Camera module for combining distant image and close image into single image

• US 20070047948A1
• Filed: 07/27/2006
• Published: 03/01/2007
• Est. Priority Date: 08/23/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Tanida, Katsunori
• Granted Patent: US 7,548,691 B2
• Time in Patent Office: Days
• US Class Current: 396/332
• CPC Class Codes: G03B 41/00 Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor

Abstract

A camera module is advantageously used in a vision system mounted on an automotive vehicle. The camera module includes a first optical system focused on distant objects such as a preceding vehicle and scenery in front of a vehicle and a second optical system focused on close objects such as raindrops on a windshield. The first optical system includes a first convex lens, a mirror or a half mirror and an imager, and the second optical system includes a second convex lens and a mirror. The distant image formed by the first optical system and the close image formed by the second optical system are combined into a combined image made on the imager in a single frame. The distant and close images are taken at the same time without adjusting the focuses in the camera module.

Claims

1. A camera module comprising:

a first optical system including a first convex lens having a first focal distance, a half mirror positioned behind the first convex lens at an inclination relative to an optical axis of the first convex lens, part of light coming out from the first convex lens passing through the half mirror, and an imager positioned behind the half mirror and

a second optical system including a second convex lens having a second focal distance which is different from the first focal distance and a mirror positioned behind the second convex lens at an inclination relative to an optical axis of the second convex lens, part of light coming out from the second convex lens being reflected on the mirror toward the half mirror so that the light reflected on the mirror is further reflected on the half mirror, wherein;

a single image is made on the imager by combining a first image formed by the light passing through the half mirror with a second image formed by the light reflected on the half mirror.

5. The camera module as in claim 1, wherein:

the camera module is mounted on an automotive vehicle;

the first focal distance is set to distant objects located in front of the automotive vehicle; and

the second focal distance is set to close objects located on a front surface of a windshield of the automotive vehicle.

9. The camera module as in claim 1, wherein:

the first convex lens is formed in a half circular shape so that part of the light coming out from the first convex lens passes through the half mirror; and

the second convex lens is formed in a half circular shape so that part of the light coming out from the second convex lens is reflected on the mirror.

2. A camera module comprising:

a first optical system including a first convex lens having a first focal distance, a first mirror positioned behind the first convex lens at an inclination relative to an optical axis of the first convex lens, part of light coming out from the first convex lens being intercepted by the first mirror and the rest of the light being led ahead without being intercepted by the first mirror, and an imager positioned behind the first mirror and

a second optical system including a second convex lens having a second focal distance which is different from the first focal distance and a second mirror positioned behind the second convex lens at an inclination relative to an optical axis of the second convex lens, part of light coming out from the second convex lens being reflected on the second mirror toward the first mirror so that the light reflected on the second mirror is further reflected on the first mirror, wherein;

a single image is made on the imager by combining a first image formed by the light led ahead without being intercepted by the first mirror with a second image formed by the light reflected on the first mirror.

6. The camera module as in claim 2, wherein:

the camera module is mounted on an automotive vehicle;

the first focal distance is set to distant objects located in front of the automotive vehicle; and

the second focal distance is set to close objects located on a front surface of a windshield of the automotive vehicle.

10. The camera module as in claim 2, wherein:

an intercepting film is formed on the second mirror so that part of the light coming out from the second convex lens is intercepted by the intercepting film.

3. A camera module comprising:

a first optical system including a first convex lens having a first focal distance, a first mirror positioned behind the first convex lens at an inclination relative to an optical axis of the first convex lens, the first mirror having a center opening through which part of light coming out from the first convex lens passes, the rest of the light coming out from the first convex lens being intercepted by the first mirror, and an imager positioned behind the half mirror and

a second optical system including a second convex lens having a second focal distance which is different from the first focal distance and a second mirror positioned behind the second convex lens at an inclination with respect to an optical axis of the second convex lens, light coming out from the second convex lens being reflected on the second mirror toward the first mirror so that the light reflected on the second mirror is further reflected on the first mirror other than the center opening, wherein;

a single image is made on the imager by combining a first image formed by the light passing through the center opening of the first mirror with a second image formed by the light reflected on the first mirror.

7. The camera module as in claim 3, wherein:

the camera module is mounted on an automotive vehicle;

the first focal distance is set to distant objects located in front of the automotive vehicle; and

the second focal distance is set to close objects located on a front surface of a windshield of the automotive vehicle.

4. A camera module comprising:

a prism forming a first optical system and a second optical system therein, the first optical system having a first focal distance and passing light from the first focal distance therethrough, the second optical system having a second focal distance which is different from the first focal distance and reflecting light form the second focal distance,

an interceptor positioned in front of the prism, the interceptor dividing light entering the camera module into a first part entering into the first optical system and the second part entering into the second optical system, and

an imager positioned behind the prism for making an image thereon, wherein;

a single image is made on the imager by combining a first image formed by the light passing through the first optical system with a second image formed by the light reflected in the second optical system.

8. The camera module as in claim 4, wherein:

the camera module is installed on an automotive vehicle;

the first focal distance is set to distant objects located in front of the automotive vehicle; and

the second focal distance is set to close objects located on a front surface of a windshield of the automotive vehicle.