JP2002042538A - Reflective lighting system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A reflector in which a bulb such as a high-pressure discharge lamp or a halogen bulb is housed in a reflector, and a light control plate such as a glass front lens or a protective cover is disposed in an opening of the reflector. It is an object of the present invention to provide a reflection-type lighting device provided with a highly-safe light-controlling plate in which a glass piece is less likely to be scattered even if a crack occurs in a shaped lamp. SOLUTION: A reflecting mirror 1 having a concave reflecting surface 15, an arc tube L1 provided in the reflecting mirror 1, and the reflecting mirror 1
And a light control plate 2 made of hard glass and provided with a tensile stress in a circumferential direction around a position facing the arc tube L1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of housing a light-emitting tube such as a high-pressure discharge lamp or a halogen bulb in a reflector, and providing a light-control plate such as a lens made of hard glass in a front opening of the reflector. The present invention relates to a reflective illumination device.

[0002]

2. Description of the Related Art In recent years, high-pressure discharge lamps such as metal halide lamps have been reduced in size and reduced in wattage, and are increasingly used as light sources for homes and shops.

[0003] In this metal halide lamp, although rarely, at the end of its life, the arc tube bulb is damaged, and the enclosed mercury and glass pieces such as bulbs are scattered, which may cause a safety problem. This is because the quartz glass of the valve material
This is because the strength decreases due to the reaction with the enclosed halide and the internal pressure increases during lighting.

Therefore, there is a double-tube structure in which the arc tube is accommodated in an outer tube made of hard glass. However, when the arc tube bursts, a thin glass outer tube is destroyed at the same time. Therefore, explosion-proof countermeasures such as surrounding the arc tube with a middle tube made of hard glass or quartz glass or covering the arc tube with a metal net to suppress light transmission loss have been adopted.

[0005] In addition, the PAR having the double pipe structure has a PAR.
An arc tube such as a metal halide lamp is housed in a concave reflector called a shape, a light control plate consisting of a front lens is placed in the opening on the front of the reflector, and a base is attached to the back of the reflector. There are discharge lamps.

The double-tube reflective discharge lamp has a high light-emitting efficiency, is simple in appearance, and is capable of protecting the outer envelope made up of a reflector and a front lens against rupture and contact of the arc tube. It is widely used because it has high safety because the glass thickness is large, and the equipment structure can be simplified.

However, recently, there has been a demand from customers for various characteristic lamps for the PAR type lamp depending on the application and the like, and the tolerance in design has been reduced, and the envelope has been damaged due to high output and the like. The danger came out.

In this PAR type lamp, it is conceivable to enclose the arc tube with an explosion-proof middle tube or a metal net. However, there are problems in space and mounting structure, and the glass thickness of the front lens is further increased. However, there is a problem in technology and cost.

In this type of PAR type lamp, as means for integrating the reflecting mirror and the front lens, the periphery of the overlapping portion of the reflecting mirror and the front lens is heated by a ring-shaped gas burner or the like, and the PAR lamp is heated by a ring-shaped gas burner. When the glass is softened and melted, the periphery of the polymerized part is pressed with a roller and fused to form a hermetic joint, or the heat-resistant adhesive interposed in the polymerized part is heated and softened to flow down, solidified, and joined. That is being done.

In the case where the above-mentioned reflecting mirror and front lens are joined by melting glass, the glass is gradually cooled after molding to remove distortion caused by thermal processing. In this slow cooling operation, distortion is reduced or eliminated as much as possible, so that cracks and cracks are not generated in the surrounding container. For example, the residual strain in the front lens has a tensile strain of 10 to 10.
It was as small as about 20 kg / mm ² . Further, in the case of bonding with an adhesive, the heat processing temperature was low, and the amount of residual strain in the front lens was even smaller than in the case of fusion.

[0011]

As described above, the surrounding container joined by fusion or adhesion has a small amount of distortion and a high strength. However, according to observations made by the present inventors, if the arc tube ruptures for some reason and the fragment collides with the front lens having a small amount of distortion, a crack occurs in the front lens, and the crack enters irregularly. The front end of the front lens extends in the circumferential direction, and sometimes the tip of the crack is connected, and the glass piece of the lens broken in a ring shape may be scattered or dropped.

The inventors of the present invention have studied the cracks variously, and have found that even if the front lens is cracked and cracked, it is possible to prevent the broken pieces from scattering or falling due to the cracking. I found it.

According to the present invention, there is provided a reflector lamp in which a bulb such as a high-pressure discharge lamp or a halogen bulb is housed in a reflector, and a light control plate such as a glass front lens or a protective cover is provided at the opening of the reflector. It is an object of the present invention to provide a reflection-type lighting device provided with a highly safe light control plate that is less likely to scatter glass fragments even when cracks occur.

[0014]

According to a first aspect of the present invention, there is provided a reflective illuminating apparatus comprising: a reflecting mirror having a concave reflecting surface; an arc tube disposed in the reflecting mirror; A light control plate made of hard glass, which is provided so as to cover the opening and has a tensile stress formed in a circumferential direction around a position facing the arc tube.

[0015] Even if the arc tube bulb housed in the envelope ruptures for some reason and the fragments hit the light control plate to cause cracks in the light control plate, the cracks extend radially to connect the cracks to each other. This is extremely low, and the risk of cracking and scattering or falling can be reduced.

The material of the reflector and the light control plate is hard glass such as quartz glass and borosilicate glass, and the reflector is made of glass of the same quality as the light control plate or metal such as iron plate and aluminum plate. Applicable.

The reflecting surface formed on the inner surface of the reflecting mirror is made of a visible light transmitting infrared reflecting film composed of a multilayer light interference film, a visible light reflecting infrared transmitting film, an optical filter film or the like, or aluminum, silver, chromium or the like. One selected from all-light reflecting films can be used.

Further, the light control plate has a front lens of a condensing (narrow angle) type, a standard (medium angle) type, a diffused (wide angle) type or the like for regulating a light distribution of emitted light, and the lens is formed on the inner surface side. A predetermined light distribution characteristic can be obtained by changing the shape and size of the lens element to be formed. In addition, the light control plate is used as a filter for changing the color of light emitted from the internal arc tube, or as a protective cover body for preventing scattering when the arc tube bulb is broken, collision with other objects, and prevention of internal contamination. Applicable to those that work.

The reflective illuminating device according to a second aspect of the present invention is characterized in that the overlapping portion between the opening of the reflecting mirror and the peripheral edge of the light control plate is hermetically joined.

In the case where the peripheral portions of the reflector and the light control plate are joined together in an airtight manner by fusion or adhesive, even if the crack is large, the two are connected because the front lens is scattered or dropped. Can be prevented.

According to a third aspect of the present invention, in the reflective lighting device, the maximum value of the tensile stress in the light control plate is 30 kg.
/ Cm ² or more.

If the maximum value of the tensile stress perpendicular to the radial direction applied to the light control plate is less than 30 kg / mm ² , cracks generated in the light control plate may be irregular or may extend in the circumferential direction of the light control plate. The tip of the crack is connected, and there is a problem that the glass piece of the lens broken in a ring shape scatters or falls. The maximum value of the tensile stress is preferably up to about 100 kg / mm ^{2. If the} amount of the distortion is large, there is a possibility that the light control plate is damaged or a crack is generated when a small amount of stress is applied.

The reflection type lighting device according to a fourth aspect of the present invention is characterized in that a tensile stress is formed on the light control plate by heat generated by rated lighting of the arc tube.

A predetermined value of tensile stress can be applied by utilizing the heat generated by self-illuminating the light-emitting tube with direct light and reflected light applied to the light control plate.

That is, when the lighting device is turned on, usually,
Since the arc tube is arranged on the central axis of the reflector, the temperature of the central part of the light control plate on the extension of the central axis becomes the highest,
Heating is performed so that the temperature decreases toward the periphery.

According to a fifth aspect of the present invention, there is provided the reflection type lighting apparatus, wherein the rated temperature of the arc tube is 300 ° C. in the radial direction of the light control plate.
The temperature gradient in the above portion is set to 5 ° C./mm or more.

If the temperature gradient is set to 5 ° C./mm or more and heating is performed, when the maximum value of the tensile stress becomes 30 kg / mm ² or more and cracks occur, the cracks extend radially. It has the same effect as described.

[0028] The reflection type illuminating device according to claim 6 of the present invention is characterized in that the arc tube is a high pressure discharge lamp or a halogen bulb.

The arc tube is a high-pressure discharge lamp such as a metal halide lamp or a mercury lamp in which a discharge electrode is disposed in the bulb, or an incandescent lamp such as a halogen bulb in which a coiled filament wound with a tungsten wire is disposed as a light source. Applicable to

In the above, there is no limitation on the bulb shape, material, or sealing structure of the lamp provided as a light emitting source in the envelope.

In the arc tube of the present invention, a multiple light interference film may be formed on the surface of the arc tube bulb. Visible light transmitting infrared reflecting film or visible light reflecting infrared transmitting film etc. formed on the surface of the bulb to improve the efficiency of the arc tube, etc. Can be.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a reflection type lighting device according to the present invention will be described below with reference to FIGS. Figure 1
Is a partial cross-sectional front view of a PAR-type (reflection type) discharge lamp HL (model name: MR150W / WW-W) for projecting light, which constitutes a reflection type illumination device. FIG. 2 is a bottom view of the light control plate in FIG. .

In the figure, reference numeral 1 denotes a PAR type (maximum diameter portion is about 121 m).
m), a hard glass such as borosilicate glass (coefficient of thermal expansion 35-40 × 10 ⁻⁷ / ° C., strain point temperature 470-5
The inner surface formed at 10 ° C.) is a paraboloid of revolution, a spheroidal surface, a spherical surface, and the like. Part 1
One.

On the inner surface of the reflecting mirror 1, there is formed a visible light reflecting infrared transmitting film made of a multi-layered light interference film such as a dichroic film or a total light reflecting film of aluminum, silver or chromium, here a dichroic film 15. is there.

Reference numeral 2 denotes a light control plate composed of a front lens and a disk-shaped front lens formed of glass of the same quality as the reflecting mirror 1 and a protective cover. The outer surface of the front lens 2 has a smooth surface. However, the inner surface side has a substantially hemispherical shape projecting as shown in an enlarged view in FIG. 2, or the surface has a substantially hemispherical shape, but the base side overlaps with an adjacent element and has a large number of lenses which look substantially hexagonal. .. (Actually formed on the entire surface, but a part thereof is shown in this figure). (Note that the lens elements 22, 22,...
The shape, arrangement, size, number, and the like of light-emitting devices vary depending on light distribution characteristics, such as a narrow-angle (light-collecting) shape, a medium-angle (standard) shape, and a wide-angle (scattered) shape. Then, the front lens 2 is covered so as to cover the opening of the reflecting mirror 1 and the opposing surfaces of the peripheral portions 11 and 21 thereof are superposed and heated and softened and melted, and then a roller is applied to the peripheral side edge of the superposed portion. The reflecting mirror 1 and the front lens 2 form an envelope 3 in the present invention.

L1 is an arc tube of a small high-pressure discharge lamp, for example, a metal halide lamp.
A crushed sealing portion 41 is formed at one end of the arc tube 4 made of quartz glass, and is formed of tungsten or the like connected to metal foils 51 made of molybdenum foil or the like sealed in the sealing portion 41. Coiled discharge electrodes 6 and 6 in which a tungsten wire is wound are provided at the tips of the internal introduction wires 52 and 52.

In the valve 4, Sn—Na—Tl
A discharge medium such as -In-Li (I, Br) -based halide, mercury, argon gas or the like is sealed so as to have a pressure of 15 to 25 atm during lighting.

The light emitting tube L1 is housed in the reflecting mirror 1 and is arranged at a position closer to the opening than the focal position of the reflecting mirror 1.
External lead-in wires 53, 53 led out of the sealing portion 41 penetrate the bottom wall of the base portion 12 of the reflecting mirror 1, and the support wire 5 whose base is brazed to a cap-shaped ferrule (not shown).
5, 55 and are electrically connected. Another conductor is connected to the ferrule (not shown), and this conductor is connected to the terminal of the base 7 attached to the base 12.

The PAR type (reflection type) discharge lamp HL is connected to a lighting circuit having a ballast and the like to be lit. The discharge lamp HL is connected to the discharge electrodes 6 in the arc tube L1.
The discharge medium emits light when excited by the discharge medium between the six discharges,
The radiated light is reflected by the direct light and the reflection film 15, enters the substantially hemispherical lens elements 22, 22,... Of the front lens 2, and is refracted by the lens elements 22, 22,.
From a wide range (wide angle).

The front lens 2 generates a tensile stress in a circumferential direction about a position facing the center of the arc tube L1 as shown by an arrow in FIG. The maximum value of the tensile stress is about 70 kg / mm ² ,
Even if the bulb 4 of the arc tube L1 housed in the surrounding container 3 ruptures for some reason and the fragment collides with the front lens 2 to cause cracks in the lens 2, the cracks extend radially and the cracks extend from each other. Are rarely connected.

Therefore, even if the front lens 2 is cracked, it is extremely rare that the front lens 2 breaks and scatters or falls, and a PAR type (reflection type) which has an excellent effect on safety and hardly affects people and articles. (Shape) A discharge lamp HL can be provided.

Incidentally, like the PAR type (reflection type) discharge lamp HL of the above embodiment, the reflection mirror 1 and the front lens 2 are used.
When the two are connected by fusion, the front lens 2 is not scattered or dropped because the two are connected even if the crack is large.

Further, a fluororesin film that acts as a joint when a crack occurs is formed on the surface of the surrounding container 3 except for the central portion of the front lens 2 where the temperature becomes high and the surface of the reflecting mirror 1 by coating. Does not matter.

The maximum value of the tensile stress applied to the front lens 2 perpendicular to the radial direction is a minimum of 30 kg / mm.
² or more, sufficient if the maximum 100 kg / mm ² degree, cracks maximum occurs in the front lens is less than 30kg / mm ² is extended in the circumferential direction of the front lens, it will sometimes led the tip of the crack In addition, there is a problem that a glass piece of a lens broken in a ring shape scatters or falls.

The maximum value of the tensile stress is 100 kg.
/ Mm ² , the distortion amount is large and the front lens 2
There is a possibility that a crack may occur if the surface is damaged or a small amount of stress is applied.

FIGS. 3 and 4 are front views, partially in section, showing another embodiment of the reflection type lighting device of the present invention. In the drawings, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. The description is omitted here.

The luminous tube of the reflection type illumination device (reflection type halogen bulb) IL shown in FIG. 3 is a halogen bulb L2, and the reflection mirror 1 is made of hard glass such as quartz glass or borosilicate glass or metal here, quartz glass. The inner surface formed by the above has a concave shape (bowl shape) such as a paraboloid of revolution, and a base portion 12 and a through hole 13 protruding in the center of the back surface are formed. A reflecting film 15 is formed on the inner surface of the reflecting mirror 1.

The light control plate forms a transparent cover member 2 made of glass of the same quality as the reflection mirror 1, and the reflection mirror 1 and the cover member 2 are made of a silicone-based material interposed between the superposed peripheral portions of the two. The surrounding container 3 is formed by joining with the heat resistant adhesive 31.

The cover member 2 is also a front surface of the above embodiment.
In the same form as the lens 2, a tensile stress is generated in the circumferential direction.
The maximum value of the tensile stress is about 65 kg /
mm ^Two It is.

In the halogen bulb L2, a pair of internal lead wires 52 and 52 made of molybdenum wire or the like are introduced into an arc tube 4 made of hard glass such as quartz glass or aluminosilicate glass. A coil-shaped filament 6F formed by winding a tungsten wire is connected to the ends of the lead wires 52, 52.

The bulb 4 is filled with a Br.Cl-based halide and an inert gas such as krypton and nitrogen.

In the halogen lamp L2, the filament 6F is adjusted to the focal position of the reflection film 15, and the crushed sealing portion 41 is accommodated in the through hole 13 of the central base portion 12 and joined via the heat-resistant adhesive 19. It is fixed. In the drawing, reference numerals 71, 71 denote a pair of terminal pins connected to the external lead wires 53, 53.

The reflection type illumination device IL is turned on when the terminal pins 71, 71 are connected to the socket. The reflective illuminator IL emits light when energized to the filament 6F in the arc tube L2 formed of a halogen bulb, and the radiated light is reflected by the direct light and the reflection film 15 and transmitted through the transparent cover member 2 to be radiated. You.

Also in this reflective illumination device IL, the arc tube L2 made of a halogen bulb reaches the end of its life or the like and the arc tube 4 ruptures and scatters, and the fragments collide with the cover member 2 and crack on the cover member 2. Even if cracks occur, the cracks are not broken radially and do not scatter or fall.

FIG. 4 shows a reflection-type lighting device (reflection-type lighting equipment) DL in which a reflection mirror and an arc tube are separate from each other, whereas the above-described FIGS. 1 and 3 are reflection-type lamps.

In FIG. 4, reference numeral 81 denotes a housing. Inside the housing 81 is a socket 8 on which a base 7 of a high-pressure discharge lamp L3 such as a metal reflector 1 and a metal halide lamp is mounted.
2 and a lighting circuit device 83 for supplying power to the socket 82 are provided.

A transparent cover member made of hard glass is attached to the opening of the housing 81 as a light control plate 2 by a screw (not shown) via a ring-shaped holder 84. It should be noted that a tensile stress is generated in the cover member 2 in the circumferential direction in the same manner as the cover member 2 of the above embodiment, and the maximum value of the tensile stress is about 60 kg / mm ² . .

As described above, the reflecting mirror 1, the light control plate 2, and the lamp L3 are not integrated, and for example, when the lamp L3 reaches the end of its life, the reflection type lighting device DL can be replaced with a new lamp L3. And even with such a configuration, the same operation and effects as those of the lighting devices HL and IL of the above-described embodiment can be obtained.

As means for applying the above-mentioned appropriate tensile stress to the light control plate (front lens or cover member),
(1) It can be performed by controlling the temperature at the time of slow cooling operation of forming a light control plate (front lens or cover member).
(2) After completion of the lighting device, the light emitting tube can be turned on, and direct light and reflected light can be applied to a light control plate (front lens or cover member) by utilizing its own heat generation.

That is, (1) can easily produce a large quantity of light control plates with uniform stress in the manufacturing process.

(2) When the lighting device is turned on, the arc tube is usually arranged on the central axis of the reflecting mirror.
In the light control plate, the temperature at the central portion on the extension of the central axis becomes the highest, and the temperature decreases toward the periphery. In the experiment of the present inventors, at the time of lighting, if a temperature gradient of a light control plate made of hard glass (strain point temperature of 470 to 510 ° C.) is set to 5 ° C./mm or more, a desired tensile stress is applied. Was completed.

FIG. 5 shows the distance r from the center of the light control plate.
FIG. 6 is a graph comparing the relationship between mm and temperature (° C.).
Temperature gradient in the light control plate ° C / mm and maximum stress kg / m
3 shows a graph comparing the relationship with m ² .

The reflecting mirror and the light control plate usually made of glass are cut by a predetermined amount of a glass lump from a glass melting furnace, dropped into a bottom mold, and pressed by a plunger mold from above. It is formed into a predetermined shape and size.

When the molded product is viewed, streaks, scissors or wrinkles, which are called scissors, remain when cutting the molten glass lump.

These wrinkles may be unsightly in appearance,
It is better not to have it, but it is very difficult to eliminate it, and this streak is also marked as one of the crack sources.

In the experiments conducted by the present inventors, the lower the stress at the streaked wrinkles in the light control plate, the stronger the strength.
The tensile stress was preferably about 30 to 60 kg / mm ² , and the presence of streak-like wrinkles was located off the center, which was inconspicuous in both strength and appearance.

The present invention is not limited to the above embodiment. For example, the arc tube accommodated in the envelope is not limited to a metal halide lamp or a halogen bulb, but may be another type of high-pressure discharge lamp or incandescent bulb.

On the surface of the arc tube composed of the high-pressure discharge lamp or the incandescent lamp, a multilayer light interference film such as a visible light transmitting infrared reflecting film or a visible light reflecting infrared transmitting film for improving the luminous efficiency is provided. A film or the like that absorbs or blocks ultraviolet rays may be formed.

Further, there are lamps of the reflection type which have different light distribution characteristics such as wide-angle, medium-angle and narrow-angle irradiation beam angles. In order to obtain desired characteristics, each lamp is engraved on a light control plate. What is necessary is just to adjust the position of the arc tube with respect to the lens element and the reflection surface.

[0070]

According to the first aspect of the present invention, even if the light control plate is cracked, it is extremely rare that the light control plate breaks and scatters or falls, and has little effect on humans or articles. It is possible to provide a reflection-type lighting device having an operational effect.

According to the second aspect of the present invention, when the peripheral portions of the reflector and the light control plate are air-tightly joined by fusion or an adhesive, they are connected even if the cracks are large, so that they are connected. The scattering and falling of the light plate can be prevented.

According to the third aspect of the invention, the same effect as described in the first aspect is exerted by regulating the maximum value of the tensile stress perpendicular to the radial direction applied to the light control plate.

According to the fourth aspect of the present invention, the arc tube accommodated in the device is turned on, and a predetermined tensile stress is applied by utilizing its own heat generated by applying direct light and reflected light to the light control plate. The same effects as those described in the first to third aspects are obtained.

According to the fifth aspect of the invention, the same effect as described in the fourth aspect can be obtained by regulating the temperature gradient in the radial direction of the light control plate.

According to the sixth aspect of the invention, the same effects as those described in the first to fifth aspects can be obtained by applying the present invention to a high-pressure discharge lamp such as a metal halide lamp and a mercury lamp and an incandescent lamp such as a halogen bulb. A reflective lighting device can be provided.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view showing an embodiment of a reflection-type lighting device (PAR-type discharge lamp) according to the present invention.

FIG. 2 is a bottom view of the light control plate in FIG.

FIG. 3 is a partially sectional front view showing another embodiment of the reflection-type lighting device (reflection-type halogen bulb) according to the present invention.

FIG. 4 is a partially sectional front view showing another embodiment of the reflection-type lighting device (reflection-type lighting fixture) according to the present invention.

FIG. 5 is a graph comparing the relationship between the distance mm from the center of the light control plate and the temperature ° C.

FIG. 6 shows a temperature gradient of the light control plate in ° C./mm and a maximum stress k.
6 is a graph comparing the relationship with g / mm 2.

[Explanation of symbols]

 HL: Reflective illuminator (PAR type discharge lamp) IL: Reflective illuminator (reflective halogen lamp) DL: Reflective illuminator (reflective lamp) L1 to L3: Reflective lamp (halogen bulb, discharge lamp) L1: arc tube of discharge lamp L2: halogen bulb 1: reflective mirror 15: reflective film 2: light control plate 3: envelope 6: discharge electrode 6F: coiled filament

Claims (6)

[Claims] 1. A reflecting mirror having a concave reflecting surface; an arc tube disposed in the reflecting mirror; and a circumference provided around the opening of the reflecting mirror and centered on a position facing the arc tube. A light control plate made of hard glass in which a tensile stress is formed in a direction. 2. The reflection-type lighting device according to claim 1, wherein the overlapping portion of the opening of the reflecting mirror and the peripheral portion of the light control plate is hermetically joined. 3. The reflection type illuminating device according to claim 1, wherein the maximum value of the tensile stress in the light control plate is 30 kg / cm ² or more. 4. The light control plate according to claim 3, wherein a tensile stress is formed on the light control plate by heat generated by rated lighting of the arc tube.
2. The reflective illumination device according to claim 1. 5. A temperature gradient at a temperature of 300 ° C. or more in the radial direction of the light control plate at the time of rated lighting of the arc tube is 5 ° C./mm.
The reflection-type lighting device according to claim 3, wherein: 6. The reflective lighting device according to claim 1, wherein the arc tube is a high-pressure discharge lamp or a halogen bulb.