Image pick-up apparatus and image pick-up system

• US 7,138,639 B2
• Filed: 11/04/2005
• Issued: 11/21/2006
• Est. Priority Date: 07/30/2001
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kameshima, Toshio
• Primary Examiner(s): Gabor, Otilia
• Application Number:
  US11/266,297
• Publication Number:
  US 20060054834A1
• Time in Patent Office: 382 Days
• Field of Search: 250/370.11, 250/363.07, 250/252.1, 250/363.09, 250/369, 348/227.1, 348/372
• US Class Current: 250/370.11
• CPC Class Codes: G01T 1/20184 Detector read-out circuitry, e.g. for clearing of traps, compensating for traps or compensating for direct hits
• CPC Class Codes: G01T 1/24 with semiconductor detectors
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14676 X-ray, gamma-ray or corpuscular radiation imagers measuring X-, gamma- or corpuscular radiation G01T1/00
• CPC Class Codes: H04N 25/617 for reducing electromagnetic interference, e.g. clocking noise
• CPC Class Codes: H04N 25/677 for reducing the column or line fixed pattern noise
• CPC Class Codes: H04N 25/745 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• 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 image pick-up apparatus comprising an area sensor in which detecting elements are two-dimensionally arranged on a substrate, and a reference supply circuit, for supplying a reference voltage to the detecting elements, which comprises a regulator for regulating the reference voltage. A low-pass filter is arranged between the regulator and the detecting elements. The reference voltage is supplied through the low-pass filter from the reference supply circuit.

Claims

1. An image pick-up apparatus comprising:

an area sensor in which detecting elements are two-dimensionally arranged on a substrate;

a reference supply circuit, for supplying a sensor bias voltage to the detecting elements of the area sensor, which comprises a regulator for regulating the sensor bias voltage; and

a low-pass filter arranged between said regulator and said detecting elements, wherein the sensor bias voltage is supplied through said low-pass filter from said reference supply circuit.

2. The image pick-up apparatus according to claim 1, wherein a cutoff frequency of said low-pass filter is determined according to required response time for the sensor bias voltage.

3. The image pick-up apparatus according to claim 1, wherein a cutoff frequency of said low-pass filter is lower than a sampling frequency of a sample hold circuit coupled to said area sensor.

4. The image pick-up apparatus according to claim 1, wherein an amplifier is placed on the output side of said low-pass filter.

5. The image pick-up apparatus according to claim 4, wherein a noise density of said amplifier is less than 3.3 nV/√

Hz.

6. The image pick-up apparatus according to claim 1, wherein said area sensor comprises a two-dimensional array of pixels, each consisting of a detecting device and a switching device, wherein said detecting device is a photoelectric conversion device and said switching device is a TFT, and wherein said photoelectric conversion element is coupled to a drain electrode of said TFT, a gate electrode of said TFT to common a gate line, a source electrode of said TFT to a common data line, said common data line to a read device, and said common gate line to a gate drive device, thereby implementing a matrix operation.

7. The image pick-up apparatus according to claim 6, wherein said read device has an amplifier coupled to said common data line and is capable of reset operation, and wherein an amplifier reset voltage of said amplifier is supplied thereto from said reference supply circuit.

8. The image pick-up apparatus according to claim 6, wherein a TFT on voltage and a TFT off voltage as a reference voltage of said TFT are supplied to said gate drive device from said reference supply circuit.

9. The image pick-up apparatus according to claim 6, wherein a bias voltage for applying the sensor bias voltage to said photoelectric conversion element, is supplied to said area sensor.

10. The image pick-up apparatus according to claim 6, wherein said photoelectric conversion element and TFT are made of amorphous silicon or polysilicon.

11. The image pick-up apparatus according to claim 6, wherein said photoelectric conversion element is a pin photodiode or MIS sensor.

12. The image pick-up apparatus according to claim 6, wherein said area sensor is an X-ray area sensor further comprising a phosphor.

13. The image pick-up apparatus according to claim 1, wherein said substrate is an insulating substrate and said reference supply circuit and LPF are formed on a crystalline substrate.

14. An image pick-up system comprising the image pick-up apparatus as set forth in claim 1, image processing means for processing a signal from said image pick-up apparatus into an image, recording means for recording a signal from said image processing means, display means for displaying a signal from said image processing means, and transmitting means for transmitting a signal from said image processing means.

15. The image pick-up system according to claim 14, further comprising a wavelength conversion element for converting radiation into wavelengths in a sensitive region of said sensor elements.

16. An image pick-up apparatus comprising:

an area sensor in which detecting elements are two-dimensionally arranged on a substrate;

a read device for reading a signal from said detecting elements, which comprises an amplifier for amplifying the signal;

a reference supply circuit, for supplying a reference voltage to the amplifier and for supplying a sensor bias voltage to the detecting elements of the area sensor, which comprises a regulator for regulating the reference voltage; and

a low-pass filter arranged between said regulator and said amplifier and arranged between said regulator and the detecting elements, wherein the reference voltage and the sensor bias voltage are supplied through said low-pass filter from said reference supply circuit.

17. An image pick-up apparatus comprising:

an area sensor in which detecting elements are two-dimensionally arranged on a substrate;

a read device for reading a signal from said detecting elements, which comprises an amplifier for amplifying the signal;

a reference supply circuit, for supplying a sensor bias voltage to said detecting elements of the area sensor and for supplying a reference voltage to said amplifier, which comprises a first regulator for regulating the sensor bias voltage and a second regulator for regulating the reference voltage;

a first low-pass filter arranged between said first regulator and said detecting elements, wherein the sensor bias voltage is supplied through said low-pass filter from said reference supply circuit; and

a second low-pass filter arranged between said second regulator and said amplifier, wherein said reference voltage is supplied through said second low-pass filter from said reference supply circuit.

18. An image pick-up apparatus comprising;

an area sensor in which detecting elements are two-dimensionally arranged on a substrate;

a reference supply circuit, for supplying a reference voltage to the detecting elements of the area sensor, which comprises a regulator for regulating the reference voltage; and

a low-pass filter arranged between the regulator and the detecting elements, wherein the reference voltage is supplied through the low-pass filter from the reference supply circuit, and the low-pass filter has a cutoff frequency set to be 3 to 10 times the frame rate of the area sensor.