JPH0325226Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention provides, for example, various transaction processing devices having a customer service section.
The present invention relates to an image display device that displays guidance information for proceeding with a transaction operation on a tube.

<Background of the invention> In recent years, in this type of image display device, in order to speed up CRT screen switching, a method has been proposed in which images are edited by transferring image data to a display memory using DMA (Direct Memory Access). However, in the case of this type of system, access to the display memory by the CRT controller is prohibited during the DMA transfer period of image data, so a blank state occurs on the display screen of the CRT. This non-display state appears as flickering on the screen during a short period of time when the screen is switched, making it extremely unsightly for customers.

<Purpose of the invention> During the DMA transfer period of image data, this invention
An object of the present invention is to provide an image display device that eliminates flickering when switching screens and realizes an easy-to-read display screen by displaying the ground color when displaying image data on an ORT as a background color.

<Configuration and Effects of the Invention> In order to achieve the above object, the image display device of this invention includes a background color setting circuit, a selection circuit, and a control circuit.

The background color setting circuit forms background color data for displaying the ground color as a background color when displaying image data on a CRT. The selection circuit selects the image data input from the display memory and the background color data input from the background color setting circuit and outputs the selected data to the CRT. The control circuit generates a signal for controlling the selection operation of the selection circuit and outputs it to the selection circuit.

Then, when the first screen and the second screen are successively generated on the CRT, the control circuit transfers image data for displaying the second screen to the display memory.
During the period of DMA transfer, a signal is generated and output that causes the selection circuit to select the input of background color data from the background color setting circuit, and when the DMA transfer is completed, the selection circuit is sent the second screen from the display memory. It generates and outputs a signal that selects the input of image data for display.

According to the present invention, during the DMA transfer period of image data, the ground color when displaying image data on the CRT is displayed as the background color, thereby preventing the occurrence of a blank state on the CRT display screen. It is possible. Therefore, the first screen and the second screen will continue to be displayed.
When generated on a CRT, the flickering caused by the above-mentioned non-display state no longer appears during the minute time when the screen is switched, and it is possible to provide a guide screen that is easier to see than ever before, achieving practical effects that achieved the purpose of the invention. play.

<Description of Embodiments> Fig. 1 shows an example of the circuit configuration of an image display device according to the present invention. It is also stored. This image data is DMA-transferred to the refresh memory 4 by the DMA control circuit 3 and edited. The refresh memory 4 is connected to the CPU (Central Processing
The image data accessed and read out by Unit) 5 and CRT controller 6 is converted into video image data consisting of three primary color signals R, G, and B by data conversion circuit 7, and then sent to video image data via second multiplexer 8. It is sent to the controller 9. The address bus of the CRT controller 6 and the data bus and control bus of the CPU 5 are connected to the refresh memory 4 via the first multiplexer 10.
The bus to the refresh memory 4 is switched by the clock k output from the oscillation circuit 11, and access to the refresh memory 4 is thereby processed in a time-division manner.

The first multiplexer 10 includes a NAND circuit 12
The operation is controlled by a control signal i outputted by.
The clock k of the oscillation circuit 11 and the switching signal j sent by the CPU 6 via the background color setting circuit 13 are input to this NAND circuit 12, and during the DMA transfer period, the switching signal j is logic "0" and the control signal is Since the signal i is a logic "1" (the control input to the first multiplexer 10 is therefore a logic "0"), the refresh memory 4 is not accessed. On the other hand, DMA
Outside the transfer period, the switching signal j is at logic "1", so that the clock k is supplied as a control input to the control signal i and also to the first multiplexer 10, with which the refresh memory 4 is accessed. is executed in a time-sharing manner.

Said switching signal j is also sent to the second multiplexer 8. This second multiplexer 8 is
When the switching signal j of logic "1" is input, the video image data from the data conversion circuit 7 is selected, and when the switching signal j of logic "0" is input, the background color data from the background color setting circuit 13 is selected. Select
Each is sent to the video controller 9. This background color data is for displaying the ground color when image data is displayed as a background color on the display screen of the CRT 2, and is composed of three primary color signals R, G, and B similarly to the video image data.

However, the first screen on the video controller 9,
Next, when transmitting video image data to continue displaying the second screen, the image data for displaying the second screen is stored in the refresh memory 4.
During DMA transfer, background color setting circuit 1
The background color data from 3 is sent to the second multiplexer 8.
(See timing charts in FIGS. 1 and 2). Upon completion of the DMA transfer, the second multiplexer 8 performs a switching operation, and video image data for second screen display is selected and sent to the video controller 9. This allows CRT2
As shown in Fig. 2 and 3, the first screen, the background color screen, and the second screen are displayed one after another, and the blank state as in the conventional example is not displayed at all, and the screen flickers when switching screens. does not appear either.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an image display device according to an embodiment of the present invention, and FIGS. 2 1 to 3 are time charts showing the circuit operation. 2...CRT, 4...refresh memory, 8...multiplexer, 13...background color setting circuit.

Claims (1)

[Claim for Utility Model Registration] In an image display device that DMA transfers image data to a display memory for editing, reads the edited image data from the display memory, and displays the image on a CRT, a background color setting circuit and a selection method are provided. circuit and a control circuit, the background color setting circuit forms background color data for displaying a ground color as a background color when displaying image data on a CRT, and the selection circuit forms background color data for displaying the ground color as a background color when displaying image data on a CRT; The control circuit generates a signal for controlling the selection operation of the selection circuit and sends it to the selection circuit. When the first screen and the second screen are successively generated on the CRT, the control circuit transfers the image data for displaying the second screen to the display memory by DMA. During this period, a signal is generated and output that causes the selection circuit to select the output of background color data from the background color setting circuit, and upon completion of the DMA transfer, the second screen from the display memory is displayed on the selection circuit. An image display device that generates and outputs a signal for selecting input image data.