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United States Patent5594231   
Link to this pagehttp://www.wikipatents.com/5594231.html
Inventor(s)Pellicori; Samuel F. (Santa Barbara, CA); Sullivan; Sean (Eugene, OR); Ahten; Michael J. (Eugene, OR)
AbstractA scanner window through which a laser beam is projected to define a scanning pattern comprises a substrate formed of light transmissive material which allows the laser beam to project through a light transmissive hard material layer deposited onto the substrate, and a light transmissive lubricous coating deposited onto the hard material resulting in the scanner window having improved resistance to abrasive wear. The present invention is also directed to a method of producing such a scanner window. The present method may incorporate various deposition techniques to form a wear resistant scanner window in accordance with the present invention.
   














 Title Information Submit all comments and votes
 
Patent Text Patent PDF Print Page Summary File History
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Drawing from US Patent 5594231
Scanner window - US Patent 5594231 Drawing
Scanner window
Inventor     Pellicori; Samuel F. (Santa Barbara, CA); Sullivan; Sean (Eugene, OR); Ahten; Michael J. (Eugene, OR)
Owner/Assignee     Spectra-Physics Scanning Systems, Inc. (Eugene, OR)
Patent assignment
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Publication Date     January 14, 1997
Application Number     08/323,844
PAIR File History     Application Data   Transaction History
Image File Wrapper   Patent Term   Fees
Litigation
Filing Date     October 17, 1994
US Classification     235/462.32 428/408 428/432 428/433 428/446 428/698 428/702
Int'l Classification     G06K 007/10
Examiner     Turner; A. A.
Assistant Examiner    
Attorney/Law Firm     Lyon & Lyon
Address
Parent Case     This is a divisional of application Ser. No. 07/647,540 filed on Jan. 29, 1991, now abandoned.
Priority Data    
USPTO Field of Search     428/408 428/432 428/433 428/701 428/698 428/446 428/702 235/462 235/467
Patent Tags     scanner window
   
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Market Size
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$5B - $10B
$2B - $5B
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Market Share
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25% - 49.99%
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 Technical Review Submit all comments and votes
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What is claimed is:

1. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window;

c. optics for projecting a laser beam through said scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, said scanner window comprising:

i. a substrate formed of light transmissive material;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of aluminum oxide, aluminum nitride, zirconium oxide, yttrium oxide, diamond film, diamond-like carbon, silicon nitride, boron nitride and combinations thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

2. A bar code scanner according to claim 1, wherein said lubricous layer is diamond-like carbon.

3. A bar code scanner according to claim 1, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

4. A bar code scanner according to claim 1, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

5. A bar code scanner according to claim 1, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

6. A bar code scanner according to claim 1, wherein said laser beam is emitted by a diode laser.

7. A bar code scanner according to claim 1, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

8. A bar code scanner according to claim 7, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

9. A bar code scanner according to claim 8, wherein said lubricous outermost layer is diamond-like carbon.

10. A bar code scanner according to claim 9, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

11. A bar code scanner according to claim 1, further comprising an adhesive material positioned between said substrate and said interlayer.

12. A bar code scanner according to claim 1, wherein said interlayer is deposited directly onto said substrate.

13. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser beam through said scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, and wherein said scanner window is comprised of an inner window and an outer window, at least one of which is wear resistant glass comprising:

i. a substrate formed of light transmissive material;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of aluminum oxide, aluminum nitride, zirconium oxide, yttrium oxide, diamond film, diamond-like carbon, silicon nitride, boron nitride and combinations thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window of wear resistant glass is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

14. A bar code scanner according to claim 13, wherein said outer window is replaceable.

15. A bar code scanner according to claim 13, wherein said lubricous layer is diamond-like carbon.

16. A bar code scanner according to claim 13, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

17. A bar code scanner according to claim 13, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

18. A bar code scanner according to claim 13, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

19. A bar code scanner according to claim 13, wherein said laser beam is emitted by a diode laser.

20. A bar code scanner according to claim 13, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

21. A bar code scanner window according to claim 20, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

22. A bar code scanner according to claim 21, wherein said lubricous outermost layer is diamond-like carbon.

23. A bar code scanner according to claim 22, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

24. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser beam through a scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, said scanner window comprising:

i. a substrate formed of light transmissive material;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of metallic oxides and metallic nitrides and combinations and admixtures thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

25. A bar code scanner according to claim 24, wherein said lubricous layer is diamond-like carbon.

26. A bar code scanner according to claim 24, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

27. A bar code scanner according to claim 24, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

28. A bar code scanner according to claim 24, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

29. A bar code scanner according to claim 24, wherein said laser beam is emitted by a diode laser.

30. A bar code scanner according to claim 24, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

31. A bar code scanner window according to claim 30, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

32. A bar code scanner according to claim 31, wherein said lubricous outermost layer is diamond-like carbon.

33. A bar code scanner according to claim 32, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

34. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser bean through a scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, and wherein said scanner window is comprised of an inner window and an outer window, at least one of which is wear resistant glass comprising:

i. a substrate formed of light transmissive material;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of metallic oxides and metallic nitrides and combinations and admixtures thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window of wear resistant glass is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

35. A bar code scanner according to claim 34, wherein said outer window is replaceable.

36. A bar code scanner according to claim 34, wherein said lubricous layer is diamond-like carbon.

37. A bar code scanner according to claim 34, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

38. A bar code scanner according to claim 34, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

39. A bar code scanner according to claim 34, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

40. A bar code scanner according to claim 34, wherein said laser beam is emitted by a diode laser.

41. A bar code scanner according to claim 34, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

42. A bar code scanner window according to claim 41, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

43. A bar code scanner according to claim 42, wherein said lubricous outermost layer is diamond-like carbon.

44. A bar code scanner according to claim 43, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

45. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window;

c. optics for projecting a laser beam through said scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, said scanner window comprising:

i. a substrate formed of light transmissive material; wherein said substrate is selected from the group consisting of borosilicate glass, soda-lime silicate (float) glass, glass ceramic, quartz, high silica content glass and combinations thereof;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of aluminum oxide, aluminum nitride, zirconium oxide, yttrium oxide, diamond film, diamond-like carbon, silicon nitride, boron nitride and combinations thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

46. A bar code scanner according to claim 45, wherein said lubricous layer is diamond-like carbon.

47. A bar code scanner according to claim 45, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

48. A bar code scanner according to claim 45, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

49. A bar code scanner according to claim 45, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

50. A bar code scanner according to claim 45, wherein said laser beam is emitted by a diode laser.

51. A bar code scanner according to claim 45, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

52. A bar code scanner window according to claim 51, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

53. A bar code scanner according to claim 52, wherein said lubricous outermost layer is diamond-like carbon.

54. A bar code scanner according to claim 53, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

55. A bar code scanner according to claim 45, further comprising an adhesive material positioned between said substrate and said interlayer.

56. A bar code scanner according to claim 45, wherein said interlayer is deposited directly onto said substrate.

57. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser beam through said scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, and wherein said scanner window is comprised of an inner window and an outer window, at least one of which is wear resistant glass comprising:

i. a substrate formed of light transmissive material; wherein said substrate is selected from the group consisting of borosilicate glass, soda-lime silicate (float) glass, glass ceramic, quartz, high silica content glass and combinations thereof;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of aluminum oxide, aluminum nitride, zirconium oxide, yttrium oxide, diamond film, diamond-like carbon, silicon nitride, boron nitride and combinations thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window of wear resistant glass is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window scanner and read successfully.

58. A bar code scanner according to claim 57, wherein said outer window is replaceable.

59. A bar code scanner according to claim 57, wherein said lubricous layer is diamond-like carbon.

60. A bar code scanner according to claim 57, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

61. A bar code scanner according to claim 59, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

62. A bar code scanner according to claim 60, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

63. A bar code scanner according to claim 62, wherein said laser beam is emitted by a diode laser.

64. A bar code scanner according to claim 57, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

65. A bar code scanner window according to claim 64, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

66. A bar code scanner according to claim 65, wherein said lubricous outermost layer is diamond-like carbon.

67. A bar code scanner according to claim 66, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

68. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser beam through a scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, said scanner window comprising:

i. a substrate formed of light transmissive material; wherein said substrate is selected from the group consisting of borosilicate glass, soda-lime silicate (float) glass, glass ceramic, quartz, high silica content glass and combinations thereof;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of metallic oxides and metallic nitrides and combinations and admixtures thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window and read successfully.

69. A bar code scanner according to claim 68, wherein said lubricous layer is diamond-like carbon.

70. A bar code scanner according to claim 68, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

71. A bar code scanner according to claim 68, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

72. A bar code scanner according to claim 68, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

73. A bar code scanner according to claim 68, wherein said laser beam is emitted by a diode laser.

74. A bar code scanner according to claim 68, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

75. A bar code scanner window according to claim 74, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

76. A bar code scanner according to claim 75, wherein said lubricous outermost layer is diamond-like carbon.

77. A bar code scanner according to claim 76, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.

78. A bar code scanner comprising:

a. a laser light source for emitting a laser beam;

b. a scanner window; and

c. optics for projecting a laser beam through a scanner window to define a scanning pattern comprised of a plurality of scan lines projecting into a volume extending beyond said scanner window, and wherein said scanner window is comprised of an inner window and an outer window, at least one of which is wear resistant glass comprising:

i. a substrate formed of light transmissive material; wherein said substrate is selected from the group consisting of borosilicate glass, soda-lime silicate (float) glass, glass ceramic, quartz, high silica content glass and combinations thereof;

ii. a light transmissive interlayer of a hard material deposited onto said substrate, wherein said hard material is selected from the group consisting of metallic oxides and metallic nitrides and combinations and admixtures thereof; and

iii. a light transmissive lubricous outermost layer deposited onto said interlayer; wherein said lubricous layer is selected from the group consisting of diamond-like carbon, diamond film, polytetrafluoroethylene, polyethylene, tin oxide, indium oxide, silicon polymers, boron nitride, aluminum oxide and combinations thereof; wherein

iv. the transmission level of said window of wear resistant glass is at least 75% so as to allow said laser beam to project through and define said scanning pattern comprised of a plurality of scan lines in said volume and further allow light reflected from a bar code within said volume to be received back through said window scanner and read successfully.

79. A bar code scanner according to claim 78, wherein said outer window is replaceable.

80. A bar code scanner according to claim 78, wherein said lubricous layer is diamond-like carbon.

81. A bar code scanner according to claim 78, wherein said scanner window has a transmission of at least 75% at a wavelength of 670 nm.

82. A bar code scanner according to claim 78, wherein said scanner window has a transmission of at least 75% at a wavelength of 633 nm.

83. A bar code scanner according to claim 78, wherein said scanner window has a transmission of at least 75% at a wavelength in the red region of the electromagnetic spectrum.

84. A bar code scanner according to claim 78, wherein said laser beam is emitted by a diode laser.

85. A bar code scanner according to claim 78, wherein the combined thickness of interlayer and said lubricous outermost layer is set in the range of 0.055 .mu.m to 15 .mu.m.

86. A bar code scanner window according to claim 85, wherein the thickness of said hard material interlayer is set in the range of about 0.05 .mu.m to 10 .mu.m.

87. A bar code scanner according to claim 86, wherein said lubricous outermost layer is diamond-like carbon.

88. A bar code scanner according to claim 87, wherein the thickness of said diamond-like carbon is set in the range of about 50.ANG. to about 5 .mu.m.
 Description Submit all comments and votes
 


BACKGROUND OF THE INVENTION

Laser scanners for use at point-of-sale checkout counters in supermarkets and other retail stores are becoming more and more common as the reliability of scanners increases and their costs decrease. The scanners are commonly mounted within the checkout counters such that they have generally upwardly facing scanner windows through which laser beams are projected in defined scanning patterns. A scanning pattern is created by a laser and associated optical components which produce a plurality of intersecting scan lines to define the pattern. An optical bar coded label including for example a UPC, EAN or JAN code on the packaging of a product presented at a counter is passed through the scan volume of a laser scanner, i.e. the volume extending beyond the face of the scanner within which bar coded labels can be read successfully. Light reflected from a bar coded label is received back through the scanner window and processed to identify the product and provide pricing information for the sale and other retailing applications such as inventory control.

Existing bar code scanners may have two windows through which the scanning beam passes, an inner window which is permanently mounted to seal and protect the scanner, and an outer window which is easily replaceable. However, scuffs and scratches in this outer scanner window due to repeated dragging of packages, cans, bottles and the like thereover reduce transmission through the scanner window. The original scan capabilities can be periodically restored by replacing the outer scanner window when the read rate falls below an acceptable value. Unfortunately, the outer scanner windows need to be replaced frequently to maintain scanner operation within acceptable levels resulting in undesirable service expenses.

Many attempts have been made in the past to provide a more durable scanner window and a method for making same. One such attempt has been to use a sapphire sheet-glass laminate to eliminate the scratching and scuffing condition since the hardness of the sapphire is much greater than any material commonly used in the packaging of merchandise items. Such windows are very expensive and therefore are limited to small window dimensions. Windows which are coated with hard thin films have been used. A tin oxide coating has been applied to transparent substrates, however, tin oxide has not provided a window having a long enough lifetime.

Yet another attempt is found in WO 87/02713 wherein a method for forming an abrasion resistant coating on a transparent substrate is disclosed. More specifically, this method uses a dual ion-beam sputtering technique to coat a transparent substrate with an aluminum oxide layer to form an abrasion resistant scanner window used in bar coding systems. This method, however, is impractical and economically infeasible as applied to the production of scanner windows. The WO 87/02713 method only provides for a deposition rate of 0.4 nanometers per minute which is extremely slow and thereby results in high production costs and low throughput productivity. Further, the maximum area of coverage is only 100 square centimeters and therefore, only four scanner windows can be coated in a single coating run.

Accordingly, it is perceived that a need exists for a bar code scanner window having the ability to resist abrasive scratching and scuffing for long periods of time without affecting the operation of the bar code scanner system. There also is a need for a method for making such a scanner window which results in high throughput productivity and low production costs.

SUMMARY OF THE INVENTION

The present invention meets these needs by providing a scanner window through which a laser