US 5,354,977 AGranted

Optical scanning head

OwnerAlex Roustaeiinventor

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Abstract

The optical scanning head for scanning one- and two-dimensional bar codes includes at least one combination of light emitting diodes arranged so the LEDs emit light at different angles to create a fan of light. The combination and arrangement of the LEDs depends on whether one- or two-dimensional bar codes are to be read. A cylindrical lens optimizes the light impinging upon the bar code. An optical module includes a light shield or "dark room" and a lens/filter assembly which focusses reflected light on the detector, made up of a CCD module for detecting the light intensity in the reflected beam over a field of view across a bar code symbol. One or more combinations of linear CCD arrays in the CCD module generate an electrical signal indicative of the detected light intensity. A trigger mechanism allows selection of the number of LEDs or linear CCD arrays to efficiently scan one- or two-dimensional bar codes, where two-dimensional bar codes require more illumination for accurate scanning.

Claims97

Dependent claims

An optical scanning device for scanning one- and two-dimensional bar codes comprising:

a printed circuit board having a front and a rear;
an LED array having a plurality of LEDs disposed near said front of said printed circuit board wherein each LED of said plurality is oriented to emit light at an angle different than other LEDs of said plurality, said angle of each LED being a non-zero angle with respect to a reference line perpendicular to said front of said circuit board, said LED array projecting a fan of light forward in a direction along said reference line;
a cylindrical lens forward of said LED array having and input edge and an output edge for focussing said fan of light into a line of light at its focal distance for illuminating a bar code within a field of view within a range of said focal distance so that reflected light is reflected therefrom;
a detector comprising at least one linear CCD array disposed near rearward of said LED array on said printed circuit board for detecting a portion of reflected light from said bar code and generating an electrical signal in response thereto wherein said electrical signal is an analog representation of said bar code;
an optical assembly for receiving said reflected light and directing said reflecting light onto said detector;
a conversion assembly for converting said electrical signal into a signal corresponding to said bar code;
and
a voltage source for providing a driving voltage to said LED array, said CCD detector and said conversion assembly.

5 more elements

An optical scanner for reading and decoding information encoded in one-dimensional and/or two-dimensional bar codes comprising alternating lines of light and dark, said optical scanner comprising:

a printed circuit board having a front, a center and a rear;
an array of light emitting diodes comprising at least one combination of light emitting diodes disposed near said front of said printed circuit board in an arrangement wherein each light emitting diode of said at least one combination emits light at an angle different from other light emitting diodes of said at least one combination so that a fan of light is projected from said array along a line perpendicular to said front of said printed circuit board;
a cylindrical lens having an input edge and an output edge disposed forward of said array of light emitting diodes for focussing said fan of light into a line of light at its focal distance onto a reference plane within a field of view containing said bar code so that light is reflected therefrom;
an optical assembly disposed at a center of said printed circuit board for receiving, concentrating and directing reflected light toward said rear of said board;
a CCD array disposed at said rear of said printed circuit board for detecting a portion of said reflected light directed thereon by said optical assembly and generating an analog representation of said bar code;
a conversion assembly for receiving and converting said analog representation into an electrical signal corresponding to said bar code;
and
a voltage source for providing a driving voltage to said array of light emitting diodes, said CCD array and said conversion assembly.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/965,991Filed 23 Oct 1992 · continuation in part
Priority: 27 Feb 1992
Granted: 11 Oct 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G06K 7/10742
Photodetector array or CCD scanning: including a diffuser for diffusing the light from the light source to create substantially uniform…
G03F 7/705
Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring…:…
G06K 7/10722
Fixed beam scanning: photodetector array or CCD scanning
G06K 7/10732
Photodetector array or CCD scanning: light sources