JPH0614122B2 - lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of the Invention] The present invention relates to a lamp in which a metal oxide film having a light diffusing property is formed on the outer surface of a glass bulb such as a light bulb or a high pressure discharge lamp.

(Prior Art) For example, in a halogen light bulb for a copying machine, light emitting portions and non-light emitting portions of a filament are alternately arranged in the tube axis direction in order to make the illuminance distribution on the illuminated surface uniform, but this is not sufficient. For this reason, it is generally performed that the bulb surface is subjected to honing processing so as to have a light diffusing property. Therefore, the light from this light bulb is diffused and the illuminance becomes uniform.

Further, there is also one in which a light-scattering fine powder such as silica is applied to the outer surface of the valve by electrostatic coating or the like.

(Problems to be Solved by the Invention) However, such a film having a light-scattering property is generally mechanically weak and easily worn, and some of the films have a decreased light-scattering property due to long-term use. Depending on the type of the light-scattering fine powder, there are some that are not compatible with the bulb and are easily peeled off.

In particular, in a lamp in which the glass bulb has a relatively high temperature, the above-mentioned problems often occur remarkably due to thermal effects.

The present invention has been made in view of the above circumstances, and provides a lamp having a light diffusion metal oxide film, which has good compatibility with a quartz glass bulb, is highly heat resistant, is resistant to peeling, and the like. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention comprises a metal oxide film on the outer surface of a quartz glass bulb having a light emitting structure,
This metal oxide film, a high-boiling organic solvent having an organic metal compound and a low-boiling organic solvent is applied to the glass bulb and baked, and the low-boiling organic solvent is evaporated to form concave holes or bubbles. At least one of them is provided, and it exhibits light diffusion.

(Function) In the present invention, since the metal oxide film having a bubble open on the upper surface and exhibiting a light-scattering property is formed on the valve surface, it is excellent in heat resistance, mechanically strong, and long-term use. A lamp that does not lose its light-diffusing property and has very little light loss can be obtained, and the mechanical strain caused by the difference in the coefficient of thermal expansion from the glass bulb that becomes hot is relieved to withstand repeated long-term thermal shock. As a result, a lamp that does not peel off can be obtained.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings.

First, FIG. 1 shows a halogen bulb for a copying machine, which is a lamp. On the outer surface of the quartz glass bulb (1), a metal oxide film (2) having a diffusive property is provided with a concave hole (23) which is a bubble opened on the film surface and a bubble (22) contained inside the film. )
The diffuser film is formed.

(3) is a sealing part formed by crushing and sealing both ends of the glass bulb (1), (4) is a molybdenum introducing foil embedded in the sealing part (3), and (5) is these introducing foils ( 4) an inner conductor wire connected to 4) and introduced into the glass bulb (1), and (6) a plurality of light emitting structures connected in series via the short-circuit wire (7) and mounted between the inner conductor wires (5) The filament, (8) is an anchor that supports the short-circuit wire (7), and (9) is connected to the introduction foil (4) through an external conductor wire (not shown) to form a sealing portion (3).
Is a terminal attached to the end surface of the. The glass bulb (1) is filled with a required halogen together with an inert gas such as argon.

The light-scattering film (2) is a thin film containing bubbles (22) and having concave holes (23) on the surface, as is apparent from the schematic diagram simulating the electron micrograph of FIG. The detailed structure is schematically shown in FIG. That is, a large number of bubbles (22) are contained in the continuous film body (21) such as titanium oxide formed on the surface of the glass bulb (1), and some of these bubbles (22) are formed in the film body (21). A concave hole (23) is formed by opening on the surface. Then these bubbles (22)
Or, the concave hole (23) scatters the transmitted light and appears opaque to the naked eye. The film thickness of this film body (21) is 0.3 to 0.8 μ.

Even though the filaments (6) are arranged intermittently in this halogen bulb, the light is scattered by the diffuser film (2) and emitted, so that there is no uneven illumination on the illuminated surface.

Further, although the quartz constituting the bulb (1) and the titanium oxide constituting the light diffusing film (2) have a large difference in thermal expansion coefficient, the light diffusing film (2) is extremely thin and the film body (21) is also present.
Since the bubbles (22) and the concave holes (23) are contained therein, the mechanical strain due to the difference in thermal expansion is relaxed, and the light-scattering film (2) is not peeled off even if it blinks again and again for a long time. Further, since the light scattering film (2) is extremely thin, the light loss is only about 3 to 4%, which is extremely advantageous. Furthermore, the film body (2
Since 1) is a continuous body, it is mechanically strong, there is no fear of abrasion, and the light scattering property does not change during long-term use.

In order to form such a light-scattering film (2), first, a solution of an organic titanium compound such as tetraisopropyl titanate in a low boiling point organic solvent is used as a high boiling point organic solvent such as di-2-ethylhexyl phthalate (dioctyl phthalate, 5 to 10% by volume of abbreviated name DOP) is added, and if necessary, an appropriate amount of a low boiling point organic solvent such as butyl acetate is added to adjust the viscosity. Then, the sealed halogen bulb is immersed in this solution, pulled up at a rate of 30 to 50 cm / min, and dried. However, the above-mentioned DOP is a colorless oily liquid that boils at 231 ° C. under a pressure of 5 mmHg and mutually dissolves in various low-boiling point organic solvents at an arbitrary ratio. Therefore, the low boiling point organic solvent only evaporates in the drying step. Then, after drying, as shown in FIG. 4, fine droplets (25) of DOP are dispersed and clouded in the gel-like coating film (24) made of an organic titanium compound.

Next, the halogen bulb having the gel-like coating film (24) formed thereon is fired in air at about 600 ° C. for about 5 minutes. Then, the DOP droplets (2
The evaporation of 5) and the decomposition of the organotitanium compound occur in tandem, and as a result, the droplets (25) expand in diameter almost at that position to form bubbles (22), and further inside the bubbles (22). The DOP vapors of are gradually replaced by the atmosphere. In addition, the liquid droplets (25) near the surface of the gel coating film (24)
Ruptures in the process of expanding the diameter and communicates with the outside air, forming a concave hole (23)
Finally, as shown in FIG. 3, a diffuser film (2) including bubbles (22) and concave holes (23) is formed in the continuous film body (21) made of titanium oxide. As is clear from this formation process, in the present invention, the bubbles (22) and the concave holes (23) are used.
Are essentially the same.

As described above, the DOP not only facilitates the film formation of the organotitanium compound, but also the liquid droplets (2
5) is formed and becomes the spores of the bubbles (22), so that the gel-like coating film (24) is effectively foamed even though it is extremely thin. Further, even if the organotitanium compound starts to decompose due to the high boiling point of DOP, a sufficient vapor pressure is maintained in the bubbles (22), so that the bubbles (2
There is no chance that 2) will be crushed and that the recess (23) will not be flattened.

If the amount of DOP added is too small, the bubbles (22) and the concave holes (23) are too small, and the light scattering property is reduced. On the contrary, DO
If the amount of P added is too large, the size of the bubbles (22) and the recesses (23) will fluctuate greatly, and the light-scattering property will locally vary, and the large recesses (2
3} may be formed.

Further, in the present invention, the constituent substance of the film body (21) is not limited to the above-mentioned titanium oxide, and may be silica (S
iO ₂ ), zinc oxide (ZnO), aluminum oxide (A
l ₂ O ₃ ), zircon oxide (ZrO ₂ ), tantalum oxide (Ta ₂ O ₅ ), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), and the like may be used. The compound may be used to form a light-scattering material in the same manner as described above.

Further, the high-boiling organic solvent is not limited to the above-mentioned DOP, and may be any one having the same physical properties and not producing a decomposition residue by firing.

Next, various high boiling point organic solvents were added to the organic titanium compound in various proportions to form a light diffusing film by the same method as described above, and the light diffusing property was investigated. The results are shown in Table 1 below.

Here, DBP is an abbreviation for dibutyl phthalate, DOP is an abbreviation for dioctyl phthalate, DAP is an abbreviation for diallyl phthalate. From Table 1, when forming a light-scattering film using an organic titanium compound, 5 to 20% by volume of DBP or DOP is added. You know what you need to do. Further, when the light scattering property may be low, DAP may be added in an amount of 10 to 20% by volume.

Next, various high boiling point organic solvents were added to the organic silicon compound in various proportions to form a light diffusing film by the same method as described above, and the light diffusing property was investigated. The results are shown in Table 2 below.

It can be understood from Table 2 that it is sufficient to add 5 to 20% by volume of DBP or DOP when forming a light-scattering film using an organic silicon compound. However, when formed under the same conditions, the titanium oxide light diffusing film is superior in light diffusing property to the silica light diffusing film. This is probably due to the difference in refractive index.

In addition, although the above-mentioned embodiment is formed on the outer surface of the halogen bulb, it is not limited to this, the inner surface of the bulb of the halogen bulb, a soft glass such as soda quartz glass or a soft glass such as borosilicate glass or an infrared bulb. It can be formed on the inner and outer surfaces of the bulb of the light bulb and the inner and outer surfaces of the outer tube of the high pressure discharge lamp.

In addition, the light diffusion film of the lamp of the present invention may have a thin diffusion film having a thickness of about 0.1 μm adhered to the surface of the same glass layer so as to have a large diffusion effect. In this case, the first thin diffuser film may be formed on the surface of the glass bulb by the above-described method, and the second and smaller thin diffuser films may be sequentially formed on the surface and laminated. In this case, as shown in FIG.
1A) and (21B) have concave holes in the diffuser film (2).
1B) and (21C) are buried in the upper part, but they remain as bubbles (22A) and (22B), and as a result, it becomes the same when a very large number of bubbles are contained in the thick diffuser film body, which is excellent. It exhibits diffused light.

Further, the light-diffusing film of the lamp of the present invention may be provided so as to be layered with another optical coating, for example, a visible light transmitting / infrared reflecting coating, and the position where it is provided may be an upper layer, a lower layer or an intermediate layer of such an optical coating. Even if it is provided at the position, the light diffusion is not impaired.

Furthermore, the method of forming a plurality of light-diffusing films by stacking layers is
It does not matter if the coating and firing are repeated for each layer or if a plurality of layers are applied and then fired.

[Advantages of the Invention] In the lamp of the present invention, since the metal oxide film having a bubble open on the upper surface and exhibiting a light-scattering property is formed on the surface of the bulb, it is excellent in heat resistance, mechanically strong and long-term. The lamp does not lose its light-scattering property even when used, and a lamp with very little light loss can be obtained, and the mechanical strain caused by the difference in the coefficient of thermal expansion from the glass bulb at high temperature is relieved, resulting in long-term repeated thermal shock. It is possible to obtain a lamp that withstands even the risk of peeling.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a halogen bulb which is an embodiment of the present invention, FIG. 2 is a schematic view simulating an electron micrograph of the outer surface of the chain line frame II portion of FIG. 1, and FIG. 3 is FIG. Fig. 4 is a model cross-sectional view based on the photograph of Fig. 4, Fig. 4 is a model cross-sectional view of coating before firing in the method for forming a light-scattering film, and Fig. 5 is a cross-sectional view schematically showing a state in which a plurality of light-scattering films are laminated. is there. (1) …… Glass bulb, (2) …… Diffusing film, (21) …… Film body, (22) …… Bubbles, (23) …… Concave hole, (24) …… Coating film, (25) ... Droplets, (22A), (22B) ... bubbles.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kano 1 of 201, 1 Funaboshi-cho, Yokosuka-shi, Kanagawa Inside the Yokosuka factory of Toshiba Corporation (56) Reference JP-A-49-30027 (JP, A) Showa 57-198401 (JP, A) Actually opened Showa 56-167303 (JP, U)

Claims (1)

[Claims] 1. A quartz glass bulb and a metal oxide film on the outer surface of the quartz glass bulb having a light emitting structure, the metal oxide film being a high boiling organic solvent containing an organometallic compound and a low boiling organic solvent. Is applied to the glass bulb and fired, and has at least one of concave holes or bubbles formed by evaporation of the low boiling point organic solvent, and exhibits a light diffusing property.