U.S. patent application number 11/737221 was filed with the patent office on 2008-07-24 for plane lens sheet using light transmission rate difference.
Invention is credited to Hyunin CHUNG.
Application Number | 20080174877 11/737221 |
Document ID | / |
Family ID | 39561152 |
Filed Date | 2008-07-24 |
United States Patent
Application |
20080174877 |
Kind Code |
A1 |
CHUNG; Hyunin |
July 24, 2008 |
PLANE LENS SHEET USING LIGHT TRANSMISSION RATE DIFFERENCE
Abstract
Disclosed herein is a plane lens sheet using a light
transmission rate difference, which is used for stereoscopic
printing for a lenticular system and an integral photography method
and has a plane surface while innumerable lenses are arranged on
the surface thereof so that it looks like a flat transparent sheet,
improves the quality of stereoscopic products employing the lens
sheet and facilitates the maintenance of the stereoscopic products.
The plane lens sheet includes: a concave lens layer 20 and a convex
lens layer 30 laminated on each other in such a manner as to adhere
to each other with the same radius curvature to form a superposed
lens sheet, the concave lens layer 20 and the convex lens layer 30
being made of a transparent synthetic resin and having the same
lens pitch and different light transmission rates; a thin flat
transparent upper protection layer 10 formed on the concave lens
layer 20; a transparent layer 50 formed below the convex lens layer
30 for forming the focal length of the laminated concave lens layer
and convex lens layer; and a thin flat transparent lower protection
layer 70 formed below the transparent layer 50.
Inventors: |
CHUNG; Hyunin; (Seoul,
KR) |
Correspondence
Address: |
LADAS & PARRY LLP
224 SOUTH MICHIGAN AVENUE, SUITE 1600
CHICAGO
IL
60604
US
|
Family ID: |
39561152 |
Appl. No.: |
11/737221 |
Filed: |
April 19, 2007 |
Current U.S.
Class: |
359/619 |
Current CPC
Class: |
G02B 30/27 20200101;
G03B 35/24 20130101 |
Class at
Publication: |
359/619 |
International
Class: |
G02B 27/10 20060101
G02B027/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2006 |
KR |
10-2006-0138521 |
Claims
1. A plane lens sheet using a light transmission rate difference
comprising: a concave lens layer and a convex lens layer laminated
on each other in such a manner as to adhere to each other with the
same radius curvature to form a superposed lens sheet, the concave
lens layer and the convex lens layer being made of a transparent
synthetic resin and having the same lens pitch and different light
transmission rates: a thin flat transparent upper protection layer
formed on the concave lens layer; a transparent layer formed below
the convex lens layer for forming the focal length of the laminated
concave lens layer and convex lens layer; and a thin flat
transparent lower protection layer formed below the transparent
layer.
2. The plane lens sheet using a light transmission rate difference
according to claim 1, wherein the convex lens layer and the
transparent layer are formed integrally with each other so that the
convex lens layer is formed in a thickness corresponding to the
focal length of convex lenses forming the convex lens layer.
3. The plane lens sheet using a light transmission rate difference
according to claim 1 or 2, wherein the convex lenses of the convex
lens layer and concave lenses of the concave lens layer are
arranged in a lenticular mode in which the lenses are continuously
arranged in a semi-cylindrical shape.
4. The plane lens sheet using a light transmission rate difference
according to any one of claims 1 to 3, wherein a focal length
printing layer for expressing a sense of depth is printed on the
top or bottom face of the lower protection layer.
5. The plane lens sheet using a light transmission rate difference
according to any one of claims 1, 2 and 3, wherein a non-focal
length printing layer is printed on the top face of the concave
lens layer, the top face of the upper protection layer or the
bottom face of the convex lens layer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a plane lens sheet using a
light transmission rate difference, and more particularly, to a
plane lens sheet using a light transmission rate difference, which
is used for stereoscopic printing for a lenticular system and an
integral photography method and has a plane surface while
innumerable lenses are arranged on the surface thereof so that it
looks like a flat transparent sheet, improves the quality of
stereoscopic products employing the lens sheet and facilitates the
maintenance of the stereoscopic products.
[0003] 2. Background of the Related Art
[0004] Generally, a stereo lens sheet includes innumerable lenses
formed in a pattern on its surface so that the surface Looks
embossed. The lenses of the stereo lens sheet are used to obtain
refractive effect. However, the surface of the stereo lens sheet is
embossed because of the lenses formed thereon, and thus there are
many problems in manufacturing products employing the stereo lens
sheet and managing The products. That is, particles collect between
embossed portions on the surface of the lens sheet and they are
difficult to remove by cleaning. Accordingly, the transparency of
the lens sheet is deteriorated so that the life span of the lens
sheet is shortened.
[0005] Furthermore, the embossed surface of the lens sheet causes
diffused reflection so that products employing the lens sheet look
lusterless. Thus, it is difficult to produce a lustrous lens
sheet.
[0006] A stereoscopic printing lens sheet has a lens pitch that
determines the resolution of a three-dimensional (3D) object. The
correlation of the resolution of stereo graphic and sense of depth
is obtained based on the lens pitch. When the lens pitch is
increased, the interval of lenses of the lens sheet is widened,
which means the lenses have a large size. Thus, the resolution of
stereo graphic seems poor while the sense of depth seems improved
when the stereo graphic is seen with the naked eye.
[0007] Accordingly, to improve both resolution and sense of depth,
a method of increasing the radiuses of curvature of the lenses of
the lens sheet was used to improve the sense of depth while
narrowing the interval of the lenses. However, this method narrows
a 3D object recognition angle though it improves resolution and
sense of depth.
SUMMARY OF THE INVENTION
[0008] Accordingly, the present invention has been made in view of
the above-mentioned problems occurring in the prior art, and it is
a primary object of the present invention to provide a plane lens
sheet using a light transmission rate difference, which has a
perfectly plane surface to prevent foreign substances from being
collected between lenses and remove surface diffused reflection
generated in the lens sheet to reproduce highly lustrous vivid
colors and gives a higher resolution and a better sense of depth as
compared to the conventional stereoscopic printing lens sheet.
[0009] To accomplish the above object of the present invention,
there is provided a plane lens sheet using a light transmission
rate difference comprising: a concave lens layer and a convex lens
layer laminated on each other in such a manner as to adhere to each
other with the same radius curvature to form a superposed lens
sheet, the concave lens layer and the convex lens layer being made
of a transparent synthetic resin and having the same lens pitch and
different light transmission rates; a thin flat transparent upper
protection layer formed on the concave lens layer; a transparent
layer formed below the convex lens layer for forming the focal
length of the laminated concave lens layer and convex lens layer;
and a thin flat transparent lower protection layer formed below the
transparent layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other objects, features and advantages of the
present invention will be apparent from the following detailed
description of the preferred embodiments of the invention in
conjunction with the accompanying drawings, in which:
[0011] FIG. 1 is an exploded perspective view of a plane lens sheet
according to an embodiment of the present invention;
[0012] FIG. 2 is a cross-sectional view of the plane lens sheet
according to an embodiment of the present invention;
[0013] FIG. 3 is a cross-sectional view showing transmission and
refraction of light in a conventional stereoscopic printing lens
sheet and the plane lens sheet according to the present
invention;
[0014] FIG. 4 is a cross-sectional view showing a focus forming
process according to refraction of light in the plane lens sheet
according to the present invention;
[0015] FIG. 5 is a cross-sectional view of a plane lens sheet
according to another embodiment of the present invention;
[0016] FIG. 6 is a cross-sectional view of a plane lens sheet
according to another embodiment of the present invention;
[0017] FIG. 7 is a cross-sectional view showing a maximum effective
angle representing stereo graphic in the plane lens sheet according
to the present invention;
[0018] FIG. 8 is a plan view of a lens pattern array according to
integral photography, which is used in the plane lens sheet
according to an embodiment of the present invention; and
[0019] FIG. 9 is an exploded perspective view of a plane lens sheet
according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The present invention will now be described more fully with
reference to the accompanying drawings, in which exemplary
embodiments of the invention are shown.
[0021] As shown in FIGS. 1 through 9, a plane lens sheet 1
according to the present invention includes a convex lens layer 30.
The convex lens layer 30 is formed by molding a transparent
synthetic resin into hemispherical convex lenses 31 arranged in
every direction. The convex lenses 31 are arranged in such a manner
that a cross angle of virtual lines passing the centers of the
convex lenses 31 makes 60.degree. or 90.degree..
[0022] A concave lens layer 20 is formed on the convex lens layer
30. The concave lens layer 20 is made of a transparent synthetic
resin and has a light transmission rate different from that of the
convex lens layer 30. The concave lens layer 20 includes concave
lenses 21 that have the same radius of curvature as that of the
convex lenses 31 and are arranged in the same manner as the convex
lenses 31. The concave lenses 21 adhere to the convex lenses 31.
The present invention is characterized in that the convex lens
layer 31 and the concave lens layer 21 are formed of a transparent
synthetic resin having different light transmission rates.
[0023] A thin flat upper protection layer 10 is coated on the
concave lens layer 20. A transparent layer 50 is located below the
convex lens layer 30. The transparent layer 50 is in the form of a
sheet with a thickness corresponding to the focal length of the
convex lenses 31. The transparent layer 50 may be integrated with
the convex lens layer 30. In this case, the convex lens layer 30 is
formed in a thickness corresponding to the focal length of the
convex lenses 31.
[0024] A thin flat transparent lower protection layer 70 is coated
on the bottom face of the transparent layer 50. A focal length
printing layer 60 is printed on the bottom face of the transparent
layer 50. The focal length printing layer 60 is represented as an
image formed by computer graphics. The image must be located at the
focal points of the convex lenses 31 such that an observer can
sequentially see images divided based on the pitch of the convex
lenses 31 when focal regions are magnified, as shown in FIG. 7. The
focal length printing layer 60 may be formed below the lower
protection layer 70.
[0025] A non-focal length printing layer 40 (shown in FIGS. 5 and
6) is printed on the surface of the concave lens layer 20, the
surface of the upper protection layer 10 or the bottom face of the
convex lens layer 30. The non-focal length printing layer 40 is not
stereo- or special-effect-processed. The non-focal length printing
layer 40 is used to minimize Moire generated from the correlation
of offset printing halftone dots and the convex lenses 31 and
represent distinct pictures. That is, a new printing layer is
formed in a region out of the focal regions of the convex lenses 31
to improve sense of depth and definition. Accordingly, the
non-focal length printing layer 40 can be located in regions as
shown in FIGS. 5 and 6 or other regions according to its use.
[0026] The convex lenses 31 of the convex lens layer 30 and the
concave lenses 21 of the concave lens layer 20 can be arranged in a
lenticular mode in which lenses are continuously arranged in a
semi-cylindrical shape.
[0027] The plane lens sheet 1 according to the present invention
includes the convex lens layer 30 and the concave lens layer 20,
which are made of a transparent synthetic resin having different
light transmission rates and adhere to each other, performs cubic
or special effect and compensates for shortcomings of the
conventional stereoscopic printing lens sheet.
[0028] Referring to FIG. 3, a portion A shows transmission and
refraction directions of light in a conventional stereoscopic
printing lens sheet, which explains that the normal magnifying
glass effect is obtained. In the conventional stereoscopic printing
lens sheet, however, the surfaces of the convex lenses 31 are
exposed so that particles can easily collect between lenses and
diffused reflection occurs according to the radiuses of curvatures
of the convex lenses 31. This diffused reflection hinders the
expression of the color of the focal length printing layer 60 and
deteriorates the quality of products using the stereoscopic
printing lens sheet. This problem can be solved by coating a
transparent material on the convex lenses 31 to flatten the surface
of the convex lens layer 30.
[0029] However, when the transparent material is coated on the
convex lenses 31 made of a transparent material to fill up valleys
between convex lenses, the convex lens layer looks a transparent
flat sheet like a glass plate. Thus, when the concave lenses 21 are
superposed on the convex lenses 31 having the same light
transmission rate as that of the concave lenses 21, the unique
characteristic of the lenses disappears so that light transmits the
convex lens layer 30 without being refracted, as shown in a portion
B of FIG. 3.
[0030] To solve the aforementioned problem, it is required that the
transparent material coated on the convex lens layer 30 not only
fills up valleys between convex lenses 31 but also serve as another
lens. As shown in a portion C of FIG. 3, when the concave lenses 21
having a light transmission rate different from that of the convex
lenses 31 are located on the convex lens layer 30 and light is
transmitted, a focal point is formed although the focal length L is
longer than the focal length I of the conventional stereoscopic
printing lens sheet shown in the portion A of FIG. 3 because the
light transmission rate of the concave lens layer 20 is higher than
that of the convex lens layer 30.
[0031] An increase in the focal length can create a new advantage.
That is, the radius of curvature of the convex lens 31 is increased
to lengthen the focal length of the lens sheet in order to improve
the sense of depth in a prior art. In this case, the maximum stereo
recognition effective angle .theta. of the observer is narrowed, as
shown in FIG. 7.
[0032] However, the present invention uses the refraction of light
of the concave lens 21 instead of increasing the radius of
curvature of the convex lens 31, and thus it is possible to
maintain or increase the maximum stereo recognition effective angle
.theta. of the observer while maintaining the lens pitch
determining the resolution of the lens sheet.
[0033] If the increase in the focal length of the convex lens 31
increases the thickness of the product employing the lens sheet and
material consumption and raises the manufacturing cost of the
product, the plane lens sheet according to the present invention
can be manufactured such that it has the same thickness as the
conventional stereoscopic printing lens sheet. That is, the radius
of curvature of the convex lens 31 is decreased while maintaining
the lens pitch, as shown in FIG. 4.
[0034] As described above, in the plane lens sheet using a light
transmission rate difference according to the present invention,
the surface of the convex lens layer 30 is flattened to prevent
foreign substances from being collected in a gap between
neighboring convex lenses 31 to distinctly represent graphic images
of the focal length printing layer 60 expressing the sense of
depth. Furthermore, surface diffused reflection generated in the
conventional lens sheet is removed to reproduce highly lustrous
vivid colors. Moreover, a higher resolution and a better sense of
depth of the lens sheet can be provided as compared to the
conventional stereoscopic printing lens sheet.
[0035] While the present invention has been described with
reference to the particular illustrative embodiments, it is not to
be restricted by the embodiments but only by the appended claims.
It is to be appreciated that those skilled in the art can change or
modify the embodiments without departing from the scope and spirit
of the present invention.
* * * * *