Thin sheet mirror and Nd2O3 doped glass

• US 20020155301A1
• Filed: 12/13/2001
• Published: 10/24/2002
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Stewart, Ronald L.
• Granted Patent: US 6,881,489 B2
• Time in Patent Office: Days
• US Class Current: 428/433
• CPC Class Codes: C03C 3/095 containing rare earths
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

A reflecting mirror comprising a sheet of an alkali metal-zinc-borosilicate glass bonded to a reflecting surface, the glass sheet having a thickness less than 0.5 mm, and being doped with Nd₂O₃ in an amount sufficient to substantially reduce the spectral transmission of the glass in the wavelength range of 565-595 nm.

Claims

1. A reflecting mirror comprising a sheet of an alkali metal-zinc-borosilicate glass bonded to a reflecting surface, the glass sheet having a thickness less than 0.5 mm, and being doped with Nd₂O₃ in an amount sufficient to substantially reduce the spectral transmission of the glass in the wavelength range of 565-595 nm.

2. A reflecting mirror in accordance with claim 1 wherein the glass sheet has a thickness of 0.3 to 0.4 nm.

3. A reflecting mirror in accordance with claim 1 wherein the transmitted radiation at a wavelength of 585 nm is less than 50%.

4. A reflecting mirror in accordance with claim 3 wherein the transmitted radiation at 585 nm is less than 30%.

5. A reflecting mirror in accordance with claim 1 wherein the glass is doped with at least 5% Nd₂O₃ by weight.

6. A reflecting mirror in accordance with claim 1 wherein the reflecting surface is a silver coating on the back of the glass sheet.

7. A thin sheet of alkali metal-zinc-borosilicate glass containing sufficient Nd₂O₃ to reduce the transmission of radiation at a wavelength of 585 nm to a value less than 50%.

8. A glass sheet in accordance with claim 7 in which the content of Nd₂O₃ is at least 5% by weight.

9. A glass sheet in accordance with claim 7 wherein the sheet has a thickness less than 0.5 mm.

10. A glass sheet in accordance with claim 7 wherein the glass has a liquidus viscosity of at least 20,000 poises and a softening point temperature in the range of 700-750°

C.

11. A glass sheet in accordance with claim 7 wherein the glass has a composition, expressed in weight percent on an oxide basis, consisting essentially of the following oxides within the indicated ranges: