JP2903531B2 - Data converter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data conversion device for converting outline data representing the outline of a character such as a character or a symbol into dot data, and more particularly to a data conversion device for converting a line constituting a character. It is about width correction.

2. Description of the Related Art When data representing characters such as characters and symbols are processed using a computer and displayed in any form such as printing or display, it is widely used to form dot data for each pixel, which is the minimum processing unit. Have been done. At this time, if dot data is created in advance for all the characters to be displayed and stored in the memory, an extremely large memory is required, so that the character is defined by the outline as described in JP-B-53-41017. It is desirable that the data is stored as outline data representing the image data and converted to dot data by a device including dot data setting means at the time of display such as printing and display.

To convert the outline data into dot data, a pixel screen is used. The pixel screen defines pixels by a plurality of X direction defining lines and Y direction defining lines parallel to the X axis and the Y axis orthogonal to each other in one plane, and the dot data setting means includes: When the outline of the character is superimposed on the pixel screen,
The dot data corresponding to the pixel whose outline includes a portion equal to or more than a predetermined reference is set as existence data representing the existence of a dot.

However, when outline data is converted to dot data and a character is displayed in this manner, even if the character is composed of the same line depending on the position where the character is displayed, a certain standard is set inside the line. If the number, position, etc. of the pixels included are different, the width of the character constituting line, that is, the number of pixels included in the width direction in two outlines defining the character constituting line in the width direction is always the same. Not necessarily. The width of the character composition line is determined by the size that the character is displayed with good appearance when designing the designer, but the width of the character composition line differs depending on the display position, and if the expected width can not be obtained In this case, the balance of the entire character is lost, and the appearance is deteriorated. In addition, when the character constituent line is an inclined line or a curve inclined with respect to the X-axis direction and the Y-axis direction of the pixel screen, the state in which one character constituent line is superimposed on the pixel screen is partially different. The width is often partially different, and it is not easy to display with good appearance.

An object of the present invention is to provide a data conversion device that can convert outline data into dot data so that the width of a character constituent line that is actually displayed is close to the width determined by the outline data. It was done.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention, as shown in FIG. 1, sets the outline of a character represented by outline data in the X-axis direction and the Y-axis direction, which are orthogonal to each other. When it is assumed that pixels are superimposed on a pixel screen that defines pixels by a plurality of X-direction definition lines and a plurality of Y-direction definition lines that are parallel to each other, the dot data of the pixels corresponding to the character configuration lines forming the character are represented by dots. A data conversion device for converting the outline data into the dot data, comprising: (a) defining the character constituent line;
A target line width which is an interval in a direction parallel to one of the X-direction defining line and the Y-direction defining line of the book outline, and a character constituent line thereof are formed based on the existence data. Target line width / display line width comparing means for comparing each of the plurality of one specified lines with the display line width displayed by the dot, and (b) the target line width / display line width comparing means. As a result of the comparison, for each of the one specified line, when the target line width is larger than the display line width by the first set value or more, the presence data increase that increases the number of the presence data, and the display line width is more than the target line width. A gist of the invention is to provide line width correction means for performing at least one of the existing data reduction for reducing the number of existing data when the value is larger than the second set value and reducing the difference between the target line width and the display line width. Things.

Action and Effect The target line width, which is the distance between two outlines defining the character constituent line in the direction parallel to the X-direction defining line or the Y-direction defining line, is a line width capable of displaying the character with good visibility. Usually, a slight difference occurs between the target line width and the display line width whose size depends on the dot shape, size, and the like. Accordingly, by setting a set value and correcting the display line width when the difference between the target line width and the display line width is larger than the set value so that the difference between the target line width and the target line width becomes small, The constituent lines can be displayed with a width close to the target line width. In particular, in the present invention,
A target line width which is an interval in a direction parallel to one of the X-direction definition line and the Y-direction definition line of the two contour lines defining the character constituent line, and a display line width displayed by dots. Are compared by the target line width / display line width comparing means for each of the one prescribed line, and the display line width is corrected for each of the one prescribed line by the line width correcting means based on the comparison result. Therefore, it is possible to display even portions such as inclined lines and curves with a uniform width, and display quality can be improved.

Embodiment Hereinafter, a case where the present invention is applied to a device that converts outline data into dot data in a laser printer will be described in detail with reference to the drawings.

FIG. 2 is a diagram mainly showing a part related to data conversion in a control circuit of the laser printer. The microcomputer unit 10, which is a main component of the control circuit, includes a CPU 12, a character ROM 14, a program ROM 16, a text memory 18, a working memory 20, a dot data memory 22, and a target coordinate memory.
24, a display coordinate memory 26, and a pixel designation memory 27.
These CPUs 12 and the like are connected by a bus 28.
Is connected to an input device 30 and a printing unit 32. The input device 30 is for inputting necessary data to the microcomputer unit 10, and the printing unit 32 is for inputting necessary data to the microcomputer unit.
This is a part for performing printing by a laser printing method based on a command from 10. Oh, the resolution of this laser printer is
30 dots / inch.

As shown conceptually in FIG. 3, the CPU 12 is provided with a data reading unit 36, a line width correcting unit 38 for correcting the line width, a data setting unit 40 for setting the dot data to presence data representing the presence of a dot, and the like. Have been. The text memory 18 stores document data composed of code data input from the input device 30, and the working memory 20 stores data necessary for executing a program. Further, the dot data obtained by the setting of the data setting unit 40 is stored in the dot data memory 22, and the intersection of the contour defining the character constituting line and the pixel defining line of the pixel screen described later is stored in the target coordinate memory 24. The coordinates are stored. further,
The display coordinates memory 26 stores the coordinates of both ends (not the coordinates of the pixel center but the coordinates of the ends of the pixels) of the column of the pixels displaying the character constituent lines on each pixel defining line. A number that has the coordinates stored in the memory 26 and specifies the position of the pixel that displays the character constituent line is stored.

The character ROM 14 stores outline data of characters such as alphabets and other characters and symbols. As shown in FIG. 5 by taking the alphabet “U” as an example, the character is composed of one or more character constituent lines 44.
(Consider that the character configuration line of U is one.)
Each character constituent line is defined by two outlines 46 in the width direction and the length direction, respectively, and the outlines 46 are gathered to form the outline of the character. As shown in FIG. 5, the coordinate plane for determining the outline of the character has a vertical (Y-axis) and horizontal (X-axis) of 1000 × 10
00 and the capital letter of the alphabet is Y
Axis coordinates are drawn between 200 and 1000, and lowercase letters are drawn between 0 and 200. When a contour of a character is designed on such a coordinate plane, outline data is created for each line element connecting points indicated by black circles in the outline of the outline, and the type of the line element and both ends. , And one contour line may be composed of two or more line elements. The coordinates of these points are sequentially stored along a fixed direction (indicated by an arrow in the figure) defined on the contour line. Of the two points at both ends of each line element, the point stored first is The starting point, and the point stored later is the end point. The outline data includes straight line data (code data indicating that it is a straight line) when the line element is a straight line, and coordinates indicating the start point and end point, and data indicating that the line element is a curve when the line element is a curve. It includes the function formula of the curve and the coordinates of the starting point, the ending point, and the auxiliary point. In the case of an arc, it includes data indicating the arc and the coordinate data of the starting point, the ending point, and the center point of the circle. Character RO
M14 also stores the number N of line elements for each character.

In this laser printer, the conversion of outline data into dot data is performed using the pixel screen 52 shown in FIG. 6 and assuming that the outline of the character is superimposed on the pixel screen 52. The pixel screen 52 is a computational one for converting outline data to dot data, but is shown here as an actual one for easy understanding. The pixel here is a minimum printing unit when printing is performed by the laser, and the pixel screens 52 are orthogonal to each other in one plane, and are respectively parallel to the X-axis direction and the Y-axis direction. , Pixels are defined by a plurality of pixel section lines p (shown by solid lines in the figure) provided at equal intervals, and the pixels are square in this embodiment. Further, x, which passes through the pixel center point and is parallel to the X-axis direction and the Y-axis direction, respectively.
A direction defining line x and a y-direction defining line y (shown by a broken line in the figure) are set. A coordinate value indicating a position on the pixel screen 52 is attached to the pixel dividing line p, and the positions of the x-direction defining line x and the y-direction defining line y can be represented by a Y coordinate value and an X coordinate value, respectively. The dot data for printing or not is created for each pixel, but in this laser printer, a dot is formed at a pixel including the pixel center point in the outline of the character, and the dot of that pixel is formed. The data is set to 1. Note that the pixel may have a rectangular shape or another shape.

The pixel screen 52 is supposed to correspond to the printing surface of the printing paper, but FIG. 6 shows only one character for easy understanding. Therefore, in the entire pixel screen 52, the coordinate values actually assigned to the pixel dividing lines p, x direction defining line x, y direction defining line y are obtained by adding appropriate integers to the values given in FIG. Although it is a value, here, only one character is considered.

In addition, this laser printer can display characters of 4.8 points, 10 points, 12 points, 20 points, 24 points, and 30 points.
Printing can be performed in any size such as points, and the number of pixels constituting one character differs depending on the printing size, and the value on a 1000 × 1000 coordinate plane corresponding to one side of one pixel differs. Assuming that a character at a certain point is represented by C × C pixels, one side of one pixel is equivalent to 1000 / C, and assuming that one scale of the pixel screen 52 is 1000 / C, superimposition of the outline of the character is performed. Done. Here, a case in which one character performs printing at 4.8 points represented by 20 × 20 pixels will be described. In this case, one graduation on the pixel screen 52 corresponds to 50 on the 1000 × 1000 coordinate plane, and the pixel division line p of the pixel screen 52 in FIG. 6 is assigned a value on the 1000 × 1000 coordinate plane. ing. The value assigned alongside the scale value is a number that designates the position of each pixel on the entire pixel screen 52. One pixel is assigned as 1, and the position in the X-axis direction is designated. The position of the pixel on the pixel screen 52 can be specified by a combination of the number and the number specifying the position in the Y-axis direction. For example, a pixel defined by a pixel division line p having an X coordinate value of 100 or 150 and a pixel division line p having a Y coordinate value of 100 or 150 can be specified by (2,2). When the outline of the character is superimposed on the pixel screen 52, the coordinate value of the reference point of each character on the pixel screen 52 is also determined based on the print position data, and the coordinate value of the obtained reference point is calculated. Superposition is performed using the above.

As described above, since the position of the character outline on the pixel screen 52 is affected not only by the size of the character but also by the printing position, the number of pixels for displaying the character configuration line changes even for the same character configuration line. May occur. In this laser printer, the width of the character configuration line in the direction parallel to the X axis is a width, and if dots formed in one pixel are represented by circles, then two characters of the alphabet “U” as shown in FIG. The outline of the arm is designed so that its width is displayed in the same size, but the width may be different at the time of printing. In the case of a line inclined with respect to the X-axis and the Y-axis as shown by a curve 54 in FIG. 6, even if the width is designed to be the same in the length direction, a circle (open circle) In some cases, the widths of the character constituent lines printed by the dots represented by are partially different.

On the other hand, in the present laser printer, the character constituting lines can always be printed with a width corresponding to the width defined by the outline, and the program ROM 16 stores the line width shown in the flowchart in FIG. Various programs necessary for printing are stored, including a data conversion program having a correction function. Hereinafter, the conversion of the outline data into the dot data will be described using the curve 54 in FIG. 6 as an example. The conversion of outline data to dot data in this laser printer is as follows:
This is performed by obtaining the positions of the pixels at both ends of the pixels displaying the character constituent line in the width direction, and setting dot data corresponding to the pixels between the pixels (including both end pixels) to 1 at a stroke. Is the Japanese patent application filed by the applicant
This is the same as the data conversion device described in JP-A-63-269074. Further, printing is not indispensable for understanding the present invention, and therefore detailed description is omitted. However, in this laser printer, printing is performed for each page. Data for one page is read out of the document data stored in the text memory 18, and outline data of a large number of characters corresponding to the data is converted into dot data and printed.

First, in step S1 (hereinafter abbreviated as S1; the same applies to other steps), the outline data of the character, the number N of line elements, and the x-direction defining line x
After reading the number S (this number S is stored in association with the print size and is 20 when the print size is 4.8 points), one of the line elements and the x-direction The X coordinate of the intersection with the line x is calculated and stored in the target coordinate memory 24. This calculation is performed as shown by the arrow
The process is performed from the start point to the end point of the outline forming 54. The intersection is a point indicated by a black circle in the figure, and the X coordinate of the intersection is Y representing the position of the x-direction defining line x as shown in FIG.
It is stored corresponding to the coordinates. As shown in FIG. 12, when the end point of the line element of the character constituent line 56 and the start point of the line element for which the next intersection is to be found are exactly on the x-direction defining line x, the X coordinate of the same intersection is 2 Are stored. The X coordinate of the intersection is calculated two by two for each character constituent line, and the X coordinate of the intersection is calculated for one line element.
Once the coordinates have been calculated, n is incremented by 1 in S3, and then a determination is made in S4 as to whether or not the calculation of the intersections has been completed for all the line elements. Execution returns to S2.

If calculating the intersection of all the line elements of a single character has been completed, after the n ₁ is 0 at S5, and X coordinates stored in the target coordinate memory 24 is rearranged in the ascending order in S6, The pairs are arranged in pairs starting from the smallest one. The X coordinate of the intersection is obtained for each line element,
In S2, since the X coordinate values are stored in the memory 24 in the order in which they were obtained, the X coordinate value may be obtained before the smaller line element for the larger line element. They are lined up and can be rearranged in ascending order. X direction definition line x for one character constituent line
Since two target coordinates are obtained for each, if the X coordinates of the intersections are rearranged in ascending order and paired two by two, a character constituent line always exists between the two X coordinate values. The difference is each x between the two contour lines of the character constituent line.
It represents the interval on the direction defining line x, that is, the width. Hereinafter, the X coordinate of the intersection of the line element and the x-direction defining line x is referred to as a target coordinate, and the difference between the two target coordinates is referred to as a target line width.

Next, in S7, display coordinates are calculated based on the target coordinates. The display coordinates are the coordinates of the outer ends of the dots at both ends of the dot row that displays the curve 54 on one x-direction defining line x, and are the closest to the target coordinates among the pixel division lines p parallel to the Y axis. The coordinates of the nearby pixel division line p are obtained as display coordinates. The point of intersection between the pixel division line p at which the display coordinates are determined and the x-direction defining line x is indicated by a cross.

The display coordinates obtained in this way are stored for each x-direction defining line x as shown in FIG. Target coordinates are curves
Since two display coordinates are obtained for each of the 54 and the display coordinates are obtained based on each of the target coordinates, the difference between the two display coordinates from the smallest one indicates that the width of the curve 54 is actually displayed. Become. This width is called a display line width. When the display coordinates have been calculated for all the target coordinates, the difference between the target line width and the display line width is calculated for each x-direction prescribed line x in S8. After the smaller value is subtracted from the larger value of the target coordinate pair to determine the target line width, and the smaller value is subtracted from the larger value of the display coordinate pair to determine the display line width. , The target line width is subtracted from the display line width, and the difference is obtained, and this difference is stored in the working memory 20 together with the sign.

Subsequently, in S9, it is determined whether or not the absolute value of the line width difference is equal to or larger than a set value. In the present embodiment, the set value is set to 25, which is one half of the coordinate value of one side of one pixel. By comparing the absolute value of the line width difference with the set value, the target line width and the display line are compared. Common setting value regardless of which width is larger
25 determines whether or not the line width needs to be corrected. If the set value 25 is both the first set value and the second set value, and the absolute value of the line width difference is smaller than the set value, the line width difference is within an acceptable range and no correction is performed. If so, the display line width is corrected in S10.

The target line width and the display line width obtained for the x-direction defining line x in which the Y coordinate of the curve 54 is 175 and 225, respectively, will be described as an example. The target coordinates obtained for the x-direction defining line x of Y coordinate 175 are 190,330, the display coordinates are 200,350, the target line width is 140, the display line width is 150, and the absolute value of the difference is smaller than the set value, No line width correction is made.

On the other hand, for the x-direction defining line x with the Y coordinate value of 225, the target coordinates are 180,315 and the display coordinates are 200,300,
Since the target line width is 135 and the display line width is 100, and the absolute value of the difference between the target line width and the display line width is larger than the set value, the display line width is corrected. This correction is performed by correcting the display coordinates. Of the two target coordinates and display coordinates,
The difference between the smaller coordinates and the larger coordinates is determined, and the display coordinates with the larger absolute value of the difference are corrected. The value of the display coordinates is increased or decreased, and whether the value is increased or decreased depends on which of the display line width and the target line width is larger. If the sign of the line width difference stored in S8 is read out and the sign is negative and the display line width is smaller than the target line width, and if the smaller display coordinate is to be corrected, the smaller the X coordinate, the smaller the X coordinate. Is corrected to the X coordinate of the pixel division line p in the Y-axis direction adjacent to. If the larger display coordinate is to be corrected, the X coordinate is corrected to the X coordinate of the pixel division line p in the Y-axis direction adjacent to the larger X coordinate. on the other hand,
If the smaller display coordinates are to be corrected when the display line width is larger than the target line width, the smaller display coordinates are corrected to the X coordinate of the pixel division line p in the Y-axis direction adjacent to the larger X coordinate side. If the coordinates are to be corrected, the coordinates are corrected to the X coordinate of the pixel division line p in the Y-axis direction adjacent to the side having the smaller X coordinate. If the difference between the smaller coordinate and the larger coordinate is the same, any of the display coordinates may be corrected, but here, the smaller display coordinate is corrected.

Looking at the target coordinates 180 and 315 and the display coordinates 200 and 300 obtained for the x-direction defining line x of Y coordinate 225, the absolute value of the difference between the smaller coordinates is larger, and the display line width is larger than the target line width. Due to the small size, the display coordinates 200 are modified to 150, thereby increasing the display line width by one pixel. In the present embodiment, the setting value is set to one half of the coordinate value of one side of one pixel because the display line width is increased or decreased by one pixel by correcting the display coordinates. If it is smaller than one half, the amount of increase / decrease due to the correction of the display coordinates is larger than the difference between the target line width and the display line width. is there. If the set value is set to one half of one side of one pixel, the amount of increase or decrease of the line width due to the correction of the display coordinates is equal to or less than the line width difference, and the correction does not increase the difference. If a plurality of character constituent lines intersect with the same x-direction defining line x and the target coordinates and the display coordinates are each calculated as an even number larger than two, the line width difference is calculated in ascending order from the smallest one. It is performed between individual coordinates, and when the presence or absence of line width correction is determined in S9, if there is at least one coordinate whose line width needs to be corrected in one x direction defining line x, S9 becomes YES, Necessary modifications are made.

If it is determined whether or not the display line width has been corrected and corrected for one x-direction defining line x, n _{2 in} S11.
Is incremented by 1, a determination is made in S12 as to whether or not the display line width has been corrected and whether or not the display line width has been corrected for all the x-direction prescribed lines x. This determination is NO, and the program proceeds to step S12. Execution returns to S8. Hereinafter, S8 to S12 are repeatedly executed until S12 becomes YES.

S12 in S13 if the is YES, with n ₂ is 0, the number specifying the position of the pixel of a dot data to 1 based on the display coordinate are determined. As described above, the display coordinates are the X coordinates of the pixel division line p parallel to the Y axis.
If the X coordinate is obtained for the smaller target coordinate of the target coordinates treated as a pair two by two, a pixel division line p having the X coordinate and an X
The number of the pixel defined by the pixel division line p adjacent to the side having the larger coordinate is the number specifying the position in the X-axis direction of the pixel for which the dot data is set to 1. For the larger display coordinates, the pixel division line p having the display coordinates and the pixel division line p in the Y-axis direction adjacent to the pixel division line p on the side where the X coordinate is smaller than the pixel division line p. The number is the designated number in the X-axis direction. This number is stored for each x-direction defining line x. In this case, as shown in FIG. 10, the x-direction defining line x is represented by a number designating the pixel that includes it in the Y-axis direction. The position of the pixel on the pixel screen 52 can be designated from the position of the x-direction defining line x in the Y-axis direction and the position of the display coordinates in the X-axis direction. Thus, the pixel numbers obtained from the two display coordinates specify the positions of the pixels at both ends of all the pixels that display the curve 54 in the width direction.
With respect to the x-direction defining line x having the Y coordinate of 225, the position designation number of the corrected display coordinate is obtained, and thereby the number of the pixel forming the dot indicated by the hatched circle in FIG. 6 is obtained. A dot is formed for the pixel, and this portion of the curve 54 is displayed with a width close to the target line width.

When the display line width is larger than the target line width by a set value or more, the line width is corrected as follows, and the designated number of the pixel for setting the dot data to 1 is obtained. In the character configuration line 58 shown in FIG. 11, the target coordinates of the x-direction defining line x with the Y coordinate of 325 are 315,380, the display coordinates are 300,400, the target line width is 65, the display line width is 100, and two Of the display coordinates, 400 having the larger absolute value of the difference from the target coordinates is corrected to 350. From the display coordinates 300 and 350, the designation number of the pixel for which the dot data is set to 1 is two, and two dots are obtained. As a result, a dot indicated by a hatched circle is not printed, and the width of the character constituting line 58 is the same by one dot. It will be printed in the size.

In the case of the character constituent line 56 shown in FIG. 12, two identical values are obtained as the target coordinates, and the display coordinates are obtained for each of them. Since the same coordinates are set as two display coordinates, the display line width and the target line width are both 0, S9 becomes NO, and the display coordinates are not corrected. When the two display coordinates have the same value, the number designating the position of the pixel for which the dot data is set to 1 designates the position of the pixel on the side where the target coordinates are located with respect to the display coordinates. And two designated numbers of the pixel are stored.

Further, as shown in FIG. 13, when the character constituting line 60 is parallel to the Y axis and is located with the y direction defining line y interposed between two adjacent pixel dividing lines p, 1 One pixel is defined, and the X coordinates of two pixel division lines p parallel to the Y axis are respectively set as display coordinates. In this case, if the width of the character constituent line 60 is larger than 25, S9 becomes NO and the line width is not corrected, but if the width is 25 or less, the difference between the target line width and the display line width is set value. As described above, the line width is corrected.
One of the two display coordinates is corrected so that the display line width is shortened. However, the two display coordinates have the same value, and the number specifying the position of the pixel for setting the dot data to 1 is , A number specifying the position of the pixel on the side where the target coordinates are located with respect to the display coordinates.

As shown in FIG. 14, when the character constituting line 62 is parallel to the Y axis and is located between two adjacent y direction defining lines y, it is located between the y direction defining lines y and Are stored as the display coordinates. In this case, if the target line width is smaller than 25, S9 becomes NO, the display coordinates are not corrected, and the position designation number of the pixel for setting the dot data to 1 is such that the target coordinates are on one side of the pixel division line p. When the target coordinates are located on both sides of the pixel division line p, the target coordinates are set to the number of the pixel where the target coordinate is located. When the distance between each of the two target coordinates and the pixel division line p is the same, the number is one of the two pixels defined by the pixel division line p having the display coordinates. . On the other hand, if the target line width is larger than 25, S9 becomes YES and the display line width is corrected. However, since the two target coordinates are located on both sides of the pixel division line p, the distance from the pixel division line p is The display coordinates are corrected to the X coordinate of the pixel division line p on the side where the larger target coordinate is located. If the distance from the pixel division line p is the same, the coordinate is corrected to the X coordinate of the pixel division line p on one of the pixels.

If the numbers specifying the pixel positions have been calculated for all the x-direction defining lines x, dot data is set in S14. This setting is performed by setting the dot data of the pixels located between the two numbers in ascending order of the pixel designation numbers stored in the pixel designation memory 27 to one at a time. The data is stored in the dot data memory 22. The dot data of the pixel specified by the pixel specification number is also set to 1.

This setting is performed collectively in units of one byte. The microcomputer unit 10 can process 1-byte data in parallel. Since dot data of one pixel is represented by one bit, dot data of eight pixels are set at a time. In this setting, the two pixel designation numbers forming a pair are separated on a byte-by-byte basis on the basis of the coordinates of the bits that separate one byte (the coordinates of the bits that separate adjacent bytes). And the dot data corresponding to the pixel where the character exists are set to 1 collectively.

A description will be given based on FIG. 15 by taking, as an example, the pixel designation number obtained for the x-direction defining line x whose position in the Y-axis direction is 4. Note that this number represents the actual position of the pixel on the pixel screen 52. First, two number pairs (3,
The coordinate 7 of the bit, which is larger than the smaller number among 5) and forms a 1-byte delimiter, and the larger pixel designation number 5 are compared. Since the pixel designation number is smaller, the character configuration line represented by this number pair is included in one byte, and the dot data respectively corresponding to the pixel designation numbers 3 and 5 are collectively set to 1. In FIG. 15, a hatched circle represents dot data set to 1. If the larger one of the two pixel designation numbers is larger than the one-byte separating coordinate, the pixel between the separating coordinate and the smaller pixel specifying number is included in one byte. That is, they are collectively set to 1, after which the number of groups having 8 as one unit is calculated in the remaining numbers, and dot data is set for each byte.

As described above, in the data conversion apparatus according to the present embodiment, the number of display pixels is corrected by comparing the actual width when the character constituent line is printed with the width between the contour lines, which is the expected width. Since the lines are displayed with a width close to the expected width, the same character component line may differ in width depending on the printing position, or the width of one character component line may differ partially Disappears, and characters can be printed with good visibility.

The data that needs to be given in advance to correct the line width are character outline data, the number N of line elements, and the number S of pixel defining lines. The amount of stored data can be reduced as compared with the case where the data is given in advance.

As is apparent from the above description, in the present embodiment, the portion of the program ROM 16 that stores S13 and S14 and the data setting unit 40 constitute dot data setting means,
The portion of the program ROM 16 that stores S2 to S9 and the line width correction unit 38 of the CPU 12 constitute a target line width / display line width comparison unit,
The portion that stores S10 of the program ROM 16 and the line width correction unit 38 of the CPU 12 constitute a line width correction unit.

In the above embodiment, the first set value and the second set value for determining whether to correct the display line width are set to the same value, but may be set to different values.

Further, in the above embodiment, the line width is corrected both in the case where the display line width is larger than the target line width by the set value or more, and in the case where the target line width is larger than the display line width by the set value or more. Alternatively, the line width may be adjusted only in one of the cases.

Further, the line width may be corrected only when the print size is 12 points or less.

Further, the setting of the dot data is not limited to finding the positions of the pixels at both ends of the pixel displaying the character constituent line in the width direction, and setting the dot data to one at a time. Dot data corresponding to a pixel satisfying a certain criterion such as
The presence data may be set one by one. In this case, the line width is corrected after setting the dot data.

Further, in the above embodiment, X of the pixel screen 52
The axis direction is set to the width direction, and the line width of the character component line is corrected. However, the Y axis direction may be set to the width direction, and the line width of the character component line may be corrected.
It may be performed together with the correction of the axial width.

Further, when the difference between the target line width and the display line width is still equal to or greater than the set value as a result of correcting the display coordinates, the display coordinates may be further corrected. Note that even in the above case, it is not always necessary to make all the corrections necessary to make the difference between the target line width and the display line width smaller than the set value. Once correction is made, a display line width closer to the target line width can be obtained than when no correction is made at all, and display quality can be improved.

Furthermore, the outline data may be configured by other means, such as by expressing only the coordinates. When represented only by coordinates, for a character composed of a plurality of straight lines, outline data is composed of a group of coordinate data for each line element of the contour, and for a character including a curve, the outline data is necessary to define the curve. The outline data is configured to include a coordinate data group of a plurality of points.

Further, the present invention can be applied not only to a printer other than a laser printer but also to an apparatus which needs to convert outline data of characters such as characters and symbols into dot data in addition to the printer. can do.

Although not specifically exemplified, the present invention can be implemented in various modified and improved embodiments based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing the configuration of a data conversion device according to the present invention. FIG. 2 is a block diagram showing a control circuit of a laser printer having a data converter according to one embodiment of the present invention. FIG. 3 is a diagram conceptually showing a CPU constituting the control circuit. FIG. 4 is a flowchart showing a data conversion program among the programs stored in the program ROM of the control circuit. Fifth
The figure shows the outline of the letter "U". Sixth
The figure is a diagram showing a curve converted by the data conversion device overlaid on a pixel screen. FIG. 7 is a diagram showing the letter "U" overlaid on the pixel screen.
FIG. 8 shows the target coordinates obtained for the curve of FIG.
It is a figure showing and showing for every direction regulation line x. FIG. 9 is a table showing the display coordinates obtained for the above-mentioned curve for each of the x-direction defining lines x. FIG. 10 is a table showing the designation numbers of the display pixels obtained for the above-mentioned curves in a table for each x-direction defining line x. FIG. 11 is a diagram for explaining the correction for shortening the display line width. FIG. 12, FIG. 13 and FIG. 14 are diagrams for explaining the calculation of the target coordinates, the display coordinates, and the designated numbers of the display pixels of the character constituent lines. FIG. 15 is a diagram for explaining setting of dot data performed based on the designated number of the display pixel. 1: Microcomputer 44: Character composition line, 46: Contour line 52: Pixel screen, 54: Curve 56, 58, 60, 62: Character composition line x: x direction regulation line, y: y direction regulation line p: pixel section line

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G09G 5/24-5/28

Claims (1)

(57) [Claims] 1. A pixel defining a contour of a character represented by outline data by a plurality of X-direction defining lines and a plurality of Y-direction defining lines parallel to each other in an X-axis direction and a Y-axis direction orthogonal to each other. Provided is a dot data setting unit that sets dot data of a pixel corresponding to a character configuration line configuring a character to presence data representing the presence of a dot, assuming that the character is superimposed on the screen,
In a data conversion device for converting outline data into dot data, the X of two contour lines that define the character constituent line
A target line width which is an interval in a direction parallel to one of the direction defining line and the Y direction defining line, and a display in which the character constituent line is displayed by dots formed based on the existence data. A target line width / display line width comparing means for comparing the line width with each of the plurality of one specified lines; and a result of the comparison by the target line width / display line width comparing means. For each, the presence data increase to increase the number of existing data when the target line width is larger than the display line width by the first set value, and the presence data increase when the display line width is larger than the target line width by the second set value or more. A line width correcting means for performing at least one of the existing data reduction to reduce the difference between the target line width and the display line width.