摘要:
Microbolometer pixel structures including membrane material in a current path between at least two spaced electrodes, the membrane material having multiple openings defined in the current path that are configured such that substantially the entire volume of electrically conductive membrane material in at least a portion of the current path contributes to conduction of current between the electrical contacts.
摘要:
An infrared detector (10) includes a substrate (16) having thereon an array of detector elements (21, 139). Each detector element has a membrane (41, 81, 91, 111, 141), which includes an amorphous silicon layer (51, 142) in contact with at least two electrodes (53, 56-57, 92, 112-113, 143-145) that are made of a titanium/aluminum alloy which absorbs infrared radiation. In order to obtain a desired temperature coefficient of resistance (TCR), the amorphous silicon layer may optionally be doped. The effective resistance between the electrodes is set to a desired value by appropriate configuration of the electrodes and the amorphous silicon layer. The membrane includes two outer layers (61-62, 146-147) made of an insulating material. Openings (149) may optionally be provided through the membrane.
摘要:
Method of preferentially-ordering a thermally sensitive element (50) may comprise the step of forming a first thin film layer of electrically conductive material (75). A thin film layer of thermally sensitive material (80) may be formed on a surface of the first layer of electrically conductive material (75). A second thin film layer of electrically conductive material (85) of lanthanum strontium cobalt oxide (LSCO) may be formed on a surface of the layer of thermally sensitive material (80) opposite the first thin film layer (75). A nucleation layer (87) may be formed in communication with the surface of the layer of thermally sensitive material (80) opposite the first thin film layer (75). The layer of thermally sensitive material (80) may be crystallized beginning at the surface of the thermally sensitive layer (80) in communication with nucleation layer (87). The nucleation layer (87) may be removed.
摘要:
Thermal sensor (36) mounted to a substrate (34). The thermal sensor may include a first thin film electrode (52), a nucleation element (55), a thermally sensitive element (50) and a second thin film electrode (54). The first thin film electrode (52) may be disposed adjacent to the nucleation element(52). The thermally sensitive element (50) may be in electrical communication with the first thin film electrode (52). The thermally sensitive element (50) may comprise a plurality of preferentially-ordered crystals. The second thin film electrode (54) may be in electrical communication with the thermally sensitive element (50) opposite the nucleation element (55).
摘要:
One or more thin film layers of material may be formed on an integrated circuit substrate and anisotropically etched to produce a monolithic thermal detector. A first layer of material may be placed on the integrated circuit substrate and anisotropically etched to form a plurality of supporting structures for the thermal sensors of the associated focal plane array. The thermal sensors of the focal plane array may be provided by anisotropically etching one or more thin film layers of material formed on the supporting structures. In an exemplary thermal detector, one of the thin film layers preferably includes pyroelectric material such as barium strontium titanate. A layer of thermal insulating material may be disposed between the integrated circuit substrate and the pyroelectric film layer to allow annealing of the pyroelectric film layer without causing damage to the associated integrated circuit substrate. In addition to the layer of insulating material, a heat sink may be disposed on the integrated circuit substrate opposite from the pyroelectric film layer to protect the integrated circuit substrate while annealing the pyroelectric film layer. Alternatively, a thermal isolation structure may be formed between the pyroelectric film layer and its associated supporting structures to allow annealing of the pyroelectric film layer without substantial heating of the underlying circuit substrate.
摘要:
In an exemplary thermal imaging system (20, 120, 220 and 320), a thermal isolation structure (50 and 150) is disposed on an integrated circuit substrate (70 and 170) for electrically connecting and mechanically bonding a focal plane array (30 and 230) of thermal sensors (40 and 240). Each mesa-type structure (52, 54 and 152) includes at least one mesa conductor (56, 58, 156 and 158) that extends from the top of the mesa-type structure (52, 54 and 152) to an adjacent contact pad (72 and 74). The mesa conductors (56, 58, 156 and 158) provide both biasing voltage (V.sub.B) for the respective thermal sensor (40 and 240) and a signal flow path (V.sub.S) for the respective thermal sensor (40 and 240). The mesa conductors (56, 56, 156 and 158) may be used to provide biasing voltage (V.sub.B) to either a single ferroelectric element (242) or a pair of ferroelectric elements (42 and 44). When the focal plane array (30 and 230) is bonded to the corresponding array of mesa-type structures (52, 54 and 152), a thermally isolated, but electrically conductive path is provided between electrodes (43 and 45) of the thermal sensor (40 and 240) and the corresponding contact pad (72 and 172) of the integrated circuit substrate (70 and 74).
摘要:
A thermal detection system (100, 200) includes a focal plane array (102, 202), a thermal isolation structure (104, 204) and an integrated circuit substrate (106, 206). The focal plane array (102, 202) includes thermal sensors (114, 214) formed from a pyroelectric element (116, 216), such as barium strontium titanate (BST). One side of the pyroelectric element (116, 216) is coupled to a contact pad (110, 210) disposed on the integrated circuit substrate (106, 206) through a mesa strip conductor (112, 212) of the thermal isolation structure (104, 204). The other side of the pyroelectric element (116, 216) is coupled to a common electrode (120, 220). In one embodiment, slots (128) are formed in the common electrode (120) intermediate the thermal sensors (114) to improve inter-pixel thermal isolation. In another embodiment, slots (236) are formed in the optical coating (224) to improve inter-pixel thermal isolation. The common electrode (120, 220) may be formed from a thermally insulating material, such as a silicon monoxide and chromium matrix (cermet) or other metal oxide.
摘要:
A video system is disclosed having a weapon-mounted video camera (12) transmitting video signals to a remotely located video display (14). The video display is mounted to the helmet (40) of a soldier (36), and includes a sight reticle (50) superimposed on the image of the target (46) so that the soldier (36) can aim the weapon (38) by moving it until the target object (46) as displayed by the video display (14) is aligned with the sight reticle (50). A low probability of transmission interception of the video signals is accomplished by using a nonvisible light carrier wavelength in free space, which wavelength is characterized by a high degree of absorption due to atmospheric water vapor.
摘要:
A Stirling-cycle refrigerator including a compressor portion having two cnders with respective pistons therein, and an expansion portion with a cylinder having first and second distinct spaces, and with opposite ends of an expansion piston in the distinct spaces. The two cylinders of the compressor portion are connected by respective refrigerant conduits to the two spaces of the expansion portion. The end of the expansion piston in the first space has a regenerator therein. The two pistons of the compressor are driven 180.degree. out of phase, whereby the respective conduits simultaneously induce compression in the first expansion portion space and expansion in the second. The conduit between the second space and the respective compressor cylinder additionally includes a regenerator.
摘要:
Read-out cell systems are disclosed for image detectors, including infrared image detectors, that provide improved sensitivity by providing in-cell subtraction through the use of a voltage ramp signal generated using a reference pixel and a feedback amplifier. The ramp voltage is generated using a reference pixel and an amplifier having feedback. The ramp voltage is then provided to a plurality of read-out cells. The ramp voltage can be coupled to an input transistor to provide current subtraction prior to the integration node. The ramp voltage can also be provided to integration capacitors within the read-out cells to provide current subtraction directly to the integration node. Further, a temperature-independent fixed current source can also be utilized to further control current subtraction.