Patent Application
20140029087
This application claims the benefit of priority under U.S.C §119(a) to Korea Patent Application No. 10-2012-0081381 filed on Jul. 25, 2012, and Korean Patent Application No. 10-2013-0080405 filed on Jul. 9, 2013, the contents of each of which are incorporated herein in their entirety.
1. Field of the Disclosure
Embodiments of the disclosure relate to a switchable lens device, a method of manufacturing the same, and a 2-dimensional (2D) and 3-dimensional (3D) image display device using the same.
2. Discussion of the Related Art
A 3D image display device may be classified into one of a stereoscopic display device using glasses or an autostereoscopic display device called a glasses-free 3D display.
In general, the stereoscopic display device spatially separates an image into a left eye image and a right eye image and displays them, or separates the image into the left eye image and the right eye image in a time division manner and displays them. However, when a viewer watches a 3D image through the stereoscopic display device, the viewer feels inconvenient because he/she has to wear glasses. Hence, the autostereoscopic display device has been developed.
The autostereoscopic display device generally has optical elements, such as a parallax barrier and a lenticular lens, for separating optical axes of the left eye image and the right eye image, disposed in front of or behind a display screen, thereby implementing the 3D image.
However, such a related art autostereoscopic display device displays the 3D image, but has the problem not to display a 2D image.
A switchable lens device includes a first base film, a first lens layer which is formed on the first base film, has a first refractive index in a first direction, has a second refractive index less than the first refractive index in a second direction vertical to the first direction, and has concave surfaces, a second lens layer which has convex surfaces filled in the concave surfaces of the first lens layer and has the first refractive index, and a second base film attached to the second lens layer.
In another aspect, there is a 2D/3D image display device including a display panel configured to display an image using light linearly polarized in a first direction, a polarization control unit configured to selectively switch light of the first direction to light linearly polarized in a second direction vertical to the first direction, and a switchable lens device configured to refract light incident from the polarization control unit using a difference of a refractive index and separate the refracted light into light for a left eye image and light for a right eye image to implement a 3D image, or transmit the light incident from the polarization control unit without a change to implement a 2D image.
In yet another aspect, there is a method of manufacturing a switchable lens device including forming a first lens layer, which has a first refractive index in a first direction, has a second refractive index less than the first refractive index in a second direction vertical to the first direction, and has concave surfaces, on a first base film, filling a second lens layer having the first refractive index in the concave surfaces of the first lens layer to form convex surfaces, and forming a second base film on the second lens layer.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. It will be paid attention that detailed description of known arts will be omitted if it is determined that the arts can mislead the embodiments of the invention.
A 2-dimensional (2D) and 3-dimensional (3D) image display device according to an exemplary embodiment of the invention is described below with reference to
As shown in
The display panel 100 is a display device displaying 2D image data and 3D image data. The display panel 100 includes a flat panel display, such as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an electroluminescence device (EL) including an inorganic light emitting display and an organic light emitting display, and an electrophoresis display (EPD). In the following description, the embodiment of the invention will be described using the liquid crystal display as an example of the display panel 100. Other flat panel displays may be used.
The display panel 100 includes a thin film transistor (TFT) substrate on which a pixel array including TFTs is formed, a color filter substrate on which color filters representing colors are formed, and a liquid crystal layer disposed between the TFT substrate and the color filter substrate. Polarizing plates, of which light absorption axes form about 90° with each other, are respectively attached to the surfaces of the TFT substrate and the color filter substrate of the display panel 100. Hence, light incident on the display panel 100 in a horizontal direction or a vertical direction is linearly polarized in a direction forming about 90° with a light absorption axis of the incident light and then comes out of the display panel 100.
The polarization control unit 200 is disposed on the display panel 100. The polarization control unit 200 transmits light supplied from the display panel 100 without a change or linearly polarizes the light by about 90°, and then supplies the light to the switchable lens device 300. The polarization control unit 200 may be applied to a liquid crystal panel driven in a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in-plane switching (IPS) mode, and a fringe field switching (FFS) mode.
The switchable lens device 300 is disposed on the polarization control unit 200. The switchable lens device 300 transmits light supplied from the polarization control unit 200 without a change to display a 2D image, or separates the light into light corresponding to a right eye image and light corresponding to a left eye image to display a 3D image, depending on a polarization direction of the light supplied from the polarization control unit 200.
Configuration and operations of the polarization control unit 200 are below described with reference to
As shown in
Each of the first substrate 210 and the second substrate 220 is formed of glass or transparent plastic.
Each of the first electrode 230 and the second electrode 240 is formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), and gallium-doped zinc oxide (GZO).
Liquid crystal molecules configuring the liquid crystal layer 250 are formed of positive liquid crystals. The positive liquid crystals are liquid crystals defined by the fact (i.e., Δε>0) that a long axis direction permittivity (ε∥) of the liquid crystal molecules is greater than a short axis direction permittivity (ε⊥) of the liquid crystal molecules. The positive liquid crystals are arranged between alignment layers (not shown) respectively attached to the first electrode 230 and the second electrode 240 and are pre-tilted.
As shown in
Next, the switchable lens device 300 of the 2D/3D image display device according to the embodiment of the invention is described with reference to
As shown in
The first film 310 is formed of a material having a low retardation equal to or less than about 100 nm, and isotropic and uniaxial characteristics. For example, the first film 310 may be selected from a group including polyethylene terephthalate (PET), triacetyl cellulose (TAC), and polycarbonate (PC).
The first film 310 may secure a back distance required when the switchable lens device 300 is attached to the display panel 100. Thus, additional means for securing the distance between the display panel 100 and the switchable lens device 300 is not necessary.
Further, because the first film 310 has the low retardation, the first film 310 does not recognize a retardation of light emitted from the display panel 100. Hence, the first film 310 may prevent a reduction in a 3D crosstalk characteristics.
The second film 320 may be formed of the same material as the first film 310. For example, the second film 320 may be formed of polyethylene terephthalate (PET), triacetyl cellulose (TAC), and polycarbonate (PC). Alternatively, the second film 320 may be formed of a different material from the first film 310.
The first lens layer 330 is formed by curing ultraviolet (UV) curable liquid crystals in a state where the UV curable liquid crystals are orientated in a vertical direction (z-axis direction in
The first lens layer 330 has a first refractive index ‘ne’ and a second refractive index ‘no’ depending on a direction of liquid crystal molecule because of refractive index anisotropy of the liquid crystal molecule. More specifically, the first lens layer 330 has the first refractive index ‘ne’ in a long axis direction of the liquid crystal molecule, but has the second refractive index ‘no’ which is smaller than the first refractive index ‘ne’ in a short axis direction of the liquid crystal molecule. Because a long axis of the liquid crystal molecules of the first lens layer 330 according to the embodiment of the invention is arranged in the same direction as the vertical direction (z-axis direction in
The second lens layer 340 is formed in the concave surfaces 330a so as to flatly cover the concave surfaces 330a of the first lens layer 330. The second lens layer 340 may be formed of a transparent resin and has the same refractive index (i.e., first refractive index ‘ne’) as the refractive index in the long axis direction of the first lens layer 330.
Because the material for forming the first lens layer 330 of the switchable lens device 300 having the above-described configuration may be reduced, the manufacturing cost may be reduced. As shown in
As described above, the first lens layer 330 has the first refractive index ‘ne’ and the second refractive index ‘no’ depending on a polarization direction of light, and the second lens layer 340 has the first refractive index ‘ne’.
According to Snell's law, when light passes through two different media each having a different refractive index, an incident angle a and a refractive angle β of the light at a boundary between the two media hav.e a relationship of no.sinα=ne.sinβ. However, because the second refractive index ‘no’ is less than the first refractive index ‘ne’, the incident angle a has to be greater than the refractive angle β so as to satisfy Snell's law. Thus, a boundary between the first lens layer 330 and the second lens layer 340 has to form the concave surface 330a, so that the light for the left eye image and the light for the right eye image are converged on the focus of the switchable lens device 300. On the contrary, when the boundary between the first lens layer 330 and the second lens layer 340 forms a convex surface, the light for the left eye image and the light for the right eye image are not converged on the focus of the switchable lens device 300. Hence, the light for the left eye image and the light for the right eye image are not separated.
A process for displaying the 2D image and the 3D image through the 2D/3D image display device according to the embodiment of the invention is described below with reference to
In a 3D image mode, while light passes through the polarization control unit 200 to which an electric field is not applied, a polarization axis of the light rotates from the vertical direction ‘{circumflex over (×)}’ (z-axis direction in
Because the liquid crystal molecules configuring the first lens layer 330 of the lens cell LCC of the switchable lens device 300 are orientated in the vertical direction, a polarization direction of light incident on the first lens layer 330 is the same as the short axis direction of the liquid crystal molecules. Thus, the first lens layer 330 functions as a layer having the second refractive index ‘no’, and the second lens layer 340 functions as a layer having the first refractive index ‘ne’. Hence, according to Snell's law, light is refracted by the concave surface 330a of the first lens layer 330 and is converged on a focus ‘p’. As a result, while the light passes through the switchable lens device 300, the light is separated into a travelling path of light corresponding to the right eye image and a travelling path of light corresponding to the left eye image and is converged on different focuses, thereby displaying the 3D image.
In a 2D image mode, when light passes through the polarization control unit 200 to which the electric field is applied, the light passes through the polarization control unit 200 without a change in a polarization axis. Thus, before and after the light passes through the polarization control unit 200, the light has a polarization axis of the vertical direction ‘{circumflex over (×)}’ (z-axis direction in
Hence, in the 2D image mode, the light having the polarization axis of the vertical direction ‘{circumflex over (×)}’ is supplied to the switchable lens device 300.
Because the liquid crystal molecules of the first lens layer 330 of the lens cell LCC of the switchable lens device 300 are orientated in the vertical direction, a polarization direction of light incident on the first lens layer 330 is the same as the long axis direction of the liquid crystal molecules. Thus, the first lens layer 330 functions as a layer having the first refractive index ‘ne’, and the second lens layer 340 functions as a layer having the first refractive index ‘ne’. Hence, light passes through the switchable lens device 300 while the light is not refracted by the switchable lens device 300, thereby displaying the 2D image.
A method of manufacturing the switchable lens device 300 according to the embodiment of the invention is described below with reference to
The refractive index of the second lens layer 340 of the switchable lens device 300 according to the embodiment of the invention is the same as the refractive index ‘ne’ in the long axis direction of the liquid crystal molecules configuring the first lens layer 330. Namely, a refractive index of the UV curable resin configuring the second lens layer 340 is the same as the refractive index ‘ne’ in the long axis direction of the liquid crystal molecules of the first lens layer 330. The liquid crystal molecules of the first lens layer 330 have the high refractive index of about 1.75 in the long axis direction. The high refractive index UV curable resins, which have been currently developed, uses a solvent as a menstruum.
The method of manufacturing the switchable lens device 300 generally includes forming an uneven surface (concave surface or convex surface) on the first lens layer 330 or the second lens layer 340 using a mold. However, when the uneven surface is formed using the mold, a material forming the uneven surface must not include a solvent because the solvent may dissolve the mold. Thus, it was impossible to form a convex surface on the second lens layer 340 of the high refractive index using the mold in a related art.
On the other hand, the method of manufacturing the switchable lens device 300 according to the embodiment of the invention makes it possible to form the second lens layer 340 of the high refractive index using the mold.
As shown in
Subsequently, convex surfaces 40a are formed on the UV curable resin 11 using a first mold 20, and at the same time, ultraviolet ray is irradiated onto the UV curable resin 11 using a lamp 30 to cure the UV curable resin 11.
As shown in
As shown in
As shown in
As described above, a first lens layer 330 having a concave surface 330a may be formed on the second base film 70 by removing the first refractive index layer 40 and the first base film 10 in the base panel.
As shown in
As shown in
The method of manufacturing the switchable lens device 300 according to the embodiment of the invention may include forming an uneven surface using a UV curable resin of the low refractive index ‘no’ on the reactive mesogen in the form of pattern transfer and then applying a high refractive index UV curable resin including a solvent on the uneven surface, instead of forming the uneven surface using the UV curable resin of the high refractive index ‘ne’ using the mold.
Another method of manufacturing the switchable lens device 300 according to the embodiment of the invention is described below with reference to
As shown in.
As shown in
As shown in
The above-described method of manufacturing the switchable lens device according to the embodiment of the invention forms the uneven surface on the reactive mesogen and then applies the high refractive index UV curable resin including the solvent on the uneven surface, instead of forming the uneven surface using the UV curable resin of the high refractive index ‘ne’ using the mold. Hence, the switchable lens device may be manufactured.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0081381 | Jul 2012 | KR | national |
| 10-2013-0080405 | Jul 2013 | KR | national |
