Image pick-up apparatus and image pick-up system

• US 20060054834A1
• Filed: 11/04/2005
• Published: 03/16/2006
• Est. Priority Date: 07/30/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kameshima, Toshio
• Granted Patent: US 7,138,639 B2
• Time in Patent Office: Days
• US Class Current: 250/370.110
• 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 and an image pick-up system constructed to prevent occurrence of random noise in a photographed image due to a random noise component produced in a reference supply circuit. An image pick-up apparatus has an area sensor driven by matrix driving, and a reference supply circuit for supplying a reference voltage for driving of the area sensor, and the reference voltage is supplied through a low-pass filter (LPF) coupled to the reference supply circuit. Further, a cutoff frequency of the low-pass filter is preferably determined so that an effective value of noise of the reference voltage having passed through the low-pass filter becomes not more than one-tenth of an effective value of random noise produced in pixels of the area sensor.

Claims

1-18. -18. (canceled)

19. 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, which comprises a regulator for regulating the reference voltage; and

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

20. The image pick-up apparatus according to claim 19, wherein a cutoff frequency of said low-pass filter is determined according to required response time for the reference voltage.

21. The image pick-up apparatus according to claim 19, 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.

22. The image pick-up apparatus according to claim 19, wherein an amplifier is placed on the output side of said low-pass filter.

23. The image pick-up apparatus according to claim 22, wherein a noise density of said amplifier is less than 3.3 nV/√

{square root over (Hz)}.

24. The image pick-up apparatus according to claim 19, 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.

25. The image pick-up apparatus according to claim 24, 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 as a reference voltage of said amplifier is supplied thereto from said reference supply circuit.

26. The image pick-up apparatus according to claim 24, 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.

27. The image pick-up apparatus according to claim 24, wherein a bias voltage for applying a bias voltage to said photoelectric conversion element, as said reference voltage, is supplied to said area sensor.

28. The image pick-up apparatus according to claim 24, wherein said photoelectric conversion element and TFT are made of amorphous silicon or polysilicon.

29. The image pick-up apparatus according to claim 24, wherein said photoelectric conversion element is a pin photodiode or MIS sensor.

30. The image pick-up apparatus according to claim 24, wherein said area sensor is an X-ray area sensor further comprising a phosphor.

31. The image pick-up apparatus according to claim 19, wherein said substrate is an insulating substrate and said reference supply circuit and LPF are formed on a crystalline substrate.

32. An image pick-up system comprising the image pick-up apparatus as set forth in claim 19, 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.

33. The image pick-up system according to claim 32, further comprising a wavelength conversion element for converting radiation into wavelengths in a sensitive region of said sensor elements.

34. 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, which comprises a regulator for regulating the reference voltage; and

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

35. 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 first reference voltage to said detecting elements and for supplying a second reference voltage to said amplifier, which comprises a first regulator for regulating the first reference 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 first reference 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 second reference voltage is supplied through said second low-pass filter from said reference supply circuit.