Thermal infrared camera

• US 6,133,569 A
• Filed: 03/31/1998
• Issued: 10/17/2000
• Est. Priority Date: 04/03/1997
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shoda, Mashahiro, Ishizuya, Tohru
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Gabor, Otilia
• Application Number:
  US09/050,974
• Time in Patent Office: 931 Days
• Field of Search: 250/332, 250/330, 250/334, 250/352
• US Class Current: 250/332
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 5/061 by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0802 Optical filters
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/0893 Arrangements to attach devices to a pyrometer, i.e. attaching an optical interface; Spatial relative arrangement of optical elements, e.g. folded beam path G01J5/049 takes precedence

Abstract

A thermal infrared camera includes a thermal infrared image pickup element with a plurality of light-receiving parts generating heat in response to incident infrared radiation. The incident infrared radiation is detected using changes in electrical characteristics of each of the plurality of light-receiving parts, an image-focusing optical system used for image pickup, and a temperature-controlled infrared radiation blocking body that has an opening for conducting infrared radiation from the image-focusing optical system to the thermal infrared image pickup element. The temperature-controlled infrared radiation blocking body is positioned around the thermal infrared image pickup element. The thermal infrared image pickup element is mounted on a first temperature control means used to control a temperature of the thermal infrared image pickup element.

Claims

1. A thermal infrared camera comprising:

a thermal infrared image pickup element having a plurality of light-receiving parts generating heat in response to incident infrared radiation, wherein the incident infrared radiation is detected using changes in electrical characteristics of each of the plurality of light-receiving parts;

an image-focusing optical system used for image pickup; and

a temperature-controlled infrared radiation blocking body having an opening for conducting infrared radiation from the image-focusing optical system to the thermal infrared image pickup element, the temperature-controlled infrared radiation blocking body being positioned around the thermal infrared image pickup element,

wherein the thermal infrared image pickup element is mounted on a first temperature control means used to control a temperature of the thermal infrared image pickup element, and

wherein the temperature-controlled infrared radiation blocking body is thermally coupled to a second temperature control means having a different temperature from the first temperature control means.

2. The thermal infrared camera of claim 1, wherein the temperature-controlled infrared radiation blocking body is thermally coupled to the first temperature control means.

3. The thermal infrared camera of claim 1, wherein the temperature-controlled infrared radiation blocking body has a lower temperature than the thermal infrared image pickup element as a result of the second temperature control means being controlled to a lower temperature than the first temperature control means.

4. The thermal infrared camera of claim 1, wherein a wavelength-limiting filter is thermally coupled with the temperature-controlled infrared radiation blocking body and is positioned on a side of the temperature-controlled infrared radiation blocking body facing the thermal infrared image pickup element.

5. The thermal infrared camera of claim 1, wherein a neutral density filter is thermally coupled with the temperature-controlled infrared radiation blocking body and is positioned on a side of the temperature-controlled infrared radiation blocking body facing the thermal infrared image pickup element.

6. The thermal infrared camera of claim 1, wherein the image-focusing optical system is aperture-matched to the thermal infrared image pickup element.

7. The thermal infrared camera of claim 1, wherein the temperature-controlled infrared radiation blocking body and the thermal infrared image pickup element are inside one vacuum vessel.

8. A thermal infrared camera comprising:

a thermal infrared image pickup element having a plurality of light-receiving parts generating heat in response to incident infrared radiation, wherein the incident infrared radiation is detected using changes in electrical characteristics of each of the plurality of light-receiving parts;

an image-focusing optical system used for image pickup; and

a temperature-controlled infrared radiation blocking body having an opening for conducting infrared radiation from the image-focusing optical system to the thermal infrared image pickup element, the temperature-controlled infrared radiation blocking body being positioned around the thermal infrared image pickup element,

wherein the thermal infrared image pickup element is mounted on a first temperature control means used to control a temperature of the thermal infrared image pickup element, and

wherein an optically variable diaphragm is thermally coupled with the temperature-controlled infrared radiation blocking body and is positioned on an infrared radiation incident side of the thermal infrared image pickup element.

9. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element; and

a temperature control element for controlling a temperature of the thermal infrared image pickup element in response to a temperature detector positioned near the thermal infrared image pickup element,

wherein the temperature control element includes a plurality of Peltier elements, and wherein the infrared radiation blocking body is controlled to a different temperature from the thermal infrared image pickup element.

10. The thermal infrared camera of claim 9, further including an optical filter positioned between the optical imaging system and the thermal infrared image pickup element.

11. The thermal infrared camera of claim 9, wherein the optical filter includes at least one of a neutral density filter, a low-pass filter, a band-pass filter, and a high-pass filter.

12. The thermal infrared camera of claim 9, wherein the optical filter is thermally coupled to the infrared radiation blocking body.

13. The thermal infrared camera of claim 9, wherein each of the plurality of Peltier elements includes a different number of stages.

14. The thermal infrared camera of claim 9, wherein the thermal infrared image pickup element includes a plurality of light detectors.

15. The thermal infrared camera of claim 14, wherein each of the plurality of light detectors is one of a capacitive type pickup, a ferroelectric type pickup, a pyroelectric type pickup, or a thermistor type pickup.

16. The thermal infrared camera of claim 9, wherein the optical imaging system includes a lens.

17. The thermal infrared camera of claim 9, wherein the optical imaging system is aperture-matched to the thermal infrared image pickup element.

18. The thermal infrared camera of claim 9, wherein the temperature control element includes a Peltier element.

19. The thermal infrared camera of claim 9, wherein the thermal infrared image pickup element outputs an electrical signal in response to incident infrared radiation.

20. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element;

a temperature control element for controlling a temperature of the thermal infrared image pickup element in response to a temperature detector positioned near the thermal infrared image pickup element, and

a variable diaphragm positioned between the optical imaging system and the thermal infrared image pickup element.

21. The thermal infrared camera of claim 20, wherein the variable diaphragm is thermally coupled to the infrared radiation blocking body.

22. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element; and

a temperature control element for separately controlling a temperature of the thermal infrared image pickup element and of the infrared radiation blocking body in response to a temperature detector positioned near the thermal infrared image pickup element,

wherein the optical imaging system is aperture matched to the thermal infrared pickup element.

23. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element; and

a first temperature control element for controlling a temperature of the thermal infrared image pickup element in response to a temperature detector positioned near the thermal infrared image pickup element; and

a second temperature control element for controlling a temperature of the infrared radiation blocking body.

24. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element;

a first Peltier element for controlling a temperature of the thermal infrared image pickup element in response to a temperature detector positioned near the thermal infrared image pickup element; and

a second Peltier element for controlling a temperature of the infrared radiation blocking body,

wherein portions of the second Peltier element are installed over the first Peltier element, and

wherein the optical imaging system is aperture matched to the thermal infrared pickup element.

25. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body having extensions for blocking stray light, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element;

a first Peltier element for controlling a temperature of the thermal infrared image pickup element in response to a temperature detector positioned near the thermal infrared image pickup element; and

a second Peltier element for controlling a temperature of the infrared radiation blocking body,

wherein portions of the second Peltier element are installed over the first Peltier element.

26. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element; and

a temperature control element for separately controlling a temperature of the thermal infrared image pickup element and of the infrared radiation blocking body in response to a temperature detector positioned near the thermal infrared image pickup element; and

an optical filter positioned between the optical imaging system and the thermal infrared image pickup element, the optical filter including at least one of a neutral density filter, a low-pass filter, a band-pass filter, and a high-pass filter,

wherein the optical filter is thermally coupled to the infrared radiation blocking body.

27. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element; and

a temperature control element for controlling a temperature of the thermal infrared image pickup element and of the infrared radiation blocking body in response to a temperature detector positioned near the thermal infrared image pickup element; and

a variable diaphragm positioned between the optical imaging system and the thermal infrared image pickup element,

wherein the variable diaphragm is thermally coupled to the infrared radiation blocking body, and

wherein the optical imaging system is aperture matched to the thermal infrared pickup element.

28. A thermal infrared camera comprising:

a housing;

a vacuum vessel positioned inside the housing and enclosing a thermal infrared image pickup element and an infrared radiation blocking body, wherein the infrared radiation blocking body partially encloses the thermal infrared image pickup element;

an optical imaging system for projecting an image onto the thermal infrared image pickup element;

a temperature control element for controlling a temperature of the thermal infrared image pickup element and the infrared radiation blocking body in response to a temperature detector positioned near the thermal infrared image pickup element;

an optical filter positioned between the optical imaging system and the thermal infrared image pickup element, the optical filter including at least one of a neutral density filter, a low-pass filter, a band-pass filter, and a high-pass filter, wherein the optical filter is thermally coupled to the infrared radiation blocking body; and

a variable diaphragm positioned between the optical imaging system and the thermal infrared image pickup element, wherein the variable diaphragm is thermally coupled to the infrared radiation blocking body,

wherein the temperature control element includes a plurality of Peltier elements,

wherein each of the plurality of Peltier elements includes a different number of stages, and

wherein the infrared radiation blocking body is controlled to a different temperature from the thermal infrared image pickup element.