Em Microelectronic-Marin Sa

Em(us) Design, Inc

Honeywell G.m.b.h.

Literal Corporation

Information Storage, Inc.

Em Microelectronics-US, Inc

Media Security Incorporated and Associates

James Harold Lauffenburger

Kevin Scott Buescher

Gil Afriat

Robert Rudolf Rotzoll

Lawrence Bieber

Michel Willemin

André Grandjean

John William Arachtingi

Sylvain Grosjean

Marc Degrauwe

Marc Morin

George S Moore

Steve S Popovich

Tzuo-Chang Lee

Andre Novickis

George F Denehy

The automatic gain control unit for a radiofrequency receiver includes a first current source for charging a storage capacitor by a first current, four comparators for comparing on the lower side an in-phase positive intermediate signal, an in-phase negative intermediate signal, a quarter-phase positive intermediate signal, a quarter-phase intermediate signal with a first reference threshold to a high amplitude level of the intermediate signals. Each comparator controls a MOS transistor connected in series between a second current source and the storage capacitor in order to discharge the storage capacitor when each transistor is in a conductive state. A bi-stable trigger element is connected to the storage capacitor and to provide an AGC signal depending on the voltage level on the storage capacitor for attenuating or not the gain of the low noise amplifier or of a mixer unit amplifier of the receiver.

Automatic gain control unit for a low power receiver or transceiver

The invention concerns an optical pointing device comprising a coherent light source for illuminating a surface portion with radiation, a driver of the coherent light source for controlling coherent light emissions, a photodetector device responsive to radiation reflected from the illuminated surface portion, processing means for determining, based on the photodetector device response, a measurement of relative motion between the optical pointing device and the illuminated portion of the surface, wherein the coherent light source driver is a fault-tolerant driver comprising redundant power control means for limiting the output power of coherent light emissions.

Single fault laser driver control for optical mouse

A method for detecting lift from a surface portion of an optical pointing device comprising a coherent light source, a photodetector device including an array of pixels, and extracting motion features including comparators with an adjustable offset value, the method comprising the steps of: (i) illuminating the surface portion with radiation by the coherent light source; (ii) detecting radiation patterns reflected from the illuminated surface portion with the photodetector device; (iii) comparing light intensity between neighbouring pixels in the detected radiation patterns; (iv) extracting motion features as a function of the result of the comparison; (v) counting the total number of motion features extracted; (vi) increasing or decreasing the comparator offset value when the total number of motion features increases or decreases; (vii) comparing the comparator offset value with an offset threshold; (viii) enabling detection of a lift condition if the comparator offset value is lower than the offset threshold.

Enhanced lift detection technique for a laser illuminated optical mouse sensor

A method for operating an optical motion sensing device comprising a light source and a photodetector device, said method comprises the steps of: a) illuminating a surface portion with radiation by means of the light source; b) detecting radiation patterns reflected from the illuminated surface portion by means of the photodetector device; c) extracting motion features from the detected radiation patterns by comparing light intensity between neighbouring pixels of said photodetector device by means of comparators with a determined hysteresis threshold; d) detecting and measuring displacement with respect to the illuminated surface portion based on said extracted motion features; e) determining whether the optical motion sensing device is moving or at rest; f) adjusting said determined hysteresis threshold of the comparators between at least a low and a high hysteresis values, consisting in selecting said low hysteresis value when the optical motion sensing device is moving and selecting said high hysteresis value when the optical motion sensing device is at rest.

Method, sensing device and optical pointing device including a sensing device for comparing light intensity between pixels

A method for operating an optical sensing device having a light source and a photodetector device with at least one photosensitive element. A surface portion is illuminated with radiation by the light source and the radiation reflected from the illuminated surface portion is detected with a photosensitive element. While said surface portion is being illuminated, an output signal of the photosensitive element over time is integrated, the output signal integration level is compared with a first integration reference level during integration; the integration step is interrupted if the output signal integration level has reached the first integration reference level, or the comparison step is repeated until a first integration period has elapsed if the output signal integration level has not reached the first integration reference level.

Method of optimization of measurement time for optical mouse sensor

A method for extending battery life in an optical pointing device powered by one or more battery cells (), the optical pointing device including an optical motion sensing device () for tracking motion with respect to a surface (S) and comprising motion sensing circuitry () coupled to an optical sensor () and at least one light source () for illuminating a portion of the surface. The method comprises the steps of (i) monitoring the power output of the said one or more battery cells (), (ii) detecting when the said power output falls below a certain threshold indicative of a low battery status (EOL) and (iii) upon detection of the low battery status, switching the optical pointing device into a low power consumption mode where power consumption of the optical pointing device is reduced and performance of the optical motion sensing device is partially degraded. An optical pointing device implementing this method.

Extension of battery life in a battery-powered optical pointing device

There is described a method of post-processing and reporting detected displacement in an optical pointing device as well as a sensing device for an optical pointing device implementing this method. Displacement is detected and a first count representative of a magnitude of the detected displacement is accumulated in an associated accumulation unit, this first count representing the magnitude of the detected displacement at a first resolution (or detection resolution). The first count accumulated in the accumulation unit is processed to convert this first count into a report count representing the magnitude of the detected displacement at a second resolution (or reporting resolution) lower than the first resolution. This report count is then reported, for instance to a PC or an external controller. These operations are repeated to generate periodic motion reports at the second resolution.

Displacement data post-processing and reporting in an optical pointing device

There is described a method of operating an optical motion sensing device comprising a light source and a photodetector device, the method comprising the steps of a) illuminating a surface portion with radiation by means of the light source, b) detecting radiation reflected from the illuminated surface portion by means of the photodetector device, c) detecting and measuring displacement with respect to the illuminated surface portion; and d) outputting motion reports that are each representative of a magnitude of the detected displacement, steps a) to d) defining a flash period and being repeated at a selected flash rate. The method further comprises the steps of e) comparing the magnitude of the detected displacement with a determined displacement threshold, and f) increasing or decreasing the flash rate if the magnitude of the detected displacement is respectively greater or lower than the displacement threshold. There is also described an optical motion sensing device implementing this method.

Method of operating an optical motion sensing device and optical motion sensing device implementing this method

There is described a method as well as a device for motion detect ion in an optical sensing device, such as an optical mouse. A photodetector array comprising a plurality of pixels is used to detect successive light intensity patterns of an illuminated portion of a surface with respect to which a measurement of relative motion is to be determined. Light intensity between neighbouring pixels is compared in order to determine edge direction data descriptive of light intensity differences between the pixels, such data including (i) a first edge condition, or positive edge, defined as a condition wherein light intensity of a first pixel is less than light intensity of a second pixel, and (ii) a second edge condition, or negative edge, defined as a condition wherein light intensity of the first pixel is greater than light intensity of the second pixel. Through comparison of this edge direction data with edge direction data determined from a previous illumination (or by comparing data extracted from this edge direction data) a measurement of the relative motion of the optical sensing device with respect to the illuminated portion of the surface is determined.

Method and sensing device for motion detection in an optical pointing device, such as an optical mouse

There is described an optical sensing device, a method for controlling operation of an optical sensing device comprising a light source for illuminating a surface portion with radiation, a photodetector device having at least one photosensitive element responsive to radiation reflected from the illuminated surface portion, and conversion means for integrating an output signal of said at least one photosensitive element over time during an integration period of variable duration, which duration depends on power of the light source and level of radiation reflected from the illuminated surface portion. The optical sensing device further comprises a regulating system for controlling power if the light source as a function of a comparison between a parameter representative of the evolution of the integration of the output signal of the said at least one photosensitive element and at least one reference value. Regulation is advantageously performed by timing the duration of the integration period or by determining the rate of evolution of the integrated signal, comparing this duration or rate of evolution with at least one reference value and controlling power of the light source as a function of the result of the comparison. There is also described an optical pointing device implementing the above regulation scheme as well as an optical sensing device exploiting this scheme so as to sense proximity of the illuminated surface portion with respect to the optical sensing device.

Method and system for optimizing illumination power and integration time in an optical sensing device

There is described a method, a sensing device as well as an optical pointing device including a sensing device for comparing light intensity between pixels. Light intensity between pairs of pixels of a photodetector array is compared as follows. First and second output signals generated by the photosensitive elements of a first and a second pixel of each pair are integrated over time to respectively provide first and second integrated signals. Integration of the first output signal is interrupted at the end of a first time period and the resulting first integrated signal is stored. Integration of the second output signal is continued until the end of a second time period and the resulting second integrated signal is compared to the stored first integrated signal to provide an output signal representative of an edge condition between the first and second pixel.

An amplifier circuit ( ) having a rotating input stage has a switching network ( ) connected to an input ( ). A number of parallel transconductance gain stages ( ) are connected to the switching network ( ). An auto-zeroing circuit ( ) is connected to the switching network ( ). A second transconductance gain stage ( ) is connected to the parallel transconductance gain stages ( ).

Photodetector preamplifier circuit having a rotating input stage

A low-corner frequency high pass filter circuit ( ) includes an operational amplifier ( ). The operational amplifier ( ) has an inverting input ( ) and a non-inverting input ( ). A series capacitor ( ) has a first end connected to the non-inverting input ( ) of the operational amplifier ( ). A second end of the series capacitor ( ) is connected to an input signal ( ). A low gain amplifier ( ) has an input connected to an output ( ) of the operational amplifier ( ) and has an output ( ) connected to the non-inverting input ( ) of the operational amplifier ( ). The low gain amplifier ( ) performs the function of large value resistor.

Integrated low-corner frequency high pass filter circuit

A parasitically compensated resistor ( ) for integrated circuits includes a substrate ( ). A polysilicon resistor ( ) is formed in the substrate ( ). The polysilicon resistor ( ) has a first end connected to a first lead ( ) and a second end connected to a second lead ( ). A conductive layer ( ) is capacitively connected to the polysilicon resistor ( ).

Parasitically compensated resistor for integrated circuits

An amplifier circuit ( ) for a photodetector includes a transconductance variable gain stage ( ). The transconductance variable gain stage ( ) has an input ( ) capable of connecting to the photodetector and an output ( ). A transconductance gain stage ( ) has an input ( ) connected to the output ( ) of the transconductance variable gain stage ( ). A feedback resistor ( ) is connected between an output ( ) of the transconductance gain stage ( ) and the input ( ) of the transconductance gain stage ( ).

Growing community of inventors

Colorado Springs, CO, United States of America

James Harold Lauffenburger