| 摘要 |
A watchman's tour recording system includes a portable housing containing a data reader for reading and recording data from tour stations and a printer for printing out recorded station data and entry time in alphanumeric form. The printer is located in a locked compartment and is accessible by supervisory personnel for periodic tour entry monitoring. Station keys carry coded identification as a linear array of apertures filled with alternative pellet materials which are transmissive or non-transmissive to infrared light but are visibly indistinguishable. Strobe holes are positioned in a parallel linear array for synchronizing data reading. During assembly, the pellets are mutually distinguishable by split and continuous rings which serve as energy directors during ultrasonic welding of the pellets into the key, and which are hidden from view in the assembled product. A key reader in the portable housing includes a passage across which three infrared beams are directed toward respective infrared detectors, one for successively reading coded pellet data during key insertion and withdrawal, another for detecting strobe holes, and a third for detecting full insertion of the key. The strobe hole detector beam is pulsedly emitted until a key entry is sensed; thereafter, a read mode of limited duration is established wherein all three beams are energized continuously, and during which a key must be inserted and withdrawn for a valid code reading to take place. Data detected during insertion and withdrawal is compared to assure valid readings.
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