Sensor module with integrated signal processing
A sensor module comprises a radiation-sensitive sensor element ( 12 ), a sensor signal processing circuit ( 13, 41 a, 44 a ) receiving the output signal of the sensor element ( 12 ) and obtaining a radiation-dependent first electric signal therefrom, a temperature-sensitive reference means ( 14, 15, 41 b, 43, 44 b ) providing a temperature-dependent second electric signal and a signal combining means ( 16 ) for combining the two electric signals. The sensor signal processing circuit ( 13, 41 a, 44 a ), the reference means ( 14, 15, 41 b, 44 b ) and the combining means ( 16 ) are formed on a single chip ( 20, 21 ), and the chip ( 20, 21 ) and the sensor element ( 12 ) are accommodated in a common housing ( 22, 62, 64 ).
1. Sensor module comprising
a radiation-sensitive sensor element providing a radiation-dependent electric output signal,
a sensor signal processing circuit receiving the output signal from the sensor element and providing a radiation-dependent first electric signal,
a temperature-sensitive reference means comprising a reference element thermally coupled to the sensor element and one or several squaring means connected to the reference element for simulating the temperature dependency of the photo-electric conversion characteristics of the sensor element and providing a temperature-dependent second electric signal, and
a combination means for combining the two electric signals, characterised in that
the sensor signal processing circuit, the temperature-sensitive reference means and the signal combining means are formed on a single, and
the chip and the sensor element are accommodated in a common housing.
2. Sensor module according to claim 1 , characterised in that the housing is provided with electrically conductive or semi-conductive walls.
3. Sensor module according to claim 1 , characterised in that the housing has a cylindrical shape and the cylinder has a diameter of less than 10 mm.
4. Sensor module according to claim 1 , characterised in that the sensor signal processing circuit is provided with a first amplifier.
5. Sensor module according to claim 1 , characterised in that the reference means comprises a reference element and a second amplifier.
6. Sensor module according to claim 1 , further comprising a compensation means for compensating the influence of the power dissipation of electronic components on the output signal.
7. Sensor module according to claim 1 , further comprising a radiation-transmissible window provided in the housing said window being electrically conductive or semi-conductive or having an electrically conductive or semi-conductive coating.
8. Sensor module according to claim 7 , further comprising an image element in the window of the housing.
9. Sensor module according to claim 1 , further comprising an optical imaging element provided in the housing.
10. Sensor module according to claim 9 , characterised in that the imaging element comprises a lens or a mirror.
11. Sensor module according to claim 1 , further comprising digital programming means provided in the housing for setting operating parameters of the sensor module.
12. Sensor module according to claim 1 , characterised in that the combination means is an integrator amplifier.
13. Sensor module according to claim 1 , characterised in that the combination means is a digital circuit receiving the signals from the sensor means and the reference means via A/D converters and outputting a digital, temporally serial signal.
14. Sensor module according to claim 1 , characterised in that the combination means is a digital circuit outputting digital signal as YES/NO values to be used for monitoring a temperature threshold or for controlling one or more temperatures to one or more target values, the one or more target values being programmable.
15. The sensor module of claim 1 wherein the reference means comprises elements for characteristics simulation, the elements simulating characteristics of the sensor element with an exponential function or a power function.
16. Sensor module according to claim 1 , characterised in that the combination means is a digital circuit outputting digital signal as YES/NO values to be used for monitoring a temperature threshold and for controlling one or more temperatures to one or more target values, the one or more target values being programmable.