JPH04174401A - Reflecter - Google Patents

Abstract

PURPOSE:To improve thermal shock resistance and heat/moisture resistance by providing the mirror face of a reflector base body made of brilliant alumi num alloy with a surface protecting layer composed of two layers, namely a lower layer formed of silicon dioxide and an upper layer formed of tantalum pentoxide. CONSTITUTION:A reflector base body 1 is formed of brilliant aluminum alloy (A5650) by the rolling method. After the base body 1 is precisely cleaned and dried sufficiently, it is attached inside a vacuum depositing vessel, and a target formed of silicon dioxide is heated by electron beam to vapor-deposit a lower layer 3a onto the mirror face 2 of the base body 1. An upper layer 3b is then vapor-deposited on the lower layer 3a using a target formed of tantalm pentoxide to laminatedly form a surface protecting layer 3 for producing a reflector A suitable for this invention. A similar effect can be obtained by vapor-depositing a surface protecting layer formed of aluminum nitride.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reflector plate used for constructing a lighting system of OA equipment or the like.

[Conventional technology]

A reflector used in a lighting device equipped with a light source in OA equipment such as a copying machine is a device that efficiently reflects the luminous flux emitted from the light source in a desired direction to illuminate a necessary target. The shape of the mirror surface varies depending on the purpose, from flat to spherical, ellipsoidal, parabolic, etc.

Although the reflective plate in such lighting systems does not need to have a particularly precise mirror surface, it does have a special shape, so it is usually formed into the desired shape by rolling or casting aluminum alloy, or by cutting, and then the reflective surface is It is manufactured by mirror-finishing the parts by lapping or electropolishing.

When such a reflector is used, for example, in the lighting system of a copying machine, it is exposed to repeated flashing irradiation from a halogen lamp used as a light source, so when used continuously, the temperature of the detector plate may rise to around 250 to 300°C. There was a problem in that the reflective surface was oxidized and turned into alumite, which gradually caused cranks to occur and the mirror surface to become rough.

On the other hand, in order to prevent oxidation deterioration of the mirror surface,
A method of providing a silicon layer as a protective film has been proposed, but even reflectors configured in this way cannot sufficiently suppress deterioration over time such as cracks and peeling in the usage environment, and the heat resistance and moisture resistance are also poor. It wasn't satisfying.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to have excellent heat resistance and moisture resistance, and to prevent peeling due to oxidation even when used repeatedly under significantly changing environmental conditions. To provide a reflector that can be stably used for a long period of time without causing roughness.

[Means to solve the problem]

The object of the present invention is to provide a surface protective layer with a two-layer structure of a lower layer of silicon dioxide and an upper layer of tantalum pentoxide or a single-layer structure of aluminum nitride on the mirror surface portion of a bright aluminum alloy reflector substrate having a predetermined shape. This can be achieved by a reflective plate characterized by the provision of a reflector plate.

The substrate constituting the reflector of the present invention is a bright aluminum alloy that is formed into a desired shape by rolling, casting, cutting, etc., and then mirror-finished by lapping, electrolytic polishing, etc. A substrate similar to that used as a substrate is used.

In the present invention, a two-layer surface protective layer is provided by sequentially laminating a lower layer of silicon dioxide and an upper layer of tantalum pentoxide on the mirror surface portion of the substrate by, for example, vacuum evaporation or sputtering, or a surface protective layer of aluminum nitride is provided. A surface protective layer having a single layer structure is provided by the same method as described above to form a reflective plate. The thickness of such a surface protective layer is 0.41 to 0.5 in the case of a two-layer structure of silicon dioxide and tantalum pentoxide.
It is about μm, preferably around 0.3 μm (
In the case of a single layer structure of aluminum nitride, it is 0.08~0゜2.
The thickness is preferably about μm, preferably around 0.12 μm.

[For production]

The reflective plate of the present invention is provided with a protective layer having excellent thermal shock resistance and temperature and humidity resistance, and has significantly improved durability.

[Example 1] Using a bright aluminum alloy (A5650), a reflector substrate 1 having the cross-sectional shape shown in FIG. 1 was produced by a rolling method.
It was created.

After thorough precision cleaning and drying of this substrate 1, it was installed in a vacuum evaporation tank and heated to about 170°C with a vacuum degree of I
The lower layer 3a having a thickness of 0.17 μm was deposited on the mirror surface portion 2 of the substrate 1 by evacuation to X 10 −′ Torr and first heating a silicon dioxide target with an electron beam. Subsequently, the lower layer 3a is formed using a target of tantalum pentoxide.
An upper layer 3b with a thickness of 0.16 μm is deposited on top of the layer 3b with a thickness of 0.16 μm.
A reflective plate A of the present invention was obtained by laminating a surface protective layer 3 with a thickness of 33 μm.

[Example 2] In the same manner as in Example 1 except that the reflector substrate was formed of bright aluminum alloy (A6063), a lower layer of silicon dioxide with a thickness of 0.14 μm and a lower layer of silicon dioxide with a thickness of 0. ．．
A top layer of tantalum pentoxide of 15 μm is laminated to a thickness of 0.2
A surface protective layer of 9 μm was formed to obtain a reflective plate B of the present invention.

[Example 3] Using the same reflector substrate as used in Example 1, 5
An aluminum nitride target was evaporated by electron beam heating in a nitrogen gas atmosphere of X 10-5 to I
A surface protection layer of aluminum nitride was deposited to obtain a reflector C of the present invention.

[Example 4] A surface protective layer of aluminum nitride with a thickness of 0.10 μm was vapor-deposited on the mirrored portion of the substrate according to the same procedure as in Example 3 except that the same reflector substrate as used in Example 2 was used. As a result, a reflector plate of the present invention was obtained.

[Comparative Example 1] The same reflector substrate as used in Example 1 was used, and silicon dioxide with a thickness of 0.30 μm was deposited on the mirrored portion of the substrate in the same manner as in Example 1 except that only a silicon dioxide target was used. A control reflector E was obtained by depositing the layer.

[Comparative Example 2] In exactly the same manner as in Comparative Example 1, a silicon dioxide layer with a thickness of 0.15 μm was deposited on the mirror surface portion of the substrate, and a control reflector F was formed.
I got it.

[Test example]

These reflectors were subjected to the following temperature/humidity resistance test and lighting test (thermal shock test) to examine their durability.

After being allowed to stand for 100 hours in an atmosphere with an indigo temperature of 80° C. and a relative humidity of 90%, it was dried and the state of the surface protective layer was observed.

In the control reflectors E and F, clouding and peeling occurred in the protective layer, whereas in the reflectors A, B, C, and D of the present invention, the protective layer was cloudy and peeled.
In addition to the occurrence of cloudiness, no changes were observed.

A test was conducted for 100 hours in which irradiation for 6 seconds and turning off for 5 seconds was repeated 20 times using a 1350 W halogen lamp, followed by a rest for 10 minutes, and the state of the surface protective layer was observed.

In the control reflector E, some peeling occurred in the protective layer, and in F, further cracking and peeling occurred, whereas in the reflectors A, B, C, and D of the present invention, no changes were observed. Ta.

〔Effect of the invention〕

The reflector of the present invention has excellent temperature and humidity resistance and thermal shock resistance, and has the advantage of being able to be used stably over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a reflector of the present invention. DESCRIPTION OF SYMBOLS 1... Reflector base, 2... Mirror surface part, 3... Surface protective layer, 3a... Lower layer, 3b... Upper layer. Patent applicant Reiko Co., Ltd. Figure 1

Claims (1)

[Claims] A surface protective layer having a two-layer structure of a lower layer of silicon dioxide and an upper layer of tantalum pentoxide or a single-layer structure of aluminum nitride is provided on the mirror surface portion of a bright aluminum alloy reflector substrate having a predetermined shape. a reflector.