KR102024250B1

KR102024250B1 - Optical Film

Info

Publication number: KR102024250B1
Application number: KR1020150139699A
Authority: KR
Inventors: 김신영; 벨리아에프 세르게이; 이지연; 박문수
Original assignee: 주식회사 엘지화학
Priority date: 2015-10-05
Filing date: 2015-10-05
Publication date: 2019-09-23
Also published as: KR20170040564A

Abstract

The present application relates to an optical film and the use of the optical film, can provide an optical film exhibiting selective transmission and blocking properties according to the viewing angle, such an optical film is a security film of a display device such as LCD, smart window and It can be usefully used for sun glass.

Description

Optical film

This application relates to the use of an optical film and an optical film.

The use of security films is increasing due to the importance of information protection or personal privacy. For example, Patent Document 1 discloses a security film to which Micro Louver technology is applied. The micro louver film has a structure in which a plurality of fine louvers are patterned at regular intervals. The plurality of fine louvers formed inside the louver film have an effect (direction control effect) of controlling the propagation direction of light passing through the louver film to a predetermined outflow angle range. Therefore, unnecessary leakage of the liquid crystal panel transmitted light in the lateral direction can be prevented, and such a louver film is also called a light control film. However, in the micro louver film, the aspect ratio is a main factor of the performance of the security film, but as the line width increases, the height may decrease, but when the line width increases, the transmittance decreases by that amount.

Patent Document 1: Korean Laid-Open Patent Publication No. 2007-0090662

This application provides the use of an optical film and an optical film.

The present application relates to an optical film. Exemplary optical films include a first linear polarizer, a first liquid crystal film, and a second liquid crystal film. The first liquid crystal film and the second liquid crystal film may be sequentially formed on the first linear polarizer. In addition, each of the first liquid crystal film and the second liquid crystal film may be a nonlinear spray-oriented liquid crystal film. 1 exemplarily shows an optical film having a structure in which a first linear polarizer 101, a first nonlinear spray oriented liquid crystal film 102, and a second nonlinear spray oriented liquid crystal film 103 are sequentially formed.

As used herein, the term "polarizer" refers to a functional layer that exhibits selective transmission and blocking properties, such as reflection or absorption properties, for incident light. For example, the polarizer may have a function of transmitting light vibrating in one direction from incident light vibrating in various directions and blocking light vibrating in the other direction. As used herein, the term "linear polarizer" refers to a case where linearly polarized light that selectively transmits light vibrates in one direction and linearly polarized light that vibrates in a direction perpendicular to the vibration direction of the linearly polarized light. The kind of the linear polarizer is not particularly limited and, for example, as a reflective polarizer, for example, a dual brightness enhancement film (DBEF), a lyotropic liquid crystal (LLC layer) or a wire grid polarizer Or the like, and as an absorption type polarizer, for example, an anisotropic polarizer in which a polymer stretched film such as a PVA stretched film or the like is used as a host or a liquid crystal polymerized in an oriented state, and arranged according to the alignment of the liquid crystal. Guest-host type polarizers using dye as guest may be used, but are not limited thereto.

As used herein, the term "spray orientation" means an orientation state in which the tilt angle of the liquid crystal compound present in the liquid crystal film is gradually changed in accordance with the thickness direction of the liquid crystal film. As used herein, the term "tilt angle" means the minimum angle between the optical axis of the liquid crystal compound and the surface of the liquid crystal film. In this specification, the term "average tilt angle" means the tilt angle when the average value of the tilt angles of all the liquid crystal compounds or the arrangement of all the liquid crystal compounds is converted into an average value. As used herein, the term “optical axis” means an axis in the direction of a rod-like major axis when the liquid crystal compound is in a rod shape, and an axis in the normal direction of the disc plane when the liquid crystal compound is in the shape of a disc. Therefore, in this specification, "the liquid crystal film contains the liquid crystal compound spray-oriented" means that when the liquid crystal compound is rod-shaped, the major axis direction gradually changes according to the thickness direction of the liquid crystal film, or the liquid crystal compound is the original In the case of the shape, it means that the normal direction of the disc plane gradually changes depending on the thickness direction of the liquid crystal film.

In one example, the spray orientation is, for example, within a range where the minimum tilt angle of the liquid crystal compound in the liquid crystal film is about 0 degrees to 20 degrees, and within a range where the maximum tilt angle is about 70 degrees to 90 degrees, wherein the tilt angle is It can mean the orientation state which gradually changes along the thickness direction of a liquid crystal film.

Spray orientation can be divided into linear spray orientation and non-linear spray orientation. In the present specification, the term “linear spray orientation” refers to an alignment state in which a graph shown by using a thickness of the liquid crystal film as an x-axis and a local tilt angle corresponding to the thickness as a y-axis represents a linear graph. That is, it means an alignment state whose slope is constant. In one example, the linear spray orientation is based on the x-axis (i.e. x = 0 to 1.0) of the ratio z / d of the corresponding thickness z to the total thickness d of the liquid crystal film (ie, corresponding to that thickness). The tilt angle of the graph shown on the x-axis is set so that the local tilt angle is the y-axis, and the interval (b) between the minimum and maximum tilt angles on the y-axis is equal to the interval (a) within the range of x = 0 to 1.0. Can therefore mean a constant orientation state, for example an orientation state in which the mean tilt factor is in the range of about 0.95 to 1.05 (see graph A in FIG. 15).

In contrast, in the present specification, the term "non-linear spray orientation" refers to an alignment state in which a graph shown with a thickness of the liquid crystal film as the x-axis and a local tilt angle corresponding to the thickness as the y-axis represents the nonlinear graph. That is, it means the orientation state whose slope changes with the thickness of a liquid crystal film. In one example, the nonlinear spray orientation may refer to an orientation state in which the tilt of the tilt angle with respect to the thickness of the liquid crystal film is gradually increased or gradually decreased. In one example, the non-linear spray orientation is the x-axis (ie, x = 0 to 1.0) corresponding to the thickness, with the ratio z / d of the corresponding thickness z to the total thickness d of the liquid crystal film The tilt angle of the graph shown on the x-axis is set so that the local tilt angle is the y-axis, and the interval (b) between the minimum and maximum tilt angles on the y-axis is equal to the interval (a) within the range of x = 0 to 1.0. Gradually decrease along with an average tilt factor of less than about 0.95 (see graph B in FIG. 15) or gradually increasing along the x-axis, with an average tilt factor of greater than about 1.05. (See graph C of FIG. 15).

In one specific example, the non-linear spray orientation gradually decreases along the x-axis in terms of effectively implementing selective transmission and blocking characteristics according to the viewing angle as described below, while the average tilt factor is Or less than about 0.95, for example, about 0.9 or less, about 0.8 or less, about 0.7 or less. In this case, the lower limit of the average slope may be about 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more or 0.6 or more.

As long as there is no particular mention of the tilt factor in the present specification, it may mean a tilt factor value derived by measuring the phase difference of the film for each angle using Axoscan (Axometrix Co., Ltd.). The tilt factor of the spray oriented liquid crystal film can be adjusted by adjusting the process temperature in the manufacture of the spray oriented liquid crystal film. In one example, the spray oriented liquid crystal film may be prepared by curing a layer of a known spray oriented liquid crystal composition. Curing in the above may be performed by irradiating ultraviolet rays to the layer of the spray-oriented liquid crystal composition, it is possible to adjust the tilt factor of the spray-oriented liquid crystal film by adjusting the temperature at the time of irradiation of the ultraviolet rays. For example, the tilt factor tends to increase as the temperature at the time of ultraviolet irradiation increases.

When the first and second liquid crystal films in the optical film are each nonlinear spray oriented liquid crystal films, the optical film is advantageous in exhibiting selective transmission and blocking properties that differ in the viewing angle. In this case, the average tilt angle of the first and / or second liquid crystal film may be, for example, in the range of 45 degrees to 55 degrees. When the first and second liquid crystal films each implement a non-linear spray orientation at the front, they can function as linear twisted nematic films at an inclination angle, which is advantageous in showing selective transmission characteristics according to the viewing angle. Therefore, when the average tilt angle of the first and / or second liquid crystal film is within the above range, it is advantageous to exhibit selective transmission characteristics according to the viewing angle.

In one example, the first and / or second nonlinear spray oriented liquid crystal film may be a single layer liquid crystal film comprising a nonlinear spray oriented liquid crystal compound. In the present specification, a single layer means a case in which a liquid crystal film is formed of one liquid crystal layer, and thus, for example, a liquid crystal film having a structure in which two or more liquid crystal layers are laminated is excluded from a single liquid crystal film. When the first and / or second liquid crystal nonlinear spray oriented film is a single layer liquid crystal film, the first and / or second nonlinear spray oriented liquid crystal film can be formed by using a nonlinear spray oriented liquid crystal known in the art. .

In another example, the first and / or second nonlinear spray oriented liquid crystal film may include a linear spray oriented liquid crystal film and a retardation film satisfying the following general formula 1 and having a positive thickness direction retardation value defined by the following formula B: have. Such a retardation film may be called a + C plate. In the above, the linear spray oriented liquid crystal film means a liquid crystal film including a linear spray oriented liquid crystal compound. In addition, the case where the linear spray-oriented liquid crystal film and the + C plate are thus included is a non-linear spray orientation having the average tilt angle as compared with the case where the single-layer liquid crystal film containing the non-linear spray-oriented liquid crystal compound is formed. It may be advantageous in terms of implementing a state.

In addition, as a specific example of the implementation of the non-linear spray-oriented liquid crystal film as described above, the first and second non-linear spray-oriented liquid crystal film may each include a pair of linear spray-oriented liquid crystal film and + C plate. That is, the first nonlinear spray oriented liquid crystal film may include the first linear spray oriented liquid crystal film and the + C plate, and the second nonlinear spray oriented liquid crystal film may include the second linear spray oriented liquid crystal film and the + C plate. Alternatively, as another specific example of the implementation of the nonlinear spray oriented liquid crystal film as described above, the first linear spray orientation is arranged by placing one + C plate between the first linear spray oriented liquid crystal film and the second linear spray oriented liquid crystal film. The effect of the 1st nonlinear spray orientation liquid crystal film which consists of a liquid crystal film and 1/2 + C plate, and the 2nd linear spray orientation liquid crystal film and the 2nd nonlinear spray orientation liquid crystal film which consists of 1/2 + C plate appears It can also be implemented.

In addition, in the implementation of the non-linear spray-oriented liquid crystal film as described above, the first liquid crystal film adjacent to the first linear polarizer has a linear spray-oriented liquid crystal film constituting the first liquid crystal film to the first linear polarizer compared to the retardation film. It may be arranged to be adjacent.

[Formula 1]

n _x ≒ n _y ≠ n _z

[Formula B]

Rth = d × (nz-ny)

In Formula 1 or Formula B, d is the thickness of the retardation film, nx is the refractive index in the slow axis direction in the plane of the retardation film, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the retardation film, nz is the retardation It is the refractive index of the thickness direction of the film, ie, the direction perpendicular to both the slow axis and the direction perpendicular thereto.

The retardation film may be called a + C plate. The retardation film may include a liquid crystal compound present in a vertical alignment state. As used herein, the term “vertical orientation” is about 90 degrees to about 65 degrees, about 90 degrees to about 75 degrees, about 90 degrees to about 80 degrees, about 90 degrees to about 85 degrees, with respect to the liquid crystal film plane of the optical axis. It may mean having a tilt angle of 90 degrees.

The thickness of the first and / or second nonlinear spray oriented liquid crystal film may be appropriately adjusted in consideration of the refractive index anisotropy of the spray oriented liquid crystal, the retardation value of the liquid crystal film, and the aspect of forming a uniform coating. For example, the first and second nonlinear spray oriented liquid crystal films may each have a diameter of about 0.1 μm to about 5 μm, about 0.5 μm to about 5 μm, about 1 μm to about 5 μm, about 1.5 μm to about 4.5 μm, and about 2 μm. To about 4 μm, about 2.5 μm to 3.5 μm, or about 2.75 μm to 3.25 μm, but the thickness range is not necessarily limited to the above range.

Further, the thicknesses of the first and / or second nonlinear spray-oriented liquid crystal films exhibit a selective transmission characteristic at an inclination angle, so that the cut-off angle, i.e., the angle of the east angle at which the transmittance is the first minimum and the cut-off angle And then transmittance at an angle. In one example, as the thickness of the first and / or second non-linear spray oriented liquid crystal film increases, the cut-off angle decreases, and the transmittance at the cut-off angle tends to decrease. Therefore, in consideration of the blocking performance of the optical film, it may be advantageous to design a thick thickness of the liquid crystal film. However, as the thickness of the first and / or second nonlinear spray-oriented liquid crystal film increases, the transmittance tends to rise relatively quickly at an angle after the cut-off angle. In consideration of the tendency of the selective transmission characteristic according to the thickness of the liquid crystal film, it may be appropriate to make the thickness ranges of the first and second nonlinear spray-oriented liquid crystal films within the above ranges, respectively. However, as described above, the thicknesses of the first and / or second non-linear spray-oriented liquid crystal films are not limited to the above ranges, and the cut-off angle and the cut-off angle and subsequent angles, which are selectively required for transmission characteristics, are optional. It may also be adjusted to a thickness outside the above range in consideration of the transmittance of.

In one example, the liquid crystal compound included in the first and / or second nonlinear spray oriented liquid crystal film may be a polymerizable liquid crystal compound. The first and / or second nonlinear spray oriented liquid crystal film may include, for example, a polymerizable liquid crystal compound in a polymerized form. As used herein, the term "polymerizable liquid crystal compound" may mean a compound containing a site capable of exhibiting liquid crystallinity, for example, a mesogen skeleton, and the like, and also including one or more polymerizable functional groups. . In addition, "the polymerizable liquid crystal compound is contained in a polymerized form" may mean a state in which the liquid crystal compound is polymerized to form a skeleton such as a main chain or side chain of the liquid crystal polymer in the liquid crystal film. As the polymerizable liquid crystal compound, a rod-shaped polymerizable liquid crystal compound or a polymerizable liquid crystal compound of disc development can be appropriately selected and used.

The optical film can, for example, exhibit selective transmittance according to the viewing angle. In one example, the optical film may exhibit a low transmittance when observed at a predetermined tilt angle and an inclination angle, and may exhibit a high transmittance when observed at an inclination angle of a tilt angle other than the predetermined tilt angle. As used herein, the term "tilt angle and east angle" can be described with reference to FIG. 2. For example, if the plane (xy plane) by the x-axis and the y-axis in FIG. 2 is the surface of the optical film, the inclination angle is the angle formed by the normal of the xy plane, that is, the z-axis in FIG. (Θ in FIG. 2). In addition, copper angle means the angle (Φ of FIG. 2) which the projection of the x-axis and the xy plane of the observation direction P make, for example. Unless otherwise specified herein, inclined light may mean light incident at an inclination angle within a range of about 30 degrees to 50 degrees.

The optical film can design selective transmittance according to the viewing angle, for example, by adjusting the optical axes of the first and second nonlinear spray oriented liquid crystal films and the absorption axes of the first linear polarizers. Hereinafter, in this specification, the term "vertical, orthogonal, horizontal or parallel" means substantially vertical, orthogonal, horizontal or parallel in a range which does not impair the desired effect. Accordingly, each term may include, for example, an error within ± 15 degrees, within ± 10 degrees, within ± 5 degrees, or within ± 3 degrees.

In one example, the projection of the average optical axis of the first and / or second non-linear spray oriented liquid crystal film onto the first and second non-linear spray oriented liquid crystal film planes may be parallel to the absorption axis of the first linear plane. As used herein, the term “average optical axis” may mean the sum of vectors of optical axes existing in the liquid crystal film.

In one specific example, the projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the first and second nonlinear spray oriented liquid crystal film planes may be parallel to the absorption axis of the first linear plane, respectively. Such an optical film may exhibit a relatively low transmittance, for example, when observed at an inclination angle of 85 to 95 and at an inclination angle of 265 to 275 degrees. Such optical films also exhibit relatively high transmittances when observed at a tilt angle other than the tilt angle, for example, at a tilt angle of 355 degrees to 5 degrees and at a tilt angle of 175 degrees to 185 degrees. Can be.

In one example, the optical film may have a transmittance of about 30% or less for light incident at an inclination angle of 50 degrees at an angle of 85 to 95 degrees and light incident at an angle of inclination of 50 degrees at an angle of 265 degrees to 275 degrees. In addition, the optical film may exhibit transmittance of about 80% or more with respect to light incident at an inclination angle of 50 degrees at an 355 to 5 degree angle and light incident at an inclination angle of 50 degrees at an angle of 175 degrees to 185 degrees.

In the present specification, when describing the transmittance with respect to the inclination angle, unless otherwise specified, it may mean a transmittance at an inclination angle of about 50 degrees. In addition, in the present specification, when describing the transmittance with respect to the tilt angle, unless otherwise specified, it may mean a transmittance with respect to the tilt angle when the absorption axis of the first wire knitting machine is viewed at about 0 degrees and about 180 degrees of the tilt angle.

In another example, the projection of the average optical axis of the first and / or second nonlinear spray oriented liquid crystal film to the plane of the first and second nonlinear spray oriented liquid crystal film, respectively, is at least about 10 degrees with the absorption axis of the first linear polarizer. It may be arranged to form an angle. The angle may be more specifically about 10 degrees or more, about 12.5 degrees or more, about 15 degrees or more, about 17.5 degrees or more, or about 20 degrees or more, but the present invention is not limited thereto. Can be appropriately selected. Such an optical film may exhibit a relatively low transmittance when observed at an inclination angle of 85 to 95 and at an inclination angle of 265 degrees to 275, and has a relatively low transmittance, for example, a tilt angle other than the above A relatively high transmittance may be exhibited with respect to the observation at an inclination angle of 355 degrees to 5 degrees and the observation angle at an inclination angle of 175 degrees to 185 degrees.

In one example, the optical film may have a transmittance of about 10% or less with respect to light incident at an inclination angle of 50 degrees at an 85 to 95 degree of longitude, and may have a transmittance of about 10% or less at an angle of inclination of 50 at an angle of 265 to 275. A transmittance of about 60% or less can be exhibited. In addition, the optical film may exhibit transmittance of about 80% or more with respect to light incident at an angle of inclination of 50 degrees at an angle of 355 degrees to 5 degrees and light incident at an angle of inclination of 50 degrees at an angle of 175 degrees to 185 degrees.

In another example, the projection of the average optical axis of the first and / or second non-linear spray oriented liquid crystal film to the first and / or second non-linear spray oriented liquid crystal film plane is arranged to be parallel to the absorption axis of the first linear plane. Can be. In one specific example, the projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the first and second nonlinear spray oriented liquid crystal film planes may be arranged to be parallel to the absorption axis of the first linear plane. Such an optical film may exhibit a relatively low transmittance when observed at an inclination angle of 355 degrees to 5 degrees and at an inclination angle of 175 degrees to 185 degrees. When observed at an inclination angle other than the same angle, for example, at an inclination angle of 85 to 95 degrees, and at an inclination angle of 265 degrees to 275 degrees, a relatively high transmittance may be exhibited.

In one example, the optical film may have a transmittance of about 30% or less for light incident at an inclination angle of 50 degrees at an 355 to 5 degree angle and light incident at an inclination angle of 50 degrees at an angle of 175 degrees to 185 degrees, respectively. have. In addition, the optical film may exhibit transmittance of about 80% or more with respect to light incident at an angle of inclination of 50 degrees at an angle of 85 to 95 degrees and light incident at an angle of inclination of 50 degrees at an angle of 265 to 275 degrees.

In the present application, the design of the optical axis of the first and second non-linear spray-oriented liquid crystal film and the absorption axis of the first linear polarizer is not limited to the above and may be appropriately changed in consideration of the selective transmittance according to the desired viewing angle.

The rotation direction of the spray orientation of the 1st and / or 2nd nonlinear spray orientation liquid crystal film can be suitably selected within the range which does not impair the objective of this application. As used herein, the term "rotation direction of spray orientation" may mean a direction in which the tilt angle increases. For example, when the direction in which the tilt angle increases is clockwise, it may be referred to as a right rotation spray orientation, and when the direction in which the tilt angle is increased is counterclockwise, it may be referred to as a left rotation spray orientation. In one example, the rotation directions of the spray orientations of the first and second non-linear spray-oriented liquid crystal films may be the same. For example, the first and second nonlinear spray alignment liquid crystal films may each have a right turn spray orientation state or a left turn spray orientation state respectively. In another example, the first and second nonlinear spray oriented liquid crystal films may have different rotation directions of the spray orientation. For example, the first nonlinear spray orientation liquid crystal film has a right rotation spray orientation, the second nonlinear spray orientation liquid crystal film has a left rotation spray orientation, or the first nonlinear spray orientation liquid crystal film has a left rotation spray orientation, and the second The non-linear spray orientation liquid crystal film may have a right turn spray orientation.

The tilt angle at the interface between the first and second nonlinear spray oriented liquid crystal films can be appropriately adjusted within a range that does not impair the object of the present application. In the present specification, the "tilt angle at the interface between the first and second nonlinear spray-oriented liquid crystal films" is the tilt angle and the second nonlinear spray orientation of the region closest to the second nonlinear spray-oriented liquid crystal film in the first nonlinear spray-oriented liquid crystal film. In the liquid crystal film, the angle formed by the tilt angle of the region nearest to the first nonlinear spray-oriented liquid crystal film may mean. In one example, the tilt angle at the interface between the first and second nonlinear spray oriented liquid crystal films is about 0 to 20 degrees, about 0 to 18 degrees, about 0 to 16 degrees, about 0 to 14 degrees 0 degrees to 12 degrees or about 0 degrees to 10 degrees. In another example, the tilt angle at the interface between the first and second nonlinear spray oriented liquid crystal films is about 70 degrees to 90 degrees, about 72 degrees to 90 degrees, about 74 degrees to 90 degrees, about 76 degrees to 90 degrees , About 78 degrees to 90 degrees or about 80 degrees to 90 degrees.

3 and 4 are exemplary diagrams for explaining the rotation direction and the tilt angle at the interface of the spray orientation of the first and / or second nonlinear spray-oriented liquid crystal film. In one example, the optical film has a first nonlinear spray orientation liquid crystal film 102 and a second nonlinear spray orientation liquid crystal film 103 each having a right rotation spray orientation, as shown in FIG. 3, and the first and second nonlinearities. The tilt angle at the interface between the spray-oriented liquid crystal films can achieve about 0 degrees (the -axis is the optical axis). In another example, the optical film has a left rotation spray orientation, the second nonlinear spray orientation liquid crystal film 103 has a right rotation spray orientation, as shown in FIG. 4, The tilt angle at the interface between the first and second non-linear spray oriented liquid crystal films can be about 80 degrees to 90 degrees (the -axis being the optical axis).

The optical film may further include a third nonlinear spray oriented liquid crystal film. Specific details of the nonlinear spray orientation in the third nonlinear spray orientation liquid crystal film may be the same as those described in the items of the first and second nonlinear spray orientation liquid crystal films. In one example, a third nonlinear spray oriented liquid crystal film may be present between the first nonlinear spray oriented liquid crystal film 102 and the second nonlinear spray oriented liquid crystal film 103, as shown in FIG. 5. In this case, the first and second nonlinear spray-oriented liquid crystal films may have the same rotation direction of the spray orientation, for example, may have the same right-turn spray orientation. In addition, as shown in FIG. 5, the tilt angle at the interface between the third nonlinear spray oriented liquid crystal film and the first nonlinear spray oriented liquid crystal film and / or between the third nonlinear spray oriented liquid crystal film and the first nonlinear spray oriented liquid crystal film. The tilt angle at the interface can be about 70 to 90 degrees, about 72 to 90 degrees, about 74 to 90 degrees, about 76 to 90 degrees, about 78 to 90 degrees, or about 80 to 90 degrees, respectively. Can be. Such an optical film is advantageous in that it uniformly exhibits selective transmission characteristics according to the viewing angle with respect to light of a wide wavelength band, for example, light of the entire wavelength band of visible light. That is, the optical film may exhibit excellent color characteristics because it exhibits uniform transmission characteristics in a wide wavelength band.

In addition to the first and second nonlinear spray oriented liquid crystal films, the optical film may further include a retardation film, which may be referred to as the + C plate described above. In one example, the retardation film may be present between the first and second non-linear spray oriented liquid crystal films, as shown in FIG. 7. In this case, the first and second nonlinear spray-oriented liquid crystal films may have the same rotation direction of the spray orientation, for example, may have the same right-turn spray orientation. 6, the tilt angle at the interface between the retardation film and the first nonlinear spray oriented liquid crystal film and / or the tilt angle at the interface between the retardation film and the first nonlinear spray oriented liquid crystal film is about 0 to 20 degrees. Degrees, about 0 degrees to 18 degrees, about 0 degrees to 16 degrees, about 0 degrees to 14 degrees, about 0 degrees to 12 degrees, or about 0 degrees to 10 degrees. Such an optical film is advantageous in that it uniformly exhibits selective transmission characteristics according to the viewing angle with respect to light of a wide wavelength band, for example, light of the entire wavelength band of visible light. That is, the optical film may exhibit excellent color characteristics because it exhibits uniform transmission characteristics in a wide wavelength band.

The optical film may also further comprise a twisted nematic liquid crystal layer or a half wavelength phase delay layer. The twisted nematic liquid crystal layer or 1/2 wavelength phase delay layer 201 is, for example, between the first linear polarizer 101 and the first nonlinear spray-oriented liquid crystal film 102. May exist.

As used herein, the term "twist nematic liquid crystal layer" means a layer including a twisted oriented nematic liquid crystal compound, and the layer may be, for example, a liquid crystal polymer layer. The liquid crystal polymer layer may mean, for example, a layer in which a polymerizable liquid crystal compound is polymerized in a twisted orientation to form a polymer. In the present specification, "the liquid crystal compound is twisted-oriented" may mean a spirally oriented structure in which the waveguides of the liquid crystal molecules are oriented in a layer while being twisted along the spiral axis. This structure is similar to the so-called cholesteric alignment form, but the twisted nematic liquid crystal layer has a thickness less than the pitch when the waveguide of the liquid crystal molecules is referred to as a "pitch" for completing a 360 degree rotation. Can be distinguished from the cholesteric orientation. That is, in the twisted nematic liquid crystal layer, the waveguide of the liquid crystal molecules may not rotate 360 degrees. Such twisted nematic liquid crystal layer may be formed, for example, on a suitable film or sheet.

In the present specification, the “n wavelength phase retardation characteristic” may mean a characteristic capable of retarding incident light by n times the wavelength of the incident light within at least a portion of a wavelength range. Accordingly, the 1/2 phase delay layer may mean a property that phase delays incident light by 1/2 times the wavelength of the incident light within at least a portion of the wavelength range. The half-wavelength phase delay layer may express, for example, a planar phase difference within a range of 200 nm to 290 nm or 220 nm to 280 nm with respect to a wavelength of 550 nm. The 1/2 wavelength retardation layer is not particularly limited as long as it exhibits the above phase retardation characteristics. For example, a liquid crystal film or a polymer stretched film can be used.

If the optical film further comprises a twisted nematic liquid crystal layer or a half wavelength phase delay layer, the plane of the liquid crystal film of the absorption axis of the first polarizer described above and the average optical axis of the first and second nonlinear spray-oriented liquid crystal films It is possible to reverse the tendency of the selective transmission characteristic according to the east angle at the angle and the inclination angle formed by the projection of. In the following examples, the numerical values for the transmittance and the inclination angle may be equally applied.

For example, when the optical film comprises a twisted nematic liquid crystal layer or a 1/2 phase delay layer between the first linear polarizer and the first nonlinear spray oriented liquid crystal film, the first and second nonlinear spray oriented liquid crystal films When the projection of the average optical axis to the plane of the first and second non-linear spray-oriented liquid crystal films is parallel to the absorption axis of the first linear polarizer, respectively, when observed at an inclination angle of 355 to 5 and at an angle of 175 to 185, respectively. A relatively low transmittance may be observed with respect to the observation at an inclination angle, and may be observed at an inclination angle other than the inclination angle, for example, at an inclination angle of 85 to 95 degrees and at an inclination angle of 265 to 275 degrees. It can show a relatively high transmittance with respect to

Alternatively, when the optical film comprises a twisted nematic liquid crystal layer or a 1/2 phase delay layer between the first linear polarizer and the first nonlinear spray oriented liquid crystal film, the average optical axis of the first and second nonlinear spray oriented liquid crystal films When the projections of the first and second nonlinear spray-oriented liquid crystal films of the liquid crystal film are perpendicular to the absorption axis of the first linear polarizer, respectively, when observed at an inclination angle of 85 to 95 and at an inclination angle of 265 degrees to 275. Regarding the case of observation, relatively low transmittance may be observed, and the case of observation at an inclination angle other than the inclination angle, for example, at an inclination angle of 355 degrees to 5 degrees, and at an inclination angle of at least 175 degrees to 185 degrees It can exhibit a relatively high transmittance with respect to.

In the optical film of the present application, as described above, the projection of the average optical axis of the first and second non-linear spray-oriented liquid crystal films onto the first and second non-linear spray-oriented liquid crystal film planes forms the absorption axis of the first linear polarizer. Depending on the angle, the transmission angle may exhibit a selective transmission angle at an inclination angle. In particular, the angle of view as compared to the case where the projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the first and second nonlinear spray oriented liquid crystal film planes is parallel when perpendicular to the absorption axis of the first linear polarizer. It is advantageous for showing uniform and sharp elliptic transmittance in all directions. Thus, the first nonlinear spray orientation of the optical film in designing the optical film to exhibit a relatively low transmittance when observed at an inclination angle of 85 to 95 and at an inclination angle of 85 to 95 and at an inclination angle of 265 to 275. Twist nematic liquid crystal layer or 1/2 wavelength phase delay layer is arrange | positioned between a liquid crystal film and a 1st linear polarizer, and the 1st and 2nd nonlinear spray orientation liquid crystal film of the average optical axis of a 1st and 2nd nonlinear spray orientation liquid crystal film It may be advantageous in that the projection onto the plane is perpendicular to the absorption axis of the first linear polarizer in terms of indicating a decrease in the transmittance of a uniform ellipse shape in all directions of the east-angle angle, but is not necessarily limited thereto.

The optical film may further include an adhesive layer. As shown in FIG. 8, the first non-linear spray oriented liquid crystal film 102 and the second non-linear spray oriented liquid crystal film 103 may be present in an attached state by the pressure-sensitive adhesive layer 301. As an adhesive layer, it can select from a well-known adhesive layer suitably, and can use within the range which does not impair the objective of this application. For example, the cured product of the composition containing the curable compound may be used as the pressure-sensitive adhesive layer, and a heat curable or ultraviolet curable compound may be used as the curable compound, but is not limited thereto. Moreover, the type of adhesive layer can also be suitably selected within the range which does not impair the objective of this application. For example, a solid adhesive, a semisolid adhesive, an elastic adhesive, or a liquid crystal adhesive can be selected suitably and used. Solid adhesives, semisolid adhesives or elastic adhesives may be referred to as pressure sensitive adhesives (PSAs) and may be cured before bonding objects are bonded. The liquid adhesive may be referred to as so-called optical clear resin (OCR), and may be cured after the bonding object is bonded. According to one embodiment of the present application, PSA may be used as an adhesive, but is not limited thereto.

The optical film may further include a base layer. The substrate layer may be adjacent to the first and / or second non-linear spray oriented liquid crystal film. In one example, as shown in FIG. 9, the substrate layer 401A is adjacent to the opposite side on which the second nonlinear spray oriented liquid crystal film 103 of the first nonlinear spray oriented liquid crystal film 102 is formed, that is, The first nonlinear spray oriented liquid crystal film 102 and the first linear polarizer 101 are present, or the base layer 401B is formed of the first nonlinear spray oriented liquid crystal film 103 of the second nonlinear spray oriented liquid crystal film 103 ( 102 may be present adjacent to the opposite side formed.

As a base material layer, a well-known raw material can be used without a restriction | limiting in particular. For example, inorganic films, plastic films, etc., such as a glass film, a crystalline or amorphous silicon film, a quartz, or an Indium Tin Oxide (ITO) film, can be used. As the base material layer, an optically anisotropic base material layer such as an optically isotropic base material layer or a retardation layer can be used.

Examples of the plastic substrate layer include triacetyl cellulose (TAC); Cyclo olefin copolymer (COP) such as cyclo olefin polymer (COC) and norbornene derivatives; Poly (methyl methacrylate); PC (polycarbonate); PE (polyethylene); PP (polypropylene); PVA (polyvinyl alcohol); DAC (diacetyl cellulose); Pac (Polyacrylate); PES (poly ether sulfone); PEEK (polyetheretherketon PPS (polyphenylsulfone), PEI (polyetherimide); PEN (polyethylenemaphthatlate); PET (polyethyleneterephtalate); PI (polyimide); PSF (polysulfone); PAR (polyarylate) or amorphous fluorine resin The substrate layer may include a coating layer of a silicon compound such as gold, silver, silicon dioxide or silicon monoxide, or a coating layer such as an antireflection layer, if necessary.

In one example, a substrate layer having a small on-plane retardation value may be used as the substrate layer. The substrate layer may be, for example, a normal TAC in an unstretched state having a plane retardation value of about 10 nm or less, or a no retardation TAC (NRT) having a plane retardation value of about 10 nm or less and a thickness direction retardation value of about 5 nm. Or ORT (O-retardation TAC), or COP or COC which is substantially free of retardation phase difference, but may be used, but is not limited thereto. The type of substrate layer described above may be appropriately selected according to the purpose of the optical film. have.

The optical film may further include one or more alignment films. The alignment film can adjust the projection of the average optical axis of the first and / or second nonlinear spray-oriented liquid crystal film onto the liquid crystal film. The alignment layer may be present adjacent to the first and / or second non-linear spray oriented liquid crystal film. In one example, the alignment film is adjacent to the opposite side on which the second nonlinear spray alignment liquid crystal film of the first nonlinear spray alignment liquid crystal film is formed or opposite to the first nonlinear spray alignment liquid crystal film of the second nonlinear spray alignment liquid crystal film is formed. May be adjacent to the side. In addition, in the case where the optical film includes two substrate layers as shown in FIG. 10, the alignment films 501A and 501B are disposed between the substrate layer 401A and the first nonlinear spray-oriented liquid crystal film 102 and the substrate layer 401B, respectively. And the second non-linear spray-oriented liquid crystal film 103 can be disposed. As the alignment film, an alignment film known to be capable of exhibiting orientation characteristics by a non-contact method such as irradiation of linearly polarized light including a contact alignment film or a photoalignment film compound such as a rubbing alignment film can be used without limitation.

The optical film may also further comprise a second linear polarizer. The second linear polarizer 601 may be present adjacent to the first nonlinear spray oriented liquid crystal film opposite side of the second nonlinear spray oriented liquid crystal film 103, for example, as shown in FIG. 11. As for the definition and type of the second linear polarizer, the contents described in the items of the first linear polarizer may be applied in the same manner. In one example, the optical film may be arranged such that the absorption axis of the second linear polarizer is parallel to the absorption axis of the first linear polarizer. Such an optical film, for example, weakens the vibration direction of the polarized light through which the first and second non-linear spray-oriented liquid crystal films pass through the linear polarizer of any one of the first and second linear polarizers when observed at an oblique angle of a predetermined radial angle. It can be rotated to 80 degrees to 90 degrees, and since the polarized light rotated in the vibration direction does not pass through the other linear polarizer, the transmittance can be adjusted when observed at an inclination angle of a predetermined radius.

The present application also relates to the use of the optical film. The optical film may exhibit selective transmission and blocking characteristics according to a tilt angle at a predetermined tilt angle. Such an optical film may be usefully used as a security film or an antireflection film of a display device. The optical film may be disposed on the observer side of the display device.

In one example, the observer can observe the image of the display device relatively well when observing the display device at a viewing angle exhibiting transmission characteristics, and the observer can observe the display device at a viewing angle exhibiting blocking characteristics. The optical film can function as a security film of the display device because the image of the film cannot be observed relatively well.

In another example, when the display device is used in an external environment having a reflective function, a phenomenon in which an image of the display device is reflected on the external environment having the reflective function may be reduced, so that the display device may be used as an antireflection film. An external environment having the reflection function may exemplify a window of a vehicle. For example, when the display device is arranged so that an observer can observe the display device at an elevation angle exhibiting transmission characteristics, and the display device is arranged such that an external environment having a reflection function is located at an elevation angle exhibiting blocking characteristics, The image of the display device can be observed, and the phenomenon in which the image of the display device is reflected by the reflective external environment can be reduced. For example, when the external environment having the reflective function is a window of the vehicle, when the display device is disposed to be viewed from the side of the driver's seat of the vehicle, the image of the display device is reflected on the front window of the vehicle and reflected to the viewer. The phenomenon can be reduced.

In one example, the display device may be a liquid crystal display device. The liquid crystal display may sequentially include a light source, a liquid crystal panel, and an optical film of the present application.

As the light source, for example, a direct type or edge type backlight unit (BLU) commonly used in a liquid crystal display (LCD) may be used. In addition to the above, various kinds of light sources may be used without limitation.

The liquid crystal panel may include, for example, a first substrate, a pixel electrode, a first alignment layer, a liquid crystal layer, a second alignment layer, a common electrode, and a second substrate sequentially formed from the light source side. On the first substrate on the light source side, for example, an active driving circuit including a TFT (Thin Film Transistor), wiring, or the like may be formed as a driving element electrically connected to the transparent pixel electrode. The pixel electrode may include, for example, indium tin oxide (ITO) or the like, and may function as an electrode for each pixel. In addition, a 1st or 2nd alignment film can contain materials, such as a polyimide, for example.

The liquid crystal layer may include an appropriate kind of liquid crystal according to the mode of the liquid crystal display device to be driven. For example, the optical film of the present invention may be applied to the liquid crystal display device of the in-plane switching (IPS), twisted nematic (TN) mode to adjust the transmission characteristics according to the viewing angle, but the mode of the liquid crystal display device is necessarily limited thereto. However, the present invention may be applied to liquid crystal display devices of various modes.

In one example, when the optical film of the present invention is applied to the liquid crystal display device of the IPS mode, it is advantageous to exhibit selective transmission and blocking characteristics according to the viewing angle. In another example, when the optical film of the present invention is applied to the liquid crystal display device of the TN mode, when the additional optical film is further disposed as necessary, it exhibits selective transmission and blocking characteristics according to the viewing angle It may be more advantageous. As the separate optical film, a 1/2 wavelength phase delay layer or a twisted nematic liquid crystal layer may be exemplified. When the 1/2 wavelength phase delay layer is used as the separate optical film, the optical axis of the 1/2 wavelength phase delay layer and the absorption axis of the first linear polarizer are about 20 degrees to 25 degrees, specifically about 22 degrees to about 23 degrees. More specifically, the angle may be about 22.5 degrees. The liquid crystal layer may have a function of transmitting or blocking light from a light source for each pixel by a voltage applied from a driving circuit. The common electrode includes, for example, ITO and can function as a common counter electrode.

The liquid crystal display device may further include upper and lower polarizer plates that are present above and below the liquid crystal panel. The lower polarizer may, for example, be disposed closer to the light source side than the upper polarizer. In one example, the upper polarizer may play a role corresponding to the second linear polarizer described in the item of the optical film. For example, the optical film may be disposed such that the second nonlinear spray oriented liquid crystal film and the upper polarizer of the liquid crystal panel are attached.

In one example, the optical film may be disposed such that an absorption axis of the first linear polarizer and an absorption axis of the upper polarizer of the liquid crystal panel are parallel to each other. 12 exemplarily shows a liquid crystal display device including a first linear polarizer 101, a first nonlinear spray oriented liquid crystal film 102, a second nonlinear spray oriented liquid crystal film 103, and an upper polarizing plate 701 in sequence. Indicates. Such a liquid crystal display device may include, for example, when the liquid crystal display device is observed at an inclination angle of a predetermined tilt angle in a state where the first linear polarizer is adjacent to an observer, the first and second nonlinear spray-oriented liquid crystal films are formed on the upper part of the liquid crystal panel from the light source. It may serve to rotate the vibration direction of the polarized light passing through the polarizing plate to about 80 degrees to 90 degrees, the polarized light rotated in the vibration direction does not pass through the first linear polarizer of the optical film can reduce the transmittance.

In the above, as long as the liquid crystal display device includes the optical film of the present application, other components or structures are not particularly limited, and all contents known in the art may be appropriately applied.

The optical film of the present application may also be usefully used for smart windows or sun glasses. As used herein, the term "smart window" refers to a window having a function of controlling the transmittance of incident light, for example, sunlight, so-called smart blinds, electronic curtains, variable transmittance glass, or dimming glass. It is a concept encompassing a functional element called. As used herein, the term "sun glass" may refer to a functional element for protecting the eyes from sunlight. For example, the smart window or the sun glass including the optical film of the present application, as shown in Figure 13, in particular, the transmittance for light incident at an inclination angle of a predetermined radius can be lowered, and the mirror other than the predetermined angle of inclination Transmittance with respect to the light incident at the angle of inclination may have a characteristic that can be increased. Therefore, the optical film of the present application can be usefully used for smart windows or sun glasses that want to exhibit selective transmittance according to the viewing angle. In the above, as long as the smart window or the sun glass includes the optical film of the present application, other parts or structures are not particularly limited, and all contents known in the art may be appropriately applied.

The present application can provide an optical film that exhibits selective transmission and blocking characteristics according to the viewing angle, and the optical film can be usefully used for security films, smart windows, and sun glasses of display devices such as LCDs.

1 is a schematic diagram of an optical film of the present application.
2 is a schematic diagram for explaining an inclination angle and an east angle.
3 to 6 are spray orientation schematic diagrams of the first and second non-linear spray-oriented liquid crystal films.
7-11 is a schematic diagram of the optical film of this application.
12 is a schematic view of the liquid crystal display device of the present application.
FIG. 13 is a schematic diagram illustrating selective transmission and blocking characteristics according to a viewing angle of a smart window or sunglasses of the present application.
14 is a structure of an optical film of Example 1.
It is a schematic diagram for demonstrating spray orientation.

Hereinafter, the above contents will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present application is not limited by the contents given below.

Example One

The optical film of Example 1 having the structure of FIG. 14 was prepared. Specifically, after forming a photo alignment layer on the NRT base film (fuji) (301A, 301B), cyano biphenyl acrylate, cyano phenyl cyclohexane-based acrylate and cyano phenyl ester-based on the photo alignment layer A solid content of 95% by weight of a polymerizable liquid crystal compound (manufactured by Merck) made of acrylate and 5% by weight of Igacure 907 (Swiss, Ciba-Geigy), a photoinitiator, was mixed. The spray-oriented liquid crystal composition prepared by dissolving in a toluene solvent was coated through a bar coating, and then the coating layer was left to dry in an oven at about 80 ° C. for 2 minutes.

Next, by irradiating the dried coating layer with ultraviolet light (300mW / cm ² ) for about 10 seconds while maintaining the temperature at about 80 ℃, a first linear spray-oriented liquid crystal film 106A having a thickness of about 3.5um was prepared. . Next, the second linear spray oriented liquid crystal film 106B was manufactured by the same method as the manufacturing method of the said 1st linear spray oriented liquid crystal film. The bottom tilt angles of the first and second linear spray oriented liquid crystal films were about 0 degrees, the top tilt angle of the air plane was about 90 degrees, and the linear spray oriented liquid crystal films having a tilt factor of about 1.0.

Next, a + C plate 105 having a thickness of about 3.3 μm, a Rin value of about 10 nm or less, and an Rth value of about 400 nm is attached between the surfaces of the first and second linear spray-oriented liquid crystal films. The laminated body of the nonlinear spray orientation liquid crystal film like the laminated | stacked two nonlinear spray orientation liquid crystal film whose tilt factor is less than about 0.95 was manufactured. In the above, the tilt angles in the air plane of the first and second linear spray-oriented liquid crystal films were attached to be the same.

Next, the first absorption linear polarizer 101 is disposed on the opposite side on which the liquid crystal film 102 of the base film 301A is formed, and on the opposite side on which the liquid crystal film 103 of the base film 301B is formed. The second absorption type linear polarizer 601 serving as the upper polarizer of the LCD was disposed. The optical film of Example 1 is arrange | positioned so that the projection of the average optical axis of the said 1st and 2nd linear spray oriented liquid crystal films 106A, 106B to the liquid crystal film plane may be parallel with the absorption axis P ₁ of a 1st linear polarizer, respectively. and, the second linear polarizer is disposed's absorption axis (P ₂₎ is also parallel to the first linear polarization absorption axis (P ₁₎ party.

Example 2

The first and second spray-aligned liquid crystals in the same manner as in Example 1 except that the temperature of the coating layer of the spray-aligned liquid crystal composition during ultraviolet irradiation was maintained at 40 ° C. in the manufacturing steps of the first and second spray-oriented liquid crystal films. A film was prepared. The tilt factors of the prepared first and second spray oriented liquid crystal films were about 0.7, respectively.

Next, the 1st and 2nd linear spray oriented liquid crystal films were attached so that the tilt angles in the air plane might be the same.

Next, the optical film of Example 2 was produced by disposing the first and second absorption type linear polarizers in the same manner as in Example 1.

Comparative example One

The same manner as in Example 1, except that in Example 1, a 3M vehicle light control film (LCF) (DBEF and the louver film having a laminated structure) was used instead of the laminate of the nonlinear spray-oriented liquid crystal film. Comparative Example 1 was prepared.

Comparative example 2

Comparative Example 2 was prepared in the same manner as in Example 1 except that the + C plate was not disposed between the surfaces of the first and second linear spray-oriented liquid crystal films in Example 1.

Evaluation example 1 Transmittance Evaluation at Front Luminance and Vertical Tilt Angle

Example 1 and Comparative Examples 1-2 were evaluated using Axoscan (Axometrics, Inc.), and the transmittances according to the inclination angles of 30 degrees and 50 degrees at the front luminance and the upper and lower sides (90 and 270 degrees of east angle) and the results were evaluated. It is shown in Table 1 below.

Example 1 Comparative Example 1 Comparative Example 2 Front brightness 91% 83% 91% 30 degrees tilt angle 23% 20% 46% 50 degrees up and down inclination 10% 10% 10%

101: first linear polarizer
102: first nonlinear spray-oriented liquid crystal film
103: second nonlinear spray-oriented liquid crystal film
104: third nonlinear spray-oriented liquid crystal film
105: retardation film
106A and 106 B: First and second linear spray oriented liquid crystal film
201: twisted nematic liquid crystal layer or 1/2 wavelength phase delay layer
301: adhesive layer
401A and 401B: substrate layer
501A, 501B: alignment film
601: second polarizer
701: upper polarizer

Claims

A first linear polarizer; And first and second non-linear spray-oriented liquid crystal films sequentially formed on the first linear polarizer,
The projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the plane of the first and second nonlinear spray oriented liquid crystal films is parallel to the absorption axis of the first linear polarizer, respectively, and the inclination angle is 85 to 95 degrees at an east angle. Transmittance of 30% or less for light incident at 50 degrees and incident angle 50 degrees at an angle of 265 to 275 degrees at an angle of
The projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the plane of the first and second nonlinear spray oriented liquid crystal films forms an angle of 10 degrees or more with the absorption axis of the first linear polarizer, respectively, and has a radial angle of 85 to 95 degrees. Shows a transmittance of 10% or less for light incident at an inclination angle of 50 degrees and a transmittance of 60% or less for light incident at an inclination angle of 50 degrees at an east angle of 265 to 275 degrees; or
The projection of the average optical axis of the first and second nonlinear spray oriented liquid crystal films onto the plane of the first and second nonlinear spray oriented liquid crystal films is orthogonal to the absorption axis of the first linear polarizer, respectively, and has an inclination angle at an east angle of 355 to 5 degrees. An optical film exhibiting a transmittance of 30% or less with respect to light incident at 50 degrees and light incident at an inclination angle of 50 degrees at 175 to 185 degrees (where 0 and 180 degrees of east angle are angles of the absorption axis of the first linear polarizer).

The optical film of claim 1, wherein the first or second nonlinear spray oriented liquid crystal film is a single layer liquid crystal film comprising a nonlinear spray oriented liquid crystal compound.

The optical film of claim 1, wherein the first or second non-linear spray-oriented liquid crystal film comprises a linear spray-oriented liquid crystal film and a phase difference film satisfying the following general formula 1 and having a positive thickness direction retardation value defined by the following formula B:
[Formula 1]
n _x ≒ n _y ≠ n _z
[Formula B]
Rth = d × (nz-ny)
In Formula 1 or Formula B, d is the thickness of the retardation film, nx is the refractive index in the slow axis direction in the plane of the retardation film, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the retardation film, nz is the retardation It is refractive index of thickness direction of film

The optical film of claim 1, wherein the tilt factor of the first or second non-linear spray oriented liquid crystal film is less than 0.95 or greater than 1.05.

delete

The optical film of claim 1, wherein the first and second nonlinear spray-oriented liquid crystal films have the same rotation direction of the spray orientation.

The optical film of claim 1, wherein the tilt angles at the interface between the first nonlinear spray oriented liquid crystal film and the second nonlinear spray oriented liquid crystal film constitute 0 to 10 degrees of each other.

The optical film of claim 1, wherein the first and second nonlinear spray-oriented liquid crystal films have different rotational directions of spray orientation.

The optical film of claim 1, wherein the tilt angles at the interface between the first and second nonlinear spray-oriented liquid crystal films form 80 degrees to 90 degrees with each other.

The optical film of claim 1, further comprising a third nonlinear spray oriented liquid crystal film.

16. The liquid crystal film of claim 15, wherein the third non-linear spray-oriented liquid crystal film is present between the first and second non-linear spray-oriented liquid crystal films having the same rotational direction, and the third non-linear spray-oriented liquid crystal film and the first non-linear spray-oriented liquid crystal film And the tilt angle at the interface between the third nonlinear spray-oriented liquid crystal film and the tilt angle at the interface between the second nonlinear spray-oriented liquid crystal film is in the range of 80 to 90 degrees, respectively.

The optical film according to claim 1, further comprising a retardation film satisfying the following general formula 1 and having a positive thickness direction retardation value defined by the following formula B:
[Formula 1]
n _x ≒ n _y ≠ n _z
[Formula B]
Rth = d (nz-ny)
In Formula 1 or Formula B, d is the thickness of the retardation film, nx is the refractive index in the slow axis direction in the plane of the retardation film, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the retardation film, nz is the retardation It is the refractive index of the thickness direction of a film.

18. The retardation film of claim 17, wherein the retardation film is present between the first and second nonlinear spray oriented liquid crystal films having the same rotational direction of spray orientation, and the tilt angle and the phase difference at the interface between the retardation film and the first nonlinear spray oriented liquid crystal film. An optical film in which the tilt angles at the interface between the film and the second nonlinear spray oriented liquid crystal film are each within a range of 0 degrees to 10 degrees.

The optical film of claim 1, further comprising a twisted nematic liquid crystal layer or a half-wave retardation layer present between the first linear polarizer and the first non-linear spray oriented liquid crystal film.

The optical film of claim 1, further comprising a base layer present between the first linear polarizer and the first nonlinear spray oriented liquid crystal film or adjacent to the top of the second nonlinear spray oriented liquid crystal film.

The optical film of claim 1, further comprising a second linear polarizer present adjacent to the second nonlinear spray oriented liquid crystal film.

22. The optical film of claim 21, wherein absorption axes of the second linear polarizer and the first linear polarizer are parallel to each other.

A liquid crystal display device comprising the liquid crystal panel and the optical film of claim 1.

24. The liquid crystal device of claim 23, further comprising an upper polarizer plate adjacent to one surface of the liquid crystal panel, wherein the optical film of claim 1 is disposed such that the upper polarizer plate and the second nonlinear spray-oriented liquid crystal film are present. Display device.

The liquid crystal display of claim 24, wherein an absorption axis of the upper polarizer and an absorption axis of the first linear polarizer are parallel to each other.

Smart window comprising the optical film of claim 1.

Sunglasses comprising the optical film of claim 1.