Cypress Semiconductor Corporation

Silicon Light Machines Corporation

Brian Todoroff

Yansun Xu

John Frame

Steven Sanders

Clinton Carlisle

Jahja I Trisnadi

Robert J Lang

Douglas Webb

Brett Alan Spurlock

Jinghui Mu

Jeffry C Bailey

KeCai Zeng

Optical navigation modules and methods of operating the same to sense relative movement between the optical navigation module and a tracking surface are provided. In one embodiment, the optical navigation module comprises: (i) a light source to illuminate at least a portion of a surface relative to which the optical navigation module is moved; (ii) an integrated circuit (IC) including a photo-detector array (PDA) to detect a light pattern propagated onto the PDA from the surface, and a signal processor to translate changes in the light pattern propagated onto the PDA into data representing motion of the optical navigation module relative to the surface; and (iii) a substrate to which the light source and IC are mounted, the substrate including an aperture in a light path between the surface and the PDA. Other embodiments are also disclosed.

Optical navigation module with capacitive sensor

An optical navigation apparatus including a package incorporating a light source and a single die of silicon. The single die of silicon includes a photodiode array configured at the detection plane to receive the speckle pattern of the scattered light from the collection optics, circuitry configured to process signals from the photodiode array to determine changes in position of the apparatus relative to the tracking surface, analog circuitry configured to control and drive current through the light source, interface circuitry configured to communicate position data by outputting the position data via a data interface, a microcontroller comprising a processor core and memory for storing computer-readable code and data, and a system bus configured to communicate instructions and data between the microcontroller and said digital, analog, and interface circuitries. Other embodiments, aspects and features are also disclosed.

Optical navigation system using a single-package motion sensor

An optical navigation system and method are provided. In one embodiment, the method includes: (i) generating for a first group of photosensitive elements a first quasi-sinusoidal signal at a first time, and a second quasi-sinusoidal signal at a second time in response to motion of light received thereon in a first direction; (ii) computing from the first and second quasi-sinusoidal signals a phase angle change; and (iii) computing from the first and second quasi-sinusoidal signals a radius value. Other embodiments are also described.

Circuit and method for determining motion with redundant comb-arrays

One embodiment relates to a method of tracking motion using a speckle-based motion sensor. A distance moved is determined by a first signal processing procedure, and a distance moved is determined by a second signal processing procedure. Selection between said distances is made based on whether the distance determined by the first signal processing procedure exceeds a predetermined threshold distance. According to a preferred embodiment, the first signal processing procedure makes a more accurate determination of distance for slower speeds, while the second signal processing procedure makes a more accurate determination of distance for higher speeds. Other embodiments, aspects and features are also disclosed.

Processing methods for speckle-based motion sensing

A method is provided for sensing displacement of an optical sensor relative to a surface, the sensor having at least first and second arrays with a plurality of photosensitive elements. The method involves: (i) generating for each array first set of quasi-sinusoidal signals at a first time and a second set of quasi-sinusoidal signals at a second time in response to motion of light received thereon; (ii) computing from said first and second sets of signals phase angle changes for signals received from each array; (iii) computing from said first and second sets of signals radius values for signals received from each array; (iv) computing unwrapped phase angle changes for signals received from each array; and (v) combining said unwrapped phase angle changes for each of said arrays using radius-weighted-averaging to provide a single weighted average of unwrapped phase angle change resulting from said motion of light.

One embodiment relates to a method of sensing motion of an optical sensor relative to a surface. A first resolution and a second resolution are set. Measurement signals are obtained from a sensor array, and the motion of the optical sensor relative to the surface is tracked using the measurement signals. The tracking of the motion in a first dimension is performed at the first resolution, and the tracking of the motion in a second dimension is performed at the second resolution. Another embodiment relates to an optical sensor apparatus for sensing motion relative to a surface, wherein the tracking of the motion is performed at a variable resolution along each of two axes. Other embodiments and features are also disclosed.

Optical navigation sensor with variable tracking resolution

One embodiment relates to a method of velocity prediction using a sensor array. Differential signals are obtained from the sensor array at multiple frame rates. A first velocity prediction is determined from the differential signals at a first frame rate, and a second velocity prediction is determined from the differential signals at a second frame rate. Another embodiment relates to an optical navigation apparatus which includes a sensor array, differential circuitry, driver circuitry, and a signal processing device. The driver circuitry is configured to drive the sensor array and differential circuitry so as to operate at multiple frame rates in an interleaved manner. The signal processing device is configured to compute a first velocity prediction from the differential signals at a first frame rate and to compute a second velocity prediction from the differential signals at a second frame rate. Other embodiments and features are also disclosed.

Method and apparatus for robust velocity prediction

A circuit and method are provided for reducing power consumption in an optical navigation system for use in an input device to sense displacement of the device relative to a surface. Generally, the system includes: (i) an optical sensor having at least first and second arrays of photosensitive elements; (ii) imaging optics to map an illuminated portion of the surface to the optical sensor; (iii) a signal processor including a first and second sensor circuits coupled to the respective first and second arrays to generate from each array a set of signals in response to motion of light received thereon; and (iv) a control circuit capable of independently switching power to the sensor circuits. In one embodiment, the control circuit powers down one sensor circuit when the strength of the set of signals from the other is greater than a predetermined minimum thereby maintaining device performance. Other embodiments are also disclosed.

Circuit and method for reducing power consumption in an optical navigation system having redundant arrays

A method is provided for determining motion of an optical sensor including a periodic photo-diode array relative to a surface. The method includes steps of (i) generating sets of quasi-sinusoidal signals responsive to motion along first and second directions; (ii) combining the sets of signals to generate a wrapped phase angle value for each direction at a first time; (iii) combining the sets of signals at a second time to generate a second wrapped phase angle value for each direction; (iv) computing wrapped phase angle changes for each direction between the first time and the second time; (v) computing velocity predictors for each direction using corrected average phase angle changes from a number of preceding successive frames; (vi) calculating the number of full 27&#x3c0; rotations needed to unwrap the phase angle changes for each direction using the velocity predictors; and (vii) computing the unwrapped or corrected phase angle changes.

Method for determining motion using a velocity predictor

A signal processing circuit and processing method are provided for measuring an analog signal from a photo-detector. Generally, the method includes steps of: (i) sampling and storing a characteristic of the signal at a first predetermined time following a reset of the circuit; (ii) sampling the characteristic of the signal at a second predetermined time following a reset or initialization of the circuit; (iii) determining a difference between the stored characteristic of the signal sampled at the first predetermined time and the characteristic of the signal sampled at the second predetermined time; and (iv) converting the determined difference to a digital value and determining a slope of the signal from the digital value and the difference between the first and second predetermined times. Thus, the measurement of the slope is independent of and substantially unaffected by absolute values of the characteristics measured at the first and second predetermined times.

Signal processing circuit and method for use with an optical navigation system

A signal processor and method are provided for detecting movement of a surface relative to an optical sensor having an array of photosensitive elements. Generally, the method involves: (i) sampling each of a number (M) of phase signals from the photosensitive elements, each of the M signals having a magnitude (A) and including a tracking signal at a frequency being tracked and a background signal at other frequencies that offsets the tracking signal, where i, an index of the signals, is a whole number between 0 and M-1; (ii) eliminating the offset to the tracking signal due to the background signal to generate M non-offset phase signals having a magnitude (A'); (iii) adjusting phase angles (&#x3b8;) of the non-offset phase signals to generate M weighted phase signals (A&#x2032;&#x3b8;&#x2032;); and (iv) combining each of the M weighted phase signals (A&#x2032;&#x3b8;&#x2032;) to generate an average weighted phase having a phase angle (&#x3b8;), that when tracked over time indicates a direction and velocity of the movement of an image of the surface mapped to the array.

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San Jose, CA, United States of America

Brian Todoroff