JP4780556B2 - Tactile display and method for manufacturing the same - Google Patents

Description

  The present invention relates to a tactile display for presenting mechanical stimulation to the skin and transmitting two-dimensional or three-dimensional information to a human.

In recent years, the development of miniaturization of tactile displays used for sensory substitution, such as Braille displays and shape displays used for virtual reality, has been carried out.
For the interval substitution, the tactile information presentation method determines the actual information transmission result. Many current tactile displays employ a spatial information presentation type in which tactile stimulation elements are arranged in a two-dimensional matrix.
Usually, when depending on the state of tactile stimulation on the active skin, the entire pattern indicating the information to be presented is collectively displayed on the tactile display (see, for example, Patent Document 1).

Here, the braille display is one in which unevenness is formed on the entire display surface by driving up and down mechanical tactile stimulation elements arranged in a two-dimensional matrix.
For example, when the tactile stimulation element is formed of a pin array, the uneven element is kept as it is in time, and when the user touches with the finger, the displayed information is recognized by the finger skin sensation.
A braille display consists of a 6-pin or 8-pin unit, and a two-dimensional pattern information presentation device composed of a plurality of pins for displaying pattern information. It has been.
JP 2003-122246 A

However, the braille display shown in Patent Document 1 includes a solenoid-type actuator and an inorganic semiconductor control circuit.
For this reason, the power consumption required for the mechanical drive of the actuator for presenting tactile stimuli is considerably larger than that of other electronic circuits in the above Braille display, and in order to design a portable tactile display. It is necessary to provide a battery with a large amount of electric power.
In addition, since the braille display has a plurality of tactile pins as tactile stimulation elements arranged in a matrix, the capacity of the part that houses the mechanism for driving the tactile part is much larger or larger than the actual tactile part.・ The weight is excessive and the portability is not good.
In addition, the braille display is made of an inorganic material and has a high rigidity, and thus has a weakness in impact resistance.
Furthermore, since the conventional tactile display is made of an inorganic material, the tactile display is not flexible and the tactile display portion is not deformed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tactile display having excellent portability, resistance to impact, etc., and flexibility, and a method for manufacturing the same.

  The tactile display of the present invention is a tactile display provided with a tactile display unit in which stimulation sites for stimulating the tactile sensation are formed in a matrix, and has a long shape formed of a polymer material that drives the stimulation site up and down. It has a polymer actuator and an organic transistor formed of an organic material that controls the driving of the polymer actuator.

The tactile display of the present invention is characterized in that the longitudinal direction of each polymer actuator is arranged in an oblique direction on the display plane of the tactile display unit .

  The tactile display according to the present invention is characterized in that each of the polymer actuators is fixed to a spacer having an equal driving range in the longitudinal direction.

  The tactile display of the present invention is characterized in that the entire tactile display portion including the upper part of the stimulation site is covered with a fluorine-coated silicon rubber protective sheet.

  The tactile display according to the present invention is characterized in that the tactile display unit is composed of a plurality of blocks, and each block is formed as a braille display having a stimulation portion having a resolution corresponding to one braille character.

  The method for manufacturing a tactile display of the present invention is a method for manufacturing a tactile display provided with a tactile display unit in which stimulation sites for stimulating a tactile sense are formed in a matrix, and is formed of a polymer material that drives the stimulation site up and down. An actuator forming step of forming an actuator layer made of a long polymer actuator provided for each tactile display unit, and an organic material formed of an organic material that controls driving of the polymer actuator in units of stimulation sites A transistor sheet forming process for forming a transistor sheet composed of transistors, and bonding in which the actuator layer and the transistor sheet are overlapped and bonded so that the positions of the polymer actuators and the transistors that drive the actuators face each other. And a process.

The tactile display manufacturing method of the present invention is characterized in that, in the actuator creating step, the longitudinal direction of each polymer actuator is formed in an oblique direction on the display plane of the tactile display unit .

  The method for manufacturing a tactile display according to the present invention is characterized in that, in the actuator creation step, the polymer actuators are fixed to spacers that equalize the vertical driving distance.

  The method for manufacturing a tactile display according to the present invention is characterized in that, in the bonding step, the contact pads of the organic transistors in the transistor sheet and the polymer actuator are bonded by a conductor paste.

  The method for manufacturing a tactile display according to the present invention further includes a step of covering the entire tactile display portion including the upper part of the stimulation site with a fluorine-coated silicon rubber protective sheet.

As described above, according to the tactile display of the present invention, since the polymer actuator is used for driving the stimulation site, the actuator can be downsized and the drive mechanism for the stimulation site can be simplified. Since the overall configuration can be greatly reduced, the size and weight can be reduced, and the power consumption can be greatly reduced, the portability can be improved as compared with the conventional example.
Further, according to the tactile display of the present invention, since it is formed of a polymer (actuator part) and an organic material (transistor part), it is strong against impact and has excellent flexibility, and deforms the tactile display part. And can be easily attached to the human body.

In addition, according to the tactile display of the present invention, since the upper part of the tactile display unit is covered with the silicon rubber sheet processed with fluorine, the water resistance can be improved as compared with the conventional example.
In addition, according to the tactile display of the present invention, since the coefficients of contraction and expansion due to temperature of the polymer (actuator part) and the organic material (transistor part) are almost equal, an actuator formed of an inorganic material against thermal stimulation. And a combination of a transistor formed of an organic material and a combination of an actuator formed of a polymer material and a transistor formed of an inorganic material, the strength can be improved.

Hereinafter, a tactile display according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing a structure of a braille display (as an application of a tactile display) as one configuration example of the embodiment.
A braille display according to an embodiment has a structure in which a frame layer 100, an actuator layer 200 composed of polymer actuators, and a transistor sheet 300 composed of organic transistors are combined. FIG. 1 shows a plan view of the braille display as viewed from above, but shows a configuration in which the frame layer 100 and the actuator layer 200 are partially removed so that the state of the lower layer can be confirmed.
As can be seen by looking at the frame layer 100, the tactile display unit is composed of a plurality of blocks, and each block has a matrix of stimulating parts with a resolution of one Braille character (for example, one stimulating part is one dot, 3 × 2 horizontally) Dot). As will be described later, this stimulation site is moved up and down by a polymer actuator, stimulates the skin of the finger, makes the user perceive information as nerve stimulation, and transmits information.

The organic transistor performs control to drive the polymer actuator up and down, and is disposed so as to face a position substantially overlapping the polymer actuator to be driven in plan view. The circuit configuration of the organic transistor is, for example, a matrix configuration as shown in FIG. Transistors that drive the polymer actuators are arranged at positions where the bit lines BL1 to BL21 and the word lines WL1 to WL8 intersect. When driving an actuator, a signal is applied to the bit line and word line that intersect at the organic transistor corresponding to the actuator, thereby driving the polymer actuator up and down from the organic transistor to the actuator electrode. A voltage will be applied.
In the frame layer 100, holes are opened at positions corresponding to the respective stimulation sites in the block of the tactile display unit. When the polymer actuator is pushed upward by the polymer actuator, the stimulation site protrudes from the frame layer surface from the hole. On the other hand, when the polymer actuator returns to the original position, the upper part of the stimulation site is almost the same as the frame layer surface. It will be the same or located below.

Next, with reference to FIG. 3, the structure of the stimulation site, the polymer actuator, and the organic transistor will be described. FIG. 3 is a conceptual diagram showing a cross-sectional structure of a portion corresponding to one stimulation site in the block.
The structure of the transistor sheet 300 is that a metal (for example, Cr / Au) gate electrode 302 is formed on the surface of a substrate 301 of an insulating organic thin film (for example, PEN; polyethylene naphthalate, PI; an insulator such as polyimide). Then, a gate insulating film 303 is formed to cover the gate electrode 302 and the exposed substrate 301, and a channel layer 304 having the same width as the gate electrode 302 is formed on the surface of the gate insulating film 303 so as to face the gate electrode 302. Then, a source electrode 305A and a drain electrode 305B are formed at each end of the pattern of the channel layer 304.

In addition, an insulating organic thin film (for example, parylene resin) is formed on the surface of the back surface of the substrate 301 and the source electrode 305A, the drain electrode 305B, the channel layer 304, and the exposed gate insulating film 303, respectively. The sealing film 306 is formed.
In addition, the source electrode 305A and the pad 310 on the sealing film 307 on the back surface are connected by a conductor 309 filled in the via hole 308 penetrating the sealing film 307, the substrate 301 gate, and the insulating film 303. Here, the source electrode 305A is connected to the back electrode of the actuator 202 via the pad 310, the drain electrode 305B is connected to one of the bit lines, and the gate electrode 302 is connected to one of the word lines.

  Next, in the structure of the actuator layer 200, the length of the polymer actuator 202 formed in a long shape in the inner direction of the block and the driving direction of each polymer actuator 202 in the block is uniform. The spacer 201 is attached to one end of the upper portion of the polymer actuator 202. Here, the polymer actuator 202 is driven by ionic conduction by utilizing the fact that the cation in the polymer electrolyte moves to the cathode side due to the application of voltage and the difference in swelling occurs between the front and back surfaces and deforms in a stretchable manner. An actuator, for example, Nafion (registered trademark) manufactured by DuPont is processed and formed. In addition, a hemispherical member 203 (as a material, for example, POM; polyacetal) has a spherical surface upward, that is, a spherical portion protrudes from the surface of the tactile display unit at the other end of the upper portion of the polymer actuator 202. Is provided.

In addition, each of the polymer actuators 202 has electrodes (surface electrodes, back electrodes) formed on both surfaces thereof, and the longitudinal direction is parallel to an oblique direction with respect to the lower side of the block, for example, an angle direction of 45 degrees. Is formed. Here, a predetermined voltage, for example, a ground voltage is applied to the surface electrode on the surface.
Then, the back electrode of the polymer actuator 202 and the pad 310 of the organic transistor that controls the driving of each polymer actuator 202 are electrically coupled by a conductive paste for bonding 400 (for example, silver (Ag) paste). The Here, each polymer actuator 202 and the organic transistor that drives each polymer actuator 202 are arranged at substantially opposite positions.

Next, the structure of the frame layer 100 includes a frame 101 formed of a plastic film (for example, PET; polyethylene terephthalate), and a protective sheet 102 (fluorine-coated silicon rubber, for example, affixed to the upper surface of the frame 101. , PDMS; polydimethylsilane).
In the tactile sensation display portion of the frame layer 100, when the hemispherical member 203, which is the stimulation site in block units, is moved up and down by the polymer actuator 202, the upper part of the hemispherical member 203 is A protruding hole is opened. Here, the protruding upper portion of the hemispherical member 203 pushes up the protective sheet 102 to form a protruding portion on the upper surface of the frame layer 100, and this protruding portion allows the user to perceive it as skin irritation.
The frame layer 100 and the actuator layer 200 are bonded to each other by adhering the surface of the spacer 201 of the actuator layer 200 and the frame 101 of the frame layer 100.

The planar structure of the polymer actuator 202 has the shape shown in FIGS. 4A and 4B, and FIG. 4A shows a tactile display unit formed by a plurality of blocks. (B) is the figure which expanded one block.
In this embodiment, the resolution is 3 × 2 6 dots (one stimulation site corresponds to 1 dot), and a hemispherical member 203 as a stimulation site is provided at the end of the polymer actuator 202. As already described, the polymer actuator 202 is formed in a long shape whose longitudinal direction is parallel to an angle direction of 45 degrees with respect to the bottom of the block. As a result, the length of the polymer actuator 202 in the longitudinal direction can be increased as compared with other arrangements, and the vertical driving distance (displacement) of the hemispherical member 203 can be maximized with the set block area. Can be taken to.

  As shown in FIG. 4C, when the organic transistor is turned on (On) and a potential higher than that of the front electrode is applied to the back surface electrode, the polymer actuator 202 is driven in the upward direction according to the potential ( And the hemispherical member 203 provided at the end is pushed upward, and the upper portion of the hemispherical member 203 is projected from the hole of the frame 101 above the surface of the frame 101. As a result, the hemispherical member 203 pushes up the protective sheet 102, forms irregularities that can be perceived by the skin of the finger on the surface of the protective sheet 102, that is, the tactile display, and performs display processing of data perceived by the tactile sense.

  On the other hand, as shown in FIG. 4D, the polymer actuator 202 returns to an equilibrium state when the organic transistor is turned off and a potential similar to the surface potential is applied to the back surface potential. The hemispherical member 203 provided on the frame 101 is returned to its original position, and is displaced from the hole of the frame 101 to a position where the hemispherical member 203 does not protrude above the surface of the frame 101. As a result, the hemispherical member 203 does not push up the surface of the protective sheet 102 and has a flat surface without any irregularities on the surface of the protective sheet 102.

The organic transistors are arranged in the planar shape shown in the plan view of the entire transistor sheet 300 shown in FIG. As shown in FIG. 5 (b), which is an enlarged view of the region surrounded by the frame in FIG. 5 (a), the three organic transistors in the region surrounded by the frame in the upper right part are respectively arranged on the left side of FIG. 4 (b). The polymer actuator 202 is driven, and the three organic transistors in the region surrounded by the lower left frame drive the polymer actuator 202 arranged on the right side of FIG. FIG. 5C is a conceptual diagram showing the correspondence between the organic transistors in FIG. 5B on the circuit configuration shown in FIG. In this organic transistor, the planar structure of each organic transistor has a shape shown in FIG. 5D, and the channel width formed for taking a large amount of current (the length of the channel perpendicular to the carrier flow direction). And the cross-sectional area of the channel is increased.
Although not shown in FIG. 5, two organic transistors are allocated to one of the polymer actuators 202 for improving the yield (within the frame shown in FIG. 5B). As a result of the organic transistor operation check, one of the polymer actuators 202 that does not operate when one of them does not operate or the one that does not need to operate when both operate Disconnect the organic transistor from the circuit.
When checking the operation of this organic transistor, if the BL (bit line) is connected, it is not possible to check the operation of each organic transistor alone, so it is separated at this point and the organic transistor to be used is determined. After that, the BL is wired, and a process of separating the inoperative or unnecessary organic transistor from the polymer actuator 202 is performed.

Next, the manufacturing method of the Braille display mentioned above is demonstrated below.
<Method for producing transistor sheet>
A method of manufacturing each organic transistor in the transistor sheet will be described with reference to FIG. FIG. 6 is a conceptual diagram showing a cross-sectional structure of the organic transistor in each process of manufacturing the organic transistor.
In the process of FIG. 6A, the metal material of the gate electrode is formed on the upper surface of the polyimide substrate 301 having a thickness of 75 μm at a growth rate of about 0.1 nm / second at a degree of vacuum of about 10 ⁻⁴ Pa. A thin film of Cr: 5 nm / Au: 50 nm is deposited by vacuum evaporation. Then, in patterning, the thin film of the metal material other than that for forming the gate is removed, and the pattern of the gate electrode 302 is formed.

Next, in the process of FIG. 6B, polyimide is applied to the upper surface of the gate electrode 302 and the exposed upper surface of the substrate 301 by spin coating to a thickness of 240 nm on the upper surface of the gate electrode 302, and then in a clean oven. , 120 ° C. (1 hour) → 150 ° C. (1 hour) → 180 ° C. (1 hour) in this order to form the gate insulating film 303.
Next, in the step of FIG. 6C, the channel layer is formed on the surface of the gate insulating film 303 at a growth rate of 1 nm / min or less by vacuum deposition in a vacuum degree of 2 to 5 × 10 ⁻⁵ Pa. As a material, a pentacetane thin film is grown to 50 nm.
Then, by patterning, the pattern of the channel layer 304 is formed at a position having the same width as the pattern of the gate electrode 302 and overlapping in plan view.

Next, deposition of about 0.1 nm / second is performed as a source / drain electrode material on the upper surface of the channel layer 304 and the exposed upper surface of the channel layer 304 and the gate insulating film 303 at a vacuum of about 10 ⁻⁴ Pa. Vacuum deposition is performed at a speed, and a thin Au film is deposited to a thickness of 50 nm.
Then, by patterning, electrode patterns of the source electrode 305A and the drain electrode 305B are respectively formed on both ends of the upper portion of the channel layer 304 so as to have a predetermined channel length (a separation distance between the source electrode and the drain electrode). To do.

Next, in the process of FIG. 6E, parylene is deposited to a thickness of 8 μm on the lower surface of the substrate 301 by a CVD (chemical vapor deposition) method to grow a sealing film 307.
Then, via holes 308 that penetrate the substrate 301, the gate insulating film 303, and the sealing film 307 are opened in the vicinity of the source electrode 305 that is separated from the source electrode 305 A, the gate electrode 302, and the channel layer 304 by a CO 2 laser.
Next, in the process of FIG. 6F, for example, Au is filled as a conductor in the hole 308, and Au is deposited as a conductor connecting the filled Au to the source electrode 305A, for example. A conductor 309 is formed.
Then, a pad 400 electrically connected to the conductor 309 is formed on the back surface of the sealing film 307 by, for example, Au.
Finally, parylene is deposited to a thickness of 8 μm on the surface of the organic transistor on the side of the source electrode 305A and the drain electrode 305B by a CVD (chemical vapor deposition) method to grow a sealing film 306.

<Method for manufacturing actuator layer>
In the following description, a portion surrounded by a two-dot chain line in the conceptual diagram of a cross section of each figure indicates a part of the process (current process) being described.
Although the manufacturing process of the polymer actuator in one block of the tactile display unit will be described, the other blocks are also formed in the same process, and the actuator layer 200 that performs tactile display at the stimulation site composed of the plurality of blocks is formed. The
As a material of the polymer actuator, an ion conductive actuator film such as a Nafion (registered trademark) film (product number NE-1110) manufactured by DuPont is used.
1. The surface treatment for the actuator film is performed by the following cleaning treatment.
a. Infiltrate for 1 hour in 5% aqueous H2O2 solution at 70 ° C to 80 ° C b. Infiltrate in H2O (pure water) at 70 ° C to 80 ° C for 1 hour c. Infiltrate 1M (molar) HCl aqueous solution at 70 ° C. to 80 ° C. for 1 hour d. 1 hour infiltration into H2O (pure water) at 70-80 ℃

2. In order to improve the plating in the next step, the surface of the actuator film is roughened (for example, filed), and ultrasonic cleaning of both sides is performed for 10 minutes.
3. A surface electrode and a back electrode are formed by immersing in a [AuCl2 (phen)] Cl aqueous solution at room temperature for a predetermined time or longer, for example, 12 hours, and performing electroless plating.
4. Immerse in Na2SO3 solution at 60 ° C. for 5 hours to reduce the plating surface.
The processes 3 and 4 are repeated 3 to 7 times.
Ion exchange is performed by immersing in an aqueous solution of LiCl (gold complex) having a concentration of 5.1 M for a certain period of time, for example, 12 hours.
7). As shown in the plan view of the actuator film in FIG. 7A, the actuator film is patterned to form a long polymer actuator 202 in the internal direction of the block. The polymer actuator 202 is provided at the position shown in the cross-sectional view of the braille display of FIG. 7B, and as shown in FIG. 7A, the inner side of the actuator block is inclined with respect to the bottom of the block. For example, it is formed so that the long direction corresponds to an angle direction of 45 °.

8). In order to control each polymer actuator 202 independently, as shown in the plan view of the actuator film in FIG. 8A, a part of the plating on the back surface is removed (insulating grooves for dividing the back surface electrode are formed), The back electrode of each polymer actuator 202 is electrically separated.
In addition, as shown in the cross-sectional view of the braille display in FIG. 8B, as the position where the polymer actuator plating is removed on the back surface of the polymer actuator 202, the vicinity of the block inner periphery, that is, the back electrode And in the region where the connecting portion where the conductive paste 400 is connected and the inner periphery of the block are connected. On the other hand, the surface electrode is common and is fixed to the ground potential after assembly.

9. On the upper surface of the polymer actuator 202, as shown in the plan view of the actuator film in FIG. 9A, a hemispherical member 203 is provided at the end opposite to the portion connected to the outer periphery of the block as a stimulation site for stimulating the skin. Is attached with a silicon / acrylic double-sided adhesive sheet so that the curved portion is positioned on the upper side.
The arrangement of the hemispherical member 203 can improve the alignment accuracy by a method in which a frame 101 described later is attached to the upper surface of the spacer 201 and then the opening of the frame 101 is used. Further, as shown in the cross-sectional view of the braille display of FIG. 9B, the hemispherical member 203 is made of, for example, a columnar material of POM that is sufficiently larger than the diameter of the hemisphere (a size that includes a sphere) by wear processing. After being processed into a spherical shape of 1.8 mm, it is made by processing from one side of the sphere with a file into a hemispherical shape.

10. The position shown in the cross-sectional view of the braille display of FIG.
Further, as shown in the plan view of the spacer 201 in FIG. 10B, a spacer 201 having a shape covering the portion other than the driving portion of the polymer actuator 202, for example, a thin film of PEN having a thickness of 125 μm is used. Thus, processing is performed to open the opening 201A with the same length of the drive portion in the longitudinal direction of each polymer actuator 202 in the same block, and as shown in the plan view of the spacer 201 in FIG. The actuator portion 202 is adhered to the entire surface of the actuator film so that the opening 201A corresponds to the driving portion (movable portion) 202.

  The spacer 201 is in contact with the pad 310 so that stress is not applied to the pad 310 when the back electrode at the end on the side of the block of the actuator 202 and the pad 310 of the organic transistor are connected. In order to prevent the polymer actuator 202 from being driven in the region of the back electrode, and as shown in the plan view of the state in which the spacer 201 is superimposed on the upper surface of the actuator film in FIG. In order to make the length of the driving portion uniform, the spacer 201 fixes the extra length portion that exceeds the uniform length L of the polymer actuator 202, thereby suppressing the vertical driving operation. Yes. Thereby, the length of the driving portion of each polymer actuator 202 in the block is matched, and the displacement (displacement amount) of each polymer actuator 202 in the vertical drive (perpendicular to the display surface) is made substantially the same. It is used to obtain a space that allows vertical movement. In the present embodiment, the length L of the driving portion of the polymer actuator 202 is, for example, 4 mm (FIG. 3).

<Frame layer manufacturing method>
Next, creation of the frame layer 100 will be described.
In the frame 101, for example, when a PET thin film having a thickness of 500 μm is attached to the spacer 201, as shown in the cross-sectional view of the braille display in FIG. In the position where the hemispherical member 203 protrudes upward from its surface, the diameter larger than the diameter (1.8 mm) of the hemispherical member 203 as shown in the plan view of the frame 101 in FIG. The hole 105 of 2 mm to 2.1 mm is formed by opening processing, for example, drilling with a drill. Here, the frame 101 and the spacer 201 shown in the plan view of FIG. 13 are attached using a silicon / acrylic double-sided adhesive sheet.

After the attachment of the frame 101 and the spacer 201, as described above, the hemispherical member 203 is dropped from the hole 105 so that the spherical surface faces upward, and is attached to the upper surface of the open end of the polymer actuator 202. To do. At the time of dropping, an adhesive is applied to the position where the polymer actuator 202 is disposed.
Then, after the hemispherical member 203 is disposed at the end of the polymer actuator 202, a fluorine-coated PDMS thin film having a thickness of 10 μm is adhered to the upper surface of the frame 101 by a silicon / acrylic double-sided adhesive sheet. . The thin film of PDMF is formed on a glass previously coated with fluorine by CVD or the like, and the formed thin film of PDMF is transferred to the upper surface of the frame 101. At this time, the fluorine coated on the glass is also transferred at the same time, and is adhered to the upper surface of the frame 101 in a state where the upper surface of the PDMF (that is, the surface to which the user's skin is in close contact) is coated with fluorine.

As described above, since the frame layer 100 and the actuator layer 200 are already bonded, the transistor layer 300 and the actuator layer 200 are connected to complete the assembly of the braille display.
Here, the pad 400 formed on the back surface of each organic transistor of the transistor layer 300 and the back electrode of the polymer actuator 202 driven by the organic transistor are electrically and physically connected by silver paste.

<Actuator performance evaluation>
Next, the measurement result of the drive characteristics of the Braille actuator formed as described above will be illustrated and described.
FIG. 14 shows the correspondence of the drain-source current IDS when the drain-source voltage VDS is changed for each gate voltage VGS in the prepared organic transistor, and the horizontal axis shows the drain-source voltage VES (V The vertical axis represents the drain-source current IDS (μA). The gate voltage VGS (V) is changed in increments of 2 V from “−10 V” to “0 V”. As can be seen from FIG. 14, when the gate voltage VGS is “0 V”, the drain-source current IDS is also “0 A”, the on / off operation is normally performed, the organic transistor has a switching function, and the gate Modulation that the drain-source current IDS can be changed by changing the voltage VGS and the drain-source voltage VDS.

Further, from the IDS-VGS characteristics (drain-source voltage VDS = -10 V) shown in FIG. 15, the mobility of the organic transistor of this embodiment was determined to be 1 cm / Vs. From this IDS-VGS characteristic, it can be seen that the on / off ratio of the current value is 106 when the off current is the minimum current value when a positive voltage is applied as a bias. In FIG. 15, the horizontal axis represents the gate voltage VGS (V), and the vertical axis represents the drain-source current IDS (A).
FIG. 16 shows the correspondence between the drain-source current IDS and the on / off ratio of the current value and the time of immersion in pure water. The horizontal axis indicates the time (minutes) of direct immersion in pure water, the right vertical axis indicates the drain-source current IDS (A), and the left vertical axis indicates the on / off ratio of the current value. . Here, the gate voltage VGS and the drain-source voltage VDS are “−40 V”, respectively, and the ratio W / L of the channel width W to the channel length L of the organic transistor is 10. As can be seen from FIG. 16, the organic transistor of this embodiment has a parylene protective film (sealing films 307 and 306) formed on the surface. There is no change in the inter-source current IDS and the on / off ratio of the current value, and the water resistance is excellent, and it can be applied to applications requiring water resistance.

  Next, FIG. 17 shows the applied voltage and displacement (or displacement) of the polymer actuator. The polymer actuator in the present embodiment has a length in the longitudinal direction of 4 mm and a width of 1 mm. In FIG. 17, the horizontal axis represents time (seconds), the vertical axis of the upper graph represents the voltage value applied between the back electrode and the front electrode of the polymer actuator, and the vertical axis of the lower graph represents the polymer. The displacement (mm) in the vertical drive of the edge part which opposes an electrode in the elongate direction of an actuator is shown. From FIG. 17, it can be seen that there is a displacement of about 0.3 mm at the time of −3 V and at the time of 3 V, that is, due to the change in the applied voltage of 6 V, and a displacement that can be sufficiently detected by the tactile sense of the skin is obtained. Further, there is a response speed of 2 Hz or more from the period of the voltage change pulse applied between the front electrode and the back electrode (2 Hz in the figure), and it can sufficiently cope with the change as a tactile display.

FIG. 18 is a diagram showing the relationship between the voltage applied between the back electrode and the front electrode and the displacement in the vertical drive of the end of the polymer actuator facing the electrode in the longitudinal direction of the polymer actuator. . In FIG. 18, the horizontal axis of the graph represents the voltage (V) applied between the back electrode and the front electrode of the polymer actuator, and the vertical axis represents the displacement (mm) in the vertical drive of the polymer actuator. It can be seen that the displacement increases with respect to FIG. 17 if sufficient time is taken. For example, when sufficient time is taken, the displacement is 0.4 mm at 3 V, while when operated at 2 Hz, the displacement is 0.25 to 0.3 mm at 3 V.
FIG. 19 is a diagram showing the relationship between the voltage applied between the back surface electrode and the front surface electrode and the practically generated force in the vertical drive of the end of the polymer actuator facing the electrode in the longitudinal direction of the polymer actuator. It is. In FIG. 19, the horizontal axis of the graph indicates the voltage (V) applied between the back electrode and the front electrode of the polymer actuator, and the vertical axis indicates the practically generated force (gf) in the vertical drive of the polymer actuator. . From FIG. 19, when the user touches the display with a finger, a sufficiently uneven tactile sensation can be given.

  Next, FIG. 20 is applied between the back electrode and the front electrode measured in a state where the organic transistor described above and the polymer actuator provided with the hemispherical member are combined and assembled as shown in FIG. FIG. 6 is a diagram showing a relationship between voltage to be applied and displacement in an up-and-down drive of an end portion of the polymer actuator facing the electrode in the longitudinal direction of the polymer actuator. In FIG. 20, the horizontal axis indicates time (seconds), the vertical axis of the upper graph indicates the voltage value (V) applied between the back electrode and the front electrode of the polymer actuator, and the vertical axis of the lower graph. Shows the displacement (mm) in the vertical drive of the end facing the electrode in the longitudinal direction of the polymer actuator. The numerical values described in the upper and lower graphs indicate the gate voltage VGS of the organic transistor.

FIG. 21 is an enlarged graph of the time interval in the lower graph of FIG. 20. The horizontal axis represents time (seconds), and the vertical axis represents the electrode in the longitudinal direction of the polymer actuator. The displacement (mm) in the vertical drive of the edge part which opposes is shown. As can be seen from FIG. 21, when the gate voltage VGS of the organic transistor is applied at −30 V, the polymer actuator is displaced 0.2 mm per second in the vertical drive, and the unevenness of the display portion is formed as a numerical tactile display. The displacement required to be recognized by tactile sensation was obtained.
FIG. 22 shows the correspondence between the drain-source current IDS, the displacement speed in the vertical drive of the polymer actuator, and the gate voltage VGS. The horizontal axis indicates the gate voltage VGS (V), the right vertical axis indicates the displacement speed (mm / min) in the vertical drive of the polymer actuator, and the left vertical axis indicates the drain-source current IDS (A). ing. As shown in FIG. 22, as the gate voltage VGS is increased, the drain-source current IDS is increased, that is, the rate of voltage increase between the front electrode and the back electrode of the polymer actuator is improved. You can see that the speed is improved

Next, FIG. 23 is a figure which shows the photograph which shows the unevenness | corrugation of one block in the display part of the tactile display actually assembled. The length in the longitudinal direction of the scale bar in each figure is 1 mm.
The upper photograph in FIG. 23 (a) shows that the polymer actuator is driven upward (up) by applying a driving voltage between the back electrode and the top electrode, and is projected on the display surface by the hemispherical member. 23A shows a protruding state, and the lower photograph in FIG. 23A shows that the polymer actuator has the same voltage between the back electrode and the top electrode, returns to the position before driving (Down), and the protruding portion disappears. Shows the state. FIG. 23B shows a state in which all the left columns of the block are driven in a convex state, and all the right columns of the block are not driven. FIG. 23C shows a display state of a pattern different from that in FIG.

It is a conceptual diagram which shows the planar shape of each component of the tactile display by one Embodiment of this invention. It is a conceptual diagram which shows the circuit structural example of the transistor sheet 300 in FIG. It is a conceptual diagram which shows the cross-sectional structure for 1 dot in the tactile display by one Embodiment of this invention. 3 is a conceptual diagram illustrating an example of a structure of a polymer actuator in an actuator layer 200. FIG. It is a conceptual diagram which shows the structural example of the organic transistor of the transistor sheet 300 in FIG. It is the conceptual diagram which showed the cross section in each manufacturing process explaining the process of manufacturing the organic transistor of this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a conceptual diagram explaining the process of manufacturing the polymer actuator in this embodiment. It is a figure which shows the graph of the VDS-IDS characteristic of the organic transistor in this manufactured this embodiment. It is a figure which shows the graph of the VGS-IDS characteristic of the organic transistor in this manufactured this embodiment. It is a figure which shows the graph of the water resistance of the organic transistor in this manufactured this embodiment. It is a figure which shows the response speed of the polymer actuator in this manufactured this embodiment, and the characteristic of the displacement of an up-down drive. It is a figure which shows the relationship between the applied voltage of the polymer actuator in this manufactured this embodiment, and the displacement amount of an up-down drive. It is a figure which shows the relationship between the applied voltage of the polymer actuator in this manufactured this embodiment, and the practical repulsive force in an up-down drive. It is a figure which shows the displacement amount and displacement speed of the polymer actuator in the assembled display. It is a figure which shows the displacement speed of the polymer actuator in the assembled display display. It is a figure which shows the displacement speed of the polymer actuator in the assembled display display. In this embodiment, it is a figure which shows the photograph of the drive state of 1 block in the display part of the tactile display actually produced.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Frame layer 101 ... Spacer 102 ... Protection sheet 105 ... Hole 200 ... Actuator layer 201 ... Spacer 202 ... Polymer actuator 203 ... Hemispherical member 300 ... Transistor sheet 301 ... Substrate 302 ... Gate electrode 303 ... Gate insulating film 304 ... Channel layer 305A ... Source electrode 305B ... Drain electrodes 306, 307 ... Sealing film 308 ... Via hole 309 ... Conductor 400 ... Conductor paste

Claims (10)

A tactile display provided with a tactile display unit in which stimulation sites for stimulating a tactile sense are formed in a matrix.
An elongated polymer actuator formed of a polymer material that drives the stimulation site up and down;
A tactile display comprising: an organic transistor formed of an organic material that performs drive control of the polymer actuator. 2. The tactile display according to claim 1, wherein a longitudinal direction of each of the polymer actuators is arranged in an oblique direction on a display plane of the tactile display unit.   3. The tactile display according to claim 1, wherein each of the polymer actuators is fixed to a spacer having an equal driving range in the longitudinal direction.   The tactile display according to any one of claims 1 to 3, wherein the entire tactile display part including the upper part of the stimulation site is covered with a fluorine-coated silicon rubber protective sheet.   5. The tactile display unit includes a plurality of blocks, and each block is formed as a braille display having a stimulation portion having a resolution corresponding to one braille character. Tactile display A method for manufacturing a tactile display provided with a tactile display unit in which stimulation sites for stimulating a tactile sense are formed in a matrix.
An actuator creating step of forming an actuator layer made of a polymer actuator having a long shape provided for each tactile display unit formed of a polymer material that drives the stimulation site up and down;
A transistor sheet creating step for forming a transistor sheet composed of an organic transistor formed of an organic material that controls driving of the polymer actuator in units of stimulation sites;
A tactile display manufacturing method comprising: a bonding step of overlapping and bonding an actuator layer and a transistor sheet so that each polymer actuator and a transistor that drives each actuator face each other . The tactile display manufacturing method according to claim 6, wherein, in the actuator creating step, the longitudinal direction of each polymer actuator is formed to be an oblique direction on a display plane of the tactile display unit .   The tactile display manufacturing method according to claim 6 or 7, wherein, in the actuator creating step, each of the polymer actuators is fixed to a spacer having an equal driving range in the longitudinal direction.   9. The bonding process according to claim 6, wherein the bonding step is performed by bonding a contact pad of each organic transistor in the transistor sheet and a polymer actuator with a conductive paste. A method for manufacturing a tactile display.   10. The method of manufacturing a tactile display according to claim 6, further comprising a step of covering the entire tactile display portion including the upper part of the stimulation site with a protective sheet of silicon rubber coated with fluorine.

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