US-12619046-B2 - Optical system

US12619046B2US 12619046 B2US12619046 B2US 12619046B2US-12619046-B2

Abstract

An optical system is provided. The optical system includes a fixed unit, an actuating unit, a lens unit and a metalens. The actuating unit is connected to the fixed unit. The lens unit is adapted to be moved by the actuating unit relative to the fixed unit. The metalens is adapted to be moved between a first position and a second position relative to the lens unit. When the metalens is in the first position, the metalens is not on a light path of the lens unit. When the metalens is in the second position, the metalens is on the light path of the lens unit.

Inventors

Chih-Wei Weng
Chao-Chang Hu
Yung-Hsien YEH
MAO-KUO HSU

Assignees

ACTUTEK CORPORATION

Dates

Publication Date: 20260505
Application Date: 20220329

Claims (12)

1 . An optical system, comprising: a fixed unit; an actuating unit, connected to the fixed unit; a lens unit, adapted to be moved by the actuating unit relative to the fixed unit; a metalens, wherein the metalens is adapted to be moved between a first position and a second position relative to the lens unit, and when the metalens is in the first position, the metalens is not on a light path of the lens unit, and when the metalens is in the second position, the metalens is on the light path of the lens unit; and a metalens, wherein the metalens is adapted to be disposed on a light path of the lens unit, the metalens comprises a plurality of metastructures, and the metastructures are disposed only in local areas of the metalens, wherein the actuating unit moves the lens unit to provide an anti-shake optical compensation in a central compensation way, the metalens comprises a central area and a peripheral area, the peripheral area surrounds the central area, and the metastructures are only disposed in the peripheral area, wherein the peripheral area comprises a first annular area and a second annular area, the first annular area surrounds the central area, the second annular area surrounds the first annular area, the metastructures comprise a plurality of first metastructures and a plurality of second metastructures, the first metastructures are disposed in the first annular area, the second metastructures are disposed in the second annular area, and a compensation ability of the first metastructures differs from a compensation ability of the second metastructures.
2 . The optical system as claimed in claim 1 , wherein the metalens is rotated between the first position and the second position.
3 . The optical system as claimed in claim 2 , further comprising a impelling unit, wherein the metalens is connected to the impelling unit, and the impelling unit is adapted to rotate the metalens between the first position and the second position.
4 . The optical system as claimed in claim 3 , wherein the impelling unit comprises a magnetic member and a coil, the metalens is connected to the magnetic member, the coil is adapted to apply a magnetic field to the magnetic member, and the magnetic member moves the metalens between the first position and the second position.
5 . The optical system as claimed in claim 1 , wherein the lens unit comprises an inlet side, and when the metalens is in the second position, the metalens covers the inlet side.
6 . The optical system as claimed in claim 1 , wherein the lens unit comprises an outlet side, and when the metalens is in the second position, the metalens covers the outlet side.
7 . The optical system as claimed in claim 6 , further comprising an image sensor, wherein when the metalens is in the second position, the metalens is located between the image sensor and the lens unit.
8 . The optical system as claimed in claim 1 , further comprising an impelling unit, a sensor unit and a central processer, wherein the metalens is connected to the impelling unit, the sensor unit is adapted to detect a tremor amplitude and to provide a sensing signal, and the central processer activates the actuating unit according to the sensing signal to move the lens unit, and when the central processer activates the actuating unit, the central processer also activates the impelling unit to move the metalens from the first position to the second position.
9 . The optical system as claimed in claim 1 , wherein a height of each first metastructure is the same with a height of each second metastructure.
10 . The optical system as claimed in claim 9 , wherein a width of each first metastructure is smaller than a width of each second metastructure.
11 . The optical system as claimed in claim 1 , wherein an arrangement density of the first metastructures is smaller than an arrangement density of the second metastructures.
12 . An optical system, comprising: a fixed unit; an actuating unit, connected to the fixed unit; a lens unit, adapted to be moved by the actuating unit relative to the fixed unit; a metalens, wherein the metalens is adapted to be moved between a first position and a second position relative to the lens unit, and when the metalens is in the first position, the metalens is not on a light path of the lens unit, and when the metalens is in the second position, the metalens is on the light path of the lens unit; and a metalens, wherein the metalens is adapted to be disposed on a light path of the lens unit, the metalens comprises a plurality of metastructures, and the metastructures are disposed only in local areas of the metalens, wherein a diameter of the central area is ⅖ of a diagonal length of the metalens.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/167,300, filed Mar. 29, 2021, and U.S. Provisional Application No. 63/299,616, filed Jan. 14, 2022, the entirety of which are incorporated by reference herein. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an optical system, and in particular to an optical system with an optical image stabilization (OIS) function. Description of the Related Art In the conventional optical system with the optical image stabilization (OIS) function, the lens unit is moved to provide the optical compensation, and the image of the optical system is stabilized. However, after the movement of the lens unit, the light path is still displaced, and the image quality is deteriorated. Particularly, if the anti-shake optical compensation is provided in a central compensation way, the imaging quality of the peripheral portion of the image will be poor. If the anti-shake optical compensation is provided in a peripheral compensation way, the imaging quality of the central portion of the image will be poor. In order to overcome the above-mentioned defects, the anti-shake optical compensation is provided in the central compensation way, and the size of the lens unit is increased to improve the quality of the whole image. However, the size and the cost of the lens unit and its peripheral components are increased, which is not conducive to the requirements of a thin and low-cost product. BRIEF SUMMARY OF THE INVENTION Embodiments of the invention are provided to address the aforementioned difficulty. In one embodiment, an optical system is provided. The optical system includes a fixed unit, an actuating unit and a lens unit. The actuating unit is connected to the fixed unit. The lens unit is adapted to be moved by the actuating unit relative to the fixed unit. In one embodiment, the optical system further comprises a metalens. The metalens is adapted to be moved between a first position and a second position relative to the lens unit. When the metalens is in the first position, the metalens is not on a light path of the lens unit. When the metalens is in the second position, the metalens is on the light path of the lens unit. In one embodiment, the metalens is rotated between the first position and the second position. In one embodiment, the optical system further comprises a impelling unit. The metalens is connected to the impelling unit. The impelling unit is adapted to rotate the metalens between the first position and the second position. In one embodiment, the impelling unit comprises a magnetic member and a coil, the metalens is connected to the magnetic member, the coil is adapted to apply a magnetic field to the magnetic member, and the magnetic member moves the metalens between the first position and the second position. In one embodiment, the lens unit comprises an inlet side, and when the metalens is in the second position, the metalens covers the inlet side. In one embodiment, the lens unit comprises an outlet side, and when the metalens is in the second position, the metalens covers the outlet side. In one embodiment, the optical system further comprises an image sensor. When the metalens is in the second position, the metalens is located between the image sensor and the lens unit. In one embodiment, the optical system further comprises a sensor unit and a central processer, the sensor unit is adapted to detect a tremor amplitude and to provide a sensing signal, and the central processer activates the actuating unit according to the sensing signal to move the lens unit, and when the central processer activates the actuating unit, the central processer also activates the impelling unit to move the metalens from the first position to the second position. In one embodiment, the metalens is adapted to be disposed on a light path of the lens unit, the metalens comprises a central area, a peripheral area and a plurality of metastructures, the peripheral area surrounds the central area, the metastructures are selectively disposed in the central area or the peripheral area. In one embodiment, the actuating unit moves the lens unit to provide an anti-shake optical compensation in a central compensation way, and the metastructures are only disposed in the peripheral area. In one embodiment, the peripheral area comprises a first annular area and a second annular area, the first annular area surrounds the central area, the second annular area surrounds the first annular area, the metastructures comprise a plurality of first metastructures and a plurality of second metastructures, the first metastructures are disposed in the first annular area, the second metastructures are disposed in the second annular area, and a compensation ability of the first metastructures differs from a compensation ability of the second metastructures. In one embodiment, a height of each first metastructure is the s