Omnivision Technologies, Inc.

Lindsay Alexander Grant

Dyson Hsinchih Tai

Keiji Mabuchi

Yoshiyuki Matsunaga

Duli Mao

Gang Chen

Yuanwei Zheng

Chih-Wei Hsiung

Kazufumi Watanabe

Qin Wang

Vincent Venezia

Yin Qian

Sohei Manabe

Cunyu Yang

Young Woo Jung

Guannan Chen

Zhiqiang Lin

Sing-Chung Hu

Eric Webster

Tiejun Dai

Rui Wang

Boyd Fowler

Ming Zhang

Chen-Wei Lu

Eric A G Webster

Alireza Bonakdar

Chin Poh Pang

Kevin W Johnson

Xianmin Yi

Wei Zheng

Chia-Chun Miao

Dyson Hsin-Chih Tai

Qingwei Shan

Olivier Bulteel

Chun-Yung Ai

Philip John Cizdziel

Shao-Fan Kao

Jens Landgraf

Geunsook Park

Jingming Yao

An image sensor includes a plurality of pixels and includes a photodiode configured to operate in both modes of a linear mode for linearly responding to a light incident amount and a photo-voltaic mode for logarithmically responding to the light incident amount, a source follower circuit configured to output a signal voltage according to a signal generated according to an output of the photodiode, an AD converter configured to convert the signal voltage output from the source follower circuit into digital signal data, a frame memory configured to store signal data of one frame, and a conversion function configured to generate, from signal data of a current frame and signal data of a previous frame, an optical signal relating to the light incident amount.

Image sensor and optical signal generation method

An image sensor including a plurality of pixels arranged in a matrix. Each of the pixels includes a photodiode configured to operate both in a linear mode in which the photodiode shows a linear response to a light incident amount and in a photovoltaic mode in which the photodiode shows a logarithmic response to the light incident amount, a pixel source follower transistor configured to output a signal voltage corresponding to a signal generated based on an output of the photodiode, a pixel switch transistor configured to turn on/off an output of the pixel source follower transistor, a holding capacitor connected to an output end of the pixel switch transistor and configured to hold a voltage corresponding to the output of the photodiode, and an output source follower circuit configured to output the voltage held by the holding capacitor as a signal voltage to an AD converter.

Image sensor operating in a reset free photovoltaic mode

A pixel of an image sensor includes a photodiode, a reset transistor, a peak hold transistor, and a first capacitor and a second capacitor. The pixels include, a first mode in which the noise and image output voltages of the photodiode are held in the first and second capacitors, respectively, and a second mode in which the output voltage of the photodiode in a state where the reset transistor is turned on to reset the photodiode is held in the first capacitor or the second capacitor. In the first mode, an image signal corresponding to the light incident amount of the photodiode and a noise signal when the light incident amount is relatively low are obtained. In the second mode, a noise signal when the light incident amount of the photodiode is relatively high is obtained.

Photo voltaic image sensor to supress black solar

An image sensor includes: a photodiode configured to be reset for each one frame period, to accumulate charges corresponding to incident light for one frame period, and to output an output voltage corresponding to the accumulated charges; and a holding capacitor configured to accumulate charges corresponding to an output signal of the photodiode. The output signal of the photodiode for one frame is integrated, the integrated output signal is accumulated in the holding capacitor, and a first signal is output. After the holding capacitor is refreshed, a voltage corresponding to the output voltage of the photodiode is held in the holding capacitor, and a second signal is output.

Image sensor to suppress flicker

In a case where a photodiode is in a saturated state, the photodiode can be transited from the saturated state to an unsaturated state during a period when a knee pulse is supplied from a knee pulse supplying unit. The knee pulse supplying unit preferably supplies the knee pulse a plurality of times during one frame period.

Image sensor having pixels in linear mode and photovoltaic mode

An image sensor includes a sensor substrate and a circuit substrate. The sensor substrate includes a plurality of sensor substrate-side pixels. Each of the sensor substrate-side pixels includes a photodiode configured to operate in a photovoltaic mode, a reset transistor configured to reset the photodiode, and a pixel source follower transistor connected to an output of the photodiode. The circuit substrate includes circuit substrate-side pixels corresponding to the respective sensor substrate-side pixels of the sensor substrate. Each of the circuit substrate-side pixels includes a peak hold circuit configured to hold a peak of an output of the pixel source follower transistor by receiving the output of the pixel source follower transistor, and a readout source follower transistor configured to read out a voltage held in a holding capacitor. The sensor substrate-side pixels and the respective corresponding circuit substrate-side pixels are connected to each other.

Image sensor operating in a photovoltaic mode

A pixel circuit includes: a phototransistor configured to receive, by one region of a source and a drain, inflow of photo-carriers generated by light entering a substrate, and configured to output a voltage signal from the one region; and a blocking layer provided on another region of the drain and the source and on a side of a channel far from a surface, and configured to prevent the photo-carriers from directly flowing into the other region. The phototransistor causes a sub-threshold current to flow between the source and the drain in a pinch-off state. Each of the source and the drain of the phototransistor is periodically reset to a reset voltage. The reset voltage is set to a voltage between a voltage at which a dark current of the phototransistor becomes zero and a voltage at which a bias voltage of the phototransistor becomes zero.

Photo-voltaic phototransistor in forward bias

A pixel circuit includes: a photodiode configured to operate in a photovoltaic mode and to accumulate charges corresponding to an incident light amount; a reset transistor configured to reset the accumulated charges of the photodiode; and a peak hold circuit configured to hold an output corresponding to the accumulated charges of the photodiode, the peak hold circuit including a peak hold transistor connected to an output end of the photodiode, a switching transistor configured to turn on/off an output of the peak hold transistor, and a holding capacitor configured to hold an output of the switching transistor. The peak hold transistor operates in a state where no carrier charge or only one carrier charge is present on a channel.

Image sensor including peak hold circuit

A method of counting photons using a plurality of single photon avalanche diodes (SPADs), including initiating a detection phase, enabling each single photon avalanche diode (SPAD) of the plurality of SPADs for a period of time within the detection phase, accumulating a SPAD event from each SPAD of the plurality of SPADs, wherein each SPAD event corresponds to a detection of a single photon, determining a counter code at an end of the detection phase, where the counter code corresponds to accumulated SPAD events, and enabling one or more SPADs of the plurality of SPADs within an exposure phase based on the counter code, where the counter code is greater than an expected number of the SPAD events during the exposure phase, and where the expected number of SPAD events during the exposure phase is based on the counter code that is determined at the end of the detection phase.

Low power single photon avalanche diode photon counter with peak current suppression technique

A pixel-array substrate includes a semiconductor substrate with a pixel array, a back surface, and a front surface, and a guard ring formed of a doped semiconductor, enclosing the pixel array, and extending into the semiconductor substrate from the front surface, the back surface forming a trench extending into the semiconductor substrate, the trench overlapping the guard ring. A method for reducing leakage current into a pixel-array includes doping a semiconductor substrate to form a guard ring that extends into the semiconductor substrate from a front surface, encloses a pixel array, excludes a periphery region, and resists a flow of electric current, and forming, into a back surface of the semiconductor substrate, a trench that penetrates into the back surface and overlaps the guard ring, the guard ring and the trench configured to resist the flow of electric current between the pixel array and the periphery region.

Electrical isolation in pixel-array substrates using combination of doped semiconductor guard rings and overlapping isolation trenches

A light-trapping image sensor includes a pixel array and a lens array. The pixel array is formed in and on a semiconductor substrate and including photosensitive pixels each including a reflective material forming a cavity around a portion of semiconductor material to at least partly trap light that has entered the cavity. The cavity has a ceiling at a light-receiving surface of the semiconductor substrate, and the ceiling forms an aperture for receiving the light into the cavity. The lens array is disposed on the pixel array. Each lens of the lens array is aligned to the aperture of a respective cavity to focus the light into the cavity through the aperture.

Light-trapping image sensors

An image sensor includes a substrate. An array of photodiodes is disposed in the substrate. A plurality of spacers is arranged in a spacer pattern. At least one spacer of the plurality of spacers has an aspect ratio of 18:1 or greater. A buffer layer is disposed between the substrate and the spacer pattern. An array of color filters is disposed in the spacer pattern.

Fully buried color filter array of image sensor

Backside illuminated sensor pixel structure. In one embodiment, and image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that are disposed in a semiconductor substrate. Individual photodiodes of the pixel array are configured to receive an incoming light through a backside of the semiconductor substrate. A front side of the semiconductor substrate is opposite from the backside. A plurality of transistors disposed proximate to the front side of the semiconductor substrate, are arranged in a row along an outer perimeter of the photodiodes of the respective pixel; and a plurality of isolation structures arranged to bracket the row of transistors along the outer perimeter of the photodiodes. A plurality of contacts electrically contacting the plurality of isolation structures, and the contacts are configured to voltage-bias the plurality of isolation structures.

Negatively biased isolation structures for pixel devices

A semiconductor device that includes a metal pad buried in the semiconductor substrate that is electrically connected to a metal interconnection structure and electrically isolated from the semiconductor substrate. The semiconductor substrate forms an opening that extends from a back surface to the metal pad. A method for manufacturing a semiconductor device with buried metal pad including depositing, in a recess of a semiconductor substrate, a metal pad, isolating the pad from the substrate, electrically connecting the metal pad to the frontside of the substrate and connecting the metal pad to the backside of the substrate with an opening. A method for stabilizing through-silicon via connections in semiconductor device including electrically coupling a metal interconnection structure to a metal pad submerged in a semiconductor substrate and forming a through-silicon via into the semiconductor substrate that contacts the metal pad.

Semiconductor device with buried metal pad, and methods for manufacture

An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by two micro-lenses, respectively. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array. A PDAF micro-lens is formed on the coating layer to cover the first image sensor pixels.

Growing community of inventors

Campbel, CA, United States of America

Lindsay Alexander Grant