Radiography apparatus, radiography system, and control method thereof
AssigneeCanon Kabushiki Kaisha
InventorsKatsuro Takenaka, Tadao Endo, Toshio Kameshima, Tomoyuki Yagi
Life of this patent
Estimating the term…
Abstract
At least one exemplary embodiment is directed to a radiography apparatus configured to have an offset reading period, where during the offset reading period an offset reading operation is performed without illumination by radiation (e.g., X-rays). The offset reading period can be different from a radiation (e.g., X-ray) reading period in timings of applying a gate pulse. During the offset reading period, a pixel addition can be performed such that the switching elements corresponding to two or more lines are concurrently turned on-off thus reducing the offset reading period.
Claims11
A radiography apparatus, comprising:
- a conversion circuit unit including a plurality of conversion elements arranged in a row-column pattern and configured to convert radiations into an electrical signal;
- a drive circuit configured to control the driving of the conversion circuit unit;
- a reading circuit configured to read the electrical signal outputted from the conversion circuit unit;
- and
- a signal-processing unit configured to process the electrical signal outputted from the reading circuit,
- wherein, in an object-image reading operation, the conversion circuit unit detects an object image based on illuminated radiations, and the drive circuit drives the conversion circuit unit so as to allow the reading circuit to read a signal based on the object image, and, in an offset-data reading operation, the conversion circuit unit detects offset data in a period where the radiations are not illuminating, and the reading circuit reads a signal based on the offset data, and
- wherein, when the numbers of lines driven concurrently by the drive circuit in the object-image reading is represented by n (equal to 1 or greater) and the numbers of lines driven concurrently by the drive circuit in offset-data reading operations is represented by m, the drive circuit controls the conversion circuit unit so as to satisfy the expression:
- n<m.
A radiography system, comprising:
- a radiation source configured to emit radiations;
- a conversion circuit unit having a plurality of conversion elements arranged in a row-column pattern and configured to convert a portion of the radiations into an electrical signal;
- a drive circuit configured to control the driving of the conversion circuit unit;
- a reading circuit configured to read the electrical signal outputted from the conversion circuit unit;
- a signal-processing unit configured to process the electrical signal outputted from the reading circuit, and
- a control unit configured to control the drive circuit, the conversion circuit unit, the reading circuit, and the signal-processing unit,
- wherein, in an object-image reading operation, the conversion circuit unit detects an object image based on illuminated radiations, and the drive circuit drives the conversion circuit unit so as to allow the reading circuit to read a signal based on the object image, and, in an offset-data reading operation, the conversion circuit unit detects offset data in a period where the radiations are not illuminated, and the reading circuit reads a signal based on the offset data, and
- wherein, when the numbers of lines driven concurrently by the drive circuit in the object-image and offset-data reading operations are respectively represented by n (equal to 1 or greater) and m, wherein the drive circuit, the conversion circuit unit, and the reading circuit are controlled so as to satisfy the expression:
- n<m.
A control method of a radiography system, comprising:
- an object-image reading operation in which a conversion circuit unit detects an object image based on illuminated radiations and a drive circuit which drives the conversion circuit unit so as to allow a reading circuit to read a signal based on the object image, and
- an offset-data reading operation in which the conversion circuit unit detects offset data in a period where there is no illuminated radiations, and the reading circuit reads a signal based on the offset data,
- wherein, when the numbers of lines driven concurrently by the drive circuit in the object-image and offset-data reading operations are respectively represented by n (equal to 1 or greater) and m, the expression:
- n<m is satisfied.
A program instructing a computer to execute control of a radiography system, wherein the computer instructs a radiography apparatus to execute an object-image reading operation in which a conversion circuit unit detects an object image based on illuminated radiations and a drive circuit drives the conversion circuit unit so as to allow a reading circuit to read a signal based on the object image, and an offset-data reading operation in which the conversion circuit unit detects offset data in a period where the radiations are not illuminating, and the reading circuit reads a signal based on the offset data, and
- wherein, when the numbers of lines driven concurrently by the drive circuit in the object-image and offset-data reading operations are respectively represented by n (equal to 1 or greater) and m, the computer instructs the radiography apparatus to execute the reading operations so as to satisfy the expression:
- n<m.
Dependencies are inferred from the claim text.