JPS5949579B2 - Copy machine sheet conveyance system drive mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet conveyance system drive mechanism for a copying machine in which a photoreceptor and a sheet conveyance system are driven using the same power source.

There are two types of photoreceptors: edged photoreceptors and endless photoreceptors.

For edged photoreceptors, the image must be formed at a predetermined location on the photoreceptor so that the image is not formed at the edges. On the other hand, the sheet conveyance system operates from the paper feeding position to the transfer position, and from the transfer position until the end of the sheet passes the paper ejection position.
Must be driven continuously. By the way, the sum of the length from the paper feed position to the paper discharge position and the length of the sheet used (hereinafter referred to as the sheet conveyance length).

) is equal to the maximum effective image length of the edged photoreceptor or matches a length divided by an integer (hereinafter referred to as image length),
Since the image formation timing and the conveyance timing can be synchronized, the photoreceptor and the sheet conveyance system can be continuously driven at the same time using the same power source without forming an image at the edge. However, while the length of sheets used varies, the conveyance length of the paper is set to convey the maximum sheet, and when conveying short sheets with this device, the conveyance timing and Due to the relationship with the image forming timing, it is necessary to temporarily stop the photoreceptor and drive only the sheet conveyance system.

In order to make this type of drive possible, conventionally the photoreceptor and the sheet conveyance system were driven separately by providing a clutch device on the same power source or using separate power sources. Ta. However, this method has the disadvantage of complicating the structure of the copying machine. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sheet conveyance system drive in which a photoconductor and a sheet conveyance system are driven using the same power source, and the sheet conveyance system is driven by a simple device even after the photoconductor has stopped. The goal is to provide a mechanism.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention. The first gear 2 coaxially fixed to the photoreceptor drum 1 is
It meshes with the small diameter second gear 3. The second gear 3 is coaxially fixed to a separation roller 5 for separating the sheet 4 from the photoreceptor surface after transfer. The separation roller 5 is also provided with a large-diameter third gear 6 coaxially and rotatably engaged with a small-diameter fourth gear 7 provided separately. And in this fourth gear 7,
A flywheel 8 is fixed coaxially. The sheet conveyance system includes a paper feed roller 9, a separation roller 5, a fixing roller 10, and a paper discharge roller 11.

These are controlled identically via chain 12. FIG. 2 is a schematic plan view of FIG. 1.

Reference numeral 1 indicates a photosensitive drum, 2 is a first gear, 3 is a second gear, 5 is a separation roller, 6 is a third gear, 7 is a fourth gear, 8 is a flywheel, 10 is a fixing roller, 11 is the paper ejection roller. These are supported by a side plate 13 of the copying machine. Reference numeral 14 indicates a sheet feeding belt that is stretched between the fixing roller 10 and the guide roller 10a. The second gear 3 is fixed to the shaft 5a of the separation roller 5, while the third gear 6 is rotatably attached to the shaft 5a via a bearing. Also, axis 5
A chain wheel 16 incorporating a one-way clutch 15 is fixed to a, and the chain wheel 16 and the third gear 6 are connected by a torsion spring 17. Fixing roller-10
A chain wheel is also provided on each of the paper discharge rollers 11, and a chain 12 is passed between each chain wheel and a chain wheel provided on a paper feed roller (not shown). The one-way clutch 15 is set so that the separation roller shaft 5a is driven by the photoreceptor drum 1, and the separation roller shaft 5a is not driven by the flywheel 8. Ru.

That is, when the photosensitive drum 1 is moved by a power source (not shown), the separation roller shaft 5a is driven via the first gear 2 and the second gear 3, and accordingly, the separation roller
5 and chain wheel 16 are driven. When the chain wheel 16 is driven, the third gear 6 connected by the torsion spring 17 is driven, and then the fourth gear 7 and the flywheel 8 are driven. Then, the fixing roller is connected via the chain 12.
10, the paper ejection roller 11, etc. are driven. On the other hand, when the photosensitive drum 1 receives a signal and stops, the separation roller shaft 5
a also stops. At this time, the kinetic energy stored in the flywheel 8 continues to rotate the flywheel 8 due to the action of the one-way clutch 15, and is transferred to the chain wheel 16 via the fourth gear 7, the third gear 6, and the torsion spring 17. to drive. In this way, even after the photoreceptor has stopped, the fixing roller remains
10, a sheet conveyance system such as a paper discharge roller 11 is driven. The time for driving the sheet conveyance system after the photoconductor stops is determined by the relationship between the photoconductor image length and the sheet conveyance length, but in order to secure this time, a flywheel with an appropriate second moment of inertia is selected. It will be done. Generally, this time is not very long, so a small flywheel can be used and there is no need to make the device large. The means for storing kinetic energy can also be a spring instead of a flywheel.

As the spring, a mainspring spring or a coil spring is used, but in this case, the return action of the spring is utilized, so a corresponding design change is required. As described above, according to the present invention, in a copying machine in which the photoconductor and sheet conveyance system are driven using the same power source, a kinetic energy storage member is provided in the photoconductor drive system, and this member is connected to the sheet conveyance system. ,
Since the sheet conveyance system is driven by this stored energy even after the photoreceptor is stopped, the structure is extremely simple and the sheet can be conveyed efficiently.

The present invention can also be applied to a copying machine that uses an endless photoreceptor and also functions as a developing device and a residual toner cleaning device.

In other words, in such a copying machine, residual toner in non-image areas cannot be sufficiently cleaned.
Image formation is performed at a predetermined position on the photoreceptor so that an image is not formed on this portion or so that an image is always formed avoiding this portion. Therefore, this part can be regarded as the same as the end of an edged photoreceptor, so
This invention based on this premise can be applied and similar effects can be obtained. Further, the photoreceptor according to the present invention is not necessarily drum-shaped, and the present invention is similarly applicable to a belt-shaped photoreceptor.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a schematic plan view of FIG. 1 above. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 2... First gear, 3... Second gear, 4... Sheet, 5
...Separation roller, 6...Third gear,
7... Fourth gear, 8... Flywheel, 9... Paper feed roller, 10... Fixing roller, 11... Paper ejection roller, 12...
・Chain, 13... Copy machine side plate, 14...
... Sheet conveyance belt, 15 ... One-way clutch, 16 ... Chain wheel, 17 ... Torsion spring.

Claims (1)

[Claims] 1. In a transfer type electrophotographic copying machine in which a sheet conveyance system is rotationally driven using the same power source as a power source that rotationally drives a photoconductor, the photoconductor is connected between the photoconductor drive member and the sheet conveyance drive system. A flywheel is provided via a one-way clutch that allows power from the body to be transmitted to the sheet conveyance system but not in the opposite direction, and stores energy in this flywheel while the photoreceptor is rotating. A sheet conveyance system drive mechanism for a copying machine, wherein after the sheet conveyance drive system is stopped, the sheet conveyance drive system is continuously driven by the accumulated energy.