Embodiments of high-resolution optical encoders having phased-array photodetectors
and integrated on semiconductor chips. Emitters, detectors, and encoders disks
are described which can be easily produced with semiconductor processes, such as
a detector array provided with lens to collimate light and enhance detection. Integrated
sensor chips include an array of photodetectors that receive energy from a beam
emitted from an emitter and modulated by an encoder disk, analog-to-digital converters,
state machines, counters, a communication module, a sensor processing unit, and
a force computation unit. One embodiment includes low resolution and high resolution
modes and an emitter controlled by sensor circuitry. A detector for an optical
encoder can be provided on a single chip that includes a first array of photodetectors
used for absolute sensing of a moving object, and a second array of photodetectors
used for incremental sensing of the moving object.
