Optical unit and display device having the same

A display device includes: a display unit, displaying an image; and an optical unit including a first substrate on the display unit, a first electrode on the first substrate, a liquid crystal layer on the first electrode and configured to be responsive to a vertical electric field or a horizontal electric field, a second electrode on the liquid crystal layer, an insulation layer on the second electrode, a third electrode on the insulation layer, and a second substrate on the third electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0109159 filed in the Korean Intellectual Property Office on Nov. 4, 2010, the entire contents of which are incorporated herein by reference.

BACKGROUND

Embodiments relate to an optical unit. More particularly, embodiments relate to an optical unit recognizing images displayed through a display unit into 3D images as a stereoscopic image, and a display device including the same.

2. Description of the Related Art

Recently, a 3D display has been applied to various fields, i.e., medicine, games, advertisements, education, military, etc. A holographic or stereoscopic scheme has been studied as a scheme to display 3D images.

The stereoscopy scheme separates two 2D images having binocular disparity into left and right eyes of a user, respectively. Thus, a person may recognize 3D images. In the stereoscopy scheme, there is a spectacles scheme using polarization and shutters as a unit to see images separated for both eyes and a non-spectacles scheme forming a visual field by directly dividing images from a display.

The information in the Background is only for enhancing an understanding of the described technology. Thus, it may contain information that does not form the prior art already known to a person of ordinary skill in the art in this country.

SUMMARY

An exemplary embodiment may be directed to an optical unit and a display device including the same capable of selecting a spectacles scheme and a non-spectacles scheme.

A first embodiment may provide a display device including: a display unit, displaying an image; and an optical unit including a first substrate on the display unit, a first electrode on the first substrate, a liquid crystal layer on the first electrode and configured to be responsive to a vertical electric field or a horizontal electric field, a second electrode on the liquid crystal layer, an insulation layer on the second electrode, a third electrode on the insulation layer, and a second substrate on the third electrode.

The first electrode may include: a plurality of first sub-electrodes separated from each other and extending in a first direction; a first connection electrode connecting ends of the plurality of first sub-electrodes; a plurality of the second sub-electrodes between neighboring first sub-electrodes of the plurality of first sub-electrodes, the second sub-electrodes separated from each other and extending in the first direction; and a second connection electrode separated from the first connection electrode via a second sub-electrode of the plurality of second sub-electrodes, the second sub-electrode interposed between the second connection electrode and the first connection electrode, and connecting ends of the plurality of second sub-electrodes.

The third electrode may have a plate shape.

The liquid crystal layer may be configured to be responsive to the vertical electric field.

The third electrode may be applied with a first voltage, and a first sub-electrode of the plurality of first sub-electrodes may be applied with a second voltage greater than the first voltage.

The second electrode and the second sub-electrode of the plurality of second sub-electrodes may be applied with the first voltage.

The liquid crystal layer may include a liquid crystal, the liquid crystal corresponds to the neighboring first sub-electrodes and has a lens shape, and the display unit may display a left-eye image and a right-eye image as an image between the neighboring first sub-electrodes.

The liquid crystal layer may be configured to be responsive to the horizontal electric field.

The optical unit may further include an alignment layer at least one of between first electrode and the liquid crystal layer and between the second electrode and the liquid crystal layer and rubbed in the second direction intersecting the first direction.

The second electrode may include a plurality of the third sub-electrodes separated from each other and extending in the second direction.

The plurality of third sub-electrodes may include a plurality of openings separated from and extending in the second direction.

A third voltage may be sequentially applied from one of the third sub-electrodes which third sub-electrode is adjacent to one end of the second substrate to another third sub-electrode of another end of the second substrate of the plurality of third sub-electrodes, and the third electrode may be applied with a fourth voltage.

The liquid crystal layer may include a liquid crystal, the liquid crystal corresponds to the third sub-electrode applied with the third voltage and may be arranged such that the long axis thereof may be aligned in a direction parallel to the first direction, and the display unit may display one image of a left-eye image and a right-eye image as an image corresponding to the third sub-electrode applied with the third voltage.

The second electrode may include: a plurality of the fourth sub-electrodes separated from each other and extending in the second direction; a third connection electrode connecting the ends of the plurality of fourth sub-electrodes; a plurality of fifth sub-electrodes between neighboring fourth sub-electrodes of the plurality of fourth sub-electrodes, the fifth sub-electrodes being separated from each other and extending in a second direction; and a fourth connection electrode separated from the third connection electrode via a fifth sub-electrode interposed therebetween and connecting ends of the plurality of fifth sub-electrodes.

A fourth sub-electrode of the plurality of fourth sub-electrodes and the fifth sub-electrode of the plurality of fifth sub-electrodes may be applied with a fifth voltage.

The liquid crystal layer may include a liquid crystal, the liquid crystal corresponds to the fourth sub-electrode and the fifth sub-electrode applied with the fifth voltage, the liquid crystal may be arranged such that a long axis thereof may be arranged in a direction parallel to the first direction, and the display unit may display one image of a left-eye image and a right-eye image as an image.

Polarizing spectacles facing the optical unit and including a left eye polarizing plate having one optical axis among a first optical axis parallel to the first direction and a second optical axis parallel to the second direction and a right eye polarizing plate having the other optical axis among the first optical axis and the second optical axis may be further included.

The optical unit may further include a first retarder on the second substrate, and the polarizing spectacles may further include a second retarder on the left eye polarizing plate and the right eye polarizing plate and facing the first retarder.

The first retarder and the second retarder may be ¼ wavelength plates.

A second embodiment may provide an optical unit facing a display unit and including: a first substrate on the display unit; a first electrode on the first substrate; a liquid crystal layer on the first electrode and configured to be responsive to a vertical electric field or a horizontal electric field; a second electrode on the liquid crystal layer; an insulation layer on the second electrode; a third electrode on the insulation layer; and a second substrate on the third electrode.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

In addition, parts not related to the description are omitted for clear description, and like reference numerals designate like elements and similar constituent elements throughout the specification.

Further, constituent elements having the same configurations in the exemplary embodiments are described in a first exemplary embodiment using like reference numerals, and only configurations different from those in the first exemplary embodiment will be described in the other exemplary embodiments.

Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, present embodiments are not limited to the illustrated sizes and thicknesses.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for convenience of description. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present.

In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Further, in the specification, “on” implies being positioned above or below a target element and does not imply being necessarily positioned on the top on the basis of a gravity direction.

A display device1000according to the first exemplary embodiment will be described with reference toFIG. 1toFIG. 7.

FIG. 1is a perspective view of a display device according to the first exemplary embodiment. For better understanding and ease of description,FIG. 1shows the second substrate of an optical unit that is rotated 180 degrees according to an induced line for the inside of the second substrate of the optical unit to be displayed.

As shown inFIG. 1, a display device1000according to the first exemplary embodiment selectively display one image of a 3D image of a non-spectacles scheme, and a 3D image and a 2D image of a spectacles scheme, and includes a display unit100, an optical unit200, and polarizing spectacles300. Here, the polarizing spectacles300are used when the display device1000displays the 3D image of the spectacles scheme, and is not used when the display device1000displays the 3D image of the non-spectacles scheme.

The display unit100displays the image, and may be an organic light emitting diode (OLED) display, a liquid crystal display (LCD), or a plasma display panel (PDP).

The display unit100displays a left-eye image and a right-eye image in order to allow a user to recognize the 3D image, or selectively displays a both-eye image in order to allow the user to recognize the 2D image.

When the display unit100is a liquid crystal display (LCD), the display unit100includes a display panel including both substrates and liquid crystals positioned between the substrates, and a backlight unit irradiating light to the display panel. Both substrates may include a substrate body made of glass, plastic, or metal, and a metal pattern formed on the substrate body and used as an electrode and a color filter. A longitudinal or transverse electric field is formed in space between the substrates, such that a liquid crystal layer serves as a shutter in accordance with a longitudinal or transverse electric field. Therefore, the display unit100selectively displays the 2D image or the 3D image. When the display unit100is an organic light emitting diode display, the display unit100includes both substrates and an organic light emitting diode positioned between the substrates. The organic light emitting diode is a self-light emitting diode, and an organic emission layer included in the organic light emitting diode emits light to selectively display the 2D image or the 3D image. When the display unit100is a plasma display panel (PDP), the display unit100includes both substrates forming a barrier rib and plasma positioned inside the substrates and the barrier rib. The plasma emits light for the display unit100to selectively display the 2D image or the 3D image.

FIG. 2is a cross-sectional view taken along the line II-II ofFIG. 1.

As shown inFIG. 1andFIG. 2, an optical unit200optically converts the image in order to allow a user to recognize the image displayed by the display unit100as the 3D image, and includes a first substrate210, a first electrode220, a first alignment layer230, a liquid crystal layer240, a second alignment layer250, a second electrode260, an insulation layer270, a third electrode280, and a second substrate290.

The first substrate210is formed as a transparent substrate made of glass or plastic, and may have flexibility. The first electrode220is positioned on the first substrate210.

The first electrode220includes a transparent conducting material such as indium tin oxide (ITO) or indium zinc oxide (IZO), is formed on the first substrate210, and includes a first sub-electrode221, a first connection electrode222, a second sub-electrode223, and a second connection electrode224.

A plurality of first sub-electrodes221extend in a first direction of an x-axis direction shown inFIG. 1, and are separated from each other. The plurality of first sub-electrodes221having a stripe shape extend in the first direction and are separated from each other.

The first connection electrode222connects ends of the plurality of the first sub-electrodes221, so if the first connection electrode222is applied with a voltage, the plurality of first sub-electrodes221connected to the first connection electrode222are also applied with the voltage.

The second sub-electrode223is disposed between neighboring first sub-electrodes221among the plurality of the first sub-electrodes221, and the plurality of second sub-electrodes223extend in the first direction and are separated from each other. Thus, a plurality of the second sub-electrodes223and a plurality of the first sub-electrodes221are alternately disposed.

The second connection electrode224is separated from the first connection electrode222via a plurality of the first sub-electrodes221and a plurality of the second sub-electrode223disposed therebetween, and connects the ends of a plurality of the second sub-electrodes223. If the second connection electrode224is applied with a voltage, a plurality of the second sub-electrodes223connected to the second connection electrode224are also applied with the voltage.

The first alignment layer230is formed on the first electrode220.

The first alignment layer230is formed on the first substrate210, is positioned between the first electrode220and the liquid crystal layer240, and covers the first electrode220. The first alignment layer230is rubbed in a y-axis direction shown inFIG. 1, as the second direction, intersecting the first direction for aligning a liquid crystal241included in the liquid crystal layer240. The first alignment layer230is in contact with the liquid crystal layer240, and the liquid crystal241included in the liquid crystal layer240is aligned by the first alignment layer230such that the long axis thereof is arranged parallel to the second direction in a state that the liquid crystal layer240is not applied with an electric field. The liquid crystal layer240is positioned on the first alignment layer230.

The liquid crystal layer240is positioned between the first electrode220and the second electrode260, and includes the liquid crystal241. A vertical electric field or a horizontal electric field is selectively formed to the liquid crystal layer240by the voltage that is selectively applied to the first electrode220, the second electrode260, and the third electrode280, and the liquid crystal241is tilted according to the vertical electric field or the horizontal electric field. Thus, the long axis of the liquid crystal241is rearranged. The display unit100displays at least one of the left-eye image and the right-eye image as the image. Thus, the display device1000displays the 3D image. When the electric field is not applied to the liquid crystal layer240, the display unit100displays a both-eye image as the image. Thus, the display device1000displays the 2D image. The state that the liquid crystal241is rearranged according to the vertical electric field or the horizontal electric field formed to the liquid crystal layer240and the display of the image for the display unit100according thereto will be described later. The second alignment layer250is positioned on the liquid crystal layer240.

The second alignment layer250is formed on the second substrate290, being disposed between the liquid crystal layer240and the second electrode260, and covers the second electrode260. The second alignment layer250is rubbed in the second direction as the y-axis direction shown inFIG. 1, intersecting the first direction for the alignment of the liquid crystal241included in the liquid crystal layer240. The second alignment layer250is in contact with the liquid crystal layer240, and the liquid crystal241, in the liquid crystal layer240, is aligned by the second alignment layer250in the state that the electric field is not applied to the liquid crystal layer240such that the long axis thereof is arranged parallel to the second direction. The second electrode260is positioned on the second alignment layer250.

The second electrode260includes the transparent conducting material, i.e., ITO or IZO, is formed on the second substrate290, and includes a third sub-electrode261.

A plurality of third sub-electrodes261extend in the second direction as the y-axis direction ofFIG. 1and are separated from each other. The plurality of third sub-electrodes261include a plurality of openings262, respectively, extending in the second direction with a stripe shape and separated from each other. The plurality of the third sub-electrodes261include a plurality of sub-electrodes, respectively, disposed between the neighboring openings262.

Each elongation direction of the first sub-electrode221included in the first electrode220and the third sub-electrode261of the second sub-electrode223and the second electrode260is mutually intersected.

The insulation layer270is formed on the second electrode260.

The insulation layer270is formed on the second electrode260and is disposed between the second electrode260and the third electrode280. The insulation layer270prevents shorting between the second electrode260and the third electrode280.

The third electrode280is formed on the insulation layer270with a plate shape, and is disposed between the insulation layer270and the second substrate290. The third electrode280includes the transparent conducting material, i.e., ITO or IZO.

The second substrate290may be a transparent substrate, i.e., glass or plastic, like the first substrate210, and may have flexibility.

As described above, the polarizing spectacles300may face the optical unit200. However, the polarizing spectacles300are only used when the display device1000displays the 3D image of the spectacles scheme.

The polarizing spectacles300face the optical unit200and include a left eye polarizing plate310, having a first optical axis parallel to the first direction as the x-axis ofFIG. 1, and a right eye polarizing plate320, having a second optical axis parallel to the second direction as the y-axis shown inFIG. 1. The left eye polarizing plate310of the polarizing spectacles300may have the second optical axis, and the right eye polarizing plate320may have the first optical axis.

The display device1000according to the first exemplary embodiment displays the 3D image of the non-spectacles scheme, and the 3D image and the 2D image of the spectacles scheme. A display of the 3D image of the non-spectacles scheme through the display device1000according to the first exemplary embodiment will be described with reference toFIG. 3andFIG. 4. The polarizing spectacles300are not used when the display device1000displays the 3D image of the non-spectacles scheme.

When the display device1000according to the first exemplary embodiment displays the 3D image of the non-spectacles scheme, the control of the optical unit200will be described.

FIG. 3is an enlarged view of a portion A ofFIG. 2, where a vertical electric field is formed at a liquid crystal layer.

As shown inFIG. 3, a vertical electric field is formed to the liquid crystal layer240by different voltages that are respectively applied to the first electrode220and the third electrode280, and the liquid crystal241is arranged with a lens shape by the vertical electric field. If the third electrode280of the plate shape is applied with the first voltage V1, the first sub-electrode221of the first electrode220is applied with the second voltage V2, larger than the first voltage V1. The second sub-electrode223and the second electrode260are not applied with the voltage and are floated. Thus, the vertical electric field of the lens shape is formed to the liquid crystal layer240by the different voltages that are applied to the third electrode280and the first sub-electrode221of the first electrode220, and the liquid crystal241is rearranged according to the vertical electric field of the lens shape such that the long axis thereof is tilted like the lens shape shown inFIG. 3.

In the state that the first sub-electrode221of the first electrode220is applied with the second voltage V2, the third electrode280is applied with the first voltage V1and the second electrode260and the second sub-electrode223of the first electrode220are applied with the first voltage V1, so the vertical electric field of the lens shape may be formed to the liquid crystal layer240, the liquid crystal241may be arranged with the lens shape by the vertical electric field.

In the state that the third electrode280is applied with the first voltage V1, the first sub-electrode221of the first electrode220is applied with the second voltage V2and the second electrode260and the second sub-electrode223of the first electrode220are selectively applied with the first voltage V1, the vertical electric field formed to the liquid crystal layer240may be minutely controlled. As a result, the lens shape in which the liquid crystal241included in the liquid crystal layer240is arranged may be minutely controlled.

A display operation of a display unit100, when the liquid crystal241of the liquid crystal layer240is arranged with the lens shape, will be described.

FIG. 4is a view to explain recognition of a 3D image through a non-spectacles scheme in a display device, according to the first exemplary embodiment.

As shown inFIG. 4, when the liquid crystal241of the liquid crystal layer240of the optical unit200is arranged with the lens shape between the neighboring first sub-electrodes221, the display unit100displays the left-eye image L and the right-eye image R as the image between the neighboring first sub-electrodes221. The optical unit200serves as a viewing zone separation unit that separates a left-eye image L and a right-eye image R that are displayed by the display unit100to be recognized in a left eye and a right eye, respectively.

The liquid crystal241is arranged with the lens shape between the neighboring first sub-electrodes221by the vertical electric field formed at the liquid crystal layer240such that a plurality of lens are formed in the liquid crystal layer240. When the left-eye image L and the right-eye image R are displayed in the display unit100at positions corresponding to each of the plurality of lenses of the liquid crystal layer240, the left-eye image L is refracted through the liquid crystal layer240to be recognized by a user's left eye and the right-eye image R is refracted through the liquid crystal layer240to be recognized by a user's right eye. Thus, a user recognizes an image from the display1000as the 3D image by binocular disparity.

When the display unit100displays the both-eye image in the state that the electric field is formed at the liquid crystal layer240of the optical unit200, the both-eye image displayed from the display unit100is recognized by both the user's eyes through the lens unit200. This allows the user to recognize the 2D image from the display1000.

The display device1000according to the first exemplary embodiment forms the vertical electric field to the liquid crystal layer240of the optical unit200to form a plurality of lens to the liquid crystal layer240such that a refractive degree of an image recognized by the user through the optical unit200from the display unit100can be controlled. Thus, the 3D image may be recognized to the user. The display device1000according to the first exemplary embodiment displays the 3D image of the non-spectacles scheme.

Display of the 3D image of the spectacles scheme through the display device1000according to the first exemplary embodiment will be described with reference toFIG. 5toFIG. 7. When the display device1000displays the 3D image of the spectacles scheme, the polarizing spectacles300are used.

When the display device1000according to the first exemplary embodiment displays the 3D image of the spectacles scheme, the control of the optical unit200will be described.

FIG. 5is a cross-sectional view taken along the line V-V ofFIG. 1where a horizontal electric field is formed at the liquid crystal layer.FIG. 6is a top view of the liquid crystal layer shown inFIG. 5.

As shown inFIG. 5andFIG. 6, the horizontal electric field is formed at the liquid crystal layer240by the same or different voltages respectively applied to the second electrode260and the third electrode280such that the long axis of the liquid crystal241is arranged in the direction parallel to the first direction as the x-axis by the horizontal electric field. If a third voltage V3is sequentially applied from the third sub-electrode261adjacent to one end of the second substrate290among a plurality of the third sub-electrodes261to the third sub-electrode261adjacent to the other end of the second substrate, and the third electrode280is applied with a fourth voltage V4that is the same as the third voltage V3or not, the long axis of the first liquid crystal241corresponding to the third sub-electrode261to which the third voltage V3is not applied is arranged parallel to the second direction as the y-axis that is the rubbing direction of the first alignment layer230and the second alignment layer250. However, the long axis of the second liquid crystal241corresponding to the third sub-electrode261to which the third voltage V3is applied is tilted according to the horizontal electric field, and the long axis of the second liquid crystal241is arranged in the direction parallel to the x-axis as the first direction. When a plurality of the third sub-electrodes261are sequentially applied with the third voltage V3, the long axis of the liquid crystal241corresponding to the third sub-electrode261applied with the third voltage V3is arranged from the state parallel to the second direction into the state parallel to the first direction by the horizontal electric field.

The display state of the display unit100will be described when the long axis of the liquid crystal241of the liquid crystal layer240is sequentially arranged from the state parallel to the second direction into the state parallel to the first direction.

FIG. 7is a view to explain recognition of a 3D image through a spectacles scheme in a display device according to the first exemplary embodiment.

As shown inFIG. 7, when the long axis of the liquid crystal241of the liquid crystal layer240of the optical unit200is sequentially arranged corresponding to the third sub-electrode261applied with the third voltage V3from the state parallel to the second direction into the state parallel to the first direction, the display unit100displays the left-eye image L as the image corresponding to the third sub-electrode261applied with the third voltage V3, and the right-eye image R as the image corresponding to the third sub-electrode261that is not applied with the third voltage V3among the left-eye image L and the right-eye image R. The left-eye image L emitted from the display unit100is linearly polarized into an image having the optical axis parallel to the first direction while passing through the liquid crystal layer240corresponding to the region where the horizontal electric field is formed, and the right-eye image R emitted from the display unit100is linearly polarized into an image having the optical axis parallel to the second direction while passing through the liquid crystal layer240corresponding to the region where the horizontal electric field is not formed.

The user wearing the polarizing spectacles300recognizes the left-eye image L passing through the optical unit200and having the optical axis parallel to the first direction to the left eye through the left eye polarizing plate310having the first optical axis parallel to the first direction, and simultaneously recognizes the right-eye image R passing through the optical unit200and having the optical axis parallel to the second direction to the right eye through the right eye polarizing plate320having the second optical axis parallel to the second direction. Thus, the user recognizes the 3D image from the display device1000. The optical unit200functions as a polarization switch unit, changing each optical axis of the left-eye image L and the right-eye image R that are displayed by the display unit100, to be different from each other.

As an example, in the case in which the 3D image having a scan velocity of 60 Hz is displayed, when the left-eye image L or the right-eye image R is displayed at the display unit100with a scan velocity of 120 Hz and the optical unit200is synchronized thereto, the user recognizes the image having the 60 Hz scan velocity. The 60 Hz scan velocity may prevent the overall resolution from being deteriorated.

In the display device1000according to the first exemplary embodiment, the horizontal electric field is formed as the liquid crystal layer240of the optical unit200such that the original direction of the long axis of the liquid crystal241is arranged into the different direction. Thus, the optical axis of the image that is emitted from the display unit100and is recognized to the user through the optical unit200is controlled, and as a result the 3D image is may be recognized by the user through the polarizing spectacles300. The display device1000according to the first exemplary embodiment displays the 3D image of the spectacles scheme.

As described above, the display device1000according to the first exemplary embodiment selectively applies the voltage to the first electrode220, the second electrode260, and the third electrode280to form the vertical electric field or the horizontal electric field to the liquid crystal layer240for forming the different arrangement of the liquid crystal241. Thus, one display device1000selectively displays the 3D image of the spectacles scheme and the 3D image of the non-spectacles scheme. The display device1000, capable of selecting the spectacles scheme or the non-spectacles scheme for the user, may be provided.

A display device1002according to the second exemplary embodiment will be described with reference toFIG. 8toFIG. 10.

FIG. 8is a cross-sectional view of a display device according to the second exemplary embodiment.

As shown inFIG. 8, an optical unit200optically converts the image in order to allow a user to recognize the image displayed by the display unit100as the 3D image, and includes a first substrate210, a first electrode220, a first alignment layer230, a liquid crystal layer240, a second alignment layer250, a second electrode260, an insulation layer270, a third electrode280, a second substrate290, and a first retarder295.

The first retarder295is positioned on the second substrate290and is a ¼ wavelength plate. The optical axis of the first retarder295is tilted by 45 degrees or 135 degrees compared with the first direction as the x-axis, and the left-eye image L and the right-eye image R that are emitted from the display unit100and are linearly polarized while passing through the liquid crystal layer240formed with the horizontal electric field are circularly polarized while passing through the first retarder295. The image emitted from the display unit100and sequentially passing through the liquid crystal layer240and the first retarder295is circularly polarized. The image emitted from the display unit100and passing through the optical unit200has a circularly polarized optical axis.

The polarizing spectacles300further includes a second retarder330positioned on the left eye polarizing plate310and the right eye polarizing plate320and facing the first retarder295.

The second retarder330is a ¼ wavelength plate, similar to the first retarder295. The optical axis of the second retarder330is tilted by 45 degrees or 135 degrees compared with the left eye polarizing plate310and the right eye polarizing plate320, and the image that is emitted from the display unit100and has a circularly polarized optical axis while passing through the optical unit200is linearly polarized while passing through the second retarder330. The image emitted from the display unit100and having the circularly polarized optical axis through the optical unit200is again linearly polarized while passing through the second retarder330, and the linearly polarized image is recognized by the left eye and the right eye of the user through the left eye polarizing plate310and the right eye polarizing plate320.

A path of an image from the display unit100to the polarizing spectacles300will be described with reference toFIG. 9.

FIG. 9is a view showing a path through which an image emitted from a display unit is incident to polarizing spectacles in a display device, according to the second exemplary embodiment.

As shown inFIG. 9, the image IM emitted from the display unit100is linearly polarized while passing through the liquid crystal layer240formed with the horizontal electric field to have the optical axis parallel to the first direction or the second direction. The linearly polarized image IM is left-circularly polarized or right-circularly polarized, while again passing through the first retarder295as the ¼ wavelength plate.

The image IM that is left-circularly polarized or right-circularly polarized is linearly polarized to have the optical axis parallel to the first direction or the second direction while again passing through the second retarder330of the polarizing spectacles300. The linearly polarized image IM is transmitted to the left eye polarizing plate310or the right eye polarizing plate320, thereby being recognized by the left eye or the right eye of the user.

The linearly polarized image that is transmitted from the display unit100to the liquid crystal layer240is circularly polarized and is circularly polarized while passing through the first retarder295and the second retarder330. The linearly polarized image is transmitted to the left eye polarizing plate310or the right eye polarizing plate320and is recognized by the left eye or the right eye of the user.

An effect of a display device1002according to the second exemplary embodiment will be described with reference toFIG. 10.

FIG. 10is a view to explain an effect of a display device according to the second exemplary embodiment.

As shown inFIG. 10(a) and (b), in the display device1002according to the second exemplary embodiment, although the polarizing spectacles300face the front side of the display unit100and optical unit200and the polarizing spectacles300are tilted with respect to the display unit100and the optical unit200, the image emitted from the display unit100and passing though the optical unit200is circularly polarized, and the circularly polarized image is incident to the polarizing spectacles300in the circularly polarized state such that a difference is not generated between the optical axis of the image emitted from the display unit100and passing through the optical unit200and the optical axis of the left eye polarizing plate310and the right eye polarizing plate320of the polarizing spectacles300. The linearly polarized image emitted from the display unit100and passing through the optical unit200is circularly polarized while passing through the first retarder295and then is incident to the polarizing spectacles300, and the image that is circularly polarized and incident to the polarizing spectacles300is again linearly polarized while passing through the second retarder330and is recognized by the left eye or the right eye of the user through the left eye polarizing plate310or the right eye polarizing plate320, such that the luminance of the image emitted from the display unit100and passing through the optical unit200is not deteriorated until the image passes through the polarizing spectacles300.

As described above, in the display device1002according to the second exemplary embodiment, although the polarizing spectacles300are inclined for the display unit100and the optical unit200, when the image emitted from the display unit100and passing through the optical unit200is incident to the polarizing spectacles300, the luminance is not deteriorated.

A display device1003according to the third exemplary embodiment will be described with reference toFIG. 11andFIG. 12.

FIG. 11is a perspective view of a display device according to the third exemplary embodiment. For better understanding and ease of description, the second substrate of the optical unit is rotated by 180 degrees according to an induced line inFIG. 11for the inside of the second substrate of the optical unit to be shown.FIG. 12is a cross-sectional view taken along the line XII-XII ofFIG. 11.

As shown inFIG. 11andFIG. 12, an optical unit200of the display device1003according to the third exemplary embodiment optically converts the image in order to allow a user to recognize the image displayed by the display unit100as the 3D image, and includes a first substrate210, a first electrode220, a first alignment layer230, a liquid crystal layer240, a second alignment layer250, a second electrode260, an insulation layer270, a third electrode280, and a second substrate290.

The second electrode260includes the transparent conducting material, i.e., ITO or IZO, is formed on the second substrate290, and includes a fourth sub-electrode266, a third connection electrode267, a fifth sub-electrode268, and a fourth connection electrode269.

A plurality of the fourth sub-electrodes266extend in the second direction as the y-axis direction and are separated from each other. The plurality of fourth sub-electrodes266are separated from each other in the stripe state and extend in the second direction.

The third connection electrode267connects the ends of the plurality of fourth sub-electrodes266. If the third connection electrode267is applied with the voltage, the plurality of fourth sub-electrodes266connected to the third connection electrode267are applied with the voltage.

The fifth sub-electrode268is positioned between the neighboring fourth sub-electrodes266among the plurality of fourth sub-electrodes266and the plurality of fifth sub-electrode268are separated from each other and extend in the second direction. Thus, the plurality of fifth sub-electrodes268and the plurality of fourth sub-electrodes266are alternately disposed.

The fourth connection electrodes269are separated from the third connection electrode267via the plurality of fourth sub-electrode266and the plurality of fifth sub-electrodes268disposed therebetween, and connect the ends of the plurality of the fifth sub-electrodes268. If the fourth connection electrode269is applied with the voltage, the plurality of fifth sub-electrodes268connected to the fourth connection electrode269are applied with the voltage.

A display operation for the 3D image of the spectacles scheme of a display unit10003according to the third exemplary embodiment will be described.

When the display device1003according to the third exemplary embodiment displays the 3D image of the spectacles scheme, the control of the optical unit200will be described.

The horizontal electric field is formed by the voltage applied to the second electrode260in the liquid crystal layer240, and the long axis of the liquid crystal241is arranged in the direction parallel to the first direction as the x-axis by the horizontal electric field. If a plurality of the fourth sub-electrodes266and a plurality of the fifth sub-electrodes268are equally applied the fifth voltage, or a plurality of the fourth sub-electrodes266are applied with the fifth voltage and a plurality of the fifth sub-electrodes268are applied with the sixth voltage different from the fifth voltage such that the horizontal electric field is formed in the liquid crystal layer240, the long axis of the liquid crystal241of the liquid crystal layer240is tilted according to the horizontal electric field such that the long axis of the liquid crystal241is arranged in the direction parallel to the first direction as the x-axis. When the second electrode260is applied with the voltage, the long axis of the liquid crystal241of the liquid crystal layer240is arranged from the state parallel to the second direction by the horizontal electric field into the state parallel to the first direction. The display unit100displays the left-eye image L among the left-eye image L and the right-eye image R. When the second electrode260is not applied with the voltage such that the long axis of the liquid crystal241of the liquid crystal layer240is parallel to the second direction, the display unit100displays the right-eye image R among the left-eye image L and the right-eye image R.

When the second electrode260is applied with the voltage such that the horizontal electric field is formed in the liquid crystal layer240, the left-eye image L emitted from the display unit100is linearly polarized into the image having the optical axis parallel to the first direction while passing through the liquid crystal layer240. When the voltage is applied to the second electrode260such that the horizontal electric field is not formed at the liquid crystal layer240, the right-eye image R emitted from the display unit100is linearly polarized into the image having the optical axis having the second direction while passing through the liquid crystal layer240.

The user wearing the polarizing spectacles300recognizes the left-eye image L passing through the optical unit200and having the optical axis parallel to the first direction to the left eye through the left eye polarizing plate310having the first optical axis parallel to the first direction, and simultaneously recognizes the right-eye image R passing through the optical unit200and having the optical axis parallel to the second direction to the right eye through the right eye polarizing plate320having the second optical axis parallel to the second direction. Thus, the user recognizes the 3D image from the display device1000. The optical unit200functions as a polarization switch unit changing each optical axis of the left-eye image L and the right-eye image R that are displayed by the display unit100to be different from each other.

The display device1003according to the third exemplary embodiment selectively applies the voltage to the first electrode220, the second electrode260, and the third electrode280to form the vertical electric field or the horizontal electric field to the liquid crystal layer240for forming the different arrangement of the liquid crystal241. Thus, one display device1003selectively displays the 3D image of the spectacles scheme and the 3D image of the non-spectacles scheme. The display device1003is capable of selecting the spectacles scheme or the non-spectacles scheme for the user.

By way of summation and review, a spectacles scheme alone suffers from the disadvantage that wearing spectacles is inconvenient. And yet, the non-spectacles scheme alone, which directly divides the images from the display, may result in inferior resolution, and the viewing angle may be narrow.

According to present embodiments, an optical unit capable of selecting the spectacles scheme and the non-spectacles scheme and a display device including the same are provided.

Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation.