Title:
POSITIONING TABLE DEVICE
Document Type and Number:
Japanese Patent JPH01298410
Kind Code:
A
Abstract:
PURPOSE:To remove a photoswitch and to flexibly cope with the position change of a stroke end limit and an origin by providing a special pattern on an encoder plate to execute the needle position detection. CONSTITUTION:An absolute encoder plate 11 has position detecting patterns S0-S2 of a possible magnet and a continuous pattern L0 in which the period is two time as much as a minimum resolution. By moving on an encoder plate 11 with an encoder sensor part, an output e0 is obtained from a phototransistor 13 and the output e0 is inputted through a level converting circuit 14A and an A/D converter 14B to a linear approximate ROM 14C. At a voltage setting part 15, a reference voltage VT is set and the input of a comparator 16 is obtained. By the adjustment of a reference voltage VT, the fine change of a limit position and an origin position can be performed. Thus, a photoswitch can be removed, and the coping can be executed flexibly with the change of the limit position and the origin position.
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Inventors:
OISHI SHINJI
KORENAGA NOBUSHIGE
KORENAGA NOBUSHIGE
Application Number:
JP12829788A
Publication Date:
December 01, 1989
Filing Date:
May 27, 1988
Export Citation:
Assignee:
CANON KK
International Classes:
H02K41/03; G05D3/12; (IPC1-7): G05D3/12; H02K41/03
Attorney, Agent or Firm:
Yoshikazu Tani