Optical system, optical apparatus, imaging apparatus, and method for manufacturing optical system and imaging apparatus

Patent metadata

Field	Value
Publication number	US-12019225-B2
Application number	US-202017424469-A
Country	US
Kind code	B2
Filing date	Jan 21, 2020
Priority date	Jan 23, 2019
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

There are provided an optical system having high resolution and high optical performance and reduced in size, an optical apparatus including the optical system, an imaging apparatus, and a method for manufacturing the optical system and imaging apparatus. An optical system UL of a camera module 10, which is incorporated in an optical apparatus, such as a camera 60, is an optical system that forms an image of an object, includes a correction member having a correction surface 11a, a first reflection surface 12a, which reflects light having passed through the correction surface 11a, and a second reflection surface 13a, which reflects the light reflected off the first reflection surface 12a, and satisfies predetermined conditions.

First claim

The invention claimed is:

1. An optical system that forms an image of an object, the optical system comprising:
a light incident surface on which light from an object side is incident;
a first reflector that reflects the light having passed through the light incident surface; and
a second reflector that reflects the light reflected off the first reflector,
wherein the following conditional expression is satisfied:
TL< 15.0 mm

where TL: distance from a surface closest to the object side in the optical system to an image plane in a direction of an optical axis that intersects the image plane.

2. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
10.00°<ω

where ω: half angle of view of the optical system.

3. The optical system according to claim 1 ,
wherein a medium in an optical path between the first reflector and the second reflector is a light transmissive member having a refractive index,
the light incident surface is formed at an object-side, light incident surface of the light transmissive member,
a reflection surface as the first reflector is formed at an image-side surface of the light transmissive member that is a surface on which the light having passed through the light incident surface is incident,
a reflection surface as the second reflector is formed at the object-side surface of the light transmissive member that is a surface on which the light reflected off the first reflector is incident, and
a light exiting surface which is the image-side surface of the light transmissive member, on which the light reflected off the second reflector is incident, and via which the light exits out of the light transmissive member is formed.

4. The optical system according to claim 3 , wherein the following conditional expression is satisfied:
0.5<( h 1in/ d 1− i )/( h 4/ d 4− i )<10.0

where
h1in: inner diameter of the light incident surface,
d1−1: distance between a center of the light incident surface, the center being a point through which the optical axis passes, and the image plane,
h4: outer diameter of the light exiting surface, and
d4−1: distance between a center of the light exiting surface, the center being a point through which the optical axis passes, and the image plane.

5. The optical system according to claim 3 , wherein the following conditional expression is satisfied:
0.1< r 4/ TL 3<10.0
where
r4: radius of curvature of the light exiting surface, and
TL3: distance between the reflection surface of the second reflector and the image plane.

6. The optical system according to claim 3 , wherein the following conditional expression is satisfied:
50.0< vd
where vd: Abbe number at a d-line of the medium contained in the light transmissive member.

7. The optical system according to claim 3 , wherein the light transmissive member includes a portion formed of a first light transmissive member and a portion formed of a second light transmissive member different from the first light transmissive member.

8. The optical system according to claim 7 , wherein the first light transmissive member and the second light transmissive member differ from each other in terms of at least one of an Abbe number and a refractive index.

9. The optical system according to claim 1 , further comprising sequentially from the object side:
a first optical member that transmits light; and
a second optical member that transmits light and differs from the first optical member,
wherein the light incident surface is formed at an object-side surface of the first optical member,
a reflection surface as the second reflector is formed at an image-side surface of the first optical member, and
a reflection surface as the first reflector is formed at an object-side surface of the second optical member.

10. The optical system according to claim 9 , wherein a medium in an optical path between the first reflector and the second reflector is air.

11. The optical system according to claim 1 , wherein the first reflector and the second reflector are each formed of a single reflection surface.

12. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
−0.1< f/fx< 0.1

where
f: overall focal length of the optical system, and
fx: focal length of the light incident surface or an optical member on which the light incident surface is formed.

13. The optical system according to claim 1 ,
wherein the reflection surface of the first reflector and the reflection surface of the second reflector are each a spherical surface.

14. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
3.0< M< 8.0
where
M=f/f 1,

f: overall focal length of the optical system, and
f1: focal length of the first reflector.

15. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
f< 500 mm
where f: overall focal length of the optical system.

16. The optical system according to claim 1 ,
wherein an optical axis of the reflection surface of the first reflector coincides with an optical axis of the reflection surface of the second reflector.

17. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
2.0< Fno< 15.0
where Fno: f-number of the optical system.

18. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
1.0< D 1/ D 2<6.0
where
D1: outer diameter of a reflection surface of the first reflector, and
D2: outer diameter of a reflection surface of the second reflector.

19. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
0.4< RL/TL< 1.2
where
RL: distance between a reflection surface of the first reflector and a reflection surface of the second reflector in the direction of the optical axis of the optical system.

20. The optical system according to claim 1 , wherein the following conditional expression is satisfied:
0.5< D 1/ RL< 2.0
where
D1: outer diameter of a reflection surface of the first reflector, and
RL: distance between a reflection surface of the first reflector and a reflection surface of the second reflector in the direction of the optical axis of the optical system.

21. An optical apparatus comprising:
the optical system according to claim 1 ; and
an image sensor that captures an image formed by the optical system.

22. The optical apparatus according to claim 21 , wherein the following conditional expression is satisfied:
5.0< D 0/ Y< 15.0
where
D0: outer diameter of a light incident surface closest to the object side in the optical system, and
Y: maximum image height on the image sensor.

23. The optical apparatus according to claim 21 ,
wherein the imaging apparatus includes the optical system as a plurality of optical systems and the image sensor as a plurality of image sensors,
the imaging apparatus further includes a generator that generates a single image based on a plurality of image signals outputted from the plurality of image sensors, and
the following conditional expression is satisfied:
0.30< Nc /( Nd×n )<1.00

where
Nd: number of pixels of the image sensor,
n: number of the image sensors used to generate the image, and
Nc: number of pixels in the image.

24. The optical apparatus accor

Assignees

• Nikon Corp

Inventors

• Iwane Toru
• Tokunaga Kyoya
• Ito Tomoki
• Suwa Kyoichi

Classifications

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/54

  Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils · CPC title

• H04N23/45

  for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images · CPC title

• G02B17/082

  using three curved mirrors (G02B17/0864, G02B17/0896 take precedence) · CPC title

• G02B17/0852

  having a field corrector only · CPC title