KR20240039333A - Local dimming transmittance variable liquid crystal cell and curved transmittance variable film cell comprising the same - Google Patents

Abstract

The present invention relates to a local dimming variable transmittance liquid crystal cell and a variable transmittance film cell including the same. In particular, there is no diffraction phenomenon for external point light sources, linear stains are minimized in the non-conductive area of the pixel electrode gap when no voltage is applied, and eyewear As shown, when attaching a variable transmittance film cell to the inner curved surface of a curved optical substrate, the viscoelastic properties of the adhesive layer provided on the top and bottom of the liquid crystal cell are adjusted to effectively prevent liquid crystal agglomeration or bubble generation inside the liquid crystal cell containing liquid crystal. It provides controllable passively driven local dimming transmittance variable liquid crystal cells and film cells.

Description

Local dimming variable transmittance liquid crystal cell and curved transmittance variable film cell including the same {LOCAL DIMMING TRANSMITTANCE VARIABLE LIQUID CRYSTAL CELL AND CURVED TRANSMITTANCE VARIABLE FILM CELL COMPRISING THE SAME}

The present invention relates to a variable transmittance liquid crystal cell and a variable transmittance film cell including the same. More specifically, a variable transmittance liquid crystal cell that can be attached to the inner curved surface of a curved optical substrate and can vary the transmittance for each region and the same. It relates to a film cell containing variable transmittance.

Recently, various display devices that help humans experience virtual environments have been developed, and representative examples include virtual reality (VR) devices and augmented reality (AR).

A virtual reality device is a device that implements a virtual image on a display device, and an augmented reality device is a device that provides information to a display device by adding a virtual image to a real image.

In particular, the display device used in the augmented reality device must not only ensure transparency and clarity so that the user can directly view images of the real world, but also must ensure visibility of the part where the virtual image appears overlapping.

However, in reality, the brighter the image of the real world, the lower the display intensity of the virtual image overlaid on the real image, resulting in a problem that the visibility of the virtual information experienced by the user deteriorates.

A variable transmittance film cell refers to a composite film that can vary the transmittance of electromagnetic waves, such as visible light, penetrating the film depending on whether external electrical energy is applied.

A variable transmittance film cell using liquid crystal mixed with a dichroic dye has a dichroic effect in the space formed by two opposing electrode films (for example, an electrode layer and an alignment layer formed on a base film) and an outer encapsulation part. It may include a liquid crystal layer mixed with a dye, and the liquid crystal may be aligned depending on whether voltage is applied or not, and the dichroic dye may also be aligned and the transmittance may be varied.

Variable transmittance devices can easily transmit and block light coming from outside, so they can be used as smart windows for buildings, sunroofs and side glasses for automobiles, and light shields for transparent displays. In addition, it can be used to improve information visibility in eyewear products such as windshields for bikes, smart glasses for sports, and eyewear for augmented reality. However, existing variable transmittance film cells can only uniformly control variable transmittance in the entire visible area of the film cell, so a technology that can selectively control variable transmittance (local dimming) in only a portion of the film cell is required.

Korean Patent Publication No. 2020-0082056 (2020. 07. 08.)

The present invention is intended to effectively improve the visibility problem of the augmented reality device described above. By selectively varying the transmittance of only the desired visible region through patterning of the conductive layer of the upper and lower conductive substrates in the transmittance variable liquid crystal cell, the display is limited to a certain region. The purpose is to provide a film cell with variable transmittance that can effectively improve the visibility of images or information.

In addition, in the present invention, pixel electrodes and wiring electrodes were implemented by patterning only the transparent conductive layers of the upper and lower transparent conductive substrates in the variable transmittance liquid crystal cell. At this time, the gap in the non-conductive area between the pixel electrodes was set so that it was not visible, and the line width of the wiring electrode was set so that it was not visible. Another purpose is to configure a liquid crystal cell with variable transmittance so that the width of the edge (bezel part) of the liquid crystal cell does not become too wide or problems occur in control with electrical signals by setting the gap of the non-conductive area between the and wiring electrodes. there is.

Meanwhile, in the present invention, going further than achieving overall dimming by applying a voltage to the entire area of the transmittance variable film cell, the present invention achieves local dimming by selectively applying a voltage only to a desired area. The purpose is to achieve.

In this regard, conventionally, in order to easily and effectively implement local transmittance variation, ITO (indium tin oxide) is used as the first pixel electrode on the first (upper) transparent substrate and the second pixel electrode on the second (lower) transparent substrate. Transparent electrodes such as the like were used, and a separate opaque metal electrode material was used to apply scan signals and data signals to the pixel electrodes. In addition, the scan line and data line are additionally patterned on another layer (meaning another layer in the film thickness direction) adjacent to the pixel electrode to realize electrical connection between the first pixel electrode and the scan line or the second pixel electrode and the data line. Therefore, the manufacturing process was complicated, making it difficult to apply it to compact optical devices, and there were disadvantages in that optical diffraction patterns were generated.

In order to solve the above-described problem and achieve the purpose, in a preferred embodiment of the present invention, only the transparent electrode layer formed on the upper and lower transparent substrates is patterned using a simple laser patterning or photolithography patterning method to form the first pixel electrode, scan line, and second pixel. By forming an integrated patterned electrode layer structure of electrodes and data lines, local dimming of the transmittance of optical devices such as glasses or goggles is realized using transparent wiring electrodes, that is, transparent scan lines and data lines. did.

In the case of a film cell with variable local transmittance according to a preferred embodiment of the present invention, both the pixel electrode and the wiring electrode are located on the same layer on each of the upper and lower transparent substrates to enable passive operation, and the same transparent electrode material can be used. There are major features. Therefore, there is an advantage that local transmittance can be varied without forming the wiring electrodes for electrical connection with the pixel electrode, that is, the scan line and the data line, at separate locations and as separate electrode material layers. The transparent wiring electrode of the present invention is properly distributed to the edge (bezel) of the pixel electrode, which is a variable transmittance area, so that it can be used in augmented reality eyewear despite electrical loss, or resistance, due to the length and cross-sectional area (thickness x line width) of the transparent wiring electrode. It was confirmed that there was no problem in implementing local transmittance variation of optical devices such as goggles and goggles. In addition, in the local dimming transmittance variable cell of the existing passive or active driving method, the opaque wiring electrodes, that is, the opaque scan lines and data lines, applied to the visible area are inevitably arranged regularly, which causes diffraction of external point light sources. This causes visibility to deteriorate. On the other hand, the transparent pixel electrode and transparent wiring electrode of the present invention have the advantage of effectively reducing diffraction of external point light sources.

Therefore, the present invention not only improves the visibility of virtual images in any environment by selectively changing local transmittance, but also simplifies the product layer structure, reduces manufacturing costs by reducing manufacturing process steps, and optically reduces the diffraction phenomenon for external point light sources. It has the effect of reducing.

In addition, it can effectively improve liquid crystal agglomeration and bubble generation, which are problems when attached to the curved substrate of curved optical devices such as augmented reality eyewear and goggles, thereby improving the marketability of optical devices with local dimming variable transmittance film cells attached. There is a possible effect.

In addition, when using the local transmittance variable film cell according to the present invention, except that the transparent electrode layer is patterned and divided into pixel electrodes and wiring electrodes at the same layer location and the mechanical properties of the adhesive layers are changed for application to the curved substrate. Local dimming can be implemented, diffraction phenomenon can be reduced, and liquid crystal agglomeration and bubble generation inside the liquid crystal cell can be effectively improved without changing the individual layers within the stacked structure of the existing film cell. The manufacturing process can be simplified to reduce manufacturing costs. There is an advantage.

In addition, since the basic stacked structure of the existing variable transmittance film cell can be maintained, there is an advantage in that existing production equipment and process technology can be utilized as is.

1 is a cross-sectional view illustrating a variable transmittance film cell according to a preferred embodiment of the present invention.
Figure 2 is a cross-sectional view exemplarily showing the detailed structure of a liquid crystal cell in a preferred embodiment of the present invention.
FIG. 3 shows an example of a first electrode layer including a horizontal electrode pattern portion, and FIG. 4 shows a cross section taken along line II′ of FIG. 3 .
FIG. 5 shows an example of a second electrode layer including a vertical electrode pattern portion, and FIG. 6 shows a cross section taken along line II-II′ of FIG. 5 .
Figure 7 is an example of a patterned transparent electrode substrate for evaluating the effect of the line width, spacing, and line length of the pixel electrode pattern portion and wiring electrodes (scan lines and data lines). Figure 7(a) is an example of a patterned electrode substrate consisting of a first pixel electrode pattern portion, a scan line, and a flexible printed circuit board (FPCB) connection pad, and Figure 7(b) is an example of a second pixel electrode pattern portion and data. This is an example of a patterned electrode board consisting of lines and flexible printed circuit board (FPCB) connection pads.
8(a) to 8(d) show an example in which the wiring electrode of each electrode layer and the switching driver connected thereto in the variable transmittance liquid crystal cell for eyewear are internalized within the eyewear frame or in the sealing area of the liquid crystal cell. It is showing.
Figure 9 shows an example of a variable transmittance liquid crystal cell driven according to a preferred embodiment of the present invention, an example of selectively varying the transmittance by applying a voltage to the pattern electrode corresponding to the pixel area for which the transmittance is to be changed. It shows.
Figure 10 shows a photograph of a 5x5 matrix local dimming transmittance variable liquid crystal cell manufactured using the patterned transparent electrode substrate of Figures 7(a) and 7(b) according to a preferred embodiment of the present invention, where the transmittance is This is an example of actually implementing selective transmittance variation by applying voltage to the pattern electrode corresponding to the pixel area to be varied.
Figure 11 shows an example in which data lines are divided into two groups and formed at the top and bottom respectively to optimize the width of the wiring area.
Figure 12 shows an example of a variable transmittance film cell cut into a shape that can be attached to the inner curved surface of eyewear having a curved surface.
Figure 13 exemplarily shows a lamination process in which a variable transmittance film cell according to a preferred embodiment of the present invention is attached to an optical product having a curved surface.
Figure 14 shows a cross section of a curved optical product to which a variable transmittance film cell is attached according to a preferred embodiment of the present invention.
Figure 15 shows a cross section of a curved optical product in which a functional film is additionally laminated.
Figures 16 and 17 are cross-sectional views for comparing the shape of the cross-sectional contour of a film cell when attached to the inner surface of a curved optical product by varying the mechanical properties of the adhesive layers on the top and bottom of the liquid crystal cell. Figure 16 is a cross-sectional view of the present invention. An example is shown in which a transmittance variable film cell according to a preferred embodiment is attached to a curved optical product, and Figure 17 is a comparative example, in which the transmittance variable film cell is curved by two adhesive layers having the same very high elasticity. This shows an example of attachment to the inner curved surface of a type optical product.
FIG. 18 conceptually shows the difference in bending angle between the embodiment of FIG. 16 and the comparative example of FIG. 17.
Figure 19 is a cross-sectional view conceptually showing an example in which the neutral plane is located at the center of the liquid crystal cell when a film cell composed of a liquid crystal cell and an adhesive layer laminated above and below the liquid crystal cell is bent into a curved surface.
FIG. 20 is a cross-sectional view conceptually showing an example in which the compression area is reduced by moving the neutral plane downward compared to the example in FIG. 19.
Figure 21 is a cross-sectional view showing key parameters for calculating the position of the neutral plane in a structure in which a plurality of films are stacked.

The embodiments described below are merely intended to provide a detailed description so that a person skilled in the art can easily implement the invention, and this does not mean that the scope of protection of the present invention is limited. No. Accordingly, substitutions or changes to some components may be made without departing from the essential scope of the present invention.

In the following description, when a part is said to be 'connected' to another part, this includes not only the case where it is directly connected, but also the case where it is connected with another element or device in between. Additionally, when a part is said to 'include' a certain component, this does not mean excluding other components, unless specifically stated to the contrary, but rather may include other components.

The variable transmittance film cell in the present invention may refer to a composite film including a liquid crystal cell that can vary the transmittance of electromagnetic waves such as visible light passing through the film cell depending on whether external electric energy is applied. These variable transmittance film cells can be used alone or attached to other optical components or functional film layers.

In addition, in the case of a film cell with variable transmittance according to an embodiment of the present invention, rather than being used as a film cell alone, it may be configured to include an adhesive layer so that it can be used by being attached to another substrate such as the surface of an optical component or a functional film layer.

Therefore, in this specification, a variable transmittance film cell refers to a variable transmittance material layer that can vary the transmittance of electromagnetic waves depending on the presence or absence of external electric energy, like a liquid crystal cell, and a transparent conductive substrate for applying a voltage to this material layer. It is defined to mean a composite film containing a composite film, and can broadly include a composite film to which another functional film layer is attached via an adhesive layer.

Hereinafter, a local dimming variable transmittance film cell according to a preferred embodiment of the present invention and an optical device using the same will be exemplarily described with reference to the attached drawings. The attached drawings show a local dimming variable transmittance film cell according to the present invention. It is only for illustrative purposes, and the present invention is not limited to the examples according to the attached drawings.

Figure 1 exemplarily shows a variable transmittance film cell according to a preferred embodiment of the present invention. As shown in Figure 1, the variable transmittance film cell according to a preferred embodiment of the present invention includes a liquid crystal cell 10 and a first adhesive corresponding to a pair of adhesive layers stacked on both sides of the liquid crystal cell 10. It may include a layer 20 and a second adhesive layer 30. In addition, a first cover layer 40 and a second cover layer 50 attached to the first adhesive layer 20 and the second adhesive layer 30, respectively, may be further included. Here, the cover layer may be a release film to protect the adhesive layer from foreign substances, and may be a functional film layer to provide various functions.

The example of FIG. 1 shows the stacked structure more simply for convenience of explanation of the preferred embodiment of the present invention, and the liquid crystal cell 10 of FIG. 1 provides an overall dimming transmittance variable function. It is a cell assembly including a liquid crystal layer provided for this purpose, and an example of the specific configuration of the liquid crystal cell 10 is shown in FIG. 2.

The liquid crystal cell in the present invention is a layered structure whose transmittance can be varied through a switching operation by an externally applied electrical signal such as voltage, and may include a liquid crystal layer containing a liquid crystal compound. By using a liquid crystal compound containing a dichroic dye, variable transmittance characteristics can be realized without using a polarizing film in the film cell. On the other hand, if dichroic dye is not used, two polarizing films can be used as functional films on the top and bottom of the liquid crystal cell to vary the transmittance. In the present invention, a case containing a liquid crystal chemical mixed with a dichroic dye is described as an example, but is not necessarily limited thereto. For example, such a liquid crystal cell may be configured to vary the transmittance by inducing a change in the arrangement state of the liquid crystal compound and dichroic dye in the liquid crystal layer depending on an external signal such as a voltage signal. For example, whether an external signal such as a voltage is applied or not. It may mean a laminated structure that can be switched into states with different transmittances depending on the state.

The switchable state mode of the liquid crystal cell may be one in which transmission mode and blocking mode are determined depending on whether voltage is applied. In the transmission mode state, the transmittance of the variable transmittance film containing the liquid crystal cell is at least 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, and 60%. It may be more than 65%, 70% or more, 75% or more, or 80% or more. In addition, in the blocking mode state, the transmittance of the variable transmittance film is 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. It may be % or less, 10% or less, or 5% or less. In transmission mode, a higher transmittance is more advantageous, and in blocking mode, a lower transmittance is more advantageous. Therefore, the upper limit of the transmittance in the transmission mode state and the lower limit of the transmittance in the blocking mode state are not particularly limited, and in one example, the transmission mode state is not particularly limited. The upper limit of the transmittance may be about 90%, and the lower limit of the transmittance in the blocking mode may be about 3%.

In addition, the state change related to the transmittance is not limited to alternatively providing two state modes, a transmission mode and a blocking mode. For example, various state modes can be used to gradually control the transmittance to a desired level through voltage control. It can also be configured to provide. The structure of the variable transmittance liquid crystal cell provided to construct the variable transmittance film cell can adopt an already known structure. In this specification, such a variable transmittance liquid crystal cell is simply referred to as a liquid crystal cell, and the basic structure of the variable transmittance liquid crystal cell is Let us briefly explain through the attached example.

The liquid crystal cell in the present invention is a closed space structure having a liquid crystal layer located in the space formed by two transparent conductive substrates arranged opposite each other and the edge sealing portion 111, and the liquid crystal cell is activated depending on whether an external voltage is applied to the transparent conductive upper and lower substrates. It may be a cell assembly configured to vary the transmittance by changing the orientation state of the internal liquid crystal compound and the dichroic dye.

Referring to the liquid crystal cell example of FIG. 2, the liquid crystal cell 10 has a structure in which transparent conductive substrates are stacked up and down based on a liquid crystal layer 110 in which liquid crystal containing a dichroic dye is confined, and this transparent conductive The substrate can be divided into an upper substrate and a lower substrate. In addition, each transparent conductive substrate, that is, the upper substrate (first transparent conductive substrate) and the lower substrate (second transparent conductive substrate), have an alignment film 120 and 130, a transparent electrode layer 140 and 150, and a transparent base layer 160, respectively. , 170) may have a sequentially stacked structure and may be symmetrically stacked with respect to the liquid crystal cell 10.

For example, such a liquid crystal cell includes a first electrode layer 140 made of an indium tin oxide (ITO) thin film, etc., on a first base layer 160, which may be made of a PET (polyethylene terephthalate) film, etc., and the orientation of the liquid crystal compound. It may be a structure in which a first alignment layer 120 having a function is formed and a liquid crystal layer 110 is injected thereon. In addition, on top of the liquid crystal layer 110, a second alignment layer 130, a second electrode layer 150 of an indium tin oxide (ITO) thin film, and a second base layer 170 of a polyethylene terephthalate (PET) film are formed on the liquid crystal layer. It may be a structure sequentially stacked symmetrically with respect to (110).

A plastic film or the like can be used as a transparent base layer in the liquid crystal cell. Specific examples of plastic films include triacetyl cellulose (TAC); COP (cyclo olefin copolymer) such as norbornene derivatives; PMMA (polymethyl methacrylate); PC(polycarbonate); PE(polyethylene); PP(polypropylene); PVA (polyvinyl alcohol); DAC (diacetyl cellulose); Polyacrylate (PAC); PES (polyether sulfone); PEEK (polyether ether ketone); polyphenylene sulfide (PPS), polyether imide (PEI); PEN (polyethylene naphthalate); PET (polyethylene terephthalate); PI(polyimide); PSF (polysulfone); Examples include, but are not limited to, films containing PAR (polyarylate) or amorphous fluororesin.

Additionally, the electrode layer may be a known transparent electrode layer capable of applying electrical energy to the liquid crystal layer to change the orientation state of the liquid crystal layer. Examples of such a transparent electrode layer may be a conductive polymer layer, a conductive metal layer, a conductive nanowire layer, or a metal oxide layer such as indium tin oxide (ITO). Meanwhile, according to a preferred embodiment of the present invention, a pair of conductive electrode patterns are patterned on the base layer so that the transmittance of only a desired region within the liquid crystal cell can be locally varied (local dimming) through selective patterning of the transparent electrode layer. It can be provided with layers. This conductive electrode pattern layer can be divided into pixel electrodes and wiring electrodes (scan lines or data lines).

The alignment film is provided to orient the liquid crystal compound, and may have an alignment force capable of controlling the orientation of the liquid crystal layer. The interface between the alignment film and the liquid crystal layer can be controlled to achieve horizontal or vertical alignment without voltage being applied. If the liquid crystal is vertically aligned in the absence of voltage and the dichroic dye is also vertically aligned, it is called a vertically aligned (normally clear) guest-host liquid crystal cell. Conversely, when the liquid crystal is aligned horizontally, it is called a horizontally aligned (normally dark) guest-host liquid crystal cell. It is said. Materials known to have an alignment ability for liquid crystal molecules may be used as the alignment layer. For example, it may include a material that exhibits alignment ability by rubbing alignment or a material that exhibits alignment ability by light irradiation. Materials that exhibit orientation ability by rubbing orientation include polyimide compounds, polyvinyl alcohol compounds, polyamic acid compounds, polystyrene compounds, polyamide compounds, and polyoxy compounds. Ethylene compounds, etc. can be used, and materials that can exhibit orientation ability by light irradiation include polyimide compounds, polyamic acid compounds, polynorbornene compounds, and phenylmaleimide. Copolymer compound, polyvinyl cinnamate compound, polyazobenzene compound, polyethylene imine compound, polyvinyl alcohol compound, polyamide compound, polyethylene (polyethylene) compounds, polystyrene compounds, polyphenylene phthalamide compounds, polyester compounds, CMPI (chloromethylated polyimide) compounds, and polymethyl methacrylate compounds may be used. Any known material that can provide orientation ability other than those exemplified may be used.

The liquid crystal layer refers to a layer containing a liquid crystal compound. For example, it may be a guest-host liquid crystal layer containing a liquid crystal compound (host) and a dichroic dye (guest).

The liquid crystal compound may be present in the liquid crystal layer so that its orientation direction changes depending on whether an external voltage signal is applied. Any type of liquid crystal compound can be used as long as its orientation direction can be changed by the application of an external voltage signal. For example, the liquid crystal compound may be a smectic liquid crystal compound, a nematic liquid crystal compound, or a cholesteric liquid crystal compound. In addition, the liquid crystal compound may have dielectric anisotropy so that its orientation can be freely changed depending on the applied level of an external voltage signal, and the liquid crystal compound may be, for example, a compound that does not have a polymerizable group or a crosslinkable group.

A dichroic dye is a material whose light absorption rate varies depending on the direction of polarization, and intensively absorbs light within at least part or the entire range of visible light, for example, within the 400 nm to 700 nm wavelength range, to provide variable transmittance characteristics. It can refer to organic substances that can For example, the dichroic dye may use black dye. Such dyes are known, for example, as azo compound dyes or anthraquinone dyes, but are not limited thereto.

Additionally, a spacer 112 may be further included in the liquid crystal layer 110. This spacer 112 is present inside the sealing area and inside the liquid crystal cell visible area and has the function of maintaining the gap between the upper and lower substrates, that is, the sealing area gap and the liquid crystal cell gap (cell gap), uniformly. As such spacer 112, a column spacer or ball spacer can be used. The spacer may include one or more types selected from the group consisting of carbon-based materials, metal-based materials, oxide-based materials, and composite materials thereof. In one example, the column spacer may be formed before forming an alignment layer on the transparent electrode film on the upper or lower substrate. In one example, the ball spacer may be formed by mixing the ball spacer with the alignment layer and coating the alignment layer on the upper electrode film or lower electrode film on the upper or lower substrate. The width (diameter) and thickness (height) of the column spacer and the diameter (height) of the ball spacer can be appropriately changed depending on the specifications of the final target liquid crystal cell product. For example, by increasing the height of the spacer, a lower transmittance level can be achieved while using a liquid crystal layer containing the same concentration of dichroic dye. Conversely, lowering the height of the spacer can achieve a higher level of permeability.

The variable transmittance liquid crystal cell according to a preferred embodiment of the present invention is characterized in that it includes a pair of electrode layers made of upper and lower conductive electrode substrates patterned in a predetermined shape to provide a selective transmittance variable function for a desired area. there is.

Meanwhile, the basic structure of the liquid crystal cell shown in Figure 2 is only an example for explaining the present invention, and the local dimming variable transmittance liquid crystal cell according to the present invention shown in Figures 3 to 11 is designed to enable selective operation control. As long as it includes a pixel electrode layer obtained by patterning a single electrode layer on the same plane, it may include various electrode pattern structures that are not illustrated.

In addition, according to a preferred embodiment of the present invention, a cover layer made of a functional film or release film that can provide various functions such as preventing scratches or preventing fogging may be attached to both sides of the liquid crystal cell.

This cover layer may be a functional film layer to protect the variable transmittance film cell or provide necessary functions. Such functional films include hard coating layer, ultraviolet ray blocking layer, near-infrared blocking layer, anti-reflective layer, anti-fingerprint layer, anti-fog layer, and mirror. It may include one or more types selected from the group consisting of a layer, a polarizing film layer, a color correction layer, and a transmittance adjustment layer, and in addition to those mentioned, a functional film may be used to satisfy the required performance.

The cover layer is located on the side exposed to the outside and can function as a protective film for the inner layer. This cover layer may use a plastic film. For example, the plastic film may include triacetyl cellulose (TAC); COP (cyclo olefin copolymer) such as norbornene derivatives; PMMA (polymethyl methacrylate); PC(polycarbonate); PE(polyethylene); PP(polypropylene); PVA (polyvinyl alcohol); DAC (diacetyl cellulose); PAC (polyacrylate); PES (poly ether sulfone); PEEK (polyether ether ketone); polyphenylene sulfide (PPS), polyether imide (PEI); PEN (polyethylene naphthalate); PET (polyethylene terephthalate); PI(polyimide); PSF (polysulfide); It may include PAR (polyarylate) or amorphous fluorine resin.

These cover layers 40 and 50 may be made of a film layer that can be removed for a separate process. For example, when the cover layer is made of a release film, the release film attached to the adhesive layer of the variable transmittance film cell can be removed and then a functional film can be attached according to the required performance. Therefore, the cover layer in the present invention may be attached to the liquid crystal cell through an adhesive layer and may be a removable film layer or a permanently attached film layer.

3 to 6 show an example of an electrode layer included in a local dimming variable transmittance liquid crystal cell according to a preferred embodiment of the present invention. Hereinafter, the electrode layer will be described in detail with reference to FIGS. 3 to 6.

In forming the electrode layer according to the present invention, a pair of conductive electrode substrates to be used as electrode layers in a liquid crystal cell with variable transmittance are prepared, and laser patterning or photolithography methods, etc. are applied to each conductive substrate to obtain the required properties for the upper and lower conductive substrates. The electrode pattern portion can be formed by patterning each transparent conductive electrode substrate into a shape. In particular, a pixelated pixel electrode (pixel electrode) can be implemented by the area where the upper pattern related to the electrode pattern portion of the patterned upper electrode layer and the lower pattern related to the electrode pattern portion of the lower electrode layer intersect each other, and thus, the pixelated pixel electrode can be implemented. By appropriately controlling the switching of the pixel electrode area, selective light transmittance can be adjusted for each area.

The upper and lower patterns related to the electrode pattern portion of each conductive layer may be in the form of a pattern that can be provided in pixels to enable selective control for each region. For example, the upper pattern may be spaced apart at a distance to move in the first direction. It may be a first pixel electrode pattern portion arranged in alignment, and the lower pattern may be a second pixel electrode pattern portion spaced apart from each other and aligned in a second direction. More preferably, the conductive upper and lower patterns of the electrode layer may be formed to be perpendicular to each other, and in this example, the first direction and the second direction are perpendicular to each other. Therefore, according to a preferred embodiment of the present invention, the first pixel electrode pattern portion of the first electrode layer may be a horizontal electrode pattern portion extending in the horizontal direction, and the second pixel electrode pattern portion of the second electrode layer may be formed to extend in the vertical direction. It may be a vertical electrode pattern portion.

In this regard, Figures 3 to 6 show an example of a pair of electrode layers. Specifically, FIGS. 3 and 4 illustrate an example of a first electrode layer including a horizontal electrode pattern portion, and FIGS. 5 and 6 exemplarily illustrate a second electrode layer including a vertical electrode pattern portion.

The first electrode layer in FIG. 3 and the second electrode layer in FIG. 5 are arranged vertically with a liquid crystal layer in between, and are stacked in pairs on an upper and lower substrate to form a liquid crystal cell that performs local dimming for each pixel.

In particular, the first electrode layer in FIG. 3 and the second electrode layer in FIG. 5 may be composed of matrix-shaped pixel electrodes that form regions that intersect each other up and down with the liquid crystal layer in between, with a certain pattern shape, and the electrodes that intersect each other Transmittance can be selectively varied only in overlapping areas where power is applied to the top and bottom of the area. For example, the transmittance is variable only in electrode pixels where the horizontal electrode pattern portion to which power is applied from the upper first electrode layer and the vertical electrode pattern portion to which power is applied to the lower second front layer intersect, and the remaining pattern areas to which power is not applied are applied. In this case, no change in permeability occurs.

As shown in FIG. 3, the first pixel electrode pattern portions of the first electrode layer may be spaced apart from each other at regular intervals and may be a group of pixel electrodes extending in the horizontal direction. Additionally, as shown in FIG. 5, the second pixel electrode pattern portion of the second electrode layer may be a group of pixel electrodes that are spaced apart from each other at regular intervals and extend in the vertical direction. The smaller the separation distance (s) between pixel electrodes, the more advantageous it is to reduce light leakage. In the present invention, the ratio of the separation distance (s) to the pixel electrode pitch (p) is defined as the separation ratio (s/p), and the electrode pattern structure is designed so that the separation ratio in one direction of the pixel electrode satisfies the following equation. This reduced light leakage inside the dimming area accompanying local dimming.

Here, s is the separation distance between pixel electrodes (㎛), and p is the pitch of the pixel electrodes, which means the sum of the pixel electrode length and separation distance (㎛). Alternatively, s is the separation distance (㎛) between the pattern electrodes constituting the pixel electrode, and p is the pitch of the pattern electrode, which means the sum of the pattern electrode line width and separation distance (㎛). The spacing ratio (s/p) of pixel electrodes or pattern electrodes is a design parameter that indicates the importance of the ratio of non-conductive areas where light leakage can occur regardless of the size of the individual pixel electrodes. In a preferred embodiment of the present invention, rather than reducing the size of the pixel electrode itself or the line width of the pattern electrode to the maximum, the aim is to reduce light leakage while ensuring visibility by setting the spacing ratio (s/p) of the pixel electrode to an optimal range. There is a characteristic.

Variable transmittance film cells applied to eyewear such as augmented reality are located at a distance of about 10 to 40 mm from the eye, so they are closer than the focal distance and cannot individually detect non-conductive areas, but have a large separation ratio (s/p). In this case, the shading efficiency of the shading area may decrease and the effect of local dimming may be reduced. The separation ratio (s/p) is a concept of aperture ratio or transmittance. In the present invention, the separation ratio (s/p) corresponding to the aperture ratio is used to ensure electrical separation between each pattern electrode in an eyewear-sized transparent conductive electrode. It is desirable to keep it above 1%, that is, above 0.01. Also, from an optical point of view, it is desirable to maintain the separation ratio (s/p) at 4% or less, that is, at 0.04 or less, so that the light-shielding effect does not decrease due to an increase in the aperture ratio of the light-shielding area.

The patterned portion of the first electrode layer may be divided into a plurality of rows to form electrode pixels, and conversely, the second electrode layer may be divided into electrode portions patterned to form a plurality of columns. there is. In this specification, each electrode part divided to form a pixel electrode (pixel electrode) is referred to as a 'pattern electrode', and the pattern electrodes of the same layer gathered together and oriented in a specific direction to form a patterned electrode group are referred to as 'pixel electrode patterns'. It is referred to as ‘boo’. In this specification, “oriented in a specific direction” means that the pattern electrode is formed to have a constant or variable line width and extend in a specific direction with a main orientation. Basically, the direction in which the pattern electrode extends means an orientation direction perpendicular to the line width, and this orientation direction can be a single straight line. However, the orientation direction of the pattern electrode is not limited to a single straight line, and may be a curve extending with a main direction determined by a straight line connecting the start and end points of the pattern electrode, and each pattern electrode is spaced appropriately apart. It may be composed of grouped pixel electrode pattern portions while maintaining the distance (s). In the variable transmittance liquid crystal cell according to the present invention, a first electrode layer is formed on a first (upper) transparent substrate, a second electrode layer is formed on a second (lower) transparent substrate, and the first electrode layer is formed on the first (lower) transparent substrate. and a first pixel electrode pattern portion oriented in a direction, and the second electrode layer may include a second pixel electrode pattern portion oriented in a second direction. Preferably, the first direction and the second direction are configured to be perpendicular to each other. You can.

Meanwhile, in the examples of FIGS. 3 and 5, the pattern electrodes are depicted as being spaced apart at sufficient intervals to facilitate distinction. However, this is only an example for illustrating the invention, and preferably the spacing between pattern electrodes is minimized. You can. For example, the gap between each pattern electrode can be maintained at a small distance on the micro scale (e.g., 20㎛~80㎛) as shown in Figure 10, and in this case, the transmittance variable film cell applied to the augmented reality eyewear and When visually inspected at a distance between the eyes, the spacing between pattern electrodes is practically not discernible and only causes differences in light-shielding efficiency as an inactive area with variable transmittance. Therefore, in the present invention, in order to optimize the level of light leakage, it was confirmed that the separation ratio (s/p) to the pitch (p) of the pixel electrode is more important than the absolute value of the separation distance (s) of the pixel electrode itself, and the separation ratio (s) The optimal range of /p) was proposed.

In addition, each pattern electrode forming a pixel electrode is configured so that power corresponding to a driving signal can be applied, and may include, for example, a conductive line for applying a driving voltage, and this conductive line serves as a power supply to the pixel electrode. It functions as a wiring electrode for supplying, that is, a scan line and a data line. In particular, the present invention is characterized by using transparent electrodes located on the same layer as the pixel electrodes simply through patterning, in terms of the material and location of the wiring electrodes.

For convenience of explanation, the conductive lines connected to each pattern electrode 141 of the first pixel electrode pattern portion, illustrated as a horizontal electrode, are referred to as scan lines 142, and each pattern electrode of the second pixel electrode pattern portion, illustrated as a vertical electrode, is referred to as a scan line 142. The conductive line connected to (151) will be defined as the data line (152).

These scan lines 142 and data lines 152 are connected to the first pixel electrode pattern portion and the second pixel electrode pattern portion, respectively, and are preferably formed integrally through a process of patterning the electrode layer laminated on the base layer. It can be.

Specifically, FIG. 3 shows an example in which the scan line 142 is connected to each pattern electrode 141 of the first pixel electrode pattern portion, which is illustrated as a horizontal electrode, and is located at one end of each horizontal pattern electrode 141. Scan lines 142 are connected and formed. In addition, the scan line 142 is connected to the switching driver (C) for supplying power to each pattern electrode 141, and the scan line 142 connects the first pixel electrode pattern portion and the switching driver (C). It may be composed of a conductive line. For purposes of distinction in the drawing, the wiring electrodes are shaded, but the wiring electrodes are made of the same conductive material as the pixel electrode pattern portion and exist in the same layer location.

Likewise, Figure 5 shows an example of a second pixel electrode pattern portion exemplified as a vertical electrode and a data line 152 connected thereto, and the data line 152 also shows each pattern electrode constituting the second pixel electrode pattern portion ( 151) can be connected to the switching driver (C).

In this regard, the switching driver (C) is configured to apply a transmittance control signal for varying the transmittance to each pattern electrode of the first electrode layer and the second electrode layer, for example, to change the transmittance required for each pattern electrode. Accordingly, it may be a driving device that can be controlled to apply a predetermined driving voltage.

On the other hand, the variable transmittance liquid crystal cell according to a preferred embodiment of the present invention is characterized in that the electrode pattern portion and the conductive line included in each electrode layer are composed of a single layer in its cross section.

In relation to this, FIG. 4 shows the II' cross section of FIG. 3, showing that the first pixel electrode pattern portion and the scan line 142 are formed in the same layer based on the cross section of the first electrode layer. there is. This may be because the pixel electrode pattern portion and the scan line 142 were simultaneously patterned and formed in a single process on a single conductive substrate stacked on a base layer.

Looking at an example of this patterning process in detail, an ITO electrode layer is entirely laminated on a transparent base layer such as PET, and then the pattern electrode portion and the scan line 142 are formed into a predetermined shape through a laser patterning or photolithography process. Accordingly, patterning takes place simultaneously. Through this, it is possible to form an electrode layer in which the first pixel electrode pattern portion and the scan line 142 as shown in FIG. 3 are combined.

In addition, when the transmittance is variable, the first pixel electrode pattern portion is preferably spaced apart from the minimum separation distance to enable pixelation and classification operation, and also, due to pixelation, the divided pixel areas of the transmittance variable film are viewed from the inside or outside. In this case, it is advisable to keep it below the maximum separation distance to avoid being noticed. In particular, the present invention focused on the fact that it is important from a technical or commercial perspective that the light and darkness of the spaced areas between the pattern electrodes are not detected when the permeability variable eyewear in the non-voltage-applied state is viewed from the outside, and this was reflected in the structural design.

The scan line 142 preferably has a line width sufficiently small compared to the line width of the pattern electrode, and as shown in FIG. 5, it extends from the distal end of the pattern electrodes and gathers around the outside of the first pixel electrode pattern portion to the switching driver (C). It can have a connected structure.

In addition, as shown in FIGS. 5 and 6, a second pixel electrode pattern portion that is a group of pattern electrodes 151 spaced apart from each other and extending in a second direction, eg, a vertical direction perpendicular to the first direction, and A second electrode layer consisting of data lines 152 connected to each pattern electrode 151 can be manufactured in the same manner as the first electrode layer.

As described above, the second pixel electrode pattern portion of the second electrode layer is oriented in a second direction different from the first direction, and a data line 152 may be connected to each of the pattern electrodes 151.

The example of FIG. 5 shows an example in which the pattern electrodes 151 forming the second pixel electrode pattern portion are oriented in the vertical direction, and the data line 152 is connected to the upper end of each pattern electrode. The data line 152 is connected to the switching driver (C) like the scan line 142 of the first electrode layer, and may extend toward the switching driver (C) for this purpose.

In addition, some of the data lines 152 are connected to the upper end of the pattern electrode 151, and the remaining data lines 152 are connected to the lower end of the pattern electrode 151, and may be connected to the switching driver C. . This is because it is desirable to design the line width and spacing (s), that is, the sum of the pitches (p), of the data lines 152 gathered together to be as small as possible. The present invention is characterized in that the sum of the pitches of the wiring electrodes is included in the sealing area of the liquid crystal cell. Furthermore, the present invention is characterized in that when individually cutting the outline of an eyewear-shaped liquid crystal cell, the cutting outline is formed inside the sealing area rather than outside it. This is because if the cutting outline is formed outside the sealing area, an unwanted electrical short circuit (short circuit or electrical short) may occur between the upper and lower conductive boards.

FIG. 6 shows a cross section taken along line II-II' of FIG. 5, and shows that the second pixel electrode pattern portion and the data line 152 are formed on the same layer based on the cross section of the second electrode layer. . The data line 152 and the second pixel electrode pattern portion can be formed simultaneously through one patterning process. Preferably, the second electrode layer is entirely stacked on the base layer, and then the second pixel layer is formed on the stacked second electrode layer. The electrode pattern portion and the data line 152 can be formed as one piece through a process of simultaneously patterning the electrode pattern portion and the data line 152.

Meanwhile, the electrode layer including the first pixel electrode pattern portion in the horizontal direction and the second pixel electrode pattern portion in the vertical direction is only an example of the electrode layer constituting the liquid crystal cell according to a preferred embodiment of the present invention, and the pattern electrode portion The shape may be changed, or the length, line width, or spacing between electrodes of each electrode may be appropriately changed.

For example, in other types of electrode patterns, it may be a combination of conductive patterns that cross each other at a certain angle. Additionally, in another example, it may be a combination of conductive patterns in which first and second bar-shaped pixel electrode pattern parts intersect each other, rather than simply extending in the horizontal and vertical directions.

In addition, the length of the basic bar-shaped or modified bar-shaped pattern electrode can be designed to be different to suit the shape of the required product. For example, for eyewear, this may be done locally depending on the shape of the eyewear frame 200. This is to implement dimming. Accordingly, the positions of both end portions that specify the length of each electrode pattern can be determined according to the position of the eyewear frame 200, and are preferably predetermined from the eyewear frame 200 at a level that can maximize local dimming performance. It can be designed to be located at a separation distance of .

In addition, the combination of conductive patterns may be spaced apart at a certain line width as shown in FIGS. 3 and 5, but is not limited to this. For example, the pattern may not be uniform depending on the outer line of eyewear to which a variable transmittance film is attached. It may be arranged spaced apart by the line width. In the case of a pattern spaced apart with an uneven line width like this, it may be arranged generally parallel to the horizontal or vertical direction, for example, lines that are not constant based on the left and right or upper and lower ends of the curved lens of the eyewear. The conductive patterns having a length may be arranged generally in parallel. In the case of conductive patterns with non-uniform line widths, it is desirable to maintain a minimum separation distance for effective pixel operation of the electrodes.

In addition, the location where each pixel electrode pattern portion and the wiring electrode line, such as a scan line or data line, are connected can be appropriately changed according to the type of product to be applied.

Specifically, the passively driveable variable transmittance film cell of FIGS. 3 and 5 includes a first electrode layer including a scan line and a first pixel electrode pattern portion, and a second electrode layer including a data line and a second pixel electrode pattern portion, , it may be composed of a structure in which a liquid crystal layer is stacked between the first electrode layer and the second electrode layer. In particular, a dichroic dye (guest) and a liquid crystal mixture (host) are disposed in this liquid crystal layer, and a spacer is provided to keep the cell gap constant at intervals of several to tens of micrometers between the upper and lower electrode layers. A liquid crystal cell can be formed by cementation. The spacer may be fixed to either the first or second electrode layer. Additionally, the spacer may be a column-shaped spacer.

During vacuum bonding, bonding can be performed in a vacuum atmosphere after dispensing a solvent-free sealant to attach the upper and lower electrode layers and to confine the guest-host dichroic dye and liquid crystal mixture within the liquid crystal cell.

The surfaces of the upper and lower electrode layers are coated with an alignment film to control the orientation of the liquid crystal, and the coated alignment film is subjected to a rubbing treatment to set the initial orientation direction and pretilt angle in an unapplied voltage state. You can. The alignment layer may be a vertical alignment layer, and may maintain high transmittance (normally clear mode) in a state where no voltage is applied. In particular, in the case of a local dimming variable transmittance liquid crystal cell with high transmittance (normally clear mode) in an unapplied voltage state, the present invention coats a vertical alignment film after patterning the upper and lower electrode layers, so that a vertical alignment film is formed in the gap between the pattern electrodes. It is characterized by having This is because if the vertical alignment characteristics of the liquid crystal and the dichroic dye in the pattern electrode gap area are insufficient, a strip-shaped stain may be formed in the pattern electrode gap in the absence of voltage. On the other hand, in the case of a local dimming variable transmittance liquid crystal cell with low transmittance when no voltage is applied (normally dark mode), as shown in FIG. 10, even though the horizontal alignment film is removed from the pattern electrode gap, the strip-shaped stain is not visible, so there is a horizontal alignment at the pattern electrode gap. There is no need to limit the presence or absence of an alignment film.

Immediately after vacuum bonding the upper and lower electrode layers, a solvent-free sealant is UV cured on the edges of the variable permeability film cell to create an initial solid state, thereby preventing leakage of the guest-host dichroic dye and liquid crystal mixture and trapping the dichroic dye and liquid crystal mixture within the liquid crystal cell space. Complete vacuum bonding of the upper and lower electrode layers. Afterwards, the variable permeability film cell can be stored in a heated state of 90 to 110 degrees to induce further complete curing of the sealant and increase in adhesion. In the process of completely curing the sealant of the variable permeability film cell by storing it in the heated state, the variable permeability film cell is fixed with a certain pressure on the inner surface of a curved jig having a certain radius of curvature to create a local dimming variable permeability film cell having a curved shape. It can be manufactured.

Figures 7a and 7b show examples of designing the first electrode layer and the second electrode layer, respectively.

The line spacing between pattern electrodes forming each pixel electrode pattern portion can be set to, for example, 30㎛, and the prepared transparent conductive substrate is adjusted to a predetermined line spacing between pattern electrodes to remove the ITO thin film at 30㎛ intervals while removing the pattern electrodes ( 141, 151) can be formed, respectively. In addition, in the case of the scan line 142 and the data line 152 corresponding to the wiring electrodes, it has been verified that signals can be applied with a line width of 30㎛, and therefore, the required line width of the wiring electrode, for example, 30㎛, can be set. By removing the remaining part, a wiring electrode with a thin line width can be manufactured. 7A and 7B, the flexible printed circuit board (FPCB) connection pads 143 and 153 corresponding to the contact point with the switching driver (C) relate to an example in which the ITO thin film is maintained without removal, and this flexible printed circuit board ( The shape of the FPCB connection pads 143 and 153 may be appropriately changed depending on the required connection method with the switching driver C. The line width of these wiring electrodes, that is, the scan line and the data line, is, for example, 30㎛ or more, the line length is, for example, 30cm or less, the spacing between lines is, for example, 30㎛ or more, and the sheet resistance is transparent with a sheet resistance of 280 Ohm/Sq or less. It was confirmed that local dimming of the electrode was possible.

The variable transmittance liquid crystal cell and the variable transmittance film cell according to a preferred embodiment of the present invention can be effectively applied to a variable transmittance optical device provided with a frame 200 on the edge, and can be effectively used in eyewear for augmented reality (AR). You can. For example, eyewear for augmented reality (AR) includes an opaque frame 200 provided to fix an optical lens, etc., and a switching driver C may be installed in this frame 200. Therefore, in a preferred embodiment of the present invention, the switching driver C is installed on the frame 200 of the optical device, and the wiring electrodes connected to the switching driver C, that is, the scan line 142 and the data line 152, are installed in the frame 200 of the optical device. ) is characterized in that it is connected to the switching driver (C) through the frame 200. More specifically, the scan line 142 and the data line 152 are included within the liquid crystal cell sealing area, and the sealing area is included in the frame 200 area of the optical device.

In this way, by internalizing the switching driver (C) and the wiring electrode within the frame 200 of the eyewear, exposure of the switching driver (C) and the wiring electrode to the outside can be reduced, and the visible area of the eyewear can be maximized. there is.

In addition, according to a preferred embodiment of the present invention, the position of the switching driver (C) and the scan line 142 and data line 152 are adjusted to minimize the length of the wiring electrode and maximize space efficiency due to internalization of the wiring electrode. The connection method can be restricted.

In this regard, Figures 8 (a) to (d) show an example in which the wiring electrode of each electrode layer and the switching driver (C) connected thereto in the variable transmittance liquid crystal cell for eyewear are internalized within the eyewear frame 200; there is.

As shown in Figures 8 (a) to (d), a pair of electrode layers included in the variable transmittance liquid crystal cell constitute a pixel electrode in the form of an (Am, Bn) matrix to provide a pixelated variable transmittance region. , shows an example of installing a switching driver near the corner of the pixel electrode. For example, consider a pixel electrode in the form of an (Am, Bn) matrix consisting of a first pixel electrode pattern portion made of m pattern electrodes and a second pixel electrode pattern portion made of n pattern electrodes. The pattern electrodes of the first pixel electrode pattern part are called A1, A2, A3,....An, respectively, and the pattern electrodes of the second pixel electrode pattern part are called B1, B2, B3,....Bn, respectively, and each pixel If the position of is expressed as the coordinates of a pair of pattern electrodes crossing that position, it can be defined as (A1, B1) pixel, (A1, Bn) pixel, (Am, B1) pixel, and (Am, Bn) pixel. According to one implementation of the present invention, within the adjacent frame area (shaded area at the corner) for the (A1, B1) pixel, (A1, Bn) pixel, (Am, B1) pixel or (Am, Bn) pixel. It is characterized in that the entire switching driver (C) or a part of the switching driver (C) is located.

Here, the adjacent frame area for a specific pixel refers to a frame area defined by the extension lines (L1, L2) of the side boundaries of the pattern electrodes constituting the pixel in the pixel located at the edge of the pixel electrode. Accordingly, the frame area for the corner portion of the pixel electrode may refer to the area shown in (a) to (d) of Figures 8.

In this example, as shown in (a) to (d) of Figure 8, the switching driver (C) is entirely or at least partially (A1, B1) pixel, (A1, Bn) pixel, (Am, B1) pixel or (Am, Bn) The scan line 142 and the data line 152, which are located in the adjacent frame area for the pixel and extend from each pattern electrode of the first and second pixel electrode pattern portions, are operated by a switching driver through the frame. Connected to (C). Hereinafter, for convenience of explanation, the pattern electrode constituting the first pixel electrode pattern portion will be referred to as the first pattern electrode, and the pattern electrode constituting the second pixel electrode pattern portion will be referred to as the second pattern electrode.

In particular, the scan line 142 and the data line 152 are wired from the positions of a pair of pattern electrodes constituting a pixel for the frame area so that they can be moved the shortest distance to the corner frame area where the switching driver C is installed. Electrodes (scan lines and data lines) can be extended. That is, as shown in FIGS. 8(a) to 8(d), when positioning the switching driver in the frame area adjacent to the corner, the scan line and data line connected thereto are pixels not connected to the corresponding line. It can be configured to extend from the position of the adjacent pattern electrode of the electrode pattern part to the switching driver. That is, the scan line extends from the pattern electrode position of the second pixel electrode pattern part constituting the selected pixel to the switching driver, and the data line extends from the pattern electrode position of the first pixel electrode pattern part constituting the selected pixel to the switching driver. can be formed.

For example, the example in FIG. 8(a) shows an example where the switching driver is located in a frame area adjacent to the (A1, B1) pixel. The scan lines 142 are all configured to extend from the right side of the pixel electrode, and this is to minimize the length of the scan line connected to the switching driver C. That is, when the scan line is connected to each pattern electrode constituting the first pixel electrode pattern portion, the starting point of the scan line is the pattern electrode constituting the second pixel electrode pattern portion, that is, (A1, B1) among the second pattern electrodes. It may be configured to depend on the position of the second pattern electrode constituting the pixel. Therefore, according to a preferred embodiment of the present invention, the scan line may be formed extending from the position of the second pattern electrode (B1 pattern electrode) constituting the (A1, B1) pixel to the switching driver.

The data lines 152 may also be configured to minimize the length of the data line connected to the switching driver C. In FIG. 8(a), the data lines 152 all extend from the upper side of the pixel electrode. It is structured as such. Like the scan line, the starting point of the data line may be configured to depend on the position of the pattern electrode constituting the first pixel electrode pattern portion, that is, the first pattern electrode constituting the (A1, B1) pixel, , Preferably, a data line may be formed extending to the switching driver at the position of the first pattern electrode (A1 pattern electrode) constituting the (A1, B1) pixel, as shown in FIG. 8(a).

By forming the wiring electrode with this structure, the wiring electrode and the switching driver (C) can be placed intensively in the upper and left areas of the eyewear frame, as shown in Figure 8(a), so the length of the wiring electrode is short. It has the advantage of maximizing the space efficiency of eyewear.

Meanwhile, Figure 8(b) shows that the switching driver (C) is located in the adjacent frame area to the (A1, Bn) pixel, and the scan line 142 and data line 152 are located at the top and right of the frame, respectively. It is the same as the example in Figure 8(a) except for.

In addition, Figures 8(c) and 8(d) show that the switching driver (C) is located in an adjacent frame area to the (Am, B1) pixel or (Am, Bn) pixel, respectively, and the switching driver (C) is located adjacent to the switching driver (C). The position is the same as the previous example except that the scan line 142 and the data line 152 are located.

Figure 9 shows an example of a variable transmittance liquid crystal cell driven according to a preferred embodiment of the present invention, showing an example of selectively varying the transmittance by applying a voltage to the pattern electrode for the pixel area for which the transmittance is to be changed. It is showing.

In the example of FIG. 9, input is applied to pattern electrodes A2 and A3 of the first pixel electrode pattern portion corresponding to the horizontal electrode and to pattern electrodes B1, B2, and B3 of the second pixel electrode pattern portion corresponding to the vertical electrode, This is an example of changing the transmittance.

Figure 10 is a photograph of an example of a 5×5 variable transmittance liquid crystal cell (normally dark mode) actually implemented according to a preferred embodiment of the present invention, showing variable transmittance for the (A1, B3) pixel and (A5, B3) pixel. This is a photo of an example that was accomplished.

Meanwhile, according to another preferred embodiment of the present invention, the second pixel electrode pattern portion in the vertical direction is divided into two groups, and the data lines 152 connected to the electrode pattern portion of each group are separated into upper and lower sections. It may be possible.

In relation to this, FIG. 11 shows an example in which the data lines 152 are divided into two groups and formed upward and downward, respectively. In the case of an electrode layer structure composed of upper and lower sections as shown in Figure 11, there is an advantage in that the width of the upper and lower bezels of the eyewear frame can be reduced by about half.

In addition, the variable transmittance film cell according to the present invention is characterized in that it can be effectively attached to an optical component having a curved surface, such as an optical lens for eyewear or an optical lens for augmented reality. In particular, the variable transmittance film cell according to a preferred embodiment of the present invention can reduce performance degradation or defects due to bending of the film cell as it is attached to a curved surface, especially the generation of bubbles inside the liquid crystal cell.

In this regard, the adhesive layer is provided to attach the liquid crystal cell to another adjacent layer, and adhesive layers may be formed on both sides of the liquid crystal cell, respectively. In particular, either of the two adhesive layers formed on both the upper and lower sides of the liquid crystal cell can be used to directly attach the liquid crystal cell to an optical component such as a lens having a curved surface.

Meanwhile, like the previous functional film, curved optical components can be attached through a subsequent process, and the variable transmittance film cell according to the present invention is not only directly attached to these curved optical components, but can also be attached to the curved optical components. It includes a film cell with variable transmittance prepared by attaching a release film on the adhesive layer. Therefore, in preferred embodiments of the present invention, a transmittance variable film cell in which an adhesive layer is exposed so as to be attached to a curved optical component, a transmittance variable film cell in which the adhesive layer is not exposed by a cover layer, or a curved optical component It may include a variable transmittance film cell directly attached to the.

In this regard, Figure 1 shows an example in which a liquid crystal cell forms a stacked cross-sectional structure while contacting adjacent cover layers 40 and 50 and adhesive layers 20 and 30.

As described above, the adhesive layer is provided to effectively attach a lens or a cover layer to a liquid crystal cell, and the adhesive layer in the present invention is used to encompass an adhesive layer and an adhesive layer. This adhesive layer may be formed using, for example, a silicone-based, acrylic-based, or urethane-based pressure sensitive adhesive (PSA) composition or an optically clear adhesive (OCA) composition. Particularly preferably, the adhesive layer may be an OCA film layer formed of a silicone-based optically clear adhesive (OCA) composition.

An adhesive layer made of an OCA composition can exhibit adhesiveness by curing before being attached to an object to be attached, and a known adhesive composition can be used as a film layer using such an OCA composition.

The adhesive layer provided in the variable permeability film may be a cured product of the adhesive composition in a cured state. Here, 'cured body' refers to a material in which the components contained in the adhesive composition have developed the adhesiveness or tackiness of the adhesive composition through physical mixing or chemical reaction. In order to cure the composition, heat and/or A process of applying appropriate energy to the adhesive composition by applying light may be performed.

The variable transmittance film cell according to a preferred embodiment of the present invention is based on providing a cured adhesive layer, and the properties such as the storage modulus of the adhesive layer, which will be described later, are all values measured on the cured adhesive layer. It can be done as a standard.

The adhesive composition may include, for example, a curable compound. As used herein, the term 'curable compound' may refer to a compound having one or more curable functional groups. The adhesive composition may include, for example, a thermosetting compound, an active energy ray curable compound, or both a thermosetting compound and an active energy ray curable compound.

In one example, the curable compound may be an acrylic monomer, an epoxy monomer, or a silicone monomer, but is not limited thereto, and any known monomer component known to be capable of forming an adhesive may be used.

In one example, the adhesive layer may be an acrylic adhesive, a urethane adhesive, or a silicone adhesive. According to an embodiment of the present invention, an acrylic adhesive may be used as the adhesive layer.

Based on an exemplary embodiment having the same configuration as described above, an example of attaching a variable transmittance film cell to a curved optical component according to a preferred embodiment of the present invention will be described with reference to FIGS. 12 to 14.

Figure 12 shows an example of a planar variable transmittance film cell cut into a shape that can be attached to eyewear having a curved surface, and Figure 13 shows a variable transmittance film cell according to a preferred embodiment of the present invention attached to a product having a curved surface. This is an exemplary illustration of the lamination process. Additionally, Figure 14 shows a cross-section of a curved optical product to which a variable transmittance film cell is attached according to a preferred embodiment of the present invention.

As shown in FIG. 13, the variable transmittance film cell in the form of a flat film is integrally attached in close contact with a curved optical component such as a lens, thereby completing the curved optical product as shown in FIG. 14.

At this time, before performing the lamination process as shown in FIG. 13, the variable transmittance film cell can be cut in advance into the shape required for the optical product and used. Figure 12 shows an example of a variable transmittance film cell cut in this way, showing an example in which the variable transmittance film cell is cut in advance according to the shape of the lens of the eyewear. In particular, the present invention is characterized in that the film cell cutting outline is located inside the liquid crystal cell sealing area.

When explaining the lamination process with reference to FIG. 13, a film cell having a laminated structure as shown in FIG. 1 is first prepared, and the outermost first release film layer of the prepared film cell with variable transmission is removed. Afterwards, as the first release film layer is removed, the exposed first adhesive layer 20 of the variable transmittance film cell is attached to the inner curved surface of the curved lens 60 to manufacture a curved optical device capable of variable transmittance.

Figure 14 shows a cross-section of a curved optical product with a variable transmittance film cell attached. As shown in Figure 14, the variable transmittance film cell attached to the lens forms a constant curved shape along the profile of the lens.

Figure 15 shows an example of a process for manufacturing a curved optical product by additionally laminating functional films, in which the second release film layer is removed and a functional film layer 70 with the required performance is additionally laminated. An example of a layered structure for an optical device is shown. Preferably, the lamination process of the functional film layer 70 may be performed before the lamination process with the curved lens 60, and the transmittance variable film to which the functional film layer 70 is attached through the lamination process as shown in FIG. 13 The cell can be attached to the curved lens 60.

Meanwhile, the adhesive layer provides an attachment function to a lens or a cover layer and at the same time attaches the variable transmittance film cell to an optical member having a curved surface, thereby reducing the generation of bubbles inside the liquid crystal cell of the variable transmittance film cell.

When a film cell with variable transmittance is attached to an optical member with a single or double curved surface, especially when attached to the inner curved surface of the optical member, the stress applied to the internal laminated structure of the liquid crystal cell as the film cell is bent to match the shape of the curved surface. Changes occur, and these stress changes may cause bubbles to form within the liquid crystal cell.

According to a preferred embodiment of the present invention to solve this bubble generation problem, the two adhesive layers are characterized by having different viscoelastic properties.

In addition, the two adhesive layers are an acrylic or silicone-based pressure sensitive adhesive (PSA) composition or optically transparent with a 180-degree peel adhesive strength (speed 15 in/min) of 30N/100mm or more between the curved optical substrate and the cover layer. It may be formed of an adhesive (optically clear adhesive: OCA) composition. More preferably, the second adhesive layer 30 of the two adhesive layers is formed of an acrylic adhesive having an adhesive strength of 50 N/100mm or more, and the cover layer is composed of a film layer made of PC or PMMA to provide a second adhesive layer according to bending. Peeling of the adhesive layer can be prevented.

Specifically, according to a preferred embodiment of the present invention, the variable transmittance film cell includes a pair of adhesive layers disposed above and below the liquid crystal cell, and is designed to alleviate the generation of bubbles inside the liquid crystal cell when attached to a curved optical component. Each adhesive layer may be configured to have different viscoelastic properties.

The viscoelastic properties of the adhesive layer can be expressed as the storage modulus (G'), the loss modulus (G''), and the loss coefficient tanδ value corresponding to their ratio as follows.

Even if the size of the complex elastic modulus (G ^* = G'+iG”) is the same, the higher the storage modulus, the harder and more elastic the adhesive is. The higher the loss modulus, the softer and more viscous the adhesive. It can be said to be high. Since the adhesive has both elasticity and viscosity, it can be expressed as the loss coefficient tanδ value, which is the ratio of the loss modulus and storage modulus.

When comparing two adhesive layers with similar complex elastic modulus sizes, the adhesive layer with a relatively large tanδ value can be said to be an adhesive layer with strong soft viscous characteristics, and the adhesive layer with a relatively small tanδ value can be said to be an adhesive layer with strong soft viscous characteristics. The adhesive layer having strong elastic properties can be said to be an adhesive layer.

According to a preferred embodiment of the present invention, among the two adhesive layers of the variable transmittance film cell, the adhesive layer located closer to the inner curved surface of the curved optical member, for example, is directly attached to the optical component such as the lens 60. In the case of the first adhesive layer 20, an adhesive layer with relatively soft characteristics is disposed, and the adhesive layer in the opposite position, that is, the second adhesive layer 30, is relatively spaced from the optical components such as lenses. ) is characterized by arranging an adhesive layer with relatively hard characteristics.

In configuring the two adhesive layers to have the required physical properties, the variable transmittance film cell according to a preferred embodiment of the present invention is characterized by separately arranging the two adhesive layers based on the storage modulus. In this example, the first adhesive layer (adjacent to the curved optical component), which requires relatively soft properties, is configured to have a low storage modulus value, while the second adhesive layer (adjacent to the curved optical component), which requires relatively hard properties, is configured to have a low storage modulus value. (separated from the optical component) can be configured to have a high storage modulus value. Therefore, according to a preferred embodiment of the present invention, the storage modulus (G') of the second adhesive layer may be configured to have a larger value than the storage modulus (G') of the first adhesive layer.

The storage modulus of the first adhesive layer 20 may have a storage modulus (G') value selected from the range of 0.05 MPa to 0.2 MPa. If the storage modulus of the first adhesive layer 20 is less than 0.05 MPa, excessive deformation due to bending may cause uneven physical distortion and lose its function as an optical adhesive layer, and if the storage modulus of the first adhesive layer 20 is more than 0.2 MPa, the film Tensile stress on the lens side due to bending deformation of the cell cannot be effectively alleviated, which may cause problems such as the generation of bubbles within the liquid crystal cell.

Additionally, the second adhesive layer 30 may have a storage modulus (G') selected from the range of 2 MPa to 6 MPa. If the storage modulus of the second adhesive layer 30 is less than 2 MPa, the extra length created by the compressive stress applied to the adjacent cover layer and the transparent conductive substrate causes an irregular increase in the cell gap and the resulting irregular increase in the cell gap within the liquid crystal cell. The effect of sufficiently reducing the generation of bubbles cannot be achieved, and if the storage modulus is greater than 6 MPa, peeling may occur at the interface between the second adhesive layer 30 and the liquid crystal cell or functional cover layer.

As an example of an optical component, a lens with a radius of curvature of 70 mm or more can be applied. However, in optical components with a large degree of bending with a radius of curvature of less than 70 mm, for example, a radius of curvature of 60 mm, the effect of suppressing the generation of bubbles by controlling the viscoelastic properties of the adhesive is effective. It may be limited. On the other hand, the effect of suppressing the generation of bubbles in the liquid crystal cell through controlling the viscoelastic properties of the two adhesive layers is effective even for lenses with a sufficiently large radius of curvature. In theory, the variable transmittance film cell according to the present invention can be applied to lenses that are not flat but have an almost infinite radius of curvature. Therefore, according to a preferred embodiment of the present invention, it can be applied to optical components having a radius of curvature of 70 mm or more. You can. However, the present invention can be more effectively applied to lenses with a curvature radius of 120 mm or less, where bubble generation problems frequently occur, and therefore can be more preferably applied to optical components with a curvature radius of 70 mm to 120 mm.

In the example where the radius of curvature of the lens is 70 mm to 120 mm, according to a preferred embodiment of the present invention, the storage modulus of the first adhesive layer 20 is 0.1 MPa, and the storage modulus of the second adhesive layer 30 is 5 MPa. You can.

The storage modulus of the second adhesive layer 30 is preferably set to be sufficiently larger than the storage modulus of the first adhesive layer 20. For example, the storage modulus of the first adhesive layer 20 is set to be sufficiently larger than the storage modulus of the first adhesive layer 20. It may be 10 times or more, preferably 25 to 50 times or more, than the storage elastic modulus of 30).

In addition, more preferably, a loss coefficient may be additionally considered in addition to the storage modulus of the two adhesive layers, and in this example, the loss coefficient (tanδ) of the first adhesive layer 20 is the loss coefficient of the second adhesive layer 30. It can be configured to have a value larger than the coefficient (tanδ). As described above, the loss coefficient is a parameter determined by the ratio of the loss modulus and the storage modulus. In considering the loss coefficient along with the storage modulus, the loss coefficient (tanδ) of the first adhesive layer 20 is that of the second adhesive layer. By configuring the layer 30 to have a larger value than the loss coefficient (tanδ), it is possible to effectively provide the tensile stress relief function required for the first adhesive layer 20 adjacent to the lens.

In this way, by arranging the adhesive layers with significantly different storage moduli and loss coefficients at the top and bottom, it is effective in preventing stress changes and extra lengths applied to the upper and lower laminated structure of the film cell, as well as the resulting lifting of the cell gap. In response, the generation of bubbles inside the liquid crystal cell can be suppressed.

It is presumed that the mechanism for suppressing the generation of internal bubbles is to minimize the generation of internal stress in the liquid crystal cell due to a significant difference in the viscoelastic properties of the upper and lower adhesive layers of the liquid crystal cell. In explaining this, the transmittance variable according to the preferred embodiment of the present invention will be described. See Figure 16, which shows a film cell, and Figure 17, which provides a comparative example.

Figures 16 and 17 schematically show the change in the outer part of the liquid crystal cell according to the bending of the variable transmittance film cell. When attaching the film cell to the inner surface of a curved optical product, the viscoelastic properties of the adhesive layer are changed. It is provided to compare changes in the bending shape of the cross-sectional contour of the liquid crystal cell.

First, Figure 16 conceptually shows a cross-section of an example in which a variable transmittance film cell including two adhesive layers having different viscoelastic properties is attached to a lens according to a preferred embodiment of the present invention, and Figure 17 shows a conceptual view. As a comparative example, a cross-section of a variable transmittance film cell in which two adhesive layers having the same very high elasticity are disposed above and below a liquid crystal cell is attached to a lens is conceptually shown. The examples of Figures 16 and 17 show examples of implementing variable transmittance film cells under the same conditions except that the viscoelastic properties of the adhesive layer are different, and the thickness of the adhesive layer is also the same. In relation to the mechanical properties of each adhesive layer, the storage elastic modulus of the upper first adhesive layer 20 in FIG. 16 is G ₁ ', the storage elastic modulus of the lower second adhesive layer 30 is G ₂ ', and the storage elastic modulus of the upper first adhesive layer 20 in FIG. 16 is G 2 '. When the storage elastic modulus is G ₃ ' (in the example of FIG. 8, the upper and lower adhesive layers are configured identically), each storage elastic modulus has the following relationship: G ₁ ' ≪ G ₃ ' ≤ G ₂ '. In addition, the loss coefficient (tanδ) of the upper first adhesive layer 20 in FIG. 16 is T ₁ , the loss coefficient of the lower second adhesive layer 30 is T ₂ , and the loss coefficient of the adhesive layer in FIG. 17 is T ₃ D. When doing so, each loss coefficient may have the following relationship: T ₁ ≫ T ₃ ≥ T ₂ .

Before describing FIGS. 16 and 17, the “bending angle” used in this specification can be defined as follows. Specifically, the “bending angle” in this specification refers to the radius of curvature of the lens, based on the cross section of the liquid crystal cell, when attaching a liquid crystal cell having a certain length (l) to the curved lens 60 in a flat state before bending. The angle formed by the extension lines of both outer ends of the liquid crystal cell required according to can be defined as the bending angle of the liquid crystal cell. That is, when attaching a variable transmittance film cell on the curved lens 60 as shown in FIGS. 16 and 17, both sides of the liquid crystal cell on the cross section are directed toward the center of curvature of the bent liquid crystal cell, based on the cross section of the variable transmittance film cell. The angle formed by the extension line at the end can be referred to as the bending angle of the liquid crystal cell, and the bending angle under ideal conditions (when the liquid crystal cell is attached in parallel with the curved surface of the lens with a constant gap) is the curvature of the curved lens 60. The degree of bending is determined by the radius and the length (l) of the liquid crystal cell, and the bending angle under these ideal conditions can be referred to as the reference bending angle.

Meanwhile, as shown in FIGS. 16 and 17, a change in the bending angle occurs due to a change in the viscoelasticity of the adhesive layer based on the cross section of the liquid crystal cell having a constant length (l).

Specifically, as the liquid crystal cell is attached to the curved surface of the lens, it is bent to form a predetermined bending angle according to the curvature of the lens. Compared to the reference bending angle (θ) of the comparative example of FIG. It has a small bending angle (θ'), which is schematically shown in Figures 18(a) and (b).

This difference in bending angle occurs because, in the case of the first adhesive layer 20 attached to the inside of the curved lens, the adhesive layer with relatively soft characteristics is located adjacent to the tensile area of the liquid crystal cell due to bending. This is because, on the other hand, the second adhesive layer 30 located far away from the lens is located adjacent to the compressed area of the liquid crystal cell and has a relatively hard adhesive layer, thereby resisting the compressive force.

That is, in the case of the embodiment of FIG. 16, the first adhesive layer 20 adjacent to the tensile area of the liquid crystal cell relieves the tensile force applied to the liquid crystal cell in the tensile area, especially the adjacent transparent conductive base layer, while compressing the liquid crystal cell. The second adhesive layer 30 adjacent to the area and the cover layer attached thereto function as a reinforcing layer that suppresses length deformation of the liquid crystal cell in the compressed area and the transparent conductive base layer adjacent thereto. Therefore, as shown in FIG. 16, the bending angle (θ') determined according to the curvature of the lens curved surface is formed at an angle smaller than the reference bending angle (θ) in the comparative example of FIG. 17, and the outer portion (contour) of the cross section of the film layer ) is deformed, and this change in bending angle reduces the change in length of the liquid crystal cell, especially the distortion of the length in the compressed area, which is assumed to be the cause of bubble generation, and the lifting phenomenon of the cell gap due to this. Therefore, the generation of bubbles in the liquid crystal layer can be suppressed.

Figure 18 schematically shows the difference in bending angle (difference in bending angle between the embodiment of Figure 16 and the comparative example of Figure 17), and despite the curvature of the same lens as in Figure 18, in the two examples It shows that there is a difference in bending angle. Figure 18 (a) shows the comparative example of Figure 17, and Figure 18 (b) shows the example of Figure 16. Due to this difference in bending angle, the lower side of the liquid crystal layer, that is, Since the compressive stress acting on the compressed region of the liquid crystal layer is relatively reduced, the change in length of the lower part of the liquid crystal layer can be suppressed and the generation of internal bubbles can be reduced.

Meanwhile, from the perspective of the neutral plane on the cross section of the liquid crystal cell and adhesive layer laminate (hereinafter referred to as 'liquid crystal cell assembly'), in the embodiment of FIG. 16, unlike the comparative example of FIG. 17, the position of the neutral plane is downward. It can be moved, and as a result, the compressive stress at the bottom of the liquid crystal cell can be reduced, thereby reducing the generation of bubbles in the liquid crystal cell.

In this regard, based on the cross section of the variable permeability film cell, areas subject to tensile stress or compressive stress appear depending on the location inside the film cell, and in these areas, the length changes due to the deformation of the film cell, that is, the bending of the film cell. occurs. On the other hand, there is a surface with no change in length at the middle position of the cross section of the variable transmittance film cell, and this surface is called a neutral surface.

In other words, as the film cell is attached to the inside of the curved optical lens and bent, the attached upper surface receives tensile stress and the lower surface deforms under compressive stress. At this time, the neutral plane located between the upper and lower surfaces In the case of , since no tensile or compressive deformation occurs, a neutral plane is formed where the strain rate is substantially 0.

In this regard, Figure 19 shows an example of a symmetrical liquid crystal cell composed of two adhesive layers with the same thickness and same physical properties, and an adhesive layer laminated above and below the adhesive layer, where the neutral plane is located in the center of the cross section.

Meanwhile, in the case of such a symmetrical liquid crystal cell and adhesive layer laminate, that is, a 'liquid crystal cell assembly', when attached to the inner curved surface of a curved optical substrate, large bubbles of a size visible to the naked eye appear inside the liquid crystal cell over time. Problems may arise.

To solve this problem, in the present invention, the tension area and compression area of the upper and lower portions of the liquid crystal cell are divided based on the neutral plane, and adhesive layers with different viscoelasticity for each region are laminated on the top and bottom of the liquid crystal cell to determine the position of the neutral plane. By changing the , it is configured to prevent the generation of bubbles inside the liquid crystal cell over time when attached to the inner curved surface of the curved optical substrate.

Specifically, in the case of the lower part of the liquid crystal cell, that is, a position relatively spaced from the curved optical member, the liquid crystal layer inside the liquid crystal cell and the lower layer lamination structure constitute a compressed area. At this time, it is presumed that the occurrence of fine irregularities on the substrate inside the liquid crystal cell due to the compressive force applied to the corresponding laminated structure is a factor in the generation of bubbles inside the liquid crystal cell. Therefore, in the present invention, in the stacked structure of the liquid crystal cell assembly of the variable transmittance film cell, the second adhesive layer 30 is configured to be relatively hard to suppress deformation of the lower part of the liquid crystal cell. On the other hand, in the case of the upper part of the liquid crystal cell, that is, the position adjacent to the curved optical member, the liquid crystal layer inside the liquid crystal cell and the upper laminated structure constitute a tensile area, thereby alleviating tension on the base layer, etc. inside the liquid crystal cell. The first adhesive layer 20 is made of a soft adhesive layer so that it can be used.

Therefore, according to a preferred embodiment of the present invention, the storage elastic modulus of the first adhesive layer 20 located on the upper part of the liquid crystal layer and adjacent to the curved optical member is lower than that of the second adhesive layer located spaced apart from the curved optical member. It can be configured to have a value significantly smaller than the storage modulus of (30).

In this way, when the soft first adhesive layer 20, which has a relatively small storage modulus, is directly attached to the lens, the first adhesive layer 20 is in the tension area inside the liquid crystal cell as the film cell is bent, and the lens It functions as a relief layer that relieves the tensile force generated by bending depending on the curvature. On the other hand, by placing the hard second adhesive layer 30, which has a relatively high storage modulus, on the opposite side of the lens, the second adhesive layer 30 functions as a reinforcing layer for the compressed area inside the liquid crystal cell. Therefore, the generation of bubbles inside the liquid crystal layer can be effectively prevented through the stacked structure of the film cell in which the two adhesive layers are placed separately at the top and bottom.

Through the laminated structure including the first adhesive layer 20 and the second adhesive layer 30 having different viscoelasticities as described above, the upper soft first adhesive layer 20 close to the curved optical substrate is resistant to bending. While relatively alleviating the deformation, the lower hard second adhesive layer 30, which is spaced apart from the curved optical substrate, suppresses the deformation of the liquid crystal cell, thereby relatively reducing the deformation of the lower part of the liquid crystal cell and causing air bubbles to form in the lower part of the liquid crystal cell. occurrence can be suppressed.

More preferably, to reinforce the function of the hard second adhesive layer 30, a cover layer made of a harder material such as polycarbonate (PC), triacetyl cellulose (TAC), etc. can be added. .

In addition, from the viewpoint of the position of the neutral plane, in the variable transmittance film cell according to the preferred embodiment of the present invention, the neutral plane is moved downward by adjusting the viscoelasticity of the first adhesive layer 20 and the second adhesive layer 30. There is a characteristic.

It is presumed that the occurrence of bubbles inside the liquid crystal cell is due to excessive compressive stress being applied to the lower surface of the liquid crystal cell, that is, the compressed area of the liquid crystal cell, resulting in a length margin in the lower outer shape of the cross section of the film cell. In order to effectively suppress this bubble generation mechanism, the present invention moved the neutral plane of the variable permeability film cell downward to control the position of the neutral plane to reduce the compressive stress applied to the lower side of the liquid crystal cell.

In this regard, Figure 19 shows an example of a symmetrical liquid crystal cell composed of two adhesive layers with the same thickness and same physical properties and an adhesive layer laminated above and below the adhesive layer, showing that the neutral plane is located at the center of the laminated structure. .

Meanwhile, the present invention is characterized by controlling the viscoelastic properties of each adhesive layer and moving the neutral plane of the liquid crystal cell assembly downward to reduce the compressive area of the liquid crystal cell. In this way, the neutral plane is moved downward. An example is shown in Figure 20.

As shown in FIG. 20, when the neutral plane is moved downward to the lower region of the liquid crystal cell assembly, the magnitude of compressive stress applied to the lower region inside the liquid crystal cell assembly can be reduced as the neutral plane is lowered, thereby reducing the amount of compressive stress applied to the lower region of the liquid crystal cell assembly. The occurrence of bubbles inside the cell can be suppressed.

The formula below is a formula for calculating the position of the neutral plane in a structure in which a plurality of films are stacked as shown in FIG. 21.

(λ is the position of the neutral plane, E _i is the storage elastic modulus of the ith film, h _i is the position of the upper surface layer of the ith film, t _i is the thickness of the ith film, h ₀ = 0.)

According to the above formula, when applying an adhesive layer whose viscoelasticity is adjusted so that the storage modulus (E2) of the second adhesive layer has a larger value than the storage modulus (E1) of the first adhesive layer, two layers with the same storage modulus are formed. Compared to the comparative example including an adhesive layer, the position of the neutral plane can be moved downward to the lower side of the liquid crystal cell.

Through this, the position of the neutral plane can be moved downward to the lower side of the film cell, which belongs to the compressed area of the cross-section, so the compressive stress applied to the lower surface of the liquid crystal cell can be relatively reduced, thereby reducing the generation of bubbles. .

Meanwhile, as the position of the neutral plane moves downward, the magnitude of the tensile stress applied to the upper part of the liquid crystal cell may relatively increase, but this tensile stress is not directly related to the generation of bubbles inside the liquid crystal cell. This means that extra length does not occur in the area of the film cell where tensile stress is applied, but extra length does occur on the side of the film where compressive stress occurs, so the cell gap is lifted on the side where the extra length occurs, causing bubbles to form. It is presumed that this is because it occurs. In addition, a spacer is inserted inside the liquid crystal cell. This spacer maintains the cell spacing inside the liquid crystal cell, thereby preventing deformation of the liquid crystal cell due to tensile stress. For this reason, in this patent, when a transmittance-variable film cell is attached to the inner curved surface of a curved optical component, the compressive stress in the compressed area adjacent to the liquid crystal cell is minimized to minimize the generation of bubbles in the liquid crystal cell, or the transparent conductive film cell adjacent to the liquid crystal cell is minimized. A method to reinforce the deformation of film length was presented. When a film cell is attached to the outer curved surface of a curved optical component, the reason why bubbles are less likely to be generated inside the liquid crystal cell is that the hard optical component acts as a reinforcing layer and resists the compressive force in the compression area, and the tensile stress generated in the tensile area is not affected by any part of the liquid crystal cell. This is because it does not cause the cell gap to float, but rather causes the cell gap to close.

In the above, the present invention has been described in detail based on examples and accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the content described in the claims described later.

10: liquid crystal cell
20: first adhesive layer 30: second adhesive layer
40: first cover layer 50: second cover layer
60: Curved lens 70: Functional film layer
110: liquid crystal layer
111: sealing part 112: spacer
120: first alignment layer 130: second alignment layer
140: first electrode layer 150: second electrode layer
160: first base layer 170: second base layer
141: Pattern electrode (first pixel electrode pattern portion)
142: scan line
143: Flexible printed circuit board (FPCB) connection pad
151: Pattern electrode (second pixel electrode pattern portion)
152: data line
153: Flexible printed circuit board (FPCB) connection pad
200: Eyewear frame

Claims (16)

Liquid crystal layer for variable transmittance;
a first base layer located on top of the liquid crystal layer;
a second base layer located below the liquid crystal layer;
a first electrode layer stacked on the first base layer toward the liquid crystal layer; and
It includes a second electrode layer stacked on the second base layer toward the liquid crystal layer,
The first electrode layer is made of a single layer including a first pixel electrode pattern portion made of pattern electrodes extending in a first direction and a scan line connected to the first pixel electrode pattern portion,
The second electrode layer is a liquid crystal cell with variable transmittance consisting of a single layer including a second pixel electrode pattern portion made of pattern electrodes extending in a second direction and a data line connected to the second pixel electrode pattern portion.
In claim 1,
The first electrode layer is made of a single layer formed by patterning the first pixel electrode pattern portion and the scan line according to a predetermined shape on the first base layer,
The second electrode layer is a liquid crystal cell with variable transmittance, characterized in that it is made of a single layer formed by patterning the second pixel electrode pattern portion and the data line according to a predetermined shape on the second base layer.
In claim 1,
A switching driver connected to the scan line and the data line and capable of applying a transmittance control signal to each pixel electrode pattern portion of the first electrode layer and the second electrode layer through the scan line and the data line; further comprising a. A liquid crystal cell with variable transmittance, characterized in that.
In claim 3,
The first electrode layer and the second electrode layer constitute a pixel electrode in the form of an (Am, Bn) matrix, and at least a portion of the switching driver includes (A1, B1) pixels of the pixel electrode in the (Am, Bn) matrix form. A liquid crystal cell with variable transmittance, characterized in that it is located within the frame area adjacent to the selected pixel by any one of the pixels consisting of a group of (A1, Bn) pixels, (Am, B1) pixels, and (Am, Bn) pixels.
In claim 4,
The adjacent frame area is an area defined by an extension of the side boundary of the pattern electrode constituting the selected pixel,
The scan line is formed extending from each pattern electrode of the first pixel electrode pattern portion to the switching driver at a position of a pattern electrode of the second pixel electrode pattern portion constituting the selected pixel,
The data line is formed to extend from each pattern electrode of the second pixel electrode pattern portion to the switching driver at a pattern electrode position of the first pixel electrode pattern portion constituting the selected pixel.
In claim 3,
The first pixel electrode pattern portion is made of pattern electrodes extending in a horizontal direction, and the second pixel electrode pattern portion is made of pattern electrodes extending in a vertical direction,
The pattern electrodes constituting the second pixel electrode pattern portion in the vertical direction are divided into two groups, and a data line connected to the pattern electrode of the first group extends from the upper side of each pattern electrode to the switching driver, and the second group A variable transmittance liquid crystal cell, characterized in that the data line connected to the pattern electrode of the group extends from the lower side of each pattern electrode to the switching driver.
In claim 1,
A first transparent conductive substrate in which the first electrode layer and a first alignment layer are laminated on the first base layer, and a second transparent conductive substrate in which the second electrode layer and a second alignment layer are laminated on the second base layer. In order to do this, it further includes a sealing part formed with a predetermined line width on the edge of the liquid crystal layer,
The sum of the pitches of the scan lines is configured to be smaller than the line width of the sealing part at the corresponding position, so that the scan lines are located within the sealing part,
A liquid crystal cell with variable transmittance, characterized in that the sum of pitches of the data lines is configured to be smaller than the line width of the sealing portion at the corresponding position, and the data line is located within the sealing portion.
In claim 7,
The variable transmittance liquid crystal cell is a variable transmittance liquid crystal cell, characterized in that it is cut along a virtual cutting line within the linewidth area of the sealing part.
In claim 1,
A first alignment layer is stacked between the first electrode layer and the liquid crystal layer,
A second alignment layer is stacked between the second electrode layer and the liquid crystal layer,
The first alignment layer and the second alignment layer are vertical alignment layers for normally clear mode,
The first alignment film layer and the second alignment film layer are formed by patterning the first electrode layer and the second electrode layer and then applying an alignment film coating to form a vertical alignment film between each patterned electrode.
In claim 1,
A first alignment layer is stacked between the first electrode layer and the liquid crystal layer,
A second alignment layer is stacked between the second electrode layer and the liquid crystal layer,
The first alignment layer and the second alignment layer are horizontal alignment layers for normally dark mode,
The first alignment layer and the second alignment layer may be formed by patterning the first electrode layer and the second electrode layer and then applying an alignment layer coating to form a horizontal alignment layer between each pattern electrode, or patterning may be performed after coating the alignment layer to form each layer. A liquid crystal cell with variable transmittance, characterized in that the horizontal alignment layer between pattern electrodes is removed.
In claim 1,
A liquid crystal cell with variable transmittance, characterized in that the maximum length of a unit pixel formed by a combination of the first pixel electrode pattern portion and the second pixel electrode pattern portion is 2 mm or more and 5 mm or less.
In claim 1,
The spacing ratio (s/p) of the pattern electrodes is 0.01 < s/p < 0.04
(Here, s is the separation distance between pattern electrodes, and p is the sum of the line width and separation distance of the pattern electrodes)
A liquid crystal cell with variable transmittance, characterized in that.
A liquid crystal cell with variable transmittance according to any one of claims 1 to 12;
A first adhesive layer located on one side of the liquid crystal cell; and
A variable transmittance film cell including a second adhesive layer located on the other side of the liquid crystal cell,
The first adhesive layer of the variable transmittance film cell is an attachment surface for attachment to the inner curved surface of the curved optical substrate,
A variable permeability film cell, wherein the storage modulus of the second adhesive layer has a greater value than the storage modulus of the first adhesive layer.
In claim 13,
A film cell with variable permeability, characterized in that the loss coefficient (tanδ=G”/G’) of the first adhesive layer has a greater value than the loss coefficient (tanδ=G”/G’) of the second adhesive layer.
In claim 13,
A film cell with variable transmittance, characterized in that the curved optical substrate is a lens for eyewear or augmented reality.
In claim 13,
A variable transmittance film cell, characterized in that the bending angle (θ') of the liquid crystal cell has a smaller value than the reference bending angle (θ) of the liquid crystal cell required according to the radius of curvature of the curved optical substrate.

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