JP2002060100A - Method of controlling electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feed mechanism of a continuous recording paper printer capable of achieving both a high quality and stable printing and a paper charging in the continuous recording paper printer of electrophotographie system having a tractor for continuous recording paper feeding disposed between a photosensitive drum and a fixing device and a feed roller disposed at the front of the photosensitive drum. SOLUTION: While a continuous recording paper is fed, the rotation of the feed roller is stopped, a paper sheet is prevented from being loosened merely by the resistance of the roller and, only when the paper sheet is fed and stopped, the roller is rotated so as to be pulled in the direction reverse to the feeding direction of the tractor for feeding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for controlling the paper feed of continuous recording paper in an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic apparatus will be described with reference to FIG.

A photosensitive portion on the surface of the photosensitive drum 1 is exposed to laser light to form a latent image on the surface. The toner is adhered to the latent image by the developing device 2 and developed. The transfer unit 3 transfers the image onto the continuous recording paper 5 sent by the transport tractor 4. Thereafter, the continuous recording paper 5 is sent to the fixing device 6 and fixed, passes through the fixing roller 7 and is sent out to the stacker 8 to finish printing.

The fixing device 6 of such an electrophotographic continuous recording paper printing apparatus generally includes a heat roll 9 heated to a high temperature and a backup roll 10 made of a heat-resistant elastic material such as silicon rubber. The heat roll 9 and the backup roll 10 are pressurized at a predetermined pressure. The recording paper 5 to which the toner has been transferred is sandwiched between the heat roll 9 and the backup roll 10 and fed, and the transferred toner is pressurized and heated and fused to be fixed.

The recording paper 5 is located between the photosensitive drum 1 and the fixing device 6.
Is disposed. Also,
A transport roller 11 is disposed upstream of the photosensitive drum 1 in the continuous recording paper transport direction.

The transport roller 11 rotates so as to pull the recording paper 5 in a direction opposite to the feeding direction with a certain tension so as not to loosen the recording paper 5 on the photosensitive drum 1 during printing. This is because if the recording paper 5 is loosened on the photosensitive drum 1, the recording paper 5 may be wound around the photosensitive drum, or the printing may be distorted, resulting in poor print quality.

Next, an outline of the operation during paper transport will be described with reference to FIG.

FIG. 3 is a time chart showing a conventional sheet feeding operation during sheet conveyance (during printing or sheet loading). The operation is valid when the signal is "1" or "-1",
“0” indicates that the operation is stopped. Also,
"Positive" when the rotation direction is the same as the paper feed direction during operation,
In the case of the rotation direction opposite to the paper feed direction, the polarity is described as “negative”. The recording paper 5 is set on the transport tractor 4. The transport tractor 4, the transport roller 11, and the fixing roller 7 start driving. The transport tractor 4 and the fixing roller 7 are
Starts to be sent to the stacker 8, and the transport roller 11 starts rotating in the opposite direction to the transport tractor 4 in order to prevent the paper from becoming slack as in the case of printing. The recording paper 5 is conveyed to the fixing device 6 and the fixing roller 7 rotating in the same direction as the transport tractor by the rotation of the transport tractor 4 and sent out to the stacker 8.

[0009]

The conventional paper feed mechanism has the following problems because the transport roller rotates in the opposite direction to the transport tractor during transport of the paper.

(1) Since the recording paper is fed by the transport tractor, fluctuations in the transporting force (paper tension) due to fluctuations in the rotation of the transport roller acting in the reverse direction cause blurring on the recording paper during transfer, causing print blur. Cause Further, the recording paper feed hole is torn, causing the tractor pin to come off.

(2) It is effective to increase the transporting force (paper tension) of the transporting roller due to the increase in the effect of the resistance force for preventing the photosensitive drum from becoming loose and preventing the paper from meandering. However, the perforation during loading of the paper makes the tractor pin more likely to come off.

An object of the present invention is to provide a paper feed mechanism which solves the above-mentioned problems and realizes both high-quality and stable recording paper printing and paper loading.

[0013]

According to the present invention, there are provided means for solving the above-mentioned problems: (1) The rotation of the transport roller is stopped during the transport of the paper, and the looseness of the paper is prevented only by the resistance of the roller. (2) Only when the paper transport is stopped, rotate the tractor to pull in the direction opposite to the feed direction.

[0014]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 is a time chart showing a sheet feeding operation during sheet conveyance showing an example of the operation of the present invention. When the signal is “1”, the operation is valid. When the signal is “0”, it indicates that the operation is stopped. In the case of the same rotation direction as the paper feed direction during operation, the polarity is described as “positive”.

The rotation of the transport tractor 4 and the fixing roller 7 is started so that the recording paper 5 is sent out to the stacker 8 from the signal of the paper loading start. The recording paper 5 while the paper is loaded is sent only by the tractor pins of the transport tractor 4 until the paper reaches the fixing roller 7. Therefore, when the paper tension of the transport roller 11 is strong, a feeding failure may occur. However, at the end of loading of the paper, the transport roller 11 stops after rotating for a predetermined time in the direction opposite to the transport tractor 4 in order to prevent the paper from becoming loose.

Next, in the sheet feeding operation during printing, the transport tractor 4 and the fixing roller 7 rotate so as to send the recording sheet 5 to the stacker 8. The transport roller 11 is stopped. The recording paper 5 on the photosensitive drum 1 during printing is not loosened by the feeding force of the transport tractor and the resistance of the transport roller 11. Therefore, the recording paper 5 to be transferred is not affected by the rotation fluctuation of the transport roller 11, and high-quality stable printing without print blurring can be performed. However, at the end of printing, transport roller 1
1 stops after rotating for a predetermined time in the direction opposite to the transport tractor 4 in order to prevent the paper from becoming loose.

[0018]

According to the present invention, the rotation of the transport roller is stopped during the transport of the paper, the slack of the paper is prevented only by the resistance of the roller, and the paper is pulled in the direction opposite to the feed direction of the tractor only when the transport of the paper is stopped. By rotating the feed roller, print fluctuations due to rotation fluctuations of the transport roller do not occur, slack in the photosensitive drum is prevented, and no special parts or mechanisms are added, and high quality stable printing and paper loading Can be achieved.

[Brief description of the drawings]

FIG. 1 is a time chart showing one embodiment of the present invention.

FIG. 2 is a schematic diagram of an electrophotographic apparatus for continuous recording paper printing.

FIG. 3 is a time chart showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 4 ... Transport tractor, 5 ... Recording paper, 7
... fixing roller, 11 ... transport roller.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H072 CA01 CA04 HA04 JA02 3F103 AA02 BA03 BA11 BE03 EA15

Claims (2)

[Claims] A photosensitive drum; a developing device for forming a toner image on the photosensitive drum; a transfer device for transferring the toner image on the photosensitive drum to continuous recording paper; and a fixing device for fixing the toner image on the continuous recording paper. And an electrophotographic apparatus having a transport tractor between the photosensitive drum and the fixing device, wherein a transport roller is provided upstream of the photosensitive drum in the continuous recording paper transport direction, and the transport roller is stopped during continuous recording paper transport. A method for controlling an electrophotographic apparatus, comprising: 2. The control method for an electrophotographic apparatus according to claim 1, wherein the transport roller is rotated in the direction opposite to the transport tractor only when the transport of the continuous recording paper is completed.