Double-sided display device

Abstract

Disclosed is a double-sided display device including: a backlight unit having a light guide plate; a first display panel disposed on the first light exit surface of the backlight unit; and a second display panel disposed on a second light exit surface of the backlight unit opposite to the first light exit surface, in which the first display panel and the second display panel are mounted to be inclined at a predetermined angle with respect to the backlight unit. Accordingly, power consumption of the double-sided display device may be reduced and image quality may be improved.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2023-0130867, filed on September 27, 2023, which is hereby incorporated by reference in its entirety. Technical Field

[0002] The present disclosure relates to a dual-sided display device in which display panels share a backlight unit and are thus mounted on two surfaces of the backlight unit, and more particularly, to a heterogeneous dual display device in which display panels mounted on two surfaces of the backlight unit are tilted at a predetermined angle. Background Art

[0003] Typically, a display device displays an image. For example, the display device may include a liquid crystal panel disposed on a backlight unit. The backlight unit may provide light to the liquid crystal panel. For example, the backlight unit may include at least one light source element. The liquid crystal panel may realize a specific image using an electric field formed between a pixel electrode and a common electrode. For example, a liquid crystal display panel may include a liquid crystal layer disposed between a first display substrate and a second display substrate.

[0004] The display device may be installed in various places. For example, the display device may be installed in a car, a subway, a train, a store, etc. In particular, in order to enable a viewer to view the display device from opposite sides, two display panels may share one backlight unit and thus be installed on two surfaces of the backlight unit.

[0005] However, if two display panels are installed in parallel with two surfaces of a shared backlight unit, image quality may be deteriorated depending on a viewing position of a viewer.

[0006] Furthermore, even if two display panels are mounted on both surfaces of the backlight unit so as to be inclined at a predetermined angle, brightness may not be uniform, and image quality (front side of screen (FOS)) may be deteriorated. Summary of the invention

[0007] Accordingly, the present disclosure is directed to a double-sided display device that substantially overcomes one or more problems due to limitations and disadvantages of the related art.

[0008] An object of the present disclosure is to provide a special-shaped double-sided display device capable of ensuring uniform brightness and improved image quality when two display panels are mounted on both surfaces of a backlight unit so as to be inclined at a predetermined angle suitable for a viewing position of a viewer.

[0009] Objectives to be achieved by the present disclosure are not limited to the above-mentioned objectives, and other objectives not mentioned herein will be clearly understood by those skilled in the art from the following description.

[0010] Other advantages, purposes and features of the present disclosure will be partially described in the subsequent description, some of which will become apparent to those of ordinary skill in the art after studying the following or may be learned through the practice of the present disclosure. These purposes and other advantages of the present disclosure can be achieved and obtained through the written description and claims thereof and the structures specifically pointed out in the drawings.

[0011] To achieve these objectives and other advantages and in accordance with the purposes of the present disclosure, as embodied and generally described herein, a double-sided display device includes: a backlight unit having a light guide plate; a first display panel, the first display panel being arranged on a first light exit surface of the backlight unit; and a second display panel, the second display panel being arranged on a second light exit surface of the backlight unit opposite to the first light exit surface, wherein the first display panel and the second display panel are installed to be inclined at a predetermined angle relative to the backlight unit.

[0012] The double-sided display device may further include: a first diffuser, which is arranged on the rear surface of the first display panel facing the first light exit surface of the backlight unit; and a second diffuser, which is arranged on the rear surface of the second display panel facing the second light exit surface of the backlight unit.

[0013] Instead of the first diffuser and the second diffuser, the double-sided display device may further include: a first polarizing plate, which is arranged on the rear surface of the first display panel facing the first light exit surface of the backlight unit, and the first polarizing plate has the same haze as the first diffuser; and a second polarizing plate, which is arranged on the rear surface of the second display panel facing the second light exit surface of the backlight unit, and the second polarizing plate has the same haze as the second diffuser.

[0014] The first display panel and the second display panel may be inclined at an angle of 1 to 25 degrees.

[0015] The backlight unit may include: a light source configured to emit light to a light incident surface of the light guide plate; a first optical sheet located on a first light exiting surface of the light guide plate; and a second optical sheet located on a second light exiting surface of the light guide plate opposite to the first light exiting surface. The first display panel and the second display panel may be tilted at a predetermined angle relative to the backlight unit around an edge of a surface of the light guide plate opposite to the light incident surface of the light guide plate.

[0016] It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. In the drawings:

[0018] Figure 1 is a schematic cross-sectional view of a double-sided display device implemented using a liquid crystal display device according to one embodiment;

[0019] Figure 2 is a schematic cross-sectional view of a double-sided display device using one backlight unit according to one embodiment;

[0020] Figure 3 is a diagram showing a position where a double-sided display device according to an embodiment of the present disclosure is installed;

[0021] Figure 4 is a schematic cross-sectional view of a double-sided display device according to an embodiment of the present disclosure;

[0022] Figure 5 is a schematic cross-sectional view of a double-sided display device according to another embodiment of the present disclosure;

[0023] Figure 6 shows the characteristics of various double-sided display devices according to one embodiment;

[0024] Figure 7 shows characteristics of a double-sided display device according to a tilt angle of a first liquid crystal panel and a second liquid crystal panel according to one embodiment;

[0025] Figure 8Characteristics of a double-sided display device according to one embodiment in which a first liquid crystal panel and a second liquid crystal panel are installed to be inclined at a predetermined angle relative to a backlight unit around an edge of a surface of a light guide plate opposite to a light incident surface of the light guide plate, and characteristics of a double-sided display device according to one embodiment in which a first liquid crystal panel and a second liquid crystal panel are installed to be inclined at a predetermined angle relative to a backlight unit around an edge of a light incident surface of the light guide plate. DETAILED DESCRIPTION

[0026] The details of the above purposes, technical configurations and effects of the present disclosure will be clearly understood from the following detailed description in conjunction with the accompanying drawings, which illustrate some embodiments of the present disclosure. Although exemplary embodiments of the present disclosure will be described, it will be apparent that those skilled in the art can practice the technical spirit of the present disclosure without being constrained or limited by the embodiments.

[0027] In addition, throughout the application, the same reference numerals represent the same components, and in the drawings, the length and thickness of a layer or region may be exaggerated for convenience. In addition, when a first element is referred to as being "on" a second element, the first element may be directly on the second element or indirectly on the second element with a third element interposed therebetween.

[0028] It will be understood that the terms "first" and "second" are used herein to describe various elements and are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0029] The terms used in the following description are only used to describe specific embodiments and are not intended to limit the present disclosure. Singular expressions include plural meanings unless the singular expressions are obviously different in context. In this application, the terms "comprise", "include" and "have" should be understood to represent the presence of specific characteristics, numbers, steps, operations, elements, parts or their combinations, but do not exclude the presence or addition of one or more other characteristics, numbers, steps, operations, elements, parts or their combinations.

[0030] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art. It should be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having the same meaning as the terms in the context of the relevant technology, and should not be interpreted as having an ideal or overly formal meaning unless clearly defined in this application.

[0031] In order to realize a double-sided display device using a liquid crystal display device, two liquid crystal display panels may be used.

[0032] Figure 1 is a schematic cross-sectional view of a double-sided display device implemented using a liquid crystal display device.

[0033] like Figure 1 As shown in the figure, a double-sided display device implemented using a liquid crystal display device includes: a first liquid crystal panel 10 and a second liquid crystal panel 20; and backlight units 70 and 80, which are arranged between the first liquid crystal panel 10 and the second liquid crystal panel 20 and are configured to emit light to the first liquid crystal panel 10 and the second liquid crystal panel 20, respectively.

[0034] The first liquid crystal panel 10 includes an upper substrate 10a and a lower substrate 10b with liquid crystal injected therebetween, and includes a spacer (not shown) for maintaining a constant gap between the upper substrate 10a and the lower substrate 10b. The second liquid crystal panel 20 includes an upper substrate 20a and a lower substrate 20b with liquid crystal injected therebetween, and includes a spacer (not shown) for maintaining a constant gap between the upper substrate 20a and the lower substrate 20b.

[0035] A plurality of black matrices and color filters are formed on the upper substrates 10a and 20a of the first liquid crystal panel 10 and the second liquid crystal panel 20, respectively. In addition, signal lines such as a plurality of gate lines (not shown) and data lines (not shown) are formed on each of the lower substrates 20b of the first liquid crystal panel 10 and the second liquid crystal panel 20, and a plurality of thin film transistors are formed in the intersection regions between the gate lines and the data lines.

[0036] A lower polarizing plate (not shown) is attached to the rear surface of each of the first liquid crystal panel 10 and the second liquid crystal panel 20 to polarize light from each of the backlight units 70 and 80, and an upper polarizing plate (not shown) is attached to the front surface of each of the first liquid crystal panel 10 and the second liquid crystal panel 20 to polarize light that has passed through each of the first liquid crystal panel 10 and the second liquid crystal panel 20.

[0037] The backlight units 70 and 80 include: light sources 72 and 82; light source housings 74 and 84 surrounding the light sources; light guide plates 50 and 60 configured to guide light introduced thereinto from the light sources 72 and 82 to travel to the first liquid crystal panel 10 and the second liquid crystal panel 20; a first optical sheet 30 stacked on the front surface of the light guide plate 50; and a second optical sheet 40 stacked on the rear surface of the light guide plate 60. The first optical sheet 30 and the first optical sheet 40 each include a plurality of optical sheets 32, 34, 36, 42, 44, and 46.

[0038] Each of the light sources 72 and 82 may be implemented as one or more light emitting diodes (LEDs) disposed in a row on a flexible circuit board (not shown), and may be disposed on one side surface of a corresponding one of the light guide plates 50 and 60. Light emitted from each of the light sources 72 and 82 is introduced into a corresponding one of the light guide plates 50 and 60 through a light incident surface formed on a side surface of each of the light guide plates 50 and 60. Each of the light source housings 74 and 84 includes a reflective surface formed on an inner surface thereof. Light emitted from each of the light sources 72 and 82 is reflected by the reflective surface of the corresponding one of the light source housings 74 and 84 and travels to the light incident surface of the corresponding one of the light guide plates 50 and 60.

[0039] Each of the light guide plates 50 and 60 converts light introduced thereinto from a corresponding one of the light sources 72 and 82 through its light incident surface into light distributed on its surface and guides the converted light to travel to a corresponding one of the first and second liquid crystal panels 10 and 20 .

[0040] The first optical sheet 30 is attached to the front surface of the light guide plate 50, and includes one or more first diffusion sheets 32, and one or more first prism sheets 34 and 36. The first optical sheet 30 serves to diffuse light introduced therein from the surface of the light guide plate 50 and uniformly irradiate the entire area of ​​the first liquid crystal panel 10.

[0041] The second optical sheet 40 is attached to the rear surface of the light guide plate 60, and includes one or more second diffusion sheets 42, and one or more second prism sheets 44 and 46. The second optical sheet 40 serves to diffuse light introduced therein from the surface of the light guide plate 60 and uniformly irradiate the entire area of ​​the second liquid crystal panel 20.

[0042] A lower cover 92 of the first liquid crystal panel 10 and a lower cover 94 of the second liquid crystal panel 20 may be included.

[0043] Reference Figure 1 The described double-sided display device requires two liquid crystal panels 10 and 20, two optical sheets 30 and 40, two light guide plates 50 and 60, and two light sources 72 and 82, resulting in increased cost and increased power consumption.

[0044] In order to overcome this disadvantage, a double-sided display device may be implemented using two liquid crystal panels and one backlight unit. Such a double-sided display device may be configured such that two liquid crystal panels are attached to both sides of the backlight unit.

[0045] Figure 2 is a schematic cross-sectional view of a double-sided display device using one backlight unit according to one embodiment.

[0046] like Figure 2As shown in the figure, a double-sided display device implemented using a backlight unit includes: a first liquid crystal panel 110 and a second liquid crystal panel 120; and a backlight unit 170, which is arranged between the first liquid crystal panel 110 and the second liquid crystal panel 120 and is configured to emit light to the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0047] The first liquid crystal panel 110 includes an upper substrate 110a and a lower substrate 110b with liquid crystal injected therebetween, and includes a spacer (not shown) for maintaining a constant gap between the upper substrate 110a and the lower substrate 110b. The second liquid crystal panel 120 includes an upper substrate 120a and a lower substrate 120b with liquid crystal injected therebetween, and includes a spacer (not shown) for maintaining a constant gap between the upper substrate 120a and the lower substrate 120b.

[0048] A plurality of black matrices and color filters are formed on each of the upper substrates 110 a and 120 a of the first and second liquid crystal panels 110 and 120 .

[0049] Signal lines such as a plurality of gate lines (not shown) and data lines (not shown) are formed on each of the lower substrates 110b and 120b of the first and second liquid crystal panels 110 and 120, and a plurality of thin film transistors are formed in crossing regions between the gate lines and the data lines.

[0050] An upper polarizing plate (not shown) is attached to a front surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light from the backlight unit 170, and a lower polarizing plate (not shown) is attached to a rear surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light that has passed through each of the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0051] The backlight unit 170 includes: a light source 172; a light source housing 174 surrounding the light source; a light guide plate 150, the light guide plate 150 being configured to guide light introduced therein from the light source 172 to travel to the first liquid crystal panel 110 and the second liquid crystal panel 120; a first optical sheet 130 stacked on the front surface of the light guide plate 150; and a second optical sheet 140 stacked on the rear surface of the light guide plate 150.

[0052] The light source 172 may be implemented as one or more light emitting diodes (LEDs) disposed in a row on a flexible circuit board (not shown), and may be disposed on one side surface of the light guide plate 150. Light emitted from the light source 172 is introduced into the light guide plate 150 through a light incident surface formed on a side surface of the light guide plate 150. The light source housing 174 includes a reflective surface formed on an inner surface thereof. Light emitted from the light source 172 is reflected by the reflective surface of the light source housing 174 and travels to the light incident surface of the light guide plate 150.

[0053] The light guide plate 150 converts light introduced thereinto from the light source 172 through a light incident surface thereof into light distributed on a surface thereof, and guides the converted light to proceed to the first and second liquid crystal panels 110 and 120 .

[0054] The first optical sheet 130 is attached to the front surface of the light guide plate 150 and includes one or more first diffusion sheets 132, and one or more first prism sheets 134 and 136. The first optical sheet 130 serves to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the first liquid crystal panel 110.

[0055] The second optical sheet 140 is attached to the rear surface of the light guide plate 150 and includes one or more second diffusion sheets 142, and one or more second prism sheets 144 and 146. The second optical sheet 140 serves to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the second liquid crystal panel 120.

[0056] and Figure 1 Compared with the double-sided display device shown in , the double-sided display device implemented using one backlight unit 170 can reduce costs and power consumption.

[0057] However, despite using Figure 2 A double-sided display device is realized with one backlight unit as shown in , but image quality may be deteriorated depending on an installation location or a viewing position.

[0058] Figure 3 is a diagram showing a position where a double-sided display device according to an embodiment of the present disclosure is installed.

[0059] Reference Figure 3 The double-sided display device according to an embodiment of the present disclosure may be installed, for example, on the ceiling of a carriage of a subway or a train (e.g., the Korean High Speed ​​Train (KTX) or the Super Rapid Train (SRT)), on the top of a taxi, on the ceiling of a large store, on the ceiling of a waiting room of a train station or a bus station, or on a platform of a train station or a bus station.

[0060] Figure 3 A case where a double-sided display device is installed on the ceiling of a compartment of a train is shown.

[0061] In the case of a car of KTX or SRT, there are seats facing the forward direction and seats facing the rearward direction. The double-sided display device is installed in the middle of the ceiling of the car, specifically, in a boundary area between the seats facing the forward direction and the seats facing the rearward direction, so that all passengers sitting in the seats facing the forward direction and the seats facing the rearward direction can view the double-sided display device.

[0062] In the case where the double-sided display device is installed on the ceiling of a train compartment, the double-sided display device is located at a position higher than the viewing position of the viewer (passenger).

[0063] However, when referring to Figure 1 and Figure 2 When the described double-sided display device is installed on the ceiling of a compartment of a train, that is, at a position higher than the viewing position of a viewer (passenger), the viewer (passenger) may not be able to view images displayed on the double-sided display device.

[0064] Therefore, two display panels mounted on both surfaces of the backlight unit need to be tilted at a predetermined angle so as to face a viewing position of a viewer.

[0065] However, although the two display panels are mounted on both surfaces of the backlight unit so as to be inclined at a predetermined angle, the following problems may occur: the viewer feels a difference in transparency, that is, feels as if the image floats above the display panels, the brightness is uneven, and the image quality is degraded.

[0066] Therefore, there is a need for a double-sided display device that can prevent a sense of difference in transparency from occurring and ensure uniform brightness when two display panels are mounted on both surfaces of a backlight unit so as to be inclined at a predetermined angle.

[0067] Figure 4 is a schematic cross-sectional view of a double-sided display device according to an embodiment of the present disclosure.

[0068] like Figure 4 As shown in , a double-sided display device according to one embodiment of the present disclosure may include: a first liquid crystal panel 110 and a second liquid crystal panel 120; and a backlight unit 170, which is arranged between the first liquid crystal panel 110 and the second liquid crystal panel 120 and is configured to emit light to the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0069] The first liquid crystal panel 110 and the second liquid crystal panel 120 may be disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle with respect to the backlight unit 170 .

[0070] The first liquid crystal panel 110 may include an upper substrate 110a and a lower substrate 110b with liquid crystal injected therebetween, and may include a spacer (not shown) for maintaining a constant gap between the upper substrate 110a and the lower substrate 110b. The second liquid crystal panel 120 may include an upper substrate 120a and a lower substrate 120b with liquid crystal injected therebetween, and may include a spacer (not shown) for maintaining a constant gap between the upper substrate 120a and the lower substrate 120b.

[0071] A plurality of black matrices and color filters may be formed on each of the upper substrates 110 a and 120 a of the first and second liquid crystal panels 110 and 120 .

[0072] Signal lines such as a plurality of gate lines (not shown) and data lines (not shown) may be formed on each of the lower substrates 110b and 120b of the first and second liquid crystal panels 110 and 120, and a plurality of thin film transistors may be formed in crossing regions between the gate lines and the data lines.

[0073] An upper polarizing plate (not shown) may be attached to a front surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light from the backlight unit 170, and a lower polarizing plate (not shown) may be attached to a rear surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light that has passed through each of the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0074] In addition, a first diffusion sheet 181 may be disposed on the rear surface of the lower substrate 110 b of the first liquid crystal panel 110 , and a second diffusion sheet 182 may be disposed on the rear surface of the lower substrate 120 b of the second liquid crystal panel 120 .

[0075] The backlight unit 170 may include: a light source 172; a light source housing 174 surrounding the light source; a light guide plate 150, the light guide plate 150 being configured to guide light introduced therein from the light source 172 to travel to the first liquid crystal panel 110 and the second liquid crystal panel 120; a first optical sheet 130 stacked on the front surface of the light guide plate 150; and a second optical sheet 140 stacked on the rear surface of the light guide plate 150.

[0076] The light source 172 may be implemented as one or more light emitting diodes (LEDs) disposed in a row on a flexible circuit board (not shown), and may be disposed on one side surface of the light guide plate 150. Light emitted from the light source 172 is introduced into the light guide plate 150 through a light incident surface formed on a side surface of the light guide plate 150. The light source housing 174 may include a reflective surface formed on an inner surface thereof. Light emitted from the light source 172 is reflected by the reflective surface of the light source housing 174 and travels to the light incident surface of the light guide plate 150.

[0077] The light guide plate 150 converts light introduced thereinto from the light source 172 through a light incident surface thereof into light distributed on a surface thereof, and guides the converted light to proceed to the first and second liquid crystal panels 110 and 120 .

[0078] The light guide plate 150 may include two light exit surfaces 152 and 153, and the light introduced into the light guide plate 150 from the light source 172 is irradiated to the first liquid crystal panel 110 and the second liquid crystal panel 120 from the two light exit surfaces 152 and 153, respectively, and a concave pattern 151 or a convex pattern is formed on at least one of the two light exit surfaces 152 and 153.

[0079] Although the light guide plate 150 is Figure 4 15 to include a concave pattern 151 formed on a light exiting surface 153, but the present disclosure is not limited thereto.

[0080] The first optical sheet 130 may be attached to the front surface of the light guide plate 150, and may include one or more third diffusion sheets 131 and 135, and one or more first prism sheets 133. The first optical sheet 130 may serve to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the first liquid crystal panel 110.

[0081] The second optical sheet 140 may be attached to the rear surface of the light guide plate 150, and may include one or more fourth diffusion sheets 141 and 145, and one or more second prism sheets 143. The second optical sheet 140 may serve to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the second liquid crystal panel 120.

[0082] Although the first optical sheet 130 is Figure 4 It is shown as including two diffusion sheets 131 and 135, and a prism sheet 133, and the second optical sheet 140 is Figure 4 140 is shown as including two diffusion sheets 141 and 145, and one prism sheet 143, but the present disclosure is not limited thereto. Each of the first optical sheet 130 and the second optical sheet 140 may include one diffusion sheet and two prism sheets.

[0083] like Figure 4 As shown in FIG. 1 , the first liquid crystal panel 110 and the first diffusion sheet 181 are inclined at a predetermined angle relative to the backlight unit 170 , and the second liquid crystal panel 120 and the second diffusion sheet 182 are also inclined at a predetermined angle relative to the backlight unit 170 .

[0084] That is, the first liquid crystal panel 110 and the first diffusion sheet 181 are installed to be inclined around the edge of the backlight unit 170 where the light source 172 is not provided, and the second liquid crystal panel 120 and the second diffusion sheet 182 are installed to be inclined around the edge of the backlight unit 170 where the light source 172 is not provided.

[0085] In other embodiments, the Figure 4 In the double-sided display device of the embodiment of the present disclosure shown in , the first diffusion sheet 181 and the second diffusion sheet 182 are omitted.

[0086] Figure 5 is a schematic cross-sectional view of a double-sided display device according to another embodiment of the present disclosure.

[0087] As described above, an upper polarizing plate (not shown) may be attached to a front surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light from the backlight unit 170, and a lower polarizing plate (not shown) may be attached to a rear surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light that has passed through each of the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0088] In this embodiment, instead of the first and second diffusion sheets 181 and 182, lower polarizing plates 191 and 192 having the same haze as the first and second diffusion sheets 181 and 182 may be attached to rear surfaces of the first and second liquid crystal panels 110 and 120, respectively.

[0089] like Figure 5 As shown in , a double-sided display device according to another embodiment of the present disclosure may include: a first liquid crystal panel 110 and a second liquid crystal panel 120; and a backlight unit 170, which is arranged between the first liquid crystal panel 110 and the second liquid crystal panel 120 and is configured to emit light to the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0090] The first liquid crystal panel 110 and the second liquid crystal panel 120 may be disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle with respect to the backlight unit 170 .

[0091] The first liquid crystal panel 110 may include an upper substrate 110a and a lower substrate 110b with liquid crystal injected therebetween, and may include a spacer (not shown) for maintaining a constant gap between the upper substrate 110a and the lower substrate 110b. The second liquid crystal panel 120 may include an upper substrate 120a and a lower substrate 120b with liquid crystal injected therebetween, and may include a spacer (not shown) for maintaining a constant gap between the upper substrate 120a and the lower substrate 120b.

[0092] A plurality of black matrices and color filters may be formed on each of the upper substrates 110 a and 120 a of the first and second liquid crystal panels 110 and 120 .

[0093] Signal lines such as a plurality of gate lines (not shown) and data lines (not shown) may be formed on each of the lower substrates 110b and 120b of the first and second liquid crystal panels 110 and 120, and a plurality of thin film transistors may be formed in crossing regions between the gate lines and the data lines.

[0094] An upper polarizing plate (not shown) may be attached to a front surface of each of the first liquid crystal panel 110 and the second liquid crystal panel 120 to polarize light from the backlight unit 170. A first lower polarizing plate 191 may be attached to a rear surface of the first liquid crystal panel 110 to polarize light having passed through the first liquid crystal panel 110, and a second lower polarizing plate 192 may be attached to a rear surface of the second liquid crystal panel 120 to polarize light having passed through the second liquid crystal panel 120.

[0095] The first lower polarizing plate 191 and the second lower polarizing plate 192 have the same Figure 4 The first diffusion sheet 181 and the second diffusion sheet 182 are described to have the same haze.

[0096] The backlight unit 170 may include: a light source 172; a light source housing 174 surrounding the light source; a light guide plate 150 configured to guide light introduced therein from the light source 172 to travel to the first liquid crystal panel 110 and the second liquid crystal panel 120; a first optical sheet 130 stacked on the front surface of the light guide plate 150; and a second optical sheet 140 stacked on the rear surface of the light guide plate 150.

[0097] The light source 172 may be implemented as one or more light emitting diodes (LEDs) disposed in a row on a flexible circuit board (not shown), and may be disposed on one side surface of the light guide plate 150. Light emitted from the light source 172 is introduced into the light guide plate 150 through a light incident surface formed on a side surface of the light guide plate 150. The light source housing 174 may include a reflective surface formed on an inner surface thereof. Light emitted from the light source 172 is reflected by the reflective surface of the light source housing 174 and travels to the light incident surface of the light guide plate 150.

[0098] The light guide plate 150 converts light introduced thereinto from the light source 172 through a light incident surface thereof into light distributed on a surface thereof, and guides the converted light to proceed to the first and second liquid crystal panels 110 and 120 .

[0099] The light guide plate 150 may include two light exit surfaces 152 and 153, and the light introduced into the light guide plate 150 from the light source 172 is irradiated to the first liquid crystal panel 110 and the second liquid crystal panel 120 from the two light exit surfaces 152 and 153, respectively, and a concave pattern 151 or a convex pattern is formed on at least one of the two light exit surfaces 152 and 153.

[0100] Although the light guide plate 150 is Figure 5 15 to include a concave pattern 151 formed on a light exiting surface 153, but the present disclosure is not limited thereto.

[0101] The first optical sheet 130 may be attached to the front surface of the light guide plate 150, and may include one or more third diffusion sheets 131 and 135, and one or more first prism sheets 133. The first optical sheet 130 may serve to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the first liquid crystal panel 110.

[0102] The second optical sheet 140 may be attached to the rear surface of the light guide plate 150, and may include one or more fourth diffusion sheets 141 and 145, and one or more second prism sheets 143. The second optical sheet 140 may serve to diffuse light introduced therein from the surface of the light guide plate 150 and uniformly irradiate the entire area of ​​the second liquid crystal panel 120.

[0103] Although the first optical sheet 130 is Figure 5 It is shown as including two diffusion sheets 131 and 135, and a prism sheet 133, and the second optical sheet 140 is Figure 5 140 is shown as including two diffusion sheets 141 and 145, and one prism sheet 143, but the present disclosure is not limited thereto. Each of the first optical sheet 130 and the second optical sheet 140 may include one diffusion sheet and two prism sheets.

[0104] like Figure 5 As shown in FIG. 1 , the first liquid crystal panel 110 and the first lower polarizing plate 191 are tilted at a predetermined angle relative to the backlight unit 170 , and the second liquid crystal panel 120 and the second lower polarizing plate 192 are also tilted at a predetermined angle relative to the backlight unit 170 .

[0105] That is, the first liquid crystal panel 110 and the first lower polarizing plate 191 are installed to be inclined around the edge of the backlight unit 170 where the light source 172 is not provided, and the second liquid crystal panel 120 and the second lower polarizing plate 192 are installed to be inclined around the edge of the backlight unit 170 where the light source 172 is not provided.

[0106] As mentioned above Figure 4 As described, the double-sided display device according to an embodiment of the present disclosure is configured such that a first diffusion sheet 181 is disposed on the rear surface of the lower substrate 110b of the first liquid crystal panel 110, and a second diffusion sheet 182 is disposed on the rear surface of the lower substrate 120b of the second liquid crystal panel 120. Alternatively, as described above with reference to Figure 5 As described, a double-sided display device according to another embodiment of the present disclosure is configured such that a first lower polarizing plate 191 is disposed on the rear surface of the lower substrate 110b of the first liquid crystal panel 110, and a second lower polarizing plate 192 is disposed on the rear surface of the lower substrate 120b of the second liquid crystal panel 120.

[0107] Therefore, when two display panels are mounted on both surfaces of the backlight unit so as to be inclined at a predetermined angle, it is possible to prevent a sense of difference in transparency from occurring and ensure uniform brightness.

[0108] Figure 6 The characteristics of various double-sided display devices are shown.

[0109] Figure 6 The "A" in the figure shows the Figure 2 Characteristics of a double-sided display device using one backlight unit are described.

[0110] Figure 6 "B" in FIG. 1 shows that when the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle relative to the backlight unit 170, Figure 4 and Figure 5 Characteristics of a double-sided display device in which the first and second diffusion sheets 181 and 182 or the first and second lower polarizing plates 191 and 192 are not attached to rear surfaces of the first and second liquid crystal panels 110 and 120 are described.

[0111] Figure 6 "C" in FIG. 1 shows that when the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle relative to the backlight unit 170, Figure 4 and Figure 5The characteristics of a double-sided display device described in which the first diffuser 181 and the second diffuser 182 or the first lower polarizing plate 191 and the second lower polarizing plate 192 are not attached to the rear surfaces of the first liquid crystal panel 110 and the second liquid crystal panel 120, and the first optical sheet 130 and the second optical sheet 140 are attached to the rear surfaces of the first liquid crystal panel 110 and the second liquid crystal panel 120.

[0112] Figure 6 "D" in FIG. 1 shows that when the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle relative to the backlight unit 170, Figure 4 and Figure 5 Characteristics of a double-sided display device in which the first and second diffusion sheets 181 and 182 or the first and second lower polarizing plates 191 and 192 are attached to rear surfaces of the first and second liquid crystal panels 110 and 120 are described.

[0113] from Figure 6 As can be seen from "B" and "C" in FIG. 1 , when the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle relative to the backlight unit 170, Figure 4 and Figure 5 In the described case where the first diffuser 181 and the second diffuser 182 or the first lower polarizing plate 191 and the second lower polarizing plate 192 are not attached to the rear surfaces of the first liquid crystal panel 110 and the second liquid crystal panel 120, or the first optical sheet 130 and the second optical sheet 140 are attached to the rear surfaces of the first liquid crystal panel 110 and the second liquid crystal panel 120 without the first diffuser 181 and the second diffuser 182 or the first lower polarizing plate 191 and the second lower polarizing plate 192, the viewer feels a sense of difference in transparency, that is, it feels as if the image is floating above the display panel, and the brightness uniformity is deteriorated.

[0114] On the other hand, as Figure 6 As can be seen from “D” in FIG. 1 , the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at a predetermined angle relative to the backlight unit 170, and referring to Figure 4 and Figure 5 In the described case where the first and second diffusion sheets 181 and 182 or the first and second lower polarizing plates 191 and 192 are attached to the rear surfaces of the first and second liquid crystal panels 110 and 120 , a sense of difference in transparency is prevented from occurring, and the brightness is uniform.

[0115] According to the angle at which the first liquid crystal panel 110 and the second liquid crystal panel 120 disposed on both sides of the backlight unit 170 are tilted, the characteristics of the double-sided display device may vary.

[0116] Figure 7 Characteristics of the double-sided display device according to the tilt angles of the first liquid crystal panel and the second liquid crystal panel are shown.

[0117] Figure 7 'A' in FIG. 1 shows characteristics of a double-sided display device in which the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at 15 degrees.

[0118] Figure 7 'B' in FIG. 1 shows characteristics of a double-sided display device in which the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at 25 degrees.

[0119] Figure 7 'C' in FIG. 1 shows characteristics of a double-sided display device in which the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at 35 degrees.

[0120] Figure 7 'D' in FIG. 1 shows characteristics of a double-sided display device in which the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at 45 degrees.

[0121] from Figure 7 As can be seen from “A” to “D” in FIG. 1 , when the first liquid crystal panel 110 and the second liquid crystal panel 120 are disposed on both sides of the backlight unit 170 so as to be inclined at an angle of 1 to 25 degrees, the image quality is maintained.

[0122] When the first liquid crystal panel 110 and the second liquid crystal panel 120 are installed to be inclined at a predetermined angle with respect to the backlight unit 170 , the image quality of the double-sided display device may vary according to the position of the light source 172 .

[0123] Figure 8 “A” in the figure shows the characteristics of a surface double-sided display device in which the first liquid crystal panel 110 and the second liquid crystal panel 120 are installed to be inclined at a predetermined angle relative to the backlight unit 170 around the edge of the surface of the light guide plate 150 opposite to the light incident surface of the light guide plate 150 on which the light source 172 is arranged.

[0124] Figure 8 “B” in FIG. 1 shows characteristics of a double-sided display device in which the first and second liquid crystal panels 110 and 120 are installed to be inclined at a predetermined angle relative to the backlight unit 170 around the edge of the light incident surface of the light guide plate 150 on which the light source 172 is provided.

[0125] from Figure 8It can be seen from "A" and "B" in that when the first liquid crystal panel 110 and the second liquid crystal panel 120 are installed to be inclined at a predetermined angle relative to the backlight unit 170 around the edge of the surface of the light guide plate 150 opposite to the light incident surface of the light guide plate 150 on which the light source 172 is arranged, the average brightness and brightness uniformity are higher than the average brightness and brightness uniformity when the first liquid crystal panel 110 and the second liquid crystal panel 120 are installed to be inclined around the edge of the light incident surface of the light guide plate 150 on which the light source 172 is arranged.

[0126] As described above, in the double-sided display device according to the embodiment of the present disclosure, two display panels are mounted on both surfaces of the backlight unit so as to be inclined at a predetermined angle suitable for the viewing position of the viewer, and a diffusion sheet or a polarizing plate having the same haze as that of the diffusion sheet is provided on the rear surface of each display panel. Therefore, the power consumption of the double-sided display device can be reduced, the image quality (front side of screen (FOS)) can be improved, the difference in transparency can be prevented, and uniform brightness can be ensured.

[0127] As is apparent from the above description, the double-sided display device according to the embodiment of the present disclosure has the following effects.

[0128] First, since two display panels are mounted on both surfaces of a backlight unit to be inclined at a predetermined angle suitable for a viewing position of a viewer, power consumption of a double-sided display device can be reduced and image quality (front side of screen (FOS)) can be improved.

[0129] Second, since a diffusion sheet or a polarizing plate having the same haze as the diffusion sheet is disposed on the rear surface of each of the display panels mounted on both surfaces of the backlight unit so as to be inclined at a predetermined angle, a difference in transparency can be prevented from occurring and uniform brightness can be ensured.

[0130] Those skilled in the art will appreciate that, without departing from the technical concept of the present disclosure, various modifications and substitutions may be made according to the above description. Therefore, the technical scope of the present disclosure is defined by the appended claims rather than by the detailed description of the present disclosure.

Claims

1. A double-sided display device, comprising: A backlight unit, wherein the backlight unit has a light guide plate; a first display panel, the first display panel being on a first light exiting surface of the backlight unit; as well as a second display panel, the second display panel being on a second light exiting surface of the backlight unit, the second light exiting surface being opposite to the first light exiting surface, The first display panel and the second display panel are inclined at a predetermined angle relative to the backlight unit.

2. The double-sided display device according to claim 1, further comprising: a first diffusion sheet on a rear surface of the first display panel facing the first light exiting surface of the backlight unit; and A second diffusion sheet is on a rear surface of the second display panel facing the second light exiting surface of the backlight unit.

3. The double-sided display device according to claim 2, further comprising: a first polarizing plate on a rear surface of the first display panel facing the first light exiting surface of the backlight unit, the first polarizing plate having the same haze as the first diffusion sheet; and A second polarizing plate is on a rear surface of the second display panel facing the second light exiting surface of the backlight unit, the second polarizing plate having the same haze as the second diffusion sheet. 4 . The double-sided display device according to claim 1 , wherein the first display panel and the second display panel are inclined at an angle within a range of 1 to 25 degrees.

5. The double-sided display device according to claim 1, wherein the backlight unit comprises: a light source configured to emit light to a light incident surface of the light guide plate; a first optical sheet, the first optical sheet being located on a first light exiting surface of the light guide plate; and A second optical sheet is located on a second light exiting surface of the light guide plate opposite to the first light exiting surface. 6 . The double-sided display device according to claim 5 , wherein each of the first optical sheet and the second optical sheet comprises at least one diffusion sheet and at least one prism sheet. 7 . The double-sided display device according to claim 5 , wherein the light guide plate comprises a concave pattern or a convex pattern on at least one of the first light exit surface and the second light exit surface of the light guide plate. 8 . The double-sided display device according to claim 5 , wherein the first display panel and the second display panel are inclined at the predetermined angle relative to the backlight unit around an edge of a surface of the light guide plate opposite to the light incident surface of the light guide plate. 9 . The double-sided display device according to claim 5 , wherein at least one of the first optical sheet and the second optical sheet comprises one or more diffusion sheets and one or more prism sheets. 10 . The double-sided display device according to claim 5 , wherein at least one of the first optical sheet and the second optical sheet comprises two diffusion sheets and one prism sheet. 11 . The double-sided display device according to claim 2 , wherein the first diffusion sheet and the second diffusion sheet are inclined at the predetermined angle with respect to the backlight unit. 12 . The double-sided display device according to claim 3 , wherein the first polarizing plate and the second polarizing plate are inclined at the predetermined angle with respect to the backlight unit.

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