High-resolution optical encoder with phased-array photodetectors

Abstract

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.