TWI491837B - Light guide plate for illumination and illuminating lamp - Google Patents

Description

Light guide plate and lighting fixture for lighting

The present invention relates to a light guide plate and a lighting fixture for illumination, and more particularly to a light guide plate for illumination having a plurality of concave microstructures of the same size and uniformly distributed, and a lighting fixture including the light guide plate for illumination.

The side-lighting light-emitting diode (LED) light guide plate has been developed into an important component of lighting fixtures. With the continuous promotion of lighting applications, the market demand for light-emitting diode light guide plates has become stricter, especially in the middle. The performance of large-sized lighting light guides (such as light uniformity, etc.) needs to meet market requirements. Referring to FIGS. 1 and 2, a part of a known lighting fixture is shown, which mainly comprises a light guide plate 1 and a plurality of light-emitting members 2 respectively disposed on the left and right sides of the light guide plate 1. The light guide plate 1 includes two left and right spaced and opposite light incident surfaces 11 , and an inner surface 12 and a light exit surface 13 connected between the light incident surfaces 11 and opposed to each other. Taking the printed light guide plate 1 as an example, a plurality of printed structures 14 arranged in an array may be formed by using a printed material containing a highly divergent light material, and the light is absorbed by the material of the printed structure 14 . Re-diffusion release properties, destroying the total reflection effect The internal light propagates so that the light entering the light guide plate 1 through the light incident surfaces 11 can be guided by the light exiting surface 13 and emitted from the light exit surface 13.

Since the light incident surface 11 on both sides of the light guide plate 1 is a portion where the light directly enters, the light intensity is strong, and the inner center of the light guide plate 1 gradually becomes farther away from the light incident surface 11 due to the distance from the light incident surface 11 . Therefore, the weaker the light intensity, in order to make the light guiding effect of the entire light guide plate 1 uniform, the distribution density of the plurality of printed structures 14 is not uniform, and the structure is not the same. The printed structure 14 near the light-incident surface 11 has a small distribution density and a small structural size; the distribution density of the printed structure 14 toward the center of the light guide plate 1 is larger and the structure size is larger, so as to achieve uniformity. The purpose of light guide.

In addition, there is a light-emitting diode (LED) light guide plate, which is a hemispherical shape microstructure formed on the inner surface of the light guide plate by using a transfer wheel transfer method, and the distribution density design of the hemispherical shape microstructures is substantially the same. The printing structure 14 of 1, 2 is similar, and is also designed to achieve uneven distribution of light for the purpose of uniform light guiding, but the disadvantage of the hemispherical shape microstructure is that the transfer rate of the microstructure is not good, and the light-emitting plate is exposed to the front. Poor brightness.

The applicant of the present invention solves the above-mentioned light guide effect of the light guide plate of the printed light guide plate or the hemispherical shape and the lack of uniformity of the light output light, and solves the microstructure distribution density and structure size of the printed structure 14 or the hemispherical shape. The design of complex changes, poor transfer rate, etc., so it is extremely necessary to find a solution.

Accordingly, it is an object of the present invention to provide an illumination light guide The special microstructure design of the board and the distribution of the microstructures can improve the light guide plate and the lighting fixture for the transfer rate of the microstructure formation and the uniformity of the light output of the light guide plate.

Therefore, the light guide plate for illumination according to the present invention includes: a light exit surface, an inner surface opposite to the light exit surface, at least one light incident surface connecting the light exit surface and the inner surface, and a plurality of concave shapes distributed on the inner surface microstructure. The cross-section of each concave microstructure is shaped as a quadrilateral comprising four curves, each concave microstructure having an opening on the inner surface.

Preferably, each concave microstructure is a quadrangular pyramid comprising four curved surfaces.

Preferably, the quadrangular pyramid including four curved surfaces of each concave microstructure has a width of 100 to 500 μm at the opening on the inner surface, and each concave microstructure has a depth of 20 to 100 μm. .

Preferably, the total area of the openings of the plurality of concave microstructures on the inner surface accounts for 5% to 53.6% of the inner surface area; more preferably 10% to 53.6%; optimally 12%. 53.6%.

Preferably, the plurality of concave microstructures are of the same size and uniformly distributed on the inner surface.

Preferably, the plurality of concave microstructures are of the same size and are densely distributed on the inner surface according to the distance from the light incident surface.

Preferably, each of the concave microstructures includes an end portion spaced apart from the four curved lines and adjacent to the light exiting surface with respect to the four curved lines; the light incident surface extends along a first direction, and the light incident surface The distance between the ends of the two adjacent concave microstructures in which the extending directions are parallel is L1, and the extending direction of the light incident surface The distance between the ends of the two adjacent concave microstructures is L2, L1 < L2, and L1/L2 = 0.15 to 0.90.

Preferably, the distance between the light incident surface and the end of the concave microstructure closest to the light is 1 mm to 20 mm.

Preferably, the illumination light guide plate has a width of 200 mm to 800 mm, a length of 200 mm to 1000 mm, and a thickness of 2 mm to 8 mm.

Preferably, the plurality of concave microstructures are formed on the inner surface by means of a transfer roller.

Preferably, the material of the light guide plate for illumination is a thermoplastic resin selected from the group consisting of acrylate resin, methacrylate resin, polystyrene resin, and polycarbonate. Ester resin, methyl methacrylate-styrene copolymer, acrylonitrile-styrene copolymer, and polyethylene terephthalate.

The lighting fixture of the present invention comprises: a light guide plate for illumination as described above, a light-emitting unit including a plurality of light-emitting diodes disposed on a light-incident surface of the light-guiding light guide plate, and an inner surface of the light guide plate disposed on the light guide plate for illumination The upper reflecting plate and a diffusing plate disposed below the light emitting surface of the lighting light guide plate.

The effect of the invention: by the special microstructure design of the light guide plate for illumination, the transfer rate of the concave microstructure is improved, and the special structure of the four curves of the concave microstructure is matched, so that the light of the light guide plate can be improved. The uniformity makes the illumination light of the lighting fixture uniform.

2‧‧‧Lighting board for lighting

21‧‧‧Into the glossy surface

22‧‧‧Glossy

23‧‧‧ inside

24‧‧‧ concave microstructure

241‧‧‧ Curve

242‧‧‧End

243‧‧‧ Surface

25‧‧‧First side

26‧‧‧Second side

27‧‧‧First line

28‧‧‧ second line

29‧‧‧Measurement points

3‧‧‧Lighting unit

31‧‧‧Lighting diode

4‧‧‧reflector

5‧‧‧Diffuser

61‧‧‧First direction

62‧‧‧second direction

7‧‧‧Transfer wheel

71‧‧‧90

72‧‧‧ convex microstructure

721‧‧‧ end face

722‧‧‧ first side

723‧‧‧ second side

73‧‧‧Axial direction

74‧‧‧Circumferential direction

81‧‧‧First back pressure roller

82‧‧‧Second back pressure roller

83‧‧‧Exit machine die

A, B‧‧‧

L1, L2, L3‧‧‧ distance

D1, d2, d3, d4‧‧‧ distance

W, W1, W2‧‧‧ width

T‧‧‧depth

H‧‧‧height

L‧‧‧ length

T‧‧‧ thickness

θ 1, θ 2‧‧‧ angle

Other features and effects of the present invention will be described with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a portion of an element of a known lighting fixture; FIG. 2 is a front view of FIG. 1; FIG. 3 is a perspective view of a first preferred embodiment of the lighting fixture of the present invention. FIG. 4 is a partial top plan view of a light guide plate for illumination and a light-emitting unit according to the first preferred embodiment; FIG. 5 is a partial perspective view of the light guide plate for illumination; FIG. 6 is a first preferred embodiment of the light guide plate. FIG. 7 is a partial perspective view of a transfer roller for rolling forming a plurality of concave microstructures of the illumination light guide plate; FIG. 8 is a cross-sectional view of the transfer roller along an axial direction a partial schematic view of the direction, and at the same time, the arrangement relationship of the plurality of convex microstructures in the axial direction; FIG. 9 is a partial schematic view of the transfer roller in a circumferential direction, and shows a plurality of convex microstructures along the circumference The arrangement relationship of the directions, in fact, the circumferential direction does not extend in a straight line, but FIG. 9 is drawn in an expanded manner for convenience of illustration; FIG. 10 is a schematic diagram of a wheel transfer device, and the wheel transfer device includes FIG. The transfer roller, and FIG. 10 illustrates the process of manufacturing the light guide plate for the illumination by the wheel transfer device; FIG. 11 is a schematic view of the light exiting portion of the lighting fixture of the present invention, and FIG. 11 is used for schematically measuring the light uniformity of the light fixture. How to obtain several measurement points in time; FIG. 12 is an illumination of a second preferred embodiment of the lighting fixture of the present invention FIG. 13 is a top plan view of a lighting light guide plate and a light emitting unit according to a third preferred embodiment of the lighting fixture of the present invention; and FIG. 14 is a cross section of the third preferred embodiment. See the schematic.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIGS. 3-6, a first preferred embodiment of the lighting fixture of the present invention comprises: a lighting light guide plate 2, a light emitting unit 3, a reflecting plate 4, and a diffusing plate 5. In this embodiment, the lighting direction of the lighting fixture is downward, but the implementation is not limited thereto, and may be changed depending on the application and the installation position.

The light guide plate 2 for illumination includes two light-incident surfaces 21 spaced apart from each other and opposed to each other, a light-emitting surface 22 and an inner surface 23 connected to each other between the light-incident surfaces 21, and a plurality of sizes And a concave microstructure 24 uniformly distributed on the inner surface 23. The light incident surfaces 21 of the present embodiment all extend in a first direction 61 and are spaced apart in a second direction 62 perpendicular to the first direction 61. Although the present embodiment provides two light-incident surfaces 21 for the light of the light-emitting unit 3 to be incident, the present invention may also be provided with only one light-incident surface 21, that is, at least one light-incident surface 21, in which case The light emitting unit 3 is completely disposed on one side of the illumination light guide plate 2. The light-emitting surface 22 of the present embodiment faces downward, and the inner surface 23 faces upward and is spaced upward and downward from the light-emitting surface 22.

The concave microstructures 24 of the embodiment are oriented from the inner surface 23 The direction of the light exit surface 22 is concave, and the shape of the cross section of each concave microstructure 24 is a quadrangle including four curves 241, that is, the four of each concave microstructure 24 are viewed from a top view. The curves 241 are arranged oppositely and vertically, and are connected to each other to form a quadrilateral. The four curves 241 are connected to the inner surface 23. The above-mentioned anterior-posterior two-curve curve may be an arc curve curved inward or outward, and the left and right opposite two-curve curves may also be arc curves curved inward or outward, and the curvature of the arc-shaped curve is not limited. The angle between the two ends of each curved curve to the line between the centers of the circles where the curved curve is located is θ 1 or θ 2 , preferably, 10° < θ 1 < 170 °, 10 ° < θ 2 < 170 °, more preferably, 30 ° < θ 1 < 150 °, 10 ° < θ 2 < 170 °. The cross-section of each of the concave microstructures 24 refers to a shape in which the concave microstructures 24 are transversely cut parallel to the inner surface 23 in a plan view.

Preferably, each of the concave microstructures 24 is a quadrangular pyramid structure including four curved surfaces, specifically including an end spaced apart from the four curved lines 241 and adjacent to the four curved lines 241 adjacent to the light exiting surface 22 The portion 242 and the four curved surfaces 243 connected between the curved line 241 and the end portion 242 are respectively four curved surfaces which are disposed in front, back, left and right and are connected to each other to constitute the four-corner cone. Since the area of the end portion 242 is actually the smallest, and the opening area of the plurality of concave microstructures 24 on the inner surface 23 is the largest, a structure including four quadrangular pyramids is formed. Each of the concave microstructures 24 of the present invention has an opening on the inner surface 23, the size and area of which corresponds to the oblique line area of one of the concave microstructures 24 of FIG. 4; it should be noted that the actual The upper end portions 242 are very small and are almost in the form of dots in a plan view. Component structure in each figure It is only an indication and does not represent the actual size ratio relationship.

The width W1 or W2 of each concave microstructure 24 at the opening on the inner surface 23 is 100 to 500 μm, and the depth t of each concave microstructure 24 is 20 to 50 μm. The width W1 or W2 of the quadrangular pyramid of the concave microstructure 24 on the inner surface 23 is the width of the quadrilateral of the concave microstructure close to the opening of the inner surface 23 and in contact with the inner surface 23; The depth t is the distance from the opening on the inner face 23 to the end 242. The curve design of the curved line 241 and the curved surface 243 of the present invention can generate an appropriate light guiding effect for the light rays from the respective directions, so that the light extraction efficiency can be improved to improve the light exiting from the light emitting surface 22. Light brightness.

Preferably, the total area of the openings of the plurality of concave microstructures 24 on the inner surface 23 occupies 5% to 53.6% of the area of the inner surface 23 (hereinafter referred to as the ratio of the opening area of the concave microstructures 24); The good land is 10%~53.6%; the best is 12%~53.6%. The open area of the concave microstructure 24 on the inner surface 23 refers to the area of the quadrilateral of the concave microstructure 24 which is close to the opening of the inner surface 23 and is in contact with the inner surface 23, and the inner surface 23 has the area The product of the width W of the light guide plate 2 for illumination and the length L. By the above definition, the concave microstructures 24 have an appropriate distribution density on the inner face 23, so that optimum light uniformity can be achieved.

The ratio of the opening area of the concave microstructures 24 is greater than 53.6%, which corresponds to the distribution density of the concave microstructures 24 being too high. When the density of the concave microstructures 24 is too high (the number of unit areas is too large), In the region of the light-incident surface 21 of the light guide plate 2 for illumination, there are more concave microstructures 24, so that the light of the light-emitting unit 3 enters through the light-incident surface 21 After the inside of the light guide plate 2 for illumination, the light is immediately guided by the optical effect of the concave microstructure 24 toward the light exit surface 22, so that the light guide plate 2 of the illumination is emitted near the left and right sides of the light exit surface 22. Stronger, and each of the light incident surfaces 21 is parallel to the second direction 62, and the light toward the center of the illumination light guide plate 2 becomes weaker and weaker, so that the light uniformity is lowered, and thus the open area ratio Do not be too high. On the other hand, if the ratio of the opening area of the concave microstructures 24 is less than 5%, it means that the distribution density of the concave microstructures 24 is low (the number of unit areas is small), which in turn causes the light guiding effect of the light guiding plate 2 for illumination to be changed. Poor, the amount of light that is derived is small, and the overall luminance is lowered. Therefore, preferably, the ratio of the opening area of the present invention must be controlled within a certain range.

The concave microstructures 24 of the present embodiment are the same size and evenly distributed on the inner surface 23 of the illumination light guide plate 2. The same size of the concave microstructures 24 means that each concave microstructure 24 is open on the inner surface 23. The width error does not exceed ±10% of the average width, and the depth error does not exceed ±10% of the average depth. The uniform distribution of the concave microstructures 24 on the inner surface 23 of the illumination light guide plate 2 means that the density of the concave microstructures 24 distributed on the inner surface 23 is substantially the same, and the concave microstructures 24 and the sides are not The distance to the light entrance surface 21 is far and near and there is an uneven distribution. The density of the concave microstructures 24 distributed on the inner surface 23 is how many concave microstructures 24 per mm ² area; the density of the concave microstructures 24 distributed on the inner surface 23 can be the plurality of concave shapes described above. The total area of the opening of the microstructures 24 on the inner face 23 is determined by the area of the inner face 23.

Preferably, in the concave microstructures 24, the light incident surface 21 Extending along the first direction 61, the distance between the end portions 242 of the two adjacent concave microstructures 24 parallel to the extending direction of the light incident surface 21 is L1, and two adjacent to the extending direction of the light incident surface 21 The distance of the end 242 of the concave microstructure 24 is L2. The distance between the ends 242 of any two adjacent concave microstructures 24 refers to the distance between the center point of the end 242 of one of the concave microstructures 24 and the center point of the end 242 of the other concave microstructure 24. Preferably, L1<L2, and L1/L2=0.15~0.75; when L1/L2 is greater than 0.75, after the light enters the inside of the illumination light guide plate 2, the light is immediately led out to the light exit surface 22 to obtain poor light. When L1/L2 is less than 0.15, the light is emitted from the light source plate 2 for illumination away from the light source, and the light extraction is poor.

Preferably, the distance L3 between each light incident surface 21 and the end portion 242 of the closest concave microstructure 24 is 1 mm to 20 mm. If the distance L3 is too small, the concave microstructure 24 is closer to the illumination light guide plate. After entering the light-guiding surface 2 of the light-emitting surface 2, the light is immediately received by the optical structure of the concave microstructure 24 and is led out toward the light-emitting surface 22, so that the light-guiding plate 2 for illumination is adjacent to the light-emitting surface 2 The light output from the left and right sides of 22 is strong, resulting in uneven light emission.

Preferably, the width W of the illumination light guide plate 2 (that is, the length extending along the second direction 62) is 200 mm to 400 mm, and the length L (that is, the length extending along the first direction 61) is 200 mm to 1000 mm. The thickness T (that is, the distance between the light exit surface 22 and the inner surface 23) is 2 mm to 8 mm.

The material of the light guide plate 2 for illumination is preferably a thermoplastic resin selected from the group consisting of acrylate resin, methacrylate resin, polystyrene resin, and polycarbon. An acid ester resin, a methyl methacrylate-styrene copolymer, an acrylonitrile-styrene copolymer, and polyethylene terephthalate. The above-mentioned acrylate-based resin is a polymer composed of an acrylate-based monomer, and the above-mentioned methacrylate-based resin is a polymer formed of a methacrylate-based monomer and an acrylate-based monomer. For example, polymethyl methacerylate (PMMA). The above acrylate monomer and methacrylate monomer include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid A monomer such as isopropyl ester, wherein a methyl methacrylate monomer and a methyl acrylate monomer are preferred.

The plurality of concave microstructures 24 of the present invention are formed on the inner surface 23 of the illumination light guide plate 2 by means of a transfer roller transfer. Referring to Figures 7, 8, and 9, there is shown a structure of a transfer roller 7 for molding the light guide plate for illumination of the present invention, wherein the wheel 71 of the transfer roller 7 has a plurality of spaced convex microstructures 72 thereon, and The distances d1 of the convex microstructures 72 along an axial direction 73 of the transfer roller 7 are the same, and the distances d2 of the convex microstructures 72 along a circumferential direction 74 about the axial direction 73 are the same. . Each of the convex microstructures 72 has a square end surface 721, two first side surfaces 722 connected to the end surface 721 and spaced along the axial direction 73, and two connected between the first side surfaces 722 and along The second side 723 is spaced apart in the circumferential direction 74. The sides of the end surface 721 have a side length of 5 to 20 μm , and the distance d3 of the first side surface 722 connected to the end of the wheel surface 71 is 40 to 80 μm , and the connection of the second side surfaces 723 The distance d4 of one end of the tread 71 is 40 to 80 μm ; the height h of the convex microstructure 72 is 30 to 70 μm .

Referring to Figures 5, 8, 9, and 10, when the concave microstructures 24 of the illumination light guide plate 2 are to be fabricated, a roller transfer device as shown in Fig. 10 is required. The roller transfer device has one of the above. a transfer roller 7 (not shown in FIG. 10 for simplicity, not showing the convex microstructure 72), a first back pressure roller 81 opposite to the transfer roller 7 and located at an upstream position and disposed in a gap, and a A second back pressure roller 82 disposed opposite to the transfer roller 7 and located at a downstream position and disposed in a gap. That is, the arrangement of the first back pressure roller 81, the transfer roller 7, and the second back pressure roller 82 is sequentially arranged. The temperature of the first back pressure roller 81 is 70 to 110 ° C, the temperature of the transfer roller 7 is 100 to 140 ° C, and the temperature of the second back pressure roller 82 is 100 to 140 ° C. The thermoplastic resin material of the light guide plate 2 for illumination is extruded into a molten resin through an extruder die 83, and the resin temperature is 210 to 240 °C. The molten resin is transferred by the above-mentioned roller transfer device, and the transfer roller 7 and the first back pressure roller 81 are relatively rolled, so that the transfer roller 7 is rolled and transferred, so that the illumination can be performed. The concave microstructures 24 corresponding to the convex microstructures 72 are formed by transfer on the inner surface 23 of the light guide plate 2. Referring to Figures 4, 8, and 9, wherein the distance d2 of the convex microstructures 72 substantially corresponds to the distance L1 on the illumination light guide plate 2, the aforementioned distance d1 of the convex microstructures 72 substantially corresponds to the distance The distance L2 on the light guide plate 2 for illumination. In addition, since the transfer roller 7 forms the concave microstructures 24 by means of rotational rolling on the softened illumination light guide plate 2, the concave microstructures 24 are formed with the curvatures. Curve 243 and curve 241.

Referring to FIGS. 3 and 6, the above-mentioned light-emitting unit 3 includes a plurality of light-emitting diodes 31, and the light-emitting diodes 31 are respectively disposed in groups. The light-emitting diodes 31 in each group are arranged along the first direction 61 on the side of the light-emitting surface 21. The light-emitting diodes 31 emit light to the light-incident surface 21, and the light of the light-emitting diodes 31 can enter the light-guiding plate 2 through the light-incident surface 21, and the concave micro-shapes The structure 24 can destroy the total reflection of the light inside the light guide plate, thereby causing the light to be emitted toward the light exit surface 22. Since only a single light incident surface 21 may be provided during the implementation of the present invention, only a plurality of light emitting diodes 31 may be provided on one side of one of the light incident surfaces 21.

The reflector 4 is disposed above the inner surface 23 of the illumination light guide plate 2, and is configured to reflect light passing through the light incident surface 21 and passing through the inner surface 23 toward the light exit surface 22, thereby contributing to Improve light utilization. The reflector 4 is preferably a reflector selected from the group consisting of a matte reflector or a holographic technique. The matte reflector is atomized on the reflective surface of the reflector 4, and the holographic reflector can be fabricated using a laser or embossed full image pattern.

The diffusing plate 5 described above is provided below the light-emitting surface 22 of the light-guiding light guide plate 2, and has a function of diffusing and diffusing light, thereby making the light-emitting luminance of the lamp uniform.

Referring to FIG. 11, the lighting fixture of the present invention can perform light uniformity measurement in a manner of measuring the light uniformity of the illumination fixture by taking out nine measurement points 29 and measuring each measurement point 29 respectively. The luminance value, the minimum luminance value of the nine measurement points 29 is Lmin, the maximum luminance value is Lmax, the light uniformity = (Lmin/Lmax) × 100%, and the closer the light uniformity is to 100%, the better the uniformity is. . And the nine measuring points 29 The method is as follows. It is assumed that the lengths of the two first side edges 25 of the lighting fixture are A, and the lengths of the other two second side edges 26 are B, and three of the first side edges 25 are parallel. The first line 27 arranged in front and rear, the first and the last two first lines 27 are respectively separated from the first side B/10, and the middle first line 27 is located on the two first sides Central of 25. In addition, three second lines 28 parallel to the second side edges 26 and arranged side by side are taken, and the leftmost and rightmost two second lines 28 are respectively separated from the second side A/10 by the distance, and the middle portion The second line 28 is located in the center of the two second side edges 26. The nine points respectively intersected by the three first lines 27 and the three second lines 28 are the above-mentioned nine measurement points 29.

Next, the efficacy of the present invention will be described by a specific embodiment of the present invention and a comparative example.

<Embodiment of the Invention>

A methyl methacrylate resin (manufactured by Chi Mei Industrial Co., Ltd., product name ACRYREX CM-205) was selected to extrude a molten resin through a die of the extruder, the resin temperature was 230 ° C, and the molten resin was rotated by a roller as shown in FIG. The writing device is characterized in that the temperature of the first back pressure roller 81 is 90 ° C, the temperature of the transfer roller 7 is 120 ° C, and the temperature of the second back pressure roller 82 is 120 ° C. The transfer roller 7 is constructed as shown in FIGS. 7, 8, and 9. The distance d1 of the convex microstructures 72 along the axial direction 73 of the transfer roller 7 is 400 μm ; the convex microstructures 72 are along The distance d2 in the circumferential direction 74 is 200 μm . The four sides of the end surface 721 have a side length of 14 μm , and the first side surface 722 has a one end distance d3 of 60 μm , and the second side surface 723 has a one end distance d4 of 60 μm ; The height h of the structure 72 is 50 μm .

The methacrylic resin is relatively rolled by the transfer roller 7 and the first back pressure roller 81, and can be transferred onto the methyl methacrylate resin to form a plurality of uniform and evenly distributed The concave microstructure is cooled to obtain the light guide plate for illumination, and the transfer surface is the inner surface of the light guide plate for illumination. Referring to Figures 3-6, the concave microstructure 24 on the inner surface 23 is a quadrangular pyramid having four curved surfaces, and the width W2 of the quadrangular pyramid of each concave microstructure 24 at the opening on the inner surface 23 is 260 μ m, W1 is 165 μm , depth t is 35 μm . On the inner surface 23, the distance L1 between two adjacent concave microstructures 24 parallel to the extending direction of the light incident surface 21 is 200 μm , and two adjacent concave shapes perpendicular to the extending direction of the light incident surface 21 The distance L2 of the microstructure 24 is 400 μm , and L1/L2 = 0.5. The distance L3 between the light incident surface 21 and the closest concave microstructure 24 is 10 mm; the illumination light guide 2 has a width W of 300 mm, a length L of 600 mm, and a thickness T of 3 mm. The transmissive microstructure of the illumination light guide plate 2 has a transmissive ratio of 70%, which is the height t of the concave microstructure 24 divided by the height h of the convex microstructure 72 of the transfer roller 7 (Fig. 8), multiplied by 100%, that is, (35 μm / 50 μm) × 100% = 70%; and the total area of the opening of the plurality of concave microstructures 24 on the inner surface 23 occupies the area of the inner surface 23 53.6% (the inner surface 23 area = W × L = 300 mm × 600 mm = 180,000 mm ² ). The lighting light guide plate 2, the light emitting diode 31, the reflecting plate 4, and the diffusing plate 5 are combined into a lighting fixture, and the light uniformity of the lighting fixture is measured (the measuring method is as described above and referred to FIG. 11). The light uniformity of the light is (Lmin/Lmax) × 100% = 80%.

<Comparative example>

The roller transfer device and the manufacturing method of the embodiment of the present invention differ in that the convex microstructure of the transfer roller has a hemispherical shape with a width of 270 μm and a height of 23 μm . After the transfer, a plurality of hemispherical concave microstructures are formed on the illumination light guide plate of the comparative example, and the concave microstructure of each hemispherical shape has an opening width of 270 μm on the inner surface of the light guide plate. With a depth of 8 μm , the transfer rate of the concave microstructure of the hemispherical shape was measured (8 μm / 23 μm) × 100% = 35%, and the transfer rate was rather low and worse than the present invention. The illumination light guide plate is combined with the light-emitting diode, the reflector, and the diffusion plate to form a lighting fixture, and the light uniformity of the illumination lamp is measured, and the uniformity of the light output is 58%, and the light uniformity is not good.

Referring to Figures 4, 5 and 6, in summary, by the special microstructure design of the light guide plate 2 for illumination, the transfer rate of the concave microstructures 24 is increased to match the four curves 241 of the concave microstructures 24. The design improves the uniformity of the light output of the light guide plate 2 for illumination, so that the purpose of uniform light guiding can be achieved, and the illumination light of the lighting fixture is uniform. Furthermore, if the proportion of the appropriate opening area of the concave microstructure 24 on the inner surface 23 is further matched, it is more advantageous for the uniformity of light.

Referring to FIG. 12, a second preferred embodiment of the lighting fixture of the present invention is substantially the same as the structure of the first preferred embodiment, except that each of the plurality of concave microstructures in the same row of the embodiment is 24, the position of the plurality of concave microstructures 24 adjacent to another row in a staggered configuration.

Referring to Figures 13 and 14, a third preferred embodiment of the lighting fixture of the present invention is substantially the same as the structure of the first preferred embodiment, except that the plurality of illumination light guides 2 of the present embodiment are The concave microstructures 24 are densely distributed according to the distance from the light incident surfaces 21 Inside surface 23. Therefore, the closer to the left and right sides of the illumination light guide plate 2 of the present embodiment, the more the distribution of the concave microstructures 24; the more dense the distribution of the concave microstructures 24 at the center. That is, the concave microstructures 24 of the present embodiment have a gradual density distribution in a distribution parallel to the second direction 62.

The distance between two adjacent concave microstructures 24 parallel to the extending direction of the light incident surface 21 is L1, and the distance between two adjacent concave microstructures 24 perpendicular to the extending direction of the light incident surface 21 is L2. And L2 is a gradation distance, preferably, L1/L2=0.15~0.90, which can achieve better light extraction performance. The width W1 or W2 of each concave microstructure 24 at the opening on the inner surface 23 is 100 to 500 μm, and the depth t of each concave microstructure 24 is 20 to 100 μm.

Preferably, the total area of the openings of the plurality of concave microstructures 24 on the inner surface 23 of the embodiment is 5% to 53.6% of the area of the inner surface 23; more preferably 10% to 53.6%; The good land is 12%~53.6%.

Preferably, the illumination light guide plate 2 of the present embodiment has a width W of 200 mm to 800 mm, a length L of 200 mm to 1000 mm, and a thickness T of 2 mm to 8 mm.

<Specific embodiment of the gradation density of the present invention>

A methyl methacrylate resin (manufactured by Chi Mei Industrial Co., Ltd., product name ACRYREX CM-205) was selected to extrude a molten resin through a die of the extruder, the resin temperature was 230 ° C, and the molten resin was rotated by a roller as shown in FIG. The writing device is characterized in that the temperature of the first back pressure roller 81 is 90 ° C, the temperature of the transfer roller 7 is 120 ° C, and the temperature of the second back pressure roller 82 is 120 ° C. The transfer roller 7 is configured as shown in FIGS. 7, 8, and 9. The distance d1 of the convex microstructures 72 along the axial direction 73 of the transfer roller 7 is a gradation distance, and d1 can be 240 to 930 μm . It should be noted that although FIG. 7 does not indicate the arrangement of the convex microstructures 72 along the axial direction 73, in practice, the concave microstructures for forming the gradation arrangement density of the embodiment are actually formed. 24 (Fig. 13), the structural arrangement design of the transfer roller 7 must be changed, and the arrangement of the convex microstructures 72 in the axial direction 73 is adjusted to a distance-graded arrangement; the convex microstructures 72 The distance d2 along the circumferential direction 74 is 200 μm . The four sides of the end surface 721 have a side length of 13 μm , and the first side surface 722 has a distance d3 of 106 μm , and the second side 723 has a distance d4 of 106 μm . The height h of the structure 72 is 100 μm .

The methacrylic resin is relatively rolled by the transfer roller 7 and the first back pressure roller 81, and can be transferred onto the methyl methacrylate resin to form a plurality of sizes and according to The farther away from the entrance surface, the more densely distributed concave microstructure is formed, and after cooling, the illumination light guide plate is obtained, and the transfer surface is the inner surface of the illumination light guide plate. Referring to Figures 13 and 14, the concave microstructure 24 on the inner surface 23 is a quadrangular pyramid having four curved surfaces, and the width W2 of the quadrangular pyramid of each concave microstructure 24 at the opening on the inner surface 23 is 290 μ m, W1 is 185 μm , and depth t is 72 μm . On the inner surface 23, the distance L1 between two adjacent concave microstructures 24 parallel to the extending direction of the light incident surface 21 is 300 μm , and two adjacent concave shapes perpendicular to the extending direction of the light incident surface 21 The distance L2 of the microstructure 24 is a gradual distance, and L2 can be 340 to 1030 μm . The distance L3 between the light incident surface 21 and the closest concave microstructure 24 is 10 mm; the illumination light guide 2 has a width W of 600 mm, a length L of 600 mm, and a thickness T of 4 mm. The transmissive microstructure of the illumination light guide plate 2 has a transmissive ratio of 72%, which is the height t of the concave microstructure 24 divided by the height h of the convex microstructure 72 of the transfer roller 7 (Fig. 8), multiplied by 100%, that is, (72 μ m / 100 μ m) × 100% = 72%; and the total area of the openings of the plurality of concave microstructures 24 on the inner surface 23 35.0% of the area of the inner surface 23 (the area of the inner surface 23 = W × L = 600 mm × 600 mm = 360,000 mm ² ). The lighting light guide plate 2, the light emitting diode 31, the reflecting plate 4, and the diffusing plate 5 are combined into a lighting fixture, and the light uniformity of the lighting fixture is measured (the measuring method is as described above and referred to FIG. 11). The light uniformity of the light is (Lmin/Lmax) × 100% = 75%. Therefore, this embodiment can also improve the uniformity of light.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

2‧‧‧Lighting board for lighting

22‧‧‧Glossy

23‧‧‧ inside

24‧‧‧ concave microstructure

241‧‧‧ Curve

242‧‧‧End

243‧‧‧ Surface

61‧‧‧First direction

62‧‧‧second direction

Claims (14)

A light guide plate for illumination, comprising: a light emitting surface, an inner surface opposite to the light emitting surface, at least one light incident surface connecting the light emitting surface and the inner surface, and a plurality of concave microstructures distributed on the inner surface, The cross-section of each concave microstructure is shaped as a quadrilateral comprising four curves, each concave microstructure having an opening on the inner surface. The light guide plate for illumination according to claim 1, wherein each of the concave microstructures is a quadrangular pyramid including four curved surfaces. The light guide plate for illumination according to claim 2, wherein the quadrangular pyramid including four curved surfaces of each concave microstructure has a width of 100 to 500 μm at the opening on the inner surface, and each concave microstructure The depth is 20~100μm. The light guide plate for illumination according to claim 1, wherein the total area of the openings of the plurality of concave microstructures on the inner surface accounts for 5% to 53.6% of the inner surface area. The light guide plate for illumination according to claim 4, wherein the total area of the openings of the plurality of concave microstructures on the inner surface accounts for 10% to 53.6% of the inner surface area. The light guide plate for illumination according to claim 5, wherein the total area of the openings of the plurality of concave microstructures on the inner surface accounts for 12% to 53.6% of the inner surface area. The light guide plate for illumination according to claim 1, wherein the plurality of concave microstructures are of the same size and uniformly distributed on the inner surface. The light guide plate for illumination according to claim 1, wherein the plurality of concave microstructures are of the same size and are densely distributed on the inner surface according to a distance from the light incident surface. The light guide plate for illumination according to claim 1, wherein each of the concave microstructures includes an end portion spaced apart from the four curved lines and adjacent to the light exiting surface with respect to the four curved lines; the light incident surface is along a first Extending in one direction, the distance between the ends of two adjacent concave microstructures parallel to the extending direction of the light incident surface is L1, and the ends of two adjacent concave microstructures perpendicular to the extending direction of the light incident surface The distance is L2, L1 < L2, and L1/L2 = 0.15 to 0.90. The light guide plate for illumination according to claim 1, wherein the light guide plate for illumination has a width of 200 mm to 800 mm, a length of 200 mm to 1000 mm, and a thickness of 2 mm to 8 mm. The light guide plate for illumination according to claim 1, wherein each of the concave microstructures includes an end portion spaced apart from the four curved lines and adjacent to the light exiting surface with respect to the four curved lines; the light incident surface is closest to the distance The distance between the ends of the concave microstructure is 1 mm to 20 mm. The light guide plate for illumination according to claim 1, wherein the plurality of concave microstructures are formed on the inner surface by means of a transfer roller. The light guide plate for illumination according to claim 1, wherein the material of the light guide plate for illumination is a thermoplastic resin, and the thermoplastic resin is selected from the group consisting of acrylate resins and methacrylates. Resin, polystyrene resin, polycarbonate resin, methyl methacrylate-styrene copolymer, acrylonitrile-styrene copolymer, and polyethylene terephthalate. A lighting fixture comprising: the light guide plate for illumination according to any one of claims 1 to 13; a light-emitting unit comprising a plurality of light-emitting diodes disposed on a light-incident surface of the light guide plate for illumination; The reflector is disposed above the inner surface of the illumination light guide plate, and a diffusion plate is disposed below the light exit surface of the illumination light guide plate.