JP2015064835A - Display device and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device and touch panel capable of effective feedback of a subtle touch of fingertips.SOLUTION: A display device includes a display unit 4 that displays videos, a touch panel 3 that detects a proximity position of a conductor, a mechanical vibration generation unit 6 that provides mechanical vibration to the conductor, an electrostatic attraction force generation unit 7 that causes an electrostatic attraction force to act on the conductor, and a control unit 5 that causes the mechanical vibration generation unit and electrostatic attraction force generation unit to be operated in conjunction with each other on the basis of information on the position of the conductor detected by the touch panel.

Description

  Embodiments described herein relate generally to a display device and a touch panel.

  Electronic devices such as mobile phones, personal digital assistants, and personal computers equipped with a display device having a touch panel function have been developed as a form of user interface. In an electronic device having such a touch panel function, it has been studied to add a touch panel function by separately attaching a touch panel substrate to a display device such as a liquid crystal display device or an organic EL display device.

  By the way, when the mechanical push button is pressed, the button is movable and the touch surface is uneven, so that the user can recognize which button is pressed and the execution of the input by tactile sensation. However, since the touch panel has no movement and unevenness, such a tactile sensation cannot be obtained. Therefore, various methods for artificially creating a tactile sensation have been proposed.

  For example, Patent Document 1 discloses a method of generating a tactile sensation using a “piezoelectric actuator”. Since the piezoelectric actuator vibrates by an alternating voltage, an artificial tactile sensation can be generated by an electrical signal.

JP 2011-48854 A

  As described above, regarding the tactile function, in addition to the above-described mechanical vibration, the one based on electrostatic adsorption has been studied. However, it has been pointed out that conventional methods are insufficient to effectively feed back the delicate touch of the fingertip. For example, in addition to the finger touching the touch panel, a tactile sensation is generated in the part of the hand to be held, so that there is a problem that the tactile sensation cannot be concentrated on the fingertip. There is also a problem that a tactile sensation cannot be obtained unless the finger is slid in a contact state.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the display apparatus and touch panel which can feed back the delicate touch of a fingertip effectively.

  A display device according to an aspect of the present invention includes a display unit that displays an image, a touch panel that detects a proximity position of a conductor, a mechanical vibration generation unit that applies mechanical vibration to the conductor, and the conductor. An electrostatic attraction force generating unit that applies an electrostatic attraction force, and the mechanical vibration generating unit and the electrostatic attraction force generating unit are operated in conjunction with each other based on positional information of the conductor detected by the touch panel. And a control unit.

1 is a cross-sectional view illustrating a configuration of a display device according to a first embodiment. The figure which shows the structure of the mechanical vibration generation part and electrostatic attraction force generation part of the display apparatus of 1st Embodiment. The figure which shows the structural example incorporating the electrostatic attraction force generation | occurrence | production part of the display apparatus of 1st Embodiment. The figure for demonstrating the method to prevent generation | occurrence | production of the tactile sense of the back surface side of the display apparatus of 1st Embodiment. The figure for demonstrating the method of preventing the malfunctioning of the touchscreen of the display apparatus of 1st Embodiment. The figure which shows the structure of the variation of the electrostatic attraction force generation | occurrence | production part of the display apparatus of 1st Embodiment. The figure which shows the structure of the other variation of the electrostatic attraction force generation part of the display apparatus of 1st Embodiment. The figure which shows the structure of the other variation of the electrostatic attraction force generation part of the display apparatus of 1st Embodiment. The figure for demonstrating the method to drive the mechanical vibration generation part and electrostatic attraction force generation part of the display apparatus of 1st Embodiment. The figure for demonstrating the other method of driving the mechanical vibration generation part and electrostatic attraction force generation part of the display apparatus of 1st Embodiment. The figure for demonstrating the other method of driving the mechanical vibration generation part and electrostatic attraction force generation part of the display apparatus of 1st Embodiment. Sectional drawing which shows the structure of the display apparatus of 2nd Embodiment.

FIG. 1 is a cross-sectional view illustrating the configuration of the display device according to the first embodiment.
The display device 1 according to the first embodiment includes a housing 2, a touch panel 3, a display unit 4, a control unit 5, a mechanical vibration generation unit 6, and an electrostatic attraction force generation unit 7. In addition, the display part 4 of 1st Embodiment is a liquid crystal display panel, for example. The display unit 4 may be formed as a thin display such as an OLED (organic light emitting diode).

  The touch panel 3 detects the approach (contact) position of a conductor such as a finger with a detection electrode. The detection electrode is a transparent electrode using a material such as ITO (Indium Tin Oxide) or silver nanowire, and is arranged on a substrate such as glass or plastic as a large number of vertical and horizontal mosaic electrode patterns.

  The display unit 4 has a structure in which a liquid crystal layer (not shown) is sandwiched between an array substrate (not shown) that is a pair of electrode substrates and a counter substrate (not shown). The transmittance of the liquid crystal display panel is controlled by a liquid crystal driving voltage applied to the liquid crystal layer from the pixel electrode provided on the array substrate and the common electrode provided on the counter substrate.

  The housing | casing 2 protects the touchscreen 3 and the display part 4 from the impact from the outside. The housing 2 is made of glass, but may be formed of a transparent material such as acrylic, polycarbonate, or PET.

  The mechanical vibration generator 6 applies mechanical vibration to the fingertip close to the touch panel 3. The electrostatic attraction force generation unit 7 applies an attraction force to the fingertip close to the display device 1. The control unit 5 drives the mechanical vibration generation unit 6 and the electrostatic adsorption force generation unit 7 in conjunction with each other based on the position information of the touch panel 3 to generate vibration and electrostatic adsorption force.

  FIG. 2 is a diagram illustrating a configuration of a mechanical vibration generation unit and an electrostatic attraction force generation unit of the display device according to the first embodiment.

  The mechanical vibration generator 6 shown in FIG. 2A applies a voltage to the piezoelectric element 11 that generates a mechanical displacement according to the applied voltage, the inertia mass 12 loaded on the piezoelectric element 11, and the piezoelectric element 11. A high voltage amplifier 13 and an oscillator 14 are provided. For example, the oscillator 14 outputs a sine wave signal of about 10 to 1000 Hz. The high voltage amplifier 13 amplifies the sine wave signal to a voltage of about 10 to 1000 V and applies it to the piezoelectric element 11. As a result, mechanical vibration is generated in the piezoelectric element 11 and the inertial mass 12, and the force generated by the vibration and the inertial mass is transmitted to the display device 1. Here, the voltage value (10 to 1000 V) applied to the piezoelectric element 11 can be determined according to the film thickness of the part in contact with the finger.

  The sine wave signal output from the oscillator 14 is not only continuous but may be intermittent. For example, it may be output once in a period of about 0.01 sec to 1 sec, or may be output intermittently at an interval of about 0.01 sec to 1 sec. By changing the output method, different tactile sensations can be given to the operator. The signal output from the oscillator 14 is not limited to a sine wave, and may be a rectangular wave, a sawtooth wave, or a triangular wave. Different tactile sensations can be given to the operator by changing the waveform.

  The method for generating mechanical vibration is not limited to the method using the piezoelectric element 11. For example, a method of rotating the eccentric rotational mass with a small motor capable of controlling the rotational speed may be used, or an inertial mass may be provided in an electroactive polymer that expands and contracts by an applied voltage.

  2 (b) includes an electrode 21, a dielectric 22 for insulating the electrode 21 from the human body, and a high voltage amplifier 23 and an oscillator 24 for applying a voltage that changes to the electrode 21. I have. For example, the oscillator 24 outputs a sine wave signal of about 10 to 1000 Hz. The high voltage amplifier 13 amplifies the sine wave signal to a voltage of about 10 to 1000 V and applies it to the electrode 21.

  When a voltage is applied to the electrode 21 while the finger is in contact with the dielectric 22 that is an insulator, charges having different polarities are generated between the finger and the dielectric 22, and an electrostatic adsorption force is generated between the finger and the dielectric 22. To do. Therefore, when the finger is slid in contact with the dielectric 22, a frictional force corresponding to the attracting force is generated. Here, the voltage value (10 to 1000 V) applied to the electrode 21 can be determined by the film thickness of the dielectric 22 in contact with the finger.

  By continuously outputting the signal output from the oscillator 14, it is possible to generate a certain frictional resistance on the finger to be slid. The signal output from the oscillator 14 is not limited to a sine wave, and may be a rectangular wave, a sawtooth wave, or a triangular wave. Different tactile sensations can be given to the operator by changing the waveform.

  FIG. 3 is a diagram illustrating a configuration example in which the electrostatic attraction force generation unit of the display device according to the first embodiment is incorporated.

  Inside the display device 1, an electrode 21, a dielectric 22, a high voltage amplifier 23, and an oscillator 24, which are the above-described electrostatic attraction force generation units, are provided. Here, the electrode 21 and the dielectric 22 are provided on the back surface of the display device 1 (the surface opposite to the surface on which the touch operation is performed), and on the part where the hand and fingers that hold and hold the display device 1 are in contact. . Further, a transparent dielectric 26, a transparent electrode 27, the touch panel 3, and the display unit 4 are provided in this order from the surface to the inside (surface on which a touch operation is performed) of the display device 1. The transparent electrode 27 is grounded to the ground of the housing 2.

  As a sheet material used for the transparent electrode 27, an inorganic material such as ITO or ZnO, an organic material such as PEDOT, an Ag nanowire, or a Cu mesh electrode can be used. The transparent dielectric 26 is a transparent insulator having a thickness of about 1 μm to several mm, and glass, PET, acrylic, polycarbonate, polystyrene, polystyrene, polyimide, Tio2, sio2, or the like can be used.

The sheet material used for the transparent electrode 27 on the front side has a high resistance value of 10 ⁶ to 10 ¹⁰ Ω / □. This is because the operation of the touch panel 3 is hindered when a material having a low resistance is provided on the touch panel 3 because the touch panel 3 is a capacitance type. Details of this will be described later. The resistance value of the electrode 21 on the back side is not limited as described above.

  A signal output from the oscillator 24 is amplified by the high voltage amplifier 23 and applied to the electrode 21. The finger applied to the back surface in contact with the dielectric 22 is charged by the voltage applied to the electrode 21. As a result, the finger on the surface side is charged with the human body as a conductive path, charges having different polarities are generated on the finger on the surface side and the transparent dielectric 26, and an electrostatic adsorption force is generated between the finger and the transparent dielectric 26. . Therefore, when a finger on the touch panel 3 is slid, a frictional resistance is generated only on the slid finger and a tactile sensation can be generated.

  In contrast to the configuration of the electrostatic attraction force generator 7 shown in FIG. 3, a configuration in which the output voltage of the high voltage amplifier 23 is applied to the front transparent electrode 27 and the back electrode 21 is grounded is also conceivable. However, in the method of applying a voltage to the transparent electrode 27, the voltage does not propagate to the central portion of the transparent electrode 27 due to the influence of the parasitic capacitance generated between the transparent electrode 27 and the touch panel 3, and it is difficult to obtain a tactile sensation. I understood. Therefore, as shown in FIG. 3, by forming the electrostatic attraction force generating unit 7 so that the transparent electrode 27 on the front surface side is grounded and a voltage is applied to the electrode 21 on the back surface side, a tactile sensation can be obtained without problems. Can do.

  Incidentally, in the display device 1 having the configuration shown in FIG. 3, a tactile sensation may also occur in the hand on the back surface side that holds the housing 2. This is presumably because, even on the back side, an attractive force may be generated in principle, and the tactile sensation was felt by the delicate movement of the holding hand.

  FIG. 4 is a diagram for explaining a method for preventing the occurrence of tactile sensation on the back surface side of the display device according to the first embodiment.

  As the above-mentioned countermeasure, the capacitance of the transparent dielectric 26 on the front side is made larger than the capacitance of the dielectric 22 on the back side by making the thickness of the dielectric 22 on the back side thicker than the transparent dielectric 26 on the front side. Enlarge. The vertical axis of the coordinate shown in FIG. 4 indicates the probability that a tactile sensation will occur on the back side, and the horizontal axis of the coordinate represents the ratio of the capacity of the transparent dielectric 26 on the front side to the capacity of the dielectric 22 on the back side.

  When the ratio of the horizontal axis is smaller than 1, a tactile sensation has always occurred on the finger on the back side, but as the ratio of the horizontal axis becomes 1 or more, the probability of occurrence of a tactile sensation on the back side finger has decreased. When the ratio of the horizontal axis is 2 or more, no tactile sensation occurs on the finger on the back side. From this, it is possible to prevent the occurrence of tactile sensation on the back side by setting the ratio of the capacity of the transparent dielectric 26 on the front side to the capacity of the dielectric 22 on the back side to be 2 or more.

  Next, the sheet material of the transparent electrode 27 on the front side will be described. When a capacitive touch panel is used as the touch panel 3, the touch position is determined by detecting the capacitance between the sensor electrode provided on the touch panel and the finger. Therefore, if a low resistance conductive film is interposed between the touch panel 3 and the finger, the touch position cannot be detected.

  FIG. 5 is a diagram for explaining a method for preventing an operation failure of the touch panel of the display device according to the first embodiment.

The vertical axis of the coordinates shown in FIG. 5 indicates the probability that the capacitive touch panel operates normally, and the horizontal axis of the coordinates indicates the resistance value of the sheet material of the transparent electrode 27. When the resistance value of the sheet material of the transparent electrode 27 was 1 × 10 ³ Ω / □ or less, the position of the finger could not be detected. This is because the touch panel 3 is shielded by the transparent electrode 27. When the resistance value of the sheet material of the transparent electrode 27 is 1 × 10 ⁴ Ω / mouth, the operation is unstable. In order for the touch panel 3 to operate stably, the resistance value of the sheet material needs to be 1 × 10 ⁵ Ω / □ or more. As described above, in the present embodiment, the sheet material used for the transparent electrode 27 is 10 ⁶ to 10 ¹⁰ Ω / □. Such a high resistance material can be realized by ZnO, PEDOT or the like.

  Next, a variation configuration of the electrostatic attraction force generation unit 7 will be described.

  FIG. 6 is a diagram illustrating a configuration of a variation of the electrostatic attraction force generation unit of the display device according to the first embodiment. In the electrostatic attraction force generation unit 7 shown in FIG. 6, the capacitive touch panel 3 is configured on the upper portion of the display unit 4, and the transparent electrode 27 and the transparent dielectric 26 are provided on the upper side of the touch panel 3. In this electrostatic attraction force generation unit 7, unlike the configuration shown in FIG. 3, the transparent electrode 27 is not grounded.

  Since the sensor electrode and the transparent electrode 27 in the touch panel are close to each other, a large parasitic capacitance 29 is generated between the two electrodes. Therefore, even if the transparent electrode 27 is not grounded and is in a floating state, its potential is substantially equal to the average value of each sensor electrode potential in the touch panel. Therefore, the potential of the transparent electrode 27 is almost grounded. According to the configuration of this variation, it is not necessary to provide an electrode for grounding the transparent electrode 27, and the configuration of the electrostatic attraction force generation unit 7 can be simplified.

  FIG. 7 is a diagram illustrating a configuration of another variation of the electrostatic attraction force generation unit of the display device according to the first embodiment. In the electrostatic attraction force generating unit 7 shown in FIG. 7, the surface-type capacitive touch panel 3 is configured on the display unit 4, and the transparent dielectric 26 is provided on the upper side of the touch panel 3. Unlike the configuration shown in FIG. 3, the electrostatic attraction force generation unit 7 has a different type of touch panel 3 and is not provided with a transparent electrode 27.

  The electrode of the surface-type capacitive touch panel 3 is composed of a single transparent electrode. Therefore, since the electrode of the surface-type capacitive touch panel 3 also serves as the transparent electrode 27 of the electrostatic attraction force generation unit 7, it is not necessary to provide the transparent electrode 27. As a result, the configuration of the electrostatic attraction force generation unit 7 can be simplified.

  FIG. 8 is a diagram illustrating a configuration of another variation of the electrostatic attraction force generation unit of the display device according to the first embodiment. In the electrostatic attraction force generation unit 7 shown in FIG. 8, the right-hand and left-hand electrodes 21 and the dielectric 22 are provided on the back surface side of the display device 1. A transparent electrode 27 and a transparent dielectric 26 for electrostatic attraction are provided on the touch panel. By applying high voltages having different signal waveforms to the left and right electrodes 21, it is possible to give separate sense of touch to the right and left hands.

  Next, a method for driving the mechanical vibration generator 6 and the electrostatic attraction force generator 7 will be described.

  FIG. 9 is a diagram for explaining a method of driving the mechanical vibration generating unit 6 and the electrostatic attraction force generating unit 7 of the display device according to the first embodiment.

  In the timing generation chart shown in FIG. 9, mechanical vibration is generated when a finger starts to touch the touch panel 3, and is stopped in about 0.01 to 1 sec. Thereby, it is made to sense that it touched the touch panel 3 as a click feeling. Thereafter, a signal for generating an electrostatic attraction force is generated from when the finger starts moving until the finger stops moving.

  By performing such a driving method, it becomes possible to sense both the click feeling when the finger contacts the touch panel 3 and the feeling of the suction force when the finger is moved. The timing at which the finger touches, the timing at which the finger starts to move, and the timing at which the finger starts to move are detected by the control unit 5 that controls the overall operation of the display device 1, and the mechanical vibration generating unit 6 and the electrostatic attraction force are detected. The operation with the generator 7 is controlled.

  FIG. 10 is a diagram for explaining another method for driving the mechanical vibration generating unit 6 and the electrostatic attraction force generating unit 7 of the display device according to the first embodiment.

  In the driving method shown in FIG. 10, a mechanical vibration signal and an electrostatic adsorption signal are generated simultaneously. At this time, the frequency of each signal is set to be shifted from about 1 Hz to about 200 Hz. In this way, a tactile sensation with a frequency difference is obtained. Since the force generated by mechanical vibration is related to the inertial mass and frequency, in order to generate a tactile sensation at a frequency in the vicinity of 100 Hz where the human body has a high tactile sensitivity, it is necessary to increase the size of the vibrator (weight of the inertial mass). is necessary. According to this driving method, a high frequency of 1 kHz or higher can be set by such a method, and a small and light vibrator can be used.

  FIG. 11 is a diagram for explaining another method for driving the mechanical vibration generating unit 6 and the electrostatic attraction force generating unit 7 of the display device according to the first embodiment.

  In the driving method shown in FIG. 11, the frequency of the mechanical vibration signal and that of the electrostatic chucking signal are made the same, and their phases are synchronized and generated simultaneously. Thereby, a greater tactile sensation can be given to the operator.

FIG. 12 is a cross-sectional view illustrating the configuration of the display device according to the second embodiment.
In the second embodiment, one oscillator 34 and one high-voltage amplifier 33 control the generation of mechanical vibration and the generation of electrostatic attraction force. Thus, the circuit of the display device can be simplified by adopting a configuration in which the oscillator 34 and the high voltage amplifier 33 are shared.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... Housing | casing, 3 ... Touch panel, 4 ... Display part, 5 ... Control part, 6 ... Mechanical vibration generation part, 7 ... Electrostatic adsorption force generation part, 11 ... Piezoelectric element, 12 ... Inertial mass , 13 ... high voltage amplifier, 14 ... oscillator, 21 ... electrode, 22 ... dielectric, 23 ... high voltage amplifier, 24 ... oscillator, 26 ... transparent dielectric, 27 ... transparent electrode, 33 ... high voltage amplifier, 34 ... oscillator .

Claims (10)

A display unit for displaying images;
A touch panel for detecting the proximity position of the conductor;
A mechanical vibration generator for applying mechanical vibration to the conductor;
An electrostatic attraction force generating section for applying an electrostatic attraction force to the conductor;
A display device comprising: a control unit that operates the mechanical vibration generation unit and the electrostatic attraction force generation unit in conjunction with each other based on positional information of the conductor detected by the touch panel. A housing for storing the display unit, the touch panel, the mechanical vibration generating unit, the electrostatic attraction force generating unit, and the control unit;
The electrostatic attraction force generator is
A transparent electrode on the touch panel toward the surface side of the housing, and a transparent dielectric that contacts the conductor are laminated and arranged,
An electrode and a dielectric that comes into contact with another conductor are laminated and arranged toward the back side of the housing,
The display device according to claim 1, comprising an oscillator and a high-voltage amplifier that supply a voltage that changes to the electrode.   The display device according to claim 2, wherein a ratio of a capacity per unit area of the transparent dielectric to a capacity per unit area of the dielectric is 2 or more.   The display device according to claim 3, wherein the touch panel is a surface capacitive touch panel, and a sensor electrode of the touch panel is shared with the transparent electrode. The display device according to claim 2, wherein a resistance value per unit area of the transparent electrode is 10 ⁵ Ω or more.   The display device according to claim 2, wherein the transparent electrode is in a floating state without being grounded. The controller is
When the conductor starts to contact the transparent dielectric, it generates mechanical vibrations,
The display device according to claim 2, wherein an electrostatic attraction force is applied during movement while the conductor is in contact with the transparent dielectric. The mechanical vibration generating unit includes a piezoelectric element, an inertial mass that is mechanically connected to the piezoelectric element, an oscillator that supplies a voltage that changes to the piezoelectric element, and a high-voltage amplifier.
The display device according to claim 2, wherein an oscillator and a high-voltage amplifier of the mechanical vibration generation unit and the electrostatic adsorption force generation unit are shared. A plurality of the electrostatic adsorption force generation units are provided,
The display device according to claim 2, wherein the control unit performs control so as to apply a voltage having a different waveform to each of the electrodes.   The said touch panel provided in the display apparatus of any one of Claims 1 thru | or 9.

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