KR0134298B1 - Luminance/chrominance signal retrieving apparatus for vcr - Google Patents

Abstract

The present invention relates to a brightness and color signal separation circuit of V-Cal for simplifying a circuit for separating the brightness and color signals from the mixed video signal reproduced from the recording medium. A VLC luminance and color signal separation circuit for separating and outputting a luminance signal and a color signal, respectively, comprising: trap means for removing noise components included in frequencies of luminance and color signals when an image signal is applied; Equalizing means for constantly adjusting the delay time within a band of the frequency signal of the luminance and color signals provided from the trap means; Picking means for amplifying and processing a frequency band of the luminance and color signals whose delay time is adjusted by the equalizing means; Luminance and color signal separation means for separating and providing the luminance and color signals provided by the picking means by resonance by the resonance elements of the capacitor C1 and the coil L1 connected in series; Luminance signal output buffer means for buffering and providing the luminance signal provided separately by the luminance and color signal separation means; And a color signal output buffer means for buffering and providing color signals provided separately by the luminance and color signal separation means.

Description

VCR luminance and color signal separation circuit

1 is a block diagram of a luminance and color signal separation circuit of a conventional VCR.

2 is a block diagram of a luminance and color signal separation circuit of a VCR according to the present invention.

3 is a frequency band distribution diagram of luminance and color signals of a VCR according to the present invention;

* Explanation of symbols for main parts of the drawings

11 trap circuit 12 equalization circuit

13: 4.5 MHz peaking circuit 14: 629 KHz trap circuit

15 luminance signal output buffer 16 amplifier

17: low pass filter 18, 22: color signal output buffer

21: luminance and color signal separation circuit C-C1: condenser

L-L1: Coil TR1-TR3: Transistor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance and color signal separation circuit of a video cassette recorder (hereinafter referred to as BC), and more particularly, to a luminance and color signal separation circuit for separating luminance and color signals of a video signal reproduced from a recording medium.

FIG. 1 is a diagram illustrating a conventional brightness and color signal separation circuit of a VR, and a trap for removing a noise component of 7 MHz or more to detect only a luminance frequency modulated signal from a frequency modulated signal of a brightness and color signal reproduced and applied from a recording medium. The noise component of 7MHz or more of the circuit 11 and the trap circuit 11 removes the delay time of the signal within the actual band 1.1-7MHz because the luminance frequency modulated signal is modulated by a carrier of 3.4MHz to 4.4MHz during recording. Equalize circuit 12 for adjusting the Delay Time to be constant, and resonating elements for increasing the luminance S / N ratio when reproducing a signal whose delay time is compensated in the equalizing circuit 12. 4.5MHz peaking circuit 13 to amplify, 629KHz trap circuit 14 to remove the color signal remaining on the main carrier amplified by the 4.5MHz peaking circuit 13, the 629KH an output buffer 15 for buffering and outputting the luminance frequency modulated signal from which the color signal is removed from the z trap circuit 14, and outputting the amplification unit 16 for amplifying a mixed video signal reproduced and applied from the recording medium; A low pass filter 17 for detecting a color signal from an image signal applied to the amplifier 16, and an output buffer 18 for buffering and outputting the color signal detected by the low pass filter 17. It was composed.

As described above, the conventional VLC luminance and color signal separation circuit separates and processes the mixed luminance and color signals recorded and reproduced on the recording medium, which increases the production cost of the product due to the use of many complicated components. It has been a contributing factor.

Accordingly, an object of the present invention is to provide a VRL brightness and color signal separation circuit which simplifies the separation and processing of brightness and color signals from a mixed video signal reproduced from a recording medium. .

The brightness and color signal separation circuit of V-C in accordance with the present invention for achieving the above object is provided to the brightness and color signal separation circuit of V-R for separately outputting the brightness signal and the color signal from the mixed video signal reproduced from the recording medium. And a trap means for removing noise components included in frequencies of luminance and color signals when the video signal is applied; Equalizing means for constantly adjusting the delay time within a band of the frequency signal of the luminance and color signals provided from said trap means; Picking means for amplifying and processing a frequency band of the luminance and color signals whose delay time is adjusted by the equalizing means; Luminance and color signal separation means for separating and providing the luminance and color signals provided by the picking means by resonance by the resonance elements of the capacitor C1 and the coil L1 connected in series; Luminance signal output buffer means for buffering and providing a luminance signal provided separately by said luminance and color signal separation means; And a color signal output buffer means for buffering and providing color signals provided separately by the luminance and color signal separation means.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2 is a circuit diagram of the luminance and color signal separation of the VRs according to the present invention.

As shown in FIG. 2, the configuration of the brightness and color signal separation circuit of V-C according to the present invention includes a trap circuit for removing noise components included in the frequency of the brightness and color signals when a mixed reproduction video signal is applied. 11) an equalization circuit 12 for constantly adjusting the delay time in the band of the signal output from the trap circuit 11, and amplifying the signal output from the equalizing circuit 12; A luminance and color signal separation circuit for receiving a video signal from the peaking circuit 13 and the 4.5 MHz peaking circuit 13 to set the color signal band of the video signal to a resonant frequency to output the color signal components to a minimum or maximum ( 21) a luminance and color signal output buffer 15 for buffering and outputting a video signal having a minimum color signal component, that is, a luminance signal, from the luminance and signal separation circuit 21, and the luminance; The video signal the color signal component from the color signal separation circuit 21 is a maximum that is, consists of a color signal output buffer 22 for outputting a color signal buffers.

In this case, the luminance and color signal separation circuit 21 connects a resonant element consisting of a capacitor C1 and a coil L1 connected in series between a power line (+ 5V) and a signal line, and connects a capacitor (+ 5V) to the power line (+ 5V). A contact point A is formed at the point where C1 is connected, a contact point B is formed between the capacitor C1 and the coil L1, and a point C is connected at the point where the coil L1 is connected to the signal line. To form.

On the other hand, the luminance signal output buffer 15 has a collector terminal connected to the power supply line (+ 5V), a first switching transistor TR2 connected to a base end of the signal line, and an emitter terminal connected to a luminance signal processing circuit (not shown). ) And a bias resistor R3 connected to the emitter terminal of the first switching transistor TR2.

In addition, the color signal output buffer 22 has a resonance element formed between the power line (+ 5V) and the signal line of the luminance and color signal separation circuit 21, that is, the contact point B formed between the capacitor C1 and the coil L1. A base of the second switching transistor TR3 and the second switching transistor TR3 having a base connected to the connection line of the collector terminal connected to the power supply line (+ 5V) and an emitter terminal connected to a color signal processing circuit (not shown). It consists of a bias resistor (R4) connected to the emitter stage, performing a low pass filtering function.

That is, the color signal output buffer 22 is configured to ground the frequency modulated luminance signal and to output the low frequency converted color signal to a color signal output circuit (not shown).

The detailed operation of the embodiment of the present invention configured as described above will be described in detail.

The trap circuit 11, the equalizing circuit 12, and the 4.5 MHz peaking circuit 13 process the reproduced mixed video signal, and the detailed operation thereof is the same as the process described in FIG.

In this case, the mixed video signal amplified by the 4.5 MHz peaking circuit 13 is applied to the luminance and color signal separation circuit 21, and the band distribution is applied to the frequency of the mixed video signal applied to the luminance and color signal separation circuit. Same as 3a.

That is, the luminance and color signal separation circuit 21 is a capacitor (C1) and the coil (L1) connected in series between the power line (+ 5V) and the signal line when the mixed video signal is provided by the 4.5MHz peaking circuit (13) Since the impedance becomes zero due to the resonance of, the color signal component of 629 kHz is removed and only the luminance signal component is provided to the first switching transistor TR2 of the luminance signal output buffer 15. That is, the first switching transistor TR2 of the luminance signal output buffer 15 switches only the luminance signal component from which the color signal component has been removed and provides the luminance signal processing circuit, not shown, to the luminance signal output buffer 15. The frequency band distribution of the luminance signal is shown in FIG. 3B.

On the other hand, in the color signal output buffer 22 having the low pass filtering function, the second switching transistor TR3 is connected to the contact point B between the capacitor C1 and the coil L1 so that the luminance component of 1 MHz or higher at high frequency is second switched. Grounded through transistor TR3, only a 629 kHz color signal component is extracted and provided to a color signal processing circuit (not shown).

At this time, the frequency band distribution of the color signal provided from the color signal output buffer 22 is the same as the third c.

On the other hand, the present invention is not limited to the above embodiments and can be modified without departing from the technical gist of the present application.

As described above, the VLC luminance and color signal separation circuit according to the present invention simplifies the circuit for separating the luminance and color signals from the mixed video signal reproduced from the recording medium, thereby reducing the production cost by reducing many components. It has a reducing effect.

Claims (2)

A brightness and color signal circuit of V-Cal for separately outputting a brightness signal and a color signal from a mixed video signal reproduced from a recording medium, wherein the noise component included in the frequency of the brightness and color signal is removed when the video signal is applied. Trap means for; Equalizing means for constantly adjusting a delay time in a band of frequency components of luminance and color signals provided from said trap means; Peaking means for amplifying and processing a frequency band of the luminance and color signals whose delay time is adjusted by the equalizing means; Luminance and color signal separation means for separating and providing the luminance and color signals provided by the picking means by resonance by the resonance elements of the capacitor C1 and the coil L1 connected in series; Luminance signal output buffer means for buffering the luminance signal provided separately by said luminance and color signal separation means; And a color signal output buffer means for buffering and providing a color signal provided separately by the brightness and color signal separation means. The luminance signal output buffer according to claim 1, wherein the luminance and color signal separation means includes a contact point (A) with a power supply terminal and a signal line (C) of the series-connected resonating elements (C1, L1) when the luminance signal is output. And a contact point (C) between the interconnection end (B) of the series-connected resonance elements (L, C) and the signal line when connected to the means, and the color signal output buffer means. Luminance and color signal separation circuit.