摘要:
The high-pixel-count uncooled thermal imaging arrays disclosed herein have liquid crystal (LC) microcavity transducers separate from the read-out integrated circuit (ROIC). The transducer converts incident infrared (IR) radiation in birefringence changes that can be measured with visible light. In other words, the system uses the temperature sensitivity of the LC birefringence to convert the IR scene to a visible image. Measurements on sample arrays indicate that the LC material quality is similar to that of bulk samples and has good noise performance. Additionally, high-fill-factor arrays on fused-silica substrates may be processed to enable optimization of conditions for greatly improved temperature sensitivity. An additional IR absorber layer may be integrated into the process to tune the structure for the infrared.
摘要:
Embodiments of the present invention include complementary metal-oxide-semiconductor (CMOS) readout architectures for photon-counting arrays with a photon-counting detector, a digital counter, and an overflow bit in each of the sensing elements in the array. Typically, the photon-counting detector is a Geiger-mode avalanche photodiode (APD) that emits brief pulses every time it detects a photon. The pulse increments the digital counters, which, in turn, sets the overflow bit once it reaches a given count. A rolling readout system operably coupled to each sensing element polls the overflow bit, and, if the overflow bit is high, initiates a data transfer from the overflow bit to a frame store. Compared to other photo-counting imagers, photon-counting imagers with counters and overflow bits operate with decreased transfer bandwidth, high dynamic range, and fine spatial resolution.
摘要:
A charge-coupled device having an array of pixel elements formed in a substrate, which device is operable in a first state to expand the depletion well regions of each pixel element into the substrate for storing incoming photoelectrons therein and in a second state to contract the expanded depletion well regions to prevent storage of photoelectrons in the contracted depletion well regions.
摘要:
The imager includes a lens for focusing infrared light forming a thermal image onto a liquid crystal array thereby changing the temperature of the liquid crystals to alter a physical property of the liquid crystals. A source of visible polarized light is arranged to illuminate the liquid crystal array so that the polarization of light reflected from the liquid crystal array varies with changes in temperature of the liquid crystals. A cross polarizer receives and transmits therethrough the light reflected from the liquid crystal array, the cross polarizer adapted to change the intensity of the light. An imager receives and detects the change in intensity of the light from the cross polarizer so that the thermal image is recreated as an electronic signal. In a preferred embodiment, the physical property is index of refraction and the liquid crystal array includes birefringent nematic liquid crystals.
摘要:
A large format imager includes an array of pixels for converting electromagnetic radiation into electrical signals and a trigger to from an optical pulse so as to trigger the pixels to generate an integration period. Each pixel includes a photodiode to convert light intensity of high-frequency radiation into an electrical charge, a reset switch to reset the photodiode, circuitry to enable sampling of the electrical charge produced by the photodiode, a photoswitch to convert an optical trigger pulse, received from the trigger, into an electrical signal, an inverter to produce a control signal corresponding to the electrical signal produced by the photoswitch, and control circuitry to locally generate integration control signals. The integration control signals control a start of an integration period for the photodiode, duration of the integration period for the photodiode, and the sampling of the electrical charge produced by the photodiode. The large format imager may also include a trigger for producing an electrical pulse so as to trigger the pixels to generate an integration period and tree type electrical distribution system for propagating the electrical pulse to all the pixels, wherein each pixel includes a global repeater circuit to propagate a first edge of said electrical pulse along said tree type electrical distribution system and a local repeater circuit to provide a local array of pixels with the first edge of the electrical pulse.
摘要:
The high-pixel-count uncooled thermal imaging arrays disclosed herein have liquid crystal (LC) microcavity transducers separate from the read-out integrated circuit (ROIC). The transducer converts incident infrared (IR) radiation in birefringence changes that can be measured with visible light. In other words, the system uses the temperature sensitivity of the LC birefringence to convert the IR scene to a visible image. Measurements on sample arrays indicate that the LC material quality is similar to that of bulk samples and has good noise performance. Additionally, high-fill-factor arrays on fused-silica substrates may be processed to enable optimization of conditions for greatly improved temperature sensitivity. An additional IR absorber layer may be integrated into the process to tune the structure for the infrared.
摘要:
Embodiments of the present invention include an electron counter with a charge-coupled device (CCD) register configured to transfer electrons to a Geiger-mode avalanche diode (GM-AD) array operably coupled to the output of the CCD register. At high charge levels, a nondestructive amplifier senses the charge at the CCD register output to provide an analog indication of the charge. At low charge levels, noiseless charge splitters or meters divide the charge into single-electron packets, each of which is detected by a GM-AD that provides a digital output indicating whether an electron is present. Example electron counters are particularly well suited for counting photoelectrons generated by large-format, high-speed imaging arrays because they operate with high dynamic range and high sensitivity. As a result, they can be used to image scenes over a wide range of light levels.
摘要:
A charge-coupled device imager including an array of super pixels disposed in a semiconductor substrate having a surface that is accessible to incident illumination. For each super pixel there is provided a plurality of subpixels which each correspond to one in the sequence of image frames. Each subpixel includes a doped photogenerated charge collection channel region opposite the illumination-accessible substrate surface, a charge collection channel region control electrode, doped charge drain regions adjacent to the channel region, a charge drain region control electrode, and a doped charge collection control region. To each subpixel are provided channel region and drain region control voltage connections, for independent collection and storage of photogenerated charge from the substrate at the charge collection channel region of a selected subpixel during one in the sequence of image frames and for drainage of photogenerated charge from the substrate to a drain region.
摘要:
A charge modulation device having a semiconductor region of a first conductivity type. An epitaxial layer of second conductivity type is provided on a portion of the semiconductor region so as to define an FET channel region. A first epitaxial region of the second conductivity type is provided adjacent to and in contact with the epitaxial layer so as to define an FET drain region, the first epitaxial region being electrically isolated from the semiconductor region. A second epitaxial region of the second conductivity type is provided adjacent to and in contact with the epitaxial layer so as to define an FET source region, the second epitaxial region being electrically isolated from the semiconductor region. A third epitaxial region of the first conductivity type or a metal oxide semiconductor is provided to the channel region between the source and drain regions.
摘要:
The high-pixel-count uncooled thermal imaging arrays disclosed herein have liquid crystal (LC) microcavity transducers separate from the read-out integrated circuit (ROIC). The transducer converts incident infrared (IR) radiation in birefringence changes that can be measured with visible light. In other words, the system uses the temperature sensitivity of the LC birefringence to convert the IR scene to a visible image. Measurements on sample arrays indicate that the LC material quality is similar to that of bulk samples and has good noise performance. Additionally, high-fill-factor arrays on fused-silica substrates may be processed to enable optimization of conditions for greatly improved temperature sensitivity. An additional IR absorber layer may be integrated into the process to tune the structure for the infrared.