JP3099556B2 - Data converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data converter for converting outline data representing the outline of a character such as a character or figure into dot image data.

[0002]

2. Description of the Related Art Conventionally, when data representing characters, figures, and the like (hereinafter, simply referred to as characters) is processed using a computer and displayed in any form such as printing or display, the minimum processing unit is a pixel. It is widely performed to form dot data every time. At this time, if dot image data is created in advance for the entire character to be displayed and stored in a memory, an extremely large memory is required. Therefore, as described in Japanese Patent Publication No. 53-41017, the character is It is desirable to store the outline data as outline data and to convert the data into dot image data by a device equipped with a conversion device to dot image data at the time of display such as printing and display.

For this reason, the applicant of the present invention has previously described Japanese Patent Application No. 63-269074 and Japanese Patent Application Laid-Open No. 2-2544.
No. 91 has been filed.

The former assumes that the outline of a character is superimposed on a pixel screen that defines pixels, and finds intersections of a plurality of scanning lines parallel to the x-axis of the pixel screen and passing through the pixel center point with the outline of the character. This proposes a data conversion device that arranges dots corresponding to characters based on the intersections. In this case, the intersection is regarded as the intersection of the center point of the pixel closest to the actual intersection of the contour line and the scanning line, and two intersections are provided for each character constituting line constituting the character.
Each character is determined, and a character constituent line always exists between the intersections.

[0005] Therefore, the dot data of all the pixels located between the two intersections can be arranged all at once without having to judge whether or not a character constituent line exists. The outline data can be converted to dot data. However, when the outline does not intersect with the scanning line, for example, when the interval between the outlines is small and the constituent line or figure of the character is located between two adjacent scanning lines, the coordinates of the intersection are obtained. Since the dot data cannot be arranged, the displayed character has a discontinuity even though the contour line defining the character is continuous, and there is a problem that the quality is reduced.

The latter is an invention that solves the former problem,
A scanning line having a certain direction, for example, a scanning line parallel to the x-axis of the pixel screen is set and dot data converted by the former method, and a scanning line having another direction different from that direction, for example, y of the pixel screen This is a data conversion device which sets scanning lines parallel to the axis and converts the scanning data into dot data obtained by the logical sum of the dot data similarly converted by the former method.

According to this method, the intersection of the character outline with respect to each of the scanning line parallel to the x-axis and the scanning line parallel to the y-axis is calculated. A line may be located between two adjacent scan lines, but may intersect the other scan line. Therefore, if the dot data obtained from these two scanning lines are combined, a discontinuous point that occurs when the dot data is set based on the calculation of the intersection between one of the scanning lines and the contour line corresponds to that pixel. By setting the dot data to dot data based on the calculation of the intersection of the other scanning line and the contour line, the character is displayed as a continuous part, and the character can be displayed without generating a discontinuous part.

[0008]

However, the latter method described above, that is, the dot conversion in which the scanning lines in two directions are set, has a simpler processing procedure than the dot conversion in which the scanning lines in one direction are set. , The overall processing speed decreases. This has been problematic in devices such as printers and displays that require high-speed conversion of outline data to dot data.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and provides information indicating a condition for performing dot data conversion by two-directional scanning lines for each character.
If the conditions are met, dot data conversion is performed by two-directional scanning lines, and otherwise, dot data conversion is performed by one-directional scanning lines, so that processing can be performed at high speed without generating discontinuities. To convert the outline data into dot data.

[0010]

In order to achieve this object, a data conversion apparatus according to the present invention, as shown in FIG. 1, fills outline data with a raster scan method using scanning lines having a first direction. A first filling means 1 for generating one dot image data, and a second filling means 1 for generating a second dot image by filling outline data by a raster scan method using a scanning line having a second direction different from the first direction. And a filling means 2.
A simple conversion unit 3 which is a conversion unit that uses the first dot image data as a conversion result, and converts the third dot image data obtained by the logical sum of the first dot image data and the second dot image data into a conversion result. A data conversion device for converting outline data into dot image data by selecting one of the simple conversion means 3 and the detailed conversion means 4; A selection condition storage unit 5 for storing selection condition information, which is information defining a condition for selecting the detailed conversion unit for each character, and a character to be converted;
Determining means 6 for determining whether or not to select the detailed conversion means 4 in accordance with the selection condition information corresponding to the data, and if the determination means 6 determines that the detailed conversion means is to be selected, the detailed information There is provided a conversion means 7 for performing conversion using the conversion means 4 and performing conversion using the simple conversion means 3 in other cases.

[0011] Further, the data conversion device having the above-described configuration includes:
The selection condition information stored in the selection condition storage unit 6 is size information that is an output size of an upper limit character for selecting the detailed conversion unit 4 for each character,
The determination unit 6 checks the output size of the character currently being converted, and determines that the detailed conversion unit 4 is to be selected if the output size is smaller / less than the size information. It may be determined that the conversion means 3 is selected.

[0012]

The first filling means of the data conversion apparatus according to the present invention having the above-described configuration generates the first dot image data by filling the outline data by a raster scan method using a scanning line having a first direction. The two-painting means fills the outline data with a raster scan method using a scanning line having a second direction different from the first direction to generate a second dot image. Is the conversion result, and the detailed conversion means is the conversion means that uses the third dot image data obtained by the logical sum of the first dot image data and the second dot image data as the conversion result. Yes, one of the simple conversion means and the detailed conversion means is selected, and the outline data is converted to a dot image data. Converted to data, the selection condition storing means,
Storing selection condition information, which is information defining a condition for selecting the detailed conversion means for each character,
Determine whether to select the detailed conversion means according to the selection condition information corresponding to the character to be converted,
The conversion unit performs conversion using the detailed conversion unit when the determination unit determines that the detailed conversion unit is selected, and performs conversion using the simple conversion unit otherwise.

Further, the selection condition information of the data conversion device is size information which is an output size of an upper limit character for selecting the detailed conversion means for each character, and the determination means is currently converting. The output size of the character may be checked, and if the size is less than / less than the size information, it may be determined to select the detailed conversion means, and if the size is larger / larger than the size information, it may be determined to select the simple conversion means.

[0014]

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

FIG . 2 is a block diagram showing a portion of the control circuit of the laser printer to which the present invention is applied, which mainly generates dot data from outline data. The microcomputer unit 20 which forms the main part of the control circuit includes:
CPU 22, character ROM 23, program ROM
24, a text memory 25, a working memory 26, and a dot data memory 27. These CPUs 22
Are connected to each other via a bus 28. Further, an input device 29 and a printing device 210 are connected to the microcomputer unit 20 via a bus 28.

The input device 29 is for inputting data such as a character code supplied from the outside, designation of a character size, designation of italics, rotation, and the like.

The printing device 210 is a device for printing dot image data read from the dot data memory 27 by an electrophotographic method.

The program ROM 24 stores programs for performing various controls performed in this embodiment.

The text memory 25 stores data such as a character code input from the input device 29, designation of a character size, designation of conversion such as italics and rotation, and the like.

The working memory 26 temporarily stores data required when the CPU 22 executes a program.

The dot data memory 27 stores dot data converted from outline data.

The character ROM 23 stores character outline data. The data of this character can be read one character at a time, and the data of each character is composed of outline data and the upper limit size of detailed filling. The outline data is data of coordinate values representing the outline shape of the character.
The detailed fill upper limit size is data that defines the upper limit size for performing the detailed fill described later.

The process of converting outline data to dot data according to the present embodiment will be described below with reference to the flowchart of FIG.

In step S31, one character data is read from the character ROM 23. In step S32, outline data of the character data is read from the character ROM 23.
This is a process of performing coordinate conversion from the coordinate system stored in the OM 23 to a coordinate system on the pixel screen corresponding to the output size specified in the text memory 25, and performing coordinate conversion processing such as italic and rotation by affine transformation.

In step S33, the output character size specified in the text memory 25 is compared with the upper limit size of the detailed filling of the character data, and it is determined whether or not to perform the detailed filling process. That is, if the output character size is equal to or smaller than the detailed filling upper limit size, the result is YES, and otherwise the result is NO
Becomes According to this result, in the case of NO, the simple filling process of S34 is performed, and in the case of YES, the detailed filling process of S35 is performed. The simple painting process in S34 will be described with reference to FIG.

First, in step S41, outline data is converted into dot data by a raster scan method using scanning lines parallel to the y-axis of the pixel screen. Next, S4
In step 2, the dot data obtained in step S41 is stored in the dot data memory 27.

The detailed painting means in S35 will be described with reference to FIG.

First, in step S51, dot data is generated by a raster scan method using scanning lines parallel to the y-axis of the pixel screen. Next, in step S52, dot data is generated by a raster scan method using scanning lines parallel to the x-axis of the pixel screen. In step S53, dot data obtained by the logical sum of the two dot data obtained in steps S51 and S52 is generated. Finally, the dot data obtained in S53 is stored in the dot data memory 27 in S54.

The details of the conversion process from outline data to dot data by the raster scan method are described in detail since there are many known ones in which this technology has already been put into practical use and is not a main part of the present invention. Description is omitted.

In this embodiment, an example is shown in which the data converter of the present invention is applied to a laser printer. However, the present invention is not limited to this, and it is possible to output dot data from outline data to other types of printers and display devices. Any device can be applied.

In this embodiment, the information used for the determination in S33 is based on the character size. However, the present invention is not limited to this and can be changed.

In this embodiment, the character ROM 23
Although the upper limit size of the detailed filling is set in the above, it may be set in another independent memory.

In addition, various applications are possible without departing from the spirit of the present invention.

[0034]

As is apparent from the above description, according to the data conversion apparatus of the present invention, there is provided an apparatus for converting outline data to dot data which performs processing at high speed without generating discontinuous portions. Can be. In particular,
Conversion method to be executed based on different criteria for each character
The best conversion method for that character to judge and output
Is converted to dot data using
To maintain the output quality and speed up the conversion process under optimal conditions.
Can stand.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a block diagram of a microcomputer unit of the embodiment.

FIG. 3 is a flowchart of a conversion process from outline data to dot data according to the present embodiment.

FIG. 4 is a flowchart of a simple painting process according to the present embodiment.

FIG. 5 is a flowchart of a detailed filling process according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st filling means 2 2nd filling means 3 Simple conversion means 4 Detailed conversion means 5 Selection condition storage means 6 Judgment means 7 Conversion means

Claims (2)

(57) [Claims] 1. An apparatus for converting outline data, which is data defining the shape of the outline of a character, into dot image data by arranging dots inside the outline data and painting the outline data, wherein the outline data is converted into a first direction. First filling means for generating first dot image data by filling in a raster scan method using scanning lines having the same; and filling out outline data in a raster scan method using a scanning line having a second direction different from the first direction. A simple filling means, which comprises second filling means for generating a second dot image, and which is a converting means for converting the first dot image data into a conversion result; and a first dot image data and a second dot image data. Conversion of the third dot image data obtained by the logical sum of A data conversion device for converting outline data into dot image data by selecting one of the simple conversion means and the detailed conversion means, wherein the detailed conversion means is provided for each character. A selection condition storage unit that stores selection condition information that is information that defines a selection condition, and a determination that determines whether to select the detailed conversion unit according to the selection condition information that corresponds to the character to be converted Means, when it is determined to select the detailed conversion means by the determination means, performs conversion using the detailed conversion means, otherwise, conversion means that performs conversion using the simple conversion means A data conversion device comprising: 2. The data conversion apparatus according to claim 1, wherein the selection condition information is size information that is an output size of an upper limit character for selecting the detailed conversion unit for each character. The output size of the character being converted is checked, and if the size is less than / less than the size information, it is determined that the detailed conversion unit is to be selected. If the output size is larger / more than the size information, it is determined that the simple conversion unit is to be selected. A data conversion device characterized by the following.