| US 7,512,214 B2 | ||
| Radiography apparatus, radiography system, and control method thereof | ||
| Katsuro Takenaka, Saitama-ken (Japan); Tadao Endo, Saitama-ken (Japan); Toshio Kameshima, Saitama-ken (Japan); and Tomoyuki Yagi, Saitama-ken (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Oct. 19, 2007, as Appl. No. 11/875,598. | ||
| Application 11/875598 is a continuation of application No. 11/346873, filed on Feb. 02, 2006, granted, now 7,302,039. | ||
| Claims priority of application No. 2005-049110 (JP), filed on Feb. 24, 2005. | ||
| Prior Publication US 2008/0049900 A1, Feb. 28, 2008 | ||
| Int. Cl. H05G 1/64 (2006.01) | ||
| U.S. Cl. 378—98.12 [378/98.8; 250/370.09] | 7 Claims |
| 1. 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, 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 conversion circuit unit to output a signal based on the object image, and, in an offset-data
reading operation, the conversion circuit unit detects offset data in a period when the radiations are not illuminating, and
the drive circuit drives the conversion circuit unit so as to allow the conversion circuit unit to output 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
operation is represented by n (equal to 1 or greater) and the numbers of lines driven concurrently by the drive circuit in
offset-data reading operation is represented by m, the drive circuit controls the conversion circuit unit so as to satisfy
the expression: n<m; and
a signal-processing unit configured to process the electrical signal outputted from the conversion circuit unit, wherein the
signal-processing unit includes an offset data generating unit configured to generate the offset data from the signal, and
the offset data generating unit corrects the offset data such that the accumulation time of the offset data agrees with that
of the object image.
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