Optical tracking system using variable focal length lens

• US 20050206773A1
• Filed: 11/02/2004
• Published: 09/22/2005
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Stereo D Inc., Stereo Display, Inc.
• Original Assignee: Angstrom, Inc., Stereo Display, Inc.
• Inventors: Seo, Cheong Soo, Cho, Gyoung Il, Kim, Tae Hyeon
• Granted Patent: US 7,768,571 B2
• Time in Patent Office: Days
• US Class Current: 348/340
• CPC Class Codes: G01S 3/781 Details
• CPC Class Codes: G01S 3/786 the desired condition being maintained automatically
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 27/644 compensating for large deviations, e.g. maintaining a fixed line of sight while a vehicle on which the system is mounted changes course
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors

Abstract

An optical tracking system using a variable focal length lens includes at least one camera system, and the at least one camera system includes an objective lens system, configured to receive an object image, and at least one micromirror array lens, optically coupled to the objective lens system, configured to focus the object image received by the objective lens system onto an image sensor. The image sensor is optically coupled to the micromirror array lens, configured to receive the focused object image from the micromirror array lens and to sense the focused object image. The advantages of the present invention include ability to rapidly change the focal length and optical axis of a camera system, allowing for high-resolution, wide-angle imaging.

Claims

1. An optical system comprising at least one camera system, the at least one camera system including:

an objective lens system, configured to receive an object image;

at least one micromirror array lens, optically coupled to the objective lens system, configured to focus the object image received by the objective lens system onto an image sensor; and

the image sensor, optically coupled to the micromirror array lens, configured to receive the focused object image from the micromirror array lens and to sense the focused object image.

2. The optical system of claim 1, further comprising:

an image processor, communicatively coupled to the image sensor, configured to process the object image sensed by the image sensor and to generate image data and position information of the object.

3. The optical system of claim 2, wherein:

the image processor includes an object identification and recognition algorithm.

4. The optical system of claim 2, further comprising:

a tracking controller, communicatively coupled to the image processor, configured to generate a tracking signal to control at least one of the group consisting of;

an attitude of the camera system;

an optical axis of the micromirror array lens; and

a focal length of the micromirror array lens.

5. The optical system of claim 4, wherein the tracking controller includes an attitude control algorithm to control the attitude of the camera system.

6. The optical system of claim 4, wherein the tracking controller includes a control algorithm to control at least one of the group consisting of:

the optical axis of the micromirror array lens; and

the focal length of the micromirror array lens.

7. The optical system of claim 4, further comprising:

a movement system, mechanically coupled to the camera system and communicatively coupled to the tracking controller, configured to adjust the attitude of the camera system in response to the tracking controller signal.

8. The optical system of claim 7, wherein:

the movement system includes at least one of the group consisting of;

a servo; and

a gimbal system.

9. The optical system of claim 1, wherein the at least one camera system includes a zoom lens system.

10. A method in an optical system having at least one micromirror array lens, comprising:

capturing an object image; and

focusing the object image by adjusting the micromirror array lens.

11. The method of claim 10, further comprising:

adjusting the focal length of the optical system by adjusting the micromirror array lens.

12. The method of claim 10, further comprising:

adjusting the field of view of the optical system by adjusting the micromirror array lens.

13. The method of claim 10, further comprising:

adjusting the optical axis of the optical system by adjusting the micromirror array lens.

14. The method of claim 13, wherein:

the adjusting of the optical axis of the optical system by adjusting the micromirror array lens is performed quickly to provide a large searching area.

15. The method of claim 10, further comprising:

measuring the distance a tracked object by adjusting the micromirror array lens.

16. The method of claim 10, further comprising:

measuring three-dimensional information of a tracked object by adjusting the micromirror array lens.

17. The method of claim 10, further comprising:

using a time-sharing technique with the optical system to obtain a wide field of view image and a narrow field of view image within a short time period.