KR950012371A - VCR head foreign matter detection device - Google Patents

Abstract

The present invention relates to a device for detecting whether there is a foreign material in the head of a VCR (VCR), in particular, it is possible to determine the foreign matter accurately distinguished from the case of the foreign matter attached to the regeneration of the no-signal tape or the blank section The head foreign matter detection device of VCR (VCR)

The conventional foreign matter detection method by the head cleaner control device compares the video envelope signal with the reference signal to determine whether or not foreign matter is attached, and thus reproduces a no-signal tape (BLANK tape) or a tape with a section in which no video signal is recorded. Even when there is a problem in that it is mistaken as the case of the head foreign matters attached.

Therefore, unnecessary head cleaners are generated, and errors in the determination of foreign substances are frequently caused, resulting in a lack of reliability of the device.

According to the present invention, whether foreign matter is attached to the video head by using the envelope signal and the vertical synchronizing signal of the signal reproduced in the video head and whether the control pulse reproduced in the control head is detected or whether the reproduction of the no-signal recording section is performed. Alternatively, VCR, which judges whether the empty tape is regenerated and executes accurate logic judgment on the detection of foreign matters, prevents unnecessary operation of the head cleaner and provides precision and reliability in determining the foreign matters of the video head. It is a head foreign matter detection device, and it is applied to the head cleaner of VCR.

Description

VCR head foreign matter detection device

Since this is an open matter, no full text was included.

2 is a block diagram of a head foreign matter detection device of VCR of the present invention.

3 is a signal determination chart of the head foreign matter detection device of VCR of the present invention.

4 is an operational signal waveform diagram of a head foreign matter detection device of VCR of the present invention.

Claims (2)

A video head 21 for reproducing a video signal recorded on a tape, a preamplifier 22 for outputting an RF envelope signal VIDEO ENVELOPE of the signal reproduced in the video head 21, and the preamplifier 22. A tape reproducing system 23 for separating the vertical synchronizing signal V-SYNC from the RF envelope signal output from the control unit, a control head 24 for reproducing the control pulse recorded on the video tape, and the control head 24. The servo control system 25 converts the signal reproduced by the signal into a square wave signal CTL PULSE, and outputs the video envelope signal VIDEO ENVELOPE output from the preamplifier 22 and the tape reproduction system 23. V is composed of a microcomputer 26 for determining head foreign matter detection, empty tape reproduction, and no signal interval reproduction by comparing the vertical synchronizing signal V-SYNC with the control pulse CTL PULSE output from the servo control system 25. Head of foreign substance (VCR) Detection apparatus. 2. The microcomputer 26 of claim 1, wherein the microcomputer 26 includes a vertical synchronization input unit 27 for receiving a vertical synchronization signal, a video envelope input unit 28 for receiving a video envelope signal, and a control input unit 29 for receiving a control pulse. And a comparison determination unit 20 for determining whether to detect a head foreign matter by logically determining whether each signal input through the vertical synchronization input unit 27, the video envelope input unit 28, and the control input unit 29 is detected. The VCR head foreign matter detection device comprising a counter unit (31) for providing information for determining each signal period to the comparison determination unit (30). ※ Note: The disclosure is based on the initial application.