Belt unit, transfer unit and image formation apparatus
View Patent ↗A belt unit includes rolls being rotatably supported and a belt to be conveyed by the rolls. In a dynamic viscoelasticity test with conditions of tensile load set in a frequency range of 0.01 to 100 [Hz], the belt unit satisfies 1≦G 10 /G 70 ≦3.1, and L 70 ≧10 [MPa]. A storage elastic modulus of the belt at a temperature of 10[° C.] is indicated by G 10 . A storage elastic modulus of the belt at a temperature of 70[° C.] is indicated by G 70 . A loss elastic modulus of the belt at a temperature of 70[° C.] is indicated by L 70 .
1. A belt unit comprising:
rolls being rotatably supported; and
a belt to be conveyed by the rolls,
wherein
in a dynamic viscoelasticity test with conditions of tensile load set in a frequency range of 0.01 to 100 Hz,
the belt unit satisfies
1 ≦G 10 /G 70 ≦3.1 and
L 70 ≧10[MPa]
where a storage elastic modulus of the belt at a temperature of 10° C. is indicated by G 10 , a storage elastic modulus of the belt at a temperature of 70° C. is indicated by G 70 , and a loss elastic modulus of the belt at a temperature of 70° C. is indicated by L 70 .
2. The belt unit according to claim 1 , wherein
the belt unit satisfies
G 10 ≧100 [MPa] and
G 70 ≧100 [MPa].
3. The belt unit according to claim 2 , wherein
the belt unit satisfies
G 10 ≧1000 [MPa] and
G 70 ≧1000 [MPa].
4. The belt unit according to claim 1 , wherein
the belt unit satisfies
L 70 ≧100 [MPa].
5. The belt unit according to claim 1 , wherein
the belt has a first surface facing the rolls and a second surface opposite to the first surface, and
the belt satisfies
5.5[GPa]≦Y≦10[GPa] and
50≦M≦100,
where an indentation Young's modulus on the second surface of the belt is indicated by Y and a specularity of the second surface of the belt is indicated by M.
6. The belt unit according to claim 5 , wherein
the belt satisfies
7.0[GPa]≦Y≦10[GPa] and
70≦M≦100.
7. The belt unit according to claim 1 , wherein
at least one of the rolls is a drive roll rotated by receiving a rotational drive force.
8. The belt unit according to claim 1 , wherein
the belt has a first surface facing the rolls and a second surface opposite to the first surface,
the belt unit further comprising:
a cleaning member in contact with the second surface of the belt.
9. The belt unit according to claim 8 , wherein
the cleaning member includes a blade unit in contact with the second surface of the belt.
10. A transfer unit comprising:
the belt unit according to claim 1 wherein the belt has a first surface facing the rolls and a second surface opposite to the first surface; and
a first transfer unit disposed facing the first surface and configured to transfer a developer image from an image carrier facing the second surface onto a recording medium disposed on the second surface of the belt or onto the second surface of the belt.
11. The transfer unit according to claim 10 , wherein
the belt is an endless belt that is disposed with an inner peripheral surface of the endless belt being in contact with the rolls, and is to be conveyed by the rolls,
the first surface is the inner peripheral surface of the belt, and
the second surface is an outer peripheral surface of the belt.
12. A transfer unit comprising:
the belt unit according to claim 1 wherein the belt has a first surface facing the rolls and a second surface opposite to the first surface;
a first transfer unit disposed facing the first surface and configured to transfer a developer image from an image carrier facing the second surface onto the second surface of the belt; and
a second transfer unit disposed facing the second surface and configured to transfer a developer image from the second surface onto a recording medium conveyed between the second surface and the second transfer unit.
13. The transfer unit according to claim 12 , wherein
the belt is an endless belt, disposed with an inner peripheral surface of the endless belt being in contact with the rolls, and configured to be conveyed by the rolls,
the first surface is the inner peripheral surface of the belt, and
the second surface is an outer peripheral surface of the belt.
14. An image formation apparatus comprising:
the transfer unit according to claim 10 ; and
an image formation unit having the image carrier.
15. The image formation apparatus according to claim 14 , further comprising:
a medium storage unit that stores the recording medium.
16. An image formation apparatus comprising:
the transfer unit according to claim 12 ; and
an image formation unit having the image carrier.
17. The image formation apparatus according to claim 16 , further comprising:
a medium storage unit that stores the recording medium.
18. The belt unit according to claim 1 , wherein
1800 [MPa]≦G 10 ≦9500 [MPa]
1200 [MPa]≦G 70 ≦5500 [MPa] and
100 [MPa]≦L 70 ≦800 [MPa].
19. The belt unit according to claim 18 , wherein
1 ≦G 10 /G 70 ≦3.1.
20. An image formation apparatus, comprising:
the belt unit according to claim 19 , and
an image carrier provided facing a belt surface of the belt unit.