JP2019121287A - Operation input device and touch panel - Google Patents

Abstract

To provide an operation iput device and a touch panel capable of preventing abnormal noise caused by oscillation of the touch panel.SOLUTION: A touch panel 4 of an operation input device comprises a substrate 5, a first protection film 71, and a second protection film 73. The substrate 5 oscillates at frequency of an ultrasonic bandwidth and accepts touch input operation. The first protection film 71 is placed on an operation surface of the substrate. The second protection film 73 is provided on the first protection film 71 with an air film therebetween. Convexoconcave is provided on at least one of opposed surfaces of the first protection film 71 and the second protection film 73.SELECTED DRAWING: Figure 3

Description

  Embodiments disclosed herein relate to an operation input device and a touch panel.

  Conventionally, there is an operation input device for giving a predetermined tactile sensation to a user's fingertip performing a touch operation by vibrating a touch panel operated by the user at a frequency of an ultrasonic band, for example (see, for example, Patent Document 1) .

JP, 2016-170766, A

  However, in the operation input device, the touch panel that vibrates and the fingerprint of the finger touching the touch panel may interfere with each other to generate abnormal noise. One aspect of an embodiment is made in view of the above, and it aims at providing an operation input device and a touch panel which can control generating of unusual noise accompanying vibration of a touch panel.

  The operation input device according to one aspect of the embodiment includes a substrate, a first protective film, and a second protective film. The substrate vibrates at an ultrasonic frequency and receives a touch input operation. The first protective film is provided on the operation surface of the substrate. The second protective film is provided on the first protective film via an air film.

  The operation input device and the touch panel according to one aspect of the embodiment can suppress the generation of noise due to the vibration of the touch panel.

FIG. 1 is an explanatory view showing the overall configuration of the operation input device according to the embodiment. FIG. 2 is an explanatory view showing a part of a touch panel according to a comparative example of the embodiment. FIG. 3 is an explanatory view showing a part of the touch panel according to the embodiment. FIG. 4 is an explanatory view showing a part of a touch panel according to a modification of the embodiment. FIG. 5: is explanatory drawing which shows the relationship between the level difference of the unevenness | corrugation of the 1st protective film which concerns on embodiment, and a noise level and a tactile sense level. FIG. 6 is an explanatory view showing the relationship between the level difference of unevenness of the second protective film according to the embodiment, the noise level and the tactile level.

  Hereinafter, embodiments of the operation input device and the touch panel disclosed in the present application will be described in detail with reference to the attached drawings. Note that the present invention is not limited by the embodiments described below. FIG. 1 is an explanatory view showing the overall configuration of the operation input device 1 according to the embodiment.

  In the following, for convenience, the side of the operation input device 1 which is touched by the user will be described as the upper side. Therefore, in the following description, one main surface on the upper side in the component of the operation input device 1 is referred to as an upper surface, and the other main surface is referred to as a lower surface.

  As shown in FIG. 1, the operation input device 1 includes a display 2, a support plate 3, a touch panel 4, and a control unit 11. The display 2 is, for example, an LCD (Liquid Crystal Display), and displays an image such as an icon or a switch to be subjected to touch operation by the user.

  The support plate 3 is a plate body provided on the display 2 and formed of a translucent material such as glass capable of viewing an image displayed on the display 2. The support plate 3 supports the touch panel 4 mounted on the upper surface.

  The touch panel 4 is provided on the support plate 3 as an operation unit of the operation input device 1. The touch panel 4 includes a substrate 5 sequentially stacked from the lower layer side, an adhesive layer 6, and a protective layer 7. The touch panel 4 is attached to the support plate 3 by, for example, a double-sided adhesive tape 8 attached to the peripheral edge of the lower surface of the substrate 5.

  The substrate 5 is a plate provided on the display 2 and formed of a translucent material such as glass capable of seeing an image displayed on the display 2, and the touch operation or the slide operation by the finger F of the user Accept

  The adhesive layer 6 is formed of, for example, a translucent adhesive such as silicon or acrylic, and adheres the protective layer 7 to the operation surface of the substrate 5. The protective layer 7 is bonded on the adhesive layer 6 to protect the operation surface of the substrate 5.

  In the touch panel 4, the touch sensor 9 is provided on the lower surface of the substrate 5, and the vibrator 10 is provided on an end portion of the lower surface of the substrate 5 outside the touch sensor 9. The vibrator 10 is, for example, a piezoelectric element (piezo element), and vibrates the substrate 5 according to a drive signal input from the control unit 11 to vibrate the substrate 5.

  The touch sensor 9 includes, for example, a plurality of capacitive pressure-sensitive sensors disposed in the surface direction of the substrate 5. The touch sensor 9 outputs, to the control unit 11, a voltage signal corresponding to the capacitance of each of the capacitive pressure sensors.

  The control unit 11 includes a detection unit 12 and a drive unit 13. The detection unit 12 determines the operation position of the user on the touch panel 4 based on the signal input from the touch sensor 9. Specifically, when the user operates the touch panel 4 in the touch sensor 9, the capacitance of the capacitive pressure-sensitive sensor disposed at a position corresponding to the user's operation position on the operation surface fluctuates.

  Therefore, the detection unit 12 can determine that the disposition position of the capacitive pressure-sensitive sensor in which the capacitance has changed is the operation position on the touch panel 4. The detection unit 12 outputs a signal indicating the determined operation position of the user on the touch panel 4 to a control target device (not shown) whose operation is controlled by the operation of the operation input device 1.

  The drive unit 13 outputs a drive signal for causing the touch panel 4 to vibrate at a frequency in the ultrasonic band (hereinafter, referred to as “ultrasonic vibration”) to the vibrator 10. Thereby, the vibrator 10 vibrates to ultrasonically vibrate the touch panel 4, and a squeeze film is formed on the operation surface of the touch panel 4. The squeeze film is a thin air layer formed by drawing air between the operation surface and the user's fingertip F by ultrasonic vibration of the touch panel 4. The frequency of the ultrasonic band is generally a high frequency (for example, 20 kHz or more) which can not be heard by the human ear, but may be a frequency at which the squeeze film described above is formed.

  The touch panel 4 can reduce the frictional resistance of the operation surface by forming such a squeeze film between the operation surface and the fingertip F, and can give the user who operates the operation surface with the fingertip F a smooth tactile sensation. .

  However, a general operation input device may emit an abnormal noise as the touch panel vibrates. For this reason, the touch panel 4 of the operation input device 1 according to the embodiment has a structure capable of suppressing the generation of abnormal noise caused by vibration.

  Next, with reference to FIG. 2 and the principle of generation of abnormal noise in a general touch panel as a comparative example, the structure of the touch panel according to the embodiment will be described with reference to FIG. FIG. 2 is an explanatory view showing a part of the touch panel 40 according to a comparative example of the embodiment.

  FIG. 3 is an explanatory view showing a part of the touch panel 4 according to the embodiment. In addition, about the component same as the component shown in FIG. 1 among the components shown in FIG. 2 and FIG. 3, the detailed description is abbreviate | omitted by attaching the code | symbol same as the code | symbol shown in FIG. .

  As shown in FIG. 2, in the touch panel 40 according to the comparative example, the adhesive layer 6 is provided on the upper surface of the substrate 5, and the protective layer 70 is provided on the upper surface of the adhesive layer 6. In the touch panel 40 according to the comparative example, when the substrate 5 is ultrasonically vibrated in a state where the surface F1 of the user's fingertip F (see FIG. 1) is in contact with the upper surface of the protective layer 70, the protective layer 70 and the surface F1 of the fingertip F The squeeze film A is formed between the

  Thus, the touch panel 40 according to the comparative example can provide the user with a smooth tactile sensation. However, at this time, the touch panel 40 according to the comparative example may emit abnormal noise N from the surface of the protective layer 70.

  The abnormal noise N is generated at the groove F2 of the fingerprint on the surface F1 of the fingertip F. Specifically, as shown in FIG. 2, in the touch panel 40 according to the comparative example, when the surface F1 of the user's fingertip F contacts the upper surface of the protective layer 70, the distance between the protective layer 70 and the groove F2 of the fingerprint is Space is formed.

  In the touch panel 40 according to the comparative example, when the substrate 5 is subjected to ultrasonic vibration in such a state, the ultrasonic wave emitted from the protective layer 70 and the reflected wave where the ultrasonic wave is reflected by the groove F2 of the fingerprint is the protective layer The resonance occurs in the space between the groove 70 and the groove F2 to generate an abnormal noise N.

  Therefore, in the touch panel 4 according to the embodiment, as shown in FIG. 3, the protective layer 7 provided on the operation surface of the substrate 5 via the adhesive layer 6 has a three-layer structure to generate the abnormal noise N. Suppress.

  Specifically, the protective layer 7 includes a first protective film 71 provided on the adhesive layer 6 and a second protective film 73 provided on the first protective film 71 with the air film 72 interposed therebetween. The second protective film 73 is superimposed on the first protective film 71 by, for example, an adhesive provided on an edge of the upper surface of the first protective film 71.

  The first protective film 71 and the second protective film 73 are formed of, for example, a translucent adhesive such as PET (Poly Ethylene Terephthalate). Thus, the touch panel 4 has a three-layer structure of the first protective film 71, the air film 72, and the second protective film 73.

  In the touch panel 4, although the first protective film 71 ultrasonically vibrates when the substrate 5 ultrasonically vibrates, the air film 72 intervenes between the first protective film 71 and the second protective film 73. The second protective film 73 does not vibrate ultrasonically.

  For this reason, in the touch panel 4, when the substrate 5 vibrates ultrasonically, the squeeze film A is formed on the surface of the first protective film 71, so that the surface of the first protective film 71 has a slippery feeling.

  Thus, when the user brings the surface F1 of the fingertip F into contact with the second protective film 73 and slides it, the touch panel 4 makes the first protective film 71 over the second protective film 73 with respect to the surface F1 of the user's fingertip F. Can give a smooth feel on the surface of

  At this time, in the touch panel 4, the ultrasonic wave emitted from the first protective film 71 that is ultrasonically vibrated and the reflected wave where the ultrasonic wave is reflected by the second protective film 73 resonate in the air film 72 and slightly Noise N occurs. However, since the second protective film 73 functions as a filter, the abnormal noise N generated in the air film 72 is difficult to be recognized by the user.

  As described above, since the touch panel 4 has a three-layer structure of the first protective film 71, the air film 72, and the second protective film 73, ultrasonic vibration can be applied to the user performing the touch operation while providing a slippery tactile sensation. It is possible to suppress the generation of the accompanying abnormal noise.

  Furthermore, in the present embodiment, by devising the shapes of the surfaces of the first protective film 71 and the second protective film 73 of the touch panel 4 shown in FIG. It can be reduced.

  Next, with reference to FIG. 4, a touch panel 4 a according to a modification in which the surface shapes of the first protective film 71 and the second protective film 73 are devised will be described. Drawing 4 is an explanatory view showing a part of touch panel 4a concerning a modification of an embodiment. Here, among the components shown in FIG. 4, the same components as those shown in FIG. 3 will be assigned the same reference numerals as those shown in FIG. 3 to omit detailed descriptions thereof. .

  As shown in FIG. 4, the touch panel 4 a according to the modification is the touch panel 4 shown in FIG. 3 in that the first protective film 71 has irregularities on the upper surface and the second protective film 73 has irregularities on the lower surface. It is different.

  The unevenness in the first protective film 71 is formed, for example, by applying a solvent containing particles P1 of a predetermined size on the upper surface of the first protective film 71. The height difference d1 of the unevenness of the first protective film 71 will be described with reference to FIG.

  As described above, since the first protective film 71 has irregularities on the surface facing the air film 72, the propagation direction of the ultrasonic wave emitted from the first protective film 71 is the particle P1 when the substrate 5 is ultrasonically vibrated. Can be distributed by

  Thereby, the touch panel 4 a reduces the magnitude of the abnormal noise N generated by the resonance of the ultrasonic wave emitted from the first protective film 71 and the reflected wave of the ultrasonic wave reflected by the second protective film 73. Can.

  The unevenness in the second protective film 73 is formed, for example, by applying a solvent containing particles P2 of a predetermined size on the lower surface of the second protective film 73. The height difference d2 of the unevenness of the second protective film 73 will be described with reference to FIG.

  As described above, since the second protective film 73 has unevenness on the surface facing the air film 72, the propagation of the reflected wave reflected by the second protective film 73 of the ultrasonic wave when the substrate 5 vibrates ultrasonically. The direction can be dispersed by the particles P2.

  Thereby, the touch panel 4 a reduces the magnitude of the abnormal noise N generated by the resonance of the ultrasonic wave emitted from the first protective film 71 and the reflected wave of the ultrasonic wave reflected by the second protective film 73. Can.

  In addition, as the unevenness formed on the first protective film 71 and the second protective film 73, the greater the height difference (roughness), the more remarkable the noise reduction effect appears. However, when the height difference of the unevenness formed on the first protective film 71 and the second protective film 73 is too large, the touch panel 4a can give the user who performs the touch operation a rough feeling or a rough feeling. is there.

  Therefore, the touch panel 4a is formed on the first protective film 71 and the second protective film 73 so that generation of abnormal noise due to ultrasonic vibration can be reduced while giving a tactile sensation to the user performing the touch operation as a slippery touch. The height difference of the unevenness is adjusted.

  Next, with reference to FIG. 5 and FIG. 6, the height difference of the unevenness | corrugation formed in the 1st protective film 71 and the 2nd protective film 73 is demonstrated. FIG. 5: is explanatory drawing which shows the relationship between the level difference of the unevenness | corrugation of the 1st protective film 71 which concerns on embodiment, and a noise level and a tactile sense level.

  FIG. 6 is an explanatory view showing the relationship between the level difference of unevenness of the second protective film 73 according to the embodiment, the abnormal noise level, and the tactile sensation level. The horizontal axes of the graphs shown in FIGS. 5 and 6 indicate the height difference (μm) of the unevenness, the vertical axis on the left indicates the noise level (dB), and the vertical axis on the right indicates the tactile sensation level. (Sensitivity evaluation) is shown.

  The height difference (μm) of the unevenness here is the height difference d1 from the upper surface of the first protective film 71 to the top of the particle P1 in FIG. 5, and in FIG. 6 from the lower surface of the second protective film 73. It is the height difference d2 to the lowermost part of the particle P2.

  Further, the abnormal noise level (dB) is a level of the magnitude of abnormal noise emitted from the touch panel 4. Further, the tactile sensation level (sensitivity evaluation) is the height of the slick feeling felt when the user operates the touch panel 4.

  It should be noted that the higher the touch level is, the more tactile the user is given, and the lower the touch level is, the more the user feels rough and / or uneven.

  As shown in FIGS. 5 and 6, in the abnormal noise characteristic, the greater the height difference of the unevenness of the first protective film 71 and the second protective film 73, the lower the abnormal noise level. This is because, as described above, as the height difference of the unevenness is larger, the propagation direction of the ultrasonic wave or the reflected wave of the ultrasonic wave is dispersed.

  Here, for example, as shown in FIG. 5 and FIG. 6, when the abnormal noise allowable maximum level is 70 (dB), the height difference of the unevenness of the first protective film 71 and the second protective film 73 is at least 10 ( It must be at least μm).

  On the other hand, as shown in FIG. 5 and FIG. 6, the tactile sensation level sharply increases as the height difference of the unevenness increases from the minimum value, but the height difference of the unevenness exceeds, for example, 10 (μm) The tactile level gradually decreases as the height difference of the unevenness increases.

  Such tactile sensation characteristics are considered to be due to the frictional force which changes according to the contact area between the surface F1 of the user's fingertip F and the second protective film 73. Specifically, when the user presses the surface F1 of the fingertip F against the upper surface of the second protective film 73, the second protective film 73 is curved so as to be convex downward and contacts the first protective film 71. At this time, the surface of the second protective film 73 has a shape corresponding to the unevenness of the first protective film 71 and the unevenness of the second protective film 73.

  Therefore, when the unevenness is the minimum value, that is, when the first protective film 71 and the second protective film 73 are close to a perfect plane, the contact area between the surface F1 of the user's fingertip F and the second protective film 73 Is the largest, and the friction level is large, so the tactile level is the lowest.

  Then, when the height difference between the unevenness gradually increases, the contact area between the surface F1 of the user's fingertip F and the second protective film 73 is gradually reduced, and the frictional force is also reduced accordingly, so that the tactile sensation level is improved. However, when the height difference of the unevenness becomes too large, the user notices the unevenness of the first protective film 71 and the second protective film 73 remarkably, and the touch feeling level gradually decreases.

  Here, when the graph of the tactile sensation characteristic shown in FIG. 5 and the graph of the tactile sensation characteristic shown in FIG. 6 are compared, the height difference of the unevenness of the first protective film 71 shown in FIG. As it gets larger, the tactile level drops relatively slowly. On the other hand, in the case of the second protective film 73 shown in FIG. 6, as the height difference of the unevenness becomes larger than 10 (μm), the tactile sensation level is relatively rapidly reduced.

  This is because the user directly touches the second protective film 73, so that the change in the height difference of the unevenness in the second protective film 73 is more sensitive than the change in the height difference of the unevenness in the first protective film 71.

  Further, in addition to the user indirectly touching the first protective film 71 via the second protective film 73, the surface of the first protective film 71 is squeezed by the ultrasonic vibration of the substrate 5 (see FIG. 4). Since the reference is formed, it is difficult to feel the unevenness of the first protective film 71.

  From the above, it is necessary to set the lower limit value of the height difference of the unevenness in the first protective film 71 and the second protective film 73 to 10 (μm) in order to set the abnormal noise level to the abnormal noise allowable maximum level or less. is there.

  However, in order to maintain a certain tactile sensation level, it is necessary to set the second protective film 73 smaller than the first protective film 71 for the upper limit value of the height difference of the unevenness. In other words, the upper limit value of the height difference of the unevenness in the first protective film 71 can be set larger than the upper limit value of the height difference of the unevenness in the second protective film 73.

  So, in this embodiment, when a tactile sense minimum level is a level shown in Drawing 5 and Drawing 6, height difference of unevenness which the 1st protective film 71 has is set to 10 (micrometer)-50 (micrometer). On the other hand, the height difference of the unevenness of the second protective film 73 is 10 (μm) to 20 (μm). As a result, the operation input device 1 can set the tactile sensation level to the tactile sensation minimum level or higher while keeping the abnormal noise level at the abnormal noise maximum level or lower.

  As described above, the operation input device 1 according to the embodiment includes the substrate 5, the first protective film 71, and the second protective film 73. The substrate 5 vibrates at an ultrasonic frequency and receives a touch input operation. The first protective film 71 is provided on the operation surface of the substrate 5. The second protective film 73 is provided on the first protective film 71 via an air film 72. Thereby, the operation input device 1 can suppress the generation of the abnormal noise accompanying the vibration of the touch panel 4.

  In the embodiment described above, the heights of the irregularities in the first protective film 71 and the second protective film 73 are set such that the abnormal noise level becomes lower than the abnormal noise allowable maximum level and the tactile sensation level becomes higher than the tactile sensation minimum level. Although the difference is set, this is an example.

  In the operation input device 1, the convex portions of the convex and concave portions of the first protective film 71 and the second protective film 73 are set such that the abnormal noise level becomes equal to or lower than the abnormal noise allowable maximum level and the tactile sensation level becomes equal to or higher than the tactile sensation minimum level. The interval or width may be set.

  In such a configuration, the interval and width of the convex portions can be adjusted by adjusting the size and concentration of the particles P1 and P2 to be added to the solvent to be applied to form irregularities on the first protective film 71 and the second protective film 73. Set With this configuration as well, the operation input device 1 can provide the user with a high quality tactile sensation while reducing noise and noise associated with the vibration of the touch panel 4.

  In addition, the member provided via the air film 72 on the 1st protective film 71 shown in FIG. 4 is not limited to the 2nd protective film 73, A finger tip F directly makes it to the 1st protective film 71 It may be any member as long as it can be prevented.

  In the embodiment described above, the operation input device 1 in which the touch panel 4 is superimposed on the display 2 is described as an example, but the touch panel 4 according to the present embodiment is not provided for the operation input device without the display 2 It is also possible to apply.

  For example, an operation input device provided in a center console of a vehicle and controllably controlling a control target by touch operation or slide operation without the user visually recognizing the operation surface is an operation input device provided in a dashboard of the vehicle Even the distance from the driver's ear is close.

  For this reason, the driver is likely to be sensitive to abnormal noise emitted from the operation input device provided on the center console. For this reason, the driver's comfort can be further improved by applying the touch panel 4 according to the embodiment to such an operation input device.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the invention are not limited to the specific details and representative embodiments represented and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

REFERENCE SIGNS LIST 1 operation input device 2 display 3 support plate 4, 4 a, 40 touch panel 5 substrate 6 adhesive layer 7, 70 protective layer 71 first protective film 72 air film 73 second protective film 8 double-sided tape 9 touch sensor 10 vibrator 11 controller 12 detection unit 13 drive unit A squeeze film F fingertip F1 surface F2 groove N abnormal noise

Claims (7)

A substrate that vibrates at an ultrasonic frequency and receives a touch input operation;
A protective film disposed on the operation surface of the substrate;
The said protective film has an unevenness | corrugation on the surface, and an air film is formed, The operation input device characterized by the above-mentioned. A substrate that vibrates at an ultrasonic frequency and receives a touch input operation;
A first protective film provided on the operation surface of the substrate;
And a second protective film provided on the first protective film via an air film. The first protective film is
The operation input device according to claim 2, wherein the surface facing the air film has unevenness. The unevenness of the first protective film is
The height difference is 10 μm to 50 μm. The operation input device according to claim 3. The second protective film is
The operation input device according to any one of claims 2 to 4, wherein the surface facing the air film has unevenness. The unevenness of the second protective film is
A height difference is 10 micrometers-20 micrometers. The operation input device of Claim 5 characterized by the above-mentioned. Provided as the operation unit of the operation input device
A substrate that vibrates at an ultrasonic frequency and receives a touch input operation;
A first protective film provided on the operation surface of the substrate;
And a second protective film provided on the first protective film through an air film.

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