Hui Tian

US Patent:

6498336, Dec 24, 2002

Filed:

Nov 15, 2000

Appl. No.:

09/713151

Inventors:

Hui Tian - Stanford CA
Ricardo Motta - Palo Alto CA

Assignee:

Pixim, Inc. - Mountain View CA

International Classification:

H01L 3100

US Classification:

2502141, 257436

Abstract:

An image (or other light) sensor has a reflective element under each light-sensing element. The reflective element is positioned to reflect incident light that passes through the light-sensing element without being absorbed, back towards the light-sensing element for a second chance at being absorbed. The present invention increases the effective quantum efficiency of each light-sensing element without having to increase the thickness of the absorption region within the light-sensing element. In one embodiment, each reflective element is a discrete mirror that is positioned within the sensor packaging adjacent to (e. g. , below) the integrated image sensor. In another embodiment, each reflective element is an integral part of the integrated circuit that contains the image sensor, such as a light-reflecting region formed within the substrate below the corresponding light-sensing element.

US Patent:

6498576, Dec 24, 2002

Filed:

Mar 30, 2001

Appl. No.:

09/823344

Inventors:

Hui Tian - Stanford CA
David Xiao Dong Yang - Mountain View CA

Assignee:

Pixim, Inc. - Mountain View CA

International Classification:

H03M 112

US Classification:

341155, 341156, 341139, 341122, 341 14, 341160, 341161, 348294, 348297

Abstract:

A system and method for performing low-power analog-to-digital conversion in digital imaging system utilizing a time-indexed multiple sampling technique is presented. The analog-to-digital converter is switched off when the digital image signal resulting from an exposure time selected from a plurality of exposure times satisfies a threshold value.

US Patent:

6507083, Jan 14, 2003

Filed:

Oct 5, 2000

Appl. No.:

09/680087

Inventors:

Hui Tian - Stanford CA

Assignee:

Pixim, Inc. - Mt. View CA

International Classification:

H01L 310232

US Classification:

257432, 257435, 257436

Abstract:

An image sensor has a light-shielding layer with openings corresponding to an array of light-sensing elements formed below on a substrate. Light-reflecting material is applied to form (e. g. , vertical) via walls between each opening in the light-shielding layer and the corresponding light-sensing element. Light having a non-normal angle of incidence will reflect off the vertical light-reflecting via structures towards the light-sensing elements. As such, substantially all of the light that passes through an opening in the light-shielding layer will reach the light-sensing element, even light incident at relatively low angles, thereby reducing the problem of pixel vignetting associated with prior art image sensors. As a result, the image sensor has a greater and more uniform sensitivity across the entire sensor array.

US Patent:

6542189, Apr 1, 2003

Filed:

Nov 8, 2001

Appl. No.:

10/005834

Inventors:

Hui Tian - Stanford CA

Assignee:

Pixim, Inc. - Mountain View CA

International Classification:

H04N 314

US Classification:

348297, 348364

Abstract:

A system and method for performing frequency compensation in a video digital cameral utilizing a time-indexed multiple sampling technique is presented. The frequency compensation removes distortion from the digital image signal captured by the video digital camera as compared with a human-perceived image signal.

US Patent:

6545258, Apr 8, 2003

Filed:

Mar 30, 2001

Appl. No.:

09/822036

Inventors:

Hui Tian - Stanford CA
William R. Bidermann - Los Gatos CA
David X. D. Yang - Mountain View CA
Yi-Hen Wei - San Jose CA

Assignee:

Pixim, Inc. - Mountain View CA

International Classification:

H01L 2700

US Classification:

2502141, 2502081, 257 81, 257291, 438 94, 438 96

Abstract:

Photo-sensors, such as photo-diodes, are formed using regions with cross-sections that increase the overall quantum efficiency of the resulting photo-sensor. The cross-sections have additional (e. g. , interior) side-wall interfaces, and, in some embodiments, an additional, relatively shallow bottom interface. The increased total side-wall area and any additional shallow bottom area increase the total photo-junction volume located near the surface of the device. As a result, a greater fraction of photons having relatively small absorption lengths (e. g. , blue light) will be absorbed within a photo-junction, thereby increasing the quantum efficiency for those photons. The present invention enables photo-sensors to be implemented with more uniform spectral response.

US Patent:

6803553, Oct 12, 2004

Filed:

May 23, 2001

Appl. No.:

09/863545

Inventors:

Hui Tian - Stanford CA

Assignee:

PiXIM, Inc. - Mountain View CA

International Classification:

H01L 2700

US Classification:

2502081, 2502141

Abstract:

An image sensor having a circuit to recover photo-generated charge and to apply it to reduce consumption of power from a power supply (e. g. , an external battery). In one embodiment (e. g. , FIG. 4), the image sensor has at least one light-sensing photoelement implemented in an integrated circuit and adapted to be powered by a power supply, other circuitry that consumes power during a standby operating mode for the image sensor, and a circuit configured to selectively connect the photoelement to the power-consuming circuitry. During the image sensors standby mode, the photoelement is configured to supply at least a portion of the standby current to the power consuming circuitry. In another embodiment (e. g. , FIG. 3), the image sensor has a storage device (e. g. , a capacitor), and a circuit configured to selectively connect the storage device to the photoelement or to the power-consuming circuitry.

US Patent:

6806514, Oct 19, 2004

Filed:

Oct 24, 2001

Appl. No.:

09/999730

Inventors:

Hui Tian - Stanford CA
Ricardo Motta - Palo Alto CA

Assignee:

PiXIM, Inc. - Mountain View CA

International Classification:

H01L 2710

US Classification:

257202, 257203, 257204, 257207, 257208, 348311, 348312, 348313, 348314

Abstract:

A digital pixel sensor-based modular digital imaging system includes several integrated circuit modules. At least one module includes an integrated circuit die having a digital pixel sensor array and a frame buffer, and at least one module includes an integrated circuit die having control circuitry and/or I/O circuitry. In certain embodiments all component modules are generally the same; in other embodiments the component modules include different integrated circuits that perform different functions. A higher pixel count imaging system may be made by disposing several component modules having lower pixel count digital pixel sensor arrays adjacent one another.

US Patent:

6821750, Nov 23, 2004

Filed:

Nov 20, 2001

Appl. No.:

09/989981

Inventors:

Helen H. Hobbs - Dallas TX
Bei Shan - Redwood City CA
Robert Barnes - Frisco TX
Hui Tian - Foster City CA

Assignee:

Tularik Inc. - South San Francisco CA
Board of Regents, The University of Texas System - Austin TX

International Classification:

C12N 1585

US Classification:

435 691, 4352523, 43525411, 4353201, 536 231, 536 235

Abstract:

The present invention provides nucleic acids encoding a novel ABC family cholesterol transporter, ABCG8. The herein-disclosed sequences can be used for any of a number of purposes, including for the diagnosis and treatment of cholesterol-associated disorders, including sitosterolemia, and for the identification of molecules that associate with and/or modulate the activity of ABCG8.