Image sensing apparatus and image sensing method, X-ray photographing system and its control method

• US 20020186813A1
• Filed: 05/02/2002
• Published: 12/12/2002
• Est. Priority Date: 05/08/2001
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tsuchiya, Keiji, Tamura, Toshikazu
• Application Number:
  US10/139,677
• Publication Number:
  US 20020186813A1
• Time in Patent Office: Days
• US Class Current: 378/98.8
• CPC Class Codes: H04N 25/626 Reduction of noise due to residual charges remaining after image readout, e.g. to remove ghost images or afterimages
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/671 for non-uniformity detection or correction
• CPC Class Codes: H04N 25/68 applied to defects
• CPC Class Codes: H04N 5/321 with video transmission of fluoroscopic images

Abstract

Since the duration of an idling drive period is not defined (not specified) in practical use, T1 is set to be longer than that in a normal photographing operation to make idling-dedicated idle read frames Fi in which the ON time of a TFT (82) is shorter than the normal read drive frame, so as to minimize read operations that impose a heavy load on a photodetector array (58) (especially, the TFT (82)).

Claims

1. An image sensing apparatus comprising:

an image sensing region for sensing an object image; and

a drive circuit for resetting said image sensing region at a first time interval during a first period before an image sensing operation, and for resetting said image sensing region at a second time interval during a second period prior to the first period,

wherein the first time interval is different from the second time interval.

2. The apparatus according to claim 1, wherein the second time interval is longer than the first time interval.

5. The apparatus according to claim 1, wherein said image sensing apparatus senses the object image by radiation exposure, and the first period is generated in response to a radiation exposure request before the radiation exposure.

7. The apparatus according to claim 1, wherein said image sensing apparatus senses the object image by radiation exposure, and further comprises a control circuit which controls to start radiation exposure upon completion of the reset operation when a radiation exposure request before the radiation exposure is received during the reset operation.

9. The apparatus according to claim 1, wherein said drive means reads an image charge signal in a predetermined column direction, and drives for each predetermined row at a predetermined period.

12. A computer-readable storage medium that stores a program for making a computer function as means which form an image sensing apparatus cited in claim 1.

14. A program for making a computer function as means which form an image sensing apparatus cited in claim 1.

3. An image sensing apparatus comprising:

an image sensing region for sensing an object image; and

a drive circuit for resetting said image sensing region at a predetermined interval during a first time period before an image sensing operation, and for resetting said image sensing region at a predetermined interval during a second time period prior to the first time period,

wherein the first time period is different from the second time period.

4. The apparatus according to claim 3, wherein the second time period is shorter than the first time period.

6. The apparatus according to claim 3, wherein said image sensing apparatus senses the object image by radiation exposure, and the first time period starts in response to a radiation exposure request before the radiation exposure.

8. The apparatus according to claim 3, wherein said image sensing apparatus senses the object image by radiation exposure, and further comprises a control circuit which controls to start radiation exposure upon completion of the reset operation when a radiation exposure request before the radiation exposure is received during the reset operation.

10. An image sensing method comprising the step of:

resetting an image sensing region used to sense an object image at a first time interval during a first period before an image sensing operation, and resetting the image sensing region at a second time interval during a second period prior to the first period,

wherein the first time interval is different from the second time interval.

13. A computer-readable storage medium that stores a program for making a computer execute the processing step of an image sensing method cited in claim 10.

15. A program for making a computer execute the processing step of an image sensing method cited in claim 10.

11. An image sensing method comprising the step of:

resetting an image sensing region used to sense an object image at a predetermined interval during a first time period before an image sensing operation, and resetting the image sensing region at a predetermined interval during a second time period prior to the first time period,

wherein the first time period is different from the second time period.

20. A program code for making an information processing apparatus execute a method of controlling a radiography system cited in claim 18 when said program code is loaded by said information processing apparatus.

21. A computer-readable storage medium which stores a program code cited in claim 20.

16. A radiography system which comprises a detector for detecting radiation generated by a radiation generation device, and a detector controller for initializing said detector at a predetermined timing, and controlling said detector, and takes a radiation image on the basis of the radiation detected by said detector,

wherein said detector controller comprises:

storage means for acquiring and storing a time period from when initialization of said detector starts until a radiation irradiation request signal is received; and

instruction means for, when the radiation irradiation request signal is received during an initialization process of said detector, instructing to execute a wait process for the stored time period after the initialization process, and

upon completion of the wait process by said instruction means, a radiography permission signal is sent to said radiation generation device.

17. A radiography system which comprises a detector for detecting radiation generated by a radiation generation device, and a detector controller for initializing said detector at a predetermined timing, and controlling said detector, and takes a radiation image on the basis of the radiation detected by said detector,

wherein when a radiation irradiation request signal is received during an initialization process of said detector, said detector controller sends a radiography permission signal to said radiation generation device after completion of the initialization process.

18. A method of controlling a radiography system which comprises a detector for detecting radiation generated by a radiation generation device, and a detector controller for initializing said detector at a predetermined timing, and controlling said detector, and takes a radiation image on the basis of the radiation detected by said detector,

wherein said detector controller acquires and stores a time period from when initialization of said detector starts until a radiation irradiation request signal is received,

when said detector controller receives the radiation irradiation request signal during an initialization process of said detector, said detector controller instructs to execute a wait process for the stored time period after the initialization process, and

said detector controller sends a radiography permission signal to said radiation generation device upon completion of the wait process based on the instruction.

19. A method of controlling a radiography system which comprises a detector for detecting radiation generated by a radiation generation device, and a detector controller for initializing said detector at a predetermined timing, and controlling said detector, and takes a radiation image on the basis of the radiation detected by said detector,

wherein when a radiation irradiation request signal is received during an initialization process of said detector, said detector controller sends a radiography permission signal to said radiation generation device after completion of the initialization process.