Computer input apparatus
AssigneePixart Imaging Inc.
InventorsSheng-Yeh Lai, Ming-Hui Kuo
Life of this patent
Estimating the term…
Abstract
A computer input apparatus is disclosed which has improved safety control. Computer input devices with coherent light sources are popular. However, coherent light sources may cause serious and unrecoverable injuries to human eyes. Accordingly, there are several safety specifications defined by manufacturers and governments. Therefore, an improved device is disclosed that includes a calibration circuit and a fault detection circuit to control the operation current of a coherent light source to be within the safety specifications range, and to monitor for fault conditions. Furthermore, a computer input apparatus with coherent light source can be operated without the traditional optical lens.
Claims29
A computer input apparatus, the apparatus comprising:
- a light source to project light on a working surface;
- a sensor chip to capture reflected images from said working surface;
- and
- a control circuit having a calibration circuit to control power provided to said light source.
A computer input apparatus, the apparatus comprising:
- a light source to project light on a working surface;
- a sensor chip to capture reflected images from said working surface;
- and
- a control circuit having a fault detection circuit to control power provided to said light source.
A computer input apparatus, comprising:
- a light source to project a light on a working surface;
- a sensor chip to capture reflected images from said working surface;
- a control circuit having a fault detection circuit, a first current source to provide a current flowing through said light source, and a calibration circuit to control said first current source by a first control signal to provide said current in a specific range between a threshold current and a safety current of said light source;
- wherein said fault detection circuit controls said first current source by a second control signal to avoid excessive current flowing through said light source.
Dependencies are inferred from the claim text.