KR102205118B1 - Dust cover film and head-up display device including the same - Google Patents

Abstract

Disclosed is a dust cover film included in a head-up display device. The dust cover film includes: a reflective polarizing film of which a first contraction rate of one surface is higher than a second contraction rate of the other surface; a first uniaxial oriented polyester (PET) film bonded to the one surface of the reflective polarizing film by a first bonding layer; and a second uniaxial oriented PET film bonded to the other surface of the reflective polarizing film by a second bonding layer. The first bonding layer can be formed to have a contraction rate smaller than the first contraction rate, and the second bonding layer can be formed to have a contraction rate larger than the second contraction rate. Therefore, the dust cover film can well withstand impact applied from the outside.

Description

Dust cover film and head-up display device having the same {DUST COVER FILM AND HEAD-UP DISPLAY DEVICE INCLUDING THE SAME}

The present invention relates to a dust cover film and a head-up display device having the same, and more particularly, to prevent foreign matters from penetrating into the head-up display device, and excellent transmission of an output image without deformation of the head-up display device. It relates to a dust cover film and a head-up display device having the same.

A head-up display device displays an image on the inside of a transparent windshield of a vehicle such as a vehicle or airplane. The head-up display device helps the driver to read a variety of information while looking ahead. For example, the vehicle head-up display may display key information such as vehicle speed, engine status, driving help, driving route, and warning messages.

Head-up display devices were mainly electronic components mounted on high-end vehicles, but recently they are widely applied to general mass-produced vehicles. In addition, although the head-up display device has been developed as an independent system, recently, voice recognition and motion recognition technologies are combined to provide an education/entertainment function.

For example, a head-up display device for a vehicle is installed inside an instrument panel in front of a driver's seat to display a driving information image, a light emitting unit or a backlight unit that illuminates the liquid crystal panel, and a driving information image displayed on the liquid crystal panel in an appropriate size. It may include an optical system that adjusts the focus by expanding or contracting, and a reflective mirror that reflects the driving information image adjusted by the optical system to the windshield of the vehicle to display the driving information image on the windshield of the vehicle.

A liquid crystal panel, a light-emitting unit, an optical system, a reflective mirror, and the like are built into a box-shaped housing. An opening of a predetermined size is formed in the housing so that image light reflected through the reflective mirror can be irradiated toward the front windshield of the vehicle. A dust cover is mounted at the opening to prevent foreign matter such as dust from entering the interior of the housing.

It is very difficult to maintain long-term performance of a head-up display device for a vehicle due to the characteristics of a vehicle that is exposed to the outside for a long time.

The present invention has been conceived to solve the above-described problems, and a dust cover film and a head-up display device having the same according to various embodiments of the present invention minimize deformation caused by heat and smoothly circulate heat to the outside. And, it is possible to secure durability that well withstands the impact applied from the outside.

A dust cover film according to various embodiments of the present invention includes a reflective polarizing film in which a first shrinkage rate of one surface is higher than a second shrinkage rate of the other surface, and a first adhesive layer bonded to the one surface of the reflective polarizing film. It may include a uniaxially oriented PET (polyester) film and a second uniaxially oriented PET film bonded to the other surface of the reflective polarizing film by a second adhesive layer. Here, the first adhesive layer may be formed with a shrinkage rate smaller than the first shrinkage rate, and the second adhesive layer may be formed with a larger shrinkage rate than the second shrinkage rate.

According to various embodiments of the present disclosure, a dust cover film and a head-up display device including the same may minimize light loss of an image output from the head-up display device.

The dust cover film and the head-up display device having the same according to various embodiments of the present disclosure can minimize deformation caused by heat, smoothly circulate heat to the outside, and can well withstand an impact applied from the outside.

1 illustrates a structure and an optical path of a head-up display system according to an embodiment of the present invention.
2 is a cross-sectional view of a dust cover film according to an embodiment of the present invention.
3 shows a manufacturing process of a semi-optical polarizing film according to an embodiment of the present invention.
4 shows a bending state of a reflective polarizing film according to an embodiment of the present invention.
5 is a cross-sectional view of a dust cover film according to another embodiment of the present invention.
6 is a plan view of a dust cover film according to an embodiment of the present invention.
7 is a plan view of a dust cover film according to another embodiment of the present invention.
8 is a plan view of a dust cover film according to another embodiment of the present invention.
9 is a plan view of a dust cover film according to another embodiment of the present invention.

Hereinafter, the operating principle of a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, when it is determined that a detailed description of a related known function or configuration may obscure the subject matter of the present disclosure in describing an exemplary embodiment of the present disclosure, a detailed description thereof will be omitted. In addition, terms used in the following are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition of the terms used should be interpreted based on the contents throughout the specification and functions corresponding thereto.

1 illustrates a structure and an optical path of a head-up display system according to an embodiment of the present invention.

The head-up display system 1 may include an image output unit 10, a first reflector 20, a second reflector 30, a dust cover film 40, and a windshield part 50 of a vehicle. .

The image output unit 10 outputs an image including various types of information. For example, the image output unit 10 may be implemented as a liquid crystal display (LCD). Here, the light output from the image output unit 10 may be polarized light (linearly polarized light) having a predefined optical axis.

The first reflector 20 and the second reflector 30 reflect light output from the image output unit 10. Accordingly, the optical path 60 may be formed. For example, when light output from the image output unit 10 is polarized light, the first reflector 20 and the second reflector 30 may reflect the polarized light.

The dust cover film 40 may protect the interior of the head-up display device. Specifically, the dust cover film 40 may protect the head-up display device from dust, heat, moisture, and external shock.

The dust cover film 40 may be located in a part of the optical path 60 through which the image inside the head-up display device goes to the outside. Therefore, the dust cover film 40 may be formed of a generally transparent material to increase light transmittance.

When the image output from the image output unit 10 is polarized light having a predefined optical axis, the dust cover film 40 must be formed to be suitable for transmission of the specific optical axis. Accordingly, the transmittance of light passing through the optical path 60 can be maximized. In this case, an image with high definition and high brightness may be displayed on the windshield 50.

Here, the dust cover film 40 may be convex upward or concave downward.

2 is a cross-sectional view of a dust cover film according to an embodiment of the present invention.

The dust cover film 40' includes a first uniaxially stretched PET (polyester) film 21, a first adhesive layer 22, a reflective polarizing film 23, a second adhesive layer 24, and a second uniaxially stretched PET film 25. ) Can be included.

The reflective polarizing film 23 may have reflective characteristics and polarization characteristics at the same time. As an example, in the reflective polarizing film 23, a polymer layer having the same refractive index in the x-axis and y-axis directions of the two-dimensional surface is stacked up to several tens to hundreds of layers, and the refractive index in one of the x-axis and y-axis of the two-dimensional surface By laminating tens to hundreds of these different polymer layers, it is possible to have both reflective and polarizing properties.

The reflective polarizing film 23 may transmit a part of light and reflect another part or rest of the light. Specifically, the reflective polarizing film 23 may transmit polarized light having a predefined optical axis, and reflect light having an optical axis different from the predefined optical axis.

For example, the reflective polarizing film 23 may transmit a first polarized light irradiated from the image output unit, and may reflect a second polarized light having an optical axis different from that of the first polarized light.

In the above example, the first polarized light and the second polarized light may be linearly polarized light having a preset optical axis. For example, the first polarized light may be horizontal polarized light (S polarized light), and the second polarized light may be vertical polarized light (P polarized light).

In this case, the reflective polarizing film 23 may be arranged so that the polarization direction (optical axis) of the linearly polarized light and the light transmission axis of the reflective polarizing film 23 are aligned in parallel. Through this, it is possible to maximize the transmittance of linearly polarized light, thereby minimizing luminance loss of an image displayed on the windshield. In addition, since the reflective polarizing film 23 reflects light having an optical axis different from that of the linearly polarized light, the luminance loss of an image may be further reduced compared to a general polarizing film.

The first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 may protect the reflective polarizing film 23. In addition, the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 may transmit polarized light having a predefined optical axis.

Here, the light transmission axes of the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 may be arranged to coincide with the light transmission axis of the reflective polarizing film 23. Here, the transmission axis of light passing through the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 is in the stretching direction of the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 It can be a vertical direction. When the light transmission axis of the first uniaxially oriented PET film 21, the light transmission axis 25 of the second uniaxially oriented PET film, and the light transmission axis of the reflective polarizing film 23 coincide, the luminance loss due to polarization of the image is reduced. Can be minimized.

For example, the first uniaxially stretched PET film 21 and the second uniaxially stretched PET film 25 may be stretched by aligning polymer chains in one direction compared to biaxially stretched PET. Here, the transmission axis of light passing through the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 is in the stretching direction of the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25 It can be a vertical direction.

The first adhesive layer 22 may be provided to bond the first uniaxially stretched PET film 21 to one side of the reflective polarizing film 23. In addition, the second adhesive layer 24 may be provided to bond the second uniaxially stretched PET film 25 to the other side of the reflective polarizing film 23.

For example, the first adhesive layer 22 and the second adhesive layer 24 may be an acrylic polymer resin to which a curing agent is added. Here, the acrylic polymer resin may be one of an ultraviolet (ultraviolet ray, UV) curable polymer resin, a thermosetting polymer resin, or an ultraviolet ray (UV) curable polymer resin. In addition, the content of the curing agent may be 0.01 pt to 1 pt in order to prevent clouding caused by sunlight.

For example, one side of the first uniaxially stretched PET film 21 or one side of the second uniaxially stretched PET film 25 may be disposed to protrude to the outside of the head-up display device.

In this case, in order to increase the durability of the part due to external impact, at least one of one side of the first uniaxially oriented PET film 21 and one side of the second uniaxially oriented PET film 25 has a hardness of HB (brinell harness) or more, a hard coating layer may be disposed. For example, the thickness of the hard coating layer may be at least 0.5 μm or more, and may be formed to be 1 μm or more. In addition, the hard coating layer may be formed of a transparent acrylic material having a higher hardness than the first uniaxially oriented PET film 21 and the second uniaxially oriented PET film 25.

For example, interfacial reflection may occur due to a difference in refractive index on one surface of the first uniaxially oriented PET film 21 or one surface of the second uniaxially oriented PET film 25. In order to reduce interfacial reflection, an anti-reflection layer may be disposed on at least one of one side of the first uniaxially oriented PET film 21 and one side of the second uniaxially oriented PET film 25. Here, as the antireflection layer, a plurality of thin films may be deposited or a moth eye antireflection pattern may be disposed.

For example, at least one of one side of the first uniaxially stretched PET film 21 and one side of the second uniaxially stretched PET film 25 is further provided with a hot mirror layer that reflects infrared rays and transmits visible light. Can be placed. When infrared rays are transmitted through the dust cover film 40 ′, the reflector inside the head-up display device and the image output unit may be deteriorated due to the heat of the infrared rays. By disposing the heat reflector on the dust cover film 40', visible light can be transmitted and infrared light can be selectively blocked.

For example, a direction in which the stretching of the first uniaxially oriented PET film 21 is formed and a direction in which the stretching of the second uniaxially oriented PET film 25 is formed may be parallel to each other. In this case, the optical axis of the first uniaxially oriented PET film 21 and the optical axis of the second uniaxially oriented PET film 25 are arranged in parallel to ensure high polarization transmittance.

Equation 1 is an equation for measuring polarized light efficiency (EP) (or transmission efficiency) of the dust cover film 40'.

)가 커질수록 영상의 휘도는 감소함을 확인할 수 있다.On the other hand, the performance experiment for the dust cover film 40 ′ according to an embodiment of the present invention described above was performed in a manner of rotating the dust cover film 40 ′ based on the center of the dust cover film 40 ′. . Referring to the experimental results, the polarization efficiency of the dust cover film 40' is 85% or more. In the above experiment, the angle formed by the light transmission axis of the dust cover film 40 ′ and the optical axis of the output image (

It can be seen that as) increases, the luminance of the image decreases.

In the above-described example, the dust cover film 40 ′ according to an embodiment of the present invention has been described in detail. Meanwhile, when heat is applied due to different shrinkage rates on both sides of the reflective polarizing film 23 included in the dust cover film 40 ′, it is easy to bend with the side having a large shrinkage inward. In this case, the polarization of the image output from the image output unit 10 may be distorted by the dust cover film 40 ′. Hereinafter, a characteristic in which the reflective polarizing film 23 is bent and deformed will be described, and a dust cover film according to various embodiments of the present invention for compensating for such deformation of the reflective polarizing film 23 will be described in detail.

3 shows a manufacturing process of a semi-optical polarizing film according to an embodiment of the present invention.

3, the reflective polarizing film 300 is laminated while the synthetic resin stack is expanded, and cured and contracted during cooling.

As an example, the reflective polarizing film 300 is disposed at the farthest distance from the first surface 310, which is cooled by being in close contact with the cooling roll A in a heated state, and the first surface 310 of the plurality of stacked surfaces. , And a second surface 320 that is exposed to air and gradually cooled compared to the first surface 310.

Here, since the first surface 310 is rapidly cured by the cooling roll A, the contraction is relatively large, and the second surface 320 is gradually cooled and cured by air, so that the contraction is relatively small. That is, the shrinkage rate I1 of the first surface 310 is relatively greater than the shrinkage rate I2 of the second surface 320.

4 shows a bending state of a reflective polarizing film according to an embodiment of the present invention.

Referring to FIG. 4, the shrinkage rate of the first surface 410 of the reflective polarizing film 400 is greater than that of the second surface 420. Accordingly, when heat is applied to the reflective polarizing film 400, since the shrinkage rate of the first surface 410 is greater than that of the second surface 420, the first surface 410 around the bending axis B ) Direction (or convex in the direction of the second surface 420). Here, the bending axis B of the reflective polarizing film 400 may be on the central axis of the reflective polarizing film 400. For example, the bending axis B may be inside the reflective polarizing film 400 along the central axis of the reflective polarizing film 400, or may be outside the reflective polarizing film 400 as shown in FIG. 4.

Hereinafter, various embodiments of the first adhesive layer 22 and the second adhesive layer 22 for minimizing bending deformation of the reflective polarizing films 300 and 400 in a concave direction toward the first surfaces 310 and 410 will be described. It will be described in detail. Hereinafter, detailed descriptions for configurations that overlap with the above-described contents will be omitted for convenience of description.

5 is a cross-sectional view of a dust cover film according to another embodiment of the present invention.

6 is a plan view of a dust cover film according to an embodiment of the present invention.

5 and 6, the dust cover film 40 ″ includes a first uniaxially oriented PET film 21 ′, a first adhesive layer 22 ′, a reflective polarizing film 23 ′, and a second adhesive layer 24. ') and a second uniaxially stretched PET film 25'.

The reflective polarizing film 23 ′ may have a first shrinkage ratio of one surface greater than a second shrinkage ratio of the other surface. For example, the one surface is defined as a surface closer to the first uniaxially stretched PET film 21 ′ among both surfaces of the reflective polarizing film 23 ′, and the other surface is both surfaces of the reflective polarizing film 23 ′. It may be defined as a surface closer to the second uniaxially stretched PET film 2'.

The first uniaxially stretched PET film 21 ′ may be bonded to one surface of the reflective polarizing film 23 ′ by a first adhesive layer 22 ′.

The second uniaxially stretched PET film 25 ′ may be bonded to the other surface of the reflective polarizing film 23 ′ by a second adhesive layer 24 ′.

As an example, the first adhesive layer 22 ′ and the second adhesive layer 24 ′ are line patterns 22 ′ and 24 ′ in which a plurality of adhesive lines 22 ′ and 24 ′ are disposed at a predefined distance. ) Can be formed. In this case, heat introduced by the air layer formed by the separation distance of the line pattern may be circulated.

The predefined separation distances of the above-described line patterns 22 ′ and 24 ′ may be formed to decrease from the center of the reflective polarizing film 23 ′ toward the side of the reflective polarizing film 23 ′. Accordingly, the line patterns 22 ′ and 24 ′ may be more densely disposed from the center of the reflective polarizing film 23 ′ toward the side of the reflective polarizing film 23 ′. When the reflective polarizing film 23' is bent to one side by heat, a greater force is generated on the side than the central portion of the reflective polarizing film 23', and the dust cover film 40' is convex upward or downward. In the case of concave formation, since the bending force is generated at the side portion more strongly than the central portion, the reflective polarizing film 23 is formed by arranging more line patterns 22 ′ and 24 ′ on the side than the central portion of the reflective polarizing film 23 ′. The side of') is more strongly bonded to the first uniaxially oriented PET film 21 ′ and the second uniaxially oriented PET film 25 ′ to minimize bending deformation. In addition, even if the first adhesive layer 22 ′ and the second adhesive layer 24 ′ are composed of a transparent component, some light distortion may occur, and there are more line patterns 22 ′ on the side of the reflective polarizing film 23 ′ than in the center. , 24'), it is possible to minimize distortion of light to the central portion of the reflective polarizing film 23'.

In addition, the first adhesive layer 22 ′ or the line pattern 22 ′ may be formed with a shrinkage rate smaller than the first shrinkage rate of the one surface of the reflective polarizing film 23 ′. The one side of the reflective polarizing film 23' has a higher shrinkage ratio than the other side of the reflective polarizing film 23', so that the one side of the reflective polarizing film 23' is bent concave, and the first adhesive layer 22' Alternatively, when the line pattern 22' is formed with a shrinkage rate smaller than the first shrinkage rate of the one side of the reflective polarizing film 23', the concave bending of the one side of the reflective polarizing film 23' is suppressed as much as possible. can do.

In addition, the second adhesive layer 24 ′ or the line pattern 24 ′ may be formed with a greater shrinkage rate than the second shrinkage rate of the other surface of the reflective polarizing film 23 ′. The other surface of the reflective polarizing film 23 ′ has a smaller shrinkage than that of the one surface of the reflective polarizing film 23 ′, so that the other surface of the reflective polarizing film 23 ′ is convexly bent, and the second adhesive layer 24 ′ Alternatively, when the line pattern 24 ′ is formed with a larger shrinkage rate than the second shrinkage rate of the other surface of the reflective polarizing film 23 ′, the other surface of the reflective polarizing film 23 ′ is prevented from being convexly curved. can do.

Meanwhile, the length direction C of the above-described line patterns 22 ′ and 24 ′ may be disposed in a direction orthogonal to the bending axis B of the reflective polarizing film 400 in FIG. 4. Accordingly, the above-described line patterns 22 ′ and 24 ′ can minimize the deformation of the reflective polarizing film 400 by suppressing the bending force of the reflective polarizing film 400.

7 is a plan view of a dust cover film according to another embodiment of the present invention.

Referring to FIG. 7, a grid pattern 71 and 72 in which a plurality of adhesive lines are arranged in a grid may be formed on the outer sides 71 and 72 of the line patterns 22 ″ and 24 ″. Here, the line patterns 22 ″ and 24 ″ may be defined as including the lattice patterns 71 and 72, but for convenience of description, the line patterns 22 ″ and 24 ″ and the grid patterns ( 71 and 72) are defined respectively.

In FIG. 7, grating patterns 71 and 72 formed of an adhesive are disposed on the side of the reflective polarizing film 23 ′, so that the side of the reflective polarizing film 23 ′ is a first uniaxially oriented PET film 21 ′ and 2 Bending deformation can be prevented as much as possible by binding more strongly to the uniaxially stretched PET film 25'.

Here, the lattice patterns 71 and 72 of the first adhesive layer 22 ″ may be formed with a shrinkage rate smaller than the first shrinkage rate of one surface of the reflective polarizing film 23 ′. Accordingly, the one surface of the reflective polarizing film 23 ′ has a higher shrinkage than the other surface of the reflective polarizing film 23 ′, and the reflective polarizing film 23 ′ has a concave curved surface. 22'') of the grid patterns 71 and 72 are formed with a shrinkage ratio smaller than the first shrinkage ratio of the one side of the reflective polarizing film 23', the one side of the reflective polarization film 23' is concave. You can suppress bending as much as possible.

In addition, the lattice patterns 71 and 72 of the second adhesive layer 24 ″ may be formed with a greater shrinkage rate than the second shrinkage rate of the other surface of the reflective polarizing film 23 ′. Accordingly, the other surface of the reflective polarizing film 23 ′ has a smaller shrinkage ratio than that of the one surface of the reflective polarizing film 23 ′, and the other surface of the reflective polarizing film 23 ′ is convexly bent, and the second adhesive layer ( 24'') is formed with a larger shrinkage ratio than the second shrinkage of the other side of the reflective polarizing film 23', the other side of the reflective polarizing film 23' is convex. You can suppress bending as much as possible.

8 is a plan view of a dust cover film according to another embodiment of the present invention.

Referring to FIG. 8, the first adhesive layer 22 ″′ further includes at least one first adhesive line 81 disposed orthogonal to the length direction of the line pattern 82 of the reflective polarizing film 23 ′. can do. The at least one first adhesive line 81 may be formed with a shrinkage rate smaller than the first shrinkage rate of one surface of the reflective polarizing film 23 ′.

In the example of FIG. 8 described above, the line pattern 82 and the first adhesive line 81 of the reflective polarizing film 23' are perpendicular to the length direction of the line pattern 82 and the length direction of the line pattern 82, respectively. By supporting the reflective polarizing film 23 ′ in the same direction, it is possible to minimize deformation in which the reflective polarizing film 23 ′ is concavely bent in the upward direction of one surface of the reflective polarizing film 23 ′.

9 is a plan view of a dust cover film according to another embodiment of the present invention.

Referring to FIG. 9, the second adhesive layer 24 ″′ further includes at least one second adhesive line 91 disposed to be perpendicular to the length direction of the line pattern 92 of the reflective polarizing film 23 ′. can do.

In this case, the at least one second adhesive line 91 may be formed with a greater shrinkage rate than the second shrinkage rate of the other surface of the reflective polarizing film 23 ′.

In the example of FIG. 9 described above, the line pattern 92 and the second adhesive line 91 of the reflective polarizing film 23' are perpendicular to the length direction of the line pattern 92 and the length direction of the line pattern 92, respectively. By supporting the reflective polarizing film 23 ′ in the same direction, deformation in which the reflective polarizing film 23 ′ is convexly bent in the upward direction of the other surface of the reflective polarizing film 23 ′ can be minimized.

8 and 9 described above, the thickness of the at least one first adhesive line 81 and the thickness of the at least one second adhesive line 91 are a plurality of adhesive lines included in the line patterns 82 and 92 ( 82, 92) may be formed thicker than the thickness. In addition, the width of the at least one first adhesive line 81 and the width of the at least one second adhesive line 91 are less than the widths of the plurality of adhesive lines 82 and 92 included in the line patterns 82 and 92 It can be formed widely.

Accordingly, the at least one first adhesive line 81 may exert a greater force of suppressing or supporting a force that is concavely bent outward from one surface of the reflective polarizing film 23 ′. In addition, the at least one second adhesive line 91 may exert a greater force of suppressing or supporting a force that is convexly bent outward from the other surface of the reflective polarizing film 23 ′.

In addition, in FIGS. 8 and 9 described above, at least one of the thickness and width of the plurality of adhesive lines 82 included in the line pattern 82 is of the plurality of adhesive lines 92 included in the line pattern 92. It may be formed larger than at least one of thickness and width.

In addition, in FIGS. 8 and 9 described above, at least one of the thickness and width of the at least one first adhesive line 81 may be larger than at least one of the thickness and width of the second adhesive line 91.

Accordingly, the line pattern 82 or at least one first adhesive line 81 effectively suppresses the shrinking force of one side of the reflective polarizing film 23' having a greater shrinking force than the other side of the reflective polarizing film 23'. Can do it.

According to various embodiments of the present invention described above, the first adhesive layers 22, 22', 22'', 22''' included in the dust cover films 40, 40', 40'' and the second adhesive layer ( 24, 24', 24``, 24''') is a reflective polarizing film (23, 23') and the first uniaxially stretched PET film (21, 21') is adhered, and the reflective polarizing film (23, 23') And the second uniaxially stretched PET films 24 and 24 ′ are not only adhered, but also the air layer is formed to discharge heat introduced from the outside through the air layer to adjust the temperature. This air layer can mitigate the impact from the outside.

The head-up display device including the dust cover films 40, 40', 40'' according to various embodiments of the present invention can minimize deformation caused by heat and smoothly circulate heat to the outside. It can withstand the impact applied from

In the above, preferred embodiments of the present disclosure have been illustrated and described, but the present disclosure is not limited to the specific embodiments described above, and is generally used in the technical field to which the present invention belongs without departing from the gist of the present disclosure claimed in the claims. Of course, various modifications may be made by those skilled in the art, and these modifications should not be understood individually from the technical idea or perspective of the present disclosure.

Head-up display system: 1
Video output: 10
1st reflector: 20
Second reflector: 30
Dust Cover Film: 40
Windshield: 50
Optical path: 60
Dust Cover Film: 40, 40', 40''
First uniaxially stretched PET film: 21, 21'
2nd uniaxially stretched PET film: 25, 25'
First adhesive layer: 22, 22', 22'', 22'''
Second adhesive layer: 24, 24', 24'', 24'''
Reflective polarizing film: 23, 23'

Claims (15)

A reflective polarizing film in which a first shrinkage rate on one side is higher than a second shrinkage rate on the other side;
A first uniaxially stretched PET (polyester) film bonded to the one surface of the reflective polarizing film by a first adhesive layer; And
Including; a second uniaxially stretched PET film bonded to the other surface of the reflective polarizing film by a second adhesive layer,
The first adhesive layer is formed with a shrinkage rate smaller than the first shrinkage rate,
The second adhesive layer is formed with a greater shrinkage rate than the second shrinkage rate,
The first adhesive layer and the second adhesive layer,
A plurality of adhesive lines are formed in a line pattern arranged at a predefined distance so that an air layer circulating heat is formed,
A first grid pattern in which a plurality of adhesive lines are arranged in a grid is formed outside the line pattern of the first adhesive layer,
A second grid pattern in which a plurality of adhesive lines are arranged in a grid is formed outside the line pattern of the second adhesive layer.
delete The method of claim 1,
The predefined separation distance of the line pattern is,
A dust cover film that decreases from the center of the reflective polarizing film toward the side of the reflective polarizing film.
The method of claim 1,
The first adhesive layer,
The dust cover film further comprising at least one first adhesive line disposed to be perpendicular to the length direction of the line pattern and formed with a shrinkage rate smaller than the first shrinkage rate.
The method of claim 1,
The second adhesive layer,
The dust cover film further comprising at least one second adhesive line disposed to be perpendicular to the length direction of the line pattern and formed with a greater shrinkage rate than the second shrinkage rate.
The method of claim 1,
The line pattern of the first adhesive layer,
A dust cover film that is thicker than the line pattern of the second adhesive layer and has a wider width.
delete delete The method of claim 1,
The first adhesive layer and the second adhesive layer,
Dust cover film formed of acrylic polymer resin added with a curing agent.
The method of claim 9,
The curing agent is 0.01 pt to 1 pt content, the dust cover film.
The method of claim 1,
A dust cover film in which a hard coating layer having a hardness of HB or higher is disposed on at least one surface of the first uniaxially oriented PET film and the second uniaxially oriented PET film.
The method of claim 1,
At least one surface of the first uniaxially oriented PET film and the second uniaxially oriented PET film has an anti-reflection layer for reducing interfacial reflection is disposed, the dust cover film.
The method of claim 1,
At least one surface of the first uniaxially oriented PET film and the second uniaxially oriented PET film is a heat reflector (hot mirror) layer that reflects infrared and transmits visible light is disposed, the dust cover film.
The method of claim 1,
The stretching direction of the first uniaxially stretched PET and the stretching direction of the second uniaxially stretched PET are parallel to each other, the dust cover film.
A head-up display device comprising the dust cover film of any one of claims 1, 3 to 6, and 9 to 14.

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