JPS61137191A - Scrol display unit - 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 Industrial Application] The present invention relates to a display device that displays still images containing a mixture of characters of various sizes in a smooth scrolling manner.

[Conventional technology]

As a conventional display device that displays images mainly composed of characters, when the screen of one page to be displayed is larger than the display screen, the characters are displayed one after another, and after the display screen is filled with characters, a line break is performed. At the point when
There was a scrolling type that erased the first line of the display screen, shifted the entire display screen upward by one line, and displayed the next character on the empty bottom line. According to this scrolling format, since scrolling is executed line by line, there is a problem that the display screen is scrolled unnaturally and is difficult to read.

A conventional display device that solves these problems and provides smooth scrolling is shown in FIG. 3. In FIG. 3, 1 is a code f-"-ta buffer that stores character code and control code data for one screen to be displayed, that is, one page of images; 2 is a code for reading out data from the code data buffer 1 for the display screen. A decoder decodes data into data. 3 is a key consisting of pixel units.

Character font memory stores Yarakuta font data; 4 is a pattern memory that stores data constituting the display screen in pixel units in correspondence with scanning lines; The address space is, for example, twice the Y address (number of scanning lines) space of the display screen. Reference numeral 5 denotes a character line buffer, into which one character line of character font data read from the character font memory 3 is written. 6 is a scroll offset register that outputs data 0 for controlling the offset amount of the Y address Ry of pattern memory 4 for scroll display; 7 is a cathode ray tube display device (CRT) that displays the data of pattern memory 4 on the display screen; ), 8 is the CRTT synchronization signal, a CRT controller that generates the horizontal (X) address X and Y address Ry for reading the pattern memory 4, 9 is the Y address R
This is an adder that generates y.

Next, the operation will be explained. Read out one screen worth of data stored in code data buffer 1 word by word,
The decoder 2 sequentially decodes the data. When the decoded data is a control code, the decoder 2 calculates the address position of the pattern memory 4 corresponding to the display position and sets other attributes according to this, and when the data is a character code, the decoder 2 The corresponding data is read from the character font memory 3 and written to the address position of the pattern memory 4 corresponding to the display screen. In this way, the decoder 2 successively reads out and decodes as many character codes as can be displayed on the display screen from the code data buffer 1, and sequentially writes the data read out from the character font memory 3 into the pattern memory 4 based on the decoding results.

Next, the operation of displaying the contents of the pattern memory 4 on the CnTT will be explained. Here, the display resolution of the CRT 7 is n lines x m pixels, the X address X of the pattern memory 4 is 0 to m-1, and the Y address position is Q to (n-1)+α
It is assumed that one address of the pattern memory 4 corresponds to one pixel displayed on the CRT 7. In this way, the pattern memory 4 stores X address positions O to m-1, Y
Data from decoder 2 is written in the area consisting of addresses Ry = 0 to (n-1).
The controller 8 supplies a synchronizing signal S to the CRT 7, and controls X and Y in synchronization with the scanning speed and scanning position of the CRT 7.
Generate addresses X and y, send X address X to CRT 7
x by 1 when the scanning of the display screen moves by one pixel
= Q ~ (m-1), and when the Y address y increases by one period, the Y address y increases by 1 by y
= Q to (n-1). The Y address y is input to the adder 9 together with the data stone of the scroll offset register 6. Adder 9 obtains Y address Ry of pattern memory 4 by adding both. However, addition 6
9 is the sum AY of the data δ and the Y address y of the CRT controller 8) When n-1+α, the Y address R
Let y = AY - (n-1+α). That is >mouth AY
is the maximum Y address position of pattern memory 4 = (n-1
-α), subtract n-1+α from the sum AY to bring the Y address R7 within the range of Q to (n-1+α). When the data 0 of the scroll offset register 6 is 00, the contents of the Y address y of the CRT controller 8 become the Y address Ry via the adder 9 as is. In this way, (0~m-1) X (0-n-
The area 1) corresponds to the CRT 7 display screen.

Next, a case will also be described in which the decoder 2 reads out numerical character codes that can be displayed on one display screen from the code data buffer 1 and scrolls them for display. When the decoder 2 decodes the character code and the content of the data O in the scroll offset register 6 is 0, as described above, the pattern memory 4 stores (x=0'-m-
1, data is written in the area of Ry=0 to n=1).

The decoder 2 searches the character font memory 3 for the character font corresponding to the character code to be displayed and temporarily stores the data in the character line buffer 5.
until the control code that commands a new line is read, or 1
This continues until the character line buffer 5, which has a capacity for character lines, is completely written. In this state, the data for m pixels stored in the character row buffer 5 is stored at the Y address Ry=n of the pattern memory 4, that is, at the address position of the bottom row currently displayed, and the data is stored in the scroll offset register. 6 data d is 1
will only be increased. As a result, the display screen of the CRT 7 corresponding to the Y addresses Ry=1 to n of the pattern memory 4 is scrolled upward by one line. Similarly, the next line of data is written from the character row buffer 5 to the next Y address Ry of the pattern memory 4, and the data d in the scroll offset register 6 is incremented by 1. This operation continues until all lines of data in the character row buffer 5 are transferred. Note that each time one line of data is transferred, the Y address R of the pattern memory 4 is
y and the data b of the scroll offset register 6 are:
It is incremented by 1, but is reset to O when the value exceeds n-1+α. Also, character line buffer 5
When transferring data for each line, the scrolling speed may be adjusted by adding an appropriate waiting time.

When the transfer of all line data in the character row buffer 5 is completed in this way, the decoder 2 starts reading the 9th data from the code data buffer 1 again, and similarly reads all the data in the code data buffer 1. One page of data to be repeatedly displayed is transferred to the pattern memory 4, and an image larger than the display screen is smoothly scrolled and displayed on the display screen of the CRT 7 using the data in the pattern memory 4.

[Problem that the invention seeks to solve]

Conventional scroll display devices are configured as described above, so before writing character data to be displayed into the pattern memory, one line of character data is written into the buffer, and then data is written from this buffer into the pattern memory. Since the data must be transferred to the computer, the configuration and processing operations thereof are complicated, and the displayed characters are also limited to a certain size.

This invention was made in order to solve the problems of the conventional ones as described above, and it is possible to simplify the configuration, and it can also be used for images containing characters of various sizes. An object of the present invention is to obtain a scrolling display device capable of scrolling to i.

[Means for solving problems]

In the scroll display device according to the present invention, a vertical address indicating the bottom line of character data written in a pattern memory is stored in a maximum address register, and the content of the data in this maximum address register is used to scroll the display screen. When the offset amount is smaller than the data content of the scroll offset register that controls the offset amount, the content of the scroll offset register is sequentially increased.

[Effect]

In the scroll control according to the present invention, the offset amount of the vertical address for reading out the pattern memory is controlled according to the vertical address indicating the bottom line of character data written in the pattern memory, and the display screen is smoothly scrolled. .

〔Example〕

An embodiment of the present invention will be described below.

In FIG. 1, the same reference numerals as those shown in FIG. 11 is a scroll offset register 6 which stores the maximum value Y address within the valid write area when changed.
When the data 0 of is smaller than the data of the maximum address register 10, the scroll controller sequentially increases the data δ and controls the offset value of the Y address y.

Figure 2 shows data written to pattern memory 4 and CR
This is a display screen showing correspondence with the display screen of T7. For example, when the data b of the scroll offset register 6 is k, the Y address space = ~(
The data in the area of the pattern memory 4 specified by (n-10k) is displayed on the display screen of the CRT 7.

Next, the operation will be explained. Regarding the operation of displaying the data in the pattern memory 4 on the CRT 7, as explained with reference to FIG.
The data is read word by word and sequentially decoded. Note that the control code for the data buffer 1 also includes a code specifying the character size. When a decoder 2 decodes a character code, it searches out character 7 ont data corresponding to this from a character font memory 3, converts it into data of a designated character size, and writes it into a pattern memory 4.

However, even if the character size designation is changed in the middle of a line, automatic adjustment is performed so that the bottom line of each character has the same -Y address in the pattern memory 4. Also, the Y address RY of the bottom line of the next character line is the sum of the Y address Ry of the bottom line of the previous character line and the height of the character size specified at that time. equal.

Therefore, when displaying a character of another character size on the next character line on the display screen, enter a control code that specifies the other character size in the position before the line feed code as data in code data buffer 1. It is necessary to keep it.

In this way, the decoder 2 sequentially reads data from the code data buffer 1, and further reads data from the character font memory 3 according to this data and sequentially writes it into the pattern memory 4. In this case, the Y address space of the pattern memory 4 is α(=2·)(max) than the number of lines on the display screen of the CRT 7.

Hrmx has an address space that is as large as the height of the maximum character included in the display screen. Therefore, image data larger than the area of the display screen is sequentially written from the top address of the pattern memory 4, and when changing the Y address Ry, that is, starting a line feed, the Y address R of the bottom line of the next character line is written.
y is determined by adding the Y address Ry of the bottom line of the current character row to the height of the currently specified character size. If the Y address RY obtained in this way is larger than n-1+α and there is a character whose display has ended due to scrolling from the top of the screen, the adder 9 subtracts n-1+α from Ry and adds the result to the latest character. Let the lowest Y address of the row be Ry.

This random Y address R7 is an address that specifies the leading area of the pattern memory 4.

The Y address of the bottom line of the character line before line break is written into the maximum address register 10 in order to indicate what can be displayed on the display screen among the data written in the pattern memory 4 in this way.

As mentioned before, the Y on the bottom line of the next character line
When the address Ry exceeds the data d in the scroll offset register 6, the line waits without starting a new line. In this waiting state, the scrolling progresses and the data O of the scroll offset register 6 is the Y address R7 of the bottom line.
It continues until it exceeds.

For example, in FIG. 2, the Y address Ry of the bottom line after a line break is i, and the scroll offset register 6
If the data stone is k, the line feed waits until k exceeds l.

Here, when the number of lines on the display screen is n, the pattern memory 4 has at least n-1+α=n-1+2・Hm
The reason why the ax address space is required is to allow the pattern memory 41C to exist as an area in which at least one character line is not displayed on the display screen even in the processing waiting state.

When the waiting state is released as the scroll progresses, the decoder 2 erases the area of the pattern memory 4 corresponding to the new character line. This is because when writing a character with a smaller size than the previous character line, no characters are written in the area between the top line of that character and the bottom line of the previous character line, and the previously displayed data This is to prevent any residue from remaining.

As described above, when starting a new line, only the data stone in the scroll offset register 6 is checked, and the decoder 2 reads that data and writes it into the pattern memory 4 until the code data buffer 1 is empty, and The data in the maximum address register 10 when the data buffer 1 becomes empty becomes the lowest address of the screen to be scrolled.

Next, the operation of the scroll controller 11 will be explained. The scroll controller 11 operates asynchronously with the decoder 2, and compares the data d of the scroll offset register 6 and the contents of the maximum address register 10 at regular intervals, and determines that the data δ is smaller than the data of the maximum address register 10, lid, The data d of the scroll offset register 6 is increased by 1, and when k becomes larger than n-1+α, the data d is reset to zero.

In this way, the decoder 2 uses the code data buffer 1
Data is sequentially read out from the memory, and an image based on this data is written into the pattern memory 4. Further, the data in the pattern memory 4 is read out using the offset-controlled Y address Ry, and is scroll-displayed on the display screen of the CRT 7.

In the above embodiment, the data in the pattern memory 4 is CR
Read based on Y address y of T controller 8, C
Although the case where the display is displayed on the RT7 has been described, it may be read out using an appropriate read address generator and displayed on a liquid crystal display device or a matrix display device that constitutes a large screen display device, and the same method as in the above embodiment may be used. be effective.

〔Effect of the invention〕

As described above, according to the present invention, the writing to the pattern memory and the scroll display are asynchronous, and the character font to be displayed is written directly to the pattern memory. This has the effect of smoothly scrolling and displaying text-sized images.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a scroll display device according to an embodiment of the present invention, FIG. 2 is a display screen diagram showing the contents of the pattern memory and the value of the scroll offset register, and FIG. 3 is a block diagram of a conventional scroll display device. It is. 2 is a decoder, 4 is a pattern memory, 6 is a scroll offset register, 10 is a maximum address register, 11
is a scroll controller. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A pattern memory that stores character data to be displayed on a display screen in correspondence with the scanning lines of the display screen and sequentially reads out the data in synchronization with the scanning lines, and an offset of the vertical address of the pattern memory. A scroll offset register that outputs data for controlling the value, a maximum address register that stores the vertical address indicating the bottom line of the character data written in the pattern memory, and the contents of the offset register data are A scroll controller that sequentially increases the data content of the scroll offset register when it is smaller than the data content of the maximum address register, and a scroll controller that sequentially increases the data content of the scroll offset register when the data content is smaller than the data content of the maximum address register, and when the vertical address of the pattern memory is increased, the data of the above character is A scroll display device comprising a decoder for erasing an area of the pattern memory to be stored.