JPH0115544Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an anti-glare mirror switching device that is installed in a car and that automatically switches the reflectance of the mirror according to the light irradiated on the mirror. This is what I am trying to do.

When a headlight beam from a following vehicle enters the rearview mirror of an automobile at night, the driver is dazzled by the strong reflected light. From this point of view, conventionally, the light irradiated onto the mirror is received by a light receiving element, and at night or in a tunnel, the angle of the mirror is automatically changed, making the reflectance smaller than when driving in a bright place. things are being done. In conventional automatic anti-glare mirror switching devices of this type, when the headlights or small lamps are turned on, that is, when the so-called lighting switch is turned on, a signal indicating this is sent to output power to the automatic anti-glare mirror switching device. is given,
When the lighting switch is in the OFF state, no power output is applied and the mirror is in a high reflectance state, so even if the light receiving element receives strong external light during the day, the mirror can be switched to a low reflectance state. It was being prevented. For this reason, for example, when driving through a brightly lit shopping street at night, the mirrors may operate with ambient light other than the headlights of the following vehicles, resulting in a low reflectance of the mirrors and making it difficult to see behind. Also, if the lighting switch is not turned on at dusk or early morning and the vehicle following you has its headlights on, you may be dazzled by the headlight beam of the vehicle following you. Alternatively, when the lighting switch is not turned on, the strong afternoon sun may enter from behind and reflect off the mirrors in the room, causing dazzling. Conventionally, when the lighting switch is off, the power to the anti-glare mirror switching device is turned off. However, the driver could not freely set the vehicle to the so-called night state, which caused problems.

The purpose of this invention is to create a lighting switch that can be freely manually switched between high reflectance and low reflectance even when it is off, and an anti-glare mirror that can be switched automatically when the lighting switch is on. An object of the present invention is to provide a switching device.

According to this invention, the lighting switch is configured to block the signal from the light receiving element from being supplied to the drive circuit that switches the reflectance of the mirror when the lighting switch is not lit, and the blocking means and the drive circuit An automatic/manual changeover switch is inserted between the two, and when the automatic/manual changeover switch is set to the automatic changeover position, the output signal of the light receiving element from the preceding stage is supplied to the drive circuit. With the automatic manual changeover switch set to the manual changeover position, a binary DC signal can be selectively supplied manually to the drive circuit.

An example of the anti-glare mirror switching device according to this invention will be explained below with reference to the drawings.

First, an example of the mirror and its drive mechanism is shown in the first example.
This will be explained with reference to FIGS. 3 to 3. A mirror 12 is disposed on the front surface of the body 11 so as to substantially close the opening, and a substrate 13 is placed inside the body 11 to cover the mirror 1.
It is fixed opposite to 2. A bearing 14 attached to the back surface of the mirror 12 is rotatably held on a pin shaft 15 fixed to the support 10. Also, pin shaft 1
Electromagnets 16 and 17 support 1 above and below 5.
0, and permanent magnets 18 and 19 are fixed to the back surface of the mirror 12, facing these electromagnets 16 and 17. One end of a mounting arm 22 is rotatably attached to the upper center of the body 11 via a universal joint 21. A protrusion 23 is formed protrudingly from the lower central portion of the body 11, and a light receiving element 25 is mounted on the substrate 13 so as to face the outside, facing a small hole 24 formed on the front surface of the protrusion 23. The light irradiated onto the mirror 12 is received by the light receiving element 25 .

As shown in FIG. 3, one permanent magnet 18 is magnetically attracted to the iron core of the electromagnet 16, and the other permanent magnet 19 is separated from the opposing electromagnet 17. In this state, reflected light from the glass surface of the mirror 12 enters the driver's eyes, that is, a low reflectance state occurs. When a current is applied to the electromagnet 16 to generate magnetic poles that magnetically repel the magnetic poles of the permanent magnet 18, the permanent magnet 18 separates from the electromagnet 16, the mirror 12 rotates around the axis 15, and the permanent magnet 19 becomes an electromagnet. 17, and this state is maintained. In this state, the reflected light from the reflective film of the mirror 12 is incident on the driver, resulting in a high reflectance state. A current is passed through the electromagnet 17 to cause it to magnetically repel the permanent magnet 19, thereby returning it to a low reflectance state.

Next, an example of the electric circuit of the switching device which is the main part of this invention will be explained with reference to FIG. Light receiving element 25
The light received is converted into a DC signal with a magnitude corresponding to the illuminance. In this case, the conversion characteristic is set to be a logarithmic characteristic, and the illuminance at which mutual switching between high reflectance and low reflectance occurs can be adjusted according to the user's preference. That is, operational amplifier 3
A constant current source 32 is connected to the non-inverting input side of the operational amplifier 31, and also connected to one end of a temperature compensation diode 33. The output side of the operational amplifier 31 is directly connected to its inverting input side, and is connected to the operational amplifier 36 through diodes 34 connected in parallel with opposite polarities for logarithmic characteristics.
connected to the non-inverting input side of the A malfunction prevention diode 35 is connected in parallel with the diode 34 with opposite polarity. The non-inverting input side of the operational amplifier 36 passes through a light receiving element 25 such as a photodiode,
Furthermore, it is grounded through a resistor 37. The connection point between the light receiving element 25 and the resistor 37 is connected to an operational amplifier 36.
connected to the inverting input side of the The output side of the operational amplifier 36 is connected to its inverting input side through feedback resistors 38 and 39, and a negative temperature characteristic resistance element 41 for temperature compensation is connected in parallel with the resistor 38. The collector of the transistor 42 is connected to a power supply line 43, the emitter is grounded through a variable resistor 44 for adjusting sensitivity, and a constant voltage is applied to the base from a voltage dividing circuit 45. The movable element of the variable resistor 44 is connected to the other end of the diode 33.

When the illuminance of the light received by the light receiving element 25 is high, the output voltage of the amplifier 36 is low, and when the illuminance is low, the output voltage of the amplifier 36 is high. Furthermore, when the movable element of the sensitivity adjustment variable resistor 44 is brought closer to the emitter side of the transistor 42, the output voltage of the amplifier 36 becomes higher, and the light receiving element 25 required for switching from high reflectance to low reflectance increases accordingly. The illuminance of the incident light increases, which means that the switching sensitivity decreases.

The output of the amplifier 36 is converted into one of two binary DC signals by a determination circuit 46 depending on its level.
In the determination circuit 46, for example, the input output of the amplifier 36 is supplied to the inverting input side of a comparator 47 and compared with a reference voltage from a voltage dividing circuit 48. If the output is smaller than this reference voltage, the output of the comparator 47 is set to high. The capacitor 52 is charged from the power line 43 through the resistor 49 and the diode 51 (in this example, the output of the comparator 47 is of an open collector type). The voltage at the connection point between the diode 51 and the capacitor 52 is applied to the non-inverting input side of the comparator 53 and compared with the reference voltage of the voltage divider circuit 54. When the voltage becomes higher than this reference voltage, the output of the comparator 53 becomes high. level. On the other hand, when the output of the amplifier 36 is higher than the reference voltage of the voltage dividing circuit 48, the output of the comparator 47 becomes a low level.
The charge on the capacitor 52 is discharged through the resistor 55 to the output side of the comparator 47. When the voltage at the connection point between the diode 51 and the capacitor 52 becomes lower than the reference voltage of the voltage dividing circuit 54, the output of the comparator 53 becomes a low level. The output of the comparator 53 is applied to the non-inverting input side of the comparator 47 through a resistor 56 and subjected to positive feedback. This positive feedback brings about hysteresis in the binary DC conversion characteristics for the input of the determination circuit 46. In addition, if the capacitor 52 is charged relatively quickly and strong light is incident on the mirror, the reflectance is immediately switched to low reflectance, and if the light incident on the mirror becomes weaker than a predetermined value from this state, the capacitor 52 is charged relatively quickly. Discharging is performed later than charging, and the reflectance is switched to high reflectance with a slight delay.

Based on the output of the determination circuit 46, one of the electromagnets 16 and 17 is driven through the drive circuit 57 according to the binary value. In this invention, when the lighting switch is in the non-lighting state, the output of the determination circuit 46 based on the output of the light receiving element 25 is transmitted to the drive circuit 57.
will be prevented from being supplied to Furthermore, the drive circuit 57 can be controlled by manual operation.

In this embodiment, the output of the judgment circuit 46, that is, the output of the comparator 53, is supplied to a NOR gate 59 through an inverting circuit 58, and the other input side of the NOR gate 59 is connected to a terminal 61 via a backflow blocking diode 6.
2. A signal indicating the operating state of the lighting switch is input through the resistor 63. The output of the NOR gate 59 is supplied to the drive circuit 57 through the automatic switching position 64a of the automatic manual switching switch 64 and further through the noise canceling wave generator 65. diode 6
A connection point between the resistor 2 and the resistor 63 is connected to the power supply line 43 through the resistor 66. The terminal 61 is at a low level when a lighting switch such as a headlight or a small lamp is on, and is at a high level when the lighting switch is not on. Therefore, when the lighting switch is not lit, the NOR gate 5
9 is held at a low level, that is, the output of the determination circuit 46 is prevented from being supplied to the drive circuit 57. Only when the lighting switch is in the lighting state, the output of the determination circuit 46 is supplied to the drive circuit 57 through the switch 64.

A manually operated switch 67 is connected to the manual switching position 64m of the changeover switch 64, a low reflectance position 67n of the manually operated switch 67 is connected to the power supply line 43, and a high reflectance position 67d is grounded. Therefore, by controlling the manual operation switch 67 with the changeover switch 64 connected to the manual switching position 64m side, a high level DC signal and a low level DC signal can be selected and supplied to the drive circuit 57. Note that the power line 43 is connected to one end of a light emitting element 69 such as a light emitting diode through a switch 68, and the other end of the light emitting element 69 is connected to the terminal 61 through a diode 70. Switches 64, 68 are connected so that switch 68 is turned on when changeover switch 64 is connected to automatic changeover position 64a.
is linked, the mirror is set to automatic switching state,
In addition, when the lighting switch is in the lighting state, the light emitting element 69 lights up and is displayed.

When the drive circuit 57 receives a binary DC signal therefor, it drives one of the electromagnets 16 and 17 in accordance with the binary DC signal. In this example, the drive circuit 57 drives one of the electromagnets 16 and 17 for only a certain period of time. That is, the DC signal input to the drive circuit 57 is transmitted to the monostable multivibrator 71.
It is supplied directly to the monostable multivibrator 73 through the inverting circuit 72. The outputs of the monostable multivibrators 71 and 73 are applied to the bases of transistors 74 and 75, the collectors of the transistors 74 and 75 are connected to the power supply line 43, and the emitters are connected to the drive transistor 76 through separate resistors. , 77 bases. Each emitter of the transistors 76, 77 is grounded, and each collector is connected to the electromagnet 17, 1.
It is connected to the power supply terminal 78 through the six coils 17c and 16c, respectively. When a high-level DC signal is applied to the drive circuit 57, the monostable multivibrator 71 is driven, and the output is at a high level for a certain period of time, for example, 0.1 seconds, during which the transistor 74
A current flows through the transistor 76, and the electromagnet 17 is driven. Therefore, if the electromagnet 17 and the permanent magnet 19 were in contact, they separate from each other and the mirror is switched to a low reflectance state. When a low level DC signal is input to the drive circuit 57, the monostable multivibrator 73 is driven, and for a certain period of time,
For example, the output is at a high level for 0.1 seconds, during which current flows through transistor 75 and into transistor 77, driving electromagnet 16, separating electromagnet 16 and permanent magnet 18, and switching the mirror to a high reflectance state.

In this example, the monostable multivibrator 73
The output of is input to the NOR gate 71a at the subsequent stage in the monostable multivibrator 71. Therefore, even if a high level is output from the monostable multivibrator 71 at the moment the power supply voltage is applied to the power supply terminal 78, the steady state will be reached in a short time, and if the input is at a low level, the monostable multivibrator 73
is driven, its output is given to gate 71a, and the output of monostable multivibrator 71 is forced to a low level. Since there is a delay between the electromagnets 16 and 17 being driven and the mirror switching,
When the power is turned on, the monostable multivibrator 71 is instantaneously driven as described above, and before the mirror switches to the low reflectance state, the output of the monostable multivibrator 71 is set to a low level, and the input at that time is A low level immediately sets the mirror to a high reflectance state.

A constant voltage circuit 79 is connected to the terminal 78, and its constant voltage output is applied to the power supply terminals of the power supply line 43, operational amplifier, comparator, and the like. The operator 64e of the changeover switch 64 and the operator 67e of the manual operation switch 67 can be respectively provided on the bottom surface of the mounting arm 22, as shown in FIG. 1, for example.

As described above, according to the anti-glare mirror switching device of this invention, if the automatic manual switching switch 64 is set to the automatic switching position 64a, when the lighting switch is turned on, the light receiving level of the light receiving element 25 is adjusted. The mirror is automatically switched between a high reflectance state and a low reflectance state. When the lighting switch is turned off, the NOR gate 59
The output of is fixed at a low level and the mirror is held in a high reflectance state. Moreover, even when the lighting switch is in the non-lighting state, the power supply voltage is applied to the drive circuit 57, so the automatic manual changeover switch 64 is set to the manual changeover position 64m to control the manual operation switch 67. By doing so, the mirror can be set to a low reflectance state or a high reflectance state, and as mentioned above, when the western sun is incident on the mirror, or in the evening or early morning, even if the car behind you has the lighting switch turned off, it will be difficult to When a headlight beam from a car is incident, the reflectance can be made low, which is extremely convenient.

In addition, in FIG. 4, the manual operation switch 67 is not connected to the changeover switch 64, and the manual operation switch 60 is connected to the wave generator 65 and the drive circuit 5, for example.
It may be connected to 7 connection points. An analog gate controlled by a signal indicating the state of the lighting switch may be inserted before the judgment circuit 46 so that the output of the light receiving element 25 is not supplied to the judgment circuit 46 when the lighting switch is on. Alternatively, when the writing switch is turned on, the signal can ground the inverting input side of the comparator 53, and the output of the comparator 53 can be fixed at a high level. In short, when the lighting switch is on and the automatic/manual changeover switch 64 is set to the automatic position 64a, it is only necessary to give a signal to the drive circuit 57 to set the mirror in a low reflectance state.

[Brief explanation of drawings]

Figure 1 is a front view showing an example of an anti-glare mirror, Figure 2 is a front view showing an example of an anti-glare mirror;
The figure is a sectional view taken along the line AA in Figure 1, and Figure 3 is a cross-sectional view of Figure 1.
FIG. 4 is a connection diagram showing an example of the anti-glare mirror switching device of this invention. 11: body, 12: mirror, 16, 17: electromagnet, 18, 19: permanent magnet, 25: light receiving element,
46: Determination circuit, 57: Drive circuit, 61: Terminal to which a signal indicating the state of the lighting switch is given, 64: Automatic manual changeover switch, 67: Manual operation switch.

Claims (1)

[Scope of utility model registration request] The light irradiated onto the mirror is received by a light-receiving element, and a judgment circuit converts it into one of two binary DC signals according to the output level of the light-receiving element. In the anti-glare mirror switching device configured to drive a drive circuit that switches the reflectance of the mirror accordingly, the above determination based on the output of the light receiving element is performed by a signal indicating that the lighting switch is in a non-lit state. A blocking means for blocking the output of the circuit from being supplied to the driving circuit, and a blocking means inserted between the blocking means and the driving circuit to allow the output of the determination circuit based on the light receiving element to pass through at an automatic switching position. , an automatic manual changeover switch that shuts off at the manual changeover position, and an automatic changeover means that selectively applies a binary DC signal to the drive circuit while the automatic manual changeover switch is switched to the manual changeover position. Anti-glare mirror switching device.