Imaging apparatus and a camera for vehicles

• US 20050117027A1
• Filed: 10/15/2004
• Published: 06/02/2005
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Monji, Tatsuhiko, Furusawa, Isao, Fukuhara, Masaaki
• Granted Patent: US 8,013,901 B2
• Time in Patent Office: Days
• US Class Current: 348/222.100
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: G02B 5/205 Neutral density filters
• CPC Class Codes: H04N 23/75 by influencing optical camera components

Abstract

A camera apparatus for vehicles including an imaging element and a lens comprises a gradation generation unit for stepwise changing the light amount reaching a whole or part of the imaging element. By this, a gradation region is formed on the imaging element and it absorbs assembling errors during manufacturing and positional shifts attributed to a road surface slope or the like. Even when an inverse light state is caused, it is possible to improve the image processing performance with an ecconomical configuration.

Claims

1. A camera apparatus for vehicles having an imaging element and a lens comprising:

a gradation generation unit for stepwise changing an amount of light reaching a whole or part of the imaging element.

2. A camera apparatus as claimed in claim 1, in which said gradation generation unit is a light shielding plate arranged between the imaging element and the lens.

3. A camera apparatus as claimed in claim 2, in which said gradation generation unit decides the concentration and area of the gradation according to the size and the position of the light shielding plate.

4. A camera apparatus as claimed in claim 1, in which said gradation generation unit is an ND filter arranged between the imaging element and the lens.

5. A camera apparatus as claimed in claim 1, in which said gradation generation unit is a gradation sheet arranged between the imaging element and the lens.

6. A camera apparatus as claimed in claim 1, in which said gradation generation unit is a gradation sheet arranged in front of the lens.

7. A camera apparatus as claimed in claim 1, in which said gradation generation unit changes the amount of light reaching a first direction of the imaging element and prevents changing of the amount of light reaching a second direction defining a predetermined angle with the first direction.

8. A camera apparatus as claimed in claim 1, in which said gradation generation unit generates on the imaging element,

a light shielding region where the light incident from the lens is substantially shielded,

a gradation region where the transmittance of the light incident from the lens is stepwise changed, and

a valid information region where the light incident from the lens is transmitted substantially as it is.

9. A camera apparatus as claimed in claim 8, in which when said camera apparatus is mounted on a vehicle, the valid information region is positioned above the light shielding region.

10. An image processing apparatus for vehicles comprising:

a camera unit having an imaging element and a lens, and

an image processing unit for processing image data imaged by said camera unit, and

in which said camera unit comprises a gradation generation unit for stepwise changing the amount of light reaching a whole or a part of the imaging element, and

said image processing unit uses image data outputted from the part of the imaging element among the image data imaged.

11. An image processing apparatus as claimed in claim 10, in which said gradation generation unit is a light shielding plate arranged between the imaging element and the lens.

12. An image processing apparatus as claimed in claim 10, in which said gradation generation unit decides a concentration and area of the gradation according to a size and a position of said light shielding plate.

13. An image processing apparatus as claimed in claim 10, in which said gradation generation unit is an ND filter arranged between the imaging element and the lens.

14. An image processing apparatus as claimed in claim 10, in which said gradation generation unit is a gradation sheet arranged between the imaging element and the lens.

15. An image processing apparatus as claimed in claim 10, in which said gradation generation unit is a gradation sheet arranged in front of the lens.

16. An image processing apparatus as claimed in claim 10, in which said gradation generation unit changes the amount of light reaching a first direction of the imaging element and prevents changing of the amount of light reaching a second direction defining a predetermined angle with the first direction.

17. An image processing apparatus as claimed in claim 10, in which said gradation generation unit generates on said imaging element,

a light shielding region where the light incident from said lens is substantially shielded,

a gradation region where the transmittance of the light incident from said lens is stepwise changed, and

a valid information region where the light incident from said lens is transmitted substantially as it is.

18. An image processing apparatus as claimed in claim 17, in which when said camera unit is mounted on a vehicle, the valid information region is positioned above the light shielding region.

19. An image processing apparatus as claimed in claim 10, in which said image processing unit uses pixel data having a coordinate of longitudinal direction greater or smaller than a predetermined value among pixels of the imaging element.

20. A method of mounting onto a vehicle a camera apparatus for vehicles having an imaging element and a lens and including a gradation generation unit for stepwise changing an amount of light reaching a whole or a part of the imaging element, the method comprising the steps of:

mounting said camera apparatus for vehicles at such a position that a road surface in front of the vehicle comes into a field of view and at such a direction that a ratio of the light incident into the lens and reaching the imaging element is greater at upper pixels in the whole or part of the imaging element; and

mounting said camera apparatus in such a manner that the road surface in front of the vehicle is focused on the upper pixels of the imaging element.