E2v Technologies (uk) Limited

General Electric Company

Raymond Thomas Bell

Peter James Pool

Ian Moody

Roger John Pittock

Mark Stanford Robbins

Kevin Anthony Derek Hadfield

David J Burt

Christopher J Morcom

A detector for determining the location of a pulsed laser spot reflected from a scene, which comprises a CCD sensor for imaging the scene comprising an array of pixels arranged in rows (R, R, R) and columns (C, C, C), a serial read-out register arrangement (not shown), and charge transfer electrodes (&#xd8;H, &#xd8;V, &#xd8;) capable of transferring signal charge in at least two adjacent pixels to read-out register arrangement locations representative of the row location of at least one of the adjacent pixels and the column location of at least one other of the adjacent pixels. The charge transfer electrodes are two phase, but three or more phase arrangements are also possible.

Detector for determining the location of a laser spot

A CCD sensor has a shutter to prevent frame shift smear during transfer of an image from the image region to a store region. The CCD sensor has an extended dynamic range, because each integration is in two parts, the second part of which has a different sensitivity than the first part. In order to avoid an asymmetry in the uncovering and covering of the image region, a two-bladed shutter is used.

Shutter for CCD imager

A CCD such as a frame transfer CCD has an extended dynamic range. The image built up in the image regionin each integration period is transferred to the store regionin each frame transfer period, for example, at a TV signal rate. The dynamic range is increased by dividing the integration period into two parts, and clipping the signal in the first part, but not in the second. The signal is clipped by pulsing the clock electrodes of the image region so as to combine the charges from adjacent wells together, overspill being drained into the anti-blooming structure, consequently reducing well capacity.

CCD imaging array with extended dynamic range

A system for time resolved spectroscopy comprises a CCD device arranged to receive a time varying spectrum. Time resolved spectroscopy is the analysis of a spectrum that varies with time due to any cause. The variation with time of the spectrum may be due, for example, to (i) changes of the spectrum from a given sample space with time (such as due to emission decay); and (ii) changes in the spectrum as successive portions of a sample space are sampled (such as laser scanning microscopy). The CCD device comprises an array of photosites arranged to detect the time varying spectrum and to produce signal charge representative of the spectrum, and one or more CCD multiplication registers arranged to receive the signal charge and to provide charge multiplication. An enhancement of speed and sensitivity is given by a storage area which receives the signal charge in parallel from the array of photosites to provide the charge in serial to the one or more multiplication registers.

System and method for time resolved spectroscopy

A radiation sensorincludes an array of imaging pixelselectrically connectable to a readout port. At least one first peripheral row of trigger pixelsis located at a first edge of the array, the trigger pixels also being electrically connectable to the readout port but responding faster to x-rays than the imaging pixels. At least one second peripheral row of trigger pixelsmay be located at a second edge of the array opposed to the first edge. Trigger pixelsfrom the first and second peripheral rows may be addressable alternately in a predetermined pattern to detect a radiation signal for triggering the sensor. Various methods of clocking the sensor are also described. The sensor has particular applicability to intra-oral x-ray imaging.

Sensor with trigger pixels for imaging of pulsed radiation

Effective sensitivity of a photodetector of an image sensor is controlled by partitioning signal charge from incident photons, thus producing a manageable yield and a consequently higher, photon shot noise limited, signal to noise ratio than in the prior art, when imaging high flux rates of energetic photons or particles, such as produced by x-ray generators. The invention may be applied, for example, to an image sensor with a photosensitive layer coupled to a charge collection/readout structure, e.g. photoconductor or scintillator on CMOS array, or to an intrinsically sensitive charge collection/readout structure, e.g. deep active layer CMOS. A radiation sensor pixel structurefor use in the invention includes a photodetector, a transfer gatefor controlling charge collection from the photodetector and a dump draincontrolled by a dump gate, arranged for selectively dumping charge to the dump drain means and collecting charge from the photodetector means, in a duty cycle, for varying effective sensitivity of the pixel structure. An image sensor containing such pixel structures may selectively be operated in an integration mode or a photon counting mode. Preferably the image sensor has imaging pixels and control circuitry arranged on a same semiconductor die, such as a CMOS semiconductor die.

Image sensor

An energy selective radiation sensor has a photodetector and a transfer gate for controlling transfer of charge from the photodetector to a first sense node. A first readout circuit is provided for reading out charge from the first node. In use a first charge accumulated in the photodetector from a first predetermined portion of an energy spectrum of a radiation source is transferred to the first sense node. A second charge is accumulated in the photodetector from a second predetermined portion of the energy spectrum. The first charge is readout from the first sense node with the readout circuit, the second charge transferred to the first sense node and likewise readout. In embodiments of the invention, a second sense node and second transfer gate are provided and the first charge is read out through a first sense node and the second charge through the second sense node. In further embodiments a dump drain controlled by a dump gate is also provided to permit duty cycle control of sensitivity of the photodetector by selectively dumping and storing of charge accumulated in the photodetector.

Radiation sensor

A solid state imager arrangement includes an image area, an output register which receives signal charge from the image area, a separate multiplication register into which signal charge from the output register is transferred, means for obtaining signal charge multiplication by transferring the charge through a sufficiently high field in elements of the multiplication register, and an additional register into which excess signal charge is transferred.

Solid state imager arrangements

A charge division arrangement for a CCD device for producing a divided charge output from an input charge, comprising an input for receiving an input charge, an array of elements and an output. The array of elements being arranged in rows and columns and having clock connections to allow charge in each row to be successively clocked from one row of elements to the next. At least some of the elements being arranged in a charge division unit having a first element and a second element in adjacent columns and being communicable at least temporarily so that charged introduced into the first element is divided between the first element and the second element, the charge division unit being arranged to produce divided charge for production at the output. The arrangement allows a small amount of charge to be introduced into a CCD circuit.

Solid state imager

A charge coupled device (CCD) image sensor for producing a video output for a given TV line standard wherein the image section (9) has a number of CCD elements appropriate to the given line standard and the store section (11) has a number of CCD elements appropriate to a second, higher line standard. The electronic package required to drive the sensor is then not very different from an electronic package required to drive a sensor for the higher line standard, thus making it practicable to use in the sensor an electronic package capable of use in sensors for either standard.

Frame transfer image sensor having two vertical clock standards

In a frame transfer CCD image sensor the number of charge storage locations per channel (25) in the store section (35A, B) is greater than in the image section (33). Frame transfer is effected so that after each frame transfer the image charge pattern in the image section is transferred to the store section so as to leave at least one line of charge storage locations (35B) in the store section between the image section and the charge pattern transferred to the store section which contains charge resulting only from frame shift smear and is otherwise empty of charge. Electrical circuitry (41 to 57) is provided to subtract electrical signals representing charges in the line or lines containing frame shift smear charge only from electrical signals representing the image charge pattern, thereby to cancel frame shift smear in the signals representing the image charge pattern.

Charge coupled device image sensors

A CCD frame transfer image sensor wherein the effective integration period can be shortened by electrical means. The sensor comprises an image section having a first photo-sensitive portion of an array of CCD channels and a store section having a second light shielded portion of the array. Means are provided for controlling the potentials applied to the control electrodes of the array so as to transfer along the channels charge generated in the image section into a charge sink structure during one of the active line periods at a frequency outside the bandwidth of the output signal of the sensor.

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Stanmore, United Kingdom

Raymond Thomas Bell