IMAGE FORMING APPARATUS CAPABLE OF FORMING IMAGES ON BOTH FACES OF RECORDING MEDIA

• US 20130049294A1
• Filed: 08/14/2012
• Published: 02/28/2013
• Est. Priority Date: 08/22/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: TAKANO, Kuniyori
• Granted Patent: US 8,870,183 B2
• Time in Patent Office: Days
• US Class Current: 271/225
• CPC Class Codes: B41J 13/08 Conveyor bands or like feeding devices
• CPC Class Codes: B41J 3/60 for printing on both faces of the printing material
• CPC Class Codes: B65H 2220/01 indicating an entity as a function of which control, adjustment or change is performed, i.e. input
• CPC Class Codes: B65H 2220/02 indicating an entity which is controlled, adjusted or changed by a control process, i.e. output
• CPC Class Codes: B65H 2220/11 indicating that the input or output entities exclusively relate to machine elements
• CPC Class Codes: B65H 2301/33312 forward reverse rollers pairs
• CPC Class Codes: B65H 2301/4474 Pair of cooperating moving elements as rollers, belts forming nip into which material is transported
• CPC Class Codes: B65H 2404/1115 toothed roller
• CPC Class Codes: B65H 2513/512 Starting; Stopping
• CPC Class Codes: B65H 2513/52 Age; Duration; Life time or chronology of event
• CPC Class Codes: B65H 5/021 by belts
• CPC Class Codes: B65H 5/062 between rollers or balls
• CPC Class Codes: B65H 7/00 Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
• CPC Class Codes: B65H 85/00 Recirculating articles, i.e. feeding each article to, and delivering it from, the same machine work-station more than once
• CPC Class Codes: B65H 9/006 the stop being formed by forwarding means in stand-by
• CPC Class Codes: G03G 15/6511 Feeding devices for picking up or separation of copy sheets
• CPC Class Codes: G03G 15/6564 with correct timing of sheet feeding
• CPC Class Codes: Y10S 271/902 Reverse direction of sheet movement

Abstract

An image forming apparatus includes a plurality of rotary members, a conveyance belt, an image forming device, and a switchback device. The conveyance belt is looped around the plurality of rotary members so as to circulate to intermittently feed a sheet in a sheet transport direction. The image forming device is disposed opposing the conveyance belt to form an image on the sheet fed by the conveyance belt. The switchback device is disposed downstream from the image forming device in the sheet transport direction to feed the sheet having passed the image forming device to a position downstream from the conveyance belt in the sheet transport direction and switch back the sheet. When the sheet is fed by the conveyance belt and the switchback device, a drive start timing of the switchback device is delayed from a drive start timing of the conveyance belt.

Claims

1. An image forming apparatus comprising:

a plurality of rotary members;

a conveyance belt looped around the plurality of rotary members so as o circulate to intermittently feed a sheet in a sheet transport direction;

an image forming device disposed opposing the conveyance belt to form an image on the sheet fed by the conveyance belt; and

a switchback device disposed downstream from the image forming device in the sheet transport direction to feed the sheet having passed the image forming device to a position downstream from the conveyance belt in the sheet transport direction and switch back the sheet,

wherein, when the sheet is fed by the conveyance belt and the switchback device, a drive start timing of the switchback device is delayed from a drive start timing of the conveyance belt.

3. The image forming apparatus of claim 1, wherein the drive start timing of the switchback device is delayed from an acceleration period in starting driving of the conveyance belt.

5. The image forming apparatus of claim 1, further comprising a transport passage disposed between the conveyance belt and the switchback device, the transport passage having a sheet bending portion to allow bending of the sheet.

6. The image forming apparatus of claim 1, wherein driving speed of the conveyance belt is equal to driving speed of the switchback device.

7. The image forming apparatus of claim 1, wherein, during image formation of the image forming device, the switchback device feeds the sheet.

8. The image forming apparatus of claim 1, wherein, when the sheet is fed by the conveyance belt and the switchback device, a drive stop timing of the switchback device is same as a driving stop timing of the conveyance belt.

9. The image forming apparatus of claim 1, wherein, when the sheet is fed by the conveyance belt and the switchback device, a drive stop timing of the switchback device is during driving of the conveyance belt.

2. The image forming apparatus of claim I, wherein the drive start timing of the switchback device is set to be within an acceleration period in starting driving of the conveyance belt.

4. The image forming apparatus of claim I, wherein a driving time of the switchback device is less than a driving time of the conveyance belt.

10. An image forming apparatus comprising:

a first rotary member to intermittently feed a sheet in a sheet transport direction;

a second rotary member disposed downstream from the first rotary member to receive the sheet fed by the first rotary member and feed the sheet downstream from the second rotary member in the sheet transport direction;

a support member disposed between the first rotary member and the second rotary member to support the sheet;

an image forming device disposed opposing the support member to form an image on the sheet fed by the first rotary member; and

a switchback device disposed downstream from the second rotary member in the sheet transport direction to feed the sheet having passed the image forming device to a position downstream from the second rotary member in the sheet transport direction and switch hack the sheet,

wherein, when the sheet is fed by the second rotary member and the switchback device, a drive start timing of the switchback device is delayed from a drive start timing of the second rotary member.

11. The image forming apparatus of claim 10, wherein, during image formation of the image forming device, the switchback device feeds the sheet.

12. The image forming apparatus of claim 10, wherein, when the sheet is fed by the second rotary member and the switchback device, a drive stop timing of the switchback device is same as a driving stop timing of the second rotary member.

13. The image forming apparatus of claim 10, wherein, when the sheet is fed by the second rotary member and the switchback device, a drive stop timing of the switchback device is during driving of the second rotary member.