KR20080051365A - Image display device and driving method of the same - Google Patents

Abstract

An image display device and a driving method thereof are provided to form selectively two-dimensional images and three-dimensional images by using a sub-panel including a lenticular array. A display panel(100) displays a plurality of images. A backlight unit(150) is positioned at the backside of the display panel to supply light for displaying the images. A plurality of sub-panels(110) are positioned at a front side and a rear side of the display panel to convert polarization elements of the light and to decide a path of the light. A polarization control unit(170) controls the converting operations of the sub-panels and adjusts N-dimensional images when the images are coupled with each other at a particular distance. A system control unit(160) controls the display panel, the backlight unit, and the polarization control unit.

Description

Image display device and driving method of the same

1 is a diagram for describing an operation of a general lenticular image display device.

2 is a view schematically showing the shape of a typical lenticular lens.

3 is a diagram schematically illustrating an image display apparatus according to an exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating the structure of the display panel and the subpanel.

FIG. 5 is a view illustrating a path of light adjusted according to a polarization pattern of light incident upon driving of the subpanel of FIG. 4.

<Description of the symbols for the main parts of the drawings>

100: display panel 110: subpanel

150: backlight unit 160: system control unit

170: polarization control unit

The present invention relates to an image display apparatus, and more particularly, to an image display apparatus capable of selectively implementing a two-dimensional or three-dimensional image, and an image display apparatus capable of varying an optimal viewing distance fixed during three-dimensional driving. It relates to a driving method.

In general, an image display apparatus for displaying an image includes a display panel on which an image is actually displayed and a driving unit for driving the image, and a plurality of pixels in the form of a two-dimensional matrix are formed on the display panel. Such an image display device subdivides one image to be displayed in each pixel unit and displays one screen through the display panel.

Each of the image display apparatuses has different viewing angle characteristics according to the type of implementation elements of the display panel. In particular, in the case of a liquid crystal display, an image is displayed by using light passing through the liquid crystal layer provided in the display panel. The path of the light passing through the liquid crystal layer varies depending on the viewing angle. May be displayed.

Recently, barriers are formed for each location specified between the display panel and the user, so that the pixels viewed between the barriers are different depending on the viewing angle. Barrier-type image display apparatuses for forming a viewing zone have been proposed. In the barrier image display apparatus, pixels contributing to different viewing areas are different, and by displaying different image signals with these pixels, different images may be displayed at different viewing areas.

A three-dimensional image display apparatus has been proposed in which the characteristics of the image display apparatus are applied to a three-dimensional image implementation, which is based on the stereo visual principle of two eyes.

The parallax between two eyes, that is, the binocular parallax due to the distance between two eyes that are about 65mm apart, is an important factor that makes the object look three-dimensional. Fusion of these two different images can reproduce the original depth and reality of the three-dimensional image.

The three-dimensional display is largely divided into a stereoscopic method, a volume expression method, and a holographic method, and the stereoscopic method is divided into an eyeglass type and an eyeglass type.

Among autostereoscopic 3D display methods, a lenticular method that separates and displays stereo images for left and right eyes and allows an observer to feel 3D stereoscopic images has been in the spotlight.

Briefly looking at the three-dimensional image implementation principle of the lenticular three-dimensional image display device, a plurality of semi-cylindrical lenticular lenses are placed between the user and the display panel for displaying left and right stereo images at the same time, the observer It is a way to feel the bar, described with reference to the drawings as follows.

FIG. 1 is a view for explaining an operation of a general lenticular image display apparatus. The lenticular image display apparatus 10 includes a display panel 20 and a lenticular array 30 that simultaneously display left and right images.

The display panel 20 alternately defines a left eye pixel L for displaying a left eye image and a right eye pixel R for displaying a right eye image. The lenticular array 30 includes a display panel 20 and a user 40. Placed between them. As shown in FIG. 2, the lenticular array 30 includes a plurality of semi-cylindrical lenticular lenses 32 which selectively refract light from the left and right eye pixels L and R, respectively, with respect to the user 40. It is repeatedly arranged in a stripe shape facing the direction.

Accordingly, the left eye image I _L displayed on the left eye pixel L of the display panel 20 reaches the left eye of the user 40 via the lenticular lens 32 of the lenticular array 30. The right eye image I _R displayed on the right eye pixel R of the pixel 20 reaches the right eye of the user 40 via the lenticular lens 52 of the lenticular array 30. In this case, the left / right eye image I _L , I _R ) includes separate images in consideration of parallax that can be detected by a human, respectively, and the user 40 combines the two images to recognize a 3D stereoscopic image.

In this case, the 3D image display apparatus determines an optimal viewing distance D based on the distance E between the left and right eyes, the pitch P _{LENS of the lens} , and the focal length f of the lens. This is expressed as a formula as follows.

Equation 1

D = f (1 + 2E / P _LENS )

The lenticular 3D image display device has a problem in that an optimal viewing distance D for viewing an image is extremely limited. That is, when the user is out of the optimum viewing distance (D), the normal 3D image cannot be viewed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a three-dimensional image display apparatus that overcomes a limited optimal viewing distance in a lenticular three-dimensional image display apparatus.

This is because the optimal viewing distance D is determined by Equation 1 above, and the distance E between the left and right eyes and the pitch P _{LENS of the lens} have a fixed value. To propose a three-dimensional image display device that can be changed.

In addition, a variable dimension image display apparatus capable of selectively displaying a 2D image and a 3D image is proposed.

In order to achieve the above object, the three-dimensional image display device of the present invention, a display panel for displaying a plurality of images; A backlight unit disposed on a rear surface of the display panel and configured to supply light for displaying the plurality of images; A sub-panel positioned on the front or rear of the display panel, converting the polarization component of the light and determining the path of the light; A polarization control unit controlling a conversion operation of the subpanel to adjust the plurality of images to an N-dimensional image when combining the plurality of images at a specific distance; And a system controller for controlling the display panel, the backlight unit, and the polarization control unit.

The N-dimensional image may be a two-dimensional image when the polarization component of the light passing through the subpanel is linearly polarized light.

The N-dimensional image is a three-dimensional image when the polarization component of the light passing through the sub-panel is circularly polarized light.

The subpanel comprises: a lenticular lens for selectively refracting the field of view of the light; It characterized in that it comprises a lenticular array for determining the refractive index of the lenticular lens according to the polarization form of the light.

The lenticular lens is isotropically bonded to the back surface of the anisotropic medium and the anisotropic medium in which the refractive index difference does not occur when the polarization component of the light is linearly polarized, and when the polarization component of the light is circularly polarized light. It is characterized by consisting of a medium.

The lenticular array includes two substrates bonded to each other by a predetermined distance; It characterized in that it comprises a liquid crystal layer formed between the two substrates.

The liquid crystal layer is characterized in that the liquid crystal mode, such as IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal) to rotate in the horizontal direction.

In the lenticular lens, the distance between the left and right eyes of the user is E, the pitch of the lenticular lens is P _LENS , the focal length of the lenticular lens is f, and the optimal viewing distance of the user is D.

D = f (1 + 2E / P _LENS )

It is characterized by satisfying.

The polarization control unit may supply a control signal in the form of a voltage between two substrates of the lenticular array to form an electric field between the two substrates.

As a driving method of an image display apparatus according to the embodiment of the present invention,

The system controller may control the polarization controller to vary the plurality of image types by a user's selection.

The system controller may control the polarization controller to vary the specific distance in response to the position of the user detected through a camera or a sensor provided separately.

Hereinafter, a 3D image display device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a view schematically illustrating an image display apparatus according to an exemplary embodiment of the present invention, in which a display panel 100 displaying an actual image and an image displayed according to polarization components of light supplied from the display panel 100 are illustrated. A sub-panel 110 for determining 2D and 3D of the light source, a backlight unit 150 for supplying light, a system controller 160 for controlling the panels 100 and 110 and the backlight unit 150, and a sub-panel And a polarization control unit 170 for driving 110.

The display panel 100 includes a liquid crystal layer between two substrates bonded to each other by a predetermined distance, and two polarizing plates are provided outside the two substrates. The two polarizers function to selectively transmit light oscillating randomly in a direction perpendicular to the direction of travel.

The display panel 100 displays an image by changing the refractive index of the liquid crystal layer according to the electric field formed between the two substrates and adjusting the light a incident from the backlight unit 150 provided on the rear surface.

The subpanel 110 changes the polarization component of the incident light under the control of the polarization controller 170 and changes the path of the light according to the polarization component of the light.

Here, the subpanel 110 may be provided in front of the display panel 100 as shown, and may also be provided between the display panel 100 and the backlight unit 150. In the following description, driving according to an embodiment of the present invention will be described as an example of the case provided in front of the display panel 100. Of course, depending on the position where the sub-panel 110 is provided, the polarization form of the light (a, b) supplied to each panel 100, 110 may be different.

More specifically, the light (a) supplied from the backlight unit 150 is light having no polarization component, and the light passes through the display panel and is a light (b) having linear polarization component in one direction. Incident on 110.

The backlight unit 150 includes one or more backlight lamps and driving circuits thereof, and is provided on the rear surface of the display panel 100 to supply light emitted from the backlight lamps to the display panel 100.

The system controller 160 includes a driving circuit (not shown) for controlling the magnitude of the electric field applied to the liquid crystal layer of the display panel 100, thereby controlling the display panel 100. In addition, the backlight unit 150 is turned on / off.

The polarization controller 170 controls the subpanel 110 to convert the polarization component of light incident to the subpanel 110 into linearly or circularly polarized light.

The polarization control unit 170 determines the shape of the image displayed through the display panel 100, that is, the 2D or 3D image, or determines the optimal viewing distance D of the 3D image, which is represented by Equation 1 above. On the basis of this, it is realized by changing the focal length f of the lens.

The above-described operation of the polarization controller 170 may be determined by the user, and may be driven by manually operating a separate wired or wireless controller as the user recognizes.

In addition, the polarization control unit 170 may be interlocked with the system controller 160 through a separate module capable of determining a user's position in the image display device, for example, to obtain a user position tracking result such as a camera or a sensor. ), The focal length f of the lens is automatically changed, and through this, the 3D optimal viewing distance D can be determined.

4 is a cross-sectional view illustrating the structure of the display panel and the subpanel. The display panel 100 includes two substrates 102 bonded to each other by a predetermined distance and a liquid crystal layer 105 injected between the substrates. do. Although not shown, electrodes are formed on the two substrates to form an electric field in the liquid crystal layer 105.

In addition, two polarizing plates 101 are provided outside the two substrates 102. The two polarizing plates 101 function to selectively transmit light oscillating randomly in a direction perpendicular to the traveling direction.

As illustrated, the sub-panel 110 may be disposed in front of the display panel 100 or may be disposed between the display panel 100 and the backlight unit 150 on the rear surface of the display panel 100. have.

In addition, the sub-panel 110 may include a lenticular lens 130 for selectively refracting a viewing area of light supplied from the display panel 100 and a lenticular array 140 for determining a refractive index of the lenticular lens 130 according to a polarization pattern of light. ).

Here, the lenticular lens 130 is composed of a concave isotropic medium layer 134 and an anisotropic medium layer 136, the isotropic medium layer 134 may be convex according to the designer's intention.

The liquid crystal layer 145 of the lenticular array 140 includes TN (Twist Nematic), VA (Vertical Align), etc., in which liquid crystals rotate in a vertical direction, and In-Plane Switching (IPS), and Ferroelectric Liquid Crystal (FLC), which rotate in a horizontal direction. A liquid crystal mode such as) may be applied, but is not limited to a specific liquid crystal mode.

However, TN, VA, etc., in which the liquid crystal rotates in a vertical direction, have an elliptical polarization component among polarization components of light in the liquid crystal layer, and the light path of the elliptical polarization component is changed by the lenticular lens 130. Therefore, the liquid crystal mode applied to the lenticular lens 130 is preferably applied to the IPS, FLC mode in which the liquid crystal rotates in the horizontal direction.

The backlight unit 150 supplies light to the display panel 100 or the subpanel 110.

Hereinafter, a driving method of an image display device according to an exemplary embodiment of the present invention will be described with reference to FIG. 5. In the following description, for the sake of convenience, the same components are denoted by the same reference numerals.

FIG. 5 is a view illustrating a path of light adjusted according to a polarization pattern of light incident upon driving of the subpanel of FIG. 4.

First, in 2D driving, a turn-off control signal is applied to two substrates 142 of the lenticular array 140 from the polarization controller 170 of FIG. 3, and an electric field is not formed between the two substrates 142. Accordingly, the refractive index of the liquid crystal layer 145 is not different.

Accordingly, the light b1 of the linearly polarized state incident from the display panel 100 (FIG. 3) passes through the liquid crystal layer 145 as it is and is incident on the lenticular lens 130 (b2).

The light b2 passing through the liquid crystal layer 145 passes through the isotropic medium layer 134 and the anisotropic medium layer 136 of the lenticular lens 130 (b3).

In this operation, the user recognizes the 2D image.

In addition, during 3D driving, a turn-on control signal is applied from the polarization control unit 170 of FIG. 3 to the two substrates 142 of the lenticular array 140 and between the two substrates 142 in response to the control signal. An electric field is formed, and thus the refractive index of the liquid crystal layer 145 changes.

In this case, as described above, the control signal may be determined manually by a user or automatically determined through a module provided separately.

In addition, the control signal is a signal considering the focal length f of the lens according to Equation 1, and when the optimal viewing distance D of the user is determined, the control signal is proportional to the electric field between the two substrates 142. It is a signal in the form of voltage that can be formed larger or smaller.

Subsequently, the light b1 in the linearly polarized state incident from the display panel 100 (FIG. 3) passes through the liquid crystal layer 145 and is converted into a circularly polarized state, and is incident on the lenticular lens 130 (b2).

The circularly polarized light b2 passing through the liquid crystal layer 145 is incident to the anisotropic medium layer 136 of the lenticular lens 130 without changing the state, but the isotropic medium layer 134 and the anisotropic medium layer 136 Depending on the circularly polarized state at the interface of), it is refracted at a certain angle, the light path of the light is changed (b3).

In this operation, the user perceives a 3D image by combining light having different paths.

For convenience of description, the embodiment of the present invention has been described with an example in which the display panel is a liquid crystal display, but other flat panel displays may be used, and specifically, electroluminescence. Display devices (Field Emission Display, FED), Plasma Display Panel, Organic Electro-Luminescence Display Device (OLED) and the like can be used.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

The present invention provides a two-dimensional or three-dimensional panel having a lenticular lens for selectively refracting the viewing area of light supplied from a display panel and a lenticular array for determining a refractive index of the lenticular lens according to a polarization form of light. The 3D image may be selectively implemented, and the optimal viewing distance fixed during the 3D driving may be changed manually or automatically, so that the user may view the 3D image without being limited to the optimal viewing distance.

Claims (11)

A display panel displaying a plurality of images; A backlight unit disposed on a rear surface of the display panel and configured to supply light for displaying the plurality of images; A sub-panel positioned at the front or rear of the display panel, converting the polarization component of the light and determining the path of the light; A polarization control unit controlling a conversion operation of the subpanel to adjust the plurality of images to an N-dimensional image when combining the plurality of images at a specific distance; A system controller for controlling the display panel, the backlight unit, and the polarization controller; Image display apparatus comprising a. The method of claim 1, And the N-dimensional image is a two-dimensional image when the polarization component of the light passing through the subpanel is linearly polarized light. The method of claim 1, And the N-dimensional image is a three-dimensional image when the polarization component of the light passing through the subpanel is circularly polarized light. The method of claim 1, The subpanel comprises: a lenticular lens for selectively refracting the field of view of the light; A lenticular array configured to determine a refractive index of the lenticular lens according to the polarization form of the light; Image display apparatus comprising a. The method of claim 4, wherein The lenticular lens is isotropically bonded to the back surface of the anisotropic medium and the anisotropic medium in which the refractive index difference does not occur when the polarization component of the light is linearly polarized, and when the polarization component of the light is circularly polarized light. medium; Image display device characterized in that consisting of. The method of claim 4, wherein The lenticular array includes two substrates bonded to each other by a predetermined distance; A liquid crystal layer formed between the two substrates; Image display apparatus comprising a. The method of claim 6, Wherein the liquid crystal layer is in a liquid crystal mode such as in-plane switching (IPS) or ferroelectric liquid crystal (FLC) rotating in a horizontal direction. The method of claim 4, wherein In the lenticular lens, the distance between the left and right eyes of the user is E, the pitch of the lenticular lens is P _LENS , the focal length of the lenticular lens is f, and the optimal viewing distance of the user is D. D = f (1 + 2E / P _LENS ); Image display apparatus characterized in that the. The method of claim 4, wherein The polarization controller is configured to supply a control signal in the form of voltage between two substrates of the lenticular array to form an electric field between the two substrates. In the driving method of the video display device according to claim 1, And the system controller controls the polarization controller to change the plurality of image types according to a user's selection. The method of claim 10, And the system controller controls the polarization controller to vary the specific distance in response to a location of a user detected through a camera or a sensor separately provided.

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