Infrared detection apparatus

Patent metadata

Field	Value
Publication number	US-9967484-B2
Application number	US-201615151544-A
Country	US
Kind code	B2
Filing date	May 11, 2016
Priority date	Nov 15, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

An infrared detection apparatus includes an infrared detector configured to output an electric signal corresponding to an inputted infrared ray, and a signal processor configured to compensate for a variation of the electric signal, which is outputted from the infrared detector, caused by variation of an operation temperature with a value indicating a variation of a dark current equivalent component by the operation temperature variation when becoming a second operation temperature after the operation temperature variation, the dark current equivalent component including a first dark current equivalent component calculated using a first electric signal and a second electric signal outputted from the infrared detector when infrared rays having intensities equivalent to blackbodies of a first known temperature and a second known temperature are inputted at a first operation temperature.

First claim

What is claimed is:

1. An infrared detection apparatus, comprising:
an infrared detector configured to output an electric signal corresponding to an inputted infrared ray; and
a signal processor configured to compensate for a variation of the electric signal, which is outputted from the infrared detector, caused by variation of an operation temperature with a value indicating a variation of a dark current equivalent component by the operation temperature variation when becoming a second operation temperature after the operation temperature variation, the dark current equivalent component including a first dark current equivalent component calculated using a first electric signal and a second electric signal outputted from the infrared detector when infrared rays having intensities equivalent to blackbodies of a first known temperature and a second known temperature are inputted at a first operation temperature.

2. The infrared detection apparatus according to claim 1 , wherein the signal processor calculates the first dark current equivalent component from a relational expression in which not a constant but a function of a temperature is included in a portion relating to dependency of the infrared intensity on the temperature.

3. The infrared detection apparatus according to claim 2 , wherein a function f(T) of a temperature T included in the portion of the relational expression relating to the dependency of the infrared intensity on the temperature is represented, where a peak wavelength in a wavelength response characteristic of the infrared detector is represented by λp, a real coefficient is represented by x, the Boltzmann's constant is represented by k B , the Planck's constant by h and an a speed of light in vacuum is represented by c, by

f
⁡

(
T
)

=

hc

xλ
p

⁢

k
B

⁢

T
2

4. The infrared detection apparatus according to claim 3 , wherein the real coefficient x is within a range of

hc

λ
p

⁢

k
B

⁢
T

>
1

with respect to the temperature T that satisfies

1
-

3
⁢
FWHM

2
⁢

Ln
⁡

(
2
)

⁢

λ
p

≤
x
≤

1
+

3
⁢
FWHM

2
⁢

Ln
⁡

(
2
)

⁢

λ
p

where FWHM represents the full width at half maximum in the wavelength response characteristic of the infrared detector.

5. The infrared detection apparatus according to claim 1 , wherein the signal processor calculates the first dark current equivalent component V d1 , where the first known temperature is represented by T 1 , the second known temperature by is represented by T 2 (T 2 >T 1 ), the first electric signal is represented by V 1 and the second electric signal is represented by V 2 , by

V

d
⁢

⁢
1

=

V
1

⁢

exp
⁡

(

-

hc

x
⁢

⁢

λ
p

⁢

k
B

⁢

T
2

)

-

V
2

⁢

exp
⁡

(

-

hc

x
⁢

⁢

λ
p

⁢

k
B

⁢

T
1

)

Assignees

• Fujitsu Ltd

Inventors

• Matsukura Yusuke

Classifications

• G01J5/28 Primary

  using photoemissive or photovoltaic cells · CPC title

• H04N25/65

  applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS · CPC title

• G01J2005/0077

  Imaging · CPC title

• H04N5/361 Primary

  Electricity · mapped topic

• H04N5/33

  Transforming infrared radiation (cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20) · CPC title