| 摘要 |
<p>A miniature scan engine module (28) for bar code reading and data collection systems utilizes a light source (40) and a light collector (42) flexurally supported on a platform (54) which reciprocates on pivots defined by flexures (46 and 48). The light received from the code, as it is scanned, is collected along an optical collector (42) having surface area approximately equal to the surface area of one side of the scan engine. The optical collector (42) faces the bar code and pivots with the scanning beam source (40), a laser diode. A pair of diffraction gratings (66 and 67) along a surface of the optical collector (42) which faces away from the code directs the incoming light so that it propagates internally in a substrate (65) within the body of the collector in which the gratings (66 and 67) are embedded, i.e. in the optic itself to photodetectors (68 and 73) via reflective and light concentrating surfaces over the photodetector (68 and 73). Efficient light collection capability, without the need for special optics such as lenses and collection mirrors, enables the scan engine to be configured so that it occupies a miniature volume. A data collection system, in the form of a portable terminal, has a housing (12) which provides the handle for a scanning accessory which is the scan engine module.</p> |
