Agfa-gevaert Ag

Ulrich Greis

Reinhold Deml

Wilfried Hofmann

Walter Rauffer

Dieter Giglberger

Wilhelm Kapfhammer

A layer of material which absorbs incident focussed laser light and undergoes a resultant heating is arranged in the focal plane of a lens matrix. Laser light is projected onto such layer through the lens matrix itself. The laser light is focussed by the lens elements of the lens matrix onto the layer effecting a highly localized heating of small well-defined portions of the layer. At those small well-defined portions, the material of the layer, as a result of the highly localized heating, removes itself to form the apertures of a lens-aperture matrix which is thereafter used in cooperation with the lens matrix as a rear projection or daylight projection screen.

Daylight projection screen and method and apparatus for making the same

The rear-projection viewing screen receives light incident upon its back side from the objective of a rear-projection projector and forms a corresponding image visible to a human eye viewing the front side of the viewing screen. The viewing screen is comprised of a lens-aperture matrix and an optical system cooperating with the lens-aperture matrix. The optical system serves the function of a lens matrix comprised of lens-matrix elements which focus the light from the objective of the rear-projection projector through the apertures of the lens-aperture matrix. The optical system furthermore serves the function of a field lens operative for gathering the light emanating from the objective of the projector and deflecting such light in direction toward the optical axis of the objective so as to increase the amount of light from the marginal portions of the viewing screen reaching a viewer's eye located on such optical axis.

Rear-projection viewing screen

A method and arrangement for the production of a rotationally symmetric, non-spherical optical element, in which one or more light beams are directed at a rotating light-sensitive medium, and a fixed opaque shield is situated over the light-sensitive medium to block a portion of the light beams from exposing the medium.

Method for production of rotationally symmetric non-spherical optical

An optical apparatus is provided with an objective and an autocollimation lens having a position and orientation bearing a known relationship to the position and orientation of the objective. A grating has alternating transmissive and non-transmissive portions. The grating is so positioned relative to the autocollimation path of the autocollimation lens that the latter projects an image of the grating onto the subject, and the image of the grating on the subject is projected back onto the grating. A photoelectric detector derives from the light projected back onto the grating an electrical signal indicative of the degree of focus of the objective. The setting of the objective is controlled in dependence upon the electrical signal.

Method and arrangement for automatically focussing an objective onto a

In a method of forming a Fresnel lens from a body of light-sensitive material of the type which undergoes changes in its optical path-length when exposed to light, the step of exposing each portion of such body of light-sensitive material to light to the extent necessary to impart to the respective portion the optical path-length requisite for the corresponding portion of the Fresnel lens to be formed.

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Weyarn, Germany

Ulrich Greis