close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2406580

код для вставки
Patented Aug. 27, 1946
2,406,580
‘UNITED STATES PATENT OFFICE
2,406,580
OPTICAL GLASSES
Raymond Edward Bastick, Wilfred Marsh Hamp
ton, and Ta-Hang Wang, Smethwick, Birming
ham, England, assignors to Chance Brothers
Limited, Smethwick, Birmingham, England
"No Drawing. Application January 2, 1945, Serial
No. 571,106. In Great Britain November 11,
1943
8 Claims.
(Cl. 106—53)
1
2
This-invention relates to optical glasses and
particularly glasses required for photographic
lenses.
The invention comprises glasses having the
following essential constituents and within the
range of proportions speci?ed, namely:
claim as new and desire to secure by Letters
Patent is:
1. Optical glasses having the following essen
tial constituents and within the range of pro
portions speci?ed, namely:
Per cent
Per cent
Silica (S102) _________________________ __. 10-25
Barium oxide (BaO) _________________ __ 15-35
10
Boronvoxide (B203) ___________________ __ 10-30
Lanthanum oxide (LazOz) _____________ __ 8-20
Thorium oxide (T1102) ________________ __ 3-15
Zinc oxide (ZnO) ____________________ __
.Silica (S102) _________________________ __ 10-25
Barium oxide (BaO) __________________ __ 15-3'5
Boron oxide (B203) ___________________ __ 10-30
Lanthanum oxide (LazOs) _____________ __ 8-20
Thorium oxide (T1102) ________________ __ 3-15
Zinc oxide (ZnO) __________ __-_ ________ __
2- 8
the amounts of lanthanum and thorium oxides 15
together being not more than 35% of the total
2- 8
the amounts of lanthanum and thorium oxides
together being not more than 35% of the total
glass composition.
2. Optical glasses as claimed in claim 1 and
glass composition.
containing also lead oxide, provided that the
There may also be added lead oxide, and/or
amount of barium oxide together with the zinc
other oxides of the alkaline earths, provided
and lead oxides do not exceed 45% of the total
that the amount of barium and other alkaline 20 glass composition.
earth oxides together with the zinc and lead
3. Optical glasses as claimed in claim 1 and
oxides do not exceed 45% of the total glass com
containing also other oxides of the alkaline
position.
earths, provided that the amount of barium
Further we may add oxides of zirconium,»
oxide and other alkaline earths together with
and/or aluminium and/or beryllium to min 25 the zinc oxide do not exceed 45% of the total
imise the tendency of the glass to crystallisation,
glass composition.
the amounts of such constituents being indicated
4. Optical glasses as claimed in claim 1 and
by the following examples.
containing also lead oxide,_ and other oxides of
The refractive index nd, and .Abbé constant 12,
the alkaline earths, provided that the amount of
of glasses embodying the present invention satisfy 30 barium oxide and other alkaline earths together
the relationship:
with the zinc and lead oxides do not exceed 45%
of the total glass composition.
nd>1.746-0.0021v, where v has a value lying
5. Optical glasses as claimed in claim 1 and
between 47 and 60.
containing also at least one of the oxides of
The following table gives particulars of typical
zirconium, aluminium, and beryllium for the
purpose speci?ed.
6. An optical glass having the following com
position: 15.0% of SiOz, 31.3% of BaO, 15.4% of
B203, 11.3% of ThOz, 13.0% of LazOs, 2.5% of
40 ZnO, 9.0% of PbO, 2.5% of ZrOz, and having a
glasses made in accordancewith the invention:
Constituents
A
Per cent
B
C
Per cent .Per cent
D
Per cent
‘ E
Per cent
15. 0
31. 3
15. 4
11.3
13. 0
10. 3
24. 2
21. 8
13. 4
17. 3
20. 0
36.0
24. 0
3. 5
14. 0
14.
22. 0
25. 0
12. 0
17. 0
2. 5
9.0
2. 5
5. 0
g 3. 0
6. 0
2. 0
4. 0
'
0.5
3. 0
........ .
1 645
8
1. 654
57. 1
1.709
50. 8
of 47.7.
.
7. An optical glass having the following com
position: 10.3% of S102, 24.2% of BaO, 21.8% of
45 B203,v 13.4% of 11102, 17.3% of LazOs, 5.0% of
ZnO, 3.0% of PhD, 5.0% of ZrOz, and having a
4. 0
2. 1
~
1.717
47. 7
- refractive index of 1.717 and an Abbé constant
10. 3
26. 9
24. 8
13. 5
18. 4
refractive index of 1.709 and an Abbé constant
3.0
1.691
54. 8
of 50.8.
‘
8. An optical glass having the following com
50 position: 20.0% of SiOz, 36.0% of BaO, 24.0% of
In the manufacture of glasses in accordance
B203, 3.5% of Th02, 14.0% of La203, 2.0% Of
with the invention it is important that the con
ZnO, 0.5% of A1203, and having a refractive index
stituents should be melted in crucibles made from
of 1.645'and an Abbé constant of 58.8.
, a material which is inert’ to any of the constitu
ents, platinum crucibles being preferable. .
' RAYMOND EDWARD BAS'I'ICK.
55
Having thus described our invention whatwe _
WILFRED MARSH HAMPTON.
TA-HANG WANG.
‘
Документ
Категория
Без категории
Просмотров
0
Размер файла
132 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа