Accession Number : AD0442490


Title :   DEVELOPMENT OF A PIEZOELECTRIC DYNAMIC EMBOSSER FOR USE AS A READING MACHINE,


Corporate Author : STANFORD UNIV CA STANFORD ELECTRONICS LABS


Personal Author(s) : Alonzo, G J


Report Date : Mar 1964


Pagination or Media Count : 36


Abstract : Attempts are in progress to increase the selfsufficiency of blind people by means of a device that will permit mechanical reading of printed material. In the detection of characters by tactile stimulation of the fingers, a new technique using a piezoelectric dynamic embosser is shown to be possible. The requirements imposed on the embosser in terms of the energy required by the finger and the energy available from the print-sensing probe are carefully examined. A piezoelectric transducer in a configuration known as a bimorph is found to satisfy the electromechanical conversion required without any amplifying network between the probe and transducer. The transducer is theoretically analyzed using a simple lumped model. From an equivalent circuit the properties of the transducer are easily determined. Experiments conducted on a bimorph verified the analytical results obtained. Properties of the finger, and other considerations necessary in the design of an embosser to enable the finger to detect characters, are examined. Results of tests using an experimental embosser are also presented. (Author)


Descriptors :   *READING MACHINES , PIEZOELECTRIC TRANSDUCERS , BLINDNESS , CHARACTER RECOGNITION , ELECTROMAGNETIC PROBES , MATHEMATICAL MODELS , HANDS , DETECTION , STIMULATION(PHYSIOLOGY) , CODING , PRINTING


Distribution Statement : APPROVED FOR PUBLIC RELEASE