Collimating lens

Patent metadata

Field	Value
Publication number	US-10168543-B2
Application number	US-201715643309-A
Country	US
Kind code	B2
Filing date	Jul 6, 2017
Priority date	Oct 30, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A collimating lens includes at least two lens groups, each having an aspherical surface. The collimating lens also includes a flat diffraction lens disposed nearest to an image plane.

First claim

What is claimed is:

1. A collimating lens, comprising:
a first lens group and a second lens group disposed in an order from an object side to an image side, each of the first lens group and the second lens group having an aspherical surface;
a flat diffraction lens arranged in the second lens group and disposed nearest to an image plane; and
a ring spacer disposed between and in contact with peripheries of the first lens group and the second lens group;
wherein the first lens group includes a flat first lens and a negative-powered second lens in the order from the object side to the image side; and the second lens group includes a positive-powered third lens, a flat fourth lens and the flat diffraction lens in the order from the object side to the image side.

2. The collimating lens of claim 1 , wherein the flat first lens has a planar object-side surface and a planar image-side surface; the negative-powered second lens has a planar object-side surface and an aspherical concave image-side surface; the positive-powered third lens has an aspherical convex object-side surface and a planar image-side surface; the flat fourth lens has a planar object-side surface and a planar image-side surface; and the flat diffraction lens has a planar object-side surface and a planar image-side surface.

3. The collimating lens of claim 1 , wherein the negative-powered second lens, the positive-powered third lens and the flat diffraction lens have a refractive index ranging between 1.5 and 1.6, and have an Abbe number ranging between 31 and 48.

4. The collimating lens of claim 1 , wherein the flat first lens and the flat fourth lens have a refractive index ranging between 1.5 and 1.6, and have an Abbe number ranging between 45 and 65.

5. The collimating lens of claim 1 , wherein one aspherical surface of the first lens group and the second lens group has a positive radius, and another aspherical surface of the first lens group and the second lens group has a negative radius.

6. The collimating lens of claim 1 , comprising no convex outer surface.

Assignees

• Himax Tech Ltd

Inventors

• Lin Han-Ching
• Lu Yin Dong
• Kuo Han Yi

Classifications

• G02B27/30 Primary

  Collimators · CPC title

• G02B27/4233

  having a diffractive element [DOE] contributing to a non-imaging application (diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086) · CPC title

• G02B13/18

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title

• G02B5/1876

  Diffractive Fresnel lenses; Zone plates; Kinoforms (G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08) · CPC title

• G02B9/64

  having more than six components · CPC title