U.S. Philips Corporation

Petrus N Vis

Rudolf Kemner

Jan Timmer

Edwin A Montie

Willem P Van Der Brug

Adrianus A Franken

Alfred Ketting

Adriaan J Hoeven

An image display device (1) which includes a cathode ray tube is provided with a cathode system (2) for the emission of a plurality of electron beams (3) whereby a phosphor screen (4) is scanned in order to display an image. The electron beams are modulated on the basis of an electronic image signal by means of a cathode modulator (5). The cathode modulator is arranged to scan different image lines simultaneously by means of separate electron beams. For example, the cathode modulator comprises an extension system (7) and a delay system (8) for deriving extended and delayed extended image line sections from image line sections of the electronic image signal. The cathode modulator also comprises a combination unit (9) for simultaneously supplying an extended image line section and a delayed image line section with which separate electron beams are modulated.

Image display device comprising a cathode ray tube

A phosphor screen in a display device is scanned by separate electron beams in order to generate images of different frequency content in one color in substantially the same part of the phosphor screen. The different images can be perceived as a composite image for some time. The individual electron beams can be modulated by means of a cathode modulator on the basis of a high frequency and a low frequency component of an electronic image signal or on the basis of an image component and a text component of an electronic image signal. The modulations of the individual electron beams may be slightly delayed relative to one another in order to avoid overloading of the phosphor material.

CRT display device comprising a filter in the cathode modulator

A computer tomography system includes an X-ray tube having an elongate anode across which a beam spot can be displaced, a scanogram being formed by correctly shifting the profiles measured in the various source positions with respect to one another, followed by superposition. Parts of the object which are situated in a selected layer are thus emphasized in an image, parts of the object which are situated outside the selected layer being blurred. When a point of interest in the object is determined by observation of the scanogram, the same apparatus is used to produce a tomography slice image transverse the scanogram image. An important additional advantage consists in that the permissible power to be applied to the X-ray source may be higher. Furthermore, a scanogram thus obtained is not necessarily disturbed by the failure of one or more detectors.

Computer tomography system with a scanogram

A device for measuring local X-ray absorption differences in a patient or other object has an array of ionization detector elements. Each detector element has a high voltage electrode. The high voltage source for each such electrode has associated with it an alternating voltage source in order to compensate for microphonic interference. The measuring circuit includes a demodulation compensation circuit for separation of the microphonic signal and for removing this interference from the measuring signal.

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Eindhoven, Netherlands

Petrus N Vis