JPH0948160A - Character storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store dot data in a small capacity by providing means for extracting blocks one by one from all characters and converting them to dot data of gathered shape, means for compressing the converted dot data, and means for storing the compressed dot data. SOLUTION: The address of a dot data memory 6 for storing character group including the characters receiving the printing command from a character memory 3 is read. The data are read from the address, but since the data is compressed by compressing means, it is stored in a work memory 7 while unwinding the data by unwinding means. Then, only the block of a style designated from the data stored in the memory 7 is fetched, the dot data of the designated style is restored, stored in a print memory 4, and printed. When the block is stored in the memory 7, the style is stored based on the size of the dot data of the character belonging the designated style, and stored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character storage device that compresses and stores dot data representing a character shape.

[0002]

2. Description of the Related Art Conventionally, when printing the shapes of characters or figures with a printer, those shapes are represented by dot data. Dot data is data that indicates whether or not to print for each dot, which is the minimum printing unit of the printing device. (Here, the case of printing the shape of a character But the same).

The dot data constructed as above is
When one dot is printed and one dot is not printed, one dot corresponds to one bit, which is 0 (indicates a binary number; hereinafter, described as 0b) and 1
RAM as bit map data represented by the binary value of b
And a memory such as a ROM. In the following, the dots to be printed will be bits 1b, and the dots not to be printed will be 0.
It will be described as a bit of b. For example, 24 dots x 24
In the dot data of dots, there are 576 dots,
When this is converted to bitmap data and stored in memory,
A memory capacity of 576 bits is required. (In a computer, 8 bits are often 1 byte, and when expressed in bytes, 576 bits is 72 bytes. Hereinafter, 8 bits are 1 byte without any particular explanation).

However, recently, there has been an increasing demand for displaying and printing characters with high quality, and as a result, more memory for storing dot data is required. For example, when storing dot data of 24 dots x 24 dots, 72 bytes could be stored, but when storing dot data of 48 dots x 48 dots, 288 bytes of memory are required, and 24 dots x It requires four times as much memory as the 24-dot case. Further, recently, a character storage device may be provided with a plurality of typefaces, and in this case as well, more memory for storing dot data is required. For example, 4
When one typeface is provided, four times more memory is required than when one typeface is used.

Therefore, in the past, many data compression methods such as run-length compression have been used. When the dot data is stored as bitmap data, the run length compression is 0b or 1b in the bitmap data.
Is a method of alternately storing the continuous number of.

[0006]

However, the character storage device as described above has recently been required to store dot data with a smaller memory capacity in order to realize cost reduction or size reduction of the device itself. It is rising. Therefore, conventionally, a data compression method such as run length compression in which a continuous number of 0b or 1b is alternately stored is used. However, the conventional data compression method has already reached the performance limit. Further, even if the number of typefaces is increased, the effect due to compression does not change, so the memory capacity for storing dot data also increases in proportion to the increase in the number of typefaces.

The present invention has been made in order to solve the above-mentioned conventional problems, and by changing the arrangement of dot data so that similar patterns appear unevenly in the dot data, It is an object of the present invention to provide a character storage device capable of storing dot data with a memory capacity smaller than conventional ones by increasing the effects of length compression and the like.

Further, when a character is represented by a plurality of typefaces,
In the case of the same letter, the shape is similar even if the typeface is different. Therefore, in a character storage device provided with a plurality of typefaces, it becomes easy to change the arrangement of dot data so that similar patterns appear unevenly in the dot data,
It is possible to increase the effects such as run length compression and store the dot data with a smaller memory capacity than the conventional one.

[0009]

To achieve this object, in a character storage device according to claim 1 of the present invention, a character group is composed of a plurality of characters, and the character means is divided by a dividing means. The dot data of the characters forming the group is divided into a plurality of blocks for each character, the conversion means extracts one block from all the characters forming the character group, and the dots are collected. The dot data converted into data is compressed by the compression means, and the dot data converted by the conversion means is compressed. The storage means stores the dot data compressed by the compression means.

Further, in the character storage device according to the second aspect, the plurality of characters forming the character group are one character represented by a plurality of typefaces.

Further, in the character storage device according to a third aspect of the present invention, the conversion unit extracts, from the characters, one block existing at the same coordinate of each character forming the character group, and extracts the blocks. Is converted into dot data in the form of collection.

Further, in the character storage device according to the fourth aspect, when the characters forming the character group include characters having different dot data sizes, the correcting unit sets the characters forming the character group. The dot data are all corrected to the same size, and the character group corrected by the correcting means is input to the dividing means.

Further, in the character storage device according to a fifth aspect of the present invention, among the compressed dot data stored in the storage means by the storage position acquisition means, a character group to which a character whose shape is desired to be restored belongs, The address at which the compressed dot data is stored is obtained, and the compressed dot data stored at the address obtained by the storage position acquisition unit is read by the decompressing unit to obtain the dot data before being compressed. A plurality of blocks storing dot data of a character whose shape is to be restored from the dot data developed by the developing means by the extracting means, and extracted by the extracting means by the restoring means. The shape of the character is restored using the plurality of blocks that have been created.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. A case where the present invention is applied to a dot printer will be described.

The dot data is generally stored in a memory or the like as bitmap data in which a portion to be printed is represented by a bit of 1b and a portion not to be printed is represented by a bit of 0b. Therefore, the process of converting dot data into bitmap data will be described without any particular explanation.

FIG. 1 is a block diagram showing the configuration of the control circuit of the dot printer. The microcomputer unit 1 which is the main component of this control circuit has a CPU 2, a character memory 3, a print memory 4, a program ROM 5, and A dot data memory 6 and a work memory 7 are provided.
Then, they are connected to the CPU 2 by a bus 10, and the bus 10 further includes an input unit 11 and a printing unit 12.
Is connected.

Next, the outline of each of the above components will be described. The CPU 2 controls the operation of the entire printer according to various programs stored in the program ROM 5, and the print memory 4 relates to the shape of the characters to be printed. The dot data is stored, and the input unit 11 inputs necessary data such as a character code relating to a character to be printed to the microcomputer unit 1.

The printing unit 12 is the microcomputer unit 1.
Is a part that prints characters based on commands from
The work memory 7 temporarily stores data necessary for processing when the CPU 2 executes various kinds of processing based on programs.

The character memory 3 stores a character code and a position on the dot data memory 6 in which dot data of a character corresponding to the character code is stored.

Next, in FIG. 2, the letter "H" is represented by four typefaces, 8 dots x 8 dots (8 dots x y in the direction of the x axis).
The dot data has a size of 8 dots in the direction of the axis, which will not be described below). Or later,
(A) to (d) are used to indicate respective characters and typefaces. In particular, when a typeface is shown, it is described as a typeface (a). Further, in the figure, a black-painted portion indicates a printed portion, while a white portion indicates a non-printed portion.

Further, FIGS. 5A to 5D respectively divide the dot data of the character “H” shown in FIGS. 2A to 2D into blocks of 1 × 2 dots. The symbols such as a00, a01, and b21 shown in each block are symbols indicating each block. For example, in the case of a42,
The x-coordinate of the character in (a) is 4, and the y-coordinate indicates a block located at a position of 4-5 in the y-axis direction.

Further, in the figure, the gray-painted portion corresponds to the black-painted portion in FIGS. 2A to 2D and indicates the portion to be printed. Further, the white portions also correspond to the portions filled with white in FIGS. 2A to 2D and indicate the portions that are not printed.

The dot data memory 6 stores dot data and the like relating to the shape of a character. Specifically, the dot data memory has a dot data section and a typeface data section.

The dot data section stores dot data that has been data-compressed.

The typeface data section is specifically composed of a typeface code section, a typeface position section, and a typeface size section.

A code representing each typeface is stored in the typeface code portion. In the typeface position section, the position where the blocks of the characters belonging to each typeface are stored when the blocks are collected and stored is stored, and the typeface size section stores the dot data of the characters belonging to each typeface. The size is remembered.

In this description, the font position (a) is set in the font position portion.
Is first, typeface (b) is second, typeface (c) is third,
The typeface (d) is stored as fourth, and the conversion unit collects and stores blocks of characters belonging to each typeface in this order.

Further, the dot data of the characters belonging to the typefaces (a) to (d) are all 8 dots × 8 dots, and there are 8 dots × 8 dots in the typeface size portion corresponding to each of the four typefaces. It is assumed that the size of the dot data is stored.

The dot printer having the above-mentioned configuration stores the dot data of the size of 8 dots × 8 dots of the character “H” represented by the four typefaces shown in FIGS. 2 (a) to 2 (d). The processing in the case of doing will be described with reference to the flowchart of FIG. It is also assumed that a part of the work memory 7 stores "H" dot data represented by four typefaces as shown in FIG. Further, it is assumed that the character group is composed of four characters shown in FIG. Further, the dot data of each character forming the character group is equally divided into blocks of 1 dot × 2 dots as shown in FIG. In addition, the blocks at the same coordinates of the respective characters forming the character group are extracted one by one from all the characters, and are made into dot data in the form of collecting them.

First, in S41, (a) to (d)
The dot data of the character is evenly divided into blocks each having a size of 1 dot × 2 dots. It is to be noted that FIG. 10 is a diagram showing a divided state. Incidentally, this processing is a part constituting the dividing means.

Next, in S42 to S44, blocks existing at the same coordinates of each character are extracted and converted into a collected form.

Specifically, first, in S42, it is determined whether or not the processing has been completed for all blocks of all characters. If not finished yet, the process proceeds to S43, and if finished, the process proceeds to S45.

Next, in S43, (a), (b),
The blocks existing at the same positions of the characters (c) and (d) are read one by one from all the characters. The process of S43 corresponds to the extraction means.

Next, in S44, the blocks extracted in S43 are stored in the work memory 7 in the order of blocks (a), (b), (c), and (d), and the process proceeds to S42.
The process of S44 corresponds to the converting means.

The processing of S42 to S44 will be described with a specific example.

First, in S42, it is determined that the processing has not been completed, so the process proceeds to S43.

Next, in S43, a00, b00,
The blocks of c00 and d00 are read.

Next, in S44, a00, b00,
The blocks c00 and d00 are stored in the work memory 7 in this order, and the process proceeds to S42. In terms of bitmap data, a
00 is 00b, b00 is 10b, c00 is 00b, d0
Since 0 is 11b, the bitmap data of 00100011b is stored in the work memory 7.

Next, in S42, since it is determined that the processing has not been completed, the process proceeds to S43.

Next, in S43, a01, b01,
The blocks of c01 and d01 are read and stored in order of a01, b01, c01 and d01 in S44.

Thereafter, the same processing is performed up to the blocks a73, b73, c73 and d73.

By performing the processing of S42 to S44, the dot data can be converted so that the specific pattern appears in the dot data in a biased manner. For example, a10, b
When the process of collecting the blocks of 10, c10, and d10, the bitmap data of 11111111b is stored in the work memory 7. In addition, the subsequent a1
Processing to collect blocks of 1, b11, c11, d11,
Even in the process of collecting the blocks of a12, b12, c12, d12 and the process of collecting the blocks of a13, b13, c13, d13, since the bitmap data of 11111111b is stored in the work memory 7, the work memory 7 ends up in the work memory 7. 32 bits of 1b are continuously stored, and the bits of 1b appear unevenly.

Next, in S45, the dot data converted in the processing of S42 to S44 is compressed by the compression means and stored in a part of the work memory 7. The compression means corresponds to a compression process performed by the CPU 2 using a predetermined program in the program ROM 5, and an existing run length compression or the like can be preferably used for this process. is there.

Next, in S46, the data compressed in S45 is stored in the dot data memory 6 using the storage means. Further, the position on the dot data memory 6 storing the compressed data is stored in the character memory 3,
This flowchart is finished. Incidentally, the processing of S46 is a part constituting a storage means. Further, since the specific pattern appears unevenly in the dot data due to the processing up to S44, the effect of the compression unit is increased compared to the conventional case,
It is possible to store dot data with a smaller memory capacity than before.

A process for printing a designated character by using the dot printer configured as described above will be described below with reference to the flowchart of FIG.

When receiving an instruction to print characters, this flowchart is executed. When printing characters, an instruction is issued to print which character and which typeface. As a specific example, description will be given with an example in which “H” is printed in the typeface (c). In addition, as shown in FIGS. 2A to 2D, 8 dots × 8 in which the character “H” is represented by four typefaces
It is assumed that the dot data of the dot size is stored according to the processing of the flowchart of FIG. 4 described above.

First, in S31, the address in the dot data memory 6 in which the character group including the character instructed to print is stored is read from the character memory 3. The instruction to print a character is given by the character code corresponding to the character, and the address on the dot data memory 6 corresponding to the character code is read from the character memory 3.

Next, in S32, data is read from the address of the dot data memory 6 read in S31. Since this data is compressed by the compression means, it is stored in the work memory 7 while expanding the data by the expansion means. The process of S32 is a part that constitutes the expanding means. The decompression means is for decompressing the data compressed by the compression means, and uses a method corresponding to the compression means.

Next, in S33, the position where the block of characters belonging to the designated typeface is stored and the size of the dot data of the characters belonging to the designated typeface are
It is read from the typeface data section of the dot data memory 6. A typeface code is assigned to each typeface, and the position of the block of characters belonging to the specified typeface is read from the typeface position part corresponding to the typeface code, and the specified typeface is read from the typeface size part. The dot data size of the character belonging to is read. In this description, the typeface (c) is stored in the third place, and the dot data is 8
It is read that the size is dot × 8 dots.
The process of S33 is a part that constitutes the storage position acquisition means.

Next, in S34 and S35, S32
Then, only the block of the designated typeface is taken out from the data stored in the work memory 7, and the dot data of the designated typeface is restored and stored in the print memory 4.

Specifically, in S34, it is determined whether or not the character restoration is completed. When finished, the process proceeds to S36. If not finished yet, the process proceeds to S35.

Next, in S35, the block at the position (obtained in S33) at which the block of characters belonging to the designated typeface is stored from the set of blocks collected and stored from the work memory 7 Is read and stored in the work memory 7, and the process proceeds to S34. The work memory 7
When the block is stored in the work memory 7 while restoring the designated typeface based on the size of the dot data of the characters belonging to the designated typeface (obtained in S33).
I will remember.

After that, until the character restoration is completed, S34-
Repeat S35. Incidentally, the processing of S34 and S35 is a part which constitutes the extraction means and the restoration means.

As a specific example, the work memory 7 in S32
The data expanded to is a00, b00, c00, d0
Blocks of 0 are collected and stored, and thereafter, a7
Blocks 3, 3, b73, c73, and d73 are collected and stored. Since the data for typeface (c) is stored in the third place, a00, b00, c00, and d0
When 0 blocks are collected and stored, c0
0 is read and stored in the work memory 7. Next, a01
When the blocks of b01, b01, c01, and d01 are collected and stored, c01 is read and the work memory 7
To memorize. After that, the same processing is repeated to restore the dot data as shown in FIG. 5C.

In S36, the restored dot data is transferred to the print memory 4 and the print processing is performed.

The character storage device of the present invention is not limited to the embodiment described above in detail, and various modifications can be made without departing from the spirit of the invention.

The present invention can be applied to the case where the dot data of the characters forming the character group have different sizes, and in that case, the correction means may be used. The correction means performs a process of converting the dot data of the other characters into the dot data having the largest size among the dot data of the plurality of characters.

Further, although the dot data is equally divided into blocks of 1 dot × 2 dots, it may be divided into blocks of any size.

Further, although the description has been made by using the dot data having a size of 8 × 8 dots, the dot data having an arbitrary size can be similarly processed.

The type of font is not specified, but any font may be used.

Although the same letter "H" belonging to a plurality of typefaces has been used for explanation, different letters may be used.

Although the characters belonging to a plurality of fonts have been described, the same processing may be performed on characters belonging to the same font.

Further, the present invention is not limited to the case of printing characters using a dot printer, but may be applied to the case of displaying characters on a display device such as a display.

The present invention can be applied not only to a dot printer but also to a printer that prints by another method such as a laser printer.

Alternatively, the present invention may be applied to a printing device such as a word processor, a workstation, a personal computer or the like, or a device having a display device.

[0066]

As is apparent from the above description,
According to the character storage device of the first aspect, by applying the dividing means and the converting means to the dot data of the characters forming the character group, it is possible to convert the dot data into the dot data in which similar patterns appear unevenly. . Then, the compression of the data compression method such as the run length compression is increased, and the dot data can be stored with a smaller memory capacity.

Further, according to the character storage device of the second aspect, when the character group is composed of one character represented by a plurality of fonts, the same character has different fonts. Are similar in shape. Therefore, by applying the dividing means and the converting means to the character group, it is easy to convert the dot data of the characters belonging to the character group into the dot data in which similar shapes appear unevenly, such as run length compression. The efficiency of the data compression method is increased, and the dot data can be stored with a smaller memory capacity.

Further, according to the character storage device of the third aspect, since the character group is composed of the characters having the same dot data size, the character storage device has a simpler configuration than that of the first aspect. it can.

According to the character storage device of the fourth aspect, when the character group is composed of characters having different dot data sizes, all the dot data sizes of the characters are set to the same size. be able to. Therefore, the configuration of the character storage device according to claim 3 can be used, and the configuration of the character storage device can be made simpler than that according to claim 1.

According to the character storage device of the fifth aspect, the dot data of the character stored in the character storage device of the first to fourth aspects can be restored.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a control circuit of a dot printer to which the present invention is applied.

FIG. 2 is a diagram showing dot data in each typeface related to a character “H”.

FIG. 3 is a flowchart showing a process of printing characters by a dot printer to which the present invention is applied.

FIG. 4 is a flowchart showing processing when storing dot data of characters.

FIG. 5 is a diagram showing a state in which the dot data shown in FIG. 2 is uniformly divided into 1 dot × 2 dots.

[Explanation of symbols]

 1 Microcomputer Section 2 CPU 3 Character Memory 4 Printing Memory 5 Program ROM 6 Dot Data Memory 7 Work Memory 10 Bus 11 Input Section 12 Printing Section

Claims (5)

[Claims] 1. A character storage device for storing dot data relating to the shape of a character, wherein a character group is composed of a plurality of characters, and the dot data of the characters constituting the character group is divided into a plurality of blocks for each character. A dividing means for dividing into a plurality of characters, a converting means for extracting blocks one by one from all the characters constituting the character group, and converting the blocks into dot data in a collected form, and the dot data converted by the converting means. A character storage device comprising: a compression unit for compressing; and a storage unit for storing the dot data compressed by the compression unit. 2. The character storage device according to claim 1, wherein the character group is formed by representing one character in a plurality of typefaces. 3. The converting means extracts, from each of the characters, blocks existing at the same coordinates of the respective characters forming the character group one by one, and converting the blocks into dot data in a collected form. The character storage device according to claim 1, wherein: 4. When the characters forming the character group include characters having different dot data sizes, a correction unit for correcting all the dot data sizes of the characters forming the character group to the same size. 4. The character storage device according to claim 3, further comprising: a character group corrected by the correction means as an input of the dividing means. 5. A storage position acquisition means for obtaining an address at which the compressed dot data of a character group to which a character whose shape is to be restored belongs is stored among the compressed dot data stored in the storage means, From the expansion means for reading the compressed dot data stored at the address obtained by the storage position acquisition means and expanding it to the dot data before compression, and the dot data expanded by the expansion means ,
An extracting unit that extracts a plurality of blocks in which dot data of a character whose shape is to be restored is stored, and a restoring unit that restores the shape of the character by using the plurality of blocks extracted by the extracting unit are provided. Character storage device characterized by.