JPH0333547Y2 - - 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 is particularly intended to prevent malfunctions caused by lighting of room lamps (also referred to as interior lights). This invention relates to an auto-dimming mirror device that disables the rear view mirror during daytime driving.

[Prior art]

Generally, when driving a car at night, if the 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 has been proposed, which automatically displaces the rearview mirror to prevent glare from rearward light from a following vehicle. Conventionally, this type of device uses sensors to detect ambient light and rear light, respectively.
Some vehicles are configured to compare the detection outputs of these sensors using a comparator and automatically drive the rear view mirror based on the comparison result. However, in such conventional devices, the rear light sensor that detects rear light is installed near the rearview mirror, so when the room lamp is turned on, the rear light sensor may detect that light, causing the rearview mirror to malfunction. It was hot. Furthermore, the comparator may operate during the daytime when reflected light (from the sun) enters from behind or when the car is in the shade of a tree and only the surrounding light becomes dark. Therefore, although I only want to use anti-glare at night, the back mirror moves when anti-glare is not necessary. Therefore, at night, you cannot see the back view, so there is no problem even if the back view mirror moves for a short time, but during the day, if you cannot see the back view correctly even for a short time, it becomes a problem (causing an accident) and safety. It was not good for driving.

[Summary of the idea]

The present invention was devised in view of the above points, and its purpose is to prevent malfunctions due to the lighting of interior lamps through a simple configuration, and also to disable the rear view mirror during daytime driving. The goal is to provide equipment.

In order to achieve this purpose, the present invention
In an auto-dimming mirror device configured to detect ambient light and rear light with respective sensors, compare the detection outputs of these sensors with a comparator, and drive the rearview mirror based on the comparison results, holding means that sends a pulse generated by the output of the device to a drive system that drives the rearview mirror when the room lamp is not lit, and holds the pulse just before the lighting when the room lamp is lit, and detects ambient light. An absolute value circuit is provided which receives the output of the sensor and stops the operation of the comparator when the absolute value output exceeds a predetermined set value depending on daytime brightness. 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, and 3 compares the respective outputs of the ambient light sensor 1 and rear light sensor 2 and calculates the difference voltage. Comparator 4 takes out the output voltage corresponding to comparator 3, and when the output voltage reaches a preset reference trigger level, it rises from a low level to a high level and becomes below the trigger level. A shutter trigger circuit 5 generates a pulse that sometimes falls from a high level to a low level, and 5 is a room lamp lighting check circuit 6 that sends a signal depending on whether or not the room lamp is lit in conjunction with the lighting operation of the room lamp.
This is a hold circuit for holding the output pulse of the above-mentioned Schmitt trigger circuit 4 in response to the output of the above-mentioned Schmitt trigger circuit 5. This hold circuit 5 is a hold circuit for holding the output pulse of the above-mentioned Schmitt trigger circuit 4 in response to the output of the above-mentioned Schmitt trigger circuit. The output pulse of the Schmitt trigger circuit 4 is directly transferred to the output end side, and when the output is a signal associated with the lighting of the room lamp, the output pulse of the Schmitt trigger circuit 4 immediately before the lighting is held. Then, the hold voltage is checked by the check circuit 6.
The system is designed to be reset by a signal that accompanies the room lamp being turned on and off.

Further, 7 is a delay circuit, 8 and 8a are mono-multi vibrators which input the output pulse from the delay circuit 7 and generate pulses of a fixed time width with the rising and falling pulses, respectively, and 9 and 9a are mono-multi vibrators for each of the mono-multi vibrator 8,8
This is a plunger drive circuit for driving plungers 10 and 10a, respectively, by the pulses of a, and one of the plungers 10 energizes a rearview mirror 11 mounted on the driver's seat side of the automobile to prevent glare from the rearview mirror 11 from its normal position. While driving the other plunger 10a to the position by a predetermined angle,
The rear view mirror 11, which is in the anti-glare position, is driven to return to its normal position. Also,
Reference numeral 12 denotes an absolute value circuit for receiving the output of the ambient light sensor 1 and stopping the operation of the comparator 3 when the absolute value output exceeds a set value. The value is determined so that the back mirror 11 will not operate when the amount of light increases.

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 of will increase. Then, comparator 3 becomes
An output voltage corresponding to the voltage difference between the outputs of the ambient light sensor 1 and the rear light sensor 2 is extracted, and this voltage is input to the Schmitt trigger circuit 4. Thereby, the Schmitt trigger circuit 4 is triggered when the output voltage from the comparator 3 reaches a preset trigger level, and generates a pulse that transitions from a low level to a high level. At this time, when the room lamp lighting check circuit 6 detects that the room lamp is not lit, the hold circuit 5 transfers the high level pulse from the shot trigger circuit 4 to the mono multivibrator 8 through the delay circuit 5. . As a result, the mono-multivibrator 8 generates a pulse and inputs it to the plunger drive circuit 9, which uses the pulse from the mono-multivibrator 8 to energize the plunger 10 and move the rearview mirror 11 from the normal position to the anti-glare position. Drive to. Therefore, when the headlamp light from the following vehicle continuously enters the rear light sensor 2, the plunger drive circuit 9 maintains the rearview mirror 11 in the anti-glare position so that the light from the following vehicle is within the driver's field of vision. can be prevented from entering. 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, so the mono multivibrator 8a generates a pulse when the Schmitt trigger circuit 4 falls. and inputs it to the plunger drive circuit 9a. As a result, the drive circuit 9a urges the plunger 10a to drive the rearview mirror 11, which is in the anti-glare position, to return to its original normal position.

Further, when the room lamp lighting check circuit 6 detects the lighting of the room lamp, the rear light sensor 2 receives the light from the room lamp and its output voltage increases. Therefore, the comparator 3 and the schmitt trigger circuit 4 operate in the same way as when detecting the rear light described above, but the hold circuit 5 receives the signal from the check circuit 6 when the light is turned on, and controls the output of the schmitt trigger circuit 4, that is, the room lamp. Since the low-level output immediately before the lamp is turned on is held, the operation of the circuit system thereafter remains unchanged, and malfunction of the rearview mirror 11 due to the lighting of the room lamp can be prevented. Furthermore, when the output of the ambient light sensor 1 becomes large, that is, during the daytime, the comparator 3 is disabled by the function of the absolute value circuit 12, so that the rear view mirror 11 is turned off when there is no need for anti-glare as in the conventional case. It never works.

[Effect of idea]

As explained above, according to the auto-dimming mirror device of the present invention, the rearview mirror will not malfunction even if the interior lamp is turned on while the vehicle, such as a car, is running or stopped, and the reliability of the device is improved. Since the rear view mirror is inoperative when there is no need to provide glare protection during daytime driving, this has an effect that is beneficial for safe driving.

[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...
...Hold circuit, 6... Room lamp lighting check circuit, 7... Delay circuit, 8, 8a... Mono multivibrator, 9, 9a... Plunger drive circuit, 10, 10a... Plunger, 11...
Back mirror.

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.
In an auto-dimming mirror device configured to drive a rearview mirror based on the comparison result, a pulse generated by the output of the comparator is sent to a drive system that drives the rearview mirror when the room lamp is not lit, and holding means for holding the pulse immediately before the lighting of the room lamp when the room lamp is turned on; and a holding means that receives the output of the sensor that detects ambient light, and the output of the absolute value thereof is set to a predetermined setting value according to daytime brightness. An auto-dimming mirror device characterized in that it is provided with an absolute value circuit that stops the operation of the comparator when the value exceeds the absolute value.