Optical scanning head

• US RE36,528 E
• Filed: 03/24/1995
• Issued: 01/25/2000
• Est. Priority Date: 02/27/1992
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Roustaei, Alexander R.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US08/410,509
• Time in Patent Office: 1,768 Days
• Field of Search: 235/455, 235/472, 235/462, 235/466, 235/462.41, 235/462.42, 250/568, 250/227
• US Class Current: 235/472.01
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10742 including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/1092 sensing by means of TV-scanning

Abstract

The .[.ornamental.]. design for a bar code Scanner using the Light Emitting Diode (LED), Optical Scanner assembly and Charge-Coupled Devices (CCD) capable of reading the barcode symbols at the variable distance, as shown and described. The optical passive elements for increasing the depth of field and method of fabricating the scanning head by mass-production techniques are also disclosed.

Claims

1. A device for scanning and decoding information encoded in an optical code, said device comprising:

a printed circuit board having a front, a center, and a rear with a longitudinal centerline bisecting said printed circuit board into a left side and a right side;

a plurality of LEDs disposed on said printed circuit board near said front for projecting light outward from said front, a first portion of said plurality of LEDs disposed on said left side, each LED of said first portion being directed to emit light at a non-zero angle .[.so that its light intersects.]. .Iadd.with respect to .Iaddend.said longitudinal centerline .[.at an angle different from other LEDs of said first portion.]., and a second portion disposed on said right side, each LED of said second portion being directed to emit light at a non-zero angle.[., so that its light intersects.]. .Iadd.with respect to .Iaddend.said centerline .[.at an angle different from other LEDs of said second portion.]. so that a fan of light is emitted which becomes increasingly broader at greater distances from said plurality of LEDs;

an optic module disposed at said center of said printed circuit board for filtering reflected light which is reflected from the optical code and for focusing said reflected light at a focal plane;

a CCD detector disposed at said rear of said printed circuit board substantially at said focal plane, for receiving said reflected light and generating an electrical signal in response thereto;

a conversion means for converting said electrical signal into a digital signal corresponding to said .[.bar.]. .Iadd.optical .Iaddend.code; and

a voltage source for providing a driving voltage to said plurality of LEDs, said CCD detector and said conversion means.

2. A device as in claim 1 wherein said plurality of LEDs is disposed in a generally "V"-shaped arrangement.

3. A device as in claim 1 wherein said fan of light is projected to form a field of view within which said optical code can be read.

4. A device as in claim 3 wherein said field of view is within the range of zero to 9 inches.

5. A device as in claim 1 wherein said optic module comprises a plurality of lenses disposed within a dark room for shielding out external light.

6. A device as in claim 1 .Iadd.further comprising a window disposed at said front of said circuit board .Iaddend.wherein said plurality of LEDs is disposed as close as possible to said window.

7. A device as in claim 1 wherein said plurality of LEDs comprises six LEDs with three LEDs disposed on each of said left side and said right side of said printed circuit board.

8. A device as in claim 5 wherein said plurality of lenses comprises at least two piano-convex lenses and one bi-convex lens disposed along a common optical path.

9. A device as in claim 8 wherein said optic module further comprises at least one optical filter disposed along said common optical path. .Iadd.

11. said CCD detector and said conversion means. .Iaddend..Iadd.15. The device claimed in claim 14 wherein said each LED emits light having a wavelength of 660 nm. .Iaddend..Iadd.16. The device claimed in claim 14 further comprising a light-transmissive window disposed adjacent said front of said at least one printed circuit board in front of said plurality of LEDs. .Iaddend..Iadd.17. A device for scanning and decoding information encoded in an optical code having a first width, said device comprising:

a housing having a second width at a front end at which an incident beam of light for illuminating said optical code exits said housing, said second width being smaller than said first width;

at least one printed circuit board retained within said housing and having a front corresponding to said front end of said housing, a center, a rear and a longitudinal centerline bisecting said printed circuit board into a left side and a right side;

a plurality of LEDs disposed near said front of said at least one printed circuit board for projecting light outward from said front, a first portion of said plurality of LEDs being disposed on said left side and a second portion of said plurality of LEDs being disposed on said right side, each LED of said first portion of LEDs and said second portion of LEDs being directed to emit light at a non-zero angle with respect to said centerline so that said plurality of LEDs emits a diverging incident beam of light beyond said front end of said housing;

an optic module disposed at said center of said housing for focusing reflected light which is reflected from the optical code at a focal plane;

a CCD detector disposed substantially at said focal plane on said at least one printed circuit board for receiving said reflected light and generating an electrical signal in response thereto;

a conversion means for converting said electrical signal into a digital signal corresponding to said optical code; and

a voltage source for providing voltage to said plurality of LEDs, said CCD detector and said conversion means;

wherein said device is held at a distance from said bar code symbol and said diverging incident beam of light has a width at least as wide as said first width at a point at which said diverging incident beam of light

12. contacts said optical code. .Iaddend..Iadd.18. The device claimed in claim 17 wherein said each LED emits light having a wavelength of 660 nm. .Iaddend..Iadd.19. The device claimed in claim 17 further comprising a light-transmissive window retained within said front end of said housing in front of said plurality of LEDs. .Iaddend..Iadd.20. The device claimed in claim 17 further comprising an indicator lamp disposed on said housing for providing visual indication of a successful decode by said optical scanner. .Iaddend..Iadd.21. The device claimed in claim 17 further comprising a dark room disposed on said at least one printed circuit board so that said dark room surrounds said optic module and said CCD detector. .Iaddend..Iadd.22. The device claimed in claim 12 further comprising a dark room disposed on said at least one printed circuit board, said dark room surrounding said optic module and said CCD detector. .Iaddend.

10. In a device for scanning and decoding information encoded in an optical code, said device comprising a housing having a window portion with a first width, said housing retaining therein at least one printed circuit board having a front corresponding to said window portion, a light source, an optic module for focusing reflected light which is reflected from the optical code at a focal plane, and a CCD detector disposed substantially at said focal plane for receiving said reflected light and generating an electrical signal in response thereto, each mounted within said housing, a conversion means for converting said electrical signal into a digital signal corresponding to said optical code and a voltage source for providing a driving voltage to said light source, said CCD detector and said conversion means, wherein said device has a field of view having a second width greater than the first width, an improved light source comprising:

a plurality of LEDs disposed near said front of said at least one printed circuit board, each LED of said plurality being directed to emit light in a direction different from other LEDs of said plurality, said plurality of LEDs creating an incident beam of light which increases in width as a distance from said window portion increases. .Iaddend..Iadd.11. The improved light source for a device claimed in claim 10 wherein said each LED emits light having a wavelength of 660 nm. .Iaddend..Iadd.12. In a device for scanning and decoding information encoded in an optical code at a variable distance from the device, the device comprising a housing having a housing head with a window portion, a center portion and a rear portion, and a longitudinal centerline bisecting said housing head into a left side and a right side, said housing head retaining at least one printed circuit board having a front portion adjacent said window portion, an optic module for focusing reflected light which is reflected from said optical code at a focal plane disposed in said center portion of said housing head and a CCD detector disposed on said at least one printed circuit board substantially at said focal plane, for receiving said reflected light and generating an electrical signal in response thereto, a conversion means for converting said electrical signal into a digital signal corresponding to said optical code, and a voltage source for providing a driving voltage to said plurality of LEDs, said CCD detector and said conversion means, the improvement comprising;

a plurality of LEDs disposed near said front portion of said at least one printed circuit board, a first portion of said plurality of LEDs being disposed in said left side of said housing head and a second portion of said plurality of LEDs being disposed in said right side of said housing head, each of said first portion and said second portion of said plurality of LEDs being directed to project light outward from said front through said window portion so that a fan of light is emitted which becomes increasingly broad at greater distances beyond said window portion. .Iaddend..Iadd.13. The device claimed in claim 12 wherein said each LED emits light having a wavelength of 660 nm. .Iaddend..Iadd.14. A device for scanning and decoding information encoded in an optical code having a first width, said device comprising;

at least one printed circuit board having a front, a center, a rear and a longitudinal centerline bisecting said at least one printed circuit board into a left side and a right side, said front having a second width smaller than said first width;

a plurality of LEDs disposed on said at least one printed circuit board near said front for projecting a light outward from said front, a first portion of said plurality of LEDs being disposed on said left side and a second portion of said plurality of LEDs being disposed on said right side, each LED of said first portion and said second portion of LEDs being directed to emit light at a non-zero angle with respect to said centerline so that a fan of light is emitted which has a beam width which increases at greater distances from said front of said at least one printed circuit board;

an optic module disposed at said center of said at least one printed circuit board for focusing reflected light which is reflected from the optical code at a focal plane;

a CCD detector disposed substantially at said focal plane on said at least one printed circuit board for receiving said reflected light and generating an electrical signal in response thereto;

a conversion means for converting said electrical signal into a digital signal corresponding to said optical code; and

a voltage source for providing a driving voltage to said plurality of LEDs,