Patent ID: 7327440

Claim:
A device for measuring distance over a known range comprising: a laser, a first beam splitter, a lens, a second beam splitter, a first sensor, and a second sensor; the laser being configured to emit energy at an object; the first splitter being configured to direct emitted energy along a straight line away from the device, and to direct energy, reflected from the object, toward the lens; the lens configured to focus the reflected energy onto the second splitter; the second splitter configured to split the focused energy into a number of beams that corresponds to the number of sensors; each of the sensors having a photo sensitive surface that is divided into at least two sensing areas such that the surface has an inner sensing area and an outer sensing area; and the lens being shaped and the sensors being positioned such that when the object is at the minimum distance of the known range, almost all of the energy focused on the first sensor will be focused on the inner sensing area, and when the object is at the maximum distance of the known range almost all of the energy focused on the second sensor will be focused on the inner sensing area.