JP2014063317A - Stylus pen and touch panel system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a change in writing pressure of a stylus pen to a capacitive touch panel without limiting a material and shape of a pen tip of the stylus pen.SOLUTION: A stylus pen (10) includes a pen shaft (11) and a conductive pen tip (12). The pen shaft (11) includes a cylindrical grip part (21) gripped by a user. The grip part (21) has conductivity, is electrically connected with a shaft core part (32) of the pen tip (12) through a conductive ring (14), and is an elastic body.

Description

  The present invention relates to a stylus pen and a touch panel system used for a capacitive touch panel.

  The touch panel is provided on the display screen of the display device, and detects the position on the display screen designated by the pen tip of the stylus pen, the user's finger, etc. (hereinafter referred to as “pen tip etc.”). It is a position input device that outputs position information. By using this touch panel, handwriting input by the pen tip or the like is possible.

  Among the touch panels, a capacitive touch panel that detects a position of the pen tip on the touch panel by detecting a change in capacitance between the pen tip and the conductive film of the touch panel. However, it has become popular in recent years. This touch panel is prominently mounted on, for example, mobile phones, smartphones, tablet terminals, and the like. With the spread of the touch panel, further improvement of handwriting input is required.

  For example, in the stylus pen for a touch panel described in Patent Document 1, the pen tip portion includes a pen core portion and a conductive sponge provided around the pen core portion. The contact surface between the pen tip and the capacitive touch panel includes the contact surface of the pen core and the touch panel, and the conductive sponge and the contact surface of the touch panel around the contact surface. Yes.

  According to the above configuration, input to the touch panel can be performed with a feeling close to that of handwriting on paper using a mechanical pencil, a ballpoint pen, or the like. In addition, the user can predict at which position on the contact surface between the pen tip of the stylus pen and the conductive film of the touch panel the input is performed. Furthermore, it is possible to reduce the friction when writing on the touch panel with the stylus pen and to make the user slide.

  In addition, in the information input pen described in Patent Document 2, the fiber bundle constituting the tip of the pen tip is bound to the porous by a synthetic resin adhesive in which synthetic fibers or natural fibers are bundled and a conductive material is mixed, It is fixed to the tip of the shaft body. As a result, the detection position is not shifted by the writing pressure, the sliding during the sliding operation is good, and an input that does not damage the panel surface is possible.

  In addition, in the capacitive touch pen described in Patent Document 3, the input tip is composed of a tapered fiber, and the surface of the tapered fiber is coated with a conductive resin. Further, the input tip is composed of a fiber bundle converged on the tapered fiber. As a result, from the input pad, analog input, that is, input that draws while changing the line width from a very thin drawn line to a thick line full of the brush width, such as drawn with a brush and paintbrush, etc. When “stop” or “bounce” is performed, it is possible to input a drawn line that is very unpredictable and randomly drawn.

  In addition, an input pen for a capacitive touch panel described in Patent Document 4 includes a substantially cylindrical pen body and a pen tip inserted at the tip of the pen body. At least a portion of the pen body that the user holds is made of a conductor, and the pen tip is formed of a water-absorbing material having open cells, for example, a cellulose sponge. The pen tip and the pen body are electrically connected. Thereby, it is possible to provide the input pen for the touch panel with good writing feeling and few input mistakes.

  As described above, in Patent Documents 1 to 4, the stylus pen tip shape and the like are devised to improve the sliding property between the pen tip and the capacitive touch panel, and the pen tip and the touch panel. This makes it easy to detect changes in the contact area. Thereby, the operability of the stylus pen is improved and the touch pressure of the touch panel is realized.

JP 2012-053681 A (published March 15, 2012) JP 2012-108895 A (released on June 07, 2012) JP 2012-108894 A (released on June 07, 2012) JP 2012-027689 A (released on Feb. 09, 2012)

  In the case of Patent Documents 1 to 4, the change in the contact area between the pen tip of the stylus pen and the capacitive touch panel is made to correspond to the change in writing pressure between the pen tip and the touch panel. For this reason, it is necessary to use a material that can be flexibly deformed and restored, such as a conductive sponge, a conductive fiber bundle, and a cellulose sponge, for example. As a result, there is a problem in durability because the nib is worn or the restoring property is deteriorated. In addition, the material of the nib is limited.

  The present invention has been made in view of the above problems, and its object is to detect a change in the writing pressure of the stylus pen relative to the touch panel without limiting the material and shape of the pen tip of the stylus pen. To provide a stylus pen.

  A stylus pen according to an aspect of the present invention is a stylus pen used in a capacitive touch panel, and includes a conductive pen tip and a pen shaft in order to solve the above problem. The pen shaft is provided with a grip portion that is gripped by a user, and the grip portion is an elastic body.

  According to one aspect of the present invention, when the stylus pen is pressed against the capacitive touch panel, the grip portion of the stylus pen is recessed, the internal impedance of the stylus pen is reduced, and the stylus pen is moved from the touch panel. As a result, the amount of current flowing to the user increases, and the amount of change in capacitance increases. Therefore, by examining the amount of change, it is possible to detect a change in the writing pressure of the stylus pen on the touch panel without limiting the material and shape of the pen tip.

It is sectional drawing which shows the structure of the stylus pen which concerns on one Embodiment of this invention. It is a perspective view which shows the detection principle of the touch in a projection capacitive touch panel. It is sectional drawing which shows the detection principle of the touch in the said touch panel using the said stylus pen. It is a graph which shows the variation | change_quantity of the electrostatic capacitance in the said touch panel. It is sectional drawing which shows the structure of the stylus pen which concerns on other embodiment of this invention. It is sectional drawing which shows the structure of the said stylus pen.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the structure of the stylus pen according to the present embodiment. The stylus pen according to the present embodiment is used for a projected capacitive touch panel.

(Structure of stylus pen)
As shown in FIG. 1, the stylus pen 10 of this embodiment has a configuration in which a pen tip 12 is attached to one end 20 of a cylindrical pen shaft 11 via an insulating rubber 13. Near the one end portion 20 of the pen shaft 11, there is a grip portion 21 that the user grips when using the stylus pen 10. The pen shaft 11 and the pen tip 12 are conductors formed from materials such as copper, aluminum, conductive rubber, and conductive resin.

  The nib 12 is a rounded cone. The base end portion 30 of the pen tip 12 is formed with a notch portion 31 at the periphery so as to be fitted to the one end portion 20 of the pen shaft 11. Further, an axial core portion 32 extends from the center of the base end portion 30 along the rotation axis A of the pen shaft 11 and the pen tip 12. The shaft core portion 32 penetrates the grip portion 21 of the pen shaft 11, and the tip portion 33 of the shaft core portion 32 is fixed to the pen shaft 11 by the conductive ring 14. The shaft core portion 32 of the pen tip 12 and the grip portion 21 of the pen shaft 11 are separated from each other and are electrically connected via the conductive ring 14. The tip 34 of the nib 12 is preferably rounded so as not to damage the surface of the touch panel.

  In the present embodiment, the grip portion 21 is formed thinner than other portions of the pen shaft 11. Thereby, the holding part 21 has flexibility (elasticity). Therefore, when the gripping portion 21 is pressed from the outside to the inside by a user's finger or the like, the gripping portion 21 is bent and the gripping portion 21 and the shaft core portion 32 come into contact with each other. Thereby, since the holding part 21 and the axial center part 32 are electrically connected, the impedance in the stylus pen 10 decreases. As a result, a change in the writing pressure of the stylus pen 10 with respect to the touch panel 40 can be detected. The reason will be described below.

(Touch detection principle on touch panel)
2 and 3 are a perspective view and a cross-sectional view showing the principle of detection of touch in a projected capacitive touch panel. Note that FIG. 2 shows the capacity formed by each member, and FIG. 3 shows the lines of electric force.

  As shown in FIGS. 2 and 3, the projected capacitive touch panel 40 is formed by forming transparent electrode patterns 41 and 42 in a matrix shape on a transparent substrate such as glass or plastic using ITO (Indium Tin Oxide) or the like. It is a thing. The transparent electrode patterns 41 and 42 include a plurality of drive electrodes 41 arranged along one of the x-axis direction and the y-axis direction, and a plurality of reception electrodes 42 arranged along the other. 2 and 3, the transparent substrate is omitted.

  When the stylus pen 10 contacts or approaches the touch panel 40 configured as described above, the capacitance between the drive electrode 41 and the reception electrode 42 in the vicinity thereof changes. This point will be specifically described with reference to FIGS.

  FIG. 3A shows a state where the stylus pen 10 is not present near the touch panel 40. In this case, the capacitance formed in the vicinity of the position (intersection) where the drive electrode 41 and the reception electrode 42 intersect includes a parasitic capacitance Ct0 between the drive electrode 41 and the ground, a parasitic capacitance Cr0 between the reception electrode 42 and the ground, The capacitance Ctr between the drive electrode 41 and the reception electrode 42.

  FIG. 3B shows a state where the stylus pen 10 is in contact with or close to the touch panel 40. In this case, the capacitance formed in the vicinity of the intersection is not only the parasitic capacitance Ct0 · Cr0 and the capacitance Ctr, but also the capacitance Ctp between the drive electrode 41 and the stylus pen 10, and the interval between the reception electrode 42 and the stylus pen 10. Capacitance Crp and the parasitic capacitance Cp0 between the stylus pen 10 and the ground via the user are formed, so that the overall capacitance changes.

  Therefore, by specifying the drive electrode 41 and the reception electrode 42 where the change in capacitance is detected, it is possible to specify the position on the touch panel 40 where the stylus pen 10 has touched or approached. The change in capacitance can be detected by examining the delay amount between the pulse signal driven by the drive electrode 41 and the pulse signal received by the reception electrode 42.

In the stylus pen 10 shown in FIG. 3B, the internal impedance Z from the tip 34 where the touch panel 40 contacts to the grip portion 21 gripped by the user is expressed by the following equation. Here, Z 1 is the impedance of the pen tip 12, Z 2 is the impedance of the conductive ring 14, and Z 3 is the impedance of the pen shaft 11.
Z = Z1 + Z2 + Z3 (1).

FIG. 3C shows a state in which the stylus pen 10 is pressed against the touch panel 40. In this case, since the user grips and tightens the stylus pen 10, the grip portion 21 of the stylus pen 10 is bent by the user's finger, and the grip portion 21 and the shaft core portion 32 come into contact with each other to be electrically connected. Become. As a result, the internal impedance Z from the tip 34 with which the touch panel 40 contacts to the gripping part 21 gripped by the user is represented by the following formula when the shaft core part 32 and the gripping part 21 are short-circuited.
Z = Z1 + Z3 (1).

  Accordingly, since the impedance Z from the tip 34 to the grip portion 21 decreases, the amount of current flowing from the stylus pen 10 via the user increases, and as a result, the amount of change in the overall capacitance (detection signal for detecting) is increased. Will increase. Therefore, by checking the amount of change in the capacitance, it is possible to detect the strength of the writing pressure of the stylus pen with respect to the touch panel 40.

  FIG. 4 is a graph showing the amount of change in capacitance in the touch panel 40. (A) of the figure has shown the normal state, and respond | corresponds to the state of (b) of FIG. 3 in which the holding part 21 is not bent. On the other hand, (b) of the figure shows a gripped state, and corresponds to the state of (b) of FIG. 3 where the grip portion 21 is bent. The x component and y component in the figure indicate the position coordinates of the touch panel 40, and the z component in the figure indicates the amount of change in capacitance. Referring to the figure, it can be understood that the amount of change in capacitance increases about twice as much in the state of gripping than in the normal state.

  Then, when the user tries to stop pressing the stylus pen 10 against the touch panel 40, the user stops stopping the grip part 21. As a result, the gripping portion 21 is elastically returned to the state shown in FIG. As a result, the amount of change in capacitance is restored.

  As described above, by using the stylus pen 10 of the present embodiment for the capacitive touch panel 40, it is possible to detect the two-stage writing state. Moreover, the stylus pen 10 excellent in durability and operability can be provided.

  In the present embodiment, the interior of the pen shaft 11 is hollow, but may be filled with a conductive substance such as a conductive liquid, a conductive sponge, or a conductive rubber. In this case, the impedance Z4 between the shaft core portion 32 of the pen tip 12 and the grip portion 21 of the pen shaft 11 gradually decreases as the grip portion 21 bends. The internal impedance Z from the tip 34 that contacts to the grip portion 21 gripped by the user gradually decreases. Therefore, a continuous change in the writing pressure of the stylus pen with respect to the touch panel 40 can be detected by examining the amount of change in the capacitance.

  When the conductive material is filled, it is desirable that the impedance Z2 of the conductive ring 14 is larger than the impedance Z4 through the conductive material in a normal state where the grip portion 21 is not bent. Further, the material of the gripping part 21 and the material of the conductive substance may be the same. Further, an insulating ring may be provided instead of the conductive ring 14.

  Moreover, in this embodiment, although the axial core part 32 is provided in the stylus pen 10, the axial core part 32 may be abbreviate | omitted. Even in this case, since the impedance of the space between the pen tip 12 and the gripping portion 21 decreases due to the bending of the gripping portion 21, the amount of change in capacitance increases. Therefore, a change in the writing pressure of the stylus pen with respect to the touch panel 40 can be detected by examining the amount of change in the capacitance.

  In the present embodiment, the pen shaft 11 is cylindrical, and the pen tip 12 is a rounded cone. That is, the shape of the cross section taken along a plane perpendicular to the rotation axis A of the stylus pen 10 is a circle, but the shape of the cross section is not limited to this, and may be, for example, a hexagon or a rectangle.

[Embodiment 2]
Next, another embodiment of the present invention will be described with reference to FIGS. 5 and 6 are sectional views showing the structure of the stylus pen according to the present embodiment. The stylus pen 110 of this embodiment is different from the stylus pen 10 shown in FIG. 1 in that a pen shaft 111 is provided instead of the pen shaft 11, the insulating rubber 13, and the conductive ring 14. Other configurations are the same. In addition, the same code | symbol is attached | subjected to the structure which has the function similar to the structure demonstrated in the said embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 5, the pen shaft 111 has a cylindrical shape and is fitted to the base end portion 30, the notch portion 31, and the shaft core portion 32 of the pen tip 12. Near the one end 120 of the pen shaft 111, there is a grip 121 that the user grips when using the stylus pen 110.

  In the present embodiment, at least the grip portion 121 of the pen shaft 111 is an elastic body and an insulator formed from a material such as insulating rubber or insulating resin. Accordingly, when the grip portion 121 is pressed from the outside by the user's finger 50, the pressed portion is recessed as shown in FIG. As a result, the distance between the user's finger 50 and the shaft core portion 32 of the nib 12 is shortened, so that the internal impedance Z of the stylus pen 110 is reduced. As a result, as described above, a change in the writing pressure of the stylus pen 110 with respect to the touch panel 40 can be detected.

  Accordingly, the holding portion of the stylus pen may be a hollow conductor as shown in FIG. 1 as long as it is electrically insulated from the pen shaft in a normal state, or as shown in FIGS. An intermediate insulator may be used.

(Additional notes)
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  For example, in the above-described embodiment, the projected capacitive touch panel 40 is used, but the present invention can also be applied to a surface capacitive touch panel.

[Summary]
A stylus pen according to one embodiment of the present invention is a stylus pen used in a capacitive touch panel, and includes a conductive pen tip and a pen shaft, and the pen shaft is gripped by a user. A grip portion is provided, and the grip portion is an elastic body.

  When the stylus pen having the above configuration is brought into contact with or close to the capacitive touch panel, the impedance between the touch panel and the ground of the stylus pen is set as an impedance between the touch panel and the ground. The internal impedance between the pen tip and the gripping part and the parasitic capacitance between the gripping part and the ground via the user are newly formed, and the overall capacitance between the touch panel and the ground changes. . Therefore, by detecting the change in the overall capacitance, it is possible to specify the position on the touch panel where the stylus pen touches or approaches.

  More specifically, when the stylus pen contacts or approaches the touch panel, a current flows from the transmission electrode of the touch panel to the stylus pen and the user side, thereby flowing from the transmission electrode of the touch panel to the reception electrode. The amount of current is reduced. Therefore, by amplifying a decrease (difference) in the amount of current flowing through the receiving electrode as a detection signal, the position on the touch panel where the stylus pen is in contact or approached can be specified.

  Further, when the stylus pen is pressed against the touch panel, the user applies force to the finger with the grip portion of the stylus pen, and the grip portion is pressed and recessed. This reduces the internal impedance of the stylus pen. Accordingly, the amount of current flowing to the stylus pen and the user side is further increased, and the amount of current flowing to the receiving electrode is further decreased. As a result, the magnitude of the detection signal indicating the decrease increases.

  Thereafter, in order to release the pressure on the touch panel with the stylus pen, when the user releases the pressure on the grip portion, the grip portion is elastically restored, so that the magnitude of the detection signal is returned. . Therefore, a change in the writing pressure of the stylus pen with respect to the touch panel can be detected by examining the amount of change in the magnitude of the detection signal.

  Therefore, it is possible to detect a change in the writing pressure of the stylus pen relative to the touch panel without limiting the material and shape of the pen tip. As a result, the pen nib does not need to have a flexible shape, so that there is no problem with durability. Further, the material and shape of the pen tip can be given flexibility.

  In the stylus pen according to one aspect of the present invention, it is preferable that the pen tip includes a conductive shaft core portion extending to the inside of the grip portion. In this case, since the internal impedance between the pen tip and the grip portion in the stylus pen is lowered, the amount of current flowing to the stylus pen and the user side is increased, and the amount of current flowing to the receiving electrode is decreased. Therefore, the magnitude of the detection signal indicating the decrease is increased, so that the position on the touch panel where the stylus pen touches or approaches can be detected well.

  In the stylus pen according to one aspect of the present invention, the grip portion may be a hollow conductor. In addition, when the said nib is provided with the said axial center part, it is preferable that the front-end | tip of this axial core part and the said holding part are electrically connected via the electroconductive member (conductive ring). In this case, since the internal impedance of the stylus pen is further reduced, the magnitude of the detection signal is further increased, and as a result, the position on the touch panel where the stylus pen touches or approaches can be detected better. Can do.

  Moreover, when the said nib is provided with the said axial center part, it is preferable that the said axial core part and the said holding part do not contact normally, but will contact when the said holding part dents. In this case, since the gripping portion and the shaft core portion are short-circuited due to the deformation of the gripping portion, the internal impedance of the stylus pen is significantly reduced, and the magnitude of the detection signal is significantly increased. As a result, the change in the writing pressure can be easily detected.

  Moreover, when the said nib is provided with the said axial center part, the electroconductive substance may be filled between the said axial center part and the said holding part. In this case, since the impedance between the grip portion and the shaft core portion gradually decreases as the grip portion is recessed, the magnitude of the detection signal gradually increases. As a result, a continuous change in the writing pressure can be detected.

  In the stylus pen according to one aspect of the present invention, the grip portion may be an insulator of a clog. Even in this case, when the grip portion is recessed, the electrostatic capacity in the stylus pen increases and the internal impedance of the stylus pen decreases, so that the change in the writing pressure can be detected.

  In addition, if it is a touchscreen system provided with an electrostatic capacitance type touchscreen and the stylus pen of the said structure used for this touchscreen, there can exist an effect similar to the above-mentioned.

  As described above, in the stylus pen according to the present invention, when the grip portion of the stylus pen is recessed, the internal impedance of the stylus pen decreases and the amount of change in capacitance increases. By examining, it is possible to detect a change in the writing pressure of the stylus pen with respect to the touch panel without limiting the material and shape of the pen tip. Therefore, the present invention can be applied not only to the projection type but also to any capacitive type touch panel such as a surface type.

10/110 Stylus pen 11/111 Pen shaft 12 Pen tip 13 Insulating rubber 14 Conductive ring 20/120 End portion 21/121 Grip portion 30 Base end portion 32 Axial core portion 33 Tip portion 34 Tip 40 Touch panel 41 Drive electrode 42 Receiver electrode

Claims (5)

A stylus pen used in a capacitive touch panel,
It has a conductive pen tip and a pen shaft,
The pen shaft includes a grip portion that a user grips,
The stylus pen, wherein the gripping portion is an elastic body.   The stylus pen according to claim 1, wherein the pen tip includes a conductive shaft core portion extending to the inside of the grip portion.   The stylus pen according to claim 1, wherein the grip portion is a hollow conductor.   The stylus pen according to claim 1, wherein the gripping part is an insulator of a fortress. A capacitive touch panel,
A touch panel system comprising the stylus pen according to any one of claims 1 to 4, which is used for the touch panel.

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