Abstract: A semiconductor radiation imaging device includes an array of pixel cells having an array of pixel detectors which directly generate charge in response to incident radiation and a corresponding array of individually-addressable pixel circuits. Each pixel circuit is associated with a respective pixel detector for accumulating charge directly resulting from radiation incident on the pixel detector and includes threshold circuitry and charge accumulation circuitry. The threshold circuitry is configured to discard radiation hits on the pixel detector outside a predetermined threshold range, and the charge accumulation circuit is configured to accumulate charge directly resulting from a plurality of successive radiation hits on the respective pixel detector within the predetermined threshold range.

Abstract: A semiconductor radiation imaging assembly comprises a semiconductor imaging device including at least one image element detector. The imaging device is arranged to receive a bias for forming the at least one image element detector. The assembly also includes bias monitoring means for monitoring the bias for determining radiation incident on the image element detector. Preferably, the imaging device comprises a plurality of image element detectors the bias for at least some of which is monitored for determining incident radiation. More preferably, the bias for all the detector elements is monitored.

Abstract: A radiation imaging assembly includes a radiation imaging detector (160) including a plurality of image elements from which respective signals may be produced and a plurality of contacts for outputting said signals. A first substrate (154) is provided which comprises first and second major surfaces, said first major surface supporting said radiation imaging detector and providing support contacts for cooperating with respective contacts of said radiation imaging detector when mounted on said first surface. A second substrate for supporting electronic circuitry operable for said imaging device tile is also provided, said second substrate (158) disposed opposing said first substrate, and preferably disposed within the footprint of the first substrate.

Abstract: A method, suitable for forming metal contacts 31 on a semiconductor substrate 1 at positions for defining radiation detector cells, includes the steps of forming one or more layers of material 11, 12 on a surface of the substrate with openings 23 to the substrate surface at the contact positions; forming a layer of metal 24 over the layer(s) of material and the openings; and removing metal at 28 overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer 11 to be left between individual contacts on the substrate surface, may be applied during the method. A method according to the invention prevents etchants used for removing unwanted gold (or other contact matter) coming into contact with the surface of the substrate (e.g. CdZnTe) and causing degradation of the resistive properties of that substrate. The product of the method and uses thereof are also described.

Abstract: An imaging device for radiation imaging is an array of image cells. The array of image cells consists of an array of detector cells and an array of image cell circuits. Each detector cell is connected to the corresponding cell in the array of image cell circuits. Each individual cell in the detector cell array generates a charge based on the radiation that hits the cell. Each cell in the array of image cell circuits accumulates the charge on a storage capacitor. The storage capacitor can be, for example, the gate of a transistor. Single cells in the array of image cells can be grouped together to form larger area super cells. The size of the super cell can be controlled by control signals, which select the operating mode. The output from a cell, a single cell or a super cell, is read out in current mode and is scaled according to the size of the cell. Several modes can be implemented in the imaging device.

Abstract: An imaging apparatus includes a plurality of imaging device tiles arranged on an imaging support. Each of the imaging device tiles includes an imaging device having an imaging surface and a non-active region, wherein the imaging surface of a first imaging device tile at least partially overlies the non-active region of a second imaging device tile.

Abstract: Radiation imaging apparatus includes a support structure for a number of modules which each in their turn support a number of imaging device tiles. An imaging device on each tile provides an array of radiation detector cells. With the modular construction, the apparatus can provide a large imaging array from a large number of individual tiles. The support structure may be located in or form part of an imaging cassette. The modules provide tile mounting locations in one or more rows for the imaging device tiles, whereby the tiles may be accurately mounted with respect the module and to each other prior to being mounted on the support structure. The tiles are mounted on the modules and the modules are mounted within the cassette in a removable manner to facilitate the replacement of faulty tiles when required and/or the replacement of tiles having different resolutions and/or specifications for different imaging applications. Various arrangements for electronically clustering tiles are provided.

Abstract: A semiconductor radiation imaging device is disclosed which includes an array of image elements, each image element of said array comprising an image element detector cell which generates charge in response to radiation incident on said image element and image element circuitry for accumulating said charge from said image element detector cell and for selectively outputting a signal representative of accumulated charge. The imaging device further includes a radiation sensor element, said radiation sensor element comprising a radiation detector cell integral with said image element detector cells for generating charge in response to incident radiation on said radiation sensor element and a radiation sensor output for continuously supplying charge from said radiation detector cell. Also disclosed is an imaging system employing image devices as described above, and a method of imaging radiation.

Abstract: A radiation imaging device includes an image cell array having an array of detector cells and an array of image cell circuits. Each image cell circuit is associated with a respective detector cell and includes counting. The image cell circuits may include threshold circuitry configured to receive signals generated in the respective detector cell and having values dependent on the incident radiation energy. The counting circuitry may be coupled to the threshold circuitry.

Abstract: An imaging apparatus includes a plurality of imaging device tiles arranged on an imaging support. Each of the imaging device tiles includes an imaging device having an imaging surface and a non-active region, wherein the imaging surface of a first imaging device tile at least partially overlies the non-active region of a second imaging device tile.

Abstract: An imaging device includes one detector substrate with a plurality of readout substrates connected thereto. The detector substrate has a bias contact on a first surface and a number of detector cell contacts on a second surface. The readout substrate includes a plurality of readout circuits. The readout substrates are all mechanically connected to the detector substrate with the readout circuits electrically connected to respective detector cell contacts. To allow for areas of the readout substrates with no readout circuits or gaps between readout circuits, conductive tracks lead from selected detector positions to offset readout circuit position.

Abstract: A method of autoradiography imaging includes steps of: (a) forming a subject having at least first and second markers, each marker providing radiation having a characteristic energy distribution; (b) detecting radiation from the marked subject using a semiconductor radiation detector having an array of cells, each cell recording a charge value dependent on the energy of incident radiation; (c) processing the output from the cells including discriminating charge values within at least two charge value ranges and allocating a display color value to each pixel cell position in the array dependent upon the recorded charge value; and (d) forming an image for display with individual cell positions having a color representative of the color values. The method enables multiple label or multiple marker imaging in autoradiography to be performed by energy discriminating imaging, thus enhancing experimental accuracy and reproducibility.

Abstract: An imaging device for radiation imaging is an array of image cells. The array of image cells consists of an array of detector cells and an array of image cell circuits. Each detector cell is connected to the corresponding cell in the array of image cell circuits. Each individual cell in the detector cell array generates a charge based on the radiation that hits the cell. Each cell in the array of image cell circuits accumulates the charge on a storage capacitor. The storage capacitor can be, for example, the gate of a transistor. Single cells in the array of image cells can be grouped together to form larger area super cells. The size of the super cell can be controlled by control signals, which select the operating mode. The output from a cell, a single cell or a super cell, is read out in current mode and is scaled according to the size of the cell. Several modes can be implemented in the imaging device.

Abstract: An imaging device for radiation imaging is an array of image cells. The array of image cells consists of an array of detector cells and an array of image cell circuits. Each detector cell is connected to the corresponding cell in the array of image cell circuits. Each individual cell in the detector cell array generates a charge based on the radiation that hits the cell. Each cell in the array of image cell circuits accumulates the charge on a storage capacitor. The storage capacitor can be, for example, the gate of a transistor. Single cells in the array of image cells can be grouped together to form larger area super cells. The size of the super cell can be controlled by control signals, which select the operating mode. The output from a cell, a single cell or a super cell, is read out in current mode and is scaled according to the size of the cell. The read out line is pre-charged prior to read out to reduce the effect of parasitic capacitance in the read out line.

Abstract: A radiation imaging device includes an image cell array having an array of detector cells and an array of image cell circuits. Each image cell circuit is associated with a respective detector cell and includes counting. The image cell circuits may include threshold circuitry configured to receive signals generated in the respective detector cell and having values dependent on the incident radiation energy. The counting circuitry may be coupled to the threshold circuitry.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: A semiconductor imaging device includes a semiconductor radiation detector substrate, for example of cadmium zinc telluride, with at least two faces. A first face has at least one charge output contact formed from electrically conductive material or materials and a second face having a contact formed from electrically conductive material or materials. The second face contact is for applying a bias voltage to provide an electric field between the first and second faces. The second face contact, or a third face of the semiconductor imaging device, or an edge between the second and third faces has deposited thereon at least a partial covering of a further material different from the electrically conductive material or materials of the second face contact. The deposited material can be a semiconductor, insulating or passivation material, for example aluminium nitride. Such a radiation detector can provide linear detector behaviour for all possible combinations of exposure and X-ray tube voltage.

Abstract: An imaging support for supporting a plurality of imaging device tiles at respective tile mounting locations to define a tiled imaging surface is provided. Each of the imaging device tiles has a semiconductor detector with a plurality of pixel cells coupled to a semiconductor substrate with a corresponding plurality of pixel circuits. The semiconductor detector and the semiconductor substrate are carried on a mount having an imaging device tile contact. The imaging support is configured for mounting each of the imaging device tiles on the imaging support in a non-destructive, removable manner at respective tile mounting locations, each of which includes an imaging support contact at a contact position.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: An imaging support for supporting imaging devices in respective positions to define an imaging surface is arranged to permit the imaging devices to be removably mounted on the support in a non-destructive, removable manner. In one embodiment the removable mounting is achieved by providing a source of reduced air pressure behind the imaging devices on the imaging support to suck the imaging devices onto the imaging support so that the imaging devices are accurately located on the support in a removable, non-destructive manner. The imaging devices are removable without damage to the device to be removed, the surrounding devices or the support. Defective devices can readily and quickly be replaced. Correctly functioning imaging devices can easily be removed and re-used on the same or a different imaging support.