JPS59176988A - Circuit for adjusting hue of reproducing device - Google Patents

Abstract

PURPOSE:To attain the adjustment of hue at the device side by designing that the phase difference between a color signal and a burst signal is controlled manually at the device side in a hue adjusting circuit utilized for a VTR or the like. CONSTITUTION:The burst signal and the color signal formed by applying dual axis modulation to color information are separated respectively from a composite color signal P, separated color burst signal P1 is given to a phase adjusting circuit 44 so as to change relatively the phase to the other color signal P2 and then both the signals are outputted with synthesis. In the circuit constituted in this way, the hue is adjusted by adjusting a variable resistor 51 at the device side of the VTR or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an apparatus (for example, a VTR) for reproducing color information from a recording medium storing color information.

This relates to a hue adjustment circuit used in video cameras, etc.).

(b) Conventional technology In devices such as VTRs, playback signals are transmitted to television receivers (T
In order to supply the signal to a TV receiver (TV receiver) through its antenna circuit, the signal is converted into an RF signal that can be received by a tuner in the TV receiver. The reed uses a built-in tuner to receive television signals from an antenna in order to record them on magnetic tape, which is a recording medium. Furthermore, this television signal is processed into a signal suitable for recording, and the reverse conversion is performed during playback. During these signal processing processes, the relative phase relationship between the burst signal and the color signal obtained by biaxially modulating color information may deviate. It is well known from experience that the hue of the image displayed on the screen of the TV receiver will be different when the same on-air signal is applied directly to the TV receiver and when a VTR device is interposed in between. It is being

As a method to eliminate this difference in hue, it is possible to adjust the hue adjustment circuit provided in the TV/image machine each time the VTR device is attached/detached, or to carefully examine and adjust each circuit in the VTR device and adjust it to the TV94 image machine. At the stage of adding the signal, it has been implemented to make it the same as the signal from on-air. However, the disadvantage is that the first method is complicated to operate, and the latter is expensive. Therefore, at present, while we are examining each of the above circuits to the extent that it is acceptable in terms of cost, if the hue If a discrepancy occurs, adjustments are made using two hue adjustment circuits on the TV9.This means that each time the reproduction signal from the VTR device and the on-air signal from the antenna are switched, This requires adjustment of the receiver's hue adjustment circuit, which poses a problem in operability.

(c) Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a circuit that can adjust the hue of a color composite signal to be sent to a TV receiver on the side of a device such as a VTR. It is something.

2) Composition of brightness The present invention separates a burst signal from a composite color signal and a color signal obtained by biaxially modulating color information so that the hue can be adjusted on the device side such as a VTR. ,
The device is characterized in that one of the separated signals is applied to a phase adjustment circuit to change the phase relative to the other, and then both signals, that is, a signal with phase adjustment and a signal without phase adjustment, are combined and output. It is.

(@Embodiment FIG. 1 is a block diagram of a communication system including a VTR device equipped with the circuit of the present invention, and FIG. 2 is a block diagram of the same circuit.

A received signal from the antenna (1) is applied to an input terminal (21) of a VTR device (2). The received signal from this input terminal is applied to a duplexer (22), one side is applied to an RF switch circuit (23), and the other side is applied to a tuner 4) built in the VT'R device. The RF switch (23) selects the on-air signal from the splitter (two channels) and the reproduced RF signal from the RF modulator (described later), and the selected signal is sent to the output terminal (25).
The signal is output through the antenna input terminal (5) of the TV receiver (5).

The tuner 4) output is applied to the magnetic head (28) through the recording processing circuit (26) and the recording/reproducing switching circuit (27j).
It is stored on magnetic tape (29). The stored signal is reproduced by the magnetic head (2) and transferred to the upper recording re-switching circuit (27).
) to the reproduction processing circuit (30). This reproduction processing circuit example performs inverse conversion processing of the recording processing circuit (26), and the details of the internal configuration are well known in general VTR devices! Although omitted since it is still outside the gist of the present invention, the output of the reproduction processing circuit (30) is NTSC.
Regarding the method, 158MHz burst signal (P
l), and color (
There is a color composite signal (P) containing signals I-J (P2), and a luminance signal (Q) and audio signal (R) having a complex synchronization signal. The color composite signal is applied to a hue adjustment circuit (4), where the phase between the burst signal and the color signal is adjusted as will be described later. The phase-adjusted color composite signal (P) and the luminance signal (Q
) are synthesized and RF modulated together with the audio signal (R) to form a signal equivalent to an on-air television signal. The output of the RF modulator (3) is then applied to the RF switch (23).

As shown in FIG. 2, the hue adjustment circuit (4) has an input terminal (41) for inputting a color composite signal (P), and an input terminal for inputting this color composite signal and separating and outputting a burst signal therein. 1 separation means ← 4, a second separation means (43) which inputs the color composite signal and separates the color signals therein and outputs the same, and receives the output (burst signal) of the first separation means (42). is a circuit (2) that adjusts the phase of the burst signal; and a mixing unit (ro) that inputs the output (color signal) of the second separation unit (43) and the output (color signal) of the second separation unit (43) to the phase adjustment circuit (F@) and combines the two outputs. ), and an output terminal for deriving the output of the mixing means (45), ie, the phase-adjusted color composite signal (P);
An input terminal for inputting a luminance signal (Q), a circuit for creating a burst signal extraction pulse (S) based on a synchronization signal in the luminance signal, and the first and second separating means for the pulse. (2) It is equipped with a circuit (49I(3)) provided to (43).

The first separating means (■) is a color composite signal (P) and a sampling pulse (
Since the burst signal (Pl) is output by inputting signal S), it is sufficient to perform an AND operation on both signals. Further, since the second separation means (43) inputs the color composite signal (P) and the sampling pulse (S) and outputs the color signal (P2), the sampling pulse (S)
The negative output (S) of the color signal (P2) may be ANDed. Furthermore, since the phase adjustment circuit H is used to adjust the phase of the burst signal (pl) that is the input signal, it is configured with a differentiating circuit or an integrating circuit that receives the burst signal as an input, and the resistor constituting the circuit is a variable resistor. It is good to have a container (51) (outside the block ■ to make it easier for children).

In the circuit of the present invention constructed in this manner, the hue can be adjusted by controlling the variable resistor, resistor a, on the device side, such as a VTR. In other words, by rotating the variable resistor ← back and forth, the Bernut signal +1 (PI) can be changed to the color@
This is because the phase can be shifted in a direction that advances or lags relative to the number (P2). The phase difference between the burst signal (Pl) and the color signal (P2) tends to change slightly due to slight differences in the circuits inside the device, such as a VTR. This problem can be solved by adjusting the , and there is no need to control the hue adjustment means of the TV receiver.

In this embodiment, the phase of the burst signal is adjusted, but the same effect can be achieved even if the phase of the color signal is adjusted instead of the burst signal.

(f) Effects of the Invention The present invention is configured so that the phase difference between the color signal and the burst signal can be manually adjusted on the side of a device such as a VTR. An image of a desired hue can be obtained on the screen of the TV receiver without operating the hue adjustment means.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a communication system including a VTR device equipped with the circuit of the present invention, and FIG. 2 is a plotter diagram of the same circuit. Explanation of main drawing numbers 8)...Reproducing means (magnetic head), alpha force...1st
Separation means, (43)...Second separation means, (4 furnaces...Phase adjustment circuit, (45)...Mixing circuit, @1)...Variation resistor/container 0649

Claims (1)

[Claims] (1) Twelve stages for generating a color composite signal from a recording medium storing a color composite signal including a color signal obtained by biaxially modulating a part signal and color information, and a stage for generating a color composite signal from the reproducing means. ] A first separating means for inputting a color composite signal to separate the burst signal; a second separating means for separating the color signal from the color composite signal; a phase adjustment circuit that can input the output of the second separation means to change the phase of the input signal; A hue adjustment device for a reproducing device, wherein the phase adjustment circuit is provided with a means for mixing the output of the separation means and the output of the separation means.