Electricity: motive power systems – Automatic and/or with time-delay means – Moisture content or wetness
Reexamination Certificate
1998-12-16
2001-05-29
Nappi, Robert E. (Department: 2837)
Electricity: motive power systems
Automatic and/or with time-delay means
Moisture content or wetness
C318S480000, C318SDIG002
Reexamination Certificate
active
06239570
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wiper controller apparatus of the water drop sensitive type for detecting a condition or amount or volume of water drops adhered to or present upon a surface of a window glass so as to drive the wiper, by using a light emitting element and a light receiving element.
2. Description of Prior Art
A conventional controller apparatus of the water drop sensitive type as disclosed in Japanese Patent Laid-Open No. Hei 2-67945 (1990) is already known. In this prior art document, light means (i.e., light emitting means) and detection means (i.e., light receiving means) are positioned upon an inside surface of a window glass, opposing to each other at a distance, within a wiping area of a wiper wiping an outside surface of the window glass, and the adhesion or presence of the water drops upon the outside surface of the window glass is decided or detected on the basis of a difference between output signal levels generated from the detection means before and after driving of the wiper, so as to drive the wiper. When the output signal of the detection means reaches a certain reference level, the wiper starts to be driven, while it is stopped when the output signal of the detection means falls to be less or lower than aforesaid reference level.
However, with the conventional wiper controller apparatus of the water drop sensitive type, it is impossible to remove or wipe any water drops, present, for example, due to rain, still adhered to or present upon the window glass in such an amount or volume that the output signal of the detection means does not reach the predetermined reference level, in particular after the stopping of rain, since the wiper stop being driven immediately after the output signal of the detection means came to be lower than the reference level. Further, there is also a possibility that any rain drops (water drops) adhered or present upon the window glass without being detected by the detection means may shift or slide down on the window glass (especially, for example, the front windshield of an automobile) into a view region or area other than that that is wiped by the wiper.
In particular in a case where the output signal of the detection means does not reach the reference level, there is still another drawback in that the wiper must be driven by being manually switched on again, since it does not operate automatically.
Further, with the conventional wiper controller apparatus of the water drop sensitive type, the wiper is automatically driven when the output signal from the detection means reaches the predetermined level. Therefore, it has a further drawback in that the wiper can be driven erroneously by the incidence of noise or ambient light from outside, which changes abruptly (in particular, pulse-like light) or that is caused due to the shadow of trees, buildings, tunnels and so on.
Moreover, there is another drawback in that the wiper may be accidentally driven due to electromagnetic noise or radio waves generated by such devices as VICS, mobile phones (car phones), other radio apparatus, or generated from the ignition coil of an automobile's engine, which are incident as noise upon the detection means.
SUMMARY OF THE INVENTION
For resolving the above-mentioned drawbacks, according to the present invention, there is provided a wiper controller apparatus of the water drop sensitive type, comprising: light emitting means for guiding light into a window glass so as to undergo total internal reflection within said window glass; light receiving means for receiving the light which has undergone total internal reflection within said window glass; means for detecting the amount of water drops adhered or present upon an outside surface of said window glass based on an output signal of said light receiving means, and for driving a wiper thereupon; and the apparatus further comprises, wiper driving means for driving said wiper again by only one cycle if a time interval from an initiation of said wiper exceeds a predetermined time.
Thereby, the wiper is automatically driven on the assumption that rain drops are adhered or present upon the front glass in an amount insufficient to cause the initiating of the wiper, and that rain drops not detected by the sensor have slid down into the view region of the front glass from regions other than the wiping area wiped by the wiper. Therefore, when only a few water drops are adhered to or present upon the front glass, they can be automatically wiped off.
Further, according to the present invention, there is also provided a wiper controller apparatus of the water drop sensitive type, comprising: light emitting means for guiding light into a window glass so as to undergo total internal reflection within said window glass; light receiving means for receiving the light which has undergone total internal reflection within said window glass; means for detecting the amount of water drops adhered or present upon an outside surface of said window glass based on an output signal of said light receiving means, and for driving a wiper thereupon; and further, wiper driving means for driving said wiper again by only one cycle, in the case where said wiper has been first driven by only one cycle, if a predetermined time has passed after said first driving cycle thereof.
With this arrangement, the wiper is automatically again driven by only one more cycle after a predetermined time has elapsed, even in the case where the wiper has first been driven by only one cycle after initiation thereof due to only a small amount of water drops being present. Therefore, it is possible to wipe up the water drops that are adhered to or present upon the front glass at a level not sufficient to initiate the driving of the wiper, with certainty, in particular after the raining stops.
Furthermore, according to the present invention, there is also provided a wiper controller apparatus of the water drop sensitive type, comprising: light emitting means for guiding light into a window glass so as to undergo total internal reflection within said window glass; light receiving means for receiving the light which has undergone total internal reflection within said window glass; means for detecting the amount of water drops adhered or present upon an outside surface of said window glass based on an output signal of said light receiving means, and for driving a wiper thereupon; and further, wiper driving means for driving said wiper when the signal duration time of the output signal of said light receiving means is equal to or greater than a predetermined time.
According to this arrangement, with the provision of the wiper driving means for driving said wiper when the signal duration time of the output signal of said light receiving means is equal to or greater than a predetermined time, it is possible to drive the wiper and quickly respond to the condition of the water drops being adhered or present upon the window glass, free from any interference from noise due to ambient light and/or external electromagnetic waves, changing the signal duration time thereof to a time period less or shorter than the predetermined time.
REFERENCES:
patent: 5073722 (1991-12-01), Tohge et al.
patent: 5726547 (1998-03-01), Reime
patent: 2-67945 (1990-03-01), None
Koyama Tadashi
Tanaka Shuhei
Tsunetomo Keiji
Fletcher Marlon T.
Nappi Robert E.
Nippon Sheet Glass Co. Ltd.
Pillsbury Madison & Sutro LLP
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