OPTICAL UNIT, IMAGE PICKUP DEVICE USING THE OPTICAL UNIT, AND ON-VEHICLE IMAGE DISPLAY DEVICE USING THE IMAGE PICKUP DEVICE

• US 20080112050A1
• Filed: 10/17/2007
• Published: 05/15/2008
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Nomura, Tsubasa
• Granted Patent: US 8,425,058 B2
• Time in Patent Office: Days
• US Class Current: 359/507
• CPC Class Codes: G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films G02B1/16 takes precedence
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B
• CPC Class Codes: G02B 3/00 Simple or compound lenses

Abstract

A lens unit or the like with improved ability to capture proper images by reducing the likelihood that water droplets will adhere to the lens surface and change the refractive index. A surface of a lens portion (1) is imparted with a water-repellent property and a surface of a non-lens portion (2), surrounding the lens portion (1), is imparted with a hydrophilic property. As a result, if droplets on the surface of the lens portion (1) contact the non-lens portion (2), the droplets are guided from the water-repellent surface of the lens portion (1) to the hydrophilic surface of the non-lens portion (2) thereby reducing the number of droplets residing on the lens portion (1).

Claims

1. An optical unit comprising:

a light transmissive portion; and

a light non-transmissive portion adjacent the light transmissive portion,

wherein, the light transmissive portion includes a water-repellent surface region and the light non-transmissive portion includes a hydrophilic surface region.

2. An optical unit comprising:

a light transmissive portion; and

a light non-transmissive portion adjacent the light transmissive portion,

wherein, the light transmissive portion contains a surface region that is divided into a first region that is water-repellent and a second region that is hydrophilic.

3. The optical unit according to claim 2, wherein a surface region of the light non-transmissive portion is a hydrophilic region.

4. The optical unit according to claim 3, wherein the first region is a central region of a lens portion, and the second region is a peripheral region located outside the central region.

5. The optical unit according to claim 4, wherein the hydrophilic region comprises a coating of a hydrophilic material.

6. The optical unit according to claim 4, wherein the hydrophilic region comprises a surface modification, wherein the surface modification imparts a hydrophilic property to the surface of the hydrophilic region.

7. The optical unit according to claim 2, wherein the water-repellent region comprises a coating of a water-repellent material.

8. The optical unit according to claim 2, wherein the water-repellent region comprises a surface modification, wherein the surface modification imparts a water-repellent property to the surface of the water-repellent region.

9. The optical unit according to claim 2, wherein a surface region of the light-transmissive portion and a surface region of the light non-transmissive portion includes a first coating of a water-repellent material, and a second coating over a portion of the first coating of a water-repellent material, wherein the second coating comprises a hydrophilic material, and covers the portion of the first coating corresponding to the hydrophilic region of the water-repellent surface region.

10. The optical unit according to claim 2, wherein hydrophilicity varies in the hydrophilic region.

11. The optical unit according to claim 2, wherein a drainage structure is connected to the light non-transmissive portion.

12. The optical unit according to claim 11, wherein hydrophilicity of the surface region of the light non-transmissive portion increases toward the location of the drainage structure.

13. The optical unit according to claim 12, wherein the drainage structure comprises a thin tube member.

14. The optical unit according to claim 12, wherein the drainage structure comprises a linear member having a hydrophilic surface.

15. The optical unit according to claim 12, wherein a groove portion is formed in the surface of the light non-transmissive portion.

16. The optical unit according to claim 15, wherein the groove portion includes an open groove that extends to an outer peripheral portion of the light non-transmissive portion.

17. The optical unit according to claim 12, wherein the light transmissive portion includes a transparent covering member, wherein the transparent covering member covers a portion of the surface of the light transmissive portion.

18. An image pickup device comprising:

the optical unit according to claim 2; and

an image pickup element located opposite the surface of the light transmissive portion.

19. An image pickup device for an on-vehicle image display device, comprising:

an optical unit comprising;

a light transmissive portion, wherein the light transmissive portion contains a surface region divided into a first region that is water-repellent and a second region that is hydrophilic, wherein the hydrophilicity varies in the hydrophilic region, and the first region corresponds to an image pickup region necessary for obtaining peripheral information for the vehicle, and the second region corresponds to an image pickup region not necessary for obtaining peripheral information for the vehicle; and

a light non-transmissive portion adjacent the light transmissive portion; and

an image pickup element located opposite the surface of a light transmissive portion of the optical unit.

20. The on-vehicle image display device according to claim 19, wherein the image pickup device is attached to a vehicle such that a light transmissive portion of the image pickup device is oriented non-perpendicular to the ground, wherein hydrophilicity varies in the hydrophilic region to gradually increase from an upper portion to a lower portion of the hydrophilic region.

21. The on-vehicle image display device according to claim 19, wherein the image pickup device is attached to the vehicle such that the light transmissive portion of the image pickup device is oriented down toward the ground, wherein hydrophilicity gradually increases in a direction opposite to a moving direction of the vehicle.

22. The on-vehicle image display device according to claim 20, wherein the optical unit of the image pickup device further comprises a drainage structure connected to a lower portion of the hydrophilic region of the light non-transmissive portion, and the image pickup device is attached to the vehicle such that a light transmissive portion of the image pickup device is oriented non-perpendicular to the ground.

23. The on-vehicle image display device according to claim 21, wherein the image pickup device is attached to the vehicle such that a light transmissive portion of the image pickup device is oriented down toward the ground, and the drainage structure is connected to a rear portion of the light non-transmissive portion located on the side opposite a moving direction of the vehicle.

24. The on-vehicle image display device according to claim 22, wherein a groove portion is formed in the surface of the light non-transmissive portion, and the groove portion includes an open groove that extends to an outer peripheral portion of the light non-transmissive portion.

25. The on-vehicle image display device according to claim 23, wherein a groove portion is formed in the surface of the light non-transmissive portion, and the groove portion includes an open groove that extends to an outer peripheral portion of the light non-transmissive portion.