Light diffraction film and wearable display device

Patent metadata

Field	Value
Publication number	US-11194169-B2
Application number	US-201916673214-A
Country	US
Kind code	B2
Filing date	Nov 4, 2019
Priority date	May 19, 2017
Publication date	Dec 7, 2021
Grant date	Dec 7, 2021

Abstract

A light diffraction film includes a transparent substrate; and a light diffraction layer containing a binder resin and particles, in which an average primary particle diameter of the particles is 1 μm to 10 μm, and a coverage of a surface of the transparent substrate covered with the particles is 70% to 90%.

First claim

What is claimed is:

1. A light diffraction film comprising:
a transparent substrate; and
a light diffraction layer containing a binder resin and particles,
wherein an average primary particle diameter of the particles is 1 μm to 10 μm, a coverage of a surface of the transparent substrate covered with the particles is 70% to 90%,
the particles are arranged in an in-plane direction of the light diffraction layer, and
provided that the number of the particles in a range of 100 μm×100 μm is Np, an average primary particle diameter of the particles is Dp μm, and a distance between nearest particles is Lp μm, a particle regularity represented by the following equation is equal to or higher than 30%
Regular arrangement distance Li =(4/√{square root over (3)}×10,000/2/ Np ){circumflex over ( )}(½)

Particle regularity=( Lp−Dp )/( Li−Dp ).

2. The light diffraction film according to claim 1 ,
wherein in the light diffraction layer, the number of the particles present in a direction orthogonal to the surface of the transparent substrate is not plural.

3. The light diffraction film according to claim 2 ,
wherein provided that a refractive index of the particles is np and a refractive index of the binder resin is nb, a refractive index ratio nb/np is equal to or higher than 1.03 and equal to or lower than 1.09.

4. The light diffraction film according to claim 2 ,
wherein a height h of the binder resin is equal to or greater than 70% and equal to or smaller than 300% of the average primary particle diameter of the particles.

5. A wearable display device comprising the light diffraction film according to claim 2 .

6. The wearable display device according to claim 5 further comprising:
a display; and
a lens.

7. The wearable display device according to claim 5 further comprising:
a display; and
a diffractive optical element.

8. The light diffraction film according to claim 2 ,
wherein a height h of the binder resin is equal to or greater than 100% and equal to or smaller than 300% of the average primary particle diameter of the particles.

9. The light diffraction film according to claim 1 , wherein provided that a refractive index of the particles is np and a refractive index of the binder resin is nb, a refractive index ratio nb/np is equal to or higher than 1.03 and equal to or lower than 1.09.

10. The light diffraction film according to claim 1 ,
wherein a height h of the binder resin is equal to or greater than 70% and equal to or smaller than 300% of the average primary particle diameter of the particles.

11. A wearable display device comprising the light diffraction film according to claim 1 .

12. The wearable display device according to claim 11 further comprising:
a display; and
a lens.

13. The wearable display device according to claim 11 further comprising:
a display; and
a diffractive optical element.

14. The light diffraction film according to claim 1 ,
wherein a height h of the binder resin is equal to or greater than 100% and equal to or smaller than 300% of the average primary particle diameter of the particles.

Assignees

• Fujifilm Corp

Inventors

• Saneto Ryuji
• Ibuki Shuntaro
• Ito Yoji
• Osato Mitsuo

Classifications

• G02B5/1814

  structurally combined with one or more further optical elements, e.g. lenses, mirrors, prisms or other diffraction gratings (G02B5/189 takes precedence) · CPC title

• G02B5/0278

  used in transmission · CPC title

• G02B27/1066

  for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view · CPC title

• G02B27/0172

  characterised by optical features · CPC title

• G02B5/021

  the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures · CPC title