JP6003333B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device that diffuses light from a light source unit by a light diffuser.

2. Description of the Related Art In recent years, with increasing interest in environmental problems, lighting devices that use light-emitting diode light sources as light sources are rapidly spreading because of their power saving and long life. The light emitted from the light-emitting diode light source has high straightness and hardly diffuses. Therefore, an illumination device using a light-emitting diode light source usually includes a light diffuser.
Illumination devices using light emitting diode light sources include, for example, a long light source unit in which a plurality of light emitting diode light sources are arranged in a line, and a tube-shaped light diffuser disposed on the light emitting side of the light source unit And the light diffuser has a concavo-convex pattern in which the concavo-convex repeats along the circumferential direction (Patent Document 1). The light source unit and the light diffuser in this lighting device are arranged so that the longitudinal direction of the light source unit and the repetition direction of the unevenness of the light diffuser are orthogonal to improve the light diffusibility in the short direction of the lighting device. The directivity is reduced.

JP 2010-225567 A

However, since the light diffuser in Patent Document 1 diffuses light only in the concave and convex repeat direction, the light diffusibility in the direction orthogonal to the concave and convex repeat direction is insufficient. For this reason, in the illumination device described in Patent Document 1, the light from the light-emitting diode light source that has passed through the light diffuser is in an extremely thin line shape in which the light is concentrated in a certain diffusion direction.
In view of this, the applicant of the present application has disclosed in Japanese Patent Application No. 2011-242164 (hereinafter referred to as “Prior Application 1”) two light diffusers having a concavo-convex pattern in which the concavo-convex pattern repeats along one direction so that the concavo-convex direction is different. We proposed a lighting device to be used over and over. In this lighting device, one of the two light diffusers (described as “second uneven pattern forming sheet” in the prior application 1) has an uneven pitch of 1 to 30 μm. Was necessary.
In order to reduce the cost of the lighting device of the prior application 1, the present inventors described the other light diffuser combined with the second uneven pattern forming sheet (in the prior application 1, “first uneven pattern forming sheet”). The pitch of the concavo-convex pitch of the above was studied to make the pitch suitable for mass production and easy to extrusion, specifically 200 to 2000 μm.
However, when the uneven pitch of the first uneven pattern forming sheet is 200 to 2000 μm, the invisibility of the light-emitting diode light source through the light diffuser tends to decrease. In addition, the light from the light source unit may be a plurality of streaky light (bright lines) along the longitudinal direction of the light source unit, and may be unevenly emitted in the short direction.

  The present invention suppresses each light-emitting diode light source from being viewed in the form of dots, and is excellent in light diffusibility and light uniformity in the short direction of the light source unit, and can be reduced in cost. The purpose is to provide.

The illuminating device of the present invention is an illuminating device including a light source unit in which a plurality of light-emitting diode light sources are linearly arranged, and a light diffuser provided on the light emitting side of the light source unit. A wavy first concavo-convex pattern in which the concavo-convex repeats at a constant pitch along a direction in a range of ± 20 ° with respect to a direction orthogonal to the longitudinal direction of the light source unit, and the concavo-convex form with respect to the longitudinal direction of the light source unit And an irregular second concavo-convex pattern that repeats along the direction of the range of ± 20 ° and the pitch of adjacent convex portions varies , and the first concavo-convex pattern is the most frequent pitch of the concavo-convex pattern. A ₁ is 200 to 2000 μm, the ratio (B ₁ / A ₁ ) of the average depth B ₁ of the unevenness to the most frequent pitch A ₁ is 0.05 to 0.4, and the second uneven pattern is the first Light than uneven pattern Is arranged on the unit side, projection end of the second uneven patterns is directed to the opposite side of the light source unit, 30 [mu] m beyond the modal pitch A ₂ is 1.0μm concavo-convex pattern following the irregularities with respect to the modal pitch A ₂ the ratio of the average depth _{B 2 (B 2 / a 2} ) is 0.1 to 3.0.
In the illumination device of the present invention, a cover for protecting the light source unit may be provided on the light emission side of the light source unit, and the first uneven pattern may be formed on the cover.

  The illuminating device of the present invention suppresses each light emitting diode light source from being viewed in the form of dots, and is excellent in light diffusibility and light uniformity in the short direction of the light source unit, and at low cost. it can.

It is a figure which shows typically the cross section of one Embodiment of the illuminating device of this invention. It is a perspective view which expands and shows the 1st uneven | corrugated pattern of the uneven | corrugated pattern formation body which comprises the illuminating device of FIG. It is a perspective view which expands and shows the 2nd uneven | corrugated pattern of the uneven | corrugated pattern formation body which comprises the illuminating device of FIG.

An embodiment of the lighting device of the present invention will be described.
In FIG. 1, sectional drawing of the illuminating device of this embodiment is shown. The illumination device 1 according to the present embodiment includes a light source unit 10 and a light diffuser 20 provided on the light emission side of the light source unit 10.

<Light source unit>
The light source unit used in the present invention has a plurality of light emitting diode light sources arranged in a line. The light source unit 10 used in the present embodiment is a unit in which a plurality of light emitting diode light sources 11, 11,. Each light-emitting diode light source 11 is fixed to the support 12 and may be a shell type, a surface mount type, or a chip-on-board type.
The interval between the adjacent light emitting diode light sources 11 and 11 is preferably 1 to 100 mm, although it depends on the light emission intensity of the light emitting diode light source 11. If the distance between adjacent light emitting diode light sources 11 and 11 is equal to or less than the upper limit value, the illuminance in the longitudinal direction of the light source unit 10 can be easily made uniform. However, if the interval between the adjacent light-emitting diode light sources 11 and 11 is less than the lower limit value, the number of the light-emitting diode light sources 11 increases, resulting in high cost.
There is no restriction | limiting in particular as a material of the support body 12, Resin, a metal, etc. can be used suitably. The surface 12a on the light diffuser 20 side of the support 12 is preferably made of a metal mirror surface or a white reflective surface and has light reflectivity, since the light use efficiency becomes high.
In the present specification, the longitudinal direction of the light source unit 10 (the horizontal direction in FIG. 1) is referred to as the “X direction”. A direction parallel to the light source unit 10 and orthogonal to the X direction (a direction orthogonal to the paper surface in FIG. 1) is referred to as a “Y direction”. A direction (vertical direction in FIG. 1) perpendicular to the light source unit 10 and perpendicular to the X direction is referred to as a “Z direction”.

<Light diffuser>
The light diffusing body 20 used in the present embodiment includes a transparent first uneven pattern forming body 21 disposed on the light emitting side of the lighting device 1 and a transparent second uneven surface disposed on the light source unit 10 side. Pattern forming body 22.
The first concavo-convex pattern forming body 21 includes the first concavo-convex pattern 21 a on the surface on the light source unit 10 side, and the second concavo-convex pattern forming body 22 is on the surface opposite to the light source unit 10. 22a.

(First uneven pattern)
The first concavo-convex pattern 21a is a wave-shaped pattern in which the concavo-convex portions (concave portion 21c and convex portion 21b) are repeatedly repeated along a direction in a range of ± 20 ° with respect to the Y direction. The height direction of the convex portion 21b (or the depth direction of the concave portion 21c) is along the Z direction. In addition, the first uneven pattern 21a has a substantially semicircular shape in which the convex portion 21b is highest at the center in the width direction, and the ridge line is linear. Therefore, the first uneven pattern 21a is a lenticular lens-like pattern (see FIG. 2).
The unevenness of the first uneven pattern 21a is preferably repeated along a direction in a range of ± 10 ° with respect to the Y direction, and more preferably repeated along a direction in a range of ± 5 ° with respect to the Y direction. It is particularly preferred to repeat along the Y direction. When the unevenness of the first uneven pattern 21a is repeated along the direction in a range exceeding the above range, the light diffusibility in the short direction or the uniformity of light in the short direction of the light source unit 10 may be impaired.

[Frequent pitch]
The most frequent pitch A1 of the _first uneven pattern 21a is 200 to 2000 μm, preferably 200 to 1500 μm, and more preferably 200 to 1000 μm. If the modal pitch A ₁ is below the lower limit tends to become difficult to form a concave-convex by extrusion, if more than the upper limit, diffusion of light in the lateral direction of the light source unit 10 is reduced Tend.

The most frequent pitch A ₁ is a value obtained from an expression of 1 / {√ (α _F1max ² + β _F1max ² )}.
Specifically, the modal pitch A ₁ is determined by the following method.
First, the upper surface and cross section of the first uneven pattern 21a are observed with an optical microscope. Subsequently, after converting the image of the concavo-convex structure obtained by microscopic observation into a gray scale image, two-dimensional Fourier transform is performed. The frequency (γ _F1 ) of the Fourier transform image is _smoothed , and the position (α _F1max , β _F1max ) indicating the maximum frequency is obtained from the obtained graph other than the central portion of the Fourier transform image. Then, a pitch _{A 1} modal formulas of the modal pitch _{A 1 = 1 / {√ (} α F1max 2 + β F1max 2)}.
Note that the most frequent pitch A1 of the _first concavo-convex pattern 21a may be regarded as an average value of each pitch when the uniformity of the pitch is high. The average pitch can also be obtained from an average value of 10 or more randomly extracted pitches from the cross-sectional view obtained from the microscope image, where the horizontal interval between adjacent concave portions is defined as the pitch.

[Orientation]
It is preferable that the pitch between the adjacent convex portions 21b and 21b in the first concave / convex pattern 21a is small and constant because the uniformity of light diffusion is further improved.
Here, the degree of variation in the uneven pitch is called the degree of orientation. The smaller the degree of orientation, the more uniform the pitch of the unevenness, and the larger the degree of orientation, the more uneven the pitch of the unevenness.

The degree of orientation C ₁ of the first uneven pattern 21a is preferably less than 0.1, preferably 0.05 or less, and preferably 0.01 or less. If the degree of orientation C ₁ is less than the upper limit value, the applicability of extrusion in the production of the first uneven patterns forming body 21 becomes higher.

Orientation degree C ₁ is determined by the following method.
First, a Fourier transform image obtained by obtaining the most frequent pitch A ₁ is used to create a Fourier transform image rotated by θ so that the maximum illuminance portion coincides with the α _F1 axis. Next, a parallel auxiliary line β ′ _F1 is drawn on the β _F1 axis passing through (α _F1max , β _F1max ), the auxiliary line β ′ _F1 is taken as the horizontal axis, and the illuminance (γ _F1 axis) on the auxiliary line β ′ _F1 is taken as the vertical axis. A β ′ _F1- γ _F1 diagram is created. Next, a β ″ _F1− γ _F1 diagram is created by dividing the value of the β ′ _F1 axis of the β ′ _F1− γ _F1 diagram by the reciprocal (1 / A ₁ ) of the most frequent pitch A ₁ , and this β ″ _F1 −γ The half width W of the peak (the width of the peak at a height at which the frequency is half the maximum value) is obtained from the _F1 diagram. The half-width represents the degree of orientation C _1.

[aspect ratio]
The ratio (B ₁ / A ₁ , that is, “aspect ratio”) of the average depth B ₁ of the unevenness to the most frequent pitch A ₁ in the first uneven pattern 21 a is 0.05 to 0.4, 0.07 to It is preferably 0.25, and more preferably 0.08 to 0.22.
When (B ₁ / A ₁ ) is less than the lower limit value, the light diffusibility in the short direction of the light source unit 10 tends to decrease, and when the upper limit value is exceeded, the light-emitting diode light source 11 is visible in a dot shape. In addition, the uniformity of light in the short direction of the light source unit 10 tends to be low. In particular, when the aspect ratio is high, the diffusibility in the short direction increases, but when a molded body is obtained by an extrusion molding method, the shape is likely to be disturbed and bright lines may be emitted.

Average depth B ₁ of the first uneven patterns 21a means that the average depth to the bottom of the recess 21c from the peak of the convex portion 21b of the first uneven patterns 21a. Average depth B ₁ represents determined as follows. That is, the first concavo-convex pattern 21a is observed with a microscope, and a cross-sectional view cut along the Y-axis direction is obtained from the observation. The depth to the bottom of one concave portion 21c is ½ of the sum of the distances in the Z direction from the peaks of the two adjacent convex portions 21b and 21b to the bottom of the concave portion 21c. That is, one depth _{b i} of the bottom of the recess 21c is the depth _{L i} of the bottom of the recess 21c as measured from the peak of one side of the projecting portion 21b with respect to the recess 21c, the peak of the other side of the protrusion 21b B _i = (L _i + R _i ) / 2 where R _i is the bottom depth of the recess 21c measured from the above. 10 the average value of the depth b _i of each recess 21c thus determined is the average depth B _1, since it is not realistic to determine the depth of all the concave portions 21c, which is randomly The average depth B ₁ is obtained from the above b _i .

[Material]
The 1st uneven | corrugated pattern formation body 21 may be formed by 1 layer, and may be formed by 2 layers.
When the 1st uneven | corrugated pattern formation body 21 is comprised by 1 layer, it is preferable to comprise with transparent resin. The transparent resin may be a thermoplastic resin or a thermosetting resin (thermosetting prepolymer or monomer cured product). Examples of the thermoplastic resin include acrylic resin, polyolefin, polyester, and polycarbonate. Examples of thermosetting prepolymers include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl / acrylate, polyene / acrylate, silicone acrylate, polybutadiene, and polystyrylmethyl methacrylate. It is done. Examples of the thermosetting monomer include aliphatic acrylate, alicyclic acrylate, aromatic acrylate, hydroxyl group-containing acrylate, allyl group-containing acrylate, glycidyl group-containing acrylate, carboxy group-containing acrylate, and halogen-containing acrylate.
As a method for manufacturing the first concave / convex pattern forming body 21 composed of one layer, a method of extruding a transparent resin using an opening die so that the first concave / convex pattern 21a is formed (extrusion molding method). ), A method of transferring a metal roll on which a concavo-convex pattern has been formed by cutting or the like to a transparent resin as a mold (transfer method), and the like. The extrusion method is preferable because it is suitable for mass production.
When the first concavo-convex pattern formed body 21 is composed of two layers, the surface of the concavo-convex pattern formed body composed of the one layer on which the first concavo-convex pattern 21a is not formed is polyethylene terephthalate, A substrate made of a polymer such as polymethyl methacrylate is laminated.

The first concavo-convex pattern forming body 21 includes a light diffusing agent such as an inorganic light diffusing agent composed of an inorganic compound and an organic light diffusing agent composed of an organic compound within a range that does not significantly impair optical performance such as light transmittance. It is preferable. When these light diffusing materials are included, the light diffusing effect is further enhanced, and the light-emitting diode light source can be further suppressed from being suppressed in a dot shape.
Examples of the inorganic light diffusing agent include silica, white carbon, talc, magnesium oxide, zinc oxide, titanium oxide, calcium carbonate, aluminum hydroxide, barium sulfate, glass, mica and the like.
Examples of the organic light diffusing agent include styrene polymer particles, acrylic polymer particles, and siloxane polymer particles. These light diffusing agents can be used alone or in combination of two or more.
The content of the light diffusing agent is preferably 10 parts by mass or less with respect to 100 parts by mass of the resin constituting the first concavo-convex pattern forming body 21 because the light transmittance is hardly impaired.

Usually, a cover for protecting the light source unit 10 is provided on the light emitting side of the light source unit 10. The cover itself may be used as the first uneven pattern forming body 21, and the first uneven pattern 21a may be formed on the cover. When the most frequent pitch A1 of the _first concavo-convex pattern 21a is in the above range, extrusion molding is easy. Therefore, the first concavo-convex pattern 21a can be formed simultaneously with the production of the cover by extrusion molding. Thereby, the operation | work which combines the 1st uneven | corrugated pattern formation body 21 with the 2nd uneven | corrugated pattern formation body 22 becomes easy.
When the cover itself is the first concavo-convex pattern forming body 21, the material is preferably acrylic resin, polycarbonate, or polystyrene.
The thickness of the cover is preferably 0.5 to 3 mm, and more preferably 0.7 to 2.0 mm. If the cover thickness is equal to or greater than the lower limit value, the first uneven pattern 21a can be prevented from being seen through, and if the cover thickness is equal to or less than the upper limit value, sufficient light transmittance can be ensured.

(Second uneven pattern)
The second concavo-convex pattern 22a is a wave-shaped pattern in which the concavo-convex portions (concave portion 22c and convex portion 22b) are repeated along a direction in a range of ± 20 ° with respect to the X direction (see FIG. 3). The tip of the convex portion 22b is rounded, and the height direction of the convex portion 22b (or the depth direction of the concave portion 22c) is along the Z direction.
The unevenness of the second uneven pattern 22a is preferably repeated along a direction within a range of ± 10 ° with respect to the X direction, and more preferably repeated along a direction within a range of ± 5 ° with respect to the X direction. It is particularly preferred to repeat along the X direction. In the second concavo-convex pattern 22a, when the concavo-convex is repeated along the direction of the range exceeding the range, the light diffusibility in the longitudinal direction of the light source unit 10 or the uniformity of light in the longitudinal direction may be impaired.
In addition, the repeating direction of the second uneven pattern 22a preferably intersects the repeating direction of the first uneven pattern 21a within a range of 90 ° ± 20 °, and more preferably intersects within a range of 90 ° ± 10 °. It is preferable to cross at 90 °.

[Frequent pitch]
The most frequent pitch A2 of the _second uneven pattern 22a is more than 1 μm and 30 μm or less, preferably more than 1 μm and 25 μm or less, more preferably more than 1 μm and 20 μm or less. If the modal pitch A ₂ is not more than the lower limit, there is a tendency that the diffusion of the light is reduced, if it exceeds the upper limit, there is a case where the bright line is readily released.

The most frequent pitch A ₂ is a value obtained from an expression of 1 / {√ (α _F2max ² + β _F2max ² )}.
Specifically, the modal pitch A ₂ is obtained by the following method.
First, the top surface and cross section of the second uneven pattern 22a are observed with an electron microscope. Subsequently, after converting the image of the concavo-convex structure obtained by microscopic observation into a gray scale image, two-dimensional Fourier transform is performed. The frequency (γ _F2 ) of the Fourier transform image is _smoothed , and the position (α _F2max , β _F2max ) indicating the maximum frequency is obtained from the obtained graph other than the center portion of the Fourier transform image. Then, a pitch _{A 2} modal formulas of the modal pitch _{A 2 = 1 / {√ (} α F2max 2 + β F2max 2)}.

[Orientation]
The ridgeline of the second concavo-convex pattern 22a meanders, and the pitch between the adjacent convex portions 22b, 22b varies along the direction of the second concavo-convex pattern 22a.
The degree of orientation C2 of the _second uneven pattern 22a is preferably 0.1 to 0.5. If the degree of orientation C ₂ is 0.1 to 0.5, for variations in the pitch of the second uneven patterns 22a is large, the uniformity of the lateral direction of the light source unit 10 becomes higher. When the degree of orientation C ₂ is more than 0.5, too direction is low in the second uneven patterns 22a, tends to illuminance is low.
In order to make the degree of orientation within the predetermined range, a method of applying contraction stress when manufacturing the second concavo-convex pattern forming body 22 may be appropriately selected.

Orientation degree C ₂ is determined by the following method.
First, a Fourier transform image obtained when obtaining the most frequent pitch A ₂ is used to create a Fourier transform image rotated by θ so that the maximum illuminance portion coincides with the α _F2 axis. Next, the parallel auxiliary line β ′ _F2 is drawn on the β _F2 axis passing through (α _F2max , β _F2max ), the auxiliary line β ′ _F2 is taken as the horizontal axis, and the illuminance (γ _F2 axis) on the auxiliary line β ′ _F2 is taken as the vertical axis. A β ′ _F2- γ _F2 diagram is created. Next, a β ″ _F2− γ _F2 diagram is created by dividing the value of the β ′ _F2 axis of the β ′ _F2− γ _F2 diagram by the reciprocal (1 / A ₂ ) of the most frequent pitch A ₂ , and this β ″ _F2 −γ The half width W of the peak (the width of the peak at a height at which the frequency is half the maximum value) is obtained from the _F2 diagram. The half-width represents the degree of orientation C _2.

[aspect ratio]
The ratio (B ₂ / A ₂ , that is, “aspect ratio”) of the average depth B ₂ of the unevenness to the most frequent pitch A ₂ in the second uneven pattern 22 a is 0.1 to 3.0, 0.5 to It is preferable that it is 2.5, and it is more preferable that it is 0.5-1.0.
If (B ₂ / A ₂ ) is less than the lower limit value, the light diffusibility in the longitudinal direction of the light source unit 10 tends to decrease, and if the upper limit value is exceeded, the light-emitting diode light source 11 is visually recognized in the form of dots. In addition, the uniformity of light in the longitudinal direction of the light source unit 10 tends to be low.

The average depth B ₂ of the second uneven patterns 22a means that the average depth to the bottom of the recess 22c from the peak of the convex portion 22b of the second uneven patterns 22a. Average depth _{B 2} is a convex portion 21b in the convex portion 22b, except substituting the recesses 21c in the recess 22c, calculated in the same manner as in the method of measuring the average depth _{B 1} of the first uneven patterns 21a.

[Material]
Each of the second uneven pattern forming bodies 22 may be formed of one layer or may be formed of two layers.
When the second concavo-convex pattern forming body 22 is formed of two layers, the base material made of a transparent resin and the Young's modulus at the processing temperature when obtaining the second concavo-convex pattern forming body 22 are higher than those of the base material. Is preferably composed of a hard layer having a height of 0.01 to 300 GPa. Here, the processing temperature is, for example, a heating temperature at the time of heat shrinkage in the method for manufacturing a concavo-convex pattern forming body, which will be described later. The Young's modulus is a value measured according to JIS K 7113-1995.

  Examples of the transparent resin constituting the substrate include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, polystyrene resins such as styrene-butadiene block copolymers, polyvinyl chloride, polyvinylidene chloride, and polydimethylsiloxane. Silicone resin, fluororesin, ABS resin, polyamide, acrylic resin, polycarbonate, polycycloolefin, and the like.

The hard layer may be a resin, or a metal or a metal compound.
The resin constituting the hard layer is appropriately selected depending on the type of resin constituting the base material. For example, polyvinyl alcohol, polystyrene, acrylic resin, styrene-acrylic copolymer, styrene-acrylonitrile copolymer, polyethylene terephthalate Polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, fluororesin, and the like can be used. The difference between the glass transition temperature Tg ₂ of the resin constituting the hard layer and the glass transition temperature Tg ₁ of the resin constituting the substrate, since the second uneven pattern 22a can be easily formed in the production of the uneven pattern body described later. (Tg ₂ −Tg ₁ ) is preferably 10 ° C. or higher.
When the hard layer is made of a resin, the thickness of the hard layer is preferably more than 0.05 μm and 5.0 μm or less. If the thickness of the hard layer is more than 0.05 μm and not more than 5 μm, the second uneven pattern forming body 22 can be easily manufactured.

Examples of the metal constituting the hard layer include gold, aluminum, silver, copper, germanium, indium, magnesium, niobium, palladium, lead, platinum, silicon, tin, titanium, vanadium, zinc, and bismuth.
Examples of the metal compound constituting the hard layer include titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, silicon oxide, barium fluoride, calcium fluoride, and fluoride. Examples include magnesium, zinc sulfide, and gallium arsenide.
When the hard layer is a metal or a metal compound, the thickness of the hard layer is preferably 1 to 50 nm. If the thickness of the hard layer is 1 nm or more, defects are less likely to occur in the hard layer, and if the thickness is 50 nm or less, sufficient light transmission can be secured and the second uneven pattern forming body 22 can be easily formed. Can be manufactured.

  As a method for producing the second uneven pattern forming body 22 composed of two layers, a laminated film is formed by providing a hard layer on one side of a transparent resin base material made of a heat-shrinkable film, and the laminated film. There is a method in which the hard layer is deformed to be folded by heating the substrate to shrink the substrate. Thus, the 2nd uneven | corrugated pattern 22a can be formed by changing so that a hard layer may be folded.

When the 2nd uneven | corrugated pattern formation body 22 is comprised by 1 layer, it is preferable to comprise with transparent resin. The transparent resin may be a thermoplastic resin or a thermosetting resin (thermosetting prepolymer or monomer cured product). Examples of the thermoplastic resin include acrylic resin, polyolefin, polyester, and the like. Examples of thermosetting prepolymers include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl / acrylate, polyene / acrylate, silicone acrylate, polybutadiene, and polystyrylmethyl methacrylate. It is done. Examples of the thermosetting monomer include aliphatic acrylate, alicyclic acrylate, aromatic acrylate, hydroxyl group-containing acrylate, allyl group-containing acrylate, glycidyl group-containing acrylate, carboxy group-containing acrylate, and halogen-containing acrylate.
As a method for producing a concavo-convex pattern formed body composed of one layer, nickel is plated on the surface of the concavo-convex pattern formed body composed of the two layers on which the second concavo-convex pattern 22a is formed. A method of producing a stamper and transferring the obtained nickel stamper to a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin (hereinafter referred to as “transfer method”) is used.
The concavo-convex pattern formed body composed of one layer may be laminated with a base material made of a polymer such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, etc. on the surface where the second concavo-convex pattern 22a is not formed.

  Similarly to the first concavo-convex pattern forming body 21, the second concavo-convex pattern forming body 22 may contain a light diffusing agent such as an inorganic light diffusing agent or an organic light diffusing agent for the purpose of enhancing the light diffusing effect. .

<Effect>
In the illuminating device 1 of this embodiment, the light emitted from the light source unit 10 enters the second uneven pattern forming body 22. The light incident on the second concavo-convex pattern forming body 22 is transmitted through the second concavo-convex pattern forming body 22, and then diffused and emitted mainly in the X direction by the second concavo-convex pattern 22a. The light emitted from the second concavo-convex pattern forming body 22 and reaching the first concavo-convex pattern forming body 21 is diffused mainly in the Y direction in the first concavo-convex pattern 21 a, and the first concavo-convex pattern forming body 21. After passing through, the light is emitted. Therefore, according to the light diffuser 20 in which the first uneven pattern forming body 21 and the second uneven pattern forming body 22 are combined, the light from the light source unit 10 is diffused in both the X direction and the Y direction. Can do.
Moreover, each light emitting diode light source 11 is visually recognized as a dot shape because the most frequent pitch and the aspect ratio of each of the first uneven pattern forming body 21 and the second uneven pattern forming body 22 are within the above range. Is suppressed, and the light source unit 10 has excellent light diffusibility in the short-side direction and uniformity of light in the short-side direction.
Moreover, since the 1st uneven | corrugated pattern formation body 21 can be mass-produced by extrusion molding, the illuminating device 1 can reduce cost.

<Other embodiments>
In addition, this invention is not limited to the said embodiment.
The light source unit 10 may be a linear unit in which a plurality of light emitting diode light sources 11, 11... Are linearly arranged in a plurality of rows. When the plurality of light-emitting diode light sources 11, 11... Are linearly arranged in a plurality of rows, the light-emitting diode light sources 11, 11 are also straight in the Y direction orthogonal to the X direction (longitudinal direction of the light source unit 10). However, the arrangement is not limited to this. For example, the light emitting diode light sources 11 and 11 may be arranged in a zigzag manner in the Y direction.
When the plurality of light-emitting diode light sources 11, 11... Are linearly arranged in a plurality of rows, the ratio (C / D) of the length C in the X direction to the length D in the Y direction. 2 or more. Here, the length C in the X direction is specifically the length between the light emitting diode light sources at both ends in the X direction, and the length D in the Y direction is the length between the light emitting diode light sources at both ends in the Y direction. That's it. When C / D is less than the lower limit, the illuminance is not sufficiently increased even if the light diffuser 20 is used. C / D is preferably 5 to 500, and more preferably 10 to 300.
Moreover, the repetition of the unevenness of the first uneven pattern forming body 21 used in the above embodiment may not be constant. Further, the first uneven pattern forming body 21 may include the first uneven pattern 21 a on the opposite surface of the light source unit 10.
Moreover, the unevenness | corrugation of the 2nd uneven | corrugated pattern formation body 22 used by the said embodiment does not meander, and may be linear form.

(Manufacturing example 1) Preparation of uneven | corrugated pattern formation body Polymethyl methacrylate (LH-101-10 by Fujikura Kasei Co., Ltd., mass average molecular weight 560000, polymerization dispersion degree (Mw / Mn) 3.4, glass transition temperature 100 degreeC). 50 μm thick polyethylene terephthalate shrink film (Mitsubishi Resin Hissippet LX-61S, glass transition temperature 70 ° C.) having a thickness of 50 μm that is heated and shrunk mainly in a uniaxial direction (width direction) by gravure coating. On one side of the coating, the coating thickness after drying was 2 μm. Thereby, the lamination sheet in which the surface smooth layer was formed on both surfaces of the polyethylene terephthalate shrink film was obtained.
Next, the laminated sheet is heated at 100 ° C. for 1 minute to cause heat shrinkage to 40% of the length before heating (ie, shrink at a shrinkage rate of 60%), and the hard layer is orthogonal to the shrinking direction. An uneven pattern forming body original plate having a wavy uneven pattern having periodicity along the direction was obtained.
Subsequently, the surface on which the concavo-convex pattern was formed of the obtained concavo-convex pattern forming original plate was subjected to nickel plating, and the nickel plating was peeled off to obtain a nickel plating stamper having a thickness of 300 μm. An uncured ultraviolet curable resin composition containing an epoxy acrylate prepolymer, 2-ethylhexyl acrylate, and a benzophenone photopolymerization initiator was applied to the surface of the nickel plating stamper on which the concavo-convex pattern was formed.
Next, a polyethylene terephthalate film having a thickness of 100 μm was placed on the surface of the uncured UV curable resin composition coating film not in contact with the nickel plating stamper, and pressed to bring it into close contact.
Next, ultraviolet rays were irradiated from above the polyethylene terephthalate film to cure the uncured ultraviolet curable resin composition, and the cured product thus obtained was peeled from the nickel plating stamper.
Accordingly, the waveform shape of the uneven pattern in which the asperities meanders with irregularities along one direction are repeatedly formed (modal pitch A _2: 17.2μm, the average depth of the irregularities for the modal pitch A ₂ B ₂ the ratio of _{(B 2 / a 2):} 0.6, the orientation degree: 0.3) to obtain a sheet-like concavo-convex pattern formed body having a.

(Production Example 2) Production of light source unit A A plurality of light emitting diode light sources are linearly mounted on an aluminum substrate so as to have a length of 6 cm, and these are cylindrical and have a concavo-convex pattern. The light source unit A was produced by inserting it into the inside of a polycarbonate cover a.

(Production Example 3) Production of light source unit B A raw material made of polycarbonate was extrusion-molded to obtain a long and cylindrical cover b in which a concavo-convex pattern was formed so that the concavo-convex pattern was repeated at regular intervals along one direction. .
In this example, the pitch of the concavo-convex pattern was 550 μm, and the average depth of the convex portions was 45 μm (that is, the aspect ratio B ₁ / A ₁ was 0.08). The uneven pattern was formed on the inner side of the cylinder (light emitting diode light source side), and the unevenness was periodically repeated along the direction (Y direction) perpendicular to the longitudinal direction (X direction) of the cover. And the light source unit B was produced like the manufacture example 2 except having used the cover b instead of the cover a.

Production Example 4 Production of Light Source Unit C Production Example 3 except that the pitch of the concavo-convex pattern was 250 μm and the average depth of the convex portions was 55 μm (that is, the aspect ratio B ₁ / A ₁ was 0.22). A cover c was produced in the same manner as described above. And the light source unit C was produced like the manufacture example 3 except having used the cover c instead of the cover b.

(Production Example 5) Production of light source unit D Cover d was prepared in the same manner as in Production Example 4 except that a raw material containing 100 parts by mass of polycarbonate and polystyrene beads having a volume average particle diameter of 5 μm was used instead of the raw material made of polycarbonate. Produced. And the light source unit D was produced like the manufacture example 3 except having used the cover d instead of the cover b.

Production Example 6 Production of Light Source Unit E Production Example 3 except that the pitch of the concavo-convex pattern was 800 μm and the average depth of the convex portions was 250 μm (that is, the aspect ratio B ₁ / A ₁ was 0.31). A cover e was produced in the same manner as described above. And the light source unit E was produced like the manufacture example 3 except having used the cover e instead of the cover b.

Production Example 7 Production of Light Source Unit F Production Example 3 except that the pitch of the concave / convex pattern was 250 μm and the average depth of the convex portions was 105 μm (that is, the aspect ratio B ₁ / A ₁ was 0.42). A cover f was produced in the same manner as described above. And the light source unit F was produced like the manufacture example 3 except having used the cover f instead of the cover b.

Example 1
The concavo-convex pattern formed body obtained in Production Example 1 is disposed on the inner peripheral surface of the cover b of the optical unit B obtained in Production Example 3 so that the respective concavo-convex portions are orthogonal to each other, and the concavo-convex surfaces face each other. To obtain a lighting device.

(Example 2)
The concavo-convex pattern formed body obtained in Production Example 1 is arranged on the inner peripheral surface of the cover c of the optical unit C obtained in Production Example 4 so that the concavo-convex portions are orthogonal to each other, and the concavo-convex surfaces face each other. To obtain a lighting device.

(Example 3)
The concavo-convex pattern formed body obtained in Production Example 1 is arranged on the inner peripheral surface of the cover d of the optical unit D obtained in Production Example 5 so that the respective concavo-convex portions are orthogonal to each other, and the concavo-convex surfaces face each other. To obtain a lighting device.

Example 4
The concavo-convex pattern formed body obtained in Production Example 1 is arranged on the inner peripheral surface of the cover e of the optical unit E obtained in Production Example 6 so that the respective concavo-convex portions are orthogonal to each other, and the concavo-convex surfaces face each other. To obtain a lighting device.

(Comparative Example 1)
The concavo-convex pattern formed body obtained in Production Example 1 is arranged on the inner peripheral surface of the cover f of the optical unit F obtained in Production Example 7 so that the respective concavo-convex portions are orthogonal to each other, and the concavo-convex surfaces face each other. To obtain a lighting device.

(Comparative Example 2)
The uneven | corrugated pattern formation body obtained by the manufacture example 1 was attached to the internal peripheral surface of the cover a of the optical unit A obtained by the manufacture example 2, and the illuminating device was obtained.

(Reference example)
The light source unit A (with the cover a alone and without the uneven pattern forming body of Production Example 1) was used as the lighting device.

[Evaluation]
About the obtained illuminating device, the difficulty in visually recognizing the light-emitting diode light source, the light diffusibility in the short direction, and the uniformity of the light in the short direction were evaluated by the following methods. The evaluation results are shown in Table 1.
-Difficult to see light emitting diode light source (hereinafter referred to as "LED invisibility")
The cover side surface of the lighting device was photographed, and the five evaluators visually observed the photograph, and evaluated the invisibility of the LED according to the following criteria. The photograph taken is also shown in Table 1.
○: All the evaluators felt that the bright spot of the light source (brightness unevenness caused by the pitch of the light source in the longitudinal direction) was not concerned.
Δ: One or two of the evaluators felt that the bright spot of the light source was anxious.
X: All the evaluators felt that the bright spot of the light source was anxious.
-Light diffusivity in the short direction (hereinafter referred to as "light diffusibility")
Five evaluators visually observed the photograph used for the evaluation of the invisibility of the LED, and evaluated the light diffusibility according to the following criteria.
○: All the evaluators felt that the diffusion in the short direction was a natural spread of fluorescent lamp-like.
Δ: One or two of the evaluators felt unnatural diffusion (strong directivity) and unnaturalness.
X: All the evaluators felt that the diffusibility was insufficient and unnatural.
・ Light uniformity in short direction (In the table, it is expressed as “light uniformity”)
Five evaluators visually observed the photographs used for the evaluation of the LED invisibility, and evaluated the light uniformity according to the following criteria.
○: All the evaluators felt that diffusion in the short direction was uniform.
Δ: One or two of the evaluators felt uneven.
X: All the evaluators felt it was uneven.

In the illumination devices of Examples 1 to 4 in which the pitch and aspect ratio of the concave and convex pattern of the cover and the pitch and aspect ratio of the concave and convex pattern of the concave and convex pattern forming body are within the scope of the invention according to claim 1, sufficient LEDs The invisibility of was secured. Moreover, it was excellent in light diffusibility and light uniformity in the short direction.
In the illumination device of Comparative Example 1 in which the aspect ratio of the uneven pattern of the cover was out of the scope of the invention according to claim 1 of the present application, the light uniformity in the short direction was low.
In the illuminating device of Comparative Example 2 in which the cover had no uneven pattern, the light diffusibility in the short direction was low.

DESCRIPTION OF SYMBOLS 1 Illuminating device 10 Light source unit 11 Light emitting diode light source 12 Support body 20 Light diffuser 21 1st uneven | corrugated pattern formation body 21a 1st uneven | corrugated pattern formation 22 2nd uneven | corrugated pattern formation body 22a 2nd uneven | corrugated pattern 21b, 22b Convex part 21c, 22c recess

Claims (2)

In an illuminating device comprising a light source unit in which a plurality of light emitting diode light sources are linearly arranged, and a light diffuser provided on the light emitting side of the light source unit,
The light diffuser includes a wavy first concavo-convex pattern in which the concavo-convex is repeated at a constant pitch along a direction in a range of ± 20 ° with respect to a direction orthogonal to the longitudinal direction of the light source unit, and the concavo-convex is the light source unit. An irregular second concavo-convex pattern that repeats along a direction in the range of ± 20 ° with respect to the longitudinal direction and the pitch of adjacent convex portions varies ,
In the first concavo-convex pattern, the most frequent pitch A ₁ of the concavo-convex pattern is 200 to 2000 μm, and the ratio of the average depth B ₁ of the concavo-convex to the most frequent pitch A ₁ (B ₁ / A ₁ ) is 0.05 to 0.4. And
The second concavo-convex pattern is arranged closer to the light source unit than the first concavo-convex pattern, the convex portion tip of the second concavo-convex pattern is directed to the opposite side of the light source unit, and the most frequent pitch A ₂ of the concavo-convex pattern is 1. An illumination device in which the ratio (B ₂ / A ₂ ) of the average depth B ₂ of the unevenness to the most frequent pitch A _{2 is} 0.1 to 3.0, more than 0.0 μm and 30 μm or less.   The lighting device according to claim 1, wherein a cover for protecting the light source unit is provided on a light emitting side of the light source unit, and the first uneven pattern is formed on the cover.