Whiteboard film, whiteboard, peep prevention system

Patent metadata

Field	Value
Publication number	US-12455500-B2
Application number	US-202117915526-A
Country	US
Kind code	B2
Filing date	Oct 14, 2021
Priority date	Oct 29, 2020
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

A whiteboard film ( 100 ) according to an embodiment of the present invention includes: a diffuse reflection layer ( 40 ) to diffuse-reflect visible light; an absorptive polarizing layer ( 20 ) having a first transmission axis that is parallel to a first direction; and a reflective polarizing layer ( 10 ) being disposed between the diffuse reflection layer ( 40 ) and the absorptive polarizing layer ( 20 ) and having a second transmission axis that is substantially parallel to the first direction. A whiteboard ( 100 a ) according to an embodiment of the present invention includes: a diffuse reflection plate ( 40 a ) to diffuse-reflect visible light; an absorptive polarizing layer ( 20 ) having a first transmission axis that is parallel to a first direction; and a reflective polarizing layer ( 10 ) being disposed between the diffuse reflection plate ( 40 a ) and the absorptive polarizing layer ( 20 ) and having a second transmission axis that is substantially parallel to the first direction.

First claim

The invention claimed is:

1 . A whiteboard film comprising:
a diffuse reflection layer to diffuse-reflect visible light; an absorptive polarizing layer having a first transmission axis that is parallel to a first direction; and a reflective polarizing layer being disposed between the diffuse reflection layer and the absorptive polarizing layer and having a second transmission axis that is substantially parallel to the first direction, the absorptive polarizing layer being disposed directly on or adhered to the reflective polarizing layer.

2 . The whiteboard film of claim 1 , further comprising a low-refractive index layer being disposed between the diffuse reflection layer and the reflective polarizing layer and having a refractive index that is smaller than a refractive index of the diffuse reflection layer.

3 . The whiteboard film of claim 2 , wherein the refractive index of the low-refractive index layer is 1.30 or less.

4 . The whiteboard film of claim 2 , wherein the low-refractive index layer is an air layer.

5 . A peeking prevention system comprising:
the whiteboard film of claim 1 ; and a partition to delimit from the surroundings a space in which information displayed on the whiteboard film is presented, the partition having a light-transmitting portion through which the inside of the space is viewable, wherein the light-transmitting portion includes a transparent substrate and a polarizing layer, the polarizing layer having a third transmission axis that is orthogonal to the first direction.

6 . A whiteboard comprising:
a diffuse reflection plate to diffuse-reflect visible light; an absorptive polarizing layer having a first transmission axis that is parallel to a first direction; and a reflective polarizing layer being disposed between the diffuse reflection plate and the absorptive polarizing layer and having a second transmission axis that is substantially parallel to the first direction, the absorptive polarizing layer being disposed directly on or adhered to the reflective polarizing layer.

7 . The whiteboard of claim 6 , further comprising a low-refractive index layer being disposed between the diffuse reflection plate and the reflective polarizing layer and having a refractive index that is smaller than a refractive index of the diffuse reflection plate.

8 . The whiteboard of claim 7 , wherein the refractive index of the low-refractive index layer is 1.30 or less.

9 . The whiteboard of claim 7 , wherein the low-refractive index layer is an air layer.

10 . A peeking prevention system comprising:
the whiteboard of claim 6 ; and a partition to delimit from the surroundings a space in which information displayed on the whiteboard is presented, the partition having a light-transmitting portion through which the inside of the space is viewable, wherein the light-transmitting portion includes a transparent substrate and a polarizing layer, the polarizing layer having a third transmission axis that is orthogonal to the first direction.

Assignees

• Nitto Denko Corp

Inventors

• Toyota Yuji
• Yaegashi Masahiro

Classifications

• G02B5/3033

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• G02B5/0284

  used in reflection · CPC title

• B43L1/00 Primary

  Repeatedly-usable boards or tablets for writing or drawing (drawing-boards B43L5/00) · CPC title

• G03B21/60

  characterised by the nature of the surface · CPC title

• G02B5/3083

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title