JPH0124094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-glare rearview mirror for an automobile.

A rearview mirror installed in a position that is easy for the driver to see is an image that is easy for the driver to see so that he or she can see external information behind the car without looking back. There are outside mirrors that are installed inside the car, and inside mirrors that are installed near the driver's eyes inside the car.

By the way, if low-altitude sunlight in the morning or evening or light from the headlights of a car following you at night enters the rearview mirror, the strong reflected light from the mirror will enter your eyes and cause a dangerous situation in which the driver will be dazzled.
Therefore, as a countermeasure to this problem, it is desirable to apply anti-glare treatment to the rear view mirror.

Conventionally, anti-glare inside mirrors shown in FIGS. 1 and 2 have been used as back mirrors to which this type of treatment has been applied. (Refer to page 137 of "Automotive Engineering Complete Book, Vol. 10, Electrical Components, Body Maintenance Products, Engine Parts" published by Sankaido, October 15, 1980).
This method takes advantage of the difference in reflectance between the front and back surfaces of a prism mirror, and uses the back surface with a reflectance of about 85% during the day, and the front surface with a reflectance of about 4% at night, reducing the reflectance by 2. The structure allows you to visually check the situation behind you by switching between stages. That is, in the figure, the mirror 2 of the anti-glare inside mirror 1 attached to the ceiling above the driver's seat in the vehicle is a prism mirror, and the prism 2a is provided with a reflective film 5, which will be described later.
The front surface 3 of the prism 2a is vertically inclined with respect to the back surface 4 by a prism angle θ. 5 is prism 2a
A reflective film is formed by vapor-depositing a highly reflective metal film such as aluminum or silver on the back surface 4 of the prism mirror 2, and this forms the reflective surface of the prism mirror 2.

During the daytime (Figure 1), the incident light ray α from the rear of the vehicle
Among them, the reflected light ray α ₁ reflected by the reflective surface on the back surface 4 enters the eye, but the part reflected from the front surface 3 becomes the reflected ray α ₂ on a different reflection path from the reflected light ray α ₁ and does not enter the eye. . Of the other incident ray β having an incident angle different from the incident ray α, the reflected ray β ₁ at the surface 3 enters the eye in the same way as the reflected ray α ₁ , but both the reflected rays α ₁ and β ₁ There is a large difference in reflectance, and the reflected ray β ₁
Since the light is greatly attenuated in the case of , the visible image is only that of the reflected light ray α ₁ with high reflectance, and there is no double copying.

At night (Fig. 2), the driver will be dazzled by the reflected light from the headlights of the following vehicle that is reflected by the high-reflectance rear 4 side reflective surface.To avoid this, the prism mirror 2 is placed in a vertical plane. to rotate the anti-glare switching angle θ' toward the passenger side. Then, of the incident light ray α from the headlight, the portion reflected by the reflective surface on the back side 4, which has a high reflectance, becomes a reflected ray α ₃ , which does not enter the eye, but is reflected by the surface 3, which has a low reflectance, and the light is greatly dimmed. Since only the weakly reflected light ray α ₄ that is reflected by the light enters the eye, no dazzling occurs. In this case, among another incident ray β from a direction A that is somewhat different from the incident ray α, the reflected ray β ₂ from the reflective surface on the back side 4, which has a high reflectance, enters the eye together with the reflected ray α ₄ . Also, direction A should be near the dark ceiling of the vehicle.
Since the prism angle θ and the anti-glare switching angle θ' of the mirror 2 are adjusted and set, the reflected ray β ₂ is even weaker than the reflected ray α ₄ (α ₄ >β ₂ ), and therefore The driver will only be able to see the image created by the reflected light ray _α4 .

However, in the case of such a conventional anti-glare mirror, when it is set outside the vehicle and used as an outside mirror, the direction A, which is different from the incident light ray α from the headlight of the following vehicle, is directed toward the interior of the vehicle. Unlike the dark ceiling direction, this is the relatively bright direction outside the vehicle. This relatively bright light outside the vehicle (sometimes particularly bright light from outside lights, windows, advertising lights, etc.) β is reflected by the back 4 side reflective surface, which has a high reflectance, and the reflected light beam β ₂ is transmitted to the surface with a low reflectance. 3 and enters the eye as light stronger than α ₄ (α ₄ <β ₂ ) of the headlight, which is greatly attenuated. Therefore, there was a problem in that information about the following vehicle was obstructed by other images caused by the reflected light beam β ₂ from another direction, making it impossible for the driver to see, and the mirror no longer functioned as a rear view mirror.

This invention was made by focusing on such conventional problems, and by interposing a laminated light shielding plate between the prism and the reflective film, the reflectance of strong incident light during anti-glare use is reduced. It is an object of the present invention to solve the above-mentioned problems by blocking the incident or reflected light rays on the back side reflective surface, which has a high reflection surface, to prevent them from reaching the eye point.

The present invention will be explained below based on the drawings.

FIGS. 3 to 7 are diagrams showing an embodiment of the present invention. Note that the same reference numerals are given to the same or equivalent parts as in the conventional art, and the explanation thereof will be omitted.

First, to explain the configuration, in FIGS. 3 and 4, 10 is a back mirror, 11 is the mirror body,
12 is a case in which the mirror body 11 is rotatably supported by a support shaft 13 and stored, and 14 is an anti-glare switching angle θ for non-dimming (Figure 4a) and anti-glare (Figure 4b). This is an anti-glare switching lever that rotates the mirror body 11 by . The mirror body 11 includes a prism 2a and a reflective film 5 in a conventional prism mirror 2.
A light shielding plate 15 is provided between them to form a triple structure. This light-shielding plate 15 has a light-shielding interface that intersects with a reflective surface, and is, for example, a laminated flat plate made by butting and joining each side of a large number of rectangular parallelepiped transparent acrylic resin thin plates 15a whose longitudinal direction is the vertical direction.
A light-shielding interface 15b is formed on each joint surface using a black film with a thickness of 0.01 mm to absorb light. The interval between the light-shielding interfaces 15b, 15b (i.e., the width W of the rectangular parallelepiped acrylic plate 15a) and the thickness D of the light-shielding plate 15 (i.e., the thickness of the acrylic plate) are determined by the incident external light that determines the anti-glare effect during anti-glare. Considering the field of view such as the angle of incidence, the thickness D is set to 0.76 mm and the width W is set to 0.1 mm, for example. That is, among the strong incident light rays at the time of anti-glare, the light rays incident or reflected by the reflective film 5 on the back side reflective surface 5' having a high reflectance can be blocked by a portion exceeding a certain incident angle or reflection angle. There is. In this case, the angle formed by the angle of incidence and the angle of reflection is within 90°.

Next, the effect will be explained.

FIG. 5 shows an anti-glare rearview mirror 10 of this embodiment.
An example is shown in which the method is applied to a door mirror, which is an outside mirror. Note that in the following explanation, refraction of light rays is ignored.

When the glare is not dimmed (daytime), as shown in Figure 6a,
The mirror body 11 is set in line with a reference line S. In this case, the incident light ray α from the rear view of the vehicle is reflected by the rear reflective surface 5' with high reflectance and reaches the eye point P as a strong reflected light ray _α1 that is not significantly attenuated, so the driver can see clearly. You can visually check rear information. Among the incident rays α, the surface reflected ray α ₂ reflected by the surface 3 of the mirror body 11 has a larger reflection angle than the above-mentioned reflected ray α ₁ , so it does not reach the eye point P and therefore does not form a double image. .

When anti-glare (at night or in the morning or evening), the mirror body 11 is set by rotating it by an anti-glare switching angle θ' with respect to the reference line S, as shown in FIGS. 6b and 7.
In this case, the incident light ray α from a strong light source such as the headlight of a following vehicle or sunlight is reflected by the low reflectance surface 3 of the mirror body 11, and is reflected as a surface reflected light ray α ₂ whose light intensity is significantly reduced. Since the eye point P is reached, the driver can check rearward information without being dazzled. On the other hand, the part of the incident ray α that travels inside the prism mirror 2 toward the reflecting surface 5' is
In the case of the conventional anti-glare rear mirror, it is reflected as it is from the back reflecting surface and becomes the reflected light ray _α1 having a different path from the surface reflected light ray _α2 , but in the case of the anti-glare back mirror of the present invention, for example, the seventh As schematically shown in the figure, after entering the acrylic plate 15a of the light shielding plate 15, it hits the light shielding interface 15b and is absorbed there (or, after reaching the reflecting surface 5' and being reflected, (It hits and is absorbed) and is cut off.

Furthermore, regarding the strong incident light ray β from another light source (for example, outside lights, advertising lights, window lights, etc.) in a direction different from the strong incident light ray α from the headlight of the following vehicle, the same as above, After advancing inside the mirror body 11 and entering the acrylic plate 15a of the light shielding plate 15,
The light will be absorbed by the light shielding interface 15b and will be blocked. Therefore, according to the anti-glare rearview mirror of the present invention, the driver is not dazzled when used as an inside mirror inside the car, but also when used as an outside mirror outside the car. There is no possibility that the mirror will no longer function as an anti-glare mirror.

In addition to the above-mentioned embodiments, it is also possible to create the light-shielding interface 15b by cutting a large number of extremely thin slits in a layered manner in a transparent acrylic plate, and forming a light-shielding interface made of light-absorbing paint on these slits. It will be done.

In addition to the acrylic board, cellulose acetate and butyrate can also be used as the light shielding plate.
It is also possible to further cover both edges with light shielding plates 15c, 15c as shown in the figure.

As explained above, according to this invention,
Its structure is that in an anti-glare back mirror formed by providing a reflective film on the back side of a prism to form a reflective surface, a laminated light-shielding plate is formed between the prism mirror and the reflective surface, and when used for anti-glare use. This anti-glare back mirror is characterized by blocking strong incident light from entering or reflecting from the reflective surface on the back side to prevent it from reaching the eye point, so it can be used not only inside the car but also outside the car. Therefore, an anti-glare rear mirror having sufficient anti-glare function can be obtained.

[Brief explanation of drawings]

Fig. 1 is a functional explanatory diagram of a conventional anti-glare inside mirror during daytime, Fig. 2 is a functional explanatory diagram of Fig. 1 during nighttime, Fig. 3 is a front view of one embodiment of the present invention, and Fig. 4 The figure is a cross-sectional view taken along the line -- in FIG. 3, where a shows the non-dazzling state and b shows the non-dazzling state. Fig. 5 is a partially omitted plan view of the car door mirror shown in Fig. 3 applied, and Fig. 6 is a functional overview diagram of the one shown in Fig. 3, where a shows the non-dimming state and b shows the non-dazzling state. show. FIG. 7 is a partially enlarged view of FIG. 6b, and FIG. 8 is a diagram showing another example of the light shielding plate. 2... Prism mirror, 3... Surface (of the prism mirror),
5... Reflective film, 5'... Reflective surface, 10... Anti-glare back mirror, 15... Light shielding plate, α, β... Incident light beam, α ₁ , α ₂
...Reflected ray, P...Eye point.

Claims (1)

[Claims] 1. An anti-glare mirror in which a light shielding plate is provided between the prism and the reflective film in a prism mirror, and the light shielding plate is made of a plurality of rectangular parallelepiped thin plates made of transparent acrylic resin, cellulose acetate, cellulose butyrate, etc. 1. An anti-glare back mirror characterized in that it is formed by bonding through an absorbing film or paint so that the surface that intersects with the reflective film becomes a bonding surface.