JPS59162501A - Automatic nonglaring mirror - Google Patents

Abstract

PURPOSE:To monitor the rear with proper lightness without too glaring nor too dark by varying transmittivity according to the intensity of incident light from the rear. CONSTITUTION:A photosensor 1 is arranged to detect light through a cmponent which varies in light transmittivity, e.g. liquid-crystal plate 3. The transmittivity of the liquid-crystal plate 3 is so held that the reflection of the mirror 4 is maximum in the daytime. Headlights are turned on in the nighttime or in tunnels, so a controller 5 is powered on once the headlights are turned on. When light from the headlights of a following vehicle is not incident through the rear window, the light to the photosensor 1 is weak, so the signal of the photosensor is small. The controller 5 amplifies the detection signal of the sensor or controls the transmittivity of the liquid-crystal plate 3 so that the signal is equal to some reference signal. When the rear part is dark, the signal of the sensor does not attains to a specific value, so that transmittivity is held maximum as well as in the daytime. Thus, the reflected light has invariably constant lightness and the rear is monitored without any glare.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an auto-dimming mirror, and more particularly to an auto-dimming mirror that automatically controls the reflectance of a rearview mirror for an automobile.

A car's rearview mirror is used to monitor the state of the traffic behind, such as vehicles and obstacles behind the car, through the rear window of the car, but especially at night, when the light from the headlights of the following car enters directly, , there was a risk that the driver would feel dazzled and that it would be difficult to monitor the front and rear directions.

In conventional anti-glare mirrors, as shown in Figure 1, a light sensor 1 placed at a position where it can directly sense light from behind detects strong light from behind, and the signal level and comparator? If it exceeds this value, for example, by applying a voltage to the liquid crystal plate 3 and reducing the transmittance of the light, the liquid crystal plate ? The glare was prevented by reducing the reflectance on the mirror 4 placed on the back surface of the screen.

However, such conventional devices either transmit or block light, and it is difficult to control the transmittance to an appropriate value. For this reason, when the incident light from the rear becomes strong and the glare increases to a certain extent, it turns to the fender side, but it also has the disadvantage that it is difficult to see the rear.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, and to change the transmittance according to the intensity of the incident light from the rear, thereby creating an appropriate light that is neither dazzling nor dark. The purpose of the present invention is to provide an auto-dimming mirror that can monitor the rear view clearly.

Hereinafter, the auto-dimming mirror of the present invention will be described in more detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 2 shows an embodiment of the auto-dimming mirror of the present invention. The feature of the configuration of the auto-dimming mirror of the present invention is that, as is clear from FIG.
It is arranged so that light is detected through a paulownia wood material whose light transmittance changes, that is, in this embodiment, a liquid crystal plate 3.

In the auto-dimming mirror having such a configuration, the transmittance of the liquid crystal plate 3 is set to be the highest so that the amount of reflection from the mirror 4 during the daytime is also large. At night or in a tunnel, the headlamps are turned on, so the power is turned on to the control device 5 at the same time as the headlamps are turned on. However, when the light from the headlamp of the following vehicle is not entering through the rear window, the light to the optical sensor 1 is weak, so the signal from the optical sensor becomes small. The control device 5 amplifies the detection signal from the sensor and controls the transmittance of the liquid crystal plate 3 so that it becomes equal to a certain reference signal. Now, when it is dark at the rear, the sensor signal does not reach the specified value, so the transmittance remains at its maximum, just like in the daytime.

If the following vehicle is far away and the headlights are pointing upwards, Akira will enter the vehicle as shown by arrow 6, and you will feel dazzled, but the light is relatively weak and the output from the optical sensor will be relatively small. , exceeds the reference signal, the control device 5
From then on, a voltage is applied to the liquid crystal plate to reduce the transmittance of the liquid crystal plate, and control is performed until the output from the optical sensor becomes equal to the reference signal.

When the following vehicle approaches further and the incident light 6 from the rear becomes stronger, the transmittance of the liquid crystal plate further decreases, and control is performed at a new point where the output of the sensor 1 becomes equal to the reference signal. In this way, by controlling the transmittance of the liquid crystal panel 3 according to the strength of the incident light from the rear, the reflected light always has a constant brightness, so the driver can see the front and rear lights without feeling dazzled. You can monitor the rear.

In the above embodiments, liquid crystal was used as the substance that changes the light transmittance, but the transmittance is not limited to liquid crystal, and the transmittance may be changed by coloring with an electrochromic material.

As explained above, according to the auto-dimming mirror of the present invention, by changing the transmittance according to the intensity of incident light from the rear, it is neither dazzling nor dark, and has an appropriate brightness. You can monitor the rear.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural explanatory diagram showing a conventional auto-dimming mirror, and FIG. 2 is a schematic structural explanatory diagram showing an auto-dimming mirror according to an embodiment of the present invention. 1... Optical sensor, 3... Liquid crystal plate, 4... Mirror,
5.--Control device, 6..7 Incoming rice Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Shin Kuzuno - Figure 1 Figure 2

Claims (1)

[Claims] In an anti-glare mirror in which a structure whose light transmittance changes depending on the application of an electric field is arranged in front of the mirror, an optical sensor is provided at a position to detect the light transmitted through the structure whose light transmittance changes. 1. An automatic dimming mirror, characterized in that the light transmittance of the structure is controlled by the output signal of the auto-dimming mirror.