Abstract: A data distribution system (10) including an information card (12) and a reader (14). The information card (12) includes visible indicia (20) on its front and stripe zones (34) and a ring zone (36) on its back. The zones (34, 36) are suitable for magnetically recording data, and optional characteristics for such data. The reader (14) may be a linear reader (14a), a rotary reader (14b), or a card-stationary reader (14c, 14d) and may optionally act automatically in response to reading one or more of the optional data characteristics. If the reader (14) is a rotary reader (14b) the information card (12) may particularly be loaded into a cartridge (16) which is loaded into the rotary reader (14b).

Abstract: A position determining system (10) particularly useful for translation and rotation measurement. The position of a stage (12) is optically detected using light beams (124) and sensors (132) in a detection section (112). In a control section (114), electronic processing using amplifiers (152, 166), phase-sensitive synchronous demodulators (158, 168), and filters (160, 170) then produces position signals (162, 172) which a logic unit (174) processes into a results signal (180) which is communicated via a communications link (176) to an external system (22). The external system (22) may then display the measurement results for a human user or use them as feedback to control movement of the stage (12). Optionally, the external system (22) may send instruction signals (178) via the communications link (176) to the logic unit (174) to control the operation of the position determining system (10).

Abstract: A measurement apparatus (10, 110) and methods to perform positional types of measurement with normalization respective to either or both of light beam (16, 116) intensity and measurement target (12, 112) reflectivity. A light source, such as a laser diode (14, 114), produces a light beam (16, 116) which is directed at the measurement target (12, 112). One or more beamsplitters (28, 120, 124) in the path of the light beam (16, 116) direct sample portions into one or more photodetectors (32, 36, 122, 128) to obtain either or both of illumination and reflectivity sample values. A portion of the light beam (16, 116) which is reflected by the measurement target (12, 112) is passed through and restricted by an aperture (26, 132) and then detected by a position sensitive detector (38, 134) to obtain a position value. The position value may then be normalized based on either or both of the illumination and reflectivity sample values.