Panavision Imaging LLC

Silicon Video, Inc.

Photon Vision Systems, Inc.

Michael Joyner

Jeffrey Jon Zarnowski

Ketan Vrajlal Karia

Thomas Poonnen

Li Liu

Matthew A Pace

Thomas Vogelsong

Samuel D Ambalavanar

Matthew Pace

A solid state imager converts analog pixel values to digital form on an arrayed per-column basis. An N-bit counter supplies an N-bit DAC to produce an analog ramp output with a level that varies corresponding to the contents of the counter. A latch/counter or equivalent is associated with each respective column. A clock supplies clock signal(s) to the counter elements. When the analog ramp equals the pixel value for that column, the latch/counter latches the value. The black level can be pre-set in the latch/counter or can be subtracted separately to reduce fixed pattern noise. The pixels can be oversampled for some number of times, e.g., n=16, to reduce the thermal noise of the sensors. Also, two or more pixels sharing a common sense node may be binned together, and two (or more) pixels having different integration times may be combined to obtain an output signal with enhanced dynamic range.

Image sensor ADC and CDS per column with oversampling

Improving the dynamic range of captured images is disclosed by using sub-pixel arrays to capture light at different exposures and generate color pixel outputs for an image in a single frame. Each sub-pixel array can include multiple sub-pixels. The sub-pixels that make up a sub-pixel array can include red (R) sub-pixels, green (G) sub-pixels, blue (B) sub-pixels, and in some embodiments, clear sub-pixels. Those sub-pixel arrays having clear sub-pixels effectively have a higher exposure level and can capture low-light scenes (for dark areas) better than those sub-pixel arrays without clear sub-pixels. Each sub-pixel array can produce a color pixel output that is a combination of the outputs of the sub-pixels in the sub-pixel array. Each sub-pixel in a sub-pixel array can have the same exposure time, or in some embodiments, individual sub-pixels within a sub-pixel array can have different exposure times to improve the overall dynamic range even more.

Sub-pixel array optical sensor

A solid state imager converts analog pixel values to digital form on an arrayed per-column basis. A counter is coupled to an N-bit DAC to produce an analog ramp that varies corresponding to the contents of the counter. A ripple counter is associated with each respective column. A clock or a source of counts at a predetermined sequence supplies clock signals or counts to the counter elements. Column comparators gate the counter elements when the analog ramp equals the pixel value. The counter contents feed a video output bus to produce the digital video signal. Additional black-level readout counters elements can create and store a black level digital value that is subtracted from the pixel value to reduce fixed pattern noise. The counters may employ two's complement arithmetic. An additional array of buffer counter/latches can be employed. Ripple counters can be configured as counters to capture the digital video level, and then as shift registers to clock out the video levels to an output bus. The clock pulses or counts for the DAC counter and for the ripple counters can be at the same or different rates.

Image sensor ADC and CDS per column

A solid state imaging system has at least one CMOS imager with first and second series of pixels in which the pixels of one series are offset, i.e., staggered, in respect to the pixels of the other series. Multiple imagers can be arrayed end to end, with jumper wires connecting the pixel output conductors or each so that the pixels feed into a common output amplifier for each series, to minimize chip to chip offset voltages. The pixels may be diagonally offset from one another, and a color imager can be constructed in which color ribbon filters are arranged diagonally across the imaging area. This arrangement minimizes color cross talk. An array of microlenses is situated with each microlens covering a plurality of the pixels. The different pixels under each microlens can be aligned along a diagonal. The different pixels under the same microlens can have different integration times, to increase the dynamic range of the imager(s).

Scanning imager employing multiple chips with staggered pixels

A solid state imaging system has at least one CMOS imager with first and second series of pixels in which the pixels of one series are offset, i.e., staggered, in respect to the pixels of the other series. Multiple imagers can be arrayed end to end, with jumper wires connecting the pixel output conductors or each so that the pixels feed into a common output amplifier for each series, to minimize chip to chip offset voltages. The pixels may be diagonally offset from one another, and a color imager can be constructed in which color ribbon filters are arranged diagonally across the imaging area. This arrangement minimizes color cross talk.

A solid state imaging system has at least one CMOS imager with first and second series of pixels in which the pixels of one series are offset, i.e., staggered, in respect to the pixels of the other series. Multiple imagers can be arrayed end to end, with jumper wires connecting the pixel output conductors or each so that the pixels feed into a common output amplifier for each series, to minimize chip to chip offset voltages. The pixels may be diagonally offset from one another, and a color imager can be constructed in which color ribbon filters are arranged diagonally across the imaging area. This arrangment minimizes color cross talk.

A solid state imager with pixels arranged in columns and rows has the pixels are configured into groups of at least a first pixel and a second pixel, each said group sharing a pixel output transistor having a sense electrode and an output electrode and a reset transistor having a gate coupled to receive a reset signal and an output coupled to the sense electrode of the associated shared pixel output transistor. Each of the pixels has a photosensitive element whose output electrode is coupled to the sense electrode of the shared pixel output transistor and a gate electrode coupled to receive respective first and second pixel gating signals. This configuration reduces the number of FETs to two transistors for each pair of pixels, and also can achieve true correlated double sampling correction of FPN.

Solid state imager with reduced number of transistors per pixel

Scanning image employing multiple chips with staggered pixels

A bus system and an imager for transferring signals from a plurality of signal streams to an output includes a plurality of signal buses in parallel and a control system. The control system multiplexes the signals from two or more of the plurality of signal streams onto two or more of the plurality of signal buses and allows the signals to substantially charge each of the two or more of the plurality of signal buses before demultiplexing the signals to the output. A method for transferring signals includes multiplexing signals on to two or more of a plurality of signal buses and allowing the signals to substantially charge each of the two or more of the plurality of signal buses before demultiplexing the signals to an output.

Video bus for high speed multi-resolution imagers and method thereof

An analog video bus architecture that utilizes the column parallel nature of CMOS imagers and more specifically Active Column Sensors, that eliminates the need for multi-port imagers, by increasing the useable bandwidth of single port imagers. An adaptation of this invention allows for either binning or interpolation of pixel information for increased or decreased resolution along the columns and more specifically for ACS imagers binning or interpolation along the rows. In this bus, the single video bus is replaced by multiple video buses and instead of selecting only one column for reading multiple columns are also pre-selected in-order to pre-charge the video bus. The video buses are then de-multiplexed back on to one port at the desired element rate. This architecture utilizes the column oriented video bus of CMOS imagers. It divides the large video bus capacitance by the number of video buses used. In addition, it allows multiple pixel time constants to precharge the video bus. The best commercially available imager designs now claim 40 MHz per analog port and suffer from reduced signal to noise ratios. To overcome this fundamental bandwidth limitation, imager designs in the past have had to increase the number of video ports per imager to achieve high frame rates. Multiple ports per imager breaks the focal plane into segments that are typically reassembled via post processing in a host computer. The other problem with multiple ports is each segment of the imager will have its own offsets and resultant Fixed Pattern Noise (FPN). PVS-Bus&trade; eliminates the objectionable segmentation and simplifies high-speed system design. Also, by utilizing the column parallel nature of CMOS video buses a method and improved method of using the PVS-Bus of binning and interpolation is described which results in increased frame rate, and for decreased or increased resolution.

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Cortland, NY, United States of America

Michael Joyner