JPH07146743A - Ultrasonic coordinate input pen - Google Patents

Abstract

PURPOSE:To improve transmission efficiency and writing touch by turning the transmission surface of a piezoelectric vibrator to a recessed surface whose center is provided near the tip of a pen tip part and applying resin coating on the tip of the pen tip part. CONSTITUTION:This pen is constituted of a shaft body 2, the piezoelectric vibrator 1 and the pen tip part 3 and a driving circuit 6 for driving the piezoelectric vibrator 1 by prescribed pulses is connected to the piezoelectric vibrator 1. For the piezoelectric vibrator 1, electrodes are formed on the front and back of a piezoelectric material such as PZT or the like for instance and the transmission surface 1a is the recessed surface whose center is provided near the tip of the pen tip part 3. Also, the resin coating 5 is applied on the tip of the pen tip part 3. As a coating material, epoxy resin or the like is used. Ultrasonic waves transmitted from the piezoelectric vibrator 1 which is turned to the recessed surface are focused near the tip of the pen tip part 3 and efficiently propagated to a panel surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic coordinate input pen.

[0002]

2. Description of the Related Art In recent years, personal information devices such as personal computers have been remarkably widespread, and accordingly, in addition to widely used input means such as keyboards and mice, interest in pen input has increased. There is.

FIG. 5 shows a conventional example of a coordinate input pen utilizing ultrasonic waves. In this conventional example, the ultrasonic coordinate input pen includes a shaft body 2 serving as a gripping rod, a piezoelectric vibrator 1 driven by a drive circuit 6, and a piezoelectric vibrator 1 having a rectangular parallelepiped shape.
The pen tip portion 3 is made of a material having good ultrasonic wave propagation performance, such as stainless steel.

[0004]

However, the above-mentioned conventional example has the following drawbacks. That is, first, since the transmission surface 1a of the transducer is flat and is not focused by itself, the ultrasonic transmission efficiency is poor.

Secondly, since the pen tip 3 does not attenuate ultrasonic waves and uses a metal material, the writing feel is bad. Thirdly, the driving frequency of the piezoelectric vibrator 1 is
This is due to the influence of higher-order modes of the resonance frequency in the longitudinal direction.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to provide an ultrasonic coordinate input pen having good transmission efficiency. Another object of the present invention is to provide an ultrasonic coordinate input pen having a good writing feel.

[0007]

According to the present invention, the above object is to incorporate a piezoelectric vibrator 1 into a shaft body 2 as shown in FIG.
And a pen tip 3 fixed to the tip of the shaft body 2, and the transmission surface 1a of the piezoelectric vibrator 1 is a concave surface having a center near the tip of the pen tip 3 This is accomplished by providing a pen.

Further, in the invention described in claim 2, the piezoelectric vibrator 1 is provided with radial notches 4, 4 ... And, in the invention described in claim 3, the tip of the pen tip portion 3 is formed. , Resin coating 5 is applied.

Further, in the invention of claim 4, the base end portion of the pen tip portion 3 is formed to have the same curvature as the transmission surface 1a of the piezoelectric vibrator 1.

[0010]

The ultrasonic wave transmitted from the piezoelectric vibrator 1 whose transmitting surface 1a is a concave surface having its center in the vicinity of the tip of the pen tip portion 3 is focused near the tip of the pen tip portion 3, and the panel surface is efficiently formed. Propagated to.

According to the second aspect of the invention, the radial cuts 4 formed in the piezoelectric vibrator 1 are higher-order modes of the resonance frequency in the longitudinal direction (thickness direction) with respect to the drive frequency of the piezoelectric vibrator 1. Remove the effects of

Further, in the invention of claim 3, the resin coating formed at the tip of the pen tip portion 3 provides a smooth operation feeling when the panel is touched by the tip of the pen tip portion 3 and moved. Give to users to improve writing.

In the invention according to claim 4, the pen tip portion 3
Is formed to have the same curvature as the concave surface of the piezoelectric vibrator 1, the pen tip portion 3 is fixed by simply adhering the piezoelectric vibrator 1 in close contact, and the manufacturing is simplified. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. First, FIG. 3 shows an ultrasonic coordinate input device using the ultrasonic coordinate input pen according to the present invention.

The ultrasonic coordinate input device according to this embodiment is
The panel 7 also serves as a display board, piezoelectric sensors 8 (detectors) fixed to the four corners of the panel 7, and arithmetic / control circuits 9 connected to the respective piezoelectric sensors 8, 8.

The panel 7 is made of a material having a good ultrasonic wave propagation performance (when it also serves as a display plate, a transparent body such as glass is used to enhance the visibility of the liquid crystal display surface disposed on the lower surface thereof. When an appropriate position of the panel 7 is touched by the ultrasonic coordinate input pen driven by the driving circuit 6, the ultrasonic wave transmitted from the ultrasonic coordinate input pen is transmitted to the panel. The calculation / control circuit 9 calculates the time required for the piezoelectric sensor 8 to propagate through 7 to reach each piezoelectric sensor 8.
The contact position on the panel 7 is specified by calculating

As shown in FIG. 1, the ultrasonic coordinate input pen has a rod body 2 formed in a rod shape so as to have good operability.
The piezoelectric vibrator 1 and the pen tip 3 are connected to the piezoelectric vibrator 1. A drive circuit 6 for driving the piezoelectric vibrator 1 by a predetermined pulse is connected to the piezoelectric vibrator 1.

The piezoelectric vibrator 1 has electrodes formed on the front and back sides of a well-known piezoelectric material such as PZT, and its transmission surface 1a is a concave surface having a center on the lower side, that is, on the pen tip 3 side. .

Further, in this embodiment, the piezoelectric vibrator 1
2 is provided with a plurality of notches 4, 4, ... Formed on the surface opposite to the transmission surface 1a, as shown in FIG. The notches 4 are provided to eliminate the influence of higher-order modes of the resonance frequency in the longitudinal direction (thickness direction) of the piezoelectric vibrator 1, and are formed so as to divide the piezoelectric vibrator 1 equally and radially. To be done.

When the notch 4 is formed in the piezoelectric vibrator 1, the electrode on the surface where the notch 4 is formed is divided,
Connect wiring to all of the piece-shaped electrodes, or
Consideration is given to driving all the piece electrodes at the same time, such as applying a conductive paste to the surface on which the cuts 4 are formed.

In the embodiment shown in FIGS. 1 and 2, the piezoelectric vibrator 1 is formed with a uniform thickness in order to keep the resonance frequency in the longitudinal direction constant, but as shown in FIG. It is also possible to make only the transmitting surface 1a spherical.

On the other hand, the pen tip 3 is formed in a substantially conical shape with a spherical tip at a tip made of a material that does not attenuate ultrasonic waves sent from the piezoelectric vibrator 1, for example, a metal material such as stainless steel. The directional dimension is set so that the center of the concave surface of the piezoelectric vibrator 1 is aligned with the tip of the pen tip portion 3, and the ultrasonic pulse transmitted from the piezoelectric vibrator 1 described above is forwarded at the tip of the pen tip portion 3. It is made to be scrapped.

The tip of the pen tip 3 is coated with a resin coating 5 in order to improve the writing quality on the panel 7.
Is applied. An epoxy resin or the like is used as the coating material.

Further, the base end portion (conical bottom surface portion) of the pen tip portion 3 is a convex surface having the same curvature as the concave surface of the piezoelectric vibrator 1, and the convex surface is closely attached to the piezoelectric vibrator 1. In this state, it is adhered to the piezoelectric vibrator 1.

[0025]

As is apparent from the above description, according to the present invention, since the piezoelectric vibrator is shaped so as to be focused on the tip, the ultrasonic signal from the piezoelectric vibrator can be reliably transmitted to the panel. And the position detection accuracy can be improved.

Further, the piezoelectric vibrator has radial notches,
When it is inserted, the influence of the higher-order mode of the resonance frequency in the longitudinal direction (thickness direction) of the piezoelectric vibrator can be removed, so that the signal distortion can be prevented and the position detection accuracy can be improved. Can be improved.

Furthermore, if the tip of the pen tip is coated with resin, the discomfort when touching the panel is reduced,
The writing quality can be improved. Also, if the curvature of the interface between the pen tip and the piezoelectric vibrator is the same as the curvature of the concave surface of the piezoelectric vibrator, the adhesion with the piezoelectric vibrator can be improved and the transmitted ultrasonic wave can be attenuated. In addition to being prevented, the manufacturing can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a piezoelectric vibrator, (a) is a plan view,
(B) is a side view.

FIG. 3 is a diagram showing an ultrasonic coordinate input device.

FIG. 4 is a diagram showing a modified example of the present invention.

FIG. 5 is a diagram showing a conventional example.

[Explanation of symbols]

 1 Piezoelectric vibrator 1a Transmission surface 2 Shaft body 3 Pen tip 4 Notch 5 Resin coating

Front Page Continuation (72) Inventor Izuo Anzuo 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited

Claims (4)

[Claims] 1. A piezoelectric vibrator (1) is built-in, and has a shaft body (2) and a pen tip portion (3) fixed to the tip of the shaft body (2). The transmitting surface (1a) is a concave surface having a center near the tip of the pen tip portion (3). 2. The ultrasonic coordinate input pen according to claim 1, wherein the piezoelectric vibrator (1) has radial notches (4, 4, ...). 3. The ultrasonic coordinate input pen according to claim 1, wherein a resin coating (5) is applied to the tip of the pen tip portion (3). 4. The ultrasonic wave according to claim 1, 2 or 3, wherein the base end portion of the pen tip portion (3) is formed to have the same curvature as the transmitting surface (1a) of the piezoelectric vibrator (1). Coordinate input pen.