JPH0418595A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To enable secure cursor confirmation by make a cursor display where a cursor is present before its movement continuously for a certain time while making a cursor display at the destination of the cursor at the time of the cursor movement. CONSTITUTION:When the cursor is moved, the contents of a 1st cursor address register are rewritten into the address of the movement destination first. At this time, the address before the movement is written in an (n)th cursor address register 12 from a 2nd cursor address register 11, so two cursors are displayed on a display panel. The display of the cursor at the address of the movement destination does not have sufficient brightness right after the register is rewritten since the response speed of liquid crystal is slow. The display brightness increases with time, so the addresses from the 2nd cursor address 11 to the (n)th cursor address 12 are rewritten into the address after the movement and then only one cursor is displayed on the liquid crystal panel. Consequently, the cursor is securely displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid crystal display device that simultaneously displays a cursor.

BACKGROUND OF THE INVENTION In recent years, demand for large-screen, thin liquid crystal display devices has been increasing in the field of information equipment, mainly computers, and technology related to control methods thereof is becoming important.

However, since the response speed of the simple matrix type liquid crystal display panel is slow, the cursor may become invisible when displayed while moving the cursor.

A conventional liquid crystal display device will be explained below.

FIG. 6 shows a block diagram showing the configuration of a conventional liquid crystal display device. As shown in FIG. 6, the configuration is as follows: 1 is a central processing unit (hereinafter referred to as CPU), 2 is a liquid crystal panel, 3 is a storage means VRAM (hereinafter referred to as VRAM), 4 is a conventional liquid crystal display device, 5 is a VRAM address generation unit that reads display data from VRAM3, 6 is a CP
Data can be set from the UI, cursor address register that stores the address to display the cursor, 7 is VR
A comparison circuit 8 compares the address output from the AM address generation section 5 with the data in the cursor address register 6 and generates a match signal if they match. This is a display synthesis circuit that synthesizes coincidence signals and generates liquid crystal display data.

Regarding the liquid crystal display device configured with the above-mentioned elements, the related operations of the components will be explained below.

Display data other than the cursor is written into the VRAM 3 in advance by a CPU or the like, and the VRAM address generating section 5 generates a read address for the VRAM 3 and continues to sequentially read out the display data. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a cursor, the CPUI writes the address on VRAMa where the cursor is to be displayed to the cursor address register 6. The comparison circuit 7 constantly compares the address signal generated from the VRAM address generation section 5 and the address signal of the cursor address register 6, and if they match, the comparison circuit 7 generates a match signal. This coincidence signal is used as is as cursor display data. To do this, it is necessary to synthesize the display data read from the VRAM 3 and the cursor display data from the comparator circuit 7, so the display synthesis 8 performs the synthesis and displays the final display data on the liquid crystal panel 2.
transfer data to.

When moving the cursor, by writing the destination VRAM address into the cursor address register 6 from the CPU, the output timing of the match signal generated from the comparison circuit 7 changes, and the cursor display position changes.

Problems to be Solved by the Invention However, in the conventional configuration described above, when the cursor movement speed is increased, the cursor display data generated from the comparator circuit 7 changes immediately, so the liquid crystal panel 2, which has a slow response speed, cannot display the cursor. This poses a problem in that the cursor must be moved to the next position before the cursor at the destination is displayed and the cursor disappears from the display screen.

The above describes a configuration in which a liquid crystal display device is used as a character display based on conventional character fonts.However, if a liquid crystal display device is used for general video display and a cursor display is required, the cursor display means is Although it is different in that it is displayed in the same manner as video display, it goes without saying that the above-mentioned problems caused by cursor movement are the same.

The present invention has been made in consideration of the above-mentioned conventional problems, and an object of the present invention is to provide a liquid crystal display device in which the cursor display can be reliably recognized without disappearing even when the moving speed of the cursor is increased.

Means for Solving the Problems In order to achieve the above object of the present invention, the cursor display is changed from the cursor display at the current desired position to the position where the cursor was before the cursor was moved, and the cursor remains displayed for a certain period of time. The display is performed simultaneously, and when the cursor moves continuously, each time a new cursor display position is established, the cursor display at the previous cursor display position continues for a certain period of time. This is a liquid crystal display device in which the display is stopped after the display is completed.

As a configuration, the first invention includes a first storage means for storing display data, and a second storage means for storing cursor display data.
storage means, and this first storage means. The second storage means includes address generation means for generating a display address to read data from the second storage means, and display means for displaying display data and a cursor according to the address output of the address generation means, and the second storage means: Cursor display in which new cursor display data at the destination is memorized as the cursor moves, and the cursor is also memorized to continue displaying the cursor for a certain period of time at the position where the cursor was before the cursor moved. This is a liquid crystal display device having a control means.

As a second invention, a first storage means similar to the first invention, an address generation means for generating a display address for reading display data of the first storage means, and an address for displaying a cursor are stored. a second storage means; a comparison means for comparing the addresses of the respective outputs of the address generating means and the second storage means; and outputting a match signal when they match; and reading out the match signal from the first storage means; The second storage means stores a new address of the destination as the cursor moves, and a cursor where the cursor existed before the cursor moved. This is a liquid crystal display device having a cursor display control means that stores an address continuously for a certain period of time.

As a third invention, in addition to the first and second inventions, a cursor display control means for continuously displaying a cursor at a cursor position existing before the cursor movement for a certain period of time after the cursor movement is provided. It has a brightness adjustment function that allows the brightness of the time display to be different from that of the steady display.

As a fourth invention, the second storage means of the second invention is composed of a plurality of cursor address registers, and a plurality of comparisons corresponding to comparison means to which the outputs of each of the plurality of cursor addresses are connected. This is a liquid crystal display device consisting of a circuit.

As a fifth invention, there is provided a liquid crystal display in which the second storage means of the second invention comprises a plurality of shift registers connected in series, and the comparison means comprises a comparison circuit connected to each of the shift registers. It is a device.

As a sixth invention, a cursor address comparison circuit that compares the outputs of a plurality of cursor address registers and detects a time difference in the timing of displaying the cursor is added to the fourth invention, and the output of the cursor address comparison circuit is set to a predetermined value. This is a liquid crystal display device in which the cursor display control means operates only when the value is less than or equal to , that is, when the cursor movement speed is fast.

A seventh invention is a liquid crystal display device controlled by a gate connected between the plurality of comparison circuits and the display means according to the fourth invention, and a timer connected to each of the plurality of gates.

In the first aspect of the invention, when the cursor display data is stored in the second storage means, the cursor is moved by storing the cursor display data at a new position where the cursor is to be moved. Instead of erasing the cursor display data at the position where the cursor was located before the cursor was moved, the cursor is stored so that the cursor can be displayed continuously for a certain period of time. Therefore, simultaneous display is performed for that certain period of time. In this way, at the same time as the cursor is displayed at the destination of the cursor movement, the cursor at the position where the cursor previously existed is continuously displayed for a certain period of time, and then the cursor display is stopped. This changes the cursor movement speed,
Due to the relationship between the constant display time and the liquid crystal display delay time, the image is displayed as an afterimage when the cursor is moved, so that a cursor movement locus is drawn.

This cursor display and the display data stored in the first storage means are combined and displayed by the display means in accordance with the address generated by the address generation means.

The second invention is a case where display is performed using a character font as a character display, and the cursor address stored in the second storage means is compared with the address output from the address generation means that generates the address of display data. When the addresses match, a match signal is output for displaying a cursor. This coincidence signal and the first
By combining read data from the storage means, read data display and cursor display can be performed simultaneously. The second storage means that stores this cursor address continues to store the cursor address where the cursor was located before the cursor was moved for a certain period of time. This allows the first
Similar to the invention described above, an afterimage-like cursor display is performed, and a cursor movement trajectory is drawn.

A third aspect of the invention is that the manner in which the afterimage-like cursor display of the first and second aspects is displayed can be adjusted. In other words, after the cursor is moved, the cursor is displayed at the position where the cursor was before the movement for a certain period of time, but depending on the speed of the cursor movement, multiple cranes may be displayed at the same time, and the original position of the destination may be displayed. The cursor position that should be displayed may be difficult to discern. In this case, regarding the cursor display that continues for a certain period of time and appears as an afterimage,
For example, if the display brightness is halved, a more afterimage-like cursor trajectory will be drawn. In addition, in the case of color display, if the brightness of a certain color is changed, only the cursor display part that remains as an afterimage display will have a different color, making it possible to clearly distinguish it from the original cursor display position.

In the fourth invention, each of the plurality of cursor address registers stores an address for each cursor. If the cursor is stopped, all the same addresses are HIA
t, has been done. When the cursor moves, the address of the first cursor address register is stored as the new address to which the cursor should be moved, and the remaining cursor address registers remain containing the address before the cursor movement, and these two addresses are displayed at the same time. If the cursor is subsequently moved sequentially, the first cursor address register is rewritten with the new address to be moved, and in that case, the second cursor address register is rewritten with the new address stored in the first cursor address register. The address that was previously saved will be written. In this way, the plurality of address registers are sequentially updated with new addresses. When the cursor stops, select the address representing the current cursor position as Elf? , the cursor address registers other than the first cursor address register are sequentially rewritten to the address representing the current cursor position after a certain period of time, so that one stopped cursor is no longer displayed.

In the fifth invention, since the second storage means is composed of a plurality of shift registers, the address of the current cursor position is stored in the first shift register of the shift registers connected in series, and the address of the current cursor position is sequentially The signal is transferred to the third shift register, and the same operation as in the fourth invention is performed.

In the sixth invention, a cursor address comparison circuit detects a time difference in the timing of cursor display corresponding to the cursor movement speed, and as the cursor movement speed increases and the display time at a certain position becomes shorter, the liquid crystal display When response speed becomes an issue, the cursor display control means displays an afterimage cursor for the first time.

The seventh invention is to individually set the fixed time using a timer connected to each cursor address register when rewriting the cursor address to the current cursor address after the cursor address register of the fourth invention has been continuously displayed for a certain period of time. It is possible.

EXAMPLE A first example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram showing the configuration of a liquid crystal display device according to a first embodiment of the present invention.

As shown in FIG. 1, the components are as follows: 9 is a liquid crystal display device according to the first embodiment of the present invention; 10 is a first cursor address register that stores the address of VRAM 3 for displaying a cursor; and 11 is a cursor. 12 is a second cursor address register that stores the address of VRAM3 that displays the afterimage of cursor, and 12 is a register of VRAM3 that displays the afterimage of the nth cursor (n is a positive integer), which is different from the second cursor address register. nth cursor address register for storing addresses; 13 is a VRAM address generator 5;
a first comparison circuit that compares the output data of the first cursor address register 10 and generates a match signal if they match;
14 is a second comparison circuit which compares the output data of VRAM address generator 5 and second cursor address register 1 and generates a match signal if they match; 15 is a VRAM address generator 5 and n-th cursor address register 12 compares the output data of and generates a match signal if they do not match
Comparison circuit 16 is read data from VRAM3,
First comparison circuit 13, second comparison circuit 14, nth comparison circuit 1
This is a display synthesis circuit that synthesizes the coincidence signals from 5 as cursor display data.

Further, 1 is a CPU, 2 is a liquid crystal panel, 3 is a VRAM, and 5 is a VRAM address generator, which are the same as those in the conventional example.

In this embodiment, the second storage means of the second invention is composed of a plurality of cursor address registers, and the cursor display control means of the second storage means is composed of the plurality of cursor address registers and the cursor address registers. It is composed of a CPUI.

The operation of the first embodiment of the present invention configured as above will be explained. Display data other than the cursor is written in advance by the CPU to VRAM3, and VR
The AM address generation section 5 generates a read address for the VRAM 3 and continues to read display data sequentially. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a cursor, the CPUI writes the address on the VRAM for displaying the cursor from the first cursor address register 10 to the n-th cursor address register 12. If the same address is written in each cursor address register, the first comparison circuit 13 to the nth comparison circuit 1
A coincidence signal with the same timing is generated up to 5. The display synthesis circuit 16 uses the read data from the VRAM 3 and the first
Match signals from the comparison circuit 13 to the n-th comparison circuit 15 are combined as cursor data and transferred to the liquid crystal panel 2.

Since the same data is written to each cursor address register, one cursor is displayed on the display screen.

When moving the cursor, first the first cursor address register 10 is rewritten to the address of the destination. At this time, since the addresses before movement are written in the second cursor address register 11 to the nth cursor address register 12, two cursors are displayed on the liquid crystal panel. The display of the cursor at the destination address does not have sufficient display brightness immediately after the register is rewritten because the response speed of the liquid crystal is slow. Since the display brightness is obtained over time, if the addresses from the second cursor address register 11 to the nth cursor address register 12 are then rewritten to the addresses after the movement, only one cursor will be displayed on the liquid crystal panel.

Since there are multiple cursor address registers and comparison circuits that generate cursors, if each cursor has an afterimage time difference that displays the address before movement for a certain period of time depending on the response speed of the liquid crystal panel, it is possible to apply it to any liquid crystal panel. It is possible to display the afterimage of the corresponding cursor.

As described above, according to this embodiment, by having multiple cursor address registers and comparison circuits, multiple cursors can be displayed and an afterimage can be displayed, thereby preventing the cursor from disappearing due to movement of the cursor. be able to.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a block diagram showing the configuration of a liquid crystal display device according to a second embodiment of the present invention.

As shown in FIG. 2, the constituent elements 17 are a liquid crystal display device according to the second embodiment of the present invention, 18 is a first shift register for storing the address of VRAM 3 for displaying a cursor, and 19 is a first shift register for storing the address of the VRAM 3 for displaying a cursor. A second shift register 20 is connected to each bit of the shift register 18 in a shift register configuration and stores an address for displaying the afterimage of the cursor, and 20 is an n-th shift register (n is a positive integer) ), the n-th shift register 21 stores the address for displaying the afterimage of the cursor; This is a display synthesis circuit that synthesizes matching signals as cursor display data.

1 is the CPU, 2 is the liquid crystal panel, 3 is the VRAM, 5 is the VRAM address generator, which are the same as in the conventional example, 13 is the first comparison circuit, 14 is the second comparison circuit, 1
Reference numeral 5 denotes an n-th comparison circuit, which is the same as that shown in the first embodiment. In this way, a plurality of shift registers are used in place of the plurality of cursor address registers of the first embodiment.

The operation of the second embodiment of the present invention configured as above will be explained.

Display data other than the cursor is written into the VRAM 3 in advance by a CPU or the like, and the VRAM address generator 5 generates a read address for the VRAM 3 and continues to read the display data sequentially. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a cursor, the CPUI writes the address on the VRAM where the cursor is to be displayed into the first shift register 18. Data is sequentially transferred to each shift register by a write pulse of the CPUI, and if the CPUI continues writing the same data to the first shift register 0 times, each shift register becomes the same data. Then, coincidence signals with the same timing are generated from the first comparison circuit 13 to the n-th comparison circuit 15. The display synthesis circuit 21 synthesizes the read data from the VRAM 3 and the matching signals from the first comparison circuit 13 to the n-th comparison circuit 15 as cursor data.
Transfer to LCD panel 2. Since the same data is written to each cursor address register, one cursor is displayed on the display screen.

When moving the cursor, the CPUI rewrites the first shift register 18 with the address of the destination. At this time, since the address before movement is written in the second shift register 19 to the n-th shift register 20, two cursors are displayed on the liquid crystal panel. Immediately after the register is rewritten, sufficient display brightness cannot be obtained because the response speed of the liquid crystal is slow. Since the display brightness increases over time, if the moved address is continued to be written into the first shift register 18, only one cursor will be displayed on the liquid crystal panel.

Since there are a plurality of cursor address registers and comparison circuits that generate cursors, if the addresses to be written to the first shift register 18 are sequentially changed and written, the cursor will be displayed leaving a trace. The first shift register 18 is adjusted in consideration of the afterimage time difference depending on the response speed of the liquid crystal panel.
By writing an address to the cursor, a cursor afterimage can be displayed on any liquid crystal panel.

As described above, according to this embodiment, by having a shift register that stores a plurality of cursor addresses and a comparison circuit, it is possible to display a plurality of cursors and display an afterimage. This can prevent the display from disappearing.

A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a block diagram showing the configuration of a liquid crystal display device according to a third embodiment of the present invention.

As shown in FIG. 3, 22 is a liquid crystal display device according to an embodiment of the present invention, and 23 is a first cursor address register 10 to an nth cursor address register 12.
A cursor address comparison circuit that compares the outputs of the cursor address registers up to
The read data from RAM3 and the first comparison circuit 13,
This is a display synthesis circuit that synthesizes the match signals from the second comparison circuit 14 and the n-th comparison circuit 15 as cursor display data.

Also, 1 is a CPU, 2 is a liquid crystal panel, 3 is a VRAM, and 5 is a VRAM address generator, which are the same as in the conventional example, 10 is a first cursor address register, 11 is a second cursor address register, and 12 is a An n-th cursor address register, 13 a first comparison circuit, 14 a second comparison circuit, and 15 an n-th comparison circuit are the same as those shown in the first embodiment.

The operation of one embodiment of the present invention configured as above will be explained. Display data other than the cursor is written in advance to VRAM3 by the CPU, etc.
The address generator 5 generates a read address for the VRAM 3 and continues to read display data sequentially. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a cursor, the CPUI transfers the address on the VRAMS where the cursor is to be displayed from the first cursor address register 10 to the nth cursor address register 1.
Write in 2. If the same address is written in each cursor address register, the first comparison circuit 13 to the nth comparison circuit 15 generate coincidence signals at the same timing.

The display synthesis circuit 24 synthesizes the read data from the VRAM 3 and the matching signals from the first comparison circuit 13 to the n-th comparison circuit 15 as cursor data, and transfers it to the liquid crystal panel 2. Since the same data is written to each cursor address register, one cursor is displayed on the display screen. At this time, the cursor address comparison circuit 23 compares the first cursor address register 10 to the nth cursor address register 12 at regular time intervals.
It compares the address outputs up to and recognizes that they are the same data.

When moving the cursor, first the first cursor address register 10 is rewritten to the address of the destination. The cursor address comparison circuit 23, which compares the output data of each cursor address register at fixed time intervals, is
It is recognized that the cursor address register 10 has been rewritten. Fixed time interval cursor address register 10
When the data change amount exceeds a certain value X (when the cursor movement speed is fast), the cursor address comparison circuit 2
3 generates a display synthesis control signal to the display synthesis circuit 24. The display synthesis circuit 24 receives the control signal from the cursor address comparison circuit 23, and uses the display data from the VRAM 3, the coincidence signal from the first comparison circuit 13 which is used as a cursor signal, and the cursor afterimage display signal. The coincidence signals from the second comparison circuit 14 to the n-th comparison circuit 15 are combined and transferred to the liquid crystal panel 2 as display data.

At this time, a plurality of cursors based on a plurality of cursor address registers are displayed on the liquid crystal panel as an afterimage display.

When the values of the cursor address register are compared at fixed time intervals and the data change amount is less than the fixed value X (when the cursor movement speed is slow), the cursor address comparison circuit 2
3 stops the display synthesis control signal. The display synthesis circuit 24 synthesizes the display data from the VRAM 3 and the match signal from the first comparison circuit, which is used as cursor display data, and transfers the result to the liquid crystal panel 2 as display data. At that time, display data and one cursor are displayed on the liquid crystal panel 2.

The afterimage display characteristics are the same as in the first embodiment, and since there are multiple cursor address registers and comparison circuits that generate cursors, if each cursor is given an afterimage time difference according to the response speed of the liquid crystal panel, it can be used as desired. It is possible to display a cursor afterimage that is compatible with LCD panels.

As described above, according to this embodiment, it is possible to prevent the cursor from disappearing and at the same time detect the moving speed of the cursor by providing a comparison circuit for a plurality of cursor address registers. This makes it possible to control afterimage display, eliminate unnecessary afterimage display, and further improve liquid crystal display quality.

A fourth embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows a block diagram showing the configuration of a liquid crystal display device according to a fourth embodiment of the present invention.

As shown in FIG. 4, the component 25 is the fourth component of the present invention.
26 is a first timer whose operating cycle can be changed by the CPU; 27 is a first timer;
A second timer whose operation cycle can be set by CPL'1 separately from the timer 26; 28 is the first timer 26;
An n-th timer whose operation cycle can be set by the CPU separately from the second timer 27, 29 a first gate that outputs and controls the match signal of the first comparison circuit 13 under the control of the first timer 26, and 30 a second A second gate 31 controls the output of the match signal of the comparison circuit 14 under the control of the second timer 27; 31 is an n-th gate that controls the output of the match signal of the n-th comparison circuit 15 under control of the n-th timer 28; 32 is a V RA , M
This is a display synthesis circuit that synthesizes the read data from 3 and the match signals from the first gate 29, second gate 30, and n-th gate 31 as cursor display data.

Also, 1 is the CPU, 2 is the liquid crystal panel, 31tVRAM, 5
is the VRAM address generator, which is the same as the conventional example, 10 is the first cursor address register, ]1
12 is the second cursor address register, 12 is the nth cursor address register, 13 is the first comparison circuit, 14 is the second comparison circuit, and 15 is the nth comparison circuit, which are the same as those shown in the first embodiment. be.

The operation of the fourth embodiment of the present invention configured as above will be explained. Display data other than the cursor is written in advance by the CPU to VRAM3, and VR
The AM address generation section 5 generates a read address for the VRAM 3 and continues to read display data sequentially. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a cursor, the CPUI writes the address on the VRAM for displaying the cursor from the first cursor address register 10 to the n-th cursor address register 12. If the same address is written in each cursor address register, the first comparison circuit 13 to the nth comparison circuit 1
A coincidence signal with the same timing is generated up to 5. The display synthesis circuit 32 synthesizes the read data from the VRAM 3 and the matching signals from the first comparison circuit 13 to the n-th comparison circuit 15 as cursor data, and transfers it to the liquid crystal panel 2. If the operating cycle of the first timer 26 to the nth timer 28 is set to infinity, the same data is written in each cursor address register, so one cursor is displayed on the display screen. Also, the first timer 2
If the operation cycle from the 6th timer to the nth timer 28 is set to O, the cursor will not be displayed at all.

When moving the cursor, write the destination address in the first cursor address register l○, write the address before movement in the n-th cursor address register 12, and write the destination address in the second cursor address register 11. and write an address that complements the address before moving. If the operating cycles of the first timer 26 to the nth timer 28 are sequentially decreased (and each timer is activated at the same time as the CPU updates each cursor address register),
An afterimage of the trajectory remains in the direction of movement of the cursor, making it possible to display an afterimage that gradually turns off from the old cursor display data.

As described above, according to this embodiment, by providing a plurality of gates that control the output of a plurality of cursors while preventing the cursor from disappearing, the direction of movement of the cursor becomes clearer, thereby eliminating unnecessary afterimages. It is possible to eliminate the display and further improve the quality of the liquid crystal display.

A fifth embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows a block diagram showing the configuration of a liquid crystal display device according to a fifth embodiment of the present invention.

As shown in FIG. 5, the component 33 is the fifth component of the present invention.
34 is a first timer; 3 is a liquid crystal display device in the embodiment;
5 is the second timer, 36 is the n-th timer, and 37 is the output i of the coincidence signal of the first comparison circuit 13 under the control of the first timer 34.
38 is a second gradation processing circuit whose luminance is lower than that of the first gradation processing circuit 37, and 39 is an n-th gradation processing circuit which has the lowest luminance. A gradation processing circuit, 40, read data from VRAM3,
This is a display synthesis circuit that synthesizes coincidence signals from the first gradation processing circuit 37, the second gradation processing circuit 38, and the nth gradation processing circuit 39 as cursor display data.

Also, 1 is a CPU, 2 is a liquid crystal panel, 3 is a VRAM, and 5 is a VRAM address generator, which are the same as in the conventional example, 10 is a first cursor address register, 11 is a second cursor address register, and 12 is a An n-th cursor address register, 13 a first comparison circuit, 14 a second comparison circuit, and 15 an n-th comparison circuit, which are the same as those shown in the fifth embodiment.

The operation of the fifth embodiment of the present invention configured as above will be explained. Display data other than the cursor is written in advance by the CPU to VRAM3, and VR
The AM address generation section 5 generates a read address for the VRAM 3 and continues to read display data sequentially. Due to this operation, display data other than the cursor is always displayed on the liquid crystal panel 2.

When displaying a horn, the CPU writes the address on the VRAM 5 where the cursor is to be displayed from the first cursor address register 10 to the n-th cursor address register 12. If the same address is written in each cursor address register, the first comparison circuit 13 to the n-th comparison circuit 15 generate coincidence signals at the same timing. 1st
If the operation cycles from the timer 34 to the n-th timer 36 are set to infinity, the coincidence signals from the first comparison circuit 13 and the n-th comparison circuit 15 will be the same as those from the first gradation processing circuit 37 to the n-th timer, respectively.
It is intermediately processed by the gradation processing circuits up to the gradation processing circuit 39 to become cursor data, and the display synthesis circuit 40 generates VR data.
It is combined with the display data from AM3 and transferred as display data to the liquid crystal panel 2 for display. Since the same data is written in the cursor address register, one cursor is displayed on the display screen. Furthermore, if the operating cycle from the first timer 34 to the nth timer 36 is set to O, the cursor will not be displayed at all.

When moving the cursor, write the destination address to the first cursor address register 10, write the address before movement to the n-th cursor address register 12, and write the destination address and the address before movement to the second cursor address register 11. Write the address that completes. If the operating cycles of the first timer 34 to the nth timer 36 are made smaller in order, and each timer is activated at the same time as the CPU updates each cursor address register, an afterimage of the trajectory will remain in the direction of cursor movement. Since the display data of the old cursor has a low display brightness at every gradation and the operating cycles of the first timer 34 to the n-th timer 36 are different, it is possible to display an afterimage that gradually turns off.

As described above, according to this embodiment, the direction of movement of the cursor is controlled by providing a plurality of gates and a plurality of gradation processing circuits that control the output of a plurality of cursors while preventing the cursor from disappearing. It becomes clearer, eliminates unnecessary afterimage display, and further improves the quality of the liquid crystal display.

Effects of the Invention As is clear from the above explanation, in a liquid crystal display device that displays a cursor, when the cursor is moved, at the same time as the cursor is displayed at the destination, the cursor is displayed at the position where the cursor was before the cursor was moved for a fixed period of time. By providing a cursor display control means that continuously displays the cursor for
It is possible to realize a liquid crystal display device in which the cursor can be reliably recognized even if the cursor movement speed is increased when the response speed of the liquid crystal display panel is slow.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a liquid crystal display device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a liquid crystal display device according to a second embodiment of the present invention, and FIG. FIG. 4 is a block diagram showing the configuration of a liquid crystal display device according to a fourth embodiment of the present invention. FIG. 5 is a block diagram showing the configuration of a liquid crystal display device according to a fourth embodiment of the present invention. FIG. 6 is a block diagram showing the structure of a liquid crystal display device in Example 5, and FIG. 6 is a block diagram showing the structure of a conventional liquid crystal display device. 1...CPU, 2...LCD panel, 3
...VRAM, 5...VRAM address generation section, 10...First cursor address register, 11...Second cursor address register, 12... ...nth cursor address register, 1
3...First comparison circuit, 14...Second comparison circuit, 15...Nth comparison circuit, 16...
...Display synthesis circuit.

Claims (7)

[Claims] (1) A first storage means for storing display data, a second storage means for storing cursor display data, and an address generator for generating a display address for reading data from the first and second storage means. and display means for displaying the display data and the cursor display data according to the address output of the address generation means,
The second storage means stores new cursor display data as the cursor moves, and stores the cursor for a certain period of time continuously at the position where the cursor was before the cursor moved. A liquid crystal display device having a cursor display control means. (2) a first storage means for storing display data; an address generation means for generating a display address for reading out the display data of the first storage means; and a second storage means for storing an address for displaying a cursor. storage means for comparing the address output from the address generation means with the address of the second storage means and outputting a coincidence signal; display means for synthesizing and displaying data read from the storage means; the second storage means stores a new cursor address as the cursor is moved; A liquid crystal display device having a cursor display control means that continuously stores an existing cursor address for a certain period of time. (3) Claim 1 or 2, wherein the cursor display for a certain period of time at the position where the cursor was located before the cursor moved in the cursor display control means is a display whose brightness is adjusted.
The liquid crystal display device described. (4) The liquid crystal display device according to claim 2, wherein the second storage means comprises a plurality of cursor address registers, and the comparison means comprises a plurality of comparison circuits corresponding to the plurality of cursor address registers. (5) The liquid crystal display device according to claim 2, wherein the second storage means comprises a plurality of shift registers connected in series, and the comparison means comprises a plurality of comparison circuits corresponding to the plurality of shift registers. (6) Adding a cursor address comparison circuit that compares the outputs of the cursor address registers and detects the temporal difference in cursor display timing, and only when the output of the cursor address comparison circuit is less than or equal to a predetermined value, the cursor display control means 5. The liquid crystal display device according to claim 4, wherein the liquid crystal display device operates as follows. (7) Outputs of the plurality of comparison circuits are inputted to the display means via a plurality of gates corresponding to the plurality of comparison circuits, and the plurality of gates are connected to each of the gates. Claim 4 Controlled by a plurality of timers
The liquid crystal display device described.