| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a data input device using at a tracking surface which has a light scattering property for a device. <P>SOLUTION: The device has a coherent light source which projects the coherent light beam to the tracking surface which scatters the coherent light beam projecting the tracking surface. The device has a detector relevant to the coherent light source and detects at least a part of the scattered light. The detected part of the scattered light includes a speckle pattern. And responding to the detected speckle pattern, the device has a controller which is configured so that the device may be operated by at least one of a tracking mode and a non-tracking mode, corresponding to the speckle size property of the detected speckle pattern decided by the controller. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
