KR101103282B1 - Optical sheet, manufacturing method thereof, and backlight assembly using the same - Google Patents

Abstract

(i는 양의 정수)을 갖는다. 복수의 반사체는 본체 내에 위치하고 있으며, 서로 인접한 두 반사체 사이의 간격은 W, 각각의 반사체의 두께는 t이다. 각각의 프레넬 렌즈 유닛은 해당 출사면에 위치하고 있고 폭은 P이며, 각각의 프레넬 렌즈 유닛과 간격 W는 서로 대응되는 관계로, 수식

,

을 만족할 때 입사광은 간격 W를 통과한 후, 상기 프레넬 렌즈 유닛이 광로를 수렴하며 최적의 광학효과를 제공한다. 본 발명의 광학 박막 또는 본 광학 박막을 사용한 백라이트 모듈은 비교적 높은 광강도와 우수한 조준 성능을 제공할 수 있어서 광학성능을 한층 제고할 수 있다.The present invention relates to an optical field, and more particularly, to an optical thin film, a manufacturing method thereof, and a backlight module. The optical thin film is for receiving incident light projected by one light source, and includes one main body, a plurality of reflectors, and a plurality of Fresnel lens units. The body includes one incident surface and one exit surface, and has at least one refractive index

(i is a positive integer). The plurality of reflectors are located in the body, the spacing between two adjacent reflectors is W, and the thickness of each reflector is t. Each of the Fresnel lens units is located on the exit plane, the width is P, and the distance W between each Fresnel lens unit corresponds to each other,

,

The incident light passes through the interval W, and then the Fresnel lens unit converges the optical path to provide an optimal optical effect. The optical thin film of the present invention or the backlight module using the optical thin film can provide relatively high light intensity and excellent aiming performance, thereby further improving the optical performance.

Optical thin film, optical film, backlight module, Fresnel lens

Description

TECHNICAL FIELD [0001] The present invention relates to an optical thin film, a method of manufacturing the same and a backlight module using the optical thin film, a backlight module,

The present invention relates to an optical field, and more particularly, to an optical thin film, a manufacturing method thereof, and a backlight module.

The most commonly used direct-type backlight module is mainly used for large-sized LCD monitors. The most important feature of the direct-type backlight module is that the light source device is disposed directly below the optical thin film. 1 shows a direct-type backlight module of Taiwan Patent No. I264596. The direct-type backlight module 1 includes a frame 11, a light source device 12, a reflecting member 13, and a Fresnel lens 14, . 1, a light beam is emitted from the light source device 12, a part of the light is directly input to the Fresnel lens 14, a part of the light is reflected on the reflection member 13, and indirectly reflected by the Fresnel lens 14 do. The Fresnel lens 14 converges the optical path to provide the effect of condensing light, and the light beams incident on all the Fresnel lenses 14 are emitted from the exit surface 14A in parallel.

During the implementation of the present invention, the inventors have found that existing technologies have at least the following problems.

Since the angle at which the light beam is incident and the direction in which the light beam travels are not selected using the direct type backlight module 1 of the Fresnel lens 14, the light energy generated in the light source device 12 can not be utilized sufficiently, It is not possible to provide a uniform optical effect to the monitor.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in an effort to solve the above-mentioned problems, and it is an object of the present invention to provide a direct-type backlight module having a uniform optical effect to provide a directional optical path to a large LCD monitor.

In order to achieve the above object, an embodiment of the present invention provides an optical thin film, a manufacturing method thereof, and a backlight module.

(i는 양의 정수)를 갖는 하나의 본체와, 본체 내에 위치하여 서로 인접된 두 반사체 사이의 간격은 W, 각각의 반사체의 입사광이 입사하는 방향에 따른 두께는 t인 복수의 반사체와, 각각의 프레넬 렌즈 유닛이 상기 출사면에 위치하여, 상기 출사면의 방향에서 P의 두께를 가지며, 상호 대응되는 각각의 프레넬 렌즈 유닛과 상기 간격 W를 가지며, 수식

,

을 만족할 때 상기 입사광은 상기 간격 W를 통과하며 또한 상기 두께 t에 따라 상기 입사각을 조절하여 상기 입사광의 광로를 수렴하는 복수의 프레넬 렌즈 유닛을 포함한다.The optical thin film according to an embodiment of the present invention is for receiving one incident light projected by one light source and includes one incident surface and an exit surface corresponding to each other and having a certain incident angle with respect to the incident light for receiving the incident light At least one refractive index

(i is a positive integer), a plurality of reflectors positioned in the main body and spaced apart from each other by W, a thickness t along the direction in which the incident light of each reflector is incident, and The Fresnel lens unit having the thickness of P in the direction of the exit surface and having the interval W corresponding to each of the Fresnel lens units corresponding to each other,

,

The incident light passes through the interval W, and a plurality of Fresnel lens units converge the optical path of the incident light by adjusting the incident angle according to the thickness t.

In addition, in the optical thin film, the material of the body may be selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), triacetyl cellulose (TAC), polymethacrylate styrene (Polymethylmethacrylate styrene), polystyrene (PS), or cyclic olefin copolymer. In the present invention,

Each of the Fresnel lens units of the optical thin film includes a plurality of Fresnel lenses, each of the Fresnel lenses having a first vertex and a second vertex, The second vertex and the straight line have a constant height difference, and the height of the adjacent two second vertices are different from each other, but the adjacent vertexes are adjacent to each other, The first vertices of the two Fresnel lens units have the same height.

In the optical thin film, the ratio range of the interval W to the width P is 0.2 to 0.5.

Further, a distance between the exit surface of the optical thin film and the incident surface is T, and a ratio range of the distance T and the width P is 0.8 to 1.2.

According to an embodiment of the present invention, there is provided a method of manufacturing a cured optical thin film, comprising: forming a transparent substrate having one upper surface and one lower surface, one curing agent, one mold, and a plurality of reflectors; Applying the curing agent to the lower surface of the transparent substrate; Forming a plurality of Fresnel lens units corresponding to each other by depressing the curing agent in a plurality of patterns formed on a surface of the mold; Solidifying a plurality of Fresnel lens units on the curing agent; And connecting the plurality of reflectors to the lower surface of the transparent substrate.

In addition, in the above-mentioned method of curing an optical thin film, the curing agent is a UV curable resin or a thermal-plastic resin.

Further, in the method of manufacturing a cured optical thin film, the connection of the plurality of reflectors is connected by a bonding method or a screen printing method.

A method of producing an optical thin film by extrusion molding according to an embodiment of the present invention includes: forming a transparent substrate having one upper surface and one lower surface, one mold and a plurality of reflectors; Forming a plurality of Fresnel lens units corresponding to each other on the upper surface of the transparent substrate by pressing the transparent substrate with a plurality of patterns formed on a surface of the mold; And connecting the plurality of reflectors to the lower surface of the transparent substrate.

A backlight module according to an embodiment of the present invention includes a plurality of light source devices, one optical film and one optical thin film.

The plurality of light source devices are for forming one incident light.

And the optical film is located on the opposite side of the light source device corresponding to the optical thin film to correct the optical path of the incident light.

The optical thin film is for receiving incident light projected from a light source device, and includes a main body, a plurality of reflectors, and a plurality of Fresnel lens units.

(i는 양의 정수)을 갖는다.Wherein the main body includes one incident surface and an exit surface corresponding to each other and the incident surface is for receiving the incident light and has a constant incident angle with the incident light and the main body has at least one refractive index

(i is a positive integer).

The plurality of reflectors are located in the main body, the interval between two adjacent reflectors is W, and the thickness along the direction in which the incident light of each reflector is incident is t.

,

을 만족할 때 상기 입사광은 상기 간격 W를 통과하며, 또한 상기 두께 t에 따라 상기 입사각을 조절하여 복수의 프레넬 렌즈 유닛으로 상기 입사광의 광로를 수렴한다.Wherein each of the Fresnel lens units has a thickness of P in the direction of the exit surface, and each of the Fresnel lens units and the interval W, and the formula

,

The incident light passes through the interval W and the incident angle is adjusted according to the thickness t to converge the optical path of the incident light to the plurality of Fresnel lens units.

Accordingly, the beneficial effects of the technical solution provided by the embodiment of the present invention are as follows.

The optical thin film provided by the embodiment of the present invention or the backlight module using the present optical thin film can provide relatively high light intensity and excellent collimated ability, thereby further improving the optical performance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

2 is a view showing an embodiment of the optical thin film of the present invention. The optical thin film 24 is for receiving incident light, and changes the optical path of the incident light to provide a condensing effect. The optical thin film 24 includes a single body 241, a plurality of Fresnel lens units 242, and a plurality of reflectors 243.

(i는 양의 정수)을 가지며, 단일한 재료(이때 i=1) 혹은 임의의 두 가지 이상(이때 i>1)의 상이한 굴절률

을 가진 상이한 재료로 구성할 수 있다. The main body 241 includes one incident surface 241B and one exit surface 241A corresponding to each other and the incident surface 241B is for receiving incident light and incident light is incident on the incident surface 241B A certain angle of incidence is achieved. The body 241 has a refractive index

(where i is a positive integer) and a different refractive index of a single material (where i = 1) or any two or more (where i> 1)

With different materials.

Typical materials used are polyethylene terephthalate (PET), polycarbonate (PC), triacetyl cellulose (TAC), polymethylmethacrylate styrene, polystyrene , PS), or a cyclic olefin copolymer.

The Fresnel lens unit 242 is positioned on the exit surface 241A to provide a light converging effect, and the external structure of each Fresnel lens unit 242 is the same. Therefore, the combination of the plurality of Fresnel lens units 242 enables the optical thin film 24 in the embodiment of the present invention to be applied to a large LCD monitor.

As the material of the plurality of reflectors 243, a compound of titanium dioxide, silicon dioxide, or magnesium oxide may be used. The plurality of reflectors 243 are located on the incident surface 241B side of the main body 241 and there is a gap of W between the adjacent two reflectors 243. Each reflector 243 has t .

,

을 만족할 때, 광학 박막(24)은 수직시각 및 수평시각 상에서 균일한 광강도를 가진다.There is a gap of W between the exit surface 241A of the optical thin film 24 and the incident surface 241B and the width of P in the direction of the main body 241 of the Fresnel lens unit 242 exists. The incident angle of the light beam is adjusted according to the thickness t when the incident light passes between the plurality of reflectors 243, and the plurality of Fresnel lens units 242 converge the optical path of the incident light to achieve the object of convergence. Equation

,

The optical thin film 24 has a uniform light intensity on the vertical and horizontal viewing angles.

The structure of the Fresnel lens unit and the principle of light focusing will be described in more detail in order to more clearly understand the technical features of the optical thin film according to the present invention.

Referring to FIGS. 2 and 3A, FIG. 3A is a view showing a first embodiment of the Fresnel lens unit of the optical thin film of the present invention.

As shown in FIG. 3A, the Fresnel lens unit 242 is an astigmatic lens, and the optical action provides a condensing action like a normal convex lens, and its merit is that the Fresnel lens is made of a convex lens It is thin and light, and it is advantageous for installation and setting on mechanical structure.

The Fresnel lens unit 242 is composed of a plurality of Fresnel lenses 2421. The Fresnel lenses 2421 have different outlines and each Fresnel lens 2421 has one first vertex 2421A And includes a second vertex 2421B, and the two Fresnel lenses 2421 are located on both sides of the second vertex 2421B. The plurality of second vertices 2421B are arranged in the same straight line, and the first vertex 2421A has a constant height difference from the straight line, and the height of the adjacent first vertices 2421A is different from each other.

Each of the Fresnel lenses 2421 includes one first refracting surface 2421C and one second refracting surface 2421D and the first refracting surface 2421C and the second refracting surface 2421D have a A first angle (1) and a second angle (2).

Each Fresnel lens 2421 mainly focuses incident light on a plurality of first refracting surfaces 2421C and the first refracting surface 2421C refracts the incident light L1 to refract the light ray L1, And is incident perpendicular to the surface 241A.

The first refracting surface 2421C may be formed in a curved shape, but may be replaced with a planar shape for convenience of the process. The planar first refracting surface 2421C does not significantly affect the condensing function of the optical thin film 24. [

The second refracting surface 2421D 'of the Fresnel lens according to the related art is a vertical plane, and the second refracting surface 2421D' is represented by a dotted line. The second refracting surface 2421D ' The inclined second refracting surface 2421D 'is indicated by a solid line.

Since the incidence angle of the second refracting surface 2421D 'according to the related art is too large, the incident light L2 is totally reflected and the emitted light L2 does not reach the exit surface 241A, so that the light energy is wasted However, the second refracting surface 2421D of the present invention adjusts the angle of incidence to appropriately adjust the angle of incidence so that the light L3 incident in the same direction is emitted in a refracting manner and the light L3 is emitted perpendicularly to the exit surface 241A Allows light energy to be fully utilized.

The Fresnel lens unit 242 includes a plurality of Fresnel lenses 2421 distributed in different positions and the Fresnel lens 2421 has a different outer shape so that the size of the first angle 1 is smaller than the size .

As described above, the optical thin film according to the present invention improves the optical performance of the optical thin film according to the prior art by increasing the light intensity of the light. In order to demonstrate the effect of the embodiment of the present invention, various performance test tests have been conducted based on the structural characteristics of the optical thin film.

Referring to FIG. 5, FIG. 5 is a graph showing optical performance test results under different T / P conditions for an optical thin film according to an embodiment of the present invention. The ratio of the distance T to the width P of the Fresnel lens unit , Which shows the optical performance of an optical thin film under different parameter conditions.

In Fig. 5, the abscissa indicates a different time between -90 and +90 degrees, and the ordinate indicates a light intensity value. When the T / P value is 0.6, the optical intensity of the optical thin film is about 300 or more, and when the T / P value is 1.0, the optical intensity of the optical thin film is 500 or more. Through this performance test, it can be seen that the preferable range of the ratio of the distance T to the width P is 0.8 to 1.0.

Next, FIG. 6 is a graph showing the results of an optical performance test performed on the optical thin film according to the embodiment of the present invention under the conditions of different aperture ratios. The aperture ratio of the reflector (the spacing W between the reflectors and the Fresnel lens unit Width P) of the optical thin film, and shows the light intensity values for different times between -90 and +90 of the optical thin film.

As shown in FIG. 6, when using a conventional Brightness Enhancement Film (BEF), the light intensity is within 400 candle light, whereas in the performance test performed on the optical thin film of the present invention, The light intensity of the optical thin film reached 400 to 450 candle light exceeding the light intensity of the prism sheet according to the prior art when the aperture ratio (W / P value) was 0.2 to 0.5, and when the aperture ratio was 0.2, 600 candle light.

It can be seen from this performance test that the preferable range of the ratio of the interval W to the width P is 0.3 to 0.4.

Next, Fig. 7 is a diagram comparing the optical performance test results of the optical thin film of the Fresnel lens according to the embodiment of the present invention and the prism sheet according to the prior art. 7, the curve of the Fresnel lens represents simulation data of a general vertical second refracting surface, and the curve of the refracting Fresnel lens represents simulation data of an inclined second refracting surface.

As shown in FIG. 7, when the prism sheet according to the related art is used, the light intensity is 400 or less, whereas when the optical thin film of the Fresnel lens is used, the light intensity exceeds the prism sheet according to the prior art, The light intensity of the quadratic Fresnel lens of the second refracting surface reaches 600 candle light.

The physical data suggested by the simulation data of FIG. 7 is that the collimated ability of the optical thin film using the Fresnel lens is 10% to 30% higher than that of the prism sheet according to the prior art. The effect of the structural features of the present invention can be seen through this experiment.

Next, for the reflector, the angle at which the incident light enters at a thickness t is adjusted. The structural characteristics of the optical thin film of the present invention are defined by the following formulas.

,

,

When the structural characteristic of the optical thin film satisfies the above formula, the optical thin film of the present invention can obtain a comparatively good light intensity. The results of the optical performance test conducted with the experimental parameters satisfying the above equations are as shown in Fig. FIG. 8 is a diagram showing the results of optical performance tests conducted under conditions of different reflector thicknesses for optical thin films according to an embodiment of the present invention. FIG.

As can be seen from FIG. 8, the reflector satisfies the requirement of the equation when it is 20 to 500 μm (micrometer), and the optical intensity of the optical thin film reaches 450 to 500 candle light.

Finally, in order to demonstrate that the optical performance of the present invention is superior to that of the prism sheet according to the prior art, the optical energy emitted by the optical thin film of the present invention is divided into a vertical time and a horizontal time.

9 and 10, FIG. 9 is a graph comparing an optical performance test performed at a vertical time with respect to an optical thin film according to an embodiment of the present invention and a prism sheet according to a related art, and FIG. FIG. 5 is a graph comparing optical performance test results obtained at horizontal time with respect to the optical thin film according to the embodiment and the prism sheet according to the prior art.

As shown in FIGS. 9 and 10, the optical thin film of the embodiment of the present invention can obtain a relatively high light intensity at both the vertical and horizontal viewing angles, and the condensing power of the present invention is superior to the prism sheet according to the related art. Further, as shown in Fig. 10, the horizontal view of the present invention is wider than the prism sheet according to the prior art.

In addition, the backlight module using the optical thin film is disclosed to enable the technician of the present invention to clearly understand the application of the present invention.

Referring to FIGS. 2, 3A, and 4, FIG. 4 illustrates an embodiment of a backlight module using the optical thin film of the present invention. In Fig. 4, the same components as those in Fig. 2 and Fig. 3a will not be described in the structure and function.

As shown in Fig. 4, the backlight module 2 includes one frame 21, a plurality of light source devices 22, one light source foil 24, and one optical film 25.

The frame 21 is used to support the optical thin film 24 and accommodate the light source device 22. The light source device 22 may be a cold cathode fluorescent lamp (CCFL), a light emitting diode (LED), a flat fluorescent lamp (FFL), an external electrode fluorescent lamp (EEFL) ) Or a hot cathode fluorescent lamp (HCFL).

The light beam emitted from the light source device 22 is incident into the optical thin film 24 through the gap between the reflectors 243 and converged through the condensing of the Fresnel lens unit 242, And the optical path for the light beam is corrected in the optical film 25.

Next, another embodiment of the Fresnel lens unit of the optical thin film is disclosed.

3B is a view showing a second embodiment of the Fresnel lens unit of the optical thin film of the present invention.

As shown in FIG. 3B, the Fresnel lens unit 342 functions to condense light by using a Fresnel lens. The Fresnel lens unit 342 includes a plurality of Fresnel lenses 3421 and each of the Fresnel lenses 3421 has one first vertex 3421A and one second vertex 3421B, The lenses 3421 are located on both sides of the second vertex 3421B.

The plurality of second vertexes 3421A have substantially the same height and the second vertex 3421A has a constant height difference from the straight line.

The present embodiment can achieve the same function as the Fresnel lens unit 242 of the first embodiment in accordance with the above-described structure.

Next, a method for producing the curing of the optical thin film of the present invention will be introduced.

First, a transparent substrate having one upper surface and one lower surface, a curing agent, a single mold, and a plurality of reflectors are formed. The mold can be a roller mold or a flat mold. The curing agent is an ultraviolet curing agent UV curable resin or thermal-plastic resin.

Next, a curing agent is applied to the upper surface of the transparent substrate.

A plurality of Fresnel lens units corresponding to each other are formed by pressing the curing agent into a plurality of patterns formed on the surface of the mold.

Then, a plurality of Fresnel lens units on the curing agent are cured.

Finally, a plurality of reflectors are connected to the lower surface of the transparent substrate by a bonding method or a screen printing method to complete the production of the optical thin film.

The optical thin film may be manufactured by a process of extrusion molding an optical thin film by a person skilled in the art.

First, a transparent substrate having one upper surface and one lower surface, one metal mold, and a plurality of reflectors are formed.

Next, a plurality of Fresnel lens units corresponding to each other are formed on the upper surface of the transparent substrate by pressing the transparent substrate with a plurality of patterns formed on the surface of the mold.

Finally, a plurality of reflectors are connected to the lower surface of the transparent substrate to complete the fabrication of the optical thin film.

Although the preferred embodiments of the present invention have been described in detail, the technical scope of the present invention is not limited to the above-described embodiments, but should be construed according to the claims. It will be understood by those skilled in the art that many modifications and variations are possible without departing from the scope of the present invention.

1 is a diagram illustrating a direct type backlight module of Taiwan Patent No. I264596.

2 is a view showing an embodiment of the optical thin film of the present invention.

3A is a diagram showing a first embodiment of the Fresnel lens unit of the optical thin film of the present invention.

3B is a view showing a second embodiment of the Fresnel lens unit of the optical thin film of the present invention.

4 is a view showing an embodiment of a backlight module using the optical thin film of the present invention.

5 is a diagram showing optical performance test results performed under different T / P conditions for an optical thin film according to an embodiment of the present invention.

FIG. 6 is a diagram showing the optical performance test results performed under conditions of different aperture ratios for the optical thin film according to the embodiment of the present invention. FIG.

FIG. 7 is a chart comparing optical performance test results of an optical thin film of a Fresnel lens according to an embodiment of the present invention and a prism sheet according to the prior art.

8 is a diagram showing optical performance test results performed under conditions of different reflector thicknesses for an optical thin film according to an embodiment of the present invention.

9 is a graph comparing optical performance test results obtained at a vertical time with respect to an optical thin film according to an embodiment of the present invention and a prism sheet according to the prior art.

10 is a graph comparing optical performance test results obtained at a horizontal time with respect to an optical thin film according to an embodiment of the present invention and a prism sheet according to the prior art.

Description of the Related Art

1: direct type backlight module 12: light source device

14: Fresnel lens 2: Backlight module

22: Light source device 241:

241B: incident surface 2421: Fresnel lens

2421B: second vertex 2421D, 2421D ': second refractive surface

25: optical film? 2: second angle

342: Fresnel lens unit 3421A: First vertex

11: frame 13: reflective member

14A: emitting surface 21: frame

24: Optical thin film 241A: Outgoing surface

242: Fresnel lens unit 2421A: First vertex

2421C: first refracting surface 243: reflector

? 1: first angle L1, L2, L3:

3421: Fresnel lens 3421B: Second vertex

Claims (10)

And an incident surface and an exit surface corresponding to each other and having a constant incident angle with respect to the incident light, wherein at least one refractive index

(i is a positive integer); A plurality of reflectors positioned in the body and spaced apart from each other by two adjacent reflectors, W being a thickness along a direction in which incident light of each reflector is incident; And Each of the Fresnel lens units is located on the exit surface and has a width of P in the direction of the exit surface, the ratio range of the interval W to the width P is 0.2 to 0.5, Having the interval W,

,

Wherein the incident light has a plurality of Fresnel lens units that pass through the interval W and converge the optical path of the incident light by adjusting the incident angle according to the thickness t. The method according to claim 1, The material of the body may include any one or two or more materials selected from among polyethylene terephthalate, polycarbonate, cellulose triacetate, methyl methacrylate-styrene copolymer, polystyrene or cycloolefin copolymer . The method according to claim 1, Wherein each of the Fresnel lens units includes a plurality of Fresnel lenses, each of the Fresnel lenses has a first vertex and a second vertex, And the second vertex and the straight line have a constant height difference, and the height of the adjacent two second vertices are different from each other, and the height of the adjacent two Fresnel lenses Wherein the first vertex of the unit has the same height. delete The method according to claim 1, A distance between the exit surface and the incident surface is T, and a ratio of the distance T to the width P is 0.8 to 1.2. Forming a transparent substrate having one upper surface and one lower surface, one curing agent, one mold and a plurality of reflectors; Applying the curing agent to the lower surface of the transparent substrate; Forming a plurality of Fresnel lens units corresponding to each other by depressing the curing agent in a plurality of patterns formed on a surface of the mold; Solidifying a plurality of Fresnel lens units on the curing agent; And And connecting the plurality of reflectors to the lower surface of the transparent substrate. The method of claim 6, Wherein the curing agent is an ultraviolet curing agent or a thermosetting agent. The method of claim 6, Wherein the plurality of reflectors are connected by a bonding method or a screen printing method. Forming a transparent substrate having one upper surface and one lower surface, one mold and a plurality of reflectors; Forming a plurality of Fresnel lens units corresponding to each other on the upper surface of the transparent substrate by pressing the transparent substrate with a plurality of patterns formed on the surface of the mold; And And connecting the plurality of reflectors to the lower surface of the transparent substrate. A plurality of light source devices for generating incident light and one optical thin film for receiving the incident light projected from the plurality of light source devices, And an incident surface and an exit surface corresponding to the incident light and having a constant incident angle for receiving the incident light, wherein at least one refractive index

(i is a positive integer); A plurality of reflectors positioned in the body and spaced apart from each other by two adjacent reflectors, the thickness of which is t along the direction in which the incident light of each reflector is incident; Each of the Fresnel lens units is located on the exit surface and has a width of P in the direction of the exit surface, the ratio range of the interval W to the width P is 0.2 to 0.5, Having the interval W,

,

A plurality of Fresnel lens units that converge the optical path of the incident light by adjusting the incident angle according to the thickness t; And And an optical thin film which is positioned on the opposite side of the light source device corresponding to the optical thin film and comprises an optical film for correcting the optical path of the incident light.

Images