JP2014063443A - Pen type input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pen type input device capable of allowing a user to input with an excellent inputting feeling irrespective of the material of an input plane.SOLUTION: A stylus includes: a long main body 2; a pen front end 5 disposed at the front end in a longitudinal direction of the main body 2; a coil 7 disposed to provide a magnetic field to the pen front end 5; and a power supply circuit board 8 to apply a pulse current to the coil 7. The pen front end 5 has a MR fluid 51 and a flexible container 50 storing the MR fluid 51. The container 50 is partially exposed to the outside. The viscosity of the MR fluid 51 in the container 50 changes depending on the changes of the magnetic field generated by the coil 7 according to the changes of the pulse current value. The pen front end 5 reversibly changes the hardness thereof between a first hardness and a second hardness different from each other.

Description

  The present invention relates to a pen-type input device, and more particularly to a technique for adjusting a force sense.

Display devices equipped with a touch panel, such as portable information terminals, automatic ticket vending machines, and ATMs, are widespread. There is a stylus (pen-type input device) as a pointing device (I / F) for a user to intuitively operate the input surface of these display devices. The stylus includes a long main body and a pen tip provided at the tip of the main body.
Usually, hard glass, for example, is disposed on the input surface of the display device in order to maintain display quality and protect the input surface from damage due to stylus contact. On the other hand, the nib portion of a general stylus is made of a hard material.

Therefore, when the user uses the stylus, the hard pen tip portion and the input surface come into contact with each other. For this reason, as a user's input sensation, there may be a case where the user feels a sense of incongruity considerably as compared to the writing sensation of a combination of paper and a writing instrument.
Therefore, several techniques for adjusting the input sensation (force feedback) of the stylus have been proposed. As an example, a shaft hole is provided in the pen tip portion, and a ball is disposed inside the shaft hole via an elastic body so that the ball in contact with the input surface is retreatably retracted into the shaft hole according to the user's writing pressure. There is a configuration in which the elastic force is applied. In this case, a configuration is also proposed in which a plurality of input surfaces are arranged on the display, mat particles are dispersed on each input surface so that the surface roughness is different, and the user can select a favorite input surface ( Patent Document 1).

As another example, a mechanism has been proposed in which a coil spring is used as an elastic body that elastically biases a ball, and the compression rate of the coil spring is adjusted stepwise (Patent Document 2).
In addition, the shaft body is inserted into the pen tip portion, and an electrorheological (ER) fluid is arranged so as to surround the shaft body inside the main body portion, and the viscosity is electrically adjusted to allow the shaft body to be moved in and out of the pen tip portion. The structure which controls a grade is also proposed (patent document 3).

JP 2004-220506 A JP 2009-129168 A JP 07-31650 A

However, the stylus input sensation of any of the above-described techniques is still far apart from the writing sensation of a combination of paper and writing instruments, and a stylus with a sufficient input sensation has not been realized.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a pen-type input device that can input with an excellent input feeling regardless of the material of the input surface.

  In order to solve the above-described problem, a pen-type input device according to one aspect of the present invention includes a long main body, a pen tip disposed at one end in the longitudinal direction of the main body, and a magnetic field at the pen tip. A coil portion arranged to extend, and a power supply circuit for applying a pulse current to the coil portion, and the nib portion includes a magnetorheological fluid and a storage container for storing the magnetorheological fluid The containment vessel is made of a flexible material and is disposed so that a part thereof is exposed to the outside, and the viscosity of the magnetorheological fluid changes due to a change in the magnetic field generated in the coil portion when the pulse current is applied. Therefore, the pen tip portion has a configuration in which the hardness of the pen tip portion reversibly changes to a first hardness and a second hardness, which are different from each other.

According to the pen-type input device in the above aspect, the hardness of the pen tip portion having the storage container storing the magnetorheological fluid is the first hardness or the second hardness due to the magnetic field change of the coil portion accompanying the change of the pulse current. Changes reversibly.
Therefore, when the user presses the pen tip portion against the input surface of the display device, a minute vibration accompanying the change in hardness of the pen tip portion is transmitted to the user's hand. Such input feedback is close to the writing sensation experienced by the writer when writing on the paper with a writing instrument, and is obtained regardless of the material of the input surface.

  Therefore, it is possible to provide a pen-type input device that can input with an excellent input feeling regardless of the material of the input surface of the display.

1 is an external view of a stylus 1 according to Embodiment 1. FIG. 2 is an internal configuration diagram of a stylus 1. FIG. It is a schematic diagram which shows the mode before and after the magnetic field application of MR fluid. 1 is a circuit diagram of a stylus 1. FIG. 6 is a timing chart of the potential V ₃ , the input state and output state of the flip-flop, and the on / off states of the transistors TR ₁ and TR ₂ . Time t ₀ ~t circuit diagram showing a current flow between the _two and between time t ₃ ~t ₄ and (a), up to ~t ₅ post from between and time t ₄ to ~t ₃ post from time t ₂ It is a circuit diagram (b) which shows the flow of the electric current between. 6 is a timing chart of a pulse voltage V _L applied to the coil unit 7, a pulse current I _L flowing through the coil unit 7, a pulse magnetic field intensity H generated in the coil unit 7, and a hardness change of the pen tip unit 5. FIG. 5A is a diagram showing a state of the pen tip portion 5 at the time of the first hardness (high hardness), and FIG. 5B is a diagram showing a state of the pen tip portion 5 at the time of the second hardness (low hardness). . It is a graph which shows the analysis result of the unevenness | corrugation which exists in a notebook paper surface. It is a graph which shows the spatial frequency distribution of the unevenness | corrugation of a notebook paper surface. It is a graph which shows the result of having Fourier-transformed the spatial frequency distribution of the unevenness | corrugation of a notebook paper surface. FIG. 4 is a schematic diagram (a) showing an operation when tracing a paper surface with a pen, and a schematic diagram (b) showing an operation when tracing an input surface with a stylus 1. FIG. 6 is a graph showing the relationship between the power supply and the pressure in the containment vessel when MR fluid (Example) and ER fluid (Comparative Example) are used as the fluid in the containment vessel. 6 is a circuit diagram of a stylus according to Embodiment 2. FIG. 6 is a circuit diagram of a stylus according to Embodiment 3. FIG. 14 is an external view of a display device 150 with a stylus according to a fourth embodiment. FIG. 6 is a circuit diagram of a display device 150 with a stylus according to a fourth embodiment. FIG. 10 is an external view of a stylus 1B according to Embodiment 5. FIG. FIG. 10 is a circuit diagram of a stylus according to a fifth embodiment. 10 is a control flow of a stylus setting mode according to a fifth embodiment. 14 is an external view of a stylus 1C according to Embodiment 6. FIG.

<Aspect of the Invention>
A pen-type input device according to an aspect of the present invention includes a long main body, a pen tip disposed at one end in the longitudinal direction of the main body, and a coil disposed so that a magnetic field extends to the pen tip. And a power supply circuit for applying a pulse current to the coil unit, the pen tip unit includes a magnetorheological fluid and a storage container for storing the magnetorheological fluid, and the container is flexible It is composed of a material and is arranged so that a part thereof is exposed to the outside, and the viscosity of the magnetorheological fluid changes due to the change of the magnetic field generated in the coil part with the application of the pulse current, The configuration is such that the hardness changes reversibly between a first hardness and a second hardness, which are different from each other.

Here, in another aspect of the present invention, the frequency of the pulse current may be in the range of 62.5 Hz to 525 Hz.
In another aspect of the present invention, the main body has a holding portion that holds the end of the main body portion on the other end side in the longitudinal direction inside the main body, and the coil portion is wound around the holding portion. It can also be set as the structure which is rotated.

In another aspect of the invention, the power supply circuit may include a current control unit that converts a power supply current into the pulse current.
In another aspect of the invention, the current control unit may include a timer IC.
In another aspect of the invention, the current control unit may include a microcomputer.

In another aspect of the invention, the power supply circuit may include a regulator circuit.
In another aspect of the present invention, the pulse current converted by the current control unit may be an alternating current.
In another aspect of the present invention, the magnetorheological fluid may include metal particles, a surfactant, and a fluid medium.

In another aspect of the present invention, the metal particles are at least one of magnetite and manganese zinc ferrite, and the fluid medium is at least one of water, isoparaffin, alkylnaphthalene, perfluoropolyether, and polyalphaolefin. You can also
In another aspect of the present invention, the storage container may be made of a resin material.

In this case, the resin material may be at least one of polypropylene, polyethylene, nylon, and cyclic polyolefin.
<About One Aspect of the Present Invention>
The inventors of the present invention diligently studied the stylus input sensation, and found that the writer gained good writing comfort when writing on a paper surface such as a notebook surface using a writing instrument. Detailed analysis of the shape of the notebook paper revealed that there were minute irregularities that repeated at regular intervals.

Therefore, in the pen-type input device according to one aspect of the present invention, a storage container in which a magnetorheological fluid is stored is disposed at the pen tip portion, and a coil portion is disposed so that a magnetic field reaches the storage container. During driving, a pulse current is supplied to the coil portion to generate a magnetic field, and the hardness of the pen tip portion is reversibly changed between the first hardness and the second hardness as the magnetic field strength changes.
According to the pen-type input device having such a configuration, for example, when the user presses the pen tip portion against the input surface, the user feels repulsion from the input surface when the hardness of the pen tip portion is the first hardness, In the case of the second hardness, a sense of sinking into the input surface is obtained. By repeating the first and second hardness changes of the nib portion, minute vibrations are transmitted to the user's hand, and it is possible to realize a good writing comfort (input feedback) as if writing on a paper surface with a writing instrument. Since this effect is achieved by the pen-type input device itself regardless of the material of the input surface, it is not necessary to change the surface characteristics of the input surface as in Patent Document 1, and can be obtained on the input surface of any material. .

The magnetic viscous fluid is superior in responsiveness (viscosity change amount) to the supplied electric power as compared with the magnetic fluid, the electrorheological fluid described in Patent Document 3, and the like. Therefore, the hardness change of the pen tip can be ensured by using the magnetic viscous fluid. Thereby, even if there is some variation in the perception that the user feels comfortable, it is possible to experience a good writing comfort.
Further, the pen-type input device according to the invention of one aspect of the present invention does not require a complicated adjustment mechanism for adjusting the compression rate of the coil spring in stages as in Patent Document 2, A magnetic viscous fluid that is relatively easily available is used, and a current supply circuit can be configured using a commercially available control IC, a one-chip microcomputer, or the like. For this reason, it can manufacture with the same production cost as the past, and has a big advantage in terms of feasibility.
<Embodiment 1>
Hereinafter, embodiments of the present invention will be described. Of course, the present invention is not limited to the following embodiments, and can be appropriately changed without departing from the technical scope of the present invention.
(External configuration of stylus 1)
An external configuration of a pen-type input device (hereinafter referred to as “stylus 1”) according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is an external view of the stylus 1.

The stylus 1 includes a long body part 2, a tip case part 3 disposed at one end in the longitudinal direction of the body part 2, and a knob part 23 disposed at the other end in the longitudinal direction of the body part 2. The pen tip portion 5 is partially exposed from the tip of the tip case portion 3. Openings 83 and 84 are provided on the rear end side of the main body 2, and the charging terminals 27 and 28 are exposed from the openings 83 and 84. Further, a switch unit 26 for turning on / off the power supply of the stylus 1 is provided.
(Internal configuration of stylus 1)
The internal configuration of the stylus 1 will be described with reference to FIG. FIG. 2 is a developed view (composition diagram) showing the internal configuration of the stylus 1.

The stylus 1 includes a main body part 2, a tip case part 3, a knob part 23, a spacer 24, a pressure sensitive adjustment part 4, a power supply circuit board 8, and a power supply part 9.
The pressure-sensitive adjustment unit 4 includes a nib unit 5, a container holding unit 6, and a coil unit 7.
As shown in FIG. 2, the internal structure of the stylus 1 is stored in the storage space 32 in the tip case 3 while the storage container 5 is partially exposed to the outside. Further, the power supply circuit board 8 and the power supply unit 9 are stored in the storage space 25 in the main body 2.

Hereinafter, each component of the stylus 1 will be described in order.
[Main unit 2]
The main body 2 is a cylindrical shaft body, and is made of, for example, a metal material such as aluminum or a resin material such as ABS resin. Openings 21 and 22 are provided in the same order on one end side and the other end side in the longitudinal direction of the main body 2. A female screw portion 211 that can be screwed with the male screw portion 31 of the front end case portion 3 is provided inside the opening portion 21, and a protrusion 29 is erected at the back of the female screw portion 211.
[Knob 23]
The knob part 23 is made of the same material as that of the main body part 2 as an example, and is arranged rotatably around the axis of the stylus 1 in the opening 22 of the main body part 2. The knob portion 23 is connected to the adjustment shaft of the variable resistance element R ₂ of the power supply circuit board 8 on the storage space 25 side, and when the user rotates the knob portion 23 around the axis of the main body portion 2, the variable resistance element R ₂ The resistance value can be adjusted.
[Switch section 26]
The switch portion 26 is made of an elastomer member such as synthetic rubber, and protrudes from the side surface of the main body portion 2 so as to communicate with the storage space 25. The switch unit 26 contacts the push switch 88 of the power supply circuit board 8 on the storage space 25 side, and the push switch 88 can be turned on / off every time the user presses the switch unit 26.
[Front case part 3]
The tip case part 3 is a case member having a hollow dome shape, and is made of, for example, the same material as that of the main body part 2. The tip case portion 3 has an opening 30 that exposes one end (the pen tip portion 50A) of the storage container 50, and a storage space 32 that stores the pressure-sensitive adjustment portion 4 therein.
[Spacer 24]
The spacer 24 is a disk-shaped plate having an outer diameter matched to the inner diameter of the main body 2 and is made of an insulating member such as a resin material. The spacer 24 is positioned between the protrusion 29 of the main body portion 2 and the inner peripheral surface of the tip case portion 3, and supports the container holding portion 6 and the coil portion 7 of the pressure sensitive adjustment portion 4 from the rear end side so as to support the tip case portion 3. Secure inside. Two holes 240 are provided on the surface of the spacer 24, and the conductive wires 71 and 72 of the coil portion 7 are inserted into the power supply circuit board 8 through the holes 240.
[Pressure-sensitive adjustment unit 4]
The pressure-sensitive adjusting unit 4 includes a pen point unit 5, a container holding unit 6, and a coil unit 7.

The pen tip portion 5 includes a storage container 50 and a magnetic viscous fluid 51 that is densely stored inside the storage container 50.
(i) Containment container 50
The storage container 50 is a cylindrical container whose inside is kept secret, and is made of a material having a certain flexibility, such as a resin material, which can transmit a magnetic field and is softer than the main body 2. As the resin material, at least one of polypropylene, polyethylene, nylon, and cyclic polyolefin can be used. One end of the storage container 50 in the longitudinal direction (the pen tip portion 50A) is a part that contacts the input surface of the display device. The other end portion in the longitudinal direction (rear end portion 50 </ b> B) is a portion that is housed and held in the container holding portion 6.

In addition, the nib part 50A of the storage container 50 is configured by a member having a certain hardness (for example, a ceramic member or a hard plastic member), and thus the wear resistance of the storage container 50 during use can be improved.
Further, the pen tip portion 50A may be formed of a member (for example, a silicone resin member or an elastomer member) having a constant coefficient of friction and the writing resistance at the time of input can be adjusted. However, it should be noted that if a soft material is used, a change in hardness of the pen tip portion 5 during use may be attenuated or broken.

(ii) Magnetic viscous fluid 51
The magnetic viscous fluid 51 (hereinafter referred to as “MR fluid 51”) is a non-colloidal solution containing metal particles, a surfactant, and a fluid medium. The metal particles have a particle size of about 1 to 10 μm, and are, for example, fine particles of at least one of magnetite and manganese zinc ferrite. As the fluid medium, for example, at least one of water, isoparaffin, alkylnaphthalene, perfluoropolyether, poly-α-olefin, and silicone oil can be used. A surfactant that can be dissolved in a selected fluid medium can be used.

  The ratio of the metal particles in the MR fluid 51 can be adjusted as appropriate. However, when a magnetic field is applied to the storage container 50 from the outside, at least the hardness of the pen tip 5 can be experienced. It is desirable to include a quantity of metal particles. As an example, the ratio of the metal particles is preferably about 15 vol% or more and about 20 vol%, but is not limited to this. As the commercially available MR fluid 51, for example, “softMRF” manufactured by (Kurimoto Steel Corporation) can be used. Alternatively, the MR fluid 51 can be produced using hydrocarbon oil (such as salad oil) as the fluid medium and iron powder as the metal particles. It should be noted that the MR fluid 51 should be stored densely so that bubbles and the like do not enter the storage container 50.

Here, FIG. 3A is a schematic diagram showing the state of the MR fluid 51 before application of the magnetic field, and FIG. 3B is a schematic diagram showing the state of the MR fluid 51 after application of the magnetic field.
When there is no magnetic field, the metal particles are dispersed in the MR fluid 51 (FIG. 3A). Since the metal particles are not connected to each other, the MR fluid 51 has a relatively low viscosity and is in a sol state having a small yield stress. The containment vessel 50 is easily deformed when pressure is applied from the outside, and the apparent hardness is low.

  On the other hand, when a magnetic field is applied to the storage container 50 from the outside, the metal particles dispersed inside the MR fluid 51 are arranged and connected in the direction of the magnetic field to form a chain cluster (FIG. 3B). )). Accordingly, the MR fluid 51 is in a gel state having a relatively high viscosity and a large yield stress. The containment vessel 50 is not easily deformed even when pressure is applied from the outside, and the apparent hardness is increased.

The sol-gel transition of the MR fluid 51 can be reversibly performed with good responsiveness by controlling on / off of the magnetic field applied to the MR fluid 51.
(iii) Container holding part 6
The container holding part 6 is a bottomed cylindrical container that houses and holds the other end part 50 </ b> B of the storage container 50 and is disposed as a bobbin of the coil part 7. The container holder 6 is made of a hard material that can transmit a magnetic field and has a certain hardness. As this material, a resin material is suitable, and examples thereof include ABS resin, PC resin, and styrene resin. The container holding part 6 may hold the storage container 50 by forced fitting. Moreover, you may adhere | attach the container holding | maintenance part 6 and the storage container 50 with an adhesive agent.

(iv) Coil part 7
The coil part 7 is means for applying a magnetic field to the inside of the storage container 50, and a coil body 70 formed by winding a conducting wire around the outer periphery of the container holding part 6 with a fixed number of turns, and a conducting wire 71 extended from the coil body 70. , 72. The conducting wires 71 and 72 are electrically connected to the connecting portions 81 and 82 of the mounting substrate 80 by solder welding in the same order.

As shown in FIG. 2, when the stylus 1 is viewed from the whole, the coil body 70 is wound around the container holding portion 6 around the stylus 1 in the longitudinal (Y) direction. Therefore, according to Fleming's right method rule, the direction of the magnetic field generated in the coil section 7 is the same as the longitudinal (Y) direction of the stylus 1.
[Power supply unit 9]
The power source unit 9 is a power source for supplying power to the coil unit 7, and is a DC power source using a lithium ion secondary battery here. The positive electrode terminal and the negative electrode terminal of the power supply unit 9 are electrically connected to lead members 85 and 86, respectively, and the power of the power supply unit 9 can be supplied to the coil unit 7 via the power supply circuit board 8. In the power supply circuit board 8, the power supply unit 9 is disposed so as to be chargeable from the outside via charging terminals 83 and 84.
[Power supply circuit board 8]
Power supply circuit board 8 includes a mounting substrate 80, and the control IC87, and the push switch 88, and a variable resistance element R _2.

The mounting substrate 80 includes a substrate body made of a composite material such as a glass-epoxy material, an NPN-type pulse current control transistor TR ₁ (hereinafter simply referred to as “transistor TR ₁ ”) mounted on the substrate body, and a surge. absorbing diode D _1, the resistance element R _1, and a respective element such as a capacitor C ₁ (see FIG. 4). Further, the mounting substrate 80 includes connection portions 81 and 82 and lead members 85 and 86.
[Control IC 87]
The control IC 87 is a known timer IC and is used for the purpose of generating a magnetic field by supplying a pulse current from the power supply unit 9 to the coil unit 7.

An inexpensive commercially available IC can be used as the control IC 87. For example, “LMC555” manufactured by National Semiconductor Corporation can be used.
(Circuit configuration of stylus 1)
The circuit configuration of the stylus 1 will be described with reference to FIG. FIG. 4 shows an equivalent circuit of the coil unit 7, the power supply circuit board 8, and the power supply unit 9.

A wiring 100 is connected to the positive side of the power supply unit 9 and a wiring 101 is connected to the negative side. Between the wirings 100 and 101, the first circuit unit 8A, the second circuit unit 8B, and the third circuit unit 8C are connected in parallel.
The first circuit portion 8A includes a resistance element R ₁ , a variable resistance element R ₂ , and a capacitor C ₁ connected in series from the wiring 100 side in the same order. The variable resistance element R ₂ is used for frequency adjustment of a signal output from the output (OUT) terminal of the control IC 87.

The second circuit portion 8B includes a control IC 87 in which the Vcc terminal is connected to the wiring 100, and the GND terminal is connected to the wiring 101.
The third circuit section 8C includes a coil unit 7, a transistor TR _1, and a surge absorption diode D1 which are connected. From the wiring 100 side, the coil portion 7 and the collector and emitter of the transistor TR1 are connected in series in the same order. The surge absorbing diode D ₁ is connected between both ends of the coil portion 7.

A push switch 88 is disposed between the connection of the power supply unit 9 and the wiring 100 upstream of the circuit units 8A to 8C on the positive electrode side.
Power supply circuit board 8, as a current control unit for converting the supply current from the power supply unit 9 to the pulse current, the first circuit portion 8A, the second circuit section 8B, and a transistor TR _1.
The control IC 87 includes three resistor elements R ₃ , R ₄ and R ₅ connected in series, a comparator comp1 having a − terminal connected between the resistor elements R ₃ and R _{4, and} between the resistor elements R ₄ and R _5. The comparator comp2 is connected to the + terminal, the output terminal of the comparator comp1 is connected to the R terminal, the output terminal of the comparator comp2 is connected to the S terminal, and the NPN is connected to the Q bar terminal of the flip-flop FF. Type discharge transistor TR ₂ (hereinafter simply referred to as “transistor TR ₂ ”).

The resistive element R ₃ is connected to the Vcc terminal, and the resistive element R ₅ is connected to the GND terminal. The collector of the transistor TR ₂ is connected to the discharge (DIS) terminal. The positive terminal of the comparator comp1 is connected to a threshold (THR) terminal, and the negative terminal of the comparator comp2 is connected to a trigger (TRG) terminal. Q terminal of the flip-flop FF is connected to the OUT terminal of the control IC87, OUT terminal is connected to the base of the transistor TR _1.

The collector side of the transistor TR ₂ is connected between the resistance element R ₁ and the variable resistance element R ₂ of the first circuit portion 8A via the DIS terminal. The emitter of the transistor TR ₂ is grounded.
(Power supply circuit operation)
The operation of the power supply circuit will be described with reference to FIGS. Hereinafter, the potential of the negative terminal of the comparator comp1 is referred to as “V ₁ ”, the potential of the positive terminal of the comparator comp1 is referred to as “V ₂ ”, and the potential between the variable resistance element R ₂ and the capacitor C ₁ is referred to as “V ₃ ” ( (See FIG. 4).

FIG. 5 is a timing chart of voltage V ₃ , input and output of the flip-flop FF, and ON / OFF of the transistors TR ₁ and TR ₂ . 6 between time t ₀ ~t _2, the circuit diagram showing the flow of current between the time t ₃ ~t ₄ and (a), until ~t ₃ rear than time t _2, the rear than the time t ₄ ~t FIG. 6B is a circuit diagram (b) showing a current flow up to ₅ .
(1)
Immediately after power is turned on by the push switch 88 (t = t ₀ ), the flip-flop FF has the Q terminal at H (High), the Q bar terminal at L (Low), and the transistor TR ₂ is in the off state. Accordingly, the current I ₁ flows through the capacitor C ₁ through R ₁ and R ₂ (FIG. 6A).

Immediately after the power is turned on, the capacitor C ₁ has no charge, and V ₃ rises from 0 (V). Since V ₃ is lower than V ₂ of the comparator COMP2, the S terminal of the flip-flop FF is H. As a result, the Q terminal is H and the Q bar terminal is L. On the other hand, the positive terminal of the COMP1 is lower than V _1, the output of the comparator COMP1 is L, and R terminal of the flip-flop FF is stable in L.
(2)
After a fixed time has elapsed from time t ₀ (t = t ₁ ), when V ₃ exceeds V ₂ of the comparator COMP2, the output of the comparator COMP2 becomes L, but the state of the flip-flop FF does not change. When V ₃ further rises and reaches V ₁ of the comparator COMP1 (t = t ₂ ), the output of the comparator COMP1 becomes H. As a result, the R terminal becomes H, the output state of the flip-flop FF is inverted, the Q terminal becomes L, and the Q bar terminal becomes H. At this time, OUT changes from H to L. Since the transistor TR ₂ is turned on and the junction of R ₁ and R ₂ is grounded, the current I ₁ that has been flowing to C ₁ through R ₁ and R ₂ until now does not flow to the capacitor C ₁ . Further, the electric charge accumulated in the capacitor C ₁ becomes a current I ₂ and flows out through the variable resistance element R ₂ and the transistor TR ₂ , and the capacitor C ₁ is discharged (FIG. 6B). As a result, V ₃ decreases, and the voltage at the + terminal of the comparator COMP1 becomes V ₁ or less in a short time. As a result, the R terminal immediately changes from H to L, but the output state of the flip-flop FF does not change.
(3)
After time t ₂ , the capacitor C ₁ is discharged through the transistor TR _{2 in the} on state, and the voltage of V ₃ drops. When V ₃ becomes equal to or lower than V ₂ of the comparator COMP2 (t = t ₃ ), the output of the comparator COMP2 becomes H and the S terminal also becomes H. As a result, the Q terminal changes to H and the Q bar terminal changes to L. When the Q bar terminal becomes L, the transistor TR ₂ is turned off, and the discharge of the capacitor C ₁ is stopped. In addition, a current flows through the capacitor C ₁ via R ₁ and R ₂ and charging starts immediately after the discharge is stopped (FIG. 6A). As a result, V ₃ rises, and the output of the comparator COMP2 becomes L in a short time.

Thereafter, by repeating the operation from time t ₁ to t ₃ , a rectangular wave pulse signal is output from the Q terminal at a cycle T ₀ . As a result, the transistor TR ₁ repeats the on / off operation at the cycle T ₀ , and the pulse voltage V _L and the pulse current I _L are applied from the power supply unit 9 to the coil unit 7 during the on operation. The period T ₀ is a value on the order of several milliseconds, for example.
When using “LMC555” manufactured by National Semiconductor Corporation as the control IC 87, the oscillation frequency f (= 1 / T ₀ ) can be calculated by the following relational expression (formula 1).

(Formula 1): f = 1.44 / {(2r ₁ + 2r ₂ ) · c ₁ }
Here, r ₁ and r ₂ are the resistance values of R ₁ and R ₂ , respectively, and c ₁ is the capacitance of the capacitor C ₁ .
The time Th when the Q terminal is H can be calculated by the following relational expression (formula 2).
(Formula 2): Th = 0.593 × (r ₁ + r ₂ ) × c ₁
Here, r ₁ , r ₂ , and c ₁ have the same meanings as in Formula 1.

In the stylus 1, by adjusting the resistance values r ₁ and r ₂ of the resistance element R ₁ and the variable resistance element R ₂ and the capacitance c ₁ of the capacitor C ₁ , the frequency f (1 / T _{0) is} set as a default value. ) Is set in the range of 62.5 Hz to 525 Hz, and the on-duty ratio (Th / T ₀ ) is 40%. Further, when the stylus 1 is driven, the user turns the knob unit 23 to change the resistance value of the variable resistance element R ₂ , so that the frequency f (1 / T ₀ ) and the on-duty ratio of the pulse current can be set according to the user's preference. Can be adjusted.
(Operation of stylus 1)
Next, the operation of the stylus 1 will be described with reference to FIG. FIG. 7 shows the pulse voltage (V _L ) applied from the power supply unit 9 to the coil unit 7 by the on / off operation of the transistor TR ₁ , the pulse current (I _L ) flowing through the coil unit 7, and the magnetic field strength ( 6 is a timing chart of each waveform of H) and hardness change of the pen tip portion 5.

User Power on Press switch unit 26, the transistor TR ₁ is turned on at a frequency f (1 / T _0), the rectangle having a constant on-duty ratio according to the frequency f (1 / T ₀₎ The pulse voltage V _L is applied to the coil unit 7 (FIG. 7A). As a result, a pulse current I _L flows through the coil section 7 (FIG. 7B). The peak of the pulse current I _L is slightly delayed from the peak of the pulse voltage V _{L due to} the inductance of the coil section 7.

When the pulse current I _L is applied to the coil unit 7, a magnetic field is generated in the coil unit 7 in synchronization with the application timing of the pulse current I _L (FIG. 7C). The magnetic field strength H is proportional to the current strength according to Ampere's law. Thus the waveform of the magnetic field intensity H is a pulse waveform which varies in synchronization with the pulse current I _L.
When a magnetic field is generated in the coil section 7, the viscosity of the MR fluid 51 is rapidly increased (FIG. 3B), and the apparent hardness of the storage container 50 is increased. Pulse current I _L is the magnetic field of the coil portion 7 when the maximum value is the maximum value. At this time, if the user presses the pen tip portion 5 against the input surface, the user learns a hard feedback feedback that causes the pen tip portion 5 to repel from the input surface (FIG. 8A). By a change in magnetic field strength due to a change of the pulse current I _L, the hardness of the pen tip portion 5 of the stylus 1 is in accordance with the timing at which the pulse current and the magnetic field strength becomes the maximum value, the highest as shown in FIG. 8 (a) This is the “first hardness” of the hardness (indicated as “A” in FIG. 7D).

On the other hand, when the magnetic field of the coil portion 7 starts to decrease from the maximum value, the viscosity of the MR fluid 51 decreases (FIG. 3A), and the apparent hardness of the storage container 50 decreases. At this time, if the user presses the pen tip 5 against the input surface, the storage container 50 is deformed by the pressing force, and the pressing force is distributed along the input surface. As a result, the user learns soft input feedback such that the pen tip 5 sinks into the input surface (FIG. 8B). The hardness of the pen tip portion 5 of the stylus 1 is adjusted to the “first hardness” lower than the “first hardness” as shown in FIG. 8B in accordance with the timing when the pulse current IL and the magnetic field strength H are other than the maximum values. 2 ”(indicated by“ B ”in FIG. 7D). In accordance with the frequency f (1 / T ₀ ) of the pulse current I _L , the hardness of the pen tip portion 5 reversibly changes between “first hardness” and “second hardness”.

Since the user brings the pen tip portion 5 of the stylus 1 into contact with the input surface of the display device in use, when the hardness change of the pen tip portion 5 is repeated, the length of the stylus 1 (Y ) Along the direction, a minute vibration of 65.2 Hz or more and 525 Hz or less, which is the frequency f (1 / T ₀ ) of the pulse current I _L , is transmitted. The stylus 1 realizes a writing feeling very similar to a writing feeling when writing with a writing tool on a paper surface by transmitting such minute vibrations to a user's hand during use.

Hereinafter, the reason why the above effect is achieved with the stylus 1 will be described in detail.
(About the effect of the stylus 1)
FIG. 9 is a graph showing an analysis result of about 200 μm width of 256 points in a region of 400 μm width on a general notebook paper surface by using a laser microscope. As shown in FIG. 9, there are fine irregularities having a height difference of about 50 μm on the notebook paper surface.

  FIG. 10 is a graph of the spatial frequency distribution of the unevenness of the notebook paper, which is the basis of the analysis data of FIG. 9 (range of 853 μm × width 640 μm × height 210 μm). FIG. 11 is a graph obtained by extracting data along a certain vertical direction from the data of FIG. From the results shown in FIG. 11, it was confirmed that many irregularities exist on the paper surface at a constant cycle. That is, in a region having a width of 400 μm, relatively large irregularities are present in the same order of 5 times, 6 times, and 7 times in any one of periods 57 μm, 66 μm, and 80 μm.

Here, FIG. 12A is a schematic diagram showing a state in which the paper surface is traced with a pen. When the operation of the pen is viewed microscopically, the pen tip is pushed back to the convex portion of the paper and then repeatedly sinks into the concave portion. It is considered that the writer has a writing sensation peculiar to the paper surface due to the vibration of the pen accompanying this movement.
Therefore Stylus 1, reversibly changing the hardness of the pen tip portion 5 first hardness (high hardness) and the second hardness (low hardness) at a predetermined cycle T ₀ as shown in FIG. 12 (b) Thus, the feedback is adjusted so as to obtain an input feedback close to the writing feeling when the pen tip is used to overcome the irregularities on the notebook paper surface.

When the inventors of the present application specifically investigated, the pen moving speed during general writing was approximately 0.5 to 3.0 cm / sec. When the pen is moved at this moving speed, if the pen tip gets over the irregularities appearing on the paper surface at a period of 57 μm, 66 μm, or 80 μm, the pen will have a frequency of about 62.5 times to 525 times per second. Vibration is transmitted.
Therefore, in the stylus 1, the hardness of the pen tip portion 5 is reversibly changed at a frequency f (= 1 / T ₀ ) of 62.5 Hz or more and 525 Hz or less, and the pen tip portion 5 is pushed back from the input surface. The operation of sinking is repeated (see FIG. 8). As a result, the stylus 1 provides an input feedback that is very close to the writing sensation when writing with a pen on paper.

Note that there may be a large individual difference with respect to a preferable input feedback when the stylus 1 is used. Therefore, in the stylus 1, the user rotates the knob portion 23 around the axis of the main body portion 2 to adjust the resistance value of the variable resistance element R ₂ and drives the frequency f (==) of the pulse current I _L supplied to the coil portion 7. 1 / T ₀ ) and the on-duty ratio (Th / T ₀ ) are appropriately adjusted so that the optimal feedback feedback can be adjusted for the user.

Further, in the stylus 1, excellent input feedback can be obtained by using a magnetorheological fluid having good hardness change characteristics as the hardness change means of the nib portion 5. Here, FIG. 13 is a graph showing the relationship between the supplied power and the change in the hardness of the container when the electromagnetic viscosity (ER) fluid (comparative example) and the MR fluid (example) are put in the containment container, respectively.
As shown in FIG. 13, the pen tip portion using the MR fluid has a larger hardness change with respect to the supplied power than the pen tip portion using the ER fluid. Therefore, in the stylus 1, the storage container 50 in which the MR fluid 51 is stored in the pen tip portion 5 is used so that the user can provide sufficient feedback feedback.

Hereinafter, another embodiment of the present invention will be described focusing on differences from the other embodiments.
<Embodiment 2>
FIG. 14 is a circuit diagram of a stylus according to the second embodiment. The difference from the stylus 1 is that a variable resistance element R ₆ is connected between the collector of the transistor TR ₁ and the coil portion 7 in the third circuit portion 8C ′. The adjustment axis of the variable resistance element R ₆ is arranged so that, for example, a hole is provided in the side surface of the main body 2 and exposed to the outside so that the user can adjust it with a finger.

According to such a configuration, when the resistance value of the variable resistance element R ₆ is increased (decreased), the amplitude of the pulse current I _L can be reduced (increased) steplessly, and the hardness change of the pen tip portion 5 can be reduced ( Large) can be adjusted.
<Embodiment 3>
FIG. 15 is a circuit diagram of a stylus according to the third embodiment. The difference from the stylus 1 is that power from the power supply unit 9 is supplied to the first circuit unit 8A, the second circuit unit 8B, and the third circuit unit 8C via the regulator circuit 90.

The regulator circuit 90 is composed of a known step-down regulator IC, and converts the power of the power supply unit 9 into a constant low power and outputs it. As such a regulator IC, for example, “LM317” manufactured by National Semiconductor Corporation can be used.
Even with such a configuration, the same effect as in the first embodiment can be expected. Furthermore, the power of the power supply unit 9 can be adjusted to a desired low power, and a high power type can be used for the power supply unit 9.
<Embodiment 4>
FIG. 16 is an external view of a display device 150 with a stylus (hereinafter referred to as “device 150”) according to the fourth embodiment. FIG. 17 is a circuit diagram of the device 150 including the stylus 1A. The main feature of the fourth embodiment is that an alternating current is applied to the coil section 7 to generate a magnetic field.

As shown in FIG. 16, the device 150 includes a device main body 10 including the display unit 11 and a stylus 1A. The stylus 1A and the apparatus main body 10 are connected by a cable 12.
As shown in FIG. 17, the circuit of the device 150 includes an AC / DC converter unit 93, an inverter unit 94, and a coil unit 7. In the fourth embodiment, the AC / DC converter unit 93 and the inverter unit 94 are power supply circuit units, and are housed in, for example, the apparatus main body 10.

The AC / DC conversion circuit unit 93 includes a diode bridge DB including four diodes D2 to D5, wirings 110 and 111 connected to the output side of the diode bridge DB, and wiring connected to the output side of the diode bridge DB. 112, 113, a smoothing capacitor C ₁ connected between the wirings 112, 113, and a DC / DC converter unit 91. For example, a commercial power supply 100 V 60 kHz AC power source is connected between the wirings 110 and 111.

The inverter unit 94 is a current control unit in the fourth embodiment, and the controller IC 92 connected to the output-side wires 114 and 115 of the DC / DC converter unit 91 and the wires 116 to 118 connected to the output terminals of the controller IC 92. , 120 to 122 and four switching transistors TR ₅ , TR ₃ , TR ₆ , TR ₄ each having a base connected to the wirings 117, 118, 120, 121 in the same order.

Both ends of the coil portion 7B from the wiring 119 for connecting the collector of the emitter and the transistor TR ₄ of the transistor TR _3, are connected to a wiring 123 for connecting the emitter and collector of the transistor TR ₆ of the transistor TR _5.
The controller IC 92 stores a control program in the internal memory in advance. When the device 150 is driven, the controller IC 92 switches the output timing to one of the bases of the transistors TR ₃ to TR ₆ every cycle T ₀ based on the control program, and controls these on / off. Specifically, in the first period, the controller IC 92 turns on the transistors TR ₄ and TR ₅ and turns off the transistors TR ₃ and TR ₆ . In the subsequent second period, the controller IC 92 turns on the transistors TR ₃ and TR ₆ and turns off the transistors TR ₄ and TR ₅ . The controller IC 92 repeats these two cycles of operation based on the control program.

In the device 150 having such a configuration, when the user operates the push switch 88 to turn on the power, the power from the AC power source flows to the diode bridge DB, the wiring 112 side is the positive electrode side, and the wiring 113 side is the negative electrode side. Rectified. The rectified power is smoothed by the smoothing capacitor C ₂ , input to the DC / DC converter unit 91, and converted to DC power that has been stepped down to a certain value.

The DC power output from the DC / DC converter unit 91 is input to the controller IC 92 via the wirings 114 and 115. Based on the control program stored in the internal memory, the controller IC 92 turns on the transistors TR ₄ and TR ₅ and turns off the transistors TR ₃ and TR ₆ in the first period. As a result, a current I _L1 flows through the coil portion 7 (FIG. 17). Subsequently, based on the control program, the controller IC 92 turns on the transistors TR ₃ and TR ₆ and turns off the transistors TR ₄ and TR ₅ in the second period. Thus the current I _L2 flowing in the current I _L1 in the opposite direction to the coil portion 7 (Figure 17). The controller IC 92 repeats the ON / OFF control of the first cycle and the second cycle every cycle T ₀ , so that the coil unit 7 is AC driven by the currents I _L1 and I _L2 to generate a magnetic field. The direction of each magnetic field generated in the coil unit 7 also changes in the direction along the longitudinal (Y) direction of the stylus 1A due to the difference in the direction of current flow in the coil unit 7, but the pen tip portion transmitted to the user's hand The vibration 5 is the same as in the first embodiment.

In the stylus 1A of the fourth embodiment having the above configuration, the same effect as that of the first embodiment can be expected. That is, the stylus of the present invention can be driven by either direct current or alternating current.
<Embodiment 5>
FIG. 18 is an external view of a stylus 1B according to the fifth embodiment. FIG. 19 is a circuit diagram of the stylus 1B.

  As shown in FIG. 18, the difference in appearance from the first embodiment is that a setting button 29 is provided on the main body 2 of the stylus 1B. Further, the circuit difference from the first embodiment is that, as shown in FIG. 19, the first circuit portion 8A is omitted, and the second circuit portion 8B ′ has a one-chip microcomputer 95 (hereinafter simply referred to as “microcomputer 95”). The Vcc terminal and the GND terminal of the microcomputer 95 are connected to the wirings 100 and 101 in the same order. A PC (Port C) terminal which is an I / O terminal of the microcomputer 95 is connected to the wiring 100 through a setting push switch 96. The setting push switch 96 comes into contact with the back side of the setting button 29, and when the user presses the setting button 29, the setting push switch 96 can be turned on / off.

The microcomputer 95 includes an internal memory composed of a ROM such as a flash memory, a CPU, an oscillation circuit, and a PWM (pulse width modulation) circuit. The internal memory stores in advance a setting control program for the CPU to shift to the setting mode and adjust the frequency of the pulse current I _L based on a signal input from the PC terminal when the setting push switch 96 is input. . Stylus 1B, and the pulse current I _L of the frequency f (= 1 / T ₀₎ to 62.5 Hz, the on-duty ratio of the pulse current I _L is set at 40%.

When the microcomputer 95 is composed of a commercially available one-chip microcomputer, a “PIC microcontroller” series manufactured by Microchip Technology Japan Co., Ltd. can be used.
FIG. 20 is a control flow example of a setting mode executed by the CPU of the microcomputer 95.
When the user presses the switch unit 26 to drive the stylus 1B, the CPU determines whether or not the setting button 29 has been pressed based on the setting control program (S1). When the CPU determines that the setting button 29 has been pressed in S1, the CPU starts time counting (S2). The CPU continues the time count until a predetermined time te elapses and a time-out occurs (S3). The fixed time te can be set to 5 seconds, for example. In accordance with the frequency N1 to be set, the user presses the setting button 29 within the predetermined time te for the number of inputs n that satisfies the following relational expression (Expression 3).

(Formula 3): N1 (Hz) = (62.5 + 10 × n)
Note that “62.5” in Equation 1 corresponds to the default frequency of 62.5 (Hz), but of course, this value may be any other value.
When the CPU determines that the time-out has occurred in S3, the CPU ends the time count, and measures the number of inputs n input by the user during the time count (S4). Thereafter, the CPU substitutes the number of inputs n into the relational expression (formula 3) and performs calculation, and sets the frequency N1 of the calculation result as the frequency f (= / T ₀ ) of the new pulse current I _L (S5). After S5 ends, the CPU ends the setting mode.

In such a stylus 1B of the fifth embodiment, the same effect as in the first embodiment can be expected. Further in the fifth embodiment, by using the microcomputer 95, the user can adjust the frequency by software control without using the variable resistance element R _2.
As a modification of the control flow shown in FIG. 20, the CPU can also change the on-duty ratio of the pulse current in S5. In S5 of this modified example, the CPU substitutes the number of inputs n input by the user during the time count into the following relational expression (formula 4) based on the setting control program, and calculates P1 as a new result. It is set as the oN duty ratio of the pulse current I _L (%).

(Formula 4): P1 (%) = (40 + n × 10)
Here, “40” in Equation 4 corresponds to the default value of on-duty ratio of 40 (%), but of course, this value may be a value other than 40.
<Embodiment 6>
FIG. 21 is an external view of a stylus 1C according to the sixth embodiment. The configuration of the stylus 1C is almost the same as that of the stylus 1B of the fifth embodiment. However, the main body 2 is provided with a slot 200 that communicates with the inside, and a media card MC that is a rewritable nonvolatile memory is inserted into and removed from the slot 200. The point which made it free is different. The media card MC inserted into the slot 200 is connected to the power supply circuit board 8 so that the CPU of the microcomputer 95 can be read. Note that the setting control program is not stored in the internal memory of the microcomputer 95.

The stylus 1C having such a configuration can be expected to have the same effect as the stylus 1B. That is, in the sixth embodiment, the user stores the setting control program in the media card MC in advance, and the user inserts the media card MC into the slot 200 and causes the CPU of the microcomputer 95 to read it, whereby the CPU shown in FIG. The indicated control can be executed. Further, a plurality of setting control programs having different default values in (Equation 3) or (Equation 4) shown in the fifth embodiment are stored for each of the plurality of media cards MC, and the user selects the media card MC. By doing so, it is possible to adjust the frequency or the hardness so as to suit the user's favorite writing comfort.
<Other matters>
In the first embodiment, the variable resistance element R ₂ is used in the first circuit unit 8A and the configuration in which the user can adjust the frequency and the hardness is illustrated. However, the variable resistance element R ₂ is not an essential configuration and is omitted. You can also. In this case, using conventional resistive element instead of the variable resistance element R _2. Alternatively, the first circuit unit 8A may be omitted, and any one of a commercially available control IC, regulator IC, and one-chip microcomputer provided with an oscillation circuit of a certain frequency band may be used as the control IC 87.

In the first embodiment and the like, an example in which a battery is used for the power supply unit 9 is shown, but a large-capacity electric double layer capacitor can also be used. As an example of a commercially available electric double layer capacitor, “Supercapacitor” manufactured by NEC TOKIN Corporation can be used.
Moreover, the stylus of the present invention is a stylus that can be built in a housing of a portable information terminal such as a smartphone or a tablet by making the main body 2 compact by reducing the size of the power supply unit 9 and the power supply circuit 8. You can also

  The display device used for the pen-type input device of the present invention may include any type of touch panel such as a resistive film method, a capacitance method, an electromagnetic induction method, and an infrared method.

  The pen-type input device of the present invention is, for example, as a pointing device for a display device including a portable information terminal such as a tablet, a smartphone, a portable game machine, a laptop computer, and a non-installation type car navigation system, an automatic ticket vending machine, and a touch panel such as an ATM. Wide use is possible.

1, 1A, 1B, 1C stylus (pen-type input device)
2 Body portion 3 Tip case portion 4 Pressure sensitive adjustment portion 5 Pen tip portion 6 Container holding portion 7 Coil portion 8 Power supply circuit board 8A First circuit portion 8B, 8B ′ Second circuit portion 8C, 8C ′ Third circuit portion 9 Power supply unit 10 Device main body 11 Display unit 21, 22 Opening unit 23 Knob unit 25, 32 Storage space 26 Switch unit 50 Storage container 51 Magnetorheological (MR) fluid 71, 72 Conductor 80 Mounting substrate 85, 86 Lead member 87 Control IC ( Timer IC)
88 Push switch 90 Regulator circuit 91 DC / DC converter 92 Controller IC
96 display push switch 100～105,110～123 wiring 150 with a stylus for setting apparatus 200 slot FF flip-flop D ₁ surge absorbing diode D ₂ to D ₅ diode DB diode bridge C _1, C ₂ capacitors R _1, R ₃ ~R ₅ resistance elements R ₂ , R ₆ variable resistance elements TR ₁ pulse current control transistor TR ₂ discharge transistor TR _{3 to} TR ₆ switching transistor

Claims (12)

An elongated body,
A pen tip portion disposed at one end in the longitudinal direction of the main body portion;
A coil portion arranged so that a magnetic field extends to the pen tip portion;
A power supply circuit for applying a pulse current to the coil unit,
The nib portion has a magnetorheological fluid and a storage container for storing the magnetorheological fluid;
The containment vessel is made of a flexible material and is arranged so that a part thereof is exposed to the outside,
When the pulse current is applied, the viscosity of the magnetorheological fluid changes due to a change in the magnetic field generated in the coil portion, so that the hardness of the pen tip portion is reversible between the first hardness and the second hardness. Pen-type input device that changes continuously. The pen-type input device according to claim 1, wherein a frequency of the pulse current is in a range of 62.5 Hz to 525 Hz. In the inside of the main body, it has a holding portion for holding the end of the main body of the storage container on the other end side in the longitudinal direction,
The pen-type input device according to claim 1, wherein the coil unit is wound around the holding unit. The pen-type input device according to claim 1, wherein the power supply circuit includes a current control unit that converts a power supply current into the pulse current. The pen-type input device according to claim 4, wherein the current control unit includes a timer IC. The pen-type input device according to claim 4, wherein the current control unit includes a microcomputer. The pen-type input device according to claim 4, wherein the power supply circuit includes a regulator circuit. The pen-type input device according to claim 4, wherein the pulse current converted by the current control unit is an alternating current. The pen-type input device according to claim 1, wherein the magnetorheological fluid includes metal particles, a surfactant, and a fluid medium. The metal particles are at least one of magnetite and manganese zinc ferrite,
The pen-type input device according to claim 9, wherein the fluid medium is at least one of water, isoparaffin, alkylnaphthalene, perfluoropolyether, and polyα-olefin. The pen-type input device according to claim 1, wherein the storage container is made of a resin material. The pen-type input device according to claim 11, wherein the resin material is at least one of polypropylene, polyethylene, nylon, and cyclic polyolefin.