AUTOMATIC WINDSHIELD WIPING APPARATUS BY USING MICROWAVES FOR VEHICLES

• US 3,786,330 A
• Filed: 04/28/1972
• Issued: 01/15/1974
• Est. Priority Date: 04/28/1972
• Status: Expired due to Term

• Current Assignee: Goro Inoue, Ming-Tsung Huang
• Original Assignee: Goro Inoue, Ming-Tsung Huang
• Inventors: Inoue, Goro, Huang, Ming-Tsung
• Primary Examiner(s): Dobeck, B.
• Application Number:
  US05/248,487
• Time in Patent Office: 627 Days
• Field of Search: 318/483,443,DIG.2 324/58.5B
• US Class Current: 318/483
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0855 Ultrasonic rain sensor
• CPC Class Codes: B60S 1/0859 Other types of detection of rain, e.g. by measuring friction or rain drop impact
• CPC Class Codes: Y10S 318/02 Windshield wiper controls

Abstract

An automatic windshield wiping apparatus for vehicles which comprises a raindrops detecting device comprising a microwave oscillator, a wave guide adapted for irradiating microwaves generated by the microwave oscillator on the windshield of a vehicle and means responsive to change in microwaves reflected from or transmitted through the windshield due to raindrops thereon to detect the raindrops thereby changing its output signal; and a switching circuit adapted to drive a driving motor for a wiper of the windshield responsive to the change of the output signal from the raindrops detecting device.

Claims

1. An automatic windshield wiping apparatus for vehicles comprising:

a raindrops detecting device adapted to be located near the windshield of a vehicle, said raindrops detecting device comprising;

a microwave oscillator for generating output microwaves, a waveguide having two ends operatively connected at one end to receive the output microwaves from said microwave oscillator and having the other end adapted to be disposed opposingly to one surface of said windshield so as to irradiate said output microwaves generated from said microwave oscillator on said one surface of said windshield, and first means associated with said oscillator and said waveguide for receiving a part of said microwaves irradiated on said one surface of said windshield and for producing an output signal responsive to the received microwaves, a switching circuit connected in circuit with said raindrops detecting device and including a reference signal source means for providing a reference signal and a differential amplifier for comparing the output signal produced by said first means with said reference signal and producing a further output signal when said output signal from the first means is substantially different from said reference signal, and second means connected in circuit with said switching circuit for driving a wiper on said windshield responsive to the further output signal produced by said differential amplifier.

2. An apparatus according to claim 1, wherein the other end of said waveguide is adapted to be disposed opposite to one surface of said windshield and said first means comprises a detector mounted at a predetermined position along the length of said waveguide for receiving microwaves reflected back from said windshield.

3. An apparatus according to claim 1, wherein:

the other end of said waveguide is adapted to be disposed opposite to said one surface of said windshield, and further comprising a second waveguide adapted to be disposed opposite to the other opposite surface of said windshield and in alignment with said first-mentioned waveguide; and

wherein said first means comprises a detector mounted at a predetermined position of said second waveguide for receiving microwaves transmitted through said windshield.

4. An apparatus as in claim 1 wherein said waveguide includes:

tuning stub means mounted at a predetermined position along the length of said waveguide, and horn antenna means operatively connected to said other end of the waveguide for directing said output microwaves onto said one surface of the windshield.