JPH023095A - Display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a display device capable of displaying a layout.

2. Description of the Related Art In recent years, an increasing number of display devices such as electronic typewriters and word processors have a function of displaying the character structure and arrangement image of a document on a page. There is a demand for a layout display in which each character in a document is simplified and expressed as a single point, box, or line segment, and a large page size can be displayed on the screen of a display device. The layout display in FIG. 7 shows an example of this display. The characters "F", "G", etc. in a document are made up of the smallest pixels (hereinafter referred to as dots) on the screen.

These displays make the print image of the document being created or edited clear, and layout corrections such as character arrangement and position can be easily made. This layout uses a display control method called a bitmap display control method because, as mentioned above, the character spacing and line spacing are different from normal character display.

A specific example of a bitmap display control method in a conventional layout display will be described below. FIG. 2 is a block diagram of a conventional bitmap display control system, and its display device is generally a display device whose display screen is constructed by periodic scanning using a cathode ray tube. 1 is a processing circuit;
A display control circuit 2 generates a horizontal synchronizing signal HSYNC and a vertical synchronizing signal VSYNC required by the display 9 and generates a display address for reading display data from the bitmap memory 13. The bitmap memory 13 outputs data at the address given by the display control circuit 12 at regular intervals. The output cycle is synchronized with the horizontal synchronization signal H8YNC. Bitmap memory 3
Since the display data outputted from is parallel data, the parallel data is converted into serial data in accordance with the serial scanning of the display 9 and is output to the display 9. 6 is a parallel/serial conversion circuit that converts this parallel data into serial data. 14
1 is a font memory that stores character fonts to be displayed, and 11 is a document memory that stores character data to be printed or displayed. The processing circuit 1 reads a character code from the document memory 11 and is given the address from the address bus, and the data in the given address is read from the font memory 14 and expanded into the bitmap memory 13. The operation of the human map display control system configured as described above will be explained.

For example, when displaying the character "A", the pixel group constituting this "A" is stored in the font memory 14 as shown in FIG. 4, and the processing circuit 1 sets the address of this font memory 14. The font data can be read by
0010o o o", and after retrieving this value from the font memory 14, the processing circuit 1 stores it in the bitmap memory 13. For example, if "°°A" is displayed in the upper left corner of the display 9, For example, human map memory 1
The processing circuit 1 writes font data to the address corresponding to No. 3. As shown in Figure 3, the letter "A" is composed of 16 vertically by 8 horizontally, and the font of the letter "A" is displayed by repeating reading from the font memory 14 and writing to the bitmap memory 13 16 times. do. The data written in the bitmap memory 13 is read out at regular intervals and outputted to the display 9 as a video signal by the parallel-to-serial conversion circuit 8. Since there is a one-to-one correspondence with the recording unit in this way, when displaying a layout as shown in FIG. 7, if a character exists at a character position in the document, the corresponding bitmap memory 13 Layout display is performed by setting the bit to 1 and, if no character exists, to O.

Problem to be Solved by the Invention However, in this case, in order to display one character, 16 read/write operations from the font memory to the display memory are required.
It is necessary to repeat the process several times, and display devices with low-cost, low-speed processing circuits have slow display speeds.

In particular, when scrolling to move the entire screen, the operation speed was noticeably slow. A character display method is used to solve this problem, but it is difficult to display the layout with this method.

Means for Solving the Problems In order to solve the problems, the present invention identifies the layout of a document, encodes it and stores it, and uses pattern generation means that stores a layout display pattern corresponding to the coded layout. It will be set up.

Function: With this configuration, layout display can be performed even if the display device uses a character display method.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a display device that is an embodiment of the present invention. 1 is a processing circuit that controls each device and makes logical decisions.

2 is a display control circuit which generates a horizontal synchronizing signal H3YNC and a vertical synchronizing signal VSYNC and controls writing into the display memory 3; A display memory 3 stores character codes and layout codes to be displayed by the display control circuit 2. 4 is an attribute latch circuit that holds and outputs display character attributes for a certain period of time, and 5 is a character code latch circuit that holds and outputs display character codes for a certain period of time. A font memory 7 stores character fonts as display patterns corresponding to character codes, and has a layout font area 10 storing layout patterns corresponding to layout codes as shown in FIG. .

A parallel attribute converter 6 corrects and changes the font pattern output from the font memory 7 in response to an attribute signal from the attribute latch circuit 4. A parallel attribute converter 8 converts the font pattern data of the parallel data output from the parallel attribute converter 6. This is a parallel-to-serial converter that converts font pattern data into serial font pattern data and generates a video signal.

9 performs an operation in synchronization with the horizontal synchronization signal H3YNC and vertical synchronization signal VSYNC from the display control circuit 2.
This is a display device that visually outputs the video signal from the parallel-to-serial converter 8. A document memory 11 stores character codes for printing and displaying.

The operation of the display device configured as described above will be described below. First, normal character display will be explained. For example, when displaying the character "A" stored in the document memory 11 on the display screen of the display device 9, the character code corresponding to "A" is 41h (h is a hexadecimal symbol).
Then, the display control circuit 2 writes this character code 41h into the display memory 3 corresponding to the position where it is desired to be displayed.

Display character attributes generally include reverse, underline, blink, highlight, etc. Reverse reverses the foreground of the character font (the shaded area in Figure 3) and the background of the character font (the area other than the shaded area in Figure 3), and underline draws a line under the character ( Blink is a function that causes the foreground of a character to blink.Highlight is a function that increases the brightness of the foreground of a character.In this way, by assigning a certain attribute to each display character, various It is possible to display characters.Generally, 1 byte of memory is given to each of these seven character code attribute information, and 1 bit is allocated to each attribute.Character code and attribute code is outputted from the display memory 3 according to the address given by the display control circuit 2.The outputted code is latched into each attribute latch circuit 4 and character code latch circuit 5.The latched character code is outputted. The address indicates the font position in the font memory 7 where the character font pattern is stored, and one of the many character fonts is selected.The relationship between the data in the font memory 7 and the address is shown in Figure 4. Assuming that the character font pattern consists of 16 vertical dots and 8 horizontal dots, the output from the character code latch circuit 5 is connected to address bits 4 to 11 of the font memory 7.Address bit 3 of the font memory 7 Bit O is connected to an address control line called a raster address bus output from the display control circuit 2.The raster address is selection information for the display control circuit 2 to sequentially output the arrangement of character font patterns in the horizontal direction. It is.

As shown in FIG. 3, character font patterns are arranged in the order of raster addresses. The display control circuit 2 configures pixels as characters by setting the raster address for each line. The font memory 7 outputs one raster font pattern in one byte in parallel according to the address given by the raster address and character code. The output parallel font pattern is subjected to pattern conversion in the parallel attribute converter 6 according to the attribute code corresponding to the character code. For example, when the reverse bit is on, the character font pattern for one line is inverted all at once in the parallel attribute converter 6, and the foreground and background on and off are displayed in reverse. The parallel data output from the parallel attribute converter 6 is converted into serial data by a parallel-to-serial converter 8 and transferred to a display device 9.

Next, display of layout information will be explained.

Figure 5 is a diagram showing the dot configuration for one character in the character display system, and similarly to Figure 3, there are 16 dots vertically and 8 dots horizontally.
It's a dot. The layout for 8 characters is displayed in 8 squares of 4 dots each with diagonal lines drawn here. The number of combinations of character presence/absence states in this 8-character character array is 2g = 256, and 1 byte,
In other words, one of the combinations can be specified using 8 bits. This 1-byte code is called a layout code. As shown in Figure 6, the layout font corresponding to the layout code is regularly constructed by the pattern specified by the layout code, and it is easy to convert the required layout font pattern back into the code. It has become so. When displaying a layout, use one of the layout fonts that corresponds to the character position in the document within one page of the document memory.
The presence or absence of a character is identified by the processing circuit 1 by associating one block of four vertical lines and two horizontal characters as one dot (hereinafter referred to as a layout dot) with a layout font.

Then, the layout code is stored in the display memory 3. The part of the document memory 11 on the left side of FIG. 8 is rewritten into a layout code of a layout font and stored in the display memory 3, as shown on the right side. At the same time, in order to distinguish the code from the character code, the layout bit provided in the character attribute code is turned on and written into the display memory 3. When the layout bit is on, the highest address of the font memory 7 becomes 1, and the layout font and its code set in advance at the highest address are selected, and one raster is displayed according to the raster address output from the display control circuit 2. The layout pattern is output to the display 9.

Effects of the Invention The present invention encodes the layout of characters constituting a document for each area of a predetermined number of characters, and accesses and displays the corresponding layout code from this code, so a low-speed CPU is used. Even with a character display type display device, layout display can be easily performed by adding a layout font.

[Brief explanation of the drawing]

箪 1 is a block diagram showing an example of a large-scale attack, and shows a block diagram showing the result of a nest, a block diagram, and a block diagram showing the structure of a conventional bitmap type display device. A schematic diagram showing an example of a font, Figure 4 is a schematic diagram showing the relationship between data and addresses in the character font memory, Figure 5 is a schematic diagram showing the dot configuration of a layout font, and Figure 6 is a layout code and layout. A schematic diagram showing the correspondence with fonts, Figure 7 is a schematic diagram showing the correspondence between documents and layout display screens, and Figure 8 is a schematic diagram showing the correspondence between data in the document memory and layout codes in the display memory. It is a diagram. 1... Processing circuit 2... Display control circuit 3... Display memory 7... Font memory 9... Display device 10... Layout font area 11... Document Memory Diagram Nata Otto Diagram Diagram Condolence Diagram Bit Diagram

Claims (1)

[Claims] storage means for storing character code data; identification means for identifying the layout of the character code stored in the storage means for each region of a predetermined number of characters; and encoding and storing the layout identified by the identification means. a display storage means for storing the coded layout; and a pattern generation means for storing a layout display pattern corresponding to the coded layout.
A display device comprising display means for displaying a layout display pattern from the pattern generation means.