Infrared solid-state imaging device
AssigneeMitsubishi Electric Corporation
InventorsTakahiro Onakado, Masashi Ueno
Life of this patent
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Abstract
A thermal infrared solid-state imaging device includes a horizontal scanning circuit for scanning a pixel area horizontally to read an infrared image, and vertical scanning circuits provided at both ends of the pixel area. The vertical scanning circuits drive a drive line by applying a driving voltage at both ends of the drive line (in two-end driving). Further a bias voltage is applied at the end of the pixel area to a bias line connected to differential integrating circuits.
Claims10
A thermal infrared solid-state imaging device including a pixel area having photosensitive pixels disposed two-dimensionally, the photosensitive pixel having first and second terminals and including one or more diodes connected in series, the diode including a thermally insulating structure and/or an infrared ray absorbing structure, the thermal infrared solid-state imaging device comprising:
- drive lines each connecting commonly the first terminals of the photosensitive pixels in each row of the pixel area;
- first and second vertical scanning circuits for selecting the drive line sequentially, and supplying a supply voltage to the selected drive line at both ends of the pixel area, respectively;
- signal lines connecting commonly second terminals of the photosensitive pixels in each column of the pixel area, the signal line being connected to first constant current means at end of the signal line;
- a bias line connecting in parallel second constant current means provided in each column of the pixel area, and generating a voltage drop substantially same as that of the drive line;
- a differential integrating circuit that is provided in each column of the pixel area, for integrating a difference between a voltage across the first constant current means and a voltage across the second constant current means for a predetermined period of time, and outputting the integration result;
- a horizontal scanning circuit for selecting in each column an output signal of the differential integrating circuit with respect to the pixel of the pixel area and leading the output signal to an output terminal;
- a reference signal output circuit for outputting a reference signal which changes substantially depending on the temperature change of the entire thermal infrared solid-state imaging device, the reference signal output circuit including one or plural of reference dummy pixel columns, the reference dummy pixel column including reference dummy pixels each of which does not include a thermally insulating structure and/or an infrared ray absorbing structure;
- and
- a bias generating circuit for generating a bias voltage depending on a difference between a differential signal between a voltage at a specified position on the bias line and the reference signal, and a reference voltage,
- wherein the bias voltage is applied to positions on the bias line corresponding to both ends of the pixel area.
Dependencies are inferred from the claim text.