JP2861201B2 - Data converter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data conversion device that converts outline data representing the outline of a character such as a character or a symbol into dot data.

[Prior Art] Conventionally, this type of data conversion apparatus has divided a contour of a character such as a character or a figure into a plurality of contour elements,
Corresponds to the input character code from a storage device in which type data indicating whether the demarcated outline element is a straight line element or a curve element and character data including a start point, an end point, and a control point of each outline element are stored for each character. The outline data is created by reading character data to be converted, the outline data is converted into dot data, and the dot data is output to an output device such as a laser printer.

When creating outline data, the curve elements are reproduced using one curve function (for example, a cubic Bezier function) regardless of the type of characters such as kanji, hiragana, katakana, and ANK characters.

[Problems to be Solved by the Invention] By the way, the outline shape of Chinese characters is Hiragana, Katakana, ANK
Since the curvature is large compared to characters, high-quality outline data can be obtained even when reproduced with a low-order curve function, but since a high-order curve function similar to ANK characters etc. is used, one curve element There is a problem that one or more control point data is required, the amount of character data is increased, and it takes time to reproduce a curved portion.

The present invention reduces the amount of character data by adding, to character data, order data indicating the order of a curve function that reproduces the contour curve portion, and reproducing the contour curve portion based on the order data. It is an object of the present invention to provide a data processing device capable of shortening the time required to reproduce a curve portion using a curve function.

[Means for Solving the Problems] In order to solve the above problems, a data conversion device according to the present invention divides a contour of a character such as a character or a figure into a plurality of contour elements, and extracts a curved portion in the divided contour elements. Character data storage means for storing a large number of character data consisting of order data indicating the order of a curve function for reproduction and coordinate data indicating the position of each contour element, and memory means for storing a plurality of curve functions having different orders. The character data corresponding to the input code is read out from the character storage means, and the curve portion of the contour element is reproduced by the curve function of the degree indicated by the degree data in the character data, and the character corresponding to the input code is reproduced. -By outline data creating means for creating outline data such as figures, and the outline data creating means Data conversion means for converting the created outline data into dot data.

[Operation] In the data conversion device having the above configuration, the outline data creation means reads out character data corresponding to the input character or graphic code from the character storage means, and outputs the degree indicated by the order data in the character data. The curve function of each contour element is reproduced by the curve function of (1), outline data such as characters and figures corresponding to the input code is created, and the data conversion means converts the outline data created by the outline data creation means into dot data. Convert to

Embodiment Hereinafter, a case where the present invention is applied to an apparatus for converting outline data into dot data in a laser printer will be described in detail with reference to the drawings.

FIG. 1 is a diagram mainly showing a part related to data conversion in a control circuit of a 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 short vector data memory 24. The CPU 12 and the like are connected by a bus 26, and an input device 28 and a printing unit 30 are connected to the bus 26. The input device 28 is for inputting necessary data to the microcomputer unit 10,
The printing unit 30 is a unit that performs printing by a laser printing method based on a command from the microcomputer unit 10. The resolution of this laser printer is 300 dots / inch.

As shown conceptually in FIG. 2, the CPU 12 includes a data reading unit 32, an outline data creating unit 34 for creating outline data from character data, a data converting unit 36 for converting outline data into dot data, and the like. ing.

The text memory 18 stores code data input from the input device 28, and includes a working memory.
Numeral 20 temporarily stores data necessary for executing the program. Also, short vector data memory
Reference numeral 24 stores outline data composed of a set of short vectors created by the outline data creation unit 34, and dot data obtained by conversion by the data conversion unit 36 is stored in the dot data memory 22.

The character ROM 14 constitutes a character data storage unit, and stores character data of characters such as alphabets and characters such as symbols. As shown in FIGS. 3 (a) and 3 (b), the character data includes order data 141 indicating the order of the curve function to be used to reproduce the curved portion of the character outline, and character outline. Type data 142 indicating whether the contour element divided into a plurality is a straight line or a curve, and a start point P0 and an end point P1 when the contour element is a straight line.
And the start point P0 and end point P1 and one or two control points P2 and P3 data when the contour element is a curve. The order data 141 is a character using a second-order curve function, for example, a flag "0" is stored for a kanji as shown in FIG. 3 (a), and a character using a third-order curve function, for example, hiragana, katakana , ANK characters, a flag "1" is stored as shown in FIG. 3 (b). In the type data 142, a flag "L" is stored when the contour element is a straight line, and a flag "B" is stored when the contour element is a curve.

Further, the program ROM 16 constitutes a memory means, and as a curve function for reproducing a curved portion of the contour line of the character, a function formula (1) B2 = (1-) representing a quadratic Bezier curve.
^{t) 2 P0 + 2 (1} -t) tP2 + t 2 P1 and 3 function expression representing the order Bezier curve (2) B3 = (1- t) 3 P0 + 3 (1-t) 2
tP2 + 3 (1-t) t 2 P3 + t 3 P1 ( where, P0 is the start point coordinates, P
1 is an end point coordinate, and P2 and P3 are control point coordinates. ) Is stored.

The processing performed by the CPU 12 of the data converter configured as described above will be specifically described with reference to the flowchart of FIG.

The code data input from the host computer is sequentially stored in the text memory 18, and when the storage amount reaches an appropriate amount, the CPU 12 executes the flowchart shown in FIG. First, in step S1 (hereinafter, abbreviated as S1; the same applies to other steps), the CPU 12 performs
The code data input from the text memory 18 is read, and character data corresponding to the code data is read from the character ROM 14. In the next S2, data on the contour elements in the character data is sequentially read, and it is determined whether or not the data is a curve by referring to the flag of the type data 142.

Here, if the type data 142 of the read contour element is the flag “B”, the contour element is a curve,
Executes S3, and if the type data 142 is the flag "L", the contour element is a straight line, so the CPU 12 executes S6.

In S3, the CPU 12 determines whether or not the input code data is a kanji based on whether or not the degree data 141 of the character data is a flag “0”. If the code data is a kanji, the CPU 12 executes S4. If the code data is any of hiragana, katakana, and ANK characters other than the kanji, the CPU 12 executes S5.

Outline data creation unit 3 of CPU 12 in S4, S5, S6
4 develops a quadratic or cubic Bezier curve into a short vector. That is, if the input code data is a kanji, the curved part of the contour is defined by a quadratic Bezier curve, and thus the coordinate data of the starting point P0, the ending point P1, and one control point P2 are converted into the above function. Substituting into equation (1), the function equation (1)
By expanding a number of interpolation points (Q1,
, Qn) are generated as shown in FIG. 5, and the curve points are converted into short vectors by sequentially connecting the interpolation points with straight lines. If the input code data is any of Hiragana, Katakana, or ANK characters other than Kanji, start point P0
And the end point P1 and the two control points P2 and P3 are substituted into the function equation (2) to convert the curve into a short vector. In addition, a straight contour element obtains a short vector from its start point P0 and end point P1.

Since the outline of one character is composed of a large number of straight lines and curves, the presence or absence of data corresponding to the unprocessed outline element is determined in S7, and if there is, the process returns to S2 to perform the same processing. If there is no unprocessed contour element, that is, if the outline data corresponding to the input code data is completed, the outline data composed of a large number of short vectors created in the above steps is stored in the short vector data memory 24. After being stored, the process proceeds to S8.

In S8, the data conversion unit 36 of the CPU 12 converts the outline data stored in the short vector data memory 24 into dot data. Conversion to dot data is performed using a pixel screen 52 shown in FIG. The pixel screen is a computational one for converting outline data into dot data, but is illustrated here as an actual one for easy understanding.
In addition, the pixel here is a minimum printing unit when printing is performed by a laser, and is a pixel screen 52.
Are defined by a plurality of pixel section lines p that are orthogonal to each other in one plane, are parallel to the X-axis direction and the Y-axis direction, and are provided at equal intervals. In the present embodiment, the pixels are square, and dot data is generated for each pixel to determine whether or not to print. In addition, it passes through the center point of each pixel (hereinafter, referred to as a pixel center point), and moves in the X-axis direction and Y direction.
X-direction defining line X and Y-direction defining line Y each parallel to the axial direction
Is set, and the position of each pixel is represented by the coordinates of the pixel center. Note that the pixels can be rectangular or other shapes.

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, the scale values actually assigned to the X direction defining lines X and Y direction defining lines Y in the entire pixel screen 52 are the scale values assigned to the X direction defining lines X and Y direction defining lines Y in FIG. And an appropriate integer, respectively, but here, only one character is considered.

The conversion of outline data to dot data is performed assuming that the outline of the character is superimposed on the pixel screen. In this embodiment, dots are formed at each pixel within the outline of the character. And the bit data of the pixel is set to 1. The outline includes all or a part of one pixel. In the present embodiment, the bit data of the pixel including the pixel center point in the outline is set to 1.

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.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

In the above embodiment, one degree data is provided for one character. However, degree data may be provided for each contour element related to a curve.

[Effects of the Invention] As is clear from the above description, according to the present invention, the curves of all the characters are not defined by cubic functions, but the curvatures of the curves are relatively large like kanji. Since a large one is defined by a quadratic function, the data amount of character data can be reduced and the processing time for converting character data into outline data can be shortened.

[Brief description of the drawings]

FIGS. 1 to 6 show an embodiment embodying the present invention. FIG. 1 is a block diagram of a control circuit of a laser printer having a data conversion device according to an embodiment of the present invention.
2 is a diagram conceptually showing a CPU, FIG. 3 is a diagram showing a part of character data, FIG. 4 is a flowchart showing a data conversion program, and FIG. 5 is obtained by developing a Bezier curve. FIG. 6 is a diagram showing interpolation points, and FIG. 6 is a diagram in which the outline of an alphabet (H) and the alphabet are superimposed on a pixel screen. In the figure, 14 is a character ROM (character data storage unit), 16 is a program ROM (memory means), 34 is an outline data creation unit, 36 is a data conversion unit, 141 is degree data, P0 is a start point, P1 is an end point, P2 , P3 is the control point, (P0 to P3
Is coordinate data).

Claims (1)

(57) [Claims] 1. An order data indicating an order of a curve function for dividing a contour of a character such as a character or a figure into a plurality of contour elements and reproducing a curved portion in the divided contour elements, and a position of each contour element. Character data storage means for storing a large number of character data consisting of coordinate data indicating: a memory means for storing a plurality of curve functions having different degrees; reading character data corresponding to an input code from the character data storage means; Outline data generating means for reproducing the curve portion of each contour element by a curve function of the degree indicated by the degree data in the character data, and for generating outline data such as characters and figures corresponding to the inputted code; Converts outline data created by the outline data creation means into dot data Data conversion apparatus being characterized in that a data converter.