U.S. Philips Corporation

Bartholomeus G Dillen

Rudolph M Snoeren

Antonius J Bruijns

Jan T Bosiers

An X-ray examination apparatus includes an X-ray source (1) for irradiating an object (2) by means of an X-ray beam (3) in order to form an X-ray image. An optical image is derived from the X-ray image by means of an X-ray detector (4). The optical image is picked up by means of an image pick-up apparatus (5). The image pick-up apparatus (5) includes a plurality of image sensors (6, 7) for deriving separate electronic sub-image signals from the optical image. The image pick-up apparatus also includes a subtraction unit (8) for subtracting the electronic sub-image signals from one another. The image pick-up apparatus (5) also includes a control circuit (9) which is arranged to make integration periods of individual image sensors (7, 8) commence at instants which are spaced a waiting period apart. The difference signal represents changes in the X-ray image or, when the X-ray energy is changed during the waiting period, differences in X-ray absorption due to energy-dependency.

X-ray examination apparatus including a subtraction unit

In charge-coupled imaging devices it is generally necessary to provide zones (12) in the matrix with a contact. These zones may form part, for example, of a mechanism for draining charge, for example as a protection against overexposure. In the case of imaging devices with a horizontal readout register on one side of the matrix, these contacts can be provided on the opposite side. However, it is often desirable or even necessary, as in the case of imaging devices with four-quadrant readout, to provide such contacts on the same side as the horizontal readout register. To this end, a dummy line (14'-17') is provided in accordance with the invention between the matrix and the horizontal readout register (6), said dummy line having an electrode structure which leaves room for contact windows (22) to the zones (12).

Charge-coupled imaging device having electrical connections on the

An X-ray examination apparatus (1) includes an X-ray source (2) and an X-ray image intensifier (5) for deriving an optical image from an X-ray image, which optical image is picked up by means of an image pick-up apparatus (6). The X-ray examination apparatus also includes an exposure-control system (7) for adjusting the X-ray source and/or the image pick-up apparatus on the basis of brightness values of a region of interest in the optical image. The exposure-control system includes a photodetector, for example a CCD sensor, for deriving a photodetector signal from the optical image and a photosensor for adjusting the sensitivity of the photodetector. The photodetector (9) includes an image pick-up section (11), an image memory (13) comprising separate sections, preferably including an intermediate memory (15). An electronic image in the image pick-up section is quickly transferred to an available storage section after which it is read out as an electronic image signal. For example, the electronic image is first transferred to the intermediate memory wherefrom it is quickly transferred to the image memory after which it is read out as an electronic image signal.

X-ray examination apparatus comprising an exposure-control system

In an image detection system having a CCD sensor, particularly for an x-ray examination apparatus, image read-out is substantially accelerated. This is achieved by discarding portions of the electronic image that is stored in the image storage-part of the CCD. Thus, only, portions of the image that contain relevant image information are converted into an electronic video signal.

X-ray examination apparatus

Accurately aligning opto-electronic image sensors with respect to a beam-splitter being comprised in an image sensing device is facilitated by incorporating an alignment pattern in the conductive metal stripes of the opto-electronic image sensors. When simultaneously viewed through the input face of the beam-splitter, alignment patterns of respective opto-electronic image sensors form a combined alignment patterns showing the accuracy of the alignment of the opto-electronic image sensors. By providing differences between pitches of the alignment patterns on either side of an axis of reflection, a combined alignment pattern is obtained showing various types of alignment errors, such as horizontal or vertical translation, or rotations. Quantification of alignment errors is facilitated by making use of vernier action in the combined alignment pattern.

Image sensing device with circuit layout alignment pattern

An imaging system includes an image pick-up device with an image sensor having a rectangular detection face which is subdivided into discrete detection sub-faces for converting a radiation intensity distribution on the detection face into an electric signal, the detection sub-faces being arranged in a matrix of n rows and p columns respectively dividing short and long sides of the detection face, an object plane and an optical system which images a radiation intensity distribution in a circle situated in the object plane onto an ellipse situated on the detection face in accordance with a compression factor m. The compression factor may be chosen so that the ellipse spans no more than p/2 columns of the detection face so that video images can be formed at twice the conventional rate. In the case of non-square detection sub-faces, the compression rate may be chosen so that the ellipse spans an equal number of rows and columns, thereby making each detection sub-face correspond to a square in the object plane. When several, mutually shifted image sensors are used, the compression rate of the optical system is adapted to correct a decrease in effective dimension of the detection sub-faces. A CCD sensor is used in an imaging system operating according to the NTSC standard by utilizing correct image compression.

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Eindhoven, Netherlands

Bartholomeus G Dillen