JP2001306023A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device, capable of displaying a wide range of colors, especially, colors equivalent to those of a printed matter. SOLUTION: Pixels 36 are provided with a sub-pixel 36C for emitting the color light of cyan, specified as a point on a chromaticity diagram but outside of the triangular area formed, by connecting each point of red, green, and blue on the diagram. The color area on the chromaticity diagram which is formed by connecting each point of red, green, and blue and can be displayed by an ordinary liquid crystal display can be expanded by the added portion of the sub-pixel 36C in cyan. Therefore, it is possible to display colors equivalent to those of a printed matter on the liquid crystal display by displaying a wider range of colors than conventional one by the liquid crystal display. Especially, since the sub-pixel 36C emits light of cyan color, the liquid crystal display can be arranged, so as to faithfully reproduce colors equivalent to those of a printed matter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display area formed by arranging pixels consisting of a plurality of sub-pixels in a matrix, and adding color light emitted from each sub-pixel to the image display area. An image display device that forms a color image by combining color mixing methods can be used, for example, in a display device such as a CRT or a liquid crystal, or a projection display device such as a front projector or a rear projector.

[0002]

BACKGROUND ART Liquid crystal displays, CRT displays,
Image display devices such as projectors have conventionally used red light,
Pixels composed of sub-pixels that emit green light and blue light are arranged in a matrix to form an image display area, and each sub-pixel emits light for each of red light, green light, and blue light based on input image information. Modulation is performed, and color light emitted from each sub-pixel is combined on the image display area by an additive color mixture method, thereby displaying a desired color on each pixel. For example, in the case of a liquid crystal display, one pixel is configured by combining sub-pixels of three primary colors of red, green, and blue into a triangular shape, a rectangular shape, and the like, and the pixels are arranged in a matrix on the image display area. Then, light modulation is performed in each sub-pixel based on an input image signal including red, green, and blue signals, and red, blue, and green color lights are emitted from the sub-pixels of each pixel, and each color light is mixed. Thus, a desired color is displayed on each pixel.

On the other hand, a printing apparatus such as a color printer usually employs a color display by a subtractive color mixture method. For example, cyan, magenta, and yellow are used as three primary colors, and these colors are superimposed on a printing surface. A desired color is displayed.

[0004]

When such an image display device and a printing device are connected to a personal computer or the like, and a color image displayed on the image display device is edited, color printing is attempted by the printing device. Is different from the color mixing method, the color region that can be displayed on the image display device and the color region that can be printed by the printing device are shifted from each other, and a printed matter having a desired color cannot be obtained at the time of editing. There's a problem.

[0005] The observer who observes a display image or printed matter by these devices has a wider range than the range of colors that can be displayed by combining the three primary colors of red, green, blue, cyan, magenta, and yellow. Therefore, an image display device capable of displaying a color corresponding to the visual sense of an observer is desired.

It is an object of the present invention to provide an image display device capable of displaying a wide range of colors, and in particular, capable of displaying colors corresponding to printed matter.

[0007]

In order to achieve the above object, an image display device according to the present invention comprises a plurality of sub-pixels arranged in a matrix to form an image display area. Is an image display device that forms a color image by combining the color lights emitted from the image display area by an additive color mixture method on the image display area, and is formed by connecting red, green, and blue points on a chromaticity diagram. It is characterized by including sub-pixels that emit color light of other colors defined as points on the chromaticity diagram other than the triangular area.

Here, the pixels for displaying a predetermined color may be configured by arranging sub-pixels of a plurality of colors in a plane as in the above-described liquid crystal display. A light modulation device such as a liquid crystal panel is provided for each color light to be modulated, and the light modulation device performs modulation based on image information for each color light, and then superimposes each color light on a projection surface by a prism or the like, so that each pixel is You may comprise so that a desired color can be displayed.

Pixels displaying a predetermined color are red,
At least three types of sub-pixels that emit green and blue light, and points on the chromaticity diagram other than the triangular region formed by connecting the red, green, and blue points on the chromaticity diagram It is preferable to be configured of four or more types of sub-pixels including at least one or more sub-pixels that emit color light of a color defined as Further, the sub-pixels of other colors are preferably one of the three primary colors, cyan, magenta, and yellow in the subtractive color mixture method, and particularly preferably contain at least cyan.

According to the present invention, since the pixel is configured to include the sub-pixel which emits light of another color, as shown in FIG. 1, red (R), green (G), Blue (B)
The area A on the chromaticity diagram of a color that can be displayed by a normal image display device, formed by connecting the respective points, can be expanded by an amount corresponding to the addition of sub-pixels of other colors. Therefore, by displaying a wider range of colors on the image display device than before,
A color equivalent to a printed matter can be displayed on the image display device. In particular, an image display device capable of reproducing a color equivalent to a printed matter more faithfully by setting any of the sub-pixels that emit color light of another color to cyan (C), magenta (M), or yellow (Y). It can be. Also, since cyan is a major factor in the difference between the color on the screen display and the color on the printed matter, such a difference can be obtained by adopting cyan as a sub-pixel that emits light of another color. Can be eliminated, and colors equivalent to printed matter can be reproduced more faithfully on the image display device.

In the above, the image display device described above
It is preferable to include an image processing circuit that converts an image signal composed of red, green, and blue into image signals supplied to each of four or more types of sub-pixels. Specifically, when one pixel of the image display device of the present invention is configured by four sub-pixels that emit four types of color light of red, green, blue, and cyan, the image processing circuit performs red, green, , It is preferable to convert an image signal composed of blue into an image signal composed of red, green, blue, and cyan.

As described above, by providing the image processing circuit, the image processing circuit converts an RGB signal usually used in a personal computer or the like into an image signal having four or more types of colors, and Can be displayed on the image display device. For example, as described above, one pixel of the image display device includes four sub-pixels that emit four types of color light of red (R), green (G), blue (B), and cyan (C). If you have
Consider displaying a cyan color on a pixel.

The cyan color of the RGB signal is defined as a point A1 on the side GB of the triangle consisting of the points R, G, and B in FIG. By converting the RGB signals by the image processing circuit, it is possible to display a correct cyan color at the point C on the pixel. In the conversion by the image processing circuit, a function for converting an RGB signal into an RGBC signal is set inside the image processing circuit, and the input RGB signal is arithmetically processed to perform RGB conversion
Although it is conceivable to obtain a C signal, the simplest method is to use an LU that associates an RGB signal with an RGBC signal.
T (Look Up Table) is stored in a storage area inside the image processing circuit in advance, and when a predetermined RGB signal is input to the image processing circuit, a corresponding RGBC signal is called from the LUT, and the image processing circuit What is necessary is just to output this RGBC signal. By setting such an LUT according to the printing device, it is possible to provide an image display device that can always display an image according to the print characteristics even if the printing characteristics are different depending on the printing device.

Further, the present invention is preferably applied to an image display device provided with an electro-optical element which is set in accordance with the arrangement of sub-pixels and controls lighting of color light emitted from the sub-pixel. Here, as an image display device having an electro-optical element, for example, a plurality of scanning lines, a plurality of data lines orthogonal to the scanning lines, and an electro-optical material connected in series between the scanning lines and the data lines An image display device provided with a liquid crystal display, an organic EL display, a plasma display, or the like can be used. In addition, the present invention can be applied to a driving method regardless of an active matrix or a passive matrix. That is, an image display device provided with such an electro-optical element is a CRT.
Compared to a display or the like, it has characteristics of being thin, light, and space-saving, so that it is suitable as an image display device used for a personal computer and the like, and is useful for employing the present invention in relation to a printing device of a personal computer. The nature is high.

Further, as another configuration capable of displaying an image equivalent to a printed matter on an image display device, pixels composed of sub-pixels of a plurality of colors are arranged in a matrix, and color light emitted from each sub-pixel is transmitted to an image display area. An image display device that forms a color image by combining the above by an additive color mixture method, wherein each of the sub-pixels of a plurality of colors can adopt an image display device having emission characteristics according to the color characteristics of a printed matter. Here, specifically, three types of sub-pixels that respectively emit cyan, magenta, and yellow color light can be adopted as the sub-pixels having light emission characteristics corresponding to the color characteristics of the printed matter. When the image signal input to the image display device is an RGB signal, it is preferable to provide an image processing circuit as described above, and a conversion method using an LUT can be adopted.

According to the present invention, since the sub-pixels have light emission characteristics according to the color characteristics of the printed matter, a screen corresponding to the color characteristics of the printed matter can be displayed on the image display device. Colors equivalent to printed matter can be reproduced on the image display device.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an image display system 1 according to a first embodiment of the present invention.

An image display system 1 includes a personal computer 2 that is an image processing device that creates color image data, and a liquid crystal display that is an image display device that forms and displays color image data input from the personal computer 2 as a color image. 3 and a color printer 4 that is a printing device that prints a color image created by the personal computer 2.

The personal computer 2 creates color image data with image signals of red (R), green (G), and blue (B), and outputs the created color image data to the liquid crystal display 3. Has become.

The color printer 4 adopts a subtractive color mixture color display, and uses cyan, magenta, and yellow as three primary colors, and superimposes these colors on a printing surface to display a desired color. It has become.

The liquid crystal display 3 has an image input terminal 3
1. Signal amplification circuit 32, CPU 33 for controlling the entire liquid crystal display 3, image processing circuit 34, image display area 35
It is comprised including. The image input terminal 31 receives an image signal from the personal computer 2. The signal amplification circuit 32 is connected to the image input terminal 31
The image processing circuit 3 amplifies each color of the image signal input to the
4 is output.

The image display area 35 is composed of a plurality of pixels 36 arranged in a matrix as shown in FIG. 3 on which a color image is displayed. The pixel 36 has four types of sub-pixels 36R, 36G, and 36 including three sub-pixels 36R, 36G, and 36B that emit red, green, and blue light, and a sub-pixel 36C that emits cyan light.
B and 36C are arranged in a rectangular shape, and are formed in a plane square shape. Here, the sub-pixel 36 that emits cyan light
C is red (R), green (G), blue (B) on the chromaticity diagram
Are defined as points on the chromaticity diagram other than the triangular area formed by connecting the points (FIG. 1).

Each sub-pixel 36R, 36G, 36B, 36
C, that is, for each pixel 36, as shown in FIG.
Liquid crystal element 50 which is an electro-optical element formed in a panel shape
Is provided. The liquid crystal element 50 modulates the incident color light based on image information from outside (not shown),
This is a transmission type liquid crystal element that emits a modulated light beam from the side opposite to the incident side. The liquid crystal element 50 has a twisted nematic (TN) liquid crystal 53 sealed between two transparent substrates (a counter substrate 51 and a TFT substrate 52) made of glass or the like. A common electrode 54 and a black matrix 55 for shielding unnecessary light are formed on the counter substrate 51, and a pixel electrode 56 and a thin film transistor (TFT) 57 as a switching element are formed on the other TFT substrate 52.
When a voltage is applied to the pixel electrode 56 via the TFT 57, the liquid crystal 5 sandwiched between the common electrode 54
3 is driven. Note that the TFT substrate 5
2, a plurality of scanning lines 58 and a plurality of data lines 59 are arranged so as to intersect with each other. In the vicinity of the intersection, a TFT 57 connects a gate to the scanning line 58, a source to the data line 59, and a drain to the pixel electrode 56. Placed. Then, the selection voltage is sequentially applied to the scanning lines 58, and the X-lines which are turned on accordingly are turned on.
The driving voltage of each pixel 36 is applied to the pixel electrode 56 via the TFT 57 of the pixel 36 in the axial direction. The TFT 57 is turned off by the application of the non-selection voltage, and holds the applied drive voltage in a storage capacitor (not shown). Polarizing plates 61 and 62 are provided on the light emission side and the light incidence side of the TFT substrate 52 and the counter substrate 51, respectively. That is, the driving method of the liquid crystal display 3 is an active matrix method.

With such a liquid crystal element 50, each sub-pixel 36
R, 36G, 36B, and 36C, and controls the lighting of four types of color light emitted from each of the sub-pixels 36R, 36R.
By combining the four types of color light emitted from G, 36B, and 36C on the image display area 35 by an additive color mixture method, a color image is displayed on the liquid crystal display 3 (image display area 3).
5) is formed and displayed. Therefore,
The area on the chromaticity diagram of the color that can be displayed on the ordinary liquid crystal display 3 formed by connecting the red, blue, and green points is expanded by the addition of the cyan sub-pixel 36C. Thus, a wider range of colors can be displayed on the liquid crystal display 3 than before, and colors corresponding to printed matter can be displayed on the liquid crystal display 3.

The image processing circuit 34 converts the red (R), green (G), and blue (B) image signals output from the personal computer 2 into red (R), green (G),
It converts the image signal into blue (B) and cyan (C) image signals, and includes an arithmetic processing unit and a storage unit. The arithmetic processing section is a section that converts an RGB signal into an RGBC signal according to the printing characteristics of the color printer 4. The storage unit stores an LUT in which an RGB signal of a predetermined intensity is associated with an RGBC signal of the corresponding intensity.
(Look Up Table) is provided. For example, when an RGB signal for displaying only the cyan color, for example, an RGB signal of R = 0, G = 100, and B = 100 is input to the arithmetic processing unit, the arithmetic processing unit RGBC signal of the intensity corresponding to the intensity (R = 0, G =
10, B = 10, C = 100) from the LUT, and outputs the RGBC signal. As a result, cyan is displayed in the image processing area 35. In addition,
The image signal composed of red (R), green (G), blue (B), and cyan (C) converted by the image processing circuit 34 is input to the image display area 35 through the liquid crystal element 50. .

According to this embodiment, the following effects can be obtained.

That is, since the pixel 36 is configured to include the sub-pixel 36C which emits cyan color light, the liquid crystal display 3 can reproduce a color equivalent to a printed matter more faithfully. The range of colors that can be displayed is widened, and a color corresponding to the visual sense of the observer can be displayed. Further, since a cyan color, which is a major factor of the difference between the color on the screen display and the color on the printed matter, is adopted as the sub-pixel, such a difference can be eliminated, and the printed matter on the liquid crystal display 3 can be eliminated. A considerable color can be reproduced more faithfully.

Further, since the liquid crystal display 3 is provided with the image processing circuit 34, the RGB signals normally used in the personal computer 2 and the like are converted into four types of RBGC signals by the image processing circuit 34, and the four types of color light are output. Can be displayed on the liquid crystal display 3. Also, R
Since the LUT in which the GB signal and the RGBC signal correspond to each other is provided in the storage unit in the image processing circuit 34 in advance, this LUT
Is set in accordance with the color printer 4, it is possible to provide the liquid crystal display 3 which can always display an image according to the print characteristics even if the print characteristics are different depending on the color printer 4. Further, the pixel 36
To the four types of sub-pixels 36R, 36G, 36B, 36C
Are arranged in a rectangular shape, and are formed in a plane rectangular shape, so that the arrangement of the sub-pixels 36R, 36G, 36B, and 36C can be simplified.

Further, the liquid crystal display 3 is set according to the arrangement of the sub-pixels 36R, 36G, 36B and 36C, and controls the lighting of the color light emitted from the sub-pixels 36R, 36G, 36B and 36C. Because it is configured with, compared with a CRT display, etc.,
It has features of being thin, light, and space-saving, and is suitable as an image display device used for the personal computer 2 or the like.

FIG. 5 shows an image display system 70 according to a second embodiment of the present invention. Note that the same or equivalent components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted or simplified. In the present embodiment, the image signals composed of red (R), green (G), and blue (B) output from the personal computer 2 of the first embodiment are converted into red (R), green (G), blue ( B) and an image processing circuit 34 that converts the image signals into cyan (C) image signals. The image processing circuit 34 converts the red (R), green (G), and blue (B) image signals output from the personal computer 2 into
Cyan (C), magenta (M), and yellow (Y)
The image processing circuit 71 converts the image signal into an image signal. At this time, the pixel is composed of a sub-pixel that emits cyan color light, a sub-pixel that emits magenta color light, and a sub-pixel that emits yellow color light, which have emission characteristics according to the color characteristics of the printed matter. It is configured.

The image processing circuit 71 includes an arithmetic processing unit and a storage unit. The arithmetic processing section is a section that converts an RGB signal into a CMY signal according to the printing characteristics of the color printer 4. The storage unit is provided with an LUT (Look Up Table) in which RGB signals of a predetermined strength are associated with CMY signals of the corresponding strength. For example,
When an RGB signal for displaying only green, for example, an RGB signal having an intensity of R = 0, G = 100, and B = 0 is input to the arithmetic processing unit, the arithmetic processing unit corresponds to the intensity of the RGB signal. CMY signal (C = 100, M =
0, Y = 100) from the LUT, and outputs the CMY signal. As a result, green is displayed in the image processing area 35. The image processing circuit 7
The image signal composed of cyan (C), magenta (M), and yellow (Y) converted in 1 is input to the image display area 35 through the liquid crystal element 50.

According to this embodiment, the same effects as those of the above embodiment can be obtained, and the sub-pixels have light emission characteristics corresponding to the color characteristics of the printed material. A screen corresponding to the color characteristics can be displayed, and a color equivalent to a printed matter can be reproduced on the liquid crystal display 3.

It should be noted that the present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention.

For example, the image display device is not limited to the liquid crystal display 3 having the electro-optical element.
A direct-view type in which color light emitted from each pixel of an RT display or the like according to image information is directly viewed, or a projection type such as a projector can be adopted.

The image display device of the present invention is not limited to an active matrix type liquid crystal display.
A passive matrix liquid crystal display can also be employed.

Further, in the above embodiment, the liquid crystal display 3 is provided with the sub-pixel 36C for emitting the cyan color light, but is not limited to this. For example, the liquid crystal display 3 is provided with the sub-pixel for emitting the magenta color light. Or a sub-pixel that emits yellow color light. In short, on the chromaticity diagram other than the triangular region formed by connecting the red, green, and blue points on the chromaticity diagram. What is necessary is just to have the subpixel defined as a point.

In the above embodiment, the liquid crystal display 3 includes the image processing circuits 34 and 71. However, the present invention is not limited to this. For example, if the image signal can be converted inside a personal computer, It is not necessary.

Further, in the first embodiment, the pixel is:
It was composed of four types of sub-pixels 36R, 36G, 36B, and 36C that emit red light, green light, blue light, and cyan light. However, the present invention is not limited thereto. For example, red light, green light, blue light, It may be composed of five kinds of sub-pixels which emit cyan light and magenta light, or may be composed of six kinds of sub-pixels which emit red light, green light, blue light, cyan light, magenta light and yellow light. May be.

Further, the electro-optical element is not limited to a liquid crystal element, but may be, for example, a plasma element, an organic EL element,
D (Digital Micromirror Device) or the like can be adopted. In short, it is only necessary to display an image by controlling the brightness of each pixel or each sub-pixel constituting the pixel, and may be appropriately selected in implementation.

In the second embodiment, a liquid crystal display is used as the image display device. However, the present invention is not limited to this, and a three-panel projector may be used. In this case, a light modulating device such as a liquid crystal panel is provided for each color light (RGB signal) to be mixed, and a signal (CMY signal) based on image information is modulated by the light modulating device for each color light, and then each color is processed by a prism or the like. By superimposing light on the projection surface, a desired color can be displayed on each pixel.

[0042]

As described above, according to the image display device of the present invention, the chromaticity diagram other than the triangular region formed by connecting the red, green, and blue points on the chromaticity diagram. Since it has a sub-pixel that emits color light of another color defined as the upper point, the chromaticity of the color that can be displayed on a normal image display device formed by connecting the red, blue, and green points The area on the drawing can be expanded by the amount of the addition of the sub-pixel of another color. Therefore, by displaying a wider range of colors on the image display device than before, it is possible to display colors corresponding to printed matter on the image display device. In particular, by setting the sub-pixels that emit color light of other colors to any of cyan, magenta, and yellow, it is possible to obtain an image display device that can reproduce colors corresponding to printed matter more faithfully. .

[Brief description of the drawings]

FIG. 1 is a chromaticity diagram according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an image display system in the embodiment.

FIG. 3 is a diagram showing a pixel in the embodiment.

FIG. 4 is an exploded perspective view showing the liquid crystal element in the embodiment.

FIG. 5 is a diagram illustrating an image display system according to a second embodiment of the present invention.

[Explanation of symbols]

 34, 71 Image processing circuit 35 Image display area 36 Pixel 36R, 36G, 36B, 36C Sub-pixel

Claims (7)

[Claims] An image display area is configured by arranging pixels composed of a plurality of sub-pixels in a matrix, and color light emitted from each sub-pixel is combined on the image display area by an additive color mixture method. An image display device for forming an image, the image display device having another color defined as a point on a chromaticity diagram other than a triangular region formed by connecting red, green, and blue points on the chromaticity diagram. An image display device comprising a sub-pixel that emits colored light. 2. The image display device according to claim 1, wherein said image display area is constituted by three sub-pixels which emit red, green, and blue light. An image display device comprising four or more types of sub-pixels including pixels and sub-pixels for emitting the other color light. 3. The image display device according to claim 2, further comprising an image processing circuit for converting an image signal composed of red, green, and blue into an image signal supplied to each of four or more types of sub-pixels. An image display device comprising: 4. The image display device according to claim 2, wherein the other color is cyan. 5. The electro-optical device according to claim 1, wherein the electro-optical element is set according to an arrangement of the sub-pixels and controls lighting of color light emitted from the sub-pixels. An image display device comprising: 6. An image display device for arranging pixels composed of a plurality of sub-pixels in a matrix and combining color light emitted from each sub-pixel on an image display area by an additive color mixture method to form a color image. The image display device, wherein each of the plurality of sub-pixels has a light emission characteristic according to a color characteristic of a printed matter. 7. The image display device according to claim 6, wherein the sub-pixels of the plurality of colors include a sub-pixel that emits cyan color light, a sub-pixel that emits magenta color light, and a sub-pixel that emits yellow color light. An image display device comprising: a sub-pixel for emitting light.