Pixel circuit, row selection method of pixel circuit and row selection logic circuit

Abstract

The invention discloses a pixel circuit, a row selection method of the pixel circuit and a row selection logic circuit, and relates to the technical field of uncooled infrared focal plane arrays. Thepixel circuit comprises M columns of pixel arrays consisting of N+1 rows of pixel units and P rows of blind pixel units; the blind pixel units are uniformly distributed on the upper side and the lowerside of the pixel unit arrays; each row of pixel units in any column comprises a pixel resistor and two switches connected in series with the pixel resistor; each row of blind pixel resistors in anycolumn comprises a blind pixel resistor and two switches connected in series with the blind pixel resistors, wherein M, N and P are all natural numbers, M is larger than or equal to 1, N is larger than or equal to 0, and P is larger than or equal to 4; and a row gating electric signal is used for combining the two adjacent rows of pixel units and / or blind pixel units by controlling the switches tobe closed. By adopting the circuit, the equivalent noise bandwidth of an integrator is reduced, the equivalent flicker noise coefficient is greatly reduced, and the higher readout signal-to-noise ratio is obtained.

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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