| 摘要 |
A system to project the image of a virtual input device includes a substrate bearing a diffractive pattern, and a source of collimated light, such as a laser diode. The collimated light interacts with the substrate and the pattern to project a user-viewable image that preferably is the image of a virtual input device. Interaction between a user and the projected image of the virtual input device can then be sensed, and used to input information or otherwise control a companion device, for example a PDA or a cellular telephone. |
