Photo-taking lens temperature compensation system

• US 5,679,946 A
• Filed: 06/24/1996
• Issued: 10/21/1997
• Est. Priority Date: 10/14/1993
• Status: Expired due to Fees

• Current Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Original Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Inventors: Hasegawa, Rieko, Sugihara, Yasumasa, Mukai, Hiromu
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US08/667,488
• Time in Patent Office: 484 Days
• Field of Search: 250/201.2, 250/201.3, 250/201.4, 250/201.8, 250/214 C, 250/214 LS, 250/238, 250/231.1, 354/400-410, 355/53, 355/55, 355/30, 396/97
• US Class Current: 250/201.2
• CPC Class Codes: G02B 7/028 with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation

Abstract

A system that is mounted in a camera capable of focal point detection and that performs correction of the focal point detection data in accordance with the temperature, wherein the temperature inside the photo-taking lens barrel is measured and the focal point detection data is corrected based on the temperature data for the interior of the photo-taking lens barrel. Using this construction, because the temperature of a lens element comprising the photo-taking lens can be accurately measured even where the ambient temperature of the camera has suddenly changed, for example, appropriate correction suitable for the temperature conditions may be performed. Also disclosed is a construction in which the correction of the focal point detection data is performed based on not only the temperature data but also the focal length data for the photo-taking lens. Using this construction, appropriate correction suitable for the temperature conditions may be performed even when, for example, the focal length of the photo-taking lens has changed.

Claims

1. An optical device comprising:

a lens system having at least one lens element,

a lens barrel for containing the lens system therein, said lens barrel having a cylindrical surface and a cylindrical interior volume divided into an upper quadrant region, which is located between the center axis of said cylindrical interior volume and an upper quarter segment of said cylindrical surface, and a lower three quadrant region, which is located between said center axis and the remaining lower three quarter segment of said cylindrical surface;

a temperature sensor which is provided inside of the lens barrel, said temperature sensor being located within said lower three quadrant region of said interior volume of said lens barrel.

2. The optical device as claimed in claim 1, wherein said lens system includes at least one sensitive lens element which is sensitive to temperature change.

3. The optical device as claimed in claim 2, where said temperature sensor is positioned substantially in the plane of the sensitive lens element and offset from the periphery thereof.

4. The optical device as claimed in claim 1, wherein said temperature sensor is located in the periphery of the lens element.

5. The optical device as claimed in claim 4, wherein said lens element is sensitive to temperature change.

6. The optical device as claimed in claim 1, wherein said temperature sensor is located between the lens element and said cylindrical surface.

7. The optical device as claimed in claim 1, further comprising:

a distance measuring device which measures a distance from the optical device to an object; and

a correcting device which corrects the distance measured by said distance measuring device in accordance with the temperature sensed by said temperature sensor.

8. The optical device as claimed in claim 1, wherein said lens system is a zoom lens system.

9. An optical device for a camera, said optical device comprising:

a lens system having at least one lens element;

a lens barrel for containing the lens system therein,, said lens barrel having a cylindrical surface and a cylindrical interior volume divided into an upper quadrant region which is located between the center axis of said cylindrical interior volume and an upper quarter segment of said cylindrical surface, and the remaining lower three quadrant region, which is located between said center axis and the remaining lower three quarter segment of said cylindrical surface;

a temperature sensor which is provided inside of the lens barrel, said temperature sensor being located within said lower three quadrant region of said interior volume of said lens barrel.

10. The optical device as claimed in claim 9, wherein said correcting device corrects image point position data in accordance with the temperature sensed by said sensor.

11. The optical device as claimed in claim 9, wherein said correcting device corrects a driving amount of a focusing lens of said lens system in accordance with the temperature.

12. The optical device as claimed in claim 9, wherein said lens system includes at least one sensitive lens element which is sensitive to temperature change.

13. The optical device as claimed in claim 12, where said temperature sensor is positioned substantially in the plane of the sensitive lens element and offset from the periphery thereof.

14. The optical device as claimed in claim 9, wherein said temperature sensor is located in the periphery of the lens element.

15. The optical device as claimed in claim 14, wherein said lens element is sensitive to temperature change.

16. The optical device as claimed in claim 9, wherein said temperature sensor is located between the lens element and said cylindrical surface.

17. The optical device as claimed in claim 9, wherein said lens system is a zoom lens system.

18. A method of making an optical device comprising the step of providing a lens system which includes a lens element in a lens barrel, said lens barrel having a cylindrical surface and a cylindrical interior volume divided into an upper quadrant region, which is located between the center axis of said cylindrical interior volume and an upper quarter segment of said cylindrical surface, and a lower three quadrant region, which is located between said center axis and the remaining lower three quarter segment of said cylindrical surface;

and

providing a temperature sensor in the lens barrel within said lower three quadrant region offset interior volume of said lens barrel.

19. The method as claimed in claim 18, wherein said lens element is a sensitive lens which is sensitive to temperature change.

20. The method as claimed in claim 18 wherein said temperature sensor is located on the periphery of the lens element.

21. The method as claimed in claim 18 wherein said temperature sensor is located between the lens element and said cylindrical surface.