JP2002099239A - Display method - Google Patents

Abstract

(57) [Summary] [Problem] To perform high quality sub-pixel display with less color unevenness. SOLUTION: A raster image to be displayed this time is obtained by expanding the raster image three times in a first direction to obtain triple image data composed of sub-pixels, and based on a coefficient weighted according to the luminance contribution of three primary colors RGB. Filtering the doubled image data, and forming the sub-pixels of the tripled image data after the filtering process into one pixel
And causing the display device to perform display by allocating to one of the light emitting elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display method for a display device in which light emitting elements of three primary colors of RGB are juxtaposed.

[0002]

2. Description of the Related Art Conventionally, display devices using various display devices have been used. In such a display device, for example, three light-emitting elements each emitting three primary colors of RGB, such as a color LCD and a color plasma display, are arranged in a fixed order to form one pixel, and this pixel is a first pixel.
Are arranged side by side to form a line, and this line is
In some cases, a plurality of the display screens are provided in a second direction orthogonal to the direction of.

[0003] For example, there are many display devices, such as display devices mounted on mobile phones and mobile computers, which have relatively narrow display screens and are difficult to display finely. When an attempt is made to display a small character, a photograph, a complicated picture, or the like on such a display device, a part of the image tends to be crushed and become unclear.

[0004] In order to improve display clarity on a narrow screen, a document (subtitle: "Sub Pixel Font Re") on the Internet that utilizes a point where one pixel is composed of three RGB light emitting elements is used.
ndering Technology ”) has been published. The present inventors downloaded this document from a site (http://grc.com) or its subordinates and confirmed it on June 19, 2000.

Next, this technique will be described with reference to FIGS. Hereinafter, as an example of an image to be displayed,
Take up the letter "A".

FIG. 16 schematically shows one line when one pixel is constituted by three light emitting elements as described above. The horizontal direction in FIG. 16 (the direction in which the light emitting elements of the RGB primary colors are arranged) is referred to as a first direction,
The vertical direction orthogonal to this is called the second direction.

Although the arrangement of the light emitting elements is not limited to the order of RGB, other arrangements are conceivable. However, even if the arrangement is changed, the prior art and the present invention can be similarly applied.

Then, one pixel (three light emitting elements) is arranged in a line in the first direction to form one line. Further, the lines are arranged in the second direction to form a display screen.

In the sub-pixel technique, the original image is, for example, an image as shown in FIG. In this example, the character “A” is displayed in an area of 7 pixels in each of the vertical and horizontal directions. On the other hand, in order to perform sub-pixel display, when each of the light-emitting elements of RGB is regarded as one pixel, an area of 21 (= 7 × 3) pixels in the horizontal direction and 7 pixels in the vertical direction , As shown in FIG.
Prepare a font with double resolution.

Then, as shown in FIG. 19, a color is determined for each pixel in FIG. 17 (the pixel in FIG. 17 instead of FIG. 18). However, if the image is displayed as it is, color unevenness occurs. Therefore, a filtering process using coefficients as shown in FIG. FIG. 20A shows a coefficient with respect to the luminance.
The brightness of each sub-pixel is adjusted by multiplying by a factor of 2/9 times for the next sub-pixel and 1/9 times for the next sub-pixel.

Next, these coefficients will be described in detail with reference to FIG. Now, in FIG.
“*” Indicates that any of the three primary colors of RGB may be used. And starting from the first stage from the top,
The second and third stage. The center of the third row is the coefficient of the central subpixel of interest.

Here, when going from the first stage to the second stage, RG
Energy is evenly distributed to all of the B3 primary color light emitting elements, that is, the first-stage coefficient is 1/3
Only. Similarly, when going from the second stage to the third stage,
Energy is evenly distributed, that is, the coefficient of the second stage is also only 1/3.

However, the center sub-pixel is, from the first stage,
Since it is possible to reach through three convenient paths, that is, the center, the left side, and the right side of the second stage, the synthesis coefficient of the center sub-pixel (one stage and two stages combined) is 1/3 × 1/3 + ／
× 1/3 + ／ × 1/3 = 3/9. In addition, since the sub-pixel adjacent to the center sub-pixel can reach through two paths, the synthesis coefficient is 1/3 × 1/3
+ ／ × １ ／ = 2/9. Further, since there is only one path in the next subpixel, the synthesis coefficient is 1 /
3 × １ ／ = 1/9.

[0014]

However, in practice, the light emitting elements of the three primary colors RGB have different degrees of contribution to luminance.

Therefore, when filtering is performed for displaying sub-pixels according to the conventional technique, there is a problem that color unevenness cannot be sufficiently removed and display quality is not good.

Accordingly, an object of the present invention is to provide a display method capable of removing color unevenness in sub-pixel display and performing high-quality display.

A further object of the present invention is to provide a technique capable of speeding up high-quality sub-pixel display.

[0018]

According to the present invention, a step of obtaining triple image data consisting of sub-pixels of a raster image to be displayed this time three times enlarged in a first direction;
Filtering the tripled image data based on a coefficient weighted in accordance with the luminance contribution of the three primary colors, and allocating sub-pixels of the tripled image data after filtering to the three light emitting elements constituting one pixel And causing the display device to perform display.

Alternatively, according to the present invention, a step of obtaining triple image data composed of sub-pixels obtained by enlarging a raster image to be displayed this time by three times in a first direction, and applying a coefficient ignoring the luminance contribution of the three primary colors RGB. Filtering the tripled image data, correcting the sub-pixels of the tripled image data after the filtering process based on a coefficient weighted in accordance with the luminance contribution of the three primary colors RGB, and Allocating the sub-pixels of the tripled image data to three light-emitting elements constituting one pixel, and causing the display device to perform display.

According to these configurations, the filtering process itself or the correction process after the filtering process allows the
Since sub-pixel display can be performed in accordance with the luminance contribution of the three primary colors of GB, color unevenness can be sufficiently suppressed, and high-quality sub-pixel display can be realized.

Alternatively, in the present invention, 2 to be displayed this time
Obtaining triple image data consisting of sub-pixels obtained by enlarging the value raster image by three times in the first direction; a pattern of target sub-pixels of the input triple image and values of sub-pixels on the left and right sides thereof Performing a filtering process by referring to the filtering result storage unit, and forming one sub-pixel of the tripled image data after the filtering process. Allocating to the three light emitting elements and causing the display device to perform display.

Alternatively, in the present invention, a filter result in accordance with a pattern of a total of n (n is a natural number) sub-pixel values in a first direction centering on a sub-pixel of interest of an input tripled image is obtained in advance. Obtaining triple image data consisting of sub-pixels obtained by expanding a binary raster image to be displayed this time by three times in a first direction, which is prepared in a filter result storage means, and referring to the filter result storage means. And performing a filtering process, and allocating the sub-pixels of the tripled image data after the filtering process to three light-emitting elements constituting one pixel and causing the display device to perform display.

With these configurations, high-quality sub-pixel display can be performed at high speed.

Alternatively, in the present invention, the sub-pixel of interest is updated every pixel.

With this configuration, the processing amount can be reduced to about one third and the speed can be further increased as compared with the case where the target sub-pixel is updated for each sub-pixel.

Alternatively, in the present invention, the value stored in the filter result storage means is obtained by blending at least one of the foreground color and the background color.

With this configuration, it is possible to cope with a case where either the foreground color or the background color is color.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the display method according to the first aspect, R
Three pixels that respectively emit the three primary colors of GB are arranged side by side in a fixed order to form one pixel, and these pixels are arranged side by side in a first direction to form one line, and this line is moved in the first direction. When a plurality of pixels are provided in a second direction orthogonal to each other and display is performed on a display device configuring a display screen, a raster image to be displayed this time is tripled in image data including subpixels that are three times enlarged in the first direction. And RGB3
Filtering the tripled image data based on a coefficient weighted according to the luminance contribution of the primary color, and allocating sub-pixels of the tripled image data after filtering to the three light emitting elements constituting one pixel And causing the display device to perform display.

In the display method according to the second aspect, one pixel is formed by arranging three light emitting elements respectively emitting the three primary colors of RGB in a predetermined order, and by arranging the pixels in the first direction to form one line. When a plurality of lines are provided in a second direction orthogonal to the first direction, and a display device constituting a display screen performs display, a raster image to be displayed this time is moved in the first direction. A step of obtaining triple image data composed of three times enlarged sub-pixels; a step of filtering the triple image data based on a coefficient ignoring the luminance contribution of the three primary colors RGB; and a step of filtering the triple image data after the filtering processing. Correcting the sub-pixels based on the coefficients weighted in accordance with the luminance contributions of the three primary colors RGB; Assigned to three light emitting elements constituting the, and a step of causing the display to the display device.

With these configurations, it is possible to perform sub-pixel display reflecting the luminance contribution of the three primary colors RGB, and to further reduce color unevenness and improve the quality of sub-pixel display as compared with the prior art.

In the display method according to the third aspect, the filtering process is one stage.

With this configuration, since the luminance contributions of the three primary colors RGB are reflected, color unevenness can be sufficiently suppressed even by one-stage filtering processing, and the processing speed can be improved by simple processing.

In the display method according to the fourth aspect, the filtering process is performed in two stages.

With this configuration, the luminance contributions of the three primary colors RGB are reflected in two stages, and a fine filtering process can be performed. Therefore, color unevenness can be further suppressed and display quality can be improved.

In the display method according to the fifth aspect, at least a part of the coefficients is set so that R: G: B = 3: 6: 1.

With this configuration, the brightness can be adjusted according to the actual situation.

In the display method according to the sixth aspect, at least a part of the coefficient is set based on a measured value obtained by measuring a characteristic of the display device.

With this configuration, the unique characteristics of the display device can be reflected in the filtering process.

In the display method according to the seventh aspect, the filtering process is performed on a total of three sub-pixels centering on the target sub-pixel.

According to this configuration, since the luminance contributions of the three primary colors RGB are reflected, the color unevenness can be sufficiently suppressed even in the filtering processing for a total of three sub-pixels, and the processing speed can be improved by simple processing.

In the display method according to the eighth aspect, the filtering process is performed on a total of five sub-pixels centering on the sub-pixel of interest.

With this configuration, the luminance contribution of the three primary colors RGB is reflected over a wide range, and a fine filtering process can be performed. Therefore, color unevenness can be further suppressed and display quality can be improved.

In the display method according to the ninth aspect, a total of n (n is a natural number) subpixel value patterns are followed in the first direction with the target subpixel of the input tripled image as the center. Preparing a filter result in a filter result storage means and obtaining triple image data consisting of sub-pixels obtained by expanding a binary raster image to be displayed this time by three times in a first direction; Executing a filtering process with reference to the means, and sub-pixels of the tripled image data after the filtering process by 1
Allocating to the three light emitting elements constituting the pixel and causing the display device to perform display.

With this configuration, it is possible to perform the filtering process required for the sub-pixel display by referring to the filter result storage means, and it is possible to perform the sub-pixel display at a high speed.

In the display method according to the tenth aspect, the filter result storage means is referred to for a total of 3
This is done by the value of one sub-pixel.

With this configuration, the quality of the filtering process by referring to the filter result storage means can be maintained at the same quality as the total of three filtering processes centering on the subpixel of interest. In particular, when displaying a low-gradation image, color unevenness is less noticeable, so this is practically sufficient, and the amount of filter results to be referred to is reduced to save storage space and speed up processing. Can be achieved.

In the display method according to the eleventh aspect, the filter result storage means is referred to by a total of 5
This is done by the value of two sub-pixels.
Reference is made based on the values of a total of seven sub-pixels centering on the target sub-pixel.

With these configurations, the quality of the filtering process by referring to the filter result storage means can be maintained at the same quality as the total of five or seven filtering processes centering on the subpixel of interest. . In particular, it becomes easy to cope with high-gradation image display in which color unevenness is conspicuous.

In the display method according to the thirteenth aspect, the input raster image is binary data, and a total of three sub-pixels, centering on the target sub-pixel, can have 2 @ 3 powers. , And the filter result storage means has eight sets, which is necessary and sufficient.

In the display method according to the fourteenth aspect, the input raster image is binary data, and the five sub-pixels around the target sub-pixel can have 2 @ 5 power states. 32 sets of values in the filter result storage means are necessary and sufficient. Further, in the display method according to the fourteenth aspect, since seven sub-pixels around the target sub-pixel can have 2 7 states, the value of the filter result storage means is 128 sets, which is necessary and sufficient. .

With these configurations, it is possible to reduce the number of filtering results stored in the filtering result storage means, to save a storage area, to greatly reduce the amount of calculation, and to perform high-speed filtering.

In the display method according to the sixteenth aspect, the filter result stored in the filter result storage means is determined based on a coefficient weighted according to the luminance contribution of the three primary colors RGB.

With this configuration, the processing can be completed and the speed can be greatly increased by almost only referring to the storage means, and the sub-pixel display reflecting the luminance contribution of the three primary colors RGB can be performed. In addition, the color unevenness can be further reduced, and the quality of the sub-pixel display can be improved.

In the display method according to the seventeenth aspect, the sub-pixel of interest is updated by three sub-pixels.

With this configuration, the filtering process can be performed
The processing can be performed collectively for each pixel, and the processing amount can be reduced to about one third as compared with the case where the update is performed for each subpixel, so that the speed can be further increased.

In the display method according to the eighteenth aspect, the value stored in the filter result storage means is obtained by blending at least one of a foreground color and a background color.

With this configuration, it is possible to cope with a case where at least one of the foreground color and the background color is displayed in color.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a display device according to an embodiment of the present invention.

In FIG. 1, a display information input means 1 inputs display information. Further, the display control unit 2 controls each element in FIG. 1 to perform display on the display device 3 based on the display image stored in the display image storage unit 7 (such as VRAM) for sub-pixel display. Let

The display device 3 constitutes one pixel by arranging three light-emitting elements respectively emitting the three primary colors of RGB in a predetermined order, and constitutes one line by arranging the pixels in the first direction. A plurality of such lines are provided in a second direction orthogonal to the first direction to form a display screen. In particular,
It comprises a color LCD, a color plasma display and the like, and a driver for driving each of these light emitting elements.

The triple image data storage means 4 is a triple image (sub-pixel image corresponding to three light emitting elements of RGB) corresponding to display information which can be input from the display information input means 1.
Is stored.

The filtering unit 5 performs a filtering process on the triple image stored in the triple image data storage unit 4, and stores an image obtained as a result of the filtering process in the display image storage unit 7. Here, in the first embodiment shown in FIG. 2, the filtering processing means 5 performs the filtering process with a coefficient reflecting the luminance contribution of each of the RGB light emitting elements. However, in the second embodiment, the luminance contribution is ignored. Filtering processing is performed with the set coefficients.

Next, the coefficients used in the filtering processing in the first embodiment or the correction processing in the second embodiment will be described with reference to FIGS.

First, the coefficients of only one stage are as shown in FIG. Here, in one pixel composed of three light-emitting elements (sub-pixels) of RGB, the luminance contribution is
R: G: B = 3: 6: 1.

Therefore, as shown in FIG. 4A, when the target sub-pixel is R, the left is B and the right is G, so that the left (n−1) 1 per pixel
/ 10, 3/1 for the R subpixel of the target subpixel
0/1, 6/1 on the right (n + 1 ahead) G subpixel
Energy distribution such as 0.

Therefore, when each value V is expressed by adding a subscript, the value V (n) = (1/10) after reflecting the luminance contribution degree
× Vn-1 + (3/10) × Vn + (6/10) × Vn
It becomes +1.

Similarly, when the target sub-pixel is G, the result is as shown in FIG. 4B, and when the target sub-pixel is B, the result is as shown in FIG. 4C.

Here, as apparent from FIG. 4, if only one stage of coefficient is used, this coefficient is applied to a total of three sub-pixels centering on the target sub-pixel.

Next, the two-stage coefficient will be described with reference to FIG. In the example of FIG. 5, the first stage is exactly the same as that of FIG. Then, when the sub-pixel of interest is R, as shown in FIG. 5 (a), when focusing on the branched B sub-pixel, the lower part thereof is in the order of GBR, and therefore, in order from the left, 6/10, 1/10, 3
Energy is distributed so as to be / 10.

Similarly, since the branched R sub-pixels are in the order of BRG,
Energy is distributed so as to be 1/10, 3/10, 6/10. In addition, since the branched G sub-pixels are arranged in the order of RGB,
Energy is distributed so as to be 3/10, 6/10, 1/10.

As a result, a hierarchy shown in FIG. 5A is formed. Now, focusing on the R sub-pixel (sub-pixel of interest, n) in the center of FIG. 5A, there are three paths via the B, R, and G sub-pixels in the upper row to reach this sub-pixel of interest. . Therefore, the coefficient for the value Vn of the subpixel of interest is (1/10) × (3/10)
+ (3/10) × (3/10) + (6/10) × (3 /
10) = 30/100.

When the coefficients of the other sub-pixels at the bottom are calculated in the same manner, the value V (n) = after reflection of the luminance contribution is obtained.
(6/100) × Vn−2 + (4/100) × Vn−1
+ (30/100) × Vn + (54/100) × Vn +
1+ (6/100) × Vn + 2.

Similarly, when the target sub-pixel is G, the result is as shown in FIG. 5B, and when the target sub-pixel is B, the result is as shown in FIG. 5C.

Here, as apparent from FIG. 5, when the two-stage coefficient is used, this coefficient is applied to a total of five sub-pixels centering on the sub-pixel of interest.

FIG. 6 (Equal (1/3) distribution of the second stage) and FIG. 7 (Equal (1/3) of the first stage)
3) Distribution). In this way, even if a part is evenly distributed, it is often practically sufficient if the other steps are coefficients reflecting the luminance contribution. Further, the present invention is included in the present invention even if it is expanded to three or more stages.

In the above, R: G: B = 3:
Although the coefficient of 6: 1 was used, the characteristic of the display device may be measured instead, and the coefficient may be set based on the measured value. In this case, the characteristic peculiar to the display device can be reflected in the filtering process, and the display quality can be further improved.

Based on the above description, the flow of the display method according to the first embodiment of the present invention will now be described with reference to FIG. First, in step 1, display information is input to the display information input means 1.

Then, from the triple image data storage means 4,
A triple image (sub-pixel image) corresponding to the input display information is extracted (step 2). This image is typically raster font data.

Next, at step 3, the display control means 2
Initializes the sub-pixel of interest in the acquired 3 × image to the initial position at the upper left, and in step 4, the filtering processing means 5 performs the filtering process on the sub-pixel of interest using a coefficient reflecting the luminance contribution. Do. Here, any of the coefficients shown in FIGS. 4 to 7 may be used as this coefficient.

When the filtering processing is completed, the filtering processing means 5 returns the processed image data to the display control means 2, and the display control means 2 stores the received data in the display image storage means 7 (step 5). .

The display control means 2 repeats the processing from step 4 to step 5 while updating the subpixel of interest (step 7) until the processing for all the subpixels of interest is completed (step 6).

When this repetitive processing is completed, the display control means 2 applies the triple pattern to the three light emitting elements constituting one pixel of the display device 3 based on the display image stored in the display image storage means 7. Is assigned (by sub-pixel display), and the display device 3 performs display (step 8).

If the display is not completed (step 9), the display control means 2 returns the processing to step 1.

Next, the flow of a display method according to the second embodiment of the present invention will be described with reference to FIG. First, in step 11, display information is input to the display information input means 1.

Then, from the triple image data storage means 4,
A triple image (sub-pixel image) corresponding to the input display information is extracted (step 12).

Next, at step 13, the display control means 2
Initializes the sub-pixel of interest in the obtained triple image to the initial position at the upper left, and in step 14, the filtering processing means 5 executes
Filtering is performed with a coefficient that ignores the luminance contribution.

When the filtering processing is completed, the filtering processing means 5 returns the processed image data to the display control means 2, and the display control means 2 stores the received data in the display image storage means 7 (step 15). .

The display control means 2 repeats the processing from step 14 to step 15 while updating the subpixels of interest (step 17) until the processing for all the subpixels of interest is completed (step 16).

When the repetition processing is completed, the display control means 2 causes the correction means 6 to correct the triple image in the display image storage means 7 (step 18). The correction unit 6 performs a filtering process on all the sub-pixels using a coefficient (one of FIGS. 4 to 7) reflecting the luminance contribution.

When the correction is completed, the display control means 2 assigns this triple pattern to three light-emitting elements constituting one pixel of the display device 3 based on the display image stored in the display image storage means 7. (In sub-pixel view)
The display is performed on the display device 3 (step 19).

If the display is not completed (step 20), the display control means 2 returns the processing to step 1.

Next, a third embodiment will be described with reference to FIGS. Here, in the above-described first and second embodiments, the filtering process and the correction process are performed by calculation. However, in this case, the number of repetitive calculations is large and the processing load cannot be said to be light.

Therefore, in the third embodiment, processing equivalent to the processing by calculation is realized by referring to the storage means in which the processing result is stored in advance, instead of the processing by calculation. As a result, the processing load can be significantly reduced, and the speed can be increased.
In this embodiment, typically, a binary raster image is displayed. However, a grayscale image binarized with an appropriate threshold can also be displayed.

FIG. 8 is a block diagram of a display device according to the third embodiment of the present invention. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, as described above, the filtering processing means 8 does not perform the filtering processing or the calculation performed by the correction means 6 in FIG. Instead, a filter result storage means 9 is provided, and the result of this operation is stored in the filter result storage means 9 before inputting the display information.

After the input of the display information, the filtering processing means 8 outputs a total of n (here, n = 3 or n) in the first direction from the tripled image data storage means 4 centering on the target subpixel. = 5), an address is generated from the on / off state of each subpixel, and a corresponding processing result is obtained by referring to the filter result storage means 9.

First, the case where n = 5 will be described with reference to FIG. As shown in FIG. 9A, the filtering processing unit 8 determines a subpixel of interest in a raster image (subpixel accuracy) stored in the triple image data storage unit 4. Then, on / off of a total of 5 sub-pixels in the first direction around the target sub-pixel.
Get information (bit string). In this example, on is represented by “1” (black in the figure) and off is represented by “0” (white in the figure), but may be changed as appropriate.

That is, when a bit string of five sub-pixels is obtained with the center of the sub-pixel of interest, the value (binary number) immediately becomes an address. Here, in the state shown in FIG. 9A, an address “00110” is generated.

Of course, an offset address may be appropriately set for convenience of mounting. Hereinafter, for simplicity of description, the offset address is assumed to be zero (none).

Further, when the luminance contribution is taken into consideration and not taken into account, the processing equation is different as described above. Of course, it is desirable to consider it in order to improve the display quality.

Here, when considering the luminance contribution,
As described in the description of FIGS. 5 to 7, the expression differs depending on which of the RGB light emitting elements the subpixel of interest corresponds to. Therefore, in this case, the filtering processing means 8
Is to check which light emitting element is the target sub-pixel.
Then, as shown on the right side of FIG.
The processing results for the 32 light emitting elements of RGB of “0000” to “11111” are stored in the filter result storage unit 9. Here, the filter result storage means 9 is typically constituted by a memory, and data is prepared in the form of a table as shown in the figure. May be prepared in the form of storage.

On the other hand, when the luminance contribution is not taken into account, as shown in FIG. 17, even if the sub-pixel of interest corresponds to any of the RGB light-emitting elements, there is only one equation, so the filtering processing means 8 The processing result may be obtained only by the addresses from the five sub-pixels. However, when the luminance contribution is not taken into consideration as in the second embodiment, it is desirable to separately perform correction in order to improve display quality.

Next, the contents of the filtering processing means 8 will be described more specifically with reference to FIGS. 9 (b) to 9 (e). In addition, the following numerical values are only representative examples, and it goes without saying that various changes can be made.

First, as shown in FIG. 17, when the luminance contribution is not considered, as shown in FIG.
Only one processing result is stored for each address of “0” to “11111”.

Next, when considering the luminance contribution, FIG.
As shown in (c) to (e), “00000” to “1111”
For each address of “1”, three processing results (corresponding to the case where the target sub-pixel is RGB) are stored. 9 (c) is a table of the relationship of FIG. 5, FIG. 9 (d) corresponds to FIG. 6, and FIG. 9 (e) corresponds to FIG.

Next, a case where n = 3 will be described with reference to FIG. As shown in FIG. 10A, the filtering processing unit 8 determines a subpixel of interest in a raster image (subpixel precision) stored in the triple image data storage unit 4. Then, on / o of a total of three sub-pixels in the first direction around the target sub-pixel.
ff information (bit string) is obtained. In this example, o
n is “1” (black in the figure) and off is “0” (white in the figure)
Is expressed, but may be changed as appropriate.

That is, when a bit string of three sub-pixels is obtained with the sub-pixel of interest at the center, the value (binary number) immediately becomes an address. Here, FIG.
In the state shown in (1), an address "010" is generated.

Further, when the luminance contribution is considered and when it is not considered, the processing equation is different as described above. Of course, it is desirable to consider it in order to improve the display quality.

Here, when considering the luminance contribution,
As described in the description of FIGS. 5 to 7, the expression differs depending on which of the RGB light emitting elements the subpixel of interest corresponds to. Therefore, in this case, the filtering processing means 8
Is to check which light emitting element is the target sub-pixel.
Then, as shown on the right side of FIG. 10A, the processing results of the eight light emitting elements of RGB of the addresses “000” to “111” are stored in the filter result storage unit 9.
To be stored.

On the other hand, when the luminance contribution is not taken into account, as shown in FIG. 17, even if the target sub-pixel corresponds to any of the RGB light-emitting elements, there is only one formula, so the filtering processing means 8 The processing result may be obtained only by the addresses from the five sub-pixels. However, when the luminance contribution is not taken into consideration as in the second embodiment, it is desirable to separately perform correction in order to improve display quality.

Next, the contents of the filtering processing means 8 will be described more specifically with reference to FIGS. 10 (b) to 10 (c). In addition, the following numerical values are only representative examples, and it goes without saying that various changes can be made.

First, as shown in FIG. 17, when the luminance contribution is not considered, as shown in FIG.
Only one processing result is stored for each address of “−111”.

Next, when considering the luminance contribution, FIG.
0 (c), three processing results (the sub-pixel of interest is RGB) for each of the addresses “000” to “111”.
Is stored). Incidentally, FIG. 10C is a table of the relationship of FIG.

Next, the flow of the display method of this embodiment will be described with reference to FIG. First, in steps 21 to 23, processing similar to steps 1 to 3 in FIG. 1 is performed.

Next, at step 24, the filtering processing means 8 obtains a bit string of a total of n (n = 3, 5) subpixels centered on the subpixel of interest from the tripled image data storage means 4, Is an address.

In step 25, the above-mentioned table in the filter result storage means 9 is referred to, and the processing result of this address is obtained. At this time, when taking into account the luminance contribution, the filtering processing unit 8 also examines which of the RGB the target subpixel corresponds to.

In steps 26 to 30, the same processing as in steps 5 to 9 in FIG. 1 is performed.

It will be understood from the above description that the processing equivalent to the first and second embodiments can be realized by referring to the filter result storage means 9. In addition, in this case, the amount of calculation can be greatly reduced, and the processing can be remarkably speeded up.

Next, a fourth embodiment will be described with reference to FIGS. The fourth embodiment is a further development of the third embodiment, and can further increase the processing speed. The components in the fourth embodiment are the same as those in the third embodiment, and are not shown.

However, the fourth embodiment differs from the third embodiment in the processing of the filtering processing means 8 and the contents stored in the filter result storage means 9. Embodiment 3
In the above description, the processing target is updated for each sub-pixel, but in the fourth embodiment, the processing is updated for each pixel, that is, updated. Therefore, regarding these differences, the first
This will be described with reference to an example and a second example.

[First Example] In this example, as shown in FIG. 12, the filtering processing means 8 performs processing with reference to the filter result storage means 9.

Here, at a certain point, the target pixel (3
One sub-pixel is treated as one)
It is assumed that it is at the position of the arrow 2. In FIG. 12, a
One character bcd... is image data of a corresponding sub-pixel.

At this time, the image data of the target pixel in the triple image data storage means 4 is “def”, and in the first direction, the target pixel immediately before the image data “def” in the first direction. Is image data “abc”, the image data of the next target pixel is “ghi”, and image data “jkl...

In the first example, the image data “def” of the current pixel of interest and the image data “b” two sub-pixels before it are displayed.
c "and image data" gh "two subpixels later. That is, a total of seven sub-pixels of image data are used in the first direction with the target pixel as the center.

Then, the filtering processing means 8 outputs the image data “bcdefgh” of these seven sub-pixels.
And each data is set to a bit of “0” or “1”.

More specifically, the filtering processing means 8
When the triple image data is a binary image,
Since the data “cdefgh” is originally a bit string of “0” or “1”, the image data of each sub-pixel is
Used as it is or after bit inversion.

On the other hand, when the triple image data is a multi-valued image, the filtering processing means 8 generates a binary bit string from the multi-valued image using a preset threshold.

In any case, a 7-bit binary bit string is generated. Then, the filtering processing means 8 uses this bit string as a 7-bit address as in the third embodiment.

To deal with this, in the first example, FIG.
As shown in the figure, corresponding to a 7-bit address,
A table in which RGB values are determined is prepared, and this table is stored in the filter result storage unit 9. Here, according to the 7-bit address, there are only 128 combinations of RGB values.

That is, the filtering processing means 8 generates a 7-bit bit sequence centering on the pixel of interest, and by using this as an address to refer to the table of the filter result storage means 9, the RGB value of the pixel of interest is immediately obtained. "RG
B "can be obtained. Then, the RGB value “RG
B ”is written in the corresponding area of the display image storage means 7.

When the writing is completed, the filtering processing means 8 sets the pixel of interest to one pixel (three sub-pixels).
Minute, update. That is, in the state shown in FIG.
, The target pixel is shifted by three sub-pixels, and the next target pixel is “efghjk”
, The next RGB value “R′G ′”
B ′ ”is written to the area corresponding to the next pixel.

In this way, the filter processing can be performed collectively in units of one pixel (three sub-pixels), and the number of times of address reference and table search can be reduced, thereby achieving higher-speed processing. .

[Second Example] In this example, as shown in FIG. 13, the filtering processing means 8 performs processing with reference to the filter result storage means 9.

Here, at a certain point, the target pixel (3
One sub-pixel is treated as one)
It is assumed that it is at the position of the arrow 3. In FIG. 13, a
One character bcd... is image data of a corresponding sub-pixel.

At this time, as in FIG. 12, the image data of the target pixel in the triple image data storage means 4 is “def”, and in the first direction, “de”.
The image data of the pixel of interest immediately before the image data of “f” is “abc”, the image data of the pixel of interest immediately after is “ghi”, and then “jkl ...”. It is assumed that image data continues.

Here, in the first example, two sub-pixels before and after the image data of the pixel of interest are used, but in the second example, the image data “def” of the current pixel of interest and
The image data “c” one subpixel before and the image data “g” one subpixel after are used. That is,
Image data of a total of 5 subpixels is used in the first direction with the target pixel as the center.

Then, the filtering processing means 8 extracts the image data "cdefg" of these five sub-pixels, and sets each data as "0" or "1" bits.

More specifically, the filtering processing means 8
When the triple image data is a binary image, this "c
Since the data "defg" is originally a bit string of "0" or "1", the image data of each sub-pixel is used as it is or with its bit inverted.

On the other hand, when the triple image data is a multi-valued image, the filtering processing means 8 generates a binary bit string from the multi-valued image using a preset threshold value.

In any case, a 5-bit binary bit string is generated. Then, the filtering processing means 8 uses this bit string as a 5-bit address, as in the third embodiment.

To deal with this, in the first example, FIG.
As shown in the figure, corresponding to a 5-bit address,
A table in which RGB values are determined is prepared, and this table is stored in the filter result storage unit 9.

That is, the filtering processing means 8 generates a 5-bit bit string centering on the pixel of interest and uses this as an address to refer to the table of the filter result storage means 9 to immediately obtain the RGB value of the pixel of interest. "RG
B "can be obtained. Then, the RGB value “RG
B ”is written in the corresponding area of the display image storage means 7.

When this writing is completed, the filtering processing means 8 sets the pixel of interest to one pixel (three sub-pixels).
Minute, update. That is, in the state shown in FIG.
, The target pixel is shifted by three sub-pixels, and the next target pixel has the next RGB value “R′G ′” based on the image data “fghij”.
B ′ ”is written to the area corresponding to the next pixel.

In this manner, as in the first example, the filtering process can be performed collectively in units of one pixel (three sub-pixels), and the number of times of address reference and table search can be reduced to further reduce the number of times. , High-speed processing can be realized. Also,
When a 5-bit address is used, the number of combinations of RGB values is 32, which can be handled with a smaller table amount than in the first example.

Next, each process of the display method in the fourth embodiment (common to the “first example” and “second example”) will be described with reference to FIG. First, in steps 31 to 32, the same processing as steps 1 to 3 in FIG. 1 is performed.

However, as described above, since the processing target is updated in units of one pixel (three sub-pixels), the target position is initialized in units of pixels (step 33).

Next, at step 34, the filtering processing means 8 acquires a bit string of a total of n (n = 7, 5) sub-pixels centering on the pixel of interest from the tripled image data storage means 4, and Address.

In step 35, the processing result of this address is obtained by referring to the above-mentioned table in the filter result storage means 9.

In steps 36 to 40, the same processing as in steps 5 to 9 in FIG. 1 is performed. However, in the present embodiment, in steps 37 and 38, the processing target is shifted by one pixel (3 sub-pixels), so that the target position is updated pixel by pixel.

Next, a fifth embodiment of the present invention will be described with reference to FIG. The fifth embodiment is a further development of the fourth embodiment, and can support color display.

According to the fourth embodiment (either the "first example" or the "second example"), as described with reference to FIG. 12 and FIG. 8 is the RGB value “RG
B "can be obtained.

Here, in the fifth embodiment, in addition to the processing of the fourth embodiment, the filtering processing means 8
The B value “RGB” is subjected to a blending process of the background color or the foreground color by the following equations (1) to (3), and the RGB value “R # G” of the pixel of interest is corresponding to the color display. #B
# ".

R # = R × Rf + (1-R) × Rb (1) G # = G × Gf + (1-G) × Gb (2) B # = B × Bf + (1-B) × Bb (3) )

However, in formulas (1) to (3), (R
f, Gf, Bf) is the foreground color, and (Rb, Gb, B
b) is the background color.

Of course, formulas (1) to (3) are merely preferred examples, and the present invention is not limited to these formulas. For example, adding an appropriate weight to each color component,
Various changes may be made, such as corresponding to only one of the foreground and background colors.

As described above, by performing the color blending process, a sub-pixel display corresponding to a color display can be realized.

In the above description, the information supply source from which the filtering processing means 8 obtains information on one or both of the foreground color and the background color is typically the display information input means 1, The present invention is not limited to this, and can be arbitrarily selected.

[0158]

According to the present invention, since sub-pixel display is performed by distributing energy in accordance with the luminance contribution of the three primary colors RGB, sub-pixel display with less color unevenness and high quality can be achieved.

According to the present invention, high-quality sub-pixel display can be performed at high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a display device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a display device according to Embodiment 1 of the present invention.

FIG. 3 is a flowchart of a display device according to Embodiment 2 of the present invention.

4A is a diagram illustrating a coefficient according to an embodiment of the present invention. FIG. 4B is a diagram illustrating a coefficient according to an embodiment of the present invention. FIG. 4C is a diagram illustrating a coefficient according to an embodiment of the present invention.

5A is a diagram illustrating a coefficient according to an embodiment of the present invention; FIG. 5B is a diagram illustrating a coefficient according to an embodiment of the present invention; FIG. 5C is a diagram illustrating a coefficient according to an embodiment of the present invention;

6A is a diagram illustrating a coefficient according to an embodiment of the present invention. FIG. 6B is a diagram illustrating a coefficient according to an embodiment of the present invention. FIG. 6C is a diagram illustrating a coefficient according to an embodiment of the present invention.

FIG. 7A is an explanatory diagram of a coefficient according to an embodiment of the present invention. FIG. 7B is an explanatory diagram of a coefficient according to an embodiment of the present invention.

FIG. 8 is a block diagram of a display device according to Embodiment 3 of the present invention.

9A is an explanatory diagram of a table according to the third embodiment of the present invention. FIG. 9B is an exemplary diagram of a table according to the third embodiment of the present invention. d) Exemplary table of Embodiment 3 of the present invention (e) Exemplary table of Embodiment 3 of the present invention

10A is an explanatory diagram of a table according to the third embodiment of the present invention. FIG. 10B is an exemplary diagram of a table according to the third embodiment of the present invention.

FIG. 11 is a flowchart of a display method according to the third embodiment of the present invention.

FIG. 12 is an explanatory diagram of a filtering process according to the fourth embodiment (first example) of the present invention;

FIG. 13 is an explanatory diagram of a filtering process according to the fourth embodiment (second example) of the present invention;

FIG. 14 is a flowchart of a display method according to the fourth embodiment of the present invention.

FIG. 15 is an explanatory diagram of a color blending process according to the fifth embodiment of the present invention.

FIG. 16 is a schematic view of a conventional one line.

FIG. 17 is a view showing an example of a conventional original image.

FIG. 18 is a view showing an example of a conventional triple image.

FIG. 19 is an explanatory diagram of a conventional color determination process.

20A is an explanatory diagram of a conventional filtering process coefficient, and FIG. 20B is an exemplary diagram of a conventional filtering process result.

FIG. 21 is an explanatory diagram of a conventional filtering process coefficient.

[Explanation of symbols]

 2 display control means 3 display device 4 display image storage means 5 filtering processing means 6 correction means 7 triple image data storage means 9 filter result storage means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/64 G09G 3/28 K (72) Inventor Bunpei Taji 1006 Kazuma, Oji, Kadoma, Osaka Matsushita Electric Industrial In-house F-term (reference) 5C006 AA22 AF46 AF47 AF85 BB11 5C060 BB13 BC01 BE05 BE10 HB11 HB23 JA00 5C066 AA03 CA00 CA05 CA21 EA07 EA13 EC01 GA01 HA03 KA12 KE02 KE03 KM15 5C080 AA05 AA10 BB05 JJ05 JJ05 DD

Claims (18)

[Claims] 1. A pixel is formed by arranging three light-emitting elements respectively emitting three primary colors of RGB in a predetermined order, and forming one line by arranging these pixels in a first direction. A plurality is provided in a second direction orthogonal to the first direction,
Obtaining a three-fold image data consisting of sub-pixels of a raster image to be displayed this time, three times larger in the first direction, when displaying on a display device constituting a display screen; Filtering the tripled image data based on a coefficient weighted in accordance with the degree; assigning sub-pixels of the tripled image data after the filtering process to three light emitting elements constituting one pixel; Causing the device to perform display. 2. A pixel is formed by arranging three light emitting elements respectively emitting three primary colors of RGB in a predetermined order, and forming one line by arranging the pixels in a first direction. A plurality is provided in a second direction orthogonal to the first direction,
Obtaining a three-fold image data consisting of sub-pixels of a raster image to be displayed this time, three times larger in the first direction, when displaying on a display device constituting a display screen; Filtering the tripled image data based on a coefficient ignoring the degree, and correcting the sub-pixels of the tripled image data after the filtering processing based on a coefficient weighted according to the luminance contribution of the three primary colors RGB. A display method, comprising: allocating sub-pixels of the tripled image data after the correction processing to three light-emitting elements constituting one pixel, and causing the display device to perform display. 3. The display method according to claim 1, wherein the filtering process is performed in one stage. 4. The display method according to claim 1, wherein the filtering process is performed in two stages. 5. At least a part of the coefficient is R: G: B.
5. The display method according to claim 1, wherein the display method is set to be 3: 6: 1. 6. The display method according to claim 1, wherein at least a part of the coefficient is set based on a measured value obtained by measuring a characteristic of the display device. 7. The display method according to claim 1, wherein the filtering process is performed on a total of three sub-pixels centering on a target sub-pixel. 8. The display method according to claim 1, wherein said filtering process is performed on a total of five sub-pixels centering on a sub-pixel of interest. 9. A pixel is formed by arranging three light-emitting elements for emitting the three primary colors of RGB in a predetermined order, and forming one line by arranging the pixels in a first direction. A plurality is provided in a second direction orthogonal to the first direction,
When a display device constituting a display screen performs display, a value pattern of a total of n (n is a natural number) sub-pixels in a first direction centering on a target sub-pixel of an input tripled image is set in advance. Preparing a corresponding filter result in a filter result storage means, and obtaining triple image data including sub-pixels obtained by enlarging a binary raster image to be displayed this time by three times in the first direction; Performing a filtering process with reference to the filter result storage unit; and allocating sub-pixels of the tripled image data after the filtering process to three light-emitting elements constituting one pixel, and performing display on the display device. A display method. 10. The display method according to claim 9, wherein n = 3. 11. The display method according to claim 9, wherein n = 5. 12. The display method according to claim 9, wherein n = 7. 13. A display method according to claim 10, wherein the input raster image is binary data, and said filter result storage means has eight sets of values. 14. A display method according to claim 11, wherein the input raster image is binary data, and said filter result storage means has 32 sets of values. 15. The display method according to claim 12, wherein the input raster image is binary data, and said filter result storage means has 128 sets of values. 16. A display method according to claim 10, wherein the filter result stored in said filter result storage means is determined based on a coefficient weighted in accordance with the luminance contribution of the three primary colors RGB. . 17. The apparatus according to claim 9, wherein the sub-pixel of interest is updated by three sub-pixels.
Display method of description. 18. The display method according to claim 9, wherein the value stored in the filter result storage means is obtained by blending at least one of a foreground color and a background color.