# US 2021/0278712 A1 · Peep-proof film, backlight source and display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0278712 A1
- Document ID: US20210278712A1
- Status: Published application
- Kind: A1
- Application number: 17/195,779
- Filed: 2021-03-09
- Published: 2021-09-09
- Earliest claimed: 2020-03-09
- Assignees: Hefei Boe Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Hefei BOE Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Inventors: Hai TANG; Liang GAO; Xiaolin GENG; Bing ZHANG
- Web page: https://patentgrep.com/patent/US20210278712A1

## CPC

- G02F 1/1323: {Arrangements for providing a switchable viewing angle}
- G02F 1/133606: {including a specially adapted diffusing, scattering or light controlling members}
- G02F 1/13439: {characterised by their electrical, optical, physical properties; materials therefor; method of making}
- G02F 1/167: by electrophoresis
- G02F 1/16757: Microcapsules
- G02F 1/1676: Electrodes
- G02F 1/1677: Structural association of cells with optical devices, e.g. reflectors or illuminating devices
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

The present disclosure provides a peep-proof film, the peep-proof film includes a light-transmitting film body, an electrophoretic liquid, a first electrode pattern and a second electrode pattern, the film body includes a light incident surface and a light exit surface which are opposite to each other, the first electrode pattern and the second electrode pattern are spaced in a thickness direction of the peep-proof film, the film body has a plurality of receiving cavities thereinside, the electrophoretic liquid is in the receiving cavities, the electrophoretic liquid is located between the first electrode pattern and the second electrode pattern and includes a dispersion medium and electrophoretic particles, and a refractive index of the dispersion medium is less than that of the film body. The present disclosure further provides a backlight source and a display device.

## Claims

### Claim 1

A peep-proof film, comprising: a light-transmitting film body, an electrophoretic liquid, a first electrode pattern and a second electrode pattern, the film body comprises a light incident surface and a light exit surface which are opposite to each other, the first electrode pattern and the second electrode pattern are spaced in a thickness direction of the peep-proof film, the film body has a plurality of receiving cavities thereinside, the electrophoretic liquid is in the receiving cavities, the electrophoretic liquid is located between the first electrode pattern and the second electrode pattern, and comprises a dispersion medium and electrophoretic particles, and a refractive index of the dispersion medium is less than that of the film body.

### Claim 2 (depends on 1)

The peep-proof film of claim 1, wherein the light exit surface of the film body comprises a plurality of planar connecting portions and a plurality of curved surface protrusions, each curved surface protrusion is located between two adjacent receiving cavities, and adjacent curved surface protrusions are connected by the planar connecting portion.

### Claim 3 (depends on 2)

The peep-proof film of claim 2, wherein dimensions of the peep-proof film satisfy a following relationship:
arctan
⁡
(
d
⁢
1
2
⁢
h
⁢
1
)
≤
σ
,
where d1 is a distance between opposite side surfaces of two adjacent receiving cavities;
h1 is a distance between a top surface of the receiving cavity and the light incident surface;
σ is a maximum divergence angle of light irradiated on the curved surface protrusions from the light incident side of the peep-proof film.

### Claim 4 (depends on 1)

The peep-proof film of claim 1, wherein a refractive index of the dispersion medium and the refractive index of the film body satisfy a following relationship:
arcsin
⁡
(
n
⁢
4
n
⁢
1
)
≥
π
2
-
δ
,
where n4 is the refractive index of the dispersion medium;
n1 is the refractive index of the film body;
δ is the maximum divergence angle of light reflected at a side wall of the receiving cavity.

### Claim 5 (depends on 1)

The peep-proof film of claim 1, wherein the film body comprises a first substrate and a second substrate, the first substrate and the second substrate are attached together, a surface of the second substrate facing away from the first substrate is the light incident surface, and a surface of the first substrate facing away from the second substrate is the light exit surface.

### Claim 6 (depends on 5)

The peep-proof film of claim 5, wherein the first electrode pattern comprises a plurality of first electrodes, and each receiving cavity is provided at least one of the first electrodes therein.

### Claim 7 (depends on 6)

The peep-proof film of claim 6, wherein the first electrode is disposed on a top surface of the receiving cavity with a space between each edge of the first electrode and a side wall of the receiving cavity adjacent to the edge, wherein the top surface of the receiving cavity is a surface of the receiving cavity facing the light exit surface.

### Claim 8 (depends on 6)

The peep-proof film of claim 6, wherein the receiving cavity is formed in the first substrate.

### Claim 9 (depends on 6)

The peep-proof film of claim 6, wherein the receiving cavity comprises a first receiving groove formed in the first substrate and a second receiving groove formed in the second substrate.

### Claim 10 (depends on 1)

The peep-proof film of claim 1, wherein the first electrode pattern is an entire plate-shaped electrode, the first electrode pattern is located between the first substrate and the second substrate, and the receiving cavities are formed in the second substrate.

### Claim 11 (depends on 1)

The peep-proof film of claim 1, wherein the second electrode pattern is an entire plate-shaped electrode and is made of a transparent conductive material, and the second electrode pattern is located on a light incident side of the light incident surface.

### Claim 12 (depends on 1)

The peep-proof film of claim 1, further comprising at least one reflective layer, wherein the reflective layer is disposed on a bottom surface of at least one of the receiving cavities, and wherein the bottom surface of the receiving cavity is a surface of the receiving cavity facing the light incident surface.

### Claim 13 (depends on 2)

The peep-proof film of claim 2, further comprising at least one reflective layer, wherein the reflective layer is disposed on a bottom surface of at least one of the receiving cavities, and wherein the bottom surface of the receiving cavity is a surface of the receiving cavity facing the light incident surface.

### Claim 14 (depends on 3)

The peep-proof film of claim 3, further comprising at least one reflective layer, wherein the reflective layer is disposed on a bottom surface of at least one of the receiving cavities, and wherein the bottom surface of the receiving cavity is a surface of the receiving cavity facing the light incident surface.

### Claim 15 (depends on 4)

The peep-proof film of claim 4, further comprising at least one reflective layer, wherein the reflective layer is disposed on a bottom surface of at least one of the receiving cavities, and wherein the bottom surface of the receiving cavity is a surface of the receiving cavity facing the light incident surface.

### Claim 16 (depends on 1)

The peep-proof film of claim 1, wherein the receiving cavities are parallel to each other and spaced apart from each other.

### Claim 17 (depends on 1)

The peep-proof film of claim 1, wherein the receiving cavities are intersected with each other to divide the peep-proof film into a plurality of light transmitting parts.

### Claim 18 (depends on 1)

A backlight source, comprising a light emitting panel, wherein the backlight source further comprises the peep-proof film of claim 1, and the light incident surface of the peep-proof film is opposite to a light emitting surface of the light emitting panel.

### Claim 19 (depends on 18)

The backlight source of claim 18, further comprising a reflective polarizer located on a light exit side of the peep-proof film.

### Claim 20 (depends on 14)

A display device, comprising a display panel and a backlight source, wherein the backlight source is the backlight source of claim 14 and located on a backlight side of the display device.