JPH04238391A - Font data storage method - Google Patents

Abstract

PURPOSE:To improve the storage efficiency of character pattern font data having a dot matrix format for storing in a memory medium. CONSTITUTION:The prescribed blank part of a-bytes on the left side or the right side of each of dot matrix format character patterns ('A', 'B', and 'C') having the capacity of W-bytes per one character is originally considered as a common region with the character patterns adjoining each other. When these character patterns above mentioned are in a character pattern memory medium, they are memorized as (W-a)-bytes per one character pattern.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to font data storage systems.

0002

2. Description of the Related Art In the conventional dot matrix format font data storage system, the dot patterns of characters including the margins around the characters are stored in the order of character codes.
Either calculate and refer to the font data storage address directly from the character code, or keep a separate table with the start address of the memory where the font data of each character is stored, and refer to the font data indirectly using this table. was common.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, as the dot pattern of the output device becomes finer and denser, the number of dots that make up the dot pattern of a character increases. The amount of font data that can be stored has increased, necessitating a storage medium with a larger capacity, and if the storage medium capacity is limited, the number of characters that can be stored is reduced. Also,
Recently, the number of output devices that can accommodate font data of multiple fonts and character sizes has increased, and the capacity of storage media has also increased.

The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide a font data storage method that reduces the amount of character font data and improves the utilization efficiency of a storage medium.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the font data storage system of the present invention has the following configuration. That is, in a font in which character patterns are formed in a dot matrix format, the font has a storage means for storing a plurality of character patterns, and when the plurality of character patterns are stored in the storage means, the margins of each of the plurality of character patterns are The font data storage method is characterized in that parts are stored in common.

[0006]

[Operation] With the above structure, the present invention allows the storage means to store character pattern data by sharing the margins around the characters of the dot matrix format character pattern with the margins around the characters of other character patterns. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

(Structure of Apparatus) FIG. 1 is a block diagram showing the structure of a recording apparatus for carrying out some representative embodiments of the present invention. In such a recording device, first, print data is input from an external device connected via the interface 2, and character codes, control codes, etc. constituting the print data are temporarily stored in the reception buffer memory 4. Next, the CPU 1 in the form of a microprocessor analyzes the print data in the reception buffer memory 4 according to the control program stored in the program memory 3, and outputs the output image data while appropriately referring to the font data in the font memory 5. Expand to image buffer memory 6. In parallel with this, the CPU 1 controls the recording device 7 based on the output image data developed in the image buffer memory 6, and records dot images such as characters and symbols on the recording medium.

[0009] Several embodiments executed using a recording apparatus having such a configuration will be described below.

(First Embodiment) FIG. 2 is a diagram showing a storage format for one character of font data having a 16 dot (vertical) x 16 dot (horizontal) configuration used in this embodiment. Such font data is stored in the font memory 5.

Now, each dot on the grid point that subdivides the character pattern at an appropriate resolution is stored in the font memory 5.
When a predetermined dot is included in the character pattern, the corresponding bit is set to 1, and when it is included in the background part, the corresponding bit is set to 0. This type of font data is divided vertically, with each 8 vertical dots forming a block.
Stored as byte data. As shown in Figure 2,
Each of these blocks is d0, d1, d2, ..., dw-
Call it 1. Data The font data of each character consists of W bytes, and the left margin and right margin of each character are allocated to the beginning and end of the font data string, respectively.

FIG. 3 is a diagram showing a storage form of font data having the above-mentioned storage format. In this embodiment, 8 in the vertical direction
Since each dot is stored as 1-byte data, the left and right margins of two adjacent characters, that is, the parts with a value of 0 at the beginning and end of the font data string of each character, It is stored in a format in which a bytes are overlapped with each other. In this way, the amount of font data can be reduced by a byte per character.

Next, the processing procedure for developing one character's worth of font data in the image buffer memory 6 in this embodiment will be explained using the flowchart shown in FIG.

First, in step S1, a character code n for one character is read from the reception buffer memory 4. Next, in step S2, the storage address An of the font data corresponding to the character code n is calculated using the following equation.

[0015] An=A0+(W-a)×n...(
1) In equation (1), A0 is the storage address of font data corresponding to character code 0.

In step S3, W bytes worth of font data is expanded into the image buffer memory 6 from the font data storage address An obtained by equation (1).

Therefore, according to this embodiment, when font data is expanded, the calculation of the font data storage address corresponding to the character code is carried out in the same way as the conventional method except that a bytes of overlap with adjacent font data are taken into consideration. Since the algorithm for calculating the font data storage address can be used, efficient font data storage can be performed while maintaining the conventional font data expansion process.

(Second Embodiment) FIG. 5 is a diagram showing the storage format of font data in this embodiment. In this embodiment, the font data is divided horizontally, and 8 horizontal dots each are stored as one byte of data (ie, a block). In this embodiment, when each block is stored in the font memory 5, a byte of the upper and lower margins of adjacent characters are stored in such a manner that they overlap with each other. In this way, the amount of font data can be reduced by a byte per character.

In this embodiment as well, the font data can be referenced and used in the same manner as in the first embodiment.

(Third Embodiment) In this embodiment, font data is indirectly referenced based on a lookup table that stores the start address of the memory where font data for each character is stored, and the font data of adjacent characters is A case will be described in which byte a of the data sharing portion is variable depending on the content of font data.

FIG. 6 is a diagram showing the storage format of font data in this embodiment. As shown in FIG. 6, for example,
Some characters, such as "I", have large margins, while other characters, such as "H", have small margins. In this embodiment, in such a case, the data sharing portion is increased depending on the adjacent characters (for example, "I" and "
between “H” and “I”), or a small difference (for example, between “H” and “I”
”). In this way, the data sharing area can be made larger for large characters in the margin area, and more efficient font data storage can be achieved.

Next, the processing procedure for developing one character's worth of font data in the image buffer memory 6 in this embodiment will be explained using the flowchart shown in FIG.

First, in step S11, the character code n for one character is read from the reception buffer memory 4. next,
In step S12, address Tn of the lookup table corresponding to character code n is determined by the following equation.

Tn=T0+t×n...(2)th (
2) In the equation, T0 is the start address of the lookup table, and t is the number of bytes occupied by an element for one character in the lookup table. Next, in step S13, the address Tn obtained in step S12 is accessed to obtain the font data storage address An. Finally step S14
Then, W bytes worth of font data is expanded into the image buffer memory 6 from the font data storage address An obtained in step S13.

Therefore, according to this embodiment, the data sharing portion can be made variable depending on the font data, so that more efficient font data storage can be performed. Furthermore, without changing the control program stored in the program memory 3, font data can be read from the font memory by changing only the font data and lookup table in the font memory 5.

Although the above three embodiments have been described on the assumption that the dot configuration of each character font is constant, the present invention is not limited to this. For example, the present invention can also be applied to a font with so-called proportional spacing, in which the width of each character differs.

Furthermore, the storage medium for font data is not limited to the font memory ROM, but there are also methods of storing the font data on a floppy disk or the like and reading the font data into the font memory RAM for reference and use as needed, or using an external A method of downloading font data from the device via an interface as needed may also be considered.

Furthermore, although this embodiment has been described with a configuration in which the recording device is used as an output, the present invention is not limited to this, and for example, it is also possible to output to another dot image image output device.

[0029]

As explained above, according to the present invention, the storage efficiency of font data is improved and the storage medium can be used effectively.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a recording apparatus that is a typical embodiment of the present invention.

FIG. 2 is a diagram showing the format of one character font data according to the first embodiment.

FIG. 3 is a diagram showing a storage format of font data according to the first embodiment.

FIG. 4 is a flowchart showing a font data development processing procedure according to the first embodiment.

FIG. 5 is a diagram showing a storage format of font data according to a second embodiment.

FIG. 6 is a diagram showing a storage format of font data according to a third embodiment.

FIG. 7 is a flowchart showing a font data development processing procedure according to a third embodiment.

[Explanation of symbols]

1 CPU 2 Interface 3 Program memory 4 Reception buffer memory 5 Font memory 6 Image buffer memory 7 Recording device

Claims (3)

[Claims] 1. A font in which character patterns are formed in a dot matrix format, comprising a storage means for storing a plurality of character patterns, and when storing the plurality of character patterns in the storage means, the plurality of character patterns are stored in the storage means. A font data storage method characterized by storing each blank space in common. 2. Each of the plurality of character patterns is a rectangular dot matrix, and a predetermined range on the upper, lower, right, and left sides of the rectangular dot matrix is regarded as the blank space. The font data storage method according to claim 1. 3. Each of the plurality of character patterns is a rectangular dot matrix, and the size of the margin portion is determined according to the dot pattern of each of the plurality of character patterns. The font data storage method according to paragraph 1.