COL 11(6), 061101(2013) CHINESE OPTICS LETTERS June 10, 2013
Crosstalk-free integral imaging display based on double
plano-convex micro-lens array
Yazhou Wang (
æææ
³³³
)
1
, Qionghua Wang (
uuu
)
1,2∗
, Dahai Li (
ooo
°°°
)
1
,
Huan Deng (
"""
)
1
, and Chenggao Luo (
ÛÛÛ
¤¤¤
ppp
)
1
1
School of Electronics and Information Engineering, Sichuan University, Chengdu 610065, China
2
State Key Laboratory of Fundamental Science on Synthetic Vision,
Sichuan University, Chengdu 610065, China
∗
Corresponding author: qhwang@scu.edu.cn
Received December 31, 2012; accepted February 25, 2013; posted online May 31, 2013
A crosstalk-free integral imaging display consisting of a display panel and double plano-convex micro-lens
array is proposed. The double plano-convex micro-lens array includes two micro-lens arrays, A and B.
Micro-lens array A is used to eliminate crosstalk by completely reflecting crosstalk lights. Micro-lens array
B, located near micro-lens array A, is used to display three-dimensional images. Computer simulations
based on ray-tracing are conducted. Crosstalk-free reconstruction images may be clearly observed from
the simulation results.
OCIS codes: 110.6880, 100.6890, 110.2990.
doi: 10.3788/COL201311.061101.
Integral imaging (II) is a three-dimensional (3D) dis-
play technique first proposed by Lippman in 1908
[1]
.
This technology creates true 3D images in free space
that can be seen without special glasses
[2−4]
. II ha s
been studied by many researchers because of its many
characteristics
[5,6]
. It has continuous viewing points
within the viewing a ngle and provides both vertical and
horizontal parallax, unlike lenticular-based stereoscopy.
As in hologra phy, natural and realistic 3D image s can
be displayed in full color. However, low reso lution
[7,8]
,
limited image depths
[9,10]
, narrow viewing angles
[11]
, and
crosstalk
[12]
limit the development of II. Among these
issues, crosstalk is one of the primary disadvantages of
II
[13]
.
Generally, in II, each micro-lens has its own corre-
sp onding area, i.e., elemental image, on the display panel.
Given that the location of e ach elemental image is re-
stricted, the viewing zone of the viewer is narrow in space.
When viewed outside of the viewing zone, a broken 3D
image may be observed because the 3D information ca n-
not be completely transmitted by the corresponding
micro-lens. Meanwhile, a duplicate 3D image formed by
the adjacent micro-lens is reconstructed outside of the
viewing zone. Thus, a crosstalk image is observed. 3D
images can be reconstructed without crosstalk only if
the elemental images have no interference and the lights
from each elemental image pass through the correspond-
ing micro-lens in the reconstruction stage. Instead of a
micro-lens array in the pickup s tage, a sparse camera ar-
ray can be used to produce a non-interference elemental
image array
[14]
. A field lens and aperture in the pickup
stage may b e used to avoid interferences among elemen-
tal images
[15]
. In the reconstruction s tage, an optical
barrier a rray between the micro-lens and elemental im-
age arrays may be used to prevent the crosstalk of light
from adjacent elemental image s and considerably elim-
inate crosstalk
[16]
. The use of graded-index micro- le ns
arrays in the reconstruction stage can eliminate crosstalk
and avoid pseudoscopic 3D images
[17]
. A periodic black
mask betwe e n the elemental image a nd the micro-lens
array can also be used
[18]
.
In this letter, a crosstalk-free II display based on a
double plano-convex micro-lens array is proposed. The
structure and principle of the proposed display are shown
in Fig. 1. The display consists of a display panel and
a double plano-convex micro-lens array, which is com-
posed of micro-lens arrays A and B. Micro-lens array
A is used to prevent the crosstalk of lights from the
non-corr e sponding micro-lens. For instance, light em-
anating from point Q in the second e le mental image
travels through the second micro-lens only and is com-
pletely reflected by micro-lenses 1, 3, and 4. Micro-lens
array B, located at the right side of micro-lens array A,
is used to display 3D ima ges.
The object focal plane of the micro- le ns is generally
close to the display panel in II. In Fig. 1, l
F
is the dis-
tance between the object focal plane and micro-lens array
A, and g is the distance be tween the display panel and
double micro-lens array. The value of g is determined by
the parameters of micro-lens array A. When the param-
eters of micro- le ns array B ar e adjusted, the object focal
plane of the double micro- lens ar ray becomes clos e r to the
Fig. 1. Structure and principle of the p roposed display.
1671-7694/2013/061101(4) 061101-1
c
2013 Chinese Optics Letters