JPS6146690A - Processing circuit of multi-channel signal - Google Patents

Abstract

PURPOSE:To obtain a signal processing circuit of each channel, which can solve troubles relating to a temperature characteristic, etc., by arraying symmetrically the even-number of signal processing circuits so as to make them integrated and causing the symmetry to form a difference signal between channels so as to input it. CONSTITUTION:Signals R, G and B inputted from input terminals 1, 2 and 3 are supplied to processing circuits 4, 5, 6 and 7. The strain of the processing circuits 4 and 5 and that of the processing circuits 6 and 7 are made integrated on the same chip, and action characteristics of the circuits 4 and 5 become coincident and the same coincidence can be obtained in the circuits 6 and 7. When signals processed by such processing circuits 4, 5, 6 and 7 are applied to subtractors 8 and 10 and an adder 9, a luminance signal of an NTSC system can be obtained from the adder 9, while from the subtractors 8 and 10 red and blue color difference signals can be obtained. Since these color difference signals are formed in the processing circuits of the same action characteristic, the white balance can be secured.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a multi-channel signal processing circuit that performs signal processing on simultaneous multi-channel signals, and is applicable to, for example, a Kel process circuit in a color television camera. be done.

[Conventional technology]

Traditionally, in color television cameras, process processing circuits are installed in each signal line to perform process processing such as gamma correction processing on the three primary color signals, that is, the red signal, green signal, and blue signal obtained as the photographic output of a photographed subject. It is supposed to be administered. And above 4! The process circuits of the r@ line, that is, the process circuits of each channel, were individually integrated circuits one by one, or all the channels were integrated into an integrated circuit.

In general, in multi-channel signal processing circuits such as the process circuits mentioned above, if each channel is integrated into an integrated circuit, temperature differences due to adjustment errors of each channel and differences in temperature distribution on the printed circuit board will result in differences in operating characteristics of each channel. turn into. Also, if all channels are integrated into an integrated circuit,
Although it is possible to suppress the above-described difference in operating characteristics to an extremely small level, it is still not possible to avoid the influence of differences in temperature characteristics caused by differences in temperature distribution within the integrated circuit.

Here, in the process circuit of a color television camera, differences in operating characteristics between channels affect the color of the image, causing image quality deterioration such as coloration in black and white images, for example.

[Problem that the invention seeks to solve]

That is, in a multi-channel signal processing circuit, the existence of differences between channels in the operating characteristics of each channel is a problem, and the influence of temperature characteristics is a particularly big problem.

Therefore, in view of the above-mentioned conventional problems, the present invention provides a multi-channel signal processing circuit with a novel circuit configuration in which opening of channels due to differences in temperature characteristics is not a problem.
For example, the purpose is to facilitate the integration of process circuits in color television cameras and to minimize all color errors in low-chroma images.

[Means for solving problems]

The multi-channel signal processing circuit according to the present invention has an even number of signal processing circuits arranged symmetrically to form an integrated circuit, and
The configuration is such that a difference signal between the symmetrical channels is formed and output.

[Effect]

In the multi-channel signal processing circuit according to the present invention, by arranging an even number of signal processing circuits symmetrically and integrating them into an integrated circuit, the temperature distribution within the integrated circuit is made completely uniform, and a difference signal between symmetrical channels is output. This prevents the opening of the channel lid from becoming a problem due to differences in temperature characteristics of each channel.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a multi-channel signal processing circuit according to the present invention will be described in detail below with reference to the drawings.

The block diagram in FIG. 1 shows an embodiment in which the present invention is applied to a signal processing circuit of a color television camera. In this embodiment, first to third signal input terminals 1, 2, 3 are supplied with a red signal R1, a green signal G1, and a blue signal B obtained by a color image sensor (not shown).

The signal processing circuit of this embodiment includes four process processing circuits 4, 5, 6.7, two of which are arranged symmetrically and integrated into a so-called mirror image structure. The first and second process processing circuits 4 and 5, which are symmetrically arranged and integrated on the same chip, have the same operating characteristics such as temperature characteristics due to their symmetry. Further, the third and fourth process processing circuits 6 and 7 also have the same operating characteristics. Here, the first and second process processing circuits 4
. It is assumed that the operating characteristic is expressed by Ga/ma and S number 1/(x). In addition, the first
and second process processing circuits 4, 5, third glue and fourth
The process processing circuits 6 and 7 have almost completely identical operating characteristics such as temperature characteristics within the same integrated circuit.
Since there are differences in temperature characteristics etc. for each integrated circuit, fCX) x f
(X).

However, f(x) is 1% f(x).

The first process processing circuit 4 is supplied with the red signal R from the first signal input terminal 1, and the second and third process processing circuits 5 and 6 are supplied with the red signal R from the second signal input terminal 1. The green signal G is supplied from the fourth
A blue signal G is supplied to the process processing circuit 7 from the third signal input terminal 3.

The first process processing circuit 4 performs gamma correction processing on the red signal R, and outputs a red correction output signal R8 as follows: RO=, fcR) to a first signal subtraction synthesizer 8 and a signal addition synthesizer 9. supply ! Further, the second process processing circuit 5 performs gamma correction processing on the green signal G to produce a green corrected output signal G such that Go=f(G). is supplied to the first signal subtraction combiner 8 and signal addition combiner 9. Further, the third process processing circuit 6 performs gamma correction processing on the green signal G to obtain G1=i? (G) The green color corrected output signal G1 is sent to the second signal subtraction synthesizer 10.
and is supplied to the signal addition/synthesizer 9. And the fourth above
The process processing circuit 7 performs gamma correction processing on the blue signal B to obtain a blue corrected output signal B1 as B uni r(B).
and is supplied to the signal addition synthesizer 9.

The first signal subtraction synthesizer 8 receives each of the supplied signals R5.
A difference signal CRo-Go)e between ゜ and Go is formed and supplied to the matrix circuit 11. Further, the second signal subtractive synthesizer 10 similarly forms a difference signal (B1-Gt) and supplies it to the matrix circuit 11.

The signal adder/synthesizer 9 receives each of the supplied signals R8, Go.
, G1. B1 is added and combined with a predetermined weight to form, for example, a luminance signal Y of the NT''SC method shown in the following.

In addition, the matrix circuit 11 performs the following matrix operation on each of the supplied difference signals CB, o-Go), CBl-Gl)K to obtain a red difference signal cR-y and a blue difference signal CB-. Form Yk. This matrix circuit 1
Each color difference signal CR-Y p CB-Y formed in
fC in symmetrically arranging and integrating circuits as described above.
Difference signal R8- formed by the first signal subtraction synthesizer 8 for each output signal R8, Go of the first and second process processing circuits 4, 5, which are designed to exhibit operating characteristics as shown in FIG.
Go, as well as third and fourth process processing circuits 6,
The second signal subtractive synthesizer 10 receives the IJ shadow-formed difference signal B1.7 for each output signal G1.B1. G1, so the white balance conditions (i.e. R=
G=B), it definitely becomes zero.

That is, for example, the red difference signal CR-Y is CR-Y =
0.70 (Ro-Go) -0,11 (Bl-Gl)
= 0.700'(R) -f(G)) -0,11C
PCB)-r(G)), so if R=G=B, f(x)〆f(x) becomes exactly zero, ensuring white balance. .

In addition, in the above-mentioned embodiment, four process processing circuits 4,
We adopted a configuration in which two each of 5 and 6.7 were integrated into circuits, but as shown in Fig. 2, four process processing circuits 4t
5r 6r 7 c i They are arranged symmetrically on an integrated circuit, and the difference signal R6-Go between the symmetrical channels is
, B, -01 may be formed by the respective signal subtractive synthesizers 8 and 10.

Further, gain control type amplifiers 21 and 22 each having two channels arranged symmetrically and integrated into an integrated circuit are provided on the input side of each process processing circuit 4, 5, 6, and 7 in the embodiment shown in FIG. , 23, and 24 as shown in FIG. 3, an automatic gain system @A can be achieved.

〔Effect of the invention〕

As is clear from the description of the embodiments above, in the multi-channel signal processing circuit according to the present invention, an even number of signal processing circuits are arranged symmetrically and integrated into an integrated circuit, and a difference signal between the symmetrical channels is formed. This makes it possible to perform signal processing on each channel without causing problems due to differences between channels due to differences in temperature characteristics. can be applied, and the intended purpose can be fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention when used in a signal processing circuit of a TV camera;
FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a block diagram showing still another embodiment. 4 s 5.6 v 7...Process processing circuit 8.1
0...Signal subtraction synthesizer

Claims (1)

[Claims] A multi-channel signal processing circuit configured to integrate an even number of signal processing circuits by symmetrically arranging them, and to form and output a difference signal between the symmetrical channels.