JPH0521147Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an input pen for an electromagnetic coupling type input tablet for inputting characters, figures, etc.

[Conventional technology]

FIG. 5 is a cross-sectional view showing a conventional input pen disclosed in, for example, Japanese Patent Application Laid-Open No. 134928/1983 together with an input tablet. In the figure, 2 is a detection coil, 4 is a lead wire, 5 is a switch, and 6 1 is a pen case, 7 is a shield wire, 8 and 9 are electrodes formed on the input tablet, 10 is an input plate of the input tablet, 11 is a pen shaft, and 12 is a magnetic pipe.

Next, the operation will be explained. In the input tablet, a plurality of electrodes 8 and 9 are arranged under the surface of the input plate 10 so that they are orthogonal to each other and the orthogonal electrodes are not in electrical contact. Then, alternating current is supplied from the outside to two parallel lines of these electrodes 8 and 9 to generate a magnetic field. By placing the detection coil 2 in the magnetic field generated by these two wires, an induced voltage is generated in the detection coil 2.
If the supplied alternating current is passed through different electrodes one after another,
The coordinates of the detection coil 2 on the plate surface can be determined from the induced voltage. The input pen has a pen shaft 11.
A magnetic pipe 12 is attached to the magnetic pipe 12, and a detection coil 2 is wound around this pipe 12. The voltage induced in the detection coil 2 is guided to the switch 5 by a lead wire 4. The switch 5 is turned from OFF to ON when the input pen is pressed against the input plate 10, and the lead wire 4 and the shield wire 7 are connected. It is then connected to the outside of the input pen via a shielded wire 7.

The voltage induced in the detection coil 2 is determined by the magnetic field strength generated from the input plate 10 surface, the input plate 1
The distance between 0 and detection coil 2 and the number of turns of the coil,
Determined by the winding diameter.

[Problem that the invention attempts to solve]

Conventional input pens have a problem in that noise is easily detected because the lead wire of the detection coil is drawn out long along the non-conductive pen shaft.

This invention was made to solve the above-mentioned problems, and the purpose is to obtain an input pen for an input tablet that prevents noise from entering and has high position detection accuracy.

[Means for solving problems]

The input pen for the input tablet of this invention detects the position on the input tablet by detecting the magnetic field generated by the current flowing through the electrodes formed on the input tablet. a magnetic core that passes the generated magnetic flux; a conductive holder that holds the magnetic core; a detection coil that is wound around the magnetic core and detects the magnetic field generated from the input tablet; It is equipped with a lead wire that is brought out to the outside in close contact with the holder.

[Effect]

Since the lead wire of the detection coil of this invention is brought into close contact with the conductive holder, noise in the lead wire is blocked by the electromagnetic shielding effect in which the magnetic flux passes through the conductive holder while avoiding the conductive holder.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an input pen shown together with an input tablet. In the figure, 1 is a magnetic core;
2 is a detection coil, 3 is a conductive holder, 4 is a lead wire, and 5 is a switch. The detection coil 2 is wound around the magnetic core 1, and the lead wire 4 is tightly attached to the conductive holder 3 and drawn out to the switch 5. The switch 5 is led out to the outside of the input pen via a shielded wire 7. 6 is a pencil case, 8 and 9 are electrodes formed on the input tablet, and 10 is an input plate of the input tablet.

Next, the operation will be explained. Input plate 10
A plurality of electrodes 8 and 9 are arranged under the surface of the substrate so that they are orthogonal to each other and the orthogonal electrodes are not in electrical contact with each other. An alternating current is supplied to these electrodes 8 and 9 from the outside to generate a magnetic field. By placing the detection coil 2 in the magnetic field generated from this wire, an induced voltage is generated in the detection coil 2. When the input pen is placed on the input plate 10, the switch 5 turns from OFF to ON, the lead wire 4 and the shield wire 7 are connected, and the induced voltage is transmitted through the lead wire 4, the switch 5, and the shield wire 7 for input. taken out of the pen. Since the lead wire 4 is drawn out in close contact with the conductive holder 3, the electromagnetic shielding effect of the conductive holder 3 can prevent noise from entering the lead wire.

In the above embodiment, a columnar conductive holder 3 is shown, but as in another embodiment shown in the front view of the main part in FIG. The conductive holder 13 may have a tapered portion 13a.
In the case of this embodiment, in addition to the same effect as the above embodiment, the magnetic flux interlinking with the detection coil 2 flows parallel to the chamfered surface, so that the direction of the magnetic flux near the magnetic core 1 is less likely to be disturbed. be. Alternatively, a groove 5 for attaching the magnetic core 1 may be provided in the central axis of the columnar conductive holder 14, as shown in the front view of main parts of still another embodiment in FIG. moreover,
In the above embodiment, a pen case 6 is used, but the pen case may not be used, as shown in the front view of FIG. 4, which shows still another embodiment.

[Effect of idea]

As described above, according to this invention, the position of the input tablet is detected by detecting the magnetic field generated by the current flowing through the electrodes formed on the input tablet, in which the magnetic flux generated from the input tablet is passed through. magnetic core,
A conductive holder that is housed in the pencil case and holds the magnetic core; a detection coil that is wound around the magnetic core and detects the magnetic field generated from the input tablet; By providing a lead line that is closely aligned and drawn out to the outside, noise in the lead line can be reduced, and an input pen for an input tablet with high position detection accuracy can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an input pen according to an embodiment of this invention together with an input tablet, Fig. 2 is a front view showing main parts of another embodiment of this invention, and Fig. 3 is a further embodiment of this invention. FIG. 4 is a front view showing still another embodiment of this invention, and FIG. 5 is a sectional view showing a conventional input pen together with an input tablet. In the figure, 1 is a magnetic core, 2 is a detection coil, 3 is a conductive holder, 4 is a lead wire, 6 is a pen case, and 13 and 14 are conductive holders. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) By detecting the magnetic field generated by the current flowing through the electrodes formed on the input tablet,
The device for detecting the position in the input tablet includes a magnetic core that passes magnetic flux generated from the input tablet, a conductive holder that holds the magnetic core, and a conductive holder that is wound around the magnetic core and that is generated from the input tablet. An input pen for an input tablet, comprising a detection coil for detecting a magnetic field, and a lead wire extending from the detection coil to the outside in close contact with the conductive holder. (2) The input pen for an input tablet according to claim 1, wherein the conductive holder has a tapered end on the input tablet side. (3) The input pen for an input tablet according to claim 1, wherein a groove into which a magnetic core is inserted is formed in the input tablet side end of the conductive holder.