WO2025175419A1

WO2025175419A1 - Mirror display and display system

Info

Publication number: WO2025175419A1
Application number: PCT/CN2024/077556
Authority: WO
Inventors: Wei Gang XUE; Fan Long
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2024-02-19
Filing date: 2024-02-19
Publication date: 2025-08-28
Anticipated expiration: 2026-08-19

Abstract

A display system (300) having a display (10), a partial mirror (20), and a reflective polarizer (30). The display (10) is configured to form a polarized image (11) for viewing by a viewer (310). The polarized image (11) has a first polarization state. The partial mirror (20) is disposed on the display (10). The partial mirror (20) is sufficiently optically transmissive so that the viewer (310) is able to view the polarized image (11) through the partial mirror (20) and is sufficiently optically reflective so that the viewer (310) is able to view a viewer image of the viewer (310) reflected by the partial mirror (20) toward the viewer (310). The reflective polarizer (30) is disposed between the display (10) and the partial mirror (20) and is configured to transmit at least 60% of the polarized image (11) toward the partial mirror (20) for viewing by the viewer (310) and is configured to reflect, toward the viewer (310), at least 30% of light from the viewer (310) transmitted by the partial mirror (20).

Description

MIRROR DISPLAY AND DISPLAY SYSTEM

Technical Field

The present disclosure relates to a display system and a mirror display.

Background

Typically, mirror displays are used to display basic information such as date, time, weather in public places like restaurants, railway stations, public washrooms and so on. Nowadays, the mirror displays are in more demand due to high potential of implementations, for example in a smart home ecosystem. Although the mirror displays have many benefits, there may be issues with current mirror displays. For example, the current mirror displays may provide either a good quality mirror performance or a good quality display performance.

Summary

In a first aspect, the present disclosure provides a display system. The display system includes a display configured to form a polarized image for viewing by a viewer. The polarized image has a first polarization state. The display system further includes a partial mirror disposed on the display. Furthermore, the display system includes a reflective polarizer disposed between the display and the partial mirror. For a substantially normally incident light having at least a first visible wavelength in a visible wavelength range extending from about 420 nanometers (nm) to about 680 nm, the partial mirror reflects at least 30%and transmits at least 30%of the incident light for each of the first polarization state and an orthogonal second polarization state. Further, for the substantially normally incident light having the at least first visible wavelength in the visible wavelength range, the reflective polarizer transmits at least 60%of the incident light for the first polarization state and reflects at least 60%of the incident light for the second polarization state.

In a second aspect, the present disclosure provides a mirror display. The mirror display includes a display configured to form a polarized image for viewing by a viewer. The polarized image has a first polarization state. The mirror display further includes a partial mirror disposed on the display. The partial mirror is sufficiently optically transmissive so that the viewer is able to view the polarized image through the partial mirror and is sufficiently optically reflective so that the viewer is able to view a viewer image of the viewer reflected by the partial mirror toward the viewer. Furthermore, the mirror display includes a reflective polarizer disposed between the display and the partial mirror. The reflective polarizer is configured to transmit at least 60%of the polarized image toward the partial mirror for viewing by the viewer. The reflective polarizer is further configured to reflect, toward the viewer, at least 30%of light from the viewer transmitted by the partial mirror thereby increasing a brightness of the viewer image.

The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.

Brief Description of the Drawings

Exemplary embodiments disclosed herein may be more completely understood in consideration of the following detailed description in connection with the following figures. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

FIG. 1 shows a schematic sectional view of a display system, according to an embodiment of the present disclosure;

FIG. 2 shows a schematic detailed sectional view of a partial mirror of the display system, according to an embodiment of the present disclosure;

FIG. 3 shows a schematic detailed sectional view of a reflective polarizer of the display system, according to an embodiment of the present disclosure;

FIG. 4 shows a schematic view of a display system, according to another embodiment of the present disclosure; and

FIG. 5 shows a schematic view of a display system, according to another embodiment of the present disclosure.

Detailed Description

In the following description, reference is made to the accompanying figures that form a part thereof and in which various embodiments are shown by way of illustration. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

In the following disclosure, the following definitions are adopted.

As used herein, all numbers should be considered modified by the term “about” . As used herein, “a, ” “an, ” “the, ” “at least one, ” and “one or more” are used interchangeably.

As used herein as a modifier to a property or attribute, the term “generally” , unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within +/-20 %for quantifiable properties) .

The term “substantially” , unless otherwise specifically defined, means to a high degree of approximation (e.g., within +/-10%for quantifiable properties) but again without requiring absolute precision or a perfect match.

The term “about” , unless otherwise specifically defined, means to a high degree of approximation (e.g., within +/-5%for quantifiable properties) but again without requiring absolute precision or a perfect match.

As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be construed as limiting of this disclosure. The terms “first” and “second” when used in conjunction with a feature or an element can be interchanged throughout the embodiments of this disclosure.

As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B” .

As used herein, the term “layer” generally refers to a thickness of material within a film that has a relatively consistent chemical composition. Layers may be of any type of material including polymeric, cellulosic, metallic, or a blend thereof. A given polymeric layer may include a single polymer-type or a blend of polymers and may be accompanied by additives. A given layer may be combined or connected to other layers to form films. A layer may be either partially or fully continuous as compared to adjacent layers or the film. A given layer may be partially or fully coextensive with adjacent layers. A layer may contain sub-layers.

Typically, mirror displays are being in use to display basic information such as date, time, weather in public places like restaurants, railway stations, public washrooms and so on. Nowadays, the mirror displays are in more demand due to high potential of implementations in a smart home ecosystem. Although the mirror displays have many benefits, there may be issues with current mirror displays. For example, the current mirror displays may provide either a good quality mirror performance or a good quality display performance.

The present disclosure relates to a display system. The display system includes a display configured to form a polarized image for viewing by a viewer. The polarized image has a first polarization state. The display system further includes a partial mirror disposed on the display. Furthermore, the display system includes a reflective polarizer disposed between the display and the partial mirror. For a substantially normally incident light having at least a first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm, the partial mirror reflects at least 30%and transmits at least 30%of the incident light for each of the first polarization state and an orthogonal second polarization state. Further, for the substantially normally incident light having the at least first visible wavelength in the visible wavelength range, the reflective polarizer transmits at least 60%of the incident light for the first polarization state and reflects at least 60%of the incident light for the second polarization state.

Since the display system of the present disclosure includes the reflective polarizer disposed between the display and the partial mirror, the reflective polarizer may additionally reflect, toward the viewer, at least a portion of light (i.e., the portion of light having the second polarization state) from the viewer transmitted by the partial mirror while substantially transmitting light from the display having the first polarization state. This may increase a brightness of a viewer image of the viewer which is reflected by the partial mirror toward the viewer. Therefore, the reflective polarizer may enhance the brightness of the display system without negatively affecting transmission of light from the display. In other words, the display system of the present disclosure may provide a high mirror performance, but also a high quality display performance.

Further, the display system may not require a high performance reflective polarizer having a high reflective performance (e.g., greater than about 99%) for one polarization state to enhance the brightness of the display system. Such high performance reflective polarizer may be expensive. Further, using such high performance reflective polarizers may sometimes lead to unwanted optical artifacts, such as an orange skin effect. Thus, the display system of the present disclosure may be relatively cheaper than a conventional display system which includes only the high performance reflective polarizer and may further reduce a likelihood of the optical artifacts.

In addition, as the reflective polarizer of the display system of the present disclosure may enhance the brightness of the display system, the display system may not require providing additional power to the display to obtain a high luminance performance which may otherwise cause high thermal issues and damage to the display.

Referring now to figures, FIG. 1 is a schematic sectional view of a display system 300, according to an embodiment of the present disclosure. In some embodiments, the display system 300 may be interchangeably referred to as “the mirror display 300” .

In some cases, the mirror display 300 may be implemented at public places to display information such as date, time, weather, etc. In some cases, the mirror display 300 may be implemented in smart home devices, such as smart refrigerators and smart mirrors in wash rooms, dressing rooms and bed rooms, etc. In some cases, the mirror display 300 may be implemented in makeup mirrors and fitness mirrors. In some examples, the mirror display 300 may display a makeup performance, an exercise performance, or a feedback on a health status for a viewer 310.

The display system 300 defines mutually orthogonal x, y, and z-axes. The x and y-axes are in-plane axes of the display system 300, while the z-axis is a transverse axis disposed along a thickness of the display system 300. In other words, the x and y-axes are disposed along a plane of the display system 300, while the z-axis is perpendicular to the plane of the display system 300.

The display system 300 includes a display 10 configured to form a polarized image 11 for viewing by the viewer 310. The polarized image 11 has a first polarization state. In some embodiments, the first polarization state extends along the x-axis and corresponds to a p-polarization state.

In some embodiments, the display 10 includes one or more of a light emitting diode display (LED) , an organic light emitting diode display (OLED) , a liquid crystal display (LCD) , and an electroluminescent display (EL) . In some cases, the LCD may include a thin film transistor (TFT) LCD panel.

The display system 300 further includes a partial mirror 20 disposed on the display 10. In some embodiments, the partial mirror 20 includes a metal. In some embodiments, the metal includes one or more of aluminum and silver. In some embodiments, the partial mirror 20 includes a micro-structured front surface 24 configured to face the viewer 310. In some embodiments, the partial mirror 20 is coated on a substrate 60. Furthermore, in some embodiments, the substrate 60 includes one or more of glass and plastic.

The display system 300 further includes a reflective polarizer 30 disposed between the display 10 and the partial mirror 20. The micro-structured front surface 24 further may reduce an unwanted optical artifact, such as an orange skin effect that may be otherwise caused due to the reflective polarizer 30.

In some embodiments, a first bonding layer 40 bonds the partial mirror 20 to the reflective polarizer 30. In some embodiments, a second bonding layer 41 bonds the display 10 to the reflective polarizer 30. In some embodiments, the reflective polarizer 30 is fully laminated onto the display 10 (i.e., via the second bonding layer 41) .

FIG. 2 is a schematic detailed sectional view of the partial mirror 20 of the display system 300 shown in FIG. 1, according to an embodiment of the present disclosure.

In some embodiments, the partial mirror 20 includes a plurality of first layers 21, 22 numbering at least 4 in total. In some embodiments, the plurality of first layers 21, 22 numbers at least 10, at least 20, at least 50, at least 75, at least 100, at least 150, at least 200, at least 250, or at least 300 in total.

Furthermore, in some embodiments, each of the first layers 21, 22 has an average thickness t1 of less than about 500 nanometers (nm) . The term “average thickness t1” , as used herein, refers to the average thicknesses t1 measured at multiple points across a plane (i.e., the x-y plane) of each of the plurality of first layers 21, 22. In some embodiments, each of the first layers 21, 22 has the average thickness t1 of less than about 400 nm, less than about 300 nm, or less than about 200 nm.

In some embodiments, at least some of the first layers 21, 22 in the plurality of first layers 21, 22 are dielectric. In some embodiments, at least some of the first layers 21, 22 in the plurality of first layers 21, 22 are polymeric.

In some embodiments, the plurality of first layers 21, 22 includes a plurality of alternating first A and first B layers 21, 22. Furthermore, in some embodiments, the first A layers 21 have a different composition than the first B layers 22.

In some embodiments, the partial mirror 20 further includes at least one skin layer 23 disposed on the plurality of first layers 21, 22. In some embodiments, the at least one skin layer 23 has an average thickness st1 of greater than about 500 nm. The term “average thickness st1” , as used herein, refers to the average thicknesses st1 measured at multiple points across a plane (i.e., the x-y plane) of the at least one skin layer 23 disposed on the plurality of first layers 21, 22. In some embodiments, the at least one skin layer 23 has the average thickness st1 of greater than about 750 nm, greater than about 1000 nm, greater than about 1500 nm, or greater than about 2000 nm.

In the illustrated embodiment of FIG. 2, the at least one skin layer 23 includes a pair of skin layers 23, and the plurality of first layers 21, 22 disposed between the pair of skin layers 23. The at least one skin layer 23 may protect the plurality of first layers 21, 22 and may also provide mechanical stability to the partial mirror 20. In some cases, the at least one skin layer 23 may act as protective boundary layer (PBL) .

FIG. 2 further illustrates a substantially normally incident light 45 having at least a first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm incident on the partial mirror 20. For the substantially normally incident light 45 having the at least the first visible wavelength in the visible wavelength range, the partial mirror 20 reflects at least 30%and transmits at least 30%of the incident light 45 for each of the first polarization state and an orthogonal second polarization state. In some embodiments, the orthogonal second polarization state extends along the y-axis and corresponds to an s-polarization state.

In some embodiments, for the substantially normally incident light 45 having the at least first visible wavelength in the visible wavelength range, the partial mirror 20 reflects at least 40%, at least 50%, at least 60%, or at least 70%and transmits at least 40%, at least 50%, at least 60%, or at least 70%of the incident light 45 for each of the first polarization state and the second polarization state.

Referring to FIGS. 1 and 2, the partial mirror 20 is sufficiently optically transmissive so that the viewer 310 is able to view the polarized image 11 through the partial mirror 20 and sufficiently optically reflective so that the viewer 310 is able to view a viewer image (not shown) of the viewer 310 reflected by the partial mirror 20 toward the viewer 310.

FIG. 3 shows a schematic detailed sectional view of the reflective polarizer 30 of the display system 300 shown in FIG. 1, according to an embodiment of the present disclosure.

In some embodiments, the reflective polarizer 30 includes a plurality of second layers 31, 32 numbering at least 10 in total. In some embodiments, the plurality of second layers 31, 32 numbers at least 20, at least 50, at least 75, at least 100, at least 150, at least 200, at least 250, or at least 300 in total.

Furthermore, in some embodiments, each of the second layers 31, 32 has an average thickness t2 of less than about 500 nm. The term “average thickness t2” , as used herein, refers to the average thicknesses t2 measured at multiple points across a plane (i.e., the x-y plane) of each of the plurality of second layers 31, 32. In some embodiments, each of the second layers 31, 32 has the average thickness t2 of less than about 400 nm, less than about 300, or less than about 200 nm.

In some embodiments, at least some of the second layers 31, 32 in the plurality of second layers 31, 32 are dielectric. In some embodiments, at least some of the second layers 31, 32 in the plurality of second layers 31, 32 are polymeric.

In some embodiments, the plurality of second layers 31, 32 includes a plurality of alternating second A and second B layers 31, 32. Furthermore, in some embodiments, the second A layers 31 have a different composition than the second B layers 32.

In some embodiments, the reflective polarizer 30 further includes at least one skin layer 33 disposed on the plurality of second layers 31, 32. In some embodiments, the at least one skin layer 33 has an average thickness st2 of greater than about 500 nm. The term “average thickness st2” , as used herein, refers to the average thicknesses st2 measured at multiple points across a plane (i.e., the x-y plane) of the at least one skin layer 33 disposed on the plurality of second layers 31, 32. In some embodiments, the at least one skin layer 33 has the average thickness st2 of greater than about 750 nm, greater than about 1000 nm, greater than about 1500 nm, or greater than about 2000 nm.

In the illustrated embodiment of FIG. 3, the at least one skin layer 33 includes a pair of skin layers 33, and the plurality of second layers 31, 32 is disposed between the pair of skin layers 33. The at least one skin layer 33 may protect the plurality of second layers 31, 32 and may also provide mechanical stability to the reflective polarizer 30. In some cases, the at least one skin layer 33 may act as PBL.

FIG. 3 further illustrates the substantially normally incident light 45 having at least the first visible wavelength in the visible wavelength range incident on the reflective polarizer 30. For the substantially normally incident light 45 having the at least first visible wavelength in the visible wavelength range, the reflective polarizer 30 transmits at least 60%of the incident light 45 for the first polarization state and reflects at least 60%of the incident light 45 for the second polarization state.

In some embodiments, for the substantially normally incident light 45 having the at least first visible wavelength in the visible wavelength range, the reflective polarizer 30 transmits at least 70%, at least 80%, or at least 90%of the incident light 45 for the first polarization state and reflects at least 70%, at least 80%, or at least 90%of the incident light 45 for the second polarization state.

Referring to FIGS. 1 to 3, the reflective polarizer 30 is configured to transmit at least 60%of the polarized image 11 toward the partial mirror 20 for viewing by the viewer 310 and is configured to reflect, toward the viewer 310, at least 30%of light from the viewer 310 transmitted by the partial mirror 20 thereby increasing a brightness of the viewer image. In some embodiments, the reflective polarizer 30 is configured to transmit at least 70%, at least 80%, or at least 90%of the polarized image 11 toward the partial mirror 20 for viewing by the viewer 310 and is configured to reflect, toward the viewer 310 at least 35%, at least 40%, at least 45%, or at least 50%of the light from the viewer 310 transmitted by the partial mirror 20.

Thus, the reflective polarizer 30 may additionally reflect, toward the viewer 310, at least a portion of the light from the viewer 310 having the second polarization state from an outside environment which is transmitted by the partial mirror 20 while substantially transmitting light from the display 10 having the first polarization state. This may increase the brightness of the viewer image of the viewer 310. Therefore, the reflective polarizer 30 may enhance the brightness of the display system 300 without negatively affecting transmission of light from the display 10.

The partial mirror 20 and the reflective polarizer 30, in combination, may allow substantial transmission of the polarized image 11 from the display 10 having the first polarization state and may substantially reflect the light having the second polarization state incident on the display system 300 from the outside environment.

Further, as the reflective polarizer 30 may enhance the brightness of the display system 300, the display system 300 may not require providing additional power to the display 10 to obtain a high luminance performance which may otherwise cause high thermal issues and damage to the display 10.

FIG. 4 is a schematic view of the display system 300, according to another embodiment of the present disclosure.

The display system 300 of FIG. 4 is substantially similar to the display system 300 of FIG. 1, with like elements designated by like reference characters. However, in the illustrated embodiment of FIG. 4, the display system 300 of FIG. 4 includes a partial mirror 20a. The partial mirror 20a is substantially similar and functionally equivalent to the partial mirror 20. However, in some embodiments, the partial mirror 20a is coated directly onto the reflective polarizer 30. Therefore, the display system 300 of FIG. 4 may not require the first bonding layer 40 (shown in FIG. 1) .

FIG. 5 is a schematic view of the display system 300, according to another embodiment of the present disclosure.

The display system 300 of FIG. 5 is substantially similar to the display system 300 of FIG. 1, with like elements designated by like reference characters. However, in the illustrated example of FIG. 5, the display 10 and the reflective polarizer 30 define an air gap 50 therebetween. In some embodiments, the second bonding layer 41, the display 10, and the reflective polarizer 30 define the air gap 50 therebetween. In such embodiments, the reflective polarizer 30 is frame laminated onto the display 10 (i.e., via the second bonding layer 41) . In other words, the second bonding layer 41 laminates the reflective polarizer 30 at a periphery of the display 10.

Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified by the term “about. ” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

A display system comprising:

a display configured to form a polarized image for viewing by a viewer, the polarized image having a first polarization state;

a partial mirror disposed on the display; and

a reflective polarizer disposed between the display and the partial mirror, such that for a substantially normally incident light having at least a first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm:

the partial mirror reflects at least 30%and transmits at least 30%of the incident light for each of the first polarization state and an orthogonal second polarization state; and

the reflective polarizer transmits at least 60%of the incident light for the first polarization state and reflects at least 60%of the incident light for the second polarization state.
The display system of claim 1, wherein the display comprises one or more of a light emitting diode display, an organic light emitting diode display, a liquid crystal display, and an electroluminescent display.
The display system of claim 1, wherein the partial mirror comprises a metal.
The display system of claim 3, wherein the metal comprises one or more of aluminum and silver.
The display system of claim 1, wherein the partial mirror comprises a plurality of first layers numbering at least 4 in total, each of the layers having an average thickness of less than about 500 nm.
The display system of claim 5, wherein at least some of the first layers in the plurality of first layers are dielectric.
The display system of claim 5, wherein at least some of the first layers in the plurality of first layers are polymeric.
The display system of claim 5, wherein the partial mirror further comprises at least one skin layer disposed on the plurality of first layers and having an average thickness of greater than about 500 nm.
The display system of claim 5, wherein the plurality of first layers comprises a plurality of alternating first A and first B layers, the first A layers having a different composition than the first B layers.
The display system of claim 1, wherein the reflective polarizer comprises a plurality of second layers numbering at least 10 in total, each of the second layers having an average thickness of less than about 500 nm.
The display system of claim 10, wherein at least some of the second layers in the plurality of second layers are dielectric.
The display system of claim 10, wherein at least some of the second layers in the plurality of second layers are polymeric.
The display system of claim 1, wherein the partial mirror is coated directly onto the reflective polarizer.
The display system of claim 1, wherein the partial mirror comprises a micro-structured front surface configured to face the viewer.
A mirror display comprising:

a display configured to form a polarized image for viewing by a viewer, the polarized image having a first polarization state;

a partial mirror disposed on the display, the partial mirror sufficiently optically transmissive so that the viewer is able to view the polarized image through the partial mirror and sufficiently optically reflective so that the viewer is able to view a viewer image of the viewer reflected by the partial mirror toward the viewer; and

a reflective polarizer disposed between the display and the partial mirror, the reflective polarizer configured to transmit at least 60%of the polarized image toward the partial mirror for viewing by the viewer and configured to reflect, toward the viewer, at least 30%of light from the viewer transmitted by the partial mirror thereby increasing a brightness of the viewer image.