Patent ID: 7196320

Claim:
An optical encoder adapted to be used with a movable object comprising: a light source and a light detector connected at one end of an elongated optical fiber, said light source for transmitting light into said optical fiber, said detector for receiving light from said optical fiber; a shutter that has a mass of opaque slits and a mass of transparent slits, said shutter located directly adjacent an opposite end of said optical fiber, said opposite end to emit light, said shutter functioning to permit passage of said light through said transparent slits or blocking light by said opaque slits, said shutter being movable relative to said optical fiber in coordination with the movable object; a mirror mounted exteriorly of said shutter, said mirror functioning to reflect light that has been transmitted through said transparent slits back through said transparent slits to be transmitted by said optical fibers to said detector; and a light filter assembly mounted between said shutter and said mirror, said light filter assembly being constructed of a plurality of light filters with each light filter of said light filters permitting transmission of only a specific wavelength range of light, whereby said detector is not only able to count each time light is blocked by said shutter and then transmitted by said shutter but also determine position of the movable object and direction of movement of said shutter by noting which wavelength of light is being received first by said detector and which is received second.