Radiation detecting apparatus and radiation imaging system

• US 8,680,472 B2
• Filed: 07/18/2008
• Issued: 03/25/2014
• Est. Priority Date: 07/19/2007
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mochizuki, Chiori, Watanabe, Minoru, Ishii, Takamasa
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): VU, MINDY D
• Application Number:
  US12/596,493
• Publication Number:
  US 20100294942A1
• Time in Patent Office: 2,076 Days
• Field of Search: 250/370.09, 250/370.11
• US Class Current: 250/370.09
• CPC Class Codes: G01T 1/2928 using solid state detectors
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• 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 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14658 X-ray, gamma-ray or corpuscular radiation imagers measuring X-, gamma- or corpuscular radiation G01T1/00
• CPC Class Codes: H01L 27/14663 Indirect radiation imagers, e.g. using luminescent members
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon
• CPC Class Codes: H04N 25/42 by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode
• CPC Class Codes: H04N 25/60 Noise processing, e.g. detecting, correcting, reducing or removing noise
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/673 by using reference sources
• CPC Class Codes: H04N 25/677 for reducing the column or line fixed pattern noise
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself
• 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

A radiation detecting apparatus capable of obtaining good images including decreased noise includes a plurality of pixels, each having a photoelectric conversion element for converting incident radiation into an electric signal and a first switch element, connected to the photoelectric conversion element, and a second switch element, not connected to the conversion element. A first signal line, a second signal line and a drive line are provided, where the first switch element has a first main electrode connected electrically to the first signal line, a second main electrode connected electrically to the photoelectric conversion element, and a gate electrode connected electrically to the drive line, and the second switch element has a first main electrode connected to the second signal line and a gate electrode connected electrically to the drive wiring common to the first switch element, and a differential means for outputting a signal corresponding to a difference between outputs from the first and second switch elements.

Claims

1. A radiation detecting apparatus comprising:

a plurality of pixels arranged in a matrix, each pixel having a conversion element for converting incident radiation into an electric signal, a first switch element having a gate electrode, a first main electrode, and a second main electrode connected to said conversion element, and a second switch element having a gate electrode, and a semiconductor layer having a channel portion arranged between a first region and a second region, wherein said conversion element is arranged to cover said first and second switch elements;

a first signal line electrically connected to said first main electrode of said first switch element of each pixel in a pixel column;

a second signal line electrically connected to said first region of said second switch element of each pixel in said pixel column;

a drive wiring electrically connected to said gate electrode of said first switch element and said gate electrode of said second switch element of each pixel in a pixel row; and

a differential means electrically connected to said first signal line and said second signal line for outputting a signal corresponding to a difference between outputs from said first and second switch elements,

wherein said second region of said second switch element of each pixel is left floating by omission of electrical connection to said second region or electrically connected to a wiring to which a fixed potential is supplied.

2. The radiation detecting apparatus according to claim 1, wherein the radiation is light, said conversion element is a photoelectric conversion element converting incident light into an electric signal, and

further comprising a scintillator disposed on said photoelectric conversion element of each pixel.

3. A radiation imaging system comprising:

a radiation detecting apparatus according to claim 1; and

a signal processing unit for processing a signal from the radiation detecting apparatus.

4. A radiation detecting apparatus comprising:

a plurality of pixels arranged in a matrix, each pixel having a conversion element for converting incident radiation into an electric signal, a first switch element having a gate electrode, a first main electrode, and a second main electrode connected to said conversion element, and a second switch element having a gate electrode, and a semiconductor layer having a channel portion arranged between a first region and a second region;

a first signal line electrically connected to said first main electrode of said first switch element of each pixel in a pixel column;

a second signal line electrically connected to said first region of said second switch element of each pixel in said pixel column;

a drive wiring electrically connected to said gate electrode of said first switch element and said gate electrode of said second switch element of each pixel in a pixel row; and

a differential means electrically connected to said first signal line and said second signal line for outputting a signal corresponding to a difference between outputs from said first and second switch elements,

wherein said second region of said second switch element of each pixel is electrically connected to a wiring to which a fixed potential is supplied.

5. The radiation detecting apparatus according to claim 4, wherein the radiation is light, said conversion element is a photoelectric conversion element converting incident light into an electric signal, and

further comprising a scintillator disposed on said photoelectric conversion element of each pixel.

6. A radiation imaging system comprising:

a radiation detecting apparatus according to claim 4; and

a signal processing unit for processing a signal from said radiation detecting apparatus.