JPH04125586A - Plane display driving device - Google Patents

Abstract

PURPOSE:To display data correctly by detecting the number of display dots of display data, and expanding the data corresponding to the difference of both numbers of display dots when the above-mentioned number is less than that of display dots in one prescribed direction on a display. CONSTITUTION:The number of display dots in one prescribed direction is detected by counting the number of dot clocks DCK by the detecting part of a counter, etc., and lateral display size to be comprised is judged in advance based on a detection signal Sd. When display size is less than the lateral display size on a plane display 8, an expansion display control signal S'c is generated so as to set the difference between both display size at zero at an expansion display control part 2, and it is inputted to a data size driver 6. Thereby, the driver 6 can display the data of a character and a graphic on the entire display screen of the plane display 8 correctly based on an expansion control signal Sc.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a flat display driving device for displaying data by driving a flat display such as a plasma display panel having a plurality of display cells. A flat surface that can prevent data on the display screen of a flat display from becoming difficult to see or incorrectly displayed even when the number of display dots displayed in one direction on the flat display is less than the number of display dots in one direction on the flat display. The present invention provides a display driving device, on a flat display in which a plurality of display dots are arranged in a matrix, the display dots are driven according to a control signal including at least display data and a dot clock. A flat display driving device for displaying data includes a dot number detection unit that counts the number of dot clocks to detect the number of display dots of the display data, and a dot number detection unit that detects the number of display dots of the display data, and a dot number detection unit that detects the number of display dots of the display data by counting the number of the dot clocks, and a dot number detection unit that detects the number of display dots of the display data. and an enlargement display control section for enlarging and displaying the display data according to the difference in the number of display dots in both directions when the number of display dots in one direction is smaller than a predetermined number of display dots in one direction.

[Industrial application field]

The present invention relates to a flat display driving device for driving a flat display such as a plasma display panel having a plurality of display cells to display data.

Among peripheral devices in computer systems, CRT
Display devices (hereinafter referred to as displays) have the function of visually displaying various data input from a keyboard or the like, and play an important role as an interface between humans and machines. Furthermore, in recent years, with the diversification of application fields for computer systems, there has been a demand for higher performance, smaller size, and lighter weight for the above-mentioned displays, and for this reason, the development of flat displays to replace CRTs is progressing rapidly. It is being

The present invention selectively drives display dots constituted by a plurality of display cells arranged in a matrix on the display screen of the flat display, for example, a plasma display panel, and combines these display dots to display the display screen. The above refers to a flat display driving device for displaying target data.

[Conventional technology]

FIG. 5 is a block diagram showing a conventional flat display driving device. However, here, as the flat display 8, a plasma display panel (hereinafter abbreviated as FDP) that utilizes light emission by gas discharge will be representatively explained.

Generally, on the display screen of an FDP, a plurality of X electrodes x1 to X
, and Y electrodes Y1 to Y1 are arranged. moreover,
Display cells are formed at positions corresponding to the intersections of these XYi poles X1 to X, %, and Yl to Y (for example, the intersections of X and YJ), and these display cells display a matrix pattern. Display dot (for example, 640X40
0 dot) is configured on the display screen. In order to select display dots to be subjected to light emitting display from among these display dots and display target display patterns (data) such as characters and figures correctly on the PDP, the drive shown in Fig. 5 is used. equipment is required.

In this drive device, the X
An X-side driver 6 and a Y-side driver 7 are provided that selectively supply voltages necessary for light-emitting display to the electrodes X1-X1 and Y-electrodes Y1-Y0, respectively. moreover,
On the input side of the driver 6.7 above, there is a CP' such as a microcomputer.
An external control circuit 3 configured by U is provided,
A timing generator or the like in this external control circuit 3 connects the X electrode
Various control signals SC for selecting the Y electrodes Y1 to Yl are output. Note that here, in order to select display dots for each m display cells formed on one Y electrode (for example, YJ), that is, for each line, t is used.
It is assumed that display data of 1000 yen is sent out at once, and the above lines are sequentially scanned in the Y direction at regular time intervals to display the data. Therefore, from now on, the X-side driver will be referred to as the data-side driver, and the Y-side driver will be referred to as the line-side driver. The control signal Sc includes a data signal DATA indicating the contents of a plurality of display data generated for each line, a dot clock DCK indicating the dot a position of the display data, and a dot clock DCK indicating the dot a position of the display data, and It includes a synchronization signal 5YNc etc. that defines the direction display time.

If the user sends the control signal Sc from the external control circuit 3 in order to display target data on the display screen of the PDP, the display data signal DATA etc. will be sent to the data side via a data buffer such as a line memory. In the data side driver 6 of m inputted to the driver 6, voltage is selectively supplied to m display cells on one line based on the display data signal DATA, and the corresponding display dots are displayed by emitting light. I try to let them do it. On the other hand, a synchronizing signal 5YNC and the like are input to the line side driver 7 via the scan controller 5. The line side driver 7 sequentially moves the display portion on the display screen along the Y electrodes while displaying data almost simultaneously on the display cells on each Y electrode based on the synchronization signal 5YNC. There is. Since the data display is normally repeated at a speed (repetition frequency) that does not pose a visual problem, the drive circuit allows flicker-free data to be displayed on the display screen of the PDP.

[Problem to be solved by the invention]

As mentioned above, in the conventional flat display driving device, the X direction (horizontal) on the flat display 8 such as FDP
The display data corresponding to the number of display dots is simply manually input from a signal source such as an external control circuit and displayed as is.

For example, when 640 x 400 dots, which have a standard resolution, are arranged on the flat display 8, the horizontal display data sent out by the control signal Sc from the external control circuit 3 is usually data for 640 dots. be.

However, depending on the type of the signal source, the number of horizontal display dots included in the display data in the control signal So may be less than the number of display dots on the flat display 8. For example, if the display data from the signal source contains only 320 dots of data, when this data is displayed on a flat display, the display will be to the left (left half) or to the right (right half). A problem arises in that the data on the screen becomes difficult to see. moreover,
Depending on the device, other figures or the like may be displayed in empty areas of the screen, which may cause problems such as difficulty in correctly displaying the desired data.

The present invention has been made in view of the above problems, and even if the number of display dots included in display data from an external signal source is less than the number of display dots in a predetermined direction on a flat display, It is an object of the present invention to provide a flat display driving device that can prevent data on a display screen of a display from becoming difficult to view or not being displayed correctly.

[Means to solve the problem]

FIG. 1 is a block diagram showing the basic configuration of the present invention. However, here, the X electrodes X1 to X of the flat display 8
, and the X electrode side drive circuit system such as the line side driver 7 (FIG. 5) is omitted from the illustration. Further, as control signals Sc, three types of signals are shown as representatives: a display data signal DATA, a dot clock DCK, and a synchronization signal 5YNC. Note that components similar to those described above are denoted by the same reference numerals.

In FIG. 1, the dot clock D in the control signal Sc
A dot number detection section 1 is provided which counts the number of CKs and detects the number of display dots of the display data included in the control signal Sc. Further, an enlarged display control section 2 is provided between the dot number detection section 1 and the data side driver 6. When the number of display dots detected by the dot number detection section 1 is smaller than the number of display dots in a predetermined direction on the flat display 8, the enlarged display control section 2 detects the difference between the numbers of display dots on both sides. This is for enlarging the display data and displaying it on the flat display 8 accordingly.

[For production]

In the flat display driving device of the present invention, it should be noted that the display data signal DATA in the control signal Sc is always accompanied by a dot clock DCK indicating the dot unit of the display data, and the number of dot clocks DCK is measured using a counter or the like. The number of display dots in one predetermined direction (for example, horizontally) is detected by counting by the detection unit. That is, based on the detection signal S output from the dot number detection section 1, the horizontal display size that will be formed by the number of display dots of the display data is determined in advance. When the determined display size is smaller than the horizontal display size on the flat display 8, the enlarged display control unit 2 adjusts the display data in the control signal So so that the difference in image display size becomes zero. An enlarged display control signal S' for displaying an enlarged image is generated and manually inputted to the data side driver 6. This data side driver 6 can correctly display data such as characters and figures on the entire display screen of the flat display 8 based on the enlargement control signal Sc.

Thus, in the present invention, even if the number of display dots included in the display data from the signal source is less than the number of display dots in a predetermined direction on the flat display, the data on the display screen may be displayed to the left or right. A flat display driving device is provided that is free from the possibility of erroneously displaying other data on a vacant part of a screen.

〔Example〕

FIG. 2 is a circuit diagram showing one embodiment of the present invention.

Note that in this case as well, the X electrode side drive circuit system is omitted.

Here, a counter 10 is provided as the dot number detection section 1. 20 The dot clock DCK in the control signal SC from the external control circuit 3 is input to the clock terminal (CK) of the counter 10, and its reset terminal (CL
A synchronizing signal 5YNC is input to R). Therefore, the counter 20 counts the number of display dots included in one line (horizontal) of display data defined by the synchronization signal 5YNC. This counting result is output as a detection signal S from the Ω terminal of the counter 20, etc.

Further, the enlarged display control section 2 includes a line memory 20 for data buffer provided between the external control circuit 3 and the data side driver 6, and a comparison circuit 21 such as a digital comparator provided on the output side of the counter 10. and a clock generation circuit 22 provided on the output side of this comparison circuit 21. To explain in more detail, the line memory 20 temporarily stores the display data of the display data signal DATA, which is sent out for each line at regular time intervals from the external control circuit 3 constituted by a CPU such as a microcomputer. It is. Further, the comparison circuit 21 includes a counter 2
The detection signal S from 0 is compared with a reference signal Sr indicating the number of display dots on the flat display 8.

Furthermore, the clock generation circuit 22 includes the comparison circuit 2
Based on the comparison result in step 1, a read clock RCK for the line memory 20 and a transfer lock TCK for display data read out from the line memory 20 using the read clock RCK are generated. in this case,
The above display data is input to the data side driver 6 as transfer data (corresponding to the enlarged display control signal S' in FIG. 1) by the transfer lock TCK.

FIG. 3 is a timing chart for explaining the enlarged display control operation of this embodiment. A series of operations in the flat display driving device of this embodiment will be described in more detail according to this timing chart.

For example, if the flat display 8 such as FDP is 640×40
In the case of a display resolution of 0 bits, when the display data signal DATA containing display data for 320 horizontal dots is input from an external signal source, the dot clock DCK is also input by 320 dots accordingly.

The counter 10 counts the number of these 320 dot clocks. At the same time, the display data included in the display data signal DATA is stored in the line memory 20 using the dot clock DCK as the write clock WCK. Next, the number of display dots of the display data (320 dots) is determined based on the counting result of the counter 10 and the comparison result of the comparison circuit 21.
It can be seen that the number of dots displayed horizontally on the flat display 8 is 1/2 (640 dots). Furthermore, the clock generation circuit 22
From write clock WCK (dot clock DCK>
A read clock RCK with a repetition frequency of 172
is output ((a) in FIG. 3). That is, display data is read from the line memory 20 at the normal speed of 172 using this read clock RCK (FIG. 3, b)). At this time, the clock generation circuit 2
2, a transfer lock TCK having the same repetition frequency as the write clock WCK is also output ((C) in Figure 3).
. This transfer lock TCK causes the line memory 20 to
The data read from is transferred twice and manually inputted to the data side driver 6 as transfer data ((d) in FIG. 3). Furthermore, if voltage is selectively supplied from the data side driver 6 to the X electrodes x1 to X based on the transfer data,
Data enlarged twice in the horizontal direction can be correctly displayed on the entire display screen of a flat display.

FIG. 4 is a diagram for explaining the display control operation when regular display data, for example display data for 640 dots, is sent out. In this case, the number of display dots of the display data is equal to the number of horizontal display dots on the flat display 8.

For this reason, the reading clock RCK and the transfer lock T
The repetition frequency of CK is the same as the write clock WCK.
is set to be equal to the repetition frequency of ((a) and (c) in Fig. 4). Therefore, display data manually entered from an external signal source to a line memory etc. is transferred as is to the flat display 8 as in the conventional case (Fig. 5).
((b) and (d) in Figure 4).

Up to this point, we have described the case where the number of displayed dots of Chinese characters on the flat display 8 has a relation of an integral multiple to the number of displayed dots from an external signal source, but if the number of displayed dots of both characters is other than the above. Even if there is a relationship (for example, the number of displayed dots from the signal source is 400 horizontal dots), this embodiment can be applied.

〔Effect of the invention〕

As explained above, according to the present invention, when the number of display dots included in display data from an external signal source is less than the number of display dots in a predetermined direction on a flat display, for example, in the horizontal direction, the display data is This enables a flat display drive device that eliminates the risk of data on the display screen being displayed to the left or right, or that other data is erroneously displayed in an empty area of the screen. be done. As a result, the above drive device allows
Regardless of the number of display dots of display data from a signal source, display can be performed by effectively utilizing the limited display area on a flat display.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the principle configuration of the present invention, Fig. 2 is a circuit diagram showing an embodiment of the invention, and Fig. 3 is a timing chart for explaining the enlarged display control operation of this embodiment. , FIG. 4 is a timing chart for explaining the display control operation when regular display data is manually input, and FIG. 5 is a block diagram showing a conventional flat display driving device. In the figure, 1... dot number detection unit, 2... enlarged display control unit,
3...External control circuit, 6...Data side driver, 7...Line side driver, and...Flat display.

Claims (1)

[Claims] 1. Data display by driving the display dots in response to a control signal S_c including at least display data and a dot clock on a flat display (8) in which a plurality of display dots are arranged in a matrix. A dot number detection unit (1) that counts the number of dot clocks to detect the number of display dots of the display data; (
8) An enlargement display control unit (2) for enlarging and displaying the display data according to the difference between the number of display dots in both directions when the number of display dots in one direction is less than the above predetermined number of display dots. Features of flat display drive device.