JPS5842088A - Character display - 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] The present invention relates to a character display device.

Because the number of characters in one line in the horizontal direction of a display screen of a character display device, for example, a CRT, is too large, it may not be possible to display all the characters at the same time. In this case, there is a method of sequentially displaying characters that cannot be displayed simultaneously on one screen by changing the display content on the display screen character by character. This display method is called character-by-character scrolling. If scrolling is performed continuously, there is a drawback that it is difficult to scroll to a display screen containing the desired characters because the display screen is identified in rotation during scrolling.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide a character display device capable of horizontal scrolling, that is, smooth scrolling, in units of dots forming characters.

The present invention will be described in detail below based on the drawings.

1':/8! JK An example of the present invention is shown. Here, the keyboard l as an external device is the keyboard controller 3
The screen is equipped with keys for sending character/symbol signals jD and scroll signal data jS for scrolling the screen left and right. The keyboard controller 3 encodes the signal j''D input from the keyboard l and sends it to the CRT control unit 7 as an input data signal 9.The keyboard controller 3 also encodes the signal j''D inputted from the keyboard l and sends it to the CRT control unit 7 as an input data signal 9. In response to the data jS, a scroll signal l/ is sent to the count controller 13.The dot counter 19 divides the frequency of the reference signal 17 generated from the oscillator tS to generate a character clock signal l, and sends the reference clock to the CRT control unit 7. Also, the oscillator/S generates a dot signal n with a period corresponding to the dots constituting the character to be displayed.The CRT control unit 7 generates a synchronization signal B and 9 and sends it to the video controller Z and the synchronization signal controller 31. Also, the data signal 3λD, the refresh signal 32R, and the address signal Misaki according to the input data signal 9 inputted from the keyboard controller 3 are sent to the synchronization signal B and the synchronization signal controller 31. The count controller 13 checks whether there is a scroll signal // from the keyboard controller 3 every cycle of the vertical synchronization signal B from the cR'rLt1 section 7, and outputs it to the refresh memory 33 in synchronization with the scroll signal l. If / is present, the scroll signal //'5r-is output to the counter n as the selection scroll signal 3j every period of the vertical synchronization signal B.CRT 2?
The characters to be displayed are arranged in a dot matrix of A columns x B rows as shown in FIG. The counter n is composed of an A-adic counter, and is a reversible counter that performs addition and subtraction by scrolling leftward and rightward. In this case, the scroll signal 35 from the count controller 13
The number of signals is counted, and a signal R representing the counting state is sent to the synchronization signal controller 31, and a signal 11/U representing a carry or a signal F/D 11 for performing a carry down is sent to the rewrite controller 13. Also, the carry signal
U or carry down signal 1D is outputted only during 1 cycle of vertical synchronization signal MO which is output from control unit 7, and is carried up and down in the next cycle of vertical synchronization signal B and is in a dangerous state. Unfortunately, when the count signal R from the counter r indicates a state of 1 to (A-/), the display rewriting controller q does not send the horizontal scroll signal DaS to the CRTMJ11 section 7.The carry signal from the counter n da/
When U or down signal or ID is used.

Display rewriting controller q uses horizontal scroll signal 4IS
is supplied to the cRTfal'l1 section 7.

The refresh memory 33 stores the data signal 32D sent from the CRT control section 7 to be displayed on the screen at the corresponding address. The read data signal j3 of this refresh memory 33 is sent to the character generator S3.

As shown in FIG. 3, the refresh memory 33 stores the contents of an extra column than the number of columns on the display screen, that is, up to the column next to the one character column at the right end of the display screen. The character generator SS sends a parallel signal j7 which interpolates a corresponding information pattern from the code of the data signal j3 sent from the refresh memory 33 to a parallel-to-serial (hereinafter referred to as P/S) converter j9. The synchronous signal controller 31 is
The horizontal synchronization signal 1 from the OPT control part 7 and the display period signal 61 are used as the number of counting states represented by the signal 5 of the counter n.

The dot signal n is delayed in units of dots, and the delayed horizontal synchronizing signal ID and display period signal g/D are supplied to the video controller 29. This video controller has both signals 27D from the synchronous signal controller 31,
≦/D, the video signal 67 from the P/S converter j9 and the vertical synchronization signal B from the OR1 control s7 are sent to the CRT2FK. This ORT 2? displays characters based on data input using the keyboard l.

Next, smooth scrolling will be explained. 4th I8i
! I(2) to ■ indicate the timing when horizontal smooth scrolling is not performed. In this case, the horizontal synchronization signal G and the consideration period signal 6/ from the OR1 control unit 7 are 1 without changing (delaying). They become signal 27D and signal 4/D, respectively. The video signal 67 is a dot signal at the beginning of the first character (
Displayed from 1). In this case, the outputs of the count signal of counter I, carry signal #/U, and carry down signal -ID are all O. Figures 3 (A) to (F5) show the case of scrolling by l dots to the left;
From this state, the scroll signal /l is output by operating the keyboard l, and the count in the count signal IK from the counter n becomes /. As a result, the synchronization signal controller 31 converts the horizontal synchronization signal 1 from the control section 7 and the display period signal 61 into the dot signal n from the oscillator /j.
The horizontal synchronization signal 27D and the display period signal 4/D are output with a delay of 1 dot in accordance with the timing of the signal 4/D. Also, since the carry signal F/U or the carry down signal #1D is not sent from the counter n, the horizontal scroll signal IS Fl 0R is sent from the display rewriting controller #3.
It is not output to the T control section 7. The vertical synchronizing signal B and video signal t7 from the CRT control section 7 are the same as in the case of FIG. As shown in Fig. 3, the refresh memory 33 has an extra data storage area for one character string beyond the display screen, and the output to the CRTn is not displayed at the left end of the screen in Fig. q. In the reverse Kgp diagram state, the row of leftmost L dots of the character next to the character displayed at the right end of the screen is displayed. As a result, as shown in Figure 3 (G), (C)
Displayed from. As you will see, it becomes possible to move the display on the CRT2F to the L dot branch. Scrolling to the left is now possible. Then 1 l
Let's look at the case of scrolling by a dot. As shown in FIG. 3, repeat the above operation from %7 to (mul) dots, and as shown in FIG.
A horizontal scroll signal aS from the display rewriting controller Q is sent from UK to the CRT paste section 7, and then from K to 7.
Refresh signal 32R is sent to refresh memory n, and memory n.

The contents change from Figure 3 to Figure 4/Character string. As a result, as shown in FIG. 7, since the count signal n of the counter 37 is 0, the horizontal synchronizing signal 1 and the display period signal j/ can be shifted to the left by A dots. Scrolling of more dots can be done in the same way.

Next, scrolling in the right direction will be described.

First! l! ! IK shows the case of scrolling to the right from the state shown in Figure 1. In this case, the keyboard l
In response to the scroll signal // generated by the operation of , the counter I performs subtraction counting, and a carry down signal lD and a 2-counting code n indicating the count form y(A-/) are output. This digit reduction signal F/D causes the display rewriting controller 3
The horizontal scroll signal Z is output from the CRTiIi control unit 7.
72 R-K
Accordingly, the contents of the refresh memory 33 are rewritten as shown in FIGS. 3 to 9M. In addition, a signal B indicating the counting state (A-/) is sent from the color/ring to the synchronization signal controller 31.
As shown at t%, the horizontal synchronizing signal 1 and display period signal 4/ from the CRT control unit 7 are (A −/'
) The horizontal synchronization signal 27 is delayed, respectively.
D and display period signal 4/D are output. Since the vertical synchronizing signal B and the video signal 67 do not change, the leftmost (A-/) dot row of the display screen is not displayed and is displayed next. Therefore, the L dot is scrolled to the right compared to the state shown in FIG. 3, and is displayed from % (A'). When scrolling by the number of dots □, the downshift signal 41/D is not output. In two-dot scrolling, the horizontal synchronizing signal l and display period signal t/ are delayed by (A-x) dots. By repeating the process up to the L dot in the same way, when scrolling the A dot as shown in FIG. ? Entering ``K'' allows you to scroll to the right side. The same thing can be said for scrolling to the right beyond the A dot. Also, right (left)
Even if the user scrolls to the left (right) before scrolling 7 characters in the direction, the counter I adds or subtracts the horizontal scroll signal daj, and when the digit is up, the signal #1U or the downsignal f is applied.
Since the ORT control unit 7 outputs the horizontal refresh signal only when /D is generated, smooth scrolling is possible even in such a case.

As mentioned above, one embodiment of FIG. 1 has been described, but it is also possible to realize two addition counters for rightward and leftward scrolling, and the refresh memory 33 can be placed on the opposite side of FIG. It goes without saying that this can be realized even if a data storage area for seven character strings is added.

By counting the scroll signals in this way, smooth scrolling in the horizontal direction can be easily realized by changing the horizontal synchronization signal and the display period signal in units of dots. Furthermore, if the keyboard has another character-based scroll signal key, it is possible to use dot-based smooth scrolling and character-based scrolling together.

Furthermore, it is possible to change one synchronization signal in units of one dot or more, and to perform horizontal scrolling in each unit.

According to the present invention, which has been described in detail above, it is possible to realize a character display device that eliminates the conventional drawbacks.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a character display device according to the present invention, FIG. 2 is a line diagram showing an example of a character dot configuration, and FIGS. 3, 6, and 9 are contents of refresh memory. Diagrams showing, Figure 5) ~ (7), Figure 3 (1) ~
(7), Figure 7 (2) to (G), Figure 7 (1) to (7)
and Fig. 1θ (1) to (g) are signals l...
・Keyboard, 7...CRT control section, B, E
... Synchronization signal, 33 ... Refresh memory, 1.
...Counter, #l...Display rewriting controller, 3j...Character generator s j9...Serial-parallel converter. Patent applicant Canon Co., Ltd. Kinsha Figure 1

Claims (1)

[Claims] 1) Smoothness in the horizontal direction of the display screen that displays characters
A character display device characterized by having a zoom scrolling function. 2) A patent claim characterized in that a horizontal synchronizing signal for horizontally synchronizing the display screen and a display period signal indicating a display period are synchronously controlled in units of dots constituting characters to be displayed. The character display device according to item 1 of the scope. 5) The refresh memory for storing the display contents of the display screen has an extra capacity of one character in the horizontal direction than the display screen. Character display device as described in Section.