Patent ID: 11971539
Assignee: LARGAN PRECISION CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An annular optical element, comprising:
an outer annular surface surrounding a central axis of the annular optical element;
an inner annular surface surrounding the central axis and closer to the central axis than the outer annular surface;
a first side surface connecting the outer annular surface and the inner annular surface;
a second side surface connecting the outer annular surface and the inner annular surface, wherein the second side surface is disposed correspondingly to the first side surface; and
a plurality of strip-shaped wedge structures disposed on the inner annular surface, wherein each of the strip-shaped wedge structures is disposed along a direction from the first side surface towards the second side surface;
wherein each of the strip-shaped wedge structures comprises a tapered portion connected with the inner annular surface, and the tapered portion tapers from the inner annular surface to the central axis;
wherein a number of the strip-shaped wedge structures is greater than or equal to 150, and smaller than or equal to 360.