JPH04184393A - Plotting system and data expressing system for vector font - Google Patents

Abstract

PURPOSE:To necessitate the smaller memory capacity of the work area necessary for the development of font patterns and to improve the development of magnified characters by previously dividing the font data with one character to plural block regions, developing the font data read out of vector fonts on the work area by each of block regions and transferring the data to a bit map memory by each of the block regions. CONSTITUTION:The graphic element FE of Chinese character 'NIN' is divided to the five block regions BE11 to 15 and the graphic elements FE11 to 15 of the respective block regions BE11 to 15 are plotted to the proper points of the font work region 32b. The respective block regions BE11 to 15 are thereafter transferred to the bit map region 3a and the correct font pattern EP2 is plotted. One piece of the font data FD is divided to the plural regions BE in such a manner and is developed to the regions 32b by each region BE to decrease the memory capacity of the region 32b. The possibility that the region 32b becomes short and leads to a failure in plotting decreases in the case of largely magnifying and plotting the font data FD.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vector font drawing method and data representation method.

[Conventional technology]

2. Description of the Related Art Conventionally, vector fonts (outline fonts) in which characters are expressed by outlines have been used for printing characters in printer devices.

In conventional vector fonts, data representation is performed by approximating the contours of characters with continuous straight lines or curved lines, and sequentially arranging coordinate data of the connecting points.

When drawing a character using such a vector font, the outline of the character is developed based on coordinate data read from the vector font, and the inside of the outline is filled in using, for example, a line scan method.

However, since the processing procedure for filling it out is complicated, there is a drawback that the printing speed is slow.

On the other hand, it has been proposed that the graphical elements constituting a character be approximated by one or more triangles, and that the data be expressed by continuously arranging the coordinate data of the vertices of each triangle ( JP-A-1-255888).

According to such a vector font, the outline of one or more triangles is developed in a bitmap memory based on the coordinate data read from the vector font.
Characters are drawn by filling in the inside of each triangle.

The processing for filling the inside of the triangle is relatively simple and can be performed at high speed using a hardware circuit, so it has the advantage of high printing speed.

However, in this conventional drawing method, the entire font pattern of one character is once developed in the work area based on font data read from a vector font.
After that, the expanded font pattern data was transferred to bitmap memory.

[Problems to be Solved by the Invention] As described above, in order to develop the entire font pattern of one character in the work area, a work area with a memory capacity corresponding to the font pattern is required.

For this reason, in the past, the number of font patterns that could be developed in the work area was limited to a small number, and caching was used to save the font patterns developed in the work area and transfer them to bitmap memory as needed. Because it could not be done satisfactorily, the processing efficiency when drawing vector fonts was poor.

Also, when enlarging text, the enlarged font pattern cannot be expanded to the work area (
There was also the problem that as a result, it became impossible to draw.

These problems can be solved to some extent by increasing the memory capacity of the work area, but increasing the memory capacity will also cause various problems such as higher costs, lower processing speed, and less space for other memory areas. A new problem arises.

In view of the above-mentioned problems, an object of the present invention is to provide a vector font drawing method and data representation method that requires less memory capacity in the work area required for developing font patterns and is also advantageous in expanding enlarged characters. It is said that

[Means to solve the problem]

In order to solve the above-mentioned problem, the drawing method according to the invention of claim 1 reads font data from a vector font, develops it on a work area, and transfers the data developed on the work area to a bitmap memory. In the method of drawing characters by dividing the font data for one character into multiple block areas,
Font data read from the vector font is developed on the work area for each block area, and transferred to the bitmap memory for each block area developed on the work area.

The data representation method according to the invention of claim 2 divides font data for one character into a plurality of block areas, and includes area size data indicating the size of each block area in the font data, and area size data for each block area. The data is represented by including area start data indicating the start of a block area and area end data indicating the end of each block area.

[Operation] Based on the font data read from the vector font, it is developed into a character font pattern for each block.

At that time, a block area is secured in the work area for each block area based on the area size data, and the font data between the area start data and the area end data is developed within the secured block area. .

When expansion into the work area is completed, the block area is transferred to an appropriate position on the bitmap memory at an appropriate timing.

One character is drawn by combining the respective block areas on the bitmap memory.

Note that the characters include numbers, symbols, and the like.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, the data format of the font FT according to the present invention will be explained.

FIG. 5 is a diagram showing the overall configuration of the phono-FT.

The font FT is composed of a global information section MG, a directory information section MD, and a font data information section MF.

FIG. 6 is a diagram showing the data structure of the global information section MG.

The global information section MG stores the entire management data DM of the font FT, and is referred to when the print head control section 42 selects this font FT from among a plurality of fonts.

FIG. 7 is a diagram showing the data structure of the directory information section MD.

The directory information section MD stores directory data DF for managing font data FD corresponding to each character code. The directory data DF has the same number of characters as the font FT includes, and is arranged in accordance with the order of character codes.

The data start address DFA is the start address where the font data FD corresponding to the character code is stored. Also, the cell size of each font FT (vertical y x horizontal x)
The cell size data DFS, the height from the baseline DFH, and the distance to the center line DFL are indicated by the letters (
Used to determine the drawing position of a phonotono (turn) or move the cursor position.

Next, the font data FD stored in the font data information section MF will be specifically explained using the character (number) "1" as an example.

In addition, in the following, when representing an individual or specific thing, for example, "font data FDIJ, numbers are added after the alphabetic code to represent the overall or - boat fishing name. In this case, for example, ``font data FDJ is displayed without adding numbers.

FIG. 1 is a diagram for explaining the font data representation system according to the present invention, and FIG. 2 is a diagram showing the font pattern FP of FIG.
FIG. 3 is a diagram showing font data FDI of I.

In FIG. 2, font data FD is coordinate data D
D, command data DC, and size data DS.

Figure 3 shows the coordinate data DD included in the font data FD.
FIG. 4 is a diagram showing the bit structure of command data DC included in font data FD.

The coordinate data DD has a 2-word configuration (2-byte configuration) and includes X coordinate data and y coordinate data. Note that the most significant bit (31st bit) of the coordinate data DD is set to "0" to indicate that it is coordinate data DD, and the 15th bit is also set to "0".

The command data DC has a 2-word structure, with the most significant bit (31st bit) set to “l” to indicate that it is command data DC, and the lower 7 bits (6th bit)
. . . bit 0) is a parameter to represent the contents of the command.

That is, the 6th bit of the command data DC indicates the end of one font data FD, and the command data DC indicating this is appended to the end of each font data FD.

The 5th bit is a block definition flag FGS indicating the start of the block area BE, and the 4th bit is a block data end flag FGE indicating the end of the block area BE. The data from the start to the end of the block area BE is treated as one block, and the font pattern FP is created in block units.
The expansion process is performed. Note that after the command data DC instructs the start of the block area BE, size data DS of 4 bytes follows as a parameter for defining the block size. This size data DS can be positive or negative data. This also determines the position of the block area BE relative to the current position.

The third bit is a flag for specifying whether to fill in the area inside the triangle defined by the coordinate data DD following the command data DC. When this flag is "1", drawing is prohibited, and this is valid only once for the next coordinate data DD. This flag is used when redundancy occurs such that areas to be filled out overlap due to a combination of data.

The second bit is a flag for specifying whether the coordinate data DD following this command data DC is a white vector (data that does not perform drawing) or a black vector (data that performs drawing).

When this flag is "0", that is, when a white vector is specified, the font image development unit 311 described later
The contents of the vector register 311cxe are reset, and the next coordinate data DD is set as a new starting point.

The first bit is a Bezier curve designation flag FGB for designating the Bezier curve BC. Bezier curve specification flag F
If GB is "1", the command data following this command data DC (with two coordinate data DD as control points, the current coordinate position and the previous or two points specified by the O-th end point designation flag) It is shown that this is a Bezier curve BC formed by the previous coordinate data DD.

Now, in FIG. 1, the font pattern FPI for the character "1" consists of triangles T1 to T4 and triangle T2.
It is expressed by a curved figure S1 surrounded by one side SDI of and a Bezier curve vABC1.

In other words, the graphic element FE with the number "1" is located at the points P1 and P3.
, P4, and B (see Figure 8), and a rectangular block area BE2 (see Figure 9) surrounded by points P8, P9, P7, and P4. It is expressed by combining the graphic elements FB1.2 drawn in the block area BEI,2.

The graphic elements FBI of the block area BEI are points P1 and P2
, a triangle T1 surrounded by P3, a triangle T2 surrounded by points P2, P3, and P4, and a side SD from point P2 to point P4.
Curve figure S1 surrounded by I and Bezier curve BCI
It is broken down into.

Referring also to FIG. 2, these triangles T1.2 are expressed by coordinate data DD1-4 of points P1-3 and points P2-4, which are respective vertices.

Also, the Bezier curve designation flag F of the command data DC3 indicates that the Bezier song IBcI is a Bezier curve BC.
GB, and a control point (driving point) P5 for specifying the locus of the Bezier curve BCI. It is expressed by data (Bezier curve data) such as coordinate data DD5.6 of P6.

The graphic element FE2 of the block area BE2 has points P4 and P7.
, P8, and the points P7, P8, P9
It is decomposed into a triangle T4 surrounded by .

These triangles T3.4 have their vertices at points P
4, P7, P8, and coordinate data DD4 and coordinate data DD7-9 of points P7, P8, and P9.

Next, the expansion and drawing processing of phono-FT will be explained.

Figure 13 shows a laser printer P that can draw graphics.
1 is a block diagram showing the configuration of a print system PS using the .

In the figure, a print system PS is a device laser printer P that is composed of a general-purpose data processing device 1, a file buffer 2 that temporarily stores data output from the data processing device 1 via a bus B1, and a laser printer P. consists of a bitmap type data processing section 3, a print engine 4 that forms a hard copy image using a well-known electrophotographic process using laser exposure, and accessory devices such as an external paper feed unit 5 and a sorter 6.

FIG. 14 is a block diagram showing the configuration of the control section of the laser printer P.

The data processing unit 3 includes a bitmap control unit 30 and a BM-RAM 3 which is a bitmap type readable/writable memory.
2. A focus map writing section 31 that performs drawing in the BM-RAM 32, and a font section 33 that stores a font FT.
It consists of

Connection with the print engine 4 is made through a bus B3 for control data (engine, accessory control, etc.) and a bus B4 for image data.

The print engine 4 is mainly composed of three control sections. First, an interface control section (IFC) 40 processes control data from the bitmap control section 30, controls the operation panel, and controls the overall timing of the print engine 4 through the internal bus B5. The electrophotographic processing sections 4 and 5 are controlled in accordance with data sent from the interface control section 40 through the internal bus B5.

The print head control unit 42 controls the laser exposure in the print head unit 43 according to the information sent from the IFC 40 via the bus B5 in order to write the image data sent from the bitmap writing unit 3I via the bus B4. Control.

The print data (mostly represented by a code) sent from the data processing device 1 is sent to the BM-R of the data processing section 3.
It is developed (drawn) as an actual print image on the AM 32 and output to the print engine 4. The print engine 4 modulates the laser beam according to the data from the data processing section 3 to form an image on the photoreceptor, and transfers this onto recording paper.

The data sent from the data processing device 1 includes not only print data but also codes for format control and engine mode setting.

The data processing unit 3 analyzes these protocols in addition to the print data, controls the format of the print engine 4, and issues instructions for paper feeding, optional mode changes, etc. as necessary.

In addition to the above-mentioned recording control, the print engine 4 also controls the electrophotographic system, controls the timing of recording paper, and performs control in synchronization with the feeding of paper to other accessory devices. is similar to an electrophotographic copying machine except for the scanning system.

FIG. 15 is a block diagram of the bitmap writing section 31.

The functions of the focus map writing section 31 can be roughly divided into BM-R
tiii function to AM32 and BM-R when printing
It is divided into a function of outputting AM32 data to the print engine 4.

The function of drawing to the BM-RAM 32 is further divided into two parts: drawing of figures such as lines, circles, and triangles performed by the graphic drawing section 316, and font image development section 3.
Expansion (calculation) of font data FD performed by 11
Both of these are logic units that operate based on packets (data groups) sent from the bitmap control unit 30 via the bitmap control unit interface 317.

That is, the graphic drawing unit 316 analyzes the parameters in the packet and draws it on the BM-RAM 32. In particular, in this embodiment, the font image development unit 3
A filled triangle T is drawn based on the coordinate data DD of the three vertices of the triangle T sent from 11. The drawing of the triangle T is performed by exclusive OR operation with background data as described later. done by.

At that time, each block area 8E of each font data FD divided in advance is once drawn in the font work area 32b which is a part of the BM-RAM 32, and then the data of the drawn block area BE is BM-RAM
32 to a predetermined position in the bitmap area 32a.

Further, the font image development unit 311 calculates the font data FD read from the font unit 33 via the font unit interface 314 according to the data in the packet as necessary, and then converts the font data FD to the graph ink drawing unit 316.
Send data as a packet.

The font image development unit 311, as described later,
If the font data FD includes Bezier curve BC data, obtain the Bezier curve BC and create a curved figure S surrounded by the Bezier curve BC and one side SD of the triangle T.
is further decomposed into one or more triangles and calculations are performed to obtain coordinate data of each vertex.

That is, the main function of the graphic drawing unit 316 is to develop the triangle T whose inside is filled in in the font work area 32b for each block area BE and then transfer it to the bitmap area 32a. The main function is to calculate the necessary data at high speed and send it to the graphic drawing unit 316.

On the other hand, the data output function during printing is performed by the print head controller interface 315. That is, from the bitmap control unit 30 to the interface 31
When the print start code sent via bus B4 is received, the print start code is sent via bus B4 in accordance with the synchronization signal sent from the print head control section 42 of print engine 4 via bus B4.
Data in the M-RAM 32 is output to the print hand control section 42.

No. 111 is a block diagram of the font image development section 311.

The font image development section 311 converts the font image to the font section 33 via the font section interface 314 in accordance with the font specification command, character code specification command, etc. sent from the focus map ll library section interface 317.
The character size sent from the bitmap control unit interface 317 that reads the font data FD of
Parameters such as angle are stored in the parameter register 311b.
(Rg), the vector amount of the font data FD (coordinate data DD of the vertex of the triangle T) is set in the three vector registers 311c, d, e (R1-R3), and the address calculation on the BM-RAM 32 is performed. used.

When the coordinate data DD is stored in the vector registers 311c to 311e, it is sent to the graphic drawing unit 316 as a packet of graphic data specifying the graphic of the triangle T to be filled.

The area of the triangle T to be filled in is surrounded by line segments connecting the vertices of the triangle T (that is, the sides SD), and therefore can be determined by calculation. That is, for example, it is possible to draw a filled triangle T by finding the intersections of the three sides SD and each horizontal line based on the coordinate data DD of the vertices, and drawing line segments between these intersections. can.

Since these calculations are executed by the logic circuit of the graphic drawing unit 316, calculation processing and drawing are performed at high speed.

In the calculation unit 311a, coordinate data DD of each vertex of the triangle approximated based on the data of the Bezier curve BC is calculated by calculation (see FIG. 12), which will be described in detail later.

Figures 8 and 9 show the font data FDI as BM-RA.
Figure 10 shows the font pattern FPI drawn on the BM-RAM32.
FIG.

Referring also to FIGS. 1 and 2, font data FDI of the font unit 33 is transferred to the font unit interface 314.
is read into the font image development unit 311 via
After necessary calculations are performed there, the data is sent to the graphic drawing unit 316 and expanded or drawn on the BM-RAM 32.

First, command data DCI specifies that it is a white vector, and the cursor moves to the point PO, which is the current position.
to the drawing start point PI indicated by the coordinate data DD1,
Don't draw (move).

Next, the command data DC2 specifies that it is a black vector and the start of the block area BH, and a block area BEI of the size indicated by the next size data DSL,2 is secured on the font work area 32b.

Next, the coordinate data DDI~3 is stored in the vector register 311.
After setting c to e and performing calculations, Fig. 8(a)
As shown in FIG. 3, a filled triangle T1 having these three points P1 to P3 as vertices is drawn (developed) within the block area BEI of the font work area 32b.

During this drawing, an exclusive OR operation is performed between the data of the triangle T1 and the background data, and the result is written into the block area BH.

Similarly, as shown in FIG. 8(b), three points P2
A triangle T2 having vertices ˜4 is drawn in the block area BEI.

Next, by command data DC3, Bezier curve BC
is specified, and the two previous point P2 is specified as the end point by the end point designation flag. In addition, point P2, which is the current position, is specified as the starting point, and the next coordinate data DD
5.6 specifies the control point P5.6.

When Bezier curve BCI is specified, vector register 3
The coordinate data D02 to D4 stored in 11 cm are stacked in the work area of the calculation unit 311a, and calculation processing for drawing the curved figure S1 is performed. This calculation process will be described later.

When the calculation for drawing the curved figure SL is completed, the data is sent to the graphic drawing section 316 and drawn in the block area BEI of the font work area 32b.

Similarly to the triangle T1.2, the curved figure S1 is drawn by an exclusive OR operation with the background data. In this embodiment, the curved figure S1 and the triangle T2 overlap, so the drawing shown in FIG. As shown in the figure, the portion of the curved figure S1 within the triangle T2 is erased.

However, if the curved figure S and the diagonal T do not overlap, then when the exclusive OR operation is performed, these figures will simply be added, and therefore the curved figure S will be drawn filled in. Become.

In this way, the triangle T and the curved figure S are divided into the block area B
When drawing on H, the curved figure S can be filled in or erased by writing them by exclusive OR operation with background data, so high-speed drawing can be performed with a simple logic circuit.

By the next command data DC4, the block area BE
The end of I is specified and the drawn block area BEI is transferred from the font work area 32b to the bitmap area 32.
It is transferred to a predetermined position determined by the cursor on a. At the same time, the data stacked in the calculation unit 311a is returned to the vector register 311cme.

Note that depending on the free space of the font work area 32b,
The data may be transferred all at once after drawing the next block area BE2.

Then, the start of the next block area BE2 is specified by the command data DC4, and the next size data DS3.
A block area BE2 having a size indicated by 4 is secured on the font work area 32b.

Then, as shown in FIGS. 9(a) and 9(b), triangle elements 3.4 are sequentially drawn in the block area BE2 in the same manner as in the block area BEI, and by specifying the end of the block area BE2 using the command data DC5. , block area BE2 is transferred to the bitmap area 32a. At the same time, the end of the font data FDI is declared.

Since the positional relationship of the block area BE1.2 at the time of transfer is determined by the coordinate data DD, as shown in Figure 1O, the font pattern FPI of the character "1" is BM
- Drawing is performed correctly on the RAM 32.

FIG. 11 is a diagram showing how a font pattern FP2 based on other font data FD2 is drawn on the BM-RAM 32.

In FIG. 11(b), the graphic element FE of the character “Shin”
is divided into five block areas BEII to 15, and the graphic element FEII of each block area BEII to 15 is divided into five block areas BEII to 15.
-15 is drawn at the appropriate location in the font work area 32b. Thereafter, each of the block areas BEII to BEII-15 is transferred to the bitmap area 32a, so that the first
1[Correct font pattern FP as shown in 1(a)
2 is drawn.

In this way, by dividing one font data FD (l character) into a plurality of block areas BH and developing each block area BE in the font work area 32b, the memory capacity of the font work area 32b can be reduced. can be made smaller. Further, even when drawing the font data FD after greatly enlarging it, the possibility that the font work area 32b becomes insufficient and drawing becomes impossible is reduced.

In addition, the font work area 32b is the font data FD.
, multiple font data F
D can be developed into the fontwork IM 32b, and cached by transferring it from the fontwork area 32b to the bitmap area 32a as needed.

Next, the summer processing for drawing the curved figure S will be explained.

Figure 12 4! 7 is a diagram illustrating a process for filling in a curved figure S. FIG.

The curve figure S has a starting point at point pO, an ending point at point P1, and a point 22.
．． 3 is a figure surrounded by a Bezier curve BC, which is a control point, and a line segment pOpl.

The Bezier curve BC is defined by the following equation.

X (t)=aXt”+bxt’+cxt+X.

Y (t) "ayt' + byt' + cyt + Ye, where 0≦t≦1 This Bezier piece 118c is approximated as follows.

In other words, the midpoints of line segments pop2, p2p3, and p3pl are 91, q2, and q3, and the line segments q4q5
If the midpoint of is 96, the Bezier curve BC is the point pO, q
6, a Bezier curve BCa controlled by ql and q4, and a point q6. q5 for pl. It is divided into a Bezier curve BCb controlled by q3.

The point (division point) q6 thus obtained is a point on the Bezier curve BC, and the triangle TA having the points po, q6, and pl as vertices is the roughest proximal figure of the curved figure S.

By repeating such division, the Bezier curve B
A large number of dividing points on C can be obtained, and a large number of triangles TA having vertices at these dividing points can be obtained.

In this division process, the height H of the triangle TA is a constant evaluation value,
For example, the process ends when the size becomes smaller than the size of one dot in the resolution of the laser printer P.

The curved figure S is drawn by drawing these triangles TA using the same method as described above.

That is, after the coordinate data DD of each vertex of the triangle TA is set in the vector register 311cme, the data is sent to the graphic drawing unit 316 and stored in the BM-RAM.
A filled triangle TA is drawn at a predetermined position on 32. Such processing is repeated until the height H of the triangle TA becomes smaller than the evaluation value.

In this way, since the curved figure S is approximated by the triangle TA,
Calculations for drawing the curved figure S can be performed only by addition, subtraction, multiplication, and division.

Therefore, the arithmetic unit 311a can be realized by a relatively simple logic circuit, and high-speed processing is possible.

Next, the drawing process of the font data FD will be explained based on a flowchart.

FIG. 17 is a flowchart showing the drawing process of font data FD.

Before the processing according to this flowchart, data for setting the character type of the character to be drawn and its attributes is sent via the bitmap control unit interface 317.

This specifies the character code. However, if it is not sent, it will be the default value.

Thereafter, the data start address DFA and other parameters are read from the directory information section MD of the font FT and set according to the character code.

The flag WVEC used in this flowchart becomes rl when a white vector is specified and when drawing is prohibited.

First, data is sequentially read from the first address of the font data FD and input to the bitmap writing section 31 (step #11).

It is checked whether the input data is coordinate data DD or command data DC (step #12).

If the coordinate data DD is the coordinate data DD (YES in step #12), the coordinate data DD is stored in the vector register 311c.
set to me (step #13).

Next, when the flag WVEC is "0" (step #14
(Yes in step #15), wait until the coordinate data DD of the three vertices of triangle T are aligned (Yes in step #15).
, sends the coordinate data DD to the graphic drawing section 316 (step #16).

The graphic drawing unit 316 draws a triangle child based on the coordinate data DD.

When the flag WVEC is rIJ (No in step #14), the flag WVEC is reset to "0" (step #17) and the triangle T is not drawn.

If it is command data DC (No in step #11), the following processing is performed according to its contents.

When the white vector is specified (YES in step #21), the vector register 311cme is cleared (step #22), and the flag WVEC is set to "1" (step #23).

When prohibition of drawing is specified (YES in step #3I), the flag WVEC is set to "1" (step #32).

When Bezier curve BC is specified (step #41
(Yes), the coordinate data DD to be the control point is read out (Step #42), and the drawing process of the curved figure S is performed (Step #43).

When the end of the block area BH is specified (YES in step #51), the data in the block area BE is transferred from the font work area 32b to the bitmap area 32a (step #52).

When the start of the block area BE is specified (YES in step #61), the size data DS indicating the size of the block area BE is read out (step #62), and the area is secured on the font work area 32b (step #62). 63), when the area is insufficient, if there is unnecessary data such as font cache data in the font work area 32b, the area may be secured by deleting that data.

When the end of the font data FD is specified (YES in step #71), the vector register 311cme is cleared (step #72).

FIG. 18 is a flowchart showing the drawing process of the curved figure S.

First, the start point, end point, and two control points of the Bezier curve BC are determined (step #81).

Next, as explained in FIG. 12, the Bezier piece 1i
Divide Bc into two Bezier curves BC Step #82
), the coordinate data of the dividing point, the starting point, and the ending point are set in the vector registers 311c to 311e (step #83), and a triangle T is drawn based on this (step #84).

The processes from step #81 onward are repeated until the height H of the triangle T having the dividing point as the apex becomes smaller than the evaluation value (until the result in step #85 is NO).

The above-described process is repeated until there are no other curved figures S to be subjected to the drawing process (until the result in step #86 is NO).

According to the above-described embodiment, since characters are drawn by drawing the filled triangle T, processing can be performed at high speed using a relatively simple hardware circuit.

Further, since the character is approximated by the triangle T and the curved figure S including the Bezier curve BC, the quality of the character can be improved without causing a significant increase in the amount of data.

According to the above embodiment, since the block area BE is rectangular, processing such as securing the block area BE and transferring data is easy.

In the above embodiment, the Bezier curve BC is used as the multidimensional curve.
It is possible to use various curves other than . The configurations of the font data information section MF, directory information section MD, coordinate data DD, command data DC, etc., as well as the configurations of the font image development section 311, bitmap writing section 31, laser printer P, etc., may be changed in various ways other than those described above. be able to.

〔Effect of the invention〕

According to the present invention, the memory capacity of the work area required for developing font patterns is small (only a small amount is required), so caching is easy, and it is advantageous in developing enlarged characters.
It is also advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the font data representation method according to the present invention, FIG. 2 is a diagram showing font data of the font pattern of FIG. 1, and FIG. 3 is a diagram of bits of coordinate data included in the font data. Figure 4 is a diagram showing the bit configuration of command data included in font data, Figure 5 is a diagram showing the overall configuration of the font, and Figure 6 is a diagram showing the data configuration of the global information section. Figure 7 is a diagram showing the data structure of the directory information section, Figures 8 and 9 are diagrams showing a ladder for developing and drawing font data in BM-RAM, and Figure 10 is a diagram showing the data structure of the directory information section.
A diagram showing a font pattern drawn on M, Figure 11 a diagram showing how a font pattern based on other font data is drawn in BM-RAM, and Figure 12 explaining the process for filling in a curved figure. Figure 13 is a block diagram showing the configuration of a printing system using a laser printer, Figure 14 is a block diagram showing the configuration of the control unit of the laser printer, Figure 15 is a block diagram of the bitmap writing unit, and Figure 16 is a block diagram showing the configuration of the control unit of the laser printer. The figure is a block diagram of the font image development section, FIG. 17 is a flowchart showing font data drawing processing, and FIG. 18 is a flowchart showing music 1s figure drawing processing. DESCRIPTION OF SYMBOLS 1... Data processing device, 3... Data processing part, 4...
...Print engine, 31...Bitmap writing unit, 32...BM-RAM, 32a...Bitmap header (bitmap memory), 32b...Font work area (work area), 311... ... Font image development section, 311a... Calculation section, 311cme.
...Vector register, 316...Graphic drawing unit, PS...Print system, T...Triangle, B
C... Bezier curve, S... curve figure, FT... font (vector font), FD... font data, BE... block area, DS... size data (area size data L FGS ...Block definition flag (area start data), FGE...Block data end flag (area end data).Applicant Minolta Camera Co., Ltd. Agent Patent attorney Yukio Kubo Figure 1 Cell size horizontal (X) 2 Figure 3 Coordinate data DD Figure 4 Command data DC Figure 5 Figure 6 Figure 7 Figure 7 MD Directory ↑ Information section Figure 11 Figure 12 Figure 51C Figure 16 3111t-) Image expansion section Figure 18

Claims (2)

[Claims] (1) In a method that draws characters by reading font data from a vector font, developing it on the work area, and transferring the data developed on the work area to bitmap memory, the font data for one character is Dividing the vector font into a plurality of block areas, developing the font data read from the vector font onto the work area for each block area, and transferring each block area developed on the work area to the bitmap memory. A vector font drawing method characterized by: (2) Font data for one character is divided into multiple block areas, and within the font data, area size data indicating the size of each block area and area start data indicating the start of each block area are included. and area end data indicating the end of each block area.