JPS63182155A - Font pattern imaging device - Google Patents

Abstract

PURPOSE:To reduce a storage space of a font file, shorten the period of time required for loading a font pattern and enable high-speed imaging, by providing a compressed font file, restoring an original font pattern by subjecting a compressed font pattern to a data expanding treatment, and storing the restored font pattern in a tentative storage means, and using the restored font pattern for imaging. CONSTITUTION:A font file is subjected to data compression on a block basis, and a compressed font file thus formed is stored in an auxiliary storage device 11 whereby the storage space in the device 11 occupied by the font file is markedly reduced. Therefore, it is possible to reduce the storage capacity of the storage device 11. In addition, since the quantity of data per one character in the font file is reduced, the number of times of access to the storage device 11 necessary for loading a fixed number of characters into a font buffer 16 is reduced. The period of time required for expanding the data of the compressed font file can be made to be shorter than the access time for the storage device 11. Therefore, the total period of time for font pattern imaging can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a font pattern drawing device suitable for displaying or printing high quality characters.

BACKGROUND OF THE INVENTION In order to display or print high-quality characters, it is necessary to provide a 7-ont pattern with a large number of dots, which significantly increases the amount of data for the entire font pattern. If multiple types of font patterns are installed, the amount of font pattern data becomes enormous.

Conventionally, font pattern drawing devices designed to display or print high-quality characters generally store font pattern files in an auxiliary storage device such as a 7-inch disk device.

Then, the font file is loaded in blocks from the auxiliary storage into a high-speed buffer that temporarily stores font patterns, and the necessary font patterns are extracted from the buffer and stored in focus map memory (drawing memory). By transferring, characters are drawn (not displayed yet printed).

Problems to be Solved by the Invention However, with such a configuration, a very large storage space of the auxiliary storage device is used for font files with a large amount of data. In this case, there was a problem in that almost the entire storage space of the auxiliary storage device was occupied by the font file. In other words, systems that require a large amount of auxiliary storage to store font files,
There is a problem in that the font pattern drawing device increases in price and becomes larger in size.

Also, since there is a natural restriction on the amount of data that can be loaded from the auxiliary storage device to the buffer with - times of loading operations, as the number of dots in the font pattern increases, the amount of data that can be loaded into the buffer with one loading operation is limited. The number decreases.

For example, the amount of data that can be loaded - times is 1024
In terms of bytes, a font pattern of 16 x 8 dots can load 64 characters at once, but 64 x
The 32-dot font pattern can only load 4 characters at a time.

In this way, in conventional configurations, when a font pattern has a large number of constituent dots, the number of accesses to the auxiliary storage device required to load a font pattern of a certain number of characters into the buffer increases, resulting in an increase in time. There was also the problem that the drawing processing speed decreased.

To deal with this problem, it is possible to load the entire font file on the auxiliary storage device into a high-speed buffer in advance, and use a configuration in which only the buffer is accessed during the drawing process and the auxiliary storage device is not accessed. Conceivable. However, securing a large-capacity, high-speed buffer that can store the entire font file is impractical in terms of cost and other factors.

The present invention has been made in view of the above-mentioned problems, and even when a font pattern has a large number of dots, the storage space for font files is significantly reduced compared to the conventional method, and the loading time of the font pattern is reduced compared to the conventional method. It is an object of the present invention to provide a font pattern drawing device capable of shorter and faster drawing processing.

Means to Solve the Problems In order to solve the above-mentioned problems, the present invention uses a compressed font file, which is a collection of blocks in which font patterns are compressed for each character, instead of a font file that is a collection of font patterns as they are. If necessary, extract one block of the compressed font file and perform data decompression processing to restore it to the original font pattern before data compression, and store it in the font pattern temporary storage means. , the font pattern is cut out from this temporary storage means and used for drawing.0 That is, the font pattern drawing device of the present invention has a structure in which the font pattern is cut out from this temporary storage means and used for drawing.
As shown in the complaint correspondence diagram in the figure, a file storage means 2 stores a compressed font file 1 which is a set of blocks obtained by compressing a font pattern for each character.
, a file reading means 3 for reading the compressed font file 1 from the file storage means 2 in blocks, and a data decompression means for data decompressing the block of the compressed font file read by the file reading means 3 into a font pattern before data compression. means 4, font storage means 5 for temporarily storing the font pattern data expanded by the data expansion means 4, and a font pattern to be drawn cut out from the font storage means 5 and transferred to the drawing storage means 6'. The present invention is configured to have a cutout transfer means 7 for displaying a font pattern, and an output means 8 for displaying or printing the font pattern stored in the drawing storage means 6. Since the data is provided in the form of 0, the total amount of data is significantly reduced compared to the conventional one.Therefore, the storage capacity of the file storage means 2 for storing the data can be significantly reduced.

Furthermore, since the amount of data per character in the compressed font file is reduced, the number of accesses to the font storage means 2 required to load a font pattern of a certain number of characters into the font storage means 5 is reduced. Although it takes some time to decompress the data of the compressed font file, this time can generally be made sufficiently shorter than the access time of the font storage means 2. therefore,
The time required for the entire font pattern drawing process including data decompression process can be reduced compared to the conventional method.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 2 is a hardware configuration diagram of a font pattern drawing device according to an embodiment of the present invention. In Figure 2,
9 is a central processing unit (CPU), and 10 is a main memory. This main memory 10 stores programs, data, etc. for font pattern drawing processing, etc. The file reading means 3 is realized by the central processing unit 9 under the control of this program.

Reference numeral 11 denotes an auxiliary storage device such as a hard disk device as the file storage means 2, which stores the compressed font file 1. This compressed font file 1 is formed by data compressing a font pattern of all characters by a certain number of characters in a certain order, and connecting blocks 1a of the compressed data in a certain order. Since the amount of data in each block 1a varies, a management table 12 in which storage start address information and the like of each block 1a are registered is stored in the auxiliary storage device 11. This management table 12 is
At the startup stage of this font pattern drawing device, the main memory 1
Loaded to 0.

In addition, the method for compressing font pattern data is as follows:
For example, a modified Huffman (MH) method, a modified read (MR) method, etc., which are standard data compression encoding methods in facsimile, are used.

14 is a block buffer, which is the auxiliary storage device 1
The data of one block of the compressed font file 1 read from the compressed font file 1 is temporarily stored.

15 is a data expansion circuit as the data expansion circuit 4, and the block buffer 14 is provided as an input buffer for this data expansion circuit 14. The data decompression circuit 15 operates under the control of the central processing unit 9, sequentially reads compressed data from the block buffer 15, and decompresses it into font pattern data before data compression. This data expansion process is performed using a data expansion method that corresponds to the data compression method described above.

Reference numeral 16 denotes a font buffer as the font storage means 5. This font buffer 16 has an input canister 16a for temporarily storing font pattern data expanded by the data expansion circuit 15, and a learning area. I know. The learning area also includes a resident section 16b and a temporary section! It is divided into 6e.

At the start-up stage of the font pattern drawing device, the resident section 16b is loaded with a font pattern of frequently used basic characters selected in advance, such as first-level characters. Font patterns of various characters other than the basic characters are written into the temporary section 16c at any time during the font pattern drawing processing operation, depending on the frequency of use.

Added to the font buffer 16 is a learning control table 17 related to replacement of font patterns within the learning area. This learning control table 17 includes identification information of font patterns stored in the learning area,
The storage start address information and usage frequency information are registered.

Reference numeral 18 denotes a cutout transfer circuit as the first half cutout transfer means 7. Reference numeral 19 denotes a display memory as a storage means for early drawing. The cutout transfer circuit 18 cuts out the font pattern from the learning area of the font buffer 16 and transfers it to the display memory 19 based on the storage start address information and transfer start address information of the font pattern given from the central processing unit 9. It is something that does work.

Reference numeral 20 denotes a CRT display device as the output means 8, which sequentially displays the font patterns stored in the display memo+720 on the screen.

Reference numeral 21 denotes a keyboard, which is used to input the code of the character to be drawn and its font type information.

Here, the operation of this font pattern drawing device at the startup stage will be explained. Under the control of the central processing unit 9, programs for font pattern drawing processing, management tables 12, etc. are stored in the main memory 1 from the auxiliary storage device 11.
Loaded to 0.

Next, under the control of the central processing unit 9, the block 1a of the compressed font file 1 containing the font pattern of basic characters to be stored in the resident section 16b of the font buffer 16 is read from the auxiliary storage device 11 to the block buffer 14. It will be done. When one block is read, the data decompression circuit 15 is activated by the central processing unit 9,
The block is expanded into a font pattern by data expansion circuit 15. The decompressed font pattern data is sequentially stored in the input canister 16a of the font buffer 16.

This font pattern data is sequentially written into the resident section 1.6b of the learning area under the control of the central processing unit 9, and at the same time, necessary information is set in the learning control table 17.

When the loading of the font pattern into the resident section 16b is completed in this manner, the font pattern drawing process becomes possible.

Next, the font pattern drawing processing operation of this font pattern drawing device will be explained. FIG. 3 is a schematic flowchart for explaining the operation.

When the character code and font type information are input from the keyboard 21 or the program (step 22),
The font pattern drawing processing routine starts running.

First, the central processing unit 9 controls the learning control tape.

17 is referenced, and a search for the specified font pattern is performed using the character code and font type information (step 23).O If the specified font pattern is stored in the font buffer 16, the central processing unit 9 Pattern storage start address information (learning control table 17
) and its transfer start address information are given from the central processing unit 9 to the cutout transfer circuit 18, and then the cutout transfer circuit 18 is activated (step 24).

The cutout transfer circuit 18 operates, and the specified font pattern is transferred to the font buffer 16 according to the storage start address information.
is cut out from the learning area (resident section 16b or temporary section 16C) and transferred to the storage area of the display memory 19 specified by the transfer start address information (
Step 25). This font pattern is displayed (drawn) on the upstream screen of the CRT display device.

On the other hand, the specified font pattern is in font buffer 16.
If it is not stored in the learning area of the central processing unit 9.
In step 26, the number of the block containing the specified font pattern in the compressed font file 1 is calculated.

Direct memory access (DMA) of the central processing unit 9
) mechanism reads the block 1a of the compressed font file 1 into the block buffer 14 (step 27). During this reading, the storage start address of the block to be read is found from the management table (12) on the main memory IJ 10.

Next, the data decompression circuit 15 is activated by the central processing unit 9, and the read block is decompressed into a font pattern by the data decompression circuit 15, and the font buffer 16
are sequentially transferred to the input canister 16a (step 28).
.

When such data decompression processing is completed, the central processing unit 9
Under the control of , the decompressed font pattern is transferred to the temporary part 16c of the learning area, and the font pattern is replaced (step 29). At this time, the learning control table 17 is referred to, the new font pattern is written in the storage location of the less frequently used font pattern, and the learning control table 170 is updated. In this way, control (learning) is performed such that frequently used font patterns are stored in Tenbora 9, 6c.

Once the font pattern has been replaced, step 24
Then, the font pattern is drawn as described above.

As mentioned above, the font pattern drawing device of this embodiment compresses the data of the font file in blocks and stores it in the auxiliary storage device 11 in the form of the compressed font file 1, so the font file is stored as is without data compression. The storage space of the auxiliary storage device 11 occupied by the compressed font file 1 is significantly smaller than in the case of the compressed font file 1.

Therefore, the storage capacity of the auxiliary storage device 11 can be reduced compared to the conventional case.

However, since the amount of data per character in the compressed font file 1 is reduced, the number of accesses to the auxiliary storage device 11 required to load a font pattern of a certain number of characters into the font buffer 16 is reduced. Although it takes time to decompress the data, this time can generally be made sufficiently shorter than the access time of the auxiliary storage device 11. Therefore, the time required for the entire font pattern drawing process including the data decompression process can be reduced compared to the conventional method.

In this embodiment, the file reading means was realized by program control using the functions of the central processing unit, but it may also be realized as dedicated software.

Conversely, in this embodiment, the cutout and transfer means is realized as a dedicated circuit, but it may also be realized by program control using the functions of the central processing unit.However, in this embodiment, the font pattern is not displayed and output. However, it may also be printed out. Effects of the Invention As is clear from the above explanation, the present invention provides a method for storing a compressed font file, which is a set of blocks obtained by compressing a font pattern in units of multiple characters, in a file storage means. By reading out one block of the compressed font file and performing data decompression processing, it is restored to the original font pattern before data compression, which is temporarily stored in the font storage means, and the font pattern is transferred from this font storage means. The structure is such that the pattern is cut out and used for drawing, and the storage space of the compressed font file is less than before, so it is possible to reduce the storage capacity of the file storage means, and the data per character of the compressed font file can be reduced. Since the amount is reduced, the number of accesses to the file storage means required to load a font pattern of a certain number of characters into the font storage means is reduced, so it is possible to speed up the font pattern drawing processing speed.
0 which has the effect of

[Brief Description of the Drawings] Fig. 1 is a diagram corresponding to claims of the present invention, Fig. 2 is a hardware configuration diagram of a font pattern drawing device according to an embodiment of the present invention, and Fig. 3 is a diagram of the font pattern drawing device according to an embodiment of the present invention. 1 is a schematic flowchart of the font pattern drawing processing operation. 1... Compressed font file, 2.° File storage means, 3. File reading means, 4. Data decompression means, 5. Font storage. means, 6... storage means for drawing, 7... cutout transfer means, 8... output means, 9... central processing unit (CPU), 10... main memory, 11... auxiliary memory Device, 15...Data decompression circuit, 19...Display memory, Addition...CRT display device. Name of agent: Patent attorney Toshio Nakao and one other person Figure 1 Figure 2

Claims (1)

[Claims] A file storage means for storing a compressed font file which is a set of blocks obtained by data compressing a font pattern in units of a plurality of characters, a file reading means for reading out the compressed font file from the file storage means in units of blocks, and this file reading means. data decompression means for decompressing the block of the compressed font file read by the font into a font pattern before data compression; a font storage means for temporarily storing the font pattern data decompressed by the data decompression means; A font pattern drawing device comprising a cutout transfer means for cutting out a font pattern to be drawn from a storage means and transferring it to a drawing storage means, and an output means for displaying or printing the font pattern stored in the drawing storage means.