Variable-transmittance liquid crystal cell with adjustable liquid crystal filling amount, and method for manufacturing variable-transmittance liquid crystal cell using same

Abstract

The present invention relates to a variable-transmittance liquid crystal cell and a method for manufacturing a variable-transmittance liquid crystal cell using the same, the variable-transmittance liquid crystal cell being characterized in that a liquid crystal cell internal space divided by sealant lines is configured so as to include a main filling region and a liquid crystal injection reservoir communicating with the main filling region. Particularly, the liquid crystal cell internal space divided by a sealant line as a closed curve is filled at a filling rate of less than 100% at an initial stage, and the liquid crystal filled in the liquid crystal injection reservoir can be additionally injected into the main filling region as the liquid crystal injection reservoir is exposed to atmospheric pressure. The liquid crystal filling amount to be used as the main filling area of the individual liquid crystal cell product after cutting is adjusted at a level close to 100%.

Description

Technical Field

[0001] The present invention relates to a variable transmittance liquid crystal cell and a method for manufacturing the same, and more particularly, to a variable transmittance liquid crystal cell that does not generate agglomeration spots of liquid crystal or a liquid crystal dye mixture inside the liquid crystal cell even when applied to the inner curved surface of a substrate for a curved optical device, and a liquid crystal film unit including the same and a method for manufacturing the same, in which bubbles are not generated in the liquid crystal cell due to insufficient liquid crystal over a long period of time. Background Art

[0002] A variable transmittance liquid crystal film unit means a composite film that can change the transmittance of electromagnetic waves such as visible light of a transmission film according to the presence or absence of applied external electric energy.

[0003] The variable transmittance liquid crystal film unit may include a liquid crystal cell that can control the transmission or blocking of light and a functional film. Such a variable transmittance liquid crystal cell may include a liquid crystal layer in a space formed by two electrode films arranged opposite to each other (for example, having a structure in which an electrode layer and an alignment film layer are formed on a substrate film) and a peripheral pocket portion line that is a closed curve, and the liquid crystal can be aligned and the transmittance can be changed according to the presence or absence of applied voltage. Specifically, a polarizing functional film may be attached to both sides of the liquid crystal cell to utilize the transmission and blocking of polarized light, or a liquid crystal mixed with a dichroic dye may be used to align the liquid crystal and at the same time align the dichroic dye to change the transmittance.

[0004] Since a variable transmittance device can easily achieve the transmission and blocking of light flowing in from the outside, it can be used as a building smart window, a skylight for an automobile, a side glass for an automobile, a sunvisor for an automobile, a rearview mirror for an automobile, a light shielding plate for a transparent display, etc. In addition, it can also be used for the purpose of improving the information visibility of eyewear products such as a windshield for a bicycle helmet and sports smart eyewear, and glasses for augmented reality (AR).

[0005] In a considerable part of the above-mentioned applications, it is necessary to attach to at least a part of the surface of a curved optical substrate of an optical device or to be arranged adjacent to each other according to the curvature. Therefore, it is advantageous that the variable transmittance liquid crystal film unit has an optimized structure that does not cause problems even when applied to the radius of curvature of an optical substrate.

[0006] On the other hand, when a planar variable transmittance liquid crystal cell is applied to the inside of a curved optical substrate, unevenness of the cell gap may occur inside the liquid crystal cell. In a region where the cell gap increases, there are problems such as the generation of agglomeration of the liquid crystal dye mixture or the generation of bubbles when left for a long time. Therefore, a variable transmittance liquid crystal cell and a liquid crystal film unit product that can fundamentally prevent such adverse phenomena are required.

[0007] Prior art documents

[0008] Patent documents

[0009] (Patent Document 1) Korean Patent No. 10-0741900 (July 16, 2007)

[0010] (Patent Document 2) Korean Patent No. 10-2176231 (November 3, 2020) Summary of the invention

[0011] Problems to be solved

[0012] In the vacuum lamination process applicable to the present invention, when laminating a liquid crystal cell in a vacuum state and sealing the liquid crystal dye mixture, when the liquid crystal cell is introduced into the atmospheric pressure, there may be a pressure difference between the inside and outside of the liquid crystal cell. In particular, in a state where the liquid crystal dye mixture is insufficient, due to the air pressure difference inside and outside the liquid crystal cell, when the liquid crystal cell is used for a long time, external air may penetrate, and gas and moisture dissolved in the internal liquid crystal dye mixture are always likely to form bubbles. Therefore, when laminating the liquid crystal cell in a vacuum, it is advantageous from the viewpoint of bubble generation that the filling rate of the liquid crystal dye mixture in the internal space volume is maintained at 100% or more. On the other hand, when curving a liquid crystal cell manufactured in a planar state, non-uniform deformation of the internal space occurs during the process of laminating the upper and lower substrates, causing the liquid crystal dye mixture to move. As a result, liquid crystal dye agglomeration spots may be generated. Moreover, the more the filling amount of the liquid crystal mixture, the easier it is to generate liquid crystal dye agglomeration spots.

[0013] The present invention is characterized by simultaneously solving the problems of agglomeration spots and bubbles of the liquid crystal dye mixture generated when curving a planar transmissivity variable liquid crystal cell vacuum-laminated in a planar state. In particular, an object of the present invention is to provide a method for manufacturing a liquid crystal cell in which the filling rate of the liquid crystal dye mixture filled into the liquid crystal cell can always be uniformly adjusted to an optimal level. And, an object thereof is to provide a transmissivity variable liquid crystal cell in which all the liquid crystal cells in the fabric film of the liquid crystal cell have a uniform liquid crystal filling amount.

[0014] Solutions to the problems

[0015] The transmissivity variable liquid crystal cell can be manufactured in a planar form through a vacuum lamination process.

[0016] More specifically, a planar liquid crystal cell can be manufactured by dispensing a liquid crystal and dichroic dye mixture in a prescribed amount onto a lower substrate film formed in a closed curve shape in a sealing area around the liquid crystal cell under atmospheric pressure using an uncured sealant, and then laminating the upper and lower substrate films in a vacuum state. At this time, spacers for maintaining a prescribed cell gap can be fixed while maintaining an average distance over the entire area of the substrate film in one of the above substrate films. Therefore, the entire area of the upper and lower substrate films can also be separated by spacers of a prescribed height after vacuum lamination.

[0017] The volume of the internal space of the liquid crystal cell can be determined based on the internal area of the closed curve on which the sealant line is drawn and the average height of the spacers, and the filling rate of the liquid crystal dye mixture is the ratio (%) of the volume of the internal space of the liquid crystal cell to the filling amount (volume) of the liquid crystal dye mixture filled in the internal space of the cell.

[0018] The agglomeration of the liquid crystal dye mixture is particularly prominent in a curved liquid crystal cell applied to a curved optical device. In order to suppress the generation of such agglomeration of the liquid crystal dye mixture, most preferably, in the state of being applied to a curve, the filling rate of the liquid crystal dye mixture is maintained as close to 100% as possible. When the liquid crystal filling rate is less than 100%, the possibility of generating bubbles over a long period increases, and thus a filling rate of at least 100% or more needs to be ensured.

[0019] On the other hand, assuming the application of a curve, it is difficult to accurately control the filling rate of the liquid crystal dye mixture filled in a planar liquid crystal cell. In the normal process of applying a curve to a planar liquid crystal cell, the wide area of the liquid crystal cell is compressed, reducing the cell gap, and the cell gap increases due to local deformation at a specific position of the liquid crystal cell, which may change the internal space of the liquid crystal cell. Therefore, it is more difficult to manufacture a liquid crystal cell that optimizes the filling rate of the planar liquid crystal cell, does not generate bubbles, and does not have a problem of agglomeration of the liquid crystal dye mixture when a curve is applied.

[0020] In response to this, in a preferred example of the present invention, it is characterized in that a sealant internal space divided by a sealant line as a closed curve is formed on a fabric including a plurality of liquid crystal cells, and the sealant internal space is composed of a main filling area and a liquid crystal injection reservoir communicating with the main filling area. And, it is characterized in that one side of the liquid crystal injection reservoir can be cut open to be exposed to atmospheric pressure so as to additionally inject the liquid crystal inside the liquid crystal injection reservoir into the main filling area, and according to the pressure difference between the sealant internal space and the outside generated at this time, the liquid crystal filling rate in the main filling area can be adjusted to a level close to 100%.

[0021] In particular, the sealant internal space divided by the sealant line can be separately formed into a main filling area and a liquid crystal injection reservoir communicating therewith, and the liquid crystal injection reservoir is connected to the main filling area through a communication flow path.

[0022] A portion of the liquid crystal injection reservoir can be opened by cutting or other methods, and can be exposed to atmospheric pressure through the cut portion of the liquid crystal injection reservoir. The liquid crystal injection reservoir exposed to atmospheric pressure through the cut portion can control the movement of the liquid crystal in conjunction with the atmospheric pressure, and move the liquid crystal in a direction to maintain pressure balance. At this time, according to a preferred embodiment of the present invention, when the liquid crystal unit fabric bonded in a vacuum state is observed under atmospheric pressure, the pressure of the internal space of the sealant to which the liquid crystal is allocated is relatively lower than the atmospheric pressure when the amount of liquid crystal is insufficient. Therefore, when the liquid crystal injection reservoir side is cut to expose to atmospheric pressure, additional liquid crystal can be injected into the main filling area through the connecting flow path, and the liquid crystal filling amount inside the main filling area is gradually increased, converging to a filling rate of 100%.

[0023] Furthermore, according to a preferred embodiment of the present invention, the connecting flow path between the liquid crystal injection reservoir and the main filling area can be sealed by a finishing sealant. This finishing sealant can be a liquid sealant, and after the liquid sealant is added to the liquid crystal injection reservoir, the connecting flow path can be sealed by the liquid sealant flowing into the connecting flow path side. That is, when the liquid crystal injection reservoir side is exposed to atmospheric pressure by the cut portion and the liquid crystal is injected into the main filling area, the liquid sealant can be added to the liquid crystal injection reservoir before the atmospheric pressure is reached inside the liquid crystal unit, and the sealing is achieved by the liquid sealant. This can prevent bubbles from being trapped between the internal liquid crystal and the sealing area of the liquid crystal unit. The liquid finishing sealant can be cured by UV curing or thermal curing, and the cured sealant can seal the connecting flow path between the liquid crystal injection reservoir and the main filling area.

[0024] As described above, according to a preferred embodiment of the present invention, the sealant internal space filled with liquid crystal can be formed as an internal space including the excess volume of the liquid crystal injection reservoir in addition to the main filling area, and after the sealant internal space is filled to less than 100%, one side of the liquid crystal injection reservoir is cut to be affected by atmospheric pressure, and the liquid crystal in the liquid crystal injection reservoir is additionally injected into the main filling area. Therefore, the filling rate of the liquid crystal dye mixture in the main filling area, that is, the space that becomes the individual variable transmittance liquid crystal unit through the cutting process, is controlled to converge to a desired level, preferably, a liquid crystal filling rate of 100%, thereby preventing the generation of liquid crystal agglomeration and removing the cause of long-term generation of bubbles.

[0025] Effects of the Invention

[0026] A liquid crystal filling amount adjustment type transmissivity variable liquid crystal cell and a method for manufacturing a transmissivity variable liquid crystal cell using the same according to a preferred example of the present invention can divide the internal space of a sealant in a closed curve form of vacuum bonding into a main filling region and a liquid crystal injection reservoir, and gradually inject the liquid crystal in the liquid crystal injection reservoir into the main filling region by using the pressure balance with the atmospheric pressure, and adjust the filling rate (%) in the main filling region. Thus, it has the advantage that the filling rate (%) in the main filling region can be controlled at a desired level, preferably, in an optimal state close to a filling rate of 100%.

[0027] According to an example of the present invention, the filling amount control can be achieved in a state where surface curvature is applied, and the filling amount can be optimally controlled according to the effective volume of the internal space in a state where surface curvature is applied with various radii of curvature. Therefore, it is possible to effectively suppress the generation of liquid crystal agglomeration and bubbles in a curved surface type optical device.

[0028] Moreover, according to a preferred example of the present invention, the pressure difference between the inside and outside of the liquid crystal cell is relieved, so that the generation of bubbles can be effectively prevented for a long time.

[0029] In particular, in the present invention, the liquid crystal is filled into a sealant line including a liquid crystal injection reservoir at a pressure lower than the atmospheric pressure, a part of the liquid crystal injection reservoir is cut to form a cut portion in the atmospheric pressure environment, and due to the pressure difference generated at this time, the liquid crystal can be additionally injected into the main filling region through a communication flow path between the liquid crystal injection reservoir and the main filling region. After that, the liquid crystal filling rate (%) can be optimally controlled through a simple process of sealing the communication flow path with a finishing sealant. Therefore, it has the advantages of simplified process, uniform filling rate (%) of individual liquid crystal cells in the fabric, reduction of the agglomeration and bubble defect rate of the liquid crystal dye mixture even without a separate inspection device, and cost savings in manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A cross-sectional view for exemplarily showing the basic structure of a transmissivity variable liquid crystal film cell.

[0031] Figure 2 For exemplarily showing Figure 1 a cross-sectional view of the detailed structure of a liquid crystal cell in a transmissivity variable liquid crystal film cell.

[0032] Figure 3 Conceptually shows the bonding process of attaching a planar transmissivity variable film cell to an optical product having a curved surface.

[0033] Figures 4a to 4c Schematically shows an example of the generation of liquid crystal agglomeration in a conventional transmissivity variable liquid crystal cell, Figure 4a is a top view of a transmissivity variable liquid crystal cell in which liquid crystal agglomeration occurs, Figure 4b shows a cross-sectional view taken along line A - A',Figure 4c Photographs related to an example of a transmissivity-variable guest-host liquid crystal cell caused by agglomeration of an actual liquid crystal and a dichroic dye.

[0034] Figure 5 An example of a liquid crystal filling amount-adjustable transmissivity-variable liquid crystal cell according to a preferred example of the present invention is shown, including a liquid crystal injection reservoir communicating with a main filling region.

[0035] Figure 6a And Figure 6b Shows the process of sequentially injecting liquid crystal into the entire area after vacuum bonding. Figure 6a Shows the initial injection process of liquid crystal during vacuum bonding. Figure 6b Shows that the liquid crystal dye mixture distributed in the main filling region is filled on the side of the liquid crystal injection reservoir.

[0036] Figures 7a to 7d Magnified view shows Figure 5 A part of the liquid crystal filling amount-adjustable transmissivity-variable liquid crystal cell according to a preferred example of the present invention. Figure 7a Shows the state where a first opening is formed on one side of the liquid crystal injection reservoir. Figure 7b Shows the state where a part of the liquid crystal in the liquid crystal injection reservoir moves to the main filling region through the communication flow path. Figure 7c Shows the state where a second opening is formed on the other side of the liquid crystal injection reservoir to inject a liquid sealant. Figure 7d Shows the state where the opening of the exposed communication flow path is sealed with a finishing sealant after the step of cutting the sealant line.

[0037] Figure 8 Photographs for explaining the process of filling liquid crystal from the main filling region to the side of the liquid crystal injection reservoir inside the liquid crystal cell during vacuum bonding.

[0038] Figure 9 Photographs for explaining that a pressure difference is generated due to the opening formed on one side of the liquid crystal injection reservoir, causing the liquid crystal to move toward the main filling region.

[0039] Figure 10 Photographs showing the state where the communication flow path is sealed with the liquid sealant injected through the second opening.

[0040] Explanation of reference numerals

[0041] 10: Liquid crystal cell

[0042] 20: First adhesive layer 30: Second adhesive layer

[0043] 40: First cover layer 50: Second cover layer

[0044] 60: Curved lens

[0045] 110: Liquid crystal layer

[0046] 111: Sealing part 120: First substrate

[0047] 130: Second substrate 140: Spacer

[0048] 121: First alignment film layer 131: Second alignment film layer

[0049] 122: First electrode layer 132: Second electrode layer

[0050] 123: First base material layer 133: Second base material layer

[0051] 510: Sealant line 520: Main filling area

[0052] 530: Reservoir for liquid crystal injection 540: Connecting flow path

[0053] 550: First opening 560: Second opening

[0054] L: Agglomerate of liquid crystal dye mixture CL: Cutting line

[0055] S: Final sealant Detailed implementation mode

[0056] The embodiments described below are only used to describe the invention in detail to the extent that an ordinary person skilled in the technical field to which the present invention belongs can easily implement the invention, and do not mean that the protection scope of the present invention is limited thereto. Therefore, substitution or modification of some structural elements can be achieved without departing from the necessary scope of the present invention.

[0057] In the following description, when one part is "connected" to another part, it includes not only the case of direct connection, but also the case of connection with other devices or apparatuses interposed therebetween. And when one part "includes" another structural element, unless there is a particularly opposing mention, it means that other structural elements can also be included, rather than excluding other structural elements.

[0058] The transmissivity variable liquid crystal film unit in the present invention may mean a composite film including a liquid crystal unit that can change the transmissivity of electromagnetic waves such as visible light of the transmissive liquid crystal film unit according to the presence or absence of applied external electric energy. Such a transmissivity variable liquid crystal film unit can be used alone or attached to other optical components.

[0059] Therefore, in this specification, the transmissivity variable liquid crystal film unit is defined as a composite film in the form of a thin film including a liquid crystal unit that can change the transmissivity of electromagnetic waves according to the presence or absence of applied external electric energy, and can be broadly interpreted to also include a composite film additionally attached with other functional film layers.

[0060] In particular, the transmissivity variable liquid crystal film unit according to a preferred example of the present invention can be a thin film-shaped liquid crystal film unit that can be attached to a curved optical device or the like, and can be effectively applied to glasses product groups formed in various shapes such as visors for bicycle helmets or glasses for augmented reality. In relation to this, in this specification, the glasses product groups mean a variety of product groups that, in addition to narrow-sense glasses such as glasses, are attached to other devices such as helmets and can be worn close to the eyes.

[0061] Hereinafter, with reference to the accompanying drawings, an example of a liquid crystal filling amount adjustment type transmissivity variable liquid crystal unit according to a preferred example of the present invention and a method for manufacturing a transmissivity variable liquid crystal unit using the same will be illustratively described. On the other hand, the accompanying drawings are only used to illustratively explain the transmissivity variable liquid crystal unit and the liquid crystal film unit according to the present invention, and the present invention is not limited only to the examples according to the accompanying drawings.

[0062] Figure 1 Illustratively shows the structure of a general transmissivity variable liquid crystal film unit. As Figure 1 shown, a general planar transmissivity variable liquid crystal film unit may include a liquid crystal unit 10, a first adhesive layer 20 and a second adhesive layer 30 corresponding to a pair of adhesive layers laminated on both sides of the liquid crystal unit 10. And, a first cover layer 40 and a second cover layer 50 respectively attached to the first adhesive layer 20 and the second adhesive layer 30 may also be included. Among them, the cover layer may be a release film for protecting the adhesive layer from foreign matters, and may be a functional film layer for imparting various functions.

[0063] Figure 1 For the sake of facilitating the explanation of the transmissivity variable liquid crystal film unit, the internal lamination structure is more simply shown. Figure 1 The liquid crystal unit 10 of Figure 2 is a unit assembly including a liquid crystal layer for providing a transmissivity variable function, and an example of the specific constitution of the liquid crystal unit 10 is shown in Figure 1 . On the other hand, the planar liquid crystal film unit as shown in Figure 1 can be formed into a transmissivity variable liquid crystal film unit curved through a curving process, and this curved transmissivity variable liquid crystal film unit, in addition to having a curved shape, has the same basic lamination structure as the

[0064] As a reference, Figure 2 The example of Figure 2 is used to explain the basic structure of the liquid crystal unit according to a preferred example of the present invention. Figure 2The planar liquid crystal cell shown in [Figure] can be formed into a transmissivity-variable liquid crystal cell that is curved through a curving process. Besides having a curved shape, the basic stacked structure of this curved transmissivity-variable liquid crystal cell is the same as that of the Figure 2 planar liquid crystal cell.

[0065] Hereinafter, with reference to Figure 2 , the basic structure of the transmissivity-variable liquid crystal cell will be described.

[0066] The liquid crystal cell in the present invention is a stacked structure that can change its transmissivity through a switching operation of an electrical signal externally applied such as by voltage, and may include a liquid crystal layer containing a liquid crystal compound.

[0067] In the present invention, a liquid crystal (host) and dye (guest) mixture in which a liquid crystal and a dichroic dye are mixed may be included to form the liquid crystal cell. Such a liquid crystal cell may mean that the arrangement state of the liquid crystal compound and the dichroic dye in the liquid crystal layer is induced to change according to an external signal such as a voltage signal, and the transmissivity can be changed. According to whether an external signal such as a voltage is applied or not, it can be switched to a stacked structure having different transmittance states.

[0068] The switchable state mode of the liquid crystal cell can determine the transmission mode and the blocking mode according to whether a voltage is applied. In the transmission mode state, the transmittance of the transmissivity-variable liquid crystal film unit including the liquid crystal cell can be at least about 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, or 80% or more. And, in the above-mentioned blocking mode state, the transmittance of the transmissivity-variable liquid crystal film unit can be 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 5% or less. In the transmission mode, the higher the transmittance, the more advantageous it is. In the blocking mode, the lower the transmittance, the more advantageous it is. Therefore, the upper limit of the transmittance in the above-mentioned transmission mode state and the lower limit of the transmittance in the blocking mode state are not particularly limited. In one example, the upper limit of the transmittance in the above-mentioned transmission mode state can be about 90%, and the lower limit of the transmittance in the blocking mode state can be about 3%.

[0069] Moreover, the state change related to the transmittance is not limited to selectively providing the two state modes of the transmission mode and the blocking mode. For example, it can also be configured to provide multiple state modes so that the transmittance can be controlled step by step at a desired level through voltage control. The structure of the liquid crystal cell used to form the transmissivity-variable liquid crystal film unit can adopt a known structure. In this specification, the basic structure of such a liquid crystal cell is briefly described by the attached illustrations.

[0070] The liquid crystal cell in the present invention has a sealed space structure with a liquid crystal layer located in the space formed by two oppositely disposed transparent conductive substrate films and an edge sealing portion, and may be a unit assembly formed on the upper and lower transparent conductive substrate films in such a manner that the orientation state of the liquid crystal compound and the dichroic dye inside the liquid crystal cell can be changed according to the presence or absence of an externally applied voltage, thereby changing the transmittance.

[0071] Referring to Figure 2 For example, the liquid crystal cell 10 has a structure in which transparent conductive substrate films are stacked above and below with a liquid crystal layer 110 containing a liquid crystal including a dichroic dye as a reference. Such transparent conductive substrate films can be divided into a first substrate in the upper part and a second substrate in the lower part. Moreover, each transparent conductive substrate, that is, the first substrate 120 and the second substrate 130, may have a structure in which an alignment film 121, 131, a transparent electrode layer 122, 132, and a substrate layer 123, 133 are stacked in sequence, and are stacked symmetrically with respect to the liquid crystal cell 10. For example, such a liquid crystal cell may have a structure in which a first electrode layer 122 formed of an indium tin oxide (ITO) thin film or the like and a first alignment film 121 having the ability to align liquid crystal compounds are formed on a first substrate layer 123 that can be formed of a polyethylene terephthalate (PET) film or the like, and the liquid crystal layer 110 is injected thereon. And above the liquid crystal layer 110, there may be a structure in which a second alignment film 131, a second electrode layer 132 of an ITO (indium tin oxide) thin film, and a second substrate layer 133 of a PET (polyethylene terephthalate) film are stacked symmetrically in sequence with the liquid crystal layer 110 as a reference. In one of the first substrate and the second substrate, a fixed spacer may be formed between the electrode layer and the alignment film thin film.

[0072] As the above-mentioned base material layer, a plastic film or the like can be used. Specific examples of the plastic film include cycloolefin copolymer (COP) including triacetyl cellulose (TAC), norbornene derivatives, etc., polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), diacetyl cellulose (DAC), polyacrylate (PAC), polyether sulfone (PES), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyimide (PI), polysulfone (PSF), polyarylate (PAR), or an amorphous fluororesin film, etc., but not limited thereto.

[0073] The above-mentioned electrode layer can be applied with a known transparent electrode layer that can apply electric energy to the liquid crystal layer, so as to enable the conversion of the alignment state of the liquid crystal layer. Examples of such a transparent electrode layer can use a conductive polymer layer, a conductive metal layer, a conductive nanowire layer, or a metal oxide layer such as ITO (indium tin oxide).

[0074] The above alignment film is used to align liquid crystal compounds and may have an alignment force capable of controlling the alignment of the liquid crystal layer. As the alignment film, a substance known to have an alignment force for liquid crystal molecules can be used. For example, it can be achieved by including a substance that exhibits alignment ability through rubbing alignment or a substance that exhibits alignment ability through light irradiation. As a substance that exhibits alignment ability through rubbing alignment, polyimide compounds, polyvinyl alcohol compounds, polyamic acid compounds, polystyrene compounds, polyamide compounds, polyoxyethylene compounds, etc. can be used. As a substance that can exhibit alignment ability through light irradiation, polyimide compounds, polyamic acid compounds, polynorbornene compounds, phenylmaleimide copolymer compounds, polyvinyl cinnamate compounds, polyazobenzene compounds, polyethylene imine compounds, polyvinyl alcohol compounds, polyamide compounds, polyethylene compounds, polystyrene compounds, polyphenylene phthalamide compounds, polyester compounds, chloromethylated polyimide (CMPI) compounds, polymethylmethacrylate compounds, etc. can be used. In addition to those exemplified, known substances that can provide alignment ability can be used.

[0075] The liquid crystal layer means a layer including a liquid crystal compound. For example, it can be a guest-host liquid crystal layer including a liquid crystal compound (host) and a dichroic dye (guest).

[0076] Liquid crystal compounds can be present within the liquid crystal layer to facilitate changing the alignment direction depending on whether an external voltage signal is applied. As liquid crystal compounds, all types of liquid crystal compounds can be used as long as they can change their alignment direction by applying an external signal. For example, as liquid crystal compounds, smectic liquid crystal compounds, nematic liquid crystal compounds, cholesteric liquid crystal compounds, etc. can be used. Also, the liquid crystal compound can be, for example, a compound that does not have a polymerizable group or a crosslinking group, so that its alignment direction can be freely changed by applying an external signal.

[0077] A dichroic dye is a substance whose light absorption rate varies depending on the polarization direction, and can mean an organic substance that can concentrate on absorbing light in the visible light region, for example, at least a part or the entire range within the wavelength range of 400 nm to 700 nm in order to provide variable transmittance characteristics. For example, a black dye can be used as the dichroic dye. As such dyes, for example, azo compound dyes or anthraquinone dyes are known, but not limited thereto. According to a preferred example of the present invention, in order to change the transmittance, a mixture of a liquid crystal compound and a dichroic dye can be used, and in this specification, the mixture of the liquid crystal compound and the dichroic dye is referred to as a liquid crystal dye mixture. Also, according to another preferred example of the present invention, a liquid crystal cell with a polarizing functional film attached or polarizing functional coating can be utilized, and the liquid crystal and the liquid crystal dye mixture included in such an example are collectively referred to as liquid crystal. Therefore, in this specification, liquid crystal can be interpreted as various liquid crystal mixtures that all include the liquid crystal compounds included in the liquid crystal cell in order to change the transmittance.

[0078] Hereinafter, in the present invention, the liquid crystal cell that uses a liquid crystal dye mixture to change the transmittance and its vacuum lamination manufacturing method will be mainly described, but not limited thereto.

[0079] Also, spacers 112 can be further included within the liquid crystal layer 110. Such spacers 112 are formed on the ITO layer of the first substrate or the second substrate as a whole and are fixed, having the function of maintaining the interval between the first substrate and the second substrate, that is, the cell gap, and can be provided in a state where the spacers are attached to the transparent electrode layer of the first substrate or the second substrate.

[0080] Such spacers 112 can use column spacers or ball spacers. The above-mentioned spacers may include one or more selected from the group consisting of carbon-based materials, metal-based materials, oxide-based materials, and composite materials thereof. In one illustration, the above-mentioned column spacers can be formed on the first substrate or the second substrate before forming the alignment film on the transparent electrode film. In one illustration, when applying the alignment film to the transparent electrode layer of the first substrate or the second substrate, the above-mentioned ball spacers can be formed by applying a mixture of the alignment film and the ball spacers. The above-mentioned column spacers can also be formed on the transparent electrode layer of the first substrate or the second substrate by a photolithography method. The width (diameter) and thickness (height) of the column spacers and the diameter (height) of the ball spacers can be appropriately changed according to the size of the final target product.

[0081] Moreover, in order to define the area of the liquid crystal cell, the upper and lower transparent conductive substrates of the liquid crystal cell are adhered, and a sealing portion using a curable sealant may be formed near the peripheral edge portion of the liquid crystal cell. The sealing portion may be formed by a single sealant line or may have a composite sealant line structure formed by an inner sealant and an outer sealant.

[0082] According to a preferred example of the present invention, the sealant line can be drawn in a double structure of an inner sealant line and an outer sealant line. Such a sealant line can be drawn by a sealant of the same raw material or a sealant of other raw materials. In order to correspond to the fine communication flow path structure, the width of the inner sealant line is preferably 2 mm or less after the sealing portion is adhered and cured. The outer sealant line includes a trimming line in most regions except for the opening portion of the communication flow path. The outer sealant line serves to strengthen the adhesion force between the substrate films.

[0083] On the contrary, such a sealant line can be formed by a single sealant line. In this case, the width of the sealant line can be 2 mm or more and 10 mm or less. Drawing the sealant line by a single or multiple sealant lines is only a matter of design. As long as it is related to the gist of the present invention, any form can be adopted as long as the main filling region and the liquid crystal injection reservoir are divided by the communication flow path using the sealant line and the two regions are separated by the trimming line.

[0084] The transmissivity variable liquid crystal cell according to a preferred example of the present invention may be a guest (dichroic dye)-host (liquid crystal) liquid crystal cell capable of changing the visible light transmissivity according to the presence or absence of an externally applied electric field. As described above, in the present invention, the liquid crystal film cell may mean that the functional film is attached in front of the liquid crystal cell using an adhesive. Examples of the functional film may be films having an anti-fog function, a low reflection function, an anti-reflection function, etc. The thickness of the functional film applicable in the present invention is greater than the average thickness of the first substrate film and the second substrate film, or preferably, has a thickness equal to or greater than the thickness of the liquid crystal cell. This is because a thick functional film can strengthen the length difference between the first substrate film and the second substrate film when the liquid crystal cell is applied to the inner substrate of a curved optical device, thereby widening the cell gap.

[0085] The transmissivity variable liquid crystal cell can be manufactured by placing a mixture of liquid crystal and dichroic dye between transparent conductive substrate films and laminating the first substrate film and the second substrate film under vacuum. The vacuum lamination process of the present invention has the advantage of higher productivity compared to the vacuum injection process of injecting a liquid crystal mixture through pre-formed inlets and outlets.

[0086] At this time, in order to maintain the liquid crystal cell gap, spacers are used, and in order to enclose the liquid crystal and dye mixture, it is sealed by the substrate film, and a curable sealant is used at the outer periphery of the liquid crystal cell to form a sealed portion. Under vacuum, after laminating the liquid crystal cell, the sealant is cured using UV and / or heat under atmospheric pressure conditions.

[0087] The transmissivity variable liquid crystal cell of the present invention may use a vertically aligned liquid crystal and a transparent electrode substrate film coated with a vertical alignment film so that the transmissivity becomes the highest in a state where no electric field is applied. In relation to this, in the present invention, the liquid crystal that is vertically aligned when no voltage is applied is called a vertically aligned liquid crystal, and the light transmissivity is the highest when no voltage is applied, and thus this state is called the normally clear mode. However, the problem of caking of the liquid crystal and dye mixture and the generation of bubbles during long-term use is not limited to vertically aligned liquid crystals, that is, the normally clear mode. In horizontally aligned liquid crystals, that is, the normally black mode, bubbles may also be generated over a long period of time, and caking of the liquid crystal can be observed when a voltage is applied.

[0088] Vertically aligned liquid crystal cells are suitable for sports eyewear, driver's eyewear, eyewear for bicycle helmet visors, and variable transmittance eyewear for augmented reality, because such eyewear has many uses that favor a high transparency state when no voltage is applied. Also, most optical device substrates are curved, and the variable transmittance liquid crystal cells are mainly applicable to the inner curved surface of the curved substrate. Here, "applicable" means front attachment, partial attachment, mechanical fixation, etc. Therefore, the liquid crystal filling amount adjustment type variable transmittance liquid crystal cell according to the present invention is suitable for a thin film type liquid crystal cell applicable to the curved surface of a curved optical device substrate, and in particular, is suitable for eyewear formed of vertically aligned liquid crystal cells.

[0089] On the other hand, when a liquid crystal cell fabricated in a planar state is applied to a curved substrate, as the planar state is curved, the cell gap between the first substrate film and the second substrate film decreases, and a part of the liquid crystal and the dichroic dye move to the portion with a relatively large radius of curvature, resulting in the possibility of dark liquid crystal dye agglomeration spots in the vertically aligned liquid crystal cell. When the liquid crystal dye mixture moves and aggregates, the cell gap increases. When the cell gap is greater than the twist pitch of the liquid crystal, the vertical alignment characteristics of the liquid crystal and the dichroic dye mixture deteriorate, and in the state where no voltage is applied, it appears as dark liquid crystal dye agglomeration spots. In particular, when the filling rate of the liquid crystal dye mixture in the liquid crystal cell is greater than about 102%, the darker the agglomeration spots are more easily detected. In this way, when the filled liquid crystal amount is excessive, the size of the agglomerates becomes larger and presents a darker color.

[0090] On the contrary, the smaller the filling rate of the liquid crystal dye mixture is within 100%, the weaker or less likely the agglomeration spots are to occur, but due to the air pressure difference between the inside and outside of the liquid crystal cell, the possibility of long-term bubble generation becomes higher. This is because the filling rate inside the liquid crystal cell is insufficient. When the liquid crystal amount filling the space of the liquid crystal cell is insufficient and the individual liquid crystal cells are vacuum-bonded and sealed in a vacuum state and then the atmospheric pressure is introduced, due to the air pressure difference between the inside and outside of the liquid crystal cell, the substrate film becomes a deformed bonded state, resulting in the contraction of the internal space. When observing the appearance of the liquid crystal cell with the contracted internal space in a planar state, it seems as if the liquid crystal dye mixture is completely filled and not empty as a whole. However, as the liquid crystal cell is used in various environments for a long time, finally, external air penetrates into the liquid crystal cell and bubbles are generated.

[0091] In this way, the filling rate of the liquid crystal dye mixture inside the liquid crystal cell can directly affect the generation of internal bubbles or liquid crystal agglomerates. Therefore, when applying curvature, it is necessary to optimize the filling rate to be close to 100% to eliminate the pressure difference between the inside and outside of the liquid crystal cell, in order to prevent the generation of liquid crystal dye agglomeration spots caused by the distortion and contraction of the internal space and prevent the long-term generation of bubbles.

[0092] Regarding the control of the filling rate of the liquid crystal dye mixture inside the liquid crystal cell, if the general internal filling process of the transmissivity variable liquid crystal cell fabricated through the vacuum lamination process is briefly summarized, first, a process is carried out to form a sealing portion of a sealant line in a closed curve shape in the peripheral region of the liquid crystal cell by using an uncured sealant on the substrate film with spacers fixed. After that, the liquid crystal dye mixture is dispensed in a preset amount within the closed curve of the sealant line of the sealing portion, and in a vacuum state, the substrate films are vacuum laminated to fabricate a planar liquid crystal cell.

[0093] At this time, the filling rate (%) of the liquid crystal dye mixture inside the liquid crystal cell is determined by the volume of the internal space of the liquid crystal cell (the area inside the closed curve of the sealant line × the average height of the spacers) and the filling amount (filling volume) of the liquid crystal dye mixture. For example, when the volume of the internal space of the liquid crystal cell is consistent with the filling volume of the liquid crystal dye mixture, the filling rate of the liquid crystal dye mixture becomes 100%.

[0094] When no bubbles are generated for a long time, a filling rate of more than 100% can be achieved. This is because it is a condition where the pressure difference between the inside and outside of the liquid crystal cell disappears, resulting in no deformation of the upper and lower substrate films caused by the pressure difference after vacuum lamination.

[0095] However, due to the deformation of the soft upper and lower substrate films, the height of the sealant line portion that is usually higher than the height of the spacers, and the height deviation of the spacers, etc., when calculating the volume of the internal space, there may be an error compared to the actual space volume. Also, there is an error when dispensing the liquid crystal dye mixture in a fixed amount. Therefore, due to the above errors, it is difficult to fabricate a liquid crystal cell with an accurate filling rate of 100%. As a result, it is also difficult to predict the actual filling rate of the liquid crystal cell used in the atmospheric pressure environment and whether bubbles will occur in the future even after the lamination is completed in a vacuum.

[0096] In order to reduce the possibility of bubble generation, a scheme of fabricating a liquid crystal cell with a sufficient filling rate can be considered. For example, a liquid crystal cell with a filling rate of 102% or more. However, in this case, the excessive liquid crystal filling amount may cause the local liquid crystal cell gap to exceed the average height of the spacers, and there may be black spots of the liquid crystal dye mixture generated locally. The black spots are black spots presented as amorphous spots over the entire area of the liquid crystal cell when the liquid crystal amount is overfilled, and are different from the agglomerated spots caused by the movement of the liquid crystal dye as a result of surface curvature.

[0097] When an overfilled liquid crystal cell is applied to the inner substrate of a curved optical device, the liquid crystal dye mixture moves from the region with a small radius of curvature to the region with a large radius of curvature. As a result, with the generation of a pressure difference in the internal liquid crystal dye mixture, there may occur a phenomenon of liquid crystal dye agglomeration. This phenomenon of liquid crystal dye agglomeration mainly occurs during the process of curving a planar liquid crystal cell, as the cell gap in the central part of the liquid crystal cell in the long axis direction decreases, and the liquid crystal dye mixture moves towards the edge part in the long axis direction of the liquid crystal cell.

[0098] The occurrence of the phenomenon of liquid crystal dye agglomeration may also be due to the generation of a difference in length between the respective substrate films constituting the liquid crystal cell when a planar liquid crystal cell is applied to the inner surface of the curved optical device. This difference in length between the substrate films widens the cell gap at the edge part, causing the liquid crystal dye mixture to gather there.

[0099] Correspondingly, Figure 3 The fitting process of applying a planar transmittance-variable liquid crystal cell to the inner curved surface of an optical device having a curved surface is exemplified. Herein, "applying" means including front attachment, partial attachment, and mechanical fixing.

[0100] As Figure 3 shown, in the past, a planar transmittance-variable liquid crystal film cell in a flat film form was integrally attached by being closely adhered to a curved optical component such as a lens to produce a curved optical product.

[0101] At this time, before performing the fitting process as Figure 3 shown, the transmittance-variable liquid crystal film cell can be pre-cut into the form required for the optical product and used. In a state where other functional film layers are additionally laminated, the fitting process with the curved optical component can be performed.

[0102] For example, a transmittance-variable film cell having a laminated structure as Figure 1 shown can be preferentially prepared. After removing the first cover layer 40 corresponding to the outermost first release film layer of the prepared transmittance-variable film cell, the first adhesive layer 20 of the transmittance-variable film cell exposed due to the removal of the first release film layer is applied to the inner curved surface of the curved lens 60 to produce a transmittance-variable curved optical device.

[0103] As another example, it is also possible to produce a curved optical device by forming an adhesive layer on one side of the transmittance-variable liquid crystal cell as Figure 2 shown and applying the formed adhesive layer to the inner curved surface of the curved lens 60.

[0104] In this way, in the prior art, generally, to produce as Figure 2After the planar transmissivity-variable liquid crystal cell shown in [reference], a transmissivity-variable film cell including an adhesive layer is fabricated using an adhesive film, and then, as shown in [reference], the transmissivity-variable film cell is applied to the curved substrate of the curved optical device by means of such an adhesive layer to manufacture a curved transmissivity-variable optical device. Figure 3 After the planar transmissivity-variable liquid crystal cell shown in [reference], a transmissivity-variable film cell including an adhesive layer is fabricated using an adhesive film, and then, as shown in [reference], the transmissivity-variable film cell is applied to the curved substrate of the curved optical device by means of such an adhesive layer to manufacture a curved transmissivity-variable optical device.

[0105] On the other hand, when using the manufacturing process described above, a tendency for liquid crystal agglomeration to occur inside the liquid crystal cell of the transmissivity-variable film cell has been continuously confirmed. Figures 4a to 4c Schematically shows an example of liquid crystal agglomeration occurring in a conventional transmissivity-variable liquid crystal cell.

[0106] Figure 4a Is a top view of a transmissivity-variable liquid crystal cell in which liquid crystal agglomeration occurs. Figure 4b Shows a cross-sectional view along A - A'. Figure 4c Is a photograph related to an example of an actual guest - host transmissivity-variable liquid crystal cell in which liquid crystal agglomeration occurs.

[0107] Figure 4a Shows an example in which liquid crystal agglomeration L occurs in the two side edge portions of the transmissivity-variable liquid crystal cell. Referring to the cross-sectional view of [reference], in the two side edge portions of the liquid crystal cell, due to the movement of the liquid crystal and the generation of a pressure difference, the cell gap increases, and this increase in the cell gap leads to the generation of liquid crystal agglomeration L. The liquid crystal agglomeration is different from the normal portion and is generated due to the different liquid crystal alignment states caused by the warping of the cell gap. When a dichroic dye is included, the transmissivity of the liquid crystal agglomeration portion shows a significant difference from that of the normal portion. Figure 4b Shows an example in which liquid crystal agglomeration L occurs in the two side edge portions of the transmissivity-variable liquid crystal cell. Referring to the cross-sectional view of [reference], in the two side edge portions of the liquid crystal cell, due to the movement of the liquid crystal and the generation of a pressure difference, the cell gap increases, and this increase in the cell gap leads to the generation of liquid crystal agglomeration L. The liquid crystal agglomeration is different from the normal portion and is generated due to the different liquid crystal alignment states caused by the warping of the cell gap. When a dichroic dye is included, the transmissivity of the liquid crystal agglomeration portion shows a significant difference from that of the normal portion.

[0108] Related thereto, Figure 4c Shows an example of actual liquid crystal agglomeration occurring in a liquid crystal cell. In the photograph, in the case of a normally clear guest - host liquid crystal cell in which a dichroic dye forms a liquid crystal layer together with the liquid crystal, the dichroic dye follows the alignment of the liquid crystal, so the cell gap becomes larger, and in the region where liquid crystal agglomeration occurs, the alignment of the dichroic dye is also disrupted and appears black.

[0109] When this is surface-curved, to solve the problems of liquid crystal dye caking spots and long-term bubble generation, the present invention is characterized in that a structure of a sealant line in a closed curve including a liquid crystal injection reservoir and a main filling region is formed on the lower substrate film before vacuum lamination. Such a sealant line can be a peripheral edge for dividing an internal space into which liquid crystal can be filled inside a planar liquid crystal cell, and has a closed shape to prevent the distributed internal liquid crystal from flowing out. In particular, when forming a closed seal region surrounding the internal space into which liquid crystal is filled inside a planar liquid crystal cell, such a sealant line in a closed curve form can divide the sealant internal space into a main filling region and a liquid crystal injection reservoir, and the two regions are connected by a communication flow path. Therefore, the sealant line can be integrally drawn on the lower substrate film so that the main filling region, the liquid crystal injection reservoir, and the communication flow path for connecting them can be respectively formed. After distributing the liquid crystal dye mixture in a specified amount, the upper and lower substrate films are laminated in a vacuum state to form a peripheral seal region.

[0110] In the actual manufacturing process, instead of directly vacuum laminating individual liquid crystal cells cut into the required shape, multiple individual liquid crystal cells can be arranged on a circular substrate film larger than the individual liquid crystal cells. After vacuum laminating the upper and lower circular substrate films, it is introduced in an atmospheric pressure state, and while cutting the seal part, multiple liquid crystal cells are manufactured.

[0111] According to a preferred example of the present invention, the cutting line for cutting into the required shape of an individual liquid crystal cell can be configured to open at least a part of the seal region. Preferably, the cutting line can be cut to cross a part of the communication flow path so that at least a part of the communication flow path is exposed to the outside. Here, the cutting line crossing a part of the communication flow path can mean that at least a part of the communication flow path in the seal region forming a closed curve is cut by the cutting line so that at least a part of the communication flow path is exposed. And the exposure of at least a part of the communication flow path means that a channel through which liquid crystal can pass inside the sealant line is exposed to the outside adjacent to the atmosphere. At this time, the exposed channel can include being exposed in a state of being closed by a finishing sealant after cutting or being pre-closed by a finishing sealant before cutting.

[0112] In particular, according to a preferred example of the present invention, cutting the seal part with a cutting line is only used to cut the transmissivity variable liquid crystal cell into the required shape and is not used to expose the communication flow path side. It can be carried out under the state of first closing the communication flow path with a finishing sealant to cut off the movement of the liquid crystal dye mixture, or after cutting in a way that exposes the communication flow path, a finishing sealant is injected.

[0113] Based on the cutting line and the communication flow path, the internal space of the sealant is divided into a main filling area and a reservoir for liquid crystal injection. The reservoir for liquid crystal injection functions as an auxiliary area for filling the insufficient liquid crystal amount in the main filling area. Therefore, the reservoir for liquid crystal injection can be removed through the cutting process after adjusting the liquid crystal filling amount.

[0114] Therefore, before manufacturing the final product cut into the desired shape, the transmissivity variable liquid crystal cell disk with a closed curve-shaped internal space of the sealant including the main filling area and the reservoir for liquid crystal injection can be in the form of an intermediate product. This structure is shown in Figure 5 .

[0115] Specifically, Figure 5 A preferred example according to the present invention shows an example of a liquid crystal filling amount adjustment type transmissivity variable liquid crystal cell having a reservoir for liquid crystal injection communicating with the main filling area. As Figure 5 shown, according to a preferred example of the present invention, the internal space of the sealant into which the liquid crystal dye mixture is poured is divided by a sealant line. This internal space of the sealant includes a main filling area and a reservoir for liquid crystal injection communicating therewith before cutting.

[0116] As a reference, according to a preferred example of the present invention, the sealant line can be drawn with a double structure of an internal sealant line and an external sealant line, but only one sealant line is marked in the following figures. Also, in terms of the line width of the sealant line, the same spacers as those inside the liquid crystal cell can be distributed in the same manner.

[0117] Figure 5 shows a liquid crystal cell fabric in a state where a liquid crystal dye mixture is dispensed into the sealant line 510 between a first substrate film corresponding to the upper substrate and a second substrate film corresponding to the lower substrate. Figure 5 shows the uncut liquid crystal cell fabric. In particular, Figure 5 shows an example including one individual liquid crystal cell, but differently, it can also be a liquid crystal cell fabric connected with two or more individual liquid crystal cells.

[0118] And, Figure 5 shows an example in which a reservoir for liquid crystal injection 530 is formed only on one end side of the sealant line 510, but this reservoir for liquid crystal injection 530 can be configured as two or more distinct regions. In this example, the communication flow paths 540 connected to each reservoir for liquid crystal injection 530 also need to be constituted in corresponding multiples.

[0119] As Figure 5 shown, the internal space of the sealant divided by the sealant line 510 can be distinctly formed into a main filling area 520 and a reservoir for liquid crystal injection 530 communicating therewith. The reservoir for liquid crystal injection 530 is connected to the main filling area 520 through a communication flow path 540.

[0120] The main filling region 520 means an effective liquid crystal cell region for attaching to an optical substrate and providing variable transmittance performance, and is a part that remains on the final individual product even when the sealant line 510 having a closed curve shape is cut by the cutting line CL.

[0121] On the contrary, the liquid crystal injection reservoir 530 is integrally connected to the main filling region 520 by the communication flow path 540 in the state before cutting, and forms a sealant internal space together with the main filling region 520 by the sealant line 510, but is removed from the individual variable transmittance liquid crystal cell product after cutting. Further, a predetermined portion of the liquid crystal injection reservoir 530 can be cut open to be exposed to the atmospheric pressure, and when exposed to the atmospheric pressure, a liquid crystal dye mixture can be additionally injected into the main filling region 520.

[0122] Related thereto, an opening portion can be formed in a part of the liquid crystal injection reservoir 530 by a method such as cutting, and the inside of the liquid crystal injection reservoir 530 can be exposed to the atmospheric pressure through the opening portion. The opening portion can be, for example, a cut line formed by a cutting line, and according to a preferred embodiment of the present invention, it can be a shape of the liquid crystal injection reservoir 530 having a relatively triangular shape, with the communication flow path 540 placed at the vertex position, and near the opposite side of the vertex, that is, near the lower side of the triangle opposite to the vertex at one end of the communication flow path 540, and is cut long in a manner substantially parallel to the lower side of the triangle. In this way, only the liquid crystal / dye mixture can be injected into the main filling region 520 through the communication flow path 540 in the case of pre-infiltration without bubbles by using the cut line formed near the opposite side of the vertex on the communication flow path 540 side. On the other hand, the open portion structure in the shape of a cut line near the lower side of the triangle is only an example, and any structure can be applied without limitation as long as the inside of the liquid crystal injection reservoir 530 can be exposed to the atmospheric pressure and the liquid crystal inside the liquid crystal injection reservoir 530 can be injected into the main filling region 520 according to the pressure difference from the atmospheric pressure.

[0123] The liquid crystal injection reservoir 530 exposed to the atmospheric pressure through such an opening portion can control the operation of the liquid crystal in linkage with the atmospheric pressure and move the liquid crystal in the direction of maintaining pressure balance. At this time, according to a preferred example of the present invention, when the liquid crystal filling rate is 100% or less, the internal pressure of the sealant internal space in which the liquid crystal is distributed in a vacuum state is relatively lower than the atmospheric pressure. Therefore, when the liquid crystal injection reservoir 530 side is exposed to the atmospheric pressure, the liquid crystal can be additionally injected into the main filling region 520 through the communication flow path 540, and the liquid crystal filling amount inside the main filling region 520 can be gradually increased and converge to the optimal filling rate (%), preferably a value close to 100%.

[0124] By controlling the main filling region 520 to the optimal filling amount, passive filling can be achieved using atmospheric pressure without separately controlling the filling amount. In this case, by setting the filling rate of the internal space of the initial seal portion to less than 100%, it is easy to manage the initial filling rate of the liquid crystal dye mixture within a 3% margin range according to a preset initial filling reference value (e.g., 97%). In this example, an injection time can be preset in the liquid crystal injection reservoir 530 from the time point of cutting and opening, and after this injection time, the communication flow path 540 is closed.

[0125] Moreover, according to another preferred example of the present invention, in relation to the control of the optimal filling amount of the main filling region 520, the initial filling rate of the internal space of the initial seal portion can be determined in advance considering the volumes of the main filling region 520 and the liquid crystal injection reservoir 530. The initial filling rate can be determined by a filling rate less than 100%. As the relative volume ratio of the liquid crystal injection reservoir 530 to the main filling region 520 increases, the set value of the initial filling rate becomes lower, and the filling rate margin (100 - initial filling rate) increases. When the filling rate margin increases, there is an advantage that the process easiness is improved, but there is a disadvantage that the time required for the pressure in the main filling region 520 to reach atmospheric pressure after opening the liquid crystal injection reservoir 530 to atmospheric pressure becomes longer. Therefore, the initial filling rate (%) of the internal space of the initial seal portion is preferably in the range of 98% to 96%.

[0126] Moreover, the communication flow path 540 is a flow path connecting the main filling region 520 and the liquid crystal injection reservoir 530. In particular, it can function as a supply flow path for injecting the liquid crystal dye mixture in the liquid crystal injection reservoir 530 toward the main filling region 520 side. The communication flow path 540 can be formed by a flow path having a width sufficiently smaller than the average width of the liquid crystal injection reservoir 530. Preferably, as Figure 5 shown, it can have a narrow slit shape structure connected to a vertex side cross-section of the triangular shape of the liquid crystal injection reservoir 530. However, Figure 5 this illustration is only one example, and it can be a slit connected to one side of a cross-sectional structure of other polygons such as a quadrilateral or a pentagon, or a slit structure connected to one side cross-section of other curved surface forms.

[0127] On the other hand, the liquid crystal filling rate of the sealant internal space formed by the sealant line 510 in the shape of a closed curve needs to be filled less than 100% based on the volume of the internal space. In this way, by distributing the liquid crystal dye mixture with a filling amount less than 100%, there is a smaller amount of liquid crystal dye mixture than the volume of the entire sealant internal space during the initial fitting process. On the other hand, the filling rate of the entire sealant internal space including the main filling region 520 and the liquid crystal injection reservoir 530 is less than 100%. On the contrary, when the initial liquid crystal is only distributed to the main filling region 520, the initial filling rate of the entire liquid crystal dye mixture for the main filling region 520 is greater than 100%. Among them, the filling rate of the entire liquid crystal dye mixture for the main filling region 520 means the filling amount (total filling volume) of the entire liquid crystal dye mixture only for the volume of the main filling region 520. And the total filling volume means the ratio of the filling amount (total filling volume) of the entire liquid crystal dye mixture filled in the entire sealant internal space including the main filling region 520, the communication flow path, and the liquid crystal injection reservoir 530. Only when the filling rate of the entire liquid crystal dye mixture for the main filling region 520 is greater than 100%, can the liquid crystal injection reservoir 530 be opened to the atmospheric pressure after the liquid crystal uniformly diffuses into the entire internal space of the sealant, and the liquid crystal can be re-injected into the main filling region 520 through the communication flow path 540 for additional filling, so as to make the filling rate for the main filling region 520 approach 100% and converge.

[0128] Figure 6a and Figure 6b shows the process of sequentially injecting liquid crystal into the entire area after vacuum fitting. As Figure 6a shown, during the initial injection process of injecting the liquid crystal dye mixture for the entire area by vacuum fitting, the liquid crystal is distributed to the main filling region 520 side. After that, as Figure 6b shown, the liquid crystal dye mixture distributed to the main filling region 520 side slowly fills the liquid crystal injection reservoir 530 side. In the initial distribution state as Figure 6a shown, the liquid crystal is only distributed in the main filling region 520 (actual liquid crystal cell region), so there is no liquid crystal filled in the liquid crystal injection reservoir 530 (vacuum void) at the initial stage of vacuum fitting. After that, as time passes, too much liquid crystal moves to the vacuum void side ( Figure 6b ), and finally, as Figure 5 shown, the liquid crystal not only diffuses uniformly into the main filling region 520 but also into the liquid crystal injection reservoir 530.

[0129] Related to this, Figure 8 is a photo taken step by step of the process of the liquid crystal filling from the main filling region 520 to the liquid crystal injection reservoir 530 side inside the liquid crystal cell during vacuum fitting. Figure 8 (a) andFigure 6b corresponds to a state where the liquid crystal moves toward the liquid crystal injection reservoir 530 side (the liquid crystal moves in the direction of the arrow in (b)), Figure 8 (b) The arrow direction movement), Figure 8 (b) indicates that the movement of the liquid crystal ends, as Figure 5 shown, the state where the liquid crystal fills the entire area of the liquid crystal injection reservoir 530.

[0130] As described above, the core is to adjust the filling amount of the liquid crystal dye mixture based on the filling amount (the entire filling volume) of the liquid crystal dye mixture injected during the initial liquid crystal distribution, so that the first liquid crystal filling rate, which means the entire filling volume of the main filling region 520, is greater than 100%, and the second liquid crystal filling rate, which means the entire filling volume of the entire region including the liquid crystal injection reservoir 530, is less than 100%. Thus, by opening one end of the liquid crystal injection reservoir 530, a pressure difference is generated, and the excess liquid crystal on the liquid crystal injection reservoir 530 side moves back to the main filling region 520, enabling control in such a way that the liquid crystal filling rate of the main filling region (substantially the liquid crystal cell region) converges to 100%.

[0131] When injecting liquid crystal using a normal vacuum bonding process, it is difficult to ensure the required liquid crystal filling rate due to errors in the process of calculating the volume of the internal space of the liquid crystal cell and possible errors in accurately distributing the liquid crystal amount based on the calculated internal volume. For example, there are technical difficulties in achieving a 100% liquid crystal filling rate for the main filling region 520. On the other hand, according to a preferred example of the present invention, the liquid crystal filling rate for the main filling region 520 can be ensured at the 100% level by controlling the initial liquid crystal filling volume in this way.

[0132] The process of the liquid crystal completely diffusing to the liquid crystal injection reservoir 530 side can be achieved at normal temperature or high temperature. For example, by leaving it at normal temperature for about 6 hours after vacuum bonding or leaving it at 105°C for about 1 hour after vacuum bonding, a state where the entire area including the liquid crystal injection reservoir 530 is filled with liquid crystal can be obtained. The time depends on the width of the communication flow path 540. Correlated with the temperature condition, the time for filling the liquid crystal can be shortened at high temperature compared to normal temperature.

[0133] After the liquid crystal filling process for the entire area including the main filling region 520 and the liquid crystal injection reservoir 530 is completed, a process of forming an opening in the liquid crystal injection reservoir 530 and exposing the internal space to atmospheric pressure is carried out. When one side of the liquid crystal injection reservoir 530 is exposed to atmospheric pressure through the opening, the re-injection of the liquid crystal into the main filling region 520 is achieved according to the pressure difference, and after a specified time, the liquid crystal re-injection can end naturally.

[0134] Also, according to a preferred example of the present invention, the communication flow path 540 between the liquid crystal injection reservoir 530 and the main filling region 520 can be sealed by the finishing sealant S. Such a finishing sealant S can be a liquid sealant. After the liquid sealant is introduced into the liquid crystal injection reservoir 530, the communication flow path 540 can be sealed by the liquid sealant flowing into the side of the communication flow path 540. For example, after an opening is formed in the liquid crystal injection reservoir 530 and after a predetermined time when the re-injection of the liquid crystal is completely finished, the finishing sealant S can be introduced to the side of the communication flow path 540 to completely seal the sealed region. Also, before the re-injection of the liquid crystal is completely finished, when the re-injection of the liquid crystal is sufficiently achieved at a desired level, for example, when the re-injection speed of the liquid crystal sufficiently decreases, even when the liquid crystal is in the state of being injected into the main filling region 520, before the inside of the liquid crystal cell reaches the atmospheric pressure, the liquid sealant can be introduced into the liquid crystal injection reservoir 530 to achieve sealing by the liquid sealant.

[0135] By sealing the communication flow path 540, which is the only connection channel between the main filling region 520 and the liquid crystal injection reservoir 530, with the finishing sealant S, such a sealing process can be continuously achieved with the process of re-injecting the liquid crystal, and thus air bubbles can be prevented from being trapped between the internal liquid crystal of the liquid crystal cell and the sealed region. The liquid sealant can be cured by means such as UV curing or thermal curing, and the cured sealant can completely seal the communication flow path 540 of the main filling region 520 with the finishing sealant S.

[0136] A series of processes for adjusting the liquid crystal filling amount in the liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to the present invention are shown in Figures 7a to 7d the

[0137] Figures 7a to 7d enlarged view shows Figure 5 a part of the liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to a preferred example of the present invention, Figure 7a showing the state where an opening is formed on one side of the liquid crystal injection reservoir 530, Figure 7b showing the state where a part of the liquid crystal in the liquid crystal injection reservoir 530 moves to the main filling region 520 through the communication flow path 540, Figure 7c showing the state where a second opening 560 is formed on the other side of the liquid crystal injection reservoir 530 to inject the liquid sealant, Figure 7d showing the state where the opening of the exposed communication flow path 540 is sealed with the finishing sealant S by cutting the sealant line.

[0138] Figure 7a showing the formation of a cut as Figure 5The state of the opening 550 formed by a cut line on one side of the liquid crystal injection reservoir 530 in the prepared transmissivity variable liquid crystal cell shown above. As described above, the opening 550 is used to expose the internal space of the liquid crystal cell to atmospheric pressure, providing a pressure gradient for causing a part of the liquid crystal filled in the liquid crystal injection reservoir 530 to move toward the main filling region 520 during the process of maintaining pressure equilibrium with the atmospheric pressure.

[0139] When the internal space of the liquid crystal cell is exposed to atmospheric pressure using the opening 550, as Figure 7b shown, using atmospheric pressure, a part of the liquid crystal filled in the liquid crystal injection reservoir 530 moves through the communication flow path 540 toward the main filling region 520. As this liquid crystal moves, a part of the region of the liquid crystal injection reservoir 530 exposed to the atmosphere is emptied as Figure 7b shown.

[0140] Related thereto, Figure 9 To take a photo of the liquid crystal moving toward the main filling region 520 according to the pressure difference by forming the opening 550 on one side of the liquid crystal injection reservoir 530. Figure 9 (a) shows the state where the liquid crystal uniformly diffuses into the entire internal region of the sealant line including the liquid crystal injection reservoir 530 as Figure 8 (b) shown, Figure 9 (b) shows the state where the liquid crystal moves toward the main filling region 520 side through the communication flow path 540 according to the pressure gradient (the liquid crystal moves in the arrow direction of Figure 9 (b)).

[0141] When the filling rate of the main filling region 520 reaches the required level by reinjecting the liquid crystal through the communication flow path 540, the process of closing the communication flow path 540 using the finishing sealant S and separating and removing the liquid crystal injection reservoir 530 can be implemented.

[0142] In this process, by cutting a part of the communication flow path 540 according to the cutting line CL, at least a part of the communication flow path 540 may be exposed, and the exposed communication flow path 540 can be closed using the finishing sealant S.

[0143] On the other hand, the closing process using the finishing sealant S can be continuously implemented with the liquid crystal reinjection process before the separate cutting process of cutting across the communication flow path 540 is achieved. In this example, by forming a separate opening 560 near the communication flow path 540 side of the liquid crystal injection reservoir 530 in a state where the liquid crystal reinjection is substantially completed, that is, in a state where the pressure difference causing the liquid crystal to flow into the main filling region 520 maintains pressure equilibrium, and adding and injecting a liquid sealant through the opening 560 to the communication flow path 540 side for finishing, liquid crystal leakage can be prevented and the airtightness can be improved ( Figure 7c ).

[0144] Correspondingly, the liquid sealant can be injected through the Figure 7a open portion formed in Figure 7c . Different from this, as shown in

[0145] Figure 7c , it can be injected through another separately formed open portion 560. For the sake of distinction, the open portion for exposure to atmospheric pressure can be called the first open portion 550, and the open portion for injecting the liquid sealant can be called the second open portion 560. Preferably, the second open portion 560 can be located closer to the communication flow path 540 than the first open portion 550. Figure 7c shows an example including the first open portion 550 formed by a cut line on one side of the liquid crystal injection reservoir 530 formed in a triangle, that is, near the lower side of the liquid crystal injection reservoir 530 far from the communication flow path 540, and including the second open portion 560 separated from the above-mentioned first open portion 550 and formed near the vertex of the triangle on the other side of the liquid crystal injection reservoir 530, that is, close to the communication flow path 540. Correspondingly,

[0146] As shown in Figure 7c , when the second open portion 560 is located sufficiently close to the communication flow path 540, the liquid sealant can be continuously and immediately injected into the communication flow path 540 along with the flow of the liquid crystal. Therefore, it is possible to prevent air bubbles from being trapped between the liquid crystal and the sealant or the airtightness from decreasing, and the filling rate of the liquid crystal can be optimally maintained.

[0147] After the movement of the liquid crystal by atmospheric pressure is completed and the pressure balance is maintained, the liquid sealant injected through the second open portion 560 may no longer move from the communication flow path 540 to the main filling area 520 and may remain in the communication flow path 540. Correspondingly, Figure 10 shows an example of forming the second open portion 560 for injecting the liquid sealant and injecting the liquid sealant through the second open portion 560 to seal the communication flow path 540.

[0148] After that, the liquid sealant can be cured by UV or heat curing, etc. to completely seal the communication flow path 540 to achieve airtightness, and the sealant line is cut along the preset peripheral cutting line CL to produce a transmissivity variable liquid crystal cell with the required shape.

[0149] Figure 7d shows a state where the opening of the communication flow path 540 exposed by cutting the sealant line along the cutting line CL is completely sealed with the finishing sealant S, and shows an example of the final product form cut along the pre-formed cutting line CL according to the required product shape.

[0150] On the other hand, before injecting the liquid sealant, it is also possible to apply a method of directly injecting the finishing sealant S into the opening of the exposed communication flow path 540 in a state where the communication flow path 540 is exposed to the outside by cutting the seal area along the cutting line across the communication flow path 540 to close it.

[0151] As described above, the present invention has been described in detail based on the embodiments and the drawings. However, the scope of the present invention is not limited to the above embodiments and figures, and the scope of the present invention is limited only by the content described in the above claims.

Claims

1. A transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount, which is a film type with liquid crystal filled between a first substrate film and a second substrate film, characterized in that the above-mentioned liquid crystal is filled in the internal space of the sealant line divided by the sealant line formed by a closed curve formed on the above-mentioned first substrate film or the above-mentioned second substrate film under a pressure state lower than the atmospheric pressure, forming a liquid crystal layer sealed in a vacuum state. The internal space of the above-mentioned sealant line is divided into a main filling area and a liquid crystal injection reservoir connected to the main filling area through a communication flow path. When one side of the above-mentioned liquid crystal injection reservoir in the sealed above-mentioned liquid crystal layer is opened by a first opening and exposed to the atmospheric pressure, the above-mentioned liquid crystal layer is controlled according to the pressure difference between the pressure in the internal space of the above-mentioned sealant and the atmospheric pressure, so that the liquid crystal in the above-mentioned liquid crystal injection reservoir flows into the above-mentioned main filling area, increasing the filling rate of the above-mentioned main filling area.

2. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that the above-mentioned liquid crystal is a liquid crystal dye mixture including a dichroic dye.

3. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that a film with a polarization function is attached to the outer surface of the above-mentioned liquid crystal cell of the above-mentioned first substrate film and the above-mentioned second substrate film, or a coating layer with a polarization function is formed.

4. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that after the above-mentioned liquid crystal layer distributes the above-mentioned liquid crystal on the internal area of the above-mentioned sealant line under the atmospheric pressure, the above-mentioned first substrate film and the above-mentioned second substrate film are bonded under vacuum to form.

5. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that the liquid crystal filled in the internal space of the sealant line of the above-mentioned closed curve is filled in such a way that a first liquid crystal filling rate, which means the total filling volume of the liquid crystal with respect to the volume of the main filling area in the internal space of the above-mentioned sealant line, is greater than 100%, and a second liquid crystal filling rate, which means the total filling volume of the liquid crystal with respect to the total volume of the internal space of the above-mentioned sealant line, is less than 100%.

6. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that the above-mentioned liquid crystal injection reservoir has a polygonal cross-section structure with one end of the above-mentioned communication flow path as a vertex.

7. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 6, characterized in that the above-mentioned liquid crystal injection reservoir has a triangular cross-section structure with one end of the above-mentioned communication flow path as a vertex.

8. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 6, characterized in that the above-mentioned first opening is a cut line formed parallel to the opposite side of the vertex on the communication flow path side of the above-mentioned liquid crystal injection reservoir.

9. The transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 1, characterized in that It further includes a second opening portion which is formed in the liquid crystal injection reservoir so as to be closer to the communication flow path side than the first opening portion and is opened in such a way that a finishing sealant can be injected. The communication flow path is sealed with the finishing sealant injected through the second opening portion.

10. The liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to claim 9, wherein it includes a cutting line which is formed along at least a part of the sealant line and can separate the liquid crystal injection reservoir from the main filling region by crossing the communication flow path. The opening of the communication flow path exposed by cutting the sealant line along the cutting line is sealed with the finishing sealant.

11. The liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to claim 1, wherein when the liquid crystal injection reservoir is cut with a cutting line crossing the communication flow path, it is separated from the main filling region and removed. It further includes a finishing sealant for sealing the opening of the communication flow path exposed during cutting.

12. A method for manufacturing a transmissivity-variable liquid crystal cell with adjustable liquid crystal filling amount, characterized in that, It includes: a step of forming a sealant line including a closed curve of a main filling region and a liquid crystal injection reservoir connected to the main filling region through a communication flow path on the first substrate film or the second substrate film under atmospheric pressure; a step of distributing liquid crystal in the inner area of the sealant line under atmospheric pressure, laminating the first substrate film and the second substrate film under vacuum, and filling the liquid crystal in the liquid crystal cell space; a step of forming a first opening portion on one side of the liquid crystal injection reservoir under atmospheric pressure and exposing the liquid crystal injection reservoir to atmospheric pressure through the first opening portion; a step of increasing the filling rate of the main filling region by allowing the liquid crystal in the liquid crystal injection reservoir to flow into the main filling region according to the pressure difference between the pressure in the inner space of the sealant and atmospheric pressure.

13. The method for manufacturing a liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to claim 12, wherein the liquid crystal filled in the inner space of the sealant line of the closed curve is filled in such a way that a first liquid crystal filling rate, which means the total filling volume of the liquid crystal in the inner space of the sealant line with respect to the volume of the main filling region, is greater than 100%, and a second liquid crystal filling rate, which means the total filling volume of the liquid crystal with respect to the total volume of the inner space of the sealant line, is less than 100%.

14. The method for manufacturing a liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to claim 12, wherein in the step of filling the liquid crystal, it further includes a step of distributing the liquid crystal only in the main filling region under atmospheric pressure, laminating the first substrate film and the second substrate film under vacuum, and then leaving it at a preset temperature and for a preset time under atmospheric pressure to allow the liquid crystal in the main filling region to move into the liquid crystal injection reservoir.

15. The method for manufacturing a liquid crystal filling amount adjustable transmittance variable liquid crystal cell according to claim 12, wherein the liquid crystal injection reservoir has a polygonal cross-sectional structure with one end of the communication flow path as a vertex. In the step of exposing the above-described reservoir for liquid crystal injection to atmospheric pressure, it is exposed to atmospheric pressure through the above-described first opening portion of the cut line formed facing the above-described vertex on the communication flow path side of the above-described reservoir for liquid crystal injection.

16. The method for manufacturing a transmissivity variable liquid crystal cell with adjusted liquid crystal filling amount according to claim 12, characterized in that after the step of increasing the filling rate of the above-described main filling region, it further includes a step of sealing the above-described communication flow path between the above-described reservoir for liquid crystal injection and the above-described main filling region with a finishing sealant, in the step of sealing the above-described communication flow path, a second opening portion for injecting the finishing sealant into the above-described reservoir for liquid crystal injection is formed, and after injecting the liquid finishing sealant through the above-described second opening portion, it is cured to seal the above-described communication flow path.

17. The method for manufacturing a liquid crystal filling amount-adjustable transmittance variable liquid crystal cell according to claim 16, characterized in that It further includes: a step of cutting along a cutting line crossing the above-described communication flow path to separate the above-described reservoir for liquid crystal injection from the above-described main filling region.

18. The method for manufacturing a transmissivity variable liquid crystal cell with adjustable liquid crystal filling amount according to claim 12, characterized in that, It further includes: a step of cutting along a cutting line crossing the above-described communication flow path to separate the above-described reservoir for liquid crystal injection from the above-described main filling region; and a step of applying and injecting a finishing sealant to the opening of the above-described communication flow path exposed during cutting in order to seal the opening of the above-described communication flow path.

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