JP2010129507A - Lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting apparatus having less deterioration in luminance, by carrying out prevention of glare and reducing the light source image, in LED lighting. <P>SOLUTION: The lighting apparatus has the LED light source and a light transmitting panel, having a specific irregular configuration on at least one surface arranged to face the light source on the iradiation side of the lighting apparatus, and the irregular configuration on the light transmitting panel has an average wavelength (λa) of 1 to 100 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lighting fixture having an LED light source.

  In recent years, reduction of the emission of carbon dioxide, a greenhouse gas, has been demanded from the viewpoint of preventing global warming, and accordingly, lighting fixtures having LED light sources and fluorescent light sources effective for power saving are increasing. . Lighting fixtures such as downlights and spotlights, which are often used as partial lighting, often use incandescent bulbs and mini-krypton bulbs as light sources, but these light sources have low luminous efficiency, higher efficiency and lower power consumption. Are moving to LED light sources and fluorescent light sources. In particular, LED light sources that can reduce waste with a long life and that do not contain harmful substances contribute to environmental conservation are remarkably improved in luminous efficiency, and lighting fixtures using LED light sources are rapidly spreading. For example, the idea described in Patent Document 1 is known as an idea of using an LED for a lighting fixture, and the one described in Patent Document 2 and Patent Document 3 is known as an alternative to a fluorescent lamp. However, when the light source is directly seen from the characteristics of the LED, the individual LEDs are clearly visible and are very dazzling (glare).

  For this reason, generally available lighting fixtures having LED light sources, and fluorescent lamp type LED lighting, a type in which a milk white cover is put on the LED light sources are commercially available. However, these are levels at which the LED light source can be clearly recognized in appearance, and the LED lamp image is not significantly suppressed. On the other hand, when a cover with low transmittance is used so as not to be dazzled, there arises a problem that illuminance as a function of illumination is lowered.

As mentioned above, although the prior art regarding this invention has been demonstrated, the lighting fixture which suppressed LED lamp image significantly, without reducing illumination intensity is not able to be provided.
Japanese Utility Model Publication No. 63-121461 Japanese Utility Model Publication No. 6-54103 JP 2001-351402 A

  That is, an object of the present invention is to solve the above-mentioned problems and to provide a lighting fixture that significantly suppresses an LED lamp image without reducing illuminance.

  As a result of intensive studies to solve the above problems, the present inventors arrange a light transmissive panel having a specific uneven shape on the irradiation side of a luminaire having an LED light source so as to face the light source. As a result, the inventors have found that the above object can be achieved, and have completed the present invention based on this finding.

  That is, the luminaire of the present invention is a luminaire having an LED light source, and on the irradiation side of the luminaire, a light-transmitting panel having a specific uneven shape on at least one side is arranged to face the light source. The uneven shape of the light-transmitting panel has an average wavelength (λa) of 1 μm to 100 μm.

  In the lighting device according to the present invention, it is preferable that the light transmissive panel has a diffusion angle of transmitted diffused light of 50 ° or more and 110 ° or less when a light beam is incident perpendicularly to the uneven surface.

  In the above luminaire, the P / H is preferably 0.1 or more and 10 or less when the interval between the LED light sources is P and the interval between the LED light sources and the light transmissive panel is H.

  In the above luminaire, the A / B is preferably 1.20 or less when the luminance on the LED light source is A and the luminance between the LED light source and the LED light source is B.

  ADVANTAGE OF THE INVENTION According to this invention, an LED lamp image can be suppressed significantly and a glare can be prevented and the lighting fixture with sufficient illumination intensity can be provided.

The present invention will be specifically described below.
The lighting fixture of this invention expresses a function by combining the light transmissive panel which has a specific uneven | corrugated shape on the irradiation side of the lighting fixture which has a LED light source.

  Examples of the luminaire having an LED light source that can be used in the present invention include a fluorescent lamp luminaire, a downlight, a spotlight, a ceiling light, a light-up luminaire, a line luminaire, a liquid crystal backlight, and a signboard illumination. Is mentioned.

  For example, in the case of a fluorescent lamp type lighting fixture, MLT-40WM manufactured by Momoa Alliance Co., Ltd. may be used.

  In the case of a downlight, LEDD-66001W-LS1, LEDD-66003W-LS1, manufactured by Toshiba Lighting & Technology Co., Ltd., NNN21912, NNN21910, NNN21900, NNN21637, etc. manufactured by Matsushita Electric Works, Ltd. may be mentioned. Examples of the spotlight include LEDS 80000W-LS and LEDS-80002L-LS manufactured by Toshiba Lighting & Technology Corporation. Examples of the ceiling light include LEDH8002W-LS, LEDH8002L-LS, and LEDS-31901WS-LS1 manufactured by Toshiba Lighting & Technology Corporation. Examples of LED light-up lighting fixtures used for lighting up bridges and building walls, signboard lighting, etc. include NNY24250 and NNY24251 manufactured by Matsushita Electric Works, Ltd. Examples of the line lighting fixture include LEDL-03201W-LS1 and LET-01001N-YW1 manufactured by Toshiba Lighting & Technology Corporation.

  By using the luminaire provided with the light transmissive panel of the present invention, the LED lamp image can be significantly suppressed without reducing the illuminance, and glare can be prevented.

Next, the light transmissive panel having a specific uneven shape used in the present invention will be described.
The uneven shape of the light transmissive panel used in the present invention is characterized in that the average wavelength (λa) is 1 μm to 100 μm. The resolution of the human eye is about 50 seconds in terms of viewing angle, and since the luminaire is usually 1 m or more away from the position of the human eye, the uneven wavelength can be imparted by setting the average wavelength (λa) to 100 μm or less. Becomes difficult to understand, and light with a soft feeling like a milky white frosted plate can be obtained. From the viewpoint of stably controlling the light emission pattern, the average wavelength (λa) is preferably larger than 1 μm. A more preferable average wavelength is 1 to 70 μm or less, and further preferably 1 μm to 50 μm or less.

The average wavelength (λa) here is a value calculated according to the following formula using a high-precision fine shape measuring instrument Surfcoder ET4000 manufactured by Kosaka Laboratory Ltd.
λa = 2π (Ra / Δa)
Ra is an arithmetic mean roughness, and was measured according to JIS B0601 using a high-accuracy fine shape measuring device Surfcorder ET4000 manufactured by Kosaka Laboratory Ltd.
Δa is an average gradient and was measured according to ASME B46.1: 1995, using a high-precision fine shape measuring device Surfcoder ET4000 manufactured by Kosaka Laboratory Ltd.

  Since the light-transmitting panel used in the present invention has a specific unevenness, it has light diffusibility. The light diffusing property means that the transmitted light diffuses when parallel light rays are incident perpendicularly to the uneven surface of the light transmissive panel. Specifically, it is possible to arbitrarily set the diffusion angle of the transmitted diffused light when a parallel light beam is incident perpendicularly to the uneven surface. Among these, those having a diffusion angle of 50 ° to 110 ° can be preferably used from the viewpoint of greatly suppressing the LED lamp image. Here, the diffusion angle refers to an angle (FWHM: Full Width Half Maximum) that is twice the angle (half-value angle) that attenuates to half the peak luminance when parallel light such as a laser is incident on the uneven surface. This diffusion angle can be obtained, for example, by measuring the light emission distribution of light incident from a normal angle of 0 ° with a Nippon Denshoku goniochromimeter. On the other hand, even if the diffusion angle is larger than 110 °, the effect is hardly changed, so that it is not necessary to use it substantially. Among these, in the sense of reducing the lamp image and securing the illuminance, those of 60 ° to 100 ° are particularly preferred, and those of 70 to 100 ° are particularly preferably used. This diffusion angle is preferably substantially transparent in the plane of the light transmissive panel. When it has anisotropy, it is preferably used in a range where the ratio of the diffusion angles is 1: 5 or less, and particularly preferably 1: 2 or less. When the degree of anisotropy is large, diffusion in one direction becomes insufficient, and thus it may be necessary to use a large number of light transmissive panels.

  As a method for forming a specific uneven shape on the light-transmitting panel used in the present invention, an injection molding method using a mold having an uneven shape, a transfer roll (master type) having an uneven shape, a base film, and UV Examples thereof include a transfer method in which irregularities are continuously formed on a film by roll-to-roll using a curable resin.

  As a method for producing a mold or a transfer roll having a specific uneven shape, a method by interference exposure is preferable. Concavity and convexity formation by interference exposure means that irregular speckles caused by coherent light diffused at each point on the surface where light is applied to the diffuser interfere with each other in an irregular phase relationship. It is a method of forming irregularities by exposure and development. The uneven shape obtained by the interference exposure has a fine three-dimensional structure, and the specific uneven shape required for the present invention can be formed by controlling the speckle pattern. This fine three-dimensional structure is composed of a plurality of uneven structures. The height and pitch of the concavo-convex shape is irregular and has a pseudo-random shape.

  Specifically, it can be formed as follows. First, a submaster mold in which a speckle pattern is formed in advance by interference exposure is manufactured, a metal is deposited on the submaster mold by a method such as electroforming, and the speckle pattern is transferred to the metal to manufacture a master mold. The speckle pattern is transferred to the surface of the light-transmitting resin layer by performing UV glazing using the master mold on the light-transmitting resin layer. A detailed manufacturing method of this sub-master type is disclosed in Japanese Patent No. 3341519. All this content is included here.

  The average wavelength (λa) can be controlled by adjusting the size, shape and direction of the speckle pattern. In general, the average wavelength (λa) depends on the average size and shape of the speckle. If the speckle is small, the average wavelength (λa) is small. Thus, the speckle pattern can be determined according to the desired directivity angle and diffusion angle. A detailed manufacturing method of this speckle pattern is disclosed in Japanese Patent No. 3390954. All this content is included here. The diffusion angle may be controlled by changing the pitch, height, and aspect ratio of the concavo-convex structure, or may be controlled by changing the refractive index of the light-transmitting resin layer that is cured by ultraviolet rays.

  The light-transmitting panel used in the present invention may be used as a light-transmitting panel after producing a film having a specific uneven shape, or a light-transmitting material such as polymethyl methacrylate, polycarbonate, or glass. Alternatively, the light-transmitting panel may be bonded by adhesive material or thermal transfer. The film may be a translucent material such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, etc., having a total light transmittance of 80% or more as defined in JIS K7361-1. In addition, the specific uneven | corrugated shape may be formed in the front and back both surfaces of a light transmissive panel.

  In the present invention, a layer in which metal oxide particles such as silica particles, titanium oxide particles, and alumina particles are dispersed in a resin can be provided in the light transmissive panel. By providing such a layer in which metal oxide particles are dispersed (particle dispersion layer), light transmitted through the panel can be scattered, and therefore, it is preferably used. In that case, it is preferable to use particles having a diameter of 5 μm or less as the primary particle size, and particles of 10 nm to 5 μm are preferable. By dispersing particles of such a size in the dispersion layer, the component reflected at the panel interface can be effectively discharged to the outside by the diffusion action. The particle dispersion layer can be used in the range of 0.1 to 50 μm. The amount of particles used can be in the range of 0.1 wt% to 20 wt% with respect to the resin amount of the particle dispersion layer. A specific uneven shape may be imparted to the particle dispersion layer.

  The light transmissive panel used in the present invention preferably has a haze value defined in JIS K7136 of 30% or more, more preferably 50% or more, and still more preferably 80% or more. Since the LED light source has high directivity and high luminance, when the LED light source is viewed directly, if the haze value is less than 30%, it is uncomfortable because it feels strong glare. By setting the haze value to 30% or more, the dazzling feeling can be reduced, and illumination that is gentle to the eyes can be obtained.

Next, a method for arranging the light transmissive panel used in the present invention will be described.
The light transmissive panel used in the present invention is preferably installed with a surface having a specific uneven shape as the light output side. The LED lamp image can be significantly suppressed without reducing the illuminance by installing a surface having a specific uneven shape as the light output side.

  The light transmissive panel used in the present invention preferably has a surface coated with an antireflection film. Since the total light transmittance can be improved by coating the antireflection film, it leads to further effective utilization of irradiation light.

  As shown in FIGS. 1 and 2, the light transmissive panel used in the present invention has a ratio of P to H when the distance between the LED light source is P and the distance between the LED light source and the light transmissive panel is H; / H is preferably installed so as to be 0.1 or more and 10 or less from the viewpoint of suppressing glare and LED lamp image. Although it differs depending on the light emission pattern (angle distribution) of the LED light source, P / H is preferably 10 or less when the light emission angle is as large as 140 °. On the other hand, when the light emission angle is a normal Lambertian, P / H can be preferably 2 or less.

  In this invention, you may use simultaneously the film and panel which diffuse light other than a light transmissive panel. In this case, there is a possibility that the illuminance decrease as illumination is somewhat caused, but it is effective in reducing glare.

  As shown in FIG. 3, the evaluation of the LED lamp image is based on the luminance ratio A when the luminance on the LED light source (measurement point 6) is A and the luminance between the LED light source and the LED light source (measurement point 7) is B. / B. The luminaire of the present invention has a luminance ratio A / B of 1.20 or less, a difference in luminance between the LED light source and the LED light source is small, and can greatly suppress the LED lamp image and also suppress glare. preferable.

  As mentioned above, although the lighting fixture of this invention has been demonstrated, according to this invention, the lighting fixture which suppressed LED lamp image significantly can be provided, without reducing illumination intensity.

  Next, examples carried out to clarify the effects of the present invention will be described, but the present invention is not limited to these examples.

[lighting equipment]
Fluorescent lamp type LED lighting (MLT-40WM) manufactured by Momoa Alliance Co., Ltd. and fluorescent lamp fixture (FH4841) manufactured by Mitsubishi Electric Lighting Co., Ltd. were used. In the fluorescent lamp type LED illumination (MLT-40WM), portions other than 185 mm near the center were shielded with aluminum foil (FIG. 4).

[Light transmissive panel]
Master molds having various average wavelengths (λa) were produced by controlling the speckle pattern. Next, a light transmissive panel having a specific uneven shape was produced by a transfer method using a polyethylene terephthalate base (thickness: 188 μm) and a UV curable resin. A parallel light beam was incident from the surface of the prepared panel having a concavo-convex shape, and the diffusion angle was measured with a variable angle color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd.). These results are summarized in Table 1. The sample name of the light transmissive panel was expressed according to Table 1.

[Various measurement methods]
(1) Measurement of luminance The luminance at measurement points a and b shown in FIG. 3 was measured using a luminance meter (manufactured by Konica Minolta Sensing Co., Ltd .: LS-110). The luminance ratio A / B was determined with the luminance at the measurement point a being A and the luminance at the measurement point b being B. The measurement diameter was 5 mm.

(2) Measurement of illuminance distribution Using an illuminometer (manufactured by Hioki Electric Co., Ltd., Lux HiTester 3423, JIS C1609-1993 general form AA class), the horizontal illuminance at 220 cm below the lighting fixture is measured. The measurement interval was 50 cm in each of the width direction and the depth direction.

[Example 1]
The milk white cover of fluorescent lamp type LED lighting (MLT-40WM) manufactured by Momore Alliance Co., Ltd. was replaced with a light transmissive panel (panel a in Table 1) and attached to a ceiling having a height of 220 cm. In addition, the uneven | corrugated shaped surface was made into the light emission side as the arrangement direction of a light transmissive panel. P was 10.5 mm, H was 10.5 mm, and P / H was 1.0. Thereafter, luminance measurement and illuminance distribution measurement were performed. The results of luminance measurement are shown in Table 2, and the results of illuminance distribution are shown in FIG. The luminance ratio A / B was 1.01, and the LED lamp image was greatly suppressed, and was directly visible. The illuminance at 220cm directly below the lighting fixture was 29Lx.

[Example 2]
Example 1 was repeated except that the milky white cover was changed to a light transmissive panel (panel b in Table 1). The brightness ratio A / B was 1.17, and the LED lamp image was greatly suppressed. Similar to Example 1, the illuminance directly under illumination was higher than that of Comparative Example 1 described later. These results are summarized in Table 2.

[Comparative Example 1]
Fluorescent lamp type LED lighting (MLT-40WM) manufactured by Momoa Alliance Co., Ltd., except that P was 10.5 mm, H was 9.0 mm, and P / H was 1.2. The luminance ratio A / B was 1.22, and the LED lamp image could be recognized. The illuminance at 220 cm directly below the lighting fixture was 24 Lx, which was about 20% darker than in Examples 1 and 2. These results are summarized in Table 2. FIG. 6 shows the measurement result of the illuminance distribution. Comparing FIG. 5 and FIG. 6, for example, comparing areas of 10 Lx or more, it can be seen that FIG. 5 of Example 1 is wider. That is, in comparison between Example 1 and Comparative Example 1, it was found that the brighter area was wider in Example.

  Since the lighting fixture of this invention has the characteristic which can suppress an LED lamp image significantly, without reducing illumination intensity, the utilization to the illumination field | area which has a high-intensity LED light source can be anticipated.

It is sectional drawing of a fluorescent lamp type LED lighting fixture. It is an image figure of a LED light source. It is an image figure which shows a measurement point. It is a photograph of the vicinity of the center of a fluorescent lamp type LED lighting apparatus in an example. 2 is an illuminance distribution diagram of Example 1. FIG. 6 is an illuminance distribution diagram of Comparative Example 1. FIG.

Explanation of symbols

1: LED light source 2: Milky white cover or light transmissive panel 3: Distance H between LED light source and light transmissive panel
4: LED light source 5: LED light source interval P
6: Measurement point a
7: Measurement point b

Claims (4)

  A light fixture having an LED light source, wherein a light transmissive panel having a specific concavo-convex shape on at least one side is arranged on the irradiation side of the luminaire so as to face the light source, and the ruggedness of the light transmissive panel The lighting apparatus is characterized in that an average wavelength (λa) is 1 μm to 100 μm.   2. The lighting apparatus according to claim 1, wherein the light transmissive panel has a diffusion angle of transmitted diffused light of 50 ° or more and 110 ° or less when a light beam is incident perpendicularly to the uneven surface.   The illumination according to claim 1 or 2, wherein P / H is 0.1 or more and 10 or less, where P is an interval between the LED light sources and H is an interval between the LED light sources and the light transmissive panel. Instruments.   4. A / B is 1.20 or less, where A is the luminance on the LED light source and B is the luminance between the LED light source and the LED light source. The lighting fixture as described in.