TWI859367B - Method for manufacturing glass plate - Google Patents

Abstract

The manufacturing method of the glass plate of the present invention includes: a first processing step S1, using a first grinding wheel 1 to process the end GE of the glass plate G; and a second processing step S2, using a second grinding wheel 2 to grind the end GE of the glass plate G after the first processing step S1. In the second processing step S2, the second grinding wheel 2 is relatively moved along the length direction of the end GE of the glass plate G, and the second grinding wheel 2 is relatively moved relative to the thickness direction of the glass plate G.

Description

Glass plate manufacturing method

The present invention relates to a glass plate and a method for manufacturing the same.

Displays such as liquid crystal displays and organic electroluminescence (EL) displays use glass plates. If there is damage on the edge of the glass plate, cracks will occur from the damage, so in order to prevent this, the edge of the glass plate is ground or polished.

For example, Patent Document 1 discloses a method for processing a glass plate, including: a grinding process step, in which the glass plate is transported in a specific direction and the end of the glass plate is chamfered using a grinding wheel; and a grinding process step, in which the end of the chamfered glass plate is ground using a grinding wheel.

Existing technical literature

Patent Literature

Patent document 1: Japanese Patent Publication No. 2018-103320

For example, when a glass plate is used as a substrate for a display, in the step of manufacturing electronic devices on the substrate, there is a situation where the end of the glass plate is pressed against a pin or a roller for positioning. At this time, if there is residual damage at the end of the glass plate, glass powder is likely to be generated. If the glass powder adheres to the surface of the glass plate, it will cause a broken wire defect in the electronic device. Therefore, it is expected to further improve the surface properties of the end of the glass plate.

However, if the surface properties of the entire end of the glass plate are improved, the entire end will become mirror-like, and when the end of the glass plate is photographed with a camera, it becomes difficult to detect the end.

The present invention was completed in view of the above situation, and its technical subject is: for the end of the glass plate, the generation of glass powder is reduced and it can be detected by a camera.

The present invention is used to solve the above-mentioned problem. It is a method for manufacturing a glass plate having a surface and an end. The feature of the method is that the end of the glass plate has an end face and a connecting face formed between the end face and the surface. The method comprises: a first processing step, processing the end of the glass plate using a first grinding wheel; and a second processing step, grinding the end of the glass plate after the first processing step using a second grinding wheel, and in the second processing step, the second grinding wheel is relatively moved along the length direction of the end of the glass plate while being relatively moved relative to the thickness direction of the glass plate.

According to this structure, in the second processing step, by moving the second grinding wheel relatively along the length direction of the end of the glass plate and relatively moving it in the thickness direction of the glass plate, the end surface is mainly processed, and the surface roughness of the end surface becomes smaller than the surface roughness of the connecting surface. Since the positioning pin or roller contacts the end surface with a smaller surface roughness, the generation of glass powder can be reduced. In addition, when the end of the glass plate is photographed with a camera, although the end surface becomes a mirror surface, the connecting surface is non-mirror surface, so the end can be detected based on the connecting surface.

Here, if the entire end of the glass plate is ground, the abrasive grains are easily melted due to processing heat, which increases the consumption of the grinding wheel or worsens the surface properties. Since the end surface is mainly processed in the second processing step, the processing heat can be reduced and the melting of the abrasive grains can be suppressed. Therefore, the consumption of the grinding wheel can be reduced, and the surface properties of the end surface can be further improved.

In the manufacturing method of the glass plate of the present invention, the second grinding wheel may also have a groove portion for grinding the end surface of the glass plate, the groove portion has a bottom portion in contact with the end surface of the glass plate, and a limiting surface connected to the bottom portion and contacting the connecting surface, the bottom portion of the groove portion has a width greater than the thickness of the end surface of the glass plate, and the width of the bottom portion before performing the second processing step is less than the sum of the thickness of the end surface and the relative movement distance of the second grinding wheel in the thickness direction.

According to this structure, by setting the bottom width of the groove of the second grinding wheel to the above range, the end surface of the glass plate can be better ground by the bottom of the groove when the second grinding wheel is moved relative to the glass plate, and the connecting surface of the glass plate can be brought into contact with the limiting surface of the groove. In this way, when manufacturing multiple glass plates, their ends can be processed stably.

In the manufacturing method of the glass plate of the present invention, before performing the second processing step, the second grinding wheel may have an outer peripheral surface without a groove, and in the second processing step, the end of the glass plate is ground by the outer peripheral surface of the second grinding wheel.

If a groove is formed on the outer peripheral surface of the second grinding wheel, only the groove can be used for processing, and the number of glass plates that can be processed by the second grinding wheel alone is reduced. If a second grinding wheel with an outer peripheral surface without a groove is used, most of the outer peripheral surface can be used for processing, and the number of glass plates that can be processed by the second grinding wheel alone can be greatly increased.

The present invention is used to solve the above-mentioned problem. It is a glass plate having a surface and an end. The end has an end face and a connecting surface formed between the end face and the surface. The surface roughness Ra1 of the end face is less than the surface roughness Ra2 of the connecting surface.

According to this structure, the strength of the end surface of the glass plate can be improved, and the product quality can be improved. In addition, since the positioning pin or roller contacts the end surface with a smaller surface roughness, the generation of glass powder can be reduced. Furthermore, when the end of the glass plate is photographed with a camera, although the end surface becomes a mirror surface, the connecting surface is non-mirror surface, so the end can be detected based on the connecting surface.

In the glass plate, the ratio Ra1/Ra2 of the surface roughness Ra1 of the end surface to the surface roughness Ra2 of the connecting surface may also be 0.15 to 0.6. According to this structure, since the difference in reflectivity between the end surface and the connecting surface becomes larger, when the end of the glass plate is photographed with a camera, it becomes easier to detect the end based on the connecting surface.

Furthermore, the surface roughness Ra1 of the end surface can be less than 0.06 μm. According to this structure, the generation of glass powder associated with the contact with the positioning pin or roller can be reduced reliably.

According to the present invention, the generation of glass powder can be reduced at the end of the glass plate, and a camera can be used for detection.

1: First grinding wheel

2: Second grinding wheel

2a: Outer surface of the second grinding wheel

3: First groove

3a: Bottom of the first groove

3b: Inclined surface

4: Second groove

4a: Bottom of the second groove

4b: Restricted surface

D0, D1, D2, D3: Depth dimensions

ES1: End face

ES2: Connection surface

G: Glass plate

G1: First glass plate

G2: Second glass plate

G3: The third glass plate

GC: Corner

GE: End of glass plate

GEa: Processing start end

GEb: Processing end

GS1: First Surface

GS2: Second Surface

GX1: Transport direction

GX2: Specific direction

L1, L2: distance

RC1: Axis of the first grinding wheel

RC2: Axis of the second grinding wheel

S1: First processing step

S2: Second processing step

T, T1: thickness dimension

W1, W2, W3, W4: Width dimensions

XE: Processing end position

XM1: First middle position

XM2: Second middle position

XM3: Third middle position

XM4: Fourth middle position

XM5: Fifth middle position

XM6: Sixth middle position

XM7: Seventh middle position

XM8: Eighth middle position

XS: Processing start position

Z0: base position

Z1: First position

Z2: Second position

FIG1 is a perspective view showing a method for manufacturing a glass plate according to a first embodiment.

Figure 2 is a cross-sectional view showing the first grinding wheel and the glass plate.

Figure 3 is a cross-sectional view showing the first processing step.

Figure 4 is a cross-sectional view showing the second grinding wheel and the glass plate.

Figure 5 is a diagram showing the moving trajectory of the second grinding wheel.

Figure 6 is a cross-sectional view showing the second processing step.

Figure 7 is a cross-sectional view showing the second processing step.

Figure 8 is a cross-sectional view showing the second processing step.

FIG. 9 is a diagram showing another example of the movement trajectory of the second grinding wheel.

FIG. 10 is a diagram showing another example of the movement trajectory of the second grinding wheel.

Figure 11 is a cross-sectional view showing the second processing step.

Figure 12 is a cross-sectional view showing the second processing step.

FIG13 is a cross-sectional view showing a method for manufacturing a glass plate according to a second embodiment.

Figure 14 is a cross-sectional view showing the second processing step.

Figure 15 is a cross-sectional view showing the second processing step.

Figure 16 is a cross-sectional view showing the second processing step.

Figure 17 is a cross-sectional view showing the second processing step.

Below, the form used to implement the present invention is described with reference to the drawings. Figures 1 to 12 show the first embodiment of the method for manufacturing a glass plate of the present invention.

In the following example, the case of manufacturing a rectangular glass plate G with four sides is described, but the shape of the glass plate G is not limited to this embodiment. The glass plate G is formed by a known forming method such as a float process, an overflow down-draw process, a flow hole down-draw process, and is cut into a specific size. The thickness T of the glass plate G is set to 0.2~10mm, and the size of the glass plate G is set to 200mm×300mm~3100mm×3500mm, but it is not limited to this range. In addition, as a composition of the glass plate G, alkali-free glass or aluminosilicate glass is preferred. Here, "alkali-free glass" is glass that does not substantially contain alkaline components (alkali metal oxides), specifically, glass in which the weight ratio of alkaline components is less than 1000ppm. The weight ratio of alkaline components is preferably less than 500 ppm, and more preferably less than 300 ppm.

As shown in FIG1 , the glass plate G has a first surface GS1, a second surface GS2, and ends GE corresponding to each side. In this embodiment, the end GE of two parallel sides of the four sides of the glass plate G is processed. Each end GE of the glass plate G includes a processing start end GEa and a processing end end GEb.

As shown in FIG1 , the method includes: a first processing step S1, processing the end GE of the glass plate G by a first grinding wheel 1; and a second processing step S2, processing the end GE of the glass plate G by a second grinding wheel 2 after the first processing step S1. Furthermore, XYZ in the figure is an orthogonal coordinate system. The X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is a vertical direction (up and down direction).

In the first processing step S1 and the second processing step S2, each end GE of the glass plate G is processed along its length direction (X-axis direction) from the processing start end GEa to the processing end end GEb by moving each grinding wheel 1, 2 relative to the glass plate G. For example, the end GE of the glass plate G can be processed by each grinding wheel 1, 2 by moving the glass plate G along the conveying direction GX1. Alternatively, the end GE of the glass plate G can be processed by moving each grinding wheel 1, 2 along a specific direction GX2.

The first grinding wheel 1 used in the first processing step S1 includes, for example, a pair of rotating grinding wheels. The first grinding wheel 1 is, for example, a grinding wheel for chamfering the end GE of the glass plate G. As the first grinding wheel 1, for example, an electroplated grinding wheel in which diamond abrasive grains are reinforced with a metal electroplating binder, or a metal bonded grinding wheel in which abrasive grains are reinforced with a metal binder can be preferably used.

The first grinding wheel 1 is configured to be movable in the horizontal direction (X-axis direction and Y-axis direction) and the vertical direction (Z-axis direction) by a moving mechanism. In addition, the first grinding wheel 1 rotates around its axis RC1 by a driving means such as an electric motor.

As shown in FIG. 1 and FIG. 2 , the first grinding wheel 1 has a first groove 3 for processing the end GE of the glass plate G. The first groove 3 has a bottom 3a and inclined surfaces 3b formed on both sides of the bottom 3a. In this embodiment, the first grinding wheel 1 having a first groove 3 of one level is exemplified, but the structure is not limited thereto, and a first groove 3 of multiple levels may be formed on the first grinding wheel 1. In addition, the first processing step S1 may be performed on each end GE of the glass plate G by using multiple first grinding wheels 1.

As shown in FIG. 2 , the end GE of the glass sheet G supplied to the first processing step S1 includes an end surface including a corner GC. In the first processing step S1, the corner GC of each end GE is removed by chamfering with the first grinding wheel 1.

Specifically, as shown in FIG3 , the first grinding wheel 1 grinds the end GE of the glass plate G through the bottom 3a and the inclined surface 3b. In this case, the corner GC of the end GE of the glass plate G is removed by the inclined surface 3b. By performing the first processing step S1, the end GE of the glass plate G becomes a part including the end surface ES1 (top) ground by the bottom 3a of the first grinding wheel 1 and the connecting surface ES2 ground by the inclined surface 3b of the first grinding wheel 1.

The end surface ES1 is formed in a flat or curved shape in accordance with the shape of the bottom 3a of the first grinding wheel 1. The connecting surface ES2 is a boundary formed between the end surface ES1 and the surfaces GS1 and GS2 of the glass plate G. The connecting surface ES2 is formed in a curved shape in a manner that connects the surfaces GS1 and GS2 of the glass plate G to the end surface ES1.

The second grinding wheel 2 used in the second processing step S2 includes, for example, a pair of rotating grinding wheels for grinding the end surface ES1 of the glass plate G. As the second grinding wheel 2, a resin bonded grinding wheel using a resin bond (resin adhesive) as a bonding material for the abrasive grains is preferably used.

As the resin binder, it is preferred to use a thermosetting resin. As a specific example, phenolic resins, epoxy resins, polyimide resins, polyurethane resins, etc. can be used as resin binders.

As the abrasive grains combined with the second grinding wheel 2, one kind or a mixture of two or more kinds of abrasive grains can be selected from diamond grains, aluminum oxide grains, silicon carbide grains, cubic boron nitride grains, metal oxide grains, metal carbide grains, metal nitride grains, etc. The particle size of the abrasive grains is set to, for example, #1000~3000, but is not limited to this range.

The second grinding wheel 2 is configured to be movable in the horizontal direction (X-axis direction, Y-axis direction) and the vertical direction (Z-axis direction) by a moving mechanism. In addition, the second grinding wheel 2 rotates around its axis RC2 by a driving means such as an electric motor.

As shown in FIG4 , the second grinding wheel 2 has a second groove 4 on its outer peripheral surface 2a for grinding the end GE of the glass plate G. The second groove 4 can receive substantially all of the end GE of the glass plate G, and the width dimension W1 of the second groove 4 is greater than the thickness dimension T of the glass plate G. The second groove 4 has a bottom 4a in contact with the end surface ES1 of the glass plate G, and a pair of limiting surfaces 4b formed by connecting the two sides of the bottom 4a. Furthermore, the second groove 4 can also be configured to receive a portion of the end GE of the glass plate G (for example, the end surface ES1 and the connecting surface ES2 on the side of the end surface ES1). In this case, the width dimension W1 of the second groove 4 is greater than the maximum thickness of the portion of the end GE received by the second groove 4.

The bottom 4a is configured as a curved surface or a flat surface in a manner corresponding to the end surface ES1 of the glass plate G. The limiting surface 4b is configured as a curved surface in a manner corresponding to the connecting surface ES2 of the glass plate G.

The width dimension W2 of the bottom 4a is greater than the thickness T1 of the end surface ES1 of the glass plate G. The width dimension W2 of the bottom 4a is preferably set to 1 to 2.5 times the thickness dimension T1 of the end surface ES1 of the glass plate G (T1≦W2≦2.5T1).

In this embodiment, a second grinding wheel 2 having a single-stage second groove 4 is exemplified, but the present invention is not limited to this structure, and a second grinding wheel 2 having multiple stages of second grooves 4 may be formed. In addition, the second processing step S2 may be performed on each end GE of the glass plate G using multiple second grinding wheels 2.

In the second processing step S2, the second grinding wheel 2 is relatively moved from the processing start end GEa of the glass plate G toward the processing end GEb along the length direction (X-axis direction) of the end GE, and the second grinding wheel 2 is relatively moved relative to the thickness direction (Z-axis direction) of the glass plate G.

FIG5 shows the moving trajectory of the second grinding wheel 2 in the second processing step S2. The second grinding wheel 2 moves relative to the glass plate G in the X-axis direction from the processing start position XS through the first intermediate position XM1 and the second intermediate position XM2 to the processing end position XE. The processing start end GEa of the glass plate G contacts the second groove 4 of the second grinding wheel 2 at the processing start position XS. At the processing end position XE, the second grinding wheel 2 reaches the processing end end GEb of the glass plate G.

The second grinding wheel 2 reciprocates in the Z-axis direction while moving from the machining start position XS to the machining end position XE in the X-axis direction. That is, the second grinding wheel 2 moves (rises) a distance L1 from the reference position Z0 in the Z-axis direction to reach the first position Z1. Thereafter, it moves (descends) the same distance L1 to return to the reference position Z0, and then moves (descends) a distance L2 from the reference position Z0 to reach the second position Z2.

In this embodiment, the moving distance L1 from the reference position Z0 to the first position Z1 and the distance L2 from the reference position Z0 to the second position Z2 are set equal, but are not limited to this relationship.

In this case, the sum of the moving distances L1 and L2 from the reference position Z0 (L1+L2) becomes the moving range of the second grinding wheel 2 in the Z-axis direction. It is preferred that the width dimension W1 of the second groove portion 4 of the second grinding wheel 2 before (initially) performing the second processing step S2 is smaller than the sum of the moving range (L1+L2) and the thickness dimension T of the glass plate G (W1<(L1+L2+T)). Moreover, it is preferred that the width dimension W2 of the bottom 4a of the second groove portion 4 before (initially) performing the second processing step S2 is smaller than the sum of the moving range (L1+L2) and the thickness dimension T1 of the end surface ES1 of the glass plate G (W2<(L1+L2+T1)).

Below, the specific action pattern of the second grinding wheel 2 in the second processing step S2 is described with reference to Figures 5 to 8.

As shown in Figure 5, at the machining start position XS, the second grinding wheel 2 is placed at the reference position Z0 in the Z-axis direction.

As shown in FIG6 , when the processing start end GEa of the glass plate G reaches the second grinding wheel 2, the center of the bottom 4a of the second groove 4 of the second grinding wheel 2 at the reference position Z0 in the groove width direction (Z-axis direction) contacts the end surface ES1 of the glass plate G. In this case, the connecting surface ES2 of the glass plate G does not contact the limiting surface 4b of the second groove 4. That is, a gap is formed between the connecting surface ES2 and the limiting surface 4b of the second groove 4.

As shown in FIG5 , the second grinding wheel 2 rises at a constant speed from the reference position Z0 in the Z-axis direction and reaches the first position Z1 during the movement from the machining start position XS to the first intermediate position XM1. During this movement, the glass plate G is in a state where only the end surface ES1 contacts the bottom 4a of the second groove portion 4 of the second grinding wheel 2.

When the second grinding wheel 2 reaches the first position Z1, the connecting surface ES2 on the second surface GS2 side of the glass plate G contacts the limiting surface 4b on the lower side of the second groove portion 4 at the first position Z1 as shown in FIG7. In this case, by pressing the connecting surface ES2 against the limiting surface 4b, the glass plate G is elastically deformed along the Z-axis direction. Thus, the connecting surface ES2 on the second surface GS2 side of the glass plate G is ground by the limiting surface 4b of the second groove portion 4.

Thereafter, the second grinding wheel 2 moves at a constant speed from the first position Z1 to the reference position Z0 in the Z-axis direction while moving from the first intermediate position XM1 to the second intermediate position XM2. Furthermore, as shown in FIG5 , the second grinding wheel 2 moves at a constant speed from the reference position Z0 to the second position Z2 in the Z-axis direction while moving from the second intermediate position XM2 to the machining end position XE.

When the second grinding wheel 2 moves from the first position Z1 (first intermediate position XM1) to the second position Z2 (processing end position XE), the glass plate G is in a state where only the end surface ES1 contacts the bottom 4a of the second groove 4 of the second grinding wheel 2.

When the second grinding wheel 2 reaches the second position Z2, the connecting surface ES2 on the first surface GS1 side of the glass plate G contacts the limiting surface 4b on the upper side of the second groove portion 4 at the second position Z2 as shown in FIG8. In this case, by pressing the connecting surface ES2 against the limiting surface 4b, the glass plate G is elastically deformed along the Z-axis direction. Thus, the connecting surface ES2 on the first surface GS1 side of the glass plate G is ground by the limiting surface 4b of the second groove portion 4.

In the second processing step S2, the end surface ES1 is mainly processed, so the surface roughness Ra1 (arithmetic mean roughness) of the end surface ES1 in the glass plate G after the second processing step S2 becomes smaller than the surface roughness Ra2 (arithmetic mean roughness) of the connecting surface ES2. It is preferred that the ratio Ra1/Ra2 of the surface roughness Ra1 of the end surface ES1 and the surface roughness Ra2 of the connecting surface ES2 is 0.15~0.6. It is preferred to set the surface roughness Ra1 of the end surface ES1 to 0.03~0.06μm. It is preferred to set the surface roughness Ra2 of the connecting surface ES2 to 0.1~0.2μm.

In the present invention, the surface roughness Ra1 of the end surface ES1 is measured at multiple locations in the length direction of the end surface ES1 (e.g., the periphery of the processing start position XS, the periphery of the processing end position XE, and the periphery of the intermediate position thereof), and the average value thereof is taken. In addition, the surface roughness Ra2 of the connecting surface ES2 is measured at multiple locations in the length direction of the end surface ES1, and the maximum value thereof is taken.

Figures 9 and 10 show other examples of the movement trajectory of the second grinding wheel 2 in the second processing step S2.

In the example shown in FIG. 9 , the second grinding wheel 2 passes through the first intermediate position XM1 to the fifth intermediate position XM5 when moving from the machining start position XS to the machining end position XE.

During the movement from the processing start position XS to the first intermediate position XM1, the second grinding wheel 2 does not move in the Z-axis direction (to maintain the state of the reference position Z0), but moves relatively along the X-axis direction. During the movement from the first intermediate position XM1 to the second intermediate position XM2, the second grinding wheel 2 moves (rises) from the reference position Z0 to the first position Z1 in the Z-axis direction. During the movement of the second grinding wheel 2 from the processing start position XS to the second intermediate position XM1 through the first intermediate position XM1, only the end surface ES1 of the glass plate G is ground by the bottom 4a of the second groove 4.

The second grinding wheel 2 moves relatively along the X-axis direction while maintaining the first position Z1 in the Z-axis direction while moving from the second intermediate position XM2 to the third intermediate position XM3. During the movement, the end surface ES1 of the glass plate G is ground by the bottom 4a of the second groove 4, and the connecting surface ES2 on the second surface GS2 side is ground by the limiting surface 4b on the lower side of the second groove 4.

The second grinding wheel 2 moves from the first position Z1 to the reference position Z0 in the Z-axis direction while moving from the third intermediate position XM3 to the fourth intermediate position XM4. During this movement, the connecting surface ES2 on the second surface GS2 side of the glass plate G leaves the limiting surface 4b of the second groove portion 4.

The second grinding wheel 2 moves from the reference position Z0 to the second position Z2 in the Z-axis direction while moving from the fourth intermediate position XM4 to the fifth intermediate position XM5. When the second grinding wheel 2 moves from the third intermediate position XM3 to the fifth intermediate position XM5 via the fourth intermediate position XM4, only the end surface ES1 of the end GE of the glass plate G is ground by the bottom 4a of the second groove 4.

The second grinding wheel 2 moves relatively along the X-axis direction while maintaining the second position Z2 in the Z-axis direction while moving from the fifth intermediate position XM5 to the machining end position XE. During this movement, the end surface ES1 of the glass plate G is ground by the bottom 4a of the second groove 4, and the connecting surface ES2 on the first surface GS1 side is ground by the upper limiting surface 4b of the second groove 4.

In the example shown in FIG. 10 , the second grinding wheel 2 passes through the first intermediate position XM1 to the eighth intermediate position XM8 while moving from the machining start position XS to the machining end position XE.

The second grinding wheel 2 moves from the reference position Z0 to the second position Z2 in the Z-axis direction while moving from the machining start position XS to the first intermediate position XM1. The second grinding wheel 2 moves from the second position Z2 to the reference position Z0 in the Z-axis direction while moving from the first intermediate position XM1 to the second intermediate position XM2.

The second grinding wheel 2 moves from the reference position Z0 to the first position Z1 in the Z-axis direction while moving from the second intermediate position XM2 to the third intermediate position XM3. The second grinding wheel 2 moves from the first position Z1 to the reference position Z0 in the Z-axis direction while moving from the third intermediate position XM3 to the fourth intermediate position XM4. The second grinding wheel 2 periodically repeats the same movement as described above while moving from the fourth intermediate position XM4 to the fifth intermediate position XM5, the sixth intermediate position XM6, the seventh intermediate position XM7, and the eighth intermediate position XM8.

If the second processing step S2 is repeatedly performed on multiple glass plates G, the depth of the second groove 4 of the second grinding wheel 2 increases due to the shedding of abrasive grains. FIG. 11 is a cross-sectional view of the second grinding wheel 2 when the second processing step S2 is performed multiple times. In this case, the depth dimension D1 of the second groove 4 is deeper than the initial depth dimension D0.

FIG. 12 is a cross-sectional view of the second grinding wheel 2 when the second processing step S2 is further performed multiple times through the second groove portion 4 shown in FIG. 11. In this case, the depth dimension D2 of the second groove portion 4 is further deepened compared to the depth dimension D1 in FIG. 11. As shown in FIG. 12, the bottom 4a of the second groove portion 4 is gradually deformed from the initial curved surface shape to a shape with an increased radius of curvature, i.e., a shape close to a flat surface, due to repeated second processing step S2.

As described above, in the second processing step S2, the second grinding wheel 2 is relatively moved in the Z-axis direction in such a way that the limiting surface 4b of the second groove portion 4 is necessarily in contact with the connecting surface ES2 of the glass plate G. Thus, as described above, even when the second processing step S2 is repeatedly performed, the reduction of the width dimension W2 of the bottom 4a can be suppressed, and the processing accuracy of the end surface ES1 of the end GE in each glass plate G can be maintained constant.

The glass plate manufactured in the above manner is provided in a manufacturing step of a display panel, for example. In the step of manufacturing an electronic device on the first surface GS1, there is a situation where the position of the end GE is detected by, for example, photographing the end GE with a camera. In this case, the image of the end GE photographed shows an end surface ES1 and a connecting surface ES2 with different surface roughness Ra1 and surface roughness Ra2. As described above, by performing the second processing step S2, the surface roughness Ra1 of the end surface ES1 of the end GE of the glass plate becomes smaller than the surface roughness Ra2 of the connecting surface ES2. Thus, in the photographed image, the end surface ES1 and the connecting surface ES2 can be easily distinguished. In addition, the connecting surface ES2, which is the boundary between each surface GS1, GS2 of the glass plate G and the end GE, can be easily identified, so that the end GE in the image is easily detected.

Furthermore, in the step of manufacturing electronic devices on the first surface GS1, the positioning pin or roller can contact the end surface ES1 of the glass plate G. The end surface ES1 has a smaller surface roughness Ra, so the generation of glass powder caused by the contact can be reduced.

According to the manufacturing method of the glass plate G of the present embodiment described above, the end GE of the glass plate G is polished by the second processing step S2, thereby reducing the generation of glass powder at the end GE of the glass plate G and making it easy to detect with a camera.

If the width dimension W2 of the bottom 4a of the second groove 4 of the second grinding wheel 2 is made larger than the thickness dimension T1 of the end surface ES1 of the glass plate G, the alignment operation of the new second grinding wheel 2 when replacing the second grinding wheel 2 can be performed efficiently.

Figures 13 to 17 show a second embodiment of the method for manufacturing a glass sheet of the present invention. In this embodiment, the implementation of the second processing step is different from that of the first embodiment.

As shown in FIG. 13 , the outer peripheral surface 2a of the second grinding wheel 2 before the second processing step S2 (unused) is not formed with the second groove portion 4 illustrated in the first embodiment.

As shown in FIG14, in the first second processing step S2 in this embodiment, if the first glass plate G1 contacts the outer peripheral surface 2a, the second grinding wheel 2 moves relative to the first glass plate G1 from the processing start end GEa to the processing end end GEb along the length direction (X-axis direction) of the end GE, and moves relative to the Z-axis direction (thickness direction of the first glass plate G1). As shown in FIG15, by the first second processing step S2, a second groove 4 having a width dimension W3 and a depth dimension D3 is formed on the second grinding wheel 2.

The depth dimension D3 of the second groove 4 is smaller than the initial depth dimension D0 of the second groove 4 in the first embodiment. That is, the second groove 4 in the first embodiment has the function of limiting the end GE of the glass sheet G with its limiting surface 4b when processing the glass sheet G, but the second groove 4 in this embodiment does not have this function.

When the second second processing step S2 is performed for the second time, as shown in FIG15 , the second grinding wheel 2 is arranged so that one end (the upper end) of the second groove portion 4 in the groove width direction (Z-axis direction) overlaps the end surface ES1 of the second glass plate G2. In this case, the end surface ES1 of the second glass plate G2 contacts the outer peripheral surface 2a of the second grinding wheel 2 where the second groove portion 4 is not formed.

Thereafter, similarly to the case of processing the first glass plate G1, the second grinding wheel 2 moves relatively along the length direction (X-axis direction) of the end GE from the processing start end GEa of the second glass plate G2 toward the processing end GEb, and moves relatively relative to the Z-axis direction as shown in FIG16. The second groove 4 formed by processing the first glass plate G1 is expanded in width by processing the second glass plate G2. As shown in FIG17, the width dimension W4 of the second groove 4 after processing the second glass plate G2 becomes larger than the width dimension W3 of the second groove 4 just after processing the first glass plate G1. In this case, the depth dimension D3 of the second groove 4 is substantially the same as that after the first second processing step S2 is completed.

In the third second processing step S2, the second grinding wheel 2 is arranged so as to overlap one end of the second groove portion 4 processed on the second glass plate G2 in the groove width direction (Z-axis direction) (see FIG. 17). In this case, the end surface ES1 of the third glass plate G3 contacts the outer peripheral surface 2a of the second grinding wheel 2 where the second groove portion 4 is not formed.

Thereafter, similarly to the case of processing the second glass plate G2, the second grinding wheel 2 is relatively moved in the thickness direction (Z-axis direction) of the third glass plate G3 to grind the end surface ES1. Thus, the second groove 4 of the second grinding wheel 2 in this embodiment first expands its width with the repetition of the second processing step S2. If the second groove 4 expands to the entire outer peripheral surface 2a of the second grinding wheel 2, the second grinding wheel 2 is arranged at the same position as the initial second processing step S2 to increase the depth of a portion of the second groove 4. Then, the second processing step S2 is repeated while changing the position of the second grinding wheel 2, so that the entire second groove 4 has the same depth.

The manufacturing method of the glass sheets G1 to G3 of this embodiment has the following advantages compared to the first embodiment. If the second groove 4 is formed on the outer peripheral surface 2a of the second grinding wheel 2 as in the first embodiment, only the second groove 4 in the outer peripheral surface 2a can be used for processing, and the number of glass sheets G that can be processed by the second grinding wheel 2 alone is reduced. In contrast, if the second grinding wheel 2 having an outer peripheral surface 2a without the second groove 4 is used as in this embodiment, most of the outer peripheral surface 2a can be used for processing, and the number of glass sheets G that can be processed by the second grinding wheel 2 alone can be greatly increased.

Furthermore, the present invention is not limited to the structure of the above-mentioned implementation form, nor is it limited to the above-mentioned effect. The present invention can be modified in various ways without departing from the scope of the present invention.

In the above-mentioned embodiment, an example is given in which the first processing step S1 and the second processing step S2 are performed on the ends GE of two sides of the glass plate G formed into a rectangular shape, but the present invention can also be applied to the ends GE of the other two sides.

The relative movement of the second grinding wheel 2 in the Z-axis direction in the second processing step S2 can also be performed by moving the glass plate G relative to the Z-axis direction (thickness direction).

1: First grinding wheel

2: Second grinding wheel

2a: Outer surface of the second grinding wheel

3: First groove

4: Second groove

G: Glass plate

GE: End of glass plate

GEa: Processing start end

GEb: Processing end

GS1: First Surface

GS2: Second Surface

GX1: Transport direction

GX2: Specific direction

RC1: Axis of the first grinding wheel

RC2: Axis of the second grinding wheel

S1: First processing step

S2: Second processing step

Claims (3)

A method for manufacturing a glass plate, which is a method for manufacturing a glass plate having a surface and an end, is characterized in that the method comprises: a first processing step, processing the end of the glass plate using a first grinding wheel; and a second processing step, grinding the end of the glass plate after the first processing step using a second grinding wheel, wherein the end of the glass plate supplied to the second processing step has an end face and a connecting face formed between the end face and the surface, and in the second processing step, the second grinding wheel is relatively moved along the length direction of the end of the glass plate while being relatively moved relative to the thickness direction of the glass plate, thereby processing at least the end face. The manufacturing method of the glass plate as described in claim 1, wherein the second grinding wheel has a groove portion for grinding the end surface of the glass plate, the groove portion has a bottom portion in contact with the end surface of the glass plate, and a limiting surface connected to the bottom portion and contactable with the connecting surface, the bottom portion of the groove portion has a width greater than the thickness of the end surface of the glass plate, and the width of the bottom portion before performing the second processing step is smaller than the sum of the thickness of the end surface and the relative movement distance of the second grinding wheel in the thickness direction. The method for manufacturing a glass plate as described in claim 1, wherein before performing the second processing step, the second grinding wheel has an outer peripheral surface without a groove portion, and in the second processing step, the end of the glass plate is ground by the outer peripheral surface of the second grinding wheel.

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