Abstract: An optical input device for an apparatus generates input signals by moving the device and an object (15) relative to each other and measures the movement by the effects of self-mixing in a diode laser (3, 5) and Doppler shift caused by the movement. For each measuring axis (X, Y, Z), radiation from a diode laser (3, 5) is converged on a window (12) across which the object (15) moves. Part of the radiation scattered by the object, whose frequency is Doppler-shifted due to the movement, re-enters the laser cavity (20) and causes a change in cavity properties. By measuring such a change, for example, by a photo diode, information about the movement is obtained. As the input device is small and cheap, it can be used in a number of different consumer apparatus.

Abstract: An optical input device for measuring the movement of a finger (15) ia accommodated in a housing provided with a transparent window (12) for transmitting a measurement beam (13) from a diode laser (3) to the finger and radiation reflected by the finger to a detector (4). This feature prevents that grease and dust disturb and block the measuring beam.

Abstract: An optical input device for an apparatus, generating input signals by moving the device and an object (15) relative to each other and measuring the movement by means of the effects of self-mixing in a diode laser (3,5) and Doppler shift caused by the movement. For each measuring axis (X,Y,Z) radiation from a diode laser (3,5) is converged on a window (12) across which the object (15) moves Part of the radiation scattered by the object, whose frequency is Doppler-shifted due to the movement, re-enters the laser cavity (20) and causes a change in cavity properties. By measuring such a change, for example by means of a photo diode, information about the movement is obtained. As the input device is small and cheap, it can be used in a number of different consumer apparatus.