DRUM, David L. (9105 South Lake Road, Hammondsport, New York, 14830, US)
KUDVA, Gautam N. (110 Esthers Way, Horseheads, New York, 14845, US)
LU, Sam (No. 8, Aly. 36 Ln. 140,,Dade 2nd Rd.,,Gangshan Township, Kaohsiung County 820, 820, TW)
DRUM, David L. (9105 South Lake Road, Hammondsport, New York, 14830, US)
KUDVA, Gautam N. (110 Esthers Way, Horseheads, New York, 14845, US)
LU, Sam (No. 8, Aly. 36 Ln. 140,,Dade 2nd Rd.,,Gangshan Township, Kaohsiung County 820, 820, TW)
CORNING INCORPORATED (1 Riverfront Plaza, Corning, New York, 14831, US)
| CLAIMS What is claimed is: 1. A method of finishing an edge of a material to be finished comprising the steps of: applying a removable sensing layer to a portion of the material to be finished; placing the edge of the material to be finished into a machining area; utilizing at least one sensor to sense a position of the removable sensing layer; and adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position. 2. The method of claim 1 or claim 2, wherein the material to be finished comprises a glass sheet. 3. The method of claim 1, wherein the removable sensing layer comprises a ferromagnetic material. 4. The method of claim 3, wherein the ferromagnetic material comprises a ferromagnetic tape. 5. The method of any of the preceding claims, wherein the at least one sensor comprises a plurality of sensors that each sense a corresponding spaced position of the removable sensing layer. 6. The method of any of the preceding claims, wherein the at least one sensor comprises at least one induction sensor. 7. The method of any of the preceding claims, further comprising the step of guiding the edge of the material to be finished through the machining area along a travel direction, and the sensor senses the position of the removable sensing layer along an axis transverse to the travel direction. 8. The method of any of the preceding claims, wherein a non-contact element adjusts the relative position. 9. The method of claim 8, wherein the non-contact element adjusts the relative position while guiding the edge of the material to be finished through the machining area. 10. The method of claim 8 or claim 9, wherein the non-contact element comprises at least one fiuid bearing emitting a fiuid stream against the material to be finished to adjust the relative position. 11. The method of claim 10, wherein the at least one fiuid bearing comprises a pair of opposed fluid bearings. 12. The method of any of the preceding claims, wherein a controller automatically adjusts the relative position based on a predetermined position and the sensed position of the ferromagnetic material. 13. A method of finishing an edge of a glass sheet comprising the steps of: applying a ferromagnetic material along the edge of the glass sheet; placing the edge of the glass sheet into a machining area; utilizing at least one induction sensor to sense a position of ferromagnetic material; and adjusting a relative position between the machine and the edge of the glass sheet based the sensed position, wherein the relative position is adjusted with at least one fluid bearing emitting a fiuid stream against the glass sheet. 14. The method of claim 13, wherein the ferromagnetic material comprises a ferromagnetic tape. 15. The method of claim 13 or claim 14, further comprising the step of guiding the edge of the glass sheet through the machining area along a travel direction, and the at least one induction sensor senses the position of the ferromagnetic material along an axis transverse to the travel direction. 16. The method of any of claims 13 to 15, wherein the fluid bearing adjusts the relative position while guiding the edge of the glass sheet through the machining area. 17. A method of finishing an edge of a material to be finished comprising the steps of: applying a removable sensing layer to a portion of the material to be finished; placing the edge of the material to be finished into a machining area; utilizing at least one sensor to sense a position of the removable sensing layer; adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position; machining the edge of the material to be finished; and removing the sensing layer. 18. The method of claim 17, wherein the removable sensing layer comprises a ferromagnetic material and the at least one sensor comprises at least one induction sensor. 19. The method of claim 17 or claim 18, wherein the step of machining comprises using an abrasive tool to machine the edge of the material to be finished, and wherein the step of adjusting comprises adjusting a position of the abrasive tool relative to the edge of the material to be finished. 20. The method of any of claims 17 to 19, wherein the step of machining comprises polishing the edge of the material to be finished, and wherein the step of adjusting comprises adjusting a position of the abrasive tool relative to the edge of the material to be finished. |
[0001 ] This application claims the benefit of priority to US Provisional Application No. 61/237468 filed on August 27, 2009.
TECHNICAL FIELD
[0002] The present invention relates generally to methods for finishing an edge of a material to be finished. In particular, the present invention relates to methods for finishing a glass material such as a glass sheet involving a step of adjusting the position of a finishing device such as a grinding wheel relative to the material to be finished. The present invention is useful, e.g., for precision finishing of the edges of a glass sheet suitable for a LCD substrate.
BACKGROUND
[0003] Formation of a sheet material to be finished, such as glass sheets, is desirable for various applications. After initial formation, the material to be finished frequently needs to be machined to obtain a final product having the desired peripheral shape and edge characteristics. There is a need to provide techniques for adjusting a machine for machining the edge of the material to be finished to provide consistent machining while presenting edges having favorable characteristics.
SUMMARY
[0004] The following presents a simplified summary of the disclosure in order to provide a basic understanding of some example aspects described in the detailed description.
[0005] Several aspects of the present invention are disclosed herein. It is to be understood that these aspects may or may not overlap with one another. Thus, part of one aspect may fall within the scope of another aspect, and vice versa.
[0006] Each aspect is illustrated by a number of embodiments, which, in turn, can include one or more specific embodiments. It is to be understood that the embodiments may or may not overlap with each other. Thus, part of one embodiment, or specific embodiments thereof, may or may not fall within the ambit of another embodiment, or specific embodiments thereof, and vice versa.
[0007] A first aspect of the present disclosure is a method of finishing an edge of a material to be finished comprising the steps of: applying a removable sensing layer to a portion of the material to be finished; placing the edge of the material to be finished into a machining area;
utilizing at least one sensor to sense a position of the removable sensing layer; and adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position.
[0008] In certain embodiments of the first aspect of the present disclosure, the material to be finished comprises a glass sheet.
[0009] In certain embodiments of the first aspect of the present disclosure, the material to be finished comprises a glass sheet having a thickness of at most 1000 μπι, such as at most 700 μτα, at most 500 μτα, at most 300 μτα, at most 100 μτα, even at most 10 μτα.
[0010] In certain embodiments of the first aspect of the present disclosure, the removable sensing layer comprises a ferromagnetic material.
[0011] In certain embodiments of the first aspect of the present disclosure, the ferromagnetic material comprises a ferromagnetic tape.
[0012] In certain embodiments of the first aspect of the present disclosure, the at least one sensor comprises a plurality of sensors that each sense a corresponding spaced position of the removable sensing layer.
[0013] In certain embodiments of the first aspect of the present disclosure, the at least one sensor comprises at least one induction sensor.
[0014] In certain embodiments of the first aspect of the present disclosure, the method further comprises the step of guiding the edge of the material to be finished through the machining area along a travel direction, and the sensor senses the position of the removable sensing layer along an axis transverse to the travel direction.
[0015] In certain embodiments of the first aspect of the present disclosure, a non- contact element adjusts the relative position.
[0016] In certain embodiments of the first aspect of the present disclosure, the non- contact element adjusts the relative position while guiding the edge of the material to be finished through the machining area.
[0017] In certain embodiments of the first aspect of the present disclosure, the non- contact element comprises at least one fluid bearing emitting a fluid stream against the material to be finished to adjust the relative position. [0018] In certain embodiments of the first aspect of the present disclosure, the at least one fluid bearing comprises a pair of opposed fluid bearings.
[0019] In certain embodiments of the first aspect of the present disclosure, a controller automatically adjusts the relative position based on a predetermined position and the sensed position of the ferromagnetic material.
[0020] A second aspect of the present disclosure is a method of finishing an edge of a glass sheet comprising the steps of:
applying a ferromagnetic material along the edge of the glass sheet;
placing the edge of the glass sheet into a machining area;
utilizing at least one induction sensor to sense a position of ferromagnetic material; and
adjusting a relative position between the machine and the edge of the glass sheet based the sensed position, wherein the relative position is adjusted with at least one fluid bearing emitting a fluid stream against the glass sheet.
[0021] In certain embodiments of the second aspect of the present disclosure, the ferromagnetic material comprises a ferromagnetic tape.
[0022] In certain embodiments of the second aspect of the present disclosure, the method further comprises the step of guiding the edge of the glass sheet through the machining area along a travel direction, and the at least one induction sensor senses the position of the ferromagnetic material along an axis transverse to the travel direction.
[0023] In certain embodiments of the second aspect of the present disclosure, the fluid bearing adjusts the relative position while guiding the edge of the glass sheet through the machining area.
[0024] A third aspect of the present disclosure is a method of finishing an edge of a material to be finished comprising the steps of:
applying a removable sensing layer to a portion of the material to be finished; placing the edge of the material to be finished into a machining area;
utilizing at least one sensor to sense a position of the removable sensing layer; adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position;
machining the edge of the material to be finished; and
removing the sensing layer. [0025] In certain embodiments of the third aspect of the present disclosure, the removable sensing layer comprises a ferromagnetic material and the at least one sensor comprises at least one induction sensor.
[0026] In certain embodiments of the third aspect of the present disclosure, the step of machining comprises using an abrasive tool to machine the edge of the material to be finished, and wherein the step of adjusting comprises adjusting a position of the abrasive tool relative to the edge of the material to be finished.
[0027] In certain embodiments of the third aspect of the present disclosure, the step of machining comprises polishing the edge of the material to be finished, and wherein the step of adjusting comprises adjusting a position of the abrasive tool relative to the edge of the material to be finished.
[0028] In a fourth aspect of the present disclosure, a method of adjusting a machine for machining an edge of a material to be finished comprises the steps of applying a removable sensing layer to a portion of the material to be finished, and placing the edge of the material to be finished into a machining area. The method further comprises the steps of utilizing at least one sensor to sense a position of the removable sensing layer, and adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position.
[0029] In a fifth aspect of the present disclosure, a method of adjusting a machine for machining an edge of a glass sheet comprises the steps of applying a ferromagnetic material along the edge of the glass sheet, and placing the edge of the glass sheet into a machining area. The method further comprises the steps of utilizing at least one induction sensor to sense a position of ferromagnetic material, and adjusting a relative position between the machine and the edge of the glass sheet based the sensed position. The relative position is adjusted with at least one fluid bearing emitting a fluid stream against the glass sheet.
[0030] In a sixth aspect of the present disclosure, a method of machining an edge of a material to be finished comprises the steps of applying a removable sensing layer to a portion of the material to be finished, placing the edge of the material to be finished into a machining area, and utilizing at least one sensor to sense a position of the removable sensing layer. The method further comprises the steps of adjusting a relative position between the machine and the edge of the material to be finished based on the sensed position, machining the edge of the material to be finished, and removing the sensing layer.
[0031] One or more embodiments of the various aspects of the present disclosure have one or more of the following advantages. Due to the use of a sensing and adjusting step, precision position information of the material to be finished can be obtained and used in adjusting its position relative to the machine component adapted for the finishing function such as a grinding wheel, achieving the precision edge finishing of the edge. The process can accommodate the buckling, warping, bending and other distortion and/or movement of a thin sheet material such as a glass sheet to achieve dynamic edge finishing with a high consistency and repeatability. The process is especially advantageous for the edge finishing of glass sheets having a thickness of at most 1000 μτα, such as lower than 700 μτα, lower than 500 μτα, lower than 300 μτα, lower than 100 μτα, or even lower than about 10 μτα.
[0032] Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the invention as described in the written description and claims hereof, as well as the appended drawings.
[0033] It is to be understood that the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework to understanding the nature and character of the invention as it is claimed.
[0034] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] These and other aspects are better understood when the following detailed description is read with reference to the accompanying drawings, in which:
[0036] FIG. 1 is a schematic view of an example machine for machining a material to be finished and a material to be finished being positioned outside of the machine;
[0037] FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;
[0038] FIG. 3 is similar to FIG. 2 with an edge of the material to be finished being placed into a machining area;
[0039] FIG. 4 is similar to FIG. 3, with a sensor being used to sense a position of a removable sensing layer; [0040] FIG. 5 is similar to FIG. 4, with a relative position between the machine and the edge of the material to be finished being adjusted based on the sensed position; and
[0041] FIG. 6 is a schematic view of another example machine with the edge of the material to be finished being placed into the machining area.
DETAILED DESCRIPTION
[0042] As used herein, the term "finishing" is intended to mean the processing of a material, including but not limited to: mechanical processing and modification, such as grinding, chamfering, polishing, patterning, cutting, scoring, machining, material removal, material addition, and the like; chemical processing such as chemical polishing, ion exchanging, etching, exposure to other chemicals, and the like; optical processing, such as irradiating, laser ablating, and the like; and combinations thereof. In the detailed description of the various aspects and embodiments of the present disclosure below, emphasis is given on machining. One having ordinary skill in the art, upon reading the present disclosure and having benefited from the teaching herein, will readily understand that the present invention can be applied to other edge finishing processes as well.
[0043] Examples will now be described more fully hereinafter with reference to the accompanying drawings in which example embodiments are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, aspects may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
[0044] Example methods herein involve materials to be finished that are brittle with a low thickness. The materials to be finished can have a wide range of thicknesses. For example, a thin glass sheet can be used having a thickness "T" that is within a range from about 100 μι ίο about 1000+ μιη, such as about 600 μιη, about 500 μτα, about 400 μτα, about 300 μτα, about 200 μτα, about 100 μτα, and the like, although other lesser or greater thicknesses may be incorporated with further examples.
[0045] As mentioned supra, thin glass sheets tend to be very flexible, and are prone to buckling, warping, bending or other distortion when subjected to even minor mechanical stress during edge finishing, acceleration or deceleration. This poses great challenges to the repeatable, consistent and precise edge finishing required of high precision glass sheets, such as those for LCD substrates. The quality of the finished edges of a LCD substrate and other optoelectronic devices has great impact on the strength of the substrate and the final fabricated device. Due to the capability of the method of the present disclosure to dynamically detect and adjust the relative position of the glass sheet relative to the finishing device such as the grinding wheel, the present invention method is particularly advantageous for finishing the edges of such thin glass sheets, especially those having a thickness lower than about 500 μτα. In addition, the present invention method is particularly advantageous for finishing a moving glass sheet, which are more prone to shape and positional shift, especially those having a thickness lower than about 500 μπι.
[0046] The materials to be finished may comprise glass such as transparent, translucent, colored, or other glass types. In a further example, materials to be finished may comprise a polymer such as a composite including glass and a polymer. In further examples, the material to be finished may comprise crystalline material such as a quartz composition, ceramic, or glass ceramic. Materials to be finished may be used for a variety of applications. In one example, the material to be finished may comprise a glass for a display assembly, such as a liquid crystal display or other display device. For instance, as shown, a material to be finished 101 may be provided that includes a glass sheet material configured for use with LCD display applications. The material to be finished can be constructed with a wide variety of shapes such as planar, cylindrical, conical, frustoconical shape, or other shapes.
[0047] Referring now to FIG. 1, a schematic view is illustrated of an example machine 103 for machining an edge 105 of a material to be finished 101. For clarity, machining of only one edge 105 is discussed herein, with the understanding that the machine 103 can be adapted to machine various edges of the material to be finished 101. For example, the top and bottom edges of the material to be finished 101 can be machined simultaneously.
[0048] Various techniques can be used to machine the edge 105 of the material to be finished 101. For instance, machining can include, either alone or in combination, grinding, scoring, etching, polishing, or complete cutting through, where each results in shaping the edge 105 of the material to be finished 101. For example, grinding of the edge 105 can be performed to increase its resistance to breakage from rubbing and impact, as well as to increase its ability to withstand vibration during shipping. The machining can be carried out at substantially all locations along the edge. Alternatively, the machining can be conducted at spaced locations along the edge. Still further, the machining can be continuous or pulsed. For example, machining can comprise a pulsed or non-pulsed operation applied at spaced locations or at substantially all locations along the edge.
[0049] In the illustrated example, the machine 103 can include at least one machining area 107 for receiving and machining the edge 105 of the material to be finished 101. As shown, the machine 103 can include an abrasive tool 109, such as a grinding wheel for grinding the edge 105 of the material to be finished 101. In one example shown in FIG. 2, the abrasive tool 109 can have a generally circular peripheral working edge with a concave machining profile 201 so as to machine the edge 105 with a convex profile (not shown). The concave machining profile 201 can be adapted to grind the edge 105 to have a convex profile with a radius of about 1/2 of the thickness T, such as about 250 μιη to about 350 μιη, although other radii may be incorporated with further examples. The edge 105 can also be machined to have various other profiles, such as chamfered, etc. In addition or alternatively, the machine 103 can include a polishing tool 111, such as a polishing wheel for polishing or cleaning the edge 105 of the material to be finished 101. In one example, the polishing tool 111 can be disposed downstream from the abrasive tool 109 so as to polish or clean the edge 105 after the grinding operation.
[0050] The machine 103 can further include a non-contact element 113 adapted to guide the edge 105 of the material to be finished 101 through the machining area 107 along a travel direction S. In one example, the non-contact element 113 can include a plurality of elements, such as pair of fluid bearings 203, 205 each provided with one or more nozzles 207, 209 emitting a fluid stream adapted to laterally support the material to be finished 101. Thus, the material to be finished 101 does not directly contact the non- contact element 113, but is instead laterally supported by the fluid stream. In one example, the fluid can include water (i.e., water bearings), though various other liquids, gasses, etc. can be used. The pair of fluid bearings 203, 205 can be arranged in an opposed relationship and be spaced a predetermined and fixed distance D away from each other, such as about 2 mm to about 2.5 mm, though various distances are contemplated. As shown in FIG. 2, the fluid bearings 203, 205 can be located on either side of the material to be finished 101 so as to apply force to one or both sides of the material to be finished 101 in the same or varying degrees. The fluid bearings 203, 205 can also be located generally above the abrasive and/or polishing tools 109, 111 so as to not interfere with the machining operation(s). [0051] The machine 103 can further include various other structures adapted to guide the edge 105 of the material to be finished 101 through the machining area 107. For example, the machine 103 can include one or more rollers 115 or the like to facilitate movement of the material to be finished 101 along the travel direction S. Movement of the material to be finished 101 can be bottom-edge (i.e., edge 105) conveyed. During the machining, where the edge 105 is to be machined is the bottom edge, the fluid bearings 203, 205 can provide lateral support for the sides of the material to be finished 101, and a vacuum chuck 117 can be used to convey the material to be finished 101 along the travel direction S. In one example, the vacuum chuck 117 can be about 75 mm wide (tall) and extend about the length of the sheet (e.g., up to 3.2 meters). The vacuum chuck 117 can also be located on either or both sides of the material to be finished 101. The vacuum chuck 117 can be run on linear rails or the like that provide the accuracy and stiffness desired to convey the material to be finished 101. For clarity, the rollers 115 and vacuum chuck 117 are illustrated schematically in FIGS. 1 and 6, and are not shown in FIGS. 2- 5.
[0052] As can be appreciated, edge grinding of a glass surface with a fixed position equipment setup can yield ground edge variation. Due to the low lateral stiffness of the glass, the glass can warp, bend of flex during transport and during application of grinding forces. This distortion can cause variation in edge grinding as well as in contact between the glass and the bearing surface resulting in either edge or surface damage. To provide a substantially uniform desired edge, and/or account for glass bending and other glass positioning variations, example methods adjusting the machine 103 for machining the edge 105 of the material to be finished 101 will now be described.
[0053] Referring to FIGS. 2-5, one example method can include the step of utilizing at least one sensor 211 to sense a position of the material to be finished 101, and the step of adjusting a relative position between the machine 103 and the edge 105 of the material to be finished 101 based on the sensed position. In one example, a single sensor 211 can be utilized to sense a single position of the removable sensing layer 213, or can even be used multiple times to sense multiple positions of the removable sensing layer 213 when the material to be finished 101 moves through the machine 103. In another example, the at least one sensor 211 can include a plurality of sensors 601, 603, 605, 607 (see FIG. 6) that each sense a corresponding spaced position of the removable sensing layer 213. It is also contemplated that a plurality of removable sensing layers (not shown) can be utilized with a single or even a plurality of sensors. Because the material to be finished 101 is generally laterally supported within the machine 103 by fluid emitted from non-contact fluid bearings, the sensor(s) 211 should be capable of operating in a fluid environment. For example, where a pair of fluid bearings 203, 205 is used, the sensor(s) 211 should be capable of operating in a water environment where a portion, such as all, of the material to be finished 101 is coated with fluid, such as water.
[0054] In one example, the at least one sensor 211 can be an induction sensor. An induction sensor is an electronic proximity sensor, which detects metallic objects, such as ferromagnetic objects, without touching them. Generally, an induction sensor includes an induction loop, and an electric current is provided to generate a magnetic field. The inductance of the loop changes according to material(s) inside the magnetic field, and since metals are generally more effective inductors than other materials, the presence of metal increases the current flowing through the loop. This change can be detected by sensing circuitry (not shown), which can provide a signal when a metallic object is detected. For example, the sensing circuitry can be part of the sensor 211, or can be remote from the sensor and adapted to receive input from the sensor 211. Thus, because magnetic fields are generally unaffected by fluids, such as water, an induction sensor can be particularly useful for applications where fluids are present. For clarity, the examples will be described herein with the at least one sensor 211 being an induction sensor, though it is contemplated that the sensor 211 can also include various other contact or non-contact sensors, such as physical contact sensors, hydraulic or pneumatic sensors, laser sensors, ultrasonic sensors, capacitive sensors, and/or the like.
[0055] In one example, the induction sensor 211 can include a relatively high accuracy compact sensor with a resolution of about 2 microns and a measuring range of about 0 - 10 mm. For example, the induction sensor 211 can be a Keyence inductive displacement sensor model EX-422V sensor head that can be mated to a Keyence model EX-V10 controller for capturing sensor output via a data acquisition system, which can provide an output showing positional displacement.
[0056] However, some materials to be finished 101, such as a glass sheet, may not contain metallic elements capable of being detected by an induction sensor. Thus, the method can include the step of applying a removable sensing layer 213 to a portion of the material to be finished 101. In one example, the removable sensing layer 213 can include a ferromagnetic material. For example, the ferromagnetic material can include a ferromagnetic tape that is removably applied to the material to be finished 101 by an adhesive or the like, though various other removable materials can also be used. The removable sensing layer 213 can be applied along, such as on, adjacent, over, or parallel to the length or direction of the edge 105 of the material to be finished 101. For example, as shown, the removable sensing layer 213 can be applied to at least one portion of the material to be finished 101 along the edge 105.
[0057] The removable sensing layer 213 can be applied substantially continuous along the edge 105, or alternatively can be applied at spaced locations along the edge 105. For example, as shown in FIG. 1, the removable sensing layer 213 can be applied substantially continuously along one side face of the material to be finished 101 while being parallel at a spaced distance from the edge 105. It can be desirable to carefully apply the ferromagnetic tape when the material to be finished 101 is relatively dry to ensure that the thickness of the tape is substantially uniform with little, such as no, perturbations or ripples. Substantial uniformity of the tape thickness is desirable so as to accurately sense a position of the material to be finished 101, and disturbances in the ferromagnetic tape, such as ripples, air bubbles, etc., between the tape and the glass can lead to measurement error. Because the thickness T of the material to be finished 101 and the spacing D between the fluid bearings 203, 205 are both generally controlled and predetermined, the removable sensing layer 213 can be applied to as few as one portion (e.g., one face) of the material to be finished 101 for accurately sensing a position thereof relative to the machine 103. Additionally, it can be beneficial to utilize a fluid-resistant removable sensing layer 213 due to the fluid emitted by the fluid bearings 203, 205.
[0058] As further shown in FIG. 2, the example method can further include the step of placing the edge 105 of the material to be finished 101 into the machining area 107. For example, as shown, the material to be finished 101 can be located generally above the machining area 107 and can be placed therein by movement along the direction of arrow P. In another example, the material to be finished 101 can be placed within the machining area 107 by movement along the direction of arrow S of FIG. 1, or even various other directions.
[0059] Once placed within the machining area 107, the position of the material to be finished 101 can be sensed to provide a substantially uniform desired edge and/or account for glass bending and other glass positioning variations, etc. As shown in FIG. 3, the edge 105 of the material to be finished 101 may be out of alignment with the concave machining profile 201 of the abrasive tool 109. For example, where the abrasive tool 109 is positioned generally centrally between the pair of fluid bearings 203, 205, the material to be finished 101 can be positioned relatively closer to one of the fluid bearings 203, 205. A first offset distance di between one side face 301 of the material to be finished 101 and one fluid bearing 203 may be different than a second offset distance d 2 between a second side face 303 of the material to be finished 101 and the other fluid bearing 205. If no adjustments are made, a misaligned profile may be ground into the edge 105.
[0060] Turning to FIG. 4, the method can further include the step of utilizing the at least one sensor 211 to sense a position of the removable sensing layer 213. For example, the at least one induction sensor 211 can be used to sense a position of the ferromagnetic material via the generation of a magnetic field 401. The presence of the removable sensing layer 213 inside the magnetic field can change the inductance of the sensor 211. The change can be detected by sensing circuitry (not shown) coupled to the sensor 211, which can provide a signal showing positional displacement between the sensor 211 and the removable sensing layer 213. For example, the sensor 211 can be used to sense a distance between the one fluid bearing 203 and the adjacent side face 301, which can be based upon a sensed distance between the sensor 211 and the removable sensing layer 213.
[0061] Because the removable sensing layer 213 will have a predetermined thickness, and/or because the sensor 211 may be positioned variously relative to the one fluid bearing 203, the output of the sensor 211 can be calibrated, such as with appropriate predetermined variables, to provide an accurate offset distance measurement di between the one fluid bearing 203 and the adjacent side face 301. In one example, the calibration portion can include exposing the sensor 211 to the removable sensing layer 213, and using a 3-point system where the removable sensing layer 213 is placed in contact with the material to be finished 101, at full scale and at half scale. The readings can be recorded and used to translate the raw eddy current field data provided by the sensor 211 into a distance between the sensor 211 and the material to be finished 101. Thus, for example, once calibration and measurements on a set of master sheets is completed, the system can be programmed to compensate for the errors in the direction perpendicular to direction of travel.
[0062] The step of sensing the position of the removable sensing layer 213 can be performed in a static manner (i.e., the material to be finished 101 is stationary relative to the machine 103), or in a dynamic manner (i.e., the material to be finished 101 is in motion relative to the machine 103). The step of sensing a position of the removable sensing layer 213 can even be performed in a static manner followed by a dynamic manner, or vice versa. For example, as shown in FIG. 4, the method can include step of guiding the edge 105 of the material to be finished 101 through the machining area 107 along the travel direction of arrow S (i.e., see FIG. 1), and the sensor 211 can sense the position of the removable sensing layer 213 along an axis (i.e., Z-axis) generally transverse to the travel direction of arrow S.
[0063] In addition or alternatively, the step of sensing a position of the removable sensing layer 213 can be performed under dry or wet conditions. For example, as shown in FIG. 4, the step of sensing can be performed while the fluid bearings 203, 205 are each emitting a fluid stream 403, 405 to support the material to be finished 101 within the machine 103. Because the magnetic field generated by the induction sensor 211 is generally impervious to the fluid streams 403, 405, the step of sensing the position of the material to be finished 101 is thereby unaffected by the fluid.
[0064] Turning now to FIG. 5, the method can further include the step of adjusting a relative position between the machine 103 and the edge 105 of the material to be finished 101 based on the sensed position. For example, the relative position between the machine 103 and the material to be finished 101 can be adjusted to place the edge 105 of the material to be finished 101 in alignment with the concave machining profile 201 of the abrasive tool 109.
[0065] Generally, the total spacing D between the fluid bearings 203, 205 can be equal to the sum of the first offset distance (i.e., between the one side face 301 of the material to be finished 101 and the one fluid bearing 203), the thickness T of the material to be finished 101, and the second offset distance (i.e., between the second side face 303 of the material to be finished 101 and the other fluid bearing 205). In one example, where the abrasive tool 109 is positioned generally centrally between the pair of fluid bearings 203, 205, and the thickness T generally does not change, a relative position between the machine 103 and the edge 105 of the material to be finished 101 can be adjusted until the first adjusted offset distance cb is generally equal to the second adjusted offset distance d 4 . Thus, a position of the removable sensing layer 213 can be sensed from only a single side, though various other measurements can also be taken. Still, depending upon the geometry of the various components of the machine 103, the relative adjustment can also be performed to various other specifications between the machine 103 and the material to be finished 101, such as where the abrasive tool 109 (or other tool, etc.) is not disposed generally centrally between the fluid bearings 203, 205.
[0066] The relative adjustment can be performed in various manners. In one example, the non-contact element 113 can adjust the relative position, such as while guiding the edge 105 of the material to be finished 101 through the machining area 107. For example, at least one of the fluid bearings 203, 205 can emit the fluid stream 403, 405 against the material to be finished 101 to adjust the relative position. The supportive force applied by each of the fluid streams 403, 405 can be individually adjusted in various manners to thereby place the edge 105 of the material to be finished 101 in alignment with the abrasive tool 109 (or other tool, etc.). The fluid streams 403, 405 can be individually adjusted in various manners, such as by adjusting the pressure, mass flow, volume flow, spray pattern, direction, and/or other characteristic(s). In another example, where the fluid bearings 203, 205 contain a plurality of fluid nozzles 207, 209 (see FIG. 4), the net fluid streams 403, 405 can be effectively adjusted by activating, deactivating, or adjusting at least one of the plurality of fluid nozzles 207, 209.
[0067] In addition or alternatively, either or both of the fluid bearings 203, 205 can be physically adjusted in various manners, such as displacement along at least one displacement axis (i.e., X, Y, Z axes) and/or angularly adjustment along at least one axis of rotation (i.e., yaw, pitch, roll). In addition or alternatively, any or all of the other machine elements, such as the abrasive tool 109, polishing tool 111, or the like, can also be physically adjusted in various manners, such as displacement along at least one displacement axis (i.e., X, Y, Z axes) and/or angularly adjustment along at least one axis of rotation (i.e., yaw, pitch, roll).
[0068] It is contemplated that the steps of sensing a position of the removable sensing layer 213, and thereafter adjusting a relative position of the machine 103 and the edge 105, can be performed in an iterative manner until a desired goal is achieved. For example, the steps of sensing and adjusting can be performed until the sensed position of the removable sensing layer 213 achieves a predetermined threshold, and/or a
predetermined range. In one example, the steps of sensing and adjusting can be performed until a sensed first offset distance di between one side face 301 of the material to be finished 101 achieves a predetermined threshold distance, and/or is within a predetermined range of distances (see FIG. 3). In another example, the steps of sensing and adjusting can be performed until first adjusted offset distance cb is generally equal to the second adjusted offset distance d 4 (see FIG. 5). The steps of sensing and adjusting can be performed in an iterative manner based upon a single sensor 211 sensing a single or even multiple positions of the removable sensing layer 213, or even based upon a plurality of sensors 601, 603, 605, 607 each sensing a single or even multiple positions of the removable sensing layer 213. In addition or alternatively, the steps of sensing and adjusting can be performed in an iterative manner based upon a comparison of at least two sensed positions, using either a single sensor 211 or a plurality of sensors 601, 603, 605, 607. In one example, the steps of sensing and adjusting can be performed in an iterative manner until a comparison of sensed positions between two of the plurality of sensors 601, 603 achieves a predetermined threshold, and/or a predetermined range.
[0069] Upon a desired adjustment, a method of machining the edge 105 of the material to be finished 101 can include the steps of machining the edge 105 of the material to be finished 101, and subsequently removing the sensing layer 213 from the material to be finished 101. Various post-processing steps may also be performed to clean the material to be finished 101 after removing the removable sensing layer 213. Thus, where the step of machining includes, for example, using an abrasive tool 109 to machine the edge 105 of the material to be finished 101 or using a polishing tool 111 to polishing the edge 105 of the material to be finished 101, and the step of adjusting can include adjusting the position of the abrasive tool 109 and/or the polishing tool 111 relative to the edge 105 of the material to be finished 101.
[0070] It is also contemplated that the steps of sensing a position of the removable sensing layer 213, and thereafter adjusting a relative position of the machine 103 and the edge 105, can be performed at least one time, such as a single time or a plurality of times. In one example, the step of adjusting can be performed once, such as on a test sample material to be finished 101 or even on a production material to be finished 101. A production run of various numbers of material to be finished 101 can then be machined. The step of adjusting can be repeated to check for accuracy after a predetermined number of units and/or predetermined amount of time, etc. In another example, the step of adjusting can be performed on each unit of material to be finished 101 to be machined. For example, the material to be finished 101 can have a first displacement during the initial grinding, and then a second displacement prior to stabilizing at a new equilibrium position during the main and/or final grinding. [0071] In addition or alternatively, the step of adjusting a relative position between the machine 103 and the edge 105 of the material to be finished 101 can be performed in a manual, semi-automatic, or even fully-automatic manner. In one example, adjustment of the machine 103 can be performed manually by adjusting one or more elements of the machine 103 based upon one or more sensed positions of the removable sensing layer 213. In another example, as shown in FIG. 6, adjustment of the machine 103 can be performed automatically in a single or even continuous manner. For example, a controller 609 can automatically adjust the relative position, such as based on a predetermined position and the sensed position of the ferromagnetic material 213. In another example, to allow for minor variations, the controller 609 can be configured to make no corrective adjustments unless the sensed position is beyond a predetermined threshold distance or beyond a predetermined range of distances. The controller 609 can be configured to be in wired or wireless communication to any number of elements, such as any or all of the abrasive tool 109, polishing tool 111, fluid bearings 203, 205, one or more sensors 211, 601, 603, 605, 607, etc.
[0072] The controller 609 can be configured to transmit and/or receive various types of information to or from any or all of the above-described elements, such as sensed position data, adjustment data, etc. For example, the controller 609 can receive sensed position data from one or more sensors 211, 601, 603, 605, 607, and can transmit adjustment data (i.e., adjustment commands) to any or all of the abrasive tool 109, polishing tool 111, fluid bearings 203, 205, etc. In another example, the controller 609 can receive reference position data from any or all of the movable and/or adjustable elements. The controller 609 can perform single or continuous, iterative, semi-automatic or fully automatic, sensing and adjusting of the machine 103. The controller 609 may even control movement of the material to be finished 101 thought the machine 103, such as via the rollers 115 and/or vacuum chuck 117, etc. For example, one or more sensors 211, 601, 603, 605, 607 can be used to determine when the material to be finished 101 has moved to a particular portion of the machine 103, such as entered or exited the machine 103.
[0073] The controller 609 can be an electronic controller and can include a processor. The controller 609 can include one or more of a microprocessor, a
microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or the like. The controller 609 can further include memory and can store program instructions that cause the controller 609 to provide the functionality ascribed to it herein. The memory can include one or more volatile, non-volatile, magnetic, optical, or electrical media, such as read-only memory (ROM), random access memory (RAM), electrically-erasable programmable ROM (EEPROM), flash memory, or the like. The controller 609 can further include one or more analog-to -digital (A/D) converters for processing various analog inputs to the controller. The controller 609 can also be integrated into an engine control unit (ECU). Signal conditioning and/or line isolation can be used to provide cleaner signal and reduce, such as eliminate, noise in the signal data. It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claimed invention.
[0074] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claimed invention.