Wand type optical reader
First Claim
1. A laser wand for reading optically encoded information comprising:
- means for producing a focussed laser light beam having a fixed focal point directed toward optically encoded information;
a photodetector for sensing light reflected back from the optically encoded information; and
means, coupled to the means for producing the focussed laser light beam, for contacting a surface on which the optically encoded information is formed to selectively define at least two different distances between the means for producing the focussed laser light beam and the optically encoded information, whereby the diameter of the focussed laser light beam at its point of impact on the optically encoded information will be different for each of the two different distances.
1 Assignment
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Accused Products
Abstract
A laser wand for reading optically encoded indicia has a wand shaped housing for housing a light emitter which for emits a focussed laser light beam having a fixed focal point beyond which said light beam diverges. The light beam is directed towards a surface on which the indicia is disposed. A spacer is also provided for alternatively defining different separation distances between the light emitter and indicia. At a first separation distance, the light beam forms a sensing spot of a first size on the surface on which the indicia is disposed. This sensing spot is effective for reading indicia having a first physical characteristic. At a second separation distance, the light beam forms a sensing spot of a second size, which is larger than the first size, on the surface on which the indicia is disposed. This later sensing spot is effective for reading indicia having a second physical characteristic different from the first physical characteristic. For example, indicia having the first physical characteristic may be of a higher density than indicia having the second physical characteristic.
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Citations
20 Claims
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1. A laser wand for reading optically encoded information comprising:
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means for producing a focussed laser light beam having a fixed focal point directed toward optically encoded information; a photodetector for sensing light reflected back from the optically encoded information; and means, coupled to the means for producing the focussed laser light beam, for contacting a surface on which the optically encoded information is formed to selectively define at least two different distances between the means for producing the focussed laser light beam and the optically encoded information, whereby the diameter of the focussed laser light beam at its point of impact on the optically encoded information will be different for each of the two different distances. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of reading optically encoded information comprising:
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producing a focussed laser light beam having a fixed focal point; contacting the surface on which the optically encoded information is formed to define a first distance between said focal point of the focussed laser light beam and the optically encoded information; directing the focussed laser light beam toward optically encoded information; sensing light reflected back from the optically encoded information; contacting the surface on which the optically encoded information is formed to define a second distance between the focal point of the focussed laser light beam and the optically encoded information, wherein said second distance is different from said first distance; directing the focussed laser light beam toward the optically encoded information; and sensing light reflected back from the optically encoded information to fully read the optically encoded information.
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10. A method of reading optically encoded information of different densities comprising:
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producing a focussed laser light beam having a fixed focal point; contacting a surface on which optically encoded information of a first density is formed to define a first distance between the focal point of the focussed laser light beam and the optically encoded information; directing the focussed laser light beam toward optically encoded information of the first density; sensing light reflected back and deriving therefrom an electrical representation of the optically encoded information of the first density; contacting a surface on which optically encoded information of a second density is formed to define a second distance between the focal point of the focussed laser light beam and the optically encoded information, wherein said second density is different from said first density and said second distance is different from said first distance; directing the focussed laser light beam toward the optically encoded information of the second density; and sensing light reflected back and deriving therefrom an electrical representation of the optically encoded information of the second density.
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11. A laser wand for reading optically encoded indicia comprising:
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a wand shaded housing; a light emitter, housed within said housing, for emitting a focussed laser light beam having a fixed point beyond which said light beam diverges, said light beam being directed towards a surface on which said indicia is disposed; a spacer capable of alternatively defining a first separation distance and a second separation distance, different from said first separation distance, between said light emitter and said indicia;
whereinat said first separation distance, said light beam forms a sensing spot of a first size on said surface and effective for reading indicia having a first physical characteristic; at said second separation distance, said light beam forms a sensing spot of a second size, larger than the first size, on said surface and effective for reading indicia having a second physical characteristic different from the first physical characteristic. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification