JPS5880984A - Video recording and preproducing device - Google Patents

Abstract

PURPOSE:To perform recording to and reproduction from low-density recording media by temporarily storing a video signal in a memory in the form of a converted digital signal, reading it at a low-speed and converting it into an analog signal, and recording the signal on a magnetic tape. CONSTITUTION:A video signal generated by a video signal generating means 1 is digitized by an A/D converter 2 and stored in a memory 3 at a high speed. The video signal stored in the memory 3 while read out at a low speed is converted by a D/A converter 5 into an analog signal, which is applied through a recording circuit 6 to a recording head 7 to be recorded on a magnetic tape. The recorded video signal is reproduced by a reproducing head 8, passed through a regenerating circuit 9, and converted by an A/D converter 10 into a digital signal, which is stored in a memory 11 at a low speed. The signal in the memory 11 is converted into an analog signal at a high speed by a D/A converter 13 to obtain the signal which is nearly as fast as a video signal of TV broadcasting. This signal is applied through a video circuit 14 to a video device 15 to be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for recording and reproducing video signals such as television images, and an object of the present invention is to enable recording and reproduction on a low-density recording medium.

Video tape recorders and the like are conventionally known as video recording and reproducing devices, but since these devices record video signals directly onto a recording medium, they require a wide signal band and a high-density recording medium, and they also require a head However, it cannot be said that it is economically viable for the purposes of simple still images and slow-scan video, as it requires special equipment.

The present invention eliminates the above-mentioned drawbacks of the conventional technology, and has a simple structure suitable for integrated circuit implementation.

This allows video to be recorded and played back on easy-to-use low-density tape. DESCRIPTION OF THE PREFERRED EMBODIMENTS The video recording and reproducing apparatus of the present invention will be described below with reference to drawings of an embodiment.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a video signal generating means, specifically a video signal source generated by a television broadcast receiver, a video camera, a computer, etc. be.

These signals are digitized by an analog-to-digital converter 2 (hereinafter simply referred to as MCU converter for simplicity), and are recorded in the memory 3 at high speed as one screen of video data. In order to associate the screen position with the recording area in the memory 3, the address counter 4 writes data to a predetermined address. The video data thus stored in the memory 3 is read out at a low speed suitable for low-density recording media, and at the same time is read out by a digital-to-analog converter 6 (hereinafter simply referred to as a D converter). , convert to analog signal. The low-speed analog signal with a narrow band thus obtained is applied to the recording head 7 through the recording circuit 6 and recorded on the magnetic tape.

The recorded video signal is reproduced by a reproduction head 8 and applied to the MCU converter 1o through a reproduction circuit 9, where it is digitized and stored in a memory 11 at low speed. The address counter 12 is for incrementing the address in the memory 11 without obtaining a correspondence between the image position and the address in the memory 11 during this period. The data in the memory 11 is converted into analog data at high speed by the D-muconmeter 13, and converted into a signal having a speed and band comparable to that of a video signal in ordinary TV broadcasting. This signal is transferred to the video circuit 1
4 to the video device 16 to reproduce the video.

In the embodiment shown in FIG. 1, each circuit constituting the video recording device and the video reproducing device is configured separately, but as shown in FIG. D
Mukon meter 18. Address counter 19. The clock generation circuit 20i may be shared and used as a video recording device and a video reproducing device. That is, when configured in this way, separate changeover switches 51-1, 51-2, and
51-5, these changeover switches 5l-1, 81-
Switch between recording and playback by switching 2, selector switch 5
1-6 may be used to switch the frequency of the clock signal.

As is clear from the above embodiments, the present invention is fast.

A wideband video signal is converted from analog to digital, temporarily stored in memory, read out at low speed, and converted from digital to analog, thereby reducing the speed.

This converts the video signal into a narrowband video signal that can be easily recorded on low-speed magnetic tape. During playback, the low-speed, narrowband playback signal is converted from analog to digital, and then the signal is written to memory and recorded at high speed. By reading out and performing analog-to-digital conversion, it can be reproduced as a high-speed, wideband video signal, and the original video can be easily reproduced using a video device (such as a cathode ray tube).

Therefore, according to the present invention, images can be easily recorded and played back even on commonly used acoustic tapes such as compact cassettes, and simple still images,
A new application as a slow scan TV can be considered, and it is extremely effective in practice.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the video recording and reproducing apparatus of the present invention, and FIG. 2 is a block diagram of another embodiment. 1... Video signal generating means, 2, 10.16...
...Analog-digital converter, 3,11.17...
····memory,! , 13.18...Digital analog converter, 4, 12, 19...Address counter, 6...Recording circuit, 7.8...
...Head, 9...Reproduction circuit, 14...
...Video circuit, 16...Video device, 2o...
...Clock generation circuit.

Claims (2)

[Claims] (1) Comprising a means for obtaining a video signal, an analog-to-digital converter, and a memory, the video signal is digitized by the analog-to-digital converter and temporarily stored in the memory, and the write speed at the time of storage is A video recording device that reads the data in the memory at a speed different from that of the above, converts it into an analog signal using a digital-to-analog converter, and records the obtained signal on an external recording medium such as a magnetic tape, and a magnetic tape. A means for reproducing an analog signal from an external recording medium such as, an analog-to-digital converter, and a memory is provided, the analog signal is digitized by the analog-to-digital converter, and the digital signal is temporarily stored in the memory. A video playback device configured to read data in the memory at a speed different from the writing speed of the memory, convert it into an analog signal using a digital-to-analog converter, and display the obtained signal on a video device using a video circuit. A video recording and reproducing device consisting of a device. (2) The analog-to-digital converter, memory, and digital-to-analog converter installed in the video recording device and video reproducing device can each have their operating speeds varied by clock signals. The video recording and reproducing device according to claim 1, wherein the video recording and reproducing device is used in common with video reproducing devices.