US Patent No. 9,288,409

IMAGE PICKUP APPARATUS, IMAGE PICKUP SYSTEM, AND METHOD FOR CONTROLLING IMAGE PICKUP APPARATUS


Patent No. 9,288,409
Issue Date March 15, 2016
Title Image Pickup Apparatus, Image Pickup System, And Method For Controlling Image Pickup Apparatus
Inventorship Atsushi Iwashita, Honjo (JP)
Toshio Kameshima, Kumagaya (JP)
Tomoyuki Yagi, Honjo (JP)
Katsuro Takenaka, Honjo (JP)
Hideyuki Okada, Honjo (JP)
Sho Sato, Kumagaya (JP)
Eriko Sugawara, Honjo (JP)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 9,288,409

1. An image pickup apparatus comprising:
a detector that includes a plurality of conversion elements which convert radiation into charge and that executes image pickup
operations in which electrical signals based on the charge are output;

a control unit that controls the detector such that the detector executes, in a period between a first image pickup operation
and a second image pickup operation, which is executed after the first image pickup operation, among the image pickup operations
that are performed a plurality of times, inter-image pickup operations including a first inter-image pickup operation for
suppressing a lag generated by the first image pickup operation and a second inter-image pickup operation for obtaining, from
the detector, dark signals based on charges included in the conversion elements that are in a state in which the radiation
is not radiated after the first inter-image pickup operation; and

a signal processing unit that executes arithmetic processing on the electrical signals output from the detector,
wherein the signal processing unit
calculates a correction coefficient using a first time until the conversion elements begin to accumulate charges for the second
inter-image pickup operation after the first inter-image pickup operation is completed, a second time until the second inter-image
pickup operation begins after the first inter-image pickup operation is completed, and the dark signals,

predicts an amount of offset to be included in electrical signals output from the detector in the second image pickup operation
using a third time until the conversion elements begin to accumulate charges for the second image pickup operation after the
first inter-image pickup operation is completed, a fourth time until an operation for outputting the electrical signals begins
in the second image pickup operation after the first inter-image pickup operation is completed, and the correction coefficient,
and

executes calculation using the electrical signals and the amount of offset output from the detector in the second image pickup
operation.