Abstract: The present invention relates to an optical encoder for measuring the speed and direction of a moving raster. The raster may be moving linearly or angularly and may further be connected to a moving element, such as a spinning shaft, of which speed and orientation measurement Is sought. The raster may comprise a slit plate or the like and include many formations in sequence. The formations may be successively opaque and transparent to light. The raster modulates light from a light source and the modulated light is detected by at least one set of three photodetectors. Output of the photodetectors is then used to generate a reference signal to which individual outputs are compared. The results of the comparisons are indicative of the speed and direction of the raster and moving element to which the raster is attached.

Abstract: A method for a quantitative detection of a linear movement or rotary movement. The method includes the steps of emitting radiation from at least two light emitters in a pulsed mode at a same clock frequency or different clock frequencies and detecting the radiation from the two light emitters by a detection device. It furthermore includes the steps of increasingly shadowing the radiations by a movable grid device or separating signals originating from different light emitters by an evaluation circuit coupled to said detection device.

Abstract: An optical device for quantitative detection of linear or rotary movements, in which light beams from two light emitters pass through a grid disk which images the movement and has translucent areas and opaque areas. A single photo receiver is also provided in which the transmitted light strikes the photo receiver. The light emitters are actuated in a pulsed mode. The pulses are separated from one another in an evaluation circuit that is coupled to the photo receiver.

Abstract: The present invention relates to an optical encoder for measuring the speed and direction of a moving raster. The raster may be moving linearly or angularly and may further be connected to a moving element, such as a spinning shaft, of which speed and orientation measurement is sought. The raster may comprise a slit plate or the like and include many formations in sequence. The formations may be successively opaque and transparent to light. The raster modulates light from a light source and the modulated light is detected by at least one set of three photodetectors. Output of the photodetectors is then used to generate a reference signal to which individual outputs are compared. The results of the comparisons are indicative of the speed and direction of the raster and moving element to which the raster is attached.

Abstract: A surface acoustic wave filter is disclosed having an interdigitated structure of transducer fingers on a piezo substrate. Spurious signals are suppressed by employment of a slanted placement of transducer fingers at an output region of a weighted input transducer or at an input region of a weighted output transducer.