Abstract: A method for providing a touch interface on a display is described. The method includes providing an emitter on a first side of the display and providing a detector on a second side of the display. The emitter provides an electromagnetic signal to the display. The electromagnetic signal has a path from the emitter to the detector through the display in the absence of a user's touch such that the electromagnetic signal is detected by the detector in the absence of the user's touch. The path includes at least one total internal reflection in the display. The emitter and the detector are configured such that the user's touch at any of the at least one total internal reflection alters the path such that a portion of the electromagnetic signal does not reach the detector.

Abstract: A system for providing a touch interface on a display are described. The system include providing an emitter on a first side of the display and providing a detector on a second side of the display. The emitter provides an electromagnetic signal to the display. The electromagnetic signal has a path from the emitter to the detector through the display in the absence of a user's touch such that the electromagnetic signal is detected by the detector in the absence of the user's touch. The path includes at least one total internal reflection in the display. The emitter and the detector are configured such that the user's touch at any of the at least one total internal reflection alters the path such that a portion of the electromagnetic signal does not reach the detector.

Abstract: A dual beam laser array provides two overlapping beams for use in a direct read after write (DRAW) optical data storage system. A first portion of the overlapping beams is directed to a first optical detector and a second portion of the overlapping beams is directed to a second optical detector. A logic circuit connected to the optical detectors generates power signals representative of the power levels of each of the overlapping beams without the need to completely separate the beams.

Abstract: A holographic scanner includes a rotating glass disk carrying a plurality of scan line generating holograms, a laser light source and means for detecting reflected optical energy. The scanner is improved by adding a plurality of relatively small position-indicating holograms in alternation with the scan line generating holograms. The position-indicating holograms redirect the laser beam along desired paths on the same side of the disk as the laser. The redirected laser beam may be detected by the system photodetector or an auxiliary photodetector to provide signals indicating the current disk position. The position information can be used by a system processor to optimize scanner parameters as a function of the characteristics of the next active scan line generating hologram.

Abstract: An optical scanner is improved by securing beam directing holograpic films to the transparent scanner window. The films alter the paths of beams at the window to provide scanning beams suitable for rear or side scanning of label-carrying products. A vertical scanning beam, which sweeps a path parallel to the window's leading edge, might be used to detect the approach of a product to be scanned.