JPS5856872B2 - Expanded character pattern encoder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an enlarged character pattern encoder that can easily encode enlarged characters in a system that encodes and transmits character information by run-length encoding, especially when characters are displayed (or printed) in a dot pattern. The present invention relates to an enlarged character pattern encoder that obtains the following.

In conventional devices of this kind, when transmitting an enlarged character code, either (1) the dot pattern memory that stores the dot pattern of the character before encoding is replaced with the enlarged dot pattern, or (2) the dot pattern is A method is being considered in which the contents of the dot pattern memory are converted into an enlarged dot pattern and then encoded without replacing the memory.

However, according to these methods, in the case of (1) above,
Since the dot pattern of characters is fixed, it is virtually impossible to encode various dot sizes in a single dot pattern memory.

It is also possible to create dot patterns by providing dot pattern memories corresponding to many different dot sizes and switching between them, but this is uneconomical.

Furthermore, in the case of (2) above, in order to encode it, it is necessary to write the pattern into a line buffer for one line and then encode it, and if the number of hits per line is large, a large number of line buffers are required. There are drawbacks such as.

In order to solve these drawbacks, the present invention stores the lengths of white and black runs of character dot patterns in advance, thereby requiring only one type of memory for storing characters and eliminating the need for line buffers. The purpose is to enable easy expansion (including reduction) without having to do so.

The drawings will be explained in detail below.

The figure shows an embodiment of the present invention, where 100 is a character code/line number/sword address conversion unit, 101, 102° 103.10
4 is a basic pattern run memory, 105 is a change point storage memory, 106 is a readout control unit, 107 is a readout number counter, 108 is a pixel level determination unit, 109 is a run enlargement unit, 110 is a run enlargement control unit, and 111 is a A register for the cumulative number of continuous pixels between characters, in which the number of pixels corresponding to the character interval between one character and another adjacent character, for example, white, is set; 112 is a run length encoding unit; 113;
is a shift register for parallel-to-serial conversion.

Also, in the signal lines in the figure, A is the run sequence number line, and B is the read/write line.
C is a next character code read command line, D is a run length code output line, E is an encoding end signal line, X is a character code line, and Y is a line number line.

The operation of the diagram will be explained.

For the purpose of explanation, the present invention uses basic pattern run memories 101, 102, 103, . . . that store basic pattern runs.
In 104, it is virtually assumed that there is a pixel immediately before the starting point pixel (the first pixel of the row), and that pixel is assumed to be white.

Note that there is essentially no difference as a black pixel.

Therefore, the basic pattern run memory 101, 102°1
The length of the first run of the row with 03, 104 is the value "0"
If , it means that the first pixel is black.

It is also assumed that the pixel at the end of one line is a black pixel.

In the case of the present invention, enlargement processing is performed based on the following idea.

That is, (4) create a run-length font memory corresponding to the character pattern (basic pattern) expressed in the basic dot matrix size, and (B) create each run (basic pattern) read from the run memory constituting the run-length font memory. (C) Determine continuous pixels between characters and multiply by a constant, ■)
A run length code for the enlarged character is created using the enlarged run obtained in (B) above and the enlarged run obtained in (C) above.

In the figure, first, the character code line X and line number line Y are
It is assumed that this is set in advance.

The character code and
A run memo IJ 101 in which the line number-address conversion unit 100 converts character codes and line numbers into basic patterns.

102, 103, 104 and change point storage memory 10
5 into an address for access.

Basic pattern run memory 101, 102゜103.1
The output line 04 is connected to the run enlarger 109 and the cumulative number of continuous pixels between characters register 111.

On the other hand, the output of the change point storage memory 105 is input to the read control section 106 and compared in magnitude with the data of the read number counter 101.

If the content of the change point storage memory 105 is larger than the number of readout counters 107, the readout control unit 106
issues a READ command to the basic pattern run memories 101 to 104 via the read control unit B, and causes the run length information stored in the basic pattern run memories 101 to 104 to be output.

The run sequence number at this time is read number counter 1.
This is the run sequence number line A which is the output of 07.

The data output from the basic pattern run memories 101 to 104 is input to the run expansion unit 109 under the control of the run expansion control unit 110, where it is converted to a length multiplied by a predetermined constant. It is input to run-length encoding section 112 together with level information.

The run-length encoding unit 112 is constituted by, for example, a ROM, and performs run-length encoding using a table look-up method based on the input run length and its pixel level.

This encoding can be done using conventional techniques.

The coded data for one run is stored in the parallel-to-serial conversion shift register 113 and output to the run-length code output line as necessary.

When the encoding is finished, the run-length encoding unit 112
The read control unit 106 is activated via the encoding end signal line E, and information on the length of the next run is read out.

This is done by incrementing the reading number counter 107 by the encoding end signal line E, and incrementing the run sequence number address of the run memories 101 to 104 of the basic pattern.

Repeat this below. In this manner, when the number in the reading number counter 107 matches the number in the change point storage memory 105, the state of the next character code read command signal line C is changed.

Assume that the next character code appears on the character code line X as a result of this.

At the same time, the next character code read command signal line C activates the run expansion control section 110.

The run expansion control section 110 operates as follows.

First, when the state of the next character code read command signal line C changes, that is, when all the runs for one scan line of one character are output, the cumulative number of continuous pixels between characters register 111
The length of the last run of the run series of the previous character and the pixel level at that time are stored.

Thereafter, the pixel level determining unit 108 determines the pixel level of the next character, and if it matches the pixel level stored in the cumulative number of continuous pixels between characters register 111, the pixel level of the next character is read from the run memory. The sum of the length of the first run and the length of the run stored in the cumulative number of continuous pixels between characters register 111 is calculated, and the result is taken as the run between characters.

That is, the length of the run is set in the cumulative number of consecutive pixels between characters register 111.

Next, in cases other than the above, that is, when the pixel level of the next character is different from the pixel level of the cumulative number of continuous pixels between characters register 111, that is, when a black pixel starts for the next character, the continuous pixels between characters are as follows. You can tell that it's finished,
The run length at this time is sent to the run expansion unit 109 and encoded.

The completion of this encoding is known from the encoding end signal line E.
The next run of continuous pixels between characters is sent to the run enlarger 109.

The above is the operation of the run expansion control section 110.

Thereafter, the routine again enters into an operation routine for comparing the contents of the change point storage memory 105 and the reading number counter 107, and the following operations are repeated.

In one embodiment of the present invention, the operation is as described above, and the enlargement process is performed.

Note that the run expansion unit 109 described in the embodiment is configured with conventional technology such as a multiplier, but if the constant determined by the run expansion unit 109 is made fully variable by the programmer, several types of expansion can be performed in one line. Encoding can be easily performed even when characters are lined up.

As described above, according to the present invention, enlarged dot patterns can be easily created from the same font memory, and even if one line is long, it is easy to create because no line buffer is used. There are advantages to being able to do this.

The latter advantage depends on the number of bits in the cumulative number of continuous pixels between characters register 111, but this length can be increased by a power of 2, so if the line length is finite, a line buffer is used. It is much more advantageous than the case.

[Brief explanation of the drawing]

The figure shows the configuration of an embodiment of the present invention. In the figure, 100... Character code/line number-address conversion section, 101, 102, 103, 104...
- Basic pattern run memo IJ, 105...change point storage memory, 106...readout control unit,
107... Readout number counter, 108...
... Pixel level determination section, 109 ... Run enlargement section, 110 ... Run enlargement control section, 111 ...
... Cumulative number of continuous pixels between characters register, 112...
...Run length encoding unit, 113...Shift register for parallel-to-serial conversion, A...Run sequence number line, B...Readout control line, C...
...Next character code read command line, D...Run length code output line, E...Encoding end signal line, X...Character code line, Y... ...Line number line.

Claims (1)

[Claims] 1. A basic pattern run memory that stores the length of black and white pixel runs in either the row or column direction of the character pattern when expressed in the basic dot matrix size;
A run-length font memory is provided, which is composed of a change point storage memory that stores the number of change points of black and white pixels in either the row or column direction of the character pattern, and a run length font memory that stores the change point number of black and white pixels in either the row or column direction of the character pattern, and a run length font memory that stores the change point number of black and white pixels in either the row or column direction of the character pattern. A readout control unit that sequentially reads out the run memory of the basic pattern, and a pixel level determination unit that determines whether the pixel being read by the readout control unit is at a white level or a black level, The length of each run read from the run memory of the pattern and the length of the run corresponding to the run between characters read from the run memory of the basic pattern,
1. An enlarged character pattern encoder, characterized in that the enlarged or reduced character pattern is enlarged or reduced according to a fixed or rewritably given constant, and the enlarged or reduced run is run-length encoded.