Display device and electronic device

Abstract

To provide a display apparatus and an electronic apparatus capable of achieving both a force feedback function and a tactile function and having high strength.SOLUTION: A display apparatus according to the present invention comprises a display panel, a touch panel, a spacer, a tactile panel, and a piezoelectric actuator. The touch panel is arranged on the display panel and comprises a first main surface on the display panel side and a second main surface opposite to the first main surface. The tactile panel is arranged on the spacer and comprises a third main surface facing the second main surface with a gap therebetween and a fourth main surface opposite to the third main surface. The piezoelectric actuator is arranged on the third main surface and generates vibrations. Assuming that the thickness from the second main surface to the fourth main surface is a first thickness and the thickness from the second main surface to the third main surface is a second thickness, the first thickness is not less than 0.5 mm and not more than 1.5 mm, and is not less than the thickness obtained by adding 0.3 mm to the second thickness and not more than the thickness obtained by adding 1 mm to the second thickness.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a display device and an electronic device capable of providing a tactile sensation. [Background technology]

[0002] Some smartphones and car navigation systems are equipped with a force feedback function that generates vibrations when the touch panel is operated, notifying users that their input has been accepted. In recent years, haptic technology has been developed that not only notifies users by vibrating in various ways, but also by providing a variety of vibrations to express the feel of displayed objects and to grasp the operating position.

[0003] This type of tactile technology can be realized by vibrating a piezoelectric actuator attached to a tactile panel at an ultrasonic frequency. Standing waves are formed in the tactile panel by the ultrasonic vibration, and when the tactile panel is touched with a finger or the like, a tactile sensation can be sensed. By changing the signal pattern supplied to the piezoelectric actuator, a wide variety of tactile sensations can be expressed. Therefore, a separate tactile panel is required to express tactile sensations on a touch panel.

[0004] Here, display panels such as liquid crystal displays are equipped with reinforced cover glass to protect the surface, and glass with a thickness of 0.2 to 1.0 mm is used to ensure strength. In addition, for example, Patent Document 1 discloses a liquid crystal display reinforcement structure that improves the strength of the display panel by providing an arched display panel on the front surface of the liquid crystal display. Patent Document 2 discloses a display panel device that provides both cooling function and strength improvement by providing a heat sink on the back surface of the liquid crystal display. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-215087 A [Patent Document 2] JP 2006-53529 A Summary of the Invention [Problem to be solved by the invention]

[0006] Furthermore, a haptic function driven by ultrasonic waves using a piezoelectric actuator can be achieved by placing the piezoelectric actuator at the edge of the haptic panel and generating standing waves over the entire surface of the panel. However, to provide a force feedback function driven by low frequency vibrations using a piezoelectric actuator, the piezoelectric actuator must be placed directly under the back surface of the haptic panel, because the low frequency vibrations will attenuate midway through the panel and will not function if placed in the same position. Therefore, it is not possible to achieve both an ultrasonic haptic function and a low frequency force feedback function with a single piezoelectric actuator.

[0007] In view of the above circumstances, an object of the present invention is to provide a display device and electronic device that are capable of achieving both a force feedback function and a tactile function and have high strength. [Means for solving the problem]

[0008] In order to achieve the above object, a display device according to one embodiment of the present invention includes a display panel, a touch panel, a spacer, a tactile panel, and a piezoelectric actuator. The touch panel is disposed on the display panel, and has a first main surface facing the display panel, and a second main surface opposite to the first main surface. The spacer is disposed on the second major surface. The tactile panel is disposed on the spacer and has a third main surface facing the second main surface with a gap therebetween, and a fourth main surface opposite the third main surface. The piezoelectric actuator is disposed on the third main surface and generates vibrations. If the thickness from the second main surface to the fourth main surface is the first thickness, and the thickness from the second main surface to the third main surface is the second thickness, the first thickness is 0.5 mm or more and 1.5 mm or less, and is greater than or equal to the second thickness plus 0.3 mm and less than or equal to the second thickness plus 1 mm.

[0009] The display device may further include a drive unit that supplies to the piezoelectric actuator an ultrasonic drive signal that causes the piezoelectric actuator to vibrate in an ultrasonic band, and a low-frequency drive signal that causes the piezoelectric actuator to vibrate in a low-frequency band.

[0010] The spacer has an elastic modulus of 1.0×10 6 Pa or more 6.0×10 6 It may be made of a material having a resistance of 0.1 Pa or less.

[0011] The second thickness may be not less than 0.05 mm and not more than 0.8 mm.

[0012] The tactile panel may have a rectangular shape with a longer side having a width that is 1 to 2.5 times the shorter side.

[0013] The tactile panel may be made of resin or glass.

[0014] In order to achieve the above object, an electronic device according to an embodiment of the present invention includes a display panel, a touch panel, a spacer, a tactile panel, and a piezoelectric actuator. The touch panel is disposed on the display panel, and has a first main surface facing the display panel, and a second main surface opposite to the first main surface. The spacer is disposed on the second major surface. The tactile panel is disposed on the spacer and has a third main surface facing the second main surface with a gap therebetween, and a fourth main surface opposite the third main surface. The piezoelectric actuator is disposed on the third main surface and generates vibrations. If the thickness from the second main surface to the fourth main surface is the first thickness, and the thickness from the second main surface to the third main surface is the second thickness, the first thickness is 0.5 mm or more and 1.5 mm or less, and is greater than or equal to the second thickness plus 0.3 mm and less than or equal to the second thickness plus 1 mm. Effect of the Invention

[0015] As described above, according to the present invention, it is possible to provide a display device and electronic device that have both a force feedback function and a tactile function and that have high strength. [Brief description of the drawings]

[0016] [Figure 1] 1 is a side view of a display device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the front surface side of the display device. [Diagram 3] FIG. 2 is a plan view of the rear surface side of the display device. [Figure 4] FIG. 2 is a cross-sectional view of the display device. [Diagram 5] FIG. 2 is an exploded schematic view showing the display device. [Figure 6] 4 is a cross-sectional view of a piezoelectric actuator included in the display device. FIG. [Figure 7] 5A to 5C are schematic diagrams illustrating the operation of the display device. [Figure 8] FIG. 2 is a schematic diagram showing the size of the display device. [Figure 9] FIG. 2 is a schematic diagram showing the size of the display device. [Figure 10] 4 is a graph showing the relationship between a first thickness and a second thickness of the display device. [Figure 11] FIG. 1 is a schematic diagram of a display device according to a comparative example. [Figure 12] FIG. 13 is a schematic diagram of a display device according to a modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The display device according to this embodiment will be described below.

[0018] [Display device configuration] Fig. 1 is a side view of a display device 100 according to an embodiment of the present invention. Fig. 2 is a plan view of the display device 100 seen from the front side, and Fig. 3 is a plan view of the display device 100 seen from the back side. Fig. 4 is a cross-sectional view of the display device 100, taken along line AA in Figs. 2 and 3. Fig. 5 is a schematic exploded view of the display device 100 shown in Fig. 4.

[0019] As shown in these figures, the display device 100 includes a display panel 101, a touch panel 102, a spacer 103, a tactile panel 104, and a piezoelectric actuator 105. As shown in Figures 2 and 3, the display device 100 is flat and has a rectangular shape when viewed in a direction perpendicular to the thickness direction. In each figure of the present disclosure, the longitudinal direction of the display device 100 is the X direction, the lateral direction is the Y direction, and the thickness direction is the Z direction.

[0020] The display panel 101 is a panel that displays an image, and is a display panel that uses liquid crystal or organic EL (electro-luminescence), etc. The configuration of the display panel 101 is not particularly limited, and it can be a display having a general configuration.

[0021] The touch panel 102 is disposed on the display panel 101, and detects a touch on the display device 100 by a user's finger or the like. As shown in Fig. 5, the touch panel 102 includes a touch panel body 111 and a cover glass 112. The touch panel body 111 includes an array of touch sensors. The touch sensors are preferably of a capacitive type. The cover glass 112 is bonded to the touch panel body 111, and protects the touch panel body 111.

[0022] Hereinafter, of the main surfaces of touch panel 102, the main surface on the display panel 101 side is referred to as first main surface 102a, and the main surface opposite to first main surface 102a is referred to as second main surface 102b. The main surface of touch panel 102 on the touch panel main body 111 side is first main surface 102a, and the main surface on the cover glass 112 side is second main surface 102b.

[0023] The spacers 103 are disposed on the second main surface 102b of the touch panel 102, and separate the touch panel 102 from the tactile panel 104. The spacers 103 have a strip shape as shown in Figures 2 and 3, and are disposed one by one along the long sides of the display device 100. The spacers 103 have an elastic modulus of 1.0 x 10 6 Pa or more 6.0×10 6 It is preferable to use a material having a resistance of 0.1 Pa or less, and specifically, it is preferable to use a material made of urethane rubber, polyurethane, PET (polyethylene terephthalate), or the like.

[0024] The tactile panel 104 is placed on the spacer 103 and presents a tactile sensation to the user. As shown in FIG. 1, the tactile panel 104 has a longer side than other members such as the touch panel 102, and has a portion 104a that protrudes from the other members. A piezoelectric actuator 105 is joined to this portion 104a, and vibrations are generated by the piezoelectric actuator 105. The tactile panel 104 is made of a light-transmitting material such as glass or resin. The surface of the tactile panel 104 facing the touch panel 102 is a third main surface 104b, and the main surface opposite the third main surface 104b is a fourth main surface 104c.

[0025] The tactile panel 104 is separated from the touch panel 102 by the spacer 103, and the third main surface 104b faces the second main surface 102b of the touch panel 102 with a gap therebetween. The gap between the second main surface 102b and the third main surface 104b is referred to as gap R hereinafter.

[0026] The piezoelectric actuator 105 is joined to the tactile panel 104 and generates vibrations. As shown in Fig. 1, the piezoelectric actuator 105 is joined to the third main surface 104b of the tactile panel 104 at a portion 104a. Fig. 6 is a cross-sectional view of the piezoelectric actuator 105. As shown in the figure, the piezoelectric actuator 105 includes a piezoelectric body 121, a first electrode 122, and a second electrode 123. The piezoelectric body 121 is made of a piezoelectric material such as PZT (lead zirconate titanate).

[0027] The first electrode 122 includes a first internal electrode 124 and a first external electrode 125. The first internal electrode 124 is made of a conductive material and is provided in a plurality of layers in the piezoelectric body 121. The first external electrode 125 is made of a conductive material and is connected to the first internal electrode 124. The second electrode 123 includes a second internal electrode 126 and a second external electrode 127. The second internal electrode 126 is made of a conductive material and is provided in a plurality of layers in the piezoelectric body 121. The second external electrode 127 is made of a conductive material and is connected to the second internal electrode 126.

[0028] As shown in Fig. 5, the first internal electrodes 124 and the second internal electrodes 126 are alternately arranged and face each other via the piezoelectric body 121. The number of layers of the first internal electrodes 124 and the second internal electrodes 126 is not limited to three each. As shown in Figs. 2 and 3, a first wiring 128 is connected to the first electrode 122, and a second wiring 129 is connected to the second electrode 123. The first wiring 128 and the second wiring 129 are connected to a driving unit (not shown) and transmit a driving signal output from the driving unit to the first electrode 122 and the second electrode 123.

[0029] When a voltage is applied between first electrode 122 and second electrode 123 by this drive signal, the piezoelectric body 121 is deformed by the inverse piezoelectric effect, generating vibration. Here, in the display device 100, the control unit can supply an ultrasonic drive signal to the piezoelectric actuator 105 to cause the piezoelectric actuator 105 to vibrate in the ultrasonic band (20 kHz or more). Also, the control unit can supply a low-frequency drive signal to the piezoelectric actuator 105 to cause the piezoelectric actuator 105 to vibrate in the low-frequency band (300 Hz or less).

[0030] As shown in FIG. 5, the piezoelectric actuator 105 may have a laminated structure in which first electrodes 122 and second electrodes 123 are alternately laminated with piezoelectric bodies 121 interposed therebetween, or may have another structure.

[0031] [Display device operation] The operation of the display device 100 will now be described. Fig. 7 is a schematic diagram showing the operation of the display device 100. As shown in the figure, when a user vibrates the piezoelectric actuator 105 (see Fig. 1) with a finger F in contact with the fourth main surface 104c of the tactile panel 104, the vibration is transmitted to the tactile panel 104, causing the tactile panel 104 to vibrate. This allows the finger F to sense touch. The piezoelectric actuator 105 may be vibrated in the ultrasonic band or in the low frequency band.

[0032] Here, the tactile panel 104 and the touch panel 102 are separated by a gap R, so that vibrations of the tactile panel 104 are prevented from being attenuated by the touch panel 102. Furthermore, contact of a finger F with the tactile panel 104 is detected by the touch panel 102. Furthermore, an image displayed by the display panel 101 can be viewed via the touch panel 102 and the tactile panel 104.

[0033] [Size of each part] The size of each part of the display device 100 will be described. Fig. 8 and Fig. 9 are schematic diagrams showing the size of each part of the display device 100. As shown in Fig. 9, the thickness from the second main surface 102b to the fourth main surface 104c, that is, the total thickness of the gap R and the tactile panel 104, is defined as a first thickness D1. The thickness from the second main surface 102b to the third main surface 104b, that is, the thickness of the gap R, is defined as a second thickness D2. The thickness of the cover glass 112 is defined as a third thickness D3, and the thickness of the tactile panel 104 is defined as a fourth thickness D4.

[0034] FIG. 10 is a graph showing the preferred ranges of the first thickness D1 and the second thickness D2, and the preferred ranges of the first thickness D1 and the second thickness D2 are shown by shading. As shown in the figure, the second thickness D2 is preferably 0.05 mm or more and 0.8 mm or less. In addition, in FIG. 10, the first thickness D1 obtained by adding 0.3 mm to the second thickness D2 is shown as "D1=D2+0.3", and the first thickness D1 obtained by adding 1 mm to the second thickness D2 is shown as "D1=D2+1". As shown by shading in FIG. 10, the first thickness D1 is preferably 0.5 mm or more and 1.5 mm or less, and is greater than the thickness obtained by adding 0.3 mm to the second thickness D2 (D2+0.3) and less than the thickness obtained by adding 1 mm to the second thickness D2 (D2+1).

[0035] This is because, when the first thickness D1 is less than 0.5 mm or less than the thickness (D2+0.3) obtained by adding 0.3 mm to the second thickness D2, the tactile panel 104 comes into contact with the touch panel 102 when it vibrates, and the vibration is attenuated. Also, when the first thickness D1 exceeds 1.5 mm or exceeds the thickness (D2+1) obtained by adding 1 mm to the second thickness D2, the vibration of the tactile panel 104 is affected and touch detection by the touch panel 102 becomes difficult.

[0036] The third thickness D3 (see FIG. 9) is preferably 0 mm or more and 0.5 mm or less, and the fourth thickness D4 is preferably 0.3 mm or more and 1.0 mm or less. FIG. 11 is a cross-sectional view showing, for comparison, a display device 200 that does not have a tactile panel. As shown in the figure, the display device 200 includes a display panel 201 and a touch panel 202, and the touch panel 202 includes a touch panel body 211 and a cover glass 212. As shown in FIG. 11, the thickness of the cover glass 212 is defined as a fifth thickness D5. The fifth thickness D5 needs to be 0.2 mm or more and 1.0 mm or less to ensure the strength of the display device 200.

[0037] In contrast, the display device 100 (see FIG. 9) includes the tactile panel 104, and thus the fourth thickness D4, which is the thickness of the tactile panel 104, and the second thickness D2, which is the thickness of the gap R, are added to the touch panel 102, improving the strength of the display device 100. This allows the third thickness D3, which is the thickness of the cover glass 112, to be reduced to 0 mm or more and 0.5 mm or less. Furthermore, to generate a low-frequency driven force feedback function using the piezoelectric actuator 105, it is preferable to set the fourth thickness D4 to 0.3 mm or more and 1.0 mm or less so that the low-frequency vibration is not attenuated during transmission through the tactile panel 104.

[0038] 8, the planar shape of tactile panel 104 is preferably 1 to 2.5 times the length H, where W is the width along the long side of tactile panel 104 and H is the width along the short side of tactile panel 104. The total width S of spacers 103 is preferably 0.4% to 10% of width H, and width H is preferably 50 mm to 250 mm, and width S is preferably 1 mm to 5 mm.

[0039] [Effects of display device] As described above, in the display device 100, the tactile panel 104 is disposed on the touch panel 102 via the gap R. Therefore, even if ultrasonic vibrations are generated in the tactile panel 104 by the piezoelectric actuator 105, the tactile panel 104 does not come into contact with the touch panel 102, and vibrations are not inhibited by contact. Furthermore, in order for the tactile panel 104 and the gap R to prevent external physical shocks from being transmitted to the touch panel 102 and the display panel 101, the third thickness D3 (see FIG. 9 ), which is the thickness of the cover glass 112, can be made thin or eliminated. This makes it possible to reduce the overall thickness of the display device 100 even when a tactile presentation mechanism is added.

[0040] Furthermore, by setting the fourth thickness D4, which is the thickness of the tactile panel 104, to 0.3 mm or more and 1.0 mm or less, it is possible to prevent attenuation of the low-frequency vibration of the tactile panel 104. Therefore, as shown in Fig. 1, a force feedback function can be realized by generating low-frequency vibration in a piezoelectric actuator 105 arranged in the vicinity of the end portion of the tactile panel 104. Therefore, in the display device 100, it is possible to realize a tactile function by the ultrasonic vibration of the tactile panel 104 and a force feedback function by the low-frequency vibration of the tactile panel 104 with one piezoelectric actuator 105.

[0041] [Variations] FIG. 12 is a schematic diagram of a display device 100 according to a modified example of the present invention. As shown in the figure, the touch panel 102 may not include the cover glass 112 (see FIG. 1) and may include only the touch panel body 111. In this structure, the touch panel body 111 also serves as the cover glass. As shown in FIG. 12, if the thickness of the touch panel body 111 is a sixth thickness D6, the sixth thickness D6 can be set to 0.2 mm or more and 0.5 mm or less. Even in this structure, the fourth thickness D4, which is the thickness of the tactile panel 104, and the second thickness D2, which is the thickness of the gap R, are added on the touch panel 102, and the strength of the display device 100 is improved, so that the sixth thickness D6 can be made thinner to 0.2 mm or more and 0.5 mm or less. [Explanation of symbols]

[0042] 100…Display device 101…Display panel 102...Touch panel 102a...first main surface 102b...Second main surface 103…Spacer 104…Tactile panel 104b…Third main surface 104c…4th principal surface 105...Piezoelectric actuator 111…Touch panel main unit 112…Cover glass

Claims

1. A display panel; a touch panel disposed on the display panel, the touch panel having a first main surface on the display panel side and a second main surface opposite to the first main surface; a spacer disposed on the second major surface; a tactile panel disposed on the spacer, the tactile panel having a third main surface facing the second main surface with a gap therebetween, and a fourth main surface opposite the third main surface; a piezoelectric actuator that is disposed on the third main surface and generates vibrations; Equipped with When a thickness from the second main surface to the fourth main surface is defined as a first thickness, and a thickness from the second main surface to the third main surface is defined as a second thickness, the first thickness is 0.5 mm or more and 1.5 mm or less, and is greater than or equal to a thickness obtained by adding 0.3 mm to the second thickness and less than or equal to a thickness obtained by adding 1 mm to the second thickness. Display device.

2. The display device according to claim 1 , The piezoelectric actuator further includes a drive unit that supplies to the piezoelectric actuator an ultrasonic drive signal that causes the piezoelectric actuator to vibrate in an ultrasonic band, and a low-frequency drive signal that causes the piezoelectric actuator to vibrate in a low-frequency band. Display device.

3. The display device according to claim 1 or 2, The spacer has an elastic modulus of 1.0×10 ６ Pa or more 6.0×10 ６ Made of materials with a viscosity of less than Pa Display device.

4. The display device according to any one of claims 1 to 3, The second thickness is equal to or greater than 0.05 mm and equal to or less than 0.8 mm. Display device.

5. The display device according to any one of claims 1 to 4, The tactile panel has a rectangular shape in which the width of the long side is 1 to 2.5 times the width of the short side. Display device.

6. The display device according to any one of claims 1 to 5, The tactile panel is made of resin or glass. Display device.

7. A display panel; a touch panel disposed on the display panel, the touch panel having a first main surface on the display panel side and a second main surface opposite to the first main surface; a spacer disposed on the second major surface; a tactile panel disposed on the spacer, the tactile panel having a third main surface facing the second main surface with a gap therebetween, and a fourth main surface opposite the third main surface; a piezoelectric actuator that is disposed on the third main surface and generates vibrations; Equipped with When a thickness from the second main surface to the fourth main surface is defined as a first thickness, and a thickness from the second main surface to the third main surface is defined as a second thickness, the first thickness is 0.5 mm or more and 1.5 mm or less, and is greater than or equal to a thickness obtained by adding 0.3 mm to the second thickness and less than or equal to a thickness obtained by adding 1 mm to the second thickness. electronic equipment.

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