JPH028315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for displaying a color image, and more specifically, the present invention relates to a method for displaying a color image, and more specifically, a plurality of binary display cells for each color are made to correspond to picture elements of an image to be displayed, and a display method is provided for each color of each picture element. The present invention relates to a method for displaying an image having gradations of light and shade according to a so-called dither method in which a binary display cell is activated by level-discriminating the brightness of the image.

In the prior art based on such a dither method, each of a large number of submatrices constituting an image frame is configured by arranging binary display cells for each of three colors in total: red, green, and blue. A binary display cell is black when it is not activated.
Therefore, with such prior art, it is difficult to improve brightness.

An object of the present invention is to provide a method for displaying color images based on a dither method with improved brightness.

The present invention configures an image frame by arranging a plurality of submatrices each consisting of red, green, blue, and a plurality of white binary display cells. The brightness level of the red component in the image signal corresponding to the matrix is level-discriminated using a single red discrimination level, the brightness level of the green component is level-discriminated using a single green discrimination level, and then the blue component is level-discriminated. Level discrimination is performed on the brightness level of the brightness level using a single discrimination level for blue, and based on the result, the red, green, and blue binary display cells of the individual sub-matrix are activated, and each of the red, green, and blue values is activated. A white brightness level is determined from the brightness level of the component, the white brightness level is discriminated at a plurality of discrimination levels, and one of the plurality of white binary display cells of the individual sub-matrix is selected according to the discrimination result. This method of displaying a color image is characterized in that a color image is displayed by activating only the number of submatrices to display each submatrix.

FIG. 1 is a block diagram of one embodiment of the present invention. The image captured by the imaging device 1 is displayed in color on the display 2.

FIG. 2 is a front view of the entire display 2. FIG. This image frame 3 is composed of a large number of 4×4 sub-matrices 4, which will be described below, arranged adjacently.

FIG. 3 is an enlarged front view of the submatrix 4. Each submatrix 4 has the same configuration.
Binary display cells R, G, B, W0 to W3 are arranged adjacent to each other to form a submatrix 4. These binary display cells R, G, B, W0 to W3 are black when not activated. Binary display cell R
turns red when activated, and the binary display cell G
becomes green when activated, and binary display cell B becomes blue when activated. Also, binary display cell W
0-W3 are white when activated. Vertical and horizontal lengths of image frame 3 shown in Figure 2
For example, d1 may be 8 inches, and the vertical and horizontal lengths d2 of the submatrix 4 may be 1.2 mm.

FIG. 4 is an enlarged sectional view of a portion of image frame 3 representing submatrix 4. FIG. A space 7 between the transparent glass plate 5 and the substrate 6 is under reduced pressure, and an X electrode 8 extending in the left-right direction in FIG.
and a Y electrode 9 extending in the vertical direction in FIG. 4 are arranged. Each intersection of these electrodes 8, 9 corresponds to display cells R, G, B, W0 to W3, respectively. By applying a voltage between these electrodes 8 and 9, a plasma discharge is generated within the space 7. This plasma discharge causes fluorescent substances, conveniently indicated by reference symbols R, W0, W2, etc., to emit light through the glass plate 5, and colors are displayed. In this embodiment, the display device 2 has the structure shown in FIG. 4, but as another embodiment of the present invention, the display device 2 may be a printer configured to emit ink corresponding to each color using an X-Y plotter or the like. It may also be a means for displaying other images.

Referring again to FIG. 1, the picture elements of the image to be displayed captured by the imaging device 1 are color separated into red, green and blue in the color separation circuit 10, and the signal representing the luminance level is are derived to lines SR, SG and SB, respectively. these lines
Signals from SR, SG, and SB are applied to a comparator circuit 11 and also to an arithmetic circuit 12. In the arithmetic circuit 12, red from lines SR, SG, and SB,
Let the brightness levels corresponding to green and blue be r, g,
b, the brightness level w of white corresponding to white is calculated from the line SW as shown in equation 1, and a signal representing the brightness level w is derived and sent to the comparator circuit 11.
given to.

w=0.6g+0.3r+0.1b...(1) The comparison circuit 11 detects red, green, and
The blue and white luminance levels r, g, b, and w are time-sequentially differentiated based on the discrimination level from the discrimination level setting circuit 13, and the level discrimination output is provided to the drive circuit 14.

FIG. 5 is a diagram for explaining discrimination levels. When the luminance levels of red, green, blue, and white are divided into relatively equal parts from 0 to 100, the discrimination level of red is lR as shown in Fig. 5, and the discrimination level of green is lR. The discrimination level of blue is indicated by lG as shown in FIG. 2, and the discrimination level of blue is indicated by lB as shown in FIG. In this embodiment, lR=lB=50 is chosen, but in other embodiments of the invention these discrimination levels lR, lG and lB may be different from each other. Red included in each submatrix 4,
A plurality of (four in this embodiment, as is clear from FIG. 3) binary display cells R, G, and B for each color of green and blue have a common discrimination level lR,
They have lG and lB respectively. That is, the brightness level of the red component is level-discriminated by a single red discrimination level, the brightness level of the green component is level-discriminated by a single green discrimination level, and the brightness level of the blue component is Level discrimination is performed using a single discrimination level for blue. Each of these discrimination levels lR, lG, lB
may have the same value, but may also have mutually different values. In the embodiment shown in FIG. 3, there are a total of four binary display cells R in one submatrix,
As described below, all the red binary display cells R are activated simultaneously when the brightness level of the red color is equal to or higher than the discrimination level lR, and when the brightness level of the red color is lower than the discrimination level lR. When 4
The two binary display cells R all remain inactive, and the same holds true for the other binary display cells G and B. In the embodiment shown in FIG. 3, a total of four red binary display cells R are provided, but there may be a plurality of other cells or a single cell. blue 2
Although there may be four value display cells G and B, there may be a plurality of other value display cells, or there may be a single value display cell.

The discrimination levels of the binary display cells W0 to W3 representing white are determined to l0 to l3, respectively, as shown in FIG. Binary display cells R, G, and B are activated when their respective luminance levels are equal to or higher than their respective discrimination levels lR, lG, and lB, and when their respective luminance levels are less than their respective discrimination levels lR, lG, and lB. Remains inactive. Also, the binary display cell W0 representing white
is activated when the white luminance level w is equal to or higher than the discrimination level l0, and remains inactive when the luminance level w is less than the discrimination level l0. Binary display cell WB1
is activated when the white luminance level w is greater than or equal to the discrimination level l1, and remains inactive when it is less than l1. The display cell W2 has a white luminance level w
is activated above discrimination level l2 and remains inactive below l2. Furthermore, display cell W3
is activated when its luminance level w is above the discrimination level l3, and remains inactive below l3. The relative levels of these discrimination levels l0 to l3 are generally expressed by the second equation.

lm=100(2m+1)/2n...(2) Here, m is the subscript 0 to discrimination level l0 to l3.
3, and n is the total number of discrimination levels l0 to l3 (4 in this case). Therefore l0=12.5,
ll=37.5, l2=62.5, l3=87.5. Drive circuit 1
4 applies a voltage to the X electrode 8 and the Y electrode 9 in response to the level discrimination output from the comparison circuit 11 to generate plasma discharge, and the binary display cells R, G, B, W0 in the image frame 3 ~Selectively activates W3. The brightness of the image frame 3 obtained in this way is clearly improved compared to the prior art described above.

FIG. 6 shows a 6×6 submatrix 15 of another embodiment of the invention. This submatrix 15
What should be noted here is that the binary display cells that become white when activated are indicated by reference marks W0 to W17, and the brightness discrimination levels of their subscripts 0 to 17 are determined by the second equation above. It is determined accordingly.

FIG. 7 is a front view of a submatrix 16 according to still another embodiment of the present invention. This submatrix 16 has 5×5 binary display cells R, G, B, W.
The brightness discrimination level of the binary display cells W0 to W9, which are composed of cells W0 to W8 and are white when activated, corresponds to the subscripts 0 to 8 of those binary display cells W0 to W9. It is determined by the above-mentioned second equation.

For comparison, a conventional submatrix 17 is shown in FIG. In this prior art, the brightness of the binary display cell R that becomes red when activated is 4
It is activated by level discrimination at two discrimination levels.
Similarly, the brightness of the binary display cell G, which turns green when activated, is also level-discriminated at four discrimination levels. Furthermore, the brightness of the binary display cell B, which becomes blue when activated, is level-discriminated at eight discrimination levels. Compared to the prior art shown in FIG. 8, the brightness of the embodiments shown in FIGS. 1 to 7 is clearly improved.

The first reference photograph attached at the same time shows the image frame 3 according to the embodiment of the present invention shown in FIGS. 1 to 5,
The second reference photograph shows an image frame consisting of the submatrix 15 of the embodiment of the present invention shown in FIG.
The third reference photograph shows a prior art image frame consisting of the sub-matrix 17 shown in FIG. As described above, the inventor's experiments have confirmed that the brightness of the image frame is improved in the first and second reference photographs according to the present invention compared to the prior art of the third reference photograph.

As described above, according to the present invention, it is possible to improve the brightness when displaying a color image using the so-called dither color image display method.

In particular, according to the present invention, the binary values of active and inactive of the binary display cells in each submatrix can be stored in a memory, etc., so the storage capacity of the memory can be reduced, and The effect of facilitating various image processing is achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is a front view of the image frame 3 of the display device 2 shown in the first figure, FIG. 3 is an enlarged front view of the submatrix 4 constituting the image frame 3, and FIG.
FIG. 5 is an enlarged cross-sectional view of a part of the binary display cell R,
A diagram for explaining the luminance discrimination levels of G, B, W0 to W3, FIG. 6 is a front view of the submatrix 15 of another embodiment of the present invention, and FIG. 7 is a still another embodiment of the present invention. FIG. 8 is a front view of the submatrix 17 of the prior art. 1... Imaging device, 2... Display device, 3... Image frame, 4, 15, 16, 17... Submatrix, 10... Color separation circuit, 11... Comparison circuit, 1
2... Arithmetic circuit, 13... Discrimination level setting circuit,
14...Drive circuit.

Claims (1)

[Scope of Claims] 1. An image frame is configured by arranging a plurality of submatrices each consisting of red, green, blue, and a plurality of white binary display cells, and in each submatrix constituting the image frame, The brightness level of the red component in the image signal corresponding to each submatrix is level-discriminated using a single red discrimination level, the brightness level of the green component is level-discriminated using a single green discrimination level, and The luminance level of the blue component is level-discriminated using a single blue discrimination level, and based on the result, the red, green, and blue binary display cells of the individual sub-matrix are activated, and the red, green, Determine the white brightness level from the brightness level of each blue component, discriminate this white brightness level at a plurality of discrimination levels, and select the discrimination result among the plurality of white binary display cells of the individual sub-matrix. A color image display method characterized by displaying a color image by displaying individual submatrices by activating the number according to the number of submatrices.