JPH0226592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dot printer equipped with a character generator.

Conventionally, in this type of dot-type printer, when character data for the character "h" is stored in the character generator, it is stored in a dot pattern as shown in a in Fig. When character data is stored, it is stored in a dot pattern as shown in FIG. 1B. In other words, the character generator forms eight bit columns numbered 1 to 1 in the vertical direction as a storage area for each character data, and forms 9 bit rows numbered 1 to 9 in the horizontal direction, for a total of 72 bits. It formed an area. This is because the character "j" needs to be printed two dot lines lower than the character "h".

In this way, in conventional dot printers, character data is stored in the character generator in the same pattern as the dot print pattern, resulting in a large amount of wasted memory space in the character generator. There was a problem.

This invention was devised to solve such problems, and it is possible to prevent wastage of the memory area of the character generator as much as possible, improve the memory usage efficiency of the character generator, and furthermore, it is possible to improve the memory usage efficiency of the character generator. It is an object of the present invention to provide a dot printer capable of realizing data processing when reading character data and printing dots with a simple configuration.

As shown in FIG. 2, this invention reduces the storage area for character data by 1 bit row compared to the conventional one.
It has 64 bits in columns x 8 rows, and each bit in the 8th row is used as a flag storage section for positioning the dot print of the dot row pattern in the row direction. That is, as shown in FIG. 2a, for the character "h", the flag in the dot pattern print positioning flag storage section corresponding to each dot row is set to "0", and the character data is printed as is, and the second dot is printed.
As shown in Figure b, for the letter "j", the flags in the dot pattern print positioning flag storage unit corresponding to the columns B, C, D, and E in which dot array patterns are stored are set to "1" (Figure B). Inside is ``・''
It is shown as ), and when printing dots, it is determined that the flag "1" is set, and the dot row is lowered by two rows, resulting in the dot print pattern shown in c in Fig. 2, i.e., b in Fig. 1.
Print out a similar pattern. In this way, a print pattern similar to the conventional one can be obtained. The flag in the print positioning flag storage section is determined by reading out both the flag and the dot row pattern of the character data into an existing accumulator.

The present invention uses such a method to store and read character data in a character generator, and achieves the above-mentioned object.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is a character generator in which character data is stored in the form of a dot pattern, and 2
3 is the ROM (read-only memory) that stores the program data that controls the entire printer system, and 3 is the CPU that controls the system.
(central processing unit). In particular, data discrimination program data 21 and data shift program data 22 are stored in the ROM 2.
The CPU 3 is provided with an accumulator 31, a program interpretation circuit 32, and the like. In the figure, 4 is a chip selector, 5 is an output port, and 6 is a dot pin driver circuit. CPU3 mentioned above
The character generator 1 and ROM 2 are connected to each other by a data bus 7 and an address bus 8, and the CPU 3 and chip selector 4 are connected to each other by the address bus 8, and the CPU 3 and the chip selector 4 are connected to each other by the address bus 8.
and output port 5 are connected by the data bus 7. The CPU 3 interprets and executes instructions based on the program data in the ROM 2. The chip selector 4 decodes the address signal from the address bus 8 and selects the character generator 1, ROM 2, and output port 5. The output port 5 is connected to the transistors Tr ₁ to Tr of the dot pin driver circuit 6.
I am trying to drive Tr ₉ . The driver circuit 6 operates the drive coils _C1 to _C9 of the corresponding dot pins by the operation of the transistors _Tr1 to _Tr9 , respectively. Character data is stored in the character generator 1 in a dot pattern as shown at a and b in FIG.

The CPU 3 processes the character data in the character generator 1 based on the flowchart shown in FIG. That is, the character data in the character generator 1 is specified, and the character data is read out as bit data for each dot row of one to one and stored in the accumulator 31. At this time, the bit signal of the dot pattern print positioning flag is stored at the leftmost position. Subsequently, the accumulator 31 is rotated to the left by one digit according to the data shift program data 22. Note that when the rotation is made to the left, "0" is stored at the rightmost end of the accumulator 31. As a result, the bit signal of the dot pattern print positioning flag is set in the cycle flag CYF provided corresponding to the accumulator 31. Then, CYF is determined by data discrimination program data 21.
= 1 or not. (Discrimination means) When CYF=1 is determined by this check, the accumulator 31 is further rotated to the left by one digit according to the data shift program data 22. Also CYF≠
If 1 is determined, the data shift program data 22 rotates the accumulator 31 to the right by one digit to return the bit signal of the cycle flag CYF to the leftmost end of the accumulator 31. That is, the bit data in the accumulator 31 is returned to the state at the time of reading. (Selection means) For example, when the bit data read into the accumulator 31 is "01111111", a of FIG.
As shown in FIG. 5, the accumulator 31 rotates left, then right. When the bit data is "10100000", the accumulator 31 rotates left, then rotates as shown in b of FIG. A counterclockwise rotation process will be performed. Finally, the bit data stored in the accumulator 31 is transferred to the output port 5.
Transistors Tr ₁ to _{Tr 9} of the dot pin drive circuit 6 are selectively operated by the dot pin drive signal from the dot pin drive coils C ₁ to _{C 9} of the dot pins.
will be selectively energized. Therefore, the letter "j" stored in the character generator 1 in the dot pattern shown by b in Fig. 2 will eventually be printed out in the dot pattern shown by c in Fig. 2. .

In this way, the character data for the character generator can be stored in 8 columns and 8 rows, that is, in a 64-bit memory area, which is 8 bits less than the conventional 72-bit system, so the memory area is reduced. It is possible to prevent waste of memory as much as possible and improve memory usage efficiency.

In addition, the bit signal of the print positioning flag along with the dot row pattern of the character data is read out to the existing accumulator, and the read data is controlled to rotate one digit to the left, and the bit signal is transferred to the existing accumulator. cycle flag
CYF is set and determined, and based on the determined content, the accumulator is further rotated one digit to the left or one digit to the right to shift the dot print in the row direction, that is, to position it. Data processing to print data can be performed with a simple configuration without using a dedicated circuit.

In the above embodiment, when "1" is set in the dot print row positioning flag storage section, the dot print row is lowered by two rows, but this is not necessarily the case, and vice versa. When "1" is set to "1", the dot print line may be moved up two lines; in this case, the character "h" may be moved up two lines.

As described in detail above, according to the present invention, a character generator is provided which stores character data formed into a dot pattern, and required character data is read out for each dot row from this character generator, and the dot row is In a dot type printer that prints a character in dots by driving a dot pin driver based on a pattern, the character generator sets a flag for printing position in the row direction of the dot pattern for each dot column pattern storage area in the character data storage area. A storage section is formed, each dot row pattern is read out to an accumulator along with a print positioning flag, the flag in the print positioning flag storage section is taken out from this accumulator, the contents of the flag are determined, and the contents of the flag are determined based on the determination result. Since it is possible to select whether or not to shift the dot row pattern by a predetermined dot in the row direction of the dot print, waste of the memory area of the character generator can be prevented as much as possible, improving the memory usage efficiency of the character generator. In addition, it is possible to provide a dot type printer which can realize data processing when reading character data from a character generator and printing dots with a simple configuration.

[Brief explanation of drawings]

1A and 1B are diagrams showing an example of a storage pattern of character data in a conventional character generator, and FIGS. 2A and 2B are diagrams showing an example of a storage pattern of character data in a character generator in the present invention. FIG. 2c is a diagram showing an example of a print pattern of character data in the present invention, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. A flowchart showing character data call processing,
FIGS. 5a and 5b are diagrams showing bit data processing in the accumulator in the same embodiment. 1...Character generator, 2...ROM (read only memory), 3...CPU (central processing unit), 31...accumulator, 5...output port, 6...dot pin driver circuit.

Claims (1)

[Claims] 1. Equipped with a character generator storing character data converted into a dot pattern, the required character data is read out for each dot row from this character generator, and the dot pin driver is driven based on the dot row pattern. In a dot type printer that prints characters in dots, the character generator includes a flag storage section for print positioning in the row direction of the dot pattern provided for each dot row pattern storage area in the character data storage area; an accumulator that stores together the dot row pattern of each dot row pattern storage area read from the character data storage area and the flag of the print positioning flag storage section with the flag positioned at one end; A cycle flag memory in which a flag in the print positioning flag storage section is set by one-digit rotation in one direction, a determining means for determining the contents of the flag set in this memory, and a determining means based on the determination result by this determining means. A selection means is provided for selectively controlling the accumulator to rotate by one digit in the other direction and control to rotate it by an additional digit in one direction, and the content of the accumulator after the rotation is controlled by the selection means is provided. A dot type printer, characterized in that it outputs a dot row pattern for printing and drives the dot pin driver.