JPH0333546Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an auto-dimming mirror device installed in vehicles such as automobiles, and in particular uses a sensor that detects ambient light to adjust the low beam and high beam of headlamps. This invention relates to an auto-dimming mirror device that can also be switched.

[Prior art]

Generally, when driving a car at night, if light from the headlights of a car following enters the rear view mirror, the driver may feel dazzled and have trouble driving. Therefore, a so-called auto-dimming mirror device is known, which automatically displaces the rearview mirror to prevent glare caused by rear light from a person following you. This device is configured to detect ambient light and rear light using sensors, compare the detection outputs of these sensors using a comparator, and automatically drive the rearview mirror based on the comparison results. .

Incidentally, there are conventional devices that use optical sensors to automatically switch between low beam and high beam headlights, but they have the disadvantage of being uneconomical in terms of cost if both of these independent devices are installed in a car.

[Summary of the idea]

The present invention was developed in consideration of the above points, and its purpose is to create an auto-dimming mirror device that combines both functions by switching the headlamp between low beam and high beam using a sensor that detects ambient light. Our goal is to provide the following.

In order to achieve this purpose, the present invention
An auto-dimming mirror device configured to detect ambient light and rear light with sensors, compare the detection outputs of each sensor with a comparator, and automatically drive the rearview mirror based on the comparison results. , comprising a circuit that receives the detection output of the ambient light sensor and generates a pulse at a preset trigger level from the detection output, and a switching means that switches the headlamp between low beam and high beam using the pulse obtained from the circuit. It was forced upon me. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

〔Example〕

The drawing is a block diagram showing a schematic configuration of an auto-dimming mirror device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes an ambient light sensor installed in front of the vehicle to detect ambient light (also referred to as forward light);
Reference numeral 2 denotes a rear light sensor installed near the rear view mirror, which will be described later, to detect rear light from the headlights of a following vehicle. Reference numeral 3 compares the respective outputs of the ambient light sensor 1 and the rear light sensor 2, and calculates the difference voltage between them. A comparator that takes out the corresponding output voltage, 4 is comparator 3
A Schmitt trigger that generates a pulse that takes the output voltage of the input as an input and rises from a low level to a high level when the output reaches a preset reference trigger level, and falls from a high level to a low level when the output falls below the trigger level. circuit, 5 is a delay circuit,
6 and 6a are mono multivibrators that receive the output pulse from the delay circuit 5 and generate pulses of a fixed time width with the rising and falling pulses, respectively. These are plunger drive circuits for driving plungers 8 and 8a, respectively, and one plunger 8 urges a rearview mirror 9 mounted on the driver's seat side to drive the rearview mirror 9 from a normal position to an anti-glare position by a predetermined angle. At the same time, the other plunger 8a is
The back mirror 9, which is in the anti-glare position, is driven to return to its normal position. In addition, 10
is an absolute value circuit that receives the output of the ambient light sensor 1 and stops the operation of the comparator 3 when its absolute value output exceeds a set value. The back mirror 9 is set to a value that does not operate when the amount of light increases.

Further, reference numeral 11 inputs the output of the ambient light sensor 1, and when the output reaches a preset reference trigger level, it rises from a low level to a high level, and when it falls below the trigger level, it changes from a high level to a low level. A stop trigger circuit generates a falling pulse, and 12 is a stop check circuit that receives a speed signal from a speed sensor (not shown) and checks whether the car is stopped. A high level signal is generated when the value is below the set value, and a low level signal is generated when the value is below the set value. 13 is an AND gate, 14 is a delay circuit,
15 is the pulse from the delay circuit 14 and relay 1
This relay 16 has its switching contact 17 connected between the battery power supply B and the headlamp 18, and the switching contact 17
When the head lamp 18a is in contact with the fixed contact 17a, the upward head lamp 18a is turned on to emit a high beam, and when it is in contact with the fixed contact 17b, the downward head lamp 18b is turned on and a low beam is emitted. ing.

Next, the operation of the above embodiment will be explained. Here, it is assumed that the ambient light sensor 1 and the rear light sensor 2 output voltages proportional to the amount of light they receive. Therefore, when driving at night, when the amount of light received by both the ambient light sensor 1 and the rear light sensor 2 is small, the output voltages of these sensors 1 and 2 become small, and no output voltage is taken out from the comparator 3. When the rear light sensor 2 receives light from the headlights of the following vehicle, the sensor 2
The output voltage becomes larger, and the comparator 3 takes out an output voltage corresponding to the difference voltage between the outputs of the ambient light sensor 1 and the rear light sensor 2. At this time, the Schmitt trigger circuit 4 is triggered when the output voltage from the comparator 3 reaches a preset trigger level, and a pulse rising from a low level to a high level is obtained from this circuit. Then, this pulse is delayed for a predetermined time by the delay circuit 5 and then input to the mono multivibrator 6. As a result, the mono-multivibrator 6 generates a pulse and inputs it to the plunger drive circuit 7, and the drive circuit 7 uses the pulse from the mono-multivibrator 6 to energize the plunger 8 and move the rearview mirror 9 from its normal position to the anti-glare position. Drive into position. Therefore, when the headlamp light from the following vehicle continuously enters the rear light sensor 2, the plunger drive circuit 7
is held in the anti-glare position to prevent light from following vehicles from entering the driver's field of vision. When the light from the following vehicle no longer enters the rear light sensor 2, the pulse of the Schmitt Trigger circuit 4 falls from a high level to a low level.
A generates a pulse at the falling edge of the Schmitt trigger circuit 4 and inputs it to the plunger drive circuit 7a. Thereby, this drive circuit 7a drives the plunger 8a.
is energized to drive the rearview mirror 9, which is in the anti-glare position, to return to its original normal position. It should be noted that when the output of the ambient light sensor 1 becomes large, the comparator 3 is disabled by the function of the absolute value circuit 10, so that the rear view mirror 9 does not operate.

On the other hand, at night, the switching contact 17 is brought into contact with the fixed contact 17a as shown in the figure, and the upward head lamp 18 is turned on.
When the vehicle is traveling with the lights on (a) and the vehicle passes an oncoming vehicle, when the ambient light sensor 1 receives light from the oncoming vehicle, the output voltage of the sensor 1 increases. Then, the Schmitt trigger circuit 11 is triggered when the output voltage of the sensor 1 reaches a preset trigger level, and generates a pulse that rises from a low level to a high level. At this time, since the AND gate 13 is opened by the signal from the stop check circuit 12, the high level pulse from the stop trigger circuit 11 is inputted to the relay drive circuit 15 through the delay circuit 14. This results in
The relay drive circuit 15 drives the relay 16 and switches its switching contact 17 to a fixed contact 17b opposite to that shown in the figure, thereby turning on the downward head lamp 18b.
is selected, the headlamp 18 switches from high beam to low beam. Then, when the output voltage of the ambient light sensor 1 becomes lower than the trigger level of the Schmitt trigger circuit 11, the pulse falls from the high level to the low level, and at the same time, the relay drive circuit 15 deenergizes the relay 16, and its switching contact 1
7 will return to its original state. Note that since the AND gate 13 closes in response to a signal from the stop check circuit 12 when the vehicle is stopped, the head lamp 18 is not switched based on the detection output of the ambient light sensor 1.

In the embodiment described above, the headlamp 18 is switched from low beam to high beam when the output of the ambient light sensor 1 exceeds the trigger level of the shutter trigger circuit 11, but the output of the ambient light sensor 1 is inversely proportional to the amount of light received. As output,
It is also possible to configure the headlamp 18 to be switched from the high beam to the low beam when the output becomes below the trigger level of the shot trigger circuit 11.

[Effect of idea]

As explained above, the auto-dimming mirror device of the present invention utilizes the ambient light sensor of the conventional auto-dimming mirror device to adjust the low beam of the headlamp.
By switching the high beam, both functions can be realized without using a dedicated sensor, and therefore an economically inexpensive device can be provided.

[Brief explanation of the drawing]

The drawing is a block diagram showing a schematic configuration of an auto-dimming mirror device according to an embodiment of the present invention. 1... Ambient light sensor, 2... Rear light sensor, 3
...Comparator, 4...Schmitt trigger circuit, 5...
...Delay circuit, 6, 6a... Mono multivibrator, 7, 7a... Plunger drive circuit, 8,
8a...Plunger, 9...Back mirror, 11
... Schmitt trigger circuit, 13 ... AND gate, 14 ... Delay circuit, 15 ... Relay drive circuit, 16 ... Relay, 18 ... Head lamp.

Claims (1)

[Scope of utility model registration request] Ambient light and rear light are detected by sensors, and the detection outputs of each sensor are compared with a comparator.
An auto-dimming mirror device configured to drive a rearview mirror based on the comparison result includes a circuit that receives the detection output of the ambient light sensor and generates a pulse at a preset trigger level. 1. An auto-dimming mirror device comprising: switching means for switching between a low beam and a high beam of a headlamp using pulses obtained from the circuit.