EP0259894A2
Expired / Lapsed
EP
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Position detecting apparatus
Assignee: Wacom Co Ltd
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Filing: 1987-09-14
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Granted: —
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Expires: 2007-09-14
Abstract
Abstract A position detecting apparatus for detecting a position pointed by a pointer (60) on a system such as a digitizer has the following parts: a position detection section (10) having a plurality of loop coils (11-1 to 11-48) arrayed in a side-by-side fashion in the direction of position detection; a selection circuit (20) for successively selecting the loop coils one-by-one; a transmission circuit (40) for generating an A.C. signal of a predetermined frequency to be delivered to the selected loop coil; a receiving circuit (50) adapted to detect an induced voltage of a frequency substantially the same as that of the A.C. signal from among various voltages induced in the selected loop coil; a connection switching circuit (30) for connecting the selected loop coil alternately to the transmission circuit and the receiving circuit; a position pointer (60) having a tuning circuit (61) including a coil and a capacitor and adapted to resonate with an electric wave produced by the loop coil which is supplied with the A.C. signal; and a processing device (70) for determining the position pointed by the position pointer by processing signals representing the levels of voltages induced in the loop coils.
Inventors
- 👤 Tsuguya Yamanami
- 👤 Takahiko Funahashi
- 👤 Toshiaki Senda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 17:09
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/046; G06F3/033; G06F3/0354; G06F3/03545
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
178 words
A position detecting apparatus comprising: a position detection section (10) having a plurality of loop coils (11-1 to 11-48) arrayed in a side-by-side fashion in the direction of position detection; a selection circuit (20) for successively selecting said loop coils one-by-one; a transmission circuit (40) for generating an A.C. signal of a predetermined frequency to be delivered to the selected loop coil; a receiving circuit (50) adapted to detect an induced voltage of a frequency substantially the same as that of said A.C. signal from among various voltages induced in said selected loop coil; a connection switching circuit (30) for connecting said selected loop coil alternately to said transmission circuit and said receiving circuit; a position pointer (60) having a tuning circuit (61) including a coil (612) and a capacitor (613,615) and adapted to resonate with an electric wave produced by said loop coil which is supplied with said A.C. signal; and a processing device (70) for determining the position pointed by said position pointer by processing signals representing the levels of voltages induced in said loop coils.
Claim 2
Dependent Claim
178 words
A position detecting apparatus comprising: a position detection section (10) having a plurality of loop coils (11-1 to 11-48) arrayed in a side-by-side fashion in the direction of position detection; a selection circuit (20) for successively selecting said loop coils one-by-one; a transmission circuit (40) for generating an A.C. signal of a predetermined frequency to be delivered to the selected loop coil; a receiving circuit (50) adapted to detect an induced voltage of a frequency substantially the same as that of said A.C. signal from among various voltages induced in said selected loop coil; a connection switching circuit (30) for connecting said selected loop coil alternately to said transmission circuit and said receiving circuit; a position pointer (60) having a tuning circuit (61) including a coil (612) and a capacitor (613,615) and adapted to resonate with an electric wave produced by said loop coil which is supplied with said A.C. signal; and a processing device (70) for determining the position pointed by said position pointer by processing signals representing the levels of voltages induced in said loop coils.
Claim 3
Dependent Claim
210 words
A position detecting apparatus comprising: a position detection section (81,82) having a plurality of X-loop coils arrayed in a side-by-side fashion in X-di rection and a plurality to Y-loop coils arrayed in a side-by-side fashion in Y-direction; X- and Y-selection circuits (83,84) for successively selecting said loop coils one-by-one from said X-loop coils and from said Y-loop coils, respectively; a transmission circuit (40) for generating an A.C. signal of a predetermined frequency to be delivered to the selected X- and Y-loop coils; a receiving circuit (50) adapted to detect an induced voltage of a frequency substantially the same as that of said A.C. signal from among various voltages induced in said selected X- and Y-loop coils; X- and Y-connection switching circuits (85,86) for connecting said selected X- and Y-loop coils alternately to said transmission circuit and said receiving circuit; a position pointer (60) having a tuning circuit (61) including a coil (612) and a capacitor (613,615) and adapted to resonate with an electric wave produced by said X- and Y-loop coils supplied with said A.C. signal; and a processing device (87) for determining the position pointed by said position pointer both in X- and Y-directions by processing signals representing the levels of voltages induced in said X- and Y-loop coils.
Claim 4
Dependent Claim
210 words
A position detecting apparatus comprising: a position detection section (81,82) having a plurality of X-loop coils arrayed in a side-by-side fashion in X-di rection and a plurality to Y-loop coils arrayed in a side-by-side fashion in Y-direction; X- and Y-selection circuits (83,84) for successively selecting said loop coils one-by-one from said X-loop coils and from said Y-loop coils, respectively; a transmission circuit (40) for generating an A.C. signal of a predetermined frequency to be delivered to the selected X- and Y-loop coils; a receiving circuit (50) adapted to detect an induced voltage of a frequency substantially the same as that of said A.C. signal from among various voltages induced in said selected X- and Y-loop coils; X- and Y-connection switching circuits (85,86) for connecting said selected X- and Y-loop coils alternately to said transmission circuit and said receiving circuit; a position pointer (60) having a tuning circuit (61) including a coil (612) and a capacitor (613,615) and adapted to resonate with an electric wave produced by said X- and Y-loop coils supplied with said A.C. signal; and a processing device (87) for determining the position pointed by said position pointer both in X- and Y-directions by processing signals representing the levels of voltages induced in said X- and Y-loop coils.
Claim 5
Dependent Claim
72 words
A position detecting apparatus according to Claim 1 or 2, wherein said tuning circuit (61) of said position pointer is designed to vary the phase relation between the voltage applied to said tuning circuit and the current flowing in said tuning circuit in response to the state of a switch (611) so that the state of said switch can be detected by examining the phase relation between said voltage and said current.
References Cited (Backward Citations)
No citation records indexed.
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