1. An image forming apparatus, comprising:
a body;
a sheet conveyance path;
a first pair of rollers configured to rotate in a first direction to convey a sheet in a sheet conveyance direction through the sheet conveyance path by holding the sheet, the first pair of rollers configured to rotate in a second direction opposite to the first direction by a limited, predetermined rotation amount; and
a sub-unit configured to be released from the body and, during release, to cause a part of the sheet conveyance path in a vicinity of the first pair of rollers to open.
2. The image forming apparatus according to claim 1, wherein the first pair of rollers is configured to rotate in the second direction as the sub-unit is released from the body.
3. The image forming apparatus according to claim 1, wherein the sub-unit includes
a second pair of rollers configured to convey the sheet and configured to hold the sheet,
wherein, when the sheet is stopped in a position extending over the first and second pairs of rollers, releasing the sub-unit from the body allows the first pair of rollers to rotate in the second direction.
4. The image forming apparatus according to claim 1, wherein a distance in which the sheet is reversely conveyed when the first pair of rollers rotates in the second direction by the predetermined rotation amount is set to be smaller than a distance from the first pair of rollers to an image forming position located downstream of the first pair of rollers in the sheet conveyance direction.
5. The image forming apparatus according to claim 1, further comprising:
a one-way clutch attached to a shaft of one of the first pair of rollers;
a lever attached to the shaft of a first roller of the first pair of rollers through the one-way clutch, and configured to rotate between first and second positions to cause the first pair of rollers to rotate in the second direction with a limitation to the extent of the predetermined rotation amount, the lever being restricted in rotation in a forward direction when in the first position so as to restrict rotation of the first pair of rollers in the second direction;
a reverse rotation regulation member configured to contact the lever when the lever is in the second position so as to restrict rotation of the lever in a direction opposite to the forward direction.
6. The image forming apparatus according to claim 5, wherein a second roller of the first pair of rollers includes a shaft, and
wherein the lever is restricted in further rotation in a forward direction when in the first position by the shaft of the second roller of the first pair of rollers.
7. The image forming apparatus according to claim 5, wherein the first roller of the first pair of rollers includes a drive roller.
8. The image forming apparatus according to claim 5, wherein the first roller of the first pair of rollers includes rubber.
9. The image forming apparatus according to claim 5, wherein a rotation area of the lever ranging between the first and second positions is located above the first pair of rollers.
10. The image forming apparatus according to claim 5, further comprising a sign, disposed on or proximate to the lever, indicating that the lever is a member to be operated by a user while the user performs a jam clearance operation.
11. The image forming apparatus according to claim 1, wherein the sub-unit includes a duplex reverse unit configured to reverse a sheet from a first side to a second side so as to permit image forming on the second side after image forming is performed on the first side.
12. The image forming apparatus according to claim 3, wherein the sub-unit includes a duplex reverse unit configured to reverse a sheet from a first side to a second side so as to permit image forming on the second side after image forming is performed on the first side, and the second pair of rollers includes a sheet re-feeding roller.
13. The image forming apparatus according to claim 1, wherein the sub-unit includes a manual sheet feeding unit.
14. The image forming apparatus according to claim 3, wherein the sub-unit includes a manual sheet feeding unit, and the second pair of rollers includes a manual sheet feeding roller.
15. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to form images with an electronographic method.
16. The image forming apparatus according to claim 15, wherein the first pair of rollers includes a pair of registration rollers.
17. The image forming apparatus according to claim 15, further comprising:
a fixing unit configured to fix a toner image transferred onto a sheet and including
a fixing roller,
and a pressing roller in press-contact with the fixing roller, and
wherein the fixing roller is configured to be released from press-contact with the pressing roller when the sub-unit is released from the body.
18. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to form images with an ink jet method.
19. A sheet conveyance apparatus, comprising:
a sheet conveyance path; and
a pair of rollers configured to rotate in a sheet conveyance direction to convey a sheet in the sheet conveyance path by holding the sheet, and to reversely rotate in a direction opposite to the sheet conveyance direction,
wherein the reverse rotation of the pair of rollers is regulated so that the pair of rollers may reversely rotate only within a predetermined amount.
20. A sheet conveyance apparatus, comprising:
a sheet conveyance path;
a pair of rollers configured to convey a sheet in the sheet conveyance path by holding the sheet and rotating in a forward direction, and configured to reversely rotate in a direction opposite to the forward direction; and
means for manually rotating the pair of rollers in a forward direction, in increments, by no more than a predetermined amount in each increment; and
means for regulating an amount by which the pair of rollers may rotate in a reverse direction.
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. A process for regenerating a coked catalytic cracking catalyst, comprising contacting the coked catalytic cracking catalyst with an oxygen containing gas at a temperature of equal to or more than 550\xb0 C. in a regenerator to produce a regenerated catalytic cracking catalyst, heat and carbon dioxide, wherein the coked catalytic cracking catalyst comprises carbon-containing deposits, which carbon-containing deposits comprise 1 wt% to 25 wt% bio-carbon, based on the total weight of carbon present in the carbon-containing deposits,
wherein the coked catalytic cracking catalyst is produced by contacting a solid biomass material with a catalytic cracking catalyst at a temperature of more than 400\xb0 C. in a catalytic cracking reactor.
2. The process of claim 1 wherein the oxygen- containing gas comprises more than 21 vol. % oxygen, based on the total volume of the oxygen-containing gas.
3. The process of claim 1 wherein the coked catalytic cracking catalyst is produced by contacting the biomass material and a fluid hydrocarbon feed with a catalytic cracking catalyst at a temperature of equal to or more than 400\xb0 C. in a catalytic cracking reactor, wherein the catalytic cracking reactor is a riser reactor and the biomass material is supplied to the riser reactor upstream of the fluid hydrocarbon feed.
4. The process of claim 3 wherein the biomass material is a solid biomass material.
5. The process of claim 1 wherein the coked catalytic cracking catalyst is contacted with the oxygen containing gas in the regenerator at a temperature of equal to or more than 700\xb0 C.
6. The process of claim 1 wherein part of the produced heat is subsequently used to heat water andor generate pressurized steam.