JPS634204A - Glare-proof mirror for vehicle - Google Patents

Abstract

PURPOSE:To securely prevent glaring light from being reflected by a mirror by providing a reflection factor decrease control means which decreases the reflection factor of the mirror when it is decided that it is in the nighttime and the detected quantity of light varies increasingly. CONSTITUTION:Transparent plates 9 which serve as transparent electrodes and polarizing plates are provided in contact with both surfaces of a liquid crystal plate 5 arranged opposite the photodetection surface side of a light reflecting plate 3, and polarizing plates 11 are provided in contact with both surfaces of a zirconate titanate lanthanum PLZT 7. Further, the transparent plates 9 and transparent electrodes 10 are supplied with electricity from a power source (not shown in figure) through a switch circuit 13 and a control circuit 15 respectively and those circuits 13 and 15 operates under the control of a control part 6 composed of a microcomputer. An environmental illuminance detection sensor 23 which detects the illuminate at the periphery of a vehicle is provided below the vehicle front side closed surface of a case 17 and both detected values of an incident light quantity detection sensor 21 which detects the quantity of light incident on the mirror 1 and the sensor 23 are inputted to the control part 6 to vary a voltage impressed to the PLZT 7, thereby varying the reflection factor of the mirror 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-glare mirror for a vehicle in which the reflectance of the mirror can be automatically switched based on the environmental illuminance around the vehicle and the amount of light incident on the mirror.

(Prior art and its problems) The anti-glare mirror for a vehicle disclosed in 8th Bis Bulletin No. 517 automatically switches the reflectance of the mirror based on the environmental illuminance around the vehicle and the amount of light incident on the mirror. This prevents the annoyance and discomfort caused by glare from mirrors when driving at night.

Therefore, the reflectance of the mirror is switched in two stages, large and small, and when the light reflected by the mirror becomes dazzling during night driving, the reflectance is switched to the small side.

A determination as to whether the light incident on the mirror causes dazzling light is made by determining whether the amount of the incident light is equal to or greater than a specified value.

By the way, when driving at night, for example, when the light reflected from the mirror feels dazzling to the driver, it is not just the magnitude of the amount of light reflected by the mirror, but also when the light suddenly enters the mirror, or when the amount of light incident on the mirror is too small. An example is a case where the number gradually increases.

When light suddenly enters the mirror, the glare is particularly noticeable within a short time (several m5ec to several tens of m5ec) after the light enters the mirror, and after that, the eyes gradually get used to it and the feeling of glare decreases. Broca-3u Izer effect) etc.
If the incidence conditions of the incident light on the mirror differ, the feeling of glare and discomfort will differ.

However, in conventional anti-glare mirrors, the mirror reflectance is switched only in consideration of the situation in which the amount of light incident on the mirror exceeds a specified amount.

Therefore, the anti-glare effect is not necessarily achieved depending on the incident state of the incident light on the mirror, and therefore, there is a problem in that the dazzling light makes the driver feel bothered and fatigued, making it difficult to drive comfortably.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to reduce the glare caused by driving a vehicle facing forward at night by reducing the incidence of light on the mirror. An object of the present invention is to provide an anti-glare mirror for a vehicle that can reduce glare in accordance with the above.

(Configuration of the Invention) In order to achieve the above object, the present invention is configured as shown in FIG.

In the figure, the environmental illuminance detection means A detects the environmental illumination around the vehicle, and the incident light amount detection means B detects the amount of light incident on the mirror.

The day/night discrimination means C discriminates whether it is day or night depending on whether or not the ambient illuminance above a specified level is detected.

When it is roughly determined that it is night and the detected amount of incident light changes in the direction of increasing, the reflectance of the mirror is reduced by the reflectance reduction control means.

(Description of Examples) Hereinafter, preferred examples of the anti-glare mirror for automobiles according to the present invention will be described based on the drawings.

FIG. 2 shows a vehicle door mirror 1 to which the anti-glare mirror according to the present invention is applied, and in the door mirror 1, a light reflecting plate 3 formed of an aluminum film or the like is housed in a case 17. .

On the light receiving surface side of the light reflecting plate 3, a liquid crystal plate 5 is arranged opposite to each other at a predetermined interval.
T (lanthanum lead titanate zirconate) 7 is arranged.

Transparent plates 9 serving as transparent electrodes and polarizing plates are provided in close contact with both surfaces of the liquid crystal plate 5, and polarizing plates 11 are provided in close contact with both surfaces of the PLZT 7.

Furthermore, the transparent plate 9 and the transparent electrode plate 10 each have a switch circuit 1.
3 and a control circuit 15 from a power source (not shown), and the operation of the switch circuit 13 and control circuit 15 is controlled by a control section 6 composed of a microcomputer or the like.

In addition, a glass cover 19 is provided at the opening on the light receiving surface side of the case 17.
is attached, and below this glass cover 19 is an incident light amount detection sensor 21 that detects the amount of light incident on the mirror 1.
is fitted and fixed into the case 17.

An illuminance detection sensor 23 for detecting the illuminance around the vehicle is provided below the closed surface of the case 17 on the front side of the vehicle. It has been taken in.

Note that FIG. 3 schematically shows the principle of controlling the light transmittance of PLZT7, and FIG. 4 shows the principle of controlling the light transmittance of PLZT7.
An example is shown.

As understood from FIG. 5, the increase or decrease in the light transmittance of the PLZT7 corresponds to the increase or decrease in the applied voltage applied to the PLZT7.

Therefore, by changing the applied voltage applied to PLZT7, the light transmittance of PLZT7 can be changed,
Thereby, the reflectance of the mirror 1 can be changed in an analog manner.

As a result, the reflectance of the mirror 1 is gradually increased, so that the eye gradually becomes accustomed to the light reflected by the mirror 1. Therefore, it is easy to visually check following vehicles etc. using the mirror 1, and safer driving is possible.

Note that the control to reduce the reflectance of the mirror 1 may be performed not in a stepwise manner (this embodiment) but in a gradual manner.

Further, in this embodiment, the liquid crystal plate 5 and the PLZT 7 are used as means for changing the light reflectance of the mirror 1, but either -
You may also use the method.

Briefly, FIG. 6 shows a situation in which the light reflected by the mirror 1 enters the eyeball, and FIG. 7 shows a schematic diagram of the incident light amount detection sensor 21 arranged according to the situation. There is.

In FIG. 7, a large number of cylindrical members 21a for preventing unnecessary light from entering are arranged on the light receiving surface side of the incident light amount detection sensor 21, and a light sensor 21b is provided at the base of each cylindrical member 21a.
are provided for each.

The detected value obtained by the optical sensor 21b is taken in by a comparator 21G, and when the detected value exceeds a specified value, the comparator 21G turns on and outputs the detected value to the OR circuit 21d.

FIG. 8 shows a flowchart of the processing procedure performed by the control section 6.

In the first step 100 in the same figure, it is determined whether the detected illuminance value A detected by the environmental illuminance detection sensor 23 is equal to or higher than the preset illuminance value A1, and even if the detected illuminance value A is equal to or higher than the set illuminance value A1, For example, in the next step 110, it is determined that it is currently daytime.

In the next step 120, the switch circuit 13 is turned on to maximize the light transmittance of the liquid crystal plate 5 (DAY), and in the next step 130, the PL is switched on via the control circuit 15.
When the voltage applied to ZT7 is maximized, the light transmittance of PLZT7 is maximized.

As a result, the light reflectance of mirror 1 is maximized.

Further, if the detected illuminance value A is less than the set illuminance value A1 in step 100, it is assumed that it is currently nighttime, and in the next step 140, the detected light amount value ■ detected by the incident light amount detection sensor 21 is set in advance. It is determined whether the set light amount value is equal to or greater than 11.

If the detected light amount value (■) is less than or equal to the set light amount value (2), the process proceeds to step 120 and the same process as described above is performed.

Further, when the detected light amount value ■ is equal to or greater than the set light amount value 11, the light reflected by the mirror 1 is considered to be dazzling to the driver. Then, in the next step 150, the switch circuit 13 is turned off, so that the light transmittance of the liquid crystal plate 5 becomes minimum (NIGHT).

Furthermore, if the current incident light on the mirror 1 is incident in a stepwise manner as shown in FIG. 9(a), the next step 160
In this case, the PLZT 7 is controlled via the control circuit 15 to increase or decrease its light transmittance.

As can be understood from FIG. 9(b), the light transmittance control of PLZT7 is reduced to 0.01 to 0.02 the moment the incident light enters the mirror, assuming the NIGHT state is 1. , then gradually the NIGH during 0.1-0.3 seconds
Increased to T.

Note that the degree to which the light transmittance of PLZT7 is decreased or the time required to increase it to the NIGHT state can be determined as appropriate.

As is clear from the above explanation, in this embodiment, under the situation where the incident light entering the mirror during night driving is particularly incident in a stepped manner, the PL
The light transmittance of ZT7 is instantly decreased and then gradually increased.

Therefore, even if light suddenly enters the mirror 1 while driving at night, it is possible to drive comfortably without feeling bothered or uncomfortable by the glare caused by the 3ROCA-3ULZER effect.

Next, a second embodiment of the anti-glare mirror for a vehicle according to the present invention will be described.

FIG. 10 shows a vehicle door mirror 1 to which the vehicle anti-glare mirror according to the present invention is applied.

Note that the same parts as in FIG. 2 are designated by the same reference numerals, and the explanation thereof will be omitted.

In the figure, in this door mirror 1, a switch circuit 13
A has a built-in monomulti circuit, which allows the control section 6
When there is an instruction to increase the light transmittance of the liquid crystal plate 5, the switch is operated with a delay of about one second, for example.

Further, the incident light amount detection sensor 21A is provided with an adder 21e as shown in FIG. 11, and this adder 21e calculates the sum of the amounts of incident light obtained by each sensor 21b, and converts the sum into a voltage. It is output to the control section 6.

In the control unit 6, as shown in FIG. 12, the transmittance characteristics of the PLZT 7 corresponding to the voltage change amount Δ of the sequential change in the amount of incident light are stored in a storage device (not shown).

13 and 14, the processing procedure performed by the control section 6 is shown in the form of a flowchart.

In FIG. 13, in the first step 300, the illuminance value A detected by the environmental illuminance detection sensor 23 is read, and in the next step 310, it is determined whether the detected illuminance value is equal to or higher than a preset illuminance value A7. Ru.

Then, in step 310, the detected illuminance value A is changed to the set illuminance value A.
, it is determined that it is currently daytime, and the flag is set to "Off" in step 320, and the illuminance value A (, Vold) detected in step 300 is not stored.

In the next step 330, the switch circuit 13A is turned on to maximize the light transmittance of the liquid crystal plate 5, and in the next step 340, the light transmittance of the PLZT7 is maximized via the control circuit 15, and as a result, the mirror The reflectance of 1 is maximum.

Next, in step 310, if the detected illuminance value A is smaller than the set illuminance value A1, it is determined that it is currently nighttime, and in the next step 350, it is determined whether or not the flag is "0".

If the flag is Off in step 350, the output value Vold of the incident light amount detection sensor 21A is read, and in the next step 370, the output value Void is stored in a storage device (not shown).

If the flag is not "0" in step 350, the output value Void from the adder 21e has already been stored, so in the next step 380, the output value v neW subsequently obtained by the incident light rain detection sensor 21A is is loaded.

Then, in the next step 390, the difference Δ (=Vnev-Void) between the output value VOId and the output value V new is calculated.

In the next step 400, it is determined whether or not the output difference Δ is a preset value of 60 or more, and if the output difference Δ is smaller than the set value Δ0, the incident light from the headlights of the following vehicle, etc. It is assumed that there is no or is decreasing, and the process proceeds to step 330, where the same processing as above is performed.

On the other hand, if the output difference Δ is larger than the set value Δ0 in step 400, it is assumed that the light from the headlights of the following vehicle is incident on the mirror 1 and the driver feels dazzling.
In the next step 410, the switch circuit 13A is turned off. Therefore, the light transmittance of the liquid crystal plate 5 becomes minimum.

Then, to the extent that the reflectance of mirror 1 is reduced in step 410, the reflected light on mirror 1 becomes extremely dazzling light, so in the next step 420, PL is adjusted according to the output difference Δ.
The voltage applied to ZT7 is controlled via the control circuit 15.

FIG. 15 shows an example of the control up to step 420, and in the same figure, the transmittance of PLZT 7 (as a result, the reflectance of mirror 1) changes at the moment when light enters mirror 1.
is decreased in steps, and the amount of decrease is based on the characteristics shown in FIG.

Then, the transmittance of PLZT7, which was once decreased, is then gradually increased to the maximum transmittance.

In FIG. 14, in step 430, the output value V neW read in step 380 in FIG. 13 is stored as Vold, and in the next step 440, the output value of the incident light amount detection sensor 21A is read, Vn
It is considered as ew.

Then, in the next step 450, the output difference Δ between the output value V new stored in the step 430 and the output value Void read in the step 440 is calculated, and in the next step 460, the output difference Δ is within a certain range. It is determined whether the

If the output difference Δ is within a certain range in step 460, it is determined that the same amount of light continues to enter the mirror 1 from a while ago. For this reason, the processes in steps 410 and 420 in FIG. 13 are continued, and therefore the transmittance of the liquid crystal plate 5 is minimized, and
T7 has the highest light transmittance.

Then, the process returns to 430 and the same process is repeated.

If the output difference Δ is not within a certain range in step 460, it is determined that there has been some change in the incident light on the mirror 1, and in the next step 470, it is determined whether the output difference Δ is a positive value.

If the output difference Δ is positive in step 470, it is determined that stronger light than the previous one has entered, and the process returns to step 420 in FIG.
The transmittance of is changed.

Roughly speaking, if the output difference Δ is negative in step 470, it may be because, for example, the light from the headlights of the following vehicle no longer enters the mirror 1, and in this case, the switch circuit 13A is turned on in step 480. and switch circuit 1
Since 3A has a time constant, as can be understood from FIG. 15, the transmittance of the liquid crystal plate 5 does not change immediately, but increases to the maximum value after a delay of, for example, about 1 second.

Then, in the next step 490, the output value Vnew read in step 440 is stored as Void, and in the next step 500, the flag is set to "1'°."

Then, the process returns to step 300 in FIG. 13 and the same process is repeated.

As is clear from the above description, in the vehicle door mirror 1 of this embodiment, the amount by which the light transmittance of the PLZT 7 is reduced according to the output difference Δ is determined based on the characteristics shown in FIG. 12 each time the output difference Δ is calculated. Set.

Then, the light transmittance of PLZT7 is reduced by the set amount, so if the amount of reduction in the reflectance of mirror 1 is small and the anti-glare is not sufficient, or conversely, if the reflectance of mirror 1 is reduced too much and mirror 1 is Appropriate anti-glare can be achieved without any inconvenience such as the outline of the visually recognized object becoming unclear.

Therefore, it is possible to drive comfortably without the annoyance or discomfort caused by dazzling light.

Next, the processing procedure in the control section 6 in the vehicle door mirror 1 shown in FIG. 2 can be performed as shown in FIG. 16.

In addition, in FIG. 16, the PL at step 160 in FIG.
A procedure for calculating an increase or decrease in the light transmittance of ZT7 is shown.

In the same figure, in the first step 600, the detected light amount value L(t) from the incident light amount detection sensor 21 at the time is taken in, and in the next step 610, the detected light amount value L(t) is taken in.
), L(t) is calculated as the difference from the detected light amount value L(t-1>) detected one time before.

Then, in the next step 620, the reflectance B of the door mirror 1 is
is calculated by the following formula.

B=L-(t>/L (t) However, -(1) is the function F(
L(t), ΔL (t) ).

When the reflectance B of the door mirror 1 is calculated in this way, the calculated value is output in the next step 630, and the transmittance of the PLZT 7 is changed based on this output value, and as a result, the reflectance of the door mirror 1 is changed. Changed to B.

FIG. 17 shows how the PLZT7 is controlled based on the incident light incident on the mirror and the reflectance B, and the incident light on the mirror 1 is, for example, a, b, c, d. When the light transmittance changes, the light transmittance of PLZT7 changes accordingly.

For example, when the incident light is a, the incident light enters the mirror 1 in a stepwise manner, and therefore the transmittance of the mirror drops instantaneously.

Furthermore, when the incident light entering the mirror is b, the amount of light increases gradually, and therefore the transmittance of PLZT7 also gradually decreases.

In this way, the increase/decrease in the transmittance of PLZT7 is changed according to the increase/decrease state and the rate of increase/decrease of the incident light entering the mirror.

As is clear from the above description, in the processing procedure shown in FIG. 16, the reflectance of the door mirror is changed over time based on the change over time in the amount of light incident on the door mirror 1.

Therefore, when the incident light entering the mirror 1 is, for example, step-shaped, it is possible to reduce the significant glare caused by the Broca-3u I Zer effect.

Also, if the amount of light incident on the mirror 1 gradually increases, the reflectance of the door mirror will not be lowered more than necessary, so if the reflectance of the door mirror 1 decreases too much, it will not be visible on the door mirror 1. There is no inconvenience that the outline of the object becomes unclear.

(Effects of the Invention) As is clear from the above description, in the anti-glare mirror for a vehicle according to the present invention, when the amount of incident light incident on the mirror changes in the direction of increasing at night, the reflectance of the mirror decreases. It is possible to reliably prevent dazzling light from the headlights of a following vehicle from being reflected by the mirror.

Therefore, the Broca-3u I Zer effect can prevent the reflection of light that makes the driver feel dazzling, thereby eliminating the annoyance and discomfort caused by dazzling light, thereby making it possible to drive comfortably and safely.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to complaints, Fig. 2 is an explanatory diagram of the configuration of a vehicle door mirror to which the anti-glare mirror for a vehicle according to the present invention is applied, Fig. 3 is an explanatory diagram showing light transmission band control of PLZT,
The figure is an explanatory diagram showing an example of PLZT, Fig. 5 is a characteristic diagram showing the control characteristics of PLZT, Fig. 6 is an explanatory diagram showing the situation where the incident light of the door mirror reaches the eyeball, and Fig. 7 is the same as Fig. 2. An explanatory diagram of the configuration of an incident light amount detection sensor used in a door mirror, Fig. 8 is a flowchart showing the processing procedure performed by the control unit in Fig. 2, and Fig. 9 shows the light transmittance of PLZT depending on the incident light entering the mirror. FIG. 10 is a configuration explanatory diagram showing another embodiment of the vehicle anti-glare mirror according to the present invention, and FIG. 11 shows the amount of incident light used in the door mirror of FIG. 10. Explanatory diagram of the configuration of the detection sensor, 12th
The figure is a characteristic diagram showing the relationship between the degree of change in the amount of incident light and the light transmittance of PLZT, FIGS. 13 and 14 are flowcharts showing the processing procedure performed by the control unit in FIG. 10, and FIG.
The figure is a characteristic diagram showing the state in which the light transmittance of PLZT is controlled according to the incident light entering the mirror, and FIG. 16 is a flowchart showing another processing procedure of the control unit 6 used in the door mirror of FIG. , FIG. 17 is a characteristic diagram showing a state in which the light transmittance of PLZT is controlled according to the incident light entering the mirror. 1...Door mirror 3...Light reflecting plate 5...Liquid crystal plate 7...PLZT 9...Transparent plate 10...Transparent electrode plate 11...Polarizing plate 6...Control unit 13. 13A... Switch circuit 15... Control circuit 21. 21A... Incident light amount detection sensor 23... Environmental illuminance detection sensor Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 1 button Fig. 7 Fig. 8 Fig. 9 tσノ'l Lo(b) ' υ/-QJ shuttle'' Fig. 1O Fig. 7 Fig. 1/Fig. 12 Incident light amount f) Variation Degree 645 Lever C) v-VOLty Figure 14 Figure 15 Figure 16 Figure 17 Question σ b cdt Procedure Amendment Amendment July 25, 1961 1, Indication of Case Patent Application No. 147396/1982 2, Invention Name Anti-glare mirror 3 for vehicles, relationship with the case of the person making the correction Patent applicant address 2 Takaracho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture Name
(399) Nissan Motor Co., Ltd. Representative Kume
Toyo 4, Agent @101 Address: 6th floor, Toko Building, 1-15-16 Uchikanda, Chiyoda-ku, Tokyo! 295-1480 6. Target of correction Drawing 7, Contents of correction (1) Figure 17 will be corrected as shown in the attached sheet. Figure 17

Claims (1)

[Claims] (1) An environmental illuminance detection means for detecting the environmental illuminance around the vehicle; an incident light amount detection means for detecting the amount of incident light on the mirror; and a reflectance reduction control means that reduces the reflectance of the mirror when it is determined that it is night and the detected amount of incident light changes in an increasing direction. Anti-glare mirror for vehicles.