Display device with switchable viewing angle

Abstract

Disclosed is a display device with a switchable viewing angle. According to an exemplary embodiment of the present disclosure, the display device having a switchable viewing angle includes: a first polarizer that transmits P-wave or S-wave light; a viewing angle control layer disposed above the first polarizer and including a lower electrode and an upper electrode, and a liquid crystal layer disposed between the lower electrode and the upper electrode to selectively change light of the P-wave or the S-wave to the S-wave or the P-wave; and a second polarizer disposed over the viewing angle control layer and having a transmission axis perpendicular to the transmission axis of the first polarizer. Accordingly, a mode may be switched to a privacy mode and a sharing mode, and in the sharing mode, brightness may be improved without increasing power consumption.

Description

Technical Field

[0001] The present disclosure relates to a display device, and in particular, for example but not limited to, to a display device with a switchable viewing angle. Background Art

[0002] Typically, display devices are widely used as display screens for various products, such as televisions, laptop computers, monitors, and bank automated teller machines (ATMs), as well as portable electronic devices (e.g., mobile communication terminals, wearable devices, electronic notebooks, electronic books, portable multimedia players (PMPs), navigation devices, automotive equipment (e.g., windshields), ultra mobile PCs (UMPCs), mobile phones, smart phones, and tablet PCs).

[0003] Viewing angle characteristics are very important for display devices.

[0004] Even within a wide viewing angle range, a display device should produce clear and undistorted image quality. Therefore, wide viewing angle technology has been continuously developed.

[0005] However, if you want the information displayed by the display device to be invisible to other people nearby, then in addition to the wide-angle mode (normal mode), when handling confidential documents or performing tasks requiring security, you also need a narrow viewing angle mode (privacy mode) that allows the image on the screen to be seen only by the person sitting in front of the screen.

[0006] The description provided in the description of the background technology section should not be assumed to be prior art simply because it is mentioned in the description of the background technology section or is associated with the description of the background technology section. The description of the background technology section may include information describing one or more aspects of the subject technology, and the description in this part does not limit the present invention. Summary of the invention

[0007] The inventors have recognized the requirements and limitations of different viewing angle modes of a display device. Therefore, one object to be achieved by the present disclosure is to provide a display device with a switchable viewing angle capable of switching between a privacy mode and a normal mode (or a sharing mode), specifically, in the sharing mode, the brightness is improved without increasing power consumption.

[0008] Another object to be achieved by the present disclosure is to provide a display device with switchable viewing angles in which the switching speed between a privacy mode and a sharing mode is improved.

[0009] Another object to be achieved by the present disclosure is to provide a display device with switchable viewing angles with improved efficiency and fairness.

[0010] The objects of the present disclosure are not limited to the above objects, and other objects not mentioned above can be clearly understood by those skilled in the art from the following description.

[0011] According to one aspect of the present disclosure, a display device with a switchable viewing angle includes: a first polarizer that transmits P-wave or S-wave light; a viewing angle control panel that is arranged above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer, which is arranged between the lower electrode and the upper electrode to selectively change the P-wave or S-wave light into S-wave or P-wave; and a second polarizer that is arranged above the viewing angle control panel and has a transmission axis perpendicular to the transmission axis of the first polarizer.

[0012] According to another aspect of the present disclosure, a display device with a switchable viewing angle includes: a first polarizer that transmits P-wave or S-wave light; a viewing angle control panel that is arranged above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer, which is arranged between the lower electrode and the upper electrode to selectively change the P-wave or S-wave light into an S-wave or P-wave; a third polarizer that is arranged above the viewing angle control panel and has a transmission axis perpendicular to the transmission axis of the first polarizer; a first substrate that is arranged above the third polarizer; a second substrate that is opposite to the first substrate; another liquid crystal layer that is arranged between the first substrate and the second substrate; and a fourth polarizer that is arranged on the outside of the second substrate and has a transmission axis perpendicular to the transmission axis of the third polarizer.

[0013] Additional details of example implementations are included in the detailed description and the accompanying drawings.

[0014] The present disclosure may provide a display device with a switchable viewing angle, in which a polarization state and a light path of a light source are controlled to switch a privacy mode and a sharing mode, and brightness is increased in the sharing mode without increasing power consumption.

[0015] The present disclosure provides a display device with switchable viewing angles, in which twisted nematic (TN) liquid crystals with a fast response speed are used to control an optical path to increase a switching speed between a privacy mode and a sharing mode.

[0016] The present disclosure provides a display device with a switchable viewing angle, in which light is concentrated using a pixel lens, and glass is used as a base substrate to improve efficiency and fairness.

[0017] The effects according to the present disclosure are not limited to the above-exemplified contents, but more various effects are included in this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 is a schematic diagram schematically illustrating a display device with a switchable viewing angle according to various exemplary embodiments of the present disclosure;

[0020] Figure 2 is a view showing a display device with a switchable viewing angle according to various exemplary embodiments of the present disclosure;

[0021] Figure 3A and Figure 3B is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a first exemplary embodiment of the present disclosure;

[0022] Figure 4A and Figure 4B is a plan view showing a portion of a display device with a switchable viewing angle according to a first exemplary embodiment of the present disclosure;

[0023] Figure 5 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure;

[0024] Fig. 6A is a view showing a sharing mode of a display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure;

[0025] Figure 6B is a view showing a privacy mode of a display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure;

[0026] Figure 7 is a simulation result showing, by way of example, the transmission characteristics of a display device without a viewing angle control panel;

[0027] Fig. 8A and Figure 8B is a simulation result showing the transmittance characteristics of a display device with a switchable viewing angle in a privacy mode and a sharing mode according to a comparative embodiment;

[0028] Fig.9A and Fig. 9B is a simulation result showing the transmittance characteristics of the display device with switchable viewing angle in the privacy mode and the sharing mode according to the second exemplary embodiment of the present disclosure;

[0029] Fig.10 is a graph showing, by way of example, how brightness varies according to viewing angle;

[0030] Fig.11 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a third exemplary embodiment of the present disclosure;

[0031] Fig.12 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a fourth exemplary embodiment of the present disclosure;

[0032] Fig.13 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a fifth exemplary embodiment of the present disclosure;

[0033] Fig.14 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a sixth exemplary embodiment of the present disclosure;

[0034] Fig.15 is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a seventh exemplary embodiment of the present disclosure; and

[0035] Fig.16 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to an eighth exemplary embodiment of the present disclosure.

[0036] Throughout the drawings and detailed description, unless otherwise described, the same drawing reference numerals should be understood to refer to the same elements, features, and structures. The relative sizes and depictions of these elements may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0037] By referring to the exemplary embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and the methods for achieving these advantages and features will become clear. However, the present disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. The exemplary embodiments are provided only by way of example so that those skilled in the art can fully understand the disclosure of the present disclosure and the scope of the present disclosure.

[0038] The shapes, sizes, areas, ratios, angles, quantities, etc. shown in the drawings for describing the exemplary embodiments of the present disclosure are only examples, and the present disclosure is not limited thereto. Throughout the specification, the same reference numerals generally represent the same elements. In addition, in the following description of the present disclosure, the detailed explanation of the known related art may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. Terms such as "comprising", "having", "including", "containing", "constituting", "made of", "formed of", "composed of" used in this article are generally intended to allow the addition of other components, unless these terms are used together with the term "only". Unless otherwise expressly stated, any reference to the singular may include the plural.

[0039] Even if not explicitly stated, components are interpreted as including ordinary margins of error.

[0040] When terms such as "on," "over," "above," "under," "beside," "under," "near," "near," "adjacent," "on the side of," and "close" are used to describe the positional relationship between two components, one or more components may be located between the two components unless these terms are used together with the terms "immediately" or "directly."

[0041] Spatially relative terms, such as "below," "below," "under," "lower," "above," "upper," etc., may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. It should be understood that, in addition to the orientation shown in the figures, spatially relative terms may also include different orientations of elements in use or operation. For example, if the elements in the figures are inverted, elements described as being "below" or "below" other elements or features will be oriented as being "above" other elements or features. Therefore, the exemplary term "below" may include orientations below and above. Similarly, the exemplary terms "above" or "above" may include orientations "above" and "below."

[0042] When describing a temporal relationship, terms such as "after", "subsequently", "next", "following", "before", etc. may include any situation where two events are not consecutive, unless terms such as "immediately", "directly" or "directly" are explicitly used.

[0043] When one element or layer is disposed “on” another element or layer, the other layer or element may be directly on the other element or layer or interposed between the one element or layer and the other element or layer.

[0044] Although the terms "first", "second", "A", "B", "a", and "b" etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Therefore, the first component to be mentioned below may be the second component in the technical concept of the present disclosure.

[0045] In addition, when describing the components of the present disclosure, terms such as first, second, A, B, (a), (b), etc. may be used herein. Each of these terms is not used to limit the nature, order or sequence of the corresponding component, but is only used to distinguish the corresponding component from other components. In the case of describing that a certain structural element or layer is "connected", "coupled", "bonded" or "joined" to another structural element or layer, it is generally interpreted that the other structural element or layer can be directly or indirectly "connected", "coupled", "bonded" or "joined" to the structural element or layer.

[0046] The term "at least one" should be understood to include any and all combinations of one or more associated listed items. For example, the meaning of "at least one of the first, second, and third items" means the combination of all items proposed from two or more of the first, second, and third items as well as the first, second, or third item.

[0047] The term "device" as used herein may refer to a display device including a display panel and a driver for driving the display panel. Examples of display devices may include liquid crystal display panels, etc. In addition, examples of devices may include laptop computers, televisions, computer monitors, automotive devices, wearable devices, and automotive equipment devices, as well as complete electronic devices (or devices) or complete sets of devices (or devices) including liquid crystal display panels, etc. as complete products or final products, for example, mobile electronic devices such as smart phones or electronic tablets, but embodiments of the present disclosure are not limited thereto.

[0048] Like reference numerals generally refer to like elements throughout the specification.

[0049] The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present disclosure is not limited to the size and thickness of the illustrated components.

[0050] The features of the various embodiments of the present disclosure may be partially or completely attached or combined with each other and may be technically interlocked and operated in various ways, and these embodiments may be implemented independently of or in association with each other.

[0051] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the example embodiments belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0052] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0053] Figure 1 is a schematic diagram schematically illustrating a display device with a switchable viewing angle according to various exemplary embodiments of the present disclosure.

[0054] Figure 2 are views illustrating a display device with a switchable viewing angle according to various exemplary embodiments of the present disclosure.

[0055] exist Figure 1In the embodiment, for the convenience of description, among the various components of the display device 100 with a switchable viewing angle, only the display panel 110, the gate driver GD, the data driver DD and the timing controller TC are shown, but the components of the display device 100 of the present disclosure are not limited thereto. In addition, all components of each display device according to all embodiments of the present disclosure are operably connected and configured.

[0056] Reference Figure 1 According to an exemplary embodiment of the present disclosure, a display device 100 with a switchable viewing angle may include: a display panel 110, a gate driver GD, a data driver DD and a timing controller TC, the display panel 110 includes a plurality of sub-pixels SP, and the gate driver GD and the data driver DD supply various signals to the display panel 110.

[0057] The gate driver GD may supply a plurality of scan signals to the plurality of scan lines SL according to a plurality of gate control signals supplied from the timing controller TC. Figure 1 10 is shown as one gate driver GD being arranged to be spaced apart from one side of the display panel 110, but the number of gate drivers GD and their arrangement are not limited thereto. For example, two gate drivers GD may be respectively arranged on both sides of the display panel 110 and spaced apart from the display panel 110. Alternatively, the gate driver GD may be mounted on the display panel 110. In this way, the structure in which the gate driver GD is directly mounted on the display panel 110 is referred to as a gate-in-panel (GIP) structure, but is not limited thereto.

[0058] The data driver DD may convert the image data input from the timing controller TC into a data voltage using a reference gamma voltage according to a plurality of data control signals supplied from the timing controller TC. The data driver DD may supply the converted data voltage to a plurality of data lines DL. The data driver DD may be configured with at least one data IC. In this case, as an example, the data IC of the data driver DD may be connected to the non-display area NA of the corresponding side of the display panel 110, or may be directly mounted on the non-display area NA. As an example, the data IC of the data driver DD may be mounted on a flexible circuit film and connected to the non-display area NA of the corresponding side of the display panel 110.

[0059] The timing controller TC aligns the image data input from the outside to supply the image data to the data driver DD. The timing controller TC can generate a gate control signal and a data control signal using a synchronization signal (e.g., a dot clock signal, a data enable signal, and a horizontal / vertical synchronization signal) input from the outside. Here, the horizontal synchronization signal is a signal indicating the time taken for one horizontal line of the display screen, and the vertical synchronization signal is a signal indicating the time taken for one frame of the display screen. The data enable signal may correspond to a signal indicating a period of supplying a data voltage to the pixel PX. The timing controller TC supplies the generated gate control signal and data control signal to the gate driver GD and the data driver DD, respectively, to control the gate driver GD and the data driver DD.

[0060] The display panel 110 is a configuration for displaying an image to a user, and may include a plurality of sub-pixels SP. In the display panel 110, a plurality of scan lines SL and a plurality of data lines DL intersect each other, and the plurality of sub-pixels SP may be connected to the scan lines SL and the data lines DL, respectively. In addition, each of the plurality of sub-pixels SP may be connected to a high potential power line, a low potential power line, or a reference line, but is not limited thereto.

[0061] In the display panel 110 , a display area AA and a non-display area NA disposed near, surrounding, or around the display area AA may be defined.

[0062] The display area AA is an area in the display panel 110 where an image is displayed. In the display area AA, a plurality of pixel areas may be arranged in a matrix form along a plurality of row lines and column lines. A plurality of pixel areas may include pixel areas that display different colors (e.g., red (R), green (G) and blue (B) or red (R), green (G), blue (B) and white). At this time, adjacent red (R), green (G) and blue (B) pixel areas or adjacent red (R), green (G), blue (B) and white pixel areas may be used as unit pixels for displaying color images.

[0063] In the display area AA, a plurality of sub-pixels SP constituting a plurality of pixels and a circuit for driving the plurality of sub-pixels SP may be provided. The plurality of sub-pixels SP are the minimum units constituting the display area AA, and n sub-pixels SP may form one pixel. Each of the plurality of sub-pixels SP may emit light having a wavelength different from each other. The plurality of sub-pixels may include a first sub-pixel, a second sub-pixel, and a third sub-pixel emitting light of different colors from each other. For example, the plurality of sub-pixels SP may include a red sub-pixel SPR as a first sub-pixel, a green sub-pixel SPG as a second sub-pixel, and a blue sub-pixel SPB as a third sub-pixel. In addition, the plurality of sub-pixels SP may further include a white sub-pixel.

[0064] For example, a plurality of sub-pixels SP may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, wherein the red sub-pixel, the green sub-pixel, and the blue sub-pixel may be arranged in a repeated manner. Alternatively, a plurality of sub-pixels SP may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel, wherein the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the white sub-pixel may be arranged in a repeated manner, or the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the white sub-pixel may be arranged in a quadrilateral type. For example, the red sub-pixel, the blue sub-pixel, and the green sub-pixel may be arranged sequentially along the row direction, or the red sub-pixel, the blue sub-pixel, the green sub-pixel, and the white sub-pixel may be arranged sequentially along the row direction. However, in an embodiment of the present disclosure, the color type, arrangement type, and arrangement order of the sub-pixel are not limited, and may be configured in various forms according to the luminous characteristics, device life, and device specifications.

[0065] In addition, the sub-pixels may have different light-emitting areas according to the light-emitting characteristics. For example, a sub-pixel emitting light of a color different from the color of the blue sub-pixel may have a light-emitting area different from the light-emitting area of ​​the blue sub-pixel. For example, a red sub-pixel, a blue sub-pixel, and a green sub-pixel, or a red sub-pixel, a blue sub-pixel, a white sub-pixel, and a green sub-pixel may each have a different light-emitting area.

[0066] As the display panel 110 used in the exemplary embodiment of the present disclosure, all types of display panels, for example, a liquid crystal display panel, an organic electroluminescent display panel, a quantum dot display panel, and an electroluminescent display panel may be used, but the present disclosure is not limited thereto.

[0067] In each of the plurality of sub-pixels SP, a light emitting diode and a thin film transistor for driving the light emitting diode may be provided. Depending on the type of the display panel 110, the plurality of light emitting diodes may be defined in different ways. For example, when the display panel 110 is an inorganic light emitting display panel 110, the light emitting diode may be a light emitting diode (LED) or a micro light emitting diode (micro LED), and when the display panel 110 is an organic light emitting display panel, the light emitting element may be an organic light emitting diode (OLED), and the embodiments of the present disclosure are not limited thereto.

[0068] In the display area AA, a plurality of wirings for transmitting various signals to the plurality of sub-pixels SP may be provided. For example, the plurality of wirings include a plurality of data lines DL for supplying a data voltage to each of the plurality of sub-pixels SP, a plurality of scan lines SL for supplying a scan signal to each of the plurality of sub-pixels SP, and the like. The plurality of scan lines SL extend in one direction in the display area AA to be connected to the plurality of sub-pixels SP, and the plurality of data lines DL extend in a direction different from the one direction in the display area AA to be connected to the plurality of sub-pixels SP. In addition, in the display area AA, a low potential power line, a high potential power line, and the like may also be provided, but are not limited thereto.

[0069] The non-display area NA is an area where no image is displayed. The non-display area NA may be defined as an area extending from the display area AA. In the non-display area NA, a link line for transmitting a signal to the sub-pixel SP of the display area AA, a pad electrode, a driver IC such as a gate driver IC or a data driver IC, etc. may be disposed.

[0070] However, the non-display area NA may be located on the rear surface of the display panel 110 (ie, a surface on which the sub-pixels SP are not disposed) or may be omitted, and is not limited to that shown in the drawings.

[0071] In addition, drivers such as a gate driver GD, a data driver DD, and a timing controller TC may be connected to the display panel 110 in various ways. For example, the gate driver GD may be installed in the non-display area NA in a gate-in-panel (GIP) manner. In addition, the data driver DD and the timing controller TC may be formed in a separate flexible film and a printed circuit board, but are not limited thereto, and for example, the data driver DD and the timing controller TC may also be formed together. The data driver DD and the timing controller TC may be electrically connected to the display panel 110 by bonding the flexible film and the printed circuit board to the pad electrode formed in the non-display area NA of the display panel 110.

[0072] In addition, refer to Figure 2 The display device 100 with switchable viewing angles of the present disclosure may mainly include a display panel 110 for displaying an image, a viewing angle control panel 120, and a backlight unit 130 disposed below the viewing angle control panel 120. The viewing angle control panel 120 is disposed above or below the display panel 110 to selectively control the viewing angle range of the image generated by the display panel 110.

[0073] Despite Figure 2 2 and 3 , the viewing angle control panel 120 is shown as being disposed below the display panel 110 , but it is not limited thereto, and the viewing angle control panel 120 may be disposed above the display panel 110 .

[0074] In addition, for example, when the display panel 110 is configured as a liquid crystal display panel, the display panel 110 may include a first substrate, a second substrate, and a liquid crystal layer interposed between the first substrate and the second substrate.

[0075] Although not shown, the first substrate as a TFT array substrate may include gate lines and data lines crossing to define pixel areas and thin film transistors formed at the crossings of the gate lines and the data lines.

[0076] In addition, for example, in a pixel region of the first substrate, a plurality of common electrodes and a plurality of pixel electrodes are alternately disposed to generate an image.

[0077] In addition, on the second substrate serving as a color filter substrate, a black matrix having openings corresponding to each pixel area is provided, and a color filter layer including a red filter, a green filter, and a blue filter may be provided, the red filter, the green filter, and the blue filter being sequentially and repeatedly provided to correspond to the openings.

[0078] An overcoat layer may be disposed over the black matrix and the color filter layer.

[0079] In addition, a lower polarizer and an upper polarizer that selectively transmit specific light may be attached to outer surfaces of the first substrate and the second substrate, respectively. For ease of description, the lower polarizer and the upper polarizer may be referred to as a third polarizer and a fourth polarizer.

[0080] At this time, the polarization axes of the third polarizer and the fourth polarizer may be orthogonal to each other.

[0081] In addition, the viewing angle control panel 120 can be arranged above or below the display panel 110. For example, the viewing angle control panel 120 of the present disclosure mainly includes a viewing angle control layer and polarizers arranged above and below the viewing angle control layer. The viewing angle control panel 120 can control the polarization state of light in each area according to whether a voltage is applied to an electrode provided in the viewing angle control layer, thereby selectively providing light suitable for a privacy mode or a sharing mode. In the privacy mode, the light of the image reproduced in the selected area on the screen can be gathered and displayed at a narrow viewing angle. In the sharing mode, the light of the image reproduced in the selected area on the screen can be gathered and displayed at a wide viewing angle.

[0082] In addition, the backlight unit 130 may be disposed under the viewing angle control panel 120. For example, the backlight unit 130 of the present disclosure may provide polarized light (eg, P wave or S wave), but is not limited thereto.

[0083] The backlight unit 130 includes a light source such as an incandescent lamp, a fluorescent lamp, or a light emitting diode LED, and light emitted from the light source is provided to the display panel 110 via the viewing angle control panel 120 to generate an image.

[0084] In the following, reference will be made to Figure 3A , Figure 3B , Figure 4A and Figure 4B The viewing angle control panel 120 and the backlight unit 130 are described in detail.

[0085] Figure 3A and Figure 3B is a cross-sectional view showing a portion of a display device with a switchable viewing angle according to a first exemplary embodiment of the present disclosure.

[0086] Figure 4A and Figure 4B is a plan view showing a portion of a display device with a switchable viewing angle according to a first exemplary embodiment of the present disclosure.

[0087] Figure 3A and Figure 3B The structures of the viewing angle control panel 120 and the backlight unit 130 according to the first exemplary embodiment of the present disclosure are shown.

[0088] For ease of description, Figure 3A and Figure 3B A portion of a display device with a switchable viewing angle is shown, in which the display panel is omitted, and the display panel may be disposed above or below the viewing angle control panel 120 or attached in an additional manner.

[0089] Figure 3A A display device with a switchable viewing angle is shown in which a voltage is not applied to a pair of electrodes 125a and 125b, and Figure 3B A display device with a switchable viewing angle is shown in which a voltage is applied to a pair of electrodes 125a and 125b.

[0090] Figure 3A and Figure 3B Shown is a change in the polarization state of light depending on whether a voltage is applied.

[0091] also, Figure 4A and Figure 4B An arrangement of a pair of electrodes 125a and 125b is shown.

[0092] Reference Figure 3A , Figure 3B , Figure 4A 4B , the backlight unit 130 may be disposed below the viewing angle control panel 120 .

[0093] The backlight unit 130 according to the first exemplary embodiment of the present disclosure applies a polarized light source to supply light polarized as, for example, a P wave or an S wave.

[0094] According to the related art, the non-polarized light emitted from the light source is primarily polarized using a lower polarizer, and the direction of the polarized light is controlled using a liquid crystal layer, and then the light is secondarily polarized using an upper polarizer to produce an image. As described above, according to the related art, light that is primarily polarized using a lower polarizer is used, so that most of the light (about 50%) emitted from the light source is blocked and lost by the lower polarizer. When the light passes through various films including polarizers and many layers, the light that produces the final image is even less than 10% of the total light.

[0095] In addition, a reflective polarizer DBEF film (VikuitiTM DBEF) has been developed and used to reduce light loss to reduce overall power consumption. In the light incident on the DBEF film, the reflective polarizer DBEF film (dual brightness enhancement film) allows polarized waves in one direction (e.g., P waves) to pass through and reflects polarized waves in another direction (e.g., S waves). In addition, the light reflected from the reflective polarizer DBEF is reflected again from the reflective film, and in the light reflected again, the DBEF film allows polarized waves in one direction to pass through and reflects polarized waves in another direction again. In other words, the reflective polarizer DBEF film increases the availability of light by using both reflection and polarization. However, when light is reflected, light loss is caused, so that the DBEF film has limitations in reducing light loss. In addition, the reflective polarizer DBEF film has the disadvantage of high manufacturing cost.

[0096] Therefore, the first exemplary embodiment of the present disclosure uses the backlight unit 130 to which the polarized light source is applied to reduce light loss and reduce the total power consumption of the display device with a switchable viewing angle. In addition, an image can be produced without using a lower polarizing film and / or a reflective polarizer DBEF film, thereby reducing costs.

[0097] For example, the backlight unit 130 may include a non-polarity LED as a light source. In addition, the backlight unit 130 may further include a diffusion plate and a brightness enhancement film (BEF) that mix light emitted from the light source, but is not limited thereto.

[0098] For example, the LEDs are arranged on a substrate such as a printed circuit board to form an array, and may include a red LED, a green LED, and a blue LED or a white LED. The LEDs are regularly arranged above the printed circuit board to form an LED module, and a plurality of LED modules may also be used to supply light to the viewing angle control panel 120. For example, a reflective film is located below the light emitting surface of the LED to reflect light emitted from the LED upward. In addition, the LED may be provided as a package in which a non-polar light emitting diode chip is mounted.

[0099] Light emitted from the LED and then polarized into a P wave or an S wave and passing through the diffusion plate and the BEF is incident on the viewing angle control panel 120. Figure 3A and Figure 3BIn FIG. 1 , it is shown as an example that light polarized as a P wave is incident on the viewing angle control panel 120 , but the present disclosure is not limited thereto. For example, light polarized as an S wave may be incident on the viewing angle control panel 120 .

[0100] Generally, a polarizer used for a liquid crystal display panel requires a polarization degree of 98% to 100% so that the transmittance does not exceed about 40% to 50%. However, in the present disclosure, for example, a polarizer having a polarization degree of 70% to 90% and a transmittance of 60% to 80% may be used as the first polarizer 122a of the viewing angle control panel 120, and the present disclosure is not limited thereto, for example, a polarizer having a polarization degree of 75% to 85% and a transmittance of 65% to 75% may be used as the first polarizer 122a of the viewing angle control panel 120.

[0101] Next, the viewing angle control panel 120 according to the first exemplary embodiment of the present disclosure may mainly include a viewing angle control layer 129 , and first and second polarizers 122 a and 122 b disposed below and above the viewing angle control layer 129 , respectively.

[0102] For example, the first polarizer 122a may have a transmission axis that matches the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the first polarizer 122a may have a transmission axis of 0° and an absorption axis of 90° or the first polarizer 122a may have a transmission axis of approximately 0° and an absorption axis of approximately 90°.

[0103] For example, the second polarizer 122b may have a transmission axis perpendicular to the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the second polarizer 122b may have a transmission axis of 90° and an absorption axis of 0° or the second polarizer 122b may have a transmission axis of approximately 90° and an absorption axis of approximately 0°. That is, the transmission axis of the second polarizer 122b may be perpendicular to the transmission axis of the first polarizer 122a.

[0104] For reference, the polarizer has a polarizing film having a polarization function, and the polarizing film can be formed by adsorbing iodine or a dichroic dye on a polyvinyl alcohol (PVA) layer stretched in a specific direction, however, the present disclosure is not limited thereto. At this time, the transmission axis can be formed to be orthogonal to the stretching direction.

[0105] For example, a first triacetyl cellulose (TAC) layer 121a and a second TAC layer 121b may be disposed on the outside of the first polarizer 122a and the second polarizer 122b, respectively. In addition, an adhesive layer may be disposed on the outside of the second TAC layer 121b. The adhesive layer may be a layer formed of an adhesive that bonds the viewing angle control panel 120 to the display panel. For example, the adhesive layer may include a pressure sensitive adhesive (PSA).

[0106] For example, the first phase retardation compensation film 123a of the ORT may be disposed between the first polarizer 122a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0107] For example, the first protective layer 124a may be disposed between the first phase delay compensation film 123a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. For example, the first protective layer 124a may be formed of a film having a water vapor transmission rate (WVTR) of 10 -3 Up to 10 -2 g / m 2 The first protective layer 124a may be formed of silicon nitride to protect the lower electrode 125a from moisture, but is not limited thereto. For example, the first protective layer 124a may be formed of silicon oxide.

[0108] For example, the second phase retardation compensation film 123b of the ORT may be disposed between the second polarizer 122b and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0109] For example, the second protective layer 124b may be disposed between the second phase delay compensation film 123b and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. -3 Up to 10 -2 g / m 2 The second protective layer 124b may be formed of silicon nitride to protect the upper electrode 125b from moisture, but is not limited thereto. For example, the second protective layer 124b may be formed of silicon oxide.

[0110] The viewing angle control layer 129 may include a lower electrode 125 a and an upper electrode 125 b , and a liquid crystal layer 126 disposed between the lower electrode 125 a and the upper electrode 125 b .

[0111] At this time, for example, the lower electrode 125a may be configured as the entire electrode on the display area AA. For example, the lower electrode 125a extends to the non-display area NA to overlap a portion of the non-display area NA.

[0112] In contrast, for example, the upper electrode 125 b may be configured as a plurality of strips in parallel in one direction over the display area AA. Figure 4A As an example, the upper electrode 125b is arranged parallel to the data line, and Figure 4B As an example, the upper electrode 125b is shown to be arranged parallel to the gate line, but it is not limited thereto. Here, the "parallel" direction may include not only the same direction, but also substantially the same direction (i.e., the same direction taking into account process errors). In addition, when the upper electrode 125b is as Figure 4AWhen the upper electrode 125b is arranged parallel to the data line as shown, a horizontal privacy mode can be achieved, and when the upper electrode 125b is arranged parallel to the data line as shown Figure 4B When arranged parallel to the gate line, a vertical privacy mode can be achieved.

[0113] In addition, for example, the upper electrodes 125 b may be configured as a plurality of strips parallel to each other at regular intervals.

[0114] The upper electrode 125b and the lower electrode 125a may be made of a transparent conductive material having excellent transmittance, such as at least one of indium tin oxide (ITO), indium zinc oxide (IZO), carbon nanotubes, metal nanowires, and poly(3,4-ethylenedioxythiophene) (PEDOT).

[0115] In addition, the liquid crystal layer 126 may be formed of twisted nematic (TN) liquid crystal having a fast response speed.

[0116] In twisted nematic liquid crystals, the molecules are arranged in a spiral shape, and the direction of the molecules rotates for each layer, so that an overall rotating spiral structure can be formed.

[0117] In addition, when voltage is applied to the twisted nematic liquid crystal, the rotation of the liquid crystal molecules changes, and the rotation of the molecules can be used to control the transmittance. For example, when no voltage is applied, the light rotates due to the helical structure and the propagation direction of the transmitted light can be rotated.

[0118] Therefore, if Figure 3A As shown, when no electric field is applied between the upper electrode 125 b and the lower electrode 125 a , the state of the liquid crystal layer 126 is the same in all regions of the viewing angle control layer 129 .

[0119] On the contrary, Figure 3B As shown, when an electric field is applied between the upper electrode 125b and the lower electrode 125a, the liquid crystal layer 126 is different between the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided. Figure 3B As shown, the lower electrode 125a is arranged on the entire surface of the liquid crystal layer 126, and the upper electrode 125b is arranged on some parts of the surface of the liquid crystal layer 126. When an electric field is applied between the upper electrode 125b and the lower electrode 125a, the liquid crystal layer 126 is different between the area where the upper electrode 125b is arranged and the area where the upper electrode 125b is not arranged.

[0120] First, for example, refer to Figure 3A , when no electric field is applied between the upper electrode 125 b and the lower electrode 125 a , the horizontally polarized backlight having a P wave is incident on the viewing angle control panel 120 .

[0121] In this case, the first polarizer 122a has a transmission axis matching the polarization direction of the backlight, so that the backlight of the P wave can pass through the first polarizer 122a without loss.

[0122] In addition, in this case, the state of the liquid crystal layer 126 can be the same in all regions of the viewing angle control layer 129. That is, when the liquid crystal molecules of the liquid crystal layer 126 are spirally rotated, the propagation direction of light passing through the first polarizer 122a is rotated to change the polarization direction of the light of the P wave to the S wave.

[0123] Furthermore, in this case, the light whose polarization direction is changed to the S wave can pass through the second polarizer 122 b having a transmission axis perpendicular to the polarization direction of the backlight without causing a loss.

[0124] Therefore, light of the S wave passes through the viewing angle control panel 120 in both the region where the upper electrode 125 b is disposed and the region where the upper electrode 125 b is not disposed to be provided to the display panel to implement the sharing mode.

[0125] Next, refer to Figure 3B , when an electric field is applied between the upper electrode 125 b and the lower electrode 125 a , the horizontally polarized backlight having the P wave is incident on the viewing angle control panel 120 as described above.

[0126] In this case, the first polarizer 122a has a transmission axis matching the polarization direction of the backlight, so that the backlight of the P wave can pass through the first polarizer 122a without loss.

[0127] In this case, the state of the liquid crystal layer 126 may be different between the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided. That is, when the spiral rotation state of the liquid crystal molecules of the liquid crystal layer 126 is maintained in the region where the upper electrode 125b is not provided, the propagation direction of the light passing through the first polarizer 122a is rotated to change the polarization direction of the light of the P wave to the S wave. On the contrary, in the region where the upper electrode 125b is provided, the liquid crystal molecules of the liquid crystal layer 126 are rearranged by the electric field so that the spiral shape is dispersed and the liquid crystal molecules are arranged in a row. In this way, the light of the P wave passes through the TN liquid crystal layer 126 without changing the polarization state.

[0128] Furthermore, in this case, the light of the P wave may not pass through the second polarizer 122 b having a transmission axis perpendicular to the polarization direction of the backlight.

[0129] Therefore, in the region where the upper electrode 125b is not provided, the S wave light passes through the viewing angle control panel 120 to be supplied to the display panel. In contrast, in the region where the upper electrode 125b is provided, the P wave light is blocked by the second polarizer 122b to implement the privacy mode.

[0130] For example, the backlight of the P wave is partially absorbed while passing through the first polarizer 122a and about 90% thereof is transmitted, and is partially absorbed while passing through the viewing angle control layer 129 and about 80% thereof is transmitted. In addition, the light of the P wave is partially absorbed while passing through the second polarizer 122b and about 70% thereof is finally transmitted. In contrast, the light of the S wave is almost blocked by the second polarizer 122b, and about 1% thereof can be transmitted.

[0131] In contrast, it should be understood that in the case of a thin film shutter (TFS) using an unpolarized backlight light source and an electrochromic (EC) of the related art, a large amount of light is absorbed when passing through the electrochromic film and only about 35% of the light is transmitted. Therefore, in the first exemplary embodiment of the present disclosure, the viewing angle brightness is expected to be improved by about 3.6 times compared to the related art.

[0132] As described above, the first exemplary embodiment of the present disclosure can provide a display device with a switchable viewing angle, wherein the polarization state and the optical path of the backlight light source are controlled to switch between the privacy mode and the sharing mode. By setting the lower electrode 125a on the entire surface of the liquid crystal layer 126, and setting the upper electrode 125b on some parts of the surface of the liquid crystal layer 126, when the electric field is not applied between the upper electrode 125b and the lower electrode 125a, the state of the liquid crystal layer 126 is the same in all regions of the viewing angle control layer 129, and when the electric field is applied between the upper electrode 125b and the lower electrode 125a, the liquid crystal layer 126 is different between the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided, so that the display device switches between the privacy mode and the sharing mode. Specifically, in the sharing mode, the brightness is improved without increasing the power consumption.

[0133] In addition, a display device with a switchable viewing angle can be provided, which uses TN liquid crystal with a fast response speed to control the light path to increase the switching speed between the sharing mode and the privacy mode.

[0134] Furthermore, according to the present disclosure, a pixel lens is added to an upper layer of the viewing angle control panel to condense light to improve efficiency, which will be described in more detail with reference to a second exemplary embodiment of the present disclosure.

[0135] Figure 5 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a second exemplary embodiment of the present disclosure.

[0136] Fig. 6A A sharing mode of a display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure is illustrated.

[0137] Figure 6BA privacy mode of a display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure is illustrated.

[0138] Figure 5 2 shows the structures of the viewing angle control panel 220 and the backlight unit 130 according to the second exemplary embodiment of the present disclosure. Fig. 6A and Figure 6B A display device with a switchable viewing angle according to a second exemplary embodiment of the present disclosure, ie, structures of a viewing angle control panel 220 , a backlight unit 130 , and a display panel 210 , are shown.

[0139] Fig. 6A A display device with a switchable viewing angle is shown in which a voltage is not applied to a pair of electrodes 125a and 125b, and Figure 6B A display device with a switchable viewing angle is shown in which a voltage is applied to a pair of electrodes 125a and 125b.

[0140] Fig. 6A and Figure 6B The propagation state of light at a predetermined point depending on whether a voltage is applied is shown. That is, the propagation state of light in front of the display panel 210 is shown as an example.

[0141] In addition to adding a pixel lens 228 on the upper layer of the viewing angle control panel 220 and arranging the display panel 210 above the viewing angle control panel 220, Figure 5 , Fig. 6A and Figure 6B by and Figure 3A , Figure 3B , Figure 4A and Figure 4B Therefore, the same configuration is denoted by the same reference numerals, and description thereof will be omitted.

[0142] Hereinafter, an example in which the display panel 210 is composed of a liquid crystal display panel will be described, but is not limited thereto.

[0143] Reference Figure 5 , Fig. 6A and Figure 6B , the display panel 210 may be disposed above the viewing angle control panel 220, and the backlight unit 130 may be disposed therebelow.

[0144] The backlight unit 130 according to the second exemplary embodiment of the present disclosure applies a polarized light source to provide light polarized as, for example, a P wave or an S wave.

[0145] The backlight unit 130 according to the second exemplary embodiment of the present disclosure is the same as the above-described backlight unit 130 according to the first exemplary embodiment of the present disclosure, and thus a description thereof will be omitted.

[0146] In the display panel 210 of the second exemplary embodiment of the present disclosure, the array substrate 212a and the color filter substrate 212b are spaced apart from each other to face each other, and the liquid crystal layer 213 may be interposed between the array substrate 212a and the color filter substrate 212b. Here, for ease of description, the array substrate 212a and the color filter substrate 212b may be referred to as a first substrate and a second substrate, respectively.

[0147] The first substrate 212a may include gate lines and data lines crossing to define pixel areas, and thin film transistors of switching elements formed at the crossings of the gate lines and the data lines. For example, the first substrate 212a may be formed of glass or resin.

[0148] For example, an active layer of the thin film transistor may be formed of a semiconductor material such as an oxide semiconductor, an amorphous semiconductor, or a polycrystalline semiconductor, but is not limited thereto.

[0149] Oxide semiconductor materials can have excellent effects of preventing leakage current and relatively cheap manufacturing costs. Oxide semiconductors can be made of metal oxides such as zinc (Zn), indium (In), gallium (Ga), tin (Sn) and titanium (Ti) or metals such as zinc (Zn), indium (In), gallium (Ga), tin (Sn) or titanium (Ti) and combinations of their oxides. Specifically, oxide semiconductors can include zinc oxide (ZnO), zinc tin oxide (ZTO), zinc indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), indium zinc tin oxide (IZTO), indium zinc oxide (IZO), indium gallium tin oxide (IGTO) and indium gallium oxide (IGO), but are not limited thereto.

[0150] The polycrystalline semiconductor material has a fast moving speed of carriers such as electrons and holes, and thus has high mobility, and has low power consumption and excellent reliability. The polycrystalline semiconductor may be made of polycrystalline silicon (poly-Si), but is not limited thereto.

[0151] The amorphous semiconductor material may be made of amorphous silicon (a-Si), but is not limited thereto.

[0152] In addition, for example, in a pixel region of the first substrate 212 a , a plurality of common electrodes and a plurality of pixel electrodes are alternately disposed to generate an image.

[0153] In addition, on the second substrate 212b, a black matrix (not shown) having openings corresponding to each pixel area is provided, and a color filter layer 214 including a red color filter, a green color filter, and a blue color filter may be provided, and the red color filter, the green color filter, and the blue color filter are sequentially and repeatedly provided to correspond to the openings.

[0154] An overcoat layer (not shown) may be disposed over the black matrix and the color filter layer 214 .

[0155] In addition, the lower polarizer 211a and the upper polarizer 211b may be attached to outer surfaces of the first substrate 212a and the second substrate 212b, respectively. For ease of description, the lower polarizer 211a and the upper polarizer 211b may be referred to as a third polarizer and a fourth polarizer.

[0156] At this time, polarization axes of the third polarizer 211 a and the fourth polarizer 211 b may be orthogonal to each other.

[0157] As described above, the backlight of the P wave or the S wave emitted by the backlight unit 130 is incident on the viewing angle control panel 220. Fig. 6A and Figure 6B In the example, it is shown that the backlight polarized as a P wave is incident on the viewing angle control panel 220, but the present disclosure is not limited thereto. For example, the backlight polarized as an S wave may be incident on the viewing angle control panel 220.

[0158] Next, the viewing angle control panel 220 according to the second exemplary embodiment of the present disclosure may mainly include a viewing angle control layer 129 and a first polarizer 122a and a second polarizer 122b respectively disposed below and above the viewing angle control layer 129. The viewing angle control panel 220 according to the second exemplary embodiment of the present disclosure may further include a pixel lens 228 disposed above the second polarizer 122b.

[0159] For example, the first polarizer 122a may have a transmission axis that matches the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the first polarizer 122a has a transmission axis of 0° and an absorption axis of 90° or the first polarizer 122a has a transmission axis of approximately 0° and an absorption axis of approximately 90°.

[0160] For example, the second polarizer 122b may have a transmission axis perpendicular to the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the second polarizer 122b may have a transmission axis of 90° and an absorption axis of 0° or the second polarizer 122b may have a transmission axis of approximately 90° and an absorption axis of approximately 0°. That is, the transmission axis of the second polarizer 122b may be perpendicular to the transmission axis of the first polarizer 122a.

[0161] For example, the first TAC layer 121a and the second TAC layer 121b may be disposed outside the first polarizer 122a and the second polarizer 122b, respectively. In addition, an adhesive layer may be disposed outside the second TAC layer 121b. For example, the adhesive layer may include a pressure-sensitive adhesive, but is not limited thereto.

[0162] For example, the first phase retardation compensation film 123a of the ORT may be disposed between the first polarizer 122a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0163] For example, the first protective layer 124a may be disposed between the first phase delay compensation film 123a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. For example, the first protective layer 124a may be formed of a film having a water vapor transmission rate (WVTR) of 10 -3 Up to 10 -2 g / m 2 The first protective layer 124a may be formed of silicon nitride to protect the lower electrode 125a from moisture, but is not limited thereto. For example, the first protective layer 124a may be formed of silicon oxide.

[0164] For example, the second phase retardation compensation film 123b of the ORT may be disposed between the second polarizer 122b and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0165] For example, the second protective layer 124b may be disposed between the second phase delay compensation film 123b and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. -3 Up to 10 -2 g / m 2 The second protective layer 124b may be formed of silicon nitride to protect the upper electrode 125b from moisture, but is not limited thereto. For example, the second protective layer 124b may be formed of silicon oxide.

[0166] The viewing angle control layer 129 may include a lower electrode 125 a and an upper electrode 125 b , and a liquid crystal layer 126 disposed between the lower electrode 125 a and the upper electrode 125 b .

[0167] At this time, for example, the lower electrode 125a may be configured as the entire electrode above the display area AA, but is not limited thereto. For example, the lower electrode 125a extends to the non-display area NA to overlap a portion of the non-display area NA.

[0168] In contrast, for example, the upper electrode 125 b may be configured as a plurality of strips in parallel in one direction over the display area AA.

[0169] In addition, for example, the upper electrodes 125 b may be configured as a plurality of strips parallel to each other at regular intervals.

[0170] The upper electrode 125b and the lower electrode 125a may be made of a transparent conductive material, for example, at least one of indium tin oxide (ITO), indium zinc oxide (IZO), carbon nanotubes, metal nanowires, and poly(3,4-ethylenedioxythiophene) (PEDOT).

[0171] In addition, the liquid crystal layer 126 may be formed of twisted nematic (TN) liquid crystal having a fast response speed, but is not limited thereto.

[0172] In addition, if Fig. 6A As shown, when no electric field is applied between the upper electrode 125 b and the lower electrode 125 a , the state of the liquid crystal layer 126 is the same in all regions of the viewing angle control layer 129 .

[0173] On the contrary, Figure 6B As shown, when an electric field is applied between the upper electrode 125b and the lower electrode 125a, the state of the liquid crystal layer 126 is different between a region where the upper electrode 125b is provided and a region where the upper electrode 125b is not provided.

[0174] First, for example, refer to Fig. 6A , when no electric field is applied between the upper electrode 125b and the lower electrode 125a, the horizontally polarized backlight having a P wave is incident on the viewing angle control panel 220. Hereinafter, for ease of description, the behavior of the backlight having a P wave incident on the viewing angle control panel 220 at one point of the backlight unit 130 will be described by way of example.

[0175] In this case, the first polarizer 122a has a transmission axis that matches the polarization direction of the backlight, so that the P-wave backlight can pass through the first polarizer 122a without loss. For example, the P-wave backlight incident on the viewing angle control panel 220 at a point of the backlight unit 130 can pass through the first polarizer 122a in both the center direction and the left and right directions. For example, the point is the center point of the backlight unit 130, but is not limited thereto, for example, the point can be other points except the center point of the backlight unit 130.

[0176] In addition, in this case, the state of the liquid crystal layer 126 can be the same in all regions of the viewing angle control layer 129. That is, when the liquid crystal molecules of the liquid crystal layer 126 are spirally rotated, the propagation direction of the light passing through the first polarizer 122a is rotated to change the polarization direction of the P-wave light to the S-wave in both the center direction and the left and right directions. In this case, the S-wave light can pass through the viewing angle control panel 220 in both the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided.

[0177] In addition, in this case, the light whose polarization direction is changed to S wave can pass through the second polarizer 122b having a transmission axis perpendicular to the polarization direction of the backlight without causing loss. For example, the backlight propagating from the viewing angle control panel 220 to the second polarizer 122b can pass through the second polarizer 122b in both the center direction and the left and right directions.

[0178] In addition, in this case, the backlight that passes through the second polarizer 122b in both the center direction and the left and right directions is provided to the display panel 210 to realize the sharing mode. That is, not only the backlight propagating in the center direction but also the backlight propagating diagonally in the left and right directions is provided to the display panel 210, so that clear and undistorted image quality can be achieved within a wide viewing angle range.

[0179] Next, refer to Figure 6B , when an electric field is applied between the upper electrode 125 b and the lower electrode 125 a , the horizontally polarized backlight having the P wave is incident on the viewing angle control panel 120 as described above.

[0180] In this case, the first polarizer 122a has a transmission axis that matches the polarization direction of the backlight, so that the P-wave backlight can pass through the first polarizer 122a without loss. For example, the P-wave backlight incident on the viewing angle control panel 220 at a point of the backlight unit 130 can pass through the first polarizer 122a in both the center direction and the left and right directions.

[0181] In this case, the state of the liquid crystal layer 126 may be different between the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided. That is, when the spiral rotation state of the liquid crystal molecules of the liquid crystal layer 126 is maintained in the region where the upper electrode 125b is not provided, the propagation direction of the light passing through the first polarizer 122a is rotated to change the polarization direction of the light of the P wave to the S wave. In this case, the light whose polarization direction is changed to the S wave can pass through the second polarizer 122b having a transmission axis perpendicular to the polarization direction of the backlight without causing loss. For example, the backlight propagating from the viewing angle control panel 220 to the second polarizer 122b in the center direction can pass through the second polarizer 122b without causing loss.

[0182] On the contrary, in the area where the upper electrode 125b is provided, the liquid crystal molecules of the liquid crystal layer 126 are rearranged by the electric field so that the spiral shape is spread out and the liquid crystal molecules are arranged in a row. In this way, the light of the P wave passes through the TN liquid crystal layer 126 without changing the polarization state. In this case, the light of the P wave may not pass through the second polarizer 122b having a transmission axis perpendicular to the polarization direction of the backlight. For example, the backlight propagating from the viewing angle control panel 220 to the second polarizer 122b in the left and right directions (i.e., in the diagonal direction) can be blocked by the second polarizer 122b to achieve a privacy mode. That is, only the person sitting in front of the screen can view the image on the screen, thereby smoothly processing confidential documents or performing tasks requiring security.

[0183] As described above, the second exemplary embodiment of the present disclosure can provide a display device with a switchable viewing angle, wherein the polarization state and the optical path of the backlight light source are controlled to switch the privacy mode and the sharing mode. By setting the lower electrode 125a on the entire surface of the liquid crystal layer 126, and setting the upper electrode 125b on some parts of the surface of the liquid crystal layer 126, when the electric field is not applied between the upper electrode 125b and the lower electrode 125a, the state of the liquid crystal layer 126 is the same in all regions of the viewing angle control layer 129, and when the electric field is applied between the upper electrode 125b and the lower electrode 125a, the liquid crystal layer 126 is different between the region where the upper electrode 125b is provided and the region where the upper electrode 125b is not provided, so that the display device switches between the privacy mode and the sharing mode. Specifically, by making the backlight incident on the viewing angle control panel 220 at a point of the backlight unit 130, it is realized that in the privacy mode, only the person sitting in front of the screen can view the image on the screen, thereby smoothly processing confidential documents or performing tasks requiring security. In addition, in the sharing mode, the brightness is improved without increasing power consumption.

[0184] In addition, a display device with a switchable viewing angle can be provided, which uses TN liquid crystal with a fast response speed to control the light path to increase the switching speed between the sharing mode and the privacy mode.

[0185] In addition, the display device with switchable viewing angles according to the second exemplary embodiment of the present disclosure may further include a pixel lens 228 disposed in an upper layer of the viewing angle control panel 220 .

[0186] For example, a lens assembly may be disposed above the second polarizer 122b. For example, the lens assembly may include a plurality of pixel lenses 228 disposed on a substrate 227. The lens assembly may be located on a path of light emitted from the backlight unit 130.

[0187] The lower surface of each pixel lens 228 facing the second polarizer 122b may be a flat plane. The surface of each pixel lens 228 opposite to the display panel 210 may have a semicircular shape, but is not limited thereto. A plurality of pixel lenses 228 may be positioned in parallel. For example, the lens assembly may include a biconvex lens, but is not limited thereto.

[0188] For example, each pixel region of the display panel 210 may overlap with one pixel lens 228. Therefore, in the display device with a switchable viewing angle according to the second exemplary embodiment of the present disclosure, backlight passes through one pixel lens 228 to be emitted to each pixel region and provided to the user. Therefore, in the display device with a switchable viewing angle according to the second exemplary embodiment of the present disclosure, the central brightness of each pixel region can be improved.

[0189] Although not shown, the lens assembly may further include a covering layer covering the pixel lens 228. The covering layer may suppress damage to the pixel lens 228 due to external impact. For example, the semicircular surface of each pixel lens 228 may be completely covered by the covering layer. The covering layer may remove the steps caused by the pixel lens 228. For example, the covering layer may include an insulating material. For example, the covering layer may be composed of a single layer or a double layer of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto. For example, the covering layer may be formed by a single layer or a multilayer inorganic film, for example, the single layer inorganic film may be a silicon oxide (SiOx) film or a silicon nitride (SiNx) film, and the multilayer inorganic film may be formed by alternately stacking one or more layers of silicon oxide (SiOx) film, one or more layers of silicon nitride (SiNx) film, and one or more layers of amorphous silicon (a-Si), but the present disclosure is not limited thereto.

[0190] For example, a plurality of pixel lenses 228 may be disposed parallel to the data lines at regular intervals, and each pixel lens 228 may be configured as a plurality of parallel strips, but is not limited thereto.

[0191] For example, each pixel lens 228 may be disposed to correspond to a region between the upper electrodes 125 b (ie, a non-pattern region).

[0192] In addition, for example, each pixel lens 228 may be disposed to correspond to each of a red color filter, a green color filter, and a blue color filter of the color filter layer 214 .

[0193] Figure 7 The following is a simulation result showing, by way of example, the transmission characteristics of a display device that does not have a viewing angle control panel.

[0194] Fig. 8A and Figure 8B are simulation results showing transmittance characteristics of a display device with a switchable viewing angle in a privacy mode and a sharing mode according to a comparative embodiment.

[0195] Fig.9A and Fig. 9B 2 is a simulation result showing the transmittance characteristics of the display device with switchable viewing angles in the privacy mode and the sharing mode according to the second exemplary embodiment of the present disclosure.

[0196] Fig.10 is a graph showing, by example, changes in brightness according to viewing angles.

[0197] As an example, Fig. 8A and 8B The comparative embodiment describes a TFS using an unpolarized backlight source and an EC.

[0198] also, Fig. 8A , Figure 8B , Fig.9A and Fig. 9B Transmittance characteristics of a privacy mode and a sharing mode in a display device with a switchable viewing angle according to a comparative embodiment and a second exemplary embodiment of the present disclosure are respectively shown.

[0199] First, refer to Figure 7 and Fig. 8A , in a comparative embodiment, with Figure 7 Compared with the brightness of a normal backlight unit (baseline), it can be understood that in privacy mode, the brightness efficiency is about 75% at a 0° viewing angle, and about 0.5% at a 45° viewing angle.

[0200] In addition, refer to Figure 7 and Figure 8B , in a comparative embodiment, with Figure 7 Compared with the brightness of an ordinary backlight unit, it can be understood that in the shared mode, the brightness efficiency is about 75% at a 0° viewing angle, and the brightness efficiency is about 8% at a 45° viewing angle.

[0201] On the contrary, refer to Figure 7 and Fig.9A , in a second exemplary embodiment of the present disclosure, with Figure 7 Compared with the brightness of a conventional backlight unit, it can be understood that in the privacy mode, the brightness efficiency is about 75% at a 0° viewing angle, and the brightness efficiency is about 0.0% at a 45° viewing angle. That is, compared with the comparative embodiment, the brightness efficiency is not reduced at a 0° viewing angle, but is significantly reduced at a 45° viewing angle, so that the privacy mode can be properly implemented.

[0202] In addition, refer to Figure 7 and Fig. 9B , in a second exemplary embodiment of the present disclosure, with Figure 7 Compared with the brightness of the ordinary backlight unit, it can be understood that in the shared mode, the brightness efficiency is about 85% at a 0° viewing angle, and the brightness efficiency is about 17.8% at a 45° viewing angle. That is, it can be understood that the brightness is increased by two times at a 45° viewing angle compared to the comparative embodiment.

[0203] In addition, refer to Fig.10 In the case of the privacy mode according to the second exemplary embodiment of the present disclosure, it can be understood that the brightness sharply decreases as the viewing angle increases, and when the viewing angle is equal to or greater than about 30°, the brightness approaches 0.

[0204] Furthermore, in the sharing mode according to the second exemplary embodiment of the present disclosure, it can be understood that the brightness is comprehensively improved compared to the privacy mode, and the brightness does not decrease sharply even if the viewing angle increases.

[0205] In addition, the lower polarizer of the display panel replaces the upper polarizer of the viewing angle control panel, so that the second TAC layer and the upper polarizer and the second phase retardation compensation film on the upper portion of the viewing angle control panel can be deleted. This will be described in more detail with reference to the third exemplary embodiment of the present disclosure.

[0206] Fig.11 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a third exemplary embodiment of the present disclosure.

[0207] Fig.11 2 shows the structures of the viewing angle control panel 320 and the backlight unit 130 according to the third exemplary embodiment of the present disclosure. Fig.11 In the figure, for the convenience of description, the display panel above the viewing angle control panel 320 is omitted.

[0208] In addition to deleting the second TAC layer, the upper polarizer, and the second phase retardation compensation film in the upper layer of the viewing angle control panel 320, Fig.11 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0209] Reference Fig.11 As described above, the display panel may be disposed above the viewing angle control panel 320, and the backlight unit 130 may be disposed therebelow.

[0210] The backlight unit 130 according to the third exemplary embodiment of the present disclosure applies a polarized light source to supply light polarized as, for example, a P wave or an S wave.

[0211] The viewing angle control panel 320 according to the third exemplary embodiment of the present disclosure may include a viewing angle control layer 129 and a first polarizer 122a disposed below the viewing angle control layer 129. The viewing angle control panel 320 according to the third exemplary embodiment of the present disclosure may further include a pixel lens 228 disposed above the viewing angle control layer 129.

[0212] For example, the first polarizer 122a may have a transmission axis that matches the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the first polarizer 122a may have a transmission axis of 0° and an absorption axis of 90°, or the first polarizer 122a may have a transmission axis of approximately 0° and an absorption axis of approximately 90°.

[0213] For example, the first TAC layer 121 a may be disposed on the outer side of the first polarizer 122 a .

[0214] For example, the first phase retardation compensation film 123a of the ORT may be disposed between the first polarizer 122a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0215] For example, the first protective layer 124a may be disposed between the first phase delay compensation film 123a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. For example, the first protective layer 124a may be formed of a film having a water vapor transmission rate (WVTR) of 10 -3 Up to 10 -2 g / m 2 The first protective layer 124a may be formed of silicon nitride to protect the lower electrode 125a from moisture, but is not limited thereto. For example, the first protective layer 124a may be formed of silicon oxide.

[0216] For example, the second protective layer 124b may be disposed between the pixel lens 228 and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. -3 Up to 10 -2 g / m 2 The second protective layer 124b may be formed of silicon nitride to protect the upper electrode 125b from moisture, but is not limited thereto. For example, the second protective layer 124b may be formed of silicon oxide.

[0217] Furthermore, in the case of the third exemplary embodiment of the present disclosure, the second TAC layer, the second polarizer, and the second phase retardation compensation film may not be disposed over the viewing angle control layer 129. Therefore, the overall thickness of the display device with a switchable viewing angle may be reduced.

[0218] In addition, although not shown, in the display panel according to the third exemplary embodiment of the present disclosure, the first substrate and the second substrate are spaced apart from each other to face each other, and a liquid crystal layer may be interposed between the first substrate and the second substrate.

[0219] In addition, the lower polarizer and the upper polarizer may be attached to outer surfaces of the first substrate and the second substrate, respectively. For ease of description, the lower polarizer and the upper polarizer may be referred to as a third polarizer and a fourth polarizer, respectively.

[0220] At this time, the polarization axes of the third polarizer and the fourth polarizer may be orthogonal to each other.

[0221] Furthermore, in the third exemplary embodiment of the present disclosure, the third polarizer may replace the upper polarizer of the viewing angle control panel.

[0222] Thus, for example, the third polarizer may have a transmission axis perpendicular to the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the third polarizer may have a transmission axis of 90° and an absorption axis of 0°, or the third polarizer may have a transmission axis of approximately 90° and an absorption axis of approximately 0°. That is, the transmission axis of the third polarizer may be perpendicular to the transmission axis of the first polarizer 122a.

[0223] In addition, according to the present disclosure, the surface of the pixel lens may have a shape other than a semicircle, which will be described in more detail with reference to a fourth exemplary embodiment of the present disclosure.

[0224] Fig.12 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a fourth exemplary embodiment of the present disclosure.

[0225] Fig.12 2 shows the structures of the viewing angle control panel 420 and the backlight unit 130 according to the fourth exemplary embodiment of the present disclosure. Fig.12 In the figure, for the convenience of description, the display panel above the viewing angle control panel 420 is omitted.

[0226] In addition to the surface of the pixel lens 428 having a trapezoidal shape, Fig.12 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0227] Reference Fig.12 As described above, the display panel may be disposed above the viewing angle control panel 420, and the backlight unit 130 may be disposed therebelow.

[0228] In addition, the display device with switchable viewing angles according to the fourth exemplary embodiment of the present disclosure may further include a pixel lens 428 disposed in an upper layer of the viewing angle control panel 420 .

[0229] For example, a lens assembly may be disposed above the second polarizer 122b. For example, the lens assembly may include a plurality of pixel lenses 428 disposed on the substrate 227. The lens assembly may be located on a path of light emitted from the backlight unit 130.

[0230] The lower surface of each pixel lens 428 facing the second polarizer 122b may be a flat plane. The surface of each pixel lens 428 opposite to the display panel may have a trapezoidal shape, but is not limited thereto. A plurality of pixel lenses 428 may be positioned in parallel. As described above, since the surface of the pixel lens 428 has a trapezoidal shape, the backlight passing in the center direction may be increased, so that the brightness in the vertical direction may be increased. As a result, efficiency is improved.

[0231] For example, each pixel region of the display panel may overlap with one pixel lens 428. Therefore, in the display device with switchable viewing angle according to the fourth exemplary embodiment of the present disclosure, backlight passes through one pixel lens 428 to be emitted to each pixel region and provided to the user. Therefore, in the display device with switchable viewing angle according to the fourth exemplary embodiment of the present disclosure, the central brightness of each pixel region can be improved.

[0232] Although not shown, the lens assembly may further include a covering layer covering the pixel lens 428. The covering layer may suppress damage to the pixel lens 428 due to external impact. For example, the trapezoidal surface of each pixel lens 428 may be completely covered by the covering layer. The covering layer may remove the steps caused by the pixel lens 428. For example, the covering layer may include an insulating material. For example, the covering layer may be composed of a single layer or a double layer of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto. For example, the covering layer may be formed by a single layer or a multilayer inorganic film, for example, the single layer inorganic film may be a silicon oxide (SiOx) film or a silicon nitride (SiNx) film, and the multilayer inorganic film may be formed by alternately stacking one or more layers of silicon oxide (SiOx) film, one or more layers of silicon nitride (SiNx) film, and one or more layers of amorphous silicon (a-Si), but the present disclosure is not limited thereto.

[0233] For example, a plurality of pixel lenses 428 may be disposed in parallel to the data lines at regular intervals, and each pixel lens 428 may be configured as a plurality of parallel strips, but is not limited thereto.

[0234] For example, each pixel lens 428 may be disposed to correspond to a region between the upper electrodes 125 b (ie, a non-pattern region).

[0235] In addition, for example, each pixel lens 428 may be disposed to correspond to each of a red color filter, a green color filter, and a blue color filter of the color filter layer.

[0236] Furthermore, according to the present disclosure, a supporting substrate may be added below the viewing angle control layer, which will be described in more detail with reference to a fifth exemplary embodiment of the present disclosure.

[0237] Fig.13is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a fifth exemplary embodiment of the present disclosure.

[0238] Fig.13 2 shows the structures of the viewing angle control panel 520 and the backlight unit 130 according to the fifth exemplary embodiment of the present disclosure. Fig.13 In the figure, for the convenience of description, the display panel above the viewing angle control panel 520 is omitted.

[0239] In addition to adding a support substrate 529 below the viewing angle control layer 129, Fig.13 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0240] Reference Fig.13 As described above, the display panel may be disposed above the viewing angle control panel 520, and the backlight unit 130 may be disposed therebelow.

[0241] In addition, the display device with switchable viewing angles according to the fifth exemplary embodiment of the present disclosure may further include a support substrate 529 disposed under the viewing angle control layer 129 .

[0242] For example, the support substrate 529 may be formed of glass, but is not limited thereto.

[0243] For example, the support substrate 529 may be disposed between the viewing angle control layer 129 and the first polarizer 122a. For example, the support substrate 529 may be disposed between the first protective layer 124a and the first polarizer 122a. For example, the support substrate 529 may be disposed between the first protective layer 124a and the first phase delay compensation film 123a.

[0244] As described above, in the fifth exemplary embodiment of the present disclosure, the support substrate 529 is added below the viewing angle control layer 129, so that the configuration disposed above the support substrate 529 can be supported together with the viewing angle control layer 129 during the process. Therefore, the process is feasible regardless of the process temperature. Therefore, fairness is improved.

[0245] Furthermore, according to the present disclosure, a display panel may be formed on a viewing angle control panel in an additional manner, which will be described in more detail with reference to a sixth exemplary embodiment of the present disclosure.

[0246] Fig.14 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a sixth exemplary embodiment of the present disclosure.

[0247] Fig.14 A display device with a switchable viewing angle according to a sixth exemplary embodiment of the present disclosure is shown, for example, a structure including a viewing angle control panel 620 , a backlight unit 130 , and a display panel 610 .

[0248] In addition to the display panel 610 being formed on the viewing angle control panel 620 in an additional manner, Fig.14 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0249] Hereinafter, an example in which the display panel 610 is composed of a liquid crystal display panel will be described, but is not limited thereto.

[0250] Reference Fig.14 As described above, the display panel 610 may be disposed above the viewing angle control panel 620 , and the backlight unit 130 may be disposed below the viewing angle control panel 620 .

[0251] Furthermore, in the display device with switchable viewing angles according to the sixth exemplary embodiment of the present disclosure, the display panel 610 may be formed on the viewing angle control panel 620 in an additional manner.

[0252] Furthermore, in the sixth exemplary embodiment of the present disclosure, similarly to the above-described third exemplary embodiment of the present disclosure, the lower polarizer 611 a of the display panel 610 may replace the upper polarizer of the viewing angle control panel 620 .

[0253] The viewing angle control panel 620 according to the sixth exemplary embodiment of the present disclosure may include a viewing angle control layer 129 and a first polarizer 122a disposed below the viewing angle control layer 129. In addition, the viewing angle control panel 620 according to the sixth exemplary embodiment of the present disclosure may further include a pixel lens 228 disposed above the viewing angle control layer 129. For example, the pixel lens 228 may have a semicircular shape or a trapezoidal shape, but is not limited thereto.

[0254] For example, the first polarizer 122a may have a transmission axis that matches the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the first polarizer 122a may have a transmission axis of 0° and an absorption axis of 90°, or the first polarizer 122a may have a transmission axis of approximately 0° and an absorption axis of approximately 90°.

[0255] For example, the first TAC layer 121 a may be disposed on the outer side of the first polarizer 122 a .

[0256] For example, the first phase retardation compensation film 123a of the ORT may be disposed between the first polarizer 122a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary.

[0257] For example, the first protective layer 124a may be disposed between the first phase delay compensation film 123a and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. For example, the first protective layer 124a may be formed of a film having a water vapor transmission rate (WVTR) of 10 -3 Up to 10 -2 g / m 2 The first protective layer 124a may be formed of silicon nitride to protect the lower electrode 125a from moisture, but is not limited thereto. For example, the first protective layer 124a may be formed of silicon oxide.

[0258] Next, for example, the second protective layer 124b may be disposed between the pixel lens 228 and the viewing angle control layer 129, but is not limited thereto and may be omitted if necessary. For example, the second protective layer 124b may be formed by a WVTR of 10 -3 Up to 10 -2 g / m 2 The second protective layer 124b may be formed of silicon nitride to protect the upper electrode 125b from moisture, but is not limited thereto. For example, the second protective layer 124b may be formed of silicon oxide.

[0259] For example, the second phase retardation compensation film 123b of the ORT may be disposed between the pixel lens 228 and the second protective layer 124b, but is not limited thereto and may be omitted if necessary.

[0260] Furthermore, in the case of the sixth exemplary embodiment of the present disclosure, the second TAC layer and the second polarizer may not be disposed over the viewing angle control layer 129. Therefore, the overall thickness of the display device with a switchable viewing angle may be reduced.

[0261] In the display panel 610 of the sixth exemplary embodiment of the present disclosure, the first substrate 212 a and the second substrate 212 b are spaced apart from each other to face each other, and the liquid crystal layer 213 may be interposed between the first substrate 212 a and the second substrate 212 b .

[0262] In addition, the lower polarizer 611a and the upper polarizer 611b may be attached to outer surfaces of the first substrate 212a and the second substrate 212b, respectively. For ease of description, the lower polarizer 611a and the upper polarizer 611b may be referred to as a third polarizer and a fourth polarizer, respectively.

[0263] At this time, polarization axes of the third polarizer 611 a and the fourth polarizer 611 b may be orthogonal to each other.

[0264] Furthermore, in the sixth exemplary embodiment of the present disclosure, the third polarizer 611 a may replace the upper polarizer of the viewing angle control panel 620 .

[0265] Therefore, for example, the third polarizer 611a may have a transmission axis perpendicular to the polarization direction of the backlight. For example, when the backlight has a horizontal polarization of a P wave, the third polarizer 611a may have a transmission axis of 90° and an absorption axis of 0°, or the third polarizer 611a may have a transmission axis of approximately 90° and an absorption axis of approximately 0°. That is, the transmission axis of the third polarizer 611a may be perpendicular to the transmission axis of the first polarizer 122a.

[0266] In addition, the lens assembly may further include a covering layer 615 covering the pixel lens 228. The covering layer 615 may suppress damage to the pixel lens 228 due to external impact. For example, the semicircular surface or the trapezoidal surface of each pixel lens 228 may be completely covered by the covering layer 615. The covering layer 615 may remove the steps caused by the pixel lens 228. For example, the covering layer 615 may include an insulating material. For example, the covering layer 615 may be composed of a single layer or a double layer of silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto. For example, the covering layer 615 may be formed by a single layer or a multilayer inorganic film, for example, the single layer inorganic film may be a silicon oxide (SiOx) film or a silicon nitride (SiNx) film, and the multilayer inorganic film may be formed by alternately stacking one or more layers of silicon oxide (SiOx) film, one or more layers of silicon nitride (SiNx) film, and one or more layers of amorphous silicon (a-Si), but the present disclosure is not limited thereto. Therefore, the display panel 610 may be attached on the cover layer 615 .

[0267] For example, a plurality of pixel lenses 228 may be disposed parallel to the data lines at regular intervals, and each pixel lens 228 may be configured as a plurality of parallel strips, but is not limited thereto.

[0268] For example, each pixel lens 228 may be disposed to correspond to a region (ie, a non-pattern region) between the upper electrodes 125 b .

[0269] In addition, for example, each pixel lens 228 may be disposed to correspond to each of a red color filter, a green color filter, and a blue color filter of the color filter layer 214 .

[0270] As described above, in the sixth exemplary embodiment of the present disclosure, the display panel 610 is additionally formed on the viewing angle control panel 620. Therefore, there is no air gap between the viewing angle control panel 620 and the display panel 610, so that deformation due to external force can be minimized, thereby improving reliability.

[0271] Furthermore, in the present disclosure, the display panel may be constituted of an organic light emitting display panel in addition to the liquid crystal display panel, which will be described in more detail with reference to a seventh exemplary embodiment of the present disclosure.

[0272] Fig.15 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to a seventh exemplary embodiment of the present disclosure.

[0273] Fig.15 A display device with a switchable viewing angle according to a seventh exemplary embodiment of the present disclosure is shown, for example, including a structure of a viewing angle control panel 720 and an organic light emitting display panel 740. In this case, unlike the above exemplary embodiments, the organic light emitting display panel 740 is a self-luminous panel, so that a backlight unit is not required.

[0274] In addition to the display panel being composed of the organic light emitting display panel 740 and the organic light emitting display panel 740 being additionally disposed below the viewing angle control panel 720, Fig.15 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0275] Reference Fig.15 In the seventh exemplary embodiment of the present disclosure, the organic light emitting display panel 740 is disposed below the viewing angle control panel 720 , and thus a separate backlight unit is not required.

[0276] Furthermore, in the display device with a switchable viewing angle according to the seventh exemplary embodiment of the present disclosure, the organic light emitting display panel 740 may be formed under the viewing angle control panel 720 in an additional manner.

[0277] Furthermore, in the seventh exemplary embodiment of the present disclosure, a circular polarizer composed of a quarter wave plate (QWP) 741 and a linear polarizer 742 may be disposed on an upper surface of the organic light emitting display panel 740 .

[0278] For example, when the light passing through the circular polarizer passes through the linear polarizer of the first polarizer 122 a of the viewing angle control panel 720 , the light may be P-polarized light.

[0279] For example, a predetermined adhesive layer 745 may be provided between the linear polarizer 742 and the first polarizer 122a, but is not limited thereto. For example, the adhesive layer 745 may be composed of an optically transparent adhesive. For reference, in OCA, the adhesive is pre-coated on a transparent substrate (e.g., polyester film), so that objects can be bonded while maintaining optical transparency. However, the transparent substrate is not limited to polyester film.

[0280] As described above, in the seventh exemplary embodiment of the present disclosure, the organic light emitting display panel 740 is additionally formed below the viewing angle control panel 720. Therefore, there is no air gap between the viewing angle control panel 720 and the organic light emitting display panel 740, so that deformation due to external force can be minimized, thereby improving reliability.

[0281] Furthermore, according to the present disclosure, areas of the viewing angle control panel are divided to be driven in different modes, which will be described in more detail with reference to an eighth exemplary embodiment of the present disclosure.

[0282] Fig.16 is a cross-sectional view showing a portion of a display device with switchable viewing angles according to an eighth exemplary embodiment of the present disclosure.

[0283] Fig.16 2 shows the structures of the viewing angle control panel 820 and the backlight unit 130 according to the eighth exemplary embodiment of the present disclosure. Fig.16 In the figure, for the convenience of description, the display panel above the viewing angle control panel 820 is omitted.

[0284] In addition to dividing the area of ​​the viewing angle control panel 820 into different driving modes, Fig.16 By the above Figure 5 , Fig. 6A and Figure 6B The second exemplary embodiment of the present disclosure is basically constituted by the same configuration. Therefore, the same configuration is denoted by the same reference numerals, and a description thereof will be omitted.

[0285] Reference Fig.16 , as described above, the display panel may be disposed above the viewing angle control panel 820, and the backlight unit 130 may be disposed therebelow.

[0286] Furthermore, in the display device with switchable viewing angles according to the eighth exemplary embodiment of the present disclosure, the viewing angle control panel 820 may be divided into at least one or more first areas PA1 and at least one or more second areas PA2 .

[0287] For example, in the first area PA1, an electric field is not applied between the upper electrode 125b and the lower electrode 125a to implement the sharing mode, and in the second area PA2, an electric field is applied between the upper electrode 125b and the lower electrode 125a to implement the privacy mode.

[0288] Therefore, the first area PA1 may correspond to a person who requires clear and undistorted image quality within a wide viewing angle range, and the second area PA2 may correspond to a person who handles confidential documents or performs tasks requiring security.

[0289] However, the embodiments of the present disclosure are not limited thereto, and for example, the viewing angle control panel 820 may be divided into at least one or more first areas PA1 and at least one or more second areas PA2 and at least one or more third areas PA3 respectively located on both sides of the at least one or more first areas PA1.

[0290] For example, in the first area PA1, an electric field is applied between the upper electrode 125b and the lower electrode 125a to implement the privacy mode, and in the second and third areas PA2 and PA3, an electric field is not applied between the upper electrode 125b and the lower electrode 125a to implement the sharing mode.

[0291] Therefore, the second area PA2 and the third area PA3 may correspond to people who require clear and undistorted image quality within a wide viewing angle range, and the first area PA1 may correspond to people who handle confidential documents or perform tasks requiring security.

[0292] As described above, in the eighth exemplary embodiment of the present disclosure, since the area of ​​the viewing angle control panel 820 is divided to be driven in different modes, many people can select the privacy mode or the sharing mode to provide convenience.

[0293] Exemplary embodiments of the present disclosure may also be described as follows:

[0294] According to one aspect of the present disclosure, a display device with a switchable viewing angle is provided. The display device with a switchable viewing angle includes: a first polarizer that transmits light of a P wave or an S wave; a viewing angle control layer that is disposed above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer that is disposed between the lower electrode and the upper electrode to selectively change the light of the P wave or the S wave into an S wave or a P wave; and a second polarizer that is disposed above the viewing angle control layer and has a transmission axis that is perpendicular to the transmission axis of the first polarizer.

[0295] The display device with switchable viewing angle may further include: a backlight unit disposed under the first polarizer and providing polarized light of a P wave or an S wave.

[0296] The backlight unit may include a point at which polarized light of a P wave or an S wave is disposed such that the polarized light passes through the first polarizer in all center, left, and right directions.

[0297] The display device with switchable viewing angle may further include: a first triacetyl cellulose (TAC) layer disposed on an outer side of the first polarizer; and a second TAC layer disposed on an outer side of the second polarizer.

[0298] The display device with switchable viewing angle may further include: a first phase retardation compensation film disposed between the first polarizer and the viewing angle control layer; and a second phase retardation compensation film disposed between the second polarizer and the viewing angle control layer.

[0299] The display device with switchable viewing angle may further include: a first protective layer disposed between the first phase retardation compensation film and the viewing angle control layer; and a second protective layer disposed between the second phase retardation compensation film and the viewing angle control layer.

[0300] The upper electrode may be configured as a plurality of strips in parallel in one direction over the display area, and the lower electrode may be configured as an entire electrode over the display area.

[0301] Multiple strips may be parallel to each other at regular intervals.

[0302] The upper electrode may be disposed parallel to the data line.

[0303] The upper electrode may be disposed parallel to the gate line.

[0304] The liquid crystal layer may be composed of twisted nematic liquid crystal.

[0305] In response to an electric field not being applied between the upper electrode and the lower electrode, the state of the liquid crystal layer may be the same in all regions of the viewing angle control layer, and in response to an electric field being applied between the upper electrode and the lower electrode, the state of the liquid crystal layer may be different between regions where the upper electrode is provided and regions where the upper electrode is not provided.

[0306] In response to the electric field not being applied between the upper electrode and the lower electrode, in all areas of the viewing angle control layer, the polarization direction of P-wave light passing through the first polarizer can be changed to S-wave, or the polarization direction of S-wave light can be changed to P-wave.

[0307] In response to an electric field being applied between the upper electrode and the lower electrode, in a region where the upper electrode is not set, the polarization direction of P-wave light passing through the first polarizer can be changed to S-wave or the polarization direction of S-wave light can be changed to P-wave, but in a region where the upper electrode is set, P-wave or S-wave light passing through the first polarizer can pass through the liquid crystal layer without changing the polarization state.

[0308] The display device with switchable viewing angle may further include: a plurality of pixel lenses disposed above the second polarizer.

[0309] A lower surface of each pixel lens may have a flat plane, and an upper surface of each pixel lens may have a semicircular shape.

[0310] A lower surface of each pixel lens may have a flat plane, and an upper surface of each pixel lens may have a trapezoidal shape.

[0311] The display device with switchable viewing angle may further include: a covering layer disposed above the plurality of pixel lenses to cover the plurality of pixel lenses.

[0312] The display device with switchable viewing angle may further include a display panel disposed above the viewing angle control layer.

[0313] Each pixel region of the display panel may overlap with one of the pixel lenses.

[0314] A plurality of pixel lenses may be disposed parallel to the data line at regular intervals, and each pixel lens may be configured as a plurality of strips parallel to each other.

[0315] Each pixel lens may be disposed to correspond to a region between the upper electrodes.

[0316] Each pixel lens may be disposed to correspond to each of the red color filter, the green color filter, and the blue color filter.

[0317] The display panel may include: a first substrate; a second substrate; another liquid crystal layer disposed between the first substrate and the second substrate; a third polarizer disposed on the outside of the first substrate; and a fourth polarizer disposed on the outside of the second substrate and having a transmission axis perpendicular to the transmission axis of the third polarizer.

[0318] The display device with switchable viewing angle may further include: a supporting substrate disposed between the viewing angle control layer and the first polarizer.

[0319] The area of ​​the viewing angle control layer may be divided into at least two areas to be driven in different modes.

[0320] The different modes include a sharing mode and a privacy mode.

[0321] According to another aspect of the present disclosure, a display device with a switchable viewing angle is provided. The display device with a switchable viewing angle includes: a first polarizer that transmits light of a P wave or an S wave; a viewing angle control panel that is disposed above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer that is disposed between the lower electrode and the upper electrode to selectively change the light of the P wave or the S wave into an S wave or a P wave; a third polarizer that is disposed above the viewing angle control panel and has a transmission axis that is perpendicular to the transmission axis of the first polarizer; a first substrate that is disposed above the third polarizer; a second substrate that is opposite to the first substrate; another liquid crystal layer that is disposed between the first substrate and the second substrate; and a fourth polarizer that is disposed outside the second substrate and has a transmission axis that is perpendicular to the transmission axis of the third polarizer.

[0322] The display device with switchable viewing angles may further include: a plurality of pixel lenses disposed between the viewing angle control panel and the third polarizer.

[0323] The display device with switchable viewing angle may further include: a covering layer disposed above the plurality of pixel lenses to cover the plurality of pixel lenses.

[0324] The display device with switchable viewing angle may further include: an organic light emitting display panel disposed below the first polarizer; and a quarter wave plate and a linear polarizer disposed between the first polarizer and the organic light emitting display panel to provide polarized light of a P wave or an S wave.

[0325] The viewing angle control panel can be divided into at least one or more first areas and at least one or more second areas, and in the first areas, no electric field is applied between the upper electrode and the lower electrode to achieve a sharing mode, and in the second areas, an electric field is applied between the upper electrode and the lower electrode to simultaneously achieve a privacy mode.

[0326] Although the exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all aspects and will not limit the present disclosure. All technical concepts within the equivalent scope of the present disclosure should be interpreted as falling within the scope of the present disclosure.

[0327] CROSS-REFERENCE TO RELATED APPLICATIONS

[0328] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0094605 filed in the Korean Intellectual Property Office on July 20, 2023, the entire contents of which are expressly incorporated herein for all purposes.

Claims

1. A display device with a switchable viewing angle, the display device comprising: a first polarizer that transmits light of a P wave or an S wave; A viewing angle control layer, the viewing angle control layer is disposed above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer, the liquid crystal layer is disposed between the lower electrode and the upper electrode to selectively change the light of the P wave into the S wave, or selectively change the light of the S wave into the P wave; as well as A second polarizer is disposed above the viewing angle control layer and has a transmission axis perpendicular to the transmission axis of the first polarizer.

2. The display device with switchable viewing angle according to claim 1, further comprising: A backlight unit is disposed under the first polarizer and provides polarized light of the P wave or the S wave.

3. The display device with switchable viewing angle according to claim 2, wherein: The backlight unit includes a point, and The polarized light of the P wave or the S wave is arranged at the one point so that the polarized light passes through the first polarizer in all directions including a center direction, a left direction, and a right direction.

4. The display device with switchable viewing angle according to claim 1, further comprising: A first triacetyl cellulose TAC layer, wherein the first TAC layer is disposed on the outer side of the first polarizer; as well as A second TAC layer is disposed on an outer side of the second polarizer.

5. The display device with switchable viewing angle according to claim 4, further comprising: a first phase retardation compensation film, wherein the first phase retardation compensation film is disposed between the first polarizer and the viewing angle control layer; as well as A second phase retardation compensation film is disposed between the second polarizer and the viewing angle control layer.

6. The display device with switchable viewing angle according to claim 5, further comprising: A first protective layer, wherein the first protective layer is disposed between the first phase delay compensation film and the viewing angle control layer; as well as A second protective layer is provided between the second phase delay compensation film and the viewing angle control layer.

7. The display device with switchable viewing angle according to claim 1, wherein: The upper electrode is configured as a plurality of strips parallel in one direction over a display area, and the lower electrode is configured as an entire electrode over the display area.

8. The display device with switchable viewing angle according to claim 1, wherein: In response to an electric field not being applied between the upper electrode and the lower electrode, the state of the liquid crystal layer is the same in all regions of the viewing angle control layer, and Wherein, in response to the electric field being applied between the upper electrode and the lower electrode, the state of the liquid crystal layer is different between a region where the upper electrode is disposed and a region where the upper electrode is not disposed.

9. The display device with switchable viewing angle according to claim 8, wherein: In response to the electric field not being applied between the upper electrode and the lower electrode, in all areas of the viewing angle control layer, the polarization direction of the P wave light passing through the first polarizer changes to the S wave, or the polarization direction of the S wave light changes to the P wave.

10. The display device with switchable viewing angle according to claim 8, wherein: In response to the electric field being applied between the upper electrode and the lower electrode, in a region where the upper electrode is not set, the polarization direction of the P-wave light passing through the first polarizer is changed to the S-wave or the polarization direction of the S-wave light is changed to the P-wave, but in a region where the upper electrode is set, the P-wave or the S-wave light passing through the first polarizer passes through the liquid crystal layer without changing the polarization state.

11. The display device with switchable viewing angle according to claim 1, further comprising: A plurality of pixel lenses are disposed above the second polarizer.

12. The display device with switchable viewing angle according to claim 11, further comprising: A display panel is arranged above the viewing angle control layer. Wherein, each pixel region of the display panel overlaps with one of the pixel lenses.

13. The display device with switchable viewing angle according to claim 11, wherein: The plurality of pixel lenses are disposed parallel to the data lines at regular intervals, and each of the pixel lenses is configured as a plurality of strips parallel to each other.

14. The display device with switchable viewing angle according to claim 11, wherein: Each of the pixel lenses is disposed to correspond to a region between the upper electrodes.

15. The display device with switchable viewing angle according to claim 14, wherein: Each of the pixel lenses is disposed to correspond to each of the red color filter, the green color filter, and the blue color filter.

16. The display device with switchable viewing angle according to claim 12, wherein: The display panel comprises: a first substrate; a second substrate; another liquid crystal layer, the another liquid crystal layer is disposed between the first substrate and the second substrate; a third polarizer disposed outside the first substrate; and A fourth polarizer is disposed on the outer side of the second substrate and has a transmission axis perpendicular to the transmission axis of the third polarizer.

17. The display device with switchable viewing angle according to claim 1, further comprising: A supporting substrate is disposed between the viewing angle control layer and the first polarizer.

18. A display device with switchable viewing angle, the display device comprising: a first polarizer that transmits light of a P wave or an S wave; A viewing angle control layer, the viewing angle control layer is disposed above the first polarizer and includes a lower electrode and an upper electrode and a liquid crystal layer, the liquid crystal layer is disposed between the lower electrode and the upper electrode to selectively change the light of the P wave into the S wave, or selectively change the light of the S wave into the P wave; a third polarizer disposed above the viewing angle control layer and having a transmission axis perpendicular to the transmission axis of the first polarizer; a first substrate disposed above the third polarizer; a second substrate, the second substrate being opposite to the first substrate; another liquid crystal layer, the another liquid crystal layer is disposed between the first substrate and the second substrate; as well as A fourth polarizer is disposed on the outer side of the second substrate and has a transmission axis perpendicular to the transmission axis of the third polarizer.

19. The display device with switchable viewing angle according to claim 18, further comprising: A plurality of pixel lenses are disposed between the viewing angle control layer and the third polarizer.

20. The display device with switchable viewing angle according to claim 18, further comprising: an organic light emitting display panel, wherein the organic light emitting display panel is disposed below the first polarizer; as well as a quarter wave plate and a linear polarizer, wherein the quarter wave plate and the linear polarizer are disposed between the first polarizer and the organic light emitting display panel to provide polarized light of the P wave or the S wave, In which, the viewing angle control layer is divided into at least one or more first areas and at least one or more second areas, and in the first areas, no electric field is applied between the upper electrode and the lower electrode to realize the sharing mode, and in the second areas, an electric field is applied between the upper electrode and the lower electrode to simultaneously realize the privacy mode.

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