Non-contact temperature sensor with temperature compensating heat sensitive elements on plastic film

• US 6,367,972 B1
• Filed: 05/27/1999
• Issued: 04/09/2002
• Est. Priority Date: 09/29/1998
• Status: Expired due to Term

• Current Assignee: Ishizuka Electronics Corporation
• Original Assignee: Ishizuka Electronics Corporation
• Inventors: Hiroe, Kenichi, Saito, Shinichi, Okada, Toshikazu, Kamiyama, Jun, Nojiri, Toshiyuki
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): Pruchnic, Stanley J.
• Application Number:
  US09/320,576
• Time in Patent Office: 1,048 Days
• Field of Search: 374/133, 374/132, 374/121, 374/170, 327/512
• US Class Current: 374/133
• CPC Class Codes: G01J 5/06 Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity for adjusting of solid angle of collected radiation G01J5/07; means for wavelength selection G01J5/0801

Abstract

A non-contact temperature sensor includes a holder serving as a light conducting portion for guiding infrared rays incident from a first opening at its one end; a plastic film arranged at a second opening of the other end of tile light conducting portion; a cover for sealing the second opening at the other end of the holder so as to provide a space between itself and the plastic film, an infrared ray detection heat-sensitive element arranged on the side of the space of the plastic film, for detecting the infrared rays incident from the first opening; and a temperature compensating heat-sensitive means arranged in the vicinity of the holder, for detecting the temperature of the holder. In this configuration, the surface temperature of the body-to-be-detected can be precisely detected in a short time.

Claims

1. A non-contact temperature sensor comprising:

a holder serving as a light conducting portion for guiding infrared rays incident from a first opening at one of opposing ends;

a plastic film arranged at a second opening of the other end of said light conducting portion, the plastic film having a first side facing the first and second openings and a second side, opposed to the first side;

a cover for sealing the second opening at the other of the opposing ends of the holder so as to provide a space between the cover and said plastic film;

an infrared ray detecting heat-sensitive element formed on the second side of said plastic film, facing the space between the cover and the plastic film, for detecting the infrared rays incident from said first opening; and

a temperature compensating heat-sensitive means arranged in the vicinity of the holder, for detecting the temperature of said holder, both the infrared ray detecting heat-sensitive element and the temperature compensating heat-sensitive means are connected to a wiring pattern formed also on the second side of the plastic film.

2. A non-contact temperature sensor according to claim 1, wherein said temperature compensating heat-sensitive means includes a first and a second temperature compensating heat-sensitive element.

3. A detection circuit for a non-contact temperature sensor as claimed in claim 2, comprising:

a first series circuit composed of said infrared ray detecting element and said first temperature compensating element,

a second series circuit composed of said second temperature compensating element and a resistor element; and

an arithmetic unit for processing an output from said first series circuit and another output from said second circuit to detect a surface temperature of a body-to-be-detected.

4. A detection circuit according to claim 3, further comprising:

a data table used to convert a numerical output value from said arithmetic processing unit into a temperature, thereby detecting the surface temperature of an object to be detected.

5. A detection circuit for a non-contact temperature sensor as claimed in claim 1, comprising:

a first series circuit composed of said infrared ray detecting element and a resistor element;

a second series circuit composed of said temperature compensating means and another resistor element; and

an arithmetic unit for processing an output from said first series circuit and another output from said second circuit to detect a surface temperature of a body-to-be-detected.

6. A detection circuit for a non-contact temperature sensor as claimed in claim 1, comprising:

a series circuit composed of the infrared ray heat-sensitive element and the temperature compensating means, through which a constant current is passed; and

an arithmetic processing unit for processing an output from said series circuit and another output from said temperature compensating means to detect a surface temperature of a body-to-be-detected.

7. A non-contact temperature sensor according to claim 1, further comprising an infrared ray absorbing film attached to an inner wall of said holder.

8. A non-contact temperature sensor according to claim 1, further comprising:

an infrared ray reflective film located behind the plastic film to reflect heat radiated from said plastic film.

9. A non-contact temperature sensor according to claim 1, wherein said temperature compensating heat-sensitive means is attached to an outer wall of the holder.

10. A non-contact temperature sensor according to claim 1, wherein said first opening area has a horizon tally lengthy shape in section.

11. A non-contact temperature sensor according to claim 1, wherein said plastic film is made of a material selected from a group consisting of “

TEFLON”

, silicone, polyimide, polyester, polyethylene, polycarbonate and PPS.

12. A non-contact temperature sensor according to claim 1, wherein said plastic film is made of a high-polymer material with carbon black or inorganic pigment dispersed.

13. A non-contact temperature sensor comprising:

a holder having a front opening area to which infrared rays are incident;

a plastic film arranged on a back side of said holder, the plastic film having a first side facing the front opening and an second side, opposed to the first side;

a cover arranged on the back side of said holder and having a space opposite to said front opening area;

an infrared ray detecting heat-sensitive element formed on the second side of said plastic film, facing the space of the cover, for detecting the infrared rays incident from said front opening; and

a temperature compensating heat-sensitive means for detecting the temperature of said holder, the temperature compensating heat-sensitive means being formed on the second side of the plastic film, and both the infrared ray detecting heat-sensitive element and the temperature compensating heat-sensitive means are connected to a wiring pattern formed also on the second side of the plastic film.

14. A non-contact temperature sensor according to claim 13, wherein said temperature compensating heat-sensitive means includes a first and a second temperature compensating heat-sensitive element.

15. A detection circuit for a non-contact temperature sensor as claimed in claim 14, comprising:

a first series circuit composed of said infrared ray detecting element and said first temperature compensating element,

a second series circuit composed of said second temperature compensating element and a resistor element; and

an arithmetic unit for processing an output from said first series circuit and another output from said second circuit to detect a surface temperature of a body-to-be-detected.

16. A detection circuit according to claim 15, further comprising:

a data table used to convert a numerical output value from said arithmetic processing unit into a temperature, thereby detecting the surface temperature of an object to be detected.

17. A detection circuit for a non-contact temperature sensor as claimed in claim 13 comprising:

a first series circuit composed of said infrared ray detecting element and a resistor element;

a second series circuit composed of said temperature compensating means and another resistor element; and

an arithmetic unit for processing an output from said first series circuit and another output from said second circuit to detect a surface temperature of a body-to-be-detected.

18. A non-contact temperature sensor according to claim 13, further comprising a light conducting member attached to said opening area.

19. A non-contact temperature sensor according to claim 18, further comprising an infrared ray absorbing film attached to an inner wall of said light conducting member.

20. A non-contact temperature sensor according to claim 13, further comprising:

an infrared ray reflective film located behind the plastic film to reflect heat radiated from said plastic film.

21. A non-contact temperature sensor according to claim 13, wherein said light conducting portion has a horizontally lengthy shape in section.

22. A non-contact temperture sensor according to claim 13, wherein said plastic film is made of a material selected from a group consisting of “

TEFLON”

, silicone, polyimide, polyester, polyethylene, polycarbonate and PPS.

23. A non-contact temperature sensor according to claim 13, wherein said plastic film is made of a high-polymer material with carbon black or inorganic pigment dispersed.