KR20070023849A - Parallax barrier lcd which has wide viewing angle - Google Patents

Abstract

A three-dimensional image display device is provided to expand the viewing angle by forming left and right three-dimensional images by moving the position of a barrier in one panel even if the position of a viewer is changed. A three-dimensional image display device with a wide viewing angle is composed of a two-dimensional display device displaying images for left and right eyes; a variable parallax barrier positioned in the front or rear side of the two-dimensional display device to form a three-dimensional image by combining plural fine barrier electrodes; a sensor detecting the position of the variable parallax barrier; a tracking system outputting a barrier control signal to let a viewer watch the three-dimensional image by detecting the position of the viewer and the position of the barrier detected by the sensor; and a driving unit moving the barrier by receiving the barrier control signal from the tracking system and controlling each fine barrier electrode.

Description

Wide viewing angle stereoscopic display device {parallax barrier LCD which has wide viewing angle}

1 is a view showing a stereoscopic image display device disclosed in US Patent No. 6,108,029;

2 is a schematic diagram showing a conventional LCD parallax barrier;

3 and 4 are diagrams for explaining a problem of a stereoscopic image display apparatus using a conventional LCD parallax barrier,

5 shows a barrier electrode structure of a parallax barrier according to the present invention;

6 is a block diagram showing a system for implementing a wide viewing angle stereoscopic image according to the present invention;

7 is a view showing a drive unit according to the present invention,

8 is a view showing a driving state of the micro barrier electrode unit according to the present invention;

9 is a graph showing the amount of light leakage according to the relationship between the cell gap and the line width.

The present invention relates to an apparatus for displaying a stereoscopic image, and more particularly, to a wide viewing angle stereoscopic image display apparatus which provides a wide viewing angle by dividing a barrier electrode and properly combining and driving the barrier electrode according to a user's position. .

Various techniques have been proposed for a stereoscopic image display device using binocular disparity for a long time. One of the typical methods is to install a lenticular lens or a parallax barrier at a predetermined distance on a two-dimensional image panel so that different image information can be recognized on both left and right sides of the viewer to have a three-dimensional effect. to be.

A stereoscopic image display device using a lenticular lens arranges the left and right images in a stripe shape on the focal plane of a lens called a lenticular screen having a semi-cylindrical shape. Make the video visible. The width of one lens is determined by the width of the pixel of the indicator, which allows two pixels corresponding to the left and right images to enter. In this case, the pixel effect on the left side of the lens is visible only to the right eye, and the pixel on the right side is visible only to the left eye.

A stereoscopic image display apparatus using a parallax barrier is a technique of arranging thin stripe-shaped vertical slits for transmitting or blocking light at regular intervals, and then alternately arranging left and right images at appropriate intervals before or after them. Therefore, when viewed through this slit at a specific point in time, the left and right images are geometrically separated to feel a three-dimensional effect. In other words, by installing a striped parallax barrier optical plate that functions as special glasses in front of the monitor screen, users can recognize stereoscopic images without wearing glasses.

As such, a stereoscopic image display device displays a stereoscopic image using binocular parallax.

1 is a diagram illustrating a stereoscopic image display device disclosed in US Pat. No. 6,108,029. This stereoscopic image display device is constructed by providing an LCD parallax barrier 12 at a distance behind the transmissive LCD panel 11. In the transmissive LCD panel 11, the left image L and the right image R are alternately arranged with a pixel pitch P, and the LCD parallax barrier 12 has a transparent portion 12a and an opaque portion 12b. Are alternately arranged with a barrier pitch q. Light from an unillustrated light source passes through the transparent portion 12a of the LCD parallax barrier 12 and passes through the transmissive LCD panel 11 to reach both eyes RE and LE of the observer. At this time, the light passing through the right image R of the transmissive LCD panel 11 reaches the right eye RE of the observer, and the light passing through the left image L of the transmissive LCD panel 11 is the left eye of the observer ( LE) respectively. The left image L and the right image R of the transmissive LCD panel 11 receive slightly different two-dimensional image information respectively recognized by the viewer's left and right eyes, thereby obtaining image information having a three-dimensional effect.

If all the opaque portions 12b of the LCD parallax barrier 12 are made transparent, light from the light source passes evenly through the LCD parallax barrier 12 and the transmissive LCD panel 11 to reach the viewer. This stereoscopic image display device displays a two-dimensional plane image in the same manner as a conventional two-dimensional display device. That is, this stereoscopic image display device controls the opaque portion of the LCD parallax barrier 12 to display both the planar image and the stereoscopic image.

This stereoscopic image display apparatus has a condition necessary for an observer to effectively sense a three-dimensional effect, and the relation is expressed by Equation 1 below.

Where n is a positive integer, S is the distance between the left and right eyes of the observer, D is the shortest distance between the transmissive LCD panel and the observer's eye, d is the shortest distance between the LCD parallax barrier and the transmissive LCD panel, q is the LCD parallax The barrier pitch, P, of the barrier is the pixel pitch of the transmissive LCD panel.

2 is a schematic diagram showing a conventional LCD parallax barrier. Conventional LCD parallax barriers supply power to the common electrode 21 of the upper or lower plate, the opposite plate strip electrode 22 arranged at a constant barrier pitch q interval, and the common electrode 21 and the strip electrode 22. And a power supply device 23 for inducing rearrangement of the liquid crystal layer positioned between the common electrode 21 and the strip electrode 22 to control a transparent state and an opaque state. When a voltage is applied between the common electrode 21 and the strip electrode 22 in the power supply 23 or the applied voltage is cut off, the liquid crystal layer of the corresponding portion becomes transparent or opaque so that a stereoscopic or planar image is displayed. .

3 and 4 are diagrams for explaining a problem of a stereoscopic image display apparatus using a conventional LCD parallax barrier.

As shown in FIG. 3, the stereoscopic image display device displays a right image in the observer's right eye and a left image in the observer's left eye, and synthesizes the two images in the observer's brain to feel a stereoscopic feeling. However, as shown in FIG. 4, when the observer leaves a specific position, a part of the image is covered by the barrier so that the stereoscopic image is not implemented. When the observer moves from the positions of R and L to the positions of R 'and L', the position of the barrier must be shifted by W to maintain stereoscopic images.

However, since the barrier position of the conventional stereoscopic image display device is fixed, the left and right viewing angles at which an observer can see the stereoscopic image are within about 5 degrees, which is very limited.

An object of the present invention, which is designed to solve the problems of the prior art, is to subdivide the barrier electrode to move the position of the barrier when the position of the observer moves so that a wide viewing angle stereoscopic image is displayed even if the position of the observer is changed. It is to provide a video display device.

According to an aspect of the present invention, there is provided a wide viewing angle stereoscopic image display device comprising: a two-dimensional display device for displaying left and right binocular images;

A variable parallax barrier positioned on the front or rear of the 2D display device and forming a barrier for stereoscopic image formation by combining a plurality of micro barrier electrodes;

A sensor for sensing a barrier position of the variable parallax barrier;

A tracking system that senses the position of the observer and the barrier position from the sensor and outputs a barrier control signal so that the observer can enjoy a stereoscopic image;

And a driving unit which receives a barrier control signal from the tracking system and controls the plurality of micro barrier electrodes, respectively, to move the barrier position of the variable parallax barrier.

Hereinafter, a wide viewing angle stereoscopic image display device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is applied to a stereoscopic image display device that induces the left and right binocular disparity of an observer using a parallax barrier composed of an LCD in a 2D image display device to recognize a planar image as a stereoscopic image.

5 is a diagram illustrating a barrier electrode structure of a parallax barrier according to the present invention. According to the present invention, the barrier electrode is divided into eight microstrip electrodes using a micropattern technique, and the positions of the transparent and opaque portions of the parallax barrier are adjusted by adjusting the driven and non-driven portions according to the position of the observer. To be variable.

6 is a block diagram illustrating a system for implementing a wide viewing angle stereoscopic image according to the present invention. This system is composed of a fine barrier electrode portion 61, a drive portion 62, a tracking system 63, and a sensor 64.

The fine barrier electrode portion 61 is formed by dividing one conventional barrier into a plurality of barriers (eight in this embodiment) using a fine pattern technique. These multiple barriers are combined to act like one barrier. This configuration can obtain the effect of moving the barrier as shown in FIG. That is, an appropriate barrier position can be formed according to the change of the position of the observer's eye. Important variables are the number of divisions (or microbarrier electrode width), the spacing between the microbarrier electrode and the electrode, and the cell gap. The larger the number of divisions, the higher the viewing angle precision, but in reality, it is preferable to divide the display into 3 to 128 pieces due to the limitation of the electrode width formation and the driving limits. For example, when applying a qVGA-class 2.2-inch TFT LCD, when one conventional barrier electrode is divided into eight fine barrier electrodes, a stereoscopic image can be realized in units of about 2 to 4 degrees in general. There are eight lines, and the limitation of the viewing angle by the parallax barrier panel is virtually eliminated. In addition, if the distance between the electrode and the electrode is wider, the three-dimensional effect is reduced due to the light leakage phenomenon, but the smaller the better, but if the electrode distance is too narrow, the probability of adjoining adjacent electrodes increases in the process difficulty, and the process difficulty increases and becomes less than 3 ~ 4㎛ Problems arise with yield. Therefore, when cell gap is 5 micrometers, it is suitable that the space | intervals between electrodes are 1-15 micrometers.

The driver 62 is configured as shown in Fig. 7, and drives the divided microbarrier electrode in this invention. As described above, the barrier electrode can be divided in various ways, and the number of divisions is determined by the degree of realistic processability and the precision of the viewing angle. The number of contact holes and the number of driving lines 81, 82, 83, 84, 85, 86, 87, and 88 of the pad portion are also determined by the number of divisions. If one conventional barrier electrode is divided into eight, eight pad electrodes, contact holes, and driving lines are required per barrier pitch. The driving lines 81, 82, 83, 84, 85, 86, 87, and 88 are connected to the electrodes at the same positions for each barrier pitch. When the power is turned on / off for eight electrodes, the barrier is changed according to the change of the viewing angle. The position of can be changed as appropriate.

In order to manufacture the wide viewing angle stereoscopic image display apparatus of the present invention, the number of barrier electrode divisions and electrode intervals are designed in accordance with the specifications of the two-dimensional image display apparatus for forming an image. According to the design, the microbarrier electrode is formed through a photolithography process, and then a contact hole is formed through a photolithography process after depositing or applying an insulator to form contact holes in the pad portion. After forming the contact holes, the conductive pools are dispensed between the electrodes at the same position for each barrier pitch, or the transparent electrodes and the conductive metal are deposited, and the electrodes are formed through photo development. After that, a wide viewing angle liquid crystal display device is manufactured through a general liquid crystal cell manufacturing process.

The driving portion is formed by a pad portion electrode forming step, an insulating film and contact hole forming step, a driving electrode forming step, an alignment film forming step, a cell forming step, and a module step. The pad part electrode is a transparent electrode and is formed together when forming the barrier electrode. The insulating film and the contact hole forming process are formed through an application and photodevelopment process or an inorganic insulating film by deposition and photodevelopment process using the organic insulating film. The driving electrode may be formed through the deposition and photodevelopment process of the transparent electrode and the conductive metal, or may be formed by applying and applying the conductive polymer and the photodevelopment process. The alignment film forming step to the module step are the same as the general liquid crystal manufacturing step.

The tracking system 63 generates a barrier movement signal according to the position of the observer's eye and provides it to the contact hole pad unit. Sensor 64 senses the position of the barrier and provides it to tracking system 63.

Hereinafter, the operation of the micro barrier electrode will be described with reference to FIG. 8.

The microbarrier divided into several forms a barrier capable of displaying a stereoscopic image by several combinations. Track the change in the observer's eye position to shift the position of the barrier. 8A illustrates a state in which the first driving line 81 to the fourth driving line 84 are 'ON', and the fifth driving line 85 to the eighth driving line 88 are 'OFF'. Illustrated. 8B, the third driving line 83 to the sixth driving line 86 are 'ON', and the first driving line 81, the second driving line 82, and the seventh driving line 87 are shown. ) And the eighth driving line 88 are 'OFF'.

When the 'ON' and 'OFF' of each drive line are controlled in this way, the position of the barrier moves. Thus, by tracking the position of the observer and moving the position of the barrier, it is possible to enjoy a stereoscopic image wherever the observer is.

As the number of barrier divisions increases, the viewing angle precision improves, but the process and driving become difficult. Therefore, the number of divisions should be selected in consideration of the pixel size, screen size, and the like of the 2D image display device. For example, when implementing a stereoscopic image using a 2.2 "qVGA TFT LCD having a pixel width of 140 µm, if the barrier electrode is divided into eight fine barrier electrodes, the viewing angle precision is 2 to 4 degrees, and each electrode pitch is It is 35 ㎛, and it is designed and manufactured by adjusting the line width and line width according to the process conditions, and the cell gap and line width are closely related in terms of light leakage during driving.

9 is a graph showing the amount of light leakage according to the relationship between the cell gap and the line width.

In general, the smaller the line width and the higher the driving voltage, the smaller the amount of light leakage. Therefore, this line width is designed in consideration of process margin, drive voltage, cell gap, and the like. For example, when the driving voltage is 5V, the line width is designed not to exceed three times the cell gap. The line width can be designed not to exceed five times the cell gap depending on the driving voltage.

Although the technical spirit of the present invention has been described above with the accompanying drawings, it is intended to exemplarily describe the best embodiment of the present invention, but not to limit the present invention. In addition, it is obvious that any person skilled in the art may make various modifications and imitations without departing from the scope of the technical idea of the present invention.

According to the present invention as described above, even if the position of the observer is changed, the viewing angle can be enlarged by implementing the left and right stereoscopic images by moving the position of the barrier in one panel.

Claims (1)

A two-dimensional display device for displaying left and right binocular images; A variable parallax barrier positioned on the front or rear of the 2D display device and forming a barrier for stereoscopic image formation by combining a plurality of micro barrier electrodes; A sensor for sensing a barrier position of the variable parallax barrier; A tracking system that senses the position of the observer and the barrier position from the sensor and outputs a barrier control signal so that the observer can view a stereoscopic image; And a driving unit which receives a barrier control signal from the tracking system and controls the plurality of micro barrier electrodes, respectively, to move the barrier position of the variable parallax barrier.

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