Patent ID: 11921417
Assignee: LARGAN PRECISION CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 58:
59. A controllable aperture stop comprising:
a light pass portion comprising a plurality of movable blades, and the plurality of movable blades together surrounding a light pass aperture;
a fixed portion having a plurality of shaft structures respectively disposed corresponding to the plurality of movable blades;
a driving part comprising:
a rotatable element rotatable around the light pass aperture, the rotatable element connected to the plurality of movable blades, and the rotatable element configured to drive the plurality of movable blades to rotate respectively relative to the plurality of shaft structures so as to adjust a size of the light pass aperture;
a first magnet disposed on the rotatable element; and
an electronic component having a position sensing circuit, the electronic component disposed corresponding to the first magnet, and the electronic component located farther away from the light pass aperture than the first magnet to the light pass aperture; and

a plurality of rollable elements disposed between the fixed portion and the rotatable element and arranged around the light pass aperture, so that the rotatable element can be rotated relative to the fixed portion;
wherein the fixed portion comprises a frame element, the plurality of rollable elements are disposed between the frame element and the rotatable element, the frame element comprises a metal component and a clad component, and the metal component is insert-molded with the clad component to together form the frame element;
wherein the metal component comprises an attraction portion, the attraction portion is ferromagnetic and disposed corresponding to the first magnet so as to generate a magnetic attraction, the magnetic attraction forces the first magnet and the rotatable element to exert a pressure on the plurality of rollable elements, and the attraction portion and the first magnet overlap with each other in a direction parallel to a central axis of the light pass aperture;
wherein a farthest distance between the first magnet and the central axis of the light pass aperture is rm, a shortest distance between the electronic component and the central axis is rp, a shortest distance of the plurality of rollable elements and the central axis is rb, and the following conditions are satisfied:

0.5≤rm/rp<1; and

0.6≤rb/rm≤1.8.