KR102483228B1 - Light controlling device, transparent display device including the same - Google Patents

Abstract

A light control device according to the present invention includes a first substrate and a second substrate facing each other, a first electrode disposed on one surface of the first substrate facing the second substrate, and the second substrate facing the first substrate. A second electrode disposed on one surface of a substrate, a barrier rib disposed on one surface of the first electrode facing the second substrate and disposed between the first substrate and the second substrate, the first electrode and the second electrode A liquid crystal layer disposed between electrodes and transmitting or blocking light, and a first alignment layer disposed on the first electrode to align the liquid crystal layer, the first alignment layer determining the alignment direction of the liquid crystal layer. A binder positioned between the alignment material and the first electrode may be included to improve adhesion between the material and the alignment material.

Description

Light control device and transparent display device including the same {LIGHT CONTROLLING DEVICE, TRANSPARENT DISPLAY DEVICE INCLUDING THE SAME}

The present invention relates to a light control device and a transparent display device.

BACKGROUND OF THE INVENTION [0002] As we enter the information age, the display field for processing and displaying a large amount of information has developed rapidly, and in response to this, various display devices have been developed and are in the spotlight. Specific examples of such a display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), an electric light emitting display device ( and Electroluminescence Display device (ELD), Organic Light Emitting Diodes (OLED), and the like.

Recently, display devices have become thinner, lighter, and have lower power consumption, and as a result, application fields of display devices are continuously increasing. In particular, the display device is used as one of the user interfaces in most electronic devices or mobile devices.

In addition, recently, research on a transparent display device that allows a user to see an object or a background located on the rear side of the display device has been actively researched. A transparent display device has advantages in space utilization, interior design, and design, and may have various application fields. The transparent display device can solve the spatial and visual limitations of existing electronic devices by implementing functions of information recognition, information processing, and information display with transparent electronic devices. For example, the transparent display device may be applied to a window of a building or a vehicle to be implemented as a smart window that shows a background or displays an image.

The transparent display device may be implemented as an organic light emitting display device, and in this case, has an advantage of low power consumption, but has a disadvantage in that the contrast ratio is lowered in a light environment, although there is no problem in the contrast ratio in a dark environment. A contrast ratio in a dark environment may be defined as a dark room contrast ratio and a contrast ratio in a light environment may be defined as a bright room contrast ratio. That is, since the transparent display device has a transmissive area to allow viewing of objects or backgrounds located on the rear side, there is a problem in that the bright-room contrast ratio is lowered. Therefore, when the transparent display device is implemented as an organic light emitting display device, a light control device capable of implementing a light-blocking mode that blocks light and a transmission mode that transmits light is needed to prevent the bright-room contrast ratio from deteriorating.

1 is a diagram showing a general light control device, and FIG. 2 shows a manufacturing process of a general light control device.

1 and 2, a general light control device 10 includes a first substrate 1, a second substrate 2, a first electrode 3, a second electrode 4, a barrier 5, It includes a first alignment layer 6 , a second alignment layer 7 and a liquid crystal layer 8 .

Each of the first and second substrates 1 and 2 may be a plastic film. For example, each of the first and second substrates 1 and 2 includes a cellulose resin such as triacetyl cellulose (TAC) or diacetyl cellulose (DAC), norbornene derivatives, and the like. It may be a sheet or film.

Each of the first and second electrodes 3 and 4 is made of silver oxide (eg AgO or Ag ₂ O or Ag ₂ O ₃ ), aluminum oxide (eg Al ₂ O ₃ ), or tungsten oxide (eg WO). ₂ or WO ₃ or W ₂ O ₃ ), magnesium oxide (eg MgO), or molybdenum oxide (eg MoO ₃ ).

Each of the first alignment layer and the second alignment layers 6 and 7 is a vertical alignment layer for vertically arranging the liquid crystal layer 8 when a voltage is applied to the first and second electrodes 3 and 4. can

The liquid crystal layer 8 may be in a Polymer Networked Liquid Crystal (PNLC) mode including a plurality of liquid crystal cells, ionic dyes, and dichroic dyes.

As shown in FIG. 2 , in a general light control device, a first substrate 1 and a second substrate 2 are bonded through a roll-to-roll processing (R2R) process. At this time, in order to vertically align the liquid crystal layer, heat treatment at a high temperature of 180 degrees or more is required. An adhesive is also needed to bond these homeotropic alignment materials to the substrates 1 and 2. However, surface treatment having hydrophobic properties is required for vertical alignment, and such hydrophobic properties may weaken adhesive strength due to the hydrophilic properties of the first and second substrates 1 and 2 . That is, vertical alignment and adhesive strength have a trade-off relationship.

The present invention has been made to solve the above problems, and a technical problem is to obtain a light control device capable of vertical alignment of a liquid crystal layer at a low temperature.

In addition, it is another technical challenge to obtain a light control device having hydrophobicity and improved adhesion.

In order to solve the above problems, a light control device according to the present invention includes a first substrate and a second substrate facing each other, a first electrode disposed on one surface of the first substrate facing the second substrate, and the first substrate. A second electrode disposed on one surface of the second substrate facing the substrate, a barrier rib disposed on one surface of the first electrode facing the second substrate and disposed between the first substrate and the second substrate; A liquid crystal layer disposed between the first electrode and the second electrode and transmitting or blocking light, and a first alignment layer disposed on the first electrode to align the liquid crystal layer, the first alignment layer comprising the liquid crystal layer It may include an alignment material that determines an alignment direction of the alignment material and a binder positioned between the alignment material and the first electrode to improve adhesion of the alignment material.

According to the means for solving the above problems, it is possible to obtain a light control device capable of vertically aligning a liquid crystal layer at a low temperature.

In addition, according to the means for solving the above problems, it is possible to obtain a light control device having hydrophobicity and improved adhesive strength.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention will be described below, or will be clearly understood by those skilled in the art from such description and description.

1 is a view showing a conventional general light control device.
2 is a view showing a manufacturing process of a conventional general light control device.
3 is a perspective view showing a transparent display device according to the present invention.
4 is a plan view illustrating a transparent display device according to the present invention.
FIG. 5 is a diagram showing a transmission area and an emission area of the display area of FIG. 4 .
FIG. 6 is a cross-sectional view along the line II' of FIG. 5 .
7 is a perspective view showing a light control device according to the present invention.
FIG. 8 is a cross-sectional view along line II-II' of FIG. 7 .
9 is a diagram for explaining the structure of an alignment layer of a light control device according to the present invention.
10A to 10D are diagrams for explaining the effect of the light control device according to the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. It can also include non-continuous cases unless is used.

Although first, second, 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 another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

3 is a perspective view showing a transparent display device according to an exemplary embodiment of the present invention. 4 is a plan view illustrating a transparent display panel, a gate driver, a source drive IC, a flexible film, a circuit board, and a timing controller of a transparent display device according to an exemplary embodiment of the present invention. FIG. 5 is an exemplary view showing a transmissive part and a light emitting part of the display area of FIG. 4 . FIG. 6 is a cross-sectional view taken along line II′ of FIG. 5 . 7 is a perspective view showing in detail a light control device according to an embodiment of the present invention.

Hereinafter, a transparent display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3 to 7 . 3 to 7, the X axis represents a direction parallel to the gate line, the Y axis represents a direction parallel to the data line, and the Z axis represents the height direction of the transparent display device.

3 to 7 , a transparent display device according to an embodiment of the present invention includes a transparent display panel 100, a gate driver 120, a source drive integrated circuit (hereinafter referred to as "IC") (130 ), a flexible film 140, a circuit board 150, a timing controller 160, a light control device 200, and an adhesive layer 300.

The transparent display device according to the embodiment of the present invention has been described mainly as being implemented as an organic light emitting display (OLED), but may also be implemented as a liquid crystal display (LCD) or an electrophoresis display (ELD). can

The transparent display panel 100 includes a lower substrate 111 and an upper substrate 112 . The upper substrate 112 may be an encapsulation substrate. The lower substrate 111 is formed to be larger than the upper substrate 112 , and thus, a portion of the lower substrate 111 may be exposed without being covered by the upper substrate 112 .

Gate lines and data lines may be formed in the display area DA of the transparent display panel 100 , and light emitting units may be formed in intersection areas of the gate lines and data lines. The light emitting units of the display area DA may display an image.

As shown in FIG. 5 , the display area DA includes a transmission area TA and an emission area EA. In the transparent display panel 100, an object or a background located on the rear surface of the transparent display panel 100 can be seen through the transparent areas TA, and an image can be displayed through the light emitting areas EA. . Although FIG. 5 illustrates that the transmission area TA and the light emitting area EA are formed long in the gate line direction (X-axis direction), it is not limited thereto. That is, the transmission area TA and the light emitting area EA may be formed long in the data line direction (Y-axis direction).

The transmission area TA is an area through which incident light passes almost as it is. The light emitting area EA is an area that emits light. The light emitting area EA may include a plurality of pixels P, and each of the pixels P may include a red light emitting part RE, a green light emitting part GE, and a blue light emitting part BE, as shown in FIG. 5 . It has been exemplified to include, but is not limited thereto. For example, each of the pixels P may further include a white light emitting part in addition to the red light emitting part RE, the green light emitting part GE, and the blue light emitting part BE. Alternatively, each of the pixels P may emit a red light emitting part RE, a green light emitting part GE, a blue light emitting part BE, a yellow light emitting part, a magenta light emitting part, and a cyan light emitting part. Among the parts, at least two or more light emitting parts may be included.

The red light emitting part RE is an area emitting red light, the green light emitting part GE is an area emitting green light, and the blue light emitting part BE is an area emitting blue light. The red light emitting part RE, the green light emitting part GE, and the blue light emitting part BE of the light emitting area EA emit predetermined light and correspond to non-transmitting areas that do not transmit incident light.

A transistor T, an anode electrode AND, an organic layer EL, and a cathode electrode CAT are provided in each of the red light emitting unit RE, the green light emitting unit GE, and the blue light emitting unit BE, as shown in FIG. 6 . It can be.

The transistor T includes an active layer ACT provided on the lower substrate 111, a first insulating film I1 provided on the active layer ACT, and a gate electrode GE provided on the first insulating film I1. , a second insulating film I2 provided on the gate electrode GE, and a source provided on the second insulating film I2 and connected to the active layer ACT through the first and second contact holes CNT1 and CNT2. An electrode SE and a drain electrode DE are included. 6 illustrates that the transistor T is formed in a top-gate method, but is not limited thereto, and may be formed in a bottom-gate method.

The anode electrode AND is connected to the drain electrode DE of the transistor T through the third contact hole CNT3 penetrating the interlayer insulating film ILD provided on the source electrode SE and the drain electrode DE. . A barrier rib is provided between the anode electrodes AND that are adjacent to each other, so that the anode electrodes AND that are adjacent to each other can be electrically insulated from each other.

An organic layer EL is provided on the anode electrode AND. The organic layer EL may include a hole transporting layer, an organic light emitting layer, and an electron transporting layer. A cathode electrode CAT is provided on the organic layer EL and the barrier rib W. When voltage is applied to the anode electrode AND and the cathode electrode CAT, holes and electrons move to the organic light emitting layer through the hole transport layer and the electron transport layer, respectively, and combine with each other in the organic light emitting layer to emit light.

Although FIG. 6 illustrates that the transparent display panel 100 is implemented in a top emission method, it is not limited thereto and may be implemented in a bottom emission method. The light control device 200 is preferably disposed in a direction opposite to the direction in which the transparent display panel 100 emits light. Accordingly, the light control device 200 is disposed under the transparent display panel 100, that is, under the lower substrate 111, in the top emission method, and above the transparent display panel 100, that is, the upper substrate, in the bottom emission method. It is preferably arranged above (112).

In the top emission method, since the organic layer EL emits light toward the upper substrate, the transistor T may be widely provided under the barrier rib W and the anode electrode AND. Accordingly, the top emission method has an advantage in that the design area of the transistor T is wider than that of the bottom emission method. In the top emission method, it is preferable that the anode electrode AND is formed of a highly reflective metal material such as aluminum or a laminated structure of aluminum and ITO, and the cathode electrode CAT is formed of a transparent metal material such as ITO or IZO.

As described above, each of the pixels P of the transparent display device according to the exemplary embodiment of the present invention includes a transmission area TA that passes incident light almost as it is and an emission area EA that emits light. . As a result, in the embodiment of the present invention, an object or a background located on the rear surface of the transparent display device can be viewed through the transparent areas TA of the transparent display device.

The gate driver 120 supplies gate signals to the gate lines according to the gate control signal input from the timing controller 160 . 4 illustrates that the gate driver 120 is formed outside one side of the display area DA of the transparent display panel 100 by a gate driver in panel (GIP) method, but is not limited thereto. That is, the gate driver 120 may be formed on the outside of both sides of the display area DA of the transparent display panel 100 by the GIP method, or may be manufactured as a driving chip and mounted on a flexible film, and may be formed using a tape automated bonding (TAB) method. It may also be attached to the transparent display panel 100 in this way.

The source drive IC 130 receives digital video data and a source control signal from the timing controller 160 . The source driver IC 130 converts digital video data into analog data voltages according to a source control signal and supplies them to data lines. When the source drive IC 130 is manufactured as a driving chip, it may be mounted on the flexible film 140 in a chip on film (COF) or chip on plastic (COP) method.

The lower substrate 111 may be formed to be larger than the upper substrate 112 , so that a portion of the lower substrate 111 may be exposed without being covered by the upper substrate 112 . Pads, such as data pads, are provided on a portion of the lower substrate 111 that is exposed and not covered by the upper substrate 112 . Wires connecting pads and the source drive IC 130 and wires connecting pads and wires of the circuit board 150 may be formed on the flexible film 140 . The flexible film 140 is attached to the pads using an anisotropic conducting film, and thereby the pads and the wires of the flexible film 140 can be connected.

The circuit board 150 may be attached to the flexible films 140 . A plurality of circuits implemented as driving chips may be mounted on the circuit board 150 . For example, the timing controller 160 may be mounted on the circuit board 150 . The circuit board 150 may be a printed circuit board or a flexible printed circuit board.

The timing controller 160 receives digital video data and timing signals from an external system board (not shown). The timing controller 160 generates a gate control signal for controlling the operation timing of the gate driver 120 and a source control signal for controlling the source drive ICs 130 based on the timing signal. The timing controller 160 supplies gate control signals to the gate driver 120 and supplies source control signals to the source drive ICs 130 .

FIG. 8 is a cross-sectional view along the line II-II′ shown in FIG. 7 . Hereinafter, the light control device 200 according to the present invention will be described in detail with reference to FIG. 7 .

The light control device 200 may block incident light in a light blocking mode and transmit incident light in a transmission mode. The light control device 200 according to the present invention includes a first substrate 210, a second substrate 220, a first electrode 230, a second electrode 240, a liquid crystal layer 250, an alignment film 260, A transparent adhesive 270 and a barrier rib 280 may be included.

Each of the first and second substrates 210 and 220 may be a plastic film. For example, each of the first and second substrates 210 and 220 may be formed of a cellulose resin such as triacetyl cellulose (TAC) or diacetyl cellulose (DAC), a COP (such as norbornene derivatives), or the like. cyclo olefin polymer), COC (cyclo olefin copolymer), PMMA (acrylic resin such as poly(methylmethacrylate), polyolefin such as PC (polycarbonate), PE (polyethylene) or PP (polypropylene), PVA ( polyester such as polyvinyl alcohol), polyether sulfone (PES), polyetheretherketone (PEEK), polyetherimide (PEI), polyethylenenaphthalate (PEN), polyethyleneterephthalate (PET), polyimide (PI), polysulfone (PSF), or fluorine It may be a sheet or film containing a fluoride resin or the like, but is not limited thereto.

A first electrode 230 is provided on one surface of the first substrate 210, and a second electrode 240 is provided on one surface of the second substrate 220 facing the first substrate 210. Each of the first and second electrodes 230 and 240 may be a transparent electrode.

Each of the first and second electrodes 230 and 240 is silver oxide (eg AgO or Ag ₂ O or Ag ₂ O ₃ ), aluminum oxide (eg Al ₂ O ₃ ), or tungsten oxide (eg WO ₂ or WO ₃ or W ₂ O ₃ ), magnesium oxide (eg MgO), molybdenum oxide (eg MoO ₃ ), zinc oxide (eg ZnO), tin oxide (eg SnO ₂ ), indium oxide (eg In ₂ O ₃ ), chromium oxide (eg CrO ₃ or Cr ₂ O ₃ ), antimony oxide (eg Sb ₂ O ₃ or Sb ₂ O ₅ ), titanium oxide (eg TiO ₂ ), nickel oxide (eg NiO ), copper oxide (eg CuO or Cu ₂ O), vanadium oxide (eg V ₂ O ₃ or V ₂ O ₅ ), cobalt oxide (eg CoO), iron oxide (eg Fe ₂ O ₃ or Fe ₃ O ₄ ), niobium oxide (eg Nb ₂ O ₅ ), indium tin oxide (eg Indium Tin Oxide, ITO), indium zinc oxide (eg Indium Zinc Oxide, IZO), aluminum doped zinc oxide (eg Aluminum doped zinc oxide (ZAO), aluminum doped tin oxide (eg, Aluminum Tin Oxide, TAO), or antimony tin oxide (eg, Antimony Tin Oxide, ATO), but is not limited thereto.

The liquid crystal layer 250 is disposed between the first electrode 230 and the second electrode 240 . The liquid crystal layer 250 includes cholesteric liquid crystals 251 , dichroic dyes 253 and a polymer network 255 .

In addition, the liquid crystal layer 250 includes a chiral dopant or a photo-sensitive chiral dopant that induces a helical structure in the cholesteric liquid crystals 251 and the dichroic dyes 253, and A photoinitiator may be further included. The cholesteric liquid crystal 251 may be referred to as a chiral nematic liquid crystal.

The cholesteric liquid crystals 251 may undergo phase change into a planar state, a focal conic state, and a homeotropic state. In the present invention, the cholesteric liquid crystals 251 included in the liquid crystal layer 250 are controlled to a homeotropic state in a transmission mode and a focal conic state in a light blocking mode.

The cholesteric liquid crystals 251 may be nematic liquid crystals. The cholesteric liquid crystals 251 may be positive liquid crystals. The positive liquid crystals are aligned in a vertical direction (Z-axis direction) by a vertical electric field when a voltage is applied to each of the first electrode 230 and the second electrode 240 .

The dichroic dyes 253 may be dyes that absorb light. For example, the dichroic dyes 253 are black dyes that absorb all visible light wavelength bands or absorb light other than a specific color (eg, red) wavelength range and a specific color (eg, red) wavelength band. It may be a dye that reflects the light of It is preferable that the dichroic dyes 253 are black dyes in order to increase the light blocking rate as in the embodiment of the present invention, but is not limited thereto.

The dichroic dye 253 may be made of a dye having a color, and has any one of black, red, green, blue, and yellow colors, or any of these colors. It can have a color that consists of a mixture. For example, when the light control device 200 is coupled to the rear surface of the transparent display panel, light coming from the rear surface must be blocked to improve visibility of the image while displaying an image. In this case, the dichroic dye 253 may consist of a black dye. In addition, by selectively changing the color of the dichroic dye 253 according to the place and purpose where the light control device 200 is used, aesthetics can be provided to the user.

Also, when the cholesteric liquid crystals 251 are positive liquid crystals, the dichroic dyes 253 may have positive liquid crystal characteristics.

The light control device 200 may increase the amount of the dichroic dyes 253 in the liquid crystal layer 250 to increase the light blocking rate in the light blocking mode, but in this case, the transmittance may decrease. Accordingly, the amount of the dichroic dyes 253 in the liquid crystal layer 250 may be set in consideration of the light blocking rate in the light blocking mode and the transmittance in the transmission mode.

The cholesteric liquid crystals 251 and the dichroic dyes 253 may be arranged in a vertical direction (Z-axis direction) in a homeotropic state. That is, the cholesteric liquid crystals 251 and the dichroic dyes 253 may be aligned in a vertical direction (Z-axis direction) in a homeotropic state.

The cholesteric liquid crystals 251 and the dichroic dyes 253 are spirally rotated by a chiral dopant in a focal conic state. Also, the cholesteric liquid crystals 251 and the dichroic dyes 252 arranged in a spiral structure are randomly arranged.

The liquid crystal layer 250 may be implemented in a transmission mode that transmits incident light and a light blocking mode that blocks incident light. In an embodiment of the present invention, it may be assumed that the light blocking mode indicates a case where the transmittance of the light control device 200 is less than a%, and the transmittance mode indicates a case where the transmittance of the light control device 200 is greater than or equal to b%. Transmittance of the light control device 200 represents a ratio of light incident to light output to the light control device 200 . For example, a% may be 10 to 50%, and b% may be 60 to 90%, but is not limited thereto.

The polymer network 255 may be formed by UV curing after mixing a monomer with the liquid crystal layer 250, and has a structure in which the polymer forms a net shape. The polymer network 255 may be formed to have a refractive index similar to that of the cholesteric liquid crystal 251 in a short axis direction. For example, if the liquid crystal layer 250 is composed of the cholesteric liquid crystal 251 having a refractive index of 1.4, a monomer having a refractive index of 1.4 may be selected from among various compounds to be used as a material of the polymer network 255.

The polymer network 255 may scatter incident light. Accordingly, the liquid crystal layer 250 including the polymer network 255 may scatter incident light more than the liquid crystal layer 250 without the polymer network 255 . As a result, a path of light incident on the liquid crystal layer 250 including the polymer network 255 is longer than a path of light incident on the liquid crystal layer 250 not including the polymer network 255 . Therefore, light incident on the liquid crystal layer 250 including the polymer network 255 may be further absorbed by the dichroic dyes 253 . Therefore, when the polymer network 255 is included as in the embodiment of the present invention, the light blocking rate may be higher than when the light is blocked without the polymer network 255.

When the cholesteric liquid crystals 251 and the dichroic dyes 253 of the liquid crystal layer 250 have positive liquid crystal characteristics, they are in a focal conic state or planar state to a homeotropic phase. In order to change the phase to a homeotropic state, a vertical electric field must be applied to the liquid crystal layer 250 .

The vertical electric field occurs when the difference between the voltage applied to the first electrodes 230 and the voltage applied to the second electrodes 240 is greater than the first reference voltage, the first electrodes arranged in the vertical direction (Z-axis direction) This means an electric field formed between the electrodes 230 and the second electrodes 240 .

Due to the vertical electric field, the liquid crystal layer 250 has a homeotropic state and is implemented in a transmission mode in which incident light is transmitted. That is, when a first voltage is applied to the plurality of first electrodes 230 and a second voltage is applied to the plurality of second electrodes 240, the cholesteric liquid crystal 251 and the dichroic dye ( 252) are in a homeotropic state.

The alignment layer 260 includes an upper alignment layer and a lower alignment layer having the same structure. The lower alignment layer may be disposed on one side of the first electrode 230, and the upper alignment layer may be disposed on the second electrode 240 or the transparent adhesive 270 on one side.

In the case of a general light control device, a high-temperature firing process is required to vertically align the liquid crystal layer 250 . However, the alignment layer 260 of the light control device 200 according to the present invention has the advantage of vertically aligning the liquid crystal layer 250 at a low temperature. It will be described in detail with reference to Chemical Formulas 1 to 4 below.

As shown in Chemical Formula 4, the vertical alignment layer of a general light control device uses a polyimide-based polymer. Such a polyimide is prepared by a nucleophilic substitution reaction between an acid anhydride of Chemical Formula 1 and an amine of Chemical Formula 2. Here, R1 is a main material forming an acid anhydride, and may be the main chain of polyimide in Formula 4, and R2 is a main material forming amine, and may be a side chain of polyimide in Formula 4 can The acid anhydride of Chemical Formula 1 and the amine of Chemical Formula 2 combine to form the structure of Chemical Formula 3, and the polyimide of Chemical Formula 4 is produced by an intramolecular reaction of Chemical Formula 3. At this time, the OH group in the structure of Chemical Formula 3 is difficult to undergo a nucleophilic substitution reaction of the unshared electron pair of the amine due to acid-base reaction at room temperature and deterioration of leaving group characteristics. That is, it is difficult for the forward reaction to form polyimide to proceed. Therefore, in the case of a vertical alignment film of a general light control device using polyimide, it is necessary to artificially proceed with a forward reaction by applying a high temperature. In general, in order to vertically align the liquid crystal layer 250, it is possible to form a uniform thin film of 1000 Å or less at 200 degrees or less and must have excellent adhesive properties.

Such a method of manufacturing a vertical alignment layer through high-temperature firing may not be suitable for a manufacturing process of a general light control device using a roll-to-roll process. This is because in the roll-to-roll process, the first substrate 210 and the second substrate 220 are vulnerable to moisture and high temperatures, and deformation of the liquid crystal layer may occur. In addition, there is a problem in that the adhesive force is weak between a substrate and a general alignment layer having a hydrophobic adhesive force.

9 and 10 are views showing the structure of the alignment layer 260 of the light control device 200 according to the present invention.

Referring to FIG. 9 , the alignment layer 260 of the light control device 200 according to the present invention is disposed on the first electrode 230 between the barrier ribs 280 to vertically align the liquid crystal layer 250 . The alignment layer 260 may be provided on one surface of the transparent adhesive 270 as well as the first electrode 230 . The alignment layer 260 includes an alignment material 261 and a binder 263.

The alignment material 261 refers to the area A shown in FIG. 9 and corresponds to the tail portion of the alignment layer 260 . The alignment material 261 may include a non-polar compound having hydrophobicity that is not friendly to water. For example, the alignment material 261 may be selected from the group consisting of -CH ₂ , -CH ₃ , -CCl ₃ , -CF ₃ , an alkyl group, and a phenyl group, but is not limited thereto.

Since the alignment material 261 has a hydrophobic property, it vertically aligns the liquid crystal layer 250 . Alkyl chains of the alignment material 261 shown in area A are aligned in a vertical direction on the surface of the substrate 210, and the vertical alignment of the liquid crystal molecules occurs due to the attraction between the alkyl chains and the molecules of the liquid crystal layer 250. Because. At this time, if the attractive force between the liquid crystal layer 250 and the alignment material 261 is weaker than the attractive force between the first substrate 210 or the electrode 230 and the alignment material 261, the surface tension of the liquid crystal layer 250 ) is oriented horizontally. Therefore, the alignment layer 260 according to the present invention can vertically align the liquid crystal layer 250 with an alkyl chain of the alignment material 261 having hydrophobicity similar to that of the liquid crystal layer 250 .

The binder 263 refers to the region B shown in FIG. 9 and corresponds to the head of the alignment layer 260 . The binder 263 may include a polar compound having hydrophilic properties close to water. For example, the binder 263 may include a silanol group, but is not limited thereto.

Since the binding agent 263 has hydrophilic properties, it can form a strong hydrogen bond with the surface of the first substrate 210 or the surface of the first electrode 230 . In general, surfaces of the first substrate 210 and the first electrode 230 have hydrophilic properties including OH groups. However, in order to increase the hydrophilic properties of the surface, hydrophilic treatment, in particular, corona discharge treatment or alkali treatment may be performed, but is not limited thereto.

Hereinafter, an adhesion reaction between the binder 263 and the surface of the first substrate 210 or the surface of the first electrode 230 will be described with reference to FIGS. 10A to 10D.

First, the material shown in FIG. 10a is hydrolyzed in water to lose chlorine (Cl) and is replaced with an OH group. As shown in FIG. 10B, the material substituted with OH represents the alignment layer 260 according to the present invention. Thereafter, the OH groups of FIG. 10B are connected to each other by condensation with neighboring OH groups to form a coupling agent as shown in FIG. 10C. Thereafter, the compound of FIG. 10C forms a strong hydrogen bond with the OH group on the surface of the first substrate 210 or the first electrode 230 and adheres to the surface of the first substrate 210 or the first electrode 230 as shown in FIG. 10D. do.

Additionally, the alignment layer 260 of the light control device 200 according to the present invention may also be disposed on the upper surface of the liquid crystal layer 250 . In this case, the alignment layer 260 contacts the hydrophobic alignment material 261 and the liquid crystal layer 250, and the binder 263 contacts the transparent adhesive 270, the second electrode 240, or the second substrate 220. can

As such, the alignment film 260 of the light control device 200 according to the present invention can vertically align the liquid crystal layer 250 even at a low temperature by using the alignment material 263 having hydrophobicity, so that the conventional light control device at a high temperature It is possible to improve problems that occurred while manufacturing (200). In addition, the alignment film silver 260 of the light control device 200 according to the present invention uses a binder 261 having hydrophilic properties to increase adhesion with the surface of the first substrate 210 or the surface of the first electrode 230. can improve

Referring back to FIG. 8 , the transparent adhesive 270 is disposed between the liquid crystal layer 250 or the alignment layer 260 and the second electrode to improve adhesion of the light control device 200 . That is, adhesion between the first substrate 210 and the second substrate 220 can be improved by increasing the contact area with the barrier rib 280 to be described later. Here, the transparent adhesive 270 may be Optical Clear Adhesive (OCA) or Optical Clear Resin (OCR), but is not limited thereto.

The barrier rib 280 is disposed on the upper surface of the first electrode 230 to face the second substrate 220 to maintain a constant gap between the first substrate 210 and the second substrate 220 . The barrier rib 280 may have a structure in which a width becomes narrower upward from a surface in contact with the first electrode 230 . In this case, the upper end of the barrier rib 280 may have a pointed structure, and the pointed structure may be attached to the transparent adhesive 270 while being inserted. In the case of a structure in which the upper end of the barrier rib 280 is inserted into the transparent adhesive 270, the adhesion area may be increased and thus the adhesion between the first substrate 210 and the second substrate 220 may be improved.

The barrier rib 280 may be formed of a transparent material. In this case, the barrier rib 280 may be formed of any one of photo resist, photocurable polymer, and polydimethylsiloxane, but is not limited thereto.

Also, the barrier rib 280 does not actively pass light or block light like the liquid crystal layer 250 . That is, when the barrier rib 280 is formed of a transparent material, it only passes light and does not play a role of blocking light. In addition, when the barrier rib 280 includes a material that absorbs light or a material that scatters light, it only scatters or blocks light and does not pass light.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention belongs that various substitutions, modifications, and changes are possible without departing from the technical details of the present invention. It will be clear to those who have knowledge of Therefore, the scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention.

100: transparent display panel 200: light control device
210: first substrate 220: second substrate
230: first electrode 240: second electrode
250: liquid crystal layer 260: alignment layer
270: transparent adhesive 280: bulkhead

Claims (9)

a transparent display panel including transmission regions that transmit incident light and light emitting regions that emit light; and
a light control device disposed on one surface of the transparent display panel and capable of a transmission mode for transmitting incident light and a shading mode for blocking incident light;
The light control device,
a first substrate and a second substrate facing each other;
a first electrode disposed on one surface of the first substrate facing the second substrate;
a second electrode disposed on one surface of the second substrate facing the first substrate;
a plurality of barrier ribs disposed on one surface of the first electrode facing the second substrate and disposed between the first substrate and the second substrate;
a liquid crystal layer disposed between the barrier ribs between the first electrode and the second electrode and transmitting or blocking light;
a lower alignment layer disposed on the first electrode to align the liquid crystal layer;
a transparent adhesive disposed on one surface of the second electrode facing the first substrate; and
An upper alignment layer disposed between the transparent adhesive and the liquid crystal layer,
The lower alignment layer includes an alignment material that determines an alignment direction of the liquid crystal layer, and a binder positioned between the alignment material and the first electrode to improve adhesion of the alignment material,
Each of the barrier ribs has a pointed structure with a width narrowing toward the second electrode from a surface in contact with the first electrode,
The pointed structure partially penetrates the upper alignment layer and is inserted into the transparent adhesive,
The liquid crystal layer widens from the lower alignment layer toward the upper alignment layer,
The first substrate is fastened to the second substrate by inserting the pointed structure into the transparent adhesive. According to claim 1,
The transparent display device of claim 1 , wherein the binder includes a polar compound of a silanol group. According to claim 1,
The alignment material is made of a hydrophobic material,
The transparent display device wherein the binder is made of a hydrophilic material. According to claim 1,
The alignment material includes at least one non-polar compound selected from the group consisting of -CH ₂ , -CH ₃ , -CCl ₃ , -CF ₃ , an alkyl group, and a phenyl group. According to claim 1,
The transparent adhesive is an optical clear adhesive (OCA) or an optical clear resin (OCR) transparent display device. According to claim 1,
The liquid crystal layer further comprises a polymer network. According to claim 1,
The upper alignment layer includes the alignment material and a binder disposed between the alignment material and the transparent adhesive,
The binder of the upper alignment layer is the same material as the binder of the lower alignment layer. delete delete

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