JPS60134929A - Input pen of input tablet device - Google Patents

Abstract

PURPOSE:To attain a high output without intensifying the magnetic field from the surface of an input plate or increasing the diameter of winding and the number of turns of a detecting coil at the tip, by providing a transformer for amplification in an input pen. CONSTITUTION:When the surface of an input plate 19 is depressed with the tip of a penholder 10, a switch mechanism 13 is turned on. A transformer 15 for amplification is attached to a printed board 14. Primary and secondary coils are lap-wound around a ferrite core in the transformer 15. An induced electromotive force is generated in a detecting coil 11 by the magnetic field which is generated by an AC current to lattice-shaped conductor narrow wires 20a and 20b provided in the input plate 19. This voltage is amplified by the transformer 15 for amplification to obtain a voltage where influences of noise from the external can be ignored even if the voltage is connected to the circuit of an input tablet body by a shield line 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an input tablet 1 used as a terminal device when inputting characters, figures, etc. to a processing device such as a combi coater.
-Relates to the input pen of the device.

Conventional configuration and problems Conventionally, in input tablet devices, multiple thin conductor wires are arranged under the surface of the input plate so that they are orthogonal to each other, and the orthogonal thin conductor wires are not electrically connected. An alternating current is supplied to these thin conductor wires to generate a magnetic field. By placing the detection coil in this generated magnetic field, an induced electromotive voltage is generated in the detection coil. If the supplied alternating current is passed through different thin conductor wires one after another, the position of the generated magnetic field on the input plate surface will be different, and if this is detected by a detection coil, the position, that is, the coordinates on the input plate surface, can be known. can.

At this time, the coil that detects the magnetic field generated on the surface of the input plate is usually an air-core coil, which is constructed by winding copper wire around a bobbin or the like. FIG. 1 shows a cross-sectional view of an example of a conventional input pen. In the figure, a pen shaft 2 is numbered inside a pen case 1. A detection coil 3 is provided at the tip of the pen case 1 to generate an induced electromotive force in response to the magnetic field generated by the input plate 7. When the tip of the pen barrel 2 is pressed against the input plate 7, it is pushed by the switch mechanism holding part 4 provided at the rear end of the pen barrel 2, turning on the switch mechanism part 5, and the detection coil 3 is turned on.
is connected to another circuit (not shown) by a shielded wire 6, and the signal entering the detection coil 3 is sent to this other circuit. Note that under the surface of the input plate 7, thin conductor wires 8a and 8b are provided in a grid pattern so as to cross each other at right angles so that there is no electrical contact with each other.
By passing an alternating current through the input pen 3b, an induced electromotive voltage is generated in the detection coil 3 of the input pen. The detection coil 3 is usually provided at the tip of the input pen.

The reason is that the voltage induced in the detection coil 3 by the magnetic field generated from the surface of the input plate 7 can be detected as efficiently as possible. Another reason is that if the detection coil 3 is too far away from the surface of the input plate 7, the strength of the magnetic field generated by the thin conductor wires 8a and 8b provided at different positions will be lost, causing misunderstandings in coordinate detection. To become.

The voltage value induced in the detection coil provided at the tip of the input pen is determined by the strength of the magnetic field generated from the input plate surface, the distance between the input plate and the detection coil, and the number and diameter of the coil. In order to obtain a high voltage value, the magnetic field generated from the input plate surface should be strengthened, the detection coil should be placed as close to the input plate surface as possible,
It is necessary to increase the winding diameter of the coil (5) and increase the number of turns per coil. ■ Increasing the magnetic field generated from the input plate surface will increase the alternating current flowing through the thin conductor wire, and the input tablet This is not a good solution as it increases the power consumption of the device.

■ Bring the detection coil close to the input plate surface,
Increasing the winding diameter of the coils and increasing the number of windings makes the tip of the input pen thicker, which has the disadvantage of making it difficult to see the trajectory of the tip of the input pen when inputting data, making it difficult to handle.

Purpose of the Invention The present invention aims to further increase the number of windings of the detection coil installed at the tip of the input pen without increasing the magnetic field generated from the surface of the input plate and without increasing the winding diameter of the detection coil. The purpose of this is to obtain high output without any problems.

Structure of the Invention The input pen of the input tablet 1m according to the present invention is provided with a detection coil at or near the tip thereof to obtain an induced electromotive force by a magnetic field generated from the input plate of the input tablet device, and the induced electromotive force is This system is equipped with a transformer that amplifies the input plate, and it is possible to increase the size of the pen without increasing the size of the pen by increasing the magnetic field generated from the input plate surface or increasing the number of turns of the coil. ]j can be obtained.

Description of examples The present invention will be explained below based on illustrated embodiments.

FIG. 2 is a side view showing an embodiment of the present invention together with an input brake 1. In the figure, 9 is a hollow pen case, and a detection coil 11 is provided at the tip thereof. Reference numeral 10 denotes a pen shaft extending from inside the tip of the pen case 9 in the axial direction. When the tip of this pen shaft 1O presses against the surface of the input plate 19, the switch mechanism 13 provided in the lower part of the pen case 9 is activated via the switch holding part 12 provided at the rear end of this pen shaft 1O. Turns on, and the self-powered pen enters the operating state.

A printed circuit board 14 is provided inside the pen case 9 above the switch mechanism 13.
An amplification transformer 15 is attached to the. This amplifying transformer 15 has a configuration in which a primary coil and a secondary coil are wound around a ferrite core.

- Both ends of the next coil are connected to both ends of the detection coil 11 wound around the tip of the pencil case 9 through terminals 1G and 16a. Further, the secondary coil is connected to the end of the shield 1a18 pulled out from the pencil case 9 and the terminals 16b, 1.
6c). An amplification transformer 15 is provided inside a shield 17 placed inside the pencil case 9. The shield 17 is the ground wire 21 of the shield wire 18
is connected to. Further, the terminal 1GO is also connected to the ground wire 21. Reference numeral 19 denotes an input plate, on which conductor thin wires 20a and 20b are arranged in a grid pattern.

According to such a configuration, an induced electromotive voltage is generated in the detection coil 11 due to a magnetic field generated by an alternating current flowing through the grid-like thin conductor wires 20a and 20b installed in the input plate 19. A transformer 15 for amplifying this voltage
By amplifying the input voltage, the voltage becomes a voltage that is not affected by noise received from the outside even when connected to the circuit of the input tablet main body using the shielded wire 18.

Next, an experimental example will be explained. That is, here, the diameter of the pen shaft 1o in FIG.
75uvn, a repen shaft 10 is attached to the tip of the pencil case 9.
The protruding length was set to 1.5 cylinders. An input pen was created by changing the coil diameter and number of turns, and connecting an amplification transformer 15 to the coil. A urethane-coated copper wire with a diameter of 70 μm was used as the winding wire. Under these conditions, an alternating current is applied to the grid-like thin conductor wires 20a and 20b of the input plate 19, the pen tip of each input pen made is brought into contact with the surface of the input plate 19, and the detection coil is Set so that the radial direction of 11 is parallel to the input plate 19 surface,
The output voltage of each input pen was measured.

In the input tablet i~ device using the input pen of the present invention, the required output voltage of the input pen is when the coil winding diameter is φ3#, the number of coil turns is 409 mm, and the amplifying transformer 15 is not used. is equal to the cutting edge voltage. Therefore, using this as a measurement standard, I investigated how much the amplification degree of lance 15 for amplification should be changed in order to obtain the standard output voltage when changing the winding diameter and number of turns of coil 11. . The results are shown in Figure 3.

In the figure, A indicates the case where the number of turns of the coil is 40 turns, B is 15 turns, and C is 10 turns, and the transformer amplification required to adjust the standard output voltage as the coil winding diameter changes. showed degree. In addition, the broken line indicates that the input pen according to the embodiment of the present invention is configured by the combination of the coil winding diameter, the number of turns, and the amplification degree of the transformer on the left side of the broken line in the graph. This is the limit line that makes it easier to see the trajectory of the tip of the pen when inputting data.This broken line is based on human sensory standards, and is not necessarily an absolute one. However, in order to make the tip of the pen easier to see, it is necessary to reduce the diameter of the coil and reduce the number of turns.

Generally, there are various methods of amplifying voltage, but in the present invention, the frequency of the induced electromotive force in the coil is relatively high at 1.8 MHz, the voltage value is low at several μV to several tens of μV, and the signal processing circuit and They are far apart (approximately 11 rL),
Since the pen is used for input purposes and needs to be moved freely, there is a risk that it will be greatly affected by external noise if the voltage remains low. Therefore, it is desirable to amplify the signal inside the pen as close as possible to the detection coil, and amplification using a transformer is most effective.

The minimum value of the winding diameter of the coil of the pen tip is determined by the thickness of the pen shaft and the required diameter of the tip of the pen case.

This also depends on the material of the pen barrel. That is,
Even if it is thin, it can be made thinner if it has strong mechanical strength, but if it is not thin, the thickness must be determined to be more suitable for the material. In the embodiment of the present invention, a stainless steel rod with a diameter of 1.5 m was used. In this case, in order to press the pen tip against the input plate and safely maintain the mechanical strength of the tip of the pen case, the maximum coil winding diameter is approximately φ25. The appropriate number of coil turns at this time was 15 turns. If the number of turns of the coil is too small, the influence of external noise between the coil and the connection to the amplification transformer will be large, so there is a limit to the number of turns, and 1O
It is not appropriate to make it less than a turn.

In addition, since the amplification transformer has a ferrite core and a primary coil and a secondary coil wound around it, it is possible to use materials that do not resonate up to the frequency of the induced electromotive force in the detection coil. is necessary.

Effects of the Invention As described above, according to the input pen of the input tab reflex 1 to device according to the present invention, by providing an amplification transformer inside the pen, the winding diameter of the detection coil installed at the tip of the pen can be adjusted. It is small and allows you to obtain the desired output level even with a small number of windings.In addition, the tip of the pen was previously thick and you could not see the movement of the tip of the pen shaft when inputting, making it difficult to handle. However, according to the present invention, the pen tip can be easily seen, making it easier to handle. Furthermore, by changing the amplification degree of the amplification lance 1 to lance, the induced electromotive voltage can be increased and outputted without changing the thickness of the pen tip, which is very effective.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example of an input pen along with input plate 1, Fig. 2 is a sectional view showing an embodiment of the human-powered pen of the present invention together with an input plate, and Fig. 3 is a sectional view showing a conventional example of an input pen with input plate. FIG. 3 is a diagram showing the required amplification degree of the transformer according to the winding diameter and number of windings of the detection coil, based on the embodiment of the present invention. 10... Pen shaft, 11... Detection coil, 15...
Transformer Figure 1 Figure 3 Output carp JL winding diameter 't/)mm)

Claims (1)

[Claims] 1. A detection coil is provided at or near the tip to obtain an induced electromotive force due to the magnetic field generated from the input plate of the input tablet device, and a transformer is provided to amplify this induced electromotive force. A pen for an input tablet device characterized by: 26 The magnetic material used for the transformer is Fukolai 1-, and the practical frequency range includes 1.8 MHz [for input of the input tablet device according to claim 1] pen.