KR102204164B1 - Opotical film for fingerprinting - Google Patents

Abstract

Disclosed is an optical film for fingerprint recognition that transmits infrared rays. The optical film for fingerprint recognition may include a base film and a prism pattern layer adhered to one side of the base film. Here, the prism pattern layer is arranged such that a plurality of prisms are arranged parallel to each other at predefined intervals to form a line pattern that transmits the infrared light, and the protruding directions of the plurality of prisms face the light source. I can.

Description

Optical film for fingerprint recognition {OPOTICAL FILM FOR FINGERPRINTING}

The present invention relates to an optical film for fingerprint recognition, and more particularly, to an optical film for fingerprint recognition capable of transmitting infrared rays.

Recently, portable electronic devices such as smartphones and tablet PCs have become common. These portable electronic devices contain personal information such as the user's address, email, and financial information, so it is important to secure security through user authentication.

User authentication technology is evolving as a method of using the user's biometric information. Here, the biometric information may be, for example, information such as a fingerprint, an iris, a face, or a voice. In particular, fingerprint authentication is being adopted in most portable electronic devices due to its convenience and high security.

Representative methods of recognizing fingerprints are electrostatic, ultrasonic, and optical. Recently, smartphones are equipped with a semiconductor sensor-based capacitive fingerprint recognition function that exhibits a high recognition rate while maintaining a small size and thin enough to not affect the design. In addition, an ultrasonic fingerprint recognition function that recognizes the difference in height of the fingerprint by measuring the arrival time of the reflected ultrasonic waves after radiating the ultrasonic waves is also installed in the smartphone. However, the capacitive fingerprint sensor has a very small size of a fingerprint area to be recognized at a time compared to the optical fingerprint sensor, and thus the false authentication rate is higher than that of the optical type, so security may be slightly lowered. The ultrasonic type is relatively good in accuracy and durability, but it is somewhat difficult to manufacture and has disadvantages in terms of price.

On the other hand, the optical fingerprint method guarantees high reliability and has excellent durability, so it is adopted in various electronic devices. The optical fingerprint recognition method is a so-called scattering method that detects light scattered from the ridge of the fingerprint that directly contacts the transparent fingerprint contact of the device, and the light that is totally reflected from the surface of the fingerprint contact corresponding to the valley of the fingerprint. It can be divided into a so-called total reflection method that detects.

The backlight unit of a small electronic device such as a smartphone is provided with various optical films, so that infrared rays cannot be transmitted. Accordingly, it is difficult to utilize an optical fingerprint recognition method using infrared rays.

The present invention has been conceived to solve the above-described problems, and an object thereof is to provide an optical film for fingerprint recognition that smoothly transmits infrared rays so that optical fingerprint authentication using infrared rays is possible even in small electronic devices such as a smart phone.

The optical film for fingerprint recognition that transmits infrared rays according to an embodiment of the present invention may include a base film and a prism pattern layer adhered to one side of the base film. Here, the prism pattern layer is arranged such that a plurality of prisms are arranged parallel to each other at predefined intervals to form a line pattern that transmits the infrared light, and the protruding directions of the plurality of prisms face the light source. I can.

According to various embodiments of the present disclosure, the optical film for fingerprint recognition may smoothly transmit infrared rays.

According to various embodiments of the present disclosure, the optical film for fingerprint recognition enables fingerprint recognition on a screen of a small electronic device such as a smartphone, thereby simplifying a display structure of a smartphone and improving user convenience.

1 is an exploded perspective view of a backlight unit according to an embodiment of the present invention.
2 is a perspective view of an optical film according to an embodiment of the present invention.
3 is a layout diagram of a performance experiment of an optical film according to an embodiment of the present invention.
4 shows results of performance tests of a prism sheet according to an embodiment of the present invention.
5 shows results of performance tests of a prism sheet according to another embodiment of the present invention.
6 shows an optical fingerprint recognition system according to an embodiment of the present invention.
7 shows an optical fingerprint recognition system according to another embodiment of the present invention.
8 shows an optical fingerprint recognition system according to another embodiment of the present invention.
9 shows an optical fingerprint recognition system 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.

The optical film according to various embodiments of the present disclosure described below may be applied to a backlight unit of various types of liquid crystal display devices (liquid crystal display (LCD) devices). However, it goes without saying that the optical film according to various embodiments of the present disclosure may be used alone or included in a means for providing a backlight in various devices other than a liquid crystal display device.

1 is an exploded perspective view of a backlight unit according to an embodiment of the present invention.

In general, a liquid crystal display device needs a backlight unit 10 that provides uniform light to the entire screen, unlike a conventional CRT. The backlight unit 10 may be provided at the rear of the liquid crystal panel to irradiate light to the liquid crystal panel.

The backlight unit 10 includes a light source 11, a reflective plate 12, a light guide plate 13, an optical film 14 and a reflective polarizing sheet 15.

The light source 11 emits light. The light source 11 may be composed of a light emitter that emits light. The light source 11 may emit light from the side of the light guide plate 13 and transmit light toward the light guide plate 13. By irradiating the light emitted from the light source 11 onto the rear surface of the liquid crystal panel, an identifiable image may be realized.

For example, the light source 11 may be one of a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED, hereinafter referred to as LED). have.

The light source 11 is divided into an edge type and a direct type according to the arrangement structure, and the direct type can realize a more detailed image than the edge type because it can be divided and driven compared to the edge type.

The reflector 12 is disposed behind the light guide plate 13 and reflects the light emitted from the rear of the light guide plate 13 to the light guide plate 13 and enters it, thereby minimizing loss of light.

The light guide plate 13 converts the light incident through the reflective plate 12 into a surface light source.

The optical film 14 is disposed above the light guide plate 13 to collect light transmitted from the light guide plate 13 and move it upward. The optical film 14 arranges a plurality of inverted prisms to totally reflect the transmitted light inside and refract it upward.

The optical film 14 may include a base film 14-1 and a prism pattern layer 14-2.

The base film 14-1 supports the prism pattern layer 14-2.

For example, the base film 14-1 may be a light-transmitting film through which light transmitted from the lower portion can be easily transmitted. In this case, the base film 14-1 may be made of a material such as PET, PC, or PP.

As another example, the base film 14-1 may be a reflective polarization sheet 14-1. In this case, the reflective polarization sheet 14-1 serves to recycle the light by transmitting one polarized light and reflecting the other polarized light downward with respect to the light collected from the plurality of prisms 14-2. For example, the reflective polarization sheet 14-1 may transmit P polarized light and reflect S polarized light.

Here, the reflective polarization sheet 14-1 is formed by stacking a plurality of layers having different refractive indices. As an example, the reflective polarization sheet 14-1 may be formed by stacking tens, hundreds, or thousands of different high refractive index layers and low refractive index layers.

The base film 14-1 may be integrated with the prism pattern layer 14-2.

The prism pattern layer 14-2 condenses the incident light and emits it upward. In the prism pattern layer 14-2, a plurality of prisms may be disposed at predetermined intervals.

For example, the prism pattern layer 14-2 is an optical pattern layer in which an optical pattern in the form of a triangular array having an inclined surface is formed under the translucent base film 14-1 to improve the luminance of the emitted light. Can be formed.

Since the description of the reflective polarization sheet 15 is duplicated with the description of the reflective polarization sheet 14-1 described above, a detailed description will be omitted. When the base film 14-1 is implemented as the reflective polarizing sheet 14-1, the backlight unit 10 may or may not include the reflective polarizing sheet 15.

It goes without saying that the configuration included in the above-described backlight unit 10 may be in various combinations. For example, the backlight unit 10 may omit some of the light source 11, the reflective plate 12, the light guide plate 13, the optical film 14, and the reflective polarization sheet 15, or may further include an additional configuration. .

For example, the backlight unit 10 may further include a diffusion sheet. Here, the diffusion sheet may uniformly disperse light incident from the light guide plate 13. The diffusion sheet is a curable resin to which beads of a light diffusing agent are added (e.g., at least one of urethane acrylate, epoxy acrylate, ester acrylate, ester acrylate, and radical-generating monomer is selected and used alone or It is mixed) It can cause light diffusion by the optical dispersion bead by applying a solution. Further, in the diffusion sheet, a protrusion pattern (or protrusion) having a uniform or non-uniform size (eg, spherical) may be formed to promote light diffusion.

Hereinafter, a detailed description of a configuration overlapping with the above-described optical film 14 will be omitted for convenience of description.

2 is a perspective view of an optical film according to an embodiment of the present invention.

Referring to FIG. 2, the optical film 20 includes a base film 21 and a prism pattern layer 22.

The base film 21 supports the prism pattern layer 22.

)은 0

보다 크고 90

보다 작도록 설정될 수 있다.The prism pattern layer 22 is adhered to one side of the base film 21 to collect light. Specifically, the prism pattern layer 22 may collect light emitted from a light source and passing through the light guide plate. For example, apex angles of a plurality of prisms included in the prism pattern layer 22 (

) Is 0

Greater than 90

It can be set to be smaller than.

In addition, the prism pattern layer 22 may transmit infrared rays. For example, the prism pattern layer 22 may transmit infrared rays emitted through an infrared light source. Here, the infrared light source may be provided separately from a light source emitting visible light. For example, the infrared light source may be included in an optical fingerprint recognition system to be described later to emit infrared for fingerprint recognition.

The prism pattern layer 22 may include a plurality of prisms 22 arranged in parallel with each other at a predefined interval A. Here, the prism pattern layer 22 may be disposed so that the protruding directions of the plurality of prisms 22 face the light source and the infrared light source.

In addition, the prism pattern layer 22 may form a line pattern having the predefined distance A between the plurality of prisms 22 arranged parallel to each other. Here, the line pattern may be a plurality of plane lines that transmit infrared rays. Specifically, each line of the line pattern may be formed with a width A. A general prism reflects and refracts infrared rays so that infrared transmittance is remarkably low. Since the plurality of line patterns transmit infrared rays, fingerprint recognition through infrared rays is possible. Through this, it is possible to drive the optical fingerprint recognition system to be described later. In addition, the optical film 20 improves the general prism pattern layer 22, which is difficult to transmit infrared rays, to greatly increase the infrared transmittance, thereby enabling optical fingerprint recognition even in a miniaturized display device.

For example, the width of the line pattern may be formed larger than the predefined interval A in an area corresponding to the position of the fingerprint. According to an embodiment of the present invention, the infrared transmittance for fingerprint recognition is increased through a line pattern formed larger than the width A in the area corresponding to the fingerprint location, and the line pattern is changed to the width A in the area other than the area corresponding to the fingerprint location. By maintaining it, it is possible to minimize the loss of light luminance and light collection efficiency.

One side of the above-described base film 21 and one side of the prism pattern layer 22 may be adhered by an adhesive. Here, the adhesive may be a pressure sensitive adhesive (PSA). Accordingly, the optical film 20 may be integrated by bonding the base film 21 and the prism pattern layer 22 to each other.

3 is a layout diagram of a performance experiment of an optical film according to an embodiment of the present invention.

)은 68

, 복수의 프리즘(33-1)의 굴절률(

)은 1.50이고, 베이스필름(33-2)의 두께는 125μm, 굴절률(

)은 1.62(베이스필름(33-2)이 반사편광시트인 경우 굴절률(

)은 1.6)이고, 프리즘 간격(33-3)은 0μm, 2μm, 4μm, 6μm 중 하나인 것으로 정의한다. 또한, 측정을 위해서 광학필름(33)은 5 X 5 mm 크기를 이용하였다.The performance test of the optical film 33 includes an LED light source 31, a light guide plate 32, an optical film 33, a front detector 34, and a back detector 35. In the following, the apex angles of the plurality of prisms 33-1 of the optical film 33 (

) Is 68

, The refractive index of the plurality of prisms (33-1) (

) Is 1.50, the thickness of the base film 33-2 is 125 μm, and the refractive index (

) Is 1.62 (if the base film 33-2 is a reflective polarizing sheet, the refractive index (

) Is 1.6), and the prism spacing (33-3) is defined as one of 0 μm, 2 μm, 4 μm, and 6 μm. In addition, for the measurement, the optical film 33 used a size of 5 X 5 mm.

The front detector 34 detects light emitted from the LED light source 31 and then condensed by the optical film 33. The photodetection of the front detector 34 is performed in a state in which the fingerprint 33-4 is not disposed.

The rear detector 35 detects light reflected by the fingerprint 33-4.

The experimental results for the performance experiment for the above-described optical film 33 will be described in detail below with reference to FIGS. 4 and 5.

4 shows the center gain of light detected by the front detector 34 and the rear detector 35. In the front detector 34, a change in luminance of light transmitted to the upper portion can be checked according to the width of the line pattern 33-3, and in the rear detector 35, the fingerprint 33- It is possible to check the change in luminance of the light reflected in 4) and transmitted to the bottom.

Specifically, referring to FIG. 4, in Experiment 1 (41), the width of the line pattern 33-3 is set to 0 μm, which is defined as a reference experiment. In Experiment 1 (41), the center gain of the front detector 34 and the rear detector 35 is defined as 100%. Here, it can be seen that there is almost no light detection in the rear detector 35.

Experiment 2 (42) is a case where the width of the line pattern 33-3 is set to 2 μm. In Experiment 2 (42), compared to Experiment 1 (41), the center gain of the front detector 34 was partially reduced to 99%, but the center gain of the rear detector 35 was remarkably improved to 271%.

Experiment 3 (43) is a case where the width of the line pattern 33-3 is set to 4 μm. In Experiment 3 (43), compared to Experiment 1 (41), the center gain of the front detector 34 was partially reduced to 98%, but the center gain of the rear detector 35 was remarkably improved to 365%.

Experiment 4 (44) is a case where the width of the line pattern 33-3 is set to 6 μm. In Experiment 4 (44), compared to Experiment 1 (41), the center gain of the front detector 34 was partially reduced to 98%, but the center gain of the rear detector 35 was remarkably improved to 456%.

Referring to Experiments 1 (41) to 4 (44) described above, as the width of the line pattern 33-3 increases, the luminance of light transmitted to the upper portion of the optical film 33 decreases very insignificantly, but the fingerprint ( It can be seen that the detection rate of light reflected by 33-4) and transmitted through the optical film 33 is significantly improved.

Through this, when the width of the line pattern 33-3 is secured, a fingerprint recognition rate may be greatly improved, and a fingerprint recognition error may be greatly reduced. The optical film 33 according to an embodiment of the present invention may propose a method in which an optical fingerprint recognition system can be adopted in a small display device such as a smart phone.

5 shows a center gain of light detected by the front detector 34. Here, the experimental conditions of FIG. 5 are the same as those of the experiment of FIG. 4. The experimental results of FIG. 5 include center gains when the widths of the line patterns 33-3 are 6 μm, 9 μm, and 12 μm.

Experiment 1 (51) is that the width of the line pattern 33-3 is set to 6 μm, and the center gain is defined as 100%.

Experiment 2 (52) is a case where the width of the line pattern 33-3 is set to 9 μm. In the case of Experiment 2 (52), the center gain of the front detector 34 was 54.7%, which was significantly reduced compared to the 100% center gain measured in Experiment 1 (51).

Experiment 3 (53) is a case where the width of the line pattern 33-3 is set to 12 μm. In the case of Experiment 3 (53), the center gain of the front detector 34 was 17.3%, which was significantly reduced compared to the center gain of 100% measured in Experiment 1 (51) or the center gain measured in Experiment 2 (52) 54.7%. .

Referring to Experiments 1 (51) to 3 (53) described above, when the width of the line pattern 33-3 exceeds 6 μm, the center gain or the center luminance rapidly decreases, and the condensing performance of the optical film 33 It can be seen that this drastically decreases. According to these experimental results, the optical film 33 can be used as a light collecting sheet only when the width of the line pattern 33-3 is formed to be 6 μm or less, and if it exceeds this, the front luminance is reduced and application as a light collecting sheet is possible. impossible.

6 shows an optical fingerprint recognition system according to an embodiment of the present invention.

Referring to FIG. 6, the optical fingerprint recognition system 60 may include an infrared light source 610, an image sensor 620, a reflector 630, and an optical film 640.

The infrared light source 610 may emit infrared LED light. For example, the infrared light source 610 may irradiate infrared rays having a wavelength of 750 nm or more. Since infrared rays have a relatively long wavelength, light loss is small and diffuse reflection is small, so that a clear image can be obtained from the image sensor 620.

The image sensor 620 senses a fingerprint image. The image sensor 620 converts infrared rays reflected from the fingerprint into electrical signals and stores them. For example, the image sensor 620 may be a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

The reflecting device 630 may refract infrared rays. For example, the reflecting device 630 may refract infrared rays emitted from the infrared light source 610 or may refract infrared rays reflected from a fingerprint. For example, the reflector 630 may include various applications for refracting the direction of light, such as at least one prism or a beam splitter.

Here, the reflecting device 630 may be formed under the reflecting plate 12 described in FIG. 1. In addition, it may be formed of a material that transmits visible light and formed on the reflective plate 12.

The optical film 640 may include a base film 641 and a prism pattern layer 642.

The prism pattern layer 642 may be disposed to face the infrared light source 610. Specifically, the prism pattern layer 642 may be disposed in a direction B in which infrared rays are incident on the prism pattern layer 642. In this case, the arrangement direction of the prism pattern layer 642 may be defined as a reverse arrangement.

A plurality of prisms included in the prism pattern layer 642 may be arranged in parallel at a predefined interval C. Here, the predefined interval C may be defined as the width C of the line pattern.

For example, the width C of the line pattern may be predefined as 2 μm, 4 μm, 6 μm, or the like. Alternatively, the width C of the line pattern may be defined as 6 μm or less. Alternatively, the width C of the line pattern may be defined as 2 μm or more and 6 μm or less.

보다 크고 90

보다 작게 형성될 수 있다. 여기서, 복수의 프리즘은 삼각형 또는 이등변 삼각형으로 형성될 수 있다.For example, the vertex angle of a plurality of prisms is 0

Greater than 90

It can be formed smaller. Here, the plurality of prisms may be formed as a triangle or an isosceles triangle.

For example, among the plurality of prisms, the spacing (or the width of the line pattern) between the plurality of third prisms 642-1, 642-2, 642-3 corresponding to the position 650 of the fingerprint may be set larger than C. have. Through this, the infrared transmittance of the region of the optical film 640 corresponding to the position 650 of the fingerprint is relatively improved than the infrared transmittance of the region of the optical film 640 corresponding to the region other than the position 650 of the fingerprint. Can be.

Hereinafter, a detailed description of the contents overlapping with the configuration of the optical fingerprint recognition system 60 described above in FIG. 6 will be omitted for convenience of description.

7 shows an optical fingerprint recognition system according to an embodiment of the present invention.

Referring to FIG. 7, the optical fingerprint recognition system 70 may include an infrared light source 710, an image sensor 720, a reflector 730, and an optical film 740.

The optical film 740 may include a base film 741 and a prism pattern layer 742.

For example, a plurality of prisms of the prism pattern layer 742 may be arranged in parallel at a predefined interval D. Here, the predefined interval D may be defined as the width D of the line pattern.

As another example, of the line patterns 742-1, 742-2, 742-3, 742-4, 742-5, and 742-6, the line patterns 742-3, 742-4 corresponding to the position 750 of the fingerprint ) May be different from the widths of the line patterns 742-1, 742-2, 742-5, and 742-6 corresponding to locations other than the location 750 of the fingerprint.

For example, the widths of the line patterns 742-1, 742-2, 742-5, and 742-6 corresponding to locations other than the location 750 of the fingerprint may be formed as D. In this case, among the line patterns 742-1, 742-2, 742-3, 742-4, 742-5, and 742-6, the line patterns 742-3 and 742-4 corresponding to the position 750 of the fingerprint ) May be formed larger than D.

According to the embodiment of the present invention described above, among the line patterns 742-1, 742-2, 742-3, 742-4, 742-5, and 742-6, the line pattern corresponding to the position 750 of the fingerprint ( By forming the width of 742-3, 742-4) larger than the width of the line patterns 742-1, 742-2, 742-5, 742-6 corresponding to locations other than the location 750 of the fingerprint, In the area of the optical film 740 corresponding to the location 750, the transmittance of infrared rays can be increased, and for the area of the optical film 740 corresponding to a location other than the location 750 of the fingerprint, the reduction in condensing performance and brightness can be minimized. have.

8 shows an optical fingerprint recognition system according to another embodiment of the present invention.

Referring to FIG. 8, the optical fingerprint recognition system 80 may include an infrared light source 810, an image sensor 820, a reflector 830, and an optical film 840.

The optical film 840 may include a base film 841 and a prism pattern layer 842.

For example, the optical film 840 may include a plurality of through holes 801. Here, the plurality of through holes 801 may be formed in a traveling direction (F or G) of infrared rays so as to transmit infrared rays. Accordingly, infrared rays may simultaneously transmit (or pass through) the base film 841 and the prism pattern layer 842. Here, the plurality of through holes 801 may be disposed at predefined intervals. In this case, the farthest distance between the two selected among the plurality of through holes 801 may be set to 10 mm. In addition, of course, the farthest distance between the two selected among the plurality of through holes 601 may be variously set, such as less than 10 mm to 10 mm or more.

Referring to FIG. 8, the optical film 840 may effectively transmit infrared rays through a plane line of the prism pattern layer 842 and a plurality of through holes 801 secured according to a predefined interval E.

9 shows an optical fingerprint recognition system according to another embodiment of the present invention.

Referring to FIG. 9, the optical fingerprint recognition system 90 may include an infrared light source 910, an image sensor 920, a reflector 930, and an optical film 940.

The optical film 940 may include a base film 941 and a prism pattern layer 942.

As an example, the optical film 940 may include a plurality of through holes 901. Here, the plurality of through-holes 901 may be formed in a traveling direction (I or J) of infrared rays so as to transmit infrared rays. Accordingly, infrared rays may simultaneously transmit (or pass) the base film 941 and the prism pattern layer 942. Here, the plurality of through holes 901 may be disposed in a region corresponding to the position of the fingerprint at predetermined intervals.

For example, a cross section of a plurality of prisms included in the prism pattern layer 942 may be formed in a trapezoidal shape. In this case, the trapezoid may be an equilateral trapezoid.

Referring to FIG. 9, the optical film 940 may effectively transmit infrared rays through a surface secured according to a predefined distance H set in a plurality of prisms 942 and a plurality of through holes 901. In addition, since the cross section of the plurality of prisms 942 is formed in a trapezoidal shape in the optical film 940, since the top surfaces of the plurality of prisms 942 are flat, the transmittance of infrared rays can be maximized.

As described above, embodiments of the present invention have been shown and described, but those skilled in the art will make various changes in form and detail without departing from the spirit and scope of the present embodiment as defined by the appended claims and equivalents thereto. You will understand that you can.

Optical film: 14, 20, 33, 640, 740, 840, 940
Base film: 14-1, 21, 33-2, 641, 741, 841, 941
Prism pattern layer: 14-2, 22, 33-1, 642, 742, 842, 942
Optical fingerprint recognition system: 60, 70, 80, 90
Infrared light source: 610, 710, 810, 910

Claims (13)

In the optical film for fingerprint recognition that transmits infrared (infrared),
Base film; And
Includes; a prism pattern layer adhered to one side of the base film,
The prism pattern layer,
A plurality of prisms are disposed parallel to each other at a predefined interval to form a line pattern that transmits the infrared rays, and the protruding directions of the plurality of prisms are disposed to face the light source,
The line pattern includes a plurality of flat lines having a predetermined interval as a width,
The interval of the line pattern is formed larger than the predefined interval in a region corresponding to the position of the fingerprint.
delete delete The method of claim 1,
The apex angle of the plurality of prisms,
0

Greater than 90

Smaller, optical film for fingerprint recognition.
The method of claim 1,
The cross section of the plurality of prisms is a triangular or trapezoidal, fingerprint recognition optical film.
The method of claim 5,
The triangle is an isosceles triangle, and the trapezoid is an isosceles trapezoid. Optical film for fingerprint recognition.
The method of claim 1,
The predefined spacing of the plurality of prisms,
Optical film for fingerprint recognition, set to 2μm, 4μm or 6μm.
The method of claim 1,
The base film and the prism pattern layer,
An optical film for fingerprint recognition, in which a plurality of through holes formed in the traveling direction of the infrared rays are disposed to transmit the infrared rays.
The method of claim 8,
An optical film for fingerprint recognition, with the longest distance between the two of the plurality of through holes set to a predefined distance.
The method of claim 8,
The plurality of through holes,
An optical film for fingerprint recognition, which is disposed in a region corresponding to the position of the fingerprint at predefined intervals.
The method of claim 1,
The base film,
An optical film for fingerprint recognition, which is a reflective polarization sheet that transmits one polarized light and reflects the other.
A backlight unit comprising the optical film for fingerprint recognition of any one of claims 1 and 4 to 11.
Liquid crystal display (LCD) panels; And
LCD device comprising a; the backlight unit according to claim 12 located under the LCD panel.

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