JPH0318818A - Matrix type display device - Google Patents

Abstract

PURPOSE:To shorten the time required for updating a screen by constituting the subject device so that one of a line direction electrode or a row direction electrode of a matrix type display panel, and the other can be switched to a scanning electrode and a signal electrode, respectively. CONSTITUTION:In the case of displaying a long screen in the horizontal direction, a selecting signal S1 = 0 is inputted to a switching circuit 4 from a control circuit 6, and an instruction is given to the switching circuit 4 so that a control signal for driving a signal electrode, and a control signal for driving a scanning electrode are inputted to a row direction electrode driving circuit 2 and a line direction electrode driving circuit 3, respectively. Also, in the case of displaying long the screen in the vertical direction, a selecting signal S1 = 1 is inputted to the switching circuit 4 from the control circuit 6, and an instruction is given to the switching circuit 4 so that the control signal for driving the scanning electrode, and the control signal for driving the signal electrode are inputted to the row direction electrode driving circuit 2 and the line direction electrode driving circuit 3, respectively. In such a way, the vertical and the horizontal display directions of the screen can be changed easily, and the time for updating the screen can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a matrix type display device that is effective for use in video and information equipment.

Conventionally, in this type of display, for example, in a matrix type display device using a ferroelectric liquid crystal with memory properties, the row electrodes are used as scanning electrodes, and voltages are sequentially applied to the scanning electrodes to perform scanning. The column direction electrodes are used as signal electrodes, and an image signal voltage is applied to the signal electrodes in synchronization with the scanning signal. In order to perform such driving, a vertical synchronizing signal VD is usually used as shown in FIG.

This is performed using signals such as the horizontal synchronization signal HD and the image signal DATA.

FIG. 5 shows a block diagram of a general matrix type liquid crystal display device. x51~X5m are column direction electrodes, Y51
= Y5n is a row direction electrode, 51 is a liquid crystal panel, 52 is a signal electrode drive circuit, 53 is a scan electrode drive circuit, 54 is a VRA
M, 55 is a control circuit, 56 is a control signal for driving signal electrodes of HD, etc., and 57 is a control signal for driving scanning electrodes of HD, VD, etc.

The control circuit 55 controls the signal electrode drive circuit 52, the scan electrode drive circuit 53, and the VRAM 54.

In FIG. 5, a vertical synchronization signal VD and a horizontal synchronization signal HD are input to a scan electrode drive circuit 53, where VD is used as a scan signal and HD is used as a shift timing signal for sequentially shifting VD and selecting a scan electrode. The scan electrode drive circuit 53 applies a scan drive voltage to the scan electrodes of the liquid crystal panel in synchronization with the HD. In addition, the signal electrode drive circuit 52
The image signal DATA is input every horizontal period, and the HD
A driving voltage is applied to the signal electrodes in synchronization with .

The scanning electrode drive circuit 53 and the signal electrode drive circuit 52 apply drive voltages to the electrodes in synchronization with the horizontal synchronizing signal HD, and sequentially scan the screen from top to bottom, thereby displaying an image.

However, as shown in FIG. 3(a), if it is easier to display the display data on both sides of a vertically long screen than on a horizontally long screen, the display device can be moved 90' as shown in FIG. 3(b). The display direction may be changed by rotating the display screen so that it can be used vertically, but in the above configuration, since the scanning direction is fixed, it is necessary to convert the display data.

Next, when a part of the display screen is changed as shown in Figures 4(a) and (g)), with the above configuration, the entire screen must be scanned and the screen rewritten, and the entire screen is updated. The time is (the number of scanning electrodes and the response speed of the liquid crystal), so the greater the number of scanning electrodes, the longer it takes to update the screen.For example, when displaying a loss cursor as shown in Figure 6, in the row direction. In the conventional configuration, the cross cursor cannot be displayed unless the entire screen is updated.

Problems to be Solved by the Invention Therefore, in the conventional matrix type display device having the configuration as shown in FIG. 5, the scanning direction cannot be changed, so when changing the direction of the display screen, it is necessary to perform data conversion. There was a problem with this.

Furthermore, in the conventional matrix type display device having the configuration shown in Fig. 5, when the display screen is changed, the entire screen is scanned and the screen is rewritten regardless of the amount of changed display data. There was a problem in that the larger the number of electrodes, the longer it took to update the screen.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a matrix type display device that solves the above problems, simplifies the control circuit, and shortens the time required for updating the screen.

Means for Solving the Problems The technical means for solving the above problems is to make it possible to switch the scanning direction of the matrix display panel to the row direction or the column direction, and the row direction electrode drive circuit and the column direction electrode drive circuit are as follows:
It is possible to drive only the electrode at a designated address.

action The effect of this technical means is as follows.

In other words, if the display screen is rotated by 90' and, for example, the long side of the screen is used vertically instead of horizontally, the row electrodes that were scan electrodes are now signal electrodes, and the column electrodes that were signal electrodes are Since the direction electrodes can be changed to scanning electrodes, screen display is possible without using data conversion means. Furthermore, since only the electrodes at designated addresses can be scanned, the display screen can be changed by scanning only the electrodes whose display data has changed, thereby reducing the screen update time.

Embodiment Hereinafter, an IJ box type display device according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows the configuration of a matrix type display device in an embodiment of the present invention.

1 is a ferroelectric liquid crystal panel; 2 is a column direction electrode drive circuit for driving the column direction electrodes; 3 is a row direction electrode drive circuit for driving the row direction electrodes. 4 is a switching circuit;
The control signal for driving the scan electrode and the control signal for driving the signal electrode are switched to be input to the column direction electrode drive circuit 2 and the row direction electrode drive circuit 3, respectively. 5 is VRAM,
Store and output image data. A control circuit 6 controls the column electrode drive circuit 2, the row direction drive circuit 3, the switching circuit 4, and the VRAM 5. 7 is a control signal for driving the scanning electrode, and 8 is a control signal for driving the signal electrode. X1~
Xm is a column direction electrode, and Yl-Yn is a row direction electrode. For simple explanation, it is assumed to be man, and the column direction is assumed to be the long side. In FIG. 1, when the screen is displayed long in the horizontal direction as shown in FIG. 3(a), the selection signal 51=
O is input to the switching circuit 4, and the switching circuit 4 is instructed to input a control signal for driving the signal electrode to the column direction electrode drive circuit and a control signal for driving the scan electrode to the row direction electrode drive circuit. The switching circuit 4 sends the display signal DATA to the column direction electrode drive circuit 2 every horizontal period m focus.
A vertical synchronizing signal V is applied to the row direction electrode drive circuit 3 every vertical period.
If the action of sending D is 0 or more, it will be displayed long in the horizontal direction as shown in FIG. 3(a).

Next, in FIG. 1, when the screen is displayed long in the vertical direction as shown in FIG. 3(b), the selection signal 51-1 is sent from the control circuit 6.
is input to the switching circuit 4, and the switching circuit 4 is instructed to input a control signal for scanning electrode driving to the column direction electrode drive circuit, a signal to the row direction electrode drive circuit, and a control signal for column drive. The switching circuit 4 is the row direction electrode drive circuit 3
The display signal DATA is sent by n bits every horizontal period, and the vertical synchronizing signal VD is sent to the column direction drive circuit 2 every vertical period. Is displayed.

As explained above, in the matrix type display device configured as shown in FIG. 1, when the display screen is rotated by 90 degrees for display, there is no need for data conversion.

Note that the same effect can be obtained even if the liquid crystal panel is a nematic liquid crystal.

(Embodiment 2) Next, screen updating in the case of changing a part of the display screen in the matrix type display device having the configuration shown in FIG. 1 will be described.

When a part of the display screen is changed, the control circuit 6 compares the current display data with the new display data, checks the address of the column direction electrode where the pixel to be updated is located, and counts the number of column direction electrodes (ml). . Similarly, the address of the row direction electrode where the pixel to be updated is located is checked, and the number nl of row direction electrodes is counted. Compare ml and nl, and as shown in FIG. 4(b), if ml<nl, the column direction electrode is used as the scanning electrode,
Designate the row direction electrodes as signal electrodes. The control circuit 6 stores the address data of the column direction electrode where the pixel to be updated is located in the VRAM.
5 to the switching circuit 4 to designate the electrode to be scanned to the column electrode drive circuit 2 through the switching circuit 4, and at the same time, the VRAM 5 outputs display data corresponding to the scanning electrode to the row direction electrode drive circuit 3.
Output to. The column direction electrode drive circuit 2 sequentially scans the electrodes at addresses specified by the control circuit 6, and in synchronization with this, the row direction electrode drive circuit 3 outputs a display signal and the display screen is updated. - If the horizontal period is tl, the time required to update the screen is ml*tl if the column direction electrodes are scan electrodes.
Therefore, the screen update time is shorter than that of the conventional configuration shown in FIG.

Conversely, by comparing ml and nl, m
If l>nl, the row direction electrodes are designated as scan electrodes, and the column direction electrodes are designated as signal electrodes. The control circuit 6 outputs the address of the row electrode where the pixel to be updated is located to the VRAM 5 and the switching circuit 4, and outputs the address of the row electrode driving circuit 3 through the switching circuit 4.
At the same time, the VRAM 5 outputs display data to the column direction electrode drive circuit 2. The directional electrode drive circuit 2 outputs a display signal, and the display screen is updated. -If Mizuko period is tl, the time required to update the screen is nl*tl,
The screen update time is shorter than that of the conventional configuration shown in FIG.

(Embodiment 3) FIG. 2 shows the configuration of a matrix type display device in an embodiment of the present invention.

21 is a ferroelectric liquid crystal panel, 22 is a column direction electrode drive circuit, which drives the column direction electrodes, and 23 is a row direction electrode drive circuit, which drives the row direction electrodes.

Reference numeral 24 denotes a switching circuit which switches the control signal for scanning electrode drive control II times signal signal electrode drive control signal to be input to the column direction electrode drive circuit 22 and the row direction electrode drive circuit 23, respectively. 26 is a VRAM that stores image data;
Output. 25 is a memory circuit that stores the cursor position;
27 is a control ji1 circuit, which includes a column direction electrode drive circuit 22,
It controls the row direction drive circuit 23, the switching circuit 24, and the VRAM 26. 28 is a control signal for driving the scanning electrode, and 29 is a control signal for driving the signal electrode. X21 to X2m are column direction electrodes, and Y21 to Y2n are row direction electrodes.

For simple explanation, it is assumed that m>n and the column direction is the long side.

FIGS. 6(a) and 6(c) are examples of screens displaying a cross cursor. 61 is a cursor in the column direction, and 62 is a cursor in the row direction.

In the following, a case will be described in which a cursor as shown in FIG. 6 is displayed in the matrix display device having the configuration shown in FIG. 2.

The selection signal 51=O is input from the control circuit 27 to the switching circuit 24, and the switching circuit 24 inputs the control signal 29 for driving the signal electrode to the column direction electrode drive circuit 22, and the control signal 29 for driving the signal electrode to the column direction electrode drive circuit 22.
3, an instruction is given to input the control n signal 28 for driving the scan electrode. The storage circuit 25 outputs the address data of the row direction cursor to the switching circuit 24 according to instructions from the control circuit 27 .

The switching circuit 24 instructs the row direction electrode drive circuit 23 the address of the row direction electrode where the row direction cursor is to be written, and the column direction electrode drive circuit 22 receives the 0 row direction electrode drive which inputs display data. Circuit 23 is switching circuit 2
4 scans the row direction electrodes at the address specified, and in synchronization with this, the column direction electrode drive circuit 22 outputs a display signal.0 Next, the selection signal 51=1 is input from the control circuit 27 to the switching circuit 24, The switching circuit 24 is instructed to input a control signal 29 for driving the signal electrode to the row direction electrode drive circuit 23 and a control signal 28 for driving the scan electrode to the column direction electrode drive circuit 22. The storage circuit 25 outputs column-direction cursor address data to the switching circuit 24 according to instructions from the control circuit 27. The switching circuit 24 instructs the column direction electrode drive circuit 22 the address of the column direction electrode for writing the column direction cursor according to the instruction from the control circuit 27, and the row direction electrode drive circuit 23 receives the 0 column direction electrode drive for manually inputting display data. circuit 2
2 scans the column direction electrode at the address specified by the switching circuit 24, and in synchronization with this, the row direction electrode drive circuit 23 outputs a display signal.

Further, when the position of the cursor changes as shown in Figure 6), the following operation occurs.

A selection signal 31-0 is input from the control circuit 27 to the switching circuit 24, and the switching circuit 24 supplies a control signal 29 for driving the signal electrode to the column direction electrode drive circuit 22, and a control signal 29 for driving the signal electrode to the column direction electrode drive circuit 22.
3, an instruction is given to input a control signal 28 for driving the scanning electrodes. The storage circuit 25 outputs the address data of the row direction cursor after being moved to the switching circuit 24 according to the instruction from the control circuit 27, and the control circuit 27 outputs the display data of the cursor to the switching circuit 24. The switching circuit 24 instructs the row direction electrode drive circuit 23 the address of the row direction electrode at which the row direction cursor is to be written, according to the instruction from the control circuit 27,
The column direction electrode drive circuit 22 inputs cursor display data.The row direction electrode drive circuit 23 scans the row direction electrode at the address specified by the switching circuit 24, and in synchronization with this, the column direction electrode drive circuit 22 The 0th order storage circuit 25 that outputs the cursor display signal is instructed by the control circuit 27 to
The address data of the row direction cursor before movement is output to the switching circuit 24 and the control circuit 27. The control circuit 27 is a VRAM
The display data on the address of the cursor in the row direction before movement is read out from 26 and output to the switching circuit 24. The switching circuit 24 instructs the row direction electrode drive circuit 23 the address of the row direction cursor before movement according to the instruction from the control circuit 27,
Display data is input to the column direction electrode drive circuit 22.

The row direction ti drive circuit 23 scans the row direction electrode at the address specified by the switching circuit 24, and in synchronization with this, the column direction electrode drive circuit 22 outputs a display signal.

Subsequently, the selection signal 51=1 is sent from the control circuit 27 to the switching circuit 2.
4, and the row direction electrode drive circuit 2 is input to the switching circuit 24.
3, an instruction is given to input the control n signal 29 for driving the signal electrode, and the control n signal 28 for driving the scanning electrode to the column direction electrode driving circuit 22. The storage circuit 25 outputs the address data of the moved column-direction cursor to the switching circuit 24 according to instructions from the control circuit 27, and the control circuit 27 outputs the display data of the cursor to the switching circuit 24. According to the instruction from the switching circuit 24↓ and the control circuit 27, the column direction electrode drive circuit 22 is instructed to specify the address of the column direction electrode where the column direction cursor is to be written, and the row direction electrode drive circuit 23 is directed to the 0th column where the cursor display data is input. The direction electrode drive circuit 22 scans the row direction electrode at the address specified by the switching circuit 24, and in synchronization with this, the row direction electrode drive circuit 23 outputs a cursor display signal. In response to the instruction, the address data of the column-row direction cursor before movement is output to the switching circuit 24 and the control circuit 27. The control circuit 27 is a VRAM
The display data on the address of the cursor in the column direction before movement is read out from 26 and output to the switching circuit 24. In response to instructions from the control circuit 27, the switching circuit 24 instructs the column direction electrode drive circuit 22 to address the column direction cursor before movement, and inputs display data to the row direction electrode drive circuit 23.

The column direction electrode drive circuit 22 scans the column direction electrode at the address instructed by the switching circuit 24, and in synchronization with this, the column direction electrode drive circuit 22 outputs a display signal. The time required to display the cursor is 4*t1, which is shorter than the time required for writing compared to the conventional configuration shown in FIG.

In addition, although the example shows the case where there is one cursor in each of the row and column directions, the same operation can be repeated in the case of multiple cursors.Furthermore, it is applicable not only to cursors but also to normal display data. However, it is effective.

ADVANTAGEOUS EFFECTS OF THE INVENTION The present invention has the advantage that in a matrix display device, the display direction of the screen repeater can be easily changed and the screen update time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a matrix type display device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a matrix type display device according to an embodiment of the present invention, and FIG. A schematic diagram showing a display example of a display device, FIG. 4 is a schematic diagram showing a display example of a matrix type display device, FIG. 5 is a block diagram showing the configuration of a conventional matrix type display device, and FIG. 6 is a matrix type display device. It is a schematic diagram showing an example of a display of a device. 1.21.51...Ferroelectric liquid crystal panel, 2゜22...Column direction electrode drive circuit, 3,23...
...Row direction electrode drive circuit, 4.24...Switching circuit, 5°25.54-...VRAM, 6.21
．． 55...=-control circuit, 7.28.57...
Control signal for scanning electric bridge drive, 8, 29.56...
signal? 118i drive control signal, 25... memory circuit, 52... signal electrode drive circuit, 53...
...Scanning electrode drive circuit.

Claims (4)

[Claims] (1) A matrix type display panel, a switching means for specifying one of the electrodes in the row direction or the electrodes in the column direction of the matrix type display panel as a scanning electrode and the other as a signal electrode, and the row of the matrix type display panel. a row direction electrode drive circuit capable of driving electrodes in the direction as scan electrodes or signal electrodes according to the designation of the switching means; and electrodes in the column direction of the matrix display panel according to the designation of the switching means. The matrix comprises a column direction electrode drive circuit that can be driven as a scan electrode or a signal electrode, and a control means for controlling the switching means, the row direction electrode drive circuit, and the column direction electrode drive circuit. 1. A matrix type display device, characterized in that one of a row direction electrode or a column direction electrode of a type display panel can be switched to a scanning electrode and the other to a signal electrode. (2) The matrix display device according to claim 1, wherein the matrix display panel is a ferroelectric liquid crystal display panel. (3) The matrix display device according to claim 2, wherein the row direction electrode drive circuit and the column direction electrode drive circuit are capable of scanning and driving only the electrodes at designated addresses. (4) The matrix display device according to claim 3, wherein the control means is configured to display a cursor on any address on the matrix display panel.