Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Peter J Quadflieg

Martin Weibrecht

Ulrich Schiebel

Walter Hillen

Gerhard Spekowius

Harald Reiter

Hans-Helmut Bechtel

Thomas Juestel

Wolfgang Busselt

Norbert Conrads

Gerhard Speckowius

Josef N Conrads

The invention relates to a display device for rendering gray tone images on a monitor () controlled by s electron rays, wherein a correction unit () is provided for generating s output image signals A, which comprise gray tone values forming part of a set K of correction gray tones, from an image signal () which comprises gray tone values forming part of a set M of original gray tones (), and the s output image signals A, after a D/A conversion, are fed each to one electron ray for a brightness-corrected rendering of a gray tone in one pixel of the monitor () for the purpose of adapting the brightness distribution of the monitor to the optimum perceptional brightness distribution.

Display device with improved representation of the shades of grey

The invention relates to a method of reproducing a gray scale image () in colors on a color monitor (), in which method each shade of gray () is assigned, using a look-up table (), a given output value (R, G, B) for driving the electron guns (R,G,B) of the color monitor. Assignment is performed in such a manner that a given color deviation is imparted to successive shades of gray, which deviation enables differentiation of the shades of gray by a human observer without such deviations becoming disturbing. Consequently, the information concerning the optical density of the original gray scale image () is preserved; this is important notably for the interpretation of medical images. Additionally, the special display properties of the monitor () and/or the ambient circumstances can be taken into account in the look-up table () in order to optimize the reproduction of the gray scale image.

Method of reproducing a gray scale image in colors

The invention relates to a color picture screen with an improved blue light emission. The blue phosphor layer comprises a first blue-emitting phosphor and a second phosphor which shows a light emission in the range from 380 to 450 nm.

Color picture screen with blue phosphor layer

The invention relates to a display device for rendering gray tone images on a monitor controlled by s electron rays. The display device includes a correction unit for generating s output image signals A composed of gray tone values forming part of a set K of correction gray tones from an image signal. The image signal is composed of gray tone values forming part of a set M of original gray tones, and the s output image signals A , after a D/A conversion, are fed each to one electron ray for a brightness-corrected rendering of a gray tone in one pixel of the monitor for the purpose of adapting the brightness distribution of the monitor to the optimum perceptional brightness distribution.

An X-ray image intensifier (1) includes an entrance screen (2) with a photocathode (3). A television camera (15) is optically coupled to the exit window (12) of the X-ray image intensifier. The X-ray image intensifier with the television camera derives a primary image signal form an X-ray image on the entrance screen. The X-ray image intensifier is provided with a radiation source (4), such as flashlights or LEDs, for irradiating the photocathode (3). Irradiation of the photocathode produces a light intensity distribution on the exit window wherefrom the television camera derives a control signal. Correction numbers are derived from the signal levels of the control signal. These correction numbers are employed for correcting the primary image signal.

Correction of fixed pattern noise

The invention relates to a device for producing X-ray images by means of a photoconductor which converts X-rays into a charge pattern, which photoconductor is charged prior to the X-ray exposure, its surface being scanned after the exposure in order to detect the charge pattern. Artefacts are liable to occur in an X-ray image when the exposure directly follows an X-ray exposure during which the photoconductor has received, at least in given areas, a high dose. These artegacts are avoided in accordance with the invention in that there is provided a recharging device which limits the decrease of the charge density on the surface of the photoconductor during the X-ray exposure to a predetermined value.

Device for producing x-ray images by means of a photoconductor

An electrostatic induction probe arrangement using several probes. The probe electrodes and the screen electrodes surrounding them are fitted to the end faces of a substrate arrangement, and the conducting paths leading to the preamplifiers are arranged in several parallel planes, perpendicular to the end face, in such a way that the signal-conducting paths connected to the probe electrodes are essentially screened by the screen-conducting paths connected to the screen electrodes.

Electrostatic induction probe arrangement using several probes

A method and apparatus for producing an X-ray exposure by means of a photoconductor. Photoconductor defect locations which appear as artefacts in the X-ray image are eliminated by subtracting a compensated dark discharge image from the X-ray image.

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Aachen, Germany

Peter J Quadflieg