Electricity: measuring and testing – Electrical speed measuring – Including speed analog electrical signal generator
Reexamination Certificate
1998-08-24
2001-06-05
Patidar, Jay (Department: 2862)
Electricity: measuring and testing
Electrical speed measuring
Including speed analog electrical signal generator
C324S166000, C324S173000, C324S207250
Reexamination Certificate
active
06242904
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotation detector for detecting a rotation speed of a rotating body, which is used for a vehicle, an airplane, a machine tool, or the like.
2. Description of the Related Art
Japanese Patent Unexamined Publication No. Hei. 2-116753 discloses a conventional rotation detector.
FIG. 4
of the publication showing the prior art discloses a rotation detecting device in which a pair of magnetic detecting elements are disposed in the vicinity of a magnetic substance rotating together with a rotating body, the respective magnetic detecting elements are connected through their respective signal processing circuits to a detecting circuit, and the rotation direction of the rotating body is detected by using phase differences of pulses generated by the pair of magnetic detecting elements.
In this rotation detecting device, the respective magnetic detecting elements are connected through the respective signal processing circuits to the detecting circuit so that the number of the required signal processing circuits is the same as that of the magnetic detecting elements. Further, the number of required signal detection lines from the detecting circuit is also the same. Thus, a circuit structure around the rotation detecting device becomes complicated.
In
FIGS. 2 and 3
of the publication disclosing the prior art, there is disclosed a rotation detector in which a gear portion of a magnetic substance set on a rotating body is asymmetrically-shaped, and waveforms of signals generated are analyzed to detect the rotation direction of the rotating body.
However, in this prior art, since the magnetic substance must be machined asymmetrically, this detector has a problem in that the machining cost becomes high. Moreover, if the number of teeth is large, formation of the gear shape is difficult and a limitation occurs in resolution. Further, in the detecting circuit, two thresholds are required for determination of the rotation direction, so that the amplitude of an output signal must be wide.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the foregoing shortcomings of the prior art.
In order to achieve the foregoing object, according to a first aspect of the present invention, a rotation detector comprises a first transmitting element and a second transmitting element each disposed opposite a gear rotor attached to a rotating body as a detected member and a signal processing device connected to the first transmitting element and the second transmitting element for generating pulse signals on the basis of rotation signals generated by the first transmitting element and the second transmitting element, wherein the rotation detector is characterized in that the signal processing device generates the pulse signals having different pulse widths in the case where the first transmitting element generates the rotation signal prior to the second transmitting element and in the case where the second transmitting element generates the rotation signal prior to the first transmitting element.
According to the rotation detector of the first aspect, since the pulse widths of the pulse signals generated by the signal processing device are made different in accordance with the rotation direction of the gear rotor attached to the rotating body as the detected member, the rotation direction of the rotating body can be detected by detecting the pulse widths of the pulse signals.
REFERENCES:
patent: 25 18 054 (1976-11-01), None
patent: 3318351 (1994-11-01), None
Iwase Eiichiro
Shirai Katsuyoshi
Suzumura Nobuyasu
Aisin Seiki Kabushiki Kaisha
Patidar Jay
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Rotation detecting device for detecting direction of rotation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rotation detecting device for detecting direction of rotation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotation detecting device for detecting direction of rotation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2543196