JPH05313625A - Method for controlling display of cursor - Google Patents

Abstract

PURPOSE:To prevent the disappearance of a display even when the speed of a cursor movement is fast and to prevent the losing sight of the cursor by an operator. CONSTITUTION:Plural XY registers R1, R2 and R3 for specifying a position for displaying the cursor and XY coordinate comparators C1, C2 and C3 for comparing positions specified by these registers and display control positions on a display device are prepared. Then, the cursor is displayed in sequence by any one of the plural XY registers R1, R2 and R3 and the XY coordinate comparators C1, C2 and C3 in accordance with the display control of the display device. Thus, a remaining image immediately before the movement of the cursor moving in accordance with the movement of the cursor is displayed. Therefore, when the cursor is displayed on a liquid crystal display, etc., whose display response time is long, the cursor during the movement is displayed as a remaining image even when a mouse, etc., is moved fast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cursor display control method in a computer system having a pointing device such as a mouse and a display such as a liquid crystal display.

[0002]

2. Description of the Related Art Generally, a pointing device such as a mouse is used as an input device in a computer system. Note that there are trackballs, touch pens, and the like as pointing devices similar to a mouse, but the mouse most widely used from now on will be described as an example. Further, as a display device, a liquid crystal display has been widely used instead of a CRT display.

FIG. 2 is a block diagram showing an example of a schematic configuration of a conventional computer system. The illustrated system includes a CPU 11, a timer controller 12, a frame memory 21, a cursor display control unit 22, an overlay control unit 23, a display timing control unit 24, a liquid crystal display (hereinafter referred to as “LCD”) 25. , Mouse interface 26 and the like. The CPU 11 controls the entire system shown in the figure. Timer controller 12
Generates a timer interrupt 36 in the CPU 11 at regular time intervals.

The frame memory 21 stores image information displayed on the LCD 25. Cursor display control unit 22
Controls the cursor display on the LCD 25. The overlay controller 23 superimposes the cursor data 33 output from the cursor display controller 22 on the image data output from the frame memory 21 to generate LCD display data 34. The display timing control unit 24 is an LCD
The display timing signal 35 necessary for displaying 25 is generated. The mouse interface unit 26 detects the movement amount of the mouse 27. CPU 11 described above, timer controller 12, frame memory 21, cursor display control unit 2
2, overlay control unit 23, display timing control unit 2
4. The mouse interface unit 26 is the system bus 3
Connected by 1. As is well known, the LCD 25 is a flat panel display device in which a liquid crystal substance is sandwiched between two substrates with electrodes, and the arrangement structure of liquid crystal molecules is changed by an applied voltage to operate as an optical shutter. Therefore, the CR that causes the electron beam from the electron gun to collide with the fluorescent screen to emit light
Unlike the T display device, the display operation is slow. That is, the display response time from the display control timing to the actual display on the LCD 25 is long.

Next, the operation of the above system will be described. First, a method of displaying an image on the LCD 25 will be described. Since the LCD 25 is a raster scan type display device, a display refresh operation is required. Therefore, the CPU 11 sets the horizontal synchronization and vertical synchronization timings in the display timing control unit 24. The display timing control unit 24 outputs a dot clock, a horizontal synchronizing signal, and a vertical synchronizing signal based on the set value. on the other hand,
The frame memory 21 outputs the image data for each dot in synchronization with the dot clock. This image data is given to the LCD 25 via the overlay controller 23,
It is displayed on the LCD 25.

Next, a method of displaying the cursor on the LCD 25 will be described. The CPU 11 sets the cursor dot pattern and the XY coordinates to be displayed on the LCD 25 in the cursor display control unit 22. The overlay controller 23
The image data output from the frame memory 21 and the cursor data 33 output from the cursor display control unit 22 are superimposed and output to the LCD 25.

FIG. 3 is a block diagram of a conventional cursor display control unit. The cursor display method will be described in detail using this. In this figure, the horizontal / vertical synchronization counter unit 41 synchronizes with the blank, horizontal synchronization, and vertical synchronization signals and changes coordinates (X1, Y) in the cycle of the dot clock.
1) is output. The XY register 42 specifies the coordinates (X2, Y2) at which the cursor is displayed. The address register 43 sets an address when writing the dot pattern of the cursor in the pattern RAM 46. The XY coordinate comparator 44 compares the coordinates (X1, Y1) output from the horizontal / vertical synchronization counter 41 with the coordinates (X2, Y2) stored in the XY register 42.

The address selector 45 is a pattern RAM
Select address 46. The pattern RAM 46 is a random access memory that stores the display pattern of the cursor.
It is a memory. In this figure, the CPU 41 first
The dot pattern of the cursor is written in the pattern RAM 46. This is a pattern RAM in the address register 43.
This is done by setting a dot pattern in the pattern RAM 46 after setting the address of 46.

Then, the X and Y coordinates for displaying the cursor are set in the XY register 42. The horizontal / vertical synchronization counter unit 41 determines the XY coordinates of the image data output from the frame memory 21 based on the dot clock, horizontal synchronization, vertical synchronization, and blank signal provided from the display timing control unit 24 shown in FIG. Ask and output this. The XY coordinate comparator 44 compares and calculates the XY coordinates (X1, Y1) output by the horizontal / vertical synchronization counter unit 41 with the XY coordinates (X2, Y2) output by the XY register 42, and calculates the address. To generate. The contents and results of this comparison and calculation are shown below.

(1) X1-X2> 15 or X1-X2 <0
When, the pattern RAM address is invalid. (2) The pattern RAM address is invalid even when Y1-Y2> 15 or Y1-Y2 <0. (3) In cases other than the above, pattern RAM address = (Y1
-Y2) * 16 + (X1-X2). The pattern RAM address thus obtained and the address output from the address register 43 are input to the address selector 45, one of them is selected by the blank signal, and input to the pattern RAM 46. The output of the address register 43 while the blank signal is on,
While off, the output of the XY coordinate comparator 44 is selected.

Next, the movement of the cursor associated with the movement of the mouse will be described. The cursor movement control uses a timer interrupt that generates an interrupt at regular time intervals. CP
U11 reads out the movement amount of the mouse 27 from the mouse interface unit 26 each time the timer controller 12 generates a timer interrupt once every 1/30 seconds, and X
The value of the Y register 42 is read, the movement amount is added to this, and the result is written in the XY register 42. By doing so, the cursor moves following the movement of the mouse 27 at regular intervals. Here, the interrupt interval is 1/100
The smaller the interval such as the second interval and the 1/200 second interval, the smoother the movement of the cursor.

[0012]

However, the above-mentioned conventional techniques have the following problems. That is, in the conventional method, when a display device such as an LCD having a long display response time is used and the moving speed of the cursor is too fast, the moving cursor is not displayed and the operator loses sight of the cursor. was there. For example, L
Display response time of CD display is 300-400m
sec. On the other hand, when you move the mouse,
The cursor is displayed only for 1/30 second (= 33 msec), then erased, moved to the next position, and again at the destination.
The operation of displaying for only / 30 seconds and deleting again is repeated. Therefore, the display signal is output only for 33 msec for the cursor at an arbitrary position during the movement. That is, since the display signal is erased within 300 to 400 msec of the display response time, a phenomenon occurs in which the operator who operates the mouse cannot see the cursor.

The present invention has been made in view of the above points, and when a display device having a long display response time such as an LCD is used and the moving speed of the cursor is too fast, the moving cursor is displayed. In order to eliminate the problem that the cursor is not displayed, it is an object of the present invention to provide a cursor display control method in which the display time of the afterimage of the cursor is controlled according to the moving speed of the mouse so that the cursor is always visible.

[0014]

According to a cursor display control method of the present invention, a cursor displayed on a display device whose display response time is long compared to the occurrence time of display control is moved by a pointing device which indicates the cursor. In the case of controlling, a register for designating a position for displaying the cursor and a plurality of coordinate comparators for comparing the position designated in the register with the display control position on the display device are respectively prepared, The cursor is sequentially displayed by any one of the plurality of registers and the coordinate comparator according to the display control of the display device, and an afterimage immediately before the movement of the moving cursor is displayed along with the movement of the cursor. It is a thing.

[0015]

In the cursor display control method of the present invention, the register for specifying the position for displaying the cursor and the coordinate comparator for comparing the position specified in the register with the display control position on the display device are provided. Multiple items are prepared for each. Then, the cursor is sequentially displayed by any of the plurality of registers and the coordinate comparator according to the display control of the display device. As a result, with the movement of the cursor, an afterimage immediately before the movement of the moving cursor is displayed. Therefore, when a cursor is displayed on a display device whose display response time is longer than the time of occurrence of display control, the cursor in the middle of movement is displayed as an afterimage even when the pointing device that points the cursor is moved quickly. .. As a result, the operator does not lose sight of the cursor.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a system to which the cursor display control method of the present invention is applied. The illustrated system includes a horizontal / vertical synchronization counter unit 1, a plurality of XY registers R1, R2, R3, and an address register 2.
And a plurality of XY comparators C1, C2, C3, an address selector 3, and a pattern RAM 4. The horizontal / vertical synchronization counter unit 1 outputs coordinates (X1, Y1) that change in a dot clock cycle in synchronization with blank, horizontal synchronization, and vertical synchronization signals.

The XY registers R1, R2 and R3 respectively specify the coordinates for displaying the cursor. The address register 5 sets an address when writing the dot pattern of the cursor in the pattern RAM 4. XY coordinate comparator C
1, C2, C3 are coordinates (X1, Y1) output from the horizontal / vertical synchronization counter unit 1 and XY registers R1, R
2, coordinates (X2, Y2) stored in R3, (X21,
Y21) and (X22, Y22) are compared. The address selector 3 selects the address of the pattern RAM 4.

The pattern RAM 4 is a random access memory for storing the cursor display pattern. The CPU 11 shown in FIG. 2 first writes the dot pattern of the cursor in the pattern RAM 4 shown in FIG. This is done by setting the address of the pattern RAM 4 in the address register 2 and then setting the dot pattern in the pattern RAM 4. And next, XY
The X coordinate and Y coordinate for displaying the cursor are set in the register R1. The horizontal / vertical synchronization counter unit 1 uses the frame memory 2 based on the dot clock, horizontal synchronization, vertical synchronization, and blank signal provided from the display timing control unit 24.
1 obtains the XY coordinates of the image data output and outputs this.

The XY coordinate comparator C1 has an XY coordinate (X1, Y1) output from the horizontal / vertical synchronization counter section 1 and an XY coordinate.
The XY coordinates (X2, Y2) output from the register R1 are compared and calculated to generate the address of the pattern RAM 4. The contents and results of this comparison and calculation are as follows as in the prior art. (1) When X1-X2> 15 or X1-X2 <0, the pattern RAM address is invalid. (2) The pattern RAM address is invalid even when Y1-Y2> 15 or Y1-Y2 <0. (3) In cases other than the above, pattern RAM address = (Y1
-Y2) * 16 + (X1-X2).

XY register R2 and XY coordinate comparator C2
The same applies to the XY register R3 and the XY coordinate comparator C3. The pattern RAM address thus obtained and the address output from the address register are
It is input to the address selector 3, one of them is selected by a blank signal, and is input to the pattern RAM 4. Address register 3 while the blank signal is on
One of the outputs of the XY coordinate comparators C1, C2, and C3 is selected during output and off. By doing so, it is possible to display a maximum of three cursors.

Next, the LCD 2 accompanying the movement of the mouse 27
The movement of the cursor on 5 will be described. When the mouse 27 is not moving, XY registers R1, R2, R3
Only one of them is used and one cursor is displayed. It is assumed that the XY register R1 is currently used. The cursor movement control uses a timer interrupt that generates an interrupt at a constant time interval as in the conventional case. CPU11
For example, each time the timer controller 12 generates a timer interrupt every 1/30 seconds, the mouse interface 26
From, the amount of movement of the mouse 27 is read. This amount of movement is X
When the cursor size is less than 16 dots in both the Y and Y directions, the CPU 11 reads the value of the XY register R1, adds the amount of movement to this value, and adds the result to the XY register R1.
Write in.

When the value of the movement amount in the X direction or the Y direction is 16 dots or more which is the size of the cursor, the CPU 11 causes the XY
The destination XY coordinates are written in the register R2. That is, X
Two cursors are displayed at the position of the Y register R1 and the position of the XY register R2. XY register R1
Is cleared at the next third timer interrupt. Therefore, the cursor at the position of the XY register R1 is displayed as an afterimage for a time corresponding to three timer interrupts.

Similarly, at the next timer interruption, if the amount of movement is less than 16 dots which is the size of the cursor in both the X and Y directions, the XY coordinates of the movement destination are written in the XY register R2. When the value of the movement amount in the X direction or the Y direction is 16 dots or more, which is the size of the cursor, the CPU 11 writes the XY coordinates of the movement destination in the XY register R3. That is, the position of the XY register R1, the position of the XY register R2, the XY
Three cursors at the position of register R3 are displayed. By doing this, the cursor will move to the mouse 2 at regular intervals.
The mouse 27 moves 16
If it moves more than a dot, the currently displayed cursor will be displayed as an afterimage.

In the above embodiment, the case where the number of cursors that can be simultaneously displayed is three has been described, but the present invention is not limited to this, and by further increasing the XY register and the XY coordinate comparator, the LCD can be displayed. It is possible to increase the afterimage displayed on the screen. Further, although the writing of the register is changed depending on whether the movement amount is larger than or equal to the size of the cursor or smaller than the size of the cursor, such a change may not be performed.

[0025]

As described above, according to the cursor display control method of the present invention, since it is possible to display a plurality of cursors at the same time, it is possible to display the afterimage of the moving cursor. In a computer system using a display device having a long response time, it is possible to prevent the operator from losing sight of the cursor even when a pointing device such as a mouse is moved at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a system to which a cursor display control method of the present invention is applied.

FIG. 2 is a block diagram of an example of a schematic configuration of a conventional computer system.

FIG. 3 is a block diagram showing a configuration of a conventional cursor display control unit.

[Explanation of symbols]

 1 horizontal / vertical sync counter 2 address register 3 address selector 4 pattern RAM R1, R2, R3 XY register C1, C2, C3 XY coordinate comparator

Claims (1)

[Claims] 1. When a cursor displayed on a display device having a display response time that is longer than the time of occurrence of display control is moved and controlled by a pointing device that points the cursor, a position for displaying the cursor is designated. And a coordinate comparator for comparing the position designated in the register with the display control position on the display device, and the cursor is controlled according to the display control of the display device. A cursor display control method characterized in that it is sequentially displayed by one of a register and a coordinate comparator, and an afterimage immediately before the movement of the moving cursor is displayed as the cursor moves.