Patent Description:
An edge defect of a glass panel is a main factor of damage reducing the reliability of the glass panel. In particular, in a flexible device including a thin glass panel that requires guaranteed edge quality for reliable bending performance, the reliability of the edge quality of a glass panel is critically important.

Edge finishing is performed in order to improve the strength of edges of a glass panel. From among technologies used for such edge finishing, heat chamfering technology is known. Heat chamfering is a technology suitable for use with thin glass plates, since no particles are created thereby. In addition, Heat chamfering may ensure superior edge strength and provide satisfactory bending performance. <CIT> relates to an apparatus for processing cut portions of glass substrates. <CIT> is directed to a glass substrate edge processing device.

The present invention relates to a heat chamfering apparatus including: a heated body configured to peel an edge of a glass panel by applying thermal shock to the glass panel while being in contact with the edge of the glass panel; and a heater heating the heated body.

The heated body includes a heated region and a contact region in a longitudinal direction thereof, the heated region being heated by the heater, and the contact region being configured to be in contact with the glass panel. The cross-sectional area of the contact region is smaller than the cross-sectional area of the contact region. The contact region has a closest point located most adjacently to the glass panel and a farthest point located farthest from the glass panel. The contact region comprises a first cross-section portion to which the closest point belongs and a second cross-section portion to which the farthest point belongs, divided by a perpendicular bisector of a line segment connecting the closest point and the farthest point, a cross-sectional area of the first cross-section portion being smaller than a cross-sectional area of the second cross-section portion.

The present invention further relates to a heat chamfering method including: peeling an edge of a glass panel by applying thermal shock to the edge of the glass panel by moving a heated body heated by a heater relatively with respect to the glass panel along and in contact with the edge of the glass panel. The heated body includes a heated region and a contact region in a longitudinal direction thereof, the heated region being heated by the heater, and the contact region being configured to be in contact with the glass panel. The cross-sectional area of the contact region is smaller than the cross-sectional area of the contact region. The contact region has a closest point located most adjacently to the glass panel and a farthest point located farthest from the glass panel. The contact region comprises a first cross-section portion to which the closest point belongs and a second cross-section portion to which the farthest point belongs, divided by a perpendicular bisector of a line segment connecting the closest point and the farthest point, a cross-sectional area of the first cross-section portion being smaller than a cross-sectional area of the second cross-section portion.

According to the present disclosure, the heat chamfering apparatus and method may obtain a necessary processing temperature and superior power efficiency.

In addition, according to the present disclosure, the heat chamfering apparatus and method may prevent a heated object from being deformed.

In addition, according to the present disclosure, the heat chamfering apparatus and method may prevent a glass panel and organic and inorganic layers formed on the glass panel from being damaged.

Furthermore, according to the present disclosure, the heat chamfering apparatus and method may be customized to a glass panel having a concave edge.

The methods and apparatuses of the present disclosure have other features and advantages that will be apparent from or that are set forth in greater detail in the accompanying drawings, the disclosures of which are incorporated herein, and in the following Detailed Description, which together serve to explain certain principles of the present disclosure.

<FIG> is a view illustrating a method of heat-chamfering a glass panel.

An edge of a glass panel <NUM> is heat-chamfered by thermal shock applied thereto. The heated body <NUM> heated by the heater <NUM> is relatively moved with respect to the glass panel <NUM> along the edge of the glass panel <NUM> while being in contact with the edge of the glass panel <NUM>, thereby peeling the edge of the glass panel <NUM>. For the relative movement, the glass panel <NUM> may be moved, the heated body <NUM> may be moved, or both the glass panel <NUM> and the heated body <NUM> may be moved.

Although the main plane of the glass panel <NUM> may have an oblong shape, the glass panel <NUM> is not limited to a specific shape and may have a polygonal shape, a circular shape, an elliptical shape, or the like. In the present disclosure, the glass panel <NUM> is not limited to a sheet having a thickness (e.g., the length in the Z-axis direction) smaller than either the transverse length (e.g., X-axis direction) or the longitudinal length (e.g., Y-axis direction) of the main plane. Rather, the glass panel <NUM> may have a variety of shapes, such as a thick block.

The glass panel <NUM> according to the present disclosure may include panels formed from any glass material (e.g., borosilicate glass).

When the main plane of the glass panel <NUM> has an oblong shape and defines an X-Y plane, the heated body <NUM> may chamfer the glass panel <NUM> by relatively moving in the X-axis direction and the Y-axis direction while sequentially being in contact with four edges of the glass panel <NUM>. The speed of the relative movement may vary depending on the composition of the glass, the heating conditions, the shape of the glass panel <NUM> to be chamfered, or the like. In response to this chamfering, a strip 100a is peeled from the edges of the glass panel <NUM>. In some embodiments, the heated body <NUM> may perform the chamfering while continuously coming into contact with the four edges without interruption. For example, when the four edges of the glass panel <NUM> are referred to as a first edge, a second edge, a third edge, and a fourth edge in the clockwise direction, the heated body <NUM> may chamfer all of the four edges of the glass panel <NUM> by relatively moving in the X-axis direction to the corner between the first edge and the second edge while being in contact with the first edge, relatively moving in the Y-axis direction to the corner between the second edge and the third edge while being in contact with the second edge, relatively moving in the X-axis direction (i.e., opposite to the direction in which the heated body <NUM> moves while in contact with the first edge) to the corner between the third edge and the fourth edge while being in contact with the third edge, and then, relatively moving in the Y-axis direction (i.e., opposite to the direction in which the heated body <NUM> moves while in contact with the second edge) to the corner between the fourth edge and the first edge while being in contact with the fourth edge.

This chamfering may peel the thin strip 100a from the glass panel <NUM> without creating particles, thereby preventing defects in the edges of the glass panel <NUM> and increasing the strength of the glass panel <NUM>.

In some embodiments, the glass panel <NUM> may be chamfered while being fixedly located on the top surface of a fixing jig (not shown). A suction hole may be formed in the surface of the fixing jig to hold the glass panel <NUM> by suction. This suction hole may be connected to a vacuum pump. When the surface of the glass panel <NUM> is held by suction, no fixing tools are required to be provided on side portions of the glass panel <NUM> to hold the glass panel <NUM>, so that the contact between the heated body <NUM> and the glass panel <NUM> may be performed without disruption along the four edges of the glass panel <NUM>.

<FIG> is a view schematically illustrating a glass panel heat chamfering apparatus.

The heat chamfering apparatus includes the heated body <NUM> configured to peel the edges of the glass panel <NUM> by applying thermal shock to the glass panel <NUM> while being in contact with the edge of the glass panel <NUM> and the heater <NUM> heating heated body <NUM>.

In some embodiments, the heated body <NUM> may include a heating rod. In some embodiments, a contact region <NUM> of the heated body <NUM> to be in contact with the glass panel <NUM> may have the shape of a cylinder. In some embodiments, the heated body <NUM> may be a metal rod. For example, the metal rod formed from MoSi<NUM> may be used as the heated body <NUM>. However, the heated body <NUM> is not limited thereto.

The heated body <NUM> includes a heated region <NUM> and a contact region <NUM> in the longitudinal direction thereof, in which the heated region <NUM> is heated by the heater <NUM>, and the contact region <NUM> is in contact with the glass panel <NUM>. The cross-sectional area of the contact region <NUM> (on the plane parallel to the main plane of the glass panel <NUM>) is smaller than the cross-sectional area of the heated region <NUM>. In some embodiments, the contact region <NUM> may have a circular cross-section with a diameter ranging from <NUM> to <NUM>, and the heated region <NUM> may have a circular cross-section with a diameter ranging from <NUM> to <NUM>. Heat applied to the heated region <NUM> may be transferred to the contact region <NUM>. The contact region <NUM> may be located on one distal end of the heated body <NUM>. The other distal end of the heated body <NUM> may be held by a holder (not shown).

At a specific point in time, the heated body <NUM> may be in point contact or line contact with the glass panel <NUM> (e.g., when a cylindrical heated body is in contact with the glass panel <NUM>) or may be in surface contact with the glass panel <NUM> (e.g., when a heated body having a flat heating surface is in contact with the glass panel <NUM>). In some embodiments, the line in the line contact and the surface in the surface contact may be parallel to a side surface (i.e., a thickness surface) of the glass panel <NUM>. However, the present disclosure is not limited thereto and the contact line or surface may be at a predetermined angle to the side surface.

The heater <NUM> may heat the heated body <NUM> by high-frequency induction heating. The heater <NUM> may heat the heated body <NUM> while enclosing the heated body <NUM>. In some embodiments, the heater <NUM> may be an induction coil. The heated body <NUM> may be located to extend through the center of the induction coil. In some embodiments, the induction coil may be implemented using a copper (Cu) coil. In addition, the induction coil may be coated with a ceramic material for electrical safety. In some embodiments, the outer diameter of the induction coil may be about <NUM>, the outer wall may be about <NUM> thick, and cooling water may flow at a flow rate of about <NUM>/min within the induction coil. The induction coil may heat the heated body <NUM> to a temperature ranging from about <NUM> to about <NUM> by transmitting power to the heated body <NUM>.

<FIG> and <FIG> are views illustrating the relationship between the shape of the heated body and a required amount of power.

<FIG> illustrates the heated body <NUM>, as well as heated bodies 210a and 210b according to comparative embodiments.

As a drawback, the heated body 210a has limited ability to increase temperature and needs a greater amount of power to obtain the same temperature. In addition, with increases in the number of uses, the heated body 210a may be deformed by heat, which is problematic.

In contrast, the heated body 210b does not have such a drawback, but organic and inorganic layers formed on the glass panel <NUM> or the glass panel <NUM> may be thermally damaged, due to the increased diameter. In addition, with increases in the diameter of the heated body 210b in contact with the glass panel <NUM>, it is more difficult to chamfer a concave edge. Thus, according to the present disclosure, the heated body <NUM> is designed such that the cross-sectional area of the contact region <NUM> (on the plane parallel to the main plane of the glass panel <NUM>) is smaller than the cross-sectional area of the heated region <NUM>.

<FIG> is a view schematically illustrating the shape of the heated body of the glass panel heat chamfering apparatus according to some embodiments of the present disclosure, and <FIG> is a view schematically illustrating the cross-section of the heated body in <FIG>.

The contact region <NUM> (on the plane parallel to the main plane of the glass panel <NUM>) has a closest point p1 located most adjacently to the glass panel <NUM> and a farthest point p2 located farthest from the glass panel <NUM>. In the heat chamfering, the closest point p1 may be a point in contact with the glass panel <NUM>, while the farthest point p2 may be a point opposite the closest point p1.

The contact region <NUM> includes a first cross-section portion and a second cross-section portion divided by a perpendicular bisector Lb of a line segment connecting the closest point p1 and the farthest point p2. Here, the closest point p1 belongs to the first cross-section portion, and the farthest point p2 belongs to the second cross-section portion. The cross-sectional area of the first cross-section portion is smaller than the cross-sectional area of the second cross-section portion.

In some embodiments, (on the plane parallel to the main plane of the glass panel <NUM>), the contact region <NUM> may include a contact zone 213a including the closest point p1 and a conduction boosting zone 213b including the farthest point p2. The contact zone 213a may have a first arc as an outline, while the conduction boosting zone 213b may have a second arc as an outline. Here, the first arc and the second arc may be concentric.

<FIG> is a view schematically illustrating the cross-section of the heated body <NUM> of the glass panel heat chamfering apparatus according to some embodiments of the present disclosure.

In some embodiments, the central angle θ1 of the first arc of the contact zone 213a may be greater than the central angle θ2 of the second arc of the conduction boosting zone 213b. The heated body <NUM> illustrated in <FIG> may be more appropriate for chamfering the concave edge than the heated body <NUM> illustrated in <FIG>.

<FIG> is a view schematically illustrating the cross-section of the heated body of the glass panel heat chamfering apparatus according to some embodiments of the present disclosure.

In some embodiments, in the contact zone 213a including the closest point p1, a first length L1 measured from the closest point p1 to farthest point p2 in a first direction may be greater than a second length L2 measured in a second direction perpendicular to the first direction.

In some embodiments, the contact zone 213a may have an elliptical arc as an outline. The first direction may be a major axis direction of the elliptical arc, while the second direction may be a minor axis direction of the elliptical arc. Since the contact zone 213a is designed so as to have an elliptical cross-section comprised of a shorter minor axis and a longer major axis, the heat chamfering apparatus appropriate for chamfering the concave edge may be provided as illustrated in <FIG>.

<FIG> is a graph illustrating the relationship among the position of the heater, the temperature of the heated body, and power.

Power supplied to the induction coil (i.e., the heater <NUM>) and the temperature of the contact region <NUM> of the heated body <NUM> were measured by changing the height of the induction coil (i.e., the distance from the top surface of the glass panel <NUM> to the induction coil) from <NUM> to <NUM>, <NUM>, <NUM>, and <NUM>. The heated body <NUM>, with the radius of the contact region <NUM> in contact with the glass panel <NUM> being <NUM> and the radius of the heated region <NUM> enclosed by the induction coil being <NUM>, was used. As a result, it was determined that, with increases in the distance, the temperature of the contact region <NUM> was lowered when the same amount of power was supplied and the amount of required power was increased for the contact region <NUM> to have the same temperature. In some embodiments, the process temperature required may be <NUM>. In some embodiments, the height of the induction coil may be lower than <NUM>, and in some of such embodiments, the height of the induction coil may be <NUM> or less. When the height of the induction coil is <NUM> or more, a sufficient amount of heat may not be applied, thereby making the heat chamfering difficult.

In order to determine the thermal effect on the glass panel <NUM>, a thermo-sensing label was attached to the glass panel <NUM>, and then, the temperature of the glass panel <NUM> was measured by changing the height of the induction coil during a heat chamfering process. For the glass panel <NUM> coated with an OLED device layer, in some embodiments, the temperature of the glass panel <NUM> may be required to be <NUM> or lower. In some of such embodiments, the required temperature of the glass panel <NUM> may be <NUM> or lower. When the height of the induction coil was <NUM>, the surface temperature of the glass panel <NUM> was increased to exceed <NUM>, thereby causing damage to the glass panel <NUM>. In contrast, when the height of the induction coil was <NUM>, the surface temperature was <NUM> or lower, thereby causing no heat damage to the glass panel <NUM>. In order to prevent the heat damage to the glass panel <NUM>, the height of the induction coil in some embodiments may be set to be higher than <NUM>. In some of such embodiments, the height of the induction coil may be <NUM> or higher.

Accordingly, for reliable processing, the height of the induction coil may be higher than <NUM> and lower than <NUM>, more particularly, range from <NUM> to <NUM>.

Claim 1:
A heat chamfering apparatus comprising:
a heated body (<NUM>) configured to peel an edge of a glass panel (<NUM>) by applying thermal shock to the glass panel (<NUM>) while being in contact with the edge of the glass panel (<NUM>); and
a heater (<NUM>) heating the heated body (<NUM>),
wherein the heated body (<NUM>) comprises a heated region (<NUM>) and a contact region (<NUM>) in a longitudinal direction thereof, the heated region (<NUM>) being heated by the heater (<NUM>), and the contact region (<NUM>) being configured to be in contact with the glass panel (<NUM>), and
the cross-sectional area of the contact region (<NUM>) is smaller than the cross-sectional area of the heated region (<NUM>);
characterized in that
the contact region (<NUM>) has a closest point (p1) located most adjacently to the glass panel (<NUM>) and a farthest point (p2) located farthest from the glass panel (<NUM>), and
the contact region (<NUM>) comprises a first cross-section portion to which the closest point (p1) belongs and a second cross-section portion to which the farthest point (p2) belongs, divided by a perpendicular bisector (Lb) of a line segment connecting the closest point (p1) and the farthest point (p2),
a cross-sectional area of the first cross-section portion being smaller than a cross-sectional area of the second cross-section portion.