Abstract: A video detector circuit is disclosed which develops a threshold level from a white or background peak signal in regions of low contrast, and from a combination of both white and black peak levels in regions of high contrast. The circuit is adjustable to compensate for variable affection performance of the detector.

Abstract: An optical character recognition system stores image data as a compressed run-length code. Preprocessing of characters for segmentation and registration is performed on the compressed data by means of tables created by a microprocessor. Only the image data required for recognition is expanded for the recognition process.

Abstract: A compact code format has marking elements of two distinctive lengths which lie across a set of parallel equal height code zones. The longer of the two lengths exceeds the length of the shorter by twice the height of a code zone, thereby providing a substantial uniformity of separation between all members of the code set.

Abstract: An identification card provided with secret data contained in the form of a wave guide hologram recorded in a layer on the card. Light for developing or displaying the hologram is introduced into a wave guide layer extending along the surface of the card through a grating that admits light only of a given wave length suitable for developing the wave guide hologram. The secrecy of the wave guide hologram is further enhanced by incorporating into the light coupling grating a further hologram by which light only of a predetermined pattern can be coupled to the wave guide for delivery to the wave guide hologram.

Abstract: A time base signal for controlling the recording of binary data is developed by measuring the velocity of a magnetic record.The velocity is measured by providing an inductive read head and a magnetoresistive read head which sense the same flux field on the magnetic record. The difference in the outputs of these read heads is a measure of the record velocity.

Abstract: A microfilm camera employs a reciprocating lens to optically arrest motion of documents traveling in a high-speed stream for photographic exposure onto stationary, incrementally advanced photographic film. The reciprocation of the lens is controlled by a closed loop servo system. To enhance performance of the servo system, the lens is supported by a four-bar linkage comprising relatively stiff light-weight arms interconnected by crossed leaf spring hinges.

Abstract: An array of individually controllable conductors presents variable data as a magnetic flux pattern that can be scanned by equipment presently used to scan prerecorded magnetic strips.

Abstract: A two-dimensional history of reflectance values, from which black-white threshold decisions are made, is stored in a relatively small amount of memory. Updating of the history by non-linear functions is accomplished through the use of look-up tables.

Abstract: A time base signal for controlling the recording of binary data is developed by measuring the velocity of a magnetic record. The velocity is measured by determining an average velocity by the time interval required for a mark recorded by a write head to move a predetermined distance to a read head and correcting the average velocity as a function of the acceleration of the record. The acceleration is determined by recording a reference frequency pattern at a first station, reading the pattern at a second station, and measuring the difference between the written and read patterns.

Abstract: Fluorescent bulbs having two phosphors emitting different colors with different persistence are used to illuminate a target object with sequentially different predetermined mixtures of light from which color separated images can be taken.

Abstract: A high aspect ratio collimating mask for use in ion beam epitaxy or ion implantation doping is formed through the use of damage-trail-forming materials which are irradiated through a mask and then etched. The high aspect ratio is obtained in part by the sequential formation of a plurality of spaced mask plates. The mask is useful in producing large scale integrated circuits by ion implantation during epitaxial growth of a crystal wafer.

Abstract: A direct heated rod-shaped cathode for an ion source is provided with a region of reduced cross-section adjacent its negative end to maximize the path length of electron movement within the discharge chamber and to provide effective control of the cathode resistance in a region that is relatively free of sputtering erosion during use.

Abstract: A power driven belt provides back-up pressure for a check or similar document bearing magnetic information as the document moves past a reading transducer. The belt is resiliently urged against cylindrical bearing surfaces adjacent the transducer to provide a non-critical geometry.