US-12625304-B2 - Optical lens assembly, imaging apparatus and electronic device

US12625304B2US 12625304 B2US12625304 B2US 12625304B2US-12625304-B2

Abstract

According to the present disclosure, an optical lens assembly includes at least two optical lens elements and at least one reflective element. The reflective element is made of a plastic material, the reflective element includes a reflective coating membrane, and the reflective coating membrane is disposed on a surface of the reflective element. The reflective coating membrane includes at least three coating layers of different materials, the at least three coating layers are respectively made of a first material, a second material and a third material, the first material mainly includes silver, the second material mainly includes titanium, the third material mainly includes chromium oxides, and the coating layer made of the first material and the coating layer made of the second material are disposed between the coating layer made of the third material and the reflective element.

Inventors

Wen-Yu Tsai
Chien-Pang Chang
Chun-Hung Teng
Kuo-Chiang Chu

Assignees

LARGAN PRECISION CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20220505
Priority Date: 20220406

Claims (13)

1 . An optical lens assembly, comprising: at least two optical lens elements; and at least one reflective element; wherein the reflective element is made of a plastic material, the reflective element comprises a reflective coating membrane, and the reflective coating membrane is disposed on a surface of the reflective element; wherein the reflective coating membrane comprises at least three coating layers of different materials, the at least three coating layers are respectively made of a first material, a second material and a third material, the first material mainly comprises silver, the second material mainly comprises titanium, the third material mainly comprises chromium oxides, and the coating layer made of the first material and the coating layer made of the second material are disposed between the coating layer made of the third material and the reflective element; wherein an average reflectance in a wavelength range of 800 nm-1000 nm of the reflective coating membrane is R80100, and the following condition is satisfied: 97.5%≤R80100; wherein the coating layer made of the second material is disposed between the coating layer made of the third material and the coating layer made of the first material; wherein a thickness of the coating layer made of the third material is Ter, and the following conditions is satisfied: 5 nm≤Tcr≤200 nm.
2 . The optical lens assembly of claim 1 , wherein the reflective coating membrane further comprises a coating layer made of a fourth material, the fourth material mainly comprises silicon compound.
3 . The optical lens assembly of claim 2 , wherein the coating layer made of the third material is disposed between the coating layer made of the fourth material and the coating layer made of the first material.
4 . The optical lens assembly of claim 3 , wherein the reflective coating membrane further comprises a coating layer made of a fifth material, the fifth material mainly comprises metal oxide, and the coating layer made of the fifth material is disposed between the coating layer made of the first material and the reflective element.
5 . The optical lens assembly of claim 4 , wherein a reflectance at a wavelength of 850 nm of the reflective coating membrane is R85, and the following condition is satisfied: 98.0%≤R85.
6 . The optical lens assembly of claim 3 , wherein an average reflectance in a wavelength range of 400 nm-1000 nm of the reflective coating membrane is R40100, and the following condition is satisfied: 98.0%≤R40100.
7 . The optical lens assembly of claim 6 , wherein a total number of the coating layers of the reflective coating membrane is tLs, and the following condition is satisfied: 4≤tLs.
8 . The optical lens assembly of claim 7 , wherein the reflective element is a prism or a mirror.
9 . The optical lens assembly of claim 1 , wherein the reflective element is disposed on an object side or an image side of the optical lens assembly.
10 . The optical lens assembly of claim 1 , wherein the reflective element is disposed between the at least two optical lens elements.
11 . The optical lens assembly of claim 1 , wherein the reflective element is horizontally-movably or rotatably disposed on an image side of the optical lens assembly.
12 . An imaging apparatus, comprising: the optical lens assembly of claim 1 ; and an image sensor disposed on an image surface of the optical lens assembly.
13 . An electronic device, which is a mobile device, and the electronic device comprising: the imaging apparatus of claim 12 .

Description

RELATED APPLICATIONS This application claims priorities to U.S. Provisional Application Ser. No. 63/191,364, filed May 21, 2021, and Taiwan Application Serial Number 111113119, filed Apr. 6, 2022, which are herein incorporated by references. BACKGROUND Technical Field The present disclosure relates to an optical lens assembly and an imaging apparatus. More particularly, the present disclosure relates to an optical lens assembly and an imaging apparatus applicable to electronic devices with high reflectivity. Description of Related Art The reflective coating membrane of the conventional reflective element is prone to problems, such as cracks or defects, due to the improper arrangement of coating layer materials or the environmental factors. Also, no matter in the visible light region or in the infrared region, the reflective efficiency of the reflective coating membrane is insufficient and the required reflectivity cannot be satisfied. Therefore, a technique of combining and arranging specific coating layers is needed to be developed to overcome the abovementioned problems. SUMMARY According to one aspect of the present disclosure, an optical lens assembly includes at least two optical lens elements and at least one reflective element. The reflective element is made of a plastic material, the reflective element includes a reflective coating membrane, and the reflective coating membrane is disposed on a surface of the reflective element. The reflective coating membrane includes at least three coating layers of different materials, the at least three coating layers are respectively made of a first material, a second material and a third material, the first material mainly includes silver, the second material mainly includes titanium, the third material mainly includes chromium oxides, and the coating layer made of the first material and the coating layer made of the second material are disposed between the coating layer made of the third material and the reflective element. When an average reflectance in a wavelength range of 800 nm-1000 nm of the reflective coating membrane is R80100, the following condition is satisfied: 97.5%≤R80100. According to another aspect of the present disclosure, an imaging apparatus includes the optical lens assembly of the aforementioned aspect and an image sensor. The image sensor is disposed on an image surface of the optical lens assembly. According to one another aspect of the present disclosure, an electronic device, which is a mobile device, includes the imaging apparatus of the aforementioned aspect. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: FIG. 1A is a surface quality image of the reflective element of the comparative embodiment. FIG. 1B is a surface quality image of the reflective element of the 1st embodiment. FIG. 2 is a relationship diagram of reflectance and wavelength of the reflective element according to the 1st embodiment. FIG. 3A is a schematic view of an arrangement of a light path folding element in the optical lens assembly of the present disclosure. FIG. 3B is a schematic view of another arrangement of the light path folding element in the optical lens assembly of the present disclosure. FIG. 3C is a schematic view of an arrangement of two light path folding elements in the optical lens assembly of the present disclosure. FIG. 3D is a schematic view of another arrangement of the two light path folding elements in the optical lens assembly of the present disclosure. FIG. 3E is a schematic view of one another arrangement of the light path folding element in the optical lens assembly of the present disclosure. DETAILED DESCRIPTION According to one aspect of the present disclosure, an optical lens assembly includes at least two optical lens elements and at least one reflective element. The reflective element is made of a plastic material, the reflective element includes a reflective coating membrane, and the reflective coating membrane is disposed on a surface of the reflective element. The reflective coating membrane includes at least three coating layers of different materials, the at least three coating layers are respectively made of a first material, a second material and a third material, the first material mainly includes silver, the second material mainly includes titanium, the third material mainly includes chromium oxides, and the coating layer made of the first material and the coating layer made of the second material are disposed between the coating layer made of the third material and the reflective element. Therefore, the reflective element of the optical lens assembly according to the present disclosure includes the combination of coating layers with high reflectivity and has the excellent ability for folding the light path by highly and effectively reflecting the light, which is