JP6755025B2 - Cover glass and touch panel device - Google Patents

Description

The present invention relates to a cover glass applicable to a touch panel or the like that accepts a touch operation from a user, and more particularly to a cover glass that allows the user to obtain an operation feeling and a touch panel device provided with the cover glass.

In recent years, a touch panel has been adopted in a wide range of fields as an interface when a user operates a device due to the advantage of being able to operate intuitively. The cover glass for the touch panel is arranged on the side where the touch panel is exposed to the user, and is configured to accept the touch operation performed by the user while visually recognizing the touch operation area on which the icon or the like is displayed. Due to the flatness of the cover glass and the improvement of design due to its high transparency, the movement to replace the touch panel is spreading to the devices that conventionally used physical buttons and keyboards. For example, there are center consoles for controlling air conditioning equipment and audio installed in automobiles, and operation panels equipped with home appliances that are operated by touch panels, and portable electronic devices such as smartphones. , Most operations can be performed by the touch panel.

However, the cover glass is often flat, and it is difficult to differentiate it in terms of design. Further, when the visually impaired person operates the touch operation area or when the touch operation area is operated in a situation where the touch operation area cannot be accurately visually recognized, a malfunction may occur.

Therefore, in the prior art, there is a technique of forming a recess in the cover glass arranged on the surface of the touch panel so that the touched region can be recognized by the sense of touch (for example, Patent Document 1). By forming such a recess, the user can easily recognize the area to be touched by the touch of a finger, and it is said that an accurate touch operation can be performed without looking at the screen.

Japanese Patent No. 5881414

However, although the above-mentioned glass substrate can determine the area to be touched, when the user touches the touch panel, it may not be known whether or not the device recognizes the touch operation. It was. Compared to physical switches, the touch panel does not change the tactile sensation transmitted to the user's finger during touch operation. Therefore, it may not be known whether or not the touch operation is actually recognized by the device, or there is a risk of malfunction.

An object of the present invention is to provide a cover glass and a touch panel device having a region whose shape is changed by a touch operation in a cover glass used for a touch panel or the like that accepts a touch operation from a user.

The cover glass according to the present invention is a cover glass configured to receive a touch operation from the user on the first main surface, and is formed at a position corresponding to a touch operation area in which the user performs some touch operation. It has at least one flexible operating part. The flexible operation portion is formed with a curved portion having a convex curved shape on the first main surface side. Further, a first concave portion including at least a curved surface shape is formed on the second main surface side of the flexible operation portion. Further, the cover glass has a compressive stress layer formed on the first main surface and the second main surface, and is curved convexly toward the first main surface side.

By forming the first recess, a difference in compressive stress is generated between the first main surface and the second main surface in the flexible operation portion. The compressive stress on the second main surface side of the flexible operation portion increases, and a convex curved portion is formed on the first main surface side. The user can visually or tactilely recognize the position to be touched by the curved portion. Further, the curved portion has a thin plate thickness, and when a load is applied from the first main surface side, the curved portion bends and deforms to the second main surface side, and when the load is removed from the curved portion, the curved portion spontaneously occurs. It is configured to return to its original shape. By providing the flexible operation unit, it becomes possible for the user to obtain feedback (click feeling) by the tactile sensation like a push button switch such as a membrane switch even in a cover glass composed of a single glass substrate. ..

Further, by bending the cover glass itself in the same direction as the convex direction of the curved portion, the curved portion after deformation can easily return to the original shape. In order to control the deformation of the curved portion, it is necessary to adjust the compressive stress and the dimensions of the first recess as described above, but by bending the cover glass itself, the curved portion is easily deformed. Therefore, the compressive stress can be easily controlled, and the degree of freedom in designing the cover glass can be increased.

Further, it is preferable that the flexible operation portion is further provided with the second concave portion on the first main surface side. A curved portion is formed on the bottom surface of the second recess. Further, the surface area of the second recess is formed to be different from the surface surface of the first recess. By forming the surface areas of the first recess and the second recess so as to be different, the compressive stresses of the first main surface and the second main surface cannot be balanced, and a curved portion is formed on the bottom surface of the second recess. It is formed. The surface areas of the first recess and the second recess can be made different by changing the depth and shape of the respective recesses. The surface area of the recessed region in the present invention is the total area of the bottom surface and the side surface of the recessed portion.

Further, it is preferable that the elastic member is arranged in the first recess. The elastic member is configured to be elastically deformed in response to the deformation of the flexible operating portion. By arranging the elastic member in this way, it is possible to control the ease of deformation of the flexible operation portion. Further, by utilizing the restoration of the elastic member when the load from the flexible operating portion is removed, the flexible operating portion can easily return to its original shape. Further, by arranging the elastic member, even if the cover glass should be damaged, it is possible to prevent the glass fragment from scattering by adhering to the elastic member.

According to the present invention, it is possible to provide a cover glass and a touch panel device having a region whose shape is changed by the touch operation in the cover glass that receives a touch operation from the user.

It is a figure which shows the controller which arranged the cover glass which concerns on one Embodiment of this invention. It is a figure which shows the cover glass. It is a figure which shows another embodiment of a cover glass. It is a figure which shows the manufacturing method of a cover glass. It is a figure which shows the manufacturing method of a cover glass.

From here, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a diagram showing a touch panel type controller 10 for operating an electronic device such as a television. The controller 10 includes at least a cover glass 12, a touch panel 14, and a display 16. Further, the controller 10 includes a flexible operation unit 30 and an information display unit 60 on the operation area. The information display unit 60 is an area in which operation information is displayed on a flat panel display or the like. The flexible operation portion 30 is formed on the cover glass 12 and is an area for the user to perform some kind of touch operation.

Subsequently, each component will be described with reference to FIG. 1B, which is a schematic cross-sectional view of the controller 10. The cover glass 12 is a glass substrate arranged on a surface exposed to the user side of the controller 10. The cover glass 12 is a single glass substrate configured to protect the controller 10 from impacts and the like, and when the user operates the controller 10, the cover glass 12 is touched. The cover glass 12 is a glass substrate having a plate shape, and in the present embodiment, aluminosilicate glass is used. The thickness of the cover glass 12 is preferably 0.3 to 1.5 mm.

The cover glass 12 has a first main surface 20 and a second main surface 22. The first main surface 20 is a main surface exposed to the user, and the second main surface 22 is a main surface facing the first main surface 20. A compressive stress layer 24 is formed on both the first main surface 20 and the second main surface 22. The compressive stress layer 24 is a layer having a higher compressive stress than the internal region of the cover glass 12 formed by a known method such as an ion exchange method. The compressive stress layers 24 formed on the first main surface 20 and the second main surface 22 are formed under the same conditions, and there is no substantial difference in the strength and depth of the compressive stress.

Further, the cover glass 12 is curved convexly toward the first main surface 20 side. The radius of curvature of the cover glass 12 can be set as appropriate. Examples of the method of bending the cover glass 12 include a method of heating the cover glass 12 to a softening point for molding. It is also possible to bend the display 16 and the touch panel 14 in a curved state by joining them together.

The touch panel 14 is arranged below the cover glass 12 and is configured to detect the area touched by the user. As the detection method of the touch panel 14, it is possible to adopt a known detection method such as a resistance film method or a capacitance method. Further, the touch panel 14 can be integrally formed with the cover glass 12 and the display 16.

The display 16 is a flat panel display such as a liquid crystal panel or an organic EL panel, and displays an image on the information display unit 60 or displays an icon indicating a touch area at a position corresponding to the flexible operation unit 30. It is configured as follows. In addition, the icon may be displayed using a transparent substrate and a backlight on which the icon is pre-printed.

The cover glass 12 has a flexible operation portion 30 in a region where the user performs a touch operation. It is preferable that the flexible operation unit 30 displays an icon or the like so that the user can easily see it. The flexible operation unit 30 is configured to bend and deform when pushed by a finger or the like by a touch operation from the user. Also, when you release your finger, it returns to its original shape.

The flexible operation portion 30 has a curved portion 32 having a convex curved surface shape on the first main surface 20 side. The curved surface shape of the curved portion 32 allows the user to visually or tactilely recognize the touch operation area. In addition to the flexible operation unit 30, the touch operation region may be formed in the information display unit 60 or in the peripheral region of the flexible operation unit 30.

A recess 34 is formed on the second main surface 22 side of the flexible operation portion 30. The concave portion 34 is a region recessed in a concave shape toward the first main surface 20 side, and is formed so as to include at least a curved surface shape. The shape of the recess 34 can form a desired shape, and it is preferable to form the recess 34 larger than the corresponding icon in consideration of visibility. Further, the recess 34 can be formed so as to include a tapered shape by forming the recess 34 by an etching process described later, and the taper angle is preferably 10 to 60 degrees. The taper angle here refers to the inclination angle of the rising surface (side surface) with respect to the bottom surface of the recess 34. By forming the flexible operating portion 30 into a tapered shape, it is possible to reduce the possibility that the flexible operating portion 30 will be damaged during deformation.

By forming the recess 34, in the flexible operation portion 30, the area of the compressive stress layer forming region on the second main surface 22 side becomes larger than that on the first main surface 20 side. As a result, the total volume of the compressive stress layer on the second main surface 22 side is larger than that on the first main surface 20 side, and the compressive stress generated on the second main surface 22 side is the first main surface. It becomes larger than the compressive stress generated on the 20 side. According to the applicant's research, the bottom surface of the recess 34 is curved convexly toward the first main surface side due to the imbalance of the compressive stresses of the first main surface 20 and the second main surface 22. However, it is known that there is a high probability that the curved portion 32 will be formed. At this time, the difference in compressive stress between the first main surface and the second main surface in the flexible operating portion 30 is preferably 10 to 1000 MPa, and the radius of curvature of the curved portion 32 is adjusted by the difference in compressive stress. It is possible to do. Further, by forming the side surface of the recess 34 so as to have a tapered shape, the surface area of the recess 34 can be made larger, so that the compressive stress of the second main surface 22 and the compression of the first main surface 20 can be obtained. It becomes easier to make a difference in stress.

Since the flexible operating portion 30 is thinner than the peripheral region due to the recess 34, when a load is applied to the flexible operating portion 30 from the first main surface 20 side by a user's touch operation, As shown in FIG. 2A, the curved portion 32 is deformed. At this time, since a space is formed in the lower portion by the concave portion 34, the flexible operating portion 30 is bent and deformed in a concave shape toward the second main surface 22 side. In order for the flexible operating portion 30 to be suitably deformed, it is preferable that the recess 34 is formed so that the thickness of the flexible operating portion 30 is 50 to 200 μm. When the plate thickness of the flexible operating portion 30 is larger than 200 μm, the flexible operating portion 30 is less likely to be deformed due to the rigidity of the cover glass 12. Further, if the flexible operation portion 30 is less than 50 μm, the strength of the cover glass 12 is lowered, so that there is a high possibility that the cover glass 12 will be damaged during the touch operation. Further, the flexible operation portion 30 has an extremely thin plate thickness, but since the compressive stress layer 24 is formed, the possibility of damage due to deformation is low.

When the user releases the finger from the flexible operating portion 30, the flexible operating portion 30 spontaneously returns from the deformed state to the original shape (see FIG. 2B). Therefore, even in the cover glass 12 made of a single glass substrate, the user can obtain a click feeling like a push button switch such as a membrane switch. It becomes easier for the user to confirm whether the touch operation is recognized by the shape change of the flexible operation unit 30, and it becomes possible to prevent an erroneous operation of the controller 10. Since the flexible operation unit 30 automatically restores the original shape after deformation, the touch operation can be repeated. It is also possible to control the radius of curvature and the amount of deflection deformation of the curved portion 32 by adjusting the plate thickness and compressive stress value of the flexible operating portion 30.

Further, since the cover glass 12 is convexly curved toward the first main surface 20, the restoring force of the flexible operating portion 30 is improved. In order for the flexible operation portion 30 to be deformed so as to obtain a click feeling, it is necessary to make a difference in compressive stress between the first main surface 20 and the second main surface 22, and the compressive stress value and the concave portion 34 You need to control the dimensions. By bending the cover glass 12, the above control becomes easy, and the degree of freedom in designing the flexible operation portion 30 can be increased.

The controller 10 of the present embodiment employs a resistive film type touch panel, and is designed so that it is difficult for the user's finger to react only by touching the touch panel. When the flexible operation unit 30 is deformed, the controller 10 is set to recognize the touch operation when the cover glass 12 and the touch panel 14 come into contact with each other, thereby reducing the risk of malfunction. It is possible to apply the cover glass 12 to the capacitive touch panel and other types of touch panels. For example, if the touch panel 14 is programmed to detect the touch operation only when the flexible operation unit 30 is deformed, or if a sensor layer or the like that detects the strength of pushing into the touch panel 14 is provided, it is static. It can also be used for the capacitance method.

Further, the cover glass 12 can be applied not only to the touch panel but also to the outer cover of a physical switch such as a membrane switch. For example, in a membrane switch, the flexible operation portion 30 may be deformed at the upper part of the switch mechanism to push the contacts arranged at the lower part so that the contacts come into contact with each other. By applying a cover glass composed of a single glass substrate to the physical switch, it is possible to improve the design.

From here, another embodiment of the cover glass will be described with reference to FIG. FIG. 3 is a diagram showing a cover glass 121 according to another embodiment of the present invention. The cover glass 121 has a compressive stress layer 24 formed on the first main surface 20 and the second main surface 22. The cover glass 121 has a flexible operation unit 30 in a touch operation area where the user performs a touch operation. The flexible operation portion 30 has an operation recess 40 formed on the first main surface 20 side and a recess 34 formed on the second main surface 22 side.

The operation recess 40 is a region recessed on the second main surface 22 side, and a curved portion 32 is formed at the bottom thereof. Since the configuration of the curved portion 32 is substantially the same as that of the above embodiment, detailed description thereof will be omitted. The operating recess 40 preferably has a curved surface shape, and more preferably has a tapered side surface. Further, the surface area of the operating recess 40 is formed to be smaller than the surface area of the recess 34. Since the operating recess 40 and the recess 34 are formed so as to have different surface areas, the compressive stresses of the first main surface 20 and the second main surface 22 cannot be balanced. Therefore, the bottom surface of the operating recess 40 is curved in a convex shape, and the curved portion 32 is formed. In the present embodiment, the depth of the operating recess 40 is made shallower than the depth of the recess 34 to break the balance of the compressive stress, but the recess 34 may be formed shallower than the operating recess 40 or used for operation. The recess 40 and the recess 34 may be formed in different shapes.

Further, the elastic member 42 is arranged in the recess 34. The elastic member 42 is configured to be deformed according to the elastic deformation of the flexible operation portion 30. Further, the elastic member 42 is preferably made of a transparent material so that the icon displayed by the display 16 can be visually recognized, and polyethylene, polypropylene or a silicon-based resin can be used. By adjusting the elasticity of the elastic member 42, it is possible to adjust the amount of bending of the flexible operating portion 30 and the load required for deformation. Further, when the finger is released from the flexible operating portion 30, the restoring force of the elastic member 42 is utilized, so that the flexible operating portion 30 can easily return to the original shape. Further, by arranging the elastic member 42, even if the flexible operation portion 30 is damaged by any chance, the fragments are hard to adhere to the elastic member 42 and scatter, so that the safety is improved.

Further, by including the transparent conductive member in the elastic member 42, it is possible to correspond to the capacitance type touch panel. As the transparent conductive member, an organic conductive material such as ITO or polythiophene, or a metal nanowire can be used. Further, a spacer may be arranged under the cover glass if necessary. As the spacer, transparent silica used for a liquid crystal substrate or the like can be used. By arranging the spacer, it is possible to control the amount of bending of the flexible operation unit 30 and the contact with the touch panel 14.

Further, in the present embodiment, since the operation recess 40 is formed, the touch operation area becomes easier to understand tactilely. Further, since the operating recess 40 has a curved surface shape and a tapered shape, there is no risk of the user's finger being injured during the touch operation.

From here, a method of manufacturing the cover glass 12 will be described with reference to FIGS. 4 (A) to 4 (D). The method for manufacturing the cover glass 12 in the present embodiment includes a protective member forming step, a patterning step, an etching step, a chemical strengthening treatment step, and a bending step.

In the protective member forming step, the main surface of the glass substrate 50 is coated with a protective film 52 having etching resistance. The glass substrate 50 is aluminosilicate glass, and the plate thickness is preferably 0.3 to 1.5 mm. The protective film 52 is configured to protect the main surface of the glass substrate 50 in the etching process described later, and has at least resistance to hydrofluoric acid. In addition to the protective film, it is also possible to use a protective material such as a photosensitive resist material.

In the patterning step, as shown in FIG. 4A, the protective film 52 is removed from one of the main surfaces corresponding to the region where the recess is to be formed, and an opening is formed. Any means may be used as the patterning means as long as the acid resistant member can be removed from the region to be etched. In this embodiment, patterning is performed using a laser device. In this embodiment, a pulse laser is used to remove only the protective film 52 without damaging the glass substrate 50. When a photosensitive resist is used as the acid-resistant member, patterning can be performed by using photolithography.

In the etching step, the region where the opening is formed is etched by bringing the glass substrate 50 into contact with the etching solution. When etching the glass substrate 50, a single-wafer type etching device that injects an etching solution onto the glass substrate 50 conveyed by a desired conveying mechanism or a glass substrate 50 is immersed in an etching tank containing the etching solution. A batch type etching device or the like can be used. As the etching solution, it is preferable to use an etching solution containing at least hydrofluoric acid, and an inorganic acid such as hydrochloric acid or a surfactant may be added in addition to hydrofluoric acid. By the etching process, the region not protected by the protective film 52 is etched to form the recess 34. The etching treatment is preferably performed until the thickness of the recess 34 is 200 μm or less.

After forming the recess 34 by etching, the protective film 52 is removed from the glass substrate 50. When removing the protective film 52, it can be peeled off by applying a physical force to the protective film 52. When a resist material is used, it can be removed by immersing the glass substrate 50 in the stripping solution.

The chemical strengthening treatment step is a step of forming a compressive stress layer on the glass substrate 50. The chemical strengthening treatment is carried out by a known method by immersing a glass substrate in a molten salt containing alkali ions. In the present embodiment, the chemical strengthening treatment was performed by immersing the glass substrate in a potassium nitrate solution heated to 400 ° C. for 4 hours. The heating temperature of potassium nitrate is preferably adjusted to 350 to 450 ° C., and the immersion time of the glass substrate is preferably about 2 to 20 hours. The depth of the compressive stress layer 24 is preferably adjusted to 5 to 50 μm. Further, the first main surface 20 and the second main surface 22 are chemically strengthened under the same conditions, and the depths of the compressive stress layers 24 are substantially the same.

By forming the compressive stress layer 24, the region facing the concave portion 34 is curved in a convex shape, and the curved portion 32 is formed (see FIG. 4C). By forming the recess 34 by etching, the possibility that the glass substrate 50 will be damaged when the curved portion 32 is formed is reduced. In particular, since the intersection of the concave portion 34 and the second main surface 22 is formed in a curved surface shape, it is possible to prevent the glass substrate 50 from being damaged even if the flexible operation portion 30 is deformed.

In the bending step, the glass substrate 50 is heated to the vicinity of the softening point and pressed against a mold set to a desired radius of curvature to be thermally deformed. After being thermally deformed, the glass substrate 50 can be cooled, and if the thickness of the glass substrate 50 is 500 μm or less, it can be laminated along the components of the touch panel such as a curved display. Therefore, it is not necessary to provide a bending step.

Further, when forming the operation recess 40 on the first main surface 20, after forming the recess 34 on the second main surface 22, the glass substrate 50 is protected again with the protective film 52 (FIG. 5 (A). )reference.). Further, as shown in FIG. 5B, the protective film 52 on the first main surface 20 side is patterned to form an opening in the region where the operation recess 40 is formed. In this state, the cover glass having recesses formed on both main surfaces can be manufactured by performing the etching process again. After that, by performing a chemical strengthening treatment and a bending treatment, a flexible operating portion having recesses formed on both main surfaces can be formed. In the present embodiment, the depth of the operating recess 40 is made shallower than the depth of the recess 40, so that the curved portion 32 is formed on the bottom surface of the operating recess 34.

The description of the embodiments described above should be considered exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims, not by the above-described embodiment. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the patent claim.

10-Controller 12-Cover glass 14-Touch panel 16-Display 20-First main surface 22-Second main surface 24-Compressive stress layer 30-Flexible operation part 32-Curved part 34-Recess 40-For operation Recess 42-elastic member

Claims (4)

A cover glass configured to receive a touch operation from the user on the first main surface side.
At least one flexible operation unit formed at a position corresponding to the touch operation area where the user performs some touch operation,
In the flexible operation portion, a curved portion having a convex curved shape formed on the first main surface side and a curved portion.
It has a first recess formed on the second main surface side so as to include at least a curved surface shape, and has.
The cover glass has a compressive stress layer formed on the first main surface and the second main surface, and is further curved in a convex shape toward the first main surface side .
The flexible operating portion is characterized in that it deforms when a load is applied from the first main surface side to the second main surface side, and spontaneously returns to the original shape when the load is removed. cover glass. The curved portion is arranged on the bottom surface of the second recess formed on the first main surface side.
The cover glass according to claim 1, wherein the depth of the second recess and the depth of the first recess are different. The cover glass according to claim 1, wherein a transparent elastic member is arranged in the first recess. A sensor module in which a sensing unit that detects a touch device from a user and a display means for displaying a touch operation area are stacked, and
A touch panel device comprising the cover glass according to any one of claims 1 to 3 arranged on the touch panel unit.

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