A pixel circuit, its row selection method, and row selection logic circuit

Abstract

The invention discloses a pixel circuit, a row selection method thereof, and a row selection logic circuit, and relates to the technical field of uncooled infrared focal plane arrays. Wherein, the pixel circuit includes a pixel array composed of M columns of pixel units of N+1 rows and blind pixel units of P rows, and the blind pixel units are evenly distributed on the upper and lower sides of the pixel unit array; The pixel unit in each row includes a pixel resistor and two switches connected in series with the pixel resistor; the blind pixel resistor in each row in any column includes a blind pixel resistor and a switch connected in series with the blind pixel resistor Two switches; among them, M, N, P are all natural numbers and M≥1, N≥0, P≥4; the row strobe electrical signal controls the closing of the switch to control the pixel units and / or blind images of two adjacent rows Units are combined; the circuit disclosed by the invention reduces the equivalent noise bandwidth of the integrator, greatly reduces the equivalent flicker noise coefficient, and obtains a higher readout signal-to-noise ratio.

Description

technical field [0001] The invention relates to the technical field of uncooled infrared focal plane arrays, in particular to a pixel circuit, a row selection method thereof, and a row selection logic circuit. Background technique [0002] In recent years, with the development of sensor technology and the advancement of readout circuit technology, it has gradually become possible to achieve a smaller thermal response time constant and a higher frame frequency under the premise of maintaining better noise performance. In rail transit, vehicle and other application scenarios, high frame rate imaging can obtain richer dynamic information for high-speed moving target objects. [0003] What factors are the frame frequency of the readout circuit related to? Assuming that there is an infrared image sensor with M columns×N rows of pixels and it is read out in a row-scanning manner, there are M column readout circuits in total, and the M column readout circuits operate all M columns...

AI Technical Summary

Problems solved by technology

In the traditional readout method, for a column circuit, only one pixel is read out for each row selection. For a large array image sensor, the row selection time of each pixel is limited, resulting in a short integration time. The equivalent noise bandwidth of the integrator is large, and more noise cannot be filtered out during readout, and the noise of a single pixel is large, so the signal-to-noise ratio read out by traditional readout circuits is severely limited

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