US 5,493,118 AGranted

Thermal image detecting system

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsIsamu Okuda, Yasuhito Mukai, Satoshi Tokushige, Morihiro Nakayama

Life of this patent

Estimating the term…

Loading patent…

Abstract

A thermal image detecting system includes a moving part having pyroelectric thermal detection element, a chopper for opening/closing a path of infrared rays and a chopper temperature detection element, a rotating section for rotating the moving part, a drive control section for driving the chopper and the rotating section, a band amplifier for amplifying a detection signal from the pyroelectric thermal detection element, a timing output section for outputting a signal synchronous with an opening/closing operation of the chopper, a peak detection section for successively holding the maximum value and the minimum value of a signal from the band amplifier, and an operational processing section for performing operational processing on a thermal image signal on the basis of a difference between the maximum value and the minimum value or a difference between a reference signal from the band amplifier in a closed state of the chopper and the maximum value, or the minimum value and the temperature of the chopper.

Claims21

Dependent claims

A thermal image detecting system comprising:

(a) a moving part including
(i) a pyroelectric thermal detection element having an electric characteristic which changes in response to infrared rays for generating a first temperature detection signal,
(ii) a chopper for opening/closing a path along which infrared rays from an object to be detected reach said pyroelectric thermal detection element, and
(iii) a chopper temperature detection element for detecting a temperature of said chopper to produce a second temperature detection signal which represents the detected temperature of said chopper;
(b) rotation means for rotating said moving part about a predetermined rotation axis;
(c) a drive control section for generating a chopper driving signal to drive said chopper and for generating a rotation means driving signal to drive said rotation means;
(d) a band amplifier for amplifying said first temperature detection signal from said pyroelectric thermal detection element;
(e) timing output means for outputting a synchronized timing signal which is synchronous with an opening/closing operation of said chopper, said timing output means comprising means, receiving said chopper driving signal from said drive control section, for outputting said synchronous timing signal;
(f) a peak detection section for holding a maximum value and a minimum value of said first temperature detection signal amplified by said band amplifier during a time interval determined by said synchronized timing signal;
and
(g) an operational processing section for producing a thermal image signal by performing operational processing with said second temperature detection signal and a difference between said maximum value and said minimum value.

8 more elements

A thermal image detecting system comprising:

(a) a moving part including
(i) a pyroelectric thermal detection element having an electric characteristic which changes in response to infrared rays for generating a first temperature detection signal,
(ii) a chopper for opening/closing a path along which infrared rays from an object to be detected reach said pyroelectric thermal detection element, and
(iii) a chopper temperature detection element for detecting a temperature of said chopper to provide a second temperature detection signal which represents the detected temperature of said chopper;
(b) rotating means for rotating said moving part around a predetermined rotation axis;
(c) a drive control section for generating a chopper driving signal to drive said chopper and a rotating means driving signal to drive said rotating means;
(d) a band amplifier for amplifying said first temperature detection signal from said pyroelectric thermal detection element;
(e) a reference signal detection section for detecting said first temperature detection signal amplified by said band amplifier in a period of time when said chopper is maintained at a closed state by said drive control section;
(f) timing output means for outputting a synchronized timing signal which is synchronous with an opening/closing operation of said chopper;
(g) a peak detection section for holding a maximum value and a minimum value of said first temperature detection signal generated by said pyroelectric thermal detection element during a time interval determined by said synchronized timing signal;
and
an operating processing section for producing a thermal image signal by performing operating processing with said second temperature detection signal and a difference between said reference signal and said maximum value or said minimum value.

9 more elements

Dependencies are inferred from the claim text.