Patents Assigned to Canesta, Inc.
  • Patent number: 7379163
    Abstract: Performance of pixel detectors in a TOF imaging system is dynamically adjusted to improve dynamic range to maximize the number of pixel detectors that output valid data. The invention traverses the system-acquired z depth, the brightness, and the active brightness images, and assigns each pixel a quantized value. Quantization values encompass pixels receiving too little light, normal light, to too much light. Pixels are grouped into quantized category groups, whose populations are represented by a histogram. If the number of pixels in the normal category exceeds a threshold, no immediate corrective action is taken. If the number of pixel receiving too little (or too much) light exceeds those receiving too much (or too little) light, the invention commands at least one system parameter change to increase (or decrease) light reaching the pixels. Controllable TOF system parameters can include exposure time, common mode resets, video gain, among others.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: May 27, 2008
    Assignee: Canesta, Inc.
    Inventors: Abbas Rafii, Salih Burak Gokturk
  • Patent number: 7379100
    Abstract: Dynamic range of photodetector sensors useable in a TOF system is enhanced by capturing images of an object using multiple exposure time settings. Longer exposure settings more appropriately capture non-reflective and/or distant objects, while shorter exposure settings more appropriately capture reflective and/or closer objects. During parallel mode operation, detection signal readouts are taken from each photodetector at different time intervals within an overall exposure time. In sequential mode operation, detection signal readouts are taken and stored for each photodetector at the end of a first exposure time interval and the photodetectors are reset. After a second, different exposure time interval readouts are taken and stored, and the photodetectors reset, etc. In these modes one of the time exposure intervals will be relatively optimum for enhanced dynamic range operation.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: May 27, 2008
    Assignee: Canesta, Inc.
    Inventors: Salih Burak Gokturk, Abbas Rafii
  • Patent number: 7375803
    Abstract: For use with an imaging system, in one aspect, the present invention implements a filter system that provides a precise narrow band pass for IR-NIR wavelengths, while also providing individual dye-type filters that can be disposed above individual RGB pixels to create dedicated red, green, and blue pixel responses. An interference dichotic filter provides a non-critical first pass band that adequately encompassed RGB wavelengths, and provides a more critical IR-NIR pass band for Z-pixels. The individual dye-type filters have individual R, G, B pass band shapes that fall within the interference filter. Preferably a dye-type NIR-IR filter is also in a common optical path with the other filters to contribute to the overall filtering. In a second aspect, the invention provides an RGB-Z system with dynamically updated image renderings to better enable a viewer of the image to acquire a sense of depth.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: May 20, 2008
    Assignee: Canesta, Inc.
    Inventor: Cyrus Bamji
  • Patent number: 7352454
    Abstract: TOF and color sensing detector structures have x-axis spaced-apart y-axis extending finger-shaped gate structures with adjacent source collection regions. X-dimension structures are smaller than y-dimension structure and govern performance, characterized by high x-axis electric fields and rapid charge movement, contrasted with lower y-axis electric fields and slower charge movement. Preferably a potential barrier is implanted between adjacent gates and a bias gate is formed intermediate a gate and associated source region. Resultant detector structures can be operated at the more extreme gate voltages that are desirable for high performance.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: April 1, 2008
    Assignee: Canesta, Inc.
    Inventors: Cyrus Bamji, Hakan Yalcin
  • Patent number: 7340077
    Abstract: Three-dimensional position information is used to identify the gesture created by a body part of interest. At one or more instances of an interval, the posture of a body part is recognized, based on the shape of the body part and its position and orientation. The posture of the body part over each of the one or more instances in the interval are recognized as a combined gesture. The gesture is classified for determining an input into a related electronic device.
    Type: Grant
    Filed: February 18, 2003
    Date of Patent: March 4, 2008
    Assignee: Canesta, Inc.
    Inventors: Salih Burak Gokturk, Carlo Tomasi, Fahri Sürücü, Abbas Rafii
  • Patent number: 7321111
    Abstract: Dynamic range of a differential pixel is enhanced by injecting, synchronously or asynchronously, a compensating offset (?COMP) into a differential signal capacitor whenever magnitude of the differential signal across the capacitor exceeds a predetermined value. Positive and negative magnitudes of ?COMP need not be equal. The number (N) of ?COMP offsets made is counted. Effective differential signal capacitor voltage V(t)=Vo±N·?COMP, where Vo is capacitor voltage. In other embodiments magnitude of ?COMP in a sequence of compensations can differ, and the sum total of compensations in recorded. Differential pixel signal/noise ratio is increased by dynamically maximizing operational amplifier gain AG for each differential pixel.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: January 22, 2008
    Assignee: Canesta, Inc.
    Inventors: Cyrus Bamji, Khaled Salama
  • Patent number: 7310431
    Abstract: A class of measurement devices can be made available using a family of projection patterns and image processing and computer vision algorithms. The proposed system involves a camera system, one or more structured light source, or a special pattern that is already drawn on the object under measurement. The camera system uses computer vision and image processing techniques to measure the real length of the projected pattern. The method can be extended to measure the volumes of boxes, or angles on planar surfaces.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: December 18, 2007
    Assignee: Canesta, Inc.
    Inventors: Salih Burak Gokturk, Carlo Tomasi, Fahri Sürücü
  • Patent number: 7283213
    Abstract: TOF system shutter time needed to acquire image data in a time-of-flight (TOF) system that acquires consecutive images is reduced, thus decreasing the time in which relative motion can occur. In one embodiment, pixel detectors are clocked with multi-phase signals and integration of the four signals occurs simultaneously to yield four phase measurements from four pixel detectors within a single shutter time unit. In another embodiment, phase measurement time is reduced by a factor (1/k) by providing super pixels whose collection region is increased by a factor “k” relative to a normal pixel detector. Each super pixel is coupled to k storage units and four-phase sequential signals. Alternatively, each pixel detector can have k collector regions, k storage units, and share common clock circuitry that generates four-phase signals. Various embodiments can reduce the mal-effects of clock signal transients upon signals, and can be dynamically reconfigured as required.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: October 16, 2007
    Assignee: Canesta, Inc.
    Inventors: Patrick O'Connor, Ilhami Torunoglu, Rajeev Nagabhirana
  • Patent number: 7212663
    Abstract: A projection array is provided that comprises a plurality of discrete projection elements. An image array is obtained of a scene with the light projected onto it that is coded using the projection array. Correspondence information is determined for each element in the image array, where the correspondence information can be used to determine which of the plurality of elements in the projection array corresponds to a particular image element. The determination of correspondence information for each element in the image array can be made independently of correspondence information for other elements in the image array.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: May 1, 2007
    Assignee: Canesta, Inc.
    Inventor: Carlo Tomasi
  • Patent number: 7203356
    Abstract: Three-dimensional position information is used to segment objects in a scene viewed by a three dimensional camera. At one or more instances of an interval, the head location of the user is determined. Object-based compression schemes are applied on the segmented objects and the detected head.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: April 10, 2007
    Assignee: Canesta, Inc.
    Inventors: Salih Burak Gokturk, Abbas Rafii
  • Patent number: 7176438
    Abstract: Effective differential dynamic range and common mode rejection in a differential pixel detector are enhanced by capturing and isolating differential detector charge output before using common mode reset to avoid detector saturation due to common mode components of optical energy to be detected. Differential charge is stored into an integration capacitor associated with an operational amplifier coupled to receive as input the differential detector outputs. Common mode reset is achieved by resetting storage capacitors coupled to the outputs of the differential detector at least once within an integration time T before storage potential exceeds a saturation voltage Vsat for the photodetector.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: February 13, 2007
    Assignee: Canesta, Inc.
    Inventors: Cyrus Bamji, Khaled Salama
  • Patent number: 7173230
    Abstract: An approach is provided for detecting EM waves using a photodetector coupled to an amplifier stage. The amplifier stage uses capacitive feedback to reduce or cancel intrinsic capacitance of the photodetector. A variety of capacitance structures may be used to provide the capacitive feedback such as shielded capacitors and capacitor arrays. The amplifier stage may be either single-ended or fully differential, depending upon the requirements of a particular application. Noise cancellation circuitry may also be included to reduce noise and offset sources present in the amplifier stage. The approach is applicable to a variety of contexts and applications. Example applications include, without limitation, detection of both brightness and Time of Flight (TOF) in 3D sensing applications. The approach may also be used to detect EM wave intensity in 2D sensing systems and, in general, for any application requiring simultaneously high speed and high sensitivity EM detection.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: February 6, 2007
    Assignee: Canesta, Inc.
    Inventor: Edoardo Charbon
  • Patent number: 7157685
    Abstract: Dynamic range of a differential pixel is enhanced by injecting, synchronously or asynchronously, a fixed compensating offset (?V) into a differential signal capacitor whenever magnitude of the differential signal across the capacitor exceeds a predetermined value. The number (N) of ?V offsets made is counted. Effective differential signal capacitor voltage V(t)=Vo+N·?V, where Vo is capacitor voltage. Differential pixel signal/noise ratio is increased by dynamically maximizing operational amplifier gain AG for each differential pixel.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: January 2, 2007
    Assignee: Canesta, Inc.
    Inventors: Cyrus Bamji, Khaled Salama
  • Patent number: 7151530
    Abstract: A system and method for determining which key value in a set of key values is to be assigned as a current key value as a result an object intersecting a region where a virtual interface is provided. The virtual interface may enable selection of individual key values in the set. The position is determined using a depth sensor that determines a depth of the position in relation to the location of the depth sensor. A set of previous key values that are pertinent to the current key value may also be identified. In addition, at least one of either a displacement characteristic of the object, or a shape characteristic of the object is determined. A probability is determined that indicates the current key value is a particular one or more of the key values in the set.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: December 19, 2006
    Assignee: Canesta, Inc.
    Inventors: Helena Roeber, Ilhami Torunoglu, Abbas Rafii
  • Publication number: 20060114333
    Abstract: Dynamic range of photodetector sensors useable in a TOF system is enhanced by capturing images of an object using multiple exposure time settings. Longer exposure settings more appropriately capture non-reflective and/or distant objects, while shorter exposure settings more appropriately capture reflective and/or closer objects. During parallel mode operation, detection signal readouts are taken from each photodetector at different time intervals within an overall exposure time. In sequential mode operation, detection signal readouts are taken and stored for each photodetector at the end of a first exposure time interval and the photodetectors are reset. After a second, different exposure time interval readouts are taken and stored, and the photodetectors reset, etc. In these modes one of the time exposure intervals will be relatively optimum for enhanced dynamic range operation.
    Type: Application
    Filed: February 14, 2005
    Publication date: June 1, 2006
    Applicant: Canesta, Inc.
    Inventors: Salih Gokturk, Abbas Rafii
  • Patent number: 7050177
    Abstract: Structured light is directed across a monitored region. An image is captured of a light pattern that forms on the object as a result of the object intersecting the structured light when the object is placed at a first position in the monitored region. A geometric characteristic is identified of the image of the light pattern. The geometric characteristic is variable with a depth of the first position relative to where the image is captured. The depth of the first position is approximated based on the measured geometric characteristic.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: May 23, 2006
    Assignee: Canesta, Inc.
    Inventors: Carlo Tomasi, Salih Burak Gokturk
  • Patent number: 7006236
    Abstract: Structured light is directed across a monitored region. An image is captured of a light pattern that forms on the object as a result of the object intersecting the structured light when the object is placed at a first position in the monitored region. A geometric characteristic is identified of the image of the light pattern. The geometric characteristic is variable with a depth of the first position relative to where the image is captured. The depth of the first position is approximated based on the measured geometric characteristic.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: February 28, 2006
    Assignee: Canesta, Inc.
    Inventors: Carlo Tomasi, Salih Burak Gokturk
  • Publication number: 20050285966
    Abstract: An RGB-Z sensor is implementable on a single IC chip. A beam splitter such as a hot mirror receives and separates incoming first and second spectral band optical energy from a target object into preferably RGB image components and preferably NIR Z components. The RGB image and Z components are detected by respective RGB and NIR pixel detector array regions, which output respective image data and Z data. The pixel size and array resolutions of these regions need not be equal, and both array regions may be formed on a common IC chip. A display using the image data can be augmented with Z data to help recognize a target object. The resultant structure combines optical efficiency of beam splitting with the simplicity of a single IC chip implementation. A method of using the single chip red, green, blue, distance (RGB-Z) sensor is also disclosed.
    Type: Application
    Filed: January 26, 2005
    Publication date: December 29, 2005
    Applicant: Canesta, Inc.
    Inventors: Cyrus Bamji, Peiqian Zhao
  • Publication number: 20050156121
    Abstract: Structures and methods for three-dimensional image sensing using high frequency modulation includes CMOS-implementable sensor structures using differential charge transfer, including such sensors enabling rapid horizontal and slower vertical dimension local charge collection. Wavelength response of such sensors can be altered dynamically by varying gate potentials. Methods for producing such sensor structures on conventional CMOS fabrication facilities include use of “rich” instructions to command the fabrication process to optimize image sensor rather than digital or analog ICs. One detector structure has closely spaced-apart, elongated finger-like structures that rapidly collect charge in the spaced-apart direction and then move collected charge less rapidly in the elongated direction. Detector response is substantially independent of the collection rate in the elongated direction.
    Type: Application
    Filed: December 30, 2004
    Publication date: July 21, 2005
    Applicant: Canesta, Inc.
    Inventors: Cyrus Bamji, Xinqiao Liu
  • Patent number: 6919549
    Abstract: Effective differential dynamic range in a differential pixel detector is increased by avoiding saturation effects due to common mode contribution in optical energy to be detected. Photocurrent generated by each photodetector pair is directly integrated by an associated capacitor over an integration time T. Within time T, before either integrated capacitor voltage reaches Vsat for the photodetector, at least one of the capacitors is reset to a voltage such that the desired differential detector signal is still determinable. Reset may be generated externally or internally to the differential pixel detector.
    Type: Grant
    Filed: April 12, 2004
    Date of Patent: July 19, 2005
    Assignee: Canesta, Inc.
    Inventors: Cyrus Bamji, Hakan Yalcin, Xinqiao Liu, Ender Tunc Eroglu