JPH0728434A - Image display device - Google Patents

Abstract

PURPOSE:To simultaneously display the same image on display devices with the same resolution and display speed and with horizontal blanking intervals different from each other. CONSTITUTION:An image display device 10 is provided with an output data pin D1 for display connecting a frame memory 11 with a first display device 13, the output data pin D2 for display connecting a buffer memory 12 with a second display device 14 and an image data input pin G inputted to the frame memory 11. Further, the butter memory 12 and the frame memory 11 are connected with the output data pin D1 for display. The image data stored in the frame memory 11 are outputted to the first display device 13 directly, and are stored in the buffer memory 12 by one scanning line each, and are converted to the display format of the second display device 14 to be outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for displaying data of one display format on a plurality of devices of different display formats.

[0002]

2. Description of the Related Art Conventionally, when one image data is displayed on a plurality of display devices having different display formats, it is not possible to display correctly on other display devices only by supplying data adapted to one display device. An image display device that provides a frame memory for temporarily storing image data to be displayed to each display device and converts the image data stored in each memory into a display format of a corresponding display device and outputs the converted image data is displayed. It is used.

[0003]

However, in the above-mentioned conventional example, since a frame memory for one screen is required for each of a plurality of display devices, the amount of hardware increases and the cost becomes high. Had.

In view of the above problems, the present invention provides a display device capable of displaying the same image substantially simultaneously with respect to a plurality of display devices having the same resolution and display speed for displaying images and different horizontal blank periods. It aims to provide less memory.

[0005]

To achieve the above object, the present invention provides a plurality of display devices having the same resolution and the same display speed but different horizontal blank periods, and a horizontal blank among the plurality of display devices. A data input unit for inputting image data in a display format of a display device having the longest period, a data conversion unit for converting image data input by the data input unit into a display format for each of the plurality of display devices, and the data A data output unit for outputting and displaying output image data of the conversion unit on a corresponding display device, wherein the data conversion unit includes a frame memory for storing the image data input by the data input unit; and the horizontal blank. The image data output from the frame memory corresponds to each display device other than the display device having the longest period, and at least one scanning line segment A buffer memory for pay, the image data stored in the buffer memory, respectively of the image display device and a data converting means for buffer memory is converted into a display format of the corresponding display device.

[0006]

With the above configuration, the image data is stored in the frame memory in the display format of the display format device having the longest horizontal blank period, and is assigned to each display format device having the same resolution and the same display speed and a short horizontal blank period. The image data for one scanning line supplied from the frame memory is stored in the buffer memory.

By converting the contents of the buffer memory into image data of a format suitable for each display device and outputting the image data, the same image is displayed substantially simultaneously on devices of display formats having different horizontal blank periods.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the image display device of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic diagram of an image display device 10 according to an embodiment of the present invention.

The image display device 10 of this embodiment includes a frame memory 11, a display output data pin D1 connected to the first display device 13, a buffer memory 12, and a second memory.
Output data pin D2 for connection to device 14 of
Image data input pin G input to the frame memory 11, the frame memory 11 and the buffer memory 12
Data input / output control means 15 for controlling the input / output of data to / from. Further, the buffer memory 12, the frame memory 11, and the display output data pin D1 are connected.

In the system of FIG. 1, the amount of display data held by the frame memory 11 is 4 bits, and the amount of data held by the buffer memory 12 is 2 bits, and the first display device 13 and the second display device are used. The resolutions of the devices 14 are 2 × 2 and are the same.

Both the first display device 13 and the second display device 14 have the same display speed, but the first display device 13 displays every one bit in the order of upper left, upper right, lower left and lower right. However, each bit display requires 1 clock time, and when the display of each scanning line is completed, a horizontal blank time of 4 clocks is required, and the second display device 14 has upper left, upper right, lower left, Each bit is displayed in the lower right order, and it takes 2 clocks to display each bit, and a horizontal blank time of 2 clocks is required when the display of each scanning line is completed. Further, it is assumed that one clock is required to store the data read from the frame memory 11 in the buffer memory 12 and further read the data from the buffer memory 12.

For the image display device 10, data b10
Consider the case where 01 is sequentially input to the data input pin G. Here, "b" represents that the following notation is a binary number.

The operation of the image display apparatus of this embodiment having the above-mentioned structure will be described with reference to FIG.
FIG. 2 is a diagram showing the timing of each signal.
Is a clock signal, (b) is an image data signal output from the frame memory and input to the first display device,
(C) is an image data signal output from the buffer memory and input to the second display device.

First, data of an image to be displayed is input to the image data input pin G.

The data input / output control means stores the input image data in the frame memory 11. Next, the data on the frame memory 11 is output to the display output data pin D1 and the buffer memory 12 according to the display format of the first display device. Actually, the data is first b1
Outputs every 1 clock in the order of 0, suspends the transfer for 4 clocks, and further outputs for every 1 clock in the order of b01, suspends the transfer for 4 clocks.

The data input / output control means sequentially stores the output from the frame memory 11 in the buffer memory, and outputs the image data stored in the buffer memory 12 to the display data output pin according to the display format of the second display device. D2
Output to.

The operation of the data input / output control means will be described more specifically. First, the data b10 of the upper scanning line is stored in the buffer memory 12 at a speed of 1 display clock, and this data is output to the display data output pin D2 at a speed of 2 display clocks. When all the data on the buffer memory 12 is output, the output is stopped for a period of 2 clocks.
During the suspension period, the data b01 of the lower scanning line from the frame memory 11 starts to be newly stored in the buffer memory 12 at the speed of one clock for each display. After the lapse of the discontinuation period, the data b01 is output at the rate of 2 clocks per display. Figure 2
The reason (c) is delayed from (b) is that the data input / output control means requires a certain amount of time.

In this way, the display data output pin D
Image data corresponding to the first and second display devices are supplied to 1 and D2, respectively, and displayed.

As described above, according to this embodiment,
A frame memory for storing image data for one screen, and 1
By providing the buffer memory for storing the image data of the scanning line segment, it is possible to display the same image substantially simultaneously on two display devices having the same resolution and the same display speed but different horizontal blank periods.

In this embodiment, the number of image display devices is two and the resolutions are both 2 × 2, the number of image data input pins is one, and the amount of display data held in the frame memory 11 is large. 4 bits, the amount of data held in the buffer memory 12 is 2 bits, the number of pins input to the first display device 13 is 1, the number of pins input to the second display device 14 is 1, the first display device The display format of 13 is displayed every 1 clock in the order of upper left, upper right, lower left, and lower right, and a horizontal blank period of 2 clocks is required for each 2 bit display. In the above description, the image display device 10 displays the upper left, the upper right, the lower left, and the lower right for every 2 clocks for each 1 bit, and requires a horizontal blank period of 2 clocks for each 2 bit display. Display speed, the number of bits, it is of course the number of pins can be applied to different other image display device.

[0021]

As described above, the image display apparatus according to the present invention provides the most horizontal blank for a plurality of devices having the same image display resolution and display speed and different horizontal blank periods. A frame memory is assigned to a display device having a long period, and a buffer memory for storing data transferred at a time corresponding to a difference between blank periods is assigned to another display device having a short horizontal blank period. The data transferred during the blank period can be displayed almost simultaneously with the display device having a long blank period, so that it can be applied to a multi-display system using a liquid crystal panel and a CRT. Becomes

[Brief description of drawings]

FIG. 1 is a schematic diagram of a system using an image display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing the timing of each signal in the embodiment of the present invention, (a) is a clock signal, (b) is an output signal from a frame memory, and (c) is an output signal from a buffer memory.

[Explanation of symbols]

 10 image display device 11 frame memory 12 buffer memory 13 first display device 14 second display device 15 data input / output control means

Claims (1)

[Claims] 1. Inputting a plurality of display devices having the same resolution and display speed and different horizontal blank periods, and image data in the display format of the display device having the longest horizontal blank period among the plurality of display devices. A data input unit, a data conversion unit that converts the image data input by the data input unit into a display format of each of the plurality of display devices, and output image data of the data conversion unit to a corresponding display device. A display data output unit, wherein the data conversion unit corresponds to each of a frame memory storing the image data input by the data input unit and a display device other than the display device having the longest horizontal blank period. A buffer memory for storing at least one scanning line of image data output from the frame memory; An image display device, comprising: data conversion means for converting stored image data into a display format of a display device corresponding to each buffer memory.