JPH08244569A - Rearview mirror for vehicle - Google Patents

Abstract

PURPOSE: To heat the whole body of a mirror surface evenly and rapidly when necessary without applying a large load to a battery, by providing the third electrode pattern composed of a conductor, and provided uncontacting with the first and the second electrode patterns; and a power source to feed the current to the first to the third electrode patterns. CONSTITUTION: In a high function mode in which water drops, the fog, the frost, and the like attached on a mirror surface are removed by applying a high heat, the first electrode pattern 3a and the second electrode pattern 3b are made in a grand potential, while the third electrode pattern 3c is made in a power source potential. As a result, the current flows from the first and the second electrode patterns 3a and 3b to the third electrode pattern 3c. The resistance of a heating element 7 is the distance from the first and the second electrode patterns 3a and 3b, to the third electrode pattern 3c. Consequently, the resistance value is small and the current amount is large, and the heating amount is large, and as a result, the removing effect of the water drops, the fog, the frost, and the like attached on the mirror surface is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle rearview mirror, and more particularly to water drops, fog, and the like attached to the mirror surface of the rearview mirror.
The present invention relates to a rearview mirror equipped with a heating element for removing frost and the like.

[0002]

2. Description of the Related Art Generally, a rearview mirror for a vehicle may have water drops, fog, frost or the like attached to the mirror surface thereof, thereby obstructing the rear view of the driver. In such a case, it is very troublesome for the driver to get out of the vehicle and remove adhering substances such as water droplets, fog, and frost each time, and if the driver continues to drive with the adhering substance, safety is impaired. Be done. Therefore, conventionally, there is a method of arranging a heater on the back side of the mirror surface of the rearview mirror and energizing the heater to apply heat to the mirror surface, thereby removing adhered substances such as water droplets, fog, and frost adhered to the mirror surface. Proposed.

Conventionally, as the rearview mirror, there have been used, for example, a real film No. 60-32146 (hereinafter referred to as a conventional example 1), a real film No. 62-123450 (hereinafter referred to as a conventional example 2) and the like. Are known. Among them, in the technique described in Conventional Example 1, as shown in FIG. 7, the heating heater 11 and the heat retaining heater 12 are wired in a rectangular wave shape, respectively, and the lead wire 1 is used during the heat retaining.
A voltage is supplied to the heater 12 for warming through the heaters 4 and 15, and the heater 11 for warming is heated through the thermostat 13 during heating.
The mirror surface of the rearview mirror is heated by supplying power to. In addition, in the technique described in the second conventional example, when any one of the rear defogger, the indoor heater, and the wiper operates, the mirror heater is energized in conjunction with the operation.

[0004]

However, in the one described in the above-mentioned conventional example 1, the heater 11 for heating and the heater 12 for warming which are composed of the electrothermal resistor are used to generate linear heat. Since it is difficult to uniformly heat the entire mirror surface, there is a large difference in the temperature distribution between the time of heating and the time of heat retention, and the heating area is also different. Further, if the electrothermal resistor is densely wired in order to uniformly heat the entire mirror surface, the length of the electrothermal resistor becomes very long, and the wiring structure becomes extremely complicated. Further, since the heating heater 11 is switched on and off using the thermostat 13, the heating heater 11 is turned on to perform heating when the temperature of the mirror surface is low, regardless of the load of the battery. Therefore, the battery may be overloaded when using a headlight, an air conditioner, or the like.

Further, in the one described in the conventional example 2, when the wiper, the rear defogger, the indoor heater and the like are interlocked, the operability is improved, but on the other hand, the load of the battery may become excessive. However, there is a drawback that the capacity of the battery and the alternator must be increased. The present invention has been made to solve such a conventional problem, and an object thereof is to apply a large load to a battery, and to make the entire mirror surface uniform,
It is to provide a rearview mirror for a vehicle that can be heated quickly when needed.

[0006]

In order to achieve the above object, the present invention is a rearview mirror for a vehicle, which is provided on a front side surface of a vehicle so as to project and a rear-view mirror surface is attached to the rear surface side of the mirror surface. A heating element that is mounted in a plane and that generates heat when energized, a first electrode pattern that is disposed on the heating element and is made of a conductor, and the first electrode pattern that is on the heating element. Between the first and second electrode patterns and the second electrode pattern formed of a conductor and separated from each other by a predetermined distance, and the first and second electrode patterns are not in contact with each other. A third electrode pattern formed of a conductor, and a power supply for supplying a current to each of the first to third electrode patterns.
Is characterized by having.

[0007]

According to the present invention having the above-described structure, the first electrode pattern to the third electrode pattern are formed on the heating element formed in a plane shape, and when it is desired to increase the heating amount, the third electrode pattern is used. The electrode pattern is used as a power supply potential, and the first and second electrode patterns are used as a ground potential. Then, the third
And the first electrode pattern and between the third and second electrode patterns are energized to generate a large amount of heat.

When it is desired to reduce the amount of heating, the third electrode pattern is released, the first (second) electrode pattern is set to the power supply potential, and the second (first) electrode pattern is set to the ground potential. . According to this, the first electrode pattern and the second electrode pattern
The distance from the electrode pattern is the first and the third, and the second and the third.
Since the distance is larger than the distance between the electrodes, the amount of heat generated is small and the battery load is small.

By switching between the above two methods of connecting the power source according to the load state of the battery, it is not necessary to increase the battery capacity and the oil generator capacity. Also, by switching the connection methods of the above two power sources according to the amount of adhered matter such as water droplets, it becomes possible to perform effective switching according to the amount of adhered matter. Further, since the mirror surface is heated by the heating element formed in a flat shape, the entire mirror surface can be heated uniformly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a vehicle rearview mirror to which the present invention is applied. As shown in the figure, this rear-view mirror includes a Cr rear surface mirror 1 as a mirror body for reflecting light from the rear, and a heating element formed on the rear surface side of the Cr rear surface mirror 1 and formed in a planar shape. Having PTC
The heater 2, the first electrode pattern 3a, the second electrode pattern 3b, and the third electrode pattern 3c formed of copper foil on the PTC heater 2, and the electrode patterns 3 described above.
a, 3b, 3c, and a connection switching device 4 that switches energization to each electrode. Further, the connection switching device 4 is a battery 5 used as a power source for the entire vehicle equipped with the rearview mirror. It is connected to and power is supplied.

FIG. 2 is an explanatory view showing a detailed structure of the PTC heater 2 and the first to third electrode patterns formed thereon. As shown in the figure, in the PTC heater 2, a heating element 7 is attached on a resin film 6, and first to third electrode patterns 3a, 3 are provided on the heating element.
b and 3c are formed.

The first electrode pattern 3a is formed in an L shape along the two side surfaces of the resin film 6, and further four branch portions are formed. Also, the second electrode pattern 3b
Is also formed in an L shape along two side surfaces of the resin film 6 different from the first electrode pattern, and four branch portions are formed. Then, the branch portion of the first electrode pattern and the branch portion of the second electrode pattern are opposed to each other while keeping a predetermined interval.

The third electrode pattern 3c is formed in a rectangular wave shape while maintaining an equal distance between the first and second electrode patterns 3a and 3b. That is, the distance between the first electrode pattern 3a and the second electrode pattern 3b is
It is longer than the distance between the first and second electrode patterns 3a and 3b and the third electrode pattern 3c, and the electrode patterns are not in contact with each other. In addition, each electrode pattern 3a, 3
b and 3c are connected to the connection terminals 8a, 8b and 8c, respectively. Further, the connection switching device 4 shown in FIG. 1 includes a power source supplied from the battery 5 and the above-mentioned connection terminals 8a,
The connection between 8b and 8c is switched based on information such as an air conditioner, a headlamp, and a speed detection signal as described later.

FIG. 3 is a sectional view of the PTC heater 2. As shown in FIG.
A flat heating element 7 is disposed on the heating element, and the first to third electrode patterns 3a, 3 are provided on the heating element.
b and 3c are formed. Next, a heating operation in the vehicle rearview mirror of the present embodiment configured as described above will be described. In the present embodiment, a high-performance mode (first mode) in which high heat is applied to remove water drops, fog, frost, etc. adhering to the mirror surface, and heat lower than this high-performance mode is applied to reduce the load on the battery. Two modes, a low power consumption mode (second mode) to be set, are determined.
It is set by the switching control device 4 shown in FIG. Among them, in the high performance mode, as shown in FIG. 4A, the first electrode pattern 3a and the second electrode pattern 3b are set to the ground potential, and the third electrode pattern 3c is set to the power supply potential (usually 12V). It is said that. Therefore, current flows from the first and second electrode patterns 3a and 3b toward the third electrode pattern 3c. The resistance of the heating element 7 at this time is from the first and second electrode patterns 3a and 3b to the third.
To the electrode pattern 3c. Therefore, since the resistance value is small, the amount of current is large, and therefore the amount of heat generated is large,
The effect of removing water drops, fog, frost, etc. adhering to the mirror surface is great. The first electrode pattern 3a and the second electrode pattern 3b
The same applies when and are used as the power supply potential and the third electrode pattern 3c is used as the ground potential.

On the other hand, in the low power consumption mode, as shown in FIG.
As shown in (b), the first electrode pattern 3a is the power supply potential, the second electrode pattern 3b is the ground potential, and
The third electrode pattern is released. Therefore, a current flows through the heating element from the first electrode pattern 3a toward the second electrode pattern 3b. In this case, the distance from the power supply potential to the ground potential is about twice or more that in the high performance mode described above, so that the resistance value is also about two times or more, and the heat generation amount is ½ or less. Therefore, the power consumption is reduced to about 1/2, and the load on the battery is significantly reduced as compared with the high performance mode. The second electrode pattern 3b is equivalent to the power supply potential, and the first electrode pattern 3a is equivalent to the ground potential.

FIG. 5A is a characteristic diagram showing the relationship between the current value and the mirror surface temperature in the high performance mode, and FIG. 5B is the relationship between the current value and the mirror surface temperature in the low power consumption mode. FIG. As can be seen from FIG. 9A, in the high performance mode, a current of about 2 amps flows in a steady state, and the temperature of the mirror surface rises to about 60 degrees. Further, in the low power consumption mode, a current of about 1 ampere flows in a steady state and the mirror surface rises to about 50 degrees as shown in FIG.

Next, a specific switching operation between the high performance mode and the low power consumption mode by the connection switching device 4 shown in FIG. 1 will be described. Normally, it is desirable to set the high performance mode when the amount of water droplets and the like attached to the mirror surface is large, so the first method is to increase the amount of water droplets and the like when the engine is started or when the vehicle is stopped such as waiting for a signal. Set to performance mode. This may be performed by detecting the speed of the vehicle and automatically switching to the high performance mode when the speed is below a predetermined value. Further, as a second method, when the amount of battery consumption such as a headlamp or an air conditioner is large, the mode is automatically switched to the low power consumption mode. As a result, the load on the battery can be reduced.

That is, the connection switching device 4 may switch between the high performance mode and the low power consumption mode based on the vehicle speed detection signal, the air conditioner operation signal, the headlamp operation signal, and the like. In addition, speed detection signal,
The mode switching using the air conditioner operating signal, the headlamp operating signal, and the like can be easily configured by using a relay circuit or the like, and thus detailed description thereof is omitted here.

FIG. 6 is a characteristic diagram showing the relationship between the current value and the mirror surface temperature when the above-mentioned first method is used. Many water drops and the like adhere to the mirror surface for a while after the engine is started. In many cases, the high-performance mode is set for the time T after the engine is started, and then the mode is automatically switched to the low power consumption mode. When the vehicle is stopped, many water droplets and the like adhere to the mirror surface as in the case of starting, and the mode is automatically switched to the high performance mode. By repeating such an operation, the high-performance mode is set only when the engine is started or when the vehicle is stopped, where a large amount of water drops adhere to improve the efficiency of water drop removal. , Will be able to reduce the load on the battery.

FIG. 6 shows an example in which the high-performance mode is set when the engine is started and the vehicle is stopped, and the low power consumption mode is set while the vehicle is running.
The low power consumption mode may be set when at least one of the air conditioner and the headlamp is operating, and the high performance mode may be set otherwise. With such a configuration, the load of the battery does not become excessive, and it is not necessary to increase the battery capacity or the alternator capacity.

In this way, according to the present embodiment, the high performance mode and the low power consumption mode are automatically switched according to the amount of water drops or the like adhering to the mirror surface and the load condition of the battery, which is convenient for the driver. It is possible to perform good mode switching. Further, since the flat PTC element is used as the heating element, it is possible to uniformly heat the entire mirror surface and to effectively remove water droplets, fog, frost, etc. Become. Furthermore, P
Since the TC element is used, the temperature can be automatically controlled, and a temperature control element such as a thermostat unlike the conventional case is not required. Further, since the electric path is formed by the electrode pattern of the copper foil having a small resistance value, the electric current capacity is large, and the electric path can be made thin, so that even a complicated wiring pattern can be easily wired.

[0022]

As described above, according to the present invention,
By forming the first to third electrode patterns on the heating element arranged on the rear surface side of the rear-view mirror and switching these connections, the first mode (high performance mode) and the second mode
Mode (low power consumption mode) is set. When a large amount of water droplets or the like is attached, the high efficiency mode is set to improve the removal efficiency. When the load on the battery is heavy, such as when using a headlight or an air conditioner, the load on the battery is reduced by setting the low power consumption mode. Therefore, it is possible to perform suitable switching control according to the attachment state of water drops or the like and the load state of the battery.

Further, since the mirror surface is heated by applying a voltage to the heating element having a planar shape, it is not necessary to locally heat the mirror surface as in the conventional case, but always to uniformly heat the entire mirror surface. Will be able to. Further, when the heating element is formed by the PTC heater, the temperature can be automatically controlled, and the temperature control element is unnecessary. Further, since the electrode pattern is made of copper foil having a small resistance value, the current capacity is large and the electric path can be made thin, so that even a complicated wiring pattern can be easily wired.

[0024]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a vehicle rearview mirror according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an electrode pattern formed on a PTC heater.

3 is a cross-sectional view of the electrode pattern shown in FIG.

FIG. 4 is an explanatory diagram showing current flows in a high performance mode and a low power consumption mode.

FIG. 5 is a characteristic diagram showing a current value and a mirror surface temperature in a high performance mode and a low power consumption mode.

FIG. 6 is a characteristic diagram showing a mode change and a mirror surface temperature change when the vehicle is started, when the vehicle is running, and when the vehicle is stopped.

FIG. 7 is an explanatory diagram showing wiring between a heating heater and a heat retaining heater according to a conventional example.

[Explanation of reference numerals] 1 Cr rear surface mirror 2 PTC heaters 3a, 3b, 3c First to third electrode patterns 4 Connection switching device 5 Battery 6 Resin film 7 Heating element 8a, 8b, 8c Connection terminal

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05B 3/84 H05B 3/20 327A

Claims (4)

[Claims] 1. A rearview mirror for a vehicle, which is provided on a front side surface of a vehicle so as to project and is provided with a mirror surface for rearward viewing. The heating element is mounted flat on the rear surface side of the mirror surface and generates heat when energized. A first electrode pattern disposed on the heating element and made of a conductor, and a first electrode pattern disposed on the heating element at a predetermined distance from each other and made of a conductor. A second electrode pattern, and between the first and second electrode patterns, the first and second electrode patterns are arranged in non-contact with each other,
A rear-view mirror for a vehicle, comprising: a third electrode pattern made of a conductor; and a power supply supplying a current to each of the first to third electrode patterns. 2. A first mode in which the first electrode pattern and the second electrode pattern are set to a ground potential (power supply potential), and the third electrode pattern is set to a power supply potential (ground potential); 2. The vehicle rearview mirror according to claim 1, wherein a second mode in which the first electrode pattern is set to a ground potential (power supply potential) and the second electrode pattern is set to a power supply potential (ground potential) is switched. 3. The rear-view mirror for a vehicle according to claim 1, wherein the heating element is composed of a PTC heater formed on a resin film. 4. The rear-view mirror for a vehicle according to claim 1, wherein the electrode pattern is made of copper foil.