Apparatus for magnetically detecting positions with minimum length magnetic information units recorded on a plurality of magnetic tracks
AssigneeHitachi, Ltd.
InventorsTadashi Takahashi, Kunio Miyashita, Syooichi Kawamata
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Abstract
The present invention relates to an apparatus for magnetically detecting positions and intends to provide a position detecting apparatus of the kind with high accuracy in which when recording magnetic signals of a predetermined length on magnetization tracks, a plurality of recording units are continuously arranged in the direction of the magnetization track and are set as the predetermined recording length, thereby sharpening the output waveform of the signal corresponding to the edge portion of the magnetization recording length. The present invention is suitable for the absolute type having a plurality of magnetization tracks.
Claims14
An apparatus for magnetically detecting positions comprising:
- a plurality of magnetic tracks, each track having at least one portion therealong where magnetic information is recorded and at least one other portion where magnetic information is not recorded, the magnetic recorded information portion extending over a different predetermined length for at least two of said plurality of tracks, each different predetermined length magnetic information recorded portion for a respective track comprising a different number of the same minimum length magnetic information units recorded continuously along the direction of extension of a respective track, each different predetermined length magnetic information recorded portion including at least two adjacent minimum length magnetic information units, each of the minimum length magnetic information units generating a magnetic signal for detection;
- magnetic sensing means disposed closely to said magnetic tracks for detecting the magnetic information recorded on said magnetic tracks and providing signals indicative of the actual length of each magnetic information recorded portion on each of said tracks so that the signals provided represent a binary 1 and binary 0 assuming that the magnetic information recorded portion of each track represents one of a binary 1 and 0 and the other portion of each track where magnetic information is not recorded represents the other of a binary 1 and 0, said magnetic sensing means including magnetic sensing devices for each track, each of said sensing devices being in the form of two magnetoresistive elements adapted for connection as part of a processing circuit and spaced a predetermined length along the track direction, each of said elements having an internal resistance which changes in accordance with the intensity of a magnetic field in the same manner irrespective of the difference of polarity of the magnetic field, and
- means for moving said magnetic tracks and said magnetic sensing means relative to one another so that the signals detected by said magnetic sensing means are indicative of a respective portion.
Dependencies are inferred from the claim text.