JPH031212A - Position indicator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a position indicator capable of transmitting information on a designated position as well as information on its operation, that is, change in usage status.

(Prior art) Conventionally, a position indicator transmits information on a specified position and change in its usage status to the tablet side, and parameters other than coordinate values, such as the thickness of a line, the hue of a specified position or area, etc. 2. Description of the Related Art Various coordinate input devices that change density (brightness) and the like are known.

The applicant filed Japanese Patent Application No. 62-208293 (Japanese Unexamined Patent Publication No. 64-5
No. 3223) (hereinafter referred to as the prior application), by exchanging radio waves between the tablet and the position indicator, the specified position by the position indicator can be detected and the state of use of the position indicator can be detected. We proposed a device that can detect changes.

To briefly explain the content of the earlier application, radio waves of a predetermined frequency are transmitted from a loop coil of a tablet, and the radio waves are received by a tuning circuit provided in a position indicator. At this time, the radio waves transmitted from the tuned circuit that received the radio waves are received by the loop coil of the tablet whose transmission of radio waves has been stopped, and an induced voltage is generated. This is sequentially switched and repeated for a plurality of loop coils, and the coordinate values of the designated position by the position indicator are detected based on the level of the induced voltage generated in each loop coil.

Further, the tuning circuit of the position indicator is configured by connecting in series a capacitor and a coil in which a core body equipped with a ferrite chip is accommodated in a manner that can be displaced and restored in the direction of the pen axis, and the tuning circuit for the position indicator is Here, the core is displaced in response to changes in pen pressure, the inductance of the coil changes, and its tuning frequency changes.The change in the tuning frequency is detected as a change in the phase angle of the induced voltage, and this This was designed to detect changes in the usage status of the position indicator.

(Problem to be Solved by the Invention) However, in the position indicator, since the inductance of the coil is changed by the displacement of the ferrite chip, a certain amount of operation stroke is essential, which changes the operator's operating feeling and the actual usage conditions. There was a problem in that the results did not necessarily match, and the result as intended by the operator could not be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a position indicator capable of transmitting information on changes in usage conditions corresponding to an operator's operating feeling.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides a position indicator for a coordinate input device equipped with a tuned circuit consisting of passive elements such as a coil and a capacitor. A first position indicator in which the inductance of the coil changes, and a rod-shaped core around which a coil is wound in the first position indicator are inserted into a pen-shaped body through one axial end of the rod-shaped core. A second position indicator is proposed, in which the second position indicator is fixedly attached so that the axial direction substantially coincides with the casing, and the other end of the core or the pen tip attached to the other end protrudes outside the casing.

(Function) According to the first position indicator, stress is applied to the core in response to changes in usage conditions, and when the inductance of the coil changes thereby, the tuning frequency of the tuning circuit changes.

According to the second position indicator, when the other end of the core or the pen tip is pressed against the input surface of the tablet, stress is applied in the axial direction of the core, but this stress is a force applied along the axial direction of the casing. , that is, it changes according to the writing pressure, and the inductance of the coil also changes according to the writing pressure.

(Embodiment) FIG. 1 shows an embodiment of the position indicator of the present invention.
In the figure, 1 is a housing, 2 is a core, 3 is a coil, 4 is a capacitor, 5 is a housing, and 6 is a pen tip.

The housing 1 is made of a non-metallic material such as synthetic resin.
and a tip cover 1b, both of which are fixed to each other by screwing or the like. Pen barrel 1a
When installing the tip cover 1b, the side has a hollow structure,
A core 2. with a cap-shaped tip cover 1b. coil 3
．． A housing portion 1c for the capacitor 4 and housing 5 is formed. Further, the bottom of the tip cover 1b is provided with a through hole 1d into which the pen tip 6 can be inserted.

The core 2 is formed by forming a well-known ferrite into a hollow cylindrical shape. The coil 3 is made by winding a predetermined number of Litz wires with low high-frequency resistance on the core 2, and both ends of the coil 3 are connected to a capacitor 4 as shown in FIG. 2, forming a well-known series resonance (M) circuit. 7.

The core 2. Coil 3 and capacitor 4 are in housing 5
It is also stored in the storage IC of the housing 1. On this occasion,
One end of the core 2 in its axial direction is connected to the casing 1 via the housing 5 so that its axial direction and the axial direction of the casing 1 almost match.
fixedly mounted on the

The pen tip 6 is integrally formed with a substantially conical main body portion 6a and a substantially cylindrical attachment portion 6b, and is fixedly attached to the other end of the core 2 in the axial direction via the attachment portion 6b. . At this time, the main body portion 6a protrudes to the outside of the housing 1 through the through hole 1d.

Here, if you hold the housing 1 with your hand or the like and press the tip of the main body part 6a of the pen tip 6 against the input surface of the tablet, etc.,
Stress corresponding to the pen pressure at that time is transmitted to the core 2 through the pen tip 6.
added to.

The relationship between the stress and the magnetic permeability of the core 2 is generally as shown below.

μnu Ms2/(K+σλ) ・・・・・・
(1) where μ is magnetic permeability, Ms is saturation magnetization, K is magnetic anisotropy constant, σ is stress, and λ is magnetostriction constant.

On the other hand, the inductance of the coil 3 is expressed as follows.

L-μ・SN2/1 ・・・・・・
(2) However, S is the cross-sectional area of the coil 3, N is the number of turns of the coil 3, and g is the length of the coil 3.

In the above equations (1) and (2), the saturation magnetization Ms, the magnetic anisotropy constant K, the magnetostriction constant λ, and the number of turns N are unchanged,
Furthermore, since the length g of the cross-sectional area S1 can be regarded as almost unchanged, the inductance of the coil 3 depends on the stress σ, and here it changes almost in inverse proportion.

Therefore, as the pen pressure gradually increases from the state of O, the inductance of the coil 3 gradually decreases, and the tuning circuit 7
The tuning frequency at gradually increases.

As described above, according to the embodiment, a stress corresponding to the brush stroke is applied to the core 2 via the pen tip 6, thereby changing the magnetic permeability of the core 2 and changing the inductance of the coil 3. Therefore, the tuning frequency of the tuning circuit 7 changes depending on the writing accuracy, and the change information is transmitted to the tablet or the like. Further, at this time, since the core 2 itself hardly deforms and the operating stroke is approximately O, change information corresponding to the operation electric shock is transmitted.

FIGS. 3(a) and 3(b) show other examples of the core and pen nib in the above embodiment. FIG. 3(a) shows a thin cylindrical core 8 and a pen nib 9 having a fitting recess into which one end of the core 8 can be fitted. Also, Fig. 3(b)
1 shows a thin cylindrical core 10 and a pen tip 11 provided with a mounting portion that can be inserted and fixed to one end of the core 10. These cores and pen nibs are prone to distortion due to stress and change in magnetic permeability.

In addition, in the explanation so far, stress is applied to the core by pressing the pen tip against the human surface of the tablet, but it may also be configured to apply stress with a finger via an operation button provided on the side. Furthermore, the shape of the casing is not limited to a pen shape. Moreover, if a structure is adopted in which stress is more easily applied to the core, a large change in magnetic permeability can be obtained with a smaller force.

(Effects of the Invention) As explained above, according to the present invention, there is provided a position indicator for a coordinate human power device equipped with a tuned circuit consisting of passive elements such as a coil and a capacitor. As a result, the tuning frequency of the tuning circuit can be changed by the stress that corresponds to changes in usage conditions, and it is possible to transmit information on changes in usage conditions to tablets, etc. along with information on specified positions. Since the core hardly deforms, it is possible to transmit information on changes in usage conditions that correspond to the operator's intentions, and since there is no need for moving parts like in the past, the structure is simple and can be provided at low cost.

Further, according to the present invention, a rod-shaped core around which a coil is wound is fixedly attached in a pen-shaped body through one end in the axial direction so that the axial direction substantially coincides with the other end of the rod-shaped core. Since the pen tip attached to the end or the other end protrudes outside the housing, when the other end of the core or the pen tip is pressed against the input surface of the tablet, stress corresponding to the pen pressure at that time is applied to the axis of the core. As the inductance of the coil changes and the tuning frequency changes, information corresponding to the pen pressure can be transmitted to a tablet or the like.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the position indicator of the present invention;
2 is a circuit diagram of a tuning circuit in the position indicator of FIG. 1, and FIGS. 3(a) and 3(b) are sectional views showing other examples of the core and the pen tip. ...Housing, 2...Core, 3...Coil, 4...Capacitor, 6...Nib, 7...Tuned circuit. Patent applicant Wacom Co., Ltd.

Claims (2)

[Claims] (1) A position indicator for a coordinate input device equipped with a tuned circuit consisting of passive elements such as a coil and a capacitor, characterized in that the inductance of the coil changes depending on the stress applied to the core. indicator. (2) A rod-shaped core around which a coil is wound is fixedly installed in a pen-shaped housing through one axial end of the rod-shaped core so that the axial direction substantially coincides with the other end of the core, or the other end of the core. 2. The position indicator according to claim 1, wherein a pen tip attached to the pen protrudes outside the housing.