Pixart Imaging Incorporated

Pixart Imaging (penang) Sdn. Bhd.

Wooi Kip Lim

Yong Yeap Tan

Sung-Han Wu

Keen-Hun Leong

Siew Chin Lee

Kwai Lee Pang

Kei Tee Tiew

A pixel circuit, comprising: a light sensing circuit, configured to operate corresponding to a light intensity of light received by the light sensing circuit; a first capacitor; a first discharging circuit, coupled to the light sensing circuit and the first capacitor, configured to discharge the first capacitor corresponding to an operation of the light sensing circuit; a first charging circuit, coupled to the first capacitor, configured to charge the first capacitor corresponding to the operation of the light sensing circuit; a second capacitor; a second discharging circuit, coupled to the light sensing circuit and the second capacitor, configured to discharge the second capacitor corresponding to the operation of the light sensing circuit; and a second charging circuit, coupled to the second capacitor, configured to charge the second capacitor corresponding to the operation of the light sensing circuit. An image sensor applying the pixel circuit is also disclosed.

Pixel circuit and image sensor

A method of an image sensor device includes: providing a pixel array having multiple bipolar junction transistor (BJT) pixel circuits arranged in N rows and M columns; and shortening a setting time period of a BJT sensing circuit in the pixel array during the setting time period by dynamically changing a bias current provided from a current source of the BJT sensing circuit during the setting time period.

Mechanism of effectively shortening settling time of pixel circuit

An optical sensor device includes a pixel array and a control circuit. The pixel array has pixel units arranged in N rows and M columns, and a pixel unit comprises: a photo transistor, configured to capture and generate a first image signal during a first shutter exposure time interval of a first time and to capture and generate a second image signal during a second shutter exposure time interval of a second time, the first time and the second time being consecutive; a first integration capacitor, coupled to the photo transistor, for storing the first image signal; and a second integration capacitor, coupled to the photo transistor, for storing the second image signal. The control circuit performs a motion detection to determine whether a motion occurs according to a difference between the two image signals.

Optical sensor mechanism capable of improving signal sensitivity of motion detection as well as consuming lower power

A method of an image sensor device includes: providing a pixel array having a plurality of pixel units; using a pixel pre-processing circuit for receiving a plurality of analog pixel signals respectively from the plurality of pixel units to perform a low-pass filter operation upon the plurality of analog pixel signals in analog domain to generate a plurality of analog processed signals, a number of the plurality of analog processed signals being smaller than a number of the plurality of analog pixel signals; using an analog-to-digital converter for converting the plurality of analog processed signals in the analog domain into a plurality of digital processed signals in digital domain; and, transmitting the plurality of digital processed signals in digital domain into a digital processing circuit coupled to the analog-to-digital converter.

Image sensor mechanism for pre-processing analog pixel data of pixel array to reduce design complexity and save power consumption for digital processing circuit

An image sensor device includes a sensor array and a processing circuit. The sensor array includes a plurality of pixel units each including a photodiode unit and a storage capacitor. The sensor array generates an image of a specific frame, and the photodiode unit is illuminated by a light ray to generate a photodiode current which is stored in the storage capacitor when the image sensor device performs an exposure operation. The processing circuit generates a reference current according to photodiode current(s) of photodiode unit(s) of pixel unit(s) before the exposure operation arranged for the specific frame starts, and predicts a length of an exposure time interval of the exposure operation for the specific frame based on the generated reference current.

Method and image sensor device capable of predicting appropriate length of exposure time interval for incoming frame(s)

An image sensor comprising a BJT pixel circuit, a biasing circuit and a comparator. The BJT pixel circuit comprises a BJT; a charging selection circuit, configured to control a first storage capacitor to be charged in a first reset time and to control a second storage capacitor to be charged to a second reset time; a discharging selection circuit, configured to control the first storage capacitor to be discharged by the BJT in a first exposure time to generate a first output voltage, and to control the second storage capacitor to be discharged by the BJT in a second exposure time to generate a second output voltage; a biasing circuit, configured to provide voltage decreasing and voltage increasing to the second output voltage to generated adjusted images; and a comparator, configured to compare the first output voltage and the adjusted voltages.

Image sensor comprising BJT pixel circuit and image sensing system applying the image sensor

An optical detecting device capable of detecting a lift height of an optical navigation apparatus is disclosed. The optical detecting device includes a sensor module and a processor. The sensor module includes a sensor array and at least one detector strip. The sensor array is adapted to acquire navigation information of the optical navigation apparatus moved relative to a working surface by sensing an illumination area, and the detector strip has a detection region across an edge of the illumination area. The processor is electrically connected to the sensor module, and adapted to compute the lift height of the optical navigation apparatus relative to the working surface according to a detection result of the detector strip.

Optical detecting device with lift height detection function

A bipolar junction transistor (BJT) pixel circuit, including: a BJT transistor, having a base coupled to a photo detector, an emitter coupled to a shutter circuit, and a collector coupled to a reference ground level; the photo detector, having first end coupled to the base of BJT transistor and second end coupled to the reference ground level, for generating base current based on light intensity of light incident on the photo detector; the shutter circuit, coupled to the emitter of the BJT transistor, for controlling exposure time of the photo detector according to a shutter signal; and a storage capacitor, coupled between the shutter circuit and an adjustable ground level different from the reference ground level, for storing image data captured by the photo detector, wherein the adjustable ground level is boosted to be higher than the reference ground level for one or more times during the exposure time.

Scheme of boosting adjustable ground level(s) of storage capacitor(s) of BJT pixel circuit(s) in pixel array circuit of image sensor apparatus

A short circuit testing method for a capacitive sensing device including a plurality of sense lines and a plurality of drive lines includes: under a short circuit testing mode, coupling at least one first line in the sense lines and drive lines to a reference level; using a sensing circuit corresponding to a specific sense line to read out a testing resultant signal; and, comparing the testing resultant signal with a reference signal to determine whether a short circuit exists.

Short circuit testing method for capacitive sensing device and the capacitive sensing device

A method applied to a BJT pixel of an image sensor apparatus includes: obtaining at least one of a surface quality signal of a first image sensed by the BJT pixel and a shutter turn-on time corresponding to the first image; and adaptively adjusting a pre-flash time of the BJT pixel for sensing of a second image according to the at least one of the surface quality signal of the first image and the shutter turn-on time corresponding to the first image; wherein the second image follows the first image.

Method applied to BJT pixel of image sensor apparatus and image sensor apparatus

A temperature detecting circuit comprising: a comparator, comprising a first comparing terminal and a second comparing terminal; a time interval computing unit; a switch module, coupled to the first comparing terminal and the second comparing terminal, comprising a reference voltage terminal coupled to a reference voltage source, and comprising a first input terminal, a second input terminal and a third input terminal; a first current source, comprising a first charging terminal coupled to the first input terminal and the second input terminal; a first capacitor, coupled to the first current source at the first charging terminal; a capacitance adjusting unit, coupled to the first capacitor; a second current source, comprising a second charging terminal coupled to the third input terminal, wherein the second current source is a current source which provides a constant current; and a second capacitor, coupled to the second current source at the second charging terminal.

Voltage comparing circuit and voltage comparing method

A voltage comparing circuit comprising: a comparator,; a time interval computing unit; a switch module,; a first current source, comprising a first charging terminal; a first capacitor, coupled to the first current source at the first charging terminal; and a capacitance adjusting unit, coupled to the first capacitor. In a first calibration mode, the first comparing terminal receives a reference voltage.

An image sensor circuit, comprises: a photo sensing circuit including a photo sensitive device for sensing a light signal to generate a photo sensing signal at a photo sensing output node; a charge storage device, coupled to an integration node; an integration switch coupled between the photo sensing output node and the integration node, operating according to an integration control signal; and a reset circuit coupled between a voltage supply and the integration node, operating according to a reset control signal and a read control signal, wherein the integration node includes an integration voltage. In a reset time period, the integration switch is conductive, and the reset circuit generates a reset signal on the integration node to bias the photo sensitive device through the integration switch to an active state and to charge the charge storage device such that the integration voltage is determined to be at a reset level.

Image sensor circuit and image sensing method

A bipolar junction transistor (BJT) pixel circuit, an image sensor and a driving method thereof are provided. The BJT pixel circuit includes a BJT, a photodetector, a feedback amplifier circuit, a shutter circuit, and a current generating unit. The photodetector generates a first base current to a base of the BJT responsive to a light incident on the photodetector. The feedback amplifier circuit is operative to increase an emitter voltage of the BJT according to the light intensity. The shutter circuit controls an exposure time of the photodetector according to a shutter signal. The current generating unit generates the second pulsed base current responsive to a trigger signal causing a base voltage of the BJT to drop while the feedback amplifier circuit operates to increase the emitter voltage of the BJT so as to build-up the base-emitter voltage to a predetermined voltage level when a light source turns on.

Bipolar junction transistor pixel circuit, driving method thereof, and image sensor

An amplifying circuit, which comprises: an amplifier, comprising a signal input terminal and a signal output terminal; a first current sinking module, for sinking a third current from the signal input terminal; and a noise sensing module, for sensing a output voltage level at the signal output terminal, for controlling the first current sinking module to sink the third current from the signal input terminal if the output voltage level is larger than a first high threshold value, and for controlling the first current sinking module not to sink the third current if the output voltage level is smaller than the first high threshold value.

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Penang, Malaysia

Wooi Kip Lim