Method of making a mirror substrate for an interior rearview mirror assembly for a vehicle

• US 9,481,303 B2
• Filed: 03/09/2015
• Issued: 11/01/2016
• Est. Priority Date: 04/23/2009
• Status: Active Grant

• Current Assignee: Magna Mirrors of America Incorporated (Magna International Incorporated)
• Original Assignee: Magna Mirrors of America Incorporated (Magna International Incorporated)
• Inventors: De Wind, Darryl P., Baur, Michael J., Perkins, Timothy G.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US14/641,813
• Publication Number:
  US 20150175074A1
• Time in Patent Office: 603 Days
• Field of Search: 359/245, 359/265, 359/267, 359/838, 451/5, 451/44, 451/119, 451/177
• US Class Current: 1/1
• CPC Class Codes: B24B 13/00 Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor edging optical work, e.g. lenses, prisms B24B9/14
• CPC Class Codes: B24B 49/00 Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation B24B33/06, B24B37/005 take precedence; if applicable to other machine tools, B23Q15/00 - B23Q17/00 take precedence
• CPC Class Codes: B24B 51/00 Arrangements for automatic control of a series of individual steps in grinding a workpiece if applicable to other machine tools, G05B takes precedence
• CPC Class Codes: B24B 9/02 characterised by a special design with respect to properties of materials specific to articles to be ground
• CPC Class Codes: B24B 9/08 of glass
• CPC Class Codes: B60R 1/04 mounted inside vehicle B60R1/025, B60R1/08 take precedence
• CPC Class Codes: B60R 1/086 using a mirror angularly movable between a position of use and a non-glare position reflecting a dark field to the user, e.g. situated behind a transparent glass used as low-reflecting surface; Wedge-shaped mirrors
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 1/1207 with lamps; with turn indicators
• CPC Class Codes: C03C 17/06 with metals C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 2217/25 Metals
• CPC Class Codes: C03C 2218/31 Pre-treatment
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: G02B 7/182 for mirrors
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells

Abstract

A method of making a mirror substrate for an interior rearview mirror assembly for a vehicle includes providing a glass substrate having a generally planar front surface, a generally planar rear surface and a circumferential perimeter edge about a periphery of said glass substrate and extending between the front and rear surfaces. A grinding wheel is moved around the periphery of a front perimeter portion of the glass substrate while rotating the grinding wheel to establish a ground generally rounded surface about and around the glass substrate periphery. A polishing wheel is moved around the glass substrate periphery while rotating the polishing wheel to establish a polished generally rounded surface about and around the glass substrate periphery. The polished generally rounded surface provides a smooth transition between the generally planar front surface of the glass substrate and a rear portion of the circumferential perimeter edge of the glass substrate.

Claims

1. A method of making a mirror substrate for an interior rearview mirror assembly for a vehicle, said method comprising:

providing a glass substrate having a generally planar front surface, a generally planar rear surface and a circumferential perimeter edge about a periphery of said glass substrate and extending between said front and rear surfaces, wherein said front surface and said perimeter edge meet at a front perimeter portion of said glass substrate that circumscribes said glass substrate;

aligning and fixturing said glass substrate at a fixture to support and position said glass substrate;

providing a grinding wheel that is rotatable about a grinding wheel axis;

providing a polishing wheel that is rotatable about a polishing wheel axis;

presenting said grinding wheel to said front perimeter portion of said glass substrate;

grinding said front perimeter portion of said glass substrate by moving said grinding wheel around the periphery of said front perimeter portion of said glass substrate while rotating said grinding wheel about said grinding wheel axis to establish a ground generally rounded surface about and around the periphery of said glass substrate; and

after grinding said front perimeter portion of said glass substrate to establish said ground generally rounded surface, presenting said polishing wheel to said ground generally rounded surface and polishing said ground generally rounded surface by moving said polishing wheel around the periphery of said glass substrate while rotating said polishing wheel about said polishing wheel axis to establish a polished generally rounded surface about and around the periphery of said glass substrate,

wherein said polished generally rounded surface provides a smooth transition between said generally planar front surface of said glass substrate and a rear portion of said circumferential perimeter edge of said glass substrate.

2. The method of claim 1, wherein at least one of said grinding wheel and said polishing wheel is attached to a movable head that is movable under computer control around the periphery of said glass substrate.

3. The method of claim 2, wherein said computer control comprises computer numerical control.

4. The method of claim 2, wherein said movable head is robotically controlled.

5. The method of claim 2, wherein said grinding wheel axis is presented to said front perimeter portion of said glass substrate at about a 90 degree angle relative to said generally planar front surface of said glass substrate.

6. The method of claim 2, wherein said polishing wheel axis is presented to said ground generally rounded surface at about a 90 degree angle relative to said generally planar front surface of said glass substrate.

7. The method of claim 2, wherein at least one of (i) said grinding wheel is pivotable to adjust said grinding wheel axis relative to said generally planar front surface of said glass substrate and (ii) said polishing wheel is pivotable to adjust said polishing wheel axis relative to said generally planar front surface of said glass substrate.

8. The method of claim 1, wherein said polished generally rounded surface has a radius of curvature of at least about 2.5 mm.

9. The method of claim 1, further comprising:

providing a rear grinding wheel that is rotatable about a rear grinding wheel axis;

presenting said rear grinding wheel to a rear perimeter portion of said glass substrate; and

grinding said rear perimeter portion of said glass substrate by moving said rear grinding wheel around the periphery of said glass substrate while rotating said rear grinding wheel about said rear grinding wheel axis to establish a rounded rear perimeter portion about and around the periphery of said glass substrate.

10. The method of claim 1, wherein said generally planar front surface is angled relative to said generally planar rear surface forming a prismatic glass substrate, said method further comprising coating said rear surface of said glass substrate with a mirror reflector to make a mirror substrate for a prismatic interior rearview mirror assembly.

11. The method of claim 1, wherein said generally planar front surface is generally parallel to said generally planar rear surface, said method further comprising coating said rear surface of said glass substrate with a transparent electrically conductive coating to make a mirror substrate for an electro-optic interior rearview mirror assembly.

12. The method of claim 1, wherein said glass substrate has a length dimension and a width dimension and wherein said length dimension is larger than said width dimension, and wherein said glass substrate has a non-rectangular shape.

13. A method of making a mirror substrate for an interior rearview mirror assembly for a vehicle, said method comprising:

providing a glass substrate having a generally planar front surface, a generally planar rear surface and a circumferential perimeter edge about a periphery of said glass substrate and extending between said front and rear surfaces, wherein said front surface and said perimeter edge meet at a front perimeter portion of said glass substrate that circumscribes said glass substrate;

aligning and fixturing said glass substrate at a fixture to support and position said glass substrate;

providing a grinding wheel that is rotatable about a grinding wheel axis;

providing a polishing wheel that is rotatable about a polishing wheel axis;

wherein at least one of said grinding wheel and said polishing wheel is attached to a movable head that is movable under computer control around the periphery of said glass substrate;

presenting said grinding wheel to said front perimeter portion of said glass substrate;

grinding said front perimeter portion of said glass substrate by moving said grinding wheel around the periphery of said front perimeter portion of said glass substrate while rotating said grinding wheel about said grinding wheel axis to establish a ground generally rounded surface about and around the periphery of said glass substrate; and

after grinding said front perimeter portion of said glass substrate to establish said ground generally rounded surface, presenting said polishing wheel to said ground generally rounded surface and polishing said ground generally rounded surface by moving said polishing wheel around the periphery of said glass substrate while rotating said polishing wheel about said polishing wheel axis to establish a polished generally rounded surface about and around the periphery of said glass substrate,

wherein said polished generally rounded surface has a radius of curvature of at least about 2.5 mm.

14. The method of claim 13, wherein at least one of (i) said grinding wheel is pivotable to adjust said grinding wheel axis relative to said generally planar front surface of said glass substrate and (ii) said polishing wheel is pivotable to adjust said polishing wheel axis relative to said generally planar front surface of said glass substrate.

15. The method of claim 13, wherein said generally planar front surface is angled relative to said generally planar rear surface forming a prismatic glass substrate, said method comprising coating said rear surface of said glass substrate with a mirror reflector to make a mirror substrate for a prismatic interior rearview mirror assembly.

16. The method of claim 13, wherein said generally planar front surface is generally parallel to said generally planar rear surface, said method further comprising coating said rear surface of said glass substrate with a transparent electrically conductive coating to make a mirror substrate for an electro-optic interior rearview mirror assembly.

17. A method of making a mirror substrate for an interior rearview mirror assembly for a vehicle, said method comprising:

providing a glass substrate having a generally planar front surface, a generally planar rear surface and a circumferential perimeter edge about a periphery of said glass substrate and extending between said front and rear surfaces, wherein said front surface and said perimeter edge meet at a front perimeter portion of said glass substrate that circumscribes said glass substrate;

aligning and fixturing said glass substrate at a fixture to support and position said glass substrate;

providing a grinding wheel that is rotatable about a grinding wheel axis;

providing a polishing wheel that is rotatable about a polishing wheel axis;

presenting said grinding wheel to said front perimeter portion of said glass substrate;

grinding said front perimeter portion of said glass substrate by moving said grinding wheel around the periphery of said front perimeter portion of said glass substrate while rotating said grinding wheel about said grinding wheel axis to establish a ground generally rounded surface about and around the periphery of said glass substrate; and

after grinding said front perimeter portion of said glass substrate to establish said ground generally rounded surface, presenting said polishing wheel to said ground generally rounded surface and polishing said ground generally rounded surface by moving said polishing wheel around the periphery of said glass substrate while rotating said polishing wheel about said polishing wheel axis to establish a polished generally rounded surface about and around the periphery of said glass substrate,

wherein at least one of (i) moving said grinding wheel is at least one of computer numerically controlled and robotically controlled and (ii) moving said polishing wheel is at least one of computer numerically controlled and robotically controlled, and

wherein said polished generally rounded surface has a radius of curvature of at least about 2.5 mm.

18. The method of claim 17, wherein said grinding wheel axis is presented to said front perimeter portion of said glass substrate at about a 90 degree angle relative to said generally planar front surface of said glass substrate, and wherein said polishing wheel axis is presented to said ground generally rounded surface at about a 90 degree angle relative to said generally planar front surface of said glass substrate.

19. The method of claim 17, wherein at least one of (i) said grinding wheel is pivotable to adjust said grinding wheel axis relative to said generally planar front surface of said glass substrate and (ii) said polishing wheel is pivotable to adjust said polishing wheel axis relative to said generally planar front surface of said glass substrate.

20. The method of claim 17, further comprising:

providing a rear grinding wheel that is rotatable about a rear grinding wheel axis;

presenting said rear grinding wheel to a rear perimeter portion of said glass substrate; and

grinding said rear perimeter portion of said glass substrate by moving said rear grinding wheel around the periphery of said glass substrate while rotating said rear grinding wheel about said rear grinding wheel axis to establish a rounded rear perimeter portion about and around the periphery of said glass substrate.