JPS61290871A - Image memory device - Google Patents

Abstract

PURPOSE:To store a picture in a memory when a picture whose picture recording is desired exists by constituting the titled device with an image signal inputting circuit, a memory for storing the output of the image signal inputting circuit, an image signal outputting circuit, and a switching circuit for switching the output of the image signal inputting circuit and the output of the memory and supplying them to the image signal outputting circuit. CONSTITUTION:An image signal supplied to an image signal input terminal 1 is A/D-converted by an A/D converter 2, stored in a memory 3, and also applied to a switching circuit 4. As for a synchronizing separator circuit 11, the same image signal as an input to the A/D converter 2 is applied, and horizontal/vertical synchronizing signals are outputted. A flip-flop 8 outputs synchronizing output 22 by making an input signal 21 synchronize with a vertical synchronizing signal 20 outputted from the synchronizing separator circuit 11, and the second flip-flop 9 receives the output of the flip-flop 8, and outputs a freeze signal 23 of one vertical period. The outputs of the flip-flops 8, 9 are provided to an OR circuit 14, and the OR circuit 14 outputs a switching signal to the switching circuit 4 and a synchronization switching circuit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention is a circuit suitable for storing image signals in a digital memory using a semiconductor or in a floppy analog memory.

[Background of the invention]

A close example of the invention is an audio or video magnetic tape recorder. When recording (or recording), these devices usually output the signal to be recorded (recorded) to a monitor terminal.

However, the present invention relates to an apparatus for storing image signals in one screen, and is essentially different from the conventional method.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image memory device that can store a screen to be recorded in a memory when the screen is monitored.

[Summary of the invention]

The present invention includes an image signal input circuit, a memory for storing an output of the image signal input circuit, an image signal output circuit, and an image signal output circuit that switches between the output of the image signal input circuit and the output of the memory. It is characterized in that it consists of a switching circuit that supplies the

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG. 1 and will be explained using an electrogram.

The image signal supplied to the image signal input terminal 1 is A/D converted by the νD converter 21C, stored in the memory 5Vc, and provided to the switching circuit 4.

The synchronization separation circuit 11 is given the same image signal as the input to the A/D converter 2, and outputs horizontal and vertical synchronization signals.

When switch 7 is closed, a signal such as 2 in FIG. 2 is applied to the input of flip-flop 8. The 7-reply filter 8 synchronizes the input signal 21 with the vertical synchronization signal 2o output from the synchronization separation circuit 11, and outputs a synchronization output 22. The second 7 flip-flop 9 is a flip-flop 8.
In response to the output of , it outputs a freeze signal 23 for one vertical period.

The outputs of the flip-flops 8 and 9 are applied to an OR circuit 14, and the OR circuit 14 outputs a switching signal 24 to the switching circuit 4 and the synchronous switching circuit 13. The states of the switching circuit 4 and the synchronous switching circuit 13 in FIG. 1 are shown when the switching signal 24 is at a high level. When the switching signal 24 is 1Hi", the switching circuit 4 outputs the output of the νD converter 2 to the D/A converter 5, and
The converter 5 performs Φ conversion → D/A conversion on the image signal applied to the image signal input terminal 1, and outputs the signal from the signal output terminal 61C.

When the switching signal 24 is High, the synchronization switching circuit 13 outputs the signal from the synchronization separation circuit 11 to the memory control circuit 10K, and the memory control circuit 10 outputs the synchronization signal of the image signal applied to the image signal input terminal 1. n synchronized with
Output the memory address of the bit to memory 3.

When the switch 7 is opened, the 7 reset signal 23 is output from the 7 reset signal 23, and during this time the memory control circuit 1
0 outputs the write enable signal WE to the memory 3.

Open the switch 7 and the switching signal 24 will be "Lo' JBz
Then, the synchronization switching circuit 15 outputs the output from the synchronization signal generation circuit 12 to the memory control circuit 10, and the memory control circuit yO outputs an address signal synchronized with the synchronization output of the synchronization signal generation circuit 12 to the memory 3. Therefore, when the switch 7 is open, the image signal can be read from the memory 3 even if no image signal is applied to the image signal input terminal 1. When the switching signal is “LO”,
The switching circuit 4 also outputs the output of the memory 3 to the D/A converter 5.

In the example of FIG. 1, the switching circuit 4 is configured to switch between the output of the A/D converter 2 and the output of the memory 5, but the image signal applied to the image input signal terminal 1 by the switching circuit 4, A similar effect can be obtained by configuring the D/A converter 5 to switch its output signal. As mentioned above, since switching can be done in the analog section, the A/D converter 2,
The memory 3 can be configured with an analog memory without using the D/A converter 3. The same is true when storing analog information on a flexible disk.

〔Effect of the invention〕

According to the present invention, if switch 7 is open, memory 3
The image signal stored in the image signal input terminal 1 can be monitored at the output terminal 6, and when a new image is to be stored in the memory, the image signal applied to the image signal input terminal 1 can be monitored at the output terminal by closing the switch 7. . While monitoring the input signal, when the screen you want to memorize appears, open the button, and the screen can be stored in the memory 3.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a timing chart thereof. 1... Image signal input terminal, 2... A/D converter, 3
...Memory, 4...Switching circuit, 5...
・D/A converter, 6...Output terminal, 7...2 Weasel, 8.9...Flip-flop, 10...Memory control circuit, 11...Synchronization separation circuit, 12...Synchronization Signal generation circuit, 13... Synchronization switching circuit, 20... Vertical synchronization signal, 24... Switching signal.

Claims (1)

[Claims] 1. An image signal input circuit, a memory that stores the output of the image signal input circuit, an image signal output circuit, and switches between the output of the image signal input circuit and the output of the memory and supplies the output to the image signal output circuit. An image memory device comprising a switching circuit.