TRIGGERING OF INTRAORAL X-RAY SENSOR USING PIXEL ARRAY SUB-SAMPLING

• US 20110013746A1
• Filed: 06/08/2010
• Published: 01/20/2011
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: Dental Imaging Technologies Corporation (Envista Holdings Corporation)
• Original Assignee: Imaging Sciences International LLC
• Inventors: Zeller, Uwe, Golay, Doug
• Granted Patent: US 9,492,129 B2
• Time in Patent Office: Days
• US Class Current: 378/98
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/512 Intraoral means
• CPC Class Codes: A61B 6/5205 involving processing of raw data to produce diagnostic data
• CPC Class Codes: A61B 6/545 involving automatic set-up of acquisition parameters
• CPC Class Codes: H04N 25/63 applied to dark current
• 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

Automatic triggering of an intraoral x-ray sensor used in a dental x-ray imaging system. The intraoral sensor has an array of pixels. The array of pixels has a plurality of lines of pixels, and each of the pixels generates an electrical signal correlated to x-ray radiation that impinges that pixel. An electronic control unit is connected to the intraoral sensor to receive electric signals from the array of pixels. The electronic control unit destructively reads pixel clusters in one or more of the plurality of lines of pixels, each of the pixel clusters located at a perimeter of the array of pixels. The electronic control unit is configured to generate a dose-correlated signal based on the signals from each of the pixel clusters in each of the one or more lines of pixels and initiate capture of an image generated with information from each of the pixels in the array of pixels, when the combined signal exceeds a predetermined threshold.

Claims

1. An intraoral x-ray system comprising:

an intraoral sensor having an array of pixels, the array of pixels having a plurality of clusters of pixels located at a perimeter of the array of pixels, each of the pixels generating an electrical signal correlated to x-ray radiation that impinges that pixel; and

an electronic control unit connected to the intraoral sensor to receive electric signals from the array of pixels, the electronic control unit destructively reading each pixel clusters one-at-a-time, the electronic control unit configured to generate a dose-correlated signal based on the signals from the pixel clusters and initiate capture of an image generated with information from each of the pixels in the array of pixels, when the dose-correlated signal exceeds a predetermined threshold.

2. The x-ray system of claim 1, wherein the electronic control unit performs pixel integration.

3. The x-ray system of claim 2, wherein the pixel integration is performed within a predetermined amount of time and each of the one or more pixels clusters are read at a fraction of the predetermined amount of time.

4. The x-ray system of claim 2, wherein the electronic control unit correlates signals from the pixels on a pixel-to-pixel basis prior to pixel integration.

5. The x-ray system of claim 1, wherein the electronic control unit carries out a rolling-shutter mode scanning of pixel clusters located at the perimeter of the array of pixels.

6. The x-ray system of claim 5, wherein the electronic control unit performs pixel integration.

7. The x-ray system of claim 6, wherein the pixel integration is performed within a predetermined amount of time and each of the one or more pixels clusters are read at a fraction of the predetermined amount of time.

8. The x-ray system of claim 6, wherein the electronic control unit correlates signals from the pixels on a pixel-to-pixel basis prior to pixel integration.

9. The x-ray system of claim 1, wherein the pixel clusters include first pixel clusters and second pixel clusters, and wherein each first pixel cluster includes a predetermined number of pixels on a left-hand side of the array of pixels in a single line of pixels and each second pixel cluster includes a predetermined number of pixels on a right-hand side of the array of pixels in a single line of pixels.

10. The x-ray system of claim 1, wherein the electronic control unit performs at least one of two types of signal conditioning, double sampling and correlated double sampling.

11. The x-ray system of claim 1, wherein the predetermined threshold is an empirical threshold.

12. The x-ray system of claim 1, wherein the predetermined threshold is determined using an adaptive technique.

13. A method of automatically triggering an intraoral x-ray sensor to capture an image, the intraoral sensor having and array of pixels, the array of pixels having a plurality of pixel clusters, the method comprising:

directing x-ray radiation toward the intraoral sensor

when x-ray radiation impinges a pixel in the array of pixels, generating an electrical signal correlated to the x-ray radiation that impinges the pixel;

processing electrical signals generated by one or more pixels in the array of pixels in an electronic control unit by destructively reading pixel clusters, wherein each of the pixel clusters is read consecutively and each is located at a perimeter of the array of pixels;

generating a combined signal based on the signals from each of the pixel clusters; and

when the combined signal exceeds a predetermined threshold, initiating capture of an image generated with information from each of the pixels in the array of pixels.

14. The method of claim 13, further comprising integrating values from pixels in the pixel clusters.

15. The method of claim 13, further comprising reading pixel clusters located at the perimeter of the array of pixels in a rolling-shutter mode.

16. The method of claim 15, further comprising integrating values from pixels in the pixel clusters.

17. The method of claim 16, further comprising performing pixel integration within a predetermined amount of time and reading each of the pixel clusters at a fraction of the predetermined amount of time.

18. The method of claim 16, further comprising correlating signals from the pixels on a pixel-to-pixel basis prior to pixel integration.

19. The method of claim 13, wherein the pixel clusters include first pixel clusters and second pixel clusters, and wherein each first pixel cluster includes a predetermined number of pixels on a left-hand side of the array of pixels in a single line of pixels and each second pixel cluster includes a predetermined number of pixels on a right-hand side of the array of pixels in a single line of pixels.

20. The method of claim 13, wherein the pixel clusters include first pixel clusters and second pixel clusters, and wherein each first pixel cluster includes a predetermined number of pixels on a left-hand side of the array of pixels in two or more lines of pixels and each second pixel cluster includes a predetermined number of pixels on a right-hand side of the array of pixels in a two or more lines of pixels.

21. The method of claim 13, further comprising performing at least one of two types of signal conditioning, double sampling and correlated double sampling.

22. The method of claim 13, further comprising determining the predetermined threshold based on empirical information.

23. The method of claim 13, further comprising determining the predetermined threshold using an adaptive technique.

24. An intraoral x-ray system comprising:

an array of pixels including a perimeter, wherein each pixel generates an electrical signal correlated to x-ray radiation that impinges that pixel;

wherein the array of pixels includes a plurality of pixel clusters including at least a first cluster and a second cluster at a first side of the perimeter, and a third cluster and a fourth cluster at a second side of the perimeter, wherein the second side of the perimeter is opposite of the first side of the perimeter;

a processor coupled to the array of pixels;

cluster select lines that are selectively enabled to couple the processor to the first cluster, the second cluster, the third cluster, and the fourth cluster to enable the processor to

destructively read the first cluster, the second cluster, the third cluster, and the fourth cluster one-at-a-time, and

determine an amount of electrical signal generated by each of the first cluster, the second cluster, the third cluster, and the fourth cluster when destructively read;

wherein the processor reads the array of pixels if the processor determines the amount of electrical signal generated crosses a threshold.