Optical scanning apparatus and method

专利名称：Optical scanning apparatus and method发明人：Wittensoldner, Christopher Joseph,Blanford,

Denis Michael,Burkey, John

Kenneth,Detwiler, Paul Oliver,Mergenthaler,Barry Myron,Hilles, Wilbur Isaac,Tom,Robert Joseph

申请号：EP91310585.4申请日：19911115公开号：EP0490498A1公开日：19920617

专利附图：

摘要：The invention relates to an optical scanning apparatus and method for scanningcoded symbols, such as bar codes, in merchandise check-out operations by using a laser(12), such as a laser diode. According to the invention continuous operation of the laser iseffected only when a coded symbol is present in a target area (18). A sensing device (22)is provided to generate voltage transitions whose frequency varies whether or not acoded symbol is present in said target area (18). The number of transitions is counted in agiven period of time and the number is evaluated to determine whether or not itrepresents the presence of a coded symbol. The intermittent operation of the laserdiode extends its useful life considerably.

申请人：NCR CORPORATION

地址：World Headquarters Dayton, Ohio 45479 US

国籍：US

代理机构：Robinson, Robert George

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