Nonsymmetric freeform surface optical system

Patent metadata

Field	Value
Publication number	US-2022252853-A1
Application number	US-202117350230-A
Country	US
Kind code	A1
Filing date	Jun 17, 2021
Priority date	Feb 5, 2021
Publication date	Aug 11, 2022
Grant date	—

Abstract

The present application relates to a nonsymmetric freeform surface optical system including a primary reflecting mirror, a secondary reflecting mirror, and a tertiary reflecting mirror. A light beam from an object is reflected on the primary reflecting mirror to form a first reflected light beam, the first reflected light beam irradiates the secondary reflecting mirror and is reflected to form a second reflected light beam, the second reflected light beam irradiates the third reflecting mirror and is reflected to form a third reflected light beam, and the third reflected light beam reaches an image surface to form an image. The nonsymmetric freeform surface optical system has no rotational symmetry and no meridional symmetry.

First claim

What is claimed is:

1 . A nonsymmetric freeform surface optical system, comprising:
a primary reflecting mirror; a secondary reflecting mirror, and a tertiary reflecting mirror; a light beam from an object is reflected on the primary reflecting mirror to form a first reflected light beam, the first reflected light beam irradiates the secondary reflecting mirror and is reflected to form a second reflected light beam, the second reflected light beam irradiates the third reflecting mirror and is reflected to form a third reflected light beam, and the third reflected light beam reaches an image surface to form an image; and the nonsymmetric freeform surface optical system has no rotational symmetry and no meridional symmetry.

2 . The nonsymmetric freeform surface optical system of claim 1 , wherein the image plane has a β tilt of 45 degrees.

3 . The nonsymmetric freeform surface optical system of claim 1 , wherein the light beam in the nonsymmetric freeform surface optical system is three-dimensionally deflected.

4 . The nonsymmetric freeform surface optical system of claim 1 , wherein a dimension of the nonsymmetric freeform surface optical system in an X direction is 200 mm, a dimension of the nonsymmetric freeform surface optical system in a Y direction is 180 mm, and a dimension of the nonsymmetric freeform surface optical system in a Z direction is 180 mm.

5 . The nonsymmetric freeform surface optical system of claim 1 , wherein a field of view of the nonsymmetric freeform surface optical system is 8°×6°, a F-number of the nonsymmetric freeform surface optical system is 1.3, an effective focal length of the nonsymmetric freeform surface optical system is 50 mm, an entrance pupil diameter of the nonsymmetric freeform surface optical system is 38.5 mm, a working wavelength of the nonsymmetric freeform surface optical system is in a range from 8 μm to 14 μm.

6 . The nonsymmetric freeform surface optical system of claim 1 , wherein the nonsymmetric freeform surface optical system has off-axis in both a meridian plane and a sagittal plane.

7 . The nonsymmetric freeform surface optical system of claim 1 , wherein a diffraction transfer function of the nonsymmetric freeform surface optical system is greater than 0.4 at 30 cycs/mm.

8 . The nonsymmetric freeform surface optical system of claim 1 , wherein mirror surfaces of the primary reflecting mirror, the secondary reflecting mirror, and the tertiary reflecting mirror have not any rotational symmetry axis.

9 . The nonsymmetric freeform surface optical system of claim 1 , wherein mirror surfaces of the primary reflecting mirror, the secondary reflecting mirror, and the tertiary reflecting mirror have not any meridian symmetry plane.

10 . A nonsymmetric freeform surface optical system, comprising:
a primary reflecting mirror; a secondary reflecting mirror; and a tertiary reflecting mirror; a light beam from an object is reflected on the primary reflecting mirror to form a first reflected light beam, the first reflected light beam irradiates the secondary reflecting mirror and is reflected to form a second reflected light beam, the second reflected light beam irradiates the third reflecting mirror and is reflected to form a third reflected light beam, and the third reflected light beam reaches an image surface to form an image; the nonsymmetric freeform surface optical system has no rotational symmetry and no meridional symmetry, the image plane has a β tilt of 45 degrees, and the light beam in the nonsymmetric freeform surface optical system is three-dimensionally deflected; a dimension of the nonsymmetric freeform surface optical system in an X direction is 200 mm, a dimension of the nonsymmetric freeform surface optical system in a Y direction is 180 mm, and a dimension of the nonsymmetric freeform surface optical system in a Z direction is 180 mm; and a field of view of the nonsymmetric freeform surface optical system is 8°×6°, a F-number of the nonsymmetric freeform surface optical system is 1.3, an effective focal length of the nonsymmetric freeform surface optical system is 50 mm, an entrance pupil diameter of the nonsymmetric freeform surface optical system is 38.5 mm, a working wavelength of the nonsymmetric freeform surface optical system is in a range from 8 μm to 14 μm.

Assignees

• Univ Tsinghua
• Hon Hai Prec Ind Co Ltd

Inventors

• Zhu Jun
• Tan yi-lin
• Jin Guo-Fan
• Fan Shou-Shan

Classifications

• G02B17/0642 Primary

  off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements · CPC title

• G02B17/06 Primary

  using mirrors only {, i.e. having only one curved mirror (used in non-imaging applications G02B19/00)} · CPC title