JPH09175859A - Embedded type display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the life of an embedded type display unit with preventing damage of a window member by embedding a protecting member having opened one face to a road surface, etc., installing a light emitter, etc., inside the protecting member and covering the opened part with a specific window member. SOLUTION: This embedded type display unit is composed of a protecting member 3 having opened one face and embedded in a floor, a wall or a ceiling, etc., and provided with a light emitter 5 or an indicator 4, etc., inside the protecting member 3 and an opening part of the protecting member 3 is covered with a window member 2 constituted with a translucent yttrium aluminum garnet sintered compact (YAG sintered compact). A translucent YAG sintered compact has high hardness and excellent wear resistance, and is hardly wounded, and preferably contains >=10% crystal having >=15μm particle diameter and has >=70% linear transmittance of visible light per 1mm thickness. Furthermore, the translucent YAG sintered compact is preferably constituted by 99.7-99.99wt.% of YAG as a main component with 0.01-0.1wt.% of at least one kind of metal such as Fe, W, Mo, Pd and Ag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device which is embedded in a road surface, floor, wall, ceiling or the like and used for the purpose of signals, signs, guides, announcements, decorations and the like.

[0002]

2. Description of the Related Art In recent years, a light system in which a light emitting body is embedded in a road surface or the like is used. For example, there is a device in which a large number of red and blue light-emitters are embedded in the road surface at both ends of a pedestrian crossing and the red or blue light is emitted on the road surface in conjunction with a pillar-shaped signal to call attention to a pedestrian.

In this case, a protective member embedded in the road surface is provided with a luminous body, and the protective member is covered with a transparent window member, which is made of glass or transparent plastic. .

In addition, for the purpose of identification, guidance, advertisement, decoration, etc., a display device in which similar luminous bodies are embedded in a road surface, a floor, a wall, a ceiling or the like of a building is used.

[0005]

However, since the window member made of glass or transparent plastic has low hardness and low abrasion resistance, it is easily scratched during use, and when the window member is scratched, it is not stained. There is a problem in that they adhere to the display effect, and are easily damaged. In addition, since transparent plastic has low heat resistance, there is a problem that, for example, when a cigarette fire is pressed, it melts.

[0006] In particular, when embedding in an outdoor road surface where people and vehicles pass, the above-mentioned problem is remarkable and there is a problem that it cannot be used for a long time.

[0007]

In order to solve the above-mentioned problems, the present invention provides a protective member having an opening on one side, a road surface, a floor,
A yttrium-aluminum-garnet (hereinafter referred to as Y
The embedded display device is characterized by being covered with a window member made of a sintered body (called AG).

YAG is a complex oxide of yttrium (Y) and aluminum (Al), which has a garnet type crystal structure, and has a chemical formula of Y ₃ Al ₅ O.
Represented by ₁₂ . The translucent YAG sintered body is excellent in translucency, has high hardness and wear resistance, and has good workability. Therefore, when it is used as a window member, it may be scratched or damaged. Prevents and can be used satisfactorily for a long time.

The translucent YAG sintered body preferably contains 10% or more of crystals having a particle size of 15 μm or more, and has a linear transmittance of visible light of 70% or more per 1 mm of thickness.

Here, 10% of crystals having a grain size of 15 μm or more are used.
The above content is included because if it is less than 10%, the linear transmittance of visible light per 1 mm of thickness is less than 70%.

Further, the translucent YAG sintered body is 9
9.7-99.99% by weight of YAG as a main component, and F
0.01 to 0.1 wt% of at least one metal selected from e, W, Mo, Pd and Ag can be contained.

This is because the above-mentioned metal serves as a nucleus in the upper sintering process to promote YAG formation and uniform grain growth.
This is because abnormal grain growth can be suppressed, whereby the light transmissivity of the YAG sintered body can be improved and the linear transmittance of visible light per 1 mm of thickness can be 70% or more. Further, since these metal components are well metallized during firing, the sintered body is not colored. Further, the content of these metal components is set to 0.01 to 0.1% by weight. When the content is less than 0.01% by weight, the effects of promoting YAG formation and uniform grain growth can be sufficiently achieved. This is because when the content exceeds 0.1% by weight, the second phase is precipitated at the grain boundaries and the translucency of the sintered body is reduced. For the above reason, the content of these metal components is 0.01 to 0.0.
The range of 5% by weight is particularly preferable, and W is the most suitable type of metal component.

Further, when the window member is constructed by laminating a translucent YAG sintered body and a transparent plate such as glass or transparent plastic, the window member having high transparency and excellent abrasion resistance can be manufactured at low cost. Obtainable.

The translucent YAG sintered body is, for example, Al ₂ O ₃ powder and Y ₂ powder each having a purity of 99.7% or more.
YAG powder having a purity of 99.9% or more was added to the O ₃ powder.
5% by weight or more, or Fe, W, Mo, P
0.01 to 0.1% by weight of at least one metal of d and Ag is added, mixed and pulverized, and then molded into a predetermined shape, and 1600 in a vacuum atmosphere or a reducing atmosphere such as H ₂ or N _2.
It is produced by firing at a temperature of 1900 ° C.

Further, the purity of A is 99.7% or more.
1 ₂ O ₃ powder and Y ₂ O ₃ powder were mixed and then calcined, and this was pulverized into a raw material powder, and this raw material powder had a purity of 99.
Add 0.5% by weight or more of YAG powder of 9% or more,
Alternatively, after adding 0.01 to 0.1% by weight of at least one metal of Fe, W, Mo, Pd, and Ag, it is molded into a predetermined shape, and the pressure is reduced to 1600 in a vacuum atmosphere or a reducing atmosphere such as H ₂ or N _2. It is also produced by firing at a temperature of ~ 1900 ° C.

Here, Al ₂ O having a purity of 99.7% or more
_The reason why the ₃ powder and the Y ₂ O ₃ powder were used is that the light transmissivity is deteriorated by impurities existing in the sintered body at a purity of less than 99.7%, and the Al ₂ O ₃ powder and the Y ₂ O ₃ powder are used. The purity of the powder is preferably 99.9% or more.

And, 99.9% of the above raw material powder
The above YAG powder is added in an amount of 0.5% by weight or more because the addition of such YAG powder to the raw material powder
This is because this YAG powder serves as a nucleus to promote YAG formation, uniform grain growth, and suppressing abnormal grain growth. Further, the amount of YAG powder added is set to 0.5% by weight or more because the Y amount is less than 0.5% by weight.
This is because the effect of accelerating the formation of AG becomes poor and it becomes impossible to achieve uniform grain growth and the translucency is lowered. Therefore, the addition amount is preferably 3% by weight or more.

The Al ₂ O ₃ powder, Y ₂ O ₃ powder and YAG powder each preferably have an average particle size of 2 μm or less. This is because when the thickness exceeds 2 μm, the activity due to sintering becomes poor, voids are easily generated, the denseness is lowered, and the translucency is lowered.

Further, the firing in a reducing atmosphere such as H ₂ or N _2, because fast diffusion H ₂ and N ₂ as compared with the waiting, because the densification of the sintered body can be easily achieved The vacuum firing is also good for the same reason.

Further, the reason for firing at 1600 to 1900 ° C is that if the temperature is lower than 1600 ° C, the sintering is insufficient and the light-transmitting property is deteriorated without being densified. If it is higher than 1900 ° C, it is abnormal. This is because grain growth occurs and pores are taken into the grains to reduce the translucency, or YAG evaporates, so that a homogeneous sintered body cannot be obtained.

The method for producing the YAG sintered body of the present invention will be specifically described below.

First, when the purity is 99.7% or more, B
Al ₂ O ₃ powder having an ET specific surface area of 5 m ² / g or more and Y ₂ O
₃ powders were adjusted so that Al ₂ O ₃ : Y ₂ O ₃ = 0.43: 0.57, and if the purity was 99.9% or more, BE
0.5% by weight of YAG powder having a T specific surface area of 5 m ² / g or more
The above is added. Instead of this YAG powder, Fe,
A metal such as W or Mo may be added.

A predetermined solvent is added to this raw material powder, and the mixture is ground by a pot mill, a rotary mill or the like. After this is dried, it is sized and shaped into a desired shape by a desired shaping means such as a die press, a cold isostatic press, an extrusion molding, and a casting molding. For example, if using a die press, 2.5t
on / cm ³ or more to maximize the density of the molded body. When the density of the molded body is increased, the sinterability is improved, the generation of voids after sintering is suppressed, and the light transmissivity can be increased,
The density is preferably 2.0 g / cm ³ or more.

The molded body thus obtained has a degree of vacuum of 1 × 10 ⁻² torr or less, preferably 1 × 10 ⁻³ or less in a vacuum atmosphere at 1600 to 1900 ° C.
Bake for 50 hours. The rate of temperature increase is preferably 200 ° C./hour or less.

Further, in the present invention, the Al ₂ O ₃ powder and the Y ₂ O ₃ powder are mixed and calcined, and then the YAG powder is added to the pulverized raw material powder, or Fe,
It is also possible to add a metal such as W or Mo, form it into a predetermined shape, and then fire it.

In this case, the calcination is performed until the stage before YAG conversion is completed, that is, until the state where YAM and YAG are mixed. Therefore, when YAM and YAG are mixed, Y
When the AG powder is added and fired, the YAG powder serves as nuclei to promote YAG formation as in the case where the calcination is not performed, and grain growth is made uniform and abnormal grain growth can be suppressed.

By the way, when a mixed powder of Al ₂ O ₃ powder and Y ₂ O ₃ powder is fired as it is at a temperature of 1600 ° C. or higher, YAM + Al ₂ O ₃ is produced from the mixed powder, and YA
The crystal changes from M + Al ₂ O ₃ to YAG, and the volume also gradually decreases. At this time, when YAM + Al ₂ O ₃ changes to YAG, volume expansion occurs temporarily, which causes voids and defects in the sintered body, making it difficult to manufacture a uniform sintered body. On the other hand, as described above, Al ₂
By calcining the mixed powder of O ₃ powder and Y ₂ O ₃ powder, it is possible to cause a temporary volume expansion from YAM + Al ₂ O ₃ to YAG at the time of calcining. Expansion does not occur, so that the generation of voids and defects in the sintered body can be suppressed, and a dense sintered body can be obtained. Further, by calcination, YAG can be formed to some extent (about 10 to 50%), and volume shrinkage can be caused, so that a molded product having a high relative density can be obtained. Further, by making YAG to some extent, abnormal grain growth of YAG can be suppressed and activation can be maintained.

The calcining is preferably carried out at 1000 to 1600 ° C. This is because if the temperature is lower than 1000 ° C., YAG formation is less likely to occur, and if the temperature is higher than 1600 ° C., activation is reduced and a dense sintered body cannot be produced, or pulverization takes a long time. The calcination is 0.
It is preferable to perform the treatment for 5 hours or more, preferably about 2 hours.

[0029]

Embodiments of the present invention will be described below.

As shown in FIG. 1, in the embedded display device of the present invention, a bottomed body protective member 3 having an opening on one side is embedded in the road surface 1 so that the opening is the upper surface, and the opening is transparent. It is covered with a window member 2 made of an optical YAG sintered body and bonded with an adhesive 7. On the back side of the window member 2, a display body 4 such as letters and drawings is printed or attached, the light emitting body 5 is arranged inside the protective member 3, and an electric wire 6 for energizing the light emitting body 5 is provided. ing. The electric wire 6 is bonded to the protective body 3 with an adhesive 7 and is covered with a protective pipe 10 outside the protective body 3.

If the light emitting element 5 is energized to emit light,
Light emission can be displayed through the window member 2. For example,
It can be used as a signal or sign by emitting light in red, blue, and yellow, and can be used for a traffic guidance system, a decorative effect, or used for advertisement, guidance, etc. by the display body 4.

Since the window member 2 is made of the above-mentioned translucent YAG sintered body, it has excellent hardness and wear resistance, so that it is not easily scratched even when it is installed on a road surface with heavy traffic. , Can maintain a clear luminous display for a long time. Further, since the translucent YAG sintered body has relatively good workability, it can be easily processed into a predetermined shape.

The window member 2 and the protective member 3 are not limited to being bonded by bonding, but may be bonded by screwing or the like. The protective member 3 is made of a material having excellent waterproofness, airtightness, and pressure resistance, and is made of, for example, ceramics.

Although not shown, the window member 2 is also provided.
If a solar cell is provided on the back side of the above and a storage battery is provided inside the protective member 3, since electricity can be generated by sunlight in the daytime and this power can be used to emit light at night, the electric wire 6 can be eliminated.

Next, another embodiment of the present invention will be described. The structure shown in FIG. 2 is basically the same as the example shown in FIG. 1, except that a reflecting mirror 8 is provided as a light emitting body on the bottom surface of the protective member 3, and an optical fiber 9 is connected instead of the electric wire 6. . When light is introduced from the optical fiber 9, it can be reflected by the reflecting mirror 8 and emitted from the window member 2 for display.

Further, another embodiment of the present invention will be described.
In FIG. 3, a display body 4 is provided on the back surface of a window member 2 made of a translucent YAG sintered body, and the display body 4 is bonded to the protection member 3 and embedded in the road surface 1. In this case, it does not emit light by itself, but it can be seen by reflection of electric light or sunlight.

As shown in FIG. 4 which is a plan view of another embodiment, if the plane shape of the window member 2 made of a translucent YAG sintered body is set to a predetermined shape such as a star or a moon, light is emitted at night. By doing so, the decorative effect can be enhanced. Alternatively, the window member 2 may be formed in a character shape to have an advertisement or guidance effect.

In the above example, the window member 2 made of the translucent YAG sintered body preferably has a thickness of 1 to 2 mm.
This is because if it is less than 1 mm, the strength is lowered and it is easily damaged, and if it exceeds 2 mm, the light-transmitting property is lowered and the cost is increased.

As yet another embodiment, as shown in FIG. 5, a translucent YAG sintered plate 12 and a glass transparent plate 1 are used.
The window member 2 can also be formed by bonding 1 with the adhesive 7.

That is, the translucent YAG sintered body has a high hardness but a slightly lower transparency than glass, while the glass has a high transparency and a low cost, but a low hardness. Therefore, by making only the surface of the road surface the translucent YAG sintered body plate 12 and the back side the glass transparent plate 11, the window member 2 having both characteristics can be obtained.

Further, as shown in FIG. 6, a translucent YAG sintered plate 12 and a glass transparent plate 11 are laminated and heated to the melting temperature of the glass to weld them together, and then cooled. The window member 2 can also be obtained by solidifying.

Further, a transparent plastic such as vinyl can be used as the transparent plate 11.

In the case of the examples of FIGS. 5 and 6, the thickness of the plate 12 of the translucent YAG sintered body is made as thin as 0.8 to 1.2 mm,
The thickness of the transparent plate 11 made of glass or transparent plastic may be appropriately determined according to the application.

In the above example, the one embedded in the road surface 1 is shown, but the embedded display device 2 of the present invention can be embedded in the floor, wall, ceiling or the like of a building for use.

[0045]

Example 1 A translucent YAG sintered body used as the window member 2 was prepared.

As a raw material powder, the purity is 99.8.
%, BET specific surface area 5 m ² / g, average particle size 0.7 μ
129 g of Al ₂ O ₃ powder and 171 Y ₂ O ₃ powder
g was prepared, and YAG powder having a purity of 99.9%, a BET specific surface area of 5 m ² / g and an average particle size of 17 μm was added thereto in an amount shown in Table 1. This raw material, 600 g of high-purity alumina balls and 300 g of isopropyl alcohol (IPA) as a solvent were put into a polypot and mixed and pulverized for 24 hours by a rotary mill. After drying the mixed slurry, a uniform powder was obtained. A molding having a density of 2.5 g / cm ³ or more was produced from this powder using a die press. The molded body was fired at the firing temperature, firing time, temperature rising rate and firing atmosphere shown in Table 1.

When the obtained sintered body was measured by an X-ray diffractometer, the production of YAG was confirmed. Then, the obtained sintered body was polished to a thickness of 1 mm and then mirror-finished with a diamond paste having a particle size of 1 μm, and then a wavelength of 600
The linear transmittance of visible light of nm was measured by an infrared spectrometer. Further, the ratio (area ratio) of YAG crystals having a crystal grain size of 15 μm or more was measured by image processing (Luzex). Further, the hardness of the obtained sintered body was measured by a Vickers test under a load of 20 kg, and the bending strength was measured according to the JISR1601 standard. Table 1 shows the results. In Table 1, No. 2 to 15 to 19
It was calcined for a time.

From these results, the obtained translucent YAG sintered body has excellent mechanical properties such as a Vickers hardness of 1300 kg / mm ² or more and a bending strength of 300 MPa or more, and among them, the crystal grain size is 15 μm or more. The ratio of YAG is 10
%, The linear transmittance of visible light per 1 mm of thickness was 70% or more, and the light transmittance was excellent.

Therefore, it can be seen that if the window member 2 is made of this translucent YAG sintered body, it is hard to be scratched due to its high hardness, and the luminous display effect can be enhanced due to its high translucency.

[0050]

[Table 1]

Example 2 Next, a translucent YAG forming the window member 2 is manufactured by another manufacturing method.
A sintered body was produced.

As raw material powder, the purity is 99.8.
%, BET specific surface area 5 m ² / g, average particle size 0.7 μ
129 g of Al ₂ O ₃ powder and 171 Y ₂ O ₃ powder
g, and this raw material and high-purity alumina balls 600
300 g of isopropyl alcohol (IPA) as a solvent was put in a polypot, and mixed and pulverized for 24 hours by a rotary mill. After drying the mixed slurry, a uniform powder was obtained.

This powder was calcined in an electric furnace at the temperature shown in Table 2, and then the auxiliary agent (metal component) shown in Table 2 was added to it, together with 600 g of high-purity alumina balls and 300 g of isopropyl alcohol (IPA) as a solvent. The mixture was put into a plastic pot and mixed and pulverized by a rotary mill for 24 hours. The mixed slurry was put into a plaster mold and cast-molded. The slurry was dried, removed from the gypsum mold, and the obtained molded body was fired at the firing temperature, firing time, and firing atmosphere shown in Table 2.

When the obtained sintered body was measured by an X-ray diffractometer, the production of YAG was confirmed. Then, the obtained sintered body was measured for linear transmittance of visible light, Vickers hardness, and bending strength in the same manner as in Example 1 above. The results are shown in Table 2.

The translucent YAG sintered body thus obtained has a linear transmittance of visible light of 50% per 1 mm of thickness.
The Vickers hardness was 1300 kg / mm ² or more, and the strength was 300 MPa or more.

Therefore, it can be seen that if the window member 2 is constructed by using this translucent YAG sintered body, it is hard to be scratched due to its high hardness, and the luminous display effect can be enhanced due to its high translucency.

[0057]

[Table 2]

[0058]

As described above, according to the present invention, a protective member having one open surface is embedded in a road surface, a floor, a wall, a ceiling, etc., and a light-emitting body, a display body, etc. are provided inside the protective member.
By forming the embedded display device by covering the opening of the protective member with the window member made of the translucent YAG sintered body, the translucent YAG sintered body has excellent translucency, high hardness, and wear resistance. Since it has excellent workability and good workability, it can be prevented from being scratched or damaged when used as a window member, and can be used favorably for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embedded display device of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the embedded display device of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the embedded display device of the present invention.

FIG. 4 is a plan view showing another embodiment of the embedded display device of the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the window member that constitutes the embedded display device of the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of the window member that constitutes the embedded display device of the present invention.

[Explanation of symbols]

 1: Road surface 2: Window member 3: Protective member 4: Display body 5: Light emitting body 6: Electric wire 7: Adhesive 8: Reflector 9: Optical fiber 10: Protective pipe 11: Transparent plate 12: Plate

Claims (4)

[Claims] 1. A protective member having an opening on one side is provided on a road surface, floor, wall,
Characterized by being embedded in a ceiling or the like, provided with a light-emitting body, a display body, etc. inside the protective member, and covering the opening of the protective member with a window member made of a translucent yttrium-aluminum-garnet sintered body. Embedded display device. 2. The translucent yttrium-aluminum-garnet sintered body comprises a crystal having a grain size of 15 μm or more.
The embedded display device according to claim 1, which contains 0% or more, and has a linear transmittance of visible light of 70% or more per 1 mm in thickness. 3. The translucent yttrium-aluminum-garnet sintered body contains 99.7 to 99.99% by weight of yttrium-aluminum-garnet as a main component, and contains Fe, W, Mo, Pd, and Ag. 2. The composition contains 0.01 to 0.1% by weight of at least one metal.
Embedded display device described. 4. The embedded display device according to claim 1, wherein the window member is formed by laminating a translucent yttrium-aluminum-garnet sintered body and a transparent plate such as glass or transparent plastic.