JPS5858673B2 - Variable size character display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables various
This invention relates to a variable size character display method that can display characters of various sizes.

The kanji display device has a dot pattern memory for various characters, reads out the memory according to the character code to obtain an image signal, and supplies this to a CRT (cathode ray tube) to display the character.

There are many types of characters, especially kanji, so you can create a dot pattern memory by selecting the characters you will use for the job.
This memory needs to be arranged according to font size.

FIG. 5 is a diagram explaining this, in which CG1 is a character pattern generator consisting of a ROM (!J-only memory) that stores various character patterns of 7 x 9 dots, CG2
．． CG3. CG4 is 16X16.24X24.32X3
This is a character pattern generator consisting of a ROM that stores various character patterns (the same characters as CG1, but of course, some or all of them may be of a different type) of a size of 2 dots.

When displaying characters, a code indicating a character and size information specifying its size are output from the code buffer CB, and character pattern generators CG1 to C are output according to the size information.
When one of G4 is selected, the one-character code becomes an address signal to address the selected character pattern generator, and output the character pattern.

In this way, each of the character pattern generators CG1 to CG, It stores a fixed character pattern size, so if characters of various sizes are to be displayed, a large number of character pattern generators must be provided. However, there are difficulties in terms of space, price, etc.

Therefore, the character pattern memory is limited to one or more types, and accordingly the character thickness is also limited to one or more types), and it is made to be selected using 1 or 2 bits of size information. is normal.

However, for example, when inserting characters into a screen displaying figures or the like, or when inserting characters into a display device that allows various animations, it is desirable to display characters of various sizes at arbitrary positions.

The present invention aims to provide a variable-size character display method that can satisfy these requirements without requiring a huge amount of memory, and its feature is that a random access memory is used in the character pattern generator. The number of bits n is calculated using the number of bits B in the row constituting one word of the memory as a unit.
BXm (n, m are integers) of various character patterns of various sizes are stored in nB dots in the first row of one character pattern in consecutive n rows of the memory, and For the nB dots in two rows, all character patterns are written in advance in the memo IJ in the order of n consecutive columns after the n rows of the memory, and then displayed on the cathode ray tube display. When displaying on a screen, the number Y indicating the vertical position of the horizontal scanning line of the displayed character, the clock number X indicating the position of the displayed character on the scanning line, and the first horizontal row of the displayed character. The first B dots are the code of the character written in the memory, represented by the row number of the memory, the horizontal size of the character to be displayed, represented by the number n of the rows, and the character to be displayed. The character pattern is displayed on the display surface by reading out the memory using a readout signal having a length in the vertical direction expressed by the number of scanning lines.

This will be explained in detail below with reference to Examples.

FIG. 1 shows an outline of an embodiment of the present invention, and shows a computer 11.
Character file 2. Interface section 3, pattern memory section 4, data buffer section 5. Leg restraint part 6. It consists of a CRT display section 7.

In a normal kanji display device, the pattern memory section 4 is composed of a character pattern generator consisting of one to several kinds of ROM as shown in FIG. Make it readable.

As shown in FIG. 6, this RAM has one byte, or eight memory cells, in the X direction (row).

Assume that the required number of memory cell groups in the Y direction is provided,
The address is a byte address.

Of course, the number of bits in the horizontal row of RAM B#t may be any number other than 1 byte, but this row corresponds to a word.
Having a part-time job is more universal.

In order to simplify the device, the size of the characters stored in this is set to IJ 8 n dots in the horizontal direction, and is matched to the boundary of the memory.

For example, if a character has a size of 32x32 as shown in Figure 2, it is divided horizontally into four bytes each.
The 4 bytes from 1 to 2 are stored in the RAM 1 sequentially in the Y direction as shown in FIG.

Therefore, in this RAM, 14 adjacent 4 bytes correspond to one line of character pattern, and in the above example, this group of 4 bytes is 32
One character is memorized side by side.

If the character pattern to be written next has a size of 16 x 16 bits, the 16 bits next to it are written in two adjacent columns (2
byte), and the character is stored in 16 of the memory cell group.

The same goes for the following, and as is clear from a comparison with FIG.
It is characterized by the fact that it is a RAM rather than an M, which reduces the chance of generating a group of idle memory cells, and the size of the characters can be any size that is an integral multiple of a byte without adding memory. be able to.

Character writing to the RAM is carried out in advance by the computer 1 by reading out the characters (including type and size) required for the job from the character file 2 and writing them into the pattern memory 4 before the job starts. I'll keep it.

What is the address of the written character in RAM? The left end of the first horizontal row of characters, in Figure 2, is the position where point P is written, and this represents each horizontal row of the RAM in order from the top, 0, 1, 2, 3.
When expressed as . . . , it becomes the number of the row containing the point P, that is, the number of the byte.

This byte address is stored in the computer 1, and this byte number is specified when reading.

FIG. 3 shows the format of the read signal output by the computer during read.

In this figure, X and Y are the character display positions, and X is the position of the character pattern starting point P on the horizontal scanning line of the CRT (normally, one horizontal scanning line 1 corresponds to 1024 clock pulses, so how many clock pulses are there? ), Y is a number counted from the top of the horizontal scanning line.

The next "character code" () is the code for the character in question, and uses the above-mentioned byte number.

The next "width" indicates the horizontal size of the character pattern in bytes, and if it is a 32x32 dot character pattern, it is 4.
If it is a 16x16 dot character pattern, it is 2.

The last "vertical line" indicates the vertical size of the character pattern, and if it is a 32x32 dot character pattern, it is 32.
．． If the character pattern is 16×16 dots, it is 16.

The usage of each piece of information on the "horizontal width" and "vertical line" will be explained later.

When displaying characters, the types of characters displayed on one screen,
Input the number of characters at position 9 into a computer, and cause the computer to output a character signal in the format shown in FIG.

These signals are temporarily stored in the code buffer of the data buffer section, sorted at the same time in order of coordinate Y, and written to the memory map in ascending order of coordinate Y.

■The number of characters on a line can be arbitrary, but the larger the number, the more registers and other various devices will be required.
For example, this number is limited to 20.

Corresponding to these 20 registers, there are 20 registers provided in the data buffer unit 5, and the above-mentioned character signals related to the horizontal scanning line at a certain point in time of α are written into these registers.

This can be easily done by sorting the character signals in the order of coordinate Y as described above.

The character signals stored in the maximum of 20 registers are read out in synchronization with the Y coordinate, that is, the scanning of the horizontal scanning line.This operation will be explained below with reference to FIG. 4 for the register.

In FIG. 4, 11 and 12 are matching circuits, and 13 is a flip-flop.

When the current Y, that is, the scanning line number matches the Y value of the character signal, the matching circuit 11 produces an output and sets the flip-flop 13.

The Q output is set to ``1'' to enable the matching circuit 12.

Next, when the current X, that is, the horizontal position of the end of the horizontal scanning line, matches the X value of the character signal, the matching circuit 12 generates an output of 1.
Enable character pattern memory RAM.

Then, the RAII character code is read out as an address signal, and a character pattern of ■life (4 bytes for 32×32 characters) is output.

This ends character pattern signal output for one scanning line for one character, and if there are other characters on the scanning line, a similar character pattern signal is output to the corresponding register.

A similar signal is output for the next second scanning line, but for the Y value, the flip-flop 1
3 remains set\, so the match circuit 12('' is enabled, and therefore the RA is activated again at the X position of the next scan line.
M is enabled.

However, this time, the adder circuit 14 operates and the number of horizontal bytes is added to the character code, so that the address signal (") specifies the second horizontal column (second group in FIG. 6).

The same goes for the following, and this character pattern signal is outputted, that is, minus 1 circuit 15 for each horizontal scanning line.
, the number of "vertical lines" of the character signal is subtracted by 1.

Therefore, when the output of the character pattern is finished (for example, when 32 lines are finished in the example shown in FIG. 2), the number of "vertical lines" becomes zero, and at this time, the flip-flop 13 is reset and one circuit goes into a rest state.

If there are characters to be displayed from the next scanning line onwards, the register which is no longer needed may input the character signal thereto and operate as described above again.

As described in detail above, according to the present invention, characters of various sizes can be displayed at any position on the screen without requiring too much memory, and especially when using a CRT with strong temporary characteristics. It is effective when used in graphical displays containing kanji.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an outline of a character display device. FIG. 2 is a diagram explaining the structure of a kanji pattern, FIG. 3 is a diagram explaining the format of a character signal used in the present invention, FIG. 4 is a block diagram showing an embodiment of the main part of the present invention, and FIG. 6 is a diagram illustrating the main parts of a conventional character display device, and FIG. 6 is an explanatory diagram showing the configuration of a character pattern generator according to the present invention. 4. With drawings. RAM is a character pattern generator, and 7 is a CRT display section.

Claims (1)

[Scope of Claims] 1. A random access memory is used as a character pattern generator, and the number of bits n B The nB dots in the first row of the character pattern are stored in n consecutive rows of the memory, and the nB dots in the second row of the sentence 'Ef-pattern are stored in the memory. All character patterns are written in advance in the memory in the order of n consecutive rows after the n horizontal rows, and when displaying on the cathode ray tube display screen, the character patterns to be displayed are A number Y indicating the vertical position of the horizontal scanning line, a clock number X indicating the position of the displayed character on the scanning line, and the first B dots of the first horizontal column of the displayed character are written to the memory. the code of the character represented by the row number of the stored memory, the horizontal size of the displayed character represented by the number n of horizontal rows, and the vertical size represented by the number of scanning lines of the displayed character. A variable size character display method, characterized in that the memory is read out using a readout signal consisting of: and the character pattern is displayed on the display surface.