IMAGING DEVICE AND MOBILE INFORMATION TERMINAL

• US 20120057071A1
• Filed: 09/06/2011
• Published: 03/08/2012
• Est. Priority Date: 09/07/2010
• Status: Active Grant

• Current Assignee: Tianjin OFILM Opto Electronics Co., Ltd.
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: TOMIOKA, Ryoko, YONEYAMA, Kazuya, SHINOHARA, Yoshikazu, NODA, Takayuki, OGINO, Tatsuyuki
• Granted Patent: US 8,908,082 B2
• Time in Patent Office: Days
• US Class Current: 348/345
• CPC Class Codes: G02B 13/004 having four lenses
• CPC Class Codes: H04N 1/00307 with a mobile telephone apparatus constructional features of portable telephone sets H04M1/0202; mobile radio systems H04W84/00
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

An imaging device with a short length and small aberration is provided. A total length D of an image-forming optical system is less than 3.6 mm. A maximum incidence angle of a principle ray on an image forming plane exceeds 33°. Conditions f/fL<−1.50 or f/fL<−0.9, and D/f<1.10 are satisfied where f denotes a focal length of the entire image-forming optical system and fL denotes a focal length of a last lens.

Claims

1. An imaging device comprising:

an image-forming optical system composed of two or more lenses; and

a solid state image sensor for capturing an image formed on an image forming plane of the image-forming optical system;

wherein, a distance between a forwardmost plane and the image forming plane of the image-forming optical system is less than 3.6 mm, and a maximum incidence angle of a principal ray incident on the image forming plane exceeds 33°

.

2. The imaging device of claim 1, wherein f/fL <

−

1.50 is satisfied where f denotes a focal length of the entire image-forming optical system and fL denotes a focal length of a last lens.

9. The imaging device of claim 1, wherein sensitivity of the solid state image sensor is greater than or equal to 20% when light is incident on its incident surface at incidence angles of ±

30°

, relative to sensitivity to normal incident light, and the incident surface is determined by the image forming plane of the image-forming optical system.

10. The imaging device of claim 9, wherein the solid state imaging device is sensitive in visible light range and non-sensitive in an IR range.

11. The imaging device of claim 1, wherein a light receiving surface of a photoelectric conversion portion of the solid state image sensor is provided closer to an incident surface of the solid state image sensor than a wiring layer, and the photoelectric conversion portion photoelectrically converts the subject light, and the wiring layer includes a circuit for reading an imaging signal on a pixel-by-pixel basis.

12. The imaging device of claim 11, wherein the photoelectric conversion portion is composed of an organic photoelectric conversion layer.

13. The imaging device of claim 11, wherein the solid state image sensor is of a back side illumination type.

14. The imaging device of claim 1, wherein the image-forming optical system does not include an IR cut filter.

15. A mobile information terminal having the imaging device of claim 1.

3. An imaging device comprising:

an image-forming optical system composed of two or more lenses; and

a solid state image sensor for capturing an image formed on an image forming plane of the image-forming optical system;

wherein, a distance D between a forwardmost plane and the image forming plane of the image-forming optical system is less than 3.6 mm, and D/f<

1.10 is satisfied where f denotes a focal length of the entire image-forming optical system.

4. The imaging device of claim 3, wherein f/fL <

−

0.90 is satisfied where fL denotes a focal length of a last lens.

5. The imaging device of claim 4, wherein the image-forming optical system is composed of three lenses including the last lens being a negative lens.

6. The imaging device of claim 3, wherein f/fL <

−

1.50 is satisfied where fL denotes a focal length of a last lens.

7. The imaging device of claim 6, wherein the image-forming optical system is composed of four lenses including the last lens being a negative lens.

8. An imaging device comprising:

an image-forming optical system composed of two or more lenses; and

a solid state image sensor for capturing an image formed on an image forming plane of the image-forming optical system;

wherein, f/fL <

−

1.5 and D/f<

1.10 are satisfied where D denotes a distance between a forwardmost plane and the image forming plane of the image-forming optical system, and f denotes a focal length of the entire image-forming optical system, and fL denotes a focal length of a last lens.