# Patent

## Title
Switchable two dimensional/three dimensional display

## Abstract

A switchable two and three dimensional display (2D/3D display) suitable for being viewed by a user is provided. The 2D/3D display includes a liquid crystal display (LCD) panel and a switchable barrier. The LCD panel has a display area, a non-display area surrounding the display area, and a first black matrix extending from the display area to the non-display area. The first black matrix has a number of openings arranged in array and merely distributed within the display area. The switchable barrier has a 3D image control area, a non-display area surrounding the 3D image control area, and a second black matrix merely disposed within the non-display area. The second black matrix surrounds the 3D image control area. An area occupied by the 3D image control area is different from an area occupied by the display area.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 97138935, filed on Oct. 9, 2008. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a switchable two dimensional/three dimensional display (2D/3D display), and more particularly to a switchable 2D/3D display equipped with a switchable barrier.
2. Description of Related Art
In recent years, continuous advancement of display technologies results in increasing demands on display quality of displays, such as image resolution, color saturation, and so on. Nevertheless, in process of purchasing a display, whether the display is able to display 3D images or not is also taken into consideration in addition to high image resolution and high color saturation.
In current 3D image display technologies, a fixed barrier is mainly utilized for controlling images captured in respective eyes of a viewer. However, according to visual characteristics of human eyes, a 3D image may be produced when two images with the same content but different parallax are respectively captured by a viewer's left and right eyes. Based on different positions of the fixed barrier, the 3D image display technologies can be approximately categorized into a front barrier 3D image display technology and a back barrier 3D image display technology.
In the front barrier 3D image display technology, the barrier is disposed in front of a display panel, i.e., the barrier is located between the display panel and human eyes. By contrast, in the back barrier 3D image display technology, the barrier is disposed between a backlight source and the display panel. The front barrier 3D image display technology is further detailed in US publication number 2004/0257531, while the back barrier 3D image display technology is described in US publication number 2007/0229654 A1.
It should be noted that a 3D image is produced by means of the fixed barrier in a spatial-multiplexed manner, whereby the resolution of a 3D display device is reduced in half even though a 3D display effect of a liquid crystal display (LCD) panel can be achieved. Besides, the 3D display equipped with the fixed barrier cannot be used to display 2D images but 3D images. Thus, the 3D display having the fixed barrier cannot be extensively applied.
To resolve said issue, a switchable barrier has been proposed and applied in a switchable 2D/3D display such that the switchable 2D/3D display is able to display 2D images when the switchable barrier is turned off. By contrast, when the switchable barrier is turned on, the switchable 2D/3D display is able to display 3D images.
FIG. 1 is a schematic cross-sectional view of a conventional switchable 2D/3D display. Referring to FIG. 1, a conventional switchable 2D/3D display 100 includes an LCD panel 110 and a switchable barrier 120. The LCD panel 110 has a display area 110a, a non-display area 110b surrounding the display area 110a, and a first black matrix 112 extending from the display area 110a to the non-display area 110b. The first black matrix 112 has a plurality of openings 112a arranged in array and merely distributed within the display area 110a. The switchable barrier 120 has a 3D image control area 120a, a non-display area 120b surrounding the 3D image control area 120a, and a second black matrix 122 merely disposed within the non-display area 120b. The second black matrix 122 surrounds the 3D image control area 120a, and an area occupied by the 3D image control area 120a is the same as an area occupied by the display area 110a. In other words, the area of the non-display area 120b is the same as the area of the non-display area 110b. 
It can be deduced from FIG. 1 that an outer edge of the 3D image control area 120a is aligned to an outer edge of the display area 110a. Hence, when the conventional switchable 2D/3D display 100 is used, it is rather perceivable that the images do not present a favorable visual effect on the edges of the images. In particular, the second black matrix 122 is not likely to completely block the viewer from visually perceiving the first black matrix 112 located on the edges of the images.
SUMMARY OF THE INVENTION
The present invention is directed to a switchable 2D/3D display which can display images with favorable visual effects on edges thereof.
In the present invention, a switchable 2D/3D display viewed by a user includes an LCD panel and a switchable barrier. The LCD panel has a display area, a non-display area surrounding the display area, and a first black matrix extending from the display area to the non-display area. The first black matrix has a plurality of openings arranged in array and merely distributed within the display area. The switchable barrier has a 3D image control area, a non-display area surrounding the 3D image control area, and a second black matrix merely disposed within the non-display area. The second black matrix surrounds the 3D image control area. An area occupied by the 3D image control area is different from an area occupied by the display area.
In an embodiment of the present invention, the switchable barrier is interposed between the LCD panel and the user, and an area occupied by the 3D image control area is smaller than an area occupied by the display area.
In an embodiment of the present invention, the second black matrix is located above the non-display area and a portion of the display area.
In an embodiment of the present invention, the second black matrix located above the portion of the display area has a width W1, and a minimum distance between the first black matrix and the second black matrix is D1, wherein

W1/D1≧WH/DH.

Here, WH is half of a width of the display area. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the LCD panel.
In an embodiment of the present invention, the LCD panel is interposed between the switchable barrier and the user, and an area occupied by the display area is smaller than an area occupied by the 3D image control area.
In an embodiment of the present invention, the first black matrix is located above the non-display area and a portion of the 3D image control area.
In an embodiment of the present invention, the first black matrix located above the portion of the 3D image control area has a width W2, and a minimum distance between the first black matrix and the second black matrix is D1, wherein

W2/D1≧WH/DH.

Here, WH is half of a width of the 3D image control area. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the switchable barrier.
In an embodiment of the present invention, the switchable 2D/3D display further includes a backlight module, and the LCD panel is interposed between the switchable barrier and the backlight module.
The present invention further provides a switchable 2D/3D display suitable for being viewed by a user. The switchable 2D/3D display includes an LCD panel and a switchable barrier. The LCD panel has a display area, a non-display area surrounding the display area, and a first black matrix extending from the display area to the non-display area. The first black matrix has a plurality of openings arranged in array and merely distributed within the display area. The switchable barrier is interposed between the LCD panel and the user. Besides, the switchable barrier has a 3D image control area, a switchable shielding area surrounding the 3D image control area, a non-display area surrounding the switchable shielding area, and a second black matrix merely disposed within the non-display area. An area occupied by the 3D image control area is smaller than an area occupied by the display area.
In an embodiment of the present invention, the area occupied by the display area is substantially equal to a total area occupied by the 3D image control area and the switchable shielding area.
In an embodiment of the present invention, the switchable shielding area is located above a portion of the display area.
In an embodiment of the present invention, the switchable shielding area has a width W3, and a minimum distance between the first black matrix and the switchable shielding area is D3, wherein

W3/D3≧WH/DH.

Here, WH is half of a width of the display area. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the LCD panel.
In an embodiment of the present invention, the switchable barrier has a first control electrode located in the 3D image control area and a second control electrode located in the switchable shielding area, and the first control electrode has a plurality of openings.
In an embodiment of the present invention, the second control electrode is a ring-shaped electrode.
In an embodiment of the present invention, the switchable 2D/3D display further includes a backlight module, and the LCD panel is interposed between the switchable barrier and the backlight module.
In the switchable 2D/3D display of the present invention, the area occupied by the 3D image control area in the switchable barrier is different from the area occupied by the display area in the LCD panel. Hence, the unfavorable visual effects occurring on edges of images displayed on the switchable 2D/3D display of the present invention can be prevented.
To make the above and other features and advantages of the present invention more comprehensible, several embodiments accompanied with figures are detailed as follows.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the invention. Here, the drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic cross-sectional view of a conventional switchable 2D/3D display.
FIG. 2 is a schematic cross-sectional view of a switchable 2D/3D display according to an embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of a switchable 2D/3D display according to another embodiment of the present invention.
FIG. 4 is a schematic cross-sectional view of a switchable 2D/3D display according to still another embodiment of the present invention.



DESCRIPTION OF EMBODIMENTS
FIG. 2 is a schematic cross-sectional view of a switchable 2D/3D display according to an embodiment of the present invention. Referring to FIG. 2, a switchable 2D/3D display 200a of the present embodiment is suitable for being viewed by a user. The switchable 2D/3D display 200a includes an LCD panel 210 and a switchable barrier 220. The LCD panel 210 has a display area 210a, a non-display area 210b surrounding the display area 210a, and a first black matrix 212 extending from the display area 210a to the non-display area 210b. The first black matrix 212 has a plurality of openings 212a arranged in array and merely (or namely only) distributed within the display area 210a. The switchable barrier 220 has a 3D image control area 220a, a non-display area 220b surrounding the 3D image control area 220a, and a second black matrix 222 merely (or namely only) disposed within the non-display area 220b. The second black matrix 222 surrounds the 3D image control area 220a, and an area occupied by the 3D image control area 220a is substantially different from an area occupied by the non-display area 220b. As shown in FIG. 2, the switchable barrier 220 of the present embodiment is interposed between the LCD panel 210 and the user, and an area occupied by the 3D image control area 220a is substantially smaller than an area occupied by the display area 210a. Specifically, the second black matrix 222 in the switchable barrier 220 is located above the non-display area 210b and a portion of the display area 210a. In addition, the second black matrix 222 is partially overlapped with the first black matrix 212 and extends inwardly from an edge of the second black matrix 220 with a predetermined width. Namely, an inner edge of the second black matrix 222 and an inner edge of the first black matrix 212 are not substantially aligned to each other.
According to the present embodiment, the second black matrix 222 is apt to block the user (or namely viewer) from visually perceiving the first black matrix 212 located on edges of images. Thereby, unfavorable visual effects occurring on the edges of the images can be prevented.
In the present embodiment, the LCD panel 210 is, for example, a twisted nematic LCD panel, and the switchable barrier 220 is, for example, a normally white mode TN-LC cell. Particularly, the LCD panel 210 can either be the twisted nematic LCD panel or any other LCD panel, such as a multi-domain vertically aligned (MVA) LCD panel, and so on. The switchable barrier 220 has a first control electrode 224 located within the 3D image control area 220a, and the first control electrode 224 has a plurality of openings 224a. 
Moreover, the switchable 2D/3D display 200a of the present embodiment can further include a backlight module 230, and the LCD panel 210 is interposed between the switchable barrier 220 and the backlight module 230.
In the present embodiment, the second black matrix 222 located above the portion of the display area 210a has a width W1, and a minimum distance between the first black matrix 212 and the second black matrix 222 is D1, wherein

W1/D1≧WH/DH.

Here, WH is about (or namely approximately) half of a width of the 3D image control area 210a. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the LCD panel 210. Positions of the user are merely exemplary in the present embodiment. Besides, the insignificant thickness of a liquid crystal layer in the LCD panel 210 can be disregarded in the present embodiment. In general, when the switchable 2D/3D display 200a is used on a monitor, the predetermined viewing distance DH ranges from about 50 cm to about 100 cm, for example. Given that the switchable 2D/3D display 200a is applied in a TV set, the predetermined viewing distance DH ranges from about 300 cm to about 500 cm, for example. It is certain that the switchable 2D/3D display 200a of the present embodiment can be applied in other fields, and the predetermined viewing distance DH can be accordingly adjusted based on actual demands.
FIG. 3 is a schematic cross-sectional view of a switchable 2D/3D display according to another embodiment of the present invention. As shown in FIG. 3, a switchable 2D/3D display 200b of the present embodiment is similar to the 2D/3D display 200a depicted in FIG. 2, while the difference therebetween lies in that the LCD panel 210 in the switchable 2D/3D display 200b is interposed between the switchable barrier 220 and the user (or namely viewer). Additionally, the area occupied by the display area 210a is substantially smaller than the area occupied by the 3D image control area 220a. In detail, the first black matrix 212 is located above the non-display area 220b and a portion of the 3D image control area 220a. 
According to the present embodiment, the first black matrix 212 is apt to block the user (or namely viewer) from visually perceiving the second black matrix 222 located on edges of images. Thereby, unfavorable visual effects occurring on the edges of the images can be prevented.
In an embodiment of the present invention, the first black matrix 212 located above the portion of the 3D image control area 220a has a width W2, and a minimum distance between the first black matrix 212 and the second black matrix 222 is D1, wherein

W2/D1≧WH/DH.

Here, WH is about (or namely approximately) half of a width of the 3D image control area 220a. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the switchable barrier 220. Positions of the user are merely exemplary in the present embodiment. Besides, the insignificant thickness of a liquid crystal layer in the switchable barrier 220 is disregarded in the present embodiment. In general, when the switchable 2D/3D display 200b is used on a monitor, the predetermined viewing distance DH ranges from about 50 cm to about 100 cm, for example. Given that the switchable 2D/3D display 200b is applied in a TV set, the predetermined viewing distance DH ranges from about 300 cm to about 500 cm, for example. It is certain that the switchable 2D/3D display 200b of the present embodiment can be applied in other fields, and the predetermined viewing distance DH can be accordingly adjusted based on actual demands.
FIG. 4 is a schematic cross-sectional view of a switchable 2D/3D display according to still another embodiment of the present invention. Referring to FIG. 4, a switchable 2D/3D display 200c of the present embodiment includes an LCD panel 210 and a switchable barrier 220. The LCD panel 210 has a display area 210a, a non-display area 210b surrounding the display area 210a, and a first black matrix 212 extending from the display area 210a to the non-display area 210b. The first black matrix 212 has a plurality of openings 212a arranged in array and merely (or namely only) distributed within the display area 210a. The switchable barrier 220 is interposed between the LCD panel 210 and the user (or namely viewer). Besides, the switchable barrier 220 has a 3D image control area 220a, a switchable shielding area 220c surrounding the 3D image control area 220a, a non-display area 220b surrounding the switchable shielding area 220c, and a second black matrix 222 merely (or namely only) disposed within the non-display area 220b. An area occupied by the 3D image control area 220a is substantially smaller than an area occupied by the display area 210a. Detailed structures of the LCD panel 210 and the switchable barrier 220 are the same as those provided in the previous embodiments, and thus no further description is provided herein.
It should be noted that the switchable barrier 220 of the present embodiment has a first control electrode 224 located in the 3D image control area 220a and a second control electrode 226 located in the switchable shielding area 220c, and the first control electrode 224 has a plurality of openings 224a. In a preferred embodiment, the second control electrode 226 is a ring-shaped electrode and may be has not any openings, for example.
As indicated in FIG. 4, the area occupied by the display area 210a is substantially equal to a total area occupied by the 3D image control area 220a and the switchable shielding area 220c. Besides, an inner edge of the non-display area 210b of the LCD panel 210 and an inner edge of the non-display area 220b of the switchable barrier 220 are substantially aligned to each other, and the switchable shielding area 220c is located above a portion of the display area 210a. 
In the present embodiment, the switchable shielding area 220c has a width W3, and a minimum distance between the first black matrix 212 and the switchable shielding area 220c is D3, wherein

W3/D3≧WH/DH.

Here, WH is about (or namely approximately) half of a width of the display area 210a. DH is a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the LCD panel 210.
In the switchable 2D/3D display of the present invention, the area occupied by the 3D image control area in the switchable barrier is substantially different from the area occupied by the display area in the LCD panel. Hence, the unfavorable visual effects occurring on edges of images displayed on the switchable 2D/3D display of the present invention can be prevented.
Although the present invention has been disclosed by the above embodiments, they are not intended to limit the present invention. Anybody skilled in the art may make some modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the protection range of the present invention falls in the appended claims.

## Claims

1. A switchable two dimensional/three dimensional display (2D/3D display), suitable for being viewed by a user, the switchable 2D/3D display comprising:
a liquid crystal display panel, having a display area, a non-display area surrounding the display area, and a first black matrix extending from the display area to the non-display area, wherein the first black matrix has a plurality of openings arranged in array and merely distributed within the display area; and
a switchable barrier, interposed between the liquid crystal display panel and the user, the switchable barrier having a three dimensional image control area, a switchable shielding area surrounding the three dimensional image control area, a non-display area surrounding the switchable shielding area, and a second black matrix merely disposed within the non-display area, wherein an area occupied by the three dimensional image control area is smaller than an area occupied by the display area.

2. The switchable 2D/3D display of claim 1, wherein the area occupied by the display area is substantially equal to a total area occupied by the three dimensional image control area and the switchable shielding area.

3. The switchable 2D/3D display of claim 1, wherein the switchable shielding area is located above a portion of the display area.

4. The switchable 2D/3D display of claim 1, the switchable shielding area having a width W3, a minimum distance between the first black matrix and the switchable shielding area being D3, wherein


W3/D1≧WH/DH,

WH being half of a width of the display area, DH being a predetermined viewing distance substantially identical to a distance from eyes of the user to an inner surface of one substrate in the liquid crystal display panel.

5. The switchable 2D/3D display of claim 1, wherein the switchable barrier has a first control electrode located in the three dimensional image control area and a second control electrode located in the switchable shielding area, and the first control electrode has a plurality of openings.

6. The switchable 2D/3D display of claim 5, wherein the second control electrode is a ring-shaped electrode.

7. The switchable 2D/3D display of claim 1, further comprising a backlight module, wherein the liquid crystal display panel is interposed between the switchable barrier and the backlight module.