JP3057279B2 - Color camera device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color camera device using, for example, a complementary color filter.

[0002]

2. Description of the Related Art In a color camera apparatus using a complementary color filter, for example, when a signal is saturated in a color image pickup section or an AGC circuit in a subsequent stage, a false signal is generated in a chroma signal, and the reproduced image quality is significantly deteriorated. Therefore, conventionally, saturation of the color imaging unit and the AGC circuit is detected, and when saturation occurs, a chroma signal is suppressed.

[0003] In such a color camera device, A / D conversion of an imaged signal is performed and signal processing is performed digitally. In that case, the configuration of the apparatus is as shown in FIG. 4, for example.

That is, in the drawing, reference numeral 1 denotes a CCD constituting a color image pickup unit, for example, provided with a complementary color filter. The signal from the CCD 1 is supplied to the AGC circuit 3 through the sampling and holding circuit 2. The signal from the AGC circuit 3 is supplied to an A / D conversion circuit 4, and the digitized signal is supplied to a terminal 5 connected to a signal processing system.

Reference numeral 6 denotes a microcomputer for control (μ-com). The control signal from the μ-com 6 is supplied to the AGC circuit 3 through the D / A conversion circuit 7, and the control signal from the μ-com 6 is supplied to the control unit of the iris 9 through the D / A conversion circuit 8.

In this apparatus, the detection of saturation is performed as follows. First, the detection of the saturation of the AGC circuit 3 is performed by supplying a signal digitized by the A / D conversion circuit 4 to the saturation detection circuit 41, and the saturation detection circuit 41 performs digital processing.

On the other hand, for detecting the saturation of the CCD 1, for example, a signal from the CCD 1 is supplied to an A / D conversion circuit 42, and a signal digitized by the A / D conversion circuit 42 is supplied to a saturation detection circuit 43. Supplied and done. Then, the signals from the saturation detecting circuits 41 and 43 are combined by a combining circuit 44 and taken out to a control signal terminal 45 for chroma signal suppression.

If the AGC circuit 3 and the iris 9 are controlled independently as described above, a malfunction may occur, for example, when an image in which a spotlight is lit in the dark is captured. That is, in this case, although the iris 9 is opened and the output of the CCD 1 is saturated,
Since the gain of the circuit 3 is small, the AGC output is not so large, and a state occurs in which the circuit is not considered to be saturated. For this reason, the detection of saturation of the CCD 1 is required for suppressing the chroma signal.

However, in this apparatus, an extra A / D conversion circuit 42 is required for detecting the saturation of the CCD 1. Therefore, the provision of this circuit has caused problems such as an increase in manufacturing cost and a deterioration in space factor.

As shown by a broken line in the figure, it is conceivable to provide the saturation detection circuit 43 in the analog portion. According to this, a 1-bit signal of "1" or "0" is sufficient as the saturation detection signal, and the A / D conversion circuit 42 has a simple configuration. However, in this case, the saturation detection circuit 43
Is formed by an analog circuit, which complicates the configuration and causes problems such as manufacturing cost and space factor.

[0011]

The problem to be solved is that an extra A / D conversion circuit is required for detecting the saturation of the CCD, which causes problems in manufacturing cost, space factor, and the like. It is.

[0012]

According to the present invention, a signal from a color image pickup unit (CCD 1) is transmitted to an AGC circuit 3 after the signal has passed through an AGC circuit 3.
The control signal is supplied to a processing system that has been subjected to / D conversion (circuit 4) and digitized (terminal 5), and a control signal that detects saturation of the color imaging unit and suppresses a chroma signal component in the processing system. In the color camera device to be formed, the A / D converted signal after the AGC circuit is
The control signal of the AGC circuit (μ-co
m6) to perform inverse correction (circuit 12) to form a signal equivalent to the signal before the AGC circuit, and to detect the saturation of the formed signal (circuit 13) to detect the saturation of the color imaging unit. This is a color camera device that is adapted to perform the operation.

[0013]

According to this, the signal after AGC is inversely corrected and A
By forming a signal equivalent to the signal before GC, the saturation of the color imaging unit can be detected in the digital portion, and good saturation detection can be performed with a simple configuration.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a CCD constituting a color image pickup section provided with, for example, a complementary color filter. This C
A signal from the CD 1 is supplied to the AGC circuit 3 through the sampling and holding circuit 2. The signal from the AGC circuit 3 is supplied to an A / D conversion circuit 4, and the digitized signal is supplied to a terminal 5 connected to a signal processing system.

Reference numeral 6 denotes a control microcomputer (μ-com). The control signal from the μ-com 6 is supplied to the AGC circuit 3 through the D / A conversion circuit 7, and the control signal from the μ-com 6 is supplied to the control unit of the iris 9 through the D / A conversion circuit 8. The above configuration is the same as the conventional one.

In this apparatus, the detection of saturation is performed as follows. First, the detection of the saturation of the AGC circuit 3 is performed by supplying a signal digitized by the A / D conversion circuit 4 to a saturation detection circuit 11, and the saturation detection circuit 11 performs digital processing.

On the other hand, the detection of saturation of the CCD 1 is based on A
The signal digitized by the / D conversion circuit 4 is supplied to the inverse correction circuit 12, and the inverse correction circuit 12
The control signal supplied to the AGC circuit 3 is supplied from om6. As a result, in the inverse correction circuit 12, the AGC
The gain control in the circuit 3 is inversely corrected, and a signal equivalent to the signal before the AGC circuit 3 is formed. This signal is supplied to the saturation detection circuit 13. And these saturation detection circuits 1
The signals from 1 and 13 are combined by a combining circuit 14 and taken out to a control signal terminal 15 for chroma signal suppression.

That is, in this device, the AGC circuit 3
Is divided by the transfer function from the CCD output to the AGC output, the output signal of the CCD 1 can be restored. Here, since the sampling and holding circuit 2 is merely a waveform shaping, the transfer function is substantially only the gain of the AGC circuit 3.

Therefore, in this device, the output signal of the CCD 1 can be restored by supplying the control signal supplied from the μ-com 6 to the AGC circuit 3 to the inverse correction circuit 12. And in this case, μ-com6
Since the control signal from is originally a digital value, an extra A /
There is no need to provide a D conversion circuit, and there is no problem in manufacturing cost, space factor, and the like during implementation.

When the signal is inversely corrected to form a signal equivalent to the signal before AGC, there are the following problems. Can circuit linearity be ignored? Is it possible to know the gain of the AGC circuit accurately? If the AGC circuit is saturated, information cannot be correctly corrected due to lack of information.

However, there is no problem for the detection of saturation because it is originally detected. For this circuit, the AGC gain is used in a range where the gain of the AGC is small. In this range, the relationship between the gain control signal and the gain is sufficiently accurate to form a control signal for chroma signal suppression. Regarding the above, when the AGC circuit 3 is saturated, the saturation is detected from this output signal, so that the saturation of the output signal of the CCD 1 may not be detected.

According to the above-described apparatus, the signal after the AGC (circuit 3) is inversely corrected (circuit 12) to form a signal equivalent to the signal before the AGC, so that the saturation of the color image pickup unit in the digital portion is achieved. (Circuit 13), and good saturation detection can be performed with a simple configuration.

FIG. 2 shows a configuration of another example. That is, when the characteristics of the saturation detection circuits 11 and 13 are equal in the above-described circuit, the circuit can be configured as shown in FIG. In this figure, the signal from the A / D conversion circuit 4 and the signal from the inverse correction circuit 12 are supplied to a synthesizing circuit 16 for extracting a signal having a higher level. The signal from the synthesizing circuit 16 is supplied to the saturation detecting circuit 17. This also makes C
Detection of saturation of CD1 and AGC circuit 3 is performed, and
In this case, one saturation detection circuit can be used.

Further, as shown in FIG. 3, the reciprocal of the control signal supplied from the μ-com 6 to the AGC circuit 3,
The value of “1” is supplied to the synthesis circuit 16. The signal from the synthesizing circuit 16 is supplied to the inverse correction circuit 12,
The signal from the inverse correction circuit 12 is supplied to a saturation detection circuit 17. Thus, the saturation of the CCD 1 and the AGC circuit 3 is detected. Note that the present application is theoretically applicable to an analog processing device.

[0025]

According to the present invention, the signal after AGC is inversely corrected to form a signal equivalent to the signal before AGC, so that the saturation of the color image pickup unit can be detected in the digital portion, and a simple configuration can be realized. Good saturation detection can now be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an example of a main part of a color camera device according to the present invention.

FIG. 2 is a configuration diagram of another example of a main part.

FIG. 3 is a configuration diagram of still another example of a main part.

FIG. 4 is a configuration diagram of a main part of a conventional color camera device.

[Explanation of symbols]

 Reference Signs List 1 CCD constituting a color imaging unit 2 Sampling hold circuit 3 AGC circuit 4 A / D conversion circuit 5 Terminal connected to signal processing system 6 Control microcomputer (μ-com) 7, 8 D / A conversion circuit 9 Iris 11, 13 Saturation detection circuit 12 Inverse correction circuit 14 Synthesis circuit 15 Control signal terminal for chroma signal suppression

Claims (1)

(57) [Claims] 1. A signal from a color image pickup unit is supplied to a processing system which is A / D converted and digitized after passing through an AGC circuit, and detects saturation of the color image pickup unit so as to be processed by the processing system. In the color camera device which forms a control signal for suppressing the chroma signal component of the A / D conversion , the A / D converted signal after the AGC circuit is subjected to the above processing.
In the science system, reverse correction is performed using the control signal of the AGC circuit to form a signal equivalent to the signal before the AGC circuit, and the saturation of the formed signal is detected to detect the saturation of the color imaging unit. A color camera device designed to perform.