JPH0695640A - Character display controller - Google Patents

Abstract

PURPOSE:To display a character with a similar character shape to an original character without displaying the oblique line part of the character with a polygonal by controlling display of the character based on character information digitizing the outline of the character. CONSTITUTION:A clock signal is generated by a clock signal generation means 1, and a horizontal synchronizing signal/vertical synchronizing signal are generated by a synchronizing signal generation means 2, and these signals are outputted to a display device drive circuit. By an outline font development means 4, outline information is read in from an external outline font information memory, and the outline information is converted to dot information and developed. The developed font is stored in a storage means 5, and by a rectangular area bit transfer means 6, an address for transferring to a display memory is generated, and an address signal (2) is outputted to a display memory control means 3 in response to an address request signal (1) from the display memory control means 3. A signal (4) is outputted by the transfer means 6 in response to a transfer request signal (3) from the storage means 5, and the font is transferred.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a character display control device. In particular, the present invention relates to an improvement for the purpose of providing a character display control device capable of improving the quality of characters displayed on the screen of a display device such as a CRT.

[0002]

2. Description of the Related Art In the prior art, in order to improve the quality of characters displayed on the screen of a display device such as a CRT,
A method of improving the resolution of a display device and increasing the number of images per character is used. As a result, for example, the screen is divided into 1120 in the horizontal direction and 750 in the vertical direction (1120 ×
750 dots), and a method of expressing one Chinese character by 24 × 24 dots is adopted. Then, the character display control device according to the related art generates a synchronization signal (for example, a horizontal synchronization signal, a vertical synchronization signal) for the display device, and is set in an external display memory in synchronization with the synchronization signal. Based on the above-described character information represented by 24 × 24 dots, a control signal for controlling light / dark of each pixel is output.

[0003]

As described above, the character display control device according to the prior art determines the pixels based on the character information represented by 24 × 24 dots set in the external display memory. Since the light / dark control is performed, the characters displayed on the display device have a broken line display, and when the characters are enlarged, the quality of the characters deteriorates.

An object of the present invention is to eliminate this drawback and to provide a character display control device capable of improving the quality of characters displayed on the screen of a display device such as a CRT.

[0005]

The above-mentioned object is to provide a clock signal generating means (1) for generating a reference clock signal.
And a synchronizing signal generating means (2) for generating a horizontal synchronizing signal and a vertical synchronizing signal based on the output of the clock signal generating means (1), and the clock signal generating means (1).
Display memory control means (3) for controlling writing and reading of information in the display memory based on the output of
And outline font expansion means (4) for converting outline information of the outline font read from an external outline font information memory into dot information, and a font in which the outline font expanded by the outline font expansion means (4) is stored. Achieved by a character display control device having expansion storage means (5) and rectangular area bit transfer means (6) for generating an address for transferring a font stored in this storage means (5) to a display memory. To be done.

The outline font in the present specification is a character displayed based on character information in which the outline of the character is digitized.

[0007]

Since the character display control device according to the present invention controls the display of the character based on the character information in which the contour of the character is digitized, the shaded portion of the character becomes a broken line display as in the case of the prior art. Instead, it is possible to display a character having a character shape closer to the original character and improve the quality of the displayed character.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A character display control device according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a character display control device according to the first embodiment.

Referring to FIG. 1, reference numeral 1 denotes a clock signal generating means for generating a reference clock signal. Reference numeral 2 is a synchronizing signal generating means for generating a horizontal synchronizing signal and a vertical synchronizing signal based on the clock signal output from the clock signal generating means 1. Reference numeral 3 indicates, for example, a blanking period so that reading of information stored in the display memory and writing of information in the display memory do not conflict with each other based on the clock signal output from the clock signal generating means 1. It is a display memory control unit that outputs a display memory address for writing information while controlling the writing of information to the display memory during the (blanking period). Four
Is an outline font expanding means for converting outline information of outline font (character information obtained by digitizing outlines of characters) read from an external outline font information memory into dot information. Reference numeral 5 is a font expanding storage means for storing the font expanded by the outline font expanding means 4. 6 generates an address for transferring the font stored in the font expanding storage means 5 to the display memory, and outputs this address to the display memory control means 3 as described above.
It is a rectangular area bit transfer means for instructing the font expansion storage means 5 to transfer information to the display memory.

Next, referring to the flow chart, the first
The operation of the character display control device according to the embodiment will be described.

FIG. 2 is a flowchart of the character display control device according to the first embodiment.

Referring to FIG. 2, the clock signal generating means 1 generates a clock signal (a).

On the basis of this clock signal, the synchronizing signal generating means 2 generates a horizontal synchronizing signal and a vertical synchronizing signal and outputs them to the display device driving circuit (b).

The outline font developing means 4 reads outline information of the outline font from the external outline font information memory (c).

The outline font expanding means 4 converts the read contour information into dot information and expands it (d).

The expanded font is stored in the font expansion storage means 5 (e).

The rectangular area bit transfer means 6 generates an address for transfer to the display memory and outputs the address signal to the display memory control means 3 in response to the address request signal from the display memory control means 3. The display memory control means 3 outputs this address to the display memory (f).

In response to the transfer request signal from the font expansion storage means 5, the rectangular area bit transfer means 6 outputs a transfer instruction signal to the font expansion storage means 5, and the font expansion storage means 5 issues this transfer instruction. In response to the signal
Transfer the stored font to the display memory (g).

FIG. 3 shows a configuration example of a display device using the above character display control device.

Next, a character display control device according to the second embodiment of the present invention will be described.

FIG. 4 is a block diagram of the second embodiment.

See FIG. 4. The present embodiment differs from the first embodiment only in that a font expansion memory is provided outside. In this case, the outline font expansion means 4 uses the memory interface 7
To access the external memory via. The symbols and operations other than the above are the same as those in the first embodiment.

[0024]

As described above, the character display control device according to the present invention includes a clock signal generation means, a synchronization signal generation means, and a display memory control means for controlling writing / reading of information in the display memory. An outline font expansion means for converting outline information of the outline font read from an external outline font information memory into dot information, a font expansion storage means for storing the font expanded by the expansion means, and the storage means. It has a rectangular area bit transfer means for generating an address for transferring the stored font to the display memory, and based on the character information obtained by digitizing the outline of the character read from the external outline font information memory. Since it controls the display of characters, it is closer to the original characters. It is possible to display the shape of the character.

Therefore, the present invention can provide a character display control device capable of improving the quality of characters displayed on the screen of a display device such as a CRT.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a character display control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of the character display control device according to the first embodiment of the present invention.

FIG. 3 is a configuration example diagram of a display device using the character display control device according to the first embodiment.

FIG. 4 is a configuration diagram of a character display control device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 clock signal generation means 2 synchronization signal generation means 3 display memory control means 4 outline font expansion means 5 font expansion storage means 6 rectangular area bit transfer means 7 memory interface address request signal address signal transfer request signal transfer instruction signal

Claims (1)

[Claims] 1. A clock signal generating means (1) for generating a reference clock signal, and a synchronizing signal generating means for generating a horizontal synchronizing signal and a vertical synchronizing signal based on an output of the clock signal generating means (1). Based on the output of the means (2) and the clock signal generating means (1),
A display memory control means (3) for controlling writing and reading of information in the display memory, and an outline font expanding means (4) for converting outline information of outline font read from an external outline font information memory into dot information. A font expansion storage means (5) for storing the outline font expanded by the outline font expansion means (4), and an address for transferring the font stored in the storage means (5) to a display memory And a rectangular area bit transfer means (6) for generating a character display control device.