JP2572884Y2 - Sensor device in automatic wiper device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device used for an automatic wiper device of an automobile.

[0002]

2. Description of the Related Art Conventionally, a capacitance type raindrop sensor having a pair of sensor electrodes is provided on a windshield glass of an automobile, and a capacitance between the sensor electrodes generated when raindrops adhere to the windshield glass. There is known an automatic wiper device that detects a raindrop from a change and automatically operates a wiper.

If the outer surface of the windshield glass freezes, the capacitance between the sensor electrodes of the raindrop sensor also changes in this case. However, when the wiper is operated during freezing, the wiper blade is damaged, and the glass temperature is detected. There has also been proposed an automatic wiper device in which a temperature sensor is provided to stop the operation of the wiper by the raindrop sensor when the glass temperature is equal to or lower than a predetermined temperature.

[0004]

In the above, the raindrop sensor and the temperature sensor are attached to the outer surface of the windshield glass, and these sensors are covered with a protective film.
If the protective film is made thin, the film is broken by sand or the like flying during traveling and the protection function of the sensor is impaired, while if the protective film is made thick, the wiping operation of the wiper is hindered. In view of the above, an object of the present invention is to provide a sensor device capable of reliably protecting a sensor without hindering a wiping operation of a wiper.

[0005]

In order to achieve the above object,
The present invention focuses on the fact that a laminated glass in which two sheets of glass are joined is used as a windshield glass, and a film-like sensor electrode constituting a raindrop sensor is interposed at the glass joint and formed into a film. Sen the temperature sensors
It was integrated into the electrode and interposed at the glass joint.

[0006]

The raindrop sensor and the temperature sensor are both interposed at the glass joint and embedded in the windshield glass, so that both sensors are reliably protected from the outside world and the wiping operation of the wiper is hindered by both sensors. Nor. Change
To, by incorporating integrally temperature sensor at the terminal portion or the like on the sensor electrode, to decrease the number of sensor terminals for external extraction, it can simplify the external wiring. In addition, a signal processing circuit connected to the raindrop sensor or the temperature sensor may be formed into an IC chip and interposed in the glass joint, whereby a digital signal from the signal processing circuit can be extracted to the outside. As compared with a case where an analog signal from the sensor is taken out to the outside, malfunction of the wiper due to a disturbance factor such as variation in resistance value of the external wiring is less likely to occur.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a windshield glass on the front side of an automobile, and a raindrop sensor 3 is provided on a plurality of areas of the windshield glass 1 wiped by a wiper 2.
Was provided.

As shown in FIGS. 2 and 3, the windshield glass 1 is composed of an outside glass 1a and an inside glass 1b.
Are bonded to each other by applying heat and pressure with an intermediate film 1c made of a transparent insulating material such as polyvinyl butyral interposed therebetween.

The raindrop sensor 3 is constituted by a capacitance type sensor in which a pair of comb-shaped sensor electrodes 31 and 32 are juxtaposed with a certain gap therebetween. An electrode-forming substance such as ITO (isodium tin oxide) is adhered to a transparent thin film by vacuum deposition, sputtering, printing, or the like on the inner surface of the outer glass 1a to be a bonding surface of the sensor electrodes 31 and 32. When the outer glass 1a and the inner glass 1b are formed and bonded to each other through the interlayer film 1c as described above, the raindrop sensor 3 is embedded in the glass bonded portion. On the inner surface of the vehicle exterior glass 1a, a thin-film temperature sensor 4 made of a heat-sensitive material whose resistance value changes according to heat of SiC or the like is located near the sensor electrodes 31 and 32.
The temperature sensor 4 is embedded in the glass joint at the time of glass joining in the same manner as the raindrop sensor 3.

The raindrop sensor 3 is connected to an external signal processing circuit 5 via terminal portions 31a and 32a connected to the sensor electrodes 31 and 32, and the temperature sensor 4 is also a thin film pair of terminal portions 4a and 4b. Is connected to the signal processing circuit 5 via the. The signal processing circuit 5 includes an oscillator 51 that generates a signal having a frequency corresponding to the capacitance of the raindrop sensor 3, a frequency-voltage converter 52, a rainfall determination circuit 5 a including a switching element 53, and a temperature sensor 4. A temperature determination circuit 5b having a comparator 54 for discriminating a voltage change due to a resistance change;
And an AND circuit 5c for inputting signals from both of the determination circuits 5a and 5b. When a high-level signal is output from the AND circuit 5c, the wiper motor 7 is operated via the control circuit 6. did.

When raindrops adhere to the outer surface of the windshield glass 1, a pair of sensor electrodes 31, 32 of the raindrop sensor 3 is formed.
The capacitance between them changes, the oscillation frequency of the oscillator 51 changes, the switching element 53 is turned off via the converter 52, and a high-level signal is output from the rainfall determination circuit 5a. On the other hand, when the glass temperature falls below a predetermined temperature (for example, 0 ° C.), a low-level signal is output from the temperature determination circuit 5b. And a low level signal is output from the AND circuit 5c, and the wiper motor 7 does not operate. Therefore, the operation of the wiper while the outer surface of the windshield glass 1 is frozen is prevented.

By the way, the windshield glass 1 may be wiped by hand during the warm-up operation after the engine is started. At this time, the operation of the wiper hinders the hand wiping operation. Sometimes, a means 8 for outputting a high level signal is provided, and the output signal is supplied to the AND circuit 6a provided in the control circuit 6 by the A signal.
When a high level signal is output from the AND circuit 6a, the wiper motor 7 is input via a wiper driving circuit 6b provided in the control circuit 6 when the AND signal is input together with the output signal from the ND circuit 5c.
Is operated, and thus the wiper is not operated until a predetermined time has elapsed after the engine is started. still,
Although not shown, when the vehicle starts, the operation of the wiper may be controlled only by the output signal of the rainfall determination circuit 5a regardless of the glass temperature.

FIG. 4 shows another embodiment, in which:
A terminal 31b branched from a terminal 31a for the electrode is formed at a terminal of one sensor electrode 31 of the raindrop sensor 3,
The temperature sensor 4 was integrated into the middle of the terminal portion 31b. When forming the sensor electrodes 31 and 32 on the inner surface of the outer glass 1a, the temperature sensor 4 is formed by chemically applying a heat-sensitive material to the inner surface in a thin film shape. According to this configuration, the terminal 31 a of the sensor electrode 31 is connected to the temperature sensor 4.
There is an advantage that the number of terminals can be reduced by sharing with one of the terminals. The temperature sensor 4 can be composed of a thin-film SiC thermistor or a thin-film platinum thermosensitive element. The latter has advantages such as stability of resistance value and large output.

In the above embodiment, the signal processing circuit 5 is arranged outside the windshield glass 1, that is, on the vehicle body side. However, the signal processing circuit 5 shown in FIG.
As shown in FIG. 5, the sensor 5 is mounted on the glass joint of the windshield glass 1 by forming the circuit 5 into a chip.
It may be interposed together.

According to this, the output terminal 5d of the signal processing circuit 5 is connected to the control circuit 6, and the operation of the wiper can be controlled by the digital signal from the circuit 5, so that the operation of each The wiper is less likely to malfunction due to a disturbance factor such as a variation in the resistance value of the external wiring, as compared with a case in which analog signals from the sensors 3 and 4 are transmitted to an external signal processing circuit. In the drawing, 5e and 5f are a power supply terminal and a ground terminal connected to the ignition switch, respectively.

[0016]

As is apparent from the above description, according to the first aspect of the present invention, both the raindrop sensor and the temperature sensor are interposed at the glass joint of the windshield glass.
The two sensors can be reliably protected from the outside world without hindering the wiping operation of the wiper, and the temperature sensor can detect the glass temperature under the same environment as the raindrop sensor, thereby reliably preventing the operation of the wiper during freezing.

Further, simplifying external wiring by reducing the number of terminals of the sensor, further according to the invention of claim 2, and digitizes external extraction signal can prevent an erroneous operation of the wiper due to disturbance factors.

[Brief description of the drawings]

FIG. 1 is a perspective view of a front part of an automobile showing a layout of a raindrop sensor.

FIG. 2 is a perspective view of a main part of a windshield glass provided with the device of the present invention.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a perspective view of a main part showing another embodiment of the present invention device

FIG. 5 is a perspective view of a main part showing still another embodiment of the device of the present invention.

[Explanation of symbols]

Reference Signs List 1 windshield glass 3 raindrop sensor 31, 32 sensor electrode 4 temperature sensor 5 signal processing circuit

Claims (2)

(57) [Scope of request for utility model registration] 1. A provided a temperature sensor for detecting a raindrop sensor and the glass temperature of the electrostatic capacity type c India windshield, Otowaipa apparatus adapted to control the operation of the wiper based on a signal from both said sensor In the above, a film-shaped sensor electrode constituting the raindrop sensor is interposed at a glass bonding portion of a laminated glass constituting a windshield glass, and the temperature sensor formed in a film-like form is attached to the sensor.
A sensor device in an automatic wiper device, wherein the sensor device is integrated with an electrode and interposed at the glass joint. 2. The method according to claim 2, wherein said glass joint is provided with said raindrop sensor.
The sensor device according to claim 1, further comprising a signal processing circuit connected to the temperature sensor .