Patents Assigned to Mesa Imaging AG
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Patent number: 8106472Abstract: The pixel for use in an image sensor comprises a low-doped semiconductor substrate (A). On the substrate (A), an arrangement of a plurality of floating areas, e.g., floating gates (FG2-FG6), is provided. Neighboring floating gates are electrically isolated from each other yet capacitively coupled to each other. By applying a voltage (V2?V1) to two contact areas (FG1, FG7), a lateral steplike electric field is generated. Photogenerated charge carriers move along the electric-field lines to the point of highest potential energy, where a floating diffusion (D) accumulate the photocharges. The charges accumulated in the various pixels are sequentially read out with a suitable circuit known from image-sensor literature, such as a source follower or a charge amplifier with row and column select mechanisms. The pixel of offers at the same time a large sensing area, a high photocharge-detection sensitivity and a high response speed, without any static current consumption.Type: GrantFiled: February 9, 2010Date of Patent: January 31, 2012Assignee: MESA Imaging AGInventors: Rolf Kaufmann, Michael Lehmann, Peter Seitz
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Publication number: 20110299059Abstract: The modulation scheme disclosed in this invention report allows for utilizing multiple 3D time-of-flight cameras at the same time by exploiting the inherent pseudo noise properties of the optical modulation signals. Compared to recent systems based on pure pseudo noise modulation signals, the stochastic measurement error in a single-camera environment is significantly reduced. The basic concept relies on the generation of a three level optical modulation signal that includes two pseudo noise sequences.Type: ApplicationFiled: April 7, 2011Publication date: December 8, 2011Applicant: MESA IMAGING AGInventors: Bernhard Buettgen, Thierry Oggier
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Publication number: 20110273561Abstract: A demodulation structure for a n-tap pixel, mainly for 3D time-of-flight (TOF) applications uses a 2-stage switch structure for demodulating a modulated electromagnetic wave. An almost arbitrary number of storage sites per pixel can be implemented enabling an almost arbitrary number of samplings captured during one exposure. It also provides the option to demodulate and integrate different phasing samples according to the different modulation frequencies within the same exposure.Type: ApplicationFiled: November 9, 2010Publication date: November 10, 2011Applicant: MESA IMAGING AGInventors: Thierry Oggier, Michael Lehmann, Bernhard Buettgen, Jonas Felber
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Publication number: 20110164132Abstract: A demodulation image sensor, such as used in time of flight (TOF) cameras, extracts all storage- and post-processing-related steps from the pixels to another array of storage and processing elements (proxels) on the chip. The pixel array has the task of photo-detection, first processing and intermediate storage, while the array of storage and processing elements provides further processing and enhanced storage capabilities for each pixel individually. The architecture can be used to address problems due to the down-scaling of the pixel size. Typically, either the photo-sensitivity or the signal storage capacitance suffers significantly. Both a lower sensitivity and smaller storage capacitances have negative influence on the image quality. The disclosed architecture allows for keeping the storage capacitance unaffected by the pixel down-scaling. In addition to that, it provides a high degree of flexibility in integrating more intelligence into the image sensor design already on the level of the pixel array.Type: ApplicationFiled: January 6, 2011Publication date: July 7, 2011Applicant: MESA IMAGING AGInventors: Bernhard Buettgen, Thierry Oggier
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Publication number: 20110149071Abstract: A method and system to compensate for stray light errors in time of flight (TOF) camera systems uses reference targets in the in the field of view (FOV) that can be used to measure stray light. In different embodiments, one or more reference targets are used.Type: ApplicationFiled: January 10, 2011Publication date: June 23, 2011Applicant: MESA IMAGING AGInventor: Thierry Oggier
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Publication number: 20110114821Abstract: The presented readout structure provides charge transport based readout of a photosensitive device with a minimum number of transport gates. The structure uses the given charge storage buckets of the photosensitive device, separated by a minimum sized barrier-gate, to transport the charge out of the pixel field. This new readout schema allows for a fast readout speed based on a 2 phase transport chain and increases the pixel's optical fill factor by significantly reducing the transport gate size compared to state-of-the-art pixels using a 3 or 4 phase CCD readout chain. This readout structure can be exploited for standard photo-detecting elements such as e.g. pinned photo-diodes or any enhanced pixel structure that has additional intelligence incorporated as well. Typical applications are 2D- or 3D-imaging.Type: ApplicationFiled: May 5, 2010Publication date: May 19, 2011Applicant: MESA Imaging AGInventors: Jonas Felber, Michael Lehmann, Berhard Buettgen
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Publication number: 20110101241Abstract: A pixel is formed in a semiconductor substrate (S) with a plane surface for use in a photodetector. It comprises an active region for converting incident light (In) into charge carriers, photogates (PGL, PGM, PGR) for generating a lateral electric potential (?(x)) across the active region, and an integration gate (IG) for storing charge carriers generated in the active region and a dump site (Ddiff). The pixel further comprises separation-enhancing means (SL) for additionally enhancing charge separation in the active region and charge transport from the active region to the integration gate (IG). The separation-enhancing means (SL) are for instance a shield layer designed such that for a given lateral electric potential (?(x)), the incident light (In) does not impinge on the section from which the charge carriers would not be transported to the integration gate (IG).Type: ApplicationFiled: January 10, 2011Publication date: May 5, 2011Applicant: MESA IMAGING AGInventors: Kaspar Cottier, Rolf Kaufmann, Rino E. Kunz, Thierry Oggier, Guy Voirin, Simon Neukom, Michael Lehmann
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Publication number: 20110101206Abstract: A new pixel in semiconductor technology comprises a photo-sensitive detection region (1) for converting an electromagnetic wave field into an electric signal of flowing charges, a separated demodulation region (2) with at least two output nodes (D10, D20) and means (IG10, DG10, IG20, DG20) for sampling the charge-current signal at least two different time intervals within a modulation period. A contact node (K2) links the detection region (1) to the demodulation region (2). A drift field accomplishes the transfer of the electric signal of flowing charges from the detection region to the contact node. The electric signal of flowing charges is then transferred from the contact node (K2) during each of the two time intervals to the two output nodes allocated to the respective time interval. The separation of the demodulation and the detection regions provides a pixel capable of demodulating electromagnetic wave field at high speed and with high sensitivity.Type: ApplicationFiled: January 5, 2011Publication date: May 5, 2011Applicant: MESA IMAGING AGInventor: Bernhard Buettgen
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Publication number: 20110089471Abstract: A demodulation pixel improves the charge transport speed and sensitivity by exploiting two effects of charge transport in silicon in order to achieve the before-mentioned optimization. The first one is a transport method based on the CCD gate principle. However, this is not limited to CCD technology, but can be realized also in CMOS technology. The charge transport in a surface or even a buried channel close to the surface is highly efficient in terms of speed, sensitivity and low trapping noise. In addition, by activating a majority carrier current flowing through the substrate, another drift field is generated below the depleted CCD channel. This drift field is located deeply in the substrate, acting as an efficient separator for deeply photo-generated electron-hole pairs. Thus, another large amount of minority carriers is transported to the diffusion nodes at high speed and detected.Type: ApplicationFiled: August 16, 2010Publication date: April 21, 2011Applicant: MESA IMAGING AGInventors: Bernhard Buettgen, Jonas Felber, Michael Lehmann, Thierry Oggier
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Patent number: 7923673Abstract: A pixel for detecting incident radiation (In) over a large area with high sensitivity and low power consumption. The pixel comprises a semiconductor substrate (1), covered by a thin insulating layer (2), on top of which a dendritic or arborescent gate structure (3) is arranged. The dendritic gate (3) is electrically connected at two or more contacts (C1, C2) with voltage sources, leading to the flow of a current and a position-dependent potential distribution in the gate (3). Due to the use of arborescent structures and various materials (31, 32), the pixel can be optimized for a certain application, in particular in terms of the electric field distribution, the RC time constant, the power consumption and the spectral sensitivity. Due to its compact size, the photo sensor can be arranged in linear or two-dimensional manner for the realization of line and area sensors.Type: GrantFiled: July 18, 2005Date of Patent: April 12, 2011Assignee: MESA Imaging AGInventors: Bernhard Büttgen, Felix Lustenberger, Peter Seitz
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Patent number: 7897928Abstract: A pixel is formed in a semiconductor substrate (S) with a plane surface for use in a photodetector. It comprises an active region for converting incident light (In) into charge carriers, photogates (PGL, PGM, PGR) for generating a lateral electric potential (?(x)) across the active region, and an integration gate (IG) for storing charge carriers generated in the active region and a dump site (Ddiff). The pixel further comprises separation-enhancing means (SL) for additionally enhancing charge separation in the active region and charge transport from the active region to the integration gate (IG). The separation-enhancing means (SL) are for instance a shield layer designed such that for a given lateral electric potential (?(x)), the incident light (In) does not impinge on the section from which the charge carriers would not be transported to the integration gate (IG).Type: GrantFiled: July 25, 2005Date of Patent: March 1, 2011Assignee: MESA Imaging AGInventors: Rolf Kaufmann, Thierry Oggier, Simon Neukom, Michael Lehmann
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Patent number: 7889257Abstract: An integrated sensor chip comprises at least one pixel. The at least one pixel comprises: one or several integration regions for receiving and storing photogenerated charges; a modulation region that moves the photogenerated charges to be stored in the at least two integration regions; and sense nodes, in which each of the sense nodes is associated with one of the integration regions, into which the photogenerated charges are moved from the integration regions during a readout stage.Type: GrantFiled: July 17, 2008Date of Patent: February 15, 2011Assignee: MESA Imaging AGInventors: Thierry Oggier, Michael Lehmann, Bernhard Buettgen
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Patent number: 7884310Abstract: A new pixel in semiconductor technology comprises a photo-sensitive detection region (1) for converting an electromagnetic wave field into an electric signal of flowing charges, a separated demodulation region (2) with at least two output nodes (D10, D20) and means (IG10, DG10, IG20, DG20) for sampling the charge-current signal at least two different time intervals within a modulation period. A contact node (K2) links the detection region (1) to the demodulation region (2). A drift field accomplishes the transfer of the electric signal of flowing charges from the detection region to the contact node. The electric signal of flowing charges is then transferred from the contact node (K2) during each of the two time intervals to the two output nodes allocated to the respective time interval. The separation of the demodulation and the detection regions provides a pixel capable of demodulating electromagnetic wave field at high speed and with high sensitivity.Type: GrantFiled: October 6, 2006Date of Patent: February 8, 2011Assignee: MESA Imaging AGInventor: Bernhard Buettgen
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Publication number: 20110025843Abstract: Improved field-of-illumination (FOI) and field-of-view (FOV) matching for 3D time-of-flight cameras is provided using light emitters with rectangular reflectors. A better adjustment of the FOI with the camera's FOV has the following advantages: optimal use of emitted light and reduced multi-path problems. Furthermore, embodiments bring the benefit for rather low-cost customization of the illumination to match the FOI to the specified FOV.Type: ApplicationFiled: July 16, 2010Publication date: February 3, 2011Applicant: MESA IMAGING AGInventors: Thierry Oggier, Michael Richter
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Publication number: 20100308209Abstract: A method and system enable the subtraction of charge carrier packages in the low-noise charge domain, which is particularly interesting for the operation of demodulation pixels when high background light signals are present. The method comprises the following steps: demodulation of an optical signal and integration of the photo-generated charge carriers; charge transfer to an external capacitance. The second step means a recombination of electrons and holes in the charge domain and an influencing of the opposite charge carriers on the second plate of the capacitance. This approach allows for low-noise subtraction of charge packages in the charge domain and, at the same time, for creating pixels with much higher fill factors because the capacitances can be optimized for storing just the differential parts, without the DC component.Type: ApplicationFiled: June 9, 2010Publication date: December 9, 2010Applicant: MESA IMAGING AGInventors: Berhard Buettgen, Michael Lehmann, Jonas Felber
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Publication number: 20100193666Abstract: The pixel for use in an image sensor comprises a low-doped semiconductor substrate (A). On the substrate (A), an arrangement of a plurality of floating areas, e.g., floating gates (FG2-FG6), is provided. Neighboring floating gates are electrically isolated from each other yet capacitively coupled to each other. By applying a voltage (V2?V1) to two contact areas (FG1, FG7), a lateral steplike electric field is generated. Photogenerated charge carriers move along the electric-field lines to the point of highest potential energy, where a floating diffusion (D) accumulate the photocharges. The charges accumulated in the various pixels are sequentially read out with a suitable circuit known from image-sensor literature, such as a source follower or a charge amplifier with row and column select mechanisms. The pixel of offers at the same time a large sensing area, a high photocharge-detection sensitivity and a high response speed, without any static current consumption.Type: ApplicationFiled: February 9, 2010Publication date: August 5, 2010Applicant: MESA IMAGING AGInventors: Rolf Kaufmann, Michael Lehmann, Peter Seitz
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Patent number: 7701028Abstract: The pixel for use in an image sensor comprises a low-doped semiconductor substrate (A). On the substrate (A), an arrangement of a plurality of floating areas e.g., floating gates (FG2-FG6), is provided. Neighboring floating gates are electrically isolated from each other yet capacitively coupled to each other. By applying a voltage (V2-V1) to two contact areas (FG1, FG7), a lateral steplike electric field is generated. Photogenerated charge carriers move along the electric-field lines to the point of highest potential energy, where a floating diffusion (D) accumulate the photocharges. The charges accumulated in the various pixels are sequentially read out with a suitable circuit known from image-sensor literature, such as a source follower or a charge amplifier with row and column select mechanisms. The pixel of offers at the same time a large sensing area, a high photocharge-detection sensitivity and a high response speed without any static current consumption.Type: GrantFiled: March 31, 2005Date of Patent: April 20, 2010Assignee: MESA Imaging AGInventors: Rolf Kaufmann, Michael Lehmann, Peter Seitz
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Publication number: 20100053405Abstract: A demodulation pixel architecture allows for demodulating an incoming modulated electromagnetic wave, normally visible or infrared light. It is based on a charge coupled device (CCD) line connected to a drift field structure. The drift field is exposed to the incoming light. It collects the generated charge and forces it to move to the pick-up point. At this pick-up point, the CCD element samples the charge for a given time and then shifts the charge packets further on in the daisy chain. After a certain amount of shifts, the multiple charge packets are stored in so-called integration gates, in a preferred embodiment. The number of integration gates gives the number of simultaneously available taps. When the cycle is repeated several times, the charge is accumulated in the integration gates and thus the signal-to-noise ratio increases. The architecture is flexible in the number of taps. A dump node can be attached to the CCD line for dumping charge with the same speed as the samples are taken.Type: ApplicationFiled: August 28, 2009Publication date: March 4, 2010Applicant: MESA IMAGING AGInventors: Michael Lehmann, Bernhard Buettgen
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Patent number: 7671671Abstract: A demodulation device (1) in semiconductor technology is disclosed. The device (1) is capable of demodulating an injected modulated current. The device (1) comprises an input node (IN1), a sampling stage (DG1, IG1, GS1, IG2, DG2) and at least two output nodes (D1, D2). The sampling stage DG1, IG1, GS1, IG2, DG2) comprises transfer means (GL, GM, GR) for transferring a modulated charge-current signal from the input node (IN1) to one of the output nodes (D1, D2) allocated to the respective time interval within the modulation period. The small size and the ability to reproduce the device (1) in standard semiconductor technologies make possible a cost-efficient integration of the device (1).Type: GrantFiled: October 5, 2006Date of Patent: March 2, 2010Assignee: MESA Imaging AGInventors: Bernhard Buettgen, Michael Lehmann, Simon Neukom, Thierry Oggier, Felix Lustenberger
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Patent number: 7622704Abstract: The present invention discloses an optoelectronic detector for light sensing. The optoelectronic detector has a photosensitive element that converts light into electrons. Efficient collection of these electrons at readout nodes, embedded in the photosensitive element, is required to make correct measurements of light characteristics such as, phase shift and intensity. This collection of electrons is achieved by applying a voltage gradient across an electrode within the optoelectronic detector. The optoelectronic detector can have multiple readout nodes. Further, the present invention discloses methods for detecting intensity and phase shift of impinging light and for suppression of background illumination while detecting the characteristics of light.Type: GrantFiled: March 17, 2009Date of Patent: November 24, 2009Assignee: MESA Imaging AGInventor: Martin Wäny