Data input device and method for detecting an off-surface condition by a laser speckle size characteristic
First Claim
1. A data input device for use with a tracking surface, said tracking surface having light-scattering properties with respect to said device, said device comprising:
- a coherent light source for projecting a coherent light beam onto said tracking surface, said tracking surface scattering the coherent light beam striking said tracking surface;
a detector associated with the coherent light source for detecting at least a portion of said scattered light, said detected portion comprising a speckle pattern; and
a controller configured to respond to the detected speckle pattern and operate the device in one of a tracking mode and a non-tracking mode depending upon a speckle size characteristic of the detected speckle pattern as determined by said controller, wherein said controller is configured to perform a spatial frequency analysis of said detected speckle pattern to determine said speckle size characteristic.
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Accused Products
Abstract
A data input device for use with a tracking surface having light-scattering properties with respect to the device is disclosed. The device comprises a coherent light source for projecting a coherent light beam onto the tracking surface. The tracking surface scatters the coherent light beam striking the tracking surface. The device further comprises a detector associated with the coherent light source for detecting at least a portion of the scattered light. The detected portion of the scattered light comprising a speckle pattern. The device further comprises a controller configured to respond to the detected speckle pattern and operate the device in one of a tracking mode and a non-tracking mode, depending upon a speckle size characteristic of the detected speckle pattern as determined by the controller.
73 Citations
39 Claims
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1. A data input device for use with a tracking surface, said tracking surface having light-scattering properties with respect to said device, said device comprising:
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a coherent light source for projecting a coherent light beam onto said tracking surface, said tracking surface scattering the coherent light beam striking said tracking surface; a detector associated with the coherent light source for detecting at least a portion of said scattered light, said detected portion comprising a speckle pattern; and a controller configured to respond to the detected speckle pattern and operate the device in one of a tracking mode and a non-tracking mode depending upon a speckle size characteristic of the detected speckle pattern as determined by said controller, wherein said controller is configured to perform a spatial frequency analysis of said detected speckle pattern to determine said speckle size characteristic. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method comprising:
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projecting a coherent light beam from a data input device onto a tracking surface having light-scattering properties, said tracking surface scattering the coherent light beam, detecting at least a portion of the light scattered by the tracking surface, said detected portion comprising a speckle pattern, determining if said device is spatially separated from said tracking surface by at least a lift-off detection distance as a function of a speckle size characteristic of said speckle pattern, and either suspending tracking of relative movement between said device and said tracking surface when said device is spatially separated from said tracking surface by at least the lift-off detection distance or maintaining tracking of relative movement between said device and said tracking surface when said device is spatially separated from said tracking surface by less than said lift-off detection distance. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A data input device for use with a tracking surface, said tracking surface having light-scattering properties with respect to said device, said device comprising
a coherent light source for projecting a coherent light beam onto said tracking surface, said tracking surface scattering the coherent light beam striking said tracking surface; -
a detector associated with the coherent light source for detecting at least a portion of said scattered light, said detected portion comprising a speckle pattern; and a controller configures to respond to the detected speckle pattern and determine a distance between the device and the tracking surface depending upon a speckle size characteristic of the detected speckle pattern as determined by said controller. - View Dependent Claims (38, 39)
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Specification