RADIATION DETECTING APPARATUS AND RADIATION IMAGING SYSTEM

• US 20100294942A1
• Filed: 07/18/2008
• Published: 11/25/2010
• Est. Priority Date: 07/19/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mochizuki, Chiori, Ishii, Takamasa, Watanabe, Minoru
• Granted Patent: US 8,680,472 B2
• Time in Patent Office: Days
• US Class Current: 250/366
• 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 noises includes a plurality of pixels, each having a photoelectric conversion element for converting an incident radiation into an electric signal and a a first switch element connected to the photoelectric conversion element and a second switch element being not connected to the conversion element; a first signal line; a second signal line; and a drive line, wherein 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, 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, each having a conversion element for converting an incident radiation into en electric signal, a first switch element connected to the conversion element and a second switch element being not connected to the conversion element;

a first signal line;

a second signal line; and

a drive wiring, wherein

the first switch element has a first main electrode connected electrically to the first signal line, a second main electrode connected electrically to the conversion element and a gate electrode connected electrically to the drive wiring,

the second switch element has a first main electrode connected electrically 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.

2. The radiation detecting apparatus according to claim 1, wherein

the conversion element is arranged to cover the f first and second switch elements.

3. The radiation detecting apparatus according to claim 1, further comprising

a reference voltage wiring, wherein the second switch element has a second main electrode connected electrically to the reference voltage wiring.

4. The radiation detecting apparatus according to claim 1, wherein

each of the pixels comprises further a dummy conversion element, and the second switch element has a second main electrode connected electrically to the dummy conversion element.

5. The radiation detecting apparatus according to claim 4, wherein

the dummy conversion element is shielded from light for detecting a dark output.

6. The radiation detecting apparatus according to claim 1, further comprising

a third switch element for resetting the conversion element, wherein the third switch element is connected electrically to the conversion element.

7. The radiation detecting apparatus according to claim 1, wherein

the radiation is light, the conversion element is a photoelectric conversion element converting an incident light into an electric signal, and

on the photoelectric conversion element, a scintillator is disposed.

8. The radiation detecting apparatus according to claim 1, further comprising

a differential unit for differentiation between the signal outputted from the first signal line and the signal outputted from the second signal line, wherein the differential unit is electrically connected to a radiation detecting substrate.

11. A radiation imaging system comprising:

a radiation detecting apparatus according to any one of claims 1 to 6; and

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

9. A radiation detecting substrate comprising:

a plurality of pixels, each having a conversion element for converting an incident radiation into en electric signal, a first switch element connected to the conversion element and a second switch element being not connected to the conversion element;

a drive wiring electrically connected to control electrodes of the first and second switch elements of each pixel in a pixel row of plural pixels arranged in one direction;

a first signal line electrically connected to a first main electrode of the first switch element of each pixel in a pixel column of plural pixels arranged in the other direction; and

a second signal line electrically connected to a first main electrode of the second switch element of the each pixel in the pixel column, wherein

the first switch element has a second main electrode connected electrically to the conversion element,

the second switch element has a first main electrode connected electrically to the second signal line and a gate electrode connected electrically to the drive wiring common to the first switch element, and

when the first and second switch elements of the pixel row are at an on state, the electric signal is outputted to the first signal line of the pixel column and a noise signal is outputted to the second signal line of the of the pixel column.

10. The radiation detecting apparatus comprising:

a radiation detecting substrate according to claim 9; and

a differential unit for differentiation between the electric signal outputted from the first signal line and the noise outputted from the second signal line, wherein the differential unit is electrically connected to the radiation detecting substrate.