EXPOSURE-SUPPRESSING IMAGING SYSTEM

• US 20150163389A1
• Filed: 12/06/2013
• Published: 06/11/2015
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: National Chung-Shan Institute of Science and Technology
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Inventors: Lo, Min-Fang, Liang, Chao-Wen, Lin, Jhe-Syuan
• Granted Patent: US 9,197,819 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 13/22 Telecentric objectives or lens systems
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 5/205 Neutral density filters
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/75 by influencing optical camera components
• CPC Class Codes: H04N 25/60 Noise processing, e.g. detecting, correcting, reducing or removing noise

Abstract

An exposure-suppressing imaging system has a first optical assembly forming a first image of an object on a focal plane thereof, a beam splitter positioned between the first optical assembly and the focal plane of the first optical assembly; an LCOS reflective light modulator positioned on the focal plane, and selectively and partially altering the reflectivity thereof to reflect the first image back to the beam splitter; a second optical assembly positioned on a side of the beam splitter and receiving the reflected first image to form a second image on a focal plane of the second optical assembly; a light sensor converting the second image into a signal; and a controller receiving the signal computed as a third image, and selectively controlling the reflectivity of the LCOS reflective light modulator according to whether the signal contains information of overexposure on the third image.

Claims

1. An exposure-suppressing imaging system installed in a motor vehicle comprising:

a first optical assembly forming a first image of an object on a focal plane thereof;

a beam splitter positioned between the first optical assembly and the focal plane of the first optical assembly;

an LCOS (Liquid Crystal on Silicon) reflective light modulator positioned on the focal plane, and selectively and partially altering the reflectivity thereof to reflect the first image back to the beam splitter;

a second optical assembly positioned on a side of the beam splitter and receiving the reflected first image to form a second image on a focal plane of the second optical assembly;

a light sensor positioned on the focal plane of the second optical assembly and converting the second image into a signal; and

a controller receiving the signal and computing the signal to generate a third image, and selectively controlling the reflectivity of the LCOS reflective light modulator according to whether the signal contains information of overexposure on the third image.

2. The exposure-suppressing imaging system as claimed in claim 1, wherein the first optical assembly has a focal length of 17 mm and a F-number (focal ratio number) of 8.

3. The exposure-suppressing imaging system as claimed in claim 1, wherein the second optical assembly has a focal length of 8.24 mm.

4. The exposure-suppressing imaging system as claimed in claim 2, wherein the second optical assembly has a focal length of 8.24 mm.

5. The exposure-suppressing imaging system as claimed in claim 2, wherein the first optical assembly is a telecentric optical imaging system.

6. The exposure-suppressing imaging system as claimed in claim 3, wherein the first optical assembly is a telecentric optical imaging system.

7. The exposure-suppressing imaging system as claimed in claim 4, wherein the first optical assembly is a telecentric optical imaging system.

8. An exposure-suppressing imaging system installed in motor vehicle comprising:

a first optical assembly forming a first image of an object at a focal plane thereof and having;

a first lens having a central concavity which radius is −

5.73 to −

7 mm defined on a first surface thereof and a convexity which radius is −

7.65 to −

9.35 mm defined on a second surface thereof;

a second lens having convexities respectively defined on a first surface and a second surface thereof with radiuses 17.36 to 21.21 mm and −

10.86 to −

13.28 mm respectively;

a third lens having a central concavity which radius is −

8.85 to −

10.81 mm defined on a first surface thereof and a planar area defined on a second surface thereof;

a fourth lens having a convexity which radius is 13.53 to 16.53 mm defined on a first surface thereof and a planar defined on a second surface thereof,

wherein the first lens, the second lens, the third lens and the fourth lens are sequentially centered on a common optical axis;

a beam splitter positioned between the first optical assembly and the focal plane of the first optical assembly;

an LCOS reflective light modulator positioned on the focal plane, and selectively and partially altering the reflectivity thereof to reflect the first image back to the beam splitter;

a second optical assembly positioned on a side of the beam splitter and receiving the reflected first image to form a second image on a focal plane of the second optical assembly, and having;

a fifth lens having a concavity which radius is −

45.71 to −

55.87 mm defined on a first surface thereof and a convexity which radius is −

13.13 to −

16.05 mm defined on a second surface thereof;

a sixth lens having convexities which radiuses are 11.18 to 13.66 mm respectively defined on a first surface and a second surface thereof;

a seventh lens coupled to the sixth lens, having a concavity which radius is −

6.12 to −

7.57 mm defined on a first surface thereof and a planar area defined on a second surface thereof;

an eighth lens having convexities which radiuses are 6.63 to 8.1 mm and −

25.43 to −

31.08 mm respectively defined on a first surface and a second surface thereof; and

a ninth lens having a central concavity which radius is −

3.30 to −

4.03 mm defined on a first surface thereof and a planar area defined on a second surface thereof,

in which the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens are sequentially centered on the common optical axis;

a light sensor positioned on the focal plane of the second optical assembly and converting the second image into a signal; and

a controller receiving the signal and computing the signal to generate a third image, and selectively controlling the reflectivity of the LCOS reflective light modulator according to whether the signal contains information of overexposure on the third image.

9. The exposure-suppressing imaging system as claimed in claim 8, wherein the first optical assembly has a focal length of 17 mm and a F-number of 8.

10. The exposure-suppressing imaging system as claimed in claim 8, wherein the second optical assembly has a focal length of 8.24 mm.

11. The exposure-suppressing imaging system as claimed in claim 9, wherein the second optical assembly has a focal length of 8.24 mm.

12. The exposure-suppressing imaging system as claimed in claim 8, wherein the first optical assembly is a telecentric optical imaging system.

13. The exposure-suppressing imaging system as claimed in claim 9, wherein the first optical assembly is a telecentric optical imaging system.

14. The exposure-suppressing imaging system as claimed in claim 11, wherein the first optical assembly is a telecentric optical imaging system.