JPH04158394A - Character generator - Google Patents

Abstract

PURPOSE:To reduce the circuit scale for the image shift value by providing a circuit converting the dot matrix data stored in a memory cell matrix into bold-faced characters vertically shiftingly from characters. CONSTITUTION:If the signal Oi sent from a scan selector 3 is H when the signal B given from the upper-level device 8 is H, the output signal ODi+1 of a BOLD (bold-faced character) circuit 4 becomes H. If the dot matrix data at H mean 'dot' and the dot matrix data at L mean 'no dot', the bold-faced dot data overlapped shiftingly by one dot below the dot matrix data stored in a memory cell matrix 2 appear on the output signals ODN-1 through OD0 of the circuit 4. When the signal B is L, signals ON-1 through OO appear as they are as the signals ODN-1 through OD0 of the circuit 4.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a character generator.

[Conventional technology]

Conventionally, a character generator used in printing devices such as printers has a configuration as shown in FIG. Then, the corresponding dot matrix data is output from the memory cell matrix 2 in units of several bits in synchronization with the scan address 5 given from the host device 8a.

[Problem to be solved by the invention]

The conventional character generator described above uses memory
The dot matrix data stored in the cell matrix 2 is sent as is to the host device as an output signal. Therefore, bold type (which is a type of emphasized printing) is used.
When printing in a font (hereinafter referred to as BOLD), it is necessary to convert the data into a BOLD font in a host device after receiving dot matrix data from a character generator.

Therefore, it is necessary to have a circuit in the host device that converts dot matrix data into BOLD font, which increases the circuit scale of the host device, and furthermore, this conversion causes a decrease in the processing speed of the host device. There was a drawback.

[Means to solve the problem]

The character generator of the present invention is a character generator that outputs dot matrix data representing a character as a set of dots from a memory cell matrix according to a request from a host device, and when an instruction is given from the host device, The dot matrix data stored in the memory cell matrix is configured to include a circuit that converts the dot matrix data stored in the memory cell matrix into a bold typeface in which the characters are shifted by one dot or several dots in the vertical direction and overlapped. There is.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention.

Character generator is character address decoder 1
, a memory cell matrix 2 , a scan selector 3 , and a BOLD circuit 4 .

The character address decoder 1 receives dots from the host device 8.
It takes character address 6, which points to the character for which matrix data is required, and stores it in memory cell matrix 2.
The read signal 7 for the address where the dot matrix data of the corresponding character above is stored is enabled.

FIG. 2 shows the state of dot matrix data for one address (that is, one character).

Dot matrix data for one character consists of (NXN) dot data (D
N-1/N-1 to Do10).

The scan selector 3 selects whether the scan address 5 given from the host device 8 is "O", l", '2", . . .
In response to the change in the output signal (ON-
1 to 00) and the dot matrix data as (D
N-110~DO10), (D N-171~DO/
1), (D N-1/2 ~ DO/2), ..., (D
N-1/N-1 to DO/N-1).

Here, memory cell matrix 2 has a dot matrix for N-bit signals (ON-1 to 00).
Data is stored in a column scan format where data appears column by column.

The BOLD circuit 4 is composed of (2N-2) NAND gates and (N-1) inverters, as shown in FIG.

When the signal B given from the host device 8 is at high level, the signal Of sent from the scan selector 3 (i=Q
, 1, ..., N-2) is at a high level, BOL
The output signal OD iH of the D circuit 4 is always at a high level.

When the signal O1 is at a low level, the signal O3+1 appears as is on the signal OD if.

If the dot matrix data has a high level meaning there is a dot and a low level means there is no dot, the character generator of this embodiment uses column data as described above.
Since it is a scan method, the output signal of the BOLD circuit 4 (
○D N-1 to ODO), BOLD dot data that is superimposed on the dot matrix data stored in the memory cell matrix 2 by shifting it one dot downward appears.

On the other hand, when signal B is low level, the signal (ON-1 to 0
0) is the output signal of the armpit BOLD circuit 4 (OD N-
1 to ODO').

In other words, in this case, the dot matrix monitor stored in the memory cell matrix 2 is output to the host device 8 as is without being converted into BOLD format.

FIG. 4 is a circuit diagram of a BOLD circuit in a second embodiment of the present invention.

The BOLD circuit 4 has (2N-4) NAND gates and (
N2) inverters.

When signal B from host device 8 is high level, scan/
When the signal Oi from selector 3 is high level, BO
The output signal ODi+2 of the LD circuit 4 is always at a high level.

When the signal Oi is at a low level, the signal Oi+2 appears as it is on the signal OD i+2.

On the other hand, when the signal B is at a low level, the signal O1 appears as it is on the output signal ODi of the BOLD circuit 4.

In other words, when signal B is at a high level, the dot matrix data stored in memory cell matrix 2 is converted to BOLD body shifted two dots downward and output, and when signal B is at a low level, it is output. The dot matrix data stored in the memory cell matrix is output as is without being converted.

〔Effect of the invention〕

As explained above, the character generator of the present invention generates one dot in the vertical direction of the character with respect to the dot matrix data stored in the memory cell matrix 2 when there is an instruction from the host device. Since the images are converted to a so-called BOLD font in which the images are overlapped with a shift of one or several dots and then output, there is no need for the host device to perform a conversion operation to the BOLD font.

This has the effect of reducing the circuit scale of the image transfer value and shortening the processing time.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention, and FIGS. 2 and 3 show dots stored in a memory cell matrix for explaining the operation of the block in FIG. 1, respectively. A diagram showing matrix data for one character and a circuit diagram of the BOLD circuit, FIG. 4 is a circuit diagram of the BOLD circuit according to the second embodiment of the present invention, and FIG. 5 is a block diagram of an example of a conventional character generator. It is a diagram. DESCRIPTION OF SYMBOLS 1... Character address decoder, 2... Memory cell matrix, 3... Scan selector, 4...
・・BOLD circuit, 5・・Scan address, 6・
...Character address, 7...Read signal.

Claims (1)

[Claims] A dot matrix that represents characters as a collection of dots.
In a character generator that outputs data from a memory cell matrix according to a request from a higher-level device, when there is an instruction from the higher-level device, the character generator outputs a character to the dot matrix data stored in the memory cell matrix. 1. A character generator characterized by having a circuit for converting the font into a bold font in which the font is shifted by one dot or several dots in the vertical direction and overlapped.