Optical navigation device having a variable depth of field

摘要

An optical navigation device containing an adjustable depth of field light source is positioned with respect to a surface such that the depth of field of light source can be adjusted to match the Z dimension of a particular surface. In one embodiment, a plurality of individual light sources are used each having a different angle of reflection from the surface. By selecting the light source having an angle of reflection to match the Z dimension of the surface to be navigated the device can be used over a wide range of Z dimensions. In one embodiment, the selection of the proper light source is accomplished upon start-up of the device with respect to a particular surface and in another embodiment a user can adjust the light surface to obtain optimal performance.