JP2518222B2 - Character generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a character generator for saving a font memory by dividing and storing a wide font pattern.

[Conventional technology]

As a conventional character generator, for example, there is one which generates a character pattern corresponding to a character code from a font ROM and stores the character pattern in an image memory. In this character generator, the font ROM stores various character patterns. For example, the character pattern "A" is
As shown in FIG. 6 (a), three 8-bit ROMs 1 to 3
It is composed by. By using these three ROMs 1 to 3, at a density of 240spi, width 24 dots and height 32 dots are 10
Characters with a size equivalent to cpi can be represented. Further, the peripheral circuit can be simplified by using three 8-bit I / O elements.

On the other hand, recently, large-capacity memory chips such as 256 Kb (kilobits) and 1 Mb (megabits) have been put to practical use, and one set of memory can accommodate a large number of characters, for example, 2048 characters, and multiple character sets can be stored. It is possible to have. Figure 6 (b) shows this example, and if one character is 32B (bytes) as shown in (a), 256 characters in 1 font set 8KB (kilobytes), 1 ROM set (4 font sets) 32KB ( In kilobytes)
It can store 1024 characters.

[Problems to be solved by the invention]

However, according to the conventional character generator, although there are narrow characters such as "I" and "j" as a character pattern, the character pattern exceeds 24 bits such as "M" and "W". For example, since some dots require 30 dots, adding a memory element for these wide dots has a disadvantage that the efficiency of use of the memory is reduced and it becomes uneconomical.

[Means for solving problems]

The present invention has been made in view of the above, and has a width of a predetermined reference size and has a width of the predetermined reference size in order to improve the usage efficiency of the memory and save the font memory. First storage means for storing the character pattern corresponding to the character font as it is and dividing and storing the character font corresponding to the character pattern having a width larger than the predetermined reference size; and a predetermined reference. A second storage unit having a width larger than the size by a predetermined width and receiving the divided character fonts and reconstructing them integrally with the original pattern; and a width larger than a predetermined reference size. There is also provided a character generator including control means for causing the character font reading means to access the second storage means when a character code corresponding to the character pattern is input. It is.

 Hereinafter, the character generator according to the present invention will be described in detail.

〔Example〕

FIG. 1 shows an embodiment of the present invention. An image signal generator 1 (a network may be configured by LAN) that inputs a character code from an external device such as a personal computer and outputs an image signal, A recording unit 2 that receives an image signal, a print command, etc. from the signal generator 1 and prints on a recording paper 5, and also supplies a clock signal, a line synchronization signal, a status signal, etc. to the image signal generator 1, It has a power supply circuit 3 for supplying power to the recording section 2 and the like, and a display panel 4 for operating the printer.

FIG. 2 shows the image signal generator 1, which includes an interface section 11 for receiving a character code from an external personal computer or the like according to the RS232C standard, a control section 12 for system control, a character pattern and a pixel pattern. Character pattern ROM 13 for storing and storing firmware, for example, having a 16-bit firmware ROM
An image handler 14 that performs a predetermined process on a character pattern or a pixel pattern, a bit map memory 15 that stores the character pattern or the pixel pattern processed by the image handler 14 in page units, and an access timing to the bit map memory 15. Memory controller 16 to control
And an interface unit that outputs an image signal to the recording unit 2.
17, an output interface section 18 for outputting a signal to the display panel, and an external character RAM 19 having a sufficient width because the main object is Chinese characters. The control unit 12 has a CPU 12a for controlling various operations, a RAM 12b for temporarily storing data and calculation results in various operations, and a divided font stored in a firmware ROM in addition to various programs for external characters. A ROM 12c that stores a program to be assembled in RAM 19, a parallel input / output circuit 12d that inputs signals of operation keys in parallel and outputs signals to the display unit in parallel, and a DMA controller 12c that controls access in data transfer between memories. Have.

3 (a), (b), and (c) show the character patterns "I", "A", and "M", and the width of "M" exceeds 24 bits and becomes about 30 bits. As shown in FIG. 3D, the character pattern ROM 13 is divided into 16 bits × 2.
It is stored in the empty area of the firmware ROM of
Further, the firmware ROM stores the flow shown in FIG.

The operation of the above configuration will be described as follows. When the power is turned on, the firmware is divided and stored in the empty area of the firmware ROM. For example, the character pattern of "M" is transferred to the external character RAM 19 and reorganized there. When a character code is input to the interface unit 11 of the image signal generator 1 from an external personal computer or the like, the CPU 12a interprets the character code and the code of the specific character,
That is, it is determined whether the character is a character that is divided and stored in an empty area of the firmware because the width exceeds 24 bits as in the above-mentioned "M", or is a normal character. If it is a code of a specific character,
A predetermined address of the RAM 19 is accessed, and the generated character pattern is subjected to predetermined processing (for example, enlargement, reduction, rotation, inversion, emphasis, etc.) in the image handler 14 and accumulated in the bitmap memory 15. On the other hand, in the case of a normal character code, a predetermined address of the character pattern ROM 13 is accessed, and the generated character pattern is stored in the bitmap memory 15 via the image handler 14.

When an image for one page is formed in the bitmap memory 15 in this way, an image signal is output to the recording unit 2 via the interface unit 17.

FIG. 5 shows the recording unit 2, 20 is a laser light source for emitting a laser beam 22, 21 and 25 are polarizers, 23 is a modulator having an image signal input terminal 24, 26 is a rotary polygon mirror, and 27 is f.
A θ lens, 28 is a photosensitive drum, 29 is a developing machine, and 30 is a transfer machine.

In the recording unit 2 having the above configuration, when an image signal is input from the interface unit 17 to the input terminal 24 of the modulator 23, the laser beam 22 emitted from the laser light source 20 is emitted.
Are modulated according to the image signal. This laser beam 22
Is subjected to scanning control by the rotary polygon mirror 26, and the fθ lens 27
To expose the photoconductor drum. The photoconductor lens 28 is charged before exposure, and an electrostatic latent image corresponding to the image in the bitmap memory 15 is formed on the photoconductor drum 28 by this exposure. The electrostatic latent image is developed with toner by the developing device 29 and transferred onto the recording paper 5 by the transfer device 30. The toner image on the recording paper 5 is fixed by a fixing device (not shown),
Recording of the image ends.

〔The invention's effect〕

As described above, according to the character generator of the present invention,
Characters such as proportional fonts are divided in the width direction and stored in the empty area of the firmware ROM, and the original pattern is reconstructed in the empty area of the external character memory that has a sufficient width before use. It is possible to save the font memory by improving the usage efficiency of.

[Brief description of drawings]

FIG. 1 is an explanatory view showing one embodiment of the present invention. Figure 2 shows the first
Explanatory drawing which shows the image signal generator in a figure. 3 (a), (b), (c), and (d) are explanatory views showing character patterns. FIG. 4 is a flow chart showing the operation of the present invention. FIG. 5 is an explanatory diagram showing a laser recording unit. FIGS. 6A and 6B are explanatory views showing the font memory. Explanation of symbols 1 …… Image signal generator 2 …… Recording unit 11 …… Interface unit 12 …… Control unit 13 …… Character pattern ROM (firmware ROM) 14 …… Image handler 15 …… Bitmap memory 16 …… Memory Controller 17, 18 …… Interface section 19 …… RAM for external characters

Claims (1)

(57) [Claims] 1. A character generator for generating a character pattern corresponding to a character code from a font ROM and accumulating it in an image memory, having a width of a predetermined reference size, and having a width of the predetermined reference size. First storage means for storing a character font corresponding to the character pattern as it is and dividing and storing a character font corresponding to the character pattern having a width larger than the predetermined reference size; and the predetermined storage means. A second storage unit having a width larger than a reference size by a predetermined width and receiving the divided character fonts and reconstructing them integrally with an original pattern; and a second storage unit larger than the predetermined reference size. A control means for causing the character font reading means to access the second storage means when a character code corresponding to a character pattern having a width of Character generator apparatus according to claim.