Transparent color contact lens

Abstract

The present invention relates to a transparent color contact lens and, more specifically, to a transparent color contact lens in which a liquid crystal layer having a cholesteric liquid crystal material is disposed on the contact lens, and thus various colors and degrees of reflectivity of the liquid crystal layer can be achieved. The transparent color contact lens includes: a lens surface layer; a cornea protection layer; and a liquid crystal layer positioned between the lens surface layer and the cornea protection layer and reflecting light having a specific wavelength. The reflectivity of light incident on the liquid crystal layer may be adjusted according to the thickness of the liquid crystal layer.

Description

Clear colored contact lenses

[0001] The present invention relates to a transparent color contact lens, and more particularly, to a transparent color contact lens capable of implementing various colors and reflectivity of a liquid crystal layer by arranging a liquid crystal layer having a cholesteric liquid crystal material on the contact lens.

[0002] With the growing number of contact lens wearers, efforts to develop various products capable of generating sustained demand have also been active. Beyond the inherent purpose of contact lenses for vision correction, the development of colored contact lenses, which offer cosmetic benefits, has emerged. This convergence of aesthetic pursuits among both men and women and product development achievements has elevated colored contact lenses to a key product category within the contact lens industry.

[0003] In particular, as the world becomes more globalized and interaction between different races and cultures increases, the demand for colored contact lenses that allow one to change the color of the eye at will is increasing.

[0004] Colored contact lenses fall into two broad categories. First, there are clear tinted lenses. These lenses were developed to emphasize transparency or block light rather than alter the iris' natural color. Therefore, clear tinted lenses have limited ability to change the iris color to a desired color, and are therefore used for purposes such as identification or UV protection rather than cosmetic purposes. Second, there are opaque tinted lenses, which can change the iris' natural color to a different color.

[0005] Traditionally, colored contact lenses were manufactured using opaque dyes as coloring agents, forming an iris-colored layer on the lens surface. However, colored contact lenses manufactured using this method suffered from limitations in expressing the iris color sufficiently brightly and clearly, as most of the light entering the eye was absorbed by the opaque dye-colored layer.

[0006] The object of the present invention is to provide a new type of transparent color contact lens capable of controlling the transparency or reflectivity of a liquid crystal layer as well as implementing various colors by introducing a cholesteric liquid crystal material into the contact lens.

[0007] A transparent color contact lens according to the present invention for achieving the above object comprises: a lens surface layer; a corneal protective layer; and a liquid crystal layer positioned between the lens surface layer and the corneal protective layer and reflecting light having a specific wavelength; and is characterized in that the reflectivity of light incident on the liquid crystal layer can be adjusted according to the thickness of the liquid crystal layer.

[0008] According to one embodiment of the present invention, the liquid crystal layer is characterized by being composed of a photocurable cholesteric liquid crystal material.

[0009] In addition, according to one embodiment of the present invention, the photocurable cholesteric liquid crystal material is characterized by including a material in which a certain amount of a reactive mesogen (RM) and a chiral dopant (CD) are mixed.

[0010] In addition, according to one embodiment of the present invention, the color of reflected light of the liquid crystal layer changes depending on the mixing ratio of the reactive mesogen and the chiral dopant.

[0011] In addition, according to one embodiment of the present invention, as the amount of the chiral dopant increases, the reflected light is characterized in that a blue shift phenomenon occurs.

[0012] In addition, according to one embodiment of the present invention, the mixing ratio of the reactive mesogen and the chiral dopant can be set to have any color having a wavelength in the visible light range.

[0013] In addition, according to one embodiment of the present invention, the center wavelength of light reflected from the liquid crystal layer is calculated as in the following <mathematical formula>.

[0014] <Mathematical formula>

[0015]

[0016] Here, n represents the refractive index of the RM material, HTP represents the helical twist power of the CD material, and x represents the weight ratio (wt%) of the CD material.

[0017] Meanwhile, a transparent color contact lens according to the present invention for achieving the above object comprises: a lens surface layer; a corneal protective layer; and a liquid crystal layer coated on the lower surface of the lens surface layer or the upper surface of the corneal protective layer and reflecting light having a specific wavelength; wherein the liquid crystal layer is composed of a photocurable cholesteric liquid crystal material in which a reactive mesogen (RM) and a chiral dopant (CD) are mixed, and the color of reflected light of the liquid crystal layer changes depending on the mixing ratio of the reactive mesogen and the chiral dopant, and the reflectivity of light incident on the liquid crystal layer can be controlled depending on the thickness of the liquid crystal layer.

[0018] According to one embodiment of the present invention, the liquid crystal layer is characterized in that it is disposed in an area remaining on the upper surface of the corneal protective layer excluding the pupil area.

[0019] In addition, according to one embodiment of the present invention, the liquid crystal layer is configured in a ring shape to surround the pupil region, and the inner diameter of the liquid crystal layer is set to be greater than the diameter of the pupil region.

[0020] In addition, according to one embodiment of the present invention, the liquid crystal layer is characterized by including a first liquid crystal layer configured in a ring shape to surround the pupil area, and a second liquid crystal layer configured in a ring shape to surround the first liquid crystal layer, but spaced apart from the first liquid crystal layer and arranged in a radial direction based on the center of the corneal protective layer.

[0021] In addition, according to one embodiment of the present invention, the liquid crystal layer has a plurality of regions divided in a radial direction or a circumferential direction based on the center of the corneal protective layer, and the photocurable cholesteric liquid crystal material in at least two regions among the plurality of regions has a mixing ratio of different reactive mesogens and chiral dopants.

[0022] In addition, according to one embodiment of the present invention, the liquid crystal layer is formed in a plurality of regions of the corneal protective layer, and at least two regions among the plurality of regions have different shapes.

[0023] Additionally, according to one embodiment of the present invention, the liquid crystal layer is characterized by having a uniform thickness over the entire area.

[0024] In addition, according to one embodiment of the present invention, the liquid crystal layer is characterized in that it is formed by stacking a plurality of layers composed of the photocurable cholesteric liquid crystal material.

[0025] In addition, according to one embodiment of the present invention, the photocurable cholesteric liquid crystal material in at least two layers among the plurality of layers is characterized by having a mixing ratio of different reactive mesogens and chiral dopants.

[0026] According to the present invention, by controlling the mixing ratio of the reactive mesogen and chiral dopant constituting the photocurable cholesteric liquid crystal material, only a specific color among the rainbow colors in the visible light band can be selectively reflected, thereby realizing a very clear iris color.

[0027] In addition, according to the present invention, by controlling the thickness of the liquid crystal layer, there is an effect of being able to implement a transparent state, a translucent state, or an opaque state of the liquid crystal layer that determines the reflectivity of light.

[0028] In addition, according to the present invention, by using a cholesteric liquid crystal material, a very thin liquid crystal layer that acts as an iris coloring layer can be produced, and there is an advantage in that a mirror-like reflection effect and color implementation are possible even in a dim, low-light environment.

[0029] In addition, according to the present invention, by stacking multiple layers of liquid crystal layers, it is possible to implement complex colors by superimposing light reflected from each layer.

[0030] In addition, according to the present invention, by arranging the liquid crystal layer in various shapes or patterns on the upper surface of the corneal protective layer, it is possible to satisfy different cosmetic needs of each user.

[0031] In addition, according to the present invention, there is an advantage in that a color contact lens can be manufactured at a cost similar to that of an opaque dye used in conventional color contact lenses.

[0032] FIG. 1 is a drawing showing the structure of a transparent color contact lens according to the present invention in isolation.

[0033] Figure 2 is a cross-sectional view of a transparent color contact lens according to the present invention.

[0034] FIG. 3 is a graph showing the extent to which the wavelength range of reflected light changes depending on the mixing ratio between RM-CD materials constituting the liquid crystal layer in one embodiment of the present invention.

[0035] FIG. 4 is a graph showing the center wavelength of light reflected according to the mixing ratio between RM-CD materials constituting the liquid crystal layer in one embodiment of the present invention.

[0036] FIG. 5 is a front view of one embodiment of a liquid crystal layer in a transparent color contact lens according to the present invention.

[0037] FIG. 6 is a side view of one embodiment of a liquid crystal layer in a transparent contact lens according to the present invention.

[0038] FIG. 7 and FIG. 8 are front views of another embodiment of a liquid crystal layer in a transparent contact lens according to the present invention, respectively.

[0039] Hereinafter, with reference to the attached drawings, a transparent color contact lens according to a preferred embodiment will be described in detail. Herein, the same reference numerals will be used for identical components, and repetitive descriptions or detailed descriptions of well-known functions and components that may unnecessarily obscure the gist of the invention will be omitted. The embodiments of the invention are provided to more fully explain the present invention to those of ordinary skill in the art. Therefore, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

[0040] FIG. 1 is a drawing showing the structure of a transparent color contact lens according to the present invention in isolation, and FIG. 2 is a cross-sectional view of a transparent color contact lens according to the present invention.

[0041] Referring to FIGS. 1 and 2, a contact lens made of a multilayer wavelength plate according to one embodiment of the present invention includes a corneal protective layer (10), a liquid crystal layer (20), and a lens surface layer (30).

[0042] The corneal protective layer (10) may be configured to come into direct contact with the eyeball when worn. Accordingly, the corneal protective layer (10) has a convex shape with a roughly constant curvature depending on the shape of the eyeball. The size or thickness of the corneal protective layer (10) may be set to various values ​​depending on the designer's intention.

[0043] The corneal protective layer (10) can be formed to a thin thickness by using a method of spraying raw materials onto a mold using a nozzle. The corneal protective layer (10) is sprayed onto a convex-shaped mold using a fine nozzle, so that it is applied onto the mold and forms a gently curved surface convexly upward, so that it can be formed to a thickness within a certain range.

[0044] The corneal protective layer (10) may be formed of a material that is harmless to the human body when in direct contact with the front surface of the eye. For example, the corneal protective layer (10) may be formed of a polymer composed of 2-hydroxyethyl methacrylate, N-vinyl pyrrolidone (NVP), ethylene glycol dimethacrylate (EGDMA), methyl methacrylate (MMA), and azobis isobutyronitrile (AIBN).

[0045] The lens surface layer (30) is a component that is exposed to the outside when worn on the eye. The lens surface layer (30) is formed to have a constant thickness to determine the degree of vision of the eye. The lens surface layer (30) has a convex shape with a roughly constant curvature, and is preferably formed into a smooth surface to ensure natural contact with the eyelid when worn.

[0046] The lens surface layer (30) can be formed of a polymer having the same composition as the polymer composition of the corneal protective layer (10).

[0047] The liquid crystal layer (20) may be positioned between the corneal protective layer (10) and the lens surface layer (30). In one embodiment of the present invention, the liquid crystal layer (20) may be coated on the upper surface of the corneal protective layer (10) (the surface opposite to the surface of the corneal protective layer where the eyeball is located) or the lower surface of the lens surface layer (30). Alternatively, the liquid crystal layer (20) may have a printed form in the form of a film. The liquid crystal layer (20) may also have a convex shape with a similar curvature to correspond to the curved surface of the corneal protective layer (10) or the lens surface layer (30). However, there is no limitation on the shape of the liquid crystal layer (20).

[0048] The liquid crystal layer (20) may be composed of a liquid crystal material. Preferably, in one embodiment of the present invention, the liquid crystal layer (20) may be composed of a photocurable cholesteric liquid crystal (PCLC).

[0049] In one embodiment of the present invention, a cholesteric liquid crystal or chiral nematic liquid crystal is induced by adding a chiral agent to a nematic liquid crystal, and can have a helical structure with a certain period of time. Nematic liquid crystals have the property of having no molecular directionality, and while maintaining an average molecular direction, they allow molecular rotation. Cholesteric liquid crystals can maintain these properties of nematic liquid crystals while adding the property of having molecules arranged in a helical shape.

[0050] When a cholesteric liquid crystal is irradiated with unpolarized light, 50% of the intensity of circularly polarized light of a given handiness (wound left-handed or right-handed depending on the handiness of the spiral) is reflected due to the interaction between incident light of a selected wavelength and the spiral structure, and the remaining 50% can be transmitted as circularly polarized light of the opposite handiness. In other words, a cholesteric liquid crystal can mean a liquid crystal having a selective reflection property that reflects a circularly polarized light component that matches the twist direction of the spiral among light incident parallel to the spiral axis in a planar state in which the spiral axis is perpendicular to the substrate, and transmits a circularly polarized light component in a different direction.

[0051] The liquid crystal layer (20) may be composed of a material including a mixture of a photoreactive material, reactive mesogen (RM), and a chiral dopant (CD).

[0052] Reactive mesogens (RMs) are liquid crystals composed of functional molecules capable of chemically reacting for photopolymerization and photocrosslinking. Reactive mesogens exhibit birefringence and can be coated thinly. Therefore, processes utilizing reactive mesogens can ensure uniform coating and alignment on substrates due to the properties of the liquid-crystalline monomer. Furthermore, photopolymerization through a reactor offers the advantage of maintaining uniform alignment while obtaining a polymer structure.

[0053] In one embodiment of the present invention, the reactive mesogen (RM) may be selected from the group consisting of RM 82, RM 257, RM308, and RMM727.

[0054] Chiral dopants (CDs) are compounds used to introduce chirality into cholesteric liquid crystals. Chiral dopants primarily control the optical properties of cholesteric liquid crystals by forming helical structures, and play a role in controlling color and optical reflection characteristics. Chiral dopants influence the molecular helical structure within cholesteric liquid crystals, inducing selective Bragg reflection. This can result in the appearance of color in cholesteric liquid crystals.

[0055] The reflected color within a cholesteric liquid crystal can be related to the pitch of the helical structure formed by the chiral dopant (CD). For example, a shorter and more dense helical pitch can result in a shorter wavelength of reflected light, while a longer helical pitch can result in a longer wavelength of reflected light.

[0056] That is, a chiral dopant (CD) can help form a pitch gradient of a helical structure by irreversibly changing the helical twisting force.

[0057] In one embodiment of the present invention, the chiral dopant (CD) may be selected from the group consisting of C15, CB15, CM21, R / S-811, CM44, CM45, CM47, R / S-2011, R / S-3011, R / S4011, R / S-5011, R / S-1011, and S811.

[0058] Hereinafter, a method for manufacturing a transparent color contact lens according to one embodiment of the present invention will be described.

[0059] A transparent color contact lens according to one embodiment of the present invention includes a step of forming individual distinct raw material polymers by differently stirring raw material polymers used to form a corneal protective layer (10), a liquid crystal layer (20), and a lens surface layer (30), a step of forming a corneal protective layer (10), a step of forming a liquid crystal layer (20), and a step of forming a lens surface layer (30).

[0060] In the step of forming the raw material polymer of the corneal protective layer (10) and the lens surface layer (30), the raw material polymer of the corneal protective layer (10) can be formed by mixing the raw materials of the corneal protective layer (10) and the lens surface layer (30) described above with a stirrer.

[0061] In the step of forming a corneal protective layer (10), the corneal protective layer (10) can be formed by spraying the raw material polymer of the corneal protective layer (10) onto the upper surface of a water mold having a convex shape upwards using a fine nozzle. However, the corneal protective layer (10) can also be formed using a pad coating method on the water mold instead of using a spray nozzle method. Thereafter, the corneal protective layer (10) can be dried using infrared rays, hot air, or the like.

[0062] In the step of forming the raw material polymer of the liquid crystal layer (20), a certain amount of reactive mesogen (RM) and chiral dopant (CD) are mixed at a first temperature and for a first time period through a stirrer, thereby forming the raw material polymer of the liquid crystal layer (20). Here, the mixing ratio of the reactive mesogen and the chiral dopant may be 0 wt to 100 wt%, respectively. This transparent CLC (Cholesteric Liquid Crystal) mixture (CLC mixture) is cooled to a second temperature lower than the first temperature.

[0063] Thereafter, a photoinitiator is mixed into the cooled CLC mixture. The photoinitiator according to the present invention may be any one commonly used in the art for photopolymerizing photocurable cholesteric liquid crystals. For example, Irgacure 183 and Irgacure 907 from Ciba may be used as the photoinitiator.

[0064] In the step of forming the liquid crystal layer (20), the CLC mixture may be inserted between two pre-prepared glass gaps and then photopolymerized. During photopolymerization, UV, visible light, electron beams, etc. may be used, but in one embodiment of the present invention, a UV curing device may be used. For photopolymerization, the UV curing device may irradiate the CLC mixture with ultraviolet rays at a specific wavelength for a certain period of time. After the photocuring of the CLC mixture is completed, the glass may be removed. Then, the CLC mixture may be manufactured in a film form. The liquid crystal layer (20) manufactured in this manner may be bonded to the upper surface of the corneal protective layer (10).

[0065] Of course, the liquid crystal layer (20) can be formed on the upper surface of the corneal protective layer (10) by various known methods such as printing or deposition.

[0066] In the step of forming the lens surface layer (30), the raw material polymer of the lens surface layer (30) is injected into a concave female mold, and then the male mold on which the corneal protection layer (10) and the liquid crystal layer (20) are formed is combined to form the lens surface layer (30) on the upper surface of the corneal protection layer (20).

[0067] In one embodiment of the present invention, the cholesteric liquid crystal composition may optionally contain a surfactant. Furthermore, the cholesteric liquid crystal composition may additionally contain other optional components as needed. Examples of optional components include a solvent, a polymerization inhibitor for improving pot life, an antioxidant for improving durability, an ultraviolet absorber, a light stabilizer, and the like. These optional components may be added in amounts that do not impair the desired optical performance.

[0068] The temperature and stirring time of the above CLC mixture, wavelength, light intensity, time, etc. of UV light can be varied to achieve different results depending on the experimental conditions.

[0069] Meanwhile, as described above, cholesteric liquid crystals have a helical structure, which reflects light at a specific wavelength. The reflection wavelength of cholesteric liquid crystals can be expressed as in <Mathematical Equation 1> below.

[0070]

[0071] <Mathematical Formula 1>

[0072]

[0073] Here, n is the average refractive index of the cholesteric liquid crystal material, λ is the reflection wavelength of the cholesteric liquid crystal, P is the pitch of the spiral, and θ represents the incident angle of the light.

[0074] Referring to the above <Mathematical Formula 1>, if the average refractive index (n) of the cholesteric liquid crystal material is constant, the reflection wavelength (λ) of the cholesteric liquid crystal depends on the pitch (P) of the spiral. In other words, the cholesteric optical material exhibits a unique reflection pattern by exhibiting selective light reflection depending on the pitch of the spiral.

[0075] Meanwhile, changes in the thickness of cholesteric liquid crystals can alter their reflectivity. As the thickness of a cholesteric liquid crystal increases, the molecular arrangement length of its constituent molecules increases, which can lengthen the path of reflected light. This generally increases the intensity of the reflected light, which in turn increases the reflectivity of the cholesteric liquid crystal. In other words, increasing the thickness of a cholesteric liquid crystal can result in a stronger reflective effect and higher reflectivity.

[0076] FIG. 3 is a graph showing the extent to which the wavelength range of reflected light changes depending on the mixing ratio between RM-CD materials constituting the liquid crystal layer in one embodiment of the present invention, and FIG. 4 is a graph showing the center wavelength of reflected light depending on the mixing ratio between RM-CD materials constituting the liquid crystal layer in one embodiment of the present invention.

[0077] As described above, the liquid crystal layer (20) can reflect light of different colors depending on the mixing ratio (e.g., weight ratio: wt%) of the reactive mesogen (RM) and the chiral dopant (CD).

[0078] [Table 1] below is a table showing some of the colors of reflected light according to the mixing ratio between RM-CD materials included in the liquid crystal layer (20) as examples. The numbers ① to ⑤ shown in FIGS. 3 and 4 are the same as the numbers ① to ⑤ shown in [Table 1] below.

[0079]

[0080]

[0081]

[0082] Referring to the above [Table 1], FIGS. 3 and 4, as the mixing ratio (weight ratio, wt%) of reactive mesogen (RM) and chiral dopant (CD) changes as in cases ① to ⑤, it is shown that light of different colors from red to purple is reflected. For example, when the weight ratios (wt%) of the reactive mesogen (RM) and the chiral dopant (CD) constituting the liquid crystal layer (20) are 95.5 and 4.5, respectively, red reflected light is generated, and when the weight ratios (wt%) of the reactive mesogen (RM) and the chiral dopant (CD) are 95.2 and 4.8, respectively, yellow reflected light is generated, and when the weight ratios (wt%) of the reactive mesogen (RM) and the chiral dopant (CD) are 94.8 and 5.2, respectively, green reflected light is generated, and when the weight ratios (wt%) of the reactive mesogen (RM) and the chiral dopant (CD) are 94.2 and 5.8, respectively Blue reflected light occurs, and when the weight ratios (wt%) of reactive mesogen (RM) and chiral dopant (CD) are 93.9 and 6.1, respectively, purple reflected light occurs.

[0083] That is, as can be confirmed in the above [Table 1], as the amount of chiral dopant (CD) increases, the color of the reflected light changes from red to purple (for example, a blue shift phenomenon may occur). Conversely, as the amount of chiral dopant (CD) decreases, the color of the reflected light changes from purple to red (for example, a red shift phenomenon may occur).

[0084] In addition, as shown in Fig. 3, it can be confirmed that the wavelength of reflected light is different in the cases of materials ① to ⑤ in which the mixing ratio (weight ratio, wt%) of reactive mesogen (RM) and chiral dopant (CD) is different.

[0085] Meanwhile, the mixing ratio of each material shown in [Table 1] may slightly change depending on the experimental conditions. In addition, the mixing ratio shown in [Table 1] is merely an example of the present invention, and the mixing ratio may be determined so that the reflected light has various colors with wavelengths in the visible light range.

[0086] Referring to Figure 4, this is a graph showing the central wavelength of reflected light as the mixing ratio in [Table 1] changes from ① to ⑤. Here, the central wavelength of light can be calculated as in <Mathematical Formula 2> below.

[0087]

[0088] <Mathematical Formula 2>

[0089]

[0090] Here, n represents the refractive index of the RM material, HTP represents the helical twist power of the CD material, and x represents the weight ratio (wt%) of the CD material.

[0091] Referring to the above <Mathematical Formula 2>, it can be confirmed that the greater the torsional force (HTP), the shorter the wavelength of the reflected light.

[0092] Meanwhile, according to another embodiment of the present invention, a photochromic polymer can be prepared by including a photosensitive fragment (CC or NN bond) in a CLC mixture. In this case, the color of the cholesteric liquid crystal structure can change depending on the UV light irradiation time.

[0093] Fig. 5 is a front view of an embodiment of a liquid crystal layer in a transparent color contact lens according to the present invention, and Fig. 6 is a side view of an embodiment of a liquid crystal layer in a transparent contact lens according to the present invention. Meanwhile, Fig. 5 illustrates a state in which the lens surface layer (30) has been removed for convenience of explanation.

[0094] Referring to FIG. 5, in a transparent contact lens according to one embodiment of the present invention, the liquid crystal layer (20) may be positioned on the upper surface of the corneal protective layer (10) except for the pupillary area (40) of the eye. Here, the pupillary area (40) may be configured as a circle having a preset size, but is not limited thereto and may have various shapes.

[0095] In one embodiment of the present invention, the liquid crystal layer (20) may be configured in a ring shape surrounding the pupil area (40). Here, the ring shape may refer to a ring shape having an inner diameter and an outer diameter. There is no limitation on the size of the ring. For example, the ring-shaped liquid crystal layer (20) may be formed to be smaller than the upper surface area of ​​the corneal protective layer (10) excluding the pupil area (40), or may be formed on the entire upper surface area of ​​the corneal protective layer (10).

[0096] Referring to FIG. 6, the liquid crystal layer (20) may be configured by stacking layers composed of the above-described cholesteric liquid crystal. Specifically, the liquid crystal layer (20) may have a shape in which the first layer (20-1), the second layer (20-2) to the n-th layer (20-n) are each configured in a ring shape and are stacked around a concentric axis (X). At this time, there is no limitation on the number of layers to be stacked. For example, the number of layers may be configured to be two or more.

[0097] In one embodiment of the present invention, each layer (20-1, 20-2, ... 20-n) may be composed of different cholesteric liquid crystals. For example, the first layer (20-1) may be composed of a cholesteric liquid crystal having a first color of reflected light by adjusting the mixing ratio of a reactive mesogen (RM) and a chiral dopant (CD), and the second layer (20-2) may be composed of a cholesteric liquid crystal having a second color of reflected light by adjusting the mixing ratio of a reactive mesogen (RM) and a chiral dopant (CD). When layers are stacked to have different colors in this way, the reflected light may have a color that is a superposition of the light reflected from each layer.

[0098] According to another embodiment of the present invention, each layer (20-1, 20-2, ... 20-n) may include the same cholesteric liquid crystal. For example, the second layer (20-2) adjacent to the first layer (20-1) may be composed of the same cholesteric liquid crystal, or the first layer (20-1) and the second layer (20-2) may be composed of different cholesteric liquid crystals, and the first layer (20-1) and the third layer may be composed of the same cholesteric liquid crystal. Of course, there is no limitation on the number of layers that are the same or different and the order in which each layer is arranged.

[0099] Meanwhile, as described above, if the thickness of the cholesteric liquid crystal changes, the reflectivity may change accordingly. According to one embodiment of the present invention, by varying the thickness of the liquid crystal layer (20), the liquid crystal layer (20) may be set to be in a completely transparent state with a reflectivity of 0%, a semitransparent state with only partial reflection, or a completely reflective state with a reflectivity of 100%.

[0100] In one embodiment of the present invention, the thickness (h) of each layer (20-1, 20-2, ... 20-n) may be formed to be the same. In this case, as the number of layers (20-1, 20-2, ... 20-n) to be stacked increases, the thickness of the liquid crystal layer (20) increases, and thus the reflectivity may increase.

[0101] Of course, according to another embodiment of the present invention, the thicknesses of each layer (20-1, 20-2, ... 20-n) of the liquid crystal layer (20) may be configured differently, or the liquid crystal layer (20) may include layers having the same thickness.

[0102] Meanwhile, according to another embodiment of the present invention, the liquid crystal layer (20) in the embodiment illustrated in FIG. 6 may have one layer. At this time, the thickness of the layer may be formed uniformly or unevenly over the entire area of ​​the liquid crystal layer (20), or may be formed unevenly in some areas and uniformly in the remaining areas.

[0103] In addition, according to another embodiment of the present invention, the liquid crystal layer (20) may have various shapes such as an ellipse or a polygon that surrounds the pupil region (40). In addition, according to another embodiment of the present invention, the inner diameter of the liquid crystal layer (20) may be set to be equal to or larger than the size of the pupil region (40).

[0104] In summary, in the present invention, the color of the liquid crystal layer (20) can be implemented by adjusting the mixing ratio of the reactive mesogen (RM) and the chiral dopant (CD) constituting the cholesteric liquid crystal, or by overlapping the reflected light through the lamination of each layer (20-1, 20-2, ... 20-n) constituting the liquid crystal layer (20). In addition, the reflectivity (or, conversely, transparency) of the liquid crystal layer (20) can be implemented by varying the thickness of the liquid crystal layer (20). This basic principle (color or reflectivity of the liquid crystal layer) of the present invention can be applied to various embodiments of the liquid crystal layer (20) described below.

[0105] FIG. 7 and FIG. 8 are front views of another embodiment of a liquid crystal layer in a transparent contact lens according to the present invention, respectively.

[0106] Referring to FIG. 7, the liquid crystal layer (20) according to another embodiment of the present invention may be formed in a ring shape that surrounds the pupil area (40) and may be configured in multiple numbers. Specifically, the first liquid crystal layer (21) may be configured in a ring shape and may be arranged in an area formed to surround the pupil area (40) on the upper surface of the corneal protective layer (10), and the second liquid crystal layer (22) may be configured in a ring shape and may be formed radially to surround the first liquid crystal layer (21) while being spaced apart from the first liquid crystal layer (21). That is, the second liquid crystal layer (21) may be formed to have an outer diameter and an inner diameter that are larger than those of the first liquid crystal layer (22).

[0107] Although only two liquid crystal layers (21, 22) are formed in Fig. 7, there is no limitation on the number of liquid crystal layers (21, 22). In addition, the distance between multiple liquid crystal layers (21, 22) can be set in various ways. In addition, the size of each liquid crystal layer (21, 22) (difference between inner and outer diameters) can also be set in various ways.

[0108] In addition, in the embodiment of the present invention illustrated in FIG. 7, the liquid crystal layer (21) may be composed of one layer. At this time, the thicknesses of the respective liquid crystal layers (21, 22) may be formed to be the same or different. In addition, the thickness of each liquid crystal layer (21) may be formed uniformly or unevenly over the entire area of ​​each liquid crystal layer (21, 22), or may be formed unevenly in some areas and uniformly in the remaining areas. For example, the first liquid crystal layer (21) and the second liquid crystal layer (22) may have different thicknesses, or the thicknesses may be formed differently over the entire area in the first liquid crystal layer (21) or the second liquid crystal layer (22). In addition, in another embodiment of the present invention, at least one of the respective liquid crystal layers (21, 22) may be composed by stacking multiple layers.

[0109] Additionally, in the embodiment of the present invention illustrated in FIG. 7, each liquid crystal layer (21, 22) may be composed of the same or different cholesteric liquid crystals. Additionally, each liquid crystal layer (21, 22) may be divided into multiple regions, and each region may be composed of the same or different cholesteric liquid crystals, and at least two of the regions may be composed of the same cholesteric liquid crystals.

[0110] In addition, each liquid crystal layer (21, 22) may have various shapes such as an ellipse or polygon that surrounds the pupil region (40). In addition, the inner diameter of each liquid crystal layer (21, 22) may be set to be equal to or larger than the size of the pupil region (40).

[0111] Referring to FIG. 8, a liquid crystal layer (20) according to another embodiment of the present invention may be configured in a ring shape surrounding a pupil region (40) and may be divided into a plurality of liquid crystal layer regions (21', 22', 23'). Here, there is no limitation on the number of liquid crystal layer regions (21', 22', 23'). In the embodiment of the present invention illustrated in FIG. 8, each region (21', 22', 23') may be divided in the radial direction with a concentric axis (X) as the center and may be arranged in the circumferential direction. In the present invention, each region (21', 22', 23') may have an approximately arc shape. The size of each region (21', 22', 23') may be the same or different from each other, and at least two regions may be configured to have the same thickness.

[0112] In the embodiment of the present invention illustrated in FIG. 8, the liquid crystal layer (21) may be composed of a single layer. At this time, the thicknesses of each liquid crystal layer region (21', 22', 23') may be formed to be the same or different from each other. Furthermore, in another embodiment of the present invention, at least one of the regions may be composed of multiple layers stacked together.

[0113] Additionally, in the embodiment of the present invention illustrated in FIG. 8, each liquid crystal layer region (21', 22', 23') may be composed of the same or different cholesteric liquid crystals, and at least two may be composed of the same cholesteric liquid crystals.

[0114] In addition, each liquid crystal layer (21, 22) may have various shapes such as an ellipse or polygon that surrounds the pupil region (40). In addition, the inner diameter of each liquid crystal layer (21, 22) may be set to be equal to or larger than the size of the pupil region (40).

[0115] Meanwhile, according to another embodiment of the present invention, the liquid crystal layer (20) may be formed into a plurality of regions to surround the pupil region (40), and each region may be divided in the radial direction with a concentric axis (X) as the center, and may have a shape in which each region is arranged in the circumferential direction so as to be spaced apart from each other. Alternatively, according to another embodiment of the present invention, the liquid crystal layer (20) may be formed into a plurality of regions to surround the pupil region (40), and each region may be divided in the circumferential direction. The description of the thickness of each region, the number of layers, and the cholesteric liquid crystal may refer to the above-described contents.

[0116] Meanwhile, according to another embodiment of the present invention, at least one region may be formed on the upper surface of the corneal protective layer (10) on which the liquid crystal layer (20) is disposed. In this region, liquid crystal layers (20) having various shapes such as symbols, characters, letters, numbers, and figures may be disposed. In addition, when the liquid crystal layer (20) is formed in a plurality of regions on the upper surface of the corneal protective layer (10), there are no restrictions on the distance between the liquid crystal layers (20) formed in each region, the arrangement, the mixing ratio of the cholesteric liquid crystal material constituting the liquid crystal layer (20), the shape or thickness of the liquid crystal layer (20), etc. In addition, the liquid crystal layer (20) may be formed in various patterns on the upper surface of the corneal protective layer (10).

[0117] According to the present invention, by adjusting the mixing ratio of cholesteric liquid crystal materials, it is possible to provide various aesthetics to color contact lenses by setting transparent, translucent, and opaque states through changing the thickness of the liquid crystal layer (20) as well as implementing various colors.

[0118] While the present invention has been described with reference to the embodiments illustrated in the accompanying drawings, these are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent embodiments are possible. Accordingly, the true scope of protection of the present invention should be determined solely by the appended claims.

Claims

1. Lens surface layer; Corneal protective layer; and A liquid crystal layer positioned between the lens surface layer and the corneal protective layer, and reflecting light having a specific wavelength; A transparent color contact lens characterized in that the reflectivity of light incident on the liquid crystal layer can be controlled according to the thickness of the liquid crystal layer.

2. In paragraph 1, A transparent color contact lens characterized in that the liquid crystal layer is composed of a photocurable cholesteric liquid crystal material.

3. In paragraph 2, A transparent color contact lens characterized in that the photocurable cholesteric liquid crystal material includes a substance in which a certain amount of a reactive mesogen (RM) and a chiral dopant (CD) are mixed.

4. In paragraph 3, A transparent color contact lens characterized in that the color of reflected light of the liquid crystal layer changes depending on the mixing ratio of the reactive mesogen and the chiral dopant.

5. In paragraph 4, A transparent colored contact lens characterized in that as the amount of the chiral dopant increases, the reflected light exhibits a blue shift phenomenon.

6. In paragraph 3, A transparent color contact lens characterized in that the mixing ratio of the above reactive mesogen and chiral dopant can be set to have any color having a wavelength in the visible light range.

7. In paragraph 3, A transparent color contact lens characterized in that the center wavelength of light reflected from the liquid crystal layer is calculated as in the <mathematical formula> below. <Mathematical formula> Here, n represents the refractive index of the RM material, HTP represents the helical twist power of the CD material, and x represents the weight ratio (wt%) of the CD material.

8. Lens surface layer; Corneal protective layer; and A liquid crystal layer coated on the lower surface of the lens surface layer or the upper surface of the corneal protective layer and reflecting light having a specific wavelength; The above liquid crystal layer is composed of a photocurable cholesteric liquid crystal material mixed with a reactive mesogen (RM) and a chiral dopant (CD). The color of the reflected light of the liquid crystal layer changes depending on the mixing ratio of the reactive mesogen and the chiral dopant. Characterized in that the reflectivity of light incident on the liquid crystal layer can be controlled according to the thickness of the liquid crystal layer. Clear colored contact lenses.

9. In paragraph 8, A transparent color contact lens, characterized in that the liquid crystal layer is disposed in an area remaining on the upper surface of the corneal protective layer, excluding the pupil area.

10. In paragraph 9, A transparent color contact lens characterized in that the liquid crystal layer is configured in a ring shape to surround the pupil region, and the inner diameter of the liquid crystal layer is set to be larger than the diameter of the pupil region.

11. In paragraph 9, A transparent color contact lens characterized in that the liquid crystal layer comprises a first liquid crystal layer configured in a ring shape to surround the pupil area, and a second liquid crystal layer configured in a ring shape to surround the first liquid crystal layer, but spaced apart from the first liquid crystal layer and arranged radially with respect to the center of the corneal protective layer.

12. In paragraph 8, The above liquid crystal layer has a plurality of regions divided in a radial or circumferential direction based on the center of the corneal protective layer, A transparent color contact lens, wherein the photocurable cholesteric liquid crystal material in at least two of the above-described multiple regions has a mixing ratio of different reactive mesogens and chiral dopants.

13. In paragraph 8, A transparent color contact lens characterized in that the liquid crystal layer is formed in a plurality of regions of the corneal protective layer, and at least two of the plurality of regions have different shapes.

14. In paragraph 8, A transparent color contact lens characterized in that the liquid crystal layer has a uniform thickness over the entire area.

15. In paragraph 8, A transparent color contact lens characterized in that the liquid crystal layer is formed by stacking a plurality of layers composed of the photocurable cholesteric liquid crystal material.

16. In paragraph 15, A transparent color contact lens, wherein the photocurable cholesteric liquid crystal material in at least two layers among the plurality of layers has a mixing ratio of different reactive mesogens and chiral dopants.

17. In paragraph 15, The liquid crystal layer is formed in multiple areas of the corneal protective layer, A transparent colored contact lens characterized in that the number of layers in at least two of the above plurality of regions is different.

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