Toric lens, optical element, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-11345102-B2
Application number	US-201916653677-A
Country	US
Kind code	B2
Filing date	Oct 15, 2019
Priority date	Oct 16, 2018
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

In a toric lens comprising a toric surface having a fine uneven structure, the fine uneven structure includes a plurality of holes, the plurality of holes have a hole depth H and a surface opening diameter φt which satisfy an expression of 0.3≤H/φt≤0.6, and (a) the plurality of holes have a hole structure having a cylindrical shape on a bottom surface side and a circular truncated cone shape having an opening diameter increasing toward a surface side, or (b) an angle θ formed between an opening portion and the surface of the plurality of holes satisfies 78°≤θ≤85°.

First claim

What is claimed is:

1. An optical element comprising an optical surface having a plurality of holes, wherein
the plurality of holes has a hole depth H and a surface opening diameter φt which satisfy an expression of 0.3≤H/φt≤0.6, and
the plurality of holes has a circular truncated cone shape distal to a bottom surface and proximal to a top surface of the optical surface, the circularly truncated cone shape having a diameter gradually increasing toward the top surface of the optical surface, and
the circular truncated cone shape has a height ht which satisfies an expression of 0.34≤ht/H≤0.64.

2. The optical element according to claim 1 , wherein the optical surface has a fine uneven structure including the plurality of holes, the fine uneven structure is formed by injection molding.

3. The optical element according to claim 1 , wherein the optical surface has a fine uneven structure, the fine uneven structure is made of a cycloolefin polymer resin.

4. The optical element according to claim 1 , wherein the optical element is formed of a single member.

5. An image forming apparatus, comprising:
an image bearing member;
a charging unit configured to charge a surface of the image bearing member;
a laser optical system member;
an exposing unit configured to expose the image bearing member to light using the laser optical system; and
a developing unit configured to, using a developer, develop an electrostatic latent image formed on the surface of the image bearing member, wherein
the laser optical system member including an optical element comprising an optical surface having a plurality of holes, the plurality of holes has a hole depth H and a surface opening diameter φt which satisfy an expression of 0.3≤H/φt≤0.6, and
the plurality of holes has a a circular truncated cone shape having a diameter gradually increasing toward the top surface of the optical surface, and
the circular truncated cone shape has a height ht satisfies an expression of 0.34≤ht/H≤0.64.

6. The optical element according to claim 1 , wherein a distance between two closest holes is no smaller than about 100 nm or no larger than about 1 μm.

7. The optical element according to claim 1 , wherein an angle θ between the top surface and a side surface of the circular truncated cone shape of the plurality of holes satisfies 78°≤0≤85°.

8. The optical element according to claim 1 , wherein the plurality of holes has a cylindrical shape proximal to the bottom surface.

9. The optical element according to claim 1 , wherein the optical surface has a fine uneven structure including the plurality of holes, the fine uneven structure is made of resin.

10. The optical element according to claim 1 , wherein the surface opening diameter φt of the holes is no less than 150 nm and no larger than about 450 nm.

11. The optical element according to claim 1 , wherein the optical element is a toric lens and the optical surface is a toric surface.

12. The optical element according to claim 11 , wherein the optical element is lighted using a laser optical system.

13. The optical element according to claim 11 , wherein a wavelength of a light through use of an element lighting laser optical system is from 380 nm to 780 nm, and a distance between two neighboring holes is no less than 250 nm and no larger than 500 nm.

Assignees

• Canon Kk

Inventors

• Terada Junji
• Yoshikawa Toshiaki
• Arai Kazuhiro
• Nakai Noriyuki
• Kameno Yu
• Takachi Miwa

Classifications

• G02B3/06 Primary

  with cylindrical or toric faces · CPC title

• G02B13/0005

  having F-Theta characteristic (scanning systems employing movable or deformable optical elements G02B26/10) · CPC title

• G03G15/043

  with means for controlling illumination or exposure (G03G15/041 takes precedence) · CPC title

• B29D11/00019 Primary

  with non-spherical faces, e.g. toric faces · CPC title

• B29D11/00509

  to make toric lenses · CPC title