Sensor characterization in memory

• US 6,320,934 B1
• Filed: 03/19/2001
• Issued: 11/20/2001
• Est. Priority Date: 06/26/2000
• Status: Expired due to Term

• Current Assignee: Blackstone Holdings L.L.C.
• Original Assignee: AFP Imaging Corporation (Biowave Innovations LLC)
• Inventors: Johnson, James, Carroll, Seamus
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): Kiknadze, Irakli
• Application Number:
  US09/812,008
• Time in Patent Office: 246 Days
• Field of Search: 378/98.8, 378/98.12, 378/98.7, 378/97, 378/98
• US Class Current: 378/98.8
• CPC Class Codes: A61B 6/51 for dentistry
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• 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 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

An X-ray image sensor comprising an array of sensor elements and a sensor characterization storage device is provided. The sensor characterization storage device stores sensor characterization information identifying defects in the array of sensor elements. The X-ray image sensor may have an intergrated interpolator, and the interpolator processes image data from the array of sensor elements by using the sensor characterization information to correct for the defects in the array of sensor elements. An X-ray imaging system comprising the X-ray image sensor and a computer also is provided. The X-ray image sensor provides to the computer a signal corresponding to image data from the array of sensor elements. The X-ray image sensor provides to the computer the sensor characterization information, and the computer processes the image data using the sensor characterization information to correct for the defects in the array of sensor elements.

Claims

1. An X-ray image sensor comprising:

an array of sensor elements; and

a sensor characterization storage device integrated in the X-ray image sensor,

wherein the sensor characterization storage device stores sensor characterization information identifying defects in the array of sensor elements.

2. The X-ray image sensor of claim 1, wherein the sensor characterization information includes a list of sensor elements corresponding to dead pixels or otherwise non-typical response pixels, rows or columns.

3. The X-ray image sensor of claim 1 further comprising an interpolator, wherein the interpolator retrieves the sensor characterization information from the sensor characterization storage device, receives a signal corresponding to image data read out from the array of sensor elements, and processes the image data using the sensor characterization information to correct for the defects in the array of sensor elements.

4. The X-ray image sensor of claim 3, wherein the interpolator replaces data from a sensor element identified in the sensor characterization information as corresponding to a dead pixel by interpolating data from sensor elements corresponding to live pixels surrounding the dead pixel.

5. The X-ray image sensor of claim 4, wherein the array of sensor elements have non-destructive readout.

6. The X-ray image sensor of claim 5, wherein the interpolator uses the sensor characterization information to identify the sensor elements corresponding to live pixels surrounding the dead pixel, and reads out the data from said sensor elements.

7. The X-ray image sensor of claim 1 further comprising a processing section having a defect determination module, wherein the defect determination module periodically determines the defects in the array of sensor elements by analyzing image data read out from the array of sensor elements, and the processing section, based on the defects information determined by the defect determination module, performs at least one of the following:

(a) generates new sensor characterization information and replace the sensor characterization information in the sensor characterization storage device with the new sensor characterization information;

(b) notifies at least one of a user and a controlling device; and

(c) shuts down the sensor.

8. The X-ray image sensor of claim 1, wherein the X-ray image sensor provides to a computing device the sensor characterization information and provides to the computing device a signal corresponding to image data read out from the array of sensor elements, and the computing device processes the image data using the sensor characterization information to correct for the defects in the array of sensor elements.

9. The X-ray image sensor of claim 8, wherein the computing device replaces data from a sensor element identified in the sensor characterization information as corresponding to a dead pixel by interpolating data from sensor elements corresponding to live pixels surrounding the dead pixel.

10. The X-ray image sensor of claim 9 further comprising a processing section having a defect determination module, wherein the defect determination module under command from the computing device uses the image data read out from the array of sensor elements to determine the defects in the array of sensor elements, and the processing section uses the defects information determined by the defect determination module to generate new sensor characterization information and replaces the sensor characterization information in the sensor characterization storage device with the new sensor characterization information.

11. The X-ray image sensor of claim 1, wherein the sensor including the sensor characterization storage device is integrated in an IC chip.

12. An X-ray imaging system comprising:

an X-ray image sensor having an integrated sensor characterization storage device, wherein the sensor characterization storage device stores sensor characterization information identifying defects in an array of sensor elements in the X-ray image sensor; and

a computer,

wherein the X-ray image sensor provides to the computer a signal corresponding to image data from the array of sensor elements.

13. The X-ray imaging system of claim 12, wherein the sensor characterization information includes a list of sensor elements corresponding to dead pixels.

14. The X-ray imaging system of claim 12, wherein the computer retrieves the sensor characterization information from the X-ray image sensor, and processes the image data from the array of sensor elements using the sensor characterization information to correct for the defects in the array of sensor elements.

15. The X-ray imaging system of claim 14, wherein the computer replaces data from a sensor element identified in the sensor characterization information as corresponding to a dead pixel by interpolating data from sensor elements corresponding to live pixels surrounding the dead pixel.

16. The X-ray imaging system of claim 12, wherein

the X-ray image sensor further comprises a processing section,

the computer generates new sensor characterization information by analyzing the image data read out from the array of sensor elements to determine the defects in the array of sensor elements, and communicates the new sensor characterization information to the processing section in the X-ray image sensor, and

the processing section replaces the sensor characterization information in the sensor characterization storage device with the new sensor characterization information from the computer.

17. The X-ray imaging system of claim 12, wherein

the X-ray image sensor further comprises a processing section having a defect determination module,

the defect determination module under command from the computer uses the image data read out from the array of sensor elements to determine the defects in the array of sensor elements, and

the processing section uses the defects information determined by the defect determination module to generate new sensor characterization information and replaces the sensor characterization information in the sensor characterization storage device with the new sensor characterization information.

18. The X-ray imaging system of claim 12, wherein an interpolator in the X-ray image sensor retrieves the sensor characterization information from the sensor characterization storage device, and processes the image data read out from the array of sensor elements using the sensor characterization information to correct for the defects in the array of sensor elements to provide a signal corresponding to adjusted image data.

19. The X-ray imaging system of claim 18, wherein the interpolator replaces data from a sensor element identified in the sensor characterization information as corresponding to a dead pixel by interpolating data from sensor elements corresponding to live pixels surrounding the dead pixel.

20. The X-ray imaging system of claim 19, wherein the array of sensor elements have non-destructive readout.

21. The X-ray imaging system of claim 20, wherein the interpolator uses the sensor characterization information to identify the sensor elements corresponding to live pixels surrounding the dead pixel, and reads out the data from said sensor elements.

22. The X-ray imaging system of claim 12, wherein the X-ray image sensor including the integrated sensor characterization storage device is integrated in an IC chip.