U.S. patent application number 12/938389 was filed with the patent office on 2012-02-23 for 3d image display device.
This patent application is currently assigned to CHUNGHWA PICTURE TUBES, LTD.. Invention is credited to Chien-Hung Chen, Chun-Chieh Chiu, Hsiang-Tan Lin, Shih-Chieh LIN.
Application Number | 20120044430 12/938389 |
Document ID | / |
Family ID | 45593803 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120044430 |
Kind Code |
A1 |
LIN; Shih-Chieh ; et
al. |
February 23, 2012 |
3D Image Display Device
Abstract
The present invention provides a 3D image display device. The 3D
image display device includes a backlight module; a first linear
polaroid disposed in front of the backlight module to polarize the
light from the backlight module; a first liquid crystal layer
disposed in front of the first linear polaroid; a second linear
polaroid disposed in front of the first liquid crystal layer, the
second linear polaroid having a determined polarizing angle to
polarize image signals; a second liquid crystal layer disposed in
front of the second linear polaroid to switch a linear polarization
orientation of image signals; and a retarding layer disposed in
front of the second liquid crystal layer to transform the linear
polarization orientation into a circular polarization
orientation.
Inventors: |
LIN; Shih-Chieh; (Sanchong
City, TW) ; Lin; Hsiang-Tan; (Keelung City, TW)
; Chen; Chien-Hung; (Tucheng City, TW) ; Chiu;
Chun-Chieh; (Luzhu Township, TW) |
Assignee: |
CHUNGHWA PICTURE TUBES,
LTD.
Bade City
TW
|
Family ID: |
45593803 |
Appl. No.: |
12/938389 |
Filed: |
November 3, 2010 |
Current U.S.
Class: |
349/15 |
Current CPC
Class: |
G02B 30/25 20200101;
H04N 13/337 20180501 |
Class at
Publication: |
349/15 |
International
Class: |
G02B 27/26 20060101
G02B027/26; G02F 1/1335 20060101 G02F001/1335 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 18, 2010 |
TW |
099127631 |
Claims
1. A 3D image display device, comprising: a backlight module; a
first linear polaroid disposed in front of said backlight module,
said first linear polaroid having a first polarization orientation;
a first liquid crystal layer disposed in front of said first linear
polaroid; a second linear polaroid disposed in front of said first
liquid crystal layer, said second linear polaroid having a second
polarization orientation; a second liquid crystal layer disposed in
front of said second linear polaroid to change a linear
polarization orientation of image signals; and a retarding layer
disposed in front of said second liquid crystal layer to transform
said linear polarization orientation into a circular polarization
orientation.
2. The device of claim 1, wherein said first polarization
orientation comprises 45 degree angle.
3. The device of claim 1, wherein said second polarization
orientation comprises 135 degree angle.
4. The device of claim 1, wherein gray levels of said second liquid
crystal layer are switched to a minimum gray level or a maximum
gray level to control said linear polarization orientation of said
image signals passing through said second liquid crystal layer.
5. The device of claim 4, wherein said minimum gray level comprises
0.
6. The device of claim 4, wherein said maximum gray level comprises
255.
7. The device of claim 1, wherein said retarding layer has a phase
retardation of quarter wavelength.
8. The device of claim 1, wherein said retarding layer remains said
image signals on an X axis and retards said image signals on a Y
axis.
9. A 3D image display device, said 3D image display device
including a first liquid crystal layer, said 3D image display
device comprising: a linear polaroid disposed in front of said
first liquid crystal layer, said linear polaroid having a
polarization orientation; a shifting layer disposed in front of
said linear polaroid to change a linear polarization orientation of
image signals; and a retarding layer disposed in front of said
shifting layer to transform said linear polarization orientation
into a circular polarization orientation.
10. The device of claim 9, wherein said polarization orientation
comprises 135 degree angle.
11. The device of claim 9, wherein gray levels of said shifting
layer are switched to a minimum gray level or a maximum gray level
to control said linear polarization orientation of said image
signals passing through said shifting layer.
12. The device of claim 11, wherein said minimum gray level
comprises 0.
13. The device of claim 11, wherein said maximum gray level
comprises 255.
14. The device of claim 9, wherein said retarding layer has a phase
retardation of quarter wavelength.
15. The device of claim 9, wherein said retarding layer remains
said image signals on an X axis and retards said image signals on a
Y axis.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This present application claims priority to TAIWAN Patent
Application Serial Number 099127631, filed Aug. 18, 2010, which is
herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to three dimensional
stereoscopic images, and more particularly to a 3D image display
device.
BACKGROUND OF THE RELATED ART
[0003] Three dimensional stereoscopic image display technology has
become the current trend in the image display technology field. The
imaging theorem for the three dimensional stereoscopic image
involves that seeing a target object by a left eye and a right eye
to get the different images, thereby forming depth perceptions with
farness and nearness. Multiple devices can be utilized to render
the left eye and the right eye to see images with different views.
Three dimensional image display devices can be classified as a
glasses type and a bare-eye type. In the glasses type 3D image
display devices, the most common ones involve the usage of shutter
glasses, polarization glasses, anaglyph glasses, and pulfrich
glasses. In the bare-eye type 3D image display devices, the most
common ones are an eHolographic type, a volumetric type and a
multiplexed 2-D type. The multiplexed 2-D type can be further
classified as a spatial-multiplexed type, a time-multiplexed type
and a tracking-based type.
[0004] Recently, the relatively mature and common stereoscopic
display technique in the market is the glasses type stereoscopic
display technique, and the shutter glasses is the relatively common
glasses type stereoscopic display device in the market, where
Nvidia is the most representative one. No matter what kinds of
devices are used, the methods for generating different information
for the left eye and the right eye are similar. Generally,
different images are provided to the left eye and the right eye
respectively to generate stereoscopic perceptions. The basic
principle for generating stereoscopic image is based on that a left
eye and a right eye separately see the object from different
angles, i.e. the images observed from the left eye and the right
eye are not completely the same. In the 3D glasses display system,
2D images of two different angles of view (L, R) are received by
the left eyeglass and the right eyeglass at different times. When
the left eye information is shown in the display, the right
eyeglass is sheltered and the left eyeglass is transparent, and
vice versa. Therefore, the left eye can see the left eye image only
and the right eye can see the right eye image only.
[0005] Currently, the 3D glasses are classified as active type 3D
glasses and passive type 3D glasses. The active type 3D glasses are
the relatively common 3D glasses in the market, but it suffers some
problems. For example, the active type 3D glasses need batteries
and therefore it induces the charging problem and it does not
satisfy the environmental protection concept. Furthermore, the
effective distance between the active type 3D glasses and the
emitter is limited and the signal emitted from the emitter may be
shielded by any objects between the active type 3D glasses and the
emitter. Moreover, the active type 3D glasses are expensive. On the
contrary, the structure of the passive type 3D glasses is simple
and can solve the problems of the active type 3D glasses.
Currently, the passive type 3D glasses are utilized in the
micro-retarder system to apply in 3D visualization. For example, in
the micro-retarder system, the first line is employed for the right
eye image and the second line is used to provide the left eye
image. The left eye image information and the right eye image
information are provided in order from the top to the bottom of the
display, and the vertical resolution of the display will be
downgraded because the pixels of the display are separated to show
the left eye image and the right eye image at the same time.
[0006] The upper polaroid of the current 3D glasses, for example
the shutter glasses, is characterized by a linear polaroid. When
the absorption axis of the linear polaroid of the 3D glasses is
parallel to the one of the upper linear polaroid of the display,
the polarized light is filtered out by the 3D glasses. Therefore,
when the user wears the 3D glasses in an unacceptable angle or
observes an object through the 3D glasses in an unacceptable angle
of view, it will cause that the image is blocked and influences the
3D observation.
[0007] Accordingly, we still need a solution which can solve the
aforementioned problems of the conventional passive type 3D
glasses, for example the limited wearing angle and the insufficient
vertical resolution.
SUMMARY
[0008] To solve the aforementioned problems of the conventional
passive type 3D glasses, for example the limited wearing angle and
the insufficient vertical resolution, the present invention
provides a 3D image display device.
[0009] In one aspect, the present invention provides a 3D image
display device, comprising a backlight module; a first linear
polaroid disposed in front of the backlight module, the first
linear polaroid having a first polarization orientation; a first
liquid crystal layer disposed in front of the first linear
polaroid; a second linear polaroid disposed in front of the first
liquid crystal layer, the second linear polaroid having a second
polarization orientation; a second liquid crystal layer disposed in
front of the second linear polaroid to change a linear polarization
orientation of image signals; and a retarding layer disposed in
front of the second liquid crystal layer to transform the linear
polarization orientation into a circular polarization
orientation.
[0010] One advantage of the present invention is that the 3D image
display device can render the user to see 3D stereoscopic images no
matter the user wears the circularly polarized glasses at any
angles.
[0011] Another advantage of the present invention is that the left
eye image with the left-circularly polarized light or the right eye
image with the right-circularly polarized light generated by the
present invention will have complete image resolution in the
horizontal or vertical direction and will not suffer the problem of
the insufficient vertical resolution.
[0012] Furthermore, another advantage of the present invention is
that the circularly polarized glasses in cooperation with the 3D
image display device do not require batteries and emitter, such
that the issues of the limited effective distance between the 3D
glasses and the emitter and shielding by other objects and the
charging problems or the environment pollution problems will be
eliminated.
[0013] These and other advantages will become apparent from the
following description of preferred embodiments taken together with
the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention may be understood by some preferred
embodiments and detailed descriptions in the specification and the
attached drawings below. The identical reference numbers in the
drawings refer to the same components in the present invention.
However, it should be appreciated that all the preferred
embodiments of the invention are provided only for illustrating but
not for limiting the scope of the claims and wherein:
[0015] FIG. 1 illustrates a structure diagram of a 3D image display
device in accordance with one embodiment of the present
invention;
[0016] FIG. 2A illustrates a diagram showing that the image light
passes through a second liquid crystal layer with a gray level of 0
in accordance with one embodiment of the present invention;
[0017] FIG. 2B illustrates a diagram showing that the image light
passes through the second liquid crystal layer with a gray level of
255 in accordance with one embodiment of the present invention;
[0018] FIG. 3A illustrates a diagram showing that the polarized
light with an angle of 135 degree passes through a retarding layer
in accordance with one embodiment of the present invention;
[0019] FIG. 3B illustrates a diagram showing that the polarized
light with an angle of 45 degree passes through the retarding layer
in accordance with one embodiment of the present invention;
[0020] FIG. 4 illustrates a signal control sequence diagram in
accordance with one embodiment of the present invention; and
[0021] FIG. 5 illustrates a flow diagram of the 3D image signal
controlling method in accordance with another embodiment of the
present invention.
DETAILED DESCRIPTION
[0022] The invention will now be described with the preferred
embodiments and aspects and these descriptions interpret structure
and procedures of the invention only for illustrating but not for
limiting the Claims of the invention. Therefore, except the
preferred embodiments in the specification, the present invention
may also be widely used in other embodiments.
[0023] The present invention provides a 3D image display device. As
shown in FIG. 1, the 3D image display device 10 of the present
invention includes a backlight module 101 to provide the back
light, and a first linear polaroid 102 disposed in front of the
backlight module 101 to polarize the light from the backlight
module 101. A first liquid crystal layer 103 is disposed in front
of the first linear polaroid 102 to display image signals. A second
linear polaroid 104, a second liquid crystal layer 105 and a
retarding layer 106 are disposed in order in front of the first
liquid crystal layer 103, successively. In other words, the second
linear polaroid 104 is disposed in front of the first liquid
crystal layer 103, and the second liquid crystal layer 105, also
referred to as the shifting layer, is disposed in front of the
second linear polaroid 104. The retarding layer 106 is disposed in
front of the second liquid crystal layer 105. It should be noted
that, in one embodiment, the second liquid crystal layer 105 and
the retarding layer 106 may be disposed in the 3D image display
device 10. In another embodiment, the second liquid crystal layer
105 and the retarding layer 106 may be disposed outside of the 3D
image display device 10, i.e. may be disposed as an attachable
device or an additional device for the display.
[0024] In one embodiment, the angle of the absorption axis of the
first linear polaroid 102 is 135 degree, and the angle of the
transmission axis of the first linear polaroid 102 is 45 degree,
which refers to that the first polarization angle is 45 degree. In
one embodiment, the angle of the absorption axis of the second
linear polaroid 104 is 45 degree and the angle of the transmission
axis of the second linear polaroid 104 is 135 degree, which means
that the second polarization angle is 135 degree.
[0025] Therefore, the polarized light with the angle of 45 degree
will be filtered out by the second linear polaroid 104, and the
polarized light with the angle of 135 degree will pass through the
second linear polaroid 104. The gray level status of the second
liquid crystal layer 105 may be switched to control the linear
polarization orientation of the image light passing through the
second liquid crystal layer 105. In one embodiment, the gray levels
of the second liquid crystal layer 105 may be switched to the
minimum gray level, for example 0.
[0026] As shown in FIG. 2A, when the gray levels of the second
liquid crystal layer 105 are switched to 0, the polarization
orientation of the image light passing through the second liquid
crystal layer 105 will not be changed. If the polarization angle of
the incident image light is 135 degree, the polarization angle of
the light passing through the second liquid crystal layer 105
remains 135 degree. In another embodiment, the gray levels of the
second liquid crystal layer 105 may be switched to the maximum gray
level, for example 255.
[0027] As shown in FIG. 2B, when the gray levels of the second
liquid crystal layer 105 are switched to 255, the polarization
orientation of the image light passing through the second liquid
crystal layer 105 will be shifted 90 degree. If the polarization
angle of the incident image light is 135 degree, the polarization
angle of the light passing through the second liquid crystal layer
105 is shifted to 45 degree.
[0028] The retarding layer 106 is able to cause phase retardation
of quarter wavelength (.lamda./4). The image signals on the Y axis
are retarded by a quarter wavelength by the retarding layer 106,
and the image signals on the X axis are remained the same.
Therefore, the retarding layer 106 transforms the linear
polarization orientation of the image light into a circular
polarization orientation, for example a right-circularly polarized
light or a left-circularly polarized light.
[0029] As shown in FIG. 3A, if the incident image light into the
retarding layer 106 is the polarized light with the angle of 135
degree, the light passing through the retarding layer 106 is
transformed into the left-circularly polarized light. As shown in
FIG. 3B, if the incident image light into the retarding layer 106
is the polarized light with the angle of 45 degree, the light
passing through the retarding layer 106 is transformed into the
right-circularly polarized light.
[0030] When a circularly polarized glasses, in which the left
eyeglass is a left circular polarizer and the right eyeglass is a
right circular polarizer, is utilized to observe the image light
passing through the retarding layer 106, the left-circularly
polarized image light and the right-circularly polarized image
light emitted from the retarding layer 106 can be seen from the
left eyeglass and the right eyeglass sequentially and respectively.
Therefore, the circular polarization orientation of the image light
emitted from the retarding layer 106 can be controlled to be
left-circularly light or right-circularly light by switching the
gray levels of the second liquid crystal layer 105, so as to
control the image data to be seen from which eyeglass of the
circularly polarized glasses.
[0031] As shown in FIG. 4, the switching times of the gray levels
of the second liquid crystal layer 105, the input times of the left
eye image and the right eye image of the first liquid crystal layer
103, and the ON/OFF times of the back light may be adjusted to
match with one another. As a result, when the gray levels of the
second liquid crystal layer 105 are switched to 0, the left eye
image is inputted into the first liquid crystal layer 103 and the
back light is turned on after the input action completes, such that
the left eyeglass of the circularly polarized glasses will receive
the left-circularly polarized light of the left eye image.
[0032] When the gray levels of the second liquid crystal layer 105
are switched to 255, the right eye image is inputted into the first
liquid crystal layer 103 and the back light is turned on after the
input action completes, such that the right eyeglass of the
circularly polarized glasses will receive the right-circularly
polarized light of the right eye image. Therefore, the left eye and
the right eye of the user who wears the circularly polarized
glasses can receive the left eye image and the right eye image at
different times respectively to observe stereoscopic images.
[0033] Accordingly, as shown in FIG. 5, in another embodiment, the
present invention provides a 3D image signal controlling method.
The 3D image signal controlling method 20 of the present invention
includes inputting the left eye image into the first liquid crystal
layer 103, turning off the back light and switching the gray levels
of the second liquid crystal layer 105 to the minimum gray level
during the first time interval in step 201. In one embodiment, the
minimum gray level may be 0. Subsequently, the input of the left
eye image is stopped, the back light is turned on and the gray
levels of the second liquid crystal layer 105 are remained as the
minimum gray level during the second time interval in step 202.
[0034] Then, the right eye image is inputted into the first liquid
crystal layer 103, the back light is turned off, and the gray
levels of the second liquid crystal layer 105 are switched to the
maximum gray level during the third time interval in step 203. In
one embodiment, the maximum gray level may be 255. Subsequently,
the input of the right eye image is stopped, the back light is
turned on, and the gray levels of the second liquid crystal layer
105 are remained as the maximum gray level during the fourth time
interval in step 204. Then, step 201 is repeated during the fifth
time interval in step 205. Subsequently, step 202 is repeated
during the sixth time interval in step 206 as well. Similarly, the
step 203 is then repeated during the seventh time interval in step
207. Subsequently, step 204 is repeated during the eighth time
interval in step 208. The steps 201-204 are instructed to
successively repeat in the aforementioned sequences.
[0035] Therefore, as aforementioned, the 3D image display device
and the 3D image signal controlling method provided by the present
invention transform the single linear polarization orientation of
the image light, for example to transform the polarized light with
the angle of 135 degree into left or right circular polarization,
through the second liquid crystal layer and the retarding layer.
The present invention also provides the left eye image with
left-circularly light or the right eye image with right-circularly
light to the circularly polarized glasses at different times by
controlling the ON/OFF times of the back light, the input times of
the left eye image and the right eye image of the first liquid
crystal layer and the switching times of the gray levels of the
second liquid crystal layer, such that the user who wears the
circularly polarized glasses can see the stereoscopic images.
[0036] Even if the user rotates the circularly polarized glasses or
shifts the angle of the circularly polarized glasses unconsciously,
the user's eyes will not receive all black images resulting from
the failure of transmission of the polarized light because the
present invention transforms the linear polarization into the
circular polarization and cooperates with the circularly polarized
glasses. That is to say, the user can see 3D stereoscopic images no
matter the user wears the circularly polarized glasses on any
angles.
[0037] Furthermore, the present invention utilizes the 3D image
signal controlling method to input the left eye image or the right
eye image at different times, thereby the left eye image with the
left-circularly light or the right eye image with the
right-circularly light have complete resolution in the horizontal
or vertical direction and the user will not suffer the problem of
the insufficient vertical resolution. Moreover, the 3D glasses in
cooperation with the 3D image display device of the present
invention are the circularly polarized glasses of the passive type
3D glasses, thereby omitting the usage of the batteries and the
emitter is practicable. The problem of the limited effective
distance between the 3D glasses and the emitter is solved, and the
shielding issue by other objects is removed, and the charging issue
or the environment pollution problem is also eliminated.
[0038] The foregoing description is a preferred embodiment of the
present invention. It should be appreciated that this embodiment is
described for purposes of illustration only, not for limiting, and
that numerous alterations and modifications may be practiced by
those skilled in the art without departing from the spirit and
scope of the invention. It is intended that all such modifications
and alterations are included insofar as they come within the scope
of the invention as claimed or the equivalents thereof.
* * * * *