JPS59149844A - Autowiper device - Google Patents

Abstract

PURPOSE:To prevent operation of a wiper at the time of car washing due to forgetting to turn off a wiper switch by controlling operation of a wiper driving circuit by means of logical sum of a pulse of the constant width from a timing pulse and a signal of waterdrop detection from a waterdrop detector. CONSTITUTION:When an autowiper switch 1 is placed in ON state, a pulse (b) of the constant width T1 is produced from a timing pulse generator 3, while a signal C of waterdrop detection corresponding to a condition of attachment of waterdrops to a window shield is sent out from a waterdrop detector 4. OR gate 5 takes logical sum of both signals (b), (c) and starts, by its output (d), a one shot.multivibrator OSM6, which sends out a pulse (e) of the constant width T2 to put a wiper driving circuit 7 in operation, and a wiper motor 8 is rotated. When the rain is over, since the wiper makes an intermittent action by the constant width T1 of the pulse (b) from the pulse generator 3, an operator puts the switch 1, as unnecessary, in OFF state. Thus, forgetting to turn off the wiper switch 1 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic wiper device that operates a wiper by detecting raindrops attached to a windshield, and is intended to stop the wiper when the wiper is not required to operate, such as when washing a car. .

For example, an auto wiper device that optically detects raindrops on the windshield and automatically operates the wiper.
Even when a car is washed at a car wash, the wipers are activated in response. In this case, if the brush of the car wash machine collides with the operating wiper, an unexpected accident may occur and the wiper itself or the window may be damaged.

The present invention aims to avoid unnecessary operation of the wiper by turning off the wiper switch when washing a car or the like.

The auto wiper device of the present invention includes a water drop detector that detects water droplets adhering to a windshield and generates a water drop detection pulse, a timing pulse generator that generates a timing pulse at a constant cycle, and logic of the timing pulse and the water drop detection pulse. an OR gate that takes a sum, a retriggerable one-shot multi-by-break activated by the output of the gate, a wiper drive circuit that operates in response to the output of the multi-by-break, and a wiper motor driven by the output of the drive circuit; The feature is that it is equipped with an auto wiper switch that forcibly stops the wiper operation by cutting off the power to some or all of these circuits, which will be explained in detail below with reference to the illustrated embodiment. do.

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a diagram of signal waveforms at various parts. In FIG. 1, 1 is an auto wiper switch, and when this switch 1 is turned on, power is supplied from the battery 2 to each signal processor, and from the timing pulse generator (for example, an astable multivib break) 3, T' A pulse b of a constant width is output at an interval of + (for example, about 10 5 ec). On the other hand, the water droplet detector 4 outputs a water drop detection signal (pulse) C depending on the state of adhesion of water droplets to the windshield. 5 is an OR gate which takes the logical sum of signals S and C and uses its output d to activate a retriggerable one-shot multi-by-break (hereinafter abbreviated as O3M) 6. This 03M6 outputs a pulse e having a constant pulse width T2 (the time from when the wiper starts until the wiper motor cam switch is turned on) from the time it is activated, and supplies this to the wiper drive circuit 7. The wiper drive circuit 7 rotates the wiper motor 8 with an output f. In this case, if pulses d continue at intervals shorter than T2, O
The 3M output output pulse width is extended and the wiper operates continuously. In this manner, the intermittent time of the wiper is automatically controlled and the wiper is switched to continuous operation according to the rain condition (the state of the water droplet detector output), thereby realizing an automatic wiper.

Furthermore, if the rain stops, the wiper will operate at the interval T1, so if the user thinks that it is not necessary, the wiper will stop by turning off the wiper switch 1. In other words, various accidents caused by forgetting to turn off the wiper switch can be prevented.

FIG. 3 shows another embodiment of the present invention, and FIG. 4 shows its operating waveform diagram. This example differs from FIG. 1 in that the timing pulse generator 3 is reset by the output C of the water droplet detector 4. In this way, as long as the water droplet detection pulse C occurs at an interval shorter than the period T1, the pulse b will not be generated, so even if the generator 3 is provided, the wiper control (intermittent operation, low speed operation, high-speed operation, etc.).

With the auto wiper device of the present invention as described above, if the auto wiper switch is left on, the wiper will move even when it is not raining, so it is possible to prevent forgetting to turn off the switch, thereby eliminating the need for car washing etc. This can prevent the wiper from moving. Furthermore, if the period T1 of the timing pulse is set to an appropriate value, a highly sensitive water droplet detector capable of detecting a small amount of rainfall becomes unnecessary, and a water droplet detector with low sensitivity is sufficient, leading to cost reduction.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is a waveform diagram of the operation of each part thereof, Fig. 3 is a block diagram showing another embodiment of the invention, and Fig. 4 is a waveform diagram of the operation of each part thereof. It is. In the figure, ■ is an auto wiper switch, 2 is a battery, 3 is a timing pulse generator, 4 is a water drop detector, 5 is an OR gate, 6 is a retriggerable one-shot multi-vibration brake, 7 is a wiper drive circuit, and 8 is a wiper motor. . Applicant: Minoru Aoyagi, Patent Attorney, Fujitsu Ten Limited

Claims (1)

[Claims] a water droplet detector that detects water droplets adhering to the windshield and generates a water WB detection pulse; a timing pulse generator that generates a timing pulse at a constant cycle; and an OR gate that takes the logical sum of the timing pulse and the water droplet detection pulse; A retriggerable one-shot multi-by-break activated by the output of the gate, a wiper drive circuit that operates in response to the output of the multi-by-break, a wiper motor driven by the output of the drive circuit, and a part or part of these circuits. An auto wiper device comprising an auto wiper switch that forcibly stops wiper operation by cutting off all power supplies.