JPH02184474A - Sheet feeder for electrophotographic printer - Google Patents

Abstract

PURPOSE:To simplify the constitution of a printer and to prevent a sheet feed roller from being contaminated with unfixed toner by providing jam discriminating means for discriminating jam of a sheet on the basis of output signals from first and second sensors for detecting toner marks, and means for inhibiting the skipping operation of the sheet feed roller on the basis of the output signal from the second sensor. CONSTITUTION:When a controller 6 receives an output signal from a first reflection type photosensor 2, it starts counting of the number of pulses of a sheet feed stepping motor 7. If a continuous sheet 1 is normally fed, a second reflection type photosensor 3 can detect corresponding toner mark until the count reaches predetermined number of discrimination pulses. If the detection signal of the corresponding toner mark is not fed, the controller 6 outputs a sheet jam signal. When the controller 6 inputs the output signal of the second reflection type photosensor 3, the controller 6 outputs a skip operation inhibit signal. Thus, the skipping operation of the sheet is inhibited. Accordingly, unfixed printing part is not fed to sheet feed rollers 4, 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a paper feeding device for an electrophotographic printer using continuous paper, and in particular, to a paper feeding device for an electrophotographic printer that uses continuous paper, and in particular, for a printer that uses flash fixing, a paper feeding device that feeds an unfixed portion of the paper to a paper feeding roller. The present invention relates to a paper feeding device that is characterized by a paper jam detection function and a paper jam detection function.

[Conventional technology] Conventionally, continuous paper jam detection methods include the following.

That is, there are a method of detecting insufficient tension of the paper, a method of detecting rotational fluctuation of the paper feed roller, and a method of sensing the paper feed hole and detecting the fluctuation of the sensing pulse.

By the way, the non-printing part of continuous paper, that is, the blank part,
When the continuous paper reaches the transfer area of the electrophotographic printer, the paper feeding device can quickly feed the continuous paper and move it to the next printing position. Such an operation is called a skip operation. In conventional paper feeding devices, this skip operation can be performed freely.

[Problems to be Solved by the Invention] Since the above-described conventional paper feeding device can perform a skip operation freely, continuous paper can be rapidly fed when a blank portion of paper comes to the transfer area. However, in the fixing area, unfixed portions of the transferred toner may still remain. If a skip operation is performed in such a case, the unfixed portion of the paper will be sent to the paper feed [1-ra] behind the fixing area.

This will not only result in the fixing not being completed, but also the paper feed roller will get dirty. As a result, there are disadvantages in that the paper gets dirty and the tension of the paper changes.

Then, when there was a blank part in the fixing area (this problem can be solved by enabling the block skip operation.
If the means for detecting the presence of blank paper in the fixing area is also used to detect paper jams, it can also be used as a detection means.
It is very convenient.

Therefore, an object of the present invention is to enable the C-pskip operation when there is a blank portion in a fixed area, and to provide an electrophotographic method in which the blank portion detecting means can also be used as a paper jam detecting means. The purpose of the present invention is to provide a paper feeding device for a printer.

1. Means for Solving the Problems] In order to achieve the above object, the paper feeding device of the electrophotographic printer according to the present invention has the following features: a first sensor for detecting toner marks on continuous paper; and a second sensor installed behind the first sensor and in front of the paper feed roller to detect and cover the toner marks. based on the sensor, the output signal of the first sensor, and the output signal of the second sensor,
a jam determining means for determining whether a paper is jammed by determining the paper passage time from the first sensor to the second sensor and comparing this with a predetermined determination time; and the second sensor. and means for inhibiting the skipping operation of the paper pick-up roller based on the output signal of the paper.

In the above configuration, the term "front" means the upstream side in the paper feeding direction, and the term "rear" means the downstream side in the paper feeding direction.

[Operation] When continuous paper is printed, toner marks are printed on one edge of the continuous paper.Therefore, there are no 1 to toner marks on the blank area of the continuous paper. The gutter mark is detected by the first sensor and the second sensor.Based on the output signals from both sensors, the paper elapsed time between the two sensors is calculated.This time is the predetermined judgment time. If it is longer than , it is determined that there is a paper jam.

Furthermore, when a toner mark is detected by the second sensor located in front of the paper feed roller, the continuous paper skip operation is prohibited. This prevents the unfixed portion from being sent to the paper feed roller.

[Example] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of one embodiment of the present invention, and FIG. 2 is a perspective view of the fixing area. Only the part of the paper feeding device that is used is depicted.

That is, components such as the photoreceptor, exposure section, transfer section, etc. are omitted. In FIG. 1, the continuous paper 1 is fed near the transfer area by a tractor unit driven by a paper feed stepping motor 7, and behind the fixing area 9 by a pair of paper feed rollers 4, 5. , in this example,
Fixing of the dove is performed by fludge fixing, or the light emitting part is not shown. Behind the transfer area, a first reflector 47f<1 to 2 is installed for detecting toner marks on the continuous paper 10. Further, a second reciprocating type bottom sensor 3 is installed immediately before the paper feed rollers 4 and 5 to detect and cover toner smear on the continuous paper 1. The outputs of these two photosensors 2 and 3 are input to a control device 6 for paper feeding.

As best shown in FIG. 2, the toner mask 8 is printed on one edge of the continuous paper 1. This part is not used during normal printing.

This toner mark 8 is used to detect and cover the fetus (printing), and is printed on the continuous paper 1 at predetermined intervals.

In this embodiment, the toner marker 8 for detecting print density is
is used for inhibiting skip operations and detecting paper jams.

Next, the operation of this embodiment will be explained. In Figure 1,
The first non-conforming bottle sensor 2 detects the toner mark on the top j. This toner mark is also detected by the second non-conforming photosensor 3 as the continuous paper 1 is fed. When the control device 6 receives the output signal from the first non-conforming photosensor 2, it starts counting the number of pulses of the paper feed stepping motor 7. If the feeding of the continuous paper is performed normally, the second foul type bobbin sensor 3 will also detect the corresponding toner mark by the time the predetermined number of determination pulses is reached. This means that the continuous paper 1 has passed between the two sensors 1 within the predetermined determination time. Even if the predetermined number of pulses is
议謬 type elementary school 1-t? When the detection signal of the corresponding J~PUMER is not received from the sensor 3, the control device 6 (J
, outputs a paper error signal.

In addition, the skip operation prohibition control is performed as follows.

When the output horn signals of the second foul-type holes 1 to 3 are input to the control device 6, the control device 6 controls the printer control device (
As shown in the figure, the skip operation prohibition 114'28 is covered by IH power. Due to this, the paper skipping operation is prohibited.

, -bb, if the skip operation is in progress, the operation command at ', will be invalidated 1. Therefore, the continuous paper 1 in the defined area 9 will be fast-forwarded toward the paper feed [-touches 4 and 5]. It's fleeting. Therefore, undetermined printed portions are not fed to the paper feed rollers 4 and 5.

[Effects of the Invention] The present invention described above has the advantage that the paper passage [1
. Therefore, the sensor 1 can be used both for detecting a paper jam and for inhibiting the 4-horn operation, which simplifies the device configuration.

In addition, due to the skip operation prohibition control, the paper feed roller is covered with an unfixed toner (C to prevent it from getting dirty).

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the second embodiment of the present invention, and Fig. 2 is a perspective view of the fixed area of the support near (q). 1... Continuous paper 2... First violation Type Ho 1 ~ Sen 1 J 3... Second waste Q = I type i] Tsukasa ~ Senri 4.5...
Paper feed [Nidora 6... Control device 8... Toner mark 9... Joseki area patent applicant 11 Denki Co., Ltd. [1 Denki Data Equipment Co., Ltd. attorney attorney] Internal use Susumu continuous paper 4. 5 Paper feed roller fixing area

Claims (1)

[Claims] A paper feeding device for an electrophotographic printer that uses continuous paper includes a paper feeding roller installed behind a fixing area, and a first roller installed in front of the fixing area for detecting toner marks on the continuous paper. a second sensor installed behind the first sensor and in front of the paper feed roller to detect the toner mark; an output signal of the first sensor; a paper passing time from the first sensor to the second sensor based on the output signal of the second sensor, and compares this with a predetermined determination time to determine a paper jam; A paper feeding device comprising: a determination unit; and a unit for inhibiting a skip operation of the paper feeding roller based on an output signal of the second sensor.