Infrared sensor and infrared sensor array using the same
First Claim
Patent Images
1. An infrared sensor comprising:
- a first infrared sensing element located on a first dielectric layer that is disposed on a silicon substrate, the first dielectric layer having a void opposite said first infrared sensing element, said first infrared sensing element producing a first output voltage depending on incident infrared rays;
a MOSFET having a gate receiving the first output voltage, a source, and a drain;
a second temperature sensing element located on a second dielectric film that is disposed on said silicon substrate, the second temperature sensing element producing a second output voltage received by the source of said MOSFET; and
a capacitor section connected to the drain of said MOSFET.
1 Assignment
0 Petitions
Accused Products
Abstract
An infrared sensor includes a first infrared sensing element separated by a dielectric layer from on a silicon substrate and thermally isolated from the substrate by a void in the dielectric layer. The sensor has a second temperature sensing element which detects the temperature of the whole sensor. The output difference between the first and second sensor elements is used as gate/source voltage of a MOSFET. The current variation of the MOSFET is read out as a discharge from a capacitor connected to the MOSFET. The noise in the sensor is suppressed, and performance is improved. An infrared sensor array includes the sensors arranged in an array.
-
Citations
13 Claims
-
1. An infrared sensor comprising:
-
a first infrared sensing element located on a first dielectric layer that is disposed on a silicon substrate, the first dielectric layer having a void opposite said first infrared sensing element, said first infrared sensing element producing a first output voltage depending on incident infrared rays;
a MOSFET having a gate receiving the first output voltage, a source, and a drain;
a second temperature sensing element located on a second dielectric film that is disposed on said silicon substrate, the second temperature sensing element producing a second output voltage received by the source of said MOSFET; and
a capacitor section connected to the drain of said MOSFET. - View Dependent Claims (2, 3, 6, 7)
-
- 4. The infrared sensor according to clam 1, wherein said first infrared sensing element comprises a first resistor and said second temperature sensing element comprises a second resistor.
-
8. An infrared sensor comprising:
-
a first infrared sensing element located on a first dielectric layer that is disposed on a silicon substrate, the first dielectric layer having a void opposite said first infrared sensing element, said first infrared sensing element producing a first output voltage changing in response to incident infrared rays;
a bipolar transistor having a base receiving the first output voltage, an emitter, and a collector;
a second temperature sensing element located on a second dielectric film that is disposed on said silicon substrate, the second temperature sensing element producing a second output voltage connected to the emitter of said bipolar transistor; and
a capacitor section connected to the collector of said bipolar transistor. - View Dependent Claims (9, 10, 11, 12)
-
-
13. An infrared sensor array comprising:
-
an at least one-dimensional array of first infrared sensing elements, each first infrared sensing element being located on a first dielectric layer that is disposed on a silicon substrate, the first dielectric layer having a void opposite each of said first infrared sensing elements, said first infrared sensing elements being arranged in columns and producing respective first output voltages;
a respective second temperature sensing element producing a second output voltage and a capacitor for each column of said array, located on a second dielectric layer on said silicon substrate; and
respective MOSFETs for each column of said array having gates receiving first output voltages of said first infrared sensing elements of a corresponding column, sources receiving the second output voltages of said second temperature sensing element corresponding to the column, and drains connected to said capacitor corresponding to the column, wherein a voltage of said capacitor, which is discharged by a voltage variation between the gate and the source of said MOSFET of the corresponding column, is output as a read-out signal.
-
Specification