Patent ID: 7265337
Filing Date: 2007-09-04
Classification: G01D,G06F,H03K

Abstract:
1. Motion sensing apparatus comprising a source of light pulses; a moveable member configured both to move and to modulate by movement the light pulses thereby creating light pulses at a first light level and light pulses at a second light level, wherein a transition from a light pulse at the first light level to a light pulse at the second light level is indicative of movement of the element; at least one light sensitive electronic component, said light sensitive electronic component responsive to at least the light pulses at the first and second light levels, the pulses at the first and second light levels creating in said light sensitive electronic component first and second responses, respectively, each response having a first response portion and a second response portion, the response portions associated with light pulses at the first light level different from the response portions associated with light pulses at the second light level, wherein the apparatus is configured to sense movement of the moveable member by detecting a transition in the response of the light sensitive electronic component from a response corresponding to the first response portion associated with a light pulse at the first light level to a response corresponding to the first response portion associated with a light pulse at the second light level.