JP2020170063A - Cover glass for flexible devices and flexible devices with it - Google Patents

Abstract

A cover glass for a flexible device in which decrease in strength is suppressed and a flexible device including the cover glass are provided. A cover glass (16) is a cover glass attached to a flexible device (10) and has a first major surface (20) and a second major surface (22). The cover glass 16 has corrugations 24 on the second major surface 22 . The wavy portion 24 has a plurality of grooves 26 that are wavy when viewed from the side in a region corresponding to the hinge portion 34 of the flexible device 10 . [Selection drawing] Fig. 3

Description

The present invention relates to a cover glass applied to a flexible device capable of bending a housing and a flexible device including the cover glass.

Portable electronic devices such as smartphones that use touch panels are used in a wide range of fields. Such an electronic device has not only a touch panel but also a display for displaying an image and a cover glass for protecting the touch panel and the display. In recent years, there are many devices with distinctive shapes of displays and cover glasses in order to differentiate them in terms of design.

Among them, flexible electronic devices have begun to be actively studied. Flexible devices can be roughly classified into those including a curved portion as a part of the device and those having flexibility to the extent that they can be folded. The latter may be particularly referred to as a foldable device (see, for example, Patent Document 1). Since the foldable device has a larger operation area than the conventional smartphone, the operability is improved. In addition, since it can be folded when it is carried, portability is not impaired. Further, since each component of the device is also thinned, the weight of the device itself can be reduced.

Japanese Unexamined Patent Publication No. 2014-161009

However, the foldable device needs to be thin enough so that each component can be bent, so that there is a problem that the strength is lowered. In particular, the cover glass for protecting the display and the housing is easily affected by the decrease in strength due to the thinning. Since the conventional cover glass has a plate thickness of about 0.5 mm, the display can be protected from impacts such as dropping. However, in order to bend the glass substrate, it is necessary to reduce the thickness to less than about 0.1 mm. Since the strength of the glass substrate largely depends on the plate thickness, the strength of the glass substrate thinned to the extent that it can be bent is extremely reduced, and the cover glass may be damaged in the conventional flexible device. Was expensive.

There is also a configuration in which a transparent cover member made of resin is arranged instead of the cover glass, but the resin material has a problem that the texture is inferior to that of the glass substrate, so that it is rarely actively adopted. Further, when the resin material is repeatedly curved, there is a problem that the curved portion is wrinkled. Therefore, a glass cover member has been required.

An object of the present invention is to provide a cover glass capable of cope with deformation such as bending and folding of a flexible device while suppressing a decrease in strength, and a flexible device provided with the cover glass.

The cover glass according to the present invention is a cover glass for a flexible device, and has a first main surface and a second main surface. The cover glass includes a corrugated portion on at least one main surface of the first main surface or the second main surface. The corrugated portion has a plurality of groove portions having a side view wave shape in the region corresponding to the bent portion of the flexible device.

The cover glass according to the present invention is a cover glass applied to a flexible device capable of bending or bending a housing. The flexible device has a bent portion such as a hinge and a bellows mechanism. The cover glass can be deformed according to the deformation of the flexible device by providing a corrugated portion in which a plurality of grooves are formed at positions corresponding to the bent portions. That is, the curvature of the cover glass is improved by reducing the plate thickness of the region where the groove is formed. Further, since the groove portion is formed in a side view wave shape, the strength is improved and the possibility of breakage when the cover glass is curved is reduced. The wavy shape in the present invention means a shape in which smooth curved concave portions and convex portions are repeatedly formed by forming groove portions at regular intervals.

Further, it is preferable that the width of the groove portion is larger than the formation interval of the groove portion. By making the width of the groove portion larger than the formation interval of the groove portion, it is possible to prevent the adjacent groove portions from coming into contact with each other when the corrugated portion is deformed.

Further, it is preferable that the groove portion is filled with a transparent elastic member. By filling with a transparent elastic member, it is possible to improve the strength of the corrugated portion. Further, when the corrugated portion is deformed, the transparent elastic member is elastically deformed, so that the cover glass is less likely to hinder the deformation of the flexible device. Further, by using a transparent elastic body having a refractive index similar to that of the cover glass, it is possible to suppress a decrease in visibility of a display image displayed on a display or the like.

Further, the flexible device according to the present invention is a flexible device to which the cover glass is attached. The cover glass is mounted on the outermost surface of the flexible device. The outermost surface here is, for example, a surface exposed to the outside such as a display surface in a device such as a smartphone or a tablet, or a housing surface on the back surface of the display surface.

Further, the cover glass may be detachable from the flexible device. By attaching the cover glass to the flexible device via an adhesive layer or the like, it becomes possible to protect the flexible device from an external impact, if necessary.

According to the present invention, it is possible to provide a cover glass for a flexible device in which a decrease in strength is suppressed and a flexible device including the cover glass.

It is a figure which shows the smartphone which concerns on one Embodiment of this invention. It is a figure which shows the structure of a cover glass. It is a figure which shows the structure at the time of bending of a smartphone. It is a figure which shows the state which attached the cover glass to the back of a smartphone. It is a figure which shows the other embodiment of a cover glass. It is a figure which shows one Embodiment of the manufacturing method of a cover glass. It is a figure which shows the other embodiment of the manufacturing method of a cover glass.

From here, an embodiment of a cover glass and a flexible device according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a smartphone 10 according to an embodiment of the present invention. The smartphone 10 includes at least a housing 12, a display 14, and a cover glass 16.

The housing 12 is a box-shaped member configured to accommodate the components of the smartphone 10. The housing 12 has a first housing portion 30, a second housing portion 32, and a hinge portion 34. The first housing portion 30 and the second housing portion 32 are made of a rigid resin material or a metal member. Electronic members such as a battery, a printed circuit board, a communication module, and a camera unit are appropriately arranged inside the first housing portion 30 and the second housing portion 32.

The hinge portion 34 is arranged between the first housing portion 30 and the second housing portion 32, and is configured to connect the first housing portion 30 and the second housing portion 30. To. The hinge portion 34 is configured to lock and rotatably support the first housing portion 30 and the second housing portion 32, respectively. When a force is applied to the housing 12, the hinge portion 34 of the flexible device 10 is rotated and deformed as shown in FIGS. 1 (A) and 1 (B). Further, in this embodiment, the flexible device is bent by using a hinge, but the deformation mechanism of the flexible device is not limited to this. For example, a bellows member may be used to deform the flexible device.

The display 14 is fixed to the upper surface portion of the housing 12, and is configured to display an image on the entire main surface of one side of the smartphone 10 including the area corresponding to the hinge portion 34. The display 14 is not particularly limited as long as it has flexibility. Specific examples of the display 14 include an organic EL display. Since the organic EL display uses a transparent resin substrate such as polyimide, it has flexibility. When a liquid crystal display is used, it may be thinned to about 0.1 mm in advance. The thinning of the liquid crystal display is performed by thinning such as wet etching. In addition, the display 14 also has a touch panel function for the user to perform a touch operation, and can detect the touch operation from the user. In addition to the configuration in which the touch panel and the display are integrated, a touch panel may be separately arranged.

The cover glass 16 is arranged above the display 14 and is configured to protect the display 14 from impact and the like. The glass substrate used for the cover glass 16 is preferably aluminosilicate glass, but is not particularly limited, and soda glass or non-alkali glass may be used. The plate thickness of the cover glass 16 can be appropriately changed depending on the configuration of the flexible device, but is preferably about 0.1 to 0.3 mm. Further, if necessary, a compressive stress layer may be formed, the compressive stress layer can be formed by a known ion exchange method, and the thickness of the formed compressive stress layer is adjusted in the range of 5 to 100 μm. To.

The cover glass 16 has a first main surface 20 exposed to the user and a second main surface 22 facing the first main surface 20. On the second main surface 22, a corrugated portion 24 is formed in a region corresponding to the hinge portion 34. The cover glass 16 is attached to the flexible device 10 via a transparent adhesive layer or the like.

As shown in FIGS. 2A and 2B, the corrugated portion 24 is a region in which a plurality of groove portions 26 are continuously formed along the entire width direction of the cover glass 16. The groove portion 26 is a region in which a concave groove is formed from the second main surface 22 toward the first main surface 20 side. The groove portion 26 exhibits a wavy shape when viewed from the side (direction in which the plate thickness side of the cover glass 16 is viewed from the front). Further, the side surface portion 261 of the groove portion 26 has a tapered shape extending toward the second main surface side 22 side, and is curved in a convex shape toward the outer side.

The width of the groove 26 is preferably about 50 to 100 μm, and the depth of the groove is preferably about 50 to 200 μm. Further, the forming interval of the groove portions 26 is preferably provided so as to be smaller than the width of the groove portions 26, and is formed so as to be, for example, about 10 to 40 μm. Further, the connecting portion between the groove portion 26 formed at both ends of the corrugated portion 24 and the second main surface 22 has a curved shape. Further, since the groove portions 26 are formed at regular intervals, rib-shaped convex portions are formed between the groove portions 26, and the upper surface of the convex portions is flush with the second main surface 22. Is formed like this.

From here, the deformation mechanism of the smartphone 10 will be described with reference to FIGS. 3 (A) to 3 (C). 3 (A) to 3 (C) are schematic cross-sectional views of the smartphone 10. The smartphone 10 applies a force from the outside to the first housing portion 30 in the direction of the arrow shown in FIG. 3B to move the first housing portion 30 to the second housing portion 30 starting from the hinge portion 34. Can be bent in the direction of the housing portion 32 of. At this time, since the first housing portion 30 and the second housing portion 32 are made of rigid members, they do not bend, but the display 14 and the cover glass 16 rotate the hinge portion 34. Curve accordingly. When the force applied to the first housing portion 30 is removed, the smartphone 10 has a planar shape as shown in FIG. 3A.

Since the thickness of the region where the groove 26 is formed is thin, the cover glass 16 can be curved following the bending of the smartphone 10. Further, the side view wavy groove portion is less likely to be damaged at the time of bending than the groove portion formed in the side view vertical shape, and the strength of the cover glass is improved. Further, by forming the side surface portion 261 of the groove portion 26 into a tapered shape, the possibility of contact with the side surface portion 261 of the adjacent groove portion 26 when the corrugated portion 24 is deformed is reduced. Further, even if they come into contact with each other, the surface is smooth and wavy, so that it is less likely to be a starting point of damage.

Further, the cover glass according to the present invention can be applied not only to protect the display surface but also to protect the back surface of a flexible device, for example. FIG. 4 is a diagram showing a smartphone 100 having a cover glass 16 mounted on the back surface. The smartphone 100 includes a first housing portion 30, a second housing portion 32, and a bellows portion 36, and the bellows portion 36 is provided between the first housing portion 30 and the second housing portion 32. Have been placed. The cover glass 16 is attached so as to cover the first housing portion 30, the second housing portion 32, and the bellows portion 36. A flexible display is provided on the main surface facing the main surface on which the cover glass 16 is mounted.

The cover glass 16 is arranged so that the second main surface 22 is in contact with the first housing portion 30 and the second housing portion 32. A corrugated portion 24 is provided on the second main surface 22 at a position corresponding to the bellows portion 36 of the smartphone 100. The smartphone 100 is configured so that the bellows portion 36 is deformed and bent by applying a force to the first housing portion 30 or the second housing portion 32. Since the corrugated portion 24 is formed at the position corresponding to the bellows portion 36 of the cover glass 16, it is possible to correspond to the deformation of the smartphone 100.

In the embodiments up to this point, the cover glass 16 as a component of the smartphone 10 has been described, but the cover glass according to the present invention may be configured to be detachably attached to a flexible device such as a smartphone. For example, an adhesive layer is formed on the main surface on which the corrugated portion of the cover glass is formed, and the cover glass can be attached to the flexible device by bringing the adhesive layer into contact with the surface to be attached such as a display. .. As the adhesive layer of the cover glass, a known acrylic resin-based adhesive, silicone-based adhesive, or the like can be used.

From here, other embodiments of the present invention will be described with reference to FIGS. 5 (A) to 5 (C). In the cover glass 160 shown in FIG. 5A, the groove portion 26 is filled with a transparent elastic body 40. The transparent elastic body 40 is an elastically deformable resin and has transparency to the extent that it does not affect the visibility of the image displayed on the display. Therefore, the transparent elastic body 40 preferably has a refractive index similar to that of the cover glass 160, and for example, an acrylic resin material or a polyolefin resin material can be used.

By filling the groove portion 26 with the transparent elastic body 40, the strength of the corrugated portion 24 is improved, and it is less likely to be damaged during bending or the like. Since the transparent elastic body 40 is elastically deformed when the cover glass 16 is bent, the influence on the deformation of the cover glass 160 is small. Further, when operating the smartphone with the touch panel, by filling the hollow portion such as the groove portion 26 with resin, the sensitivity of the touch panel is improved and erroneous operation can be prevented.

FIG. 5B is a diagram showing a cover glass 162 shown in another embodiment of the present invention. The cover glass 162 is formed with a corrugated portion 242 corresponding to the flexible device to be mounted. The region where the corrugated portion 242 is provided is thinner than the other regions of the cover glass 162. That is, the corrugated portion 242 is configured to be provided in the concave portion. The groove portion 262 is formed on the bottom surface of the concave portion. The shape and formation interval of the groove portion 262 are the same as those in the above embodiment.

By reducing the thickness of the region where the corrugated portion 242 is formed as a whole, the cover glass 162 is more likely to be curved. Further, since the region other than the corrugated portion 242 has almost no effect on the curvature of the flexible device even if the plate thickness is thick, it is possible to improve the strength of the cover glass 162.

Further, as shown in FIG. 5C, the corrugated portion 242 may be filled with the transparent elastic body 40. The transparent elastic body 40 is filled so that the second main surface 22 of the cover glass 162 and the main surface of the transparent elastic body 40 are flush with each other. By filling the transparent elastic body 40, it is possible to improve the strength of the corrugated portion 242.

The corrugated portion formed on the cover glass according to the present invention is preferably formed by an etching process. From here, an example of a method for manufacturing a cover glass will be described with reference to FIGS. 6 (A) to 6 (D). The method for producing the cover glass includes a protection step, a patterning step, a first etching step, a peeling step, and a second etching step.

The protection step is a step of coating both main surfaces of the glass base material 50 to be the cover glass with a protective mask 52 having etching resistance. As the protective mask 52, a film or a resist material having resistance to hydrofluoric acid used in the etching solution can be used.

The patterning step is a step of removing the protective mask 52 coated on the region corresponding to the groove 26 to form an opening (see FIG. 6B). The removal of the protective mask 52 can be performed using, for example, a laser device.

The first etching step is a step of performing an etching process by bringing an etching solution containing at least hydrofluoric acid into contact with the glass base material 50 to form a recess 54 (see FIG. 6B). For the etching process, for example, a method of immersing the glass base material 50 in the etching solution or a method of injecting the etching solution onto the glass base material 50 can be adopted. The peeling step is a step of removing the protective mask 52 from the glass base material 50. The removal of the protective mask 52 can be performed, for example, by applying a physical force to the protective mask 52.

The second etching step is a step of bringing the glass base material 50 into contact with the etching solution to reduce the thickness of the glass base material 50 and enlarge the recess 54 to form the groove portion 26. In the second etching step, as in the first etching step, the recess 54 is etched by bringing the etching solution containing hydrofluoric acid into contact with the glass base material 50, and the surface thereof gradually becomes smooth (). (See FIG. 6 (C)), and finally, as shown in FIG. 6 (D), a plurality of side-view wave-shaped groove portions 26 are formed. If necessary, the main surface facing the main surface on which the corrugated portion 24 is formed may be covered with a protective mask 52 or the like.

By forming the corrugated portion 24 by the etching process, the groove portion 26 is not finely scratched and the strength of the groove portion 26 is improved as compared with the case where the corrugated portion 24 is formed by machining. Further, by enlarging the concave portion 54 by the second etching process, the groove portion 26 has a curved surface shape as a whole, and a smooth wave shape can be formed. A curved surface is also formed at the connecting portion between the groove portion 26 and the main surface of the glass base material 50.

When a large glass base material with a plurality of chamfered cover glasses is used in order to increase the manufacturing efficiency of the cover glass, the glass base material 50 is appropriately cut according to the dimensions of the cover glass after the second etching step. Just do it. Further, when the groove portion 26 is filled with the transparent elastic body 40, the groove portion 26 may be filled with the resin agent by using a coating device such as a syringe.

Further, in the present embodiment, the recess 54 is formed by an etching process, but the recess 54 may be formed by using, for example, a laser beam or a mechanical cutting process. In this case, it is not necessary to perform a protective mask or patterning process. Even if fine scratches are formed on the surface of the recess 54 or the surface roughness deteriorates when the recess 54 is formed by laser or cutting, the recess 54 is enlarged by the etching process in the subsequent process, so that the recess 54 has a smooth wavy shape. It is possible to form the groove portion 26 of the above.

7 (A) to 7 (C) are views showing an example of a method for manufacturing a cover glass having a thin corrugated portion. When the plate thickness of the corrugated portion 242 is reduced as shown in FIG. 5B, a protective mask is applied to the main surface on which the corrugated portion 24 is formed before the second etching step, in addition to the region corresponding to the corrugated portion 24. 52 may be coated (see FIG. 7A). When the second etching step is executed in this state, it becomes possible to form the groove portion 262 while reducing the plate thickness of the corrugated portion 242 itself, as shown in FIGS. 7 (B) and 7 (C). ..

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 claims.

10-Smartphone 12-Case 14-Display 16-Cover glass 20-1 First main surface 22-2 Second main surface 24-Wave part 26-Groove part 34-Hinge part 40-Transparent elastic body

Claims (5)

Cover glass for flexible devices
It has a first main surface and a second main surface,
In at least one main surface of the first main surface or the second main surface
A cover glass characterized in that a corrugated portion having a plurality of groove portions having a lateral sight wave shape is provided in a region corresponding to a bent portion of the flexible device. The cover glass according to claim 1, wherein the groove forming interval is smaller than the width of the groove. The cover glass according to claim 1 or 2, wherein the groove is filled with a transparent elastic member. A flexible device to which the cover glass according to any one of claims 1 to 3 is attached.
The flexible device is characterized in that the cover glass is mounted on the outermost surface of the flexible device. The flexible device according to claim 4, wherein the cover glass is removable from the flexible device.

Images