KR102645757B1 - Cover Dust Laminate and Head Up Display including the Cover Dust Laminate - Google Patents

Abstract

This application relates to a cover dust laminate and a head-up display including the same. In the present application, it is possible to provide a cover dust laminate that prevents curl, has excellent fairness, and does not cause so-called redness even when driven or maintained under very harsh conditions (e.g., very high temperature conditions). there is. In addition, the cover dust laminate is applied to the head-up display to prevent internal components such as the image generating device from burning, while realizing clear image quality, and when displaying two independent screens, the luminance ratio of each screen is appropriate. A head-up display can be provided.

Description

Cover dust laminate and head up display including the same {Cover Dust Laminate and Head Up Display including the Cover Dust Laminate}

This application relates to a cover dust laminate and a head-up display including the same.

Head Up Discplay (HUD) is a device that visualizes vehicle driving information as a virtual image in front of the driver's field of view.

For example, as shown in FIG. 1, the head-up display 10 includes an image generating device 20 that generates an optical signal corresponding to an image, and a cover dust laminate to prevent deterioration of internal components due to external light, etc. 100), light control means (reflector 40 and/ or beam splitter, etc.).

The cover dust laminate 100 has served to prevent deterioration of internal components, for example, the image generating device 20, due to external light and to block reflected light inside the cover dust. However, the conventional cover dust laminate 100 includes an optical laminate to which a reflective polarizer is applied, so external light is reflected back to the outside and enters the driver's field of view, causing problems such as not being able to perceive a clear screen. there was.

In addition, head-up displays, especially as they are applied to vehicles, are often exposed to high-temperature environments and/or environments with large temperature changes in summer and winter, so the durability of the cover dust laminate is a problem, while fairness is impaired due to bending, etc. There were problems such as deterioration.

Accordingly, even when the head-up display is maintained and/or driven under much harsher conditions than before, for example, at very high temperatures, it is possible to maintain durability while maintaining clear image quality, and to ensure fairness by controlling curl, etc. It is required to secure.

The present application can provide a cover dust laminate that prevents curl, has excellent fairness, and does not cause so-called redness even when driven or maintained under very harsh conditions (e.g., very high temperature conditions). there is. In addition, the cover dust laminate is applied to the head-up display to prevent internal components such as the image generating device from burning, while realizing clear image quality, and when displaying two independent screens, the luminance ratio of each screen is appropriate. A head-up display can be provided.

Among the physical properties mentioned in this specification, the physical properties where measurement temperature and/or measurement pressure affect the results are the results of measurements at room temperature and/or pressure, unless specifically stated otherwise.

The term room temperature refers to a natural temperature that is not heated or reduced, for example, any temperature in the range of 10°C to 30°C, about 23°C, or about 25°C. Additionally, in this specification, the unit of temperature is °C unless otherwise specified.

The term normal pressure is the natural pressure that is not pressurized or decompressed, and usually means about 1 atmosphere of atmospheric pressure.

In the case of a physical property in which the measured humidity affects the results in this specification, the physical property is a physical property measured at room temperature and/or normal pressure with natural humidity that is not specifically adjusted.

In this specification, the term lower direction refers to the direction from the upper cover substrate of the cover dust laminate toward the absorption-type polarizer, and the term upper direction refers to the opposite direction, and refers to the direction from the absorption-type polarizer to the upper cover substrate.

The cover dust laminate of the present application may include an absorption-type polarizer, an upper cover substrate formed on an upper portion of the absorption-type polarizer, and/or a lower cover substrate formed on a lower portion of the absorption-type polarizer. As used herein, the term cover substrate may refer to a layer having a surface pencil hardness of 0.5H or more. The pencil hardness can be measured by drawing a pencil lead on the surface of the cover substrate at an angle of 45 degrees and a load of 500 g at a temperature of about 25°C and a relative humidity of 50% using a general pencil hardness measuring equipment. Pencil hardness can be measured by gradually increasing the hardness of the pencil lead until defects such as indentations, scratches, or ruptures are confirmed on the surface of the cover substrate. In other examples, the pencil hardness of the cover substrate is about 0.6H or higher, 0.7H or higher, 0.8H or higher, 0.9H or higher, 1H or higher, 2H or higher, 3H or higher, or 4H or higher, or 10H or lower, 9H or lower, 8H or lower, 7H or lower, It may be 6H or less, 5H or less, 4H or less, 3H or less, or 2H or less.

By attaching the above cover material to the upper and/or lower part of the polarizer, the cover dust laminate can be protected from external shock, and when the thickness of the upper and/or lower cover material is controlled as described later, the cover dust laminate can be formed. Curling of the sieve is prevented, ensuring excellent fairness.

In the present application, the thickness of the upper and/or lower cover substrate may be 80 μm to 2000 μm or less, respectively. In other examples, at least 90 μm, at least 100 μm, at least 110 μm, at least 120 μm, at least 130 μm, at least 140 μm, at least 150 μm, at least 160 μm, at least 170 μm, at least 180 μm, at least 190 μm, and at least 200 μm. or more, 210 μm or more, 220 μm or more, 230 μm or more, 240 μm or more, 250 μm or more, 260 μm or more, 270 μm or more, 280 μm or more, 290 μm or more, 300 μm or more, 310 μm or more, 320 μm or more, 330 μm or greater, 340 μm or greater, 350 μm or greater, 360 μm or greater, 370 μm or greater, 380 μm or greater, 390 μm or greater, 400 μm or greater, 410 μm or greater, 420 μm or greater, 430 μm or greater, 440 μm or greater, or 450 μm or less than 1900 μm, less than 1800 μm, less than 1700 μm, less than 1600 μm, less than 1500 μm, less than 1400 μm, less than 1300 μm, less than 1200 μm, less than 1100 μm, less than 1000 μm, less than 950 μm, less than 900 μm, It may be 850 μm or less, 800 μm or less, 750 μm or less, 700 μm or less, 650 μm or less, 600 μm or less, 550 μm or less, or 500 μm or less.

The cover dust laminate of the present application may have a C value of, for example, 0 or more and less than 4 according to Equation 1 below.

[Formula 1]

C=│a-b│/min(a,b)

In Equation 1, C may be the ratio of the absolute value of the difference in thickness of the cover substrate attached to both sides of the absorbing polarizer and the smaller of the thicknesses of the two cover substrates, a may be the thickness of the upper cover substrate, and b may be It may be the thickness of the lower cover substrate.

In another example, the value of C according to Equation 1 is less than 3.5, less than 3, less than 2.5, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1 It may be less than or less than 1, or more than 0.1, more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, or more than 1, but is not limited thereto.

When the cover dust laminate of the present application has a C value in the above range, curling, etc. of the cover dust laminate can be prevented, thereby ensuring excellent processability.

The cover dust laminate of the present application may also have, for example, a value of D according to Equation 2 below of 0 or more and less than 0.8.

[Formula 2]

D=│a-b│/max(a,b)

In Equation 2, D may be the ratio of the absolute value of the difference in thickness of the cover substrate attached to both sides of the absorbing polarizer and the larger value of the thickness of the two cover substrates, a may be the thickness of the upper cover substrate, and b may be It may be the thickness of the lower cover substrate.

In another example, the value of D according to Equation 2 is less than 0.79, less than 0.78, less than 0.77, less than 0.76, less than 0.75, less than 0.74, less than 0.73, less than 0.72, less than 0.71, less than 0.7, less than 0.69, less than 0.68, less than 0.67 It may be less than, less than 0.66, less than 0.65, less than 0.64, less than 0.63, less than 0.62 or less than 0.61, or more than 0.1, more than 0.2, more than 0.3, more than 0.4, more than 0.5, or more than 0.6.

When the cover dust laminate of the present application has a D value in the above range, the desired excellent effect can be obtained.

The cover dust laminate of the present application may further include other layers in addition to the cover substrate. The other layer may be, for example, a protective layer, an adhesive layer, an adhesive layer, or a hollow layer, but is not limited thereto. However, the other layer included in the cover dust laminate of the present application may have a thickness of less than 100 μm. In other words, the cover dust laminate of the present application may not include a layer with a thickness of 100 μm or more except for the cover substrate.

While controlling the thickness range of the upper and lower cover materials, the value of C according to Equation 1, and/or the value of D according to Equation 2 as above, the thickness of other layers excluding the cover material is further controlled to be less than 100 μm. By doing so, the bending (Curl) of the cover dust laminate of the present application can be more appropriately controlled.

The upper and/or lower cover substrate constituting the cover dust laminate of the present application may be a polymer film. The cover substrate may be, for example, a polymer film with a hard coating layer formed thereon, and the hard coating layer may be a known material.

The polymer film is, for example, a polyolefin resin film such as a polycarbonate resin film, a cyclic polyolefin resin film having a cyclo or norbornene structure, a cellulose resin film such as triacetylcellulose, polyethylene terephthalate, polyethylene naphthalate, etc. It may be a polyester resin film, polyethersulfone resin film, polysulfone resin film, polyamide resin film, polyimide resin film, (meth)acrylic resin film, polystyrene resin film, or polyvinyl alcohol resin film, but is limited thereto. That is not the case.

The cover dust laminate of the present application may further include an upper protective layer between the upper cover substrate and the absorption-type polarizer and/or may additionally include a lower protective layer between the lower cover substrate and the absorption-type polarizer. there is.

In the present application, the upper and/or lower protective layer may each have a thickness in the range of, for example, 10 μm to 100 μm, and in other examples, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more. , 45μm or more, 50μm or more, 55μm or more or 60μm or less, or 95μm or less, 90μm or less, 85μm or less, 80μm or less, 75μm or less, 70μm or less, 65μm or less, 60μm or less, 55μm or less, 50μm or less, 45μm or less, 40μm or less, It may be 35 μm or less or 30 μm or less.

The cover dust laminate of the present application may have an E value of, for example, 0 or more and less than 4 in Equation 3 below.

[Formula 3]

E =│A-B│/min(A, B)

In Equation 3, │A-B│ may be the absolute value of the difference between the sum of the thickness of the upper cover substrate and the thickness of the upper protective layer (A) and the sum of the thickness of the lower cover substrate and the thickness of the lower protective layer (B), min (A, B) may be the smaller of the sum of the thickness of the upper cover substrate and the thickness of the upper protective layer (A) and the sum of the thickness of the lower cover substrate and the thickness of the lower protective layer (B).

In another example, the value of E according to Equation 3 is less than 3.5, less than 3, less than 2.5, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1 Less than or less than 1, or more than 0.01, more than 0.02, more than 0.03, more than 0.04, more than 0.05, more than 0.06, more than 0.07, more than 0.08, more than 0.09, more than 0.1, more than 0.11, more than 0.12, more than 0.13, more than 0.14, more than 0.15 , 0.16 or more, 0.17 or more, 0.18 or more, 0.19 or more, 0.20 or more, 0.21 or more, 0.22 or more, 0.23 or more, 0.24 or more, 0.25 or more, 0.30 or more, 0.35 or more, 0.40 or more, 0.45 or more, 0.50 or more, 0. Above .55, 0.60 It may be 0.65 or more, 0.70 or more, 0.75 or more, 0.80 or more, 0.85 or more, 0.90 or more, 0.95 or more, or 1.00 or more, but is not limited thereto.

When the cover dust laminate of the present application has an E value in the above range, the purpose of the present application can be achieved by preventing bending of the cover dust laminate.

For example, the cover dust laminate of the present application may be a cover dust laminate having an F value of 0 or more and less than 2 according to Equation 4 below.

[Formula 4]

F = (A-B)/max(A, B)

In Equation 4, (A-B) may be the absolute value of the difference between the sum of the thickness of the upper cover substrate and the thickness of the upper protective layer (A) and the sum of the thickness of the lower cover substrate and the thickness of the lower protective layer (B), max(A, B) may be the larger of the sum of the thickness of the upper cover substrate and the upper protective layer (A) and the sum of the thickness of the lower cover substrate and the thickness of the lower protective layer (B).

In another example, the value of F according to Equation 4 is less than 1.5, less than 1.0, less than 0.9, less than 0.8, less than 0.7, or less than 0.6, or more than 0.01, more than 0.02, more than 0.03, more than 0.04, more than 0.05, more than 0.06, It may be 0.07 or more, 0.08 or more, 0.09 or more, or 0.1 or more.

When the cover dust laminate of the present application has an F value in the above range, curling, etc. can be prevented, and a cover dust laminate with excellent fairness can be provided.

The cover dust laminate of the present application may further include other layers in addition to the cover substrate and protective layer. The other layer may be, for example, an adhesive layer, an adhesive layer, or a hollow layer, but is not limited thereto. However, the thickness of other layers excluding the cover base and protective layer included in the cover dust laminate of the present application may be less than 30 μm. In other words, the cover dust laminate of the present application may not include layers with a thickness of 30 μm or more except for the cover substrate and the protective layer.

While controlling the thickness range of the upper and lower cover substrates, the value of C according to Equation 1, the value of D according to Equation 2, the value of E according to Equation 3, and/or the value of F according to Equation 4 as above, By additionally controlling the thickness of other layers excluding the cover base material and the protective layer to be less than 30 μm, the curl of the cover dust laminate of the present application can be more appropriately controlled.

For example, the cover dust laminate of the present application may have a maximum curl value of more than 0 mm and less than or equal to 80 mm. In another example, the maximum curl value is greater than 1 mm, greater than 2 mm, greater than 3 mm, greater than 4 mm, greater than 5 mm, greater than 6 mm, greater than 7 mm, greater than 8 mm, greater than 9 mm, greater than 10 mm. Over, over 11 mm, over 12 mm, over 13 mm, over 14 mm, or over 15 mm, or under 95 mm, under 90 mm, under 85 mm, under 80 mm, under 75 mm, under 70 mm, under 65 mm. , 60 mm or less, 55 mm or less, 50 mm or less, 45 mm or less, 40 mm or less, 35 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 5 mm or less, 4 It may be less than 1 mm, less than 3 mm, less than 2 mm, or less than 1 mm.

In the above, the maximum curl value is obtained by placing a ruler at 90 degrees on a flat ground at the point where it is lifted highest from the ground when the cover dust laminate is left at 110°C for 1000 hours and then placed on a flat ground. It may be a value measured from the length from the ground to the position where the cover dust laminate is lifted highest.

As the curl of the cover dust laminate is controlled as described above, fairness is improved, and when the cover dust laminate is applied to the head-up display, distortion of the head-up display screen and distortion of the appearance of the head-up display are prevented. You can.

The cover substrate and/or protective layer constituting the cover dust laminate of the present application may be a polymer film.

The polymer film is, for example, a polyolefin resin film such as a polycarbonate resin film, a cyclic polyolefin resin film having a cyclo or norbornene structure, a cellulose resin film such as triacetylcellulose, polyethylene terephthalate, polyethylene naphthalate, etc. It may be a polyester resin film, polyethersulfone resin film, polysulfone resin film, polyamide resin film, polyimide resin film, (meth)acrylic resin film, polystyrene resin film, or polyvinyl alcohol resin film, but is limited thereto. That is not the case.

In one example, the lower protective layer of the protective layers of the present application may be a polymer film having a moisture permeability of 1 g/(100 in ² × day) or more. In the above, the term moisture permeability may mean the weight of water vapor passing through the protective layer with an area of 100 in ² for 1 day (24 hours) under specified temperature and humidity, and can be measured using a moisture permeability tester (Labthink, W3/0120). The moisture permeability of the protective layer can be measured under the conditions described later.

If the moisture permeability of the lower protective layer is less than 1g/(100in ² It may be desirable for the lower protective layer to have a moisture permeability of 1 g/(100 in ² × day) or more.

More specifically, the PVA polarizer is generally highly hydrophilic, so it is very difficult to completely control moisture during the process of stacking a protective layer. On the other hand, the PVA polarizer undergoes a reaction such that KI ₅ contained in the PVA polarizer is decomposed into I ₂ and KI ₃ and/or KI ₃ is decomposed into I ₂ and I by moisture in a high temperature/high humidity environment, for example. As this occurs, polarization may be broken and reddening may occur.

Therefore, as the lower protective layer, among the above examples, cellulose resin films such as triacetylcellulose films, polycarbonate resin films, (meth)acrylic resin films, polyester resin films, etc., which have relatively high moisture permeability, may be more preferable. .

The cover dust laminate of the present application applies a lower protective layer of 1g/(100in ² can be prevented.

The upper limit of the moisture permeability of the lower protective layer is not particularly limited, but considering the possibility of moisture entering the polarizer from the outside, in one example, it may be preferable to be 100 g/(100 in ² × day) or less.

In other examples, the moisture permeability of the lower protective layer is 2 g/(100in ² ×day) or more, 3 g/(100in ² ×day) or more, 4 g/(100in ² ×day) or more, 5 g/(100in ² ×day) or more, 5.1 g/(100in ² ×day) or more, 5.2 g/(100in ² ×day) or more, 5.3 g/(100in ² ×day) or more, 5.4 g/(100in ² ×day) or more, 5.5 g/(100in ² ×day) or more, 5.6 g/(100in ² ×day) or more, 5.7 g/(100in ² ×day) or more, 5.8 g/(100in ² ×day) or more, 5.9 g/(100in ² × day) or more ^{than 6.0 g} /(100in ² /(100in ² ×day) or less, 50 g/(100in ² ×day) or less, 40 g/(100in ² ×day) or less, 30 g/(100in ² ×day) or less, 20 g/(100in ² ×day) or less ) or less, 10 g/(100in ² ×day) or less, 9.0 g/(100in ² ×day) or less, or 8.0 g/(100in ² ×day) or less.

The cover dust laminate of the present application has excellent high-temperature durability, such as being able to provide clear image quality even when maintained and/or driven at high temperatures when applied to a head-up display by applying a lower protective layer with high moisture permeability as described above. You can have

In one example, the upper protective layer of the protective layers constituting the cover dust laminate of the present application may be a retardation layer having an in-plane retardation. In this specification, the phase contrast layer is an optically anisotropic layer and may refer to an element capable of converting incident polarization by controlling birefringence. The phase difference layer may have 1/4 wavelength phase retardation characteristics or 1/2 wavelength phase retardation characteristics. In this specification, the n-wavelength phase retardation characteristic may mean a characteristic that can retard the phase of incident light by n times the wavelength of the incident light, within at least some wavelength range. Therefore, the 1/4 wavelength phase retardation characteristic may mean a characteristic that can retard the phase of incident light by 1/4 times the wavelength of the incident light within at least some wavelength range, and the 1/2 wavelength phase retardation The characteristic may refer to a characteristic that can retard the phase of incident light by 1/2 the wavelength of the incident light, within at least some wavelength range.

In this specification, the term in-plane phase difference (R _in ) is calculated using Equation 5 below.

[Formula 5]

R _in = d × (n _x -n _y )

In Equation 5, R _in is the in-plane retardation, d is the thickness of the upper protective layer, and n _x and n _y are the refractive indices in the x-axis and y-axis directions, respectively. In this specification, the terms x-axis and y-axis refer to a direction parallel to the in-plane slow axis of the upper protective layer, and the y-axis refers to a direction parallel to the in-plane fast axis of the upper protective layer, unless otherwise specified. , the x-axis and y-axis may be perpendicular to each other in the plane.

In the present application, the in-plane retardation (R _in ) of the upper protective layer for light of 550 nm wavelength may be, for example, 100 nm or more and 400 nm or less, and in other examples, 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 150 nm or more, Above 160nm, above 170nm, above 180nm, above 190nm, above 200nm, above 210nm, above 220nm, above 230nm, above 240nm, above 250nm, above 260nm, above 270nm, above 280nm, above 290nm, above 300nm, above 310nm, above 320nm , 330nm or more, 340nm or more, 350nm or more, 360nm or more, 370nm or more, 380nm or more or 390nm or less, or 390nm or less, 380nm or less, 370nm or less, 360nm or less, 350nm or less, 340nm or less, 330nm or less, 320nm or less, 310nm or less, 300nm Below, 290nm or below, below 280nm, below 270nm, below 260nm, below 250nm, below 240nm, below 230nm, below 220nm, below 210nm, below 200nm, below 190nm, below 180nm, below 170nm, below 160nm, below 150nm, below 140nm, It may be 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, 10 nm or less, or 0 nm or less.

This application also relates to a cover dust laminate including an absorptive polarizer. The term cover dust laminate is located on the path of external light incident from the head-up display to the image generating device and on the path of the optical signal emitted from the image generating device, so that at least a portion of the external light is introduced into the image generating device. It refers to an optical laminate that exists to block and transmit the optical signal emitted from the image generating device. Additionally, in the present application, the term polarizer may refer to, for example, an element or film that exhibits a polarization function.

As long as the polarizer applied in this application is an absorption type polarizer, the specific type is not limited. In the above, the absorption-type polarizer may be, for example, an absorption-type linear polarizer. The term absorptive linear polarizer transmits linearly polarized light vibrating in one direction from incident light vibrating in various directions, and absorbs light vibrating in the other direction, for example, polarized light in a direction perpendicular to the transmitted linearly polarized light. It may refer to a device that has a function.

The most common absorption type linear polarizer known is the so-called poly(vinylalcohol) (hereinafter referred to as PVA) polarizer. In this specification, the term PVA refers to polyvinyl alcohol and/or its derivatives, unless otherwise specified. PVA polarizers include, for example, stretched PVA films in which anisotropic absorbent substances such as iodine or dichroic dyes are adsorbed and oriented, or so-called coated PVA polarizers, which are formed thinly by applying PVA through a coating method. It is known that, in this application, all of the above types of polarizers can be applied.

The polarizer applied in the examples of this application is a PVA polarizer, and this polarizer is usually manufactured by applying a dyeing and stretching process to a PVA raw film. In the above manufacturing process of the PVA polarizer, additional processes such as swelling, cross-linking, cleaning, and/or complementary color processes may be performed if necessary, and the process of manufacturing the PVA polarizer through these processes is known.

In one example, the thickness of the absorption-type polarizer may be in the range of 5 μm to 50 μm. In other examples, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 11 μm, at least 12 μm, at least 13 μm, at least 14 μm, at least 15 μm, at least 16 μm, and at least 17 μm. or more, 18 μm or more, 19 μm or more, 20 μm or more, 21 μm or more, 22 μm or more, 23 μm or more, or 24 μm or more, or 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 29 μm or less, 28 μm or less, 27 μm or less, 26 μm or less, 25 μm or less, 24 μm or less, 23 μm or less, 22 μm or less, 21 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm Hereinafter, it may be 15 μm or less, 14 μm or less, 13 μm or less, or 12 μm or less, but is not limited thereto.

In one example, in order to ensure durability of the cover dust laminate, especially high-temperature reliability, a PVA polarizer containing a zinc component may be used as the polarizer. In the above, examples of the zinc component include zinc and/or zinc ions. The PVA polarizer may also contain potassium components such as potassium or potassium ions as additional components. By using a polarizer containing these ingredients, it is possible to provide a cover dust laminate that maintains stable durability even under high temperature conditions.

The content of the zinc component can be further adjusted. In one example, the content of zinc (Zn) contained in the PVA polarizer may be in the range of 500 mg/kg to 1300 mg/kg. In other examples, the content is 550 mg/kg or more, 600 mg/kg or more, 650 mg/kg or more, 700 mg/kg or more, 750 mg/kg or more, 800 mg/kg or more, 850 mg/kg or more, 900 mg. /kg or more or 910 mg/kg or more, 1250 mg/kg or less, 1200 mg/kg or less, 1150 mg/kg or less, 1100 mg/kg or less, 1050 mg/kg or less, 1000 mg/kg or less, 990 mg/kg or less, may be 980 mg/kg or less, 970 mg/kg or less, 960 mg/kg or less, 950 mg/kg or less, 940 mg/kg or less, 930 mg/kg or less, 920 mg/kg or less, or 910 mg/kg or less. there is. The zinc (Zn) content is measured by measuring the weight (mg) of zinc (Zn) contained in the PVA polarizer based on 1 kg of weight.

The content of potassium component contained in the PVA polarizer may be 0.35% by weight to 0.7% by weight. In other examples, the content of the potassium (K) component is 0.36% by weight or more, 0.37% by weight or more, 0.38% by weight or more, 0.39% by weight or more, 0.40% by weight or more, 0.41% by weight or more, 0.42% by weight or more, 0.43% by weight. or more than 0.44% by weight, more than 0.45% by weight, more than 0.46% by weight, more than 0.47% by weight, more than 0.48% by weight or more than 0.49% by weight, or less than 0.70% by weight, less than 0.60% by weight, less than 0.59% by weight, or less than 0.58% by weight. % or less, 0.57 weight% or less, 0.56 weight% or less, 0.55 weight% or less, 0.54 weight% or less, 0.53 weight% or less, 0.52 weight% or less, 0.51 weight% or less, 0.5 weight% or less, or 0.49 weight% or less. The content of the potassium (K) component is expressed as a percentage by weight of the potassium (K) component contained therein compared to 100 parts by weight of the PVA polarizer.

In the above description, the content of zinc and/or potassium components can be measured in the following manner. First, dissolve about 0.1 g of the polarizer in 2 mL of nitric acid aqueous solution with a concentration of about 65% by weight at room temperature, then dilute it with water (Deionized water) to 40 mL, and then use ICP-OES (Optima 5300) to determine the zinc (Zn) contained in the polarizer. The weight of and potassium (K) can be measured respectively.

By including a polarizer containing zinc and/or potassium in the above range, it is possible to provide a cover dust laminate that stably maintains durability even under high temperature conditions.

The polarizer applied in this application may be a polarizer manufactured according to a known polarizer manufacturing method. In addition, in the case of applying a polarizer containing the zinc and/or potassium components as a polarizer in the present application, the process conditions are controlled so that zinc and/or potassium can be included in the polarizer during the manufacturing process of the known polarizer. can do.

As described above, the PVA polarizer is usually manufactured by dyeing and stretching a PVA film (raw film), and optionally, swelling, cross-linking, washing, and/or complementary color processes are performed in addition to the iodine-based polyvinyl alcohol polarizer manufacturing process. You can. The stretching process may be performed as a separate process, or may be performed simultaneously with other processes such as dyeing, swelling, and/or crosslinking. In this manufacturing process, treatment solutions such as dyeing solution, cross-linking solution, swelling solution, cleaning solution, and/or complementary color solution are applied. By adjusting the components of this treatment solution, the inclusion of the zinc and/or potassium components is determined, or The content can be adjusted.

In the dyeing process, the anisotropic absorbent material may be adsorbed and/or oriented on the PVA polarizer. This dyeing process may be performed in conjunction with a stretching process, if necessary. Dyeing may be performed by immersing the polarizer in a solution containing an anisotropic absorbent material, for example, an iodine solution. As an iodine solution, for example, an aqueous solution containing iodine ions using iodine (I ₂ ) and an iodide compound as a solubilizing agent can be used. Examples of the iodide compound include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. The concentration of iodine and/or iodide ions in the iodine solution can be adjusted in consideration of the optical properties of the desired polarizer, and such adjustment methods are known. Typically, the iodine content in the dyeing solution (iodine solution) is about 0.01 to 5% by weight, and the concentration of the iodinated compound may be about 0.01 to 10% by weight. In other examples, the iodine content may be 0.05% by weight or more, 0.1% by weight or more, or 0.15% by weight or more, and 4.5% by weight or less, 4% by weight or less, 3.5% by weight or less, 3% by weight or less, 2.5% by weight or less, 2 It may be less than 1% by weight, less than 1.5% by weight, less than 1% by weight, or less than 0.5% by weight. In other examples, the concentration of the iodinated compound may be 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, or 2% by weight or more, and 9% by weight or less, 8% by weight or less. , it may be 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, or 3% by weight or less. In the dyeing process, the temperature of the iodine solution is typically about 20°C to 50°C, 25°C to 40°C, and the immersion time is usually about 10 seconds to 300 seconds or 20 seconds to 240 seconds, but is limited thereto. That is not the case.

The stretching process is generally performed by uniaxial stretching, but other methods of stretching, such as biaxial stretching, can also be applied if necessary. This stretching may be performed together with the dyeing process and/or the crosslinking process described later. The stretching method is not particularly limited, and for example, a wet method may be applied. In these wet methods, it is common, for example, to carry out stretching after dyeing. Stretching may be performed together with crosslinking, and may be performed multiple times or in multiple stages. The treatment liquid applied to the wet stretching method may contain the above-mentioned iodinated compound. The concentration of the iodinated compound in the treatment solution may be about 0.01 to 10% by weight. In other examples, the concentration of the iodinated compound may be 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, or 2% by weight or more, and 9% by weight or less, 8% by weight or less. , it may be 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, or 3.5% by weight or less. In stretching, the processing temperature is typically 25°C or higher, 30°C to 85°C, or 40°C to 70°C, and the processing time is usually 10 to 800 seconds or 30 to 500 seconds. It is not limited to this. During the stretching process, the total draw ratio can be adjusted considering orientation characteristics, etc., and the total draw ratio may be about 3 to 10 times, 4 to 8 times, or 5 to 7 times based on the original length of the PVA polarizer. It is not limited to this. In the above, the total draw ratio may refer to the cumulative draw ratio including the stretching in each process when stretching is also involved in other processes other than the stretching process, such as swelling, dyeing, and/or crosslinking processes. This total stretch ratio can be adjusted to an appropriate range in consideration of orientation, processability of the polarizer, stretch cutting possibility, etc.

In the manufacturing process of a polarizer, a swelling process may be performed in addition to the dyeing and stretching, and this is usually performed before the dyeing process. By swelling, contamination and anti-blocking agents on the surface of the PVA polarizer can be cleaned, and this also has the effect of reducing unevenness such as dyeing deviation. In the swelling process, water, distilled water, or pure water can typically be used. The main component of the treatment liquid is water, and if necessary, a small amount of additives such as iodinated compounds such as potassium iodide or surfactants, alcohol, etc. may be included. The processing temperature in the swelling process is typically, but not limited to, 20°C to 45°C or 20°C to 40°C. Since swelling deviations can cause dyeing deviations, process variables can be adjusted to suppress the occurrence of such swelling deviations as much as possible. Even in the swelling process, appropriate stretching may be performed arbitrarily. The stretching ratio may be 6.5 times or less, 1.2 to 6.5 times, 2 to 4 times, or 2 to 3 times based on the original length of the PVA film. Stretching during the swelling process can be controlled to be small, and can be controlled so that stretching rupture of the film does not occur.

The crosslinking process can be performed, for example, using a crosslinking agent such as a boron compound. The sequence of the crosslinking process is not particularly limited and, for example, may be performed together with the dyeing and/or stretching process, or may be performed separately. The crosslinking process may be performed multiple times. Boron compounds such as boric acid or borax may be used. Boron compounds can generally be used in the form of an aqueous solution or a mixed solution of water and an organic solvent, and an aqueous boric acid solution is usually used. The concentration of boric acid in the aqueous solution of boric acid can be selected within an appropriate range taking into account the degree of crosslinking and the resulting heat resistance. An aqueous solution of boric acid may also contain an iodide compound such as potassium iodide. The concentration of the iodinated compound in the boric acid aqueous solution may be about 0.01 to 10% by weight. In other examples, the concentration of the iodinated compound may be 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, or 2% by weight or more, and 9% by weight or less, 8% by weight or less. , it may be 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, or 3.5% by weight or less. The crosslinking process can be performed by immersing the PVA polarizer in an aqueous solution of boric acid, etc., and the processing temperature in this process is typically in the range of 25°C or more, 30°C to 85°C, or 30°C to 60°C. , processing time is typically about 5 seconds to 800 seconds or 8 seconds to 500 seconds.

Metal ion treatment may be performed in the manufacturing process of the polarizer, and this may be commonly referred to as a complementary color process. This treatment is carried out, for example, by immersing the PVA polarizer in an aqueous solution containing a metal salt. Through this, metal components such as metal ions can be contained in the polarizer. In this process, the type or ratio of the metal components can be adjusted. Examples of metal ions that can be applied include metal ions of transition metals such as cobalt, nickel, zinc, chromium, aluminum, copper, manganese, or iron, and the color tone may be adjusted by selecting an appropriate type. there is.

In order to manufacture the above-described polarizer containing zinc, a zinc component may be included in the treatment solution (aqueous solution containing a metal salt) applied in the complementary color process. However, if necessary, the zinc component may be applied during another process, and in this case, the zinc component may be included in another treatment solution such as a dye solution or cross-linking solution, or in a separate treatment solution. The zinc component can be introduced, for example, by dissolving one or more zinc salts selected from zinc chloride, zinc iodide, zinc sulfate, zinc nitrate, and zinc acetate in the aqueous solution. In this case, in order to achieve the desired zinc content, the concentration of the zinc salt can be adjusted to about 0.01 to 10% by weight. In other examples, the concentration of the zinc salt is 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, or 2% by weight or more, or 9% by weight or less, 8% by weight or less, 7 It may be % by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, or 3% by weight or less. If necessary, the treatment liquid may also contain a potassium component. Examples of the potassium component include potassium salts such as potassium iodide. The concentration of the potassium salt may be about 0.01 to 10% by weight. In other examples, the concentration is 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, 2.5% by weight or more, 3% by weight or more, 3.5% by weight or more. , it may be 4% by weight or more, 4.5% by weight or more, or 5% by weight or less, or 9% by weight or less, 8% by weight or less, 7% by weight or less, or 6% by weight or less. By applying zinc salt or potassium salt as described above in the complementary color process, the desired level of zinc and potassium components can be included in the polarizer.

In the manufacturing process of a polarizer, a cleaning process may be performed after dyeing, crosslinking, and stretching. This cleaning process can usually be performed before the complementary color process, and can be performed using water. If necessary, the water used in the cleaning process may be mixed with an appropriate amount of other components such as iodine, iodide, and other metal salts, or liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, or propanol.

After going through this process, a drying process can be performed to manufacture the polarizer. The drying process may be performed at an appropriate temperature and for an appropriate time, taking into account the moisture content required for the polarizer, for example, and these conditions are not particularly limited.

A cover dust laminate containing a polarizer containing zinc and/or potassium in the above range has excellent resistance to redness, and thus can maintain excellent optical properties even when maintained and/or driven at high temperatures.

The cover dust laminate of the present application may also not include a reflective polarizer. The term reflective polarizer may refer to an element that has the function of transmitting one polarization and reflecting the other polarization from incident light that vibrates in various directions. The reflective polarizer may include, for example, a Dual Brightness Enhancement Film (DBEF), a Lyotropic Liquid Crystal (LLC) layer, or a wire grid polarizer.

Since the cover dust laminate including the reflective polarizer reflects light vibrating in a specific direction to the outside, it can play a role in blocking external light, but especially when applied to a vehicle head-up display, which will be described later, the reflection There may be a problem that it is difficult to achieve clear image quality because the light is incident on the driver's field of view.

Therefore, the cover dust laminate of the present application may be a cover dust laminate that includes an absorptive polarizer but does not include a reflective polarizer, and through this, clear image quality can be realized when applied to a head-up display.

However, since the absorption-type polarizer is particularly vulnerable to high temperatures, high-temperature durability may be a problem when an absorption-type polarizer rather than a reflection-type polarizer is applied, such as the cover dust laminate of the present application.

Therefore, the cover dust laminate of the present application can provide a cover dust laminate with excellent high temperature durability by including a polyvinyl alcohol absorption type polarizer containing zinc and/or potassium within a certain range as described above. In addition, by designing the above-described lower protective layer to have high moisture permeability, it is possible to provide a cover dust laminate with superior high-temperature durability while realizing clear image quality.

For example, the absolute value of the change in single transmittance (ΔT _s ) according to Equation 6 below after the heat resistance test of the cover dust laminate may be 10% or less. In this specification, the term single transmittance refers to the average of the transmittance of the absorption axis and the transmittance of the transmission axis. In the above, the single transmittance is the result of measuring light in the visible light region, for example, light in the range of approximately 380 nm to 780 nm using a JASCO V-7100 spectrophotometer.

[Formula 6]

△T _s = T _a - T _i

In Equation 3, △T _s may be the change in the single transmittance, T _a is the single transmittance after the heat resistance test, and T _i may be the initial single transmittance before the heat resistance test.

In the above, the heat resistance test refers to a test in which the cover dust laminate is maintained at about 110°C for about 1000 hours.

The absolute value of the single transmittance change (△T _s ) in other examples is about 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4.9% or less, 4.8% or less, 4.7% or less, 4.6% or less. % or less, 4.5% or less, 4.4% or less, 4.3% or less, 4.2% or less, 4.1% or less, 4% or less, 3.9% or less, 3.8% or less, 3.7% or less, 3.6% or less, 3.5% or less, 3.4% or less , 3.3% or less, 3.2% or less, 3.1% or less, 3% or less, 2.9% or less, 2.8% or less, 2.7% or less, 2.6% or less, 2.5% or less, 2.4% or less, 2.3% or less, 2.2% or less, 2.1 % or less, 1.9% or less, 1.8% or less, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1.0% or less, 0.9% or less, 0.8% or less , may be 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less, or 1% or more, 1.5% or more, 2.0% or more, 2.5% or more, or 3.0% or more. there is. Ideally, as there is no change in the transmittance, there is no redundancy, so the lower limit of the absolute value of the change amount (ΔT _s ) is 0%. The absolute value of the change amount (ΔT _s ) may be approximately greater than 0% in another example.

When the polarizer and/or cover dust laminate of the present application has the above characteristics, it is possible to prevent, alleviate, alleviate, suppress and/or delay reddening, so it is operated under very harsh conditions (for example, very high temperature conditions) or It is possible to provide a cover dust laminate that does not cause so-called redness even when maintained, and when applied to a head-up display, the cover dust laminate can prevent redness of internal components such as an image generating device.

The cover dust laminate of the present application may also not include an adhesive layer, an adhesive layer, and/or a release film in the outermost layer toward the bottom of the absorption-type polarizer.

In a general optical laminate, a layer with low moisture permeability is disposed on both sides of the polarizer, or even if a layer with high moisture permeability is disposed on one side, an adhesive layer, an adhesive layer, and/or a release film are placed on the outermost layer of the side on which the layer with high moisture permeability is disposed. Thus, the surface on which the high moisture permeability layer is disposed is ultimately attached to another member such as an image generating device, so that it can have a closed structure that prevents the inflow and outflow of moisture through both sides of the polarizer.

However, in the cover dust laminate of the present application, for example, a layer with high moisture permeability is disposed in the downward direction of the absorption-type polarizer, and an adhesive layer, an adhesive layer, and/or a release film are provided in the outermost layer in the downward direction of the absorption-type polarizer. This may have a structure that does not exist. That is, the cover dust laminate of the present application can exist independently without adhesion to other members.

The cover dust laminate of the present application exists independently without adhesion to other members as described above, and does not include a layer with a moisture permeability of less than 1 g/(100 in ² × day) in the lower direction of the absorbing polarizer, so that it is a general optical laminate. Unlike a sieve, the inflow and outflow of moisture through the lower direction of the polarizer can be relatively free.

By having the above structure, the cover dust laminate of the present application can prevent internal components from burning even when applied to a head-up display and maintained and/or driven at high temperatures, and can achieve clear image quality. there is.

This application also relates to a Head Up Display including the cover dust laminate. The head-up display includes an image generating device; and a cover dust laminate, wherein an image emitted from the image generating device passes through the cover dust laminate; And it may be a head-up display on which a cover dust laminate is disposed.

In the present application, the image generating device may be an image generating device that emits an image in a linearly polarized state. For example, when using an LCD (Liquid Crystal Display) or OLED (Organic Light Emitting Diode) as the image generating device, a polarizing film is attached to the image generating device so that the emitted optical signal is in the form of linearly polarized light having a certain polarization direction. , and through this, the signal loss of optical signals transmitted to various components can be reduced as much as possible.

The present application also provides that the smaller angle between the vibration direction of linearly polarized light emitted from the image generating device and incident on the cover dust laminate and the absorption axis of the polarizer of the cover dust laminate is, for example, 50 degrees to 80 degrees. It may be a head-up display 10 in which the image generating device 20 and the cover dust laminate 100 are arranged within the range of degrees.

The angle is based on the position at which the minimum luminance is measured when the luminance of light transmitted through the cover dust laminated body 100 is measured while rotating the cover dust laminated body 100 within the head-up display 10 (0 °), which may be an angle measured clockwise or counterclockwise.

In other examples, the angle is 51 degrees or more, 52 degrees or more, 53 degrees or more, 54 degrees or more, 55 degrees or more, 56 degrees or more, 57 degrees or more, 58 degrees or more, 59 degrees or more, or 60 degrees or more, or 79 degrees. Below, it may be 78 degrees or less, 77 degrees or less, 76 degrees or less, 75 degrees or less, 74 degrees or less, 73 degrees or less, 72 degrees or less, 71 degrees or less, or 70 degrees or less.

In the present application, the head-up display may additionally include light control means. In this specification, the term light control means is a device that directs the light signal emitted from the image generating device to the windshield on which the image is displayed after passing through the cover dust laminate, for example, a reflector and/or a beam splitter, etc. You can.

In one example, the head-up display 10 includes an image generating device 20 and the cover dust laminate 100 as shown in FIG. 6, and light 200 emitted from the image generating device is transmitted through a beam splitter 30. ), some of the emitted light becomes reflected light 202 reflected in the direction of the reflector 40, and the remaining part becomes transmitted light 201 and passes through the cover dust laminate 100, thereby creating a wind It may be a head-up display that can implement two screens independent of the shield 50. As used herein, the term beam splitter refers to a device that divides one light source into two light sources. Therefore, when one light source passes through the beam splitter, part of it is transmitted and the other part is reflected and follows two different light paths. You can move.

As described above, the head-up display of the present application, in one example, can implement two independent screens. The two independent screens may be implemented in contact with each other, and therefore, it may be required that there is little difference in luminance between the two screens. The present application arranges the angle between the polarization direction of the linearly polarized light emitted from the image generating device and the absorption axis of the polarizer of the cover dust laminate as described above, thereby providing a device with clear image quality with almost no difference in luminance between two independent screens. A head-up display can be implemented.

In this specification, the term luminance refers to the light density in a specific direction, that is, the amount of light passing through a certain area and entering at a certain solid angle, and 'little difference in luminance' refers to the luminance of two independent screens. This means not only the case where is the same, but also the case where the luminance ratio is 0.5 to 1.5 or less. In other examples, the ratio may be greater than or equal to 0.52, greater than or equal to 0.54, greater than or equal to 0.56, greater than or equal to 0.58, greater than or equal to 0.60, greater than or equal to 0.62, greater than or equal to 0.64, greater than or equal to 0.66, or greater than or equal to 0.67, or greater than or equal to 1.45, greater than or equal to 1.4, greater than or equal to 1.35, or greater than or equal to 1.3. If the luminance ratio of the two independent screens satisfies the above range, for example, the driver may perceive the two independent screens as one screen.

The present application includes a cover dust laminate having the above-described characteristics, and controls the angle formed between the vibration direction of linearly polarized light emitted from an image generating device and the absorption axis of the polarizer of the cover dust laminate to the above range, such as high temperature, etc. Even under harsh conditions, red-lighting does not occur, clear picture quality can be realized, and when displaying two independent screens, a head-up display with an appropriate luminance ratio of each screen can be provided.

The present application can provide a cover dust laminate that prevents curl, has excellent fairness, and does not cause so-called redness even when driven or maintained under very harsh conditions (e.g., very high temperature conditions). there is. In addition, the cover dust laminate is applied to the head-up display to prevent internal components such as the image generating device from burning, while realizing clear image quality, and when displaying two independent screens, the luminance ratio of each screen is appropriate. A head-up display can be provided.

1 is a diagram for explaining a typical structure of a head-up display.
2 to 5 are diagrams for explaining an exemplary structure of the cover dust laminate of the present application.
Figure 6 is a diagram for explaining an exemplary structure of the head-up display of the present application.

Hereinafter, the cover dust laminate, etc. will be described in more detail through examples according to the present application, but the scope of the present application is not limited to the following.

Below, each physical property of the cover dust laminate was measured in the following manner.

One. Curl maximum measurement

In the above, the maximum value of the curl height is the position where the cover dust laminate is lifted highest from the ground when the cover dust laminate is placed on a flat ground, and then the ruler is placed at a 90 degree angle on the flat ground, and then the cover dust laminate is lifted highest from the ground. It is a measure of the length to a point.

2. Weight determination of zinc (Zn) and potassium (K) in polarizer

The weight of zinc (Zn) and potassium (K) present in the polarizer was measured in the following manner. First, dissolve about 0.1 g of the polarizer in an aqueous solution of nitric acid (2 mL) with a concentration of about 65% by weight at room temperature, dilute it to 40 mL with water (Deionized water), and then use ICP-OES (Optima 5300) to dissolve the polarizer contained in the polarizer. The weight of potassium (K) and zinc (Zn) were measured respectively.

3. Luminance measurement

Cover dust laminate (100), image generating device (LGE, LA080WV5) (20), beam splitter (Edmund, B-plate Beamsplitter) (30), reflector (Edmund, S-mirror) (40), wind The shield 50 was arranged as shown in FIG. 4, and the luminance of the screen displayed on the windshield 50 was measured while changing the angle of the cover dust laminate. When measuring, measure the luminance of the screen formed by reflected light 202 and the screen formed by transmitted light 201 using a two-dimensional luminance measuring device (Risa, Color one) at a location 50 cm away from the windshield 50. did.

Preparation Example 1. Preparation of polarizer

A PVA (poly(vinyl alcohol)) film (M3000 grade, Japan Synthetic Co., Ltd.) with a thickness of approximately 30㎛ was dyed for 60 degrees in a dyeing solution at 28°C containing 0.3% by weight of iodine (I2) and 3.0% by weight of potassium iodide (KI). It was dyed by immersing it for seconds. The dyed PVA film was then cross-linked by immersing it in an aqueous solution (cross-linking solution) at 35°C containing 1% by weight of boron and 3% by weight of potassium iodide (KI) for 60 seconds. Afterwards, the crosslinked PVA film was stretched at a stretching ratio of 5.4 times using the roll-to-roll stretching method. The stretched PVA film was washed by immersing it in ion-exchanged water at 25°C for 60 seconds, and then immersed in an aqueous solution at 25°C containing 2.5% by weight of zinc nitrate and 3% by weight of potassium iodide (KI) for 30 seconds. Afterwards, the PVA film was dried at a temperature of 80°C for 60 seconds to prepare a PVA polarizer. The final thickness of the manufactured polarizer was about 12㎛, the potassium content was about 0.49% by weight, and the zinc content was about 910mg/kg.

Preparation Example 2. Preparation of internalized layer material

Trimethylolpropane triacrylate (TMPTA) was applied as a binder, and hollow silica particles were applied to manufacture an internalization layer. As the hollow silica particles, particles with D10, D50, and D90 particle diameters of 32.1 nm, 62.6 nm, and 123.4 nm were used, respectively. In this case, the average pore size measured with a transmission electron microscope (TEM) after forming the internalization layer was approximately 38.3 nm, and the particle diameter was approximately 53 nm. The binder, the hollow silica particles, the fluorine-containing compound (RS-90, DIC) and the initiator (Irgacure 127, Ciba) were mixed at a weight ratio of 31:65:0.1:3.9 based on solid content (binder: hollow silica particles: A coating solution was prepared by diluting a fluorine compound: initiator) in MIBK (methyl isobutyl ketone), a solvent.

Example 1.

A general optical water-based adhesive layer (thickness: 100 nm) was applied to the polarizer obtained in Preparation Example 1, and a cycloolefin polymer film (Zeon) with a thickness of about 30 μm was attached. Separately, an internalized layer was formed on a triacetylcellulose film (Hyosung) with a thickness of approximately 60 μm. The internalization layer was formed by coating the internalization layer material of Preparation Example 2 with a Mayer bar, drying it at about 60°C for about 1 minute, and then irradiating it with ultraviolet rays (252mJ/cm ² ) to have a final thickness of about 450 nm. Subsequently, the laminate of the triacetylcellulose film with the internalization layer formed was attached to the laminate of the cycloolefin polymer film and the polarizer prepared above using the same water-based adhesive (thickness: 100 nm). Next, a 100 μm polycarbonate film was attached to one side of the cycloolefin polymer film of the laminate of the cycloolefin polymer film and the polarizer using an acrylic adhesive, and a 100 μm polycarbonate film was attached to one side of the triacetyl cellulose film as an adhesive. Attached. Accordingly, the structure of polycarbonate film (upper cover base) / adhesive / cycloolefin polymer film (upper protective layer) / polarizer / internalization layer / triacetylcellulose film (lower protective layer) / adhesive / polycarbonate film (lower cover base) A cover dust laminate was formed.

Examples 2 to 10.

The upper cover substrate (a), upper protective layer (a'), lower cover substrate (b), and lower protective layer (b') were manufactured in the same manner as in Example 1 except that they were different as shown in [Table 1].

The characteristics of the cover dust laminate formed in each of the above examples are listed in Table 1 below.

[Table 1]

Example 11.

The cover dust laminate 100 formed in Example 1, an image generating device (LGE, LA080WV5) 20, a beam splitter (Edmund, B-plate Beamsplitter) 30, and a reflector (Edmund, S-mirror) ) (40) is arranged as shown in FIG. 6, the cover dust laminate is rotated, and the vibration direction of the linearly polarized light incident on the cover dust laminate is aligned with the absorption axis of the absorption-type polarizer 110 of the cover dust laminate. It was arranged so that the smallest angle among the angles formed was 70 degrees.

After that, the luminance of the screen formed by the reflected light 202 and the screen formed by the transmitted light 201 are measured respectively according to the above-described luminance measurement method, and then the luminance of the screen formed by the reflected light 202 is measured by the transmitted light 201. The luminance ratio divided by the luminance of the screen formed by is summarized and listed in [Table 2] below.

Examples 12 to 40.

Except that the smaller angle between the type of cover dust laminate, the direction of vibration of linearly polarized light incident on the cover dust laminate, and the absorption axis of the polarizer of the cover dust laminate is applied as shown in [Table 2] below. Proceeded in the same way as Example 11.

[Table 2]

10: Head-up display
100: Cover dust laminate
110: absorption polarizer
121: upper protective layer 122: lower protective layer
130a: upper cover base material 130b: lower cover base material
20: Image generating device 200: Emitted light 201: Transmitted light 202: Reflected light
30: Beam splitter
40: reflector
50: Windshield

Claims (16)

image generating device; and a cover dust laminate,
the image generating device so that an image emitted from the image generating device passes through the cover dust laminate; and a cover dust laminate is disposed,
The cover dust laminate includes an absorption-type polarizer;
an upper cover substrate formed on top of the absorption-type polarizer;
a lower cover material formed below the absorption-type polarizer;
an upper protective layer present between the upper cover substrate and the absorption-type polarizer; and
It includes a lower protective layer present between the lower cover substrate and the absorption-type polarizer,
The upper and lower cover substrates are each polymer films,
A head-up display wherein each of the upper and lower cover materials has a thickness in the range of 80㎛ to 2000㎛. The head-up display according to claim 1, wherein the cover dust laminate has a C value of 0 to 4 according to Equation 1 below:
[Formula 1]
C=│ab│/min(a,b)
In Equation 1, C is the ratio of the absolute value of the difference in thickness of the cover substrate attached to both sides of the absorbing polarizer and the smaller of the thicknesses of the two cover substrates, and a is the ratio of the smaller value of the thickness of the two cover substrates, and a is the cover substrate formed on the top of the absorbing polarizer. is the thickness, and b is the thickness of the cover substrate formed on the lower part of the absorption-type polarizer. The head-up display according to claim 1, wherein the cover dust laminate has a D value of 0 to 0.8 according to Equation 2 below:
[Formula 2]
D=│ab│/max(a,b)
In Equation 2, D is the ratio of the absolute value of the difference in thickness of the cover substrate attached to both sides of the absorbing polarizer and the larger value of the thickness of the two cover substrates, and a is the ratio of the larger value of the thickness of the two cover substrates, and a is the cover substrate formed on the top of the absorbing polarizer. is the thickness, and b is the thickness of the cover substrate formed on the lower part of the absorption-type polarizer. The head-up display according to claim 1, wherein the cover dust laminate does not include a layer having a thickness of 100 μm or more, except for the cover substrate. delete delete The head-up display according to claim 1, wherein the thickness of the upper or lower protective layer is in the range of 10㎛ to 100㎛. The head-up display according to claim 1, wherein the cover dust laminate has an E value of 0 or more and less than 4 according to Equation 3 below:
[Formula 3]
E = (AB)/min(A, B)
In Equation 3, (AB) is the absolute value of the difference between the sum of the thickness of the upper cover base material and the upper protective layer and the sum of the thickness of the lower cover base material and the lower protective layer, and min(A, B) is the upper It is the smaller of the sum of the thickness of the cover base material and the thickness of the upper protective layer and the sum of the thickness of the lower cover base material and the thickness of the lower protective layer. The head-up display according to claim 1, wherein the cover dust laminate has an F value of 0 or more and less than 2 according to Equation 4 below:
[Formula 4]
F = (AB)/max(A, B)
In Equation 4, (AB) is the absolute value of the difference between the sum of the thickness of the upper cover base material and the upper protective layer and the sum of the thickness of the lower cover base material and the lower protective layer, and max(A, B) is the upper It is the larger of the sum of the thickness of the cover base material and the upper protective layer and the sum of the thickness of the lower cover base material and the thickness of the lower protective layer. The head-up display according to claim 1, wherein the cover dust laminate does not include any layer having a thickness of 30 μm or more, except for the cover substrate and the protective layer. The head-up display according to claim 1, wherein the upper protective layer and the lower protective layer are each a polymer film. The head-up display of claim 1, wherein the cover dust laminate does not include a reflective polarizer. The head-up display according to claim 1, wherein the cover dust laminate has no adhesive layer, adhesive layer, or release film on the outermost layer toward the bottom of the absorption-type polarizer. delete The head-up display according to claim 1, wherein the image generating device emits an image in a linearly polarized state. The image generating device and cover dust laminate according to claim 15, wherein the smaller angle between the polarization direction of the linearly polarized light emitted from the image generating device and the absorption axis of the polarizer of the cover dust laminate is in the range of 50 degrees to 80 degrees. Head-up display with sieve placed.