Video signal processing circuit, imaging device and video signal processing method

Abstract

A digital still camera includes an amplification circuit, a timing generator, sample hold circuits, a differential amplifier, an analog / digital conversion circuit and a control unit. The generator generates a first-pulse signal and a second-pulse signal at different timings. The circuits sample analog video signals outputted from the amplification circuit at timings when the first-pulse signal and second-pulse signal, respectively, are provided and hold levels of the analog video signals. The amplifier acquires a difference between the levels of the analog video signals. The circuit obtains adigital video signal corresponding to the analog video signal on the basis of the difference. The unit changes the timings to provide the first- and second-pulse signals to the first- and second-sample hold circuits, respectively, and a bias current depending on the driving period.

Description

technical field [0001] The invention relates to an image signal processing circuit, a photographing device and an image signal processing method. Background technique [0002] As a conventional technology, an analog signal processing unit is mounted on an imaging device such as a digital camera, and an analog signal processing unit is used to convert a CCD (Charge Coupled Device) or a MOS (Metal Oxide Semiconductor) sensor into an analog signal. The analog image signal output by the representative imaging element is converted into a digital image signal. [0003] JP2008-289136 discloses the first technology, which relates to the existing analog signal processing unit, which continues to supply power to the analog signal processing unit during the blanking period, and stops the analog signal by stopping the clock signal to the analog signal processing unit. signal processing. [0004] In addition, JP2008-289136 A discloses a second technique for stopping analog signal proce...

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Problems solved by technology

[0006] However, in the first technique of the aforementioned patent document, since the analog signal processing is stopped by stopping the clock signal to the analog signal processing unit during the blanking period, the power consumption can be reduced, but the power consumption cannot be reduced when the analog signal processing is performed.

In addition, in the second technique of the above-mentioned patent document, since the analog signal processing is stopped by cutting off a part of the power supply to the analog signal processing part during the blanking period, the power consumption can be reduced, but the power consumption cannot be reduced when the analog signal processing is performed. consumption

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