Document Type and Number:
Japanese Patent JPH0545139
Kind Code:
B2
Abstract:
PURPOSE:To increase noise resistance when rain fall is detected, by integrating values corresponding to an extended pulse width. CONSTITUTION:A rain drop detection circuit 81 outputs a rain drop detection pulse with a level corresponding to the size of rain drops passing through a detection area while a pulse extension circuit 1 outputs a pulse signal obtained by extending the pulse width of the rain drop detection pulse according to the level thereof. A comparator 2 compares an output from the circuit 1 with a threshold V1 and give comparison output '1' while the output of the circuit 1 is larger to be supplied to a wiper action timing circuit 3 through a line 88. The circuit 3 integrates the input signal through an LPF to form a wiper driving signal. Thus, rain fall can be detected by removing noise even when the noise overlaps the line 88.
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Inventors:
FUJIMURA KEIJI
OOTA ATSUSHI
IYODA NORIBUMI
MUTO MASAHITO
OOTA ATSUSHI
IYODA NORIBUMI
MUTO MASAHITO
Application Number:
JP2046486A
Publication Date:
July 08, 1993
Filing Date:
February 01, 1986
Export Citation:
Assignee:
FUJITSU TEN LTD
TOYOTA MOTOR CO LTD
TOYOTA MOTOR CO LTD
International Classes:
G01N21/59; B60S1/08; (IPC1-7): G01N21/59
Next Patent: NOISE SUPPRESSION TYPE IGNITION PLUG