JPH06183606A - Sheet conveyance device - Google Patents

Abstract

PURPOSE:To stop the conveyance of recording paper at the same time when jam occurs so as to facilitate removal of it from a conveyance passage by providing a detection member which detects conveyance speed of recording paper directly and stopping the conveyance of recording paper immediately when the least abnormality occurs to conveyance speed. CONSTITUTION:In an image forming device, recording paper P is conveyed in synchronization so that image formed in an image carrier 1 and recording paper match. At this time, one end fringe of recording paper P is sandwiched between rotary members 75, 76 provided on shafts 71, 72 of a pair of second paper supply rollers 7A and conveyed, and the rotary members 75, 76 rotate in accordance with the conveyance amount of the recording paper P. Either of linear marks 77, 78 provided in each rotary member 75, 76 is detected by a detection member S2, and the conveyance speed is obtained in CPU from the detected output. When the conveyance amount is changed, a change occurs in the rotary members 75, 76, and signal of the detection member S2 is changed, it is judged that abnormal rotation occurs, all the electromagnetic clutches C1 to C5 are turned off, and the conveyance means is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A sheet feeding device sequentially feeds and conveys sheets, and a device for printing and image forming on the sheets. When a sheet is defectively conveyed, the conveying means is immediately stopped. The present invention relates to a conveyance detection unit.

[0002]

2. Description of the Related Art Conventionally, in a printing apparatus and an image forming apparatus, in order to perform printing recording and image forming recording,
Recording sheets are fed and recorded. However, during the conveyance of the sheet, the sheet may be defectively conveyed (hereinafter referred to as jam), and the sheet conveyance may be stopped at a part of the conveying device. In such a case, if the transport device, for example, the transport belt or the transport roller is operated as it is, a sheet formed of paper or the like is wound around the transport belt or the transport roller, the sheet is broken, or a part of the sheet is transported to the transport path. Remains, the obstacles such as preventing the next sheet conveyance occur, so the sheet conveyance state is detected by a plurality of detection members, and one of the plurality of detection members is detected within a certain time from the start of sheet feeding. When the position of the member is not reached, it is determined that there is a jam, the conveyance device is stopped, and a jam signal is issued to notify the user of the occurrence of the jam. The sheet conveyance can be resumed only after the sheet is removed.

[0003]

As described above, while the sheet is conveyed by the conveying device, the sheet is caught in a part of the conveying guide portion due to bending of the sheet, curved conveyance of the sheet, or the like, or the sheet is conveyed to a part of the conveying device. In the conventional device, there is a slight time lag until the sheet does not reach the detection member position, the sheet conveyance delay is detected by the detection member, and the conveyance device is stopped via the control means. Occur. Therefore, the conveyance device forcibly conveys the sheet already jammed and stopped in a part of the conveyance path.
For example, when the user removes a sham sheet due to a jam signal, the sheet wrapped around the transport roller is further wrapped, and the sheet is torn or wraps around the transport roller in multiple layers, making it difficult to remove the sheet. May be. In such a case, it takes a lot of time to remove the sheet, which delays the start of the next printing or image forming work. Therefore, there is a drawback that it takes a lot of time for printing and image formation when a jam occurs.

The present invention is a means specifically devised for remedying the above-mentioned drawbacks. That is, when the sheet is fed from the sheet feeding device and is conveyed by the conveying device, when a jam occurs with respect to the conveying member that is in direct contact with the sheet and rotates, the jam is immediately detected and the conveying member is detected. Is intended to stop.

[0005]

According to a first aspect of the present invention, a sheet is supplied from a sheet storage portion, and a plurality of sheet conveying means feeds and conveys the sheet along the sheet guiding means.
When a defective conveyance of a sheet is detected, in the sheet conveyance device that stops the plurality of sheet conveyance means, the conveyance of the sheet is directly received from the sheet in a guide path guided along the sheet guide means. An operating member that operates, and a detecting member that detects an operating state of the operating member, and when the operating member receives defective conveyance of the sheet and the detecting member detects defective conveyance, the plurality of conveying units are operated. A sheet conveying device having stop means for stopping, and claim 2, wherein the actuating member is a rotating member that rotates in response to sheet conveyance, and claim 3 is a rotating state of the rotating member. The above object is achieved by detecting the defective conveyance by detecting the above-mentioned by the detection member.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a basic configuration diagram of an image forming apparatus A for forming characters or images. 1 is an image carrier for image formation,
Around the image carrier 1, there are provided a band electrode 2 charged on the surface of the image carrier 1 which rotates in the direction of the arrow in the order of processes, and a laser beam output means 4 controlled by a control means 3 for outputting images and characters. A laser beam output from the laser beam output means 4 is exposed through a mirror 5 on the surface of the image carrier 1 charged by the band electrode 2 to form an electrostatic latent image. A sheet in which the electrostatic latent image surface is developed by the developing device 6 with toner, and the toner image formed on the electrostatic latent image surface is fed from the paper feeding unit 7 through the second paper feeding roller pair 7A. (Hereinafter referred to as recording paper P)
Then, after the toner image is transferred by the transfer electrode 8 and the recording paper P is separated by the separation electrode 9 arranged in parallel with the transfer electrode 8,
The toner image transferred onto the recording paper P is fixed by the thermal fixing device 10. A cleaning device 11 cleans the toner remaining on the surface of the image carrier 1 after the transfer.

In the image forming apparatus A constructed as described above, when the recording paper P discharged from the heat fixing device 10 from the paper feeding section 7 is jammed during the transportation, the transportation means is stopped. The means are shown in FIG.

In FIG. 2, the same components as those in FIG. 1 will be described with the same reference numerals.

2 and 3, as shown, the second
A first rotating member 75 that can freely rotate with respect to the shafts 71 and 72 via bearings 73 and 74, respectively, on the shafts 71 and 72 of the paper feed roller pair 7A
Provide 76. A plurality of detection linear marks 77 and 78 are radially formed on a part of the first rotating members 75 and 76 as shown in FIG. S ₁ is a detection member for detecting the recording paper P passing through the second paper feed roller pair 7A, and is input to the CPU via the input device SC ₁ . The detection member S _{1 is connected} to the image forming apparatus A.
It is installed in the machine frame (not shown). The recording paper P is supplied to the paper feeding section 7
Guide plates 711, 7 for guiding the recording paper P after being fed by
The guide plate 711, 712 is configured so that one end of the recording paper P reaching the second paper feed roller pair 7A is directly sandwiched by the first rotating member 75, 76. 714
To form. The linear marks 77 and 78 are radially formed on the first rotating members 75 and 76 as described above, and the recording paper P
The first rotating members 75 and 76 are rotated by being nipped and conveyed. At that time, a detection member S ₂ for detecting one of the linear marks 77 and 78 is provided. The detection member S ₂ detects the linear mark 78 of the first rotating member 76 and inputs the linear mark 78 to the CPU via the input device SC ₂ . On the other hand, a paper discharge roller pair 7B for discharging the recording paper P, to which the toner image is transferred by the image carrier 1 on the recording paper and fixed on the thermal fixing device 10, is provided.
A detection member S ₃ for detecting whether or not the sheet has passed the paper discharge roller pair 7B is arranged in the recording paper conveyance path. The detection member S ₃ is provided on a frame body (not shown) of the image forming apparatus A. Detection member S ₃
Is connected to the CPU via the input device SC ₃ . A guide plate 715 is provided so that the recording paper P can be smoothly conveyed and discharged after the toner image is transferred, and the second rotation that rotates while nipping one end of the recording paper P guided and discharged by the guide plate 715. Member 75
1, 761 are provided on the guide plate 715, and the second rotating members 751, 76
A cutout 7151 is provided so that the 1's contact each other. Then, similarly to the first rotating members 75 and 76, a plurality of linear marks 752 and 762 for detection are radially formed on each surface. Then, the recording paper P is nipped and discharged, so that the second rotating members 751 and 7
61 rotates. At that time, a rotation detecting member S ₄ for detecting one of the linear marks 752 and 762 is provided. Paper feed unit 7, second
The paper feed roller pair 7A, the heat fixing roller 10, the paper discharge roller 7B, and the image carrier 1 have electromagnetic clutches C ₁ , C ₂ , C ₃ , respectively.
C _4, via a C ₅ is connected to the control unit SC _4, the control unit SC ₄
Connected to the CPU.

The present invention is configured as described above. First, the image forming apparatus A (not shown) is started to start C.
The PU operates the electromagnetic clutch C ₄ via the control unit SC ₄ to start the paper feeding unit 7 and start feeding the recording paper P.

Next, a description will be given according to the time chart shown in FIG.

The horizontal axis is set to time, paper feed is started at point t ₁ in the flow chart, and SA indicates the operation of the detection member S ₁ . The time T ₁ is the time when the recording paper reaches the detection member S ₁ from the start of paper feeding, and the leading edge of the recording paper P reaches the detection member S ₁ within the predetermined time set by the time TA by the software. For example, the recording paper P is normally fed and conveyed from the paper feed unit 7 to the detection member S ₁ .
Starting from this staircase, the image carrier 1 as described in FIG.
Writing is started on the surface by the laser light output means 4, and a toner image is formed on the surface of the image carrier 1 by the developing device 6. The front end of the recording paper P has already reached the second paper feed roller pair 7A and the paper feed is started so that the recording paper P coincides with the toner image.

After the paper feeding is started, the image forming apparatus A forms an image according to the flowchart shown in FIG. That is, the control of image formation and printing is started at the same time when the recording paper P passes the detection member S ₁ , and the image formation is sequentially performed on the recording paper P with the configuration of FIG. 1 while the CPU monitors the image formation state. If the recording paper P passes through the detection member S ₁ and does not pass within a constant count by the next detection member S ₃ , a jam has occurred and the operation of the image forming apparatus A is stopped. . When printing and image formation are completed on the recording paper P and there is no jam even after fixing, the recording paper P is directly discharged to the outside.

During the feeding and feeding, T ₂ is set from the start of feeding t ₁ to the point of t _{2 in} the time chart of FIG.
The image formed on the recording sheet P and the recording sheet P are fed in synchronization so that they match each other. The accurate image transfer is performed in said than said t ₂ P. At that time, as shown in FIG. 2, one edge of the recording paper P is nipped and conveyed between the first rotating members 75 and 76 provided on the shafts 71 and 72 of the second paper feed roller pair 7A, so that the first paper is conveyed.
The rotating members 75 and 76 rotate according to the amount of recording paper P conveyed.
Then, the rotation speed is detected by the detection member S _{2 by one} of the detection linear marks 77, 78 provided on the first rotation member 75, 76, and the rotation status is input to the CPU from the input device SC _2. . This situation is input to the CPU by the signal indicated by SA1 in the time chart shown in FIG. Now, when the transport amount of the recording paper P changes and the rotation members 75 and 76 change, the signal of SA1 received by the detection member S ₂ changes. Thus the input device SC ₂ also immediately determine abnormality of the rotation More CPU, jam is determined that has occurred to the recording paper P, the electromagnetic clutch C ₁ via the control unit SC ₄ from CPU,
All _{C 2, C 3, C 4} , C 5 is turned OFF, all of the conveying means is stopped. Such an operation is controlled by the flowchart shown in FIG. That is, the normal CPU has an interrupt function, is connected by a timer having a conveyance cycle of 10 msec, and the program started by the interrupt is executed every 10 msec. Therefore, FIG.
As shown in (b), the state of the detection member S ₂ is read in the timer routine to determine the change of the detection member S ₂ in a predetermined time. On the other hand, the image forming apparatus A controls the whole by a program (main routine) started by turning on the power source. Here, the jam flag approved by the timer routine is judged, and the control unit SC ₄ as described above is used. Thus, the electromagnetic clutches C ₁ , C ₂ , C ₃ , C ₄ , C ₅ are turned off to stop the recording paper conveyance of the image forming apparatus A. Therefore, the conveyance system can be stopped immediately when the recording paper P is jammed. Similarly, the recording paper P being ejected is nipped and rotated by the second rotating members 751 and 761 provided in the vicinity of the ejection roller pair 7B in the ejection direction. The rotation speed of one of the detection linear marks 752 and 762 provided on the second rotation members 751 and 761 is detected by the detection member S ₄ , and the rotation status is input to the CPU from the input device SC ₂ . This situation is input to the CPU by a signal SB1 in the flowchart shown in FIG.
Therefore, if an error occurs in the conveyance speed of the recording paper P while the image is transferred to the recording paper P, the toner image is fixed by the thermal fixing device 10, and then the paper is discharged by the paper discharge roller pair 7B, the detection member is immediately detected. From S ₄ , the CPU judges that the rotation condition is abnormal by the CPU via the input device SC _2, and it is judged that the recording paper P is in the jam state, and as described above, the control unit SC ₄ causes the electromagnetic clutches C ₁ , C to be released. ₂ , C ₃ , C ₄ , and C ₅ are turned off, and the conveyance of the recording paper P is stopped.

[0015]

As described above, the present invention is provided with a detecting member for directly detecting the state of the conveyance speed of the recording paper P when the recording paper P is jammed during the conveyance, and the conveyance speed is as low as possible. When an abnormality occurs, the recording paper conveyance is immediately stopped. Therefore, the recording sheet P is prevented from being torn in the conveying path or being wound around the conveying member to make it difficult to remove the recording sheet P. Since the recording sheet P stops when a jam occurs, the recording sheet P can be easily conveyed. Can be removed more.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an image forming process.

FIG. 2 is a perspective view showing an arrangement of a recording paper conveyance unit and a detection member according to the present invention.

FIG. 3 is a side view showing a combination of a rotating member and a sheet feeding roller of the present invention.

FIG. 4 is a front view showing radial linear marks on a rotating member.

FIG. 5 is a time chart diagram of a paper feed and detection member.

FIG. 6 is a flowchart of the present invention.

[Explanation of symbols]

A image forming apparatus 1 image carrier 7 paper feed unit P recording paper 7A second paper feed roller pair 75,76 first rotary member 751,761 second rotary member S ₁ , S ₂ , S ₃ , S ₄ detection member C ₁ , C ₂ , C ₃ , C ₄ , C ₅ electromagnetic clutch

Claims (3)

[Claims] 1. When a sheet is fed from a sheet storage section and fed and conveyed by a plurality of sheet conveying means along a sheet guiding means, and when defective conveyance of the sheet is detected, the plurality of sheet conveying means are operated. In a sheet conveying device to be stopped, an operating member that receives the conveyance of the sheet directly from the sheet and operates in a guide path that is guided along the sheet guiding means, and a detecting member that detects an operating state of the operating member. And a stop unit that stops the plurality of conveying units when the operation member receives the defective conveyance of the sheet and the detection member detects the defective conveyance. 2. The sheet conveying apparatus according to claim 1, wherein the actuating member is a rotating member that rotates in accordance with sheet conveyance. 3. The sheet conveying apparatus according to claim 2, wherein defective conveyance is detected by detecting the rotation status of the rotating member by the detecting member.