KR930015878A - NTSC / PAL type discrimination device - Google Patents

Abstract

The present invention relates to an NTSC / PAL type determination device that accurately determines whether a playback signal is an NTSC method or a PAL method using a control signal when a video tape is played back. In a conventional video cassette recorder, a playback signal of a video tape is NTSC type. In addition, there is no means to determine whether the PAL method is provided, and the NTSC / PAL type switching switch is installed, and the playback signal is processed by NTSC or PAL method according to the switching state of the switch. It was very troublesome for the user to determine whether the signal recorded on the videotape was NTSC or PAL, and to switch the NTSC / PAL switching switch.

The present invention detects the period of the control signal reproduced according to the NTSC method and the PAL method when the video tape is reproduced, and counts the pulse signal during the period of the control signal, and compares the count value with the reference value to reproduce the reproduced signal. By accurately determining whether the NTSC method or the PAL method, the user can eliminate the trouble of having to switch the switching switch by judging the method of the playback signal.

Description

NTSC / PAL type discrimination device

As this is a public information case, the full text was not included.

1 is a circuit diagram showing a discriminating apparatus of the present invention, and FIG. 2 is a flowchart showing the operation of the discriminating apparatus of the present invention.

Claims (2)

A flip-flop (1) for shaping a reproduction control signal (CTL), a delay (2) for delaying the output signal of the flip-flop (1) for a set period, a pulse generator (3) for generating a pulse signal, and A counter 4 which is reset according to the output signal of the flip-flop 1 and is enabled according to the output signal of the delayer 2 and up counts the output signal of the pulse generator 3, and the flip-flop ( A register 5 for loading and outputting the count value of the counter 4 according to the output signal of 1) and a comparator 6 for determining whether it is an NTSC or PAL method by comparing the output value of the register 5 with a reference value; And a discrimination signal delay unit 7 which detects a change in the output signal of the comparator 6 and delays the output signal when there is a change, and reproduces according to the output signal of the discrimination signal delay unit 7. NTSC / PAL processing section 8 for processing signals in NTSC or PAL method NTSC / PAL scheme determination apparatus for a. 2. The discrimination signal delay unit (7) according to claim 1, wherein the discrimination signal delay unit (7) includes an initial value register (71) for storing and outputting an initial value in advance, and the initial value resistor when the output signal of the comparator (6) changes. An N-bin counter 72 that stores the output signal of 71 and counts the output signal of the flip-flop 1, and the N-bin counter 72 when the count of the N-bin counter 72 is completed. And the AND gates AD2 for disabling and the AND gates AD2 and AD3 for outputting the output signal of the comparator 6 to the NTSC / PAL processing unit 8 according to the output signal of the AND gate AD1. NTSC / PAL type determination device characterized in that. ※ Note: The disclosure is based on the initial application.