Lenticular lens sheet and process for production thereof, and optical element
View Patent ↗Provided are a lenticular lens sheet which can be used in a stereoscopic display, a rear projection display, a projection screen, and the like, and means for manufacturing the lenticular lens sheet at low cost without using any mold. The lenticular lens sheet includes at least a transparent support substrate; a plurality of lenticular lenses; and a partition between adjacent ones of the plurality of lenticular lenses, and the lenticular lens sheet is obtained by applying a transparent resin composition ink by an inkjet method to an area partitioned by the partition and subsequently curing the transparent resin composition ink with ultraviolet rays.
1. A lenticular lens sheet, comprising:
a support substrate;
a plurality of lenticular lenses on the support substrate; and
a partition between adjacent ones of the plurality of lenticular lenses,
wherein the lenticular lens sheet is obtained by supplying a transparent resin composition ink by an inkjet method to an area partitioned by the partition and subsequently curing the transparent resin composition ink with ultraviolet rays,
wherein a cross section of the partition cut in a direction perpendicular to the plurality of lenticular lenses has a taper angle of 90° or smaller with respect to the support substrate; and
the following condition is satisfied:
A≦B (i)
A≦w 0 /8 (ii)
C<h 0 /3 (iii)
where A is upper base of the partition cross section, B is lower base of the partition cross section, C is height of the partition, w 0 is pitch of the lenticular lenses, and h 0 is height of the lenticular lenses.
2. A lenticular lens sheet according to claim 1 , wherein the transparent resin composition ink forming the plurality of lenticular lenses includes an ultraviolet curable resin composition ink containing an ultraviolet curable component of 90 wt % or more and has a residual volume ratio of 70 vol % or more after a heat treatment at a temperature of 80° C. to 140° C.
3. An optical element, comprising the lenticular lens sheet according to claim 2 .
4. A stereoscopic display, comprising the lenticular sheet according to claim 2 .
5. An optical element, comprising, the lenticular lens sheet according to claim 1 .
6. A stereoscopic display, comprising the lenticular sheet according to claim 1 .
7. A method of manufacturing a lenticular lens sheet comprising a support substrate: a plurality of lenticular lenses on the support substrate; and a partition between adjacent ones of the plurality of lenticular lenses, wherein the lenticular lens sheet is obtained by supplying a transparent resin composition ink by an inkjet method to an area partitioned by the partition and subsequently curing the transparent resin composition ink with ultraviolet rays, the method comprising:
with respect to a pitch w 0 and a height h 0 of a target lenticular lens and an angle θ 0 of the lenticular lens with respect to the support substrate,
(1) forming the partition including a surface having ink-repellency with the same pitch as the pitch w 0 of the target lenticular lenses;
(2) applying, by an inkjet method, the transparent resin composition ink curable by ultraviolet rays with an amount V (pl/μm) exceeding a volume V 0 (pl/μm) required to form the lenticular lenses or with a height h exceeding the target height h 0 with respect to the area partitioned by the partition (V 0 is calculated from a volume of the target lenticular lens as follows, where r is curvature radius of the lens cross section)
θ
0
=
2
×
tan
-
1
[
h
0
(
w
0
2
)
]
h
(
r
)
=
(
w
0
2
)
2
sin
2
θ
0
-
r
2
-
w
0
2
tan
θ
0
V
0
=
∫
-
w
0
2
w
0
2
h
(
r
)
ⅆ
r
(
pl
/
µm
)
;
(
Equation
1
)
(3) curing, the transparent resin composition ink by using the ultraviolet rays; and
(4) obtaining the target height h 0 by performing a heat treatment at a temperature of 80° C. to 140° C.
8. A method of manufacturing a lenticular lens sheet according to claim 7 , wherein a static contact angle θ L of the transparent resin composition ink forming the lenticular lenses with respect to a surface of the partition exceeds θ 0 represented by (Equation 1).
9. A method of manufacturing a lenticular lens sheet according to claim 7 , wherein a cross section of the partition cut in a direction perpendicular to the plurality of lenticular lenses has a taper angle of 90° or smaller with respect to the support substrate; and the following condition is satisfied:
A≦B (i)
A≦w 0 /8 (ii)
C<h 0 /3 (iii)
where A is upper base of the partition cross section, B is lower base of the partition cross section, C is height of the partition, w 0 is pitch of the lenticular lenses, and h 0 is height of the lenticular lenses.
10. A method of manufacturing a lenticular lens sheet according to claim 9 , wherein a static contact angle θ L of the transparent resin composition ink forming the lenticular lenses with respect to a surface of the partition exceeds θ 0 represented by (Equation 1).
11. A method of manufacturing a lenticular lens sheet according to claim 7 , wherein the transparent resin composition ink forming the plurality of lenticular lenses includes an ultraviolet curable resin composition ink containing an ultraviolet curable component of 90 wt % or more and has a residual volume ratio of 70 vol % or more after a heat treatment at a temperature of 80° C. to 140° C.
12. A method of manufacturing a lenticular lens sheet according to claim 11 , wherein a static contact angle θ L of the transparent resin composition ink forming the lenticular lenses with respect to a surface of the partition exceeds θ 0 represented by (Equation 1).