Claims
- 1. An apparatus for reading bar code symbols having parts of different light reflectivity by a scanning beam which forms a scan line across the bar code symbol, comprising:
a) focusing optics for collecting light reflected off at least a portion of the bar code symbol including a front surface for receiving the incoming light, and a first surface adjacent one end of the front surface, and a second surface adjacent to the other end of the front surface, said first and second surfaces having different light reflectivity properties, and a rear surface; and b) a photosensor positioned so as to receive light collected by said focusing optics and transmitted through said rear surface, and for generating an electrical signal indicative of the detected light intensity.
- 2. The apparatus of claim 1, wherein said first surface is disposed in a return path of light reflected from far edges of the scan line on the symbol and has a relatively greater reflectivity than said second surface.
- 3. An optical scan module, comprising:
a) a substantially rectangular module base; b) a light source mounted on the base for emitting a light beam; c) a scanning assembly for receiving the light beam and for generating therefrom a scanning beam directed to an indicia to be read for reflection therefrom; d) first and second spaced apart detectors for generating an electrical signal indicative of the indicia; and e) first and second generally concave optical elements associated with the first and second detectors, respectively, for collecting incoming light reflected from the indicia, and having different light collecting characteristics as a function of an angle of the incoming light on a surface of each optical element.
- 4. An arrangement for uniformly collecting light over a scan line swept over a symbol to be electro-optically read, the arrangement comprising:
a) a pair of photodetectors spaced apart of each other and having fields of view that overlap each other at a working distance in which the symbol is located; and b) a pair of focusing lenses, one for each photodetector, each lens having a rear surface facing a respective photodetector, a front surface facing the symbol, and a pair of side surfaces extending between the front and rear surfaces, the side surfaces having different optical properties.
- 5. An arrangement for uniformly collecting light over a scan line swept over a symbol to be electro-optically read, the arrangement comprising:
a) a pair of photodetectors spaced apart of each other and having fields of view that overlap each other at a working distance in which the symbol is located; and b) a pair of focusing lenses, one for each photodetector, each lens having a rear surface facing a respective photodetector, a front surface facing the symbol, and a pair of side surfaces extending between the front and rear surfaces, the side surfaces having the same optical properties.
RELATED APPLICATIONS
[0001] The present application is related to U.S. patent application Ser. No. 10/125,149 filed Apr. 18, 2002,which is hereby incorporated by reference.