JP2014094885A - Manufacturing method of cover glass for mobile display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cover glass for a mobile display, which is not easily broken by an impact generated when the mobile display falls.SOLUTION: Cover glass 1 for a mobile display is the cover glass for the mobile display that covers at least part of a display part 2a and a side face 2b of a mobile display 2. The cover glass 1 for the mobile display includes a planar front surface part 11 and side face parts 12 and 13. The front surface part 11 is disposed at the front of the display part 2a. The front surface part 11 extends along a first direction and a second direction vertical to the first direction. The side face parts 12 and 13 are disposed at the sides of the mobile display 2. The side face parts 12 and 13 include bend parts 12a and 13a. The bend parts 12a and 13a are bent from an end on one side in the first direction of the front surface part 11 to the back. Corner parts 12c and 13c of the side face parts 12 and 13 have a rounded shape.

Description

  The present invention relates to a cover glass for a mobile display and a method for manufacturing the same.

  In recent years, mobile devices having a display such as a mobile phone, a smartphone, a notebook personal computer, and a tablet personal computer have been widely used (hereinafter, a mobile device having a display is referred to as a “mobile display”). .

  Patent Document 1 describes a cover glass that can be used for a mobile display. The cover glass described in Patent Literature 1 includes a front surface portion that is located on the front surface of the image display portion, and bent portions that are bent from the front surface portion on both sides in the width direction of the image display portion.

JP 2012-101975 A

  The cover glass of a mobile display is required to be hard to be damaged by an impact generated when the mobile display is dropped.

  A main object of the present invention is to provide a cover glass for a mobile display which is not easily damaged by an impact generated when the mobile display is dropped.

  The cover glass for a mobile display according to the present invention is a cover glass for a mobile display that covers at least a part of a display portion and a side surface of the mobile display. The cover glass for mobile displays according to the present invention includes a flat front portion and a side portion. The front part is arranged in front of the display part. The front surface portion extends along a first direction and a second direction perpendicular to the first direction. The side part is arranged on the side of the mobile display. The side part includes a bent part. The bent portion is bent backward from one end portion in the first direction of the front surface portion. The side part has a rounded corner.

When the outer shape of the corner portion having a rounded shape is an arc shape, the length of the end portion and L ₁ from the bending start point along the outer surface of a portion other than the corner portion of the side surface portion, the side surface portion corners second length along the direction of having a rounded shape on the outer surface of when the L _2, L _1> L ₂ is it is preferred that satisfied.

More preferably, L ₁ ≧ (3/2) · L ₂ is satisfied.

  The outer shape of the corner portion having a rounded shape may be an arc shape having a radius of curvature of 0.1 mm to 5.0 mm.

  The thickness of the cover glass for mobile display according to the present invention is preferably in the range of 0.2 mm to 1.5 mm.

A second length along the direction of the corner portion having a rounded shape on the outer surface of the side portion and L _2, the first direction of the corner portion having a rounded shape on the outer surface of the side surface portion L ₃ > L ₂ may be satisfied, where L ₃ is the length along.

  The outer shape of the corner portion having a rounded shape may be an elliptical arc shape whose major axis is parallel to the first direction when viewed from the developed side.

  The manufacturing method of the cover glass for mobile displays which concerns on this invention is related with the manufacturing method of the cover glass for mobile displays which concerns on this invention. In the method for producing a cover glass for a mobile display according to the present invention, a rectangular glass flat plate having rounded corner portions is prepared. A glass plate is arranged on a forming die having a flat forming surface so that a central portion in one direction of the glass plate is located on the forming surface and an end portion is located outside the forming surface. A front part and a side part are formed by pressing downward while heating the end of the glass flat plate.

  ADVANTAGE OF THE INVENTION According to this invention, the cover glass for mobile displays which cannot be easily damaged by the impact which arises when a mobile display falls can be provided.

1 is a schematic perspective view of a cover glass for a mobile display according to an embodiment of the present invention. 1 is a schematic front view of a cover glass for a mobile display according to an embodiment of the present invention. 1 is a schematic side view of a cover glass for a mobile display according to an embodiment of the present invention. It is the schematic front view which expanded a part of cover glass for mobile displays concerning one embodiment of the present invention. 1 is a schematic side view in which a part of a cover glass for a mobile display according to an embodiment of the present invention is enlarged. It is a schematic sectional drawing for demonstrating the manufacturing process of the cover glass for mobile displays in one Embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing process of the cover glass for mobile displays in one Embodiment of this invention. It is the schematic side view which expanded a part of cover glass for mobile displays concerning a modification.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described. A ratio of dimensions of an object drawn in a drawing may be different from a ratio of dimensions of an actual object. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

(Mobile display cover glass 1)
FIG. 1 is a schematic perspective view of a cover glass for a mobile display according to the present embodiment. FIG. 2 is a schematic front view of the mobile display cover glass according to the present embodiment. FIG. 3 is a schematic side view of the cover glass for a mobile display according to the present embodiment. FIG. 4 is a schematic front view in which a part of the cover glass for mobile display according to the present embodiment is enlarged. FIG. 5 is an enlarged schematic side view of a part of the cover glass for mobile display according to the present embodiment.

  The cover glass 1 for mobile displays shown in FIGS. 1-5 is a cover which covers at least one part of the display part 2a and the side surface 2b of the mobile display 2 (refer FIG.2 and FIG.3), as FIG. 2 shows. It is glass. More specifically, the mobile display cover glass 1 is a cover glass that covers the display portion 2a of the mobile display 2 and at least a part of both side surfaces 2b in the x-axis direction (first direction). The mobile display 2 is not particularly limited as long as it is a mobile device including a display. The mobile display 2 may be, for example, a mobile phone, a smartphone, a notebook personal computer, a tablet personal computer, or the like. The mobile display 2 may be plate-shaped.

  The cover glass 1 for mobile display is preferably made of, for example, tempered glass such as chemically tempered glass or crystallized glass.

  The thickness of the mobile display cover glass 1 is not particularly limited, but is preferably 0.2 mm to 1.5 mm, more preferably 0.25 mm to 1.1 mm, and 0.3 mm to 1.0 mm. More preferably it is.

  The mobile display cover glass 1 has a front surface portion 11. The front part 11 is a part arranged in front of the display part 2a of the mobile display 2 (on the z1 side). Here, the front is the direction in which the perpendicular of the display unit 2a extends, and the side opposite to the direction in which the perpendicular extends is the rear.

  The front surface part 11 has a flat plate shape. The front surface portion 11 extends along the x-axis direction (first direction) and the y-axis direction (second direction) perpendicular to the x-axis direction (first direction). The front part 11 is rectangular. The dimension along the x-axis direction (first direction) of the front surface part 11 may be, for example, about 40 mm to 200 mm. The dimension along the y-axis direction (second direction) of the front surface part 11 may be, for example, 80 mm to 300 mm. The “flat plate” includes a substantially flat plate. For example, a “flat plate” includes a plate having one surface and another surface inclined within a range of 5 ° or less with respect to the one surface.

  A first side surface portion 12 is connected to an end portion on the x1 side in the x-axis direction (first direction) of the front surface portion 11. The first side surface portion 12 is a portion disposed on the side of the mobile display 2. Specifically, the first side surface portion 12 is disposed on the x1 side of the mobile display 2 in the x-axis direction (first direction).

  The first side surface portion 12 includes a first bent portion 12a. The first bent portion 12a is bent from the end portion on the x1 side in the x-axis direction (first direction) of the front surface portion 11 toward the rear (z2 side). The bending angle θ (see FIG. 2), which is the size of the angle formed between the tangent line of the inner wall surface at the x1 side end of the front surface portion 11 and the tangent line of the inner wall surface at the tip of the first side surface portion 12, is 90 °. It is preferably ˜170 °, more preferably 90 ° to 160 °, and still more preferably 90 ° to 150 °.

  In the present embodiment, the first side surface portion 12 includes a first bent portion 12a and a first flat plate portion 12b connected to the tip of the first bent portion 12a. However, the present invention is not limited to this configuration. The 1st side part 12 may be comprised only by the 1st bending part 12a.

  A second side surface portion 13 is connected to the x2 side end portion of the front surface portion 11 in the x-axis direction (first direction). This 2nd side part 13, the front part 11, and the 1st side part 12 are comprised by the glass plate of 1 sheet. The second side surface portion 13 is a portion arranged on the side of the mobile display 2. Specifically, the second side surface portion 13 is disposed on the x2 side of the mobile display 2 in the x-axis direction (first direction).

  The second side surface portion 13 includes a second bent portion 13a. The second bent portion 13a is bent from the end portion on the x2 side in the x-axis direction (first direction) of the front surface portion 11 toward the rear side (z2 side). The bending angle (θ) between the front surface portion 11 and the second side surface portion 13 is preferably 90 ° to 170 °, more preferably 90 ° to 160 °, and 90 ° to 150 °. Is more preferable.

  In the present embodiment, the second side surface portion 13 includes a second bent portion 13a and a second flat plate portion 13b connected to the tip of the second bent portion 13a. However, the present invention is not limited to this configuration. The 2nd side part 13 may be comprised only by the 2nd bending part 13a.

  By the way, generally, as described in Patent Document 1, the corner portions of the side surface portions are provided at right angles. That is, the corners of the side portions are not rounded. This is because if the corners of the side surface are rounded, it is difficult to produce a cover glass by softening and deforming the glass flat plate. However, when the corners of the side surfaces are provided at a right angle, the mobile display to which the mobile display cover glass is attached falls and the cover glass is easily damaged when the corners collide with the ground.

  On the other hand, in the cover glass 1 for mobile displays, the corner | angular parts 12c and 13c of the side parts 12 and 13 have the shape rounded. That is, the corner portions 12c and 13c of the side surface portions 12 and 13 are provided in an R chamfer shape. For this reason, even when the mobile display 2 to which the mobile display cover glass 1 is attached falls and the corner of the mobile display 2 collides with the ground, the impact is applied to the corners 12c and 13c of the side surfaces 12 and 13. Is difficult to be transmitted, so that the cover glass 1 for mobile display is hardly damaged.

  From the viewpoint of more effectively suppressing damage to the cover glass 1 for mobile display when dropped, the outer shapes of the corner portions 12c and 13c of the side surface portions 12 and 13 are preferably arcuate, and the radius of curvature is 0.1 mm. The above arc shape is more preferable, and an arc shape having a radius of curvature of 5.0 mm or less is more preferable.

(Manufacturing method of the cover glass 1 for a mobile display)
The manufacturing method of the cover glass 1 for mobile displays is not specifically limited. The cover glass 1 for mobile displays can be manufactured by the manufacturing method shown below, for example.

  First, a glass flat plate 20 shown in FIG. 6 is prepared. The glass flat plate 20 is a glass plate for constituting the mobile display cover glass 1. Each of the four corners of the glass flat plate 20 is for constituting the corners of the side surfaces 12 and 13. Therefore, each of the four corners of the glass flat plate 20 has a rounded shape. The thickness of the glass flat plate 20 is substantially equal to the thickness of the cover glass 1 for mobile display. The glass flat plate 20 is formed into the mobile display cover glass 1 using a forming apparatus 30.

  The molding apparatus 30 has a molding chamber 33. A heater 41 is provided in the molding chamber 33. The heater 41 radiates heat rays. Therefore, in the shaping | molding apparatus 30, the object distribute | arranged in the shaping | molding chamber 33 can be radiantly heated.

  In the molding chamber 33, the 1st and 2nd heat insulating materials 31 and 32 which have the planar shaping | molding surfaces 31b and 32b are arrange | positioned. The 1st and 2nd heat insulating materials 31 and 32 are members for suppressing that radiant heat is transmitted to the glass flat plate 20, respectively, while having a function as a shaping | molding die. The thermal conductivity of the first and second heat insulating materials 31 and 32 is preferably lower than the thermal conductivity of the glass flat plate 20. Moreover, it is preferable that the first and second heat insulating materials 31 and 32 shield the heat rays emitted from the heater 41. The 1st and 2nd heat insulating materials 31 and 32 can be comprised by the ceramics which have an alumina, silicon carbide, diatomaceous earth, etc. as a main component, for example.

  Each of the heat insulating materials 31 and 32 is provided with at least one through hole 31a and 32a. A coolant such as air is fed into the through holes 31a and 32a during heating and molding. Thereby, the temperature of the heat insulating materials 31 and 32 can be adjusted. For example, an undesired temperature increase of the heat insulating materials 31 and 32 can be suppressed.

  In forming the glass flat plate 20, first, the first portion 21, which is a central portion in one direction of the glass flat plate 20, is positioned on the forming surface 32 b of the second heat insulating material 32, and ends in the one direction. The glass flat plate 20 is arranged so that the second portions 22a and 22b, which are parts, are located outside the molding surface 32b. Thereafter, the first heat insulating material 31 is placed on the first portion 21 of the glass flat plate 20. As a result, the first portion 21 is held between the first and second heat insulating materials 31 and 32. The second portions 22 a and 22 b are not sandwiched between the first and second heat insulating materials 31 and 32.

  Next, in a state where the first portion 21 of the glass flat plate 20 is sandwiched between the first heat insulating material 31 and the second heat insulating material 32, the heater 41 is driven to radiately heat the glass flat plate 20 (heating step). ).

  Thereafter, as shown in FIG. 7, the second portions 22a and 22b are pressed downward by using the pressing tools 51 and 52 provided on both sides of the first and second heat insulating materials 31 and 32, and the second portions 22a and 22b are pressed downward. Are bent (molding step). Thereby, the front part 11 is formed from the 1st part 21, and the side parts 12 and 13 are formed from the 2nd part 22a, 22b, and the cover glass 1 for mobile displays is obtained.

  In addition, you may shape | mold by the 2nd heat insulating material 32 and the press tools 51 and 52, without providing the 1st heat insulating material 31. FIG.

  When the side portions 12 and 13 are formed by pressing the end portions of the second portions 22a and 22b with the pressing tools 51 and 52 as described above, the corner portions of the second portions 22a and 22b are rounded. The corner portion is not directly pressed by the pressing tools 51 and 52. In addition, the lengths of the second portions 22a and 22b along the x-axis direction (first direction) are shorter than the other portions at both ends in the y-axis direction (second direction). For this reason, the radius of curvature at the ends in the y-axis direction (second direction) of the bent portions 12a and 13a tends to be larger than the radius of curvature at other portions. For this reason, it is difficult to obtain the cover glass 1 for a mobile display having high shape accuracy.

Here, when the outer shape of the corners of the second portions 22a and 22b is arcuate,
L ₁ : length (mm) from the bending start point 13d to the end surface 13e along the outer surface in a portion other than the corners 12c and 13c of the side surface portions 12 and 13 (see FIG. 4),
L ₂ : Length (mm) along the y-axis direction (second direction) of corner portions 12c and 13c having a rounded shape on the outer surface of side surface portions 12 and 13 (see FIG. 5),
And when
It is preferable that L ₁ > L ₂ is satisfied. In the case of L ₁ ≦ L _2, the corners 12c and 13c having the rounded shapes of the side surface parts 12 and 13 are located, and both ends in the y-axis direction (second direction) are the y-axis of the side surface parts 12 and 13 It is difficult to mold in the same way as the central part in the direction (second direction). By satisfying L ₁ > L ₂ , the z-axis direction (first direction and second direction) of both ends of the side surface parts 12 and 13 on the outer surface of the side surface parts 12 and 13 in the y-axis direction (second direction). The length (L ₀ ) along the third direction perpendicular to the direction is present, and the cover glass 1 for mobile display can be manufactured with high shape accuracy.

Incidentally, when the second portion 22a, the outer shape of the corner portion of 22b is arcuately, _{L 2} is equal to the second portion 22a, the outer shape of the corner portion of 22b curvature radius.

  From the viewpoint of realizing higher shape accuracy, it is more preferable that L1 ≧ (3/2) · L2 is satisfied, and it is more preferable that L1 ≧ (2/1) · L2 is satisfied. When the outer shapes of the corner portions 12c and 13c having the rounded shapes of the side surface portions 12 and 13 are arc-shaped, the radius of curvature of the corner portions 12c and 13c is more preferably less than L1, and 2 / of L1 It is more preferably 3 times or less, and still more preferably 1/2 times or less of L1. Further, the radii of curvature of the corner portions 12c and 13c are preferably equal to or less than the height of the side surface portions 12 and 13 (when viewed from the x-axis direction (first direction)) when viewed from the side. It is more preferable that it is 2/3 times or less of the height of the parts 12 and 13, and it is more preferable that it is 1/2 times or less. Specifically, the radius of curvature of the corner portions 12c and 13c of the side surface portions 12 and 13 is preferably 5 mm or less, and more preferably 3 mm or less. However, if the curvature radii of the corner portions 12c and 13c of the side surface portions 12 and 13 are too small, the impact resistance during dropping may be lowered. Accordingly, the radius of curvature of the corner portions 12c and 13c of the side surface portions 12 and 13 is preferably 0.1 mm or more, more preferably 0.2 mm or more, further preferably 0.3 mm or more, 0 More preferably, it is 5 mm or more.

Incidentally, as the L ₁ is small, the cover glass 1 for mobile displays a problem that it is difficult to obtain prone to have a higher shape accuracy. Therefore, when L ₁ is 5.0 mm or less, and when it is 3.0 mm or less, it is more effective to make the corner portions 12 c and 13 c of the side surface portions 12 and 13 satisfy L ₁ > L _2. Is. The lower limit of L ₁ is not particularly limited, and is generally about 2.0 mm.

Further, the smaller the bending angle θ, the more easily the problem that it becomes difficult to obtain the mobile display cover glass 1 having higher shape accuracy. Therefore, when the bending angle θ is 120 ° or less, and further when the bending angle θ is 100 ° or less, it is more effective that the corner portions 12c and 13c of the side surface portions 12 and 13 satisfy L ₁ > L _2. It is. The lower limit value of the bending angle θ is not particularly limited, but is generally about 90 °.

  In the present embodiment, an example in which the outer shapes of the corner portions 12c and 13c of the side surface portions 12 and 13 are arc-shaped has been described. However, in this invention, the corner | angular part of a side part is not specifically limited as long as it is the rounded shape. For example, as shown in FIG. 8, the side surface portions 12 and 13 are L3: the z-axis direction (third direction) of the corner portions 12 c and 13 c having a rounded shape on the outer surface of the side surface portions 12 and 13. A shape that satisfies L3> L2 when the length (mm) along the line is satisfied. For example, the outer shape of the corner portions 12c and 13c having the rounded shape of the side surface portions 12 and 13 may be an elliptical arc shape whose major axis is parallel to the x-axis direction (first direction) when unfolded. . In that case, when pressing is performed using the press tools 51 and 52, the press tools 51 and 52 can press the portion closer to the end of the flat plate portions 12 b and 13 b in the y-axis direction (second direction). . Therefore, the cover glass 1 for a mobile display having higher shape accuracy is obtained. From the viewpoint of realizing higher shape accuracy, it is more preferable that L3 ≧ (3/2) · L2 is satisfied, and it is more preferable that L3 ≧ (2/1) · L2 is satisfied.

DESCRIPTION OF SYMBOLS 1 ... Mobile display cover glass 2 ... Mobile display 2a ... Display part 2b ... Side surface 11 ... Front part 12 ... 1st side surface part 12a ... 1st bending part 12b ... 1st flat plate part 12c ... Corner | angular part 13 ... 1st 2 side surface part 13a ... 2nd bending part 13b ... 2nd flat plate part 13c ... corner | angular part 13d ... bending start point 13e ... end face 20 ... glass flat plate 21 ... 1st part 22a, 22b ... 2nd part 30 ... Molding devices 31, 32 ... heat insulating materials 31a, 32a ... through holes 31b, 32b ... molding surface 33 ... molding chamber 41 ... heaters 51, 52 ... pressing tool

Claims (5)

A cover glass for a mobile display that covers at least a part of a display unit and a side surface of a mobile display, and is disposed in front of the display unit, in a first direction and a second direction perpendicular to the first direction. A flat front portion extending along the side, and a side portion including a bent portion that is disposed on a side of the mobile display and bends backward from one end portion of the front portion in the first direction. A cover glass for a mobile display, in which a corner portion formed by an end surface located at an end portion in the second direction of the side surface portion and an end surface located at a rear end portion of the side surface portion has a rounded shape. A manufacturing method comprising:
Preparing a rectangular glass flat plate having corners of the rounded shape;
On the first mold having a flat molding surface, the first portion of the glass flat plate serving as the front surface portion of the cover glass for mobile display is located on the molding surface, and the mobile display cover Disposing the glass flat plate so that the second portion of the glass flat plate serving as the side surface portion of the glass is located outside the molding surface;
Forming the front part and the side part by pressing downward with a pressing tool while heating the second part of the glass plate;
A method for producing a cover glass for a mobile display.   The first portion of the glass flat plate is sandwiched between the first mold and the second mold, and the second portion of the glass flat plate is pressed downward with a pressing tool while heating the second portion. The manufacturing method of the cover glass for mobile displays of Claim 1 provided with the process of forming the said side part.   The manufacturing method of the cover glass for mobile displays of Claim 1 or 2 whose outer shape of the corner | angular part which has the said rounded shape is circular arc shape.   Manufacturing of the cover glass for mobile displays as described in any one of Claims 1-3 whose external shape of the corner | angular part which has the said rounded shape is circular arc shape whose curvature radius is 0.1 mm-5.0 mm. Method.   The manufacturing method of the cover glass for mobile displays as described in any one of Claims 1-4 whose thickness of the said cover glass for mobile displays exists in the range of 0.2 mm-1.5 mm.

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