JPH04277791A - System and device for character output - Google Patents

Abstract

PURPOSE:To output characters of high quality by generating correction data which give an intermediate color or intermediate brightness between a character and its background to non-character constitution dots contacting the slanting-line parts of the character and correcting the output character. CONSTITUTION:A transfer device 7 transfers the character data from a character font ROM 8 to a corresponding display plane among display planes 2-4 corresponding to a display color. The transferred character data is character data stored in a character font ROM 8 or/and character interpolation data generated by a character output device 6. Display data stored in the respective display planes 2-4 are sent to the display device in order by a display driver 5 and displayed on a display device 1. According to the character data, the correction data for giving the intermediate color or intermediate brightness between the character and its background to the non-character constitution dots contacting the slating-line parts of the character are generated and the output character is corrected with the correction data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for outputting high-quality characters in a matrix-structured display device such as a liquid crystal display.

0002

[Prior Art] In conventional displays such as CRTs and printers such as wire dots, the brightness of the dots representing one pixel was arranged in a normal distribution, so the dot boundaries were not clear, and as a result, the diagonal areas of characters smoothness was guaranteed.

[0003] However, in liquid crystal displays, which are recently being used in laptop computers, etc., the rise in brightness representing one dot is sharp and the pixel boundaries are clear, so the quality of horizontal and vertical lines is higher than that of conventional output devices. Although the output was output, the stairway of dots indicating the diagonal line was noticeable, resulting in a deterioration in character quality.

[0004] To solve this problem, Japanese Patent Laid-Open No. 2-21
Publication No. 3891 discloses that for a character having a display pixel that is not parallel to the arrangement of pixels in a matrix, a pattern memory is prepared in advance as a pattern for displaying other pixels adjacent to the pixel in gradation. This disclosure discloses a display device that displays a text along with characters.

[0005]

However, the above-mentioned conventional technique has the disadvantage that if pattern memories are prepared for all characters having diagonal lines, the memory capacity increases. In particular, if the quality of enlarged/reduced characters is considered, it is necessary to provide the pattern memory for each character size, and the memory capacity required for the pattern memory becomes enormous.

The present invention provides a character output method and device that makes it possible to output high-quality characters even on an output device with clear pixel boundaries without having a pattern memory corresponding to each character as in the past. It's about doing.

[0007]

[Means for Solving the Problems] In order to solve the above problems, a character output method according to the present invention is a character output method that outputs characters in a dot matrix configuration, and a character output method that outputs characters having a dot matrix structure, based on character data, Correction data that gives non-character constituent dots an intermediate color or intermediate brightness between the character and the character background is generated, and output characters are corrected using the correction data.

[0008] The degree of intermediate color or intermediate brightness may be constant, or the degree of intermediate color or intermediate brightness may be determined depending on the diagonal angle of the diagonal line portion of the character.

Specifically, when the output character is a character expressed in a bitmap format, one of the dots adjacent to each other in the horizontal direction is not a dot that constitutes the character in the output bitmap data. Dots that satisfy the condition that one of the vertically adjacent dots constitutes a character are displayed as character correction data in an intermediate color or intermediate brightness.

At this time, preferably, among the dots that satisfy the conditions of the character correction data, dots that are determined to be adjacent to the intersection of the horizontal line and the vertical line of the character are not subjected to character correction. Here, for example, a horizontal line of a character is composed of two or more horizontally continuous dots, and a vertical line of the character is composed of two or more vertically continuous dots.

A character output device according to the present invention is a character output device that outputs characters in a dot matrix configuration, and includes a plurality of planes for storing display data, a character data storage means for storing character data, and a character output method. a character correction data generating means for generating character correction data; and correcting the character data or display data generated by the character data with the character correction data before or after being written on the plurality of planes. and display data correction means.

[0012] In this character output device, one of the plurality of planes may be used for storing the character correction data.

[0013]

[Operation] Based on the character data, the character correction data generation means generates correction data that gives an intermediate color or intermediate brightness between the character and the character background to the non-character constituent dots that touch the diagonally lined portion of the character. The display data correction means corrects the character data or display data generated from the character data using the character correction data before or after the character data is written on the plurality of display planes. As a result, the dots touching the hatched portions of characters can be displayed in a color or intermediate brightness between the character color and the character background color, so that the stepped hatched portions can be interpolated and the quality of the characters can be improved. Rather than preparing correction data for each character in advance,
Since it is generated based on each character data, no correction pattern memory is required.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the configuration of a display device for carrying out the present invention. 1 is a monochrome display device such as an LCD that displays characters and figures; 2 to 4 are display planes that store display data for each display color of red, green, and blue; and 5 is a display driver that transfers display data to the display device. , 6 is a character output device that creates interpolated data of the present invention, 7 is a transfer device that transfers character data, and 8 is a character font ROM that stores character data.
It is.

In the normal character output method, the transfer device 7
Character data is transferred from the character font ROM 8 to a corresponding display plane among the display planes 2 to 4 according to the display color. In the character display device of the present invention, character data is similarly transferred to the corresponding plane, but the character data to be transferred is transferred from the character data stored in the character font ROM 8 or the data stored in the character font ROM 8 to the character output device. This becomes either or both of the character interpolation data created in step 6. The transfer of character interpolation data to the display planes 2 to 4 and the transfer of character data from the character font ROM 8 to the character output device 6 may be performed by either the character output device 6 or the transfer device 7. The display data stored in each of the display planes 2 to 4 is sequentially sent to the display device by the display driver 5 and displayed on the display device 1. At this time, the display driver 5 converts the eight display colors expressed in three planes into monochrome gradation data of eight gradations in the order of density, as shown in FIG. As a result, the display device 1 performs 8-gradation monochrome display.

First, a method will be described in which, using such a display device, a single intermediate color is used on a screen with a black text background color to correct diagonal lines.

First, FIG. 8 shows which display data should be transferred to which display plane among display planes 2 to 4 for each character display color. In FIG. 8, "F" is correction data generated by the character output device 6, "FC" is logical sum data of the correction data and character data stored in the character font ROM 8, and "C" is stored in the character font ROM 8. The character data "0" shown is all 0 data. When the text color 21 is set, data such as RGB data 22 is displayed on the display plane in the text part, but data such as RGB data 23 is displayed in the correction part of the text with a black background color. is set. That is, a color having a luminance less than half of the specified character color is set as a correction color. Here, the colors shown in the correction colors 24 are used as respective correction colors. This correction color may be changed for each display character color as shown in FIG. 8, or may be the same color for all character colors. Furthermore, if the character background color is not black, the character background color may be changed depending on the character color. In this case, it is preferable to use the intermediate tone between the text color and the background color as the correction color.

FIG. 11 shows a monochrome image 8 as shown in FIG.
A flowchart of correction color determination processing in the case of gradation is shown. First, the display colors are matched in gradation order in advance, and
” is assigned (301).Next, the character display color and background color are determined based on the user's specifications (30
2). Therefore, (character gradation + background color gradation) x (1/2)
A color close to the gradation value calculated in is determined as the correction color (30
3). In this way, the correction colors for each character color shown in FIG. 8 are determined.

As an example of character display, consider the process of displaying the character "5" when the displayed character color is "white". At this time, since the correction color is magenta from FIG. 8, the display data is transferred so that the character part is "white" and the correction part is "magenta". Therefore, the transfer device 7 transfers the character data of "5" as shown in FIG. 2(1) in the character font ROM 8 to the display planes 2 to 4, and the character output device 6 The correction data shown in is transferred to display planes 2 and 4. At this time, in this embodiment, character data and correction data are logically summed and transferred. As a result, characters as shown in FIG. 2(3) are displayed on the display screen. Note that after transferring the character data, the correction data may be transferred and the logical sum may be calculated on the display plane.

Next, FIG. 3 shows the correction data generation method.
This will be explained using FIG. In the case of the states shown in FIGS. 3 (1) to (4), that is, when a non-character part (background pixel) is located at a position where the diagonal line part of the character is interpolated, correction data is generated for the pixels 31 to 34. . FIG. 9 shows a flowchart of display data generation processing including generation of such correction data. First, regarding the dot (pixel) to be judged, check whether the pixel is part of the character (set as "1") or a background pixel (set as "0") based on the character font data. (101). If the target dot is part of a character (“1”), the dot is displayed in the corresponding character color (109). Here, "display" corresponds to writing display data to display planes 2 to 4. The same applies to the following cases. The target dot is a background pixel (
If it is “0”), check the dot to the left (102
). If this dot is "0", the process moves to step 105, and if it is "1", the dots above and below are checked (103, 104). If either of the dots is "1", the target dot is displayed in the corrected color (108). If both dots are "0", the dot to the right is checked (105). If this dot is "0", the process ends, and if it is "1", the dots above and below are checked (106, 107). If either of the dots is "1", the target dot is displayed in the corrected color (108). If both dots are "0", the process ends.

In the process shown in FIG. 3, each dot is displayed, but the judgment part (101 to 107) is repeated for the display access unit (1 byte, 1 word, etc.) before displaying. Good too.

Note that if correction data is generated for all points that meet the correction data generation conditions as shown in the flowchart of FIG. Put it away. Therefore, when the conditions shown in FIGS. 4 (1) to (4) are met, that is, the background pixel is determined to be adjacent to the intersection of a horizontal line and a vertical line with a length of 2 dots or more.
In the case of 44 points, no correction data is generated. A flowchart of display data generation processing for this purpose is shown in FIG. 10(a). In this flow, the determination portion (steps 102 to 107) in the flow of FIG. 9 is replaced with new determination portions 201 to 204. Here, as shown in FIG. 10(b), dots around the target dot are represented by A to H. When the target dot is "1", the target dot is displayed in the specified character color as in the case of FIG. 9 (109). When the target dot is “0”, its “B=
1 and D=1 and C=0 and F=0'', then (2
01), the target dot is displayed in the corrected color (108). Alternatively, if "B=1, E=1, A=0, and H=0" (202), display the target dot in the corrected color (1
08). Alternatively, if "E=1, G=1, C=0, and F=0" (203), the target dot is displayed in the corrected color (108). Alternatively, if "G=1, D=1, A=0 and H=0" (204), the target dot is displayed in the corrected color (108).

In other words, the determination parts 101 and 201 to 204 in FIG. 10 are based on whether the output bitmap data is a dot that is not a character, and one of the horizontally adjacent dots and one of the vertically adjacent dots. Among the dots that satisfy the dot character correction data condition that one dot constitutes a character, if the dot is determined to be adjacent to the intersection of a horizontal line and a vertical line, it is not considered character correction data. stipulates. In this example, a vertical line corresponds to a character consisting of two or more consecutive dots in the vertical direction, and a horizontal line corresponds to a character consisting of two or more consecutive dots in the horizontal direction. do.

The character output device 6 repeats the above-described determination for non-character parts, thereby producing the image shown in FIG. 2(2).
Correction data as shown in can be created.

[0025] In the above, the case where characters are output to a monochrome display device has been considered, but it is also possible to output characters to a color display device. For example, in a color display device that has four RGBI display planes and can display 16 colors, the I plane representing brightness is used as the correction plane, and the display character color is set to R.
The configuration allows selection from eight colors that can be expressed in GB3 planes. In a display device with such a configuration, character data is transferred to one of the RGB planes corresponding to the specified display character color and the I plane, and correction data is transferred only to one of the corresponding RGB planes. good. As a result, the text portion is displayed in a bright color, and the correction portion is displayed in a dark color.

Next, a method of changing the correction color depending on the angle of the diagonally lined portion forming the character will be explained. As an example,
Consider using the display device of FIG. 1 to output the character "i" with the character background color "black" and the character color "white". Figure 5(1) shows the underlying character data. The hatched portion of this character can be classified into two angles as shown in FIGS. 6(1) and (2).

First, consider the case of the angle shown in FIG. 6(1). Assuming that a diagonal line with an angle as shown by dotted line 61 is an ideal character outline, pixels 62 and 63 should be drawn as characters in 1/3 and 3/2 of the pixel area, respectively. Therefore, this drawing area is made to correspond to the brightness,
Colors with luminance of 1/3 and 2/3 between black and white are selected as the respective correction colors. That is, from FIG. 7, in the case of pixel 62, the correction color is "red", which has about 1/3 of the brightness of white, and in the case of pixel 63, "red", which has about 2/3 of the brightness of white, is used as the correction color.
"Green" is the correction color.

In the case of FIG. 6(2), similarly, since the area to be drawn is 1/2, magenta, which has about 1/2 the brightness of white, is used as the correction color. By changing the correction color according to the diagonal angle in this way, a display as shown in FIG. 5(2) can be obtained.

[0029] Furthermore, even when information in a character font ROM such as an outline font is processed and output on a character output device without being transferred to the display plane as is, the standard character output mode and character correction data are stored in the character output device. By providing this output mode, similar corrected characters can be output.

The method for outputting high-quality characters on a display such as an LCD has been described above, but if the output device has a dot matrix configuration, high-quality characters can also be output on, for example, a plasma display or various printers.

[0031] In the printer, in the case of a color printer, the "red, green, and blue" on the display is replaced with "cyan, magenta, and yellow", and in the case of a monochrome printer, halftones are realized by using a dither pattern, etc. By doing so, processing similar to that of a display is possible.

According to the embodiment described above, interpolated data of the intermediate color or intermediate luminance (gradation) between the character color and the character background color is displayed outside the diagonally shaded area of the character, so that the liquid crystal display with the dot matrix configuration is Even on a display device with clear pixel boundaries like this, the shaded areas appear smooth. In addition, the characteristics of the display device are utilized in the horizontal and vertical line portions, and clear boundaries can be maintained, resulting in the display of sharp, high-quality characters.

[0033] Also, even in display devices with low resolution,
Even in display devices where halftones are displayed in a pseudo manner by high-speed repetition of display/non-display rather than by the intermediate luminance output of the display device, since halftones are applied only to correction data with a relatively small area, There is no possibility that the entire screen will flicker.

[0034]

According to the present invention, since correction data is generated from character data by the above-described processing, a special pattern memory for correction data is not required, and the character font capacity does not increase.

Furthermore, the present invention can be applied to any type of font, such as dot fonts and outline fonts. In particular, in outline fonts, character contours are defined by vector data, so good correction data and correction color data can be obtained, and high-quality characters can be output.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of a display device for realizing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of character data representing "5", its correction data, and display data according to an embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining conditions for generating correction data according to the present invention.

FIG. 4 is a schematic diagram for explaining exclusion conditions of the correction data generation conditions of FIG. 3;

FIG. 5 is a schematic diagram showing an example of character data and display data representing the character “i” according to another embodiment of the present invention.

6 is a schematic diagram for explaining selection conditions for correction colors in the embodiment of FIG. 5; FIG.

FIG. 7 is an explanatory diagram showing color gradation conversion of a display driver.

FIG. 8 is an explanatory diagram showing data types transferred to each display plane according to an embodiment of the present invention.

FIG. 9 is a flowchart of display data generation processing according to the present invention.

FIG. 10 is a flowchart of another display data generation process according to the present invention.

FIG. 11 is a flowchart of a process for determining a correction color as shown in FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Monochrome display device, 2-4... Display plane, 5... Display driver, 6... Character output device, 7... Transfer device, 8... Character font ROM, 23... Display data type of the present invention, 24
...Examples showing correction colors of the present invention, 31 to 34...Correction data,
41-44...Points excluded from correction data.

Claims (7)

[Claims] Claim 1: In a character output method that outputs characters in a dot matrix configuration, correction that gives an intermediate color or intermediate brightness between the character and the character background to non-character-constituting dots that touch the diagonally shaded part of the character, based on character data. A character output method characterized by generating data and correcting output characters using the correction data. 2. Corresponding to the diagonal angle of the diagonal part of the character,
2. The character output method according to claim 1, wherein the degree of intermediate color or intermediate brightness is determined. Claim 3: When the output character is a character expressed in a bitmap format, the output bitmap data is not a dot that constitutes the character, and is vertically adjacent to one of the dots that are adjacent to each other in the horizontal direction. 2. The character output method according to claim 1, wherein dots that satisfy the condition that one of the adjacent dots is a dot constituting a character are displayed as character correction data in an intermediate color or intermediate brightness. 4. A claim characterized in that among the dots that satisfy the conditions of the character correction data, dots that are determined to be adjacent dots at the intersection of the horizontal line and the vertical line of the character are not subject to character correction. Character output method described in Section 3. 5. The horizontal lines of the characters are two consecutive horizontal lines.
5. The character output method according to claim 4, wherein the vertical line of the character is comprised of two or more dots that are continuous in the vertical direction. 6. A character output device for outputting characters in a dot matrix configuration, comprising: a plurality of planes for storing display data; and character data storage means for storing character data. Character correction data generation means for generating character correction data by the character output method according to item 5, and the character data or display data generated from the character data at a stage before or after being written on the plurality of planes. a display data correction means for correcting the display data using the character correction data. 7. The character output device according to claim 6, wherein one of the plurality of planes is used for storing the character correction data.