EP0469305A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Light emitting diode scanner
Assignee: Symbol Technologies LLC
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Filing: 1991-06-28
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Granted: —
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Expires: 2011-06-28
Abstract
Abstract A portable scanning head emits and receives light from a light-emitting diode to read symbols, such as bar-code symbols. The optics within the scanner are operative for focusing a light beam and the view of a light sensor in different planes exteriorly of a scanner housing. Imaging means are provided in the unit for imaging a viewing window. The viewing window has an area smaller than that of the scan spot. The system can employ an LED as a light source and tolerate the relatively large-sized (on the order of millimeters) scan spot without sacrificing reading performance since the photodiode "sees" only that portion of the scan spot visible through the viewing window.
Inventors
- 👤 Boris Metlitsky
- 👤 Jerome Swartz
- 👤 Edward Barkan
- 👤 Howard M. Shepard
- 👤 David Goren
- 👤 Tony Biuso
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 02:03
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10881; G06K2207/00; G06K2207/1013
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
209 words
A system for reading symbols, comprising: (a) light source means for generating a light beam; (b) focusing means for focusing the light beam to a scan spot of predetermined area at a scan plane and for positioning the scan spot on a symbol located in a working distance range in the vicinity of the scan plane; (c) scanning means for sweeping the scan spot across the symbol in a scan, thereby reflecting off the symbol reflected light, at least a returning portion of which travels away from the symbol back in the direction of said source means, said returning portion of the reflected light having a variable intensity over the scan; (d) sensor means for viewing and detecting the variable intensity of said returning portion of the reflected light over a field of view, and for generating an electrical signal indicative of the detected variable light intensity; (e) signal processing means for processing the electrical signal and for generating therefrom data description of the symbol; and (f) imaging means for imaging a viewing window of the sensor means, said viewing window having an area smaller than that of the scan spot, and for positioning the viewing window at a viewing plane that is spaced away from the scan plane.
Claim 2
Independent Claim
209 words
A system for reading symbols, comprising: (a) light source means for generating a light beam; (b) focusing means for focusing the light beam to a scan spot of predetermined area at a scan plane and for positioning the scan spot on a symbol located in a working distance range in the vicinity of the scan plane; (c) scanning means for sweeping the scan spot across the symbol in a scan, thereby reflecting off the symbol reflected light, at least a returning portion of which travels away from the symbol back in the direction of said source means, said returning portion of the reflected light having a variable intensity over the scan; (d) sensor means for viewing and detecting the variable intensity of said returning portion of the reflected light over a field of view, and for generating an electrical signal indicative of the detected variable light intensity; (e) signal processing means for processing the electrical signal and for generating therefrom data description of the symbol; and (f) imaging means for imaging a viewing window of the sensor means, said viewing window having an area smaller than that of the scan spot, and for positioning the viewing window at a viewing plane that is spaced away from the scan plane.
Claim 3
Dependent Claim
45 words
The system according to claim 1, wherein the sensor means includes a photodiode having a sensor opening, and wherein the imaging means includes an apertured wall having an aperture adjacent the sensor opening and through which aperture said returning portion of the reflected light passes.
Claim 4
Dependent Claim
37 words
The system according to claim 2 wherein the aperture has a generally rectangular shape, having a shorter dimension as considered longitudinally along the symbol, and a longer dimension as considered in a direction transversely of the symbol.
Claim 5
Dependent Claim
15 words
The system according to claim 2 wherein the imaging means further includes an imaging mirror.
Claim 6
Independent Claim
178 words
A method of reading symbols, comprising the steps of: (a) generating a light beam; (b) focusing the light beam to a scan spot of predetermined area at a scan plane, the scan spot being positioned on a symbol located in a working distance range in the vicinity of the scan plane; (c) sweeping the scan spot across the symbol in a scan, at least a returning portion of light being reflected back from the symbol, said returning portion of the reflected light having a variable intensity over the scan; (d) viewing and detecting the variable intensity of said returning portion of the reflected light over a field of view by sensor means, and generating an electrical signal indicative of the detected variable light intensity; (e) processing the electrical signal and generating therefrom data representative of the symbol; and (f) imaging a viewing window of the sensor means, the viewing window having an area much smaller than that of the scan spot, and positioning the viewing window at a viewing plane that is spaced away from the scan plane.
Claim 7
Independent Claim
178 words
A method of reading symbols, comprising the steps of: (a) generating a light beam; (b) focusing the light beam to a scan spot of predetermined area at a scan plane, the scan spot being positioned on a symbol located in a working distance range in the vicinity of the scan plane; (c) sweeping the scan spot across the symbol in a scan, at least a returning portion of light being reflected back from the symbol, said returning portion of the reflected light having a variable intensity over the scan; (d) viewing and detecting the variable intensity of said returning portion of the reflected light over a field of view by sensor means, and generating an electrical signal indicative of the detected variable light intensity; (e) processing the electrical signal and generating therefrom data representative of the symbol; and (f) imaging a viewing window of the sensor means, the viewing window having an area much smaller than that of the scan spot, and positioning the viewing window at a viewing plane that is spaced away from the scan plane.
Claim 8
Independent Claim
94 words
A method of scanning bar code symbols or the like, comprising the steps of: a) generating a light beam by a light-emitting diode and focusing said light beam on a spot on a scan plane; b) focusing reflected light onto a photodetector, said reflected light returning from a symbol located in a viewing plane upon which said light beam impinges, c) limiting said reflected light reaching said photodetector to only a viewing window of size much smaller than said spot, said viewing window being defined by an aperture in the vicinity of said photodetector.
Claim 9
Independent Claim
94 words
A method of scanning bar code symbols or the like, comprising the steps of: a) generating a light beam by a light-emitting diode and focusing said light beam on a spot on a scan plane; b) focusing reflected light onto a photodetector, said reflected light returning from a symbol located in a viewing plane upon which said light beam impinges, c) limiting said reflected light reaching said photodetector to only a viewing window of size much smaller than said spot, said viewing window being defined by an aperture in the vicinity of said photodetector.
Claim 10
Independent Claim
94 words
A device for scanning bar code symbols or the like, comprising: a) a light source including a light-emitting diode for generating a light beam for focusing on a spot in a scan plane; b) a photodetector having reflected light focused thereon, said reflected light returning from a symbol located in a viewing plane upon which said light beam impinges, c) said reflected light reaching said photodetector being limited to only a viewing window of size much smaller than said spot, said viewing window being defined by an aperture in the vicinity of said photodetector.
Claim 11
Independent Claim
94 words
A device for scanning bar code symbols or the like, comprising: a) a light source including a light-emitting diode for generating a light beam for focusing on a spot in a scan plane; b) a photodetector having reflected light focused thereon, said reflected light returning from a symbol located in a viewing plane upon which said light beam impinges, c) said reflected light reaching said photodetector being limited to only a viewing window of size much smaller than said spot, said viewing window being defined by an aperture in the vicinity of said photodetector.
Claim 12
Independent Claim
80 words
A method of operating a hand-held bar code scanner, comprising the steps of: maintaining a hand-held scanner device in a quiescent state when the device is at rest, with the device having a scanner motor and a light source which are turned off in said quiescent state; detecting movement of said device when a user moves the device toward a bar code reading position; in response to said step of detecting, turning on said scanner motor and said light source.
Claim 13
Independent Claim
80 words
A method of operating a hand-held bar code scanner, comprising the steps of: maintaining a hand-held scanner device in a quiescent state when the device is at rest, with the device having a scanner motor and a light source which are turned off in said quiescent state; detecting movement of said device when a user moves the device toward a bar code reading position; in response to said step of detecting, turning on said scanner motor and said light source.
Claim 14
Dependent Claim
77 words
A bar code scanner, comprising: a) a hand-held unit having a scanner motor and a light source which are maintained in an off condition when the unit is in a quiescent state and the unit is at rest; b) a detector responsive to movement of said unit when a user moves the unit toward a bar code reading position; and c) a controller responsive to said detector for turning on said scanner motor and said light source.
Claim 15
Dependent Claim
77 words
A bar code scanner, comprising: a) a hand-held unit having a scanner motor and a light source which are maintained in an off condition when the unit is in a quiescent state and the unit is at rest; b) a detector responsive to movement of said unit when a user moves the unit toward a bar code reading position; and c) a controller responsive to said detector for turning on said scanner motor and said light source.
Claim 16
Independent Claim
80 words
A method of operating a bar code scanner, comprising the steps of: a) directing a light beam at a bar code symbol; b) detecting light reflected from said bar code symbol and generating an electrical signal in response thereto; c) passing said electrical signal through a circuit having a selectable bandwidth; d) detecting the density of representations of bar code features in said electrical signal to produce a control signal; e) changing said selectable bandwidth using ; said control signal.
Claim 17
Independent Claim
80 words
A method of operating a bar code scanner, comprising the steps of: a) directing a light beam at a bar code symbol; b) detecting light reflected from said bar code symbol and generating an electrical signal in response thereto; c) passing said electrical signal through a circuit having a selectable bandwidth; d) detecting the density of representations of bar code features in said electrical signal to produce a control signal; e) changing said selectable bandwidth using ; said control signal.
References Cited (Backward Citations)
No citation records indexed.
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