JP5875074B2 - Tactile stimulus generator and coordinate input system - Google Patents

Description

  The present invention relates to a tactile stimulus generator and a coordinate input system, and in particular, is installed in front of a coordinate input device called a touch panel or the like and transmits a controlled electrical stimulus signal to an operator (user) fingertip or the like. The present invention relates to a tactile stimulus generator that can perform such a function, and a coordinate input system including such a tactile stimulus generator.

  A coordinate input device called a touch panel or a touch screen detects the coordinate position of the fingertip on the operation surface by a change in capacitance value or the like when the user brings the fingertip close to or in contact with the operation surface. The input operation according to the coordinate position is made possible. This type of coordinate input device is installed in front of a display device such as an LCD (Liquid Crystal Display), and when the user places a fingertip on a desired operation region displayed on the screen of the display device, The operation is to be executed. As a position coordinate detection method of this type of coordinate input device, various methods such as a capacitance type, a resistance film type, a surface acoustic wave type, and an electromagnetic induction type are known.

  By the way, in this type of coordinate input device, when a user brings a body part such as his fingertip (hereinafter abbreviated as fingertip) close to or in contact with the operation surface, the fingertip is placed at a desired position on the operation surface. It is necessary to confirm visually. That is, no matter where the fingertip of the user is placed on the operation surface, there is no difference in the sense transmitted to the fingertip, so that it is difficult for the user to correctly operate if the user does not visually recognize the fingertip position on the operation surface.

  Therefore, conventionally, a tactile stimulus generation device has been proposed in which an electrical stimulus signal is transmitted to a fingertip when a user brings the fingertip close to or in contact with an operation surface. For example, in Patent Document 1 (see FIG. 11), a low-frequency (for example, 100 to 300 Hz) electric signal is supplied from a high-voltage (for example, 1 kV) voltage source 100 to the electrode 106 covered with the insulator 108, and this insulator The fingertip 120 in proximity to or in contact with the electrode 108 and the electrode 106 are capacitively coupled via the insulator 108 to transmit an electrical stimulation signal to the fingertip 120, so There has been proposed a tactile stimulus generator that is sensed by the body 122 or the like. In this conventional example, a stimulation signal is generated by using electric charges excited on the fingertip 120 by capacitive coupling with the electrode 106. Various electrical stimulation signals can be transmitted to the fingertip 120 by controlling the period of the electrical signal supplied to the electrode 106 and the like.

JP 2009-87359 A

  However, in the conventional haptic stimulus generator disclosed in Patent Document 1, for example, the fingertip 120 is brought close to or in contact with the haptic stimulus generator while a part of the user's body is touching a grounded metal or the like. When the electrode 106 supplied with an electric signal having a large voltage amplitude of about 1 kV and the fingertip 120 are capacitively coupled, an abnormal current of alternating current flows from the fingertip 120 into the user's body, causing pain to the user. There is a possibility of making it feel, and a problem has arisen from the viewpoint of safety. If the voltage amplitude of the electrical signal is reduced, the possibility that the user feels pain even if an abnormal current flows from the fingertip 120 into the user's body is reduced and safety is improved, but the stimulation signal that can be applied to the fingertip 120 Has become a problem, and it has become a problem that it is difficult for the user to sense the stimulus.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide a tactile stimulus generator that can transmit a stimulus signal that is safe and easy for a user to sense.

  In order to solve this problem, the tactile stimulus generation device according to claim 1 is capable of transmitting an electrical stimulation signal to the body specifying unit when the body specifying unit such as a user's fingertip approaches or comes into contact. A stimulus generator, a tactile transmission unit that transmits the stimulation signal to the body specifying unit by capacitive coupling with the body specifying unit, and a signal generation unit that applies a controlled electrical signal to the tactile transmission unit And the electric signal generated by the signal generator is inserted when the polarity of the first AC signal is inverted and the first AC signal whose polarity is inverted at a predetermined cycle, and from the first AC signal And a second AC signal whose polarity is inverted in a short cycle.

  In the tactile stimulus generating apparatus having this configuration, the electrical signal generated by the signal generating unit is inserted when the polarity of the first AC signal whose polarity is inverted at a predetermined period and the polarity of the first AC signal is inverted. And a second AC signal whose polarity is inverted at a shorter cycle. The polarity of such an electric signal changes (inverts) with time, and the period also changes with time. And since the stimulation signal which the change of the period added to the change of polarity is transmitted to a body specific part using such an electrical signal, it is easy for a user to perceive. Further, in the tactile stimulus generator having this configuration, the stimulus signal that is easy for the user to sense is obtained by adding a change in the period to the change in the polarity of the electrical signal, so that the voltage amplitude of the electrical signal can be reduced. For this reason, even when a part of the user's body is in contact with a grounded metal or the like and the body specifying part is brought close to or in contact with the tactile stimulus generating device, an abnormal AC current is generated from the body specifying part by the user. The possibility of flowing into the body and causing the user to feel pain is reduced, and safety can be improved. Therefore, the tactile stimulus generating apparatus having this configuration can transmit a safe and easy-to-detect stimulus signal to the body identifying unit.

  The haptic stimulus generation device according to claim 2 is the haptic stimulus generation device according to claim 1, wherein the haptic transmission unit is provided at a position covering a plurality of haptic generation electrodes and a front surface of the haptic generation electrode. The tactile sensation generating electrode is applied with the electrical signal generated by the signal generating unit, and the tactile sensation transmitting unit is proximate to the haptic generating electrode via the insulating layer. The stimulation signal is transmitted to the unit.

  In the haptic stimulus generation device having this configuration, the haptic transmission unit includes a plurality of haptic generation electrodes and an insulating layer provided at a position covering the front surface of the haptic generation electrodes. And when a body specific part is made to adjoin to a tactile sense generating electrode through an insulating layer, the distance of a body specific part and a tactile sense generating electrode can be stabilized by an insulating layer. Therefore, the body identifying part and the tactile sensation generating electrode can be stably capacitively coupled via the insulating layer. As a result, in the tactile stimulus generating apparatus having this configuration, it is possible to stably transmit a stimulus signal that can be easily detected by the user to the body identifying unit.

  The haptic stimulus generation device according to claim 3 is the haptic stimulus generation device according to claim 2, wherein the plurality of haptic generation electrodes include at least one first haptic generation electrode and at least one second haptic generation electrode. And the electrical signal includes a first electrical signal and a second electrical signal having positive and negative polarities opposite to each other, and the first electrical signal is applied to the first haptic generating electrode, The second electrical signal is applied to the tactile sensation generation electrode, and the tactile transmission unit is applied to the body specifying unit adjacent to the first tactile generation electrode and the second tactile generation electrode via the insulating layer. It is characterized by transmitting a stimulation signal.

  In the haptic stimulus generation device having this configuration, the plurality of haptic generation electrodes include at least one first haptic generation electrode and at least one second haptic generation electrode, and the electrical signals have opposite positive and negative polarities. The first electrical signal is applied to the first haptic generation electrode, and the second electrical signal is applied to the second haptic generation electrode. And if a body specific part is made to adjoin to such a 1st tactile generating electrode and such a 2nd tactile generating electrode via an insulating layer, a body specific part, a 1st tactile generating electrode, and a 2nd tactile generating electrode will be interposed via an insulating layer And are capacitively coupled. As a result, the tactile transmission unit can excite the charges distributed in a plane on the part of the body specifying unit facing the first tactile generation electrode and the second tactile generation electrode. Moreover, an electric current can be sent between the electrode patterns of a 1st tactile sensation generating electrode and a 2nd tactile sensation generating electrode via a body specific part. Since the current has a property of trying to flow through the shortest path, this current flows in a concentrated manner in a portion close to the portion between the electrode patterns of the first tactile generating electrode and the second tactile generating electrode in the body specifying part. It becomes like this. In the tactile stimulus generating apparatus having this configuration, it is possible to transmit a stimulus signal that is easy to be aware of the shape of the electrode pattern and that is more easily perceived by the user to the body identifying part by using such electric charge and current.

  The haptic stimulus generator according to claim 4 is the haptic stimulus generator according to claim 3, wherein the signal generator has a voltage amplitude of the first electric signal and a voltage amplitude of the second electric signal approximately. The electrical signals are controlled so as to be equal.

  In the tactile stimulus generator having this configuration, the voltage amplitude of the first electric signal is substantially equal to the voltage amplitude of the second electric signal. Therefore, the stimulus signal transmitted to the body specifying part by the first tactile sensation electrode and the stimulus signal transmitted to the body specifying part by the second tactile sensation electrode can be made substantially equal in strength. By arranging such a plurality of tactile generating electrodes in a uniform distribution on the front surface of the insulating layer of the tactile stimulation generating sheet, it is possible to transmit a stimulation signal with a small variation in strength depending on the position to the body specifying unit. . As a result, in the tactile stimulus generating apparatus having this configuration, it is possible to stably transmit a stimulus signal that can be easily detected by the user to the body identifying unit.

The haptic stimulus generation device according to claim 5 is the haptic stimulus generation device according to any one of claims 2 to 4, wherein the haptic transmission unit includes a resistance film provided on a front surface of the insulating layer. The surface resistivity of the resistance film is 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □.

In the haptic stimulus generating apparatus having this configuration, the haptic transmission unit includes a resistance film provided on the front surface of the insulating layer. The surface resistivity of the resistance film is 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □. Since a small amount of current flows through such a resistive film, even if frictional charging occurs between the body specific part and the resistive film when the body specific part moves while in contact with the resistive film, The excited electric charge can be diffused into the resistance film. Therefore, frictional charging between the body specifying part and the resistance film can be suppressed. As a result, there is no influence of frictional charging between the body specifying part and the resistance film, and a stimulation signal that is more easily perceived by the user can be transmitted to the body specifying part.

  A coordinate input system according to a sixth aspect includes a tactile stimulus generating device according to any one of the first to fifth aspects, and a coordinate input device capable of detecting a coordinate position when the body specifying unit approaches. The tactile stimulus generation device is installed on the front surface of the coordinate input device, and the tactile transmission unit outputs the stimulus signal in response to the coordinate position information obtained from the coordinate input device. Communicate to the body specific part.

  The coordinate input system having this configuration includes the tactile stimulus generator according to any one of claims 1 to 5. Therefore, the tactile stimulus generator can transmit a stimulus signal that is safe and easy for the user to sense. Then, such a tactile stimulus generating device is installed on the front surface of the coordinate input device, and the tactile sense transmitting unit transmits a stimulus signal to the body specifying unit corresponding to the coordinate position information obtained from the coordinate input device. ing. As a result, the coordinate input system configured as described above detects the coordinate position when the body specifying unit comes close to the coordinate input device, enables an input operation according to the coordinate position, and is safe and sensed by the user. It is possible to transmit a stimulus signal that is easy to perform to the body identifying part.

  In the tactile stimulus generator according to the present invention, the electrical signal generated by the signal generator is inserted when the polarity of the first AC signal whose polarity is inverted at a predetermined period and the polarity of the first AC signal is inverted. And a second AC signal whose polarity is inverted at a shorter cycle. The polarity of such an electric signal changes (inverts) with time, and the period also changes with time. And since the stimulation signal which the change of the period added to the change of polarity is transmitted to a body specific part using such an electrical signal, it is easy for a user to perceive. Further, in the tactile stimulus generator having this configuration, the stimulus signal that is easy for the user to sense is obtained by adding a change in the period to the change in the polarity of the electrical signal, so that the voltage amplitude of the electrical signal can be reduced. For this reason, even when a part of the user's body is in contact with a grounded metal or the like and the body specifying part is brought close to or in contact with the tactile stimulus generating device, an abnormal AC current is generated from the body specifying part by the user. The possibility of flowing into the body and causing the user to feel pain is reduced, and safety can be improved. Therefore, the tactile stimulus generating apparatus having this configuration can transmit a safe and easy-to-detect stimulus signal to the body identifying unit.

It is explanatory drawing which shows the structure of the tactile stimulus generator which concerns on embodiment of this invention. It is a disassembled perspective view which shows the usage example of the tactile stimulus generator shown in FIG. 1 with a coordinate input device. It is principal part sectional drawing which shows typically the laminated structure of the tactile sense irritation | stimulation generation | occurrence | production sheet | seat shown in FIG. 2, a transparent protective sheet, an X coordinate detection sheet, and a Y coordinate detection sheet. It is a top view which shows the electrode pattern of the X coordinate detection sheet | seat shown in FIG. It is a top view which shows the electrode pattern of the Y coordinate detection sheet | seat shown in FIG. FIG. 3 is a plan view showing an electrode pattern of the tactile stimulus generating sheet shown in FIG. 2. It is explanatory drawing which shows the circuit structural example of the signal generation part shown in FIG. It is explanatory drawing which shows the principle of operation of the tactile sense transmission part shown in FIG. It is explanatory drawing which shows the example of a characteristic of the output signal of the signal generation part shown in FIG. It is explanatory drawing which shows the characteristic of the 1st alternating current signal of the output signal shown in FIG. It is explanatory drawing which shows the characteristic of the 2nd alternating current signal of the output signal shown in FIG. It is explanatory drawing which shows typically the relationship between the surface resistivity and surface potential of the resistive film which concerns on embodiment of this invention. It is explanatory drawing which shows the structure of the conventional tactile-stimulus generator which concerns on patent document 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the configuration of a tactile stimulus generator according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram showing a configuration of a tactile stimulus generator according to an embodiment of the present invention.

  As shown in FIG. 1, in this embodiment, the tactile stimulus generator 1 is installed and used on the front surface (upper part of the drawing) of the coordinate input device 21. The tactile stimulus generator 1 and the coordinate input device 21 constitute a coordinate input system 20. The coordinate input device 21 is a sheet-like coordinate input device referred to as a touch panel, a touch screen, or the like. When the user brings a body specifying unit (hereinafter referred to as fingertip 40) such as his fingertip 40 into contact with the operation surface, The coordinate position of the fingertip 40 on the operation surface is detected by a change in capacitance value or the like, and an input operation corresponding to the coordinate position is made possible. Such a coordinate input device 21 is installed in front of a display device (hereinafter abbreviated as a display device) such as an LCD (Liquid Crystal Display) so that the user can place his fingertip on a desired operation area displayed on the screen of the display device. When 40 is set, the operation content of the operation area can be executed. The tactile stimulus generator 1 is a device for transmitting a controlled electrical stimulus signal (tactile stimulus) to the fingertip 40 whose coordinate position is detected by the coordinate input device 21.

  The haptic stimulus generator 1 includes a haptic transmission unit 2 that transmits a stimulus signal to the fingertip 40. The tactile transmission unit 2 includes a tactile stimulation generating sheet 3 and a transparent protective sheet 6 disposed on the front surface of the tactile stimulation generating sheet 3. The tactile stimulus generating sheet 3 includes a transparent insulating layer 4 and a tactile generating electrode 5 made of a transparent electrode provided on the front surface of the insulating layer 4. The transparent protective sheet 6 includes a transparent insulating layer 7 and a resistance film 8 provided on the front surface of the insulating layer 7. The tactile stimulus generator 1 further includes a signal generator 10 that applies a controlled electric signal to the tactile transmitter 2. The electrical signal generated by the signal generation unit 10 is applied to the haptic generation electrode 5 of the haptic transmission unit 2.

  Next, a usage example when the tactile stimulus generator 1 according to the embodiment of the present invention is installed on the front surface of the coordinate input device 21 will be described with reference to FIGS. FIG. 2 is an exploded perspective view showing an example of use of the tactile stimulus generator shown in FIG. 1 together with a coordinate input device. FIG. 3 is a cross-sectional view of a main part schematically showing a laminated structure of the tactile stimulus generating sheet, the transparent protective sheet, the X coordinate detection sheet, and the Y coordinate detection sheet shown in FIG. FIG. 4 is a plan view showing an electrode pattern of the X coordinate detection sheet shown in FIG. FIG. 5 is a plan view showing an electrode pattern of the Y coordinate detection sheet shown in FIG. FIG. 6 is a plan view showing an electrode pattern of the tactile stimulus generating sheet shown in FIG.

  In the usage example shown in FIG. 2, the coordinate input device 21 includes an X coordinate detection sheet 22 and a Y coordinate detection sheet 25. The Y coordinate detection sheet 25 is disposed in front of a display device (not shown), and the X coordinate detection sheet 22 is disposed in front of the Y coordinate detection sheet 25. The tactile stimulus generation sheet 3 of the tactile stimulus generation apparatus 1 is disposed on the front surface of the X coordinate detection sheet 22, and the transparent protective sheet 6 is disposed on the front surface of the tactile stimulus generation sheet 3. And the front surface of the transparent protective sheet 6 is an operation surface with which the fingertip 40 contacts. In the present embodiment, the transparent protective sheet 6 is formed integrally with the cover body 30. Further, as shown in FIG. 3, the Y coordinate detection sheet 25, the X coordinate detection sheet 22, the tactile stimulus generation sheet 3 and the transparent protective sheet 6 are laminated and used as an integral sheet.

  Next, the X coordinate detection sheet 22 of the coordinate input device 21 will be described. As shown in FIGS. 2 and 3, the X-coordinate detection sheet 22 includes a transparent insulating layer 23 made of PET or the like, and a first detection electrode made up of a rhombus-shaped transparent electrode disposed in front of the insulating layer 23. 24. As shown in FIG. 4, the first detection electrodes 24 are arranged with an even distribution to form a first detection electrode 24 group. A plurality of first detection electrodes 24 in the first detection electrode group 24 are connected in a line in the Y-axis direction (vertical direction in the drawing) to form a first detection electrode array 24A. The first detection electrode rows 24A are distributed at regular intervals in the X-axis direction (the horizontal direction in the figure).

  Next, the Y coordinate detection sheet 25 of the coordinate input device 21 will be described. As shown in FIGS. 2 and 3, the Y-coordinate detection sheet 25 includes a transparent insulating layer 26 made of PET or the like, and a second detection electrode made up of a rhombus-shaped transparent electrode disposed in front of the insulating layer 26. 27. As shown in FIG. 5, the second detection electrodes 27 are arranged with an even distribution to constitute a second detection electrode 27 group. A plurality of second detection electrodes 27 in the second detection electrode 27 group are connected in a line in the X-axis direction to form a second detection electrode array 27A. The second detection electrode rows 27A are distributed at equal intervals in the Y-axis direction.

  All of the first detection electrodes 24 of the X coordinate detection sheet 22 and all of the second detection electrodes 27 of the Y coordinate detection sheet 25 are arranged so as not to overlap each other in plan view. That is, the second detection electrodes 27 are positioned in front of the gaps formed between the adjacent first detection electrodes 24 in the first detection electrode 24 group, and the second detection electrodes 27 adjacent to each other in the second detection electrode 27 group. The first detection electrodes 24 are arranged behind the gaps formed between the electrodes 27, respectively. All the first detection electrodes 24 of the X coordinate detection sheet 22 and all of the second detection electrodes 27 of the Y coordinate detection sheet 25 are connected to a coordinate position detection circuit (not shown).

  The coordinate detection method of the coordinate input device 21 used in this embodiment is a method called a capacitance method. Since the detection principle is well-known, detailed description is omitted. However, when the user brings the fingertip 40 close, the capacitance value between the first detection electrode 24 and the second detection electrode 27 is near the fingertip 40. By decreasing, the coordinate position of the fingertip 40 can be detected based on the change in the capacitance value.

  Next, the tactile stimulus generation sheet 3 of the tactile stimulus generator 1 will be described. As shown in FIGS. 2 and 3, the tactile stimulus generating sheet 3 is composed of a transparent insulating layer 4 made of PET (polyethylene terephthalate) or the like, and a rhombus-shaped transparent electrode arranged on the front surface of the insulating layer 4. And a tactile sensation generating electrode 5. As shown in FIGS. 4 to 6, the haptic generating electrode 5 includes a plurality of first haptic generating electrodes 5 a arranged so as to overlap each electrode of the first detection electrode 24 group of the X coordinate detection sheet 22 in plan view. And a plurality of second tactile sensation generating electrodes 5b arranged to overlap each electrode of the second detection electrode 27 group of the Y coordinate detection sheet 25 in plan view. The plurality of first tactile generation electrodes 5a and the plurality of second tactile generation electrodes 5b constitute a group of tactile generation electrodes 5.

  A plurality of first tactile generation electrodes 5a in the tactile generation electrode group 5 are connected in a line in the Y-axis direction (vertical direction in the figure) in the same manner as the first detection electrodes 24, and constitute a first tactile generation electrode array 5A. doing. The first tactile sensation generating electrode rows 5A are distributed and arranged at equal intervals in the X-axis direction (the horizontal direction in the figure). The plurality of second tactile generation electrodes 5b in the tactile generation electrode group 5 are connected in a line in the X-axis direction in the same manner as the second detection electrode 27, and constitute a second tactile generation electrode array 5B. . The second tactile sensation generating electrode array 5B is distributed and arranged at equal intervals in the Y-axis direction. The first tactile sensation generating electrode array 5A and the second tactile generating electrode array 5B are disposed so as to overlap with each other in plan view, respectively.

Next, the transparent protective sheet 6 of the tactile stimulus generator 1 will be described. As shown in FIGS. 2 and 3, the transparent protective sheet 6 includes a transparent insulating layer 7 made of PET (polyethylene terephthalate) and the like, and a resistance film 8 provided on the front surface of the insulating layer 7. The front surface of the resistance film 8 is an operation surface. The resistance film 8 is for suppressing frictional charging, and the surface resistivity is 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □. Such a resistance film 8 is obtained, for example, by coating the surface of the insulating layer 7 with a transparent resistor material having a predetermined surface resistivity. As shown in FIG. 3, when the transparent protective sheet 6 and the tactile stimulus generating sheet 3 are laminated, the insulating layer 7 extends to a position covering the tactile sense generating electrode 5 group of the tactile stimulus generating sheet 3. When the fingertip 40 comes into contact with the operation surface, the fingertip 40 comes into contact with the front surface of the resistance film 8 and comes close to the tactile sense generating electrode 5 group through the resistance film 8 and the insulating layer 7.

  Next, the circuit configuration and operation principle of the tactile stimulus generator 1 will be described with reference to FIGS. FIG. 7 is an explanatory diagram showing a circuit configuration example of the signal generator shown in FIG. FIG. 8 is an explanatory diagram showing the operating principle of the tactile transmission unit shown in FIG.

  The tactile stimulus generator 1 includes a signal generator 10 that applies a controlled electric signal to the tactile transmitter 2. The signal generator 10 generates a predetermined electrical signal using, for example, the circuit illustrated in FIG. In FIG. 7, Si is a command signal within a range of ± 2V, for example. So is an electric signal (hereinafter abbreviated as an output signal So) generated by the signal generator 10 within a range of ± 2 kV, for example. A potential difference between the voltage of the command signal Si and GND (0 V), which is the reference voltage of the operational amplifier 11, is amplified by the operational amplifier 11 and then input to the drive circuit 12. Then, the voltage of the output terminal of the drive circuit 12 is fed back through the feedback circuit 13 and stabilized so that the voltage according to the command value becomes a voltage. The output terminal of the drive circuit 12 is connected to the haptic generation electrode 5 group of the haptic transmission unit 2 via the resistor 14, and the output signal So is applied to the haptic generation electrode 5 group. Two input terminals of the insulation amplifier 15 are connected to both ends of the resistor 14. Since the voltage appearing at both ends of the resistor 14 is proportional to the amount of current flowing through the resistor 14, the voltage at both ends of the resistor 14 is processed by the insulation amplifier 15 and taken out as current information I from the output terminal of the insulation amplifier 15. The amount of current flowing from the drive circuit 12 to the tactile sensation generating electrode 5 group can be monitored.

  The electrical signal used as the command signal Si is a so-called AC electrical signal whose polarity is inverted at a predetermined cycle, and the output signal So is also an AC electrical signal. The voltage amplitude and cycle of the output signal So can be controlled by changing the voltage amplitude and cycle of the command signal Si. If the output signal So is a rectangular wave or pulse, the rise time can be controlled.

  As shown in FIG. 8, in this embodiment, two or more such circuits are used, and the first and second electric signals So1 and So2 have opposite positive and negative polarities. Are generated as an output signal So. Then, the voltage amplitude of the first electric signal So1 and the voltage amplitude of the second electric signal So2 are controlled so as to have predetermined values, respectively. The first electric signal So1 is applied to the first haptic generation electrode 5a constituting the haptic generation electrode 5 group, and the second electric signal So2 is applied to the second haptic generation electrode 5b constituting the haptic generation electrode 5 group. As a result, one of the first tactile sensation generating electrode 5a and the second tactile sensation generating electrode 5b is alternately a positive electrode relative to the other, and the other is a relatively negative electrode. Since the first electric signal So1 and the second electric signal So2 are AC electric signals, the plus side electrode and the minus side electrode are switched with time. FIG. 8 shows an operation state when the first tactile sensation generating electrode 5a is a plus side electrode and the second tactile sensation generating electrode 5b is a minus side electrode.

  Further, in the present embodiment, the current information of the current flowing through the plus side electrode of the tactile generation electrode group 5 is taken as the first current information I1, and the current information of the current flowing through the minus side electrode is taken as the second current information I2, respectively, While monitoring the first current information I1 and the second current information I2 so that the amount of current flowing from the plus electrode to the fingertip 40 and the amount of current flowing from the fingertip 40 to the minus electrode are substantially equal. The amount of current is controlled. As a method of controlling the amount of current, for example, if the electrical signal is a rectangular wave or pulse, when increasing the amount of current, the rise time is shortened (rise is sharp) and the amount of current is reduced. Can be controlled by increasing the rise time (slow rise).

  In the haptic stimulus generator 1, the output signal So is applied to the haptic generation electrodes 5 of the haptic transmission unit 2 in this way. The tactile transmission unit 2 capacitively couples the fingertip 40 close to the tactile generation electrode 5 group via the resistance film 8 and the insulating layer 7 of the transparent protective sheet 6 and the tactile generation electrode 5 group, thereby capacitively coupling the fingertip 40. An electrical stimulation signal can be transmitted to the device. This stimulation signal includes a first stimulation signal using the electric charge excited on the skin of the fingertip 40 and a second stimulation signal using an electric current flowing between the electrode patterns via the fingertip 40.

  The first stimulus signal can be transmitted to the fingertip 40 as follows. As shown in FIG. 8, when the fingertip 40 comes into contact with the operation surface, the fingertip 40 comes close to the nearby tactile generation electrode 5 group via the resistance film 8 and the insulating layer 7 and is capacitively coupled to the tactile generation electrode 5 group. Since the output signal So, which is an alternating electrical signal, is applied to the tactile generation electrodes 5 group, the fingertip 40 is charged according to the voltage amplitude and period of the output signal So, and the skin of the fingertip 40 is charged. Excited. This electric charge is distributed in a plane in a portion facing the tactile sensation generating electrode 5 group in the vicinity of the fingertip 40. And the 1st stimulus signal which stimulates the fingertip 40 with this electric charge can be transmitted to the fingertip 40.

  The second stimulus signal can be transmitted to the fingertip 40 as follows. As shown in FIG. 8, when the fingertip 40 comes into contact with the operation surface, the fingertip 40 comes close to the nearby tactile generation electrode 5 group via the resistance film 8 and the insulating layer 7 and is capacitively coupled to the tactile generation electrode 5 group. Since the output signal So, which is an AC electrical signal, is applied to the tactile generation electrode 5 group, the tactile generation electrode 5 group and the fingertip 40 correspond to the voltage amplitude, period, and rise time of the output signal So. An alternating current flows between them. This current includes a current flowing from the plus side electrode of the tactile sensation generating electrode group 5 to the fingertip 40 and a current flowing from the fingertip 40 to the minus side electrode of the tactile sense generating electrode group 5. Then, by controlling the amount of current so that the amount of current flowing into the fingertip 40 from the plus side electrode and the amount of current flowing out of the fingertip 40 into the minus side electrode are substantially equal, the plus side electrode is connected via the fingertip 40. Flows to the adjacent negative electrode. Since the current has a property of trying to flow through the shortest path, the current flows in a concentrated manner in a portion of the fingertip 40 close to the electrode pattern of the plus side electrode and the minus side electrode. And the 2nd stimulation signal which stimulates the fingertip 40 with this electric current can be transmitted to the fingertip 40.

  The tactile stimulus generator 1 can transmit such a first stimulus signal and a second stimulus signal to the fingertip 40, and allows the user to sense it as a pseudo tactile stimulus that makes it easy to recognize the shape of the electrode pattern. it can. Then, by installing and using such a tactile stimulus generator 1 on the front surface of the coordinate input device 21, it is possible to feed back to the user as a tactile stimulus which region on the operation surface the fingertip 40 is placed on. become.

Next, the characteristics of the output signal So, which is an electrical signal generated by the signal generator 10, will be described with reference to FIGS. FIG. 9 is an explanatory diagram illustrating a characteristic example of an output signal of the signal generation unit illustrated in FIG. FIG. 10 is an explanatory diagram showing the characteristics of the first AC signal of the output signal shown in FIG. FIG. 11 is an explanatory diagram showing the characteristics of the second AC signal of the output signal shown in FIG.
9 to 11, the horizontal axis represents time t and the vertical axis represents voltage V.

  As illustrated in FIG. 9, the output signal So is inserted when the polarity of the first AC signal Sa1 whose polarity is inverted at a predetermined period and the polarity of the first AC signal Sa1 is inverted, and shorter than the first AC signal Sa1. It is an electric signal including the second AC signal Sa2 whose polarity is inverted with a period. As the first AC signal Sa1, for example, as shown in FIG. 10, a rectangular wave having a voltage amplitude V1, a period T1, and a rise time ta is used. As the period T1 of the first AC signal Sa1, for example, one having a period of about 2 to 10 msec (100 to 500 Hz in terms of frequency) is used. Then, the polarity of the first AC signal Sa1 is inverted every half cycle (1/2 of the cycle T1). As the second AC signal Sa2, for example, a rectangular wave having a voltage amplitude of V1 and a period of T2 is used as shown in FIG. As the period T2 of the second AC signal Sa2, for example, one having a period of about a quarter of the period T1 of the first AC signal Sa1 is used.

  In FIG. 9, as the output signal So, a signal for two cycles of the second AC signal Sa2 is inserted between the times t1 and t2 when the polarity is inverted in the signal for one cycle of the first AC signal Sa1. An example is shown. The voltage amplitude V1, the period T1, the period T2, and the rise time ta are controlled to predetermined values by changing the characteristics of the command signal Si. By applying the output signal So controlled in this way to the tactile sensation generating electrode 5 group repeatedly once or a plurality of times, an electrical stimulation signal controlled to a predetermined strength can be transmitted. At this time, the voltage of the first AC signal Sa1 at the times t1 and t2 when the polarity is inverted may not be 0, and the time period during which the voltage of the first AC signal Sa1 decreases from V1 to -V1, or from -V1 to V1 It can be anywhere as long as it increases.

  Here, as described above, the electrical stimulation signal is the first stimulation signal using the charge excited on the skin of the fingertip 40 and the second stimulation using the current flowing between the electrode patterns via the fingertip 40. Signal. And the intensity | strength of a 1st stimulus signal can be controlled by the following method, for example. When the voltage amplitude V1 of the output signal So is increased, the excited charge increases and the first stimulation signal becomes stronger. Conversely, when the voltage amplitude V1 is reduced, the excited charge is reduced and the first stimulus signal is weakened. The intensity of the second stimulation signal can be controlled by the following method, for example. When the rising time ta of the first AC signal Sa1 is shortened (the rising is sharp), the amount of current flowing into the fingertip 40 increases and the second stimulation signal becomes strong. Conversely, if the rising time ta is lengthened (rising slowly), the amount of current flowing into the fingertip 40 decreases and the second stimulus signal becomes weak. The tactile stimulus generator 1 can control the strengths of the first stimulus signal and the second stimulus signal in this way.

  The first stimulus signal is suitable for generating a uniform stimulus regardless of the electrode shape. The second stimulus signal is suitable for generating a stimulus in accordance with the electrode shape. The state of the electrical stimulus signal transmitted to the fingertip 40 can be varied by appropriately controlling the strength of the first stimulus signal and the strength of the second stimulus signal. For example, it is possible to transmit a stimulus signal that emphasizes the button-shaped edge portion of a specific button to the fingertip 40. Further, it is possible to change the stimulus signal in accordance with the position on the operation surface, and to transmit, for example, a stimulus signal reminiscent of a texture sensation to the fingertip 40. Further, for example, when an operation such as swipe input is performed, it is also possible to change the stimulation signal with time in accordance with the operation. Conversely, a stable stimulation signal can be transmitted to the fingertip 40 regardless of the electrode shape and position.

  Next, the effect of this embodiment will be described. In the tactile stimulus generator 1 according to the present embodiment, the output signal So, which is an electrical signal generated by the signal generator 10, is a first AC signal Sa1 whose polarity is inverted at a predetermined period T1 and the first AC signal Sa1. And a second AC signal Sa2 which is inserted when the polarity is inverted and whose polarity is inverted at a cycle T2 shorter than that of the first AC signal Sa1. The polarity of such an output signal So changes (inverts) with time, and the period also changes with time. And since the stimulation signal which added the change of the period to the change of polarity is transmitted to the fingertip 40 using such an output signal So, it is easy for a user to detect. Moreover, in the tactile stimulus generator 1, since the stimulus signal that is easy for the user to sense by adding a change in the period to the change in the polarity of the output signal So, the voltage amplitude of the output signal So can be reduced. Therefore, even when the fingertip 40 is brought close to or in contact with the tactile stimulus generator 1 while a part of the user's body is in contact with a grounded metal or the like, an abnormal AC current is generated from the fingertip 40 to the user's body. The possibility of flowing into the user and causing the user to feel pain is reduced, and safety can be improved. Therefore, the tactile stimulus generator 1 can transmit a stimulus signal that is safe and easy for the user to sense to the fingertip 40.

  Furthermore, in the haptic stimulus generation device 1 according to the present embodiment, the haptic transmission unit 2 includes the tactile generation electrode 5 group and the insulating layer 7 provided at a position covering the front surface of the tactile generation electrode 5 group. . When the fingertip 40 is brought close to the tactile generation electrode 5 group via the insulating layer 7, the distance between the fingertip 40 and the tactile generation electrode 5 group can be stabilized by the insulating layer 7. Therefore, it is possible to stably capacitively couple the fingertip 40 and the tactile sensation generating electrode 5 group via the insulating layer 7. As a result, the tactile stimulus generator 1 can stably transmit a stimulus signal that is easy for the user to sense to the fingertip 40.

  Furthermore, in the haptic stimulation generating apparatus 1 according to the present embodiment, the haptic generation electrode 5 group includes the first haptic generation electrode 5a and the second haptic generation electrode 5b, and the output signal So has a plus / minus polarity. The first electric signal So1 and the second electric signal So2 are opposite to each other. The first electric signal So1 is supplied to the first haptic generating electrode 5a, and the second electric signal So2 is supplied to the second haptic generating electrode 5b. Applied. Then, when the fingertip 40 is brought close to the first tactile generation electrode 5a and the second tactile generation electrode 5b via the insulating layer 7, the fingertip 40, the first tactile generation electrode 5a and the second tactile generation electrode 5b are interposed via the insulating layer 7. The tactile sensation generating electrode 5b is capacitively coupled. As a result, the tactile transmission unit 2 can excite the charges distributed in a plane on the part of the fingertip 40 facing the first tactile generation electrode 5a and the second tactile generation electrode 5b. In addition, a current can be caused to flow between the electrode patterns of the first tactile generating electrode 5a and the second tactile generating electrode 5b via the fingertip 40. Since the current has the property of trying to flow through the shortest path, this current is concentrated in the fingertip 40 at a portion near the electrode pattern between the first tactile generating electrode 5a and the second tactile generating electrode 5b. It begins to flow. The tactile stimulus generator 1 can transmit to the fingertip 40 a stimulus signal that is easy to be aware of the shape of the electrode pattern and that can be more easily sensed by the user by using such electric charge and current.

  In the tactile stimulus generator 1 according to the present embodiment, it is desirable that the output signal So is controlled so that the voltage amplitude of the first electric signal So1 and the voltage amplitude of the second electric signal So2 are substantially equal. . In such a tactile stimulus generation device 1, a stimulus signal (particularly the first stimulus signal) transmitted to the fingertip 40 by the first tactile generation electrode 5a and a stimulus signal (particularly the first stimulus signal transmitted to the fingertip 40 by the second tactile generation electrode 5b). 1 stimulus signal) can be made substantially equal in strength. By arranging such a group of tactile generation electrodes 5 on the front surface of the insulating layer 4 of the tactile stimulus generation sheet 3 with a uniform distribution, it is possible to transmit a stimulus signal having a small intensity variation depending on the position to the fingertip 40. it can. As a result, the tactile stimulus generator 1 can stably transmit a stimulus signal that is easy for the user to sense to the fingertip 40.

  Next, the effect of the resistance film 8 will be described. In the tactile stimulus generating apparatus 1 according to the present embodiment, the transparent protective sheet 6 of the tactile transmission unit 2 includes a transparent insulating layer 7 made of PET (polyethylene terephthalate) or the like. The insulating layer 7 made of such a material tends to generate frictional charging with the fingertip 40. Here, if the resistance film 8 is not provided on the front surface of the insulating layer 7, the front surface of the insulating layer 7 becomes the operation surface. When the fingertip 40 moves while being in contact with the insulating layer 7, electric charges are easily excited on the skin of the fingertip 40 due to frictional charging between the fingertip 40 and the insulating layer 7. At this time, in the tactile stimulus generator 1, the fingertip 40 is charged by using capacitive coupling between the fingertip 40 and the tactile generation electrode 5 via the insulating layer 7. Since the stimulation signal (particularly the first stimulation signal) is generated using the electric charge excited on the skin of the fingertip 40 by this charging, the frictional charging may affect the stimulation signal.

However, the tactile stimulus generator 1 according to the present embodiment includes the resistance film 8 provided on the front surface of the insulating layer 7. The surface resistivity of the resistance film 8 is 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □. The front surface of the resistance film 8 is an operation surface. Since a little current flows through the resistance film 8, even if frictional charging occurs between the fingertip 40 and the resistance film 8 when the fingertip 40 moves while being in contact with the resistance film 8, the friction charging is performed. The electric charges excited by can be diffused into the resistance film 8. Therefore, frictional charging between the fingertip 40 and the resistance film 8 can be suppressed. As a result, there is no influence of frictional charging between the fingertip 40 and the resistive film 8, and a stimulation signal that can be more easily detected by the user can be transmitted to the fingertip 40.

  Here, the surface resistivity of the resistance film 8 will be supplementarily described with reference to FIG. FIG. 12 is an explanatory diagram schematically showing the relationship between the surface resistivity and the surface potential of the resistance film according to the embodiment of the present invention. In FIG. 12, the horizontal axis represents the surface resistivity ρ, and the vertical axis represents the surface potential Vs. The surface potential Vs becomes higher as the resistance film is more easily charged, and lower as the resistance film is less likely to be charged. Therefore, the surface potential Vs is an index of the ease of charging of the resistance film.

  As shown in FIG. 12, when the surface resistivity ρ is extremely low, the value of the surface potential Vs is very low. This indicates that the current easily flows through the resistance film, and as a result, it is very difficult to be charged. The resistance film made of such a material does not cause frictional charging, but inhibits charging other than frictional charging. For example, in the present embodiment, the fingertip 40 is charged by using capacitive coupling between the fingertip 40 and the tactile sensation generating electrode 5 via the resistance film 8 and the insulating layer 7. End up. Therefore, such a material is not suitable for the resistance film 8. In charging using capacitive coupling between the fingertip 40 and the tactile generating electrode 5, the insulating layer 7 is also interposed between the fingertip 40 and the tactile generating electrode 5 together with the resistance film 8. Although the influence of the rate ρ is not great, this tendency becomes remarkable when the surface resistivity ρ is lower than ρ1 (the surface potential Vs is lower than V1).

  On the other hand, when the surface resistivity ρ is extremely high, the surface potential Vs is stabilized at a very high value. This indicates that almost no current flows through the resistance film, and as a result, it becomes very easy to be charged. With such a resistive film, frictional charging cannot be suppressed. Therefore, such a material is not suitable for the resistance film 8. When the surface resistivity ρ is higher than ρ2 (surface potential Vs is higher than V2), such a tendency becomes remarkable.

Therefore, as the material of the resistance film 8, a material having a surface resistivity ρ between ρ1 and ρ2 is suitable. When such a material is used for the resistance film 8, a slight current flows through the resistance film 8, so that when the fingertip 40 moves while being in contact with the resistance film 8, it is between the fingertip 40 and the resistance film 8. Even if frictional charging occurs, the charge excited by frictional charging can be diffused into the resistance film 8. Therefore, frictional charging between the fingertip 40 and the resistance film 8 can be suppressed. Further, the charging using capacitive coupling between the fingertip 40 and the tactile sensation generating electrode 5 is not inhibited. The values of ρ1 and ρ2 vary somewhat depending on the conditions for charging the resistive film. However, when used in the tactile stimulus generator 1 according to the present embodiment, ρ1 is about 1 × 10 ^{11 to} 5 × 10 ¹¹ Ω / □, and ρ2 Is about 5 × 10 ¹² to 1 × 10 ¹³ Ω / □. Therefore, the surface resistivity ρ of the resistive film 8 is preferably 1 × 10 ¹¹ to 1 × 10 ¹³ Ω / □, and more preferably 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □.

  Next, the effect of the coordinate input system provided with the tactile stimulus generator 1 according to the present embodiment will be described. So far, the use example in which the tactile stimulus generator 1 and the coordinate input device 21 are provided and the tactile stimulus generator 1 is installed on the front surface of the coordinate input device 21 to form the coordinate input system 20 has been described. In such a coordinate input system 20, the tactile stimulus generator 1 can transmit a stimulus signal that is safe and easy for the user to perceive. Then, such a tactile stimulus generator 1 is installed on the front surface of the coordinate input device 21, and the tactile transmission unit 2 sends a stimulus signal to the fingertip 40 according to the coordinate position information obtained from the coordinate input device 21. Is communicating to. As a result, the coordinate input system 20 detects the coordinate position when the fingertip 40 comes close to the coordinate input device 21, enables an input operation according to the coordinate position, and is safe and easy for the user to detect. A stimulation signal can be transmitted to the fingertip 40.

  As described above, in the haptic stimulus generator 1 according to the present embodiment, the output signal So, which is an electrical signal generated by the signal generator 10, is the first AC signal Sa1 whose polarity is inverted at a predetermined period T1. And a second AC signal Sa2 which is inserted when the polarity of the first AC signal Sa1 is inverted and whose polarity is inverted in a cycle T2 shorter than that of the first AC signal Sa1. The polarity of such an output signal So changes (inverts) with time, and the period also changes with time. And since the stimulation signal which added the change of the period to the change of polarity is transmitted to the fingertip 40 using such an output signal So, it is easy for a user to detect. Moreover, in the tactile stimulus generator 1, since the stimulus signal that is easy for the user to sense by adding a change in the period to the change in the polarity of the output signal So, the voltage amplitude of the output signal So can be reduced. Therefore, even when the fingertip 40 is brought close to or in contact with the tactile stimulus generator 1 while a part of the user's body is in contact with a grounded metal or the like, an abnormal AC current is generated from the fingertip 40 to the user's body. The possibility of flowing into the user and causing the user to feel pain is reduced, and safety can be improved. Therefore, the tactile stimulus generator 1 can transmit a stimulus signal that is safe and easy for the user to sense to the fingertip 40.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the scope of the object of the present invention.

  For example, the coordinate detection method of the coordinate input device used together with the tactile stimulus generator may be a method other than the electrostatic capacitance method such as a resistive film method, a surface acoustic wave method, or an electromagnetic induction method.

  The size and shape of the tactile generation electrode of the tactile stimulus generator may be different from the first detection electrode and the second detection electrode of the coordinate input device as long as the coordinate detection of the coordinate input device is not hindered. . Further, the size and shape of the haptic generating electrode at a specific position may be different from the size and shape of the haptic generating electrode at another position.

  The circuit configuration of the signal generator may be a circuit configuration other than the circuit shown in FIG. 6 as long as a predetermined electrical signal can be generated. In addition, an electrical signal having a characteristic different from that of the electrical signal applied to the haptic generation electrode at another position may be applied to the haptic generation electrode at a specific position.

  If the desired stimulation signal can be transmitted, the first AC signal and the second AC signal included in the electric signal (output signal) generated by the signal generation unit are not rectangular waves, such as sine waves or pulse waves. It may be a signal. Moreover, as long as a desired stimulus signal can be transmitted, the period of the second AC signal may be a period other than a quarter of the period of the first AC signal. For example, it may be a half cycle of the first AC signal or a 1/8 cycle.

DESCRIPTION OF SYMBOLS 1 Tactile stimulation generator 2 Tactile transmission part 3 Tactile stimulation generation sheet 4 7 23 26 Insulating layer 5 Tactile generation electrode 5a 1st tactile generation electrode 5b 2nd tactile generation electrode 5A 1st tactile generation electrode row 5B 2nd tactile generation electrode row 6 Transparent protective sheet 8 Resistive film 10 Signal generator 11 Operational amplifier 12 Drive circuit 13 Feedback circuit 14 Resistor 15 Insulation amplifier 20 Coordinate input system 21 Coordinate input device 22 X coordinate detection sheet 24 First detection electrode 24A First detection electrode array 25 Y-coordinate detection sheet 27 Second detection electrode 27A Second detection electrode array 40 Fingertip (body specifying part)

Claims (6)

A tactile stimulus generation device capable of transmitting an electrical stimulation signal to the body specifying unit when a body specifying unit such as a user's fingertip approaches or comes into contact with the body specifying unit,
A tactile transmission unit that transmits the stimulation signal to the body specifying unit by capacitively coupling with the body specifying unit; and a signal generation unit that applies a controlled electrical signal to the tactile transmission unit,
The electrical signal generated by the signal generator is inserted in a first AC signal whose polarity is inverted at a predetermined cycle and a cycle shorter than the first AC signal inserted when the polarity of the first AC signal is inverted. A tactile stimulus generating device comprising: a second AC signal whose polarity is inverted. The tactile transmission unit includes a plurality of tactile generation electrodes, and an insulating layer provided at a position covering the front surface of the tactile generation electrodes.
The electrical signal generated by the signal generation unit is applied to the tactile generation electrode,
The haptic stimulus generation device according to claim 1, wherein the haptic transmission unit transmits the stimulation signal to the body specifying unit adjacent to the haptic generation electrode through the insulating layer. The plurality of haptic generating electrodes include at least one first haptic generating electrode and at least one second haptic generating electrode;
The electrical signal includes a first electrical signal and a second electrical signal having positive and negative polarities opposite to each other,
The first electrical signal is applied to the first haptic generating electrode, and the second electrical signal is applied to the second haptic generating electrode.
The tactile transmission unit transmits the stimulation signal to the body specifying unit adjacent to the first tactile generation electrode and the second tactile generation electrode through the insulating layer. Tactile stimulation generator.   The haptic stimulation according to claim 3, wherein the signal generator controls the electric signal so that a voltage amplitude of the first electric signal is substantially equal to a voltage amplitude of the second electric signal. Generator. The tactile transmission unit includes a resistance film provided on the front surface of the insulating layer,
5. The tactile stimulus generator according to claim 2, wherein a surface resistivity of the resistance film is 5 × 10 ^{11 to} 5 × 10 ¹² Ω / □. 6. A tactile stimulus generating device according to any one of claims 1 to 5, and a coordinate input device capable of detecting a coordinate position when the body specifying part approaches,
The tactile stimulus generator is installed in front of the coordinate input device,
The coordinate input system, wherein the tactile sensation transmission unit transmits the stimulation signal to the body identification unit in accordance with the information on the coordinate position obtained from the coordinate input device.

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