Document Type and Number:
Japanese Patent JPS5026060
Kind Code:
B1
Abstract:
1,269,787. Measuring displacement electrically. INTERNATIONAL BUSINESS MACHINES CORP. 16 Oct., 1969 [31 Oct., 1968], No. 50866/69. Heading G4H. [Also in Division G1] A writing telegraph system comprises a writing tablet represented by a resistance 15 to one end of which is supplied a voltage V 1 sin #t, the other end being connected in cyclic alternation to a point at earth potential and to a point at the supply voltage V 1 so that the magnitude of the voltage V IN , at a detector 31 capacitively coupled 29 to a stylus of which the position coordinate is required, is representative in alternation of that fraction of the supply voltage coupled by the capacitance 27 but independent of stylus position (period T 1 -T 2 , Fig. 3c) and of that fraction of the supply voltage tapped off as a function of stylus position and coupled by the capacitance 29 (period T 2 -T 1 , Fig. 3c). The position-dependent voltage is integrated at 33 for a fixed time T 2 -T 1 and then the integrator is supplied with the inverted positionindependent voltage and the time t 0 , Fig. 3e, measured to restore the zero level at the integrator. Thus t 0 : T 2 - T 1 is as X:L, where X is stylus co-ordinate and L is resistor length. The time to is measured in a register 21 fed with clock 11 pulses via a counter 13, which counter drives the filter 17 to generate the supply voltage. Fig. 4 (not shown) illustrates an embodiment for measuring X and Y coordinates of the stylus.
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Application Number:
JP8393169A
Publication Date:
August 28, 1975
Filing Date:
October 22, 1969
Export Citation:
International Classes:
G01D5/12; G06F3/033; G06F3/045; H03M1/00; (IPC1-7): G06F3/00; G01B7/00; G06K9/00