Haptic detection device and haptic transmission system

Abstract

Provided is a haptic detection device capable of detecting, through a simple configuration, a sensation felt by a fingertip or the like. For this purpose, the present invention is constituted by: a piezoelectric sensor provided with a piezoelectric film that generates electrical charge by being deformed by application of pressure; and a detection circuit that converts the electrical charge generated by the piezoelectric sensor into a voltage. The piezoelectric sensor is disposed so as to be in direct or indirect contact with the skin surface, and a voltage obtained by converting the electrical charge, on the skin surface, generated by the piezoelectric sensor when an object is touched is used as a haptic detection signal. Furthermore, the haptic detection signal is sampled at a prescribed frequency, and a pulse voltage at a constant short time interval for each sampled signal is applied to an electrode in contact with the skin of a haptic sensation producer to produce a haptic sensation.

Description

Tactile detection device and tactile transmission system

[0001] The present invention relates to a tactile detection device that converts the tactile sensation felt by a fingertip or the like into data, and a tactile transmission system that transmits the tactile data obtained by the tactile detection device.

[0002] In recent years, tactile presentation devices that present simulated tactile sensations to the skin of fingers and other surfaces have been developed. For example, a tactile presentation device has been developed that uses vibrations from a vibrating member attached to a finger to reproduce various tactile sensations, such as the sensation of rubbing a finger against a smooth surface or a rough surface. By using such a tactile presentation device, it is possible to present a tactile sensation linked to a video image, giving the subject the sensation of actually touching something shown in the video.

[0003] Methods for presenting tactile sensations include physical vibrations using a vibrating member and stimulation using electrodes. Electrodes are suitable because they can be made relatively small. Patent Document 1 describes a technology in which tiny electrodes arranged on a substrate are brought into contact with the finger to present tactile sensations through electrical stimulation.

[0004] Japanese Patent Application Laid-Open No. 2020-173546

[0005] As described in Patent Document 1, while progress has been made in the development of technology for presenting tactile sensations to fingertips and the like, it cannot be said that progress has been made in technology for appropriately detecting and digitizing the tactile sensations felt by human fingertips and the like. In other words, when digitizing the tactile sensations felt by the fingertips, it is necessary to accurately detect the vibrations of the fingertips, which correspond to the tactile sensations, using a sensor or the like. Furthermore, in order to accurately detect the vibrations of the fingertips, it is necessary to attach a vibration detection sensor of a certain size to the fingertips, which requires a relatively large detection device.

[0006] If vibration detection sensors attached to fingertips or the like could be miniaturized, it would be possible to easily detect and digitize tactile sensations. Then, by transmitting the vibration data corresponding to the obtained tactile sensation to a tactile presentation device such as that described in Patent Document 1, it would be possible to present the tactile sensation felt by a tactile senser in real time to another tactile presenter. However, such a tactile presentation device could not be realized with conventional technology.

[0007] In view of the above, an object of the present invention is to provide a tactile detection device that can easily detect tactile sensations, and a tactile transmission system that transmits tactile data obtained by the tactile detection device.

[0008] The touch detection device of the present invention comprises a piezoelectric sensor having a piezoelectric film disposed on a base film that generates an electric charge when deformed by the application of pressure, and a detection circuit that converts the electric charge generated by the piezoelectric sensor into a voltage. The touch detection device of the present invention places the piezoelectric sensor in contact with the skin surface, and when an object is touched near the skin surface, the electric charge generated in the piezoelectric sensor is converted into a voltage by the detection circuit to produce a touch detection signal.

[0009] The tactile transmission system of the present invention is a tactile transmission system that transmits the tactile sensation felt by a tactile detector on his / her skin to a tactile presenter. The tactile transmission system of the present invention includes a piezoelectric sensor that is worn in direct or indirect contact with the skin surface of the tactile detector and has a piezoelectric film that generates an electric charge when deformed by the application of pressure, a detection unit that samples the tactile detection signal obtained by converting the electric charge generated by the piezoelectric sensor into a voltage at a predetermined frequency, a waveform processing unit that converts the signals sampled by the detection unit into pulse voltages with a fixed short-time interval for each sampling signal, and a pulse application unit that applies the pulse voltages with a fixed short-time interval obtained by the waveform processing unit to an electrode in contact with the skin of the tactile presenter.

[0010] According to the present invention, the tactile sensation felt by the tactile detector can be detected with high accuracy by the piezoelectric sensor to obtain a tactile detection signal. Furthermore, by sampling the obtained tactile detection signal and providing it to an electrode, the tactile sensation felt by the tactile detector can be made to be felt by another tactile presenter.

[0011] FIG. 1 is a configuration diagram showing an example of a tactile presentation device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a schematic configuration of a piezoelectric sensor according to an embodiment of the present invention. FIG. 3 is a flowchart showing an example of tactile presentation processing according to an embodiment of the present invention. FIG. 4 is a characteristic diagram showing an example of a sensor detection signal according to an embodiment of the present invention. FIG. 5 is a characteristic diagram showing an example of a tactile presentation signal according to an embodiment of the present invention. FIG. 6 is a characteristic diagram showing examples of five types of sensor detection signals according to an embodiment of the present invention. FIG. 7 is a diagram showing an example of an electrode arrangement according to a modified example of an embodiment of the present invention.

[0012] An embodiment of the present invention (hereinafter referred to as "this embodiment") will be described below with reference to the accompanying drawings. As shown in Fig. 1, the tactile transmission system of this embodiment includes tactile detection sensors 30a, 30b, 30c, 30d, and 30e attached to five fingers of a hand H1 of a tactile detector, and electrodes 23a, 23b, 23c, 23d, and 23e attached to five fingers of a hand H2 of a tactile presenter who presents the tactile sense detected by the tactile detector. The tactile sense detected by the tactile detection sensors 30a, 30b, 30c, 30d, and 30e is transmitted to and reproduced by the tactile presenter via the electrodes 23a, 23b, 23c, 23d, and 23e.

[0013] 1 shows an example in which tactile detection sensors 30a to 30e and electrodes 23a to 23e are attached to all five fingers, but the number of tactile detection sensors 30a to 30e and the number of electrodes 23a to 23e are just examples. For example, one tactile detection sensor 30a may be attached to one finger of the tactile detector, and the electrode 23a may be attached to one finger of the tactile presenter.

[0014] The tactile detection sensors 30a to 30e, the detailed configuration of which will be described later, are piezoelectric sensors that detect electric charges corresponding to the sense of touch. The tactile detection sensors 30a to 30e are connected to a tactile transmission device 10. The tactile transmission device 10 processes the detection signals of the tactile detection sensors 30a to 30e and generates signals to be applied to the electrodes 23a, 23b, 23c, 23d, and 23e.

[0015] As will be described below, the tactile transmission device 10 performs a tactile transmission process in which it receives tactile detection signals from the tactile detection sensors 30a to 30e and generates signals to be applied to the electrodes 23a to 23e based on the tactile detection signals. Therefore, the tactile transmission device 10 can also be considered a tactile detection device when viewed from the perspective of its tactile detection operation.

[0016] [Configuration of Tactile Transmission Device] The tactile transmission device 10 is configured, for example, by a computer that is an information processing device, and includes an acquisition unit 11, a waveform processing unit 12, a storage unit 13, and a transmission unit 14. The acquisition unit 11 includes a detection unit 11a that converts electric charges that change in response to tactile detection by tactile detection sensors 30a to 30e into voltage signals. The voltage signals converted by the detection unit 11a in the acquisition unit 11 are detection signals (tactile detection signals) of vibrations corresponding to the tactile sensation felt by the tactile detector. In other words, the tactile detection sensors 30a to 30e detect vibrations of the tactile detector's fingers when they touch (rub) the surface of an object, and obtain tactile detection signals corresponding to the vibrations.

[0017] For example, when a touch detector rubs the pad of a finger against a rough (finely uneven) surface, the touch sensors 30a to 30e obtain detection signals due to finger vibrations corresponding to the roughness (finely uneven). The detection signals output by the touch sensors 30a to 30e are signals due to changes in electric charge, and the detection unit 11a in the acquisition unit 11 obtains voltage detection signals (analog signals) corresponding to the finger vibrations using a current / voltage conversion circuit (not shown).

[0018] Furthermore, the acquisition unit 11 performs an acquisition process in which the analog signal, which is the tactile detection signal, is amplified by an amplifier (not shown), and then digitized and taken in. The tactile detection signal (digital signal) obtained by the acquisition unit 11 is supplied to the waveform processing unit 12.

[0019] The waveform processing unit 12 performs waveform processing to sample the supplied digitized tactile detection signal at a relatively low frequency for tactile presentation (for example, a frequency in the range of 20 Hz to 300 Hz). The sampling frequency when the signal is digitized by the acquisition unit 11 is set to a frequency higher than the sampling frequency when the signal is converted into a burst wave by the waveform processing unit 12, or the same frequency as the sampling frequency when the signal is converted into a burst wave by the waveform processing unit 12.

[0020] Furthermore, the waveform processing unit 12 maintains each sampled value of the sampled data for a relatively short time. The short time for which the voltage is applied, i.e., the ON pulse width, is set to, for example, 0.1 ms to 0.3 ms. The interval between each sampling signal (pulse signal) between the ON pulse width and the next ON pulse width, i.e., the OFF pulse width, is set to 0.2 ms or more. This allows processing to produce pulses with a constant short interval for each sampling signal.

[0021] The tactile detection signals (tactile detection data) obtained by processing by the waveform processing unit 12 are temporarily stored in the storage unit 13, and then transmitted by wire or wirelessly from the transmission unit 14 to the pulse application device 20. Note that the transmission unit 14 may transmit the outputs of the tactile detection sensors 30a to 30e processed by the waveform processing unit 12 in real time.

[0022] 1 , the pulse application device 20 includes a receiving unit 21 and a pulse application unit 22. The receiving unit 21 receives a tactile detection signal (tactile detection data) transmitted from the tactile transmission device 10. When wireless transmission is performed between the transmitting unit 14 of the tactile transmission device 10 and the receiving unit 21 of the pulse application device 20, wireless communication is performed according to the Bluetooth (registered trademark) standard, for example. The tactile detection signal received by the receiving unit 21 is supplied to the pulse application unit 22.

[0023] The pulse application unit 22 applies a pulse voltage to electrodes 23a, 23b, 23c, 23d, and 23e attached to five fingers of the tactile presenter's hand H2. The surfaces of the skin at the tips of the five fingers of the tactile presenter's hand H2 are in contact with the electrodes 23a, 23b, 23c, 23d, and 23e, respectively. Although not shown, a ground potential unit is also in contact with the surfaces of the skin of the same fingers.

[0024] The pulse applying unit 22 applies the tactile detection signal received by the receiving unit 21 to each of the electrodes 23 a, 23 b, 23 c, 23 d, and 23 e. The received tactile detection signal is a pulse signal with an ON pulse width of 0.1 ms to 0.3 ms at a frequency within the range of 20 Hz to 300 Hz. The interval between each OFF pulse signal is 0.2 ms or more.

[0025] If data specifying the finger to which the tactile sensation is to be applied is added to the tactile detection signal (tactile detection data) supplied from the pulse application unit 22 to each of the electrodes 23a, 23b, 23c, 23d, and 23e, the pulse signal is applied to one of the five electrodes 23a, 23b, 23c, 23d, and 23e that is attached to the corresponding finger.

[0026] The tactile transmission device 10 shown in Fig. 1 is configured as a computer, which is a so-called information processing device. That is, the hardware configuration of the computer as the tactile transmission device 10 is shown in the lower part of Fig. 1. The tactile transmission device 10 is configured as a CPU (Central Processing Unit) 10a, a work memory 10b, a storage 10c, an input unit 10d, and a communication interface 10e.

[0027] The CPU 10a is an arithmetic processing unit that reads out the program code of the software that realizes the functions performed by the tactile transmission device 10 from the storage 10c and causes the work memory 10b to execute the program code. The CPU 10a reads out the program code from the storage 10c and executes the arithmetic processing in the work memory 10b, thereby configuring various processing function units in the work memory 10b. For example, the work memory 10b is configured with the acquisition unit 11 and waveform processing unit 12 described above.

[0028] The storage 10c stores program data and also stores touch detection signals. The input unit 10d processes the touch detection signals from the touch detection sensors 30a to 30e. The communication interface 10e communicates with the pulse application device 20.

[0029] [Configuration Example of Tactile Detection Sensor] Fig. 2 shows a configuration example of the tactile detection sensors 30a to 30e of this example. Although Fig. 2 shows the configuration of the tactile detection sensor 30a, the other tactile detection sensors 30b to 30e also have the same configuration as the tactile detection sensor 30a.

[0030] Fig. 2A shows a cross-sectional configuration of the tactile detection sensor 30a, Fig. 2B shows an exploded view of each layer of the tactile detection sensor 30a, and Fig. 2B shows the configuration as seen from above. As shown in Fig. 2, the tactile detection sensor 30a includes a first electrode 31, an FPC (Flexible Printed Circuits) 32, a second electrode 33, a piezoelectric film 34, and a conductive thin film member 35. For example, a product called Picoleaf (trade name: registered trademark) can be used as the tactile detection sensor 30a having the configuration described below.

[0031] The first electrode 31 and the second electrode 33 are formed in advance on both main surfaces of the FPC 32. The second electrode 33 functions as a shield conductor. Although not shown in Fig. 2, the conductive thin film member 35 and the second electrode 33 are patterned on the underside of the FPC 32 so as to prevent a short circuit between them and to provide electrical continuity with the third electrode 36 shown in Fig. 2B. The piezoelectric film 34 and the FPC 32 are attached with an adhesive sheet or the like, for example.

[0032] The FPC 32 is a flexible insulating substrate made of polyimide, PET, liquid crystal polymer, or the like. The second electrode 33 is formed on the lower surface of the FPC 32. The first electrode 31 is formed on the upper surface of the FPC 32. The first electrode 31 functions as a signal electrode for detecting charges generated in the piezoelectric film 34. The first electrode 31 extends along the longitudinal direction of the FPC 32 and is electrically connected to a detection terminal (not shown). The first electrode 31 and the conductive thin film member 35 are also connected to the ground portion of the detection terminal.

[0033] The lower surface of the piezoelectric film 34 is attached to the upper surface of the first electrode 31. A conductive thin film member 35 is attached to the upper surface of the piezoelectric film 34. The conductive thin film member 35 is electrically connected to a third electrode 36 ( FIG. 2B ) formed on the upper surface of the FPC 32. The third electrode 36 extends along the longitudinal direction of the FPC 32 and is electrically connected to a detection element 37. The detection element 37 processes the change in charge obtained by the piezoelectric film 34 into a voltage signal corresponding to the change, and constitutes a part of the detection unit 11a. Note that the touch detection sensor 30a may not be equipped with the detection element 37, and the first electrode 31 and the second electrode 33 may be drawn out to the outside.

[0034] This allows the conductive thin film member 35 to function as a shield conductor. Furthermore, with this structure, both the signal electrode and the ground electrode can be taken out from the same upper surface (the same surface) of the FPC 32, facilitating mounting. It is preferable that the upper surface of the conductive thin film member 35 is further protected by being covered with a PET film or the like. Alternatively, a configuration may be adopted in which no protective film is provided on the upper surface of the conductive thin film member 35.

[0035] The conductive thin film member 35 may be, for example, a conductive nonwoven fabric with an adhesive applied thereto, or a resin-impregnated copper foil with an adhesive applied thereto. The conductive thin film member 35 is attached so as to cover the piezoelectric film 34 and also the third electrode 36. However, the conductive thin film member 35 does not necessarily have to cover the entirety of the piezoelectric film 34; it is sufficient that it covers at least a portion of the piezoelectric film 34. The conductive thin film member 35 has lower rigidity than the first electrode 31 and the second electrode 33 so as not to inhibit the deformation of the piezoelectric film.

[0036] For example, if the first electrode 31 and the second electrode 33 are made of copper foil with an elastic modulus of approximately 1.0×10 Pa and the conductive thin film member 35 is made of conductive nonwoven fabric with an elastic modulus of approximately 1.0×10 Pa to 1.0×10 Pa, deformation due to pressure is easily transmitted to the piezoelectric film 34, and deformation of the piezoelectric film 34 is not hindered. Furthermore, even if the conductive thin film member 35, the first electrode 31, and the second electrode 33 are made of the same material, making the thickness of the conductive thin film member 35 thinner than the thicknesses of the first electrode 31 and the second electrode 33 does not hinder deformation of the piezoelectric film 34.

[0037] The piezoelectric film 34 is a piezoelectric material that generates electric charges on opposing flat film surfaces by expanding and contracting, and is made of a chiral polymer. More preferably, the piezoelectric film 34 is made of uniaxially stretched polylactic acid (PLA), more specifically, L-polylactic acid (PLLA). The uniaxial stretching direction of the polylactic acid forms an angle of approximately 45° with respect to the longitudinal direction of the piezoelectric film. While this angle is most preferably 45°, it is acceptable for it to be within a range of approximately ±10°.

[0038] Chiral polymers have a helical main chain structure, and when uniaxially stretched, the molecules become oriented and exhibit piezoelectricity. Because chiral polymers exhibit piezoelectricity through molecular orientation processes such as stretching, poling is not required, as is the case with other polymers such as PVDF and piezoelectric ceramics. In particular, polylactic acid lacks pyroelectricity, meaning the detected charge amount remains constant even when heat from a user's finger or other object is transmitted. Furthermore, the piezoelectric constant of uniaxially stretched PLLA is among the highest among polymers. For example, the piezoelectric strain constant d14 of PLLA can be as high as 10-20 pC / N by adjusting the stretching conditions, heat treatment conditions, and additive blending conditions. Furthermore, the piezoelectric constant of PLLA is extremely stable and does not fluctuate over time.

[0039] The preferred stretching ratio for the piezoelectric film is approximately 3 to 8 times. Heat treatment after stretching promotes crystallization of the extended chain crystals of polylactic acid, improving the piezoelectric constant. Biaxial stretching can achieve the same effect as uniaxial stretching by varying the stretching ratio along each axis. For example, stretching a film 8 times in a certain direction (the X axis) and 2 times in the Y axis (perpendicular to the X axis) achieves a piezoelectric constant roughly equivalent to uniaxial stretching 4 times in the X axis. Because a piezoelectric film that is simply uniaxially stretched is prone to tearing along the stretching axis, biaxial stretching as described above can somewhat increase its strength. Using a chiral polymer (polylactic acid) for the piezoelectric film 34 is just one example; it could also be made from, for example, PVDF.

[0040] The signal electrode and ground electrode of the tactile detection sensor 30a configured as described above are connected to the acquisition unit 11 of the tactile transmission device 10 shown in FIG. 1 . In the example shown in FIG. 2 , the FPC 32 serving as the base film is configured in a strip shape, and the strip-shaped FPC 32 is connected in a ring shape. This results in a ring-shaped tactile detection sensor 30a that can be worn on a finger of the tactile detection user's hand H1. When worn on a finger of the hand H1, the conductive thin film member 35 on the piezoelectric film 34 is in contact with the skin surface of the finger. If a protective film is provided on the surface of the conductive thin film member 35, the conductive thin film member 35 will be in indirect contact with the skin surface of the finger. The tactile detection sensor 30a using such a piezoelectric film 34 can detect pressure (pressure) with extremely high sensitivity, and can detect minute displacements, for example, in the 1 μm range. Furthermore, the tactile detection sensor 30a using the piezoelectric film 34 does not fluctuate in sensitivity due to temperature (the wearer's body temperature) and generates little noise.

[0041] [Example of Transmission Processing of Tactile Detection Signal] Figure 3 is a flowchart showing an example of processing in the tactile transmission device 10 and the pulse application device 20. First, the tactile transmission device 10 samples the input tactile detection signal (voltage signal) at a low frequency for tactile presentation in the range of 20 Hz to 300 Hz to generate pulse data, and performs waveform processing to set the ON pulse width of each signal to 0.1 ms to 0.3 ms (step S11). The OFF pulse width here is set to 0.2 ms or more. Then, the transmission unit 14 transmits the tactile presentation data obtained in step S11 to the pulse application device 20 (step S12). The tactile transmission device 10 repeatedly executes the processing of steps S11 and S12.

[0042] The pulse application device 20 receives the tactile sensation providing data transmitted in step S12 (step S21). The pulse application unit 22 then applies a pulse voltage based on the tactile sensation providing data received in step S21 to one of the electrodes 23a to 23e of the corresponding finger (step S22). The pulse application device 20 repeatedly executes the processes of steps S21 and S22.

[0043] [Examples of Sensor Detection Signals and Electrode Application Signals] Next, examples of sensor detection signals supplied to the tactile transmission device 10 of this example and tactile presentation signals obtained by processing the sensor detection signals will be described. Figure 4 is an enlarged view of a portion of the tactile detection signals (analog signals) supplied from the tactile detection sensors 30a to 30e to the acquisition unit 11 of the tactile transmission device 10. The horizontal axis of Figure 4 represents time, and the vertical axis represents the physical quantity of the vibration situation corresponding to the tactile sensation, such as voltage.

[0044] 4, the tactile detection signal supplied to the acquisition unit 11 has a curved line with characteristic α corresponding to the vibration state indicating the tactile sensation. The fluctuation of the physical quantity of characteristic α corresponds to the tactile sensation obtained from the point touched by the tactile detection sensors 30a to 30e.

[0045] Figure 5 shows the time variation of tactile presentation data obtained when the tactile detection signal shown in Figure 4 is processed by the tactile transmission device 10 of this example. The horizontal axis of Figure 5 represents time, and the vertical axis represents the physical quantity (voltage) applied to the electrode. As already explained, the waveform processing unit 12 of the tactile transmission device 10 processes the signal to generate a pulse signal with an ON pulse width of 0.1 ms to 0.3 ms at a specific frequency (period) within the range of 20 Hz to 300 Hz. As a result, pulse signals P1, P2, P3, ... are obtained by sampling the signal values ​​at each timing of the tactile detection signal, as shown in Figure 5.

[0046] The pulse values ​​(peak values) of the pulse signals P1, P2, P3, ... shown in Fig. 5 are sampled values ​​of the tactile detection signal shown in Fig. 4 and vary depending on the tactile detection state. Here, the on-pulse width PW is set to a value between 0.1 ms and 0.3 ms, and all pulse signals P1, P2, P3, ... have the same pulse width value. In addition, the off-pulse width, which is set to 0.2 ms or more, also has the same value for all pulse signals P1, P2, P3, .... The tactile transmission device 10 outputs pulse signals P1, P2, P3, ... with such on-pulse width PW, which are applied from the pulse application device 20 to the electrodes 23a, 23b, 23c, 23d, and 23e.

[0047] As a result, the tactile transmission device 10 can present a tactile sensation similar to that detected by the tactile detection sensors 30a-30e to the tactile presenter wearing the electrodes 23a-23e. In this case, the pulse signals P1, P2, P3, ... are signals generated at intervals set to 0.2 ms or more. The tactile presenter wearing the electrodes 23a-23e can appropriately feel the electrical stimulation from the tactile transmission device 10 as a tactile sensation on their fingers.

[0048] If the pulse signal is not spaced relatively far apart as in this example, there is a possibility that the tactile presenter may feel pain when the voltage signal is applied, but in this example, it is possible to avoid causing such pain and to provide the tactile presenter with a good tactile sensation alone.

[0049] [Examples of Sensor Signals When Rubbing the Surfaces of Various Objects] Note that the examples in Figures 4 and 5 show very simple tactile detection signals, but the tactile transmission device 10 of this example is capable of detecting and transmitting tactile sensations corresponding to various tactile detection signals. Figure 6 shows examples of tactile detection signals output by the tactile detection sensors 30a to 30e when a tactile detector rubs the surfaces of five different objects. The horizontal axis of Figure 6 represents time (seconds), and the vertical axis represents physical quantity (voltage: mV). Here, an example is shown in which data was acquired for two seconds.

[0050] The data d1, d2, d3, d4, and d5 shown in FIG. 6 are examples of data obtained when the following objects are rubbed with a finger. Data d1 is a tactile detection signal obtained when a finger is rubbed on the surface of plastic cardboard (known as plastic cardboard), which is a plastic sheet with a similar structure to corrugated cardboard. Data d2 is a tactile detection signal obtained when a finger is rubbed on the surface of relatively smooth wallpaper. Data d3 is a tactile detection signal obtained when a finger is rubbed on the surface of hook-and-loop fastener (trade name: Magic Tape: registered trademark). Data d4 is a tactile detection signal obtained when a finger is rubbed on the surface of a silicone sheet. Data d5 is a tactile detection signal obtained when a finger is rubbed on the surface of an aluminum sheet.

[0051] As can be seen by comparing data d1 to d5 shown in Figure 6, the vibration conditions detected by tactile detection sensors 30a to 30e change depending on the surface condition of each material. Each piece of data d1 to d5 shown in Figure 6 is an analog waveform, but the waveform processing unit 12 of the tactile transmission device 10 in this example samples each piece of data d1 to d5 at a specific cycle (e.g., 200 Hz) as in the example of Figure 5, and applies the resulting pulse signals at intervals set to 0.2 ms or longer to electrodes 23a to 23e on the tactile presenter's fingers. This allows a tactile sensation similar to that experienced when rubbing the surface of each material to be imparted to the tactile presenter's fingers that are not touching the object.

[0052] [Another Example of Electrodes] Note that when ring-shaped electrodes 23a to 23e are worn on the fingers as shown in Fig. 1, the electrodes are located on the pads of the fingers on which the electrodes 23a to 23e are worn, and the electrodes may get in the way when the tactile presenter rubs the surface of an object with their fingers. For this reason, the electrodes 23a to 23e may be worn in a different manner than in the example shown in Fig. 1. For example, as shown in Fig. 7, electrodes 23x and 23y may be attached to the fingertips of fingers F1 and F2 in the vicinity of the nails (on the proximal side of the nails).

[0053] The electrodes 23x and 23y are attached to the proximal sides of the nails of the fingers F1 and F2, as shown in Fig. 7, and the attached electrodes 23x and 23y do not get in the way, so the tactile presenter can feel the tactile sensation by touching the surface of an object. Furthermore, even when the electrodes 23x and 23y are attached in the state shown in Fig. 7, the tactile presenter can feel the tactile sensation at the fingertips due to the applied pulse signal, just like in the case of electrodes on a ring as shown in Fig. 1.

[0054] 1, the tactile detection sensors 30a to 30e are attached to the fingertips to present a tactile sensation, but this is merely an example. The tactile detector may attach the tactile detection sensors 30a to 30e to other locations on the human skin, and the tactile presenter may attach electrodes to approximately the same locations to detect and present a tactile sensation. In the configuration shown in FIG. 1, the tactile transmission device 10 and the pulse application device 20 are configured as separate devices. Alternatively, for example, the tactile transmission device 10 and the pulse application device 20 may be integrated. In this case, for example, the tactile transmission device that integrates the two may be miniaturized so that it can be worn on the wrist of the tactile presenter, thereby more easily presenting a tactile sensation to the fingertips.

[0055] Furthermore, in the configuration shown in FIG. 1, the tactile transmission device 10 processes the tactile detection signals output by the tactile detection sensors 30a to 30e, but the tactile detection signals output by the tactile detection sensors 30a to 30e may only be subjected to tactile detection processing for storage in the memory unit 13, and past tactile detection signals stored in the memory unit 13 may be read out at any timing and similar pulse signals may be applied to the electrodes 23a to 23e.

[0056] This allows the memory unit 13 to store the tactile sensations felt when rubbing the surfaces of multiple types of objects, such as those shown in Figure 6, and makes it possible to freely present a selected tactile sensation to the tactile presenter's fingertips according to the situation at the time.

[0057] It is preferable that the signal stored in the memory unit 13 be a pulse signal that has undergone waveform processing, as shown in Fig. 5. This allows the tactile transmission device 10 to read out the data stored in the memory unit 13 and apply it directly to the electrodes without waveform processing.

[0058] 1 shows an example in which the tactile transmission device 10 is configured as a computer, which is an information processing device. However, the tactile transmission device 10 and the pulse application device 20 may be configured as devices equipped with dedicated hardware for performing their respective signal processing. When the tactile transmission device 10 is configured as a computer, a program for executing the processing procedure described in the flowchart of FIG. 2 may be prepared, installed in the tactile transmission device 10, which is a computer, and executed by the tactile transmission device 10.

[0059] REFERENCE SIGNS LIST 10...tactile transmission device, 10a...CPU, 10b...work memory, 10c...storage, 10d...input unit, 10e...communication interface, 11...acquisition unit, 11a...detection unit, 12...waveform processing unit, 13...storage unit, 14...transmission unit, 20...pulse application device, 21...reception unit, 22...pulse application unit, 23a, 23b, 23c, 23d, 23e, 23x, 23y...electrodes, 30a, 30b, 30c, 30d, 30e...tactile detection sensors, 31...first electrode, 32...FPC (Flexible printed circuits), 33...second electrode, 34...piezoelectric film, 35...conductive thin film member, 36...third electrode, 37...detection element

Claims

1. A tactile detection device comprising: a piezoelectric sensor disposed on a base film, which generates electric charges when deformed by an applied pressure; and a detection circuit that converts the electric charges generated by the piezoelectric sensor into a voltage. The piezoelectric sensor is disposed in a state of being in direct or indirect contact with the skin surface, and when an object is touched on the skin surface, the electric charges generated in the piezoelectric sensor are converted into a voltage by the detection circuit to obtain a tactile detection signal.

2. The tactile detection device according to claim 1, wherein the skin surface is the skin surface of a human, the base film of the piezoelectric sensor has a shape that can be attached or installed on the skin surface, and the tactile detection signal is a detection signal of the tactile sensation felt on the skin surface.

3. A tactile transmission system for transmitting the tactile sensation felt by a tactile sensor using the skin to a tactile presenter, comprising: a piezoelectric sensor that is worn in a state of being in direct or indirect contact with the skin surface of the tactile sensor and generates electric charges when deformed by an applied pressure; a detection unit that samples the tactile detection signal obtained by converting the electric charges generated by the piezoelectric sensor into a voltage at a predetermined frequency; a waveform processing unit that sets a pulse voltage at a constant short time interval for each sampling signal for the signal sampled by the detection unit; and a pulse application unit that applies the pulse voltage at the constant short time interval obtained by the waveform processing unit to an electrode in contact with the skin of the tactile presenter.

4. The tactile transmission system according to claim 3, wherein the predetermined frequency is a frequency between 20 Hz and 300 Hz, the on-pulse width of the pulse voltage with a short time width is set between 0.1 ms and 0.3 ms, and the off-pulse width of each pulse voltage is 0.2 ms or more.

5. The tactile transmission system according to claim 3, wherein the piezoelectric sensor is worn on the finger of the tactile sensor, the electrode is worn on the finger of the tactile presenter, and the tactile sensation felt by the finger of the tactile sensor is transmitted to the finger of the tactile presenter.

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