Title:
OPTICAL GLASS, PREFORM, AND OPTICAL ELEMENT
Document Type and Number:
WIPO Patent Application WO/2018/066577
Kind Code:
A1
Abstract:
Provided is an optical glass which has optical properties including a high refractive index and high dispersibility, and can contribute to the correction of the influence of the change in temperature on image formation properties.
The optical glass contains, in % by mass, a B2O3 component in an amount of more than 0% and equal to or less than 35.0%, a Ln2O3 component (wherein Ln represents at least one element selected from the group consisting of La, Gd, Y and Yb) in a total amount of 1.0 to 50.0% inclusive, and a BaO component in an amount of 10.0 to 50.0% inclusive, wherein the total mass of TiO2 + ZrO2 + WO3 + Nb2O5 + Ta2O5 is more than 0% and equal to or less than 50.0%. The optical glass has a refractive index of 1.75 or more and an Abbe's number of 18 to 42 inclusive, wherein the temperature coefficient (40 to 60ºC) of a relative refractive index (589.29 nm) falls within the range from +4.0 × 10-6 to -10.0 × 10-6 (ºC-1).
Inventors:
OGINO MICHIKO (JP)
Application Number:
PCT/JP2017/036033
Publication Date:
April 12, 2018
Filing Date:
October 03, 2017
Export Citation:
Assignee:
OHARA KK (JP)
International Classes:
C03C3/068; C03C3/15; G02B1/00
Domestic Patent References:
| WO2011065097A1 | 2011-06-03 |
Foreign References:
| JP2011153048A | 2011-08-11 | |||
| JP2004175632A | 2004-06-24 | |||
| JP2007022846A | 2007-02-01 | |||
| US20140287906A1 | 2014-09-25 | |||
| JPS58125637A | 1983-07-26 | |||
| JPS5950048A | 1984-03-22 | |||
| JPH05262533A | 1993-10-12 | |||
| JP2007153734A | 2007-06-21 | |||
| JP2000128568A | 2000-05-09 | |||
| JP2005179142A | 2005-07-07 | |||
| JP2006225220A | 2006-08-31 | |||
| JPS6042245A | 1985-03-06 | |||
| JP2012229135A | 2012-11-22 |
Other References:
See also references of EP 3521251A4
Attorney, Agent or Firm:
SHOBAYASHI Masayuki et al. (JP)
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