Optical symbol (bar code) reading systems having an electro-optic receptor with embedded grating rings
First Claim
1. A scanning accessory for a portable terminal for collecting and entering data which comprises a first housing defining a receptacle and having a window and a surface defining a manually graspable handle, a miniature scan engine module having means for projecting a light beam outwardly from said module, said scan engine being disposed in said receptacle with the beam projecting through said window towards said symbol, and an electro-optical receptor in said hollow body for collecting return light from said symbol in response to illumination by said beam and providing electrical signals representing said symbol, said receptor having a photodetector, a diffraction grating having a plurality of concentric rings embedded within said receptor means for directing light diffracted by said grating to said photodetector, and means in said housing for operating said scan engine.
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Accused Products
Abstract
A miniature scan engine module for bar code reading and data collection systems utilizes a light source and a light collector flexurally supported on a platform which reciprocates on pivots defined by flexures. The light received from the code, as it is scanned, is collected along an optical collector having a surface area approximately equal to the surface area of one side of the scan engine. The optical collector in which the gratings are embedded faces the bar code and pivots with the scanning beam source (a laser diode). A pair of diffraction gratings in a surface of the optical collector which faces away from the code directs the incoming light so that it propagates internally in a substrate within the body of the collector, i.e. in the optic itself to photodetectors via reflective and light concentrating surfaces over the photodetector. 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 which provides the handle for a scanning accessory which is the scan engine module.
96 Citations
34 Claims
- 1. A scanning accessory for a portable terminal for collecting and entering data which comprises a first housing defining a receptacle and having a window and a surface defining a manually graspable handle, a miniature scan engine module having means for projecting a light beam outwardly from said module, said scan engine being disposed in said receptacle with the beam projecting through said window towards said symbol, and an electro-optical receptor in said hollow body for collecting return light from said symbol in response to illumination by said beam and providing electrical signals representing said symbol, said receptor having a photodetector, a diffraction grating having a plurality of concentric rings embedded within said receptor means for directing light diffracted by said grating to said photodetector, and means in said housing for operating said scan engine.
- 21. A scan engine for providing a light beam for scanning and optically readable symbol and providing signals representing said symbol in response to illumination thereof by said beam characterized in that said engine comprises an electro-optical receptor comprising an optical collector comprising a body having first surface exposed to the light from the symbol and a second surface spaced from said first surface, a plurality of grating rings about a center disposed along said second surface for diffracting light incident thereon toward said first surface, a light coupling structure along said first surface for entering the light from the symbol into said body via said first surface for propagation in said body to said second surface and having light concentrating means, where said light diffracted by said rings toward said first surface is concentrated, and said receptor further comprising a photodetector in light receiving relationship with light from said concentrating means.
- 25. An electro optical receptor which comprises an optical collector comprising a body having a first surface exposed to incident light and a second surface spaced from said first surface, a light coupling structure defined by material forming said first surface for entering the incident light into said body via said first surface for propagation in said body to said second surface, a diffractive element embedded within said body comprising a plurality of rings around a center, said receptor further comprising an opto-electric transducer along a line transverse to said second surface through said center and in light receiving relationship with light diffracted by said element, said light reaching said transducer after reflection at said first surface and being translated into electrical signals.
- 31. A scan engine for providing a light beam for scanning an optically readable symbol and providing signals representing said symbol in response to illumination thereof by said beam characterized in that said engine comprises an electro-optical receptor comprising an optical collector comprising a body having a first surface exposed to the light from said symbol and on which said light from said symbol is incident and a second surface spaced from said first surface, a plurality of grating rings about a center, said rings being disposed along said second surface for diffracting light incident thereon towards that first surface, said first surface being reflective and transmissive of light incident thereon at greater and less than a certain angle, said light from said symbol being incident on said surface at less than said certain angle and said light diffracted by said grating being incident on said first surface at more than said certain angle whereby light from said symbol is entered into said body via said first surface for propagation in said body to said second surface, light concentrating means along said first surface where light diffracted by said rings towards said first surface is concentrated, said receptor further comprising a photodetector in light receiving relationship with light from said concentrating means.
Specification