JP2007242370A - Reflector and light source apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector of a light source apparatus which can suppress lowering of an interception effect in visible light even its lamp is lighted over a long term as well as can prevent occurrence of cracks or damages even a high-power light source lamp is used, and also to provide a light source apparatus which can prevent the leakage of visible light from the outer surface of the reflector for a prolonged period, and can prevent occurrence of cracks or damages on the reflector as well as obtain a high impact effect. <P>SOLUTION: This light source apparatus comprises a reflector having a shielding film composed mainly of CuO and a light source lamp. The reflector has a light-focusing portion of which the inner surface is coated with a reflecting film which reflects light in a visible light region and transmits light in an infrared region, and the outer surface is coated with a shielding film which absorbs light in a visible light region. It is preferable in a thickness of the shielding film that the layer composed mainly of CuO is not less than 500 nm, and the total is not more than 50 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reflector having a glass substrate whose inner surface is coated with a dielectric multilayer reflective film. The present invention also relates to a light source device that includes a reflector and a light source lamp used for general lighting, store lighting, studio lighting, and the like.

  In theatrical lighting, video lighting, traffic lighting, outdoor lighting such as amusement parks, floodlights that illuminate the distance with a small light source are used. High pressure mercury lamps, high pressure sodium lamps, etc. are used. A reflector that reflects light from such a light source lamp has a dielectric multilayer reflective film that reflects the visible light region and transmits the infrared light region on the inner surface, and is a cold mirror, a high color temperature mirror. There are various color mirrors. These mirrors use concave transparent glass with a spheroid or paraboloid on the substrate, reflect the necessary visible light to the front of the reflector, and reflect unwanted light, mainly infrared light Multi-layer film design that escapes to the back. By adopting such a film design, since infrared rays unnecessary for illumination are hardly irradiated on the front surface of the reflector, it is possible to avoid the product or person being the object to be irradiated from becoming hot.

Thus, color mirrors and high-temperature mirrors illuminate the front part of the visible light and the remaining light is emitted from the back of the reflector. Complementary colors will be released, and there will be problems in stage and store lighting production, and people behind will feel dazzling and unsightly.
Moreover, even for a cold mirror that reflects almost the entire visible region, the average reflectance in the visible region is practically reduced due to the effects of oblique incidence, etc. It is about 85 to 90%. In such a case, the remaining light that has not been emitted from the front is emitted from the back of the reflector, causing a problem in production as described above, and there are problems such as dazzling and unsightly.

FIGS. 4A and 4B are diagrams showing examples of calculation simulations of reflectance spectra of a cold mirror and a high color temperature mirror coat film. FIG. 4A shows a cold mirror, and FIG. 4B shows a high color temperature mirror. In either case, the transmittance in the wavelength band in the infrared region is high, the design is such that the radiation of heat rays to the front is suppressed as much as possible, and the irradiated object is designed not to become hot.
As shown in FIG. 4 (a), the cold mirror shows a high reflectance in the visible region of wavelength 450 nm to 700 nm, but is not 100%, and the high color temperature mirror of (b) has a wavelength higher than about 520 nm. Most of the light on the wavelength side is emitted from the back surface through the glass that is the base material of the mirror.

  Since the light not reflected by the reflecting surface is radiated from the back of the reflector, a light-shielding film that shields visible light is formed on the back of the reflector to prevent light from leaking behind the reflector. It was.

For example, in Patent Document 1, a light-shielding film having a function of absorbing visible light and transmitting infrared light is formed on the back side of the reflector base material, thereby preventing visible light from leaking to the rear side. Has been proposed.
However, in this technique, the light-shielding film is formed by depositing a film of black silicon or the like on the back side of the substrate so as to have a film thickness of 50 nm to 2 μm by vacuum deposition. For this reason, when heated at a high temperature for a long time, the phenomenon that the silicon film fades occurs, and there is a problem that visible light easily leaks from the vicinity of the light source lamp to the rear side.

For this reason, in view of heat resistance and stability that can withstand long-time lighting, it has been widely applied to apply a commercially available heat-resistant black paint.
For example, in Patent Document 2, an organic compound is combined as a binder using a composite oxide black pigment such as copper-chromium black or copper-manganese black that absorbs all wavelengths from conventional visible light to infrared light. A light shielding film is described.
Japanese Patent Application Laid-Open No. 10-069808 Japanese Patent Laid-Open No. 10-177855

Here, the light path of the light source device according to the prior art will be described with reference to FIG.
As shown in FIG. 5, most of the visible light emitted from the light source lamp 10 toward the reflector 20 is reflected by the reflecting film 24 in the concave reflecting mirror 20 as shown by the solid line, and Visible light that has passed through the partial reflection film 24 passes through the base 21 in the reflector 20 and is incident on and absorbed by the light shielding film 30 formed on the outer surface as indicated by the dotted line.

This light shielding film 31 uses a black pigment having infrared absorption in the prior art, and specifically, CuCr ₂ O ₄ , Cu (Fe, Mn) ₂ O having a particle diameter of several tens μm or more. ₄ , Cu (Fe, Cr) ₂ O ₄ , (Co, Mn) · (Fe, Cr) ₂ O ₄ , Fe ₃ O ₄ , and a compound of a heat-resistant black pigment such as carbon.
When a lamp having a high infrared radiation ratio, such as a halogen lamp, is used as the light source of the reflector, the infrared light emitted from the light source lamp 10 simultaneously with the visible light is reflected in the reflecting film 24 and the reflector 20 in the reflector 20 as indicated by a dotted line. The black pigment compound absorbs not only visible light but also infrared rays because it passes through the substrate 21 and enters the light-shielding film 31, so that the reflector becomes hot due to the heat of infrared rays absorbed by the black paint film. In some cases, cracks may occur and eventually crack.

For this reason, in a conventional light source device including a reflector and a light source lamp, the input of the light source lamp is limited, and a dark lamp with a relatively low input must be used, which is not always in line with expectations. In addition, when trying to use a bright lamp with high input, it is inevitable to change the mirror specifications, leading to a high cost.
Recently, in various fields such as theater lighting, video lighting, traffic lighting, outdoor lighting such as amusement parks, the effect of lighting is expected to be higher, and it is required to use a bright lamp with high output. For example, in the case of a halogen lamp, the use of a high output lamp widens the range of dimming, and further effects can be expected.
Therefore, the problem to be solved by the present invention is to provide a reflector that can prevent the occurrence of cracks and breakage even when a bright light source lamp with a high input is used, even if it is lit for a long time and the light-shielding property of visible light does not deteriorate. It is to provide. Furthermore, in the light source device in which the light source lamp is incorporated in the reflector, visible light can be prevented from leaking from the outer surface of the reflector over a long period of time, and a bright and high effect can be obtained and the reflector cracks and An object of the present invention is to provide a light source device capable of preventing damage.

Therefore, the reflector according to the present invention has a light collecting part that reflects light toward the front, and a reflection film that reflects light in the visible light region and transmits light in the infrared region is formed on the inner surface of the light collecting part. A reflector having a light-shielding film that absorbs visible light on its outer surface,
The light shielding film is made of a film mainly composed of CuO.

Moreover, the light source device according to the present invention has a condensing part that reflects light forward, and a reflection film that reflects light in a visible light region and transmits light in an infrared region on an inner surface of the condensing part. A light source device comprising: a reflector formed with a light-shielding film that absorbs visible light on an outer surface; and a light source lamp disposed inside a light collecting portion of the reflector,
The light shielding film of the reflector is made of a film mainly composed of CuO.
The thickness of the light shielding film is preferably 500 nm to 50 μm.
Further, the light-shielding film is formed in a multilayer structure by forming a film having a lower refractive index than a film mainly containing CuO in a laminated state on the film mainly containing CuO,
The integrated thickness of the film mainly composed of CuO is 500 nm or more, and the total thickness of the light shielding film is 50 μm or less.

Of the light leaking from the back surface of the glass substrate that composes the reflector, it can absorb the light in the visible region to prevent the light leaking from the back surface of the reflector and has high transparency to infrared rays, so the reflector is infrared It is possible to effectively prevent cracking and breakage of the reflector without being heated at. In addition, CuO has good heat resistance, and can maintain the light-shielding property of visible light for a long period without fading.
Therefore, it is possible to provide a reflector that can incorporate a bright lamp with higher input than before.

  In addition, according to the light source device of the present invention, it is possible to maintain the light shielding property of visible light over a long period of time without causing the fading of the light shielding film, and to change the specifications and materials of the reflector base material. In addition, it is possible to provide a light source device that can be equipped with a bright light source lamp with a higher input than before and has a high effect in various lighting fields.

  Hereinafter, the reflector of this invention and the light source device using the same are demonstrated in detail. FIG. 1 is an explanatory cross-sectional view showing the configuration of an example of a light source device using the reflector of the present invention. In this figure, reference numeral 10 denotes a light source lamp made of a halogen lamp, which has a bulb 11 made of quartz glass having a sealing portion 12 formed at one end and an exhaust pipe remaining portion 13 formed at the other end. A coiled filament 14 is disposed in the bulb 11 along the tube axis direction of the bulb 11 and supported by a lead rod 15. An external lead rod 16 is connected to the rear end of the lead rod 15 via a metal foil or the like.

Reference numeral 20 denotes a reflector, which is a condensing unit 22 formed with a condensing curved surface formed of a spheroid or a paraboloid, and the reflector integrally formed at the center bottom of the condensing unit 22. 20 has a glass base 21 composed of a cylindrical neck portion 23 extending in the axial direction, and a reflecting film 24 that reflects visible light and transmits infrared rays on the inner surface of the light collecting portion 22 of the base 21. Is formed. Examples of the reflective film 24 include a cold mirror, a high color temperature mirror, and various color mirrors. The spectral reflectance spectrum of the reflective film 24 varies depending on the use of the reflector 20, and in the case of the cold mirror specification, the spectral reflectance spectrum as shown in FIG. 4A is the previous diagram in the case of the high color temperature mirror specification. A spectral reflectance spectrum as shown in FIG. 4A is obtained. As the thin film material in these reflective films, there are TiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , CeO ₂ , ZnS, etc. for the high refractive index film material, and SiO ₂ , MgF _{2 for the} low refractive index film material. , Al ₂ O ₃ and the like.
As an example, a cold mirror includes, for example, a dielectric multilayer film having a thickness of 0.5 to 10 μm in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated, and mainly an infrared ray It has a function of transmitting light in the region and ultraviolet region and reflecting visible light.

  As the substrate 21 in the reflector 20, borosilicate glass having a strain point of 300 to 500 ° C. is used. In addition, those made of quartz glass, crystallized glass, and the like can be preferably used. The sealing portion 12 of the bulb 11 of the light source lamp 10 is inserted into the cylindrical hole of the neck portion 23 of the base body 21 of the reflector 20 and fixed by the adhesive S, while the front surface 20A of the reflector 20 has an opening. A transparent cover 25 is provided so as to close the cover.

A light shielding film 30 is formed on the outer surface of the base 21 of the reflector 20 to absorb visible light emitted to the outer surface of the reflector 20, transmit infrared light, and withstand high temperatures above the strain point of glass. .
The material of the film is CuO. Specifically, the film is formed by depositing ultrafine particles of CuO. This CuO has high infrared light transmittance, effectively absorbs only visible light, and has heat resistance. Optimally, CuO 100% is desirable, but other heat resistant materials such as TiO ₂ , SiO ₂ , ZnO ₂ , Fe ₂ O ₃ , NiO, in a range that does not reduce the above effect, specifically in a range less than 50%. _{ZrO 2, Co 3 O 4,} CeO 2, Al 2 O 3, may be included, such as.

The formation method of the CuO layer can be appropriately selected from a spray coating method, a dip coating method, a vacuum deposition method, a sputter deposition method, a chemical vapor deposition method, and the like, but considering the shape, simplicity, cost, etc. of the reflector to be coated For film formation, spray coating is preferred.
As the raw material solution for spray coating, either an aqueous solution or an organic solvent solution can be used, but an organic solvent solution is desirable when forming a film as homogeneous as possible. As the organic solvent solution, a solution in which CuO ultrafine particles are dispersed can be effectively used.

  It is necessary to use a CuO ultrafine particle diameter of 500 nm or less. This is because when the particle size of the ultrafine particles is 500 nm or more, the scattering of infrared rays having a wavelength of approximately 1000 nm or more is increased, the infrared transmittance of the film is deteriorated, the temperature is increased, and the surface of the fine particles is reflected. This is because the ratio of infrared light emitted from the back surface is reduced.

  Light scattering can be explained by Rayleigh scattering. Rayleigh scattering increases in proportion to the sixth power of the particle size and decreases in proportion to the fourth power of the wavelength (“Optoceramics”, Gihodo Publishing (1984)). In order not to cause a problem, the particle diameter of the particles should be 500 nm or less. On the other hand, in a film composed only of ultrafine particles, the adhesion between the film and the glass substrate is deteriorated, so it is preferable to use a solution mixed with a solution in which an organometallic salt of Cu is dissolved.

The film thickness of the final light shielding film 30 is 500 nm or more and 50 μm, preferably 500 nm to 10 μm.
When the film thickness is less than 500 nm, the visible light absorption rate is low, and a sufficient light shielding function cannot be obtained. If the film thickness is 500 nm or more, it is possible to reliably block visible light, so it may be thickly applied. However, if the film thickness exceeds 50 μm, the film easily peels off from the substrate 21, so that it is 50 μm or less, preferably 10 μm. In the following, it is more preferable to form it to 5 μm or less.

On the other hand, since the CuO layer coated on the back surface of the reflector has a refractive index of about 1.8 to 2.0, a part of infrared rays is reflected at the glass-film interface and the film-air interface, and returned to the front of the reflector. . In order to minimize this, a film having a lower refractive index than that of the CuO film, that is, a low refractive index film, an intermediate refractive index film, etc. are provided in a laminated state on the CuO film, and an antireflection function is provided. Is effective. As the material constituting the low refractive index film, SiO ₂ , MgF ₂ , Al ₂ O ₃ and the like are suitable, and as the material constituting the intermediate refractive index film, Y ₂ O ₃ , MgO and the like are suitable. Al ₂ O ₃ can also be used as an intermediate low to intermediate refractive index film.
The light shielding film may have a multilayer structure in which the antireflection film is formed as described above. Even when it is formed in such a multilayer film shape, it is necessary to design so that the thickness obtained by integrating only the CuO layers is 500 nm or more. The total thickness is preferably 50 μm or less.

If the size of the pigment is several μm or more like a general paint, reflection / absorption occurs on the surface of each pigment particle, which causes multiple reflections with many pigment particles in the film, and the optical properties of the substance The characteristics are completely different. Furthermore, in order to efficiently transmit infrared light as in the present invention, the film needs to be a homogeneous film free from cracks and heterogeneous phases. In order to obtain a homogeneous film, it is desirable that the film thickness is as thin as possible (desirably 10 μm or less) and the pigment particle diameter is as small as possible (desirably 200 nm or less). Such a characteristic membrane is limited by various factors, and cannot be considered only with some basic physical properties, but can be achieved by an experimental method. That is, in addition to CuO, candidates for visible light absorption / infrared light transmission film materials include Fe ₂ O ₃ , FeO, Cu ₂ O, Co ₃ O ₄ , Mn ₂ O ₃ , and Mn ₃ when heat resistance is taken into consideration. O _{4 and the} like are also considered to be practical.
However, in the case of a substance having a small absorption in the visible region, it is necessary to make the film thickness extremely thick, and the film becomes inhomogeneous such as a crack or becomes unusable due to peeling. In addition, a substance that absorbs too much cannot be used due to the problem that infrared light is absorbed and the reflector becomes hot. As a result of intensive studies by the present inventors, only a film containing CuO exceeding 50% is suitable for all of heat resistance, visible light absorption characteristics, and infrared absorption characteristics, and can solve the problems. It turned out that.

Here, the reflection and transmission paths of light by the reflector will be described. FIG. 2 is an explanatory view schematically showing a light path of the light source device according to the present invention. In addition, the structure demonstrated previously in FIG. 1 in the same figure is demonstrated using the same code | symbol.
As shown in FIG. 2, among the light emitted from the light source lamp 10 toward the reflector 20, most of the visible light is reflected by the reflecting film 24 in the concave reflecting mirror 20, as shown by the solid line. Become. On the other hand, visible light that has passed through the reflective film 24 passes through the base 21 in the reflector 20 and enters the light shielding film 30 formed on the outer surface, as indicated by the dotted line. As a result of the visible light being absorbed by the CuO ultrafine particles in the light shielding film 31, the visible light is reliably prevented from being emitted behind the reflector 20.
On the other hand, about the infrared rays among the light emitted from the light source lamp 10, almost all of the light passes through the reflection film 24 and passes through the base 21 in the reflector 20 as indicated by the dotted line, and further, the light shielding film 30 formed on the outer surface of the reflector. Is incident on. Most of the infrared light passes through the light shielding film 30 and is emitted as it is behind the light shielding film 30, so that the outer surface of the reflector 20 is prevented from being excessively heated. In addition, since the light shielding film 30 does not reflect infrared rays, the light shielding film 30 is not incident on the base material 21 again to be irradiated to the illuminated body, and the illuminated body is not heated.

Although the present invention has been described above, it is needless to say that the embodiment of the present application is not limited to the above items and can be modified as appropriate. For example, the light source lamp incorporated inside is not limited to an incandescent lamp such as a halogen lamp, but may be a discharge lamp such as a metal halide lamp, a short arc xenon lamp, a high pressure mercury lamp, or a high pressure sodium lamp.
In the present invention, by using a film having a high infrared transmittance, heating of the light shielding film can be prevented, and an overheated state of the reflector can be avoided. As a result, it was possible to combine a lamp with a higher input than the conventional one in the present invention, which conventionally had to prevent overheating using a dark lamp with reduced power consumption. Thus, it becomes possible to provide a light source device with high production effect. Of course, in the light shielding film of the present application, the absorption of visible light has the same characteristics as the conventional one, so that the lighting effect can be surely exhibited without feeling dazzling behind the reflector.

〔Example〕
Examples of the present invention are shown below.
On the inner surface of the concave glass substrate made of borosilicate glass, which is an illumination reflector for light projection, a cold mirror multilayer film made of TiO ₂ —SiO ₂ 23 layer so as to have the reflectance shown in FIG. It formed using the sputtering vapor deposition method.
Next, a spray coating solution for forming a visible light absorbing / infrared light transmitting film formed on the outer surface of the reflector was prepared. The solution for spray coating is 100 g of a mixture of ethanol 72 wt%, propionic acid 10 wt%, normal caprylic acid 5 wt%, and propionate copper 13 wt%, and CAI Kasei Co., Ltd. Cu Eta 15 wt% -G180, CuO ultrafine particle dispersion 300 g Are mixed. This was coated on the outer surface of the reflector using a spray method so that the film thickness was 1 μm. After drying the coat film, the reflector was placed in an electric furnace, held at 500 ° C. for 5 minutes, and baked to form a film.

[Comparative Example 1]
A reflector different from that of the example only in the configuration of the light-shielding film was produced as Comparative Example 1.
The configuration of the dielectric multilayer film formed on the reflector base and the light condensing part is the same as in the above-described embodiment. That is, a cold mirror multilayer film composed of a TiO ₂ —SiO ₂ 23 layer was formed on the inner surface of the concave glass substrate by sputtering deposition. A light shielding film was formed by applying and forming a conventional black paint on the outer surface of the reflector. The black paint was Bond X75 manufactured by Nissan Chemical Co., Ltd., and was spray-coated on the outer surface of the reflector so that the film thickness was 1 μm.

[Comparative Example 2]
A reflector was produced in the same manner as in the above example except that no light-shielding film was formed.

[Experimental Example 1]
On the other hand, in the reflector as an example of the present invention, the reflector surface temperature was 300 ° C. or less, and no problem occurred.
The spectral transmittance spectra of the reflectors of Example 1, Comparative Example 1 and Comparative Example 2 were measured. The result is shown in FIG.
As described above, Comparative Example 2 is a reflector in which a light-shielding film is not formed. However, as shown by the curve of Comparative Example 2 in FIG. 3, the light in the reflector visible region is transmitted to the outside through the reflective film. I understand that.
In Comparative Example 1, a conventional black paint is applied and formed on the outer surface of the reflector. This reflector absorbed not only visible light but all light in the entire infrared region, and the transmittance was almost 0%.
In the spectral transmittance spectrum of the example of the present invention, it can be seen that only visible light is absorbed and infrared light is substantially transmitted.

[Experimental example 2]
Subsequently, the effect of the infrared transmitting light-shielding film of the present application was verified by actually mounting the lamp on the reflectors of Example 1 and Comparative Example 1.
First, double-end type halogen lamps with a rated power consumption of 100 V to 750 W were incorporated in the respective reflectors, and the electric introduction part was melt-sealed with a burner. Further, a lens was attached to the front surface of the reflector, and the flange portion was melt-sealed with a burner. Thereafter, the inside of the reflector was evacuated and nitrogen gas was sealed at 0.5 atm to produce a light source device.
Each light source device was lit at 750 W, which is the rated power consumption of the lamp.
None of the reflectors of Examples and Comparative Example 1 leaked visible light from the back.
However, in the reflector of Comparative Example 1 coated with a conventional black paint, the reflector surface temperature became 500 ° C. or more, and cracks occurred from the vicinity of the electricity introduction part.
On the other hand, the reflector according to the example of the present invention had a surface temperature of 300 ° C. or less, and no cracks occurred in the substrate, and no problem occurred. This is because the light-shielding film of the reflector of the example has high transparency to infrared rays, so that heating of the light-shielding film was prevented, and as a result, the glass constituting the reflector substrate could be maintained below the heat-resistant temperature. by.
Further, when lighting experiments were repeated for the light source device according to the example of the present application, it was confirmed that there was no leakage of light backward after 3500 hours of lighting, and stable light shielding characteristics could be maintained. As described above, according to the present invention, the single layer mainly composed of CuO can provide the desired characteristics in any of heat resistance, visible light shielding property, and infrared transmission property. In addition, a reflector with a light-shielding film having the desired characteristics can be obtained.

It is sectional drawing for description which shows the structure in an example of the light source device using the reflector of this invention. It is explanatory drawing which showed typically the path | route of the light of the light source device concerning this invention. It is a figure which shows the spectral transmission factor spectrum of the reflector of Example 1, the comparative example 1, and the comparative example 2. FIG. It is a figure which shows a cold mirror and a high color temperature mirror coat film | membrane calculation example, (a) is a cold mirror, (b) is a thing of a high color temperature mirror. It is explanatory drawing which showed typically the path | route of the light of the light source device concerning a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source lamp 11 Bulb 12 Sealing part 13 Exhaust pipe remainder 14 Filament 15 Lead bar 16 External lead bar 20 Reflector 20A Front surface 21 Base body 22 Condensing part 23 Neck part 24 Reflective film 25 Cover 30 Light shielding film 31 Light shielding film

Claims (4)

It has a condensing part that reflects light forward, and a reflective film that reflects light in the visible light region and transmits light in the infrared region is formed on the inner surface of the light condensing part, and absorbs visible light on the outer surface. A reflector formed with a light shielding film,
The light-shielding film is made of a film mainly composed of CuO. It has a condensing part that reflects light toward the front, a reflective film that reflects visible light and transmits infrared light is formed on the inner surface of the condensing part, and absorbs visible light on the outer surface A light source device comprising a reflector having a light shielding film formed thereon, and a light source lamp disposed inside the light collecting portion of the reflector,
The light source device according to claim 1, wherein the light shielding film of the reflector is made of a film mainly composed of CuO.   The light source device according to claim 2, wherein a thickness of the light shielding film is not less than 500 nm and not more than 50 μm. The light shielding film is formed in a multilayer structure by forming a film having a refractive index lower than that of the film mainly containing CuO in a laminated state on the film mainly containing CuO,
The light source device according to claim 2, wherein a thickness obtained by integrating the films containing CuO as a main component is 500 nm or more, and a total thickness of the light shielding film is 50 μm or less.

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