Readout apparatus and imaging apparatus
AssigneeCanon Kabushiki Kaisha
InventorsToshio Kameshima, Tadao Endo, Tomoyuki Yagi, Katsuro Takenaka
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Abstract
An imaging apparatus includes a sensor array, readout apparatus, and control circuit. The readout apparatus includes first LPFs arranged in correspondence with signal lines, an analog multiplexer, and a second LPF. The cut-off frequencies of the first and second LPFs can be switched on two stages, and the control circuit switches the cut-off frequencies of the first and second LPFs in accordance with the imaging mode.
Claims14
A readout apparatus which reads out signals via a plurality of signal lines from an area sensor having pixels arranged to form rows and columns, each pixel having a photoelectric conversion device, comprising:
- a plurality of amplifiers which are arranged in correspondence with the respective signal lines each arranged in correspondence with respective one of the columns;
- a plurality of low-pass filters which are arranged in correspondence with respective ones of said plurality of amplifiers;
- and
- a conversion unit for serially converting signals that have passed through said low-pass filters and outputting the converted signals,
- wherein the cut-off frequency of said low-pass filters can be switched in accordance with a time necessary to read out signals from the area sensor to output signals for one row, and
- wherein, letting τ be a time constant of said low-pass filter, and Trow be the time necessary to read out signals from the area sensor to output signals for one row, a relation 6τ≦Trow is satisfied.
An imaging apparatus comprising:
- an area sensor having pixels arranged to form rows and columns, each pixel having a photoelectric conversion device;
- a readout apparatus which reads out output signals from said area sensor via a plurality of signal lines each arranged in correspondence with a respective one of said columns of said area sensor;
- and
- a control unit for controlling operations of said area sensor and said readout apparatus,
- wherein said readout apparatus comprises a plurality of amplifiers which are arranged in correspondence with respective ones of the signal lines, a plurality of low-pass filters which are arranged in correspondence with respective ones of said plurality of amplifiers, and a conversion unit for serially converting signals that have passed through said low-pass filters and outputting the converted signals,
- wherein cut-off frequencies of said low-pass filters can be switched on at least two stages,
- wherein said control unit has a function of switching the cut-off frequency of said low-pass filters in accordance with a time necessary to read out signals from the area sensor to output signals for one row, and
- wherein, letting τ be a time constant of said low-pass filter, and Trow be the time necessary to read out signals from the area sensor to output signals for one row, a relation 6τ≦Trow is satisfied.
Dependencies are inferred from the claim text.