JPH092212A - Heater controller for vehicle rearview mirror - Google Patents

Abstract

PURPOSE: To reduce the load of a battery by changing a heat generation mode according to the inspected results of the speed of a vehicle, the operation of a head lamp and a battery capacity in a device for controlling the passing of electricity to a heater mounted in a rearview mirror by selecting one mode among a plurality of heat generation modes. CONSTITUTION: A rearview mirror has a PTC heater 2 with a heating element on the reverse surface of a Cr back mirror 1 and the PTC heater 2 has the first electrode pattern 3a to the third electrode pattern 3c and the passing of electricity to each electrode pattern 3a to 3c is changed by a connection changing device 4. Two modes of a high performance mode in which water drops, mist and frost attached on a mirror are removed by using high heat and a low power consumption mode in which the load of a battery is reduced by using low heat are determined and these mode are changed by a change controller 4 so as to overload a battery 5 based on the states such as running and stopping of a car, turning-on and-off of a head lamp and an air conditioner, and load of the battery.

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.

As a heater control device for such a rear-view mirror, there have been hitherto been known as the actual opening No. 60-32146 microfilm (hereinafter referred to as conventional example 1) and the actual opening No. 62-12.
3450 Microfilm (hereinafter referred to as Conventional Example 2)
Etc. are known. Among them, in the technique described in the conventional example 1, as shown in FIG. 13, the heater 11 for heating and the heater 12 for warming are respectively wired in a rectangular wave shape, and at the time of warming, heat is maintained via the lead wires 14 and 15. The rear-view mirror surface is heated by applying a voltage to the heating heater 12 and also applying a voltage to the heating heater 11 via the thermostat 13 during heating. That is, when the temperature of the mirror surface rises by the operation of the thermostat 13, the mirror surface is automatically switched to the heat retention mode, and when the temperature decreases, the mode is automatically switched to the heating mode, so that the mirror surface is kept at a constant temperature. In addition, the technique described in the conventional example 2 is one of the rear defogger, the indoor heater, and the wiper.
When one of them operates, the mirror heater is energized in conjunction with this.

[0004]

However, the one described in the above-mentioned conventional example 1 merely switches between the heat retention mode and the heating mode so that the temperature of the mirror surface becomes constant, and the mirror surface is not changed. The condition of water drops, fog, frost, etc.,
The battery load situation is not taken into consideration. Therefore, even if there are few deposits on the mirror surface, a large amount of power is consumed in the heating mode, or when the air conditioner or headlamp is on and the battery capacity is low, the heating mode is set to the battery mode. The drawback is that it puts a lot of strain on you.

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 of the present invention is to apply a large load to a battery and to prevent water drops, fog, frost, etc. attached to a mirror surface. It is an object of the present invention to provide a heater control device for a rearview mirror for a vehicle, which can remove kimono efficiently.

[0006]

To achieve the above object, the present invention is a heater control device mounted on a rearview mirror for a vehicle, for controlling a heater for removing water drops, fog, frost and the like adhering to the surface of the rearview mirror. In mode switching means for switching the amount of heat generated by the heater to a plurality of modes, speed detecting means for detecting the speed of the vehicle, headlamp detecting means for detecting the operation of the headlamp, and air conditioner detecting means for detecting the operation of the air conditioner. Of the battery detection means for detecting the capacity of the battery, at least one detection signal is input, and the connection switching means for switching the mode switching means using the input signal is characterized.

[0007]

According to the present invention configured as described above, the mirror is set based on the running / stopped state of the vehicle, the on / off state of the headlamp, the on / off state of the air conditioner, and the load state of the battery. Mode switching control is performed so that the efficiency of removing water drops, fog, frost, etc. that adheres to the battery is improved and that the battery is not overloaded. For example, when the vehicle is stopped, there is a large amount of deposits, so the mode with a large amount of heat is set, and when the air conditioner is on, the load on the battery is large, so the mode with a large amount of heat is switched to a mode with a small amount of heat periodically. Thus, the heater is operated so as to remove the deposit while reducing the load on the battery.

[0008]

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 including a heater control device 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. The PTC heater 2 which has, and this PTC heater 2
The first electrode pattern 3a, the second electrode pattern 3b, and the third electrode pattern 3c, which are formed of copper foil, are connected to the respective electrode patterns 3a, 3b, 3c, and the energization of each electrode is switched. The connection switching device 4 is connected to a battery 5 used as a power source for the entire vehicle equipped with the rearview mirror, and the 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 formed on the heating element.
b and 3c are formed. First electrode pattern 3a
Is formed in an L shape along two side surfaces of the resin film 6, and further four branch portions are formed. 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. And the first
The branch portion of the electrode pattern and the branch portion of the second electrode pattern are opposed to each other with a predetermined space therebetween.

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 uses a power source supplied from a battery 5 and the above-mentioned connection terminals 8a, 8b, 8c as will be described later, as will be described later, a wiper, an air conditioner, a headlamp, and speed detection. The connection is switched based on information such as signals.

FIG. 3 is a sectional view of the PTC heater 2. As shown in FIG.
A flat heating element 7 is arranged on the heating element 7, and the first to third electrode patterns 3a, 3a,
3b 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 in which high heat is applied to remove water drops, fog, frost, etc. adhering to the mirror surface (first
Mode) and a low power consumption mode (second mode) in which the load of the battery is reduced by applying heat lower than that of the high performance mode, and these modes are switched as shown in FIG. It is set by the control device 4.

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, it is set to 12V. Therefore, a current flows from the third electrode pattern 3c toward the first and second electrode patterns 3a and 3b. The resistance of the heating element 7 at this time is the distance from the first and second electrode patterns 3a and 3b to the third 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, and the effect of removing water drops, fog, frost, etc. adhering to the mirror surface is large. The same applies when the first electrode pattern 3a and the second electrode pattern 3b 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, 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 twice or more that in the high performance mode described above, so the resistance value is also 2
It is more than double and the amount of heat generation is less than 1/2. 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
The electrode pattern 3b of the first electrode pattern 3
It is equivalent when a is set 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.

FIG. 6 is an explanatory diagram showing a specific circuit configuration of the connection switching device 4. The circuit shown in FIG.
As shown in the timing chart of FIG. 9, the high-performance mode (H mode) and the low power consumption mode (L mode) are switched. First, the configuration will be described.
The positive terminal of the battery 5 shown in FIG. 6 is branched into four systems, the first is connected to the circuit S4, the second is connected to one end of the wiper switch 21, and the third is one end of the air conditioner switch 22. And the fourth one is connected to one end of the headlamp switch 25.

The circuit S4 is for protecting the circuit when an overcurrent or overvoltage is applied to the connection switching device. The wiper switch 21 is for switching on and off a wiper mounted on the vehicle, and the other end side of the wiper switch 21 is connected to the input side of the OR circuit 28. The air conditioner switch 22 is for switching on and off the air conditioner in the vehicle, and the other end side of the air conditioner switch 22 is connected to the input side of the OR circuit 29.
The headlamp switch 25 is for switching the headlamp 26 on and off. The other end of the headlamp switch 25 is branched into two systems, one of which is connected to the AND circuit 34 via a diode.
Is connected to one input end and the timer circuit S1, and the other is connected to the contact d of the relay 60. Contact e of relay 60
Is connected to the headlamp 26 and excites the coil 61,
The connection contacts c and d are switched by non-excitation. When the input of the timer circuit S1 becomes "H", the output of the timer circuit S1 becomes "H" for the time T2, and then switches to "L".

The output side of the OR circuit 28 has an AND circuit 31.
One input end, and the heater installed in the circuit S5 is turned on,
They are connected to the bases of the transistors 51 for switching off. The output side of the OR circuit 29 has the NAND circuit 3
2 and one input terminal of the AND circuit 33, respectively. The vehicle speed switch 23 is a speedometer 2 for the vehicle.
According to No. 4, when the speed is zero (that is, stopped), it is turned off, and when the vehicle starts moving or reaches a constant speed, it is turned on. Then, the vehicle speed switch 23 has one input end of the AND circuit 31 and one input end of the AND circuit 34 via the NOT circuit 30
Each of the circuits 48 is connected to one input terminal. The output of the AND circuit 31 is the one input terminal of the NAND circuit 32 and the AND
Each of the circuits 33 is connected to one input terminal. The output of the AND circuit 34 is connected to the base of the switching transistor 27, and the on / off of the current to the base switches the excitation / non-excitation of the coil 61 by the current from the power supply terminal 59.

The output of the NAND circuit 32 is connected to the input side of the circuit S2, and the output of the AND circuit 33 is connected to the input side of the circuit S3. The circuit S3 includes NOR circuits 45, 46,
47 has a series connection, and the output side of the NOR circuit 45 is connected to one input end of the NOR circuit 45 via resistors 43 and 44, and the connecting portion between the resistors 43 and 44 is connected to one end 42a of the capacitor 42. Has been done. The other end 42b of the capacitor 42 is connected to the output side of the NOR circuit 46. The output of the NOR circuit 47 is connected to one input terminal of the AND circuit 48 via the diode 63.

The circuit S2 is a NOR circuit 39, 40, 41.
The NOR circuit 39 has a resistor 64 on the output side.
And the diode 36 in the forward direction and the resistor 65 and the diode 37 in the reverse direction are connected in parallel and via the resistor 38
9 is connected to one input end of the capacitor 35, and the parallel circuit is also connected to one end 35a of the capacitor 35. The other end 35b of the capacitor 35 is connected to the output side of the NOR circuit 40. The output side of the NOR circuit 41 is connected to the output side of the diode 63 via the diode 62, and is connected to one input end of the AND circuit 48.
The output side of the AND circuit 48 is connected to one input end of the AND circuit 49, and the other input end is connected to the output side of the timer circuit S1 via the NOT circuit 58. The output of the AND circuit 49 is the switching transistor 5 of the circuit S6.
This transistor 55 is connected to the base of No. 5 and makes one end of the exciting coil 54 conductive to the ground when the switch is turned on.

The transistor 51 of the circuit S5 described above is
When the switch is turned on, one end of the exciting coil 50 is connected to the ground. The other end of the exciting coil 50 is connected to a power supply terminal 52 and also connected to a switch 53 that is turned on and off by exciting and de-exciting the coil 50. The switch 53 is connected to the other end of the coil 54, and is also connected to the contact b of the switch 56 and the contact a of the switch 57. Each of these contacts is switched by the excitation and non-excitation of the excitation coil 54. The other end of the switch 56 is the third electrode 3
The other end of the switch 57 is connected to the first electrode 3a.
It is connected to the. Further, the second electrode 3b is connected to the ground.

Next, the specific operation of the connection switching device configured as described above will be described. According to the connection switching device shown in FIG. 6, the heater ON / OFF operation as shown in FIGS. 7 to 9 can be realized. First, an operation according to the timing chart shown in FIG. 7, that is, an operation in which the heater is in the high performance mode when the vehicle is stopped and the wiper is turned on will be described. Since the speed switch 23 is released when the vehicle is stopped, the input of the NOT circuit 30 is “L” and the output is “H”. Further, since the wiper switch 21 is connected, the OR circuit 28
The input is "H, H" and the output is "H". And OR
When the output of the circuit 28 becomes "H", a current is supplied to the base of the transistor 51 of the circuit S5, which causes a current to flow through the coil 50 to be excited, and the switch 53 is connected to the contact b. That is, the heater is turned on.

The AND circuit 31 has an input of "H,
Since the output of the AND circuit 33 is "H", the input of the AND circuit 33 is "L, H" (because the air conditioner switch 22 is released), the output is "L". Then, the NOR of the circuit S3
When the "L" level is input to one input terminal of the circuit 45, the circuit S3 operates. That is, when an “L” level signal is input to one input terminal of the NOR circuit 45, its output becomes “H”, the input of the NOR circuit 46 becomes “H, H”, and its output becomes “L”. Therefore, the input of the NOR circuit 47 becomes "L, L", and as a result, the output of the circuit S3 becomes "H".

The output side of the NOR circuit 45 is "H".
Since one end 42a of the capacitor 42 is "L",
A current will flow in this direction. After that, when electric charge is stored in the capacitor 42 and the terminal 42a becomes "H", one input end of the NOR circuit 45 connected to the resistor 44 becomes "H", so that the output of the NOR circuit 45 becomes "L". "
Becomes That is, when the output of the NOR circuit 45 becomes "H" for a while (this time is T1), it is switched to "L". Then, since the input of the NOR circuit 46 becomes "L, L", its output is "H", NOR
Since the input of the circuit 47 becomes "H, H", its output becomes "L", and as a result, the output of the circuit S3 becomes "L".

At this time, the output of the NOR circuit 45 becomes "L" and the terminal 42a of the capacitor 42 becomes "H", so that the NOR circuit 4 is connected from the capacitor 42 through the resistor 43.
A current flows to the output side of No. 5, and the terminal 42a becomes the "L" level again. Therefore, the input end of the NOR circuit 45 on the resistor 44 side becomes "L", and the output of the NOR circuit 45 becomes "H" again. The time required for the output of the NOR circuit 45 to change from "L" to "H" is the time T1 described above.

In this way, the output level of the NOR circuit 45 is alternately switched in the cycle T1, and the level at one input terminal of the AND circuit 48 also changes. Then, at the other input end of the AND circuit 48, NO
Since the "H" level signal is supplied from the T circuit 30, the output of the AND circuit 48 is the same as the output of the circuit S3. Further, since the timer circuit S1 is not operating, the output of the NOT circuit 58 holds "H", and the output of the AND circuit 48 remains as it is.
9 output.

Therefore, the current supply to the base of the transistor 55 of the circuit S6 is turned on and off in the cycle T1, and the switch 53 is connected to the contact b side as described above. The coil 54 repeats excitation and non-excitation in the cycle T1. That is, the switches 56 and 57 that operate in conjunction with the coil 54 also have the cycle T1.
Thus, the contacts a and b are sequentially switched, and as a result, the high performance mode and the low power consumption mode are alternately repeated.

Next, the mode switching operation of the heater when the vehicle is traveling from the above state, that is, the state in which the vehicle is stopped and the wiper is on, will be described. When the vehicle switches from the stopped state to the running state, the speed switch 23 changes from released to connected. As a result, the output of the NOT circuit 30 changes from "H" to "L", and the level of one input terminal of the AND circuit 48 is always "L". Therefore, the output of the AND circuit 48 is output regardless of the output of the circuit S3. Becomes "L". Therefore, no current is supplied to the base of the transistor 55 and the coil 54 is not excited, so that the switch 5
6 and 57 are connected to the contact a, respectively, and the connection is as shown in FIG. 4 (b), which is the low power consumption mode. When the wiper switch 21 is turned off, the transistor 51 becomes non-conductive, so that the switch 53 is connected to the contact a and the heater is turned off.

In this way, when the wiper is operating, as shown in the timing chart of FIG. 7, the vehicle is in the low power consumption mode while the vehicle is running, and is in the high performance mode in the cycle T1 while the vehicle is stopped. It operates so as to switch to the power consumption mode alternately. Therefore, the efficiency of removing water drops and the like becomes high especially when the vehicle is stopped, where water drops and the like tend to adhere, so that the driver can perform smooth rearward visual recognition. The time T1 is preferably set to, for example, about 5 to 10 minutes, and this time setting can be easily achieved by appropriately setting the size of the resistor 43 and the capacitance of the capacitor 42 shown in FIG. You can

Next, the operation according to the timing chart shown in FIG. 8, that is, the mode change of the heater when the vehicle is stopped with the wiper turned on and the headlamp is turned on will be described. In this case, the headlamp switch 25 is further turned on in the state shown in FIG. 7, and the timer circuit S is connected by connecting the switch 25.
The level of the signal supplied to 1 becomes "H". As a result, the output of the timer circuit S1 outputs the signal of the "H" level for the time T2, and the output of the NOT circuit 58 becomes the "L" level for the time T2. Therefore, the input of the AND circuit 49 is "H, H". Becomes "H, L", and the transistor 55 becomes non-conductive for the time T2. Therefore, the wiper is on,
If the headlamp switch 25 is turned on when the vehicle is stopped and the heater is in the high performance mode, the heater is switched to the low power consumption mode for the time T2. This makes it possible to prevent overload due to the inrush current of the headlamp. It should be noted that the time T2 may be the time required for the transient current at the start of the headlamp to stabilize, and for example, about 30 seconds to 1 minute is preferable.

When the vehicle starts running, the heater switches to the low power consumption mode by the same operation as in the example shown in FIG. Further, when the vehicle is stopped in this state (that is, the wiper is on, the headlamp is on, and the low power consumption mode), the heater is switched to the high performance mode, and at the same time, the input of the AND circuit 34 is "L, H". From "H,
Since it is switched to "H", its output switches from "L" to "H", current is supplied to the base of the transistor 27, and the coil 61 is excited, so that the contact of the switch 60 shifts from d to c. As a result, the headlamp 26 is turned off. That is, when the vehicle is stopped, the headlamp 26 is turned off to prevent overload when the heater is in the high performance mode. Note that, in the timing chart of FIG. 8, after the vehicle is stopped, the headlamp 26 is turned off, and the heater is in the high performance mode, switching to the low power consumption mode at time T1 is the same as the operation in FIG. It is the same.

Next, the operation according to the timing chart shown in FIG. 9 will be described. This example shows a change in the mode of the heater when the wiper is turned on and the air conditioner is turned on while the vehicle is stopped. The high-performance mode is switched at time T3 and the low power consumption mode is switched at time T4. This improves the efficiency of removing water drops and the like and reduces the power consumption of the battery. The operation will be specifically described below. When the wiper switch 21 is turned on and the air conditioner switch 22 is turned on when the vehicle is stopped, the input of the AND circuit 33 changes from “L, H” to “H,
The output becomes "H". As a result, the operation of the circuit S3 is stopped, and conversely, the input of the NAND circuit 32 changes from "L, H" to "H, H", so that its output becomes "L", and this "L" signal is NO of circuit S2
It is supplied to one input terminal of the R circuit 39.

The circuit S2 starts its operation when an "L" level signal is supplied, and when the "L" level signal is supplied to one input terminal of the NOR circuit 39, its output is "H". Then, the input of the NOR circuit 40 becomes "H, H", and the output becomes "L". Then, since the input of the NOR circuit 41 becomes "L, L", its output becomes "H",
It is supplied to one input terminal of the AND circuit 48 via the diode 62. When the vehicle is stopped, the speed switch 23 is released and the other input terminal of the AND circuit 48 is "H", so "H" is input to one input terminal of the AND circuit 49, If the headlamp is off, "H" is input to the other input terminal of the AND circuit 49, so that the output of the AND circuit 49 becomes "H" and the transistor 55 is turned on. Therefore, the heater mode is a high performance mode.

On the other hand, the output side of the NOR circuit 39 has a resistor 6
Terminal 3 of the capacitor 35 via the diode 4 and the diode 36
5a and this terminal 35a is at the "L" level, the capacitor 35 is connected to the output side of the NOR circuit 39.
A current flows to the terminal 35a side of the terminal 35a, and after a predetermined time (this time is T3), the terminal 35a becomes the "H" level. Then, since the input end of the NOR circuit 39 on the side to which the resistor 38 is connected also becomes the "H" level, the input of the NOR circuit 39 becomes "H, L" and its output becomes "L". As a result, the input of the NOR circuit 40 becomes “L, L”, the output becomes “H”, the input of the NOR circuit 41 becomes “H, H”, the output becomes “L”, and the transistor 55 becomes non-conductive, and as a result, The heater mode is a low power consumption mode.

After that, the output side of the NOR circuit 39 becomes "L" and the terminal 35a of the capacitor 35 becomes "H", and this time, from the capacitor 35 side to the output side of the NOR circuit 39 via the diode 37 and the resistor 65. Current flows,
After a predetermined time (this time is set to T4 [T4 ≧ T3]), the terminal 35a becomes the “L” level. Therefore, the resistance 3
The level of the input end of the NOR circuit 39 to which 8 is connected also becomes the “L” level, and the output of the NOR circuit 39 becomes “L”.
Becomes Therefore, the transistor 55 is turned on again, and the heater mode is switched from the low consumption mode to the high performance mode. That is, the high performance mode (time T3) and the low power consumption mode (time T4) are switched alternately.

As a result, when the vehicle is stopped, the wiper is on, and the air conditioner is on, a short time T
By alternately switching between the high performance mode of No. 3 and the low power consumption mode of long time T4, the efficiency of removing water drops and the like can be improved and the load of the battery can be reduced. The above times T3 and T4 can be determined by setting the capacitance of the capacitor 35 and the sizes of the resistors 64 and 65.

FIG. 10 is a circuit diagram of the connection switching device shown in FIG. 6 when the mode of the heater is controlled more accurately by taking the capacity of the battery into consideration. The heater circuit S7 shown in the figure is the same as the circuit S7 surrounded by the one-dot chain line shown in FIG. The output of the AND circuit 49 is input to one input terminal of the AND circuit 71, and the other input terminal is supplied with a signal obtained by inverting the output of the comparator circuit S8 by the NOT circuit 76.

As is well known, the comparator circuit S8 is composed of an operational amplifier 77, resistors 72 to 75, etc., and the voltage of the battery 5 is divided by the resistors 72 and 73 at the negative input terminal of the operational amplifier 77. The voltage is input.
Further, a voltage obtained by dividing the voltage of 5 V by the resistors 74 and 75 is input to the positive input terminal of the operational amplifier 77, an “H” level signal is output when the positive side is large, and an “L” level is output when the negative side is large. "Level signal is output. Now, when the battery capacity is weakened, the output of the comparator S8 becomes "H" level, and the NOT circuit 76 causes the one input terminal of the AND circuit 71 to become "L" level. Therefore, the output of the AND circuit 71 is always "L" regardless of the output of the AND circuit 49, so that the heater is always in the low power consumption mode and avoids a heavy load when the battery power source 5 is weakened. You will be able to.

In this way, if the connection switching device as shown in FIGS. 6 and 10 is used, the heater is automatically operated when the wiper is turned on during rainfall, and further, the vehicle is stopped, the vehicle is running, the air conditioner is turned off. High-performance mode and low-power consumption mode can be suitably switched depending on various conditions such as on / off, headlamp on / off, etc., so that it is possible to perform advanced heater mode switching adapted to operating conditions. become. In the above embodiment, an example in which the high performance mode and the low power consumption mode are switched using the electrode patterns 3a, 3b, 3c shown in FIG. 2 has been described, but the present invention is not limited to this. Without, for example,
An electrode pattern as shown in FIG. 11 may be used.

FIG. 11 is an explanatory view showing another electrode pattern configuration of the PTC heater 2, in which FIG.
(B) shows the side surface and (c) shows the front surface. FIG.
As shown in FIG. 5, the third electrode pattern 86c and the fourth electrode pattern 86d formed in a comb tooth shape are arranged in a zigzag pattern on the back surface side of the PTC heater 2 in a zigzag pattern. , 86d are separated by a distance w1. Further, the electrode patterns 86c and 86d are
Each of them is connected to the connection terminals 87c, 87d arranged on one short side of the PTC heating element 88, and the battery 5, shown in FIG. 1, is connected via the connection terminals 87c, 87d.
A voltage is applied from the connection switching device 4. Further, on the other short side, connection terminals 87a and 87b for connecting to the electrode patterns 86a and 86b on the front surface side shown in FIG. Side first electrode pattern 86a,
It is adapted to be connected to the second electrode pattern 86b.

The front surface of the PTC heater is substantially the same as the back surface, but the first and second comb-teeth electrode patterns 86a and 86b are formed.
The comb teeth are different from each other in that they are denser than the comb teeth of the third and fourth electrode patterns 86c and 86d. Therefore, the distance w2 between the first and second electrode patterns 86a and 86b is smaller than the distance w1 between the third and fourth electrode patterns 86c and 86d. And the whole PTC heater 2 in which each electrode pattern 86a-86d is arrange | positioned is
It is covered with a resin film 89 to be insulated from the outside and waterproof. Next, the PTC configured as described above
The operation of the heater will be described below. In this example, the electrode patterns 86c, 8 on the rear surface side of the PTC heater 2 are
A low power consumption mode in which a voltage is applied to 6d to generate heat,
Water droplets and the like adhering to the mirror surface are removed by appropriately switching between two kinds of heat generation modes of a high performance mode in which a voltage is applied to the surface side electrode patterns 86a and 86b to generate heat.

FIG. 12 is an explanatory view schematically showing a cross section of the PTC heater 2, and as shown in the figure, the third electrode pattern 86c and the fourth electrode pattern 86d are spaced from each other on the back surface of the PTC heater 2. They are separated by w1. When the third electrode pattern 86c is set to the ground potential and the fourth electrode pattern 86d is set to the power supply potential (normally 12V), a current flows from the fourth electrode pattern 86d side to the third electrode pattern 86c side, and , PTC heating element 8
Since 8 heats up and the Cr backside mirror 1 shown in FIG. 1 is heated,
It is possible to remove water droplets and the like attached to the surface of the Cr rear surface mirror 1.

On the front side of the PTC heater 2, the first
Electrode patterns 86a and second electrode patterns 86b are alternately arranged with a distance of w2 (w2 <w1). Then, assuming that the first electrode pattern 86a is the ground potential and the second electrode pattern 86b is the power source potential, the first electrode pattern 86 from the second electrode pattern 86b side.
Electric current flows to the side a, and the PTC heating element 88 generates heat. At this time, since the distance between the electrode patterns of the power supply and the ground is narrower on the surface side (w2 <w1), the resistance value becomes smaller and the current value becomes larger. Therefore, when the voltage is applied between the first and second electrode patterns 86a and 86b on the front surface side, the heat generation amount is larger than when the voltage is applied between the third and fourth electrode patterns 86c and 86d on the back surface side. It becomes larger and the Cr shown in FIG.
The efficiency of removing water drops and the like adhering to the back surface mirror 1 is improved.

That is, 86 between the first and second electrode patterns
If a mode for applying a voltage to a and 86b is a high performance mode, and a mode for applying a voltage between the third and fourth electrode patterns 86c and 86d is a low power consumption mode, it is connected to the circuit shown in FIG. As in the case of the electrode pattern shown in FIG. 2, it becomes possible to perform suitable mode switching according to the operating conditions. In the above embodiment, the PTC is used as a heater for heating the mirror surface of the rearview mirror.
Although the example of using the heater has been described, the present invention is not limited to this, and it is obvious that the present invention can be applied to a general heating wire.

[0044]

As described above, according to the present invention,
Set multiple modes according to the heating value of the heater,
The heat generation amount mode is switched to be suitable according to various conditions such as wiper on / off, air conditioner on / off, headlamp on / off, and vehicle running / stopping. Therefore, it is possible to efficiently remove water droplets, fog, and frost attached to the mirror, and reduce the load on the battery.

[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 an explanatory diagram showing a specific circuit configuration of the connection switching device.

7 is a first timing chart showing an operation example of the circuit shown in FIG.

8 is a second timing chart showing an operation example of the circuit shown in FIG.

9 is a third timing chart showing an operation example of the circuit shown in FIG.

10 is an explanatory diagram showing an example in which a circuit for determining the capacity of a battery is further added to the circuit shown in FIG.

FIG. 11 is an explanatory diagram showing another configuration example of the electrode pattern.

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

FIG. 13 is an explanatory diagram showing wiring between a heating heater and a heat retaining heater according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cr back surface mirror 2 PTC heater 3a, 3b, 3c 1st-3rd electrode pattern 4 Connection switching device 5 Battery 6 Resin film 7 Heating element 8a, 8b, 8c Connection terminal 21 Wiper switch 22 Air conditioner switch 23 Speed switch 25 Head Lamp switch

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[Procedure amendment]

[Submission date] September 28, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

The circuit S4 is for protecting the circuit when an overcurrent or overvoltage is applied to the connection switching device. The wiper switch 21 is for switching on and off a wiper mounted on the vehicle, and the other end side of the wiper switch 21 is connected to the input side of the OR circuit 28. The air conditioner switch 22 is for switching on and off the air conditioner in the vehicle, and the other end side of the air conditioner switch 22 is connected to the input side of the OR circuit 29.
The headlamp switch 25 turns the headlamp on and off.
The other end side is connected via a diode.
Then, it is connected to the timer circuit S1. When the input of the timer circuit S1 becomes "H", the output of the timer circuit S1 becomes "H" for the time T2, and then switches to "L".

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

The output side of the OR circuit 28 has an AND circuit 31.
One input end, and the heater installed in the circuit S5 is turned on,
Each is connected to the base of the transistor 51 for switching off. The output side of the OR circuit 29 has the NAND circuit 3
2 and one input terminal of the AND circuit 33, respectively. The vehicle speed switch 23 is a speedometer 2 for the vehicle.
According to No. 4, when the speed is zero (that is, stopped), it is turned off, and when the vehicle starts moving or reaches a constant speed, it is turned on. Then, the vehicle speed switch 23, it to one input terminal and one input terminal of the AND circuit 48 of the AND circuit 31 through the NOT circuit 30
Connected. The output of the A ND circuit 31, Ru it is it connected to an input end and one of the input terminals of the AND circuit 33 of the NAND circuit 32.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

When the vehicle starts running, the heater switches to the low power consumption mode by the same operation as in the example shown in FIG. Further, this state (i.e., on the wiper, the headlamp is turned on and the low power consumption mode) when, when the vehicle is stopped, the heater switches to high performance mode. What
Contact, in the timing chart of FIG. 8, vehicles are stopped, the head lamp is turned off, after the heater is turned high performance mode, switching to the low power consumption mode at the time T1 is, the operation of FIG. 7 described above It is the same.

[Procedure Amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

Claims (4)

[Claims] 1. A rear-view mirror for a vehicle, wherein a mode is selectively selected from a plurality of heat generation modes and the rear-view mirror is heated to remove water drops, fog, and frost adhering to the rear-view mirror surface. In a heater control device for controlling a heater, a speed detecting means for detecting a speed of a vehicle, a headlamp detecting means for detecting an operation of a headlamp, an air conditioner detecting means for detecting an operation of an air conditioner, and a battery detecting means for detecting a capacity of a battery. A heater control device for a rear-view mirror for a vehicle, comprising: connection switching means for inputting at least one detection signal and using the input signal to switch between the respective heat generation modes. 2. The vehicle according to claim 1, wherein the connection switching means has a wiper switch for switching on / off of the heater in conjunction with on / off operation of a wiper mounted on the vehicle. Rearview heater controller. 3. The plurality of heat generation modes include a first mode in which both heat generation and power consumption are large and a second mode in which both heat generation and power consumption are small, and the connection switching means is a wiper. A wiper switch that turns on and off in synchronization with operation, an air conditioner switch that turns on and off in conjunction with air conditioner operation, a speed switch that turns on and off when the vehicle is stopped or running is detected, and a speed switch that turns on and off in conjunction with headlamp operation A means for turning on the heater when the wiper is turned on, and a first mode and a second mode when the vehicle is stopped.
Means for switching to the second mode when the vehicle is running, and means for switching the vehicle from the first mode to the second mode for a predetermined time T2 when the headlamp is turned on when the vehicle is stopped Means for turning off the headlamp when the vehicle is stopped, and a first means when the air conditioner is turned on when the vehicle is stopped.
And the second mode at time T3 and time T, respectively.
4. A heater control device for a rear-view mirror for a vehicle according to claim 2, further comprising means for alternately switching at a cycle of 4. 4. The invention according to claim 3, wherein the connection switching means further comprises a comparing means for judging whether or not the voltage of the power supply is higher than a predetermined value, and when the voltage is lower than the predetermined value, the compulsion is forced. And a heater control device for a rear-view mirror for a vehicle, which has means for selectively switching to a second mode.