1. An optical glass comprises, denoted as weight percentages:
SiO2
>10%->22%
B2O3
3.0%-24%\u2009
ZnO
>8.0% and <30%
CaO + BaO + ZnO
10%-50%
MgO
0-3%
La2O3 + Y2O3 + Gd2O3 + Yb2O3
1.0-33%\u2009
TiO2
2.0-20%\u2009
ZrO2
\u20020-10%
Nb2O5
2.0-32%\u2009
Na2O
0-8%
K2O
\u20020-10%
WO3
2.0%-20%;\u2009
CaO
0-4.4%; and
ratio by weight of La2O3 to combined contents of La2O3, Y2O3, Gd2O3, and Yb2O3 (La2O3(La2O3+Y2O3+Gd2O3+Yb2O3)) falls within a range of 0.8 to 1,
wherein the optical glass contains no Pb and no Li2O, and
wherein the glass exhibits a refractive index (nd) in a range of 1.80 to 1.95 and an Abb\xe9 number (vd) in a range of 25 to 35.
2. An optical element comprised of the optical glass according to claim 1.
3. A method of manufacturing an optical element comprising molding a glass material comprised of the optical glass according to claim 1 in a heat-softened state.
4. The optical glass as claimed in claim 1, wherein the glass comprises BaO satisfying the weight range of BaOZnO<1.0.
5. An optical element comprised of the optical glass according to claim 4.
6. A method of manufacturing an optical element comprising molding a glass material comprised of the optical glass according to claim 4 in a heat-softened state.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An image forming apparatus wherein an image reading portion is provided in spaced relationship with a top surface of an image forming portion, the apparatus comprising:
a supporting column portion provided on the image forming portion and supporting the image reading portion in a cantilevered manner;
a tubular duct portion provided inside the supporting column portion with an axial direction being substantially a vertical direction;
an exhaust port provided at the supporting column portion for exhausting air from the duct portion; and
an intake port provided below the exhaust port for delivering air from inside the image forming portion to the duct portion,
wherein the supporting column portion comprises a supporting body having the duct portion, and wherein the supporting body is fixed to a top portion of a housing of the image forming portion.
2. The image forming apparatus according to claim 1, wherein the duct portion is made from a metal.
3. The image forming apparatus according to claim 1, wherein the exhaust portion is open toward the top direction.
4. The image forming apparatus according to claim 2, wherein the exhaust portion is open toward the top direction.
5. The image forming apparatus according to claim 4, wherein a projecting portion projecting from the image reading portion is inserted in an insertion portion provided in the supporting column portion.
6. The image forming apparatus according to claim 5, wherein the supporting column portion comprises a supporting body having the duct portion, and wherein the supporting body is fixed to a housing of the image forming portion.
7. The image forming apparatus according to claim 6, wherein the supporting body comprises:
a first supporting portion provided with the duct portion and fixed to a side surface of the housing for supporting the image reading portion; and
a second supporting portion extending from the first supporting portion in the same direction as the cantilevered manner supported image reading portion;
wherein a receiving portion for fixing the second supporting portion in place is provided on the side surface of the housing.
8. The image forming apparatus according to claim 7, wherein the receiving portion is a frame body fixed to and provided on the side surface of the housing, and wherein the second supporting portion is fixed to the frame body.
9. The image forming apparatus according to claim 3, wherein a projecting portion projecting from the image reading portion is inserted in an insertion portion provided in the supporting column portion.
10. The image forming apparatus according to claim 9, wherein the supporting column portion comprises a supporting body having the duct portion, and wherein the supporting body is fixed to a housing of the image forming portion.
11. The image forming apparatus according to claim 10, wherein the supporting body comprises:
a first supporting portion provided with the duct portion and fixed to a side surface of the housing for supporting the image reading portion; and
a second supporting portion extending from the first supporting portion in the same direction as the cantilevered manner supported image reading portion;
wherein a receiving portion for fixing the second supporting portion in place is provided on the side surface of the housing.
12. The image forming apparatus according to claim 11, wherein the receiving portion is a frame body fixed to and provided on the side surface of the housing, and wherein the second supporting portion is fixed to the frame body.
13. The image forming apparatus according to claim 1, wherein the intake port is provided in the vicinity of a heat source.
14. The image forming apparatus according to claim 13, wherein the heat source is an electric circuit board.
15. The image forming apparatus according to claim 13, wherein the heat source is a fixing device that causes toner image transferred to a recording medium to be fixed to the recording medium.
16. The image forming apparatus according to claim 15, wherein the supporting column portion is provided on one side of the image forming portion, and wherein the fixing device is located at an upper position on one side inside the image forming portion.
17. The image forming apparatus according to claim 1, wherein a projecting portion projecting from the image reading portion is inserted in an insertion portion provided in the supporting column portion.
18. The image forming apparatus according to claim 1, wherein the supporting body comprises:
a first supporting portion provided with the duct portion and fixed to a side surface of the housing for supporting the image reading portion; and
a second supporting portion extending from the first supporting portion in the same direction as the cantilevered manner supported image reading portion;
wherein a receiving portion for fixing the second supporting portion in place is provided on the side surface of the housing.
19. The image forming apparatus according to claim 18, wherein the receiving portion is a frame body fixed to and provided on the side surface of the housing, and wherein the second supporting portion is fixed to the frame body.
20. The image forming apparatus according to claim 1, wherein the supporting body comprises:
a first supporting portion provided with the duct portion and fixed to a side surface of the housing for supporting the image reading portion; and
a second supporting portion extending from the first supporting portion in the same direction as the cantilevered manner supported image reading portion;
wherein a receiving portion for fixing the second supporting portion in place is provided on the side surface of the housing.
21. The image forming apparatus according to claim 20, wherein the receiving portion is a frame body fixed to and provided on the side surface of the housing, and wherein the second supporting portion is fixed to the frame body.
22. The image forming apparatus according to claim 1, wherein the supporting column portion extends from the top of the image forming portion.
23. The image forming apparatus according to claim 1, wherein the image reading portion is hingedly connected to the supporting column portion.
24. The image forming apparatus according to claim 1, wherein the image reading portion, the image forming portion and the supporting column portion are fixed to one another.
25. The image forming apparatus according to claim 1, wherein a rectifying plate is structured in the supporting column, and the rectifying plate makes an upper space of the supporting column narrower than a lower space of the supporting column.
26. An image forming apparatus wherein an image reading portion is provided in spaced relationship with a top surface of an image forming portion, the apparatus comprising:
a supporting column portion provided on the image forming portion and supporting the image reading portion in a cantilevered manner;
a tubular duct portion provided inside the supporting column portion with an axial direction being substantially a vertical direction;
an exhaust port provided at the supporting column portion for exhausting air from the duct portion; and
an intake port provided below the exhaust port for delivering air from inside the image forming portion to the duct portion;
wherein the supporting column portion comprises a supporting body having the duct portion, and wherein the supporting body is fixed to a top portion of a housing of the image forming portion;
wherein the supporting body comprises:
a first supporting portion provided with the duct portion and fixed to a side surface of the housing, for supporting the image reading portion; and
a second supporting portion extending from the first supporting portion in the same direction as the cantilevered manner supported image reading portion;
wherein a receiving portion for fixing the second supporting portion in place is provided on the side surface of the housing; and
wherein the receiving portion is a frame body fixed to and provided on the side surface of the housing, and wherein the second supporting portion is fixed to the frame body.