JPS6135592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a jam detection device, and more particularly to a jam detection device for detecting a jam in a sheet-like object being conveyed, and more particularly to a jam detection device with an improved conveyance mechanism.

FIG. 1 is a diagram schematically showing an example of an electrophotographic apparatus to which a jam detection apparatus of the present invention is applied, which forms the background of the present invention.

In the structure, a photosensitive drum 2 is provided in front of an image support member, which is an example of a sheet-like object, or a recording paper (hereinafter referred to as recording paper) 1 in a conveyance direction, facing the recording paper 1 . The photosensitive drum 2 forms an electrostatic latent image on the surface of the recording paper 1 passing through it. A heating fixing device 3 is provided behind the photosensitive drum 2 in the conveying direction of the recording paper 1, which heats and fixes the recording paper 1 on which an electrostatic latent image has been formed. The heat fixing device 3 includes a heating resistor 3a, a heat transfer section 3b that transmits the heat of the heating resistor 3a to the recording paper 1, and an infrared lamp 3.
c and a reflecting plate 3d surrounding the infrared lamp 3c. The heat transfer section 3b and the reflection plate 3d are provided facing each other in the conveying direction of the recording paper 1. An entrance side detector 4 for detecting the presence or absence of the recording paper 1 is provided on the entrance side of the heating fixing device 3 in the conveying direction of the recording paper 1 .
As the entrance side detector 4, a photoelectric detector including a light emitting element 41 and a light receiving element 42 is used. Entrance side detector 4
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When detecting the presence of the recording paper 1, it gives a start signal to the transit time control device 5. This passage time control device 5 is set to a predetermined constant time (a time longer than the time it takes for the recording paper 1 to be conveyed from the entrance side detector 4 to the exit side detector 7, which will be described later), and is set to a start signal. It starts operating when a reset signal is applied, and stops operating when a reset signal is applied. The transit time control device 5 detects a jam on the way from the entrance side detector 4 to the exit side detector 7 when a reset signal is not applied within a certain period of time after the start signal is applied.

A conveyance mechanism 6, which will be described in detail in FIG. 2, is provided behind the heat fixing device 3 in the direction in which the recording paper 1 is conveyed. At the rear of the conveyance mechanism 6 in the conveyance direction of the recording paper 1,
Exit side detector 7 for detecting the presence or absence of recording paper 1
will be provided. As the exit side detector 7, a photoelectric detector including a light emitting element 71 and a light receiving element 72 is used like the aforementioned entrance side detector 4.

FIG. 2 is a sectional view taken along the line - in FIG. 1, and is a diagram for explaining the transport mechanism 6 in more detail.

In the configuration, the conveyance mechanism 6 includes a driving roller section 61.
and a driven roller section 62. Drive roller part 61
is configured to include a drive rotation shaft 611 and a plurality of drive rollers 612 fitted to the drive rotation shaft 611 at a certain interval. Both ends of the drive rotation shaft 611 are supported by bearings 613, and a pulley 614 is fitted to one end thereof. A belt 8 for transmitting rotational force is hung on the pulley 614. The belt 8 is further placed around a motor pulley 10 fitted onto the rotating shaft of a motor 9. When the motor 9 rotates, its rotational force is transmitted to the drive rotation shaft 611 via the belt 8. The driven roller section 62 is provided facing the drive roller section 61 so as to wind the recording paper 1 therein. The driven roller section 62 includes a driven rotation shaft 621 and a driven roller 622 that is fitted onto the driven rotation shaft 621 so as to be in contact with the drive roller 612.
including. A weight 623 is fitted to the driven rotating shaft 621 at each interval between the driven rollers 622 . As a result, the driven roller 622 comes into stronger contact with the driving roller 612. Both ends of the driven rotating shaft 621 are supported by bearings 624, and a rotation detecting means 11 for detecting the rotation of the driven roller 622 is provided at one end. The rotation detecting means 11 includes a photoelectric detector 111 and a disc-shaped object 112 having a through hole, and the center hole of the disc-shaped object 112 is fitted onto a driven rotation shaft 621, so that the disc-shaped object 112 rotates as the driven rotating shaft 621 rotates. The light emitting element included in the photoelectric detector 111 is
The positions of concentrically drilled through holes in the disc-shaped object 112 are irradiated. Therefore, the driven rotating shaft 621
When the disc-shaped object 112 is rotating normally, light from the light-emitting element passes through the through hole of the disc-shaped object 112 at regular intervals. The light receiving element included in the photoelectric detector 111 is
By receiving the light that has passed through the through hole, a signal with a constant period (for example, a pulse signal) is derived and provided to the rotation control device 12.

On the other hand, when the driven rotation shaft 621 is not rotating, the light receiving element of the photoelectric detector 111 provides a continuous high level signal or a low level signal to the rotation control device 12. In response, the rotation control device 12 derives an abnormal signal (jam occurrence signal).

Next, the operation of detecting a jam using the conventional jam detection device will be described with reference to FIGS. 1 and 2.

In the electrophotographic apparatus shown in FIG. 1, two types of jam detection are performed when detecting a jam. That is, there is a case in which the recording paper 1 is conveyed to the exit side detector 7, and a case in which the recording paper 1 is conveyed to the exit side detector 7.
This is the case after the vehicle has been transported to

First, a case where a jam occurs before the recording paper 1 is conveyed to the exit side detector 7 will be described. When the recording paper 1 formed into an electrostatic latent image on the photosensitive drum 2 passes through the entrance side detector 4, the entrance side detector 4 detects the presence of the recording paper 1. The entrance side detector 4 gives a start signal to the transit time control device 5. In response, the transit time control device 5 starts operating.

When the recording paper 1 is not conveyed to the exit side detector 7, that is, when a jam occurs on the way to the exit side detector 7, the exit side detector 7 does not detect the presence of the recording paper 1, and the passage time control device No reset signal is given to 5. Therefore, the transit time control device 5 continues to operate after receiving the signal from the entrance side detector 4. Then, when a predetermined period of time has elapsed, the passage time control device 5
A generated signal is derived to deactivate the electrophotographic device.

Next, a case will be described in which a jam occurs after the recording paper 1 is conveyed to the exit side detector 7.
In this case, since the recording paper 1 has been conveyed to the exit side detector 7, the recording paper 1 is stopped within the conveyance mechanism 6. When the recording paper 1 is stopped, the driven roller 622 is stopped and the driven rotation shaft 621 is not rotated. Therefore, the disc-shaped object 112 also stops, and the photoelectric detector 111 provides a continuous signal or a low-level signal to the rotation control device 12. In response, the rotation control device 12 derives a jam occurrence signal.

As mentioned above, the conventional jam detection device requires two types of detection devices for two types of detection operations, namely the transit time control device 5 and the rotation control device 12, which increases the number of parts and makes the device difficult to operate. The problem was that it was expensive.

Furthermore, as shown in FIG. 3, if the width of the recording paper 1 is smaller than the width of the conveyance path, the drive roller 61
A part of the recording paper 2 directly contacts the driven roller 622, and the other part contacts the recording paper 1. This creates a subtle difference between the rotational force that acts directly from the drive roller 612 to the driven roller 622 and the rotational force that acts from the drive roller 612 to the driven roller 622 via the recording paper 1. Due to this difference in rotational force, uneven rotational force is transmitted to the recording paper 1, causing the recording paper 1 to meander.

Therefore, the main object of the present invention is to provide a jam detection device that requires fewer parts and is inexpensive.

In summary, this invention consists of a drive roller that rotates together with the drive rotation shaft at a certain distance from the drive rotation shaft, an inner ring that rotates together with the drive circuit shaft, and an outer ring that does not rotate together with the drive circuit shaft. A bearing is fitted, and the bearing is fitted to a driven rotating shaft opposite to the driving rotating shaft in contact with the driving roller, and a driven roller is in contact with the bearing of the driving rotating shaft and rotates together with the driven rotating shaft. The jam is detected by fitting the sheet-like object so that the driven rotating shaft rotates only when the sheet-like object is being conveyed.

Other objects and features of the present invention will become more apparent from the detailed description given below with reference to the drawings.

FIG. 4 is a sectional view of a conveyance mechanism 6' according to an embodiment of the present invention.

In the configuration, the conveyance mechanism 6' includes a driving roller section 6.
1' and a driven roller portion 62'. The drive roller portion 61' includes a drive rotation shaft 611, a plurality of drive rollers 612 fitted to the drive rotation shaft 611 at certain intervals, an inner ring fitted to the drive rotation shaft 611, and an outer ring equipped with, for example, a ball bearing. A bearing 615 configured to be inserted is fitted. The driven roller section 62' is provided opposite the drive roller section 61' so as to wind the recording paper 1 therein. A bearing 625 having the same structure as the aforementioned bearing 615 is fitted into the driven roller portion 62' so as to face and abut the driving roller 612. A driven roller 622 is fitted onto the driven rotating shaft 621 so as to face and abut the bearing 615.
Since the drive roller section 61' and the driven roller section 62' are configured as described above, the drive rotation shaft 61'
1 rotates, the driven rotating shaft 621 does not rotate. This conveyance mechanism 6' is provided in place of the conveyance mechanism 6 shown in FIG. 1, and also functions as the exit side detector 7.

The rest of the structure is the same as that in FIG. 2, so the same parts are given the same reference numerals and detailed explanation thereof will be omitted.

The operation of detecting a jam using the jam detecting device of the present invention will be described below with reference to FIGS. 1 and 4.

First, the case until the recording paper 1 is conveyed to the exit side detector 7 will be described. The recording paper 1, which has been formed into an electrostatic latent image on the photosensitive drum 2, is transferred to the entrance side detector 4.
When the recording paper 1 passes through, the entrance side detector 4 detects the presence of the recording paper 1 and sends a start signal to the passage time control device 5.
give to The transit time control device 5 starts its operation in response to the start signal.

When the recording paper 1 reaches the transport mechanism 6', it is wound between the drive roller 612 and bearing 615 and the driven roller 622 and bearing 625 of the transport mechanism 6', and is transported. As the recording paper 1 is conveyed, the rotational force of the drive roller 612 is transmitted to the driven roller 622. In response, the driven rotating shaft 621 rotates, causing the disc-shaped object 112 to rotate. As a result, the photoelectric detector 111 receives the reset signal at
to the control device 5. As a result, the transit time control device 5 stops its operation. Therefore, the transit time control device 5 does not derive a jam occurrence signal.
Further, since the driven roller 14 rotates normally, the rotation control device 8 is given a normal signal, and therefore does not derive a jam occurrence signal.

However, if a jam occurs before the recording paper 1 reaches the transport mechanism 6', the driven rotation shaft 621 will not rotate even if the drive rotation shaft 611 rotates. That is, since the disk-shaped object 112 does not rotate, the photoelectric detector 111 does not give a reset signal to the transit time control device 5, and the transit time control device 5 continues to operate and derives a jam generation signal at a certain fixed time. do.

Next, the case after the recording paper 1 reaches the transport mechanism 6' will be described.

When the recording paper 1 is normally transported by the transport mechanism 6', the rotational force of the drive roller 612 is transmitted to the recording paper 1, and the driven roller 622 comes into contact with the recording paper 1.
rotates due to frictional force. In response, the driven rotating shaft 621 rotates, causing the disc-shaped object 112 to rotate. Accordingly, since a constant signal is provided from the photoelectric detector 111 to the rotation control device 12, the rotation control device 12 does not derive a jam generation signal.

However, if a jam occurs before the leading edge of the recording paper 1 reaches the transport mechanism 6' and the rear end of the recording paper 1 has not finished passing the transport mechanism 6', even if the drive rotation shaft 611 rotates, , recording paper 1 is stopped. Therefore, the bearings 615 and 625 idle, and the driven roller 622 slips and does not rotate. Therefore, the driven rotating shaft 621 does not rotate, and the disc-shaped object 112 does not rotate. At this time,
No pulse signal is derived from the light receiving element of the photoelectric detector 111, and therefore a high level or low level signal is given to the rotation control device 12.
In response, rotation control device 12 derives a jam occurrence signal.

By configuring the driven roller 622 to rotate only when the recording paper 1 passes as described above, there is an advantage that the rotation detection means 11 can play the role of the exit side detector 7.

In addition, the driving rotation shaft 611 and the driven rotation shaft 621
By combining rollers and bearings, the rotational force applied to the recording paper 1 can be made uniform, as shown in FIG. That is, even when conveying a narrow recording paper 1 along the conveyance path, when the drive rotation shaft 611 rotates, the drive roller 612
Since only the drive roller 612 rotates, the force acting on the recording paper 1 from the drive roller 612 becomes uniform, which has the advantage of preventing the recording paper 1 from meandering.

Although the above-described embodiments have been described with reference to an electrophotographic apparatus, it goes without saying that the technical idea of the present invention can be applied to various other apparatuses as long as they convey sheet-like objects.

As described above, according to the present invention, since the rotation detecting means also serves as the exit side detector, the number of parts can be reduced and the product can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an example of an electrophotographic apparatus to which a jam detection apparatus of the present invention is applied, which forms the background of the present invention. FIG. 2 is a sectional view taken along the line - in FIG. 1, and is a diagram for explaining the transport mechanism 6 in more detail. FIG. 3 is a diagram showing the rotational force exerted by the drive roller 612 on the recording paper 1 and the driven roller 622 in the conventional conveyance mechanism 6. FIG. 4 is a sectional view of a conveyance mechanism 6' showing an embodiment of the present invention. FIG. 5 is a diagram showing the rotational force exerted by the drive roller 612 on the recording paper 1 and the bearing 625 in the conveyance mechanism 6' of the present invention. In the figure, 1 is the recording paper, 4 is the entrance side detector,
5 is a passage time control device, 6' is a conveyance mechanism, 61' is a drive roller section, 62' is a driven roller section, 611 is a drive rotation shaft, 612 is a drive roller, 621 is a driven rotation shaft, 622 is a driven roller, 7 11 is an exit side detector, 11 is a rotation detection means, 111 is a photoelectric detector,
Reference numeral 112 indicates a disc-shaped object, and 12 indicates a rotation control device. 〓〓〓〓〓

Claims (1)

[Scope of Claims] 1. A device for detecting a jam in a sheet-like object in an apparatus including a transport mechanism for transporting a sheet-like object, wherein the sheet-like object has arrived at a position where a jam is to be detected. The conveyance mechanism includes a sheet-like object detection means for detecting a drive roller, and a first bearing means whose circumferential portion does not rotate due to rotation of the drive roller and the drive shaft at certain intervals in the axial direction of the drive shaft. Put it on,
A second bearing means is installed at a position facing the drive roller in the axial direction of the driven shaft, which is provided opposite to the drive shaft, and whose circumferential portion does not rotate due to rotation of the driven shaft. A driven roller is mounted at a position facing the first bearing means, and further includes a rotation detection means for detecting a rotation state of the driven shaft, and an output of the sheet-like object detection means and an output of the rotation detection means. A jam detection device comprising a discriminating means for discriminating a jam in a sheet-like object based on the jam. 2. The jam detection device according to claim 1, wherein the driven shaft of the transport mechanism is rotationally driven only during a period when the sheet-like object is being transported. 3. The jam detection device according to claim 1, wherein the rotation detection means is a photoelectric detection means that optically detects the rotation state of the driven shaft. 4. The rotation detection means includes a disk connected to the driven shaft and having a plurality of through holes formed on the same circumference, and a photoelectric detection means for optically detecting the through holes formed in the disk. A jam detection device according to claim 1, comprising: