Rear-view mirror and method for adjusting reflectivity of the same

Patent metadata

Field	Value
Publication number	US-10632925-B2
Application number	US-201715711849-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	Feb 16, 2017
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The present disclosure provides a rear-view mirror and a method for adjusting the reflectivity thereof. The rear-view mirror includes: a partially transmissive and partially reflective layer which has a light incidence surface for receiving external light, wherein one part of the external light reaching the light incidence surface is reflected and the other part is transmitted through the partially transmissive and partially reflective layer; and a reflective layer arranged at a side of the partially transmissive and partially reflective layer opposite to the light incidence surface, the reflective layer having a light reflection surface which is configured to at least partly reflect the light transmitted through the partially transmissive and partially reflective layer back to it, wherein an optical distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer is adjustable.

First claim

What is claimed is:

1. A rear view mirror comprising:
a partially transmissive and partially reflective layer which has a light incidence surface for receiving external light, wherein one part of the external light reaching the light incidence surface is reflected and the other part is transmitted through the partially transmissive and partially reflective layer; and
a reflective layer arranged at a side of the partially transmissive and partially reflective layer opposite to the light incidence surface, the reflective layer having a light reflection surface which is configured to at least partly reflect the light having been transmitted through the partially transmissive and partially reflective layer back to the partially transmissive and partially reflective layer,
wherein an optical distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer is adjustable to substantially change total reflection of the rear view mirror by light interference.

2. The rear-view mirror according to claim 1 , wherein a separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer is adjustable.

3. The rear-view mirror according to claim 2 , further comprising a separation distance adjusting device configured to adjust the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer to change a phase difference between light reflected by the partially transmissive and partially reflective layer and light reflected by the reflective layer.

4. The rear-view mirror according to claim 3 , wherein the separation distance adjusting device comprises a flexible connection belt, filling liquid and a storing and transporting device, and
wherein the flexible connection belt is elastic and connected to a periphery of the partially transmissive and partially reflective layer and a periphery of the reflective layer, to form a sealed space between the partially transmissive and partially reflective layer and the reflective layer;
wherein the sealed space is filled with the filling liquid; and
wherein the storing and transporting device is configured to add the filling liquid into the sealed space or to extract the filling liquid from the sealed space.

5. The rear-view mirror according to claim 4 , wherein the storing and transporting device comprises a two-way pump, a pipe and a filling liquid reservoir, and
wherein a connection portion is provided on the flexible connection belt and two ends of the pipe are respectively connected to the connection portion and an output end of the two-way pump;
wherein the two-way pump has an input end connected to the filling liquid reservoir; and
wherein the filling liquid reservoir is configured to store the filling liquid.

6. The rear-view mirror according to claim 4 , wherein the filling liquid has a same refractivity as the partially transmissive and partially reflective layer.

7. The rear-view mirror according to claim 4 , wherein the separation distance adjusting device further comprises a light intensity sensing device and a processor,
wherein the light intensity sensing device is configured to detect an intensity of light reaching the partially transmissive and partially reflective layer, to convert the detected intensity into an electrical signal that is sent to the processor; and
wherein the processor is configured to determine whether the intensity is greater than a predetermined intensity threshold from the electrical signal or not, and in response to the intensity being greater than the predetermined intensity threshold, the processor is configured to control the storing and transporting device to add the filling liquid into the sealed space to increase the separation distance between the partially transmissive and partially reflective layer and the reflective layer; otherwise, in response to the intensity not being greater than the predetermined intensity threshold, the processor is configured to control the storing and transporting device to extract the filling liquid from the sealed space to reduce the separation distance between the partially transmissive and partially reflective layer and the reflective layer.

8. The rear-view mirror according to claim 2 , wherein the rear-view mirror has an actual reflectivity satisfying:
a≥e≥a−b*c
where a is a reflectivity of the partially transmissive and partially reflective layer; b is a transmissivity of the partially transmissive and partially reflective layer; c is a reflectivity of the reflective layer; and e is the actual reflectivity of the rear-view mirror.

9. The rear-view mirror according to claim 1 , wherein a separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer satisfies:
d =(λ/2+ m λ)/2 n 2 ,

where λ is a wavelength of visible light; n 2 is a refractivity of the light incidence surface of the partially transmissive and partially reflective layer; m is an integer; and d is the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer.

10. The rear-view mirror according to claim 9 , wherein the wavelength λ of visible light is equal to 550 nm.

11. The rear-view mirror according to claim 2 , wherein the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer satisfies:
d =(λ/2+ m λ)/2 n 2 ,

where λ is a wavelength of visible light; n 2 is a refractivity of the light incidence surface of the partially transmissive and partially reflective layer; m is an integer; and d is the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer.

12. The rear-view mirror according to claim 11 , wherein the wavelength λ of visible light is equal to 550 nm.

13. The rear-view mirror according to claim 4 , wherein the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer satisfies:
d =(λ/2+ m λ)/2 n 2 ,

where λ is a wavelength of visible light; n 2 is a refractivity of the light incidence surface of the partially transmissive and partially reflective layer; m is an integer; and d is the separation distance between the light incidence surface of the partially transmissive and partially reflective layer and the light reflection surface of the reflective layer.

14. The rear-view mirror according to claim 1 , wherein an anti-reflection film is provided on the light incidence surface of the partially transmissive and partially reflective layer.

15. The rear-view mirror according to claim 1 , wherein reflectivity of the reflective layer is adjustable.

16. The rear-view mirror according to claim 1 , wherein the reflective layer comprises:
a reflective substrate;
an electrochromism reflective film arranged on the reflective substrate,
wherein the electrochromism reflective film has reflectivity which is changeable depending on a voltage applied to the electrochromism reflective film.

Assignees

• Boe Technology Group Co Ltd
• Chengdu Boe Optoelect Tech Co

Inventors

• Shi Bo
• Feng Yuanming
• Zuo Xiongcan

Classifications

• B60R1/083 Primary

  Anti-glare mirrors, e.g. "day-night" mirrors · CPC title

• B60R1/088 Primary

  using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors · CPC title

• G02B26/001

  based on interference in an adjustable optical cavity (interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26) · CPC title

• B60R1/04

  mounted inside vehicle {(B60R1/025, B60R1/08 take precedence)} · CPC title