Optical element, optical system and imaging apparatus

Patent metadata

Field	Value
Publication number	US-9654676-B2
Application number	US-201514736415-A
Country	US
Kind code	B2
Filing date	Jun 11, 2015
Priority date	Dec 17, 2012
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

An optical element in which transmittance of light monotonically decreases from a center portion toward a peripheral portion, includes a light absorbing portion, made of a material that absorbs a part of or all of visible light, formed at one surface of a transparent substrate such that its thickness monotonically increases from the center portion toward the peripheral portion; a light transmitting portion, made of a material that transmits visible light, formed on the light absorbing portion; and a transparent resin layer, made of a material that transmits visible light, formed at another surface of the transparent substrate, wherein each of the light absorbing portion, the light transmitting portion and the transparent resin layer is made of a resin material.

First claim

What is claimed is:

1. An optical element, comprising:
a transparent substrate comprising a transparent resin material;
a light absorbing portion comprising a resin material which absorbs at least a part of visible light and formed on a first surface of the transparent substrate;
a light transmitting portion comprising a resin material which transmits the visible light and formed on the light absorbing portion; and
a transparent resin layer comprising a resin material which transmits the visible light and formed on a second surface of the transparent substrate,
wherein the light absorbing portion has a first portion formed such that the light absorbing portion has a thickness which monotonically increases from a center portion toward a peripheral portion of the light absorbing portion, and a second portion formed in the peripheral portion such that the light absorbing portion has substantially a constant thickness.

2. The optical element according to claim 1 , wherein the light absorbing portion, the light transmitting portion, and the transparent resin layer satisfy 0.02×t 1 <t 2 <5×t 1 , where t 1 is a total thickness of the light absorbing portion and the light transmitting portion, and t 2 is a thickness of the transparent resin layer.

3. The optical element according to claim 1 , wherein the transparent resin layer includes at least one of a hard coat layer, an antireflection film and an antistatic film.

4. The optical element according to claim 1 , wherein each of the light absorbing portion, the light transmitting portion and the transparent resin layer has tensile stress.

5. An optical system, comprising:
the optical element according to claim 1 ; and
a lens positioned to receive the visible light from the optical element.

6. An imaging apparatus, comprising:
the optical element according to claim 1 ;
a lens positioned to receive the visible light from the optical element; and
an imaging element positioned to receive the visible light from the lens.

7. A portable electronic device having a communication function, comprising:
the imaging apparatus according to claim 6 .

8. The optical element according to claim 1 , wherein the light absorbing portion comprises the black material comprising one of titan black and carbon black.

9. An optical element, comprising:
a transparent substrate comprising a transparent resin material;
a light absorbing portion comprising a resin material which absorbs at least a part of visible light and formed on a first surface of the transparent substrate;
a light transmitting portion comprising a resin material which transmits the visible light and formed on the light absorbing portion; and
a transparent film comprising an inorganic material which transmits the visible light and formed on the light transmitting portion,
wherein the light absorbing portion has a first portion formed such that the light absorbing portion has a thickness which monotonically increases from a center portion toward a peripheral portion of the light absorbing portion, and a second portion formed in the peripheral portion such that the light absorbing portion has substantially a constant thickness.

10. The optical element according to claim 9 , wherein each of the light absorbing portion and the light transmitting portion has tensile stress, and the transparent film has compressive stress.

11. The optical element according to claim 9 , wherein the transparent film is a single layered antireflection film or an antireflection film comprising materials which are alternately stacked and whose refractive indexes are different.

12. The optical element according to claim 9 , wherein the transparent film is formed by vacuum deposition or sputtering.

13. An optical system, comprising:
the optical element according to claim 9 ; and
a lens positioned to receive the visible light from the optical element.

14. An imaging apparatus, comprising:
the optical element according to claim 9 ;
a lens positioned to receive the visible light from the optical element; and
an imaging element positioned to receive the visible light from the lens.

15. A portable electronic device having a communication function, comprising:
the imaging apparatus according to claim 14 .

16. An optical element, comprising:
a transparent substrate comprising a transparent resin material;
a transparent intermediate film comprising an inorganic material which transmits visible light and formed on a first surface of a transparent substrate;
a light absorbing portion comprising a resin material which absorbs at least a part of the visible light and formed on the transparent intermediate film; and
a light transmitting portion comprising a resin material which transmits the visible light and formed on the light absorbing portion,
wherein the light absorbing portion has a first portion formed such that the light absorbing portion has a thickness which monotonically increases from a center portion toward a peripheral portion of the light absorbing portion, and a second portion formed in the peripheral portion such that the light absorbing portion has substantially a constant thickness.

17. The optical element according to claim 16 , wherein each of the light absorbing portion and the light transmitting portion has tensile stress, and the transparent intermediate film has compressive stress.

18. The optical element according to claim 16 , wherein the transparent intermediate film is formed by vacuum deposition or sputtering.

19. An optical system, comprising:
the optical element according to claim 16 ; and
a lens positioned to receive the visible light from the optical element.

20. An imaging apparatus, comprising:
the optical element according to claim 16 ;
a lens positioned to receive the visible light from the optical element; and
an imaging element positioned to receive the visible light from the lens.

21. A portable electronic device having a communication function, comprising:
the imaging apparatus according to claim 20 .

Assignees

• Asahi Glass Co Ltd

Inventors

• Nakayama Motoshi
• Nomura Takuji
• Ono Kensuke

Classifications

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title

• H04N5/2254 Primary

  Electricity · mapped topic

• G03B9/02

  Diaphragms · CPC title

• G02B5/005 Primary

  Diaphragms (for cameras G03B9/02) · CPC title

• G02B13/004 Primary

  having four lenses · CPC title