US 12,072,238 B2
Photoconductor readout circuit
Bernd Scherwath, Ludwigshafen (DE); Peter Fejes, Ludwigshafen (DE); Celal Mohan Oeguen, Ludwigshafen (DE); Robert Gust, Ludwigshafen (DE); Robert Send, Karlsruhe (DE); and Stefan Hoos, Ludwigshafen (DE)
Assigned to TRINAMIX GMBH, Ludwigshafen am Rhein (DE)
Appl. No. 17/754,468
Filed by TRINAMIX GMBH, Ludwigshafen am Rhein (DE)
PCT Filed Oct. 8, 2020, PCT No. PCT/EP2020/078227
§ 371(c)(1), (2) Date Apr. 1, 2022,
PCT Pub. No. WO2021/069554, PCT Pub. Date Apr. 15, 2021.
Claims priority of application No. 19202131 (EP), filed on Oct. 9, 2019.
Prior Publication US 2022/0326075 A1, Oct. 13, 2022
Int. Cl. G01K 7/00 (2006.01); G01J 1/44 (2006.01); G01K 7/16 (2006.01)
CPC G01J 1/44 (2013.01) [G01K 7/16 (2013.01); G01J 2001/4446 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A device comprising
at least one photoconductor configured for exhibiting an electrical resistance Rphoto dependent on an illumination of a light-sensitive region of the photoconductor; and
at least one photoconductor readout circuit, wherein the photoconductor readout circuit is configured for determining the electrical resistance Rphoto of the photoconductor, wherein the photoconductor readout circuit comprises at least one bias voltage source configured for applying at least one modulated bias voltage to the photoconductor;
wherein the bias voltage is a periodical time-dependent bias voltage, wherein the bias voltage is selected such that an integral of charge carriers which flows through the photoconductor over a measurement period is zero, wherein the measurement period is defined by a time between two consecutive transitions of a bias voltage polarization in the same direction;
wherein the device comprises at least one first electronic circuit, wherein the first electronic circuit is configured for generating at least one first output signal, wherein a frequency of the first output signal is a mathematical function of said measurement period of the photoconductor;
wherein the device comprises at least one second photoconductor configured for exhibiting an electrical resistance Rphoto2 dependent on an illumination of its light-sensitive region, wherein the device comprises at least one second electronic circuit configured for generating a second measurement period, wherein the second electronic circuit is configured for generating at least one second output signal, wherein a frequency of the second output signal is a mathematical function of the measurement periods of the photoconductor and of the second photoconductor; and
wherein:
the second electronic circuit is a frequency mixer; or
the device comprises at least one third resistor for exhibiting an irradiation independent electrical resistance with the same temperature dependency as the photoconductor and the second photoconductor, wherein the third resistor is either a photoconductor, darkened in such a way that it experience no irradiation, or a non-photosensitive resistor, wherein the device comprises at least one third electronic circuit configured for generating a third frequency, wherein the third frequency serves as a reference frequency, wherein the reference frequency is used to generate a difference of the frequencies from the illuminated photoconductors by means of at least two electronic circuits.