) Equation 7.5
C = C0 × (MIN / MAX) + C0 Formula 7.6
M = M0 × (MIN / MAX) + M0 Formula 7.7
Y = Y0 × (MIN / MAX) + Y0 Formula 7.8
W = MIN × 2 Equation 7.9
When R = G = B = 0 C = M = Y = W = 0 Equation 7.10
However, min (A, B,...) Is a function having the smallest value among A, B,..., And max (A, B,...) Is the most among A, B,. It is a function that takes a large value. Further, after Expressions 7.1 to 7.3, values obtained by multiplying C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)) are set as new C0, M0, and Y0. .4 or later may be used.

  In Expressions 7.1 to 7.10, for example, when R = 0 and G = B = 1 (cyan), C = 1 and M = Y = W = 0 and a pure cyan color is obtained. This is the same as the formula described above. Further, for example, when R = G = B = 1 (white), C = M = Y = W = 1, and light utilization efficiency = ((2/3) × 1 × 3 + 1 × 1) / 4 = 3 / 4. In this “emphasizing white component” display, since the white component is supplemented by W, a bright display can be obtained even in a dark environment.

Alternatively, for example, the following formula can be used to display a color given by RGB data with CMYW highlighting the white component. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Equation 7A. 1
M0 = max ((B + RG) / 2, 0) Equation 7A. 2
Y0 = max ((R + GB) / 2, 0) Equation 7A. 3
MIN = min (C0, M0, Y0) Equation 7A. 4
MAX = max (C0, M0, Y0) Equation 7A. 5
C = C0 × (MIN / MAX) + C0 Formula 7A. 6
M = M0 × (MIN / MAX) + M0 Formula 7A. 7
Y = Y0 × (MIN / MAX) + Y0 Formula 7A. 8
W = 0.2R + 0.7G + 0.1B Formula 7A. 9
When R = G = B = 0 C = M = Y = W = 0 Formula 7A. 10
However, min (A, B,...) Is a function having the smallest value among A, B,..., And max (A, B,...) Is the most among A, B,. It is a function that takes a large value. In addition, Formula 7A. 1-7A. 3 and C0, M0, Y0 respectively multiplied by (R + G + B) / (2 × (C0 + M0 + Y0)) as new C0, M0, Y0 as new C0, M0, Y0. You may use after 4th.

  Equation 7A. 1 to 7A. In FIG. 10, for example, when R = 0 and G = B = 1 (cyan), C = 1, M = Y = 0, and W = 0.8, and a pure cyan color is not obtained. Further, for example, when R = G = B = 1 (white), C = M = Y = W = 1, and light utilization efficiency = ((2/3) × 1 × 3 + 1 × 1) / 4 = 3 / 4. In this “emphasizing white component” display, since the white component is supplemented by W, a bright display can be obtained even in a dark environment.

Alternatively, for example, the following formula can be used to display a color given by RGB data with CMYW highlighting the white component. However, R, G, and B shall take the value of 0-1.
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0) Equation 7B. 1
M0 = max ((B + RG) / 2, 0) Equation 7B. 2
Y0 = max ((R + GB) / 2, 0) Equation 7B. 3
MIN = min (C0, M0, Y0) Equation 7B. 4
MAX = max (C0, M0, Y0) Equation 7B. 5
C = C0 × (MIN / MAX) + C0 Formula 7B. 6
M = M0 × (MIN / MAX) + M0 Formula 7B. 7
Y = Y0 × (MIN / MAX) + Y0 Formula 7B. 8
W = (R + G + B) / 3 Formula 7B. 9
When R = G = B = 0 C = M = Y = W = 0 Formula 7B. 10
However, min (A, B,...) Is a function having the smallest value among A, B,..., And max (A, B,...) Is the most among A, B,. It is a function that takes a large value. Moreover, Formula 7B. 1-7B. 3, the values obtained by multiplying C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)) are set as new C0, M0, and Y0 as Equation 7B. You may use after 4th.

  Equation 7B. 1 to 7B. 10, for example, when R = 0 and G = B = 1 (cyan), C = 1, M = Y = 0, and W = 2/3, and the color is not pure cyan. Further, for example, when R = G = B = 1 (white), C = M = Y = W = 1, and light utilization efficiency = ((2/3) × 1 × 3 + 1 × 1) / 4 = 3 / 4. In this “emphasizing white component” display, since the white component is supplemented by W, a bright display can be obtained even in a dark environment.

  Note that color data can be converted from digital data by calculation, a method using a lookup table, or an electrical conversion from an analog signal, and any method can be used. In driving, gamma conversion is performed to correct the characteristics of the display medium and the display panel unit. In addition, when gamma correction is applied to the color data, it is preferable to perform data conversion after performing inverse gamma conversion on R, G, and B, and drive by performing gamma conversion on C, M, Y, and W. . Note that even if correction is applied to the color data, the inverse gamma conversion and gamma conversion may be omitted (ignoring errors), or the inverse gamma conversion, data conversion, and gamma conversion may be converted using an approximate expression. it can.

  Thus, the effect of adding W to CMY is exhibited in monochrome display or color display with white emphasized. Considering that it is difficult for eyes to recognize colors in a dim environment, it is important to prioritize brightness at the expense of color in dark environments. For example, color display with good color purity can be performed in a bright environment, and monochrome display with high contrast can be performed in a dim environment. Alternatively, color display with high color purity can be performed in a bright environment, and (bright) white can be emphasized in a dim environment. Alternatively, color display with good color purity can be performed in a bright environment, color display with emphasized (bright) white can be performed in a slightly dim environment, and monochrome display can be performed in a dim environment (with high contrast). However, the same display is not excluded regardless of the surrounding environment. For example, color display in which (bright) white is emphasized in all environments may be performed.

  Further, even with CMY alone, color display, color display with white emphasized, and monochrome display can be performed. For example, color display with good color purity (for example, excluding W in Formula 2.1 to Formula 2.10) is performed in a bright environment, and (bright) white is emphasized (for example, Formula 9. 1 to Expression 9.6), and monochrome display with high contrast (for example, excluding W in Expression 5.1) can be performed in a dark environment. Alternatively, only two of these can be used.

  Next, display switching of the image display apparatus will be described. FIG. 7 is a perspective view showing the image display apparatus according to the embodiment of the present invention. As shown in FIG. 7, the image display device 50 according to the embodiment of the present invention incorporates an illuminance sensor 40 to automatically switch the display described above. For example, color display with good color purity is achieved at 200 lux or higher, color display with emphasized (bright) white at 200 lux to 10 lux, and monochrome display (high contrast) at 10 lux or less. Alternatively, for example, color display with good color purity is performed at 50 lux or more, and white is emphasized at less than 50 lux. Alternatively, for example, color display with good color purity is performed at 30 lux or more, and monochrome display is performed at less than 30 lux. The setting illuminance for switching is not limited to the values listed here, and can be arbitrarily set. As the illuminance sensor 40, a photoconductive element such as CdS, a photodiode, a phototransistor, a photo IC, or the like can be used. The output voltage of the illuminance sensor 40 and the switching voltage set by a variable resistor or the like are compared by a comparator, and the output is input to the driving device. The driving device changes the conversion formula based on the data of the comparator. In order to avoid frequent changes in the display mode in the vicinity of the switching value, strictly speaking, the switching value from the dark environment to the bright environment should be set higher than the switching value from the bright environment to the dark environment. For example, it is possible to switch to color display with good color purity at 55 lux or more, switch to color display with white emphasized at 45 lux or less, and keep the previous display mode in the meantime. In addition, the display mode can be manually switched regardless of the surrounding environment by using a changeover switch or the like, for example.

  Next, the image display device 50 according to the embodiment of the present invention will be described. Examples of the image display device 50 include the electronic paper shown in FIGS. 2A and 2B, and the liquid crystal shown in FIGS. 3A, 3B, 4A, and 4B. A display device etc. are mentioned.

  As shown in FIGS. 2A and 2B, the electronic paper according to the embodiment of the present invention is a reflective display device. As shown in FIG. 2A, the electronic paper according to the embodiment of the present invention includes a substrate 1, a thin film transistor array 20, an electrophoretic body 30, a counter electrode 31, a color filter 11, and a counter substrate 32. The color filter 11 is preferably located between the counter substrate 32 and the counter electrode 31, but when the viewing direction is limited or when the thickness of the counter substrate 32 is smaller than the size of the pixel, Since the problem of parallax is small, the color filter 11 may be disposed on the opposite surface of the counter substrate 32 from the counter electrode 31. In the electronic paper according to the embodiment of the present invention, electrophoresis is performed when the thin film transistor array 20 formed on the substrate 1 is bonded to the one formed with the color filter 11 and the counter electrode 31 on another counter substrate 32. It can be produced by sandwiching the body 30. Alternatively, the thin film transistor array 20 can be formed on the substrate 1 by attaching the color filter 11, the counter electrode 31, and the electrophoretic body 30 on another counter substrate 32. The image is displayed on the counter substrate 32 side. As the electrophoretic body 30, an electrophoretic capsule, an electronic powder fluid, or the like can be used. The electrophoretic body 30 may be confined by forming a wall for each subpixel. In this method, it is necessary to precisely position the color filter 11 and the thin film transistor array 20 when the counter substrate 32 is bonded. Alternatively, as shown in FIG. 2B, the electronic paper according to the embodiment of the present invention includes a substrate 1, a color filter 11, a thin film transistor array 20, an electrophoretic body 30, a counter electrode 31, and a counter substrate 32. Yes. The color filter 11 is preferably located between the substrate 1 and the thin film transistor array 20, but when the viewing direction is limited or when the thickness of the substrate 1 is smaller than the pixel size, there is a problem of parallax. Since it is small, the color filter 11 may be disposed on the surface of the substrate 1 opposite to the thin film transistor array 20. In the electronic paper according to the embodiment of the present invention, the color filter 11 is formed on the substrate 1, the thin film transistor array 20 is formed on the color filter 11, and the counter electrode 31 is formed on another counter substrate 32. It can be produced by sandwiching the electrophoretic body 30. Alternatively, the color filter 11 is formed on the substrate 1, the thin film transistor array 20 is formed thereon, and the counter electrode 31 and the electrophoretic body 30 are formed on another counter substrate 32. it can. The image is displayed on the substrate 1 side. In the case of the electronic paper shown in FIG. 2B, since the alignment of the color filter 11 and the thin film transistor array 20 has already been completed in the manufacturing process, precise alignment is not necessary when the counter substrate 32 is bonded.

  There are transmissive, reflective, and transflective liquid crystal display devices, but the liquid crystal display device according to the embodiment of the present invention is intended to use light effectively. Is suitable. As shown in FIG. 3A, the reflective liquid crystal display device according to the embodiment of the present invention includes a substrate 1, a thin film transistor array (electrode is a reflective electrode) 20, a liquid crystal layer 33, a counter electrode 31, a color filter 11, A counter substrate 32, a quarter wavelength plate 34, and a first polarizing plate 35 are provided. An image is displayed on the first polarizing plate 35 side. The color filter 11 is preferably located between the counter substrate 32 and the counter electrode 31, but when the viewing direction is limited or when the thickness of the counter substrate 32 is smaller than the size of the pixel, Since the problem of parallax is small, the color filter 11 may be disposed on the opposite surface of the counter substrate 32 from the counter electrode 31. Alternatively, as shown in FIG. 3B, the reflective liquid crystal display device according to the embodiment of the present invention includes a counter substrate 32, a reflective counter electrode 31, a liquid crystal layer 33, a thin film transistor array 20, a color filter 11, and a substrate. 1 and a quarter wave plate 34 and a first polarizing plate 35 are provided. An image is displayed on the first polarizing plate 35 side. The color filter 11 is preferably located between the substrate 1 and the thin film transistor array 20, but when the viewing direction is limited or when the thickness of the substrate 1 is smaller than the pixel size, there is a problem of parallax. Since it is small, the color filter 11 may be disposed on the surface of the substrate 1 opposite to the thin film transistor array 20. Further, a seal portion 36 is used to enclose the liquid crystal. Here, the first quarter-wave plate 34 is used for setting the wavelength phase difference to 90 degrees (π / 2). For example, stretching of polycarbonate, polyvinyl alcohol, polyarylate, polysulfone, cycloolefin, etc. Formed from film. The first polarizing plate 35 transmits only linearly polarized light in one direction and is formed, for example, by adsorbing iodine on a polyvinyl alcohol film. Although not shown, an alignment film for aligning the liquid crystal or photo-alignment is used, and a spacer is used to make the gap constant.

  As shown in FIG. 4A, the transflective liquid crystal display device according to the embodiment of the present invention includes a backlight 39, a second polarizing plate 38, a second quarter wavelength plate 37, a substrate 1, A thin film transistor array 20, a liquid crystal layer 33, a counter electrode 31, a color filter 11, a counter substrate 32, a first quarter wavelength plate 34, and a first polarizing plate 35 are provided. An image is displayed on the first polarizing plate 35 side. The color filter 11 is preferably located between the counter substrate 32 and the counter electrode 31, but when the viewing direction is limited or when the thickness of the counter substrate 32 is smaller than the size of the pixel, Since the problem of parallax is small, the color filter 11 may be disposed on the opposite surface of the counter substrate 32 from the counter electrode 31. Alternatively, as shown in FIG. 4B, the reflective liquid crystal display device according to the embodiment of the present invention includes a backlight 39, a second polarizing plate 38, a second quarter-wave plate 37, and a counter substrate. 32, a counter electrode 31, a liquid crystal layer 33, a thin film transistor array 20, a color filter 11, a substrate 1, a first quarter wavelength plate 34, and a first polarizing plate 35. An image is displayed on the first polarizing plate 35 side. The color filter 11 is preferably located between the substrate 1 and the thin film transistor array 20, but when the viewing direction is limited or when the thickness of the substrate 1 is smaller than the pixel size, there is a problem of parallax. Since it is small, the color filter 11 may be disposed on the surface of the substrate 1 opposite to the thin film transistor array 20. Further, a seal portion 36 is used to enclose the liquid crystal. Here, the first and second quarter wave plates 34 and 37 are used for setting the phase difference of the wavelength to 90 degrees (π / 2). For example, polycarbonate, polyvinyl alcohol, polyarylate, polysulfone, It is formed from a stretched film such as cycloolefin. The first and second polarizing plates 35 and 37 transmit only linearly polarized light in one direction, and are formed, for example, by adsorbing iodine to a polyvinyl alcohol film. Although not shown, an alignment film for aligning the liquid crystal or photo-alignment is used, and a spacer is used to make the gap constant.

  In the case where the image display device is a liquid crystal display device, rewriting is always performed, so that the display mode changes immediately following the change in environment and switching of the switch. In the case of electronic paper, rewriting is performed only when the screen is changed. Therefore, a system that rewrites the current screen even when the environment changes or when the switch is switched is preferable. In the case of electronic paper, it is preferable to use a system that rewrites the current screen even when the switch is switched. In the case of a transflective liquid crystal display device, it is necessary to switch the display mode depending on the surrounding environment when the backlight is not turned on or when it is turned on weakly. When the backlight is lit strongly, the color display with good color purity may be maintained.

  Hereinafter, the configuration of the electronic paper and the liquid crystal display device according to the embodiment of the present invention will be described in detail.

  As a material of the substrate 1 and the counter substrate 32 according to the present embodiment, for example, glass is optimal, but plastic can be used. Examples of plastics include polymethyl methacrylate, polyacrylate, polycarbonate, polystyrene, polyethylene sulfide, polyethersulfone, polyolefin, polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer, polyethersulfone, triacetylcellulose, and polyvinyl fluoride film. Use plastics such as ethylene-tetrafluoroethylene copolymer resin, weather resistant polyethylene terephthalate, weather resistant polypropylene, glass fiber reinforced acrylic resin film, glass fiber reinforced polycarbonate, transparent polyimide, fluorine resin, cyclic polyolefin resin, etc. However, the present invention is not limited to these. These may be used as the single substrate 1 and the counter substrate 32, but can also be used as the composite substrate 1 and the counter substrate 32 in which two or more kinds are stacked.

  Examples of the color filter 11 according to the present embodiment include those using dyes, those using pigments, and those using interference, and are formed by exposure and development using a resist in which pigments are dispersed. The method is preferably used. The light transmittance of the color filter 11 can be adjusted by adjusting the film thickness or the pigment concentration of the color filter 11. After forming the cyan 11C, magenta 11M, and yellow 11Y of the color filter 11 in any order by coating, exposure, and development, the overcoat layer 11OC can be formed to reduce the level difference. Note that the white 11W may be formed by applying, exposing, and developing a resist to the white 11W portion, but may not be formed.

In order to improve the durability of the thin film transistor array 20, a transparent gas barrier layer (not shown) can be formed between the substrate 1 and the color filter 11 or between the color filter 11 and the thin film transistor array 20. Examples of the gas barrier layer include aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), and diamond-like carbon (DLC). The present invention is not limited to these. These gas barrier layers can also be used by laminating two or more layers. The gas barrier layer may be formed only on one side of the substrate 1 using an organic film, or may be formed on both sides. The gas barrier layer can be formed using a vacuum deposition method, an ion plating method, a sputtering method, a laser ablation method, a plasma CVD (Chemical Vapor Deposition) method, a hot wire CVD method, a sol-gel method, and the like. It is not limited.

  Next, the thin film transistor array 20 according to the present embodiment will be described. In the thin film transistor array 20 according to the present embodiment, substantially transparent materials are used as electrodes, semiconductor layers, and insulating films. Here, “substantially transparent” means that the transmittance is 70% or more within a wavelength range of 400 nm to 700 nm that is visible light.

The electrode of the substantially transparent thin film transistor 20 according to the present embodiment, that is, the gate electrode 2, the gate wiring 2 ′, the capacitor electrode 9, the capacitor wiring 9 ′, the source electrode 4, the source wiring 4 ′, the drain electrode 5, and the pixel electrode For the upper pixel electrode 10, it is preferable to use a substantially transparent conductive material thin film. As the substantially transparent conductive material, indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), zinc oxide (ZnO), cadmium oxide (CdO), indium cadmium oxide (CdIn ₂ O ₄ ), cadmium oxide Although oxide materials such as tin (Cd ₂ SnO ₄ ) and zinc oxide tin (Zn ₂ SnO ₄ ) can be used, the present invention is not limited thereto. In addition, those oxide materials doped with impurities are also preferably used. For example, indium oxide doped with tin (Sn), molybdenum (Mo), titanium (Ti), tungsten (W), gallium (Ga), cerium (Ce) and zinc (Zn), zinc oxide with aluminum (Al ) Or gallium (Ga). Among them, indium tin oxide doped with tin in indium oxide (common name: “ITO”) and indium zinc oxide doped with zinc in indium oxide (common name: “IZO”) are particularly in terms of transparency and resistivity. Can be used particularly preferably.

  Alternatively, auxiliary wiring (not shown) can be provided in contact with the substantially transparent conductive material. As the auxiliary wiring, for example, gold (Au), silver (Ag), copper (Cu), cobalt (Co), tantalum (Ta), molybdenum (Mo), chromium (Cr), aluminum (Al), nickel (Ni) ), Tungsten (W), platinum (Pt) and titanium (Ti) can be used, but the present invention is not limited thereto. In addition, alloys of these metals, those doped with impurities, and those obtained by laminating a plurality of thin films of these metals can also be used. In order not to reduce the aperture ratio of the image display device 30, it is desirable that the auxiliary wiring be patterned to be thinner than an electrode using a substantially transparent conductive material. By thinly patterning, the thin film transistor array 20 can be made substantially transparent even if the auxiliary wiring is not transparent.

  Substantially transparent conductive material thin film and auxiliary wiring can be formed by vacuum deposition, ion plating, sputtering, laser ablation, plasma CVD, photo CVD, hot wire CVD, etc. However, the present invention is not limited to these.

As the substantially transparent semiconductor layer 6, an oxide semiconductor material containing a metal oxide as a main component can be used. The oxide semiconductor material is zinc oxide which is an oxide containing one or more elements of zinc (Zn), indium (In), tin (Sn), tungsten (W), magnesium (Mg), and gallium (Ga). (ZnO), indium oxide (In ₂ O ₃ ), indium zinc oxide (In—Zn—O), tin oxide (SnO ₂ ), tungsten oxide (WO), and zinc gallium indium oxide (In—Ga—Zn—O) However, the present invention is not limited to these materials. These materials are substantially transparent and preferably have a band gap of 2.8 eV or more, and preferably a band gap of 3.2 eV or more. The structure of these materials may be any of single crystal, polycrystal, microcrystal, mixed crystal of crystal and amorphous, nanocrystal scattered amorphous, and amorphous. The film thickness of the substantially transparent semiconductor layer 6 is desirably 20 nm or more.

  Since the material of the oxide semiconductor used for the substantially transparent semiconductor layer 6 does not have photosensitivity in the visible light region, a substantially transparent thin film transistor array 20 can be manufactured, and the aperture ratio of the active matrix display device And a new display device configuration can be realized.

  The substantially transparent semiconductor layer 6 can be formed by sputtering, pulse laser deposition, vacuum deposition, CVD, MBE (Molecular Beam Epitaxy), ALD (Atomic Layer Deposition), and sol-gel. Preferably, a sputtering method, a pulse laser deposition method, a vacuum evaporation method, or a CVD method is used. Examples of the sputtering method include RF magnetron sputtering method and DC sputtering method, vacuum evaporation method includes resistance heating evaporation method, electron beam evaporation method and ion plating method, CVD method includes hot wire CVD method and plasma CVD method. It is not limited to these.

The material used for the gate insulating film 3 of the substantially transparent thin film transistor array 20 according to the embodiment of the present invention is not particularly limited, but silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide (Ta _2). Inorganic materials such as O ₅ ), yttrium oxide (Y ₂ O ₃ ), hafnium oxide (HfO ₂ ), hafnium aluminate (HfAlO), zirconium oxide (ZrO ₂ ) and titanium oxide (TiO ₂ ), or polymethyl methacrylate ( Examples thereof include organic materials such as polyacrylates such as PMMA), polyvinyl alcohol (PVA), polystyrene (PS), transparent polyimide, polyester, epoxy resin, and polyvinylphenol, but the present invention is not limited thereto. In order to suppress the gate leakage current, it is preferable that the resistivity of the insulating material is 10 ¹¹ Ω · cm or more, desirably 10 ¹⁴ Ω · cm or more. The gate insulating layer 3 is formed using a method such as vacuum deposition, ion plating, sputtering, laser ablation, plasma CVD, photo CVD, hot wire CVD, spin coating, dip coating, or screen printing. However, the present invention is not limited to these. The film thickness of the gate insulating layer 3 is preferably 50 nm or more and 2 μm or less. These gate insulating films 3 may be used as a single layer, may be a laminate of a plurality of layers, or may have a composition inclined in the growth direction.

  Although the configuration of the substantially transparent thin film transistor array 20 according to the embodiment of the present invention is not particularly limited, a bottom gate top contact type, a bottom gate bottom contact type, a top gate top contact type, and a top gate bottom contact type are used. Can do.

  The interlayer insulating film 8 according to the present embodiment is not particularly limited as long as it is insulating and substantially transparent. For example, inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide, yttrium oxide, hafnium oxide, hafnium aluminate, zirconium oxide and titanium oxide, or polyacrylate such as polymethyl methacrylate (PMMA) , Organic materials such as polyvinyl alcohol (PVA), polystyrene (PS), transparent polyimide, polyester, epoxy resin, and polyvinylphenol, but are not limited to these in the present invention. The interlayer insulating film 8 may be the same material as the gate insulating film 4 or a different material. These interlayer insulating films 8 may be used as a single layer or may be a laminate of a plurality of layers. The interlayer insulating film 8 is formed so as to cover at least the source wiring 4 ′ and the gate wiring 2 ′ in order to reduce the influence on the display.

  When the structure of the substantially transparent thin film transistor array 20 according to the present embodiment is a bottom gate type, a sealing layer (not shown) that covers the substantially transparent semiconductor layer 6 may be provided. it can. By using the sealing layer, it is possible to prevent the substantially transparent semiconductor layer 6 from being changed with time due to humidity or the like or from being affected by the interlayer insulating film 8. As the sealing layer, inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide, yttrium oxide, hafnium oxide, hafnium aluminate, zirconia oxide and titanium oxide, or polymethyl methacrylate (PMMA), etc. Organic materials such as polyacrylate, polyvinyl alcohol (PVA), polystyrene (PS), transparent polyimide, polyester, epoxy resin, polyvinyl phenol and fluorine-based resin are not limited to these. These sealing layers may be used as a single layer, or a laminate of a plurality of layers may be used.

  Furthermore, in the embodiment of the present invention, the upper pixel electrode 10 electrically connected to the pixel electrode 5 ′ may be provided. Specifically, the interlayer insulating film 8 is pattern printed by a method such as a screen printing method, and the interlayer insulating film 8 is not provided on the pixel electrode 5 ′, or a transparent resist is applied, exposed and developed to form a pixel. If formed on the electrode 5 'on the interlayer insulating film 8 having a hole, it can be connected to the pixel electrode 5'.

  The substantially transparent thin film transistor array 20 is most suitable for the image display device as shown in FIGS. 2B, 3B, and 4B, but FIG. 2A and FIG. Of course, it can also be used for an image display apparatus as shown in FIG.

  Examples 1 to 7 according to embodiments of the present invention will be described below. The present invention is not limited to the first to seventh embodiments.

  First, a glass substrate was used as the substrate 1 as shown in FIG. Next, a cyan 11C, magenta 11M, and yellow 11Y resist was applied, exposed, developed, and baked on the substrate 1 to form a cyan 11C, magenta 11M, and yellow 11Y pattern. Next, an overcoat layer 11OC was formed by applying and baking a transparent overcoat agent on the entire surface.

  Next, as shown in FIG. 5B, an ITO film is formed on the overcoat layer 11OC by a sputtering method and patterned by a photolithography method and wet etching to form a gate electrode 2, a gate wiring 2 ′, and a capacitor electrode. 9 and capacitor wiring 9 'was formed.

  Next, as shown in FIG. 5C, the gate insulating film 3 and the semiconductor layer 6 are continuously formed by a sputtering method so as to cover the gate electrode 2, the gate wiring 2 ′, the capacitor electrode 9, and the capacitor wiring 9 ′. . The gate insulating film 3 was made of SiON, and the semiconductor layer 6 was made of InGaZnO. Then, InGaZnO was patterned by photolithography and wet etching.

  Next, as shown in FIG. 5 (d), a resist pattern having a pattern opposite to that of the source electrode 4, the source wiring 4 ', the drain electrode 5, and the pixel electrode 5' is formed in advance across the semiconductor layer 6, and then ITO is formed Then, the source electrode 4, the source wiring 4 ′, the drain electrode 5, and the pixel electrode 5 ′ were formed by lift-off.

  Next, as shown in FIG. 5E, an interlayer insulating film 8 was formed on the gate wiring 2 ′, the source wiring 4 ′, and the semiconductor layer 6 by screen printing of a fluororesin. This interlayer insulating film 8 also has a sealing role. Thus, a thin film transistor substrate with the color filter 11 was produced.

  On the other hand, as shown in FIG. 2B, an ITO film was formed as a counter electrode 31 on a polyethylene terephthalate substrate as a counter substrate 32, and an electrophoretic capsule was applied as an electrophoretic body 30. The image display device 50 was manufactured by bonding to the thin film transistor substrate with the color filter 11.

  Driving is performed using data obtained by converting image data given in RGB into CMYW by calculation, color display of Expressions 1.1 to 1.4, color display of Expressions 2.1 to 2.10, Expression 3 .1 to Formula 3.10 color display, Formula 4.1 to Formula 4.10 color display, Formula 5.1 monochrome display, Formula 6.1 monochrome display, Formula 7.1 to Formula 7.10 It was confirmed that color display with the white component emphasized was possible. In addition, a CdS sensor is used as the illuminance sensor 40 to detect external illuminance, and color display of Formula 2.1 to Formula 2.10 at 55 lux or more, and white component of Formula 7.1 to Formula 7.10 at 45 lux or less. It was confirmed that automatic switching can be performed by changing the external illuminance.

  An alignment film (not shown) was applied to the thin film transistor substrate with the color filter 11 manufactured in the same manner as in Example 1, and a rubbing process was performed. An Al film is formed as a counter electrode 31 on a glass substrate as the counter substrate 32, an alignment film (not shown) is applied, and a seal portion 36 is formed around a rubbing treatment, and a spacer (not shown). 3), the TN mode liquid crystal is sealed as the liquid crystal layer 33, and the image display device 50 shown in FIG.

  Driving is performed using data obtained by converting image data given in RGB into CMYW using a lookup table, color display of Expression 1.1 to Expression 1.4, color display of Expression 2.1 to Expression 2.10, Expression 3.1 to Expression 3.10 color display, Expression 4.1 to Expression 4.10 color display, Expression 5.1 monochrome display, Expression 6.1 monochrome display, Expression 7.1 to Expression 7. It was confirmed that color display with 10 white components emphasized can be performed. In addition, a photodiode is used as the illuminance sensor 40 to detect the external illuminance, and color display of Formula 3.1 to Formula 3.10 at 35 lux or more, monochrome display of Formula 5.1 or Formula 6.1 at 25 lux or less. In the meantime, the current mode was maintained, and it was confirmed that automatic switching was possible by changing the external illuminance. Here, switching between Formula 5.1 and Formula 6.1 was performed using a switch.

First, as shown in FIG. 6A, a polyethylene naphthalate substrate was used as the substrate 1. Next, SiO ₂ was formed as a gas barrier layer (not shown) on the substrate 1 by a CVD method. Thereafter, a resist of cyan 11C, magenta 11M and yellow 11Y was applied, exposed, developed and baked on the gas barrier layer to form a pattern. Next, an overcoat layer 11OC was formed by applying and baking a transparent overcoat agent on the entire surface.

  Next, as shown in FIG. 6B, ITO is deposited on the overcoat layer 11OC by sputtering, and the gate electrode 2, the gate wiring 2 ′, the capacitor electrode 9, and the capacitor wiring 9 are formed by photolithography and wet etching. Formed.

  Next, as shown in FIG. 6C, the gate insulating film 3 and the semiconductor layer 6 are continuously formed by a sputtering method so as to cover the gate electrode 2, the gate wiring 2 ′, the capacitor electrode 9, and the capacitor wiring 9 ′. . The gate insulating film 3 was made of SiON, and the semiconductor layer 6 was made of InGaZnO. Then, InGaZnO of the semiconductor layer 6 was patterned by photolithography and wet etching.

  Next, as shown in FIG. 6 (d), a resist pattern having a pattern opposite to that of the source electrode 4, the source wiring 4 ', the drain electrode 5, and the pixel electrode 5' is formed in advance, and then ITO is formed. 4, a source wiring 4 ′, a drain electrode 5, and a pixel electrode 5 ′ were formed.

  Next, as shown in FIG. 6E, a resist pattern having a pattern opposite to that of a sealing layer (not shown) is formed in advance on the source electrode 4, the source wiring 4 ′, the drain electrode 5, and the pixel electrode 5 ′. SiON was deposited and a sealing layer was formed by lift-off. Thereafter, an interlayer insulating film 8 having an opening was formed on the pixel electrode 5 'by coating, exposing, developing, and baking a resist. Next, an ITO film was formed by sputtering, and the upper pixel electrode 10 was formed by photolithography and wet etching. Thus, a thin film transistor substrate with the color filter 11 was produced.

  On the other hand, as shown in FIG. 2B, an ITO film was formed as a counter electrode 31 on a polyethylene terephthalate substrate as a counter substrate 32, and an electrophoretic capsule was applied as an electrophoretic body 30. An image display device was manufactured by bonding to a thin film transistor substrate with the color filter 11.

  RGB analog signals are converted into CMYW signals by using an adder, a divider, a limiter, etc., and driven to perform color display of equations 1.1 to 1.4, and equations 2.1 to 2.10. Color display, Color display of Formula 3.1 to Formula 3.10, Color display of Formula 4.1 to Formula 4.10, Monochrome display of Formula 5.1, Monochrome display of Formula 6.1, Formula 7.1 It was confirmed that color display in which the white component of Expression 7.10 was emphasized could be performed. Also, the external illuminance is detected by using a photodiode as the illuminance sensor 40, and color display with good color purity of the formula 2.1 to the formula 2.10 at 210 lux or more, and the formula 7.1 to the formula at 190 lux to 15 lux. 7.10 (bright) white emphasized color display, 8 lux or less switch to monochrome display of 5.1 or 6.1 (high contrast), otherwise keep current mode, external It was confirmed that automatic switching was possible by changing the illuminance. It was also confirmed that the two types of monochrome display were manually switched, and the graph image that was difficult to see in Equation 5.1 might be easier to see in Equation 6.1.

  An image display device was produced in the same manner as in Example 3 except that the arrangement of the color filters was CMY shown in FIG.

  It was confirmed that RGB digital signals were converted into CMY signals by the calculation of equations 2.1 to 2.8 and 2.10, and were driven to perform color display. Although colors close to R, G, and B are somewhat whiter, it was confirmed that C, M, and Y can be displayed with good color purity and that there is almost no problem in normal display.

  As a color display in which the white component is emphasized, instead of Equations 7.1 to 7.10. 1 to 7A. An experiment similar to that in Example 1 was performed except that 10 was used, and it was confirmed that a good display could be performed.

  As a color display in which the white component is emphasized, the formula 7B. 1 to 7B. An experiment similar to that in Example 1 was performed except that 10 was used, and it was confirmed that a good display could be performed.

  Color display of Formulas 1.1 to 1.4, Color display of Formulas 2.1 to 2.10, Color display of Formulas 3.1 to 3.10, Color display of Formulas 4.1 to 4.10, Formula 7 When performing color display with emphasis on the white components of .1 to 7.10, correction is performed by multiplying C, M, and Y of formulas 1.1 to 1.3 by (R + G + B) / (2 × (C + M + Y)). An experiment similar to that in Example 1 is performed except that correction is performed by multiplying (R + G + B) / (2 × (C0 + M0 + Y0)) by C0, M0, Y0 such as 2.1 to 2.3, and good display can be performed. It was confirmed. Further, instead of the color display in which the white component of Expressions 7.1 to 710 is emphasized, Expression 7A. 1-7A. 10 and Equation 7A. 1-7A. It was confirmed that even when correction was performed by multiplying C3, C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)), good display was possible. Further, instead of the color display in which the white component of the expressions 7.1 to 7.10. 1-7B. 10 and Equation 7B. 1-7B. It was confirmed that even when correction was performed by multiplying C3, C0, M0, and Y0 by (R + G + B) / (2 × (C0 + M0 + Y0)), good display was possible.

  Since the image display apparatuses according to the first to seventh embodiments perform color display using a CMY conversion formula corresponding to illuminance, energy saving and sufficient brightness can be obtained. .

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Gate electrode, 2 'gate wiring, 3 ... Gate insulating film, 4 ... Source electrode, 4'
Source wiring, 5 ... Drain electrode, 5 'pixel electrode, 6 ... Semiconductor layer, 8 ... Interlayer insulating film, 9 ... Capacitor electrode, 9' capacitor wiring, 10 ... Upper pixel electrode, 11 ... Color filter, 11
C ... Cyan, 11M ... Magenta, 11Y ... Yellow, 11W ... White, 11OC ... Overcoat, 20 ... Thin film transistor array, 30 ... Electrophore, 31 ... Counter electrode, 32
Reference plate, 33 ... Liquid crystal layer, 34 ... First quarter wave plate, 35 ... First polarizing plate, 36 ... Seal portion, 37 ... Second polarizing plate, 38 ... Second quarter wavelength Board, 39 ... Backlight, 40 ...
Illuminance sensor, 50... Image display device

Claims (17)

  An image display device, wherein one pixel is composed of sub-pixels of four colors of cyan (C), magenta (M), yellow (Y), and white (W).   The image according to claim 1, having a display mode of color display and color display in which white component is emphasized, color display and color display in which white component is emphasized, or color display and monochrome display in which color display and white component are emphasized. Display device. A substrate,
A color filter formed on the substrate;
A thin film transistor array formed on the color filter;
A display medium formed on the thin film transistor array;
An image display device comprising a counter electrode formed on the display medium,
The image display device according to claim 1, wherein the image display device is a reflective display device or a transflective display device.   The image display device according to claim 3, wherein the display medium is a liquid crystal or an electrophoretic material. The substrate and the thin film transistor array are substantially transparent;
5. The image display device according to claim 3, wherein display is performed on the substrate side.   6. The image display according to claim 3, wherein the color filter includes sub-pixels of four colors of cyan (C), magenta (M), yellow (Y), and white (W). apparatus. From the color data of red (R), green (G), and blue (B),
C = max ((G + B−R) / 2, 0)
M = max ((B + RG) / 2, 0)
Y = max ((R + GB) / 2, 0)
W = 0
6. The image display device according to claim 1, further comprising data conversion means for obtaining color display CMYW color data. From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0
M = M0 × (MIN / MAX) + M0
Y = Y0 × (MIN / MAX) + Y0
W = 0
When R = G = B = 0 C = M = Y = W = 0
6. The image display device according to claim 1, further comprising data conversion means for obtaining color display CMYW color data. From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0−X
M = M0 × (MIN / MAX) + M0−X
Y = Y0 × (MIN / MAX) + Y0−X
W = X × 2
However, X is an arbitrary value of 0 ≦ X ≦ MIN when R = G = B = 0 C = M = Y = W = 0
6. The image display device according to claim 1, further comprising data conversion means for obtaining CMYW data for color display.   The conversion formula for obtaining CMYW data for monochrome display from the original data of red (R), green (G), and blue (B) can be selected from a plurality of conversion formulas. The image display device according to any one of 5. From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0
M = M0 × (MIN / MAX) + M0
Y = Y0 × (MIN / MAX) + Y0
W = MIN × 2
When R = G = B = 0 C = M = Y = W = 0
6. The image display device according to claim 1, further comprising a data conversion unit that obtains CMYW data for color display in which a white component is emphasized. From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0
M = M0 × (MIN / MAX) + M0
Y = Y0 × (MIN / MAX) + Y0
W = 0.2R + 0.7G + 0.1B
When R = G = B = 0 C = M = Y = W = 0
6. The image display device according to claim 1, further comprising a data conversion unit that obtains CMYW data for color display in which a white component is emphasized. From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0
M = M0 × (MIN / MAX) + M0
Y = Y0 × (MIN / MAX) + Y0
W = (R + G + B) / 3
When R = G = B = 0 C = M = Y = W = 0
6. The image display device according to claim 1, further comprising a data conversion unit that obtains CMYW data for color display in which a white component is emphasized. An image display device characterized in that one pixel is composed of sub-pixels of three colors of cyan (C), magenta (M), and yellow (Y),
From the color data of red (R), green (G), and blue (B),
When R + G + B> 0 C0 = max ((G + B−R) / 2, 0)
M0 = max ((B + RG) / 2, 0)
Y0 = max ((R + GB) / 2, 0)
MIN = min (C0, M0, Y0)
MAX = max (C0, M0, Y0)
C = C0 × (MIN / MAX) + C0
M = M0 × (MIN / MAX) + M0
Y = Y0 × (MIN / MAX) + Y0
When R = G = B = 0 C = M = Y = 0
An image display device comprising data conversion means for obtaining color data for color display CMY.   The image display device further includes an illuminance sensor, and automatically switches between color display, color display with emphasis on white component, and monochrome display according to external illuminance. The image display device according to claim 14. Prepare the board
One pixel on the substrate forms subpixels of four colors of cyan (C), magenta (M), yellow (Y), and white (W),
Forming a thin film transistor array including a capacitor electrode and a pixel electrode on the subpixel;
A manufacturing method of an image display device, wherein a display medium is sandwiched between the thin film transistor array and a counter electrode formed on the separate substrate by bonding the thin film transistor array and the separate substrate.   The method for manufacturing an image display device according to claim 16, wherein the display medium is a liquid crystal or an electrophoretic material.