JP2022046409A - Lighting device - Google Patents

Abstract

To extend the life of a lighting device using an FEL.SOLUTION: In a lighting device using an FEL 40, a phosphor 4 applied to a surface of a support 41 made of a substance having both good electrical conductivity and thermal conductivity has an ultrathin layer as close as possible to the minimum amount of phosphor that can be obtained. Furthermore, the phosphor 4 is provided as thin as possible without covering the front of the surface of the support 41 until the background of the support 41 can be glimpsed between the phosphors 4 and the support, and a part of the support 41 is exposed to the outside of the lighting device.SELECTED DRAWING: Figure 8

Description

The present invention relates to a configuration capable of suppressing a phenomenon in which a light emitting body stops emitting light in a short period of time due to a temperature rise under a high voltage in a lighting device using a diamond light emitting element.

There are various types of artificial lighting such as incandescent lamps, fluorescent lamps, metal halide lamps, mercury lamps, and halogen lamps. However, all of them have problems such as high power consumption and use of harmful substances such as mercury, which leads to environmental destruction. Therefore, all of the current artificial lighting is being banned from use.

In the future, instead of these artificial lightings, the Field Emission Lamp (hereinafter abbreviated as FEL), which is a lighting device using a diamond light emitting element, is attracting attention.

Japanese Unexamined Patent Publication No. 2008-10169

Although FEL is expected as a next-generation lighting device with high brightness, it has a problem that the life as a lighting device is only about one month.

The present invention has been made in view of the above circumstances, and an object of the present invention is to solve a problem currently identified as a cause of a short life of a FEL and to extend the life of the FEL to one month or more.

In FEL, a very high voltage is applied to the fluorescent material at the time of lighting, so that the temperature of the fluorescent material rises and the fluorescent material is destroyed at an early stage. This fluorophore destruction shortens the life of the FEL. In the present invention, the temperature rise of the phosphor is suppressed by cooling by utilizing convection, radiation and conduction of heat.

Specifically, the lighting device of the present invention is
Emitter and
A phosphor that receives the electrons emitted by the emitter and emits fluorescence toward the light irradiation surface, and
It has a support made of a substance that supports the phosphor and has good electric conductivity and thermal conductivity.
The fluorescent material is thinned until a part of the support is exposed in a minute gap of the fluorescent material, that is, a glimpse can be seen between the fluorescent materials. It is preferably provided on the surface.

In addition, the fluorophore has an ultrathin layer close to the minimum amount that can be obtained from the fluorophore, and the fluorophore has a part of the support between the fluorophore. It is preferable that the support is thinned until it can be glimpsed and provided on the surface of the support.

With this configuration, the lighting device of the present invention can efficiently dissipate heat generated in the phosphor during light emission from the support to the outside of the lighting device by utilizing conduction and radiation.

Here, the amount of the phosphor in the present invention is defined by another expression as follows. That is, the amount of the fluorescent substance has the amount of fluorescence required for the fluorescent substance, that is, an amount close to the minimum amount at which brightness can be obtained.

Further, the substance having good both electric conductivity and thermal conductivity is preferably a metal.

In the present invention
The emitter is provided between the phosphor and the light irradiation surface.
There is an aspect.

According to this aspect, the light generated by the phosphor is irradiated from the surface of the phosphor toward the light irradiation surface without passing through the phosphor, so that the light irradiation efficiency of the lighting device is improved.

In the present invention
Further comprising a transparent sealant covering the emitter, the support and the fluorophore
At least one end of both ends of the support penetrates the transparent sealing body and projects to the outside of the illuminating device.
The gap between the support and the transparent sealant is sealed and the inside of the transparent sealant is sealed.
There is an aspect.

In the present invention
Both ends of the support penetrate the transparent sealing body and project to the outside of the lighting device.
There is an aspect.

According to this aspect, since both ends of the support are exposed to the outside of the lighting device, heat convection, which is important when radiating heat to the space outside the device through the support, is efficiently generated. Therefore, the heat dissipation effect using conduction and radiation is further improved.

In the present invention
The support is provided on the illuminating device along the vertical direction.
There is an aspect.

According to this aspect, since the support is arranged along the vertical direction, the temperature becomes high in contact with the support and the lightened air rises. Then, new low-temperature air comes into contact with the support from the bottom, the temperature becomes high, and the lightened air rises. This state is repeated, and convection of heat, which is important when radiating (radiating) heat to the external space of the device via the support, is generated more efficiently, and the heat radiating effect is further improved.

In the present invention
The support has a tubular shape in which one end of both ends is open, and the one end projects to the outside of the lighting device.
The in-cylinder space of the support is exposed to the outside of the device via the one end.
There is an aspect.

According to this aspect, since the in-cylinder space of the support is exposed to the outside of the device without interfering with the sealing inside the lighting device, the surface area of the support exposed to the outside of the device is increased, and the heat dissipation effect is further improved. do.

In the present invention
The support has a tubular shape with both ends open, and both ends project to the outside of the lighting device.
The in-cylinder space of the support is exposed to the outside of the device via each of the both ends.
There is an aspect.

According to this aspect, since the in-cylinder space of the support is exposed to the outside of the device without hindering the sealing of the inside of the lighting device by the support, the surface area of the support exposed to the outside of the device is increased, and the heat dissipation effect is obtained. Is further improved. Further, since both ends of the in-cylinder space are exposed to the outside of the device, air circulation occurs between the in-cylinder space exposed to the outside of the device and the space outside the device. Therefore, heat convection generated inside and outside the apparatus is more efficiently generated through the air circulation, and the heat dissipation effect is further improved.

The conventional lighting device has a problem that the fluorescent substance does not emit light in a short period of time due to the temperature rise of the fluorescent substance. However, according to the present invention, the heat of the fluorescent substance generated at the time of light emission is transmitted through the support. It became possible to quickly conduct the light to the outside of the device. As a result, it is possible to suppress the temperature rise of the phosphor and extend the life of the phosphor.

Further, in the conventional lighting device, the light generated by the light emission of the phosphor has to go out through the gap of the non-light emitting phosphor, and therefore the emitted light is attenuated. On the other hand, in the lighting device of the present invention, all the emitted light reaches the surface of the lighting device, so that it is possible to provide a brighter lighting device than the conventional one.

It is a perspective view which shows the schematic structure of the FEL of Embodiment 1 of this invention. It is an enlarged sectional view of the main part which shows the main part of the FEL of Embodiment 1 of this invention. It is a conceptual diagram provided for the explanation of heat dissipation in FEL of this invention. It is a conceptual diagram provided for the description of the manufacture of FEL of this invention. It is an enlarged sectional view of the main part which shows the main part of the FEL of Embodiment 2 of this invention. FIG. 3 is an enlarged cross-sectional view of a main part showing a main part of the FEL according to the third embodiment of the present invention. It is an enlarged sectional view of the main part which shows the main part of the FEL of Embodiment 4 of this invention. FIG. 3 is an enlarged cross-sectional view of a main part showing a main part of the FEL according to the fifth embodiment of the present invention. It is an enlarged sectional view of the main part which shows the main part of the FEL of the conventional example.

Before explaining the embodiment of the present invention, the conventional FEL100 will be briefly described. In the conventional FEL 100, as shown in FIG. 9, the emitter 101 is arranged in the central portion of the apparatus, and the phosphor 103 is coated on the inner surface 102b of the exterior glass 102 to be the light irradiation surface, and the phosphor 103 and light are applied. It is integrated with the irradiation surface (exterior glass 102).

In the conventional FEL 100 having the above configuration, the electrons e ejected from the emitter 101 arranged at the center portion in the radial direction of the device toward the phosphor 103 along the outward direction in the radial direction of the device (direction of arrow A) are fluorescent. It collides only with the phosphor particles 103a located in the innermost layer portion of the body 103, and causes the phosphor particles 103a in this region to emit light. Among the light emitted in all directions, the light is emitted from the light irradiation surface 102a to the outside of the device after passing through the inside of the phosphor 103 in an attempt to irradiate the light toward the outside in the radial direction of the device. At that time, the light repeatedly collides and reflects inside the phosphor 103, and is irradiated to the outside of the device after being repeatedly attenuated.

In this way, the light generated by the emitted phosphor particles 103a has no choice but to go out of the FEL 100 in a state of being attenuated by passing through the gaps of the non-emitting phosphor particles 103. However, this is inefficient as a lighting device, needless to say.

On the other hand, FEL1 of the present invention is shown in FIGS. 1 and 2. FIG. 1 is a schematic three-dimensional view of FEL1 of the present invention, and FIG. 2 is an enlarged schematic cross-sectional view of a main part thereof. In this FEL 1, a support 2 made of a metal rod such as aluminum having high thermal conductivity is arranged at the radial center portion of the device, and the transparent sealing glass 5 serving as a light irradiation surface 5a on the outer outer peripheral portion in the radial direction of the device. Is provided, and the emitter 3 is arranged between the support 2 and the light irradiation surface 5a. The phosphor 4 is applied to the peripheral surface of the axially central portion of the support 2 located at the central portion of the apparatus. In the support 2, the central portion in the axial direction, which is the portion to which the phosphor is applied, is housed in the apparatus, and both ends in the axial direction are projected to the outside of the apparatus. Both ends of the support 2 protruding from the outside of the apparatus and the transparent sealing glass 5 are sealed. The support 2 may be formed of an integral metal rod, or the phosphor-applied portion and the device protruding portion may be formed separately and then integrated.

In FEL1, the electron e emitted from the emitter 3 provided at the radial intermediate position of the device advances toward the inside in the radial direction of the device and reaches the phosphor 4. The reached electrons collide with the phosphor particles 4a located in the outermost layer of the phosphor 4, and cause the phosphor particles 4a at this site to emit light. The emitted light is irradiated from the outermost layer portion of the phosphor toward the outer side in the radial direction of the apparatus without passing through other phosphor particles inside the phosphor 4, and then the transparent sealing glass 5 (light irradiation surface 5a). It is irradiated to the outside of the device via. As described above, the light irradiation surface 5a is made of the transparent sealing glass 5 that seals and seals the inside of the FEL 1. In FIG. 1, reference numeral 6 is a power source for supplying power to the emitter 3 and the phosphor 4.

In the FEL 1 having the above configuration, the light is irradiated to the outside of the apparatus inside the phosphor 4 without causing attenuation due to repeated collision-reflection. As is clear from the above, the FEL1 of the present invention can illuminate more efficiently than the conventional one.

Next, the reason why the FEL1 of the present invention is superior to the conventional example in durability will be described.

First, the first reason will be described. In the present invention, the heat generated in the phosphor 4 when the FEL 1 is lit can be conducted and dissipated to the outside of the FEL 1 via the support 2 made of metal, so that the temperature rise of the phosphor 4 can be efficiently suppressed. Can be done.

Next, the second reason will be described. In FEL1 of the present invention, the temperature rise of the fluorescent substance 4 is suppressed by setting the amount of the fluorescent substance 4 and the thickness of the layer to specific values. Specifically, in FEL1 of the present invention, the fluorophore 4 has an ultrathin layer as close as possible to the minimum amount of the fluorophore that can be obtained, and further, the fluorophore 4 The thickness of the layer is made as thin as possible so that the background of the support 2 can be glimpsed between the phosphors 4 without covering the entire surface of the support 2. Further, if the amount of the phosphor 4 is defined by another expression, it is as follows. That is, the amount of the fluorescent substance 4 is set to an amount as close as possible to the minimum amount capable of obtaining the fluorescent amount, that is, the brightness required for the fluorescent substance. By making the fluorescent substance 4 having such a thickness and amount, the amount of the fluorescent substance is reduced, and the temperature rise of the fluorescent substance 4 at the time of light emission is suppressed. However, even if the amount is reduced, the brightness of the FEL, that is, the values of lumens, candela, etc., does not change unless the background of the support is exposed from the phosphor.

As described above, the brightness of the FEL is the same regardless of whether the amount of the phosphor is increased or decreased, as long as the background of the support is not in a state where it can be glimpsed between the phosphors.

As described above, when the background of the support is exposed from the phosphor, the phosphor is reduced by the area of the exposed background, so that it becomes darker by that amount.

The difference between the state where the fluorescent substance is evenly applied to the entire surface of the support and the state where the fluorescent substance is applied by increasing the amount of the fluorescent substance is only that the layer of the fluorescent substance having the larger amount of the fluorescent substance becomes thicker. , The brightness of FEL is the same.

As described above, if the phosphor is evenly applied to the entire surface of the support, the emitter is applied to the surface of the support without gaps regardless of whether the amount of the phosphor increases or decreases. Since the electrons from the emitter collide with the entire surface of the support and emit light, the brightness of the FEL is the same. However, if the amount of phosphor increases, the layer becomes thicker, and if it decreases, the layer becomes thinner.

As will be described later, the thermal conductivity of the phosphor is low, so if the layer is thick, the heat generated by the collision of electrons will be generated by the next collision of electrons before being conducted to the support, and one after another. Heat is stored in the layer and becomes high temperature, reaches the temperature quenching temperature of the phosphor, and does not emit light.

As described above, the brightness at the initial stage of lighting of the FEL is the same regardless of whether the layer of the phosphor is thick or thin. However, as the thickness of the layer of the phosphor becomes thicker, the generated heat cannot be conducted to the support, so that the phosphor does not emit light. If the thickness of the layer is the same level as that of the conventional FEL, the life is one month, but if the thickness of the layer is reduced, the life is naturally longer than one month.

Here, in order to achieve a long life by applying the phosphor thinly to the background surface of the support, if the phosphor is applied thin enough to give a glimpse of the background surface of the support, the layer will be too thick and the electrons will be emitted. The thick layer that cannot conduct heat to the support before the heat generated by the collision reaches the temperature quenching temperature should be greatly reduced.

The tendency is that the layer of the phosphor is too thin and it is not always around the place where the background of the support is visible, but the part where the phosphor is applied so that the background of the support can be glimpsed always generates heat by electrons. There is a thin layer that can conduct heat to the support before the next collision.

With a fluorescent material applied so that there are few such thin layers, the layers that are too thick are sequentially quenched and darkened. Then, only a thin layer of longevity remains, resulting in a longevity but dark FEL. However, even when such a thin layer is applied so as to increase in number, there is a layer that is too thick, so that portion is quenched in sequence. However, as a result, many thin layers of longevity remain, and it is possible to make a brighter and longer-lived FEL.

As the coating structure of the phosphor 4 in FEL1 of the present invention, a conventional one can be used. As for the material of the fluorescent substance 4, the present invention can use general-purpose P22-X (r), P22-X (r), P22-X (g), P22-X (b) and the like.

The characteristics of these phosphor materials and the peak particle size (unit: μm) in the particle size distribution are as follows.

P22-X (r) Y ₂ 0 ₂ S; Eu 7.5 μm
P22-X (r) YVO ₄ ; Eu 5.0 μm
P22-X (g) ZnS; Cu, Au, Al 8.0 μm
P22-X (b) ZnS; Ag 8.0 μm
The fluorescent material having the largest peak particle size is P22-X (g) and P22-X (b), and the peak particle size is 8.0 μm. It is assumed that the phosphor 4 having such a shape is applied to the support 2 made of metal with a thickness of 0.2 mm as in the conventional case. Then, the outline of the laminated state can be estimated by the following equation (1).

0.2mm ÷ 0.008mm = 25 ... (1)
That is, in the configuration of FEL1 in which the fluorescent substance 4 is applied to the support 2 with a thickness of 0.2 mm, it can be estimated that about 25 fluorescent particle particles 4a are arranged in layers on the surface of the support 2.

The present inventor has focused on an LED in which a phosphor similar to FEL is used and whose structure is being studied in order to extend the life of the FEL. In a white LED lamp, it is known that a phosphor is heated by an LED chip having reached 70 to 100 ° C, and the heat thereof significantly reduces the emission intensity of the phosphor. This phenomenon also occurs in FEL. This phenomenon is called temperature quenching of the phosphor. The emission intensity is deteriorated due to the heat generated in the phosphor at about 70 to 100 ° C during light emission, and the conventional FEL cannot obtain a practical life due to such deterioration of the emission intensity. ..

Several thermo-quenching models of phosphors have been presented so far. In those models, the behavior of thermal oscillations of luminescent ions and their valence changes are basically considered to be related to temperature quenching. However, it has not been clarified which of these parameters is specifically related to the temperature quenching of the phosphor.

In the present invention, the life of the FEL is extended by searching for a parameter that strongly correlates with the temperature quenching of the phosphor and improving the temperature quenching of the phosphor. This will be described below.

The cause of deterioration of the fluorescent substance in FEL can be considered as follows. That is, the temperature rise caused by applying a high voltage to cause electrons to collide with the phosphor at an ultra-high speed causes the phosphor to be heated above the melting point, and the destruction of the phosphor due to the high temperature state causes temperature quenching. .. However, it is not appropriate to explain temperature quenching in this theory. The reason will be explained by taking a phosphor whose main raw material is alloy Y ₂ 0 ₃ : Eu as an example. _The melting point of yttrium oxide Y 203 _, which is one of the components of this fluorescent substance, is 2410 ° C, and the melting point of europium Eu, which is another component, is 826 ° C. Therefore, the melting point of the phosphor 4 whose main raw material is Y2 _{0 3} : Eu, which is an alloy of these metals, does not drop to the above-mentioned heating temperature of about 70 to 100 ° C. Therefore, 70 to 100 The theory that heating at about ° C melts and quenches the temperature is also inappropriate. In FEL, even if the phosphor is heated at a relatively low temperature of about 70 to 100 ° C. below its melting point, the heating causes temperature quenching.

FIG. 3 is a schematic diagram of a phosphor 4 in which a fluorescent substance 4 made of one fluorescent substance particle 4a is provided on the surface of a support 2 made of metal. In this configuration, since the thermal conductivity of the support 2 is high, even if heat is generated by the collision of high-speed electrons e in the phosphor 4, the heat is generated from the phosphor 4 which is in direct contact with the support 2. It conducts quickly to 2. Therefore, even if the electrons e collide one after another and heat is generated in the phosphor 4, the heat is efficiently conducted (propagated) to the support 2, so that heat storage does not occur in the phosphor 4. The heat is conducted from the phosphor 4 to the support 2, and accumulation begins to occur here. However, the heat is further quickly dissipated from the end of the support 2 to the outside of the device, so that the heat is stored in the phosphor of the support 2. It is unlikely that the temperature of the contact portion will rise to the temperature quenching temperature (about 70 to 100 ° C).

However, even with the configuration of the present invention, which enables highly efficient heat dissipation to the outside by providing a metal support 2 having a relatively large heat storage amount (large heat capacity) and good thermal conductivity. When there are 25 coating layers of the phosphor particles 4a that are subject to the collision of the electrons e as in the conventional FEL, the heat generated in the thick layer of the phosphor 4 can be quickly conducted to the support 2. If this is not possible, heat will be stored and the total heat storage amount per unit time of the entire phosphor 4 will exceed the maximum heat dissipation amount per unit time by the support 2, and the heat storage maintenance and heat storage in the support 2 will be maintained. The increase is inevitable. Furthermore, in this state, that is, because the phosphor 4 having a low thermal conductivity is applied to a thickness of 24 layers, the next electron collides with the support 2 before the heat generated by the collision of the electrons is conducted to the support 2. I have a fever. Even if this is repeated and heat is conducted to the support 2, if the thermal conductivity of the phosphor 4 is insufficient, the fluorescent substance 4 with which electrons collide is the highest temperature. Therefore, the surface layer of the phosphor particles 4a facing the emitter is exposed to the temperature quenching temperature, and as a result, the phosphor 4a is destroyed. The reason why the conventional FEL has a life of only one month will be explained from the other angle.

When an electron collides with a phosphor, it generates heat. The generated heat is conducted through the phosphor toward the support 2. As an example of the fluorescent substance _, yttrium oxide: Y ₂₀₃ will be described as an example. It was found that the thermal conductivity of Y 203 was _13.35 W / _m · ° C by the following formula.

Y 203; yttrium oxide _, 3.19 × 10 ^ _-2 (cal / cm / sec / ° C)
3.19 × 10 ^ -2 = 3.19 × 0.01 = 0.0319
0.0319 (cal / cm ・ sec ・ ° C) = 0.0319 [(cm ・ sec ・ ° C)] × 100 [cm / m] × 1 [° C / ° K] × 4.184 [J / cal] = (0.0319 × 4.184) × 100 ≒ 13.35W / m ・ ° C
Eu; Europium has a thermal conductivity of 13.9 W / m · ° C
Alloy of Y _{203 and Eu Y 2 0 3} : The thermal conductivity of the phosphor _containing Eu as the main component is 250 W / m · ° C for aluminum Al, 116 W / m · ° C for zinc Zn, and copper Cu. Although it is not comparable to metals such as 401W / m ・ ° C, it is considerably better than mortar 1.73W / m ・ ° C and stone 2-7W / m ・ ° C, and stainless steel is 16W / m ・ °. Considering that it is C, it seems to be a reasonable thermal conductivity. However, since the particle size of the phosphor is 0.008 mm, as described above, when the thickness of the solution is 0.2 mm, there are 25 layers. Moreover, since these 25 layers are formed by point contact, electrons collide with the emitter-side phosphor one after another to generate heat, and the heat is conducted through the point contact site and reaches the glass on the light irradiation surface. do.

However, the thermal conductivity of glass (plate glass 0.96 W / m · ° C, glass 1.05 W / m · ° C) is inferior to that of mortar and stone. While it takes time to dissipate heat through the glass, electrons collide with the emitter-side phosphor one after another to generate heat and store heat. The thermal conductivity of glass is poor. Moreover, since the fluorescent substance is directly applied to this glass, the heat capacity of the fluorescent substance having a thickness of 0.2 mm is too small.

It is proved by the conventional FEL that this mechanism has a life of only one month. The FEL of the present invention, which has an object of extending the life of the FEL to exceed one month, has solved and improved the above-mentioned problems.

(Improvement 1)
The improvement is an improvement of the support 2 and the phosphor 4. The improvement of the support 2 is that the conventional FEL applies the phosphor 4 to the glass on the light irradiation surface, whereas the FEL 1 of the present invention has a support 2 (metal) having good thermal conductivity and electric conductivity. It is being applied. This is because no matter how thick the glass is to increase its heat capacity and try to absorb the heat generated by the phosphor 4, no matter how much the generated heat conducts through the phosphor 4 and reaches the glass. Since the heat conductivity of the glass is poor, the heat conduction from the phosphor 4 to the glass proceeds slowly. Even when the heat transfer from the phosphor 4 to the glass is troublesome, the electrons collide with each other and generate heat. Therefore, the generated heat is stored in the phosphor 4 and the temperature rises, so that the life of the FEL is not extended.

The improvement of the fluorescent substance 4 will be described below.

In the conventional FEL configuration in which the phosphor 4 is applied to the support 2 to a thickness of 0.2 mm, it is estimated that about 25 fluorescent particles 4a are arranged in layers on the surface of the support 2. , There is a problem.

To improve this problem, the layers may be moved from 25 layers to 1 layer. If it is one layer, as shown in FIG. 3, electrons collide with each other to generate heat, and even if they collide one after another and generate heat or generate heat, they smoothly reach the metal of the support 2 one after another. Heat is smoothly conducted with each heat generation. The conventional FEL has 24 layers and has a life of about one month. In that case, as the number of layers is reduced to 20 layers, 10 layers, 5 layers, 3 layers, and 1 layer, the heat due to the collision between the phosphor and the electron is conducted to the support 2 without being stored in the phosphor layer, and the support 2 is used. Heat is stored in.

On the other hand, the heat generated by the collision of electrons with the support 2 is stored in the support 2. As the amount of heat storage is reduced to 20 layers, 10 layers, 5 layers, 3 layers, and 1 layer, the background of the support 2 is exposed, so that the amount of collision increases and the amount of heat storage due to heat generation also increases. .. Therefore, the smaller the layer of the phosphor 4, that is, the thinner the layer, the better, and the smaller the exposed area of the background of the support 2, the better. This is an indisputable fact.

In this way, the regulations for applying the fluorescent substance 4 to the support 2 are shown below. In the present invention, the total amount of the fluorescent substance 4 is applied to the support 2 in a state where the fluorescent substance 4 can be glimpsed between the fluorescent substances 4 without covering the entire surface of the support 2 on the emitter side. That is, even if the phosphor 4 is applied, the thickness is set so that a part of the surface portion 2a of the surface of the support 2 is exposed.

When actually applying the fluorescent substance, the object of the present invention is to make the life of the conventional FEL exceed one month because the life of the conventional FEL is one month. Therefore, first, the phosphor concentration (1: 1.8 = phosphor: solution) used in the conventional FEL must be used as a reference.

Since the solutions are the same solution, they have the same viscosity. Therefore, the thickness of the coating film when applied is almost the same. The conventional FEL phosphor uses P22. The composition of each of the phosphors (R, G, B) called P22 is as follows.

Red-Y ₂ 0 ₃ : Eu, Green-ZnS: Cu, Au, Al, Blue-ZnS: Ag, Al
The compounding ratio of R, G, and B is 41:33:26 by weight.

The compounding ratio of the conventional FEL phosphor and solution is
Fluorescent substance: Solution = 1: 1.8 (wt), and the breakdown of the solution is Solvent: Butyl acetate = 1.686.
Binder: Nitrocellulose = 0.014
Adhesive: 0.1
1.686 + 0.014 = solvent + binder is 1.7.

If this 10-fold solution is to be prepared, 1.7 g: 0.1 g = 17 g: x, and the binder of the 10-fold solution is x = 1 g. About 10 g of the solution to be applied to the test sample is sufficient.

Therefore, 17g: 0.1g = 10g: xg
x = 0.059g
1: 1.8 = x: 100.59 g
The amount of phosphor when x = 5.59 g = solution 10 g, that is, in the conventional FEL phosphor: solution = 1: 1.8, phosphor: solution = 1: 1.8 = 5.59: 10. It is 059.

Since the phosphor is a dry powder, changes in the amount of contamination do not affect the viscosity of the solution. Therefore, the standard is to have a maximum of 25 layers when the thickness of one coat is 0.2 m. Assuming that the standard 25-layer phosphor concentration is 10 g of the solution,
Fluorescent material: solution = 1: 1.8
1: 1.8 = x: 10
x = 5.56
When the solution is 10 g, the phosphor is 5.56 g. At this time, 25 layers are used and the thickness is 0.2 mm.
When the solution is 10 g, the phosphor is 2.78 g. At this time, the solution is 12.5 layers and 0.2 mm thick.
When the solution is 10 g, the phosphor is 1.39 g. At this time, the layer is 6.25 and the thickness is 0.2 mm.
When the solution is 10 g, the phosphor is 0.7 g. At this time, the solution is 3.125 layers and the thickness is 0.2 mm.
When the solution is 10 g, the phosphor is 0.34 g. At this time, the solution is 1.56 layers and 0.2 mm thick.
When the solution is 10 g, the phosphor is 0.17 g. At this time, the solution is 0.78 layer and 0.2 mm thick.
When the solution is 10 g, the phosphor is 0.087 g. At this time, the layer is 0.39 and the thickness is 0.2 mm.

Make a phosphor solution of about one layer above, apply it to the same metal piece as the support 2, and check it with a microscope. An appropriate phosphor concentration may be determined by this method.

Point 1, as described above, improve the heat conduction of the entire four layers of the phosphor, and quickly conduct the heat generated by the collision of electrons to the support 2 without being stored in the phosphor 4.

The main point 2, the volume (heat capacity) of the support 2, is set to the maximum volume that can withstand the use as each lighting fixture. For example, in the case of home lighting, a support 2 having a diameter of 6 cm and a length of about 15 cm is assumed, and in the case of work lighting, a support 2 having a diameter of 20 cm and a length of about 20 cm is assumed.

The main point 3, the conventional FEL is a thin glass having poor thermal conductivity coated with a thick fluorescent substance 4, and has a life of one month.

If the points 1 and 2 are provided, the heat of the phosphor 4 is absorbed by the volume integral of the support 2, so that the life of the phosphor 4 is extended by that amount. The conventional FEL is the above-mentioned main point 3 and has a life of one month.

Therefore, it is natural that the life of the support 2 is sufficiently longer than one month even if a part of the support 2 is exposed to the outside of the lighting device and the heat generated in the device is not dissipated to the atmosphere.

(Improvement 2)
The conventional FEL phosphor has a problem that it is directly applied to the glass on the light irradiation surface. The thermal conductivity of glass is 0.96 W / m · ° C for flat glass and 1.05 W / m · ° C for glass. This is worse than mortar 1.73 W / m · ° C and stone 2-7 W / m · ° C.

When dissipating the heat of the phosphor to the atmosphere, it is inefficient to go through the glass. In order to improve this problem, in the configuration of the present invention, the emitter 3 is arranged between the light irradiation surface 5a and the phosphor 4. The phosphor 4 is applied to the surface of a metal having high electric conductivity and thermal conductivity.

With this configuration, the heat generated by the phosphor is efficiently conducted to the metal support 2 and stored. In the configuration in which the heat stored in the support 2 is dissipated to the atmosphere, a ventilation hole is formed in the central portion of the support 2, and both ends of the ventilation hole penetrate the glass of the light irradiation surface and protrude into the atmosphere. The support of the penetrating portion penetrating the glass and the glass are adhered to complete the vacuum sealing.

In the conventional FEL, since the phosphor is directly coated on the glass of the light irradiation surface having poor thermal conductivity, heat exchange with the atmosphere is directly performed. On the other hand, in the case of the fluorescent substance, it is difficult to release the heat accumulated in the thick layer of the fluorescent substance to the atmosphere through the glass having poor thermal conductivity. Further, in addition to the poor thermal conductivity of the fluorophore itself, the powdered fluorophore has very poor thermal conductivity because it is layered by point contact. Under such circumstances, electrons collide with each other from the emitter one after another, and the phosphor generates heat. Since this state was continuous, in the conventional FEL, the fluorescent material was broken by heat and had a life of only about one month.

However, if the phosphor is applied to a metal having good thermal conductivity instead of being applied to glass, electrons collide with each other from the emitter to generate heat. Then, the heat is conducted to the metal at the contact surface between the phosphor and the metal. When the thermal conductivity of this metal is good, the heat conducted from the phosphor immediately conducts heat to the entire metal and diffuses, and the temperature of the contact surface between the phosphor and the metal does not rise. Since the volume of the metal is the heat capacity, the larger the volume of the metal, the longer it takes to raise the temperature of the contact surface between the metal and the phosphor.

However, when a phosphor is applied to glass having poor thermal conductivity, electrons collide with each other from the emitter and generate heat. Then, the heat is conducted to the glass at the contact surface between the phosphor and the glass. Since the thermal conductivity of glass is similar to that of stone and mortar, the thermal conductivity is gradual. However, the electrons from the emitter collide one after another and generate heat, so the temperature of the contact surface between the phosphor and the glass rises, and the conventional FE has a life of only one month because the phosphor is broken by the heat. ..

Here, by making the layer of the phosphor very thin, even if electrons collide with each other from the emitter and generate heat, the heat can be immediately transferred to a metal having good thermal conductivity. The body is as thin as possible until a part of the metal support is exposed in the minute gaps of the phosphor, that is, a part of the support can be glimpsed between the phosphors. It is provided on the surface of the support. Since the volume of the support is a heat capacity, the larger the volume of the support, the longer it takes to raise the temperature of the contact surface between the support and the phosphor. In other words, the life is extended.

In this way, the life can be extended to one month or more without dissipating the accumulated heat to the atmosphere. However, if the stored heat can be dissipated to the atmosphere, the power can be turned off periodically and the light can be turned off without cooling, that is, it can be continuously turned on for a long time.

In the configuration in which the heat stored in the support 2 is dissipated to the atmosphere, a ventilation hole is formed in the central portion of the support 2, and both ends of the ventilation hole penetrate the glass of the light irradiation surface and protrude into the atmosphere. The support of the penetrating portion penetrating the glass and the glass are adhered to complete the vacuum sealing.

It should be noted that "the phosphor is in a state of being as thin as possible until a part of the metal support is exposed in the minute gaps of the phosphor, that is, a part of the support is between the phosphors. "A glimpse of the state" will be described in more detail below.
(1) The part where the background of the support can be seen,
(2) A portion where the thickness of the phosphor layer is 1 to 3 fluorescent particles.
(3) A portion where the thickness of the phosphor layer is 4 to 7 fluorescent particles.
(4) It is assumed that the thickness of the layer of the phosphor is each of the portions of 8 to 24 phosphor particles.

In the portion (1), electrons from the emitter collide with the support and generate heat. Since this part has nothing to block the electrons, it keeps raising the temperature of the support. Since the heat from the phosphor is also conducted to the support, if the amount of heat released to the atmosphere of the FEL is larger than the total amount of heat from the heat from (1) above and the heat from the phosphor, the life of the FEL Is permanent. However, the smaller the amount of heat released to the atmosphere than the total amount of heat, the shorter the life of the FEL.

In the portion (2), most of the heat generated by the collision of electrons from the emitter is conducted to the support, so that almost no heat should be trapped in the layer of the phosphor. The reason for this is described in paragraphs [0055] and [0056] above. Therefore, the larger the calorific value of the part (1) in the support body is larger than the calorific value released to the atmosphere of the FEL, the shorter the life, but the calorific value of the part (1) is to the atmosphere of the FEL. If it is smaller than the amount of heat released, its life is not permanent, but it is no exaggeration to say that it is permanent.

Even if the calorific value of the part (1) in the support is smaller than the amount of heat dissipated to the atmosphere of the FEL, the life of the portion (3) is not permanent and will eventually be destroyed. This is because heat is trapped in the layer of the phosphor, and the heat rises and breaks and disappears. However, its lifespan should be quite long.

In the portion (4), the conventional FEL has about 24 layers of fluorescent material and its life is one month. If the phosphor layer is 8 to 24 layers, the life is at least one month or more.

In this way, the states (1) to (4) are mixed.

It is important that (1) is the least in the mixed state.

Next, it is the above (4) that should be reduced, and most of the above (2) and the above (3) are mixed. This mixed state is the above-mentioned "glare" or "exposed to minute gaps".

Here, the points to be noted when applying the phosphor will be specifically described.

When the phosphor is applied, the phosphor is applied in a state in which a thick layer and a thin layer are randomly mixed and disordered.

In this case, it is impossible to spread only one layer of the fluorescent substance on the surface. It is impossible to spread only two layers or spread three layers. Further, it is impossible to spread the layers in the range of 3 layers or more and 8 layers or less, that is, 3 layers to 8 layers without gaps. In this way, it is impossible to spread the powder on the surface with a specific range of thickness, that is, a specific range of layers without gaps. If there is a way to make this possible, it should be a patented technology.

That is, the number of layers of the phosphor particles cannot be used as the numerical range of the claims. Therefore, as a means of identifying and limiting the thickness of the applied fluorophore [the thickness of the fluorophore is such that a part of the support does not cover the entire surface of the support and a part of the support has minute gaps in the phosphor. The state of being exposed to the surface, that is, a state in which a part of the surface of the support is glimpsed between the phosphors without covering the entire surface of the support. ] Was used.

This is because when the background of the support becomes glimpsed between the fluorescent materials (not the number of layers of the fluorescent material), the thick layer part and the thin layer part of the fluorescent material are randomly mixed and disturbed. It is said that there is a glimpse of the background of the support between the phosphors in the state of being distributed (the state of the distribution of the phosphors). That is, the portion exposed to the minute gap of the phosphor and the portion that can be glimpsed may be one place or more.

The FEL having this configuration is installed so that the support 2 is perpendicular to the ground. As a result, the heat stored in the support 2 is dissipated in the holes of the ventilation holes because the holes are the atmosphere. The atmosphere in the vents heated by the heat of the support 2 rises and exits the vents. Then, cold air flows in from the lower part of the hole, causes heat circulation in the ventilation hole, and dissipates heat of the support 2 to the atmosphere.

In order to suppress the heat storage in the support in such FEL, in FEL1 of this embodiment, the total amount of the fluorescent substance particles 4a is regulated as follows. That is, in the present invention, the total amount of the fluorescent substance 4 is set to an ultra-thin layer in which the amount of the fluorescent substance 4 is as close as possible to the minimum amount that can be obtained in the FEL1. The thickness of the phosphor 4 does not cover the entire surface of the support 2 on the emitter side, and the phosphor 4 is in a state where a part of the support 2 is exposed to a minute gap of the phosphor 4. That is, it is applied so that it can be glimpsed between the phosphors 4, that is, even if the phosphor 4 is applied, a part 2a of the surface of the support 2 can be glimpsed between the phosphors 4. ing. By defining the thinness of the phosphor 4 in this way, the FEL of the present invention can reduce the heat caused by the collision of electrons e to the layer of the phosphor by minimizing the thickness of the layer of the phosphor. The portion that can be quickly conducted to the support 2 without storing heat has a very long life. However, the portion where the layer of the phosphor is thick and heat is stored in the layer becomes high temperature and does not emit light. One of the supports will eventually reach the end of its life due to the continuous generation of heat generated by the collision of electrons in the part that can be glimpsed between the phosphors 4. Furthermore, by covering almost the entire surface of the support 2 with the phosphor 4 except for a part thereof, it is possible to prevent the electrons e emitted from the emitter 3 from directly colliding with the support 2 as much as possible. ing.

By having the above configuration, in FEL 1, the heat storage amount of the phosphor 4 that receives the electron e and emits light to generate heat, and the total heat amount of the support itself that directly receives the electron e and generates heat are suppressed. As a result, there is a possibility that the total heat generation amount per unit time of the entire fluorescent substance 4 does not exceed the heat radiation amount to the outside of the device per unit time by the support 2, and the heat storage in the support 2 is greatly suppressed. Will be done. Moreover, since the direct heating of the support 2 due to the direct arrival of the electrons e is also suppressed, the heat storage in the support 2 is further suppressed. Therefore, it is possible to extend the life of the FEL, which is the subject of the present invention, to one month or more.

Therefore, even if the illumination time in FEL1 is long in this state, the temperature of the phosphor portion 4a of the support 2 hardly becomes the temperature quenching temperature (about 70 to 100 ° C), or the support The period in which the temperature at the portion 4a of the phosphor of the body 2 is the temperature quenching temperature (about 70 to 100 ° C) does not extend for a long period of time. As a result, the phosphor 4 (fluorescent particle 4a) is less likely to deteriorate.

In order to obtain such an effect, FEL1 further includes the following configurations. That is, a transparent sealing glass 5 that covers the emitter 3, the support 2, and the phosphor 4 is provided, and both ends of the support 2 penetrate the transparent sealing glass 5 constituting the light irradiation surface 5a of the FEL 1. It protrudes to the outside. The gap between the support 2 and the transparent sealing glass 5 is sealed, and the inside of the transparent sealing glass 5 is sealed. As a result, in FEL 1, heat can be dissipated from the outer surface of the support 2 protruding to the outside of the device, and deterioration of the phosphor 4 can be further suppressed.

In FEL 1, it is structurally necessary to bond the support 2 made of metal and the transparent sealing glass 5 with high adhesion to seal the inside of the transparent sealing glass 5. This structure is also necessary to efficiently dissipate the heat accumulated in the support 2 to the outside of the FEL 1. However, since the volume shrinkage of the metal support 2 and the transparent sealing glass 5 is significantly different, the support 2 and the transparent sealing glass 5 are adhered to each other without damaging the transparent sealing glass 5. It is not easy to seal the gaps in the glass.

Therefore, in the present embodiment, the support 2 and the transparent sealing glass 5 are adhered to each other to seal the inside of the transparent sealing glass 5 as follows. As the sealing method, an adhesive was used in this embodiment. The adhesive may be any adhesive as long as it can adhere the substance used as the support 2 and the transparent sealing substance. For example, when the support 2 is aluminum and the transparent sealing material is glass, it is recommended to use Bond Ultra Versatile SU (trade name of a versatile elastic adhesive manufactured by Konishi Co., Ltd.). ..

In order to bond the support 2 and the transparent sealing glass body 5, a sealing glass body 5 having a support mounting holes 5e and 5e having the same hole shape as the outer peripheral surface shape of the support 2 but having a slightly larger hole diameter is provided. Prepare separately. The sealing glass body 5 is provided with a joint portion 5f. Then, as shown in FIG. 4C, the support mounting holes 5e and 5e of the sealing glass body 5 are inserted into the outer periphery of the support 2, and the support 2 and the joint portion 5f are in close proximity to each other. Adhesive is poured into the gap of the support mounting hole 5e and adhered. At that time, both ends (outer ends) 2b of the support 2 are projected from the transparent sealing glass 5 to the outside of the device.

In this state, the support 2 and the transparent sealing glass 5 having the joint portion 5f are brought into close contact with each other to completely seal and seal the inside of the transparent sealing glass 5 including the central portion of the support 2.

As described above, in the configuration of the first embodiment, a sufficient amount of heat radiation of the support 2 is secured to prevent heat storage in the support 2. However, the present invention is not limited to the one in which both ends of the support penetrate the transparent sealing glass and project to the outside of the illuminating device. Even the FEL10 of the second embodiment shown in FIG. 5 is included in the present invention. In this FEL 10, only one end 11a of the support 11 penetrates the transparent sealing glass 5 and protrudes to the outside of the lighting device 10. Even with this configuration, it is possible to secure a heat dissipation amount of the support 11 and make it difficult for heat storage to occur in the support 11.

Further, as a modification of the above-mentioned FEL10, there is the FEL20 of the third embodiment shown in FIG. Although only one end 21a of the support 21 of the FEL 20 is exposed to the outside of the device, the support 21 is hollow from the partial end 21a of the support protruding to the outside of the device to the middle portion 21b in the longitudinal direction. There is. However, although the support 21 has a tubular shape, the middle portion 21b has a bottomed shape, whereby the space inside the cylinder of the FEL 20 is sealed, and the inside of the device is sealed by the transparent sealing glass 5. It is maintained.

In the FEL 20, since the support 21 exposed to the outside of the device has a bottomed cylindrical shape, the outer surface area thereof becomes large and the amount of heat radiated from the support 21 increases. Therefore, only one end 21a of the support 21 can supplement the heat radiation amount of the support 21 exposed to the outside of the device, and heat storage is less likely to occur in the support 21.

In addition, the configuration in which the middle portion 21b is formed into a bottomed tubular shape is not only provided only at one end portion 21a of the support 21, but also at both ends 31a and 31b as in the fourth embodiment shown in FIG. In the FEL 30 having the support 31 protruding from the bottom, both ends 31a and 31b may each have a bottomed tubular shape. According to this configuration, the outer surface area of the support 31 exposed to the outside from the FEL 30 becomes larger, and the heat dissipation amount of the support 31 further increases.

Further, as an embodiment of the present invention, not only the bottomed tubular support shown in FIGS. 6 and 7, but also the bottomless cylindrical support shown in FIG. 8, that is, both ends 41a. , 41b There is a FEL 40 of Embodiment 5 having a support 41 which is a bottomless cylindrical body that penetrates each other. According to this configuration, it is possible to further increase the outer surface area of the support 41 exposed to the outside from the FEL 40 while maintaining the sealing inside the device. Further, air convection (air flow circulation) can be generated between the internal space 41c of the support 41 and the space outside the device in contact with both ends 41a and 41b of the support 41. This makes it possible to more efficiently dissipate heat from the support 41 to the outside of the device.

In the FEL 40 shown in FIG. 8, a support 41 having a bottomless tubular body is provided on the transparent sealing glass 5 along the vertical direction. As a result, the warm air generated in the internal space of the support 41 rises and is easily dissipated from the upper end of the support 41 to the outside, and as the warm air is dissipated to the outside, separate air (cold air) is generated from the lower end of the support 41. ) Will easily flow into the support 41, and it will be possible to more efficiently generate air convection generated between the internal space 41c of the support 41 and the outside of the device. Therefore, heat can be dissipated more efficiently.

Although it is preferable to arrange the support 41 in the vertical direction in order to obtain the above-mentioned chimney effect of warm air, it is needless to say that the arrangement direction of the support 41 is not limited to the vertical direction in the present invention. Needless to say, even if the support 41 is provided along the lateral direction or the diagonal direction, a sufficient heat dissipation effect can be obtained.

The present invention is not limited to the above-described embodiment, and can be arbitrarily and appropriately modified / selected and adopted as necessary without departing from the spirit of the present invention. It is a thing.

1 FEL
2 Support 2a Part of the support 2b Both ends of the support 3 Emitter 4 Fluorescent particle 4a Fluorescent particle 5 Transparent sealing glass 5a Light irradiation surface 5e Support mounting hole 5f Joint part 6 Power supply 10 FEL
11 Support 11a One end of support 20 FEL
21 Support 21a One end of support 21b Midway part of support 30 FEL
31 Supports 31a, 31b Both ends of the support 40 FEL
41 Supports 41a, 41b Both ends of the support

Claims (10)

Emitter and
A phosphor that receives the electrons emitted by the emitter and emits fluorescence toward the light irradiation surface, and
A support made of a substance having good electric conductivity and thermal conductivity, which supports the phosphor,
Have,
The phosphor is provided on the surface of the support in a state of being thinned until a part of the support is exposed in a minute gap of the phosphor.
A lighting device characterized by that. A part of the support is exposed to the outside of the lighting device.
Moreover, the fluorescent substance is provided on the surface of the support in a thin state until a part of the support is exposed to the minute gaps of the fluorescent substance.
The lighting device according to claim 1, wherein the lighting device is characterized by the above. The fluorescent substance has an amount close to the minimum amount capable of obtaining the fluorescence amount, that is, the brightness required for the fluorescent substance.
The lighting device according to claim 1. The substance having good electric conductivity and thermal conductivity is a metal.
The lighting device according to any one of claims 1 to 3. The emitter is provided between the phosphor and the light irradiation surface.
The lighting device according to claim 1. Further comprising a transparent sealant covering the emitter, the support and the fluorophore
At least one end of both ends of the support penetrates the transparent sealing body and projects to the outside of the illuminating device.
The gap between the support and the transparent sealant is sealed and the inside of the transparent sealant is sealed.
The lighting device according to claim 1, wherein the lighting device is characterized by the above. Both ends of the support penetrate the transparent sealing body and project to the outside of the lighting device.
The lighting device according to claim 1, wherein the lighting device is characterized by the above. The support is provided on the illuminating device along the vertical direction.
The lighting device according to claim 7, wherein the lighting device is characterized by the above. The support has a tubular shape in which one end of both ends is open, and the one end projects to the outside of the lighting device.
The in-cylinder space of the support is exposed to the outside of the device via the one end.
The lighting device according to any one of claims 6 to 8, characterized in that. The support has a tubular shape with both ends open, and both ends project to the outside of the lighting device.
The in-cylinder space of the support is exposed to the outside of the device via each of the both ends.
The lighting device according to any one of claims 6 to 8, characterized in that.

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