JPH11249525A - Paper sheet transporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper sheet transporting device capable of correcting a lag of paper sheet transporting even if lagging occurs, and correctly performing alignment for an image and a paper sheet, by correcting transport speed of the paper sheet. SOLUTION: This device is constituted by composing plural transporting rollers 14, 15, 16, 17 and 18 transporting the paper sheet from a hopper 29 to a transfer roller 2 on which the image is transferred, regist roller 13 performing alignment of the paper sheet 40 being transported with the image, paper sheet sensors 20, 21, 22, 23, 24 and 19 detecting the presence or absence of the paper sheet 40, motors 26 and 27 rotating the plural transporting rollers 14, 15, 16, 17 and 16, a pick roller 25 picking the paper sheet from the hopper 29, and the controlling device 31. In this case, the device is provided with means correcting transporting speed of the paper sheet 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport device, and more particularly, to a printer, a facsimile machine, a copier, etc., which performs alignment between an image and paper at the time of picking the paper.
The present invention relates to a sheet transport device that corrects a delay in sheet transport in the middle of the process and accurately aligns an image with a sheet.

[0002]

2. Description of the Related Art Printers, facsimile machines, copiers, and the like, in which the position of an image and a sheet must be considered when the sheet is picked, instead of starting writing the image after the sheet reaches the registration roller In this type of conventional paper transport device, the transport of the paper is performed by using a frictional force between the pick roller and the transport roller and the paper,
When a slip phenomenon occurred between the pick roller and the transport roller and the paper, and the paper transport was delayed, the paper transport delay could be recovered within a certain time during which the paper was stopped by the registration roller. However, when the sheet is stopped by the registration roller for a predetermined time or more, there is a drawback that printing is performed in a state where the sheet and the image are misaligned.

[0003]

As described above, in the conventional paper transport apparatus, when a slip phenomenon occurs between the pick roller and the transport roller and the paper, and the transport of the paper is delayed, the paper is transported. However, there is a problem that printing is performed with a positional shift between the image and the image.

SUMMARY OF THE INVENTION It is an object of the present invention to correct a sheet conveyance speed so that even when a sheet conveyance delay occurs, the sheet can be corrected so that image and sheet alignment can be performed accurately. An object of the present invention is to provide a transport device.

[0005]

According to a first aspect of the present invention, there is provided a sheet conveying apparatus, comprising: a photosensitive belt on which an image is written; a charger for uniformly charging the surface of the photosensitive belt; A laser unit that writes an electrostatic latent image of each color, a developing device that develops the written electrostatic latent image of each color to form a toner image on the surface of the photoreceptor belt, and a transfer roller that transfers the developed image to paper And an eraser for removing charges remaining on the surface of the photoreceptor belt, a motor for driving the photoreceptor belt, a hopper for storing paper, and a plurality of transport rollers for transporting the paper from the hopper to a transfer roller on which an image is transferred. A registration roller for aligning the transferred paper with the image, a paper sensor provided on the plurality of conveyance roller units and the registration roller unit for detecting the presence or absence of paper, and a plurality of conveyance rollers. A motor for rotating the roller,
A pick roller for picking a sheet from a hopper, and a control device for controlling each of a photoreceptor belt, a developing device, and a mechanism for transporting the sheet, and a plurality of motors for rotating a plurality of transport rollers; And means for correcting the transport speed.

The means for correcting the paper transport speed is characterized in that the paper transported by the plurality of transport rollers from the hopper is temporarily stopped at the registration rollers, and the paper and the image are aligned. .

Means for correcting the paper transport speed is to adjust the timing for aligning the image and the paper by absorbing the fluctuation of the paper transport time from the time when the registration roller picks the paper with the pick roller to the time when the paper is transported to the registration roller. It is characterized in that printing is performed while rotating.

Means for correcting the paper transport speed is to correct the positional deviation between the paper and the image by increasing the paper transport speed when the paper does not reach the resist roller due to the timing of rotating the registration roller. It is characterized by.

The means for correcting the transport speed of the sheet is characterized in that it includes means for changing the transport speed of the transport roller located on the registration roller side among the plurality of transport rollers independently of the other transport rollers.

Means for correcting the paper transport speed is that the paper is picked up from the hopper at the time when the ON signal of the transported paper is detected by the paper sensor of the transport roller unit located on the registration roller side among the plurality of transport rollers. After that, the time until the paper sensor detects the ON signal is obtained, and when the value is longer than the theoretical value, the conveyance speed of the conveyance roller located on the registration roller side is increased to correct the conveyance delay. .

The means for correcting the paper transport speed is a means for changing the transport speed between a transport roller located on a pick roller side for picking up paper from a hopper and a transport roller located on a registration roller side among a plurality of transport rollers. It is characterized by having.

[0012] The means for correcting the sheet conveying speed is provided by a sheet sensor of a conveying roller portion located on a pick roller side for picking up a sheet from a hopper among a plurality of conveying rollers at the time of detecting an ON signal of the sheet conveyed. Calculate the time from when the paper is picked from the hopper to when the paper sensor detects the ON signal.If the value is longer than the theoretical value, the transport roller located on the pick roller side and the transport roller located on the registration roller side The transport speed of the transport rollers is increased to correct the transport delay, and among the multiple transport rollers, the paper sensor of the transport roller located on the registration roller side detects the ON signal of the transported paper. The time from when the paper is picked from the hopper to when the paper sensor detects the ON signal is calculated.If the value is longer than the theoretical value, the paper is positioned on the registration roller side. And correcting the transfer delay to increase the conveying speed of the conveying roller.

[0013] The laser unit is characterized by comprising a yellow laser unit, a magenta laser unit, a cyan laser unit and a black laser unit.

The developing device comprises a yellow developing device, a magenta developing device, a cyan developing device and a black developing device.

[0015]

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

FIG. 1 is a schematic structural view showing a sheet conveying device 50 of the present invention.

Referring to FIG. 1, a paper transport device 50 of the present invention connected to an information processing device 30 for processing an image and issuing a print request includes a photosensitive belt 1 on which an image is written and a surface of the photosensitive belt 1. Charger 11 for uniformly charging the surface of the photoreceptor belt 1, a yellow laser unit 3, a magenta laser unit 4, a cyan laser unit 5, and a black laser unit 6 for writing an electrostatic latent image of each color by exposing the surface of the photoreceptor belt 1; A yellow developing device 7, a magenta developing device 8, a cyan developing device 9 and a black developing device 10 for developing the written electrostatic latent images of the respective colors to form toner images on the surface of the photoreceptor belt 1; A transfer roller 2 for transferring to the paper 40, an eraser 12 for removing charges remaining on the surface of the photoconductor belt 1, a motor 28 for driving the photoconductor belt, and a paper 40 A hopper 29 to be stored, the paper 4
And a plurality of transport rollers 14, 15, 16, 17, 1 for transporting the image No. 0 from the hopper 29 to the transfer roller 2 on which the image is transferred.
8, a registration roller 13 for aligning the conveyed sheet 40 with the image, and a plurality of conveyance rollers 14, 1
Paper sensors 20, 21, provided at 5, 16, 17, 18 and the registration rollers 13 to detect the presence or absence of paper;
22, 23, 24, 19 and a plurality of transport rollers 15, 1
A motor 27 for rotating 6, 17, 18; a motor 26 for rotating the transport roller 14;
Roller 25 for picking up the photosensitive drum, photosensitive belt 1, yellow developing device 7, magenta developing device 8, cyan developing device 9
And a control device 31 for controlling each mechanism of the black developing device 10 and the conveyance of the paper 40.

In this case, the transport roller 14 is another transport roller 1
The transport speed can be changed independently of the transport rollers 15, 16, 17, and 18.
7 and 18 all have the same rotation speed, but each has a configuration in which rotation can be started and stopped independently.

Next, the operation of the paper transport apparatus 50 of the present invention configured as described above will be described.

FIGS. 2 and 3 are flow charts showing the operation of the paper conveying apparatus 50 according to the first embodiment of the present invention.

Referring to FIGS. 2, 3 and 1, first, when a print request is sent from the information processing device 30 to the control device 31 in the paper transport device 50 (step 1), the control device 31 The belt 1 is rotated to activate the yellow laser unit 3, magenta laser unit 4, cyan laser unit 5, and black laser unit 6, and the charger 11 and eraser 12 are turned on. When the activation of the yellow laser unit 3, the magenta laser unit 4, the cyan laser unit 5, and the black laser unit 6 is completed and the printer is ready for printing, the information processing device 30
Flows the image data of each color, and each laser unit 3,
4, 5 and 6 laser (not shown), photoreceptor belt 1
To start writing the image.

On the other hand, on the paper 40, the image written on the photosensitive belt 1 is transferred to the transfer roller 2, and
The transfer is started at the timing when the sheet 40 comes to the position of the transfer roller 2 when the sheet is transferred to the transfer roller 2. At this time, the size of the paper 40 to be picked is recognized (step 2).

Next, when the paper sensor 20 detects an ON signal on the picked paper 40 (step 3), the paper 4
The actual time from picking 0 to turning on the paper sensor 20 is compared with its theoretical value. If the actual transport time of the paper 40 is longer than the theoretical value, the paper 4
0 indicates that the conveyance of the sheet 40 is delayed. Therefore, the conveyance speed of the paper 40 by the conveyance roller 14 is increased, and nothing is performed if the actual conveyance time is shorter than the theoretical value. (Steps 4 and 5) When increasing the transport speed of the paper 40,
In consideration of the limit value of the speed at which the transport roller 14 is rotated, it is determined whether or not the transport of the paper 40 can be recovered before the paper 40 reaches the registration roller 13 (step 6). If possible, the paper 40 is conveyed at the maximum speed at which it can be conveyed, or a paper jam occurs (step 7).

If the delayed time can be recovered, the transport speed of the paper 40 by the transport roller 14 is increased to a speed (step 8) determined by a predetermined formula to correct the transport delay of the paper 40. At this time, among the transport rollers 15, 16, 17, and 18 before the transport roller 14, the transport roller that is recognized as still transporting the paper 40 has a different transport speed from the transport roller 14. Paper 40
Is stopped, and the paper is rotated (step 9).

Next, after the paper sensor 19 is turned on, it is determined that the paper 40 has reached the registration rollers 13 (step 10). After a predetermined time, the conveyance rollers 14, 15, 16, 17 before the registration rollers 13 are determined. , Out of 18,
The transport roller on which the paper 40 is applied is stopped (step 11).

The paper 40 reaches the registration roller 13,
At the timing when the position of the image written on the photoreceptor belt coincides with the position of one image (after a certain period of time after picking the sheet 40), the rotation of the registration roller 13 is started (step 12), and then printing is completed (step 13) ).

Next, the operation of the paper transport apparatus according to the second embodiment of the present invention will be described with reference to the drawings.

FIGS. 4, 5 and 6 are flow charts showing the operation of the sheet conveying apparatus according to the second embodiment of the present invention.

The difference between the operation of the second embodiment of the paper transport apparatus of the present invention and the operation of the first embodiment is that the transport speed is corrected by the speed correction when the transport of the paper 40 is delayed. Is changed from one to two. The same components are denoted by the same reference numerals.

Referring to FIG. 4, FIG. 5, and FIG. 6, first, when there is a print request (step 101), the size of the paper 40 to be picked is recognized and the picking of the paper 40 is started. 1 is started to write an image (step 102). When the picked sheet 40 is conveyed and reaches the sheet sensor 24 (step 103), the theoretical value of the time from picking until the sheet sensor 24 is turned on and the time actually taken (step 104). (Step 105), if the time actually taken is longer, that is, if the transport of the paper 40 is delayed, it is determined whether or not the transport delay of the paper 40 can be recovered. (Step 106),
If not possible, transport rollers 15, 16, 17, 1
The maximum speed is set at 8 (step 107).

If it is possible to recover the delay of the transport of the paper 40, the speed of the transport rollers 15, 16, 17, 18 is changed to a speed determined by a predetermined formula (step 10).
8).

Next, when the paper 40 has been transported to the paper sensor 20 (step 109), the paper 4
The theoretical value from picking 0 until the paper sensor 20 is turned on is compared with the actual value (step 110) (step 111). If the conveyance of the paper 40 is delayed, It is determined whether or not it is possible to recover the transport delay (step 112), and if not, the maximum speed at which the transport roller 14 can be rotated is set (step 113).

If it is possible to recover the delay of the transport of the paper 40, the speed of the transport roller 14 is changed to a speed determined by a predetermined formula (step 114).

The operations in steps 115 to 119 shown in FIG. 6 are the same as those in steps 9 to 13 in FIG.

If the transport speed of the paper 40 cannot be freely changed steplessly, the speed is changed by two or three steps. If the transport of the paper 40 is delayed, the transport of the paper 40 is delayed. The speed of the paper 40 is adjusted by the registration roller 13.
It is also possible to align the image with the paper 40 by lengthening the time that the image is stopped by the registration roller 13 in accordance with the speed that is faster than the prescribed time, which is included in the present invention. Needless to say.

[0036]

As described above, the paper transport apparatus of the present invention detects a delay in paper transport during paper transport, and if it is delayed, increases the speed of the transport roller to increase the delay. Is carried out until the image is transferred, so that there is an effect that the positional deviation between the image and the sheet due to the delay of the sheet conveyance can be eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a paper transport device of the present invention.

FIG. 2 is a flowchart illustrating an operation of the sheet transport device according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of the paper transport apparatus according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of the paper conveying apparatus according to a second exemplary embodiment of the present invention.

FIG. 5 is an operation flowchart illustrating a second embodiment of the paper conveying apparatus of the present invention.

FIG. 6 is an operation flowchart illustrating a second embodiment of the paper conveying apparatus of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor belt 2 transfer roller 3 yellow laser unit 4 magenta laser unit 5 cyan laser unit 6 black laser unit 7 yellow developing device 8 magenta developing device 9 cyan developing device 10 black developing device 11 charger 12 eraser 13 resist roller 14, 15 Conveying rollers 16, 17 Conveying rollers 18 Conveying rollers 19, 20 Paper sensors 21, 22, Paper sensors 23, 24 Paper sensors 25 Pick rollers 26, 27 Motor 28 Motor 29 Hopper 30 Information processing device 31 Control device 40 Paper 50 Paper conveying device

Claims (10)

[Claims] 1. A photoreceptor belt on which an image is written, a charger for uniformly charging the surface of the photoreceptor belt, and a laser unit for exposing the surface of the photoreceptor belt to write an electrostatic latent image of each color. A developing device that develops the written electrostatic latent image of each color to form a toner image on the surface of the photoreceptor belt, and a transfer roller that transfers the developed image to paper.
An eraser for removing charges remaining on the surface of the photoreceptor belt, a motor for driving the photoreceptor belt, a hopper for storing the paper, and conveying the paper from the hopper to the transfer roller on which an image is transferred. A plurality of transport rollers, a registration roller for performing alignment between the transported paper and the image, a paper sensor provided in the plurality of transport roller units and the registration roller unit to detect the presence or absence of the paper, A motor that rotates a plurality of transport rollers, a pick roller that picks up the paper from the hopper, and a control device that controls each mechanism of the photoconductor belt, the developing device, and the transport of the paper. ,
A paper transport apparatus, comprising: a plurality of motors for rotating the transport rollers; and means for correcting a transport speed of the paper. 2. The method according to claim 1, wherein the means for correcting the sheet conveying speed includes:
2. The sheet conveying device according to claim 1, wherein the sheet conveyed from the hopper by the plurality of conveying rollers is temporarily stopped at the registration roller to perform alignment between the sheet and an image. . 3. The means for correcting the paper transport speed,
The registration roller absorbs fluctuations in the transport time of the paper from the pick roller to the paper after the pick roller picks up the paper to the registration roller, and performs printing by rotating at a timing for aligning the image and the paper. The sheet conveying device according to claim 1, wherein: 4. A means for correcting the paper transport speed,
2. The image forming apparatus according to claim 1, wherein when the sheet does not reach the registration roller at a timing when the registration roller is rotated, a conveyance speed of the sheet is increased to correct a positional shift between the sheet and an image. Paper transport device. 5. The means for correcting the paper transport speed,
3. The device according to claim 1, further comprising means for changing a transport speed of a transport roller positioned on the side of the registration roller among the plurality of transport rollers independently of other transport rollers.
3. The paper transport device according to claim 3. 6. A means for correcting the paper transport speed,
The paper sensor of the transport roller unit located on the registration roller side among the plurality of transport rollers picks up the paper from the hopper at the time of detecting the ON signal of the transported paper, and then the paper sensor 6. The method according to claim 1, wherein a time until the detection of the ON signal is obtained, and when the value is longer than a theoretical value, the conveying speed of the conveying roller positioned on the registration roller side is increased to correct the conveying delay. Paper transport device according to the above. 7. The means for correcting the paper transport speed,
The apparatus according to claim 1, further comprising means for changing a transport speed between a transport roller positioned on the pick roller side and a transport roller positioned on the registration roller side for picking up the sheet from the hopper among the plurality of transport rollers. Item 2. The sheet conveying device according to Item 1. 8. The means for correcting the paper transport speed,
By the paper sensor of the transport roller unit located on the pick roller side that picks up the paper from the hopper among the plurality of transport rollers, the paper is removed from the hopper at the time of detecting the ON signal of the transported paper. Determine the time from picking until the paper sensor detects the ON signal,
When the value is longer than the theoretical value, the transport speed of the transport rollers other than the transport rollers located on the pick roller side and the transport rollers located on the registration roller side is increased to correct the transport delay, and the The paper sensor of the transport roller unit located on the registration roller side among the plurality of transport rollers picks up the paper from the hopper at the time of detecting the ON signal of the transported paper, and then turns on the paper sensor. 3. The method according to claim 1, wherein a time until signal detection is obtained, and when the value is longer than a theoretical value, a conveyance speed of a conveyance roller positioned on the registration roller side is increased to correct a conveyance delay. 3. The paper transport device according to 3, 4, or 7. 9. The sheet conveying apparatus according to claim 1, wherein said laser unit comprises a yellow laser unit, a magenta laser unit, a cyan laser unit, and a black laser unit. 10. The sheet conveying device according to claim 1, wherein said developing device comprises a yellow developing device, a magenta developing device, a cyan developing device and a black developing device.