ASIC controller for light-based sensor

摘要

A controller for a light-based touch screen including a chip package coupled with a light-based touch screen, emitter driver circuitry inside the chip package for selectively activating a plurality of photoemitters that are outside of the chip package, detector driver circuitry inside the chip package for selectively activating a plurality of photo detectors that are outside of the chip package, detector signal processing circuitry for generating detection signals representing measured amounts of light detected on the plurality of photo detectors, a first plurality of signal conducting pins for connecting the plurality of photoemitters outside the chip package to the emitter driver circuitry inside the chip package, a second plurality of signal conducting pins for connecting the plurality of photo detectors outside the chip package to the detector driver circuitry and to the detector signal processing circuitry inside the chip package, controller circuitry inside the chip package for controlling the emitter driver circuitry and the detector driver circuitry, and at least one input/output pin for communicating with a host processor and for outputting the detection signals generated by the detector signal processing circuitry to the host processor, for the host processor to identify one or more locations on the touch screen that are being touched.

主权项

1. A programmable state machine for controlling a light-based sensor comprising:
a chip package coupled with a plurality of photo-emitters mounted in a device outside of the chip package, with a plurality of photo-detectors mounted in the device outside of the chip package, and with a host processor, the chip package comprising:
an emitter driver for selectively activating the emitters;a detector driver for selectively activating the detectors;a signal processor for generating detection signals representing measured amounts of light detected on the detectors; anda scan controller for controlling said emitter and detector drivers to activate the emitters and detectors in an automated sequence that activates at least 50 distinct emitter-detector pairs within 1 millisecond, the scan controller comprising:
dedicated emitter registers for storing, prior to executing the automated sequence, parameters designating a scan sequence of the emitters that are to be activated, activated during the automated sequence;dedicated detector registers for storing, prior to executing the automated sequence, parameters designating a scan sequence of the detectors that are to be activated during the automated sequence as pairs with the activated emitters; anddedicated results registers for storing the detection signals generated by said signal processor for the at least 50 distinct emitter-detector pair activations; a first plurality of signal conducting pins for connecting the emitters to said emitter driver; a second plurality of signal conducting pins for connecting the detectors to said detector driver and to said signal processor; and at least one input/output pin for receiving parameters from the host processor to be loaded into said dedicated emitter and detector registers, for outputting an interrupt signal to the host processor after the automated sequence is terminated, and for outputting the stored detection signals in said dedicated results registers to the host processor after outputting the interrupt signal, for the host processor to identify therefrom location coordinates of an object near or touching the device.