JPS60212705A - Reflection mirror - Google Patents

Abstract

PURPOSE:To obtain the reflectivity meeting the requirements specified in automotive standards and the spectral reflective characteristic which can decrease dazzle by laminating alternately quarter-wave films consisting of a high refractive index material and quarter-wave films consisting of a low refractive index material into four layers on the rear of a glass substrate and laminating a metallic reflecting film thereon. CONSTITUTION:A TiO2 film 2, an SiO2 film 3, a TiO2 film 4 and an SiO2 film 5 are successively laminated all to a quarter-wave thickness on the rear of the glass substrate 1 and the metallic reflecting film 6 consisting of Cr or an alloy contg. Cr as an essential component is laminated to a suitable thickness on the outside thereof. The films 2, 4 have a high refractive index and the films 3, 5 have a low refractive index. The reflection mirror has further the film 6 and has therefore about 50% reflectivity meeting substantially the requirements specified in automotive standards and the satisfactory spectral reflecting characteristic which has a peak wavelength at about 470mmu and can decrease dazzle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reflecting mirror suitable for, for example, a rearview mirror for an automobile.

[Prior Art] Generally, as a reflecting mirror, there is one in which a vacuum-deposited aluminum film is formed on the back surface of a glass substrate, and a protective coating film is applied on the outside of the vacuum-deposited film. However, although this mirror has sufficient reflectance as an automobile rearview mirror (automotive standards require a reflectance of 38% or higher), its spectral reflection characteristics are nearly flat, resulting in glare. Therefore, it is not suitable for use as an automobile rearview mirror.

Therefore, conventionally, as shown in FIG. 1, 1-! 02 membrane 12.5iOzl! 13, Ti02
11914 is sequentially coated with a thickness of 1/4 wavelength, and an optical interference three-layer film surface anti-rJ4vL is used, in which a light-absorbing coating film 16 is applied to the back surface of a glass substrate 11.

However, such conventional products have a reflectance that meets automotive standards and a spectral reflection characteristic that has a peak wavelength near 410 mμ and can reduce glare, but on the other hand, they have three optical interference layers (11AI2.13). .14 is the glass substrate 11
0 Since the surface is exposed, there are disadvantages in terms of durability, such as scratches and peeling of the film when dust adheres to it or when wiping with a brush during car washing. After that, the optical interference three-layer film 12.
Since the vacuum deposition of steps 13 and 14 and the coating and baking of the light-absorbing coating film 16 must be performed in separate steps, there are drawbacks such as poor workability.

In addition, in order to prevent the optical interference 3Wi film 12, 13, 14 from being scratched or peeling off, for example, the second
If the three-layer optical interference film 12, 13, 14 is formed on the back surface of the glass substrate 11 as shown in the figure J', the reflectance will be lower than the automotive standard, and the three-layer optical interference film 12, 13, 12, 14,
The disadvantage that the vacuum deposition of step 14 and the coating and baking of the light-absorbing coating film 16 must be performed in separate steps (this cannot be solved in any way).

[Objective of the Invention] The present invention eliminates the drawbacks of the above-mentioned conventional products, provides reflectance that meets automotive standards, and spectral reflection characteristics that can reduce glare, and has good manufacturing workability and durability. The purpose of this invention is to provide an excellent reflecting mirror for the general public.

[Structure of the Invention] In order to achieve the above object, the present invention alternately stacks 4WI films of 174 wavelengths made of a high refractive index material and 174 wavelength films made of a low refractive index material on the back surface of a glass substrate. It has a structure in which a metal reflective film is laminated on top.

[Embodiments of the invention] Embodiments of the invention shown in the drawings will be described below.

FIG. 3 shows an embodiment of this invention, in which a TiO2 film 2.5iOz film 3 and a TiO2 film 4 are formed on the back surface of a glass substrate 1.
,S! 0zli! 5 are sequentially laminated to a thickness of 174 wavelengths, and a metal reflective film 6 made of Cr or an alloy containing Cr as a main component is laminated to an appropriate thickness on the outside. T
Since the i02 film 2.4 has a high 1 diffraction index, the 5iOz film 3.5 has a low refractive index, and is further provided with a metal reflective film 6, this reflector has a high diffraction index of about 5
It has a fouling rate of 0%, a peak wavelength near 470 mμ, and good spectral reflection characteristics that can reduce glare.

Further, in this reflecting mirror, the optical interference four-layer films 2 to 5 are arranged on the glass substrate 1.
The optical interference 4-layer film is not exposed on the surface of the glass substrate 1, but is provided on the back surface of the glass substrate 1 and is protected by the total reflection 16, so even if dust or dirt adheres to it or if you wipe it with a brush when washing the car, the optical interference 4-layer film will remain intact. 2 to 5 are not scratched or the film peels off. This reflective mirror can be manufactured by cutting, molding, and cleaning the glass, and then vapor depositing the four optical interference layers IQ 2 to 5 d3 J and the metal reflective film 6 in the same vacuum 5. It has good workability, stable quality, and cost reduction.

Note that ZnS or Ce is used instead of the TiO2 film 2.4.
A similar 1/4 wavelength film may be formed using 0p, a similar 174 wavelength film may be formed using MgF instead of 5iOz 3.5, and Ni1CO or these as main components may be used instead of Cr. The metal reflective film 6 may be formed of any metal containing material.

[Effect of the invention 1] Since the present invention is configured as described above, it has sufficient reflectance that meets the automobile standards and good spectral reflection characteristics that can reduce glare, and also has good workability in manufacturing. This makes it possible to stabilize quality and reduce costs, as well as improve quality due to its excellent durability, making it suitable for use as rearview mirrors for automobiles and widely applicable to other uses. It has excellent effects such as:

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a conventional one, Fig. 2 is a sectional view showing a reference example, and Fig. 3 is a sectional view showing an embodiment of the present invention. , 2.12-T i Oz
IG! , 3゜13...5i02 film, 4,14...T
iO2” film, 5...S!02 film, 6...metal reflective film, 16...light absorbing coating film Applicant: Murashi Shomeido Co., Ltd. Manager: 1 person from joint pressure chamber Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. 174 made of a high refractive index material on the back surface of the glass substrate
A reflecting mirror comprising four layers of alternating wavelength films and 174-wavelength films made of a low refractive index material, and a metal reflective film is stacked on the outside thereof. 2 1￥1 high refractive index material is Ti0z, ZnS or C
A reflecting mirror according to claim 1 consisting of e0z. 3. Anti-I) lvL according to claim 1, wherein the low refractive index material is SiO2 or MQF. 4. The reflective mirror according to claim 1, wherein the metal reflective film is made of Cr, Ni, Go, or an alloy containing these as main components.