JPH03214217A - Stylus pen - Google Patents

Abstract

PURPOSE:To accurately detect the pressing force of a stylus pen with a minute displacement of an indicator by interlocking rotatably a plate spring between the indicator and the other end of a case, and providing a strain gauge to the plate spring. CONSTITUTION:When a contact is secured between the tip of an indicator 2 and an optional point on the tablet surface, the force is applied in the lengthwise direction of a plate spring 5 in accordance with the contact force. Thus the spring 5 has a malformation and therefore a strain gauge 6 also has a malformation. Then the gauge 6 detects the value accordant with the contact pressure. Meanwhile the spring 5 itself and then the gauge 6 have virtually no malfunction when the force rectangular to the lengthwise direction of the spring 5 is applied to a stylus pen. Then no force is detected in the rectangular direction and only the contact pressure is detected. Thus it is possible to detect the pressure with high accuracy with a minute moved variable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stylus pen used in a coordinate detection device.

[Prior Art] A coordinate detection device (digitizer) has a tablet on which a large number of detection conductors are stretched in a predetermined size and shape, and when an operator indicates an arbitrary point on the tablet with a cursor or a stylus pen. , is a device that detects and stores the coordinates of the indicated point. The above-mentioned instruction with the cursor or stylus pen is made not only by drawing a line on the tablet, but also by drawing a line on the tablet, and in this case, the coordinates thereof are stored as a number of points. When giving instructions by drawing such lines, it is preferable to use a stylus pen whose external shape is similar to ordinary military writing instruments such as ballpoint pens and pencils.

An electromagnetic means such as a coil is built into the case constituting the stylus pen, and when this electromagnetic means is excited, an ffl mark at a point indicated by the stylus pen is detected.

In recent years, when using such a stylus to give instructions, it has been proposed to detect the pressure when the stylus is brought into contact with the tablet and use this pressure data to perform a specific function. There is. For example, when drawing a gland on the tablet 1, attempts have been made to determine the thickness of the line according to the pressing force of the stylus pen. This pressure detection mechanism is composed of a coil, a core that is connected to the tip of the stylus pen and moves within the coil, and a spring that biases the core. The pressing force of the stylus pen is detected by moving the stylus inside the coil to change the inductance of the coil and extracting the change in inductance.

[Problems to be Solved by the Invention] By the way, in order to accurately detect the magnitude of pressure in the stylus pen equipped with the pressure detection mechanism described above, it is necessary to adjust the amount of movement of the core, that is, the tip of the stylus pen in contact with the tablet. The amount of axial movement of the tip of the stylus must be considerably large, but if the amount of axial movement of the tip of the stylus pen is large, fluctuations during use will also be large, making it difficult to use as a stylus pen. .

An object of the present invention is to provide a stylus pen that can accurately detect pressure with a small amount of movement.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a stylus pen for indicating an arbitrary point on a tablet in which a large number of external mark detection conductors are connected. case and
an indicator protruding from one end of the case and brought into contact with the surface of the tablet; a spring mounted between the indicator and the inner wall of the case; It is characterized by comprising a leaf spring mounted between the other end and rotatably engaged with each end, and a strain gauge provided at a predetermined location of the leaf spring. .

[When the tip of the action indicator comes into contact with any point on the surface of the tablet, a force corresponding to the contact pressure is applied in the length direction of the leaf spring, causing deformation of the handling spring. As a result, the strain gauge is also deformed, and a value corresponding to the contact pressure is detected. On the other hand, when a force is applied to the stylus pen in a direction perpendicular to the above direction, the leaf spring itself hardly deforms;
The strain gauge also hardly deforms, so the force in the perpendicular direction is not detected, and only the contact pressure can be detected.

[Example code] Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1(a) is a side sectional view of a stylus pen according to an embodiment of the present invention, and FIG. 1(b) is a line Ib shown in FIG. 1(a).
It is a sectional view along -Ib. In each case, 1 is an elongated case made of synthetic resin, 1a is a hollow part of the case 1, 1b is a through hole drilled in the center of the right end wall of the case 1, and 1c is a shoulder formed in the right end wall. . 2 is an indicator inserted into the through hole 1b of the case 1, 2a is the tip of the indicator 2 protruding from the case 1, 2b is the collar of the indicator 2 located in the hollow part 1a of the case 1, and 2c is the indicator This is a 7-shaped groove formed on the other end of 2. 3 is the shoulder of case 1] C and indicator 2
It is a coil spring mounted between the collar 2b and the indicator 2, and urges the indicator 2 to the left in the figure.

4 is a holder fixed to the right end wall of the case 1, and 4a is a 7-shaped groove formed at the tip of the holder 4.

Reference numeral 5 denotes a leaf spring, which is mounted between the figure 7-shaped 'd42c of the indicator 2 and the figure 7-shaped groove 4a of the holder 4. With this configuration, a small pressure of the coil spring 3 is applied to the release spring 5, thereby preventing it from falling off from each J2c and 4a. In other words, the release spring 5 is only pressed into engagement with the grooves 2c and 4a with a small pressure. This leaf spring 5 has both end portions 5a and a central portion 5b raised upward from the both end portions 5a in FIG. 1(a). 6 indicates strain gauges attached to both sides of the central portion 5b. The strain gauge 6 generates strain due to deformation, and changes its resistance value in accordance with the strain. Note that in the illustrated stylus pen, illustration of the electromagnetic means described above is omitted.

Next, the operation of the fifth embodiment will be explained with reference to FIGS. 2 and 3. These figures 2 and 3 are similar to figure 1 (a
) is the same side sectional view as that shown in FIG. 1(a), and the same parts as shown in FIG. Now, when the operator holds this stylus pen and indicates any point on the tablet using the tip 2a of the indicator 2, the tip 2a
In Fig. 2, align the axis of the tablet (-
A pressing force is generated in the direction (dotted chain line). As a result, the indicator 2 is displaced as shown by the broken line against the spring force of the leaf spring 5, and as a result, the leaf spring 5 is deformed as shown by the broken line. Along with this, the strain gauges 6 are also deformed, the strain gauges 6 on the upper surface elongate and the strain gauges 6 on the lower surface contract, and the resistance value of each strain gauge 6 changes accordingly.

By detecting changes in these resistance values with a detection circuit (not shown), it is possible to detect the pressing force acting on the tip 2a of the indicator 2, that is, the pressure with which the operator presses the stylus pen. Since changes in the resistance value of the strain gauge can be detected sensitively even when the strain gauge is slightly deformed, there is no need to displace the indicator 2 by a large amount.

This detected pressure is used in a purposeful manner in a control unit consisting of a computer.

For example, in addition to using it to determine the line thickness mentioned above, when an operator draws a character on a tablet, the pressing force of each part when the character is drawn is used to It becomes possible to display and print the characters on a printer or the like as if they were drawn with a brush.

By the way, as mentioned above, it is desirable that the stylus pen be similar in shape, size, and weight to a normal writing instrument. For this reason, a ladle with high rigidity is used for detection 1,
It is not possible to increase the thickness of the case 1, and the case 1 must necessarily be formed using a thin synthetic resin or the like.

Therefore, when a force in a direction perpendicular to the axial direction of the stylus pen is applied to the stylus pen, the case of the stylus pen is easily deformed. If the vertical component force is detected due to such deformation, a force unrelated to the stylus pen's pressing force will be detected as the pressing force, making it impossible to accurately detect the pressing force. Become.

However, with the configuration of this embodiment, it is possible to prevent the vertical component force from being detected by the strain gauge 6. This will be explained with reference to FIG. Now, arrow B is drawn on the stylus pen of this embodiment.

Assume that a force is applied in a direction perpendicular to the axis as shown by B'. At this time, the case 1 is deformed as shown. However, the leaf spring 5 has seven grooves 2c.

Since the leaf spring 5 is only engaged in line contact with the leaf spring 5
can be tilted freely within the plane of the drawing paper.

Therefore, even if the case 1 of the stylus pen is deformed as shown in FIG.
The strain gauge itself undergoes almost no deformation, the strain gauge 6 also does not deform, and the force in the vertical component is not detected. Also, the third
Even if a force component perpendicular to the plane of the paper acts in the figure, since this direction is the width direction of the leaf spring 5, the rigidity of the leaf spring 5 against the force component in this direction is high, and the leaf spring 5, and therefore the strain gauge 6, has a high rigidity. Almost no deformation occurs.

In this way, in this example, a leaf spring is installed between the two grooves in the shape of a 7-shape, and a strain gauge is attached to this leaf spring, so that the stylus pen can be adjusted by a minute movement of the indicator. The pressing force can be accurately detected. Furthermore, even if a force in the vertical direction acts on the axis of the case, the force in the vertical direction will not be detected because both ends of the leaf spring are engaged with the figure 7-shaped grooves. , it is possible to prevent this force from appearing as noise.

In the description of the above embodiment, an example was described in which the indicator and the holder are engaged with the leaf spring by line contact engagement using a 7-shaped groove formed in the indicator and the holder. It is also possible that both ends of the spring are pointed and the grooves of the indicator and holder are conical grooves for point contact engagement. Also, it is clear that the gauge can be attached to only one side.

[Effects of the Invention] As described above, in the present invention, a leaf spring is rotatably engaged between the indicator and the other end of the case, and a strain gauge is provided on the leaf spring.

The pressing force of the stylus pen can be accurately detected by minute displacements of the indicator.

[Brief explanation of drawings]

1(a) and (b) are side sectional views and plan sectional views of a stylus pen according to an embodiment of the present invention, and FIGS. 2 and 3 are stylus pens shown in FIGS. 1(a) and 3(b). It is a side sectional view explaining operation of a pen. 1...Case, 2...Indicator, 2G...
...Groove, 3...Coil spring, 4...Holding body,
4a...groove, 5...temporary spring, 6...strain gauge. Figures (a) (b)

Claims (2)

[Claims] (1) A stylus pen that indicates an arbitrary point on a tablet to which a large number of coordinate detection conductors are stretched, including an elongated hollow case, and an indicator that protrudes from one end of the case and is brought into contact with the surface of the tablet; A spring is mounted between the indicator and the inner wall of the case, and a spring is rotatably engaged between an end of the indicator and the other end of the case within the case. A stylus pen characterized by comprising a leaf spring mounted on the plate and a strain gauge provided at a predetermined location of the leaf spring. (2) In claim (1), the leaf spring has both end portions that engage with the respective end portions, and is formed continuously with the both end portions and extends in a direction perpendicular to the axial direction thereof with respect to the both end portions. 1. A stylus pen comprising: a central portion having a misalignment and having the strain gauge provided thereon;