Abstract: The present invention describes a process and a device for perception-optimized transmission of video and audio data. The picture coming from a video source is compared with a reference picture. The picture differences are investigated for perception-relevant picture data and transmitted to a receiver in accordance with their priority. If the amount of data required for refreshing exceeds the capacity of the data channel, the less relevant data (lower priorities) is held back. A particular embodiment of the present invention comprises storing the individual pictures as structured difference pictures. The present invention can be applied analogously to the transmission of audio data.

Abstract: The present invention describes a device and a method to prevent RSI symptoms when keys are operated, and it contains a measuring device (4) to determine the force acting on the key, a device to compare the measured force with a finger stress model, and a device to make critical finger impact values (14, 16) perceptible. The inventive device may be positioned directly on the keyboard (2) as a stand-alone device, or it may be designed as part of a data processing system.

Abstract: A rod-shaped device for spatial data acquisition includes a shank (1) with at least two separated, substantially identical marker field structures (3, 4) on the surface of the shank (1). The marker field structures (3, 4) are resolvable for imaging purposes by an optical position and orientation determination system for determining the position and orientation of an object in space. That system includes imaging apparatus (5) with a field of vision containing the rod-shaped device to capture position data of the rod shaped device. A computer (6) connected to the image apparatus receives the position data and calculates the position and orientation of the object in space.

Abstract: A method of user command or data acquisition in a processing system that allows for analysis of human hand and finger motions. The activities are then interpreted as operations on a physically non-existent input device. The resulting optical user/computer interface complements the visual screen-to-user path with a hand-to-image data acquisition link from the user to the processor unit. It allows for the emulation of different types of manually operated input devices (mouse, keyboard, etc.). Mechanical input units can be replaced by virtual devices, optimized for the current application and for the user's physiology. The speed, simplicity and avoidance of ambiguity of manual data input will be maintained. Sensing of finger motions can generate feedback to reduce the hazard of repetitive strain injury (RSI) syndrome.

Abstract: A microscope interferometer is described, that scans an object surface through a membrane mask with a multitude of pinholes. Light reflected back through the pinholes interferes with the darkfield image of the mask surface. The mask to object separation can be stabilized by an air flow through the pinholes. Image processing techniques allow to overcome the Abbe diffraction limit for the lateral resolution.

Abstract: An optical analyzer for determining changes of the polarization plane in a light beam (4) comprises a substrate (20) supporting a photodetector array (21) and a system of imaging mirrors (22-24) underneath a parallel plate (25) of high-quality optical glass. The lower surface of the glass plate is covered by a system (26) of dielectric multilayers which acts as a polarizing beam splitter over a large range of angles of incidence. The optical beam (4) enters the analyzer through the glass plate to impinge under an oblique angle of incidence on a first mirror (24) which rotates the plane of polarization in the beam by 45 degrees with respect to the polarizing beam splitter, which then generates two beams partial (202,203) to be eventually directed to photodetector array (21). The beam analyzer is used in magneto-optical storage system to extract an information signal and to generate servo control signals for the focus and track positions of the beam.

Abstract: A rotary access arm, e.g. for an optical disk has crossed voice coil actuators (6a,b) for in-plane and vertical movements, e.g. track and focus control; the actuators are secured to its distal end in close proximity to the focussing optical system (5a,b). The heavy elements like laser light source (8) and beam analyzer (11) are arranged near the rotational axis (10) of the arm (or are completely separated therefrom) allowing a very lightweight construction. In an optical storage system using stacked disks coaxial access arms with individual position control are provided. For increased reliability of operation each access arm has two focussing optical systems at its distal end, viewing in opposite directions, and a bistable optical switch (12) to selectively focus the laser beam on one of the two adjacent optical disks. The focussing optical system can be realized with individual lenses or with two conjugate plano-aspheric lenses bonded to a 90.degree. reflection prism.

Abstract: A conventional interferometer arrangement (e.g., test glass 12) is illuminated with white light and the resultant colored interference field is recorded by a color TV camera (16). The three output signals (R, G, B) of the color TV camera are directly, or after linear combination, converted into digital values and subsequently serve to address a digital storage (179) in which the phase difference of the interfering waves is stored for each R, G, B combination. The values read from storage are reconverted into analog signals and displayed as so-called pseudo-interference fringes on a TV monitor (18). A computer (19) for the further processing of the read data may be connected to the storage output.

Abstract: Low loss optical couplers for an optical data bus include a first component having permanent input/output connections to the bus and a reference face capable of reflecting energy from the input to the output. If optical energy is to be coupled into or out of the bus, a second component is secured to the first component. The second component has input and/or output optical connections and a reference face which contacts at least part of the reference face of the first component and which permits optical energy to be transferred between the two components. Frequency-selective encoders and decoders using active optical devices are also disclosed.

Abstract: A self-focussing coupler for optical fibers includes a transparent body having the configuration of a paraboloid of revolution. One or more optical fibers are connected to the body at or near the point of focus. A flat face is formed at a normal to the axis of symmetry. A coupler assembly is formed by bringing the faces of two couplers together. Different optical components (beam splitting plates, bandpass filters, etc.) may be placed in an interface gap and bypass fibers may be added to alter the functions of the coupler assembly.

Abstract: A radiation analyzing system including a beam splitting prism, an analyzer and a photodiode array arranged in an evaluation plane. Upon passing through the prism radiation to be analyzed is split into two beams vertically linearly polarized to each other which include a small angle and show a phase shift that is a function of the distance from the optical axis. The difference of the phase positions of these two beams is a function of their distance from the left or right edge of the prism. The analyzer, which is arranged behind the prism and whose axis of polarization is inclined relative to the directions of polarization of the two vertically polarized beams, produces a periodic intensity distribution when the impinging radiation is polarized at least partly and has a component in parallel to the axis of the analyzer.