Eyepiece

Patent metadata

Field	Value
Publication number	US-10606065-B2
Application number	US-201615578708-A
Country	US
Kind code	B2
Filing date	Nov 11, 2016
Priority date	Oct 14, 2016
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

The present invention provides an eyepiece. The eyepiece is composed of one lens, which comprises a first surface and a second surface that are opposite, wherein, the first surface is a curved surface, and the second surface is a Fresnel structure surface; the Fresnel structure surface is formed by a plurality of annular zones that are sequentially arranged, to form a sawtooth surface, and each of the annular zones is formed by a working surface and a non-working surface, the working surface is an aspheric surface, and the non-working surface is a straight bevel; and the eyepiece satisfies the following conditional expression: 85°<FOV<130°, and 0°≤θi≤5°; wherein, FOV is a maximum angle of view of the eyepiece, and θi is the angle between the non-working surface of the ith annular zone and the optical axis.

First claim

What is claimed is:

1. An eyepiece, composed of one lens, having a first surface and a second surface that are opposite, wherein, the first surface is a curved surface, and the second surface is a Fresnel structure surface; the Fresnel structure surface is a sawtooth surface formed by a plurality of annular zones that are sequentially arranged, and each of the annular zones is formed by a working surface and a non-working surface; and
wherein the eyepiece satisfies 85°<FOV<130°, where FOV is a maximum angle of view of the eyepiece;
wherein, on the second surface, a width zi of the i-th annular zone that is counted from a near optical axis of the second surface towards an edge of the second surface satisfies 0.08 mm≤zi≤3.5 mm; and a depth di of the i-th annular zone satisfies 0 mm<di≤0.5 mm; and
wherein, the first surface is provided thereon with a plurality of periodic phase annular zones, a descending step is provided between any two neighboring periodic phase annular zones located from a near optical axis of the first surface towards an edge of the first surface, each descending step has a depth t equal to that of other descending step, and the depth t of the descending step satisfies 0.0005 mm<t<0.0025 mm, wherein the depth of the descending step is a distance measured parallel to an optical axis of the eyepiece.

2. The eyepiece according to claim 1 , wherein: in the second surface, the working surface of the i-th annular zone is an aspheric surface, and the non-working surface of the i-th annular zone is a straight bevel, wherein an angle θi between the non-working surface of the i-th annular zone and the optical axis satisfies: 0°<θi<5°.

3. The eyepiece according to claim 1 , wherein: the plurality of annular zones in the Fresnel structure surface of the second surface of the eyepiece are arranged on a basal surface, and the basal surface is a flat surface.

4. The eyepiece according to claim 1 , wherein: the plurality of annular zones in the Fresnel structure surface of the second surface of the eyepiece are arranged on a basal surface, and the basal surface is a curved surface.

5. The eyepiece according to claim 1 , wherein, the eyepiece satisfies: 0<SAG1/DY<0.2 where, SAG1 is an axis distance between an intersection point of the first surface and the optical axis and a vertex of an effective radius of the first surface; and DY is an effective external diameter of the eyepiece.

6. The eyepiece according to claim 1 , wherein, the eyepiece satisfies: 7 mm≤ED≤20 mm where, ED is an axis distance between a pupil of a human eye and the first surface when the eyepiece is working.

7. The eyepiece according to claim 1 , wherein, the eyepiece satisfies: 25 mm≤EFL≤50 mm where, EFL is an effective focal length of the eyepiece.

8. The eyepiece according to claim 1 , wherein, the eyepiece satisfies: 0.02<CT/DY<0.4 where, CT is a center thickness of the eyepiece, and DY is an effective external diameter of the eyepiece.

Assignees

• Zhejiang Sunny Optics Co Ltd

Inventors

• Song Litong
• Dai Fujian
• Jin Yinfang

Classifications

• G02B25/001 Primary

  Eyepieces · CPC title

• G02B27/0018

  with means for preventing ghost images (anti-reflection coatings G02B1/11) · CPC title

• G02B27/0172

  characterised by optical features · CPC title

• G02B2027/012

  comprising devices for attenuating parasitic image effects · CPC title

• G02B3/04

  with continuous faces that are rotationally symmetrical but deviate from a true sphere {, e.g. so called "aspheric" lenses} · CPC title