US 12,263,555 B2
Glass article and method of producing glass article
Toru Momose, Tokyo (JP); Osamu Sato, Shizuoka (JP); Hirofumi Yamamoto, Shizuoka (JP); and Nobuhiko Takeshita, Tokyo (JP)
Assigned to AGC INC., Tokyo (JP)
Filed by AGC Inc., Tokyo (JP)
Filed on Mar. 26, 2024, as Appl. No. 18/616,813.
Application 18/616,813 is a continuation of application No. 17/969,012, filed on Oct. 19, 2022, granted, now 11,969,857.
Application 17/969,012 is a continuation of application No. PCT/JP2021/007736, filed on Mar. 1, 2021.
Claims priority of application No. 2020-076645 (JP), filed on Apr. 23, 2020.
Prior Publication US 2024/0227117 A1, Jul. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B24B 37/08 (2012.01); B24B 37/28 (2012.01)
CPC B24B 37/08 (2013.01) [B24B 37/28 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method of producing a glass article comprising:
holding a carrier having a circular shape, in which a glass substrate having a circular shape is retained, with an upper surface plate and a lower surface plate; and
polishing the glass substrate by rotating the carrier with respect to the upper surface plate and the lower surface plate, to obtain the glass article, wherein:
the glass substrate is disposed in the carrier such that, in a top plan view,
a center Oc of the carrier is included in a region of the glass substrate, and
a center Og of the glass substrate is shifted from the center Oc of the carrier,
wherein the glass article comprises a first surface having a circular shape wherein:
a radius R of the glass article is within a range of from 50 mm to 150 mm inclusive,
when, in the glass article, to is a thickness at the center Og, a first end is one end portion, t1 is a thickness at the first end, tx′ is a thickness at any position X, except the first end and the center Og, between the first end and the center Og, and
a thickness is measured from a first-surface side of the glass article by an optical interferometry type thickness measurement method, conditions of
0.1 mm<to<2 mm  expression (1),
1<to/t1≤1.1  expression (2),
to>tx′>t1  expression (3), and
txn≥(to−t1)×(n/5)+t1  expression (4)
are satisfied, where n is any integer from 1 to 5, and txn represents a thickness at a position Xn of R×(n/5) from the first end toward the center Og, and wherein
when a second end is an end portion opposite to the first end with respect to the center Og, t2 is a thickness at the second end, tx” is a thickness at any position W, except the second end and the center Og, between the second end and the center Og, and
a thickness is measured from a first-surface side of the glass article by the optical interferometry type thickness measurement method, conditions of
1<to/t2≤1.1  expression (5),
to>tx″>t2  expression (6), and
twn≥(to−t2)×(n/5)+t2  expression (7)
are satisfied, where n is any integer from 1 to 5, and twn represents a thickness at a position Wn of R×(n/5) from the second end toward the center Og,
wherein:
the glass article has a thickness that monotonically decreases from the center Og toward each of the end portions,
the glass article comprises glass having a refractive index of 1.6 or more, and
the glass article comprises glass having a surface roughness of 0.5 nm or less.