JP2002271681A - Television camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a television camera that composites a long-exposure video signal and a short-exposure video signal to obtain a video signal with a high dynamic range and to realize low power consumption by stopping a circuit for the short exposure video signal in a long exposure mode. SOLUTION: A CPU discriminates whether a mode is set to a long exposure mode or a compositing mode, depending on a level of a video signal from a DSP(digital signal processor) and stops an on-off circuit to stop supply of a clock to the circuit for the short-exposure video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a television camera for outputting a wide dynamic video signal in which the gradation is continuously varied over a wide range of subject illuminance.

[0002]

2. Description of the Related Art Conventional techniques include, for example, Japanese Patent Application No. Hei.
As described in the specification attached to 1-269379, a video signal (long-exposure video signal) obtained by exposure and accumulation for a long period from an image sensor, and an image obtained by exposure and accumulation for a short period There is a television camera that can output a wide dynamic video signal by synthesizing a signal (short exposure video signal).

[0003]

In the above-mentioned prior art,
A video signal (first video signal) obtained by exposure and accumulation for a long period, a video signal obtained by exposure and accumulation for a long period, and a video signal obtained by exposure and accumulation for a short period were synthesized. Generally, either one of the combined video signal and the second video signal is output.

At this time, when the first video signal is being output, the video signal (short exposure video signal) obtained by exposure and accumulation for a short period of time is the output first video signal. Since it is unnecessary for signal generation, the operation of a circuit for generating and processing the short-exposure video signal is unnecessary, and the operation of the circuit consumes extra power.

An object of the present invention is to detect the operating state of a television camera and stop the operation of a circuit for generating and processing a short exposure video signal when the above-mentioned first video signal is being output. Another object is to make the television camera operate with lower power consumption.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an image pickup device for accumulating electric charges obtained by photoelectric conversion, and an electric charge which has been exposed and accumulated for a longer period from the image pickup device. First signal processing means for performing signal processing on a long-exposure video signal according to the first and second signal processing means, and second signal processing means for performing signal processing on a short-exposure video signal based on accumulated charge that has been exposed and stored for a shorter time from the imaging device; A television comprising: means for synthesizing a long exposure video signal and a short exposure video signal respectively output from the first signal processing means and the second signal processing means; and means for outputting the synthesized video signal obtained by the synthesis. In the camera device, there is provided means for detecting an operation state of the camera, and the operation of the second signal processing means is stopped according to the operation state detected by the detection means.

[0007]

FIG. 1 shows an example of a block configuration of a television camera according to the present invention. In FIG. 1, a long-exposure video signal and a short-exposure video signal output from a CCD image sensor 1 are input to an A / D converter 2 and an A / D converter 5, respectively. Converted to a signal.

The digital long exposure video signal output from the A / D converter 2 and the digital short exposure video signal output from the A / D converter 5 are digital
The signals are input to a signal processor (DSP) 3 and a DSP 6, and are subjected to signal processing such as color separation, white balance control, contour correction, and gamma correction according to the input video signals.

[0009] The long exposure video signal output from the DSP 3 is input to the synthesis processing circuit 4. On the other hand, the short exposure video signal output from the DSP 6 is also input to the synthesis processing circuit 4.

The synthesizing circuit 4 synthesizes the input long-exposure video signal and short-exposure video signal in accordance with a control signal from the CPU 10 to generate and output a synthesized video signal having a wide dynamic range. It operates as a mode or a long exposure mode in which the input long exposure video signal is output as it is. The video signal output from the synthesis processing circuit 4 is input to the D / A converter 7 and is converted from a digital video signal to an analog video signal. The analog video signal obtained by the conversion is converted into a predetermined signal format by the encoder 8, and then output to a subsequent stage (not shown).

Here, the CPU 1 for the synthesis processing circuit 4
The control signal from 0 is based on the video signal level information from the DSPs 3 and 6, for example, if the video signal level from the long exposure video signal from the DSP 3 is lower than a predetermined level in most areas of the video. If the low level state is determined, the long exposure mode control is performed. If the low level state is not determined, the synthesis mode control is performed.

In the long exposure mode, CP
The U10 controls the ON / OFF circuit 11 to stop the supply of the operation clock to the A / D converter 5 and the DSP 6 on the short exposure video signal side, thereby stopping the operation of the processing circuit for the short exposure video signal. Let it. By doing so, the power consumption of the television camera in the long exposure mode can be further reduced.

[0013]

As described above, according to the present invention, the processing circuit for the short exposure video signal is stopped in the long exposure mode,
Power consumption of the television camera can be reduced, and the reliability of the television camera can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a block configuration of a television camera of the present invention.

[Explanation of symbols]

1: CCD image sensor, 2, 5: A / D converter,
3, 6: DSP, 4: synthesis processing circuit, 7: D / A converter, 8: encoder, 9: video output terminal,
10: CPU, 11: ON / OFF circuit.

Claims (1)

[Claims] An image pickup device for accumulating electric charges obtained by photoelectric conversion; a first signal processing unit for performing signal processing on a long exposure video signal based on the electric charges exposed and accumulated for a longer period from the image pickup device; A second signal processing unit for performing signal processing on a short-exposure video signal based on the accumulated charge that has been exposed for a shorter time from the image sensor, and a long exposure output from the first signal processing unit and the second signal processing unit, respectively; Means for synthesizing a video signal and a short-exposure video signal, and a television camera device comprising means for outputting the synthesized video signal obtained by the synthesis, comprising: means for detecting an operation state of the camera; A television camera device, wherein the operation of the second signal processing means is stopped according to the operation state detected by the detection means.