US 2026/0036726 A1Published application

Light diffusion control member and reflection-type display body

AssigneesLintec Corporation, Tohoku University

InventorsKentaro KUSAMA, Hiroki FUKUSHIMA, Takahiro ISHINABE, Hideo FUJIKAKE

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Abstract

A light diffusion control member includes a light diffusion control layer having a regular internal structure that includes a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index, and a diffusion pressure sensitive adhesive layer containing light-diffusing fine particles. L1, L2, and L3 identified from reflected light measured for the light diffusion control member (1a, 1b) satisfy the following expressions: (1) L1>1.00; (2) 0.70≤L2≤1.00; and (3) L3<2.00.

Claims7

Dependent claims

A light diffusion control member comprising:

a light diffusion control layer having a regular internal structure that includes a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index;
and
a diffusion pressure sensitive adhesive layer that is laminated on one surface side of the light diffusion control layer and contains light-diffusing fine particles,
wherein, provided that:
an arbitrary point on a surface on the light diffusion control member side of a measurement sample obtained by laminating an arbitrary surface of the light diffusion control member on a reflective surface of an arbitrary mirror is irradiated with a light ray having an angle of 30° with respect to a normal to the surface from each of four directions of azimuth angles of 0°, 90°, 180°, and 270° with the point as a center to generate reflected light that is diffused and reflected from the point for each of the azimuth angles, for the reflected light that travels within a plane including the point and the normal and forms an angle of 30° or less with the normal, a value of a standard deviation (cd/m2) of luminance is calculated for each of the azimuth angles, and the azimuth angle that gives a largest standard deviation is as defined an exclusion angle;
an arbitrary point on the surface on the light diffusion control member side of the measurement sample is irradiated with a light ray having an angle of 30° with respect to the normal to the surface from each of three directions of azimuth angles excluding the exclusion angle out of the four directions of azimuth angles to generate reflected light that is diffused and reflected from the point for each of the three directions of azimuth angles, luminance (cd/m2) of the reflected light that travels in a front direction of the surface is measured for each of the three directions of azimuth angles, and a minimum luminance value of the three obtained luminance values is defined as Lmin while a maximum luminance value is defined as Lmax;
and
an arbitrary point on one surface of any standard white plate is irradiated with a light ray having an angle of 30° with respect to the normal from the azimuth angle, at which the Lmin is measured, to generate reflected light that is diffused and reflected from the point in the front direction, and a value luminance (cd/m2) of the of reflected light is defined as LSTD,
L1 represented by L1=Lmin/LSTD satisfies Expression (1) below
L
1
>
1.
,
(
1
)
L2 represented by L2=Lmin/Lmax satisfies Expression (2) below
0.7
≤
L
2
≤
1.
,
(
2
)
when values of standard deviations (cd/m2) relating to the three directions of azimuth angles excluding the exclusion angle out of the four directions of azimuth angles are L3, L3 in all the three directions satisfies Expression (3) below
L
3
<
2
⁢
.00
.
(
3
)

36 more elements

Dependencies are inferred from the claim text.

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Abstract

A light diffusion control member comprising:

a light diffusion control layer having a regular internal structure that includes a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index;
and
a diffusion pressure sensitive adhesive layer that is laminated on one surface side of the light diffusion control layer and contains light-diffusing fine particles,
wherein, provided that:
an arbitrary point on a surface on the light diffusion control member side of a measurement sample obtained by laminating an arbitrary surface of the light diffusion control member on a reflective surface of an arbitrary mirror is irradiated with a light ray having an angle of 30° with respect to a normal to the surface from each of four directions of azimuth angles of 0°, 90°, 180°, and 270° with the point as a center to generate reflected light that is diffused and reflected from the point for each of the azimuth angles, for the reflected light that travels within a plane including the point and the normal and forms an angle of 30° or less with the normal, a value of a standard deviation (cd/m2) of luminance is calculated for each of the azimuth angles, and the azimuth angle that gives a largest standard deviation is as defined an exclusion angle;
an arbitrary point on the surface on the light diffusion control member side of the measurement sample is irradiated with a light ray having an angle of 30° with respect to the normal to the surface from each of three directions of azimuth angles excluding the exclusion angle out of the four directions of azimuth angles to generate reflected light that is diffused and reflected from the point for each of the three directions of azimuth angles, luminance (cd/m2) of the reflected light that travels in a front direction of the surface is measured for each of the three directions of azimuth angles, and a minimum luminance value of the three obtained luminance values is defined as Lmin while a maximum luminance value is defined as Lmax;
and
an arbitrary point on one surface of any standard white plate is irradiated with a light ray having an angle of 30° with respect to the normal from the azimuth angle, at which the Lmin is measured, to generate reflected light that is diffused and reflected from the point in the front direction, and a value luminance (cd/m2) of the of reflected light is defined as LSTD,
L1 represented by L1=Lmin/LSTD satisfies Expression (1) below
L
1
>
1.
,
(
1
)
L2 represented by L2=Lmin/Lmax satisfies Expression (2) below
0.7
≤
L
2
≤
1.
,
(
2
)
when values of standard deviations (cd/m2) relating to the three directions of azimuth angles excluding the exclusion angle out of the four directions of azimuth angles are L3, L3 in all the three directions satisfies Expression (3) below
L
3
<
2
⁢
.00
.
(
3
)

36 more elements