JP2001322725A - Image forming device and additional paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that when an image forming process is stopped as a result of a recording material running out due to a relation between a timing of image formation on an image carrier and the paper recording timing of the recording material occasioned by the increase of a speed and coloring and increase the burden of a cleaning device, in an image forming device provided with an addition paper feeding part. SOLUTION: By situating a part to reverse a conveyance direction in a paper feed passage running from an addition paper feeding part to a transfer position, the paper feed passage is increased in length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having an improved recording material feeding section, an image forming apparatus having an improved recording material conveying section, and an additional feeding apparatus used in the image forming apparatus. .

[0002]

2. Description of the Related Art (1) Development of an image forming apparatus for forming an image on a recording material includes not only higher image quality but also higher speed and color. As means for increasing the speed, a means for operating the image forming section and a paper supply section for supplying the recording material to the image forming section at a higher speed and a means for shortening the image interval are used in combination.

(2) In an image forming apparatus for forming an image on a recording material, a conveyance failure such as a jam of the recording material in the image forming apparatus, that is, a jam processing such as removal of the jammed recording material in response to a jam. Usually, a mechanism is provided.

Conventional jam processing mechanisms include a mechanism that opens a guide plate that forms a recording material conveyance path, a mechanism that divides an image forming apparatus into upper and lower parts, and that opens an upper portion about an axis.
There is a type in which a conveyance section of a recording material is unitized and the unit is pulled out.

[0005]

(1) The high-speed means for shortening the image interval causes the following problem when the recording material is lost in the recording material storage means and the image formation is stopped. is there.

When it is detected that the recording material has run out in the recording material storage means, an image has already been formed on the image carrier, and when the image formation is stopped, the image is formed on the image carrier. A step of removing the image is required. When such an image removing process is repeated every time the recording material is exhausted in the recording material storage means, the load on the cleaning device increases, and the deterioration of the cleaning blade, which is a main component of the cleaning device, is accelerated. Further, the toner for forming the image is wastefully consumed, which is not preferable.

As described above, the phenomenon that an unnecessary image is formed when the image formation is stopped when the recording material runs out is caused by the time required for the image to move to the transfer position after the image is formed on the image carrier. This is likely to occur in an image forming apparatus having a structure that is longer than the moving time of the recording material in which the recording material is carried out by the paper feeding means and moves to the transfer position.

Incidentally, in the image forming apparatus, a recording material storing means is provided in the main body of the image forming apparatus.
It is common practice to add an additional paper supply unit having a large capacity recording material storage unit. However, the recording material carried out from such an additional paper supply unit is configured to go straight to the normal transfer position. ing. This will be described with reference to FIG. 1 showing an image forming apparatus according to an embodiment of the present invention.

An additional sheet feeding section B is added to the image forming apparatus main body A. The recording material P is transferred from a conveying roller 45 provided at a recording material outlet of the additional sheet feeding section to a registration roller 20 in a linear conveying path. It is transported through E. As is clear from the figure,
The conveyance path E of the recording paper P from the additional paper supply unit B is extremely short.
Depending on the arrangement of each part of the image forming apparatus, the transport path E often becomes shorter than the length of the image moving path from the image forming position G to the transfer position T. In particular, in a color image forming apparatus in which a plurality of image forming units are provided, as shown in FIGS. 5 and 8, the distance from the image forming position G of the first image forming unit to the transfer device T is increased. In many cases, the moving time of the image is longer than the moving time of the recording material P.

As a result, in the image forming apparatus provided with the additional sheet feeding section, unnecessary image formation is likely to occur.

A first object of the present invention is to solve such a problem in an image forming apparatus having an additional sheet feeding unit.

(2) The prior art described above is effective for jams in the vicinity of the outer cover of the image forming apparatus, but opens the transport path for jams inside the image forming apparatus. It is not effective because it is difficult to provide this space inside the image forming apparatus. However, in a large-sized image forming apparatus, the weight and volume of the opening / closing section are increased, which causes a problem in the jam processing operation. In the related art, since the conventional unit pulls out the unit in the front direction of the image forming apparatus, the unit is pulled out at right angles to the moving direction of the recording material, and the jammed recording material is bent in the process of pulling out the unit, There is a problem that it is crushed and broken, making it difficult to remove.

A second object of the present invention is to solve the above-mentioned problem in the conventional jam processing mechanism.

[0014]

The above-mentioned object of the present invention is achieved by the following inventions.

1. Image carrier, image forming means arranged to face the image carrier and forming an image on the image carrier, transfer means for transferring the image formed on the image carrier to a recording material, recording material Image forming apparatus including a fixing unit for fixing an image transferred to a recording medium, a paper supply unit for supplying a recording material to a transfer position formed by the transfer unit, and a main body paper supply unit for supplying the recording material to the paper supply unit The main body is provided with an additional paper supply unit having an additional paper supply unit for storing a recording material in the main body and an additional paper supply unit for discharging the recording material from the additional paper supply unit. The additional paper supply unit paper supply means is provided substantially in parallel with the paper supply unit, and the first paper supply unit for carrying out the recording material from the additional paper supply unit recording material storage means, and conveys the recording material from the first discharge unit. A second unloading unit that substantially reverses the direction and transports the paper toward the paper feeding unit; Part image forming apparatus characterized by comprising a recording material presence detecting means provided in the vicinity of.

2. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus main body is provided with a reversing conveyance section for substantially reversing the recording material from the second unloading section and conveying the recording material toward the sheet feeding unit.

3. The recording material is fed based on the detection result of the recording material presence / absence detecting unit rather than the image movement time from the image forming position of the image forming unit to the transfer position, and then the recording material is fed, and the transfer is performed. 3. The image forming apparatus according to the above item 1 or 2, wherein the time required to reach the position is longer.

4. The image forming apparatus according to any one of claims 1 to 3, wherein the image carrier is formed of a photoconductor, and includes a plurality of image forming units that form a plurality of images on the photoconductor.

5. The image bearing member is formed of an intermediate transfer member,
A photoconductor, an electrostatic latent image forming unit, a developing unit that develops an electrostatic latent image to form an image on the photoconductor, and a transfer unit that transfers an image formed on the photoconductor to the intermediate transfer body. The image forming apparatus according to any one of claims 1 to 3, further comprising a plurality of the image forming units.

6. After determining the paper feed based on the detection result of the recording material presence / absence detecting means based on the moving time of the image from the image forming position of the leading image forming means of the plurality of image forming means to the transfer position, and then performing recording. Material is fed,
6. The image forming apparatus as described in 4 or 5 above, wherein a time required to reach the transfer position is longer.

7. 7. The image forming apparatus according to claim 1, wherein the image carrier has a belt shape.

8. The image forming apparatus according to any one of claims 1 to 3, further comprising a back surface feeding unit configured to form an image on one side and reverse the recording material that has passed through the fixing unit, and to convey the recording material to the feeding unit.
8. The image forming apparatus according to claim 7.

9. Image carrier, image forming means arranged to face the image carrier and forming an image on the image carrier, transfer means for transferring the image formed on the image carrier to a recording material, recording material Image forming apparatus including a fixing unit for fixing an image transferred to a recording medium, a paper supply unit for supplying a recording material to a transfer position formed by the transfer unit, and a main body paper supply unit for supplying a recording material to the paper supply unit A main body, an additional paper supply unit for storing the recording material, an additional paper supply unit for carrying out the recording material from the additional paper supply unit, and a vicinity of the additional paper supply unit Having a recording material presence / absence detecting means provided in the main body paper feeding section, an additional paper feeding section provided substantially in parallel with the main body paper feeding section, and the recording material carried out by the additional paper feeding section paper feeding means, After the conveyance direction is almost reversed, the reversal conveyance is supplied to the paper feeding means. Image forming apparatus, wherein a provided in the image forming apparatus main body.

10. After determining the sheet feeding based on the detection result of the recording material presence / absence detecting unit, rather than the image moving time from the image forming position of the image forming unit to the transfer position,
10. The image forming apparatus according to 9, wherein a time period from when the recording material is fed to when the recording material is reached is longer.

[11] 11. The image forming apparatus according to 9 or 10, wherein the image carrier is made of a photoreceptor, and has a plurality of the image forming means for forming a plurality of images on the photoreceptor.

12. The image bearing member is an intermediate transfer member, a photosensitive member, an electrostatic latent image forming unit, a developing unit for developing an electrostatic latent image to form an image on the photosensitive member, and an image formed on the photosensitive member The image forming apparatus according to the above item 9 or 10, further comprising a plurality of the image forming units having a transfer unit for transferring the image to the intermediate transfer body.

13. After determining the paper feed based on the detection result of the recording material presence / absence detecting means based on the moving time of the image from the image forming position of the leading image forming means of the plurality of image forming means to the transfer position, and then performing recording. 13. The image forming apparatus as described in 11 or 12, wherein the time from when the sheet is fed to when the sheet reaches the transfer position is longer.

14. The image forming apparatus according to any one of Items 9 to 13, wherein the image carrier has a belt shape.

15. The image forming apparatus according to claim 1, further comprising a back-side paper feeding unit that reverses the surface of the recording material on which an image is formed on one side and has passed through the fixing unit and conveys the recording material to the paper feeding unit.
15. The image forming apparatus according to any one of claims 14 to 14.

16. Recording material storage means for storing the recording material,
A first unloading unit that unloads the recording material in the recording material storage unit in a first direction, and a recording material from the first unloading unit is inverted and delivered in a second direction substantially opposite to the first direction; An additional sheet feeding device, comprising:

17. An image carrier, an image forming unit disposed to face the image carrier, and forming an image on the image carrier;
A transfer unit that transfers an image formed on the image carrier to a recording material, and a recording material that is transported substantially horizontally from a transfer position formed by the image carrier and the transfer unit; In the image forming apparatus having a fixing unit for fixing the above image, the fixing unit is provided so as to be able to be taken out in a direction along a moving direction of a recording material passing through the fixing unit. apparatus.

18. An image carrier, an image forming unit disposed to face the image carrier, and forming an image on the image carrier;
A transfer unit for transferring an image formed on the image carrier to a recording material, and a recording material conveyed from a transfer position formed by the image carrier and the transfer unit, and an image on the recording material An image forming apparatus having a fixing unit for fixing the recording material includes a conveyance path including a substantially horizontal paper supply path for supplying the recording material to the transfer position, and the conveyance path is substantially opposite to the moving direction of the recording paper. An image forming apparatus provided so as to be able to be taken out in a direction.

19. The image forming apparatus according to claim 17 or 18, further comprising a door that opens and closes in a direction substantially perpendicular to the moving direction of the recording material and opens the vicinity of the transfer position.

20. 20. The image forming apparatus according to any one of claims 17 to 19, further comprising a paper discharge path that guides the recording material after fixing and discharges the paper, which is taken out integrally with the fixing unit.

21. 21. The image forming apparatus according to claim 20, wherein the paper discharge path is openable after being taken out.

22. The printer has a shuntable paper discharge path for guiding the recording material after fixing and discharging the paper, and the paper discharge path is provided so that the fixing unit can be taken out after the paper discharge path is evacuated. 20. The image forming apparatus according to any one of 17 to 19 above, wherein

23. 23. The image forming apparatus according to any one of claims 18 to 22, wherein the conveying path includes a sheet feeding unit that conveys a recording material to the transfer position in synchronization with image formation on the carrier. apparatus.

24. The image forming apparatus according to any one of Items 18 to 23, wherein the transport path includes the transfer unit.

25. The transfer path is capable of being opened at least partially after being taken out.
25. The image forming apparatus according to any one of items 24 to 24.

26. The image forming apparatus according to any one of claims 17 to 25, wherein the image carrier is formed of a photoconductor, and includes a plurality of image forming units that form a plurality of images on the photoconductor.

27. The image bearing member is an intermediate transfer member, a photosensitive member, an electrostatic latent image forming unit, a developing unit for developing an electrostatic latent image to form an image on the photosensitive member, and an image formed on the photosensitive member 27. The image forming apparatus according to any one of claims 17 to 26, further comprising: a plurality of the image forming units including a transfer unit that transfers the image to the intermediate transfer member.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment FIG. 1 is a diagram showing a configuration of an image forming apparatus according to a first embodiment of the present invention. The image forming apparatus is an image forming apparatus main body A
And an additional paper feeding section B. The additional paper feeding unit B is detachably attached to the image forming apparatus main body A.

Reference numeral 1 denotes a drum-shaped photoreceptor as an image carrier. The photoreceptor is an organic photoreceptor in which an organic photoconductive layer is formed on a conductive drum such as aluminum or the like.
An a-Si photoconductor on which a -Si photoconductive layer is formed is used. 2 is a charging device as a charging unit including a scorotron charger having a control grid and a charging electrode,
A uniform potential is formed on the photoconductor 1. Reference numeral 3 denotes an exposure device as an exposure unit having a laser diode as a light source and having a scanning optical system including a polygon mirror, a mirror, and a lens. The exposure device 3 performs dot exposure on the photosensitive member 1 in accordance with image data to form an electrostatic latent image. I do. In addition, as the exposure device, a conventionally known arbitrary scanning exposure device such as a scanning exposure device having a light emitting diode array and an image-forming optical fiber and a liquid crystal is used. Reference numeral 4 denotes a developing device as a developing unit that develops the electrostatic latent image on the photoconductor 1 using a one-component developer or a two-component developer. Develop to form an image on photoconductor 1.

To the developing sleeve 4SL, a developing bias having the same polarity as that of the electrostatic latent image on the photoconductor 1 is applied, and reversal development for attaching toner to an exposed portion on the photoconductor 1 is performed. In addition,
It is also possible to apply a bias potential having a polarity opposite to that of the electrostatic latent image on the photoreceptor to the developing sleeve 4SL to perform regular development. Reference numeral 5 denotes a transfer device as a transfer unit that charges the recording material P to a polarity opposite to that of the toner on the photoconductor 1 and transfers the toner on the photoconductor to the recording material P. At a transfer position T where the transfer device 5 faces the photoconductor 1, an image is transferred from the photoconductor 1 to the recording material P. Reference numeral 6 denotes a separation device that removes electricity from the recording material P and separates the recording material P from the photoconductor 1. Reference numeral 7 denotes a fixing device as a fixing unit having a heating roller having a heat source such as a halogen lamp and a pressure roller which presses against the heating roller. The fixing device 7 conveys the recording material P substantially horizontally and forms an image on the recording material P. Establish. 8
Is a cleaning device as cleaning means for cleaning the photoreceptor 1 having passed through the separating device 6. 9
Is a back surface feeding means for reversing the recording material P having an image formed on the front surface and re-feeding it to the transfer position T. Reference numeral 11 denotes a switching guide member that guides the recording material P that has passed through the fixing device 7, and switches between guiding the recording material P that has passed through the fixing device 7 to the paper discharge tray 10 or the back surface paper feeding unit 9. Is performed by the switching guide member 11. Reference numeral 20 denotes a recording material P which is synchronized with image formation on the photoconductor 1 and is transferred to the photoconductor 1 and the transfer device 5.
Is a registration roller as a sheet feeding means for transporting the sheet to a transfer position T formed by the image forming apparatus. Reference numerals 21 and 22 denote paper cassettes as main body recording material storage means.
The recording material P is supplied to the registration roller 20 via 3 and 24. The paper feed cassettes 21 and 22 and the paper feed paths 23 and 24 form a main body paper feed unit that supplies a recording material to a paper feed unit.

In accordance with the rotation of the photosensitive member 1 as indicated by the arrow, an electrostatic latent image is formed on the photosensitive member 1 by charging by the charging device 2 and exposure by the exposure device 3. The electrostatic latent image is developed by the developing device 4 to form an image on the photoconductor 1. The formed image is transferred by the transfer device 5 and fixed on the recording material P by the fixing device 7. The recording material P after the fixing is discharged to the discharge tray 10 as it is. In the double-sided mode, the recording material P is guided by the switching guide member 11 and conveyed to the back-side paper feeding unit 9. After being turned over, the sheet is again conveyed to the transfer position T and the image is transferred to the back surface. The photoconductor 1 that has passed the transfer position T is cleaned by the cleaning device 8.

Reference numeral 30 denotes a paper feeding table as an additional paper feeding section recording material storage means, which is configured to be able to move up and down, and is moved up and down in accordance with the amount of the recording material P by driving means (not shown). Is always maintained at a substantially constant height to support the recording material P. Reference numeral 31 denotes a first unloading unit that separates the recording material P into one sheet and unloads the recording material P in a first direction V1. Reference numeral 32 substantially reverses the direction of the recording material P from the first unloading unit 31 so that the first direction V1 is Is a second unloading section for unloading in a substantially opposite second direction V2, and these unloading sections constitute an additional sheet feeding section sheet feeding means.

The first carrying-out section 31 includes a sending roller 41 for taking out the recording material P on the sheet feeding table 30 from above, and a separating / conveying roller 42 for separating and conveying the recording material P sent by the sending roller 41 into one sheet. And a separating roller 43 for separating the sheet into one sheet. The second unloading section 32 includes transport rollers 44 and 45 for transporting the recording material P in the direction V2 and a guide path 46 for changing the direction of the recording material P. Reference numeral 47 denotes a sensor as a recording material presence / absence detecting means for detecting the presence / absence of the recording material P on the paper feed table 30, and a conventionally known optical sensor or a mechanical sensor such as a microswitch is used.

As is apparent from the drawing, the recording material P on the paper feed table 30 is temporarily moved away from the image forming apparatus main body A in the direction V.
After the sheet is unloaded by the first unloading unit 31 and then conveyed to the registration roller 20 by the second unloading unit 32 after reversing the direction, the length of the sheet feeding path from the additional sheet feeding unit B is The length is much longer than the length of the paper feed path from the additional paper feed unit. With such a configuration, the problem of the timing of forming an image on the photoconductor 1 and feeding the recording material P, which has conventionally been a problem, is solved.

Next, this point will be described with reference to FIG. Time required for the image to move from the image forming position G where the toner is transferred from the developing sleeve 4SL of the developing device 4 to the photoconductor 1 to form an image, to the transfer position T where the image is transferred to the recording material P by the transfer device 5 Is assumed to be t1. What is compared with the moving time t1 of the image is the time from when the feeding of the recording material P is determined to when the sheet feeding is started and when the recording material P reaches the transfer position T. That is, it is the time from when the sensor 47 detects the presence or absence of the recording material to when the recording material P reaches the transfer position T. This time is a time t2 from when the sensor 47 detects the presence or absence of the recording material P to when the feeding roller 41 is activated and the feeding is started, and when the leading edge of the recording material P is transferred from the activation of the feeding roller 41 to the transfer position T. Is reached during the time t3.

If t1 <(t2 + t3), when the absence of the recording material is detected and the image formation is stopped, the image forming process can be stopped without performing the image formation by the developing device 4. In the illustrated image forming apparatus, this relationship is sufficiently satisfied.

(2) Second Embodiment FIG. 2 shows a second embodiment of the present invention. In the example of FIG.
The additional paper supply unit B is provided on the paper discharge side of the image forming apparatus main body A. In the example of FIG.
1. An additional paper supply unit having a separation conveyance roller 42 and a separation roller 43 is provided in the additional paper supply unit B, and the direction of the recording paper P conveyed from the additional paper supply unit is almost reversed. Transport section HT that transports the sheet to the registration roller 20
Is provided in the image forming apparatus main body A. Also in this example, since the distance from the additional paper supply unit paper supply means to the transfer position T is sufficiently longer than the distance from the image forming position G to the transfer position T,
The relationship of t1 <(t2 + t3) is sufficiently satisfied, and it is possible to sufficiently prevent unnecessary image formation from being performed when the recording sheet P runs out and the image formation is stopped.

(3) Third Embodiment FIG. 3 shows a third embodiment of the present invention. In the example of FIG. 3, an additional paper supply unit B having a first discharge unit 31 and a second discharge unit 32 is provided in an additional paper supply unit B provided on the paper discharge side of the image forming apparatus main body A. As is apparent from FIG. 3, also in this example, since the distance from the additional sheet feeding unit sheet feeding means to the transfer position T is sufficiently longer than the distance from the image forming position G to the transfer position T, t1 <(t2 + t3). Is sufficiently satisfied, and unnecessary image formation can be sufficiently prevented from being performed when the recording sheet P is exhausted on the sheet supply table 30 and image formation is stopped.

(4) Fourth Embodiment FIG. 4 shows a color image forming apparatus according to a fourth embodiment of the present invention. In this example, the driving roller R1 and the driven roller R2
A belt-shaped photoreceptor 50 is used as an image carrier that is stretched between them, and forms a color image as an image forming unit including a charging device 51, an exposure device 52, and a developing device 53 in opposition to the photoreceptor 50. Image forming section 1Y for forming a yellow image, image forming section 1M for forming a magenta image, and image forming section 1 for forming a cyan image
C, an image forming section 1K for forming a black image is arranged.

The other components are substantially the same as those shown in FIG. 1, and the description of each component is omitted.

In accordance with the rotation of the photosensitive member 50 as indicated by the arrow, a color image is formed in each image forming section at a controlled timing, and is superimposed on the photosensitive member 50 to form a full-color image. The formed full-color image is collectively transferred to the recording material P by the transfer device 5, and a full-color image is formed on the recording material P. The photoreceptor 50 after the transfer is cleaned by the cleaning device 8. Further, after the recording material P after the transfer is fixed by the fixing device 7, the sheet
Is discharged. In double-sided image formation, the recording material P on which an image is formed on the front surface is fed to the back sheet feeding means 9 by the switching guide member 11 after passing through the fixing device 7. In the color image forming apparatus, a plurality of image forming units 1Y, 1
As a result, M, 1C, and 1K are provided in parallel with the photoconductor 50. As a result, the image forming unit 1Y that initially forms an image on the photoconductor 50 moves from the image forming position G to the transfer position T. The moving distance of the image, that is, the moving time becomes longer. Therefore, the moving time of the image from the image forming position G to the transfer position T tends to be longer than the moving time of the recording material P from the recording paper storage unit to the transfer position T. As shown in FIG. 4, the first unloading unit 31 and the second unloading unit 3
2, the conveying distance of the recording material P was increased, so that the relationship described in the first embodiment, that is, t1 <(t2 + t
When the relationship of 3) is satisfied and the image forming is stopped when the recording material P runs out on the sheet feeding table 30, it is possible to prevent unnecessary image formation from being performed.

(5) Fifth Embodiment FIG. 5 shows a color image forming apparatus according to a fifth embodiment of the present invention.

In the color image forming apparatus shown in FIG. 5, an image forming section as a plurality of image forming means, ie, an image forming section as a plurality of image forming means, is opposed to an intermediate transfer body 60 as an image carrier stretched between a driving roller R1 and a driven roller R2. An image forming unit 2Y for forming a yellow image, an image forming unit 2M for forming a magenta image, an image forming unit 2C for forming a cyan image, and an image forming unit 2K for forming a black image.

Each of the image forming sections 2Y, 2M, 2C and 2K has a photosensitive member 61, a charging device 62, an exposing device 63, a developing device 64, a transfer device 65, and a cleaning device 66. In the drawing, reference numerals are given to the respective portions only for the image forming portion 2Y, and the other portions are omitted.

In accordance with the rotation of the intermediate transfer member 60 indicated by the arrow, a color image is formed in each image forming portion at a controlled timing, and the color image formed in each image forming portion is transferred by the transfer device 65 to the intermediate transfer member 60. And the full-color image formed by being superimposed on the intermediate transfer body 60 is collectively transferred to the recording material P by the transfer device 65,
A full-color image is formed on the recording material P. In the color image forming apparatus, the plurality of image forming units are
As a result, the moving time t1 during which the image moves from the image forming position G to the transfer position T of the image forming unit 2Y where the image is first formed on the intermediate transfer body 60, as is apparent from FIG. [FIG. 8B] becomes longer. Therefore, the distance from the developing device 53 to the transfer position T is more likely to be longer than the distance from the recording material presence / absence detecting means provided in the recording paper storage unit to the transfer position T. As shown in FIG. 5, the first unloading unit 31 and the second unloading unit 32 are provided in the additional sheet feeding unit B, and the conveying path of the recording material P is lengthened. t1 <(t2 + t3)
Is satisfied, the unnecessary image formation can be prevented from being performed when the image formation is stopped when the recording material P runs out on the sheet supply table 30.

(6) Embodiment 6 FIG. 6 shows an image forming apparatus according to Embodiment 6 of the present invention.

This embodiment is an improvement of the jam processing mechanism in the event of a jam such as a recording material jamming in the image forming apparatus.

Reference numeral 71 denotes a drum-shaped photoreceptor as an image carrier. The photoreceptor is an organic photoreceptor having an organic photoconductive layer formed on a conductive drum such as aluminum or an a-Si photoconductive drum. An a-Si photoconductor on which a layer is formed is used. Reference numeral 72 denotes a charging device as a charging unit including a scorotron charger having a control grid and a charging electrode, and forms a uniform potential on the photoconductor 71 by charging.
An exposure device 73 uses a laser diode as a light source and has a scanning optical system including a polygon mirror, a mirror, and a lens. The exposure device 73 performs dot exposure on the photosensitive member 71 in accordance with image data to form an electrostatic latent image. I do. In addition,
As the exposure device, any conventionally known scanning exposure device such as a scanning exposure device having a light emitting diode array and an image-forming optical fiber, and a liquid crystal is used. Reference numeral 74 denotes a developing device as a developing unit that develops the electrostatic latent image on the photoconductor 71 using a one-component developer or a two-component developer, and develops the electrostatic latent image on the photoconductor 71 with a developing sleeve. Thus, an image is formed on the photoconductor 71.

A developing bias having the same polarity as that of the electrostatic latent image on the photoconductor 71 is applied to the developing sleeve, and reversal development is performed in which toner is adhered to an exposed portion on the photoconductor 71. Note that it is also possible to apply a bias potential having a polarity opposite to that of the electrostatic latent image on the photoconductor to the developing sleeve to perform normal development. 75
Is a transfer device as transfer means for charging the recording material P to a polarity opposite to that of the toner on the photoconductor 71 and transferring the toner on the photoconductor to the recording material P. Reference numeral 76 denotes a separation device that charges the recording material P after transfer with an AC corona to remove the charge from the recording material P, and separates the recording material P from the photoconductor 71. Reference numeral 77 denotes a fixing device as a fixing unit having a heating roller having a heat source such as a halogen lamp and a pressure roller pressed against the heating roller. The fixing device 77 conveys an image on the recording material P while conveying the recording material P substantially horizontally. Establish. Reference numeral 78 denotes the photoconductor 7 that has passed through the separation device 76.
1 is a cleaning device as a cleaning means for cleaning 1. Reference numeral 79 denotes a back-side paper feeding unit for reversing the recording material P on which an image is formed on the front surface and feeding it again to the transfer position T. A switching guide member 81 guides the recording material P that has passed through the fixing device 77. The switching guide member 81 guides the recording material P that has passed through the fixing device 77 to the discharge tray 80 or a reverse discharge path 89.
The switching guide member 81 switches whether the sheet is guided to the back-side sheet feeding means 79. Reference numeral 82 denotes a recording material P which is synchronized with image formation on the photosensitive member 71,
5 is a registration roller as a sheet feeding means for transporting to a transfer position T formed by the transfer roller 5. Reference numerals 83 and 84 denote paper cassettes, which supply the recording material P to the registration rollers 82 via paper feed paths 85 and 86, respectively.

In accordance with the rotation of the photosensitive member 71 indicated by the arrow, an electrostatic latent image is formed on the photosensitive member 71 by charging by the charging device 72 and exposure by the exposure device 73. The electrostatic latent image is developed by the developing device 74 to form an image on the photoconductor 71. The formed image is transferred by the transfer device 75 and fixed on the recording material P by the fixing device 77. The recording material P after the fixing is discharged to the discharge tray 80 as it is. In the double-sided mode, the recording material P is guided by the switching guide member 81 and conveyed to the back-side paper feeding means 79. After being turned over, the sheet is again conveyed to the transfer position T and the image is transferred to the back surface.

The present embodiment has a reverse discharge mode in which the recording material P on which an image is formed is turned upside down and discharged, and in the reverse discharge mode, the recording material P passing through the fixing device 77 is used. Is conveyed to the reverse sheet discharging path 89 by the switching guide member 81. In the reverse discharge path 89, the recording material P is conveyed in the reverse direction after being conveyed and conveyed out, guided by the switching guide member 88 to the discharge roller 87, and discharged to the discharge tray 80 by the discharge roller 87. .

The photosensitive member 71 that has passed the transfer position T is cleaned by the cleaning device 78.

A reading device 90 reads an image of a document and generates image data. In the present embodiment, the fixing device 77, the discharge roller 87, the switching guide member 81, and the switching guide member 88 are formed in a unit U1 indicated by a dotted line, and as shown by an arrow W1, the conveying and discharging direction of the recording material P. It has a configuration that can be pulled out. Note that, depending on the configuration of the apparatus, it may be configured such that only the fixing device 77 can be formed in the unit U1 and pulled out. For example, a unit U1 having no reverse sheet discharge function or double-sided function, or a unit having the reverse sheet discharge function or the double-sided function with another structure can be configured such that only the fixing device 77 is detachable.

By pulling out the unit U1, the jammed recording material P having the vicinity of the transfer position T open can be easily taken out.

In this embodiment, the transfer device 7
5. The separating device 76 and the registration roller 82 are formed in a unit U2 indicated by a dotted line, and are configured to be able to be pulled out in a direction indicated by an arrow W2, that is, in a direction opposite to a conveying direction of the recording material. The unit U2 has a transport path including a paper feed path for transporting the recording material P substantially horizontally and supplying the recording material P to the transfer position as shown in the drawing. The transfer device 75 and the separation device 76 are included in the unit U2, and are configured to be able to be pulled out from the image forming apparatus main body. Then, after the units U1 and U2 are respectively taken out, the transport paths in these units can be opened.

With this configuration, the space in the vicinity of the transfer position T is widely opened, so that the jammed recording material P can be easily taken out, and the jammed recording material P can be easily processed in the unit. become.

The door DR indicated by the alternate long and short dash line can be opened by turning about the axis DRX.
After U2 is pulled out, the door DR is turned around the axis DRX and opened, and the recording material conveyance path is opened to the operation side of the operator, so that the jammed recording material P can be removed. Door DR
Is provided on the front of the image forming apparatus, and is attached to the image forming apparatus so as to be rotatable around the axis DRX in the front of the paper of FIG. 6. By opening the door DR, the front of the image forming apparatus is opened. You.

(7) Seventh Embodiment FIG. 7 shows a seventh embodiment of the present invention.

In this embodiment, the discharge rollers 87
Paper discharge unit U including the switching guide members 81 and 88
3 is attached to the exterior panel PN of the image forming apparatus, and as shown in the figure, the exterior panel PN is opened and the paper unit U3 is evacuated as shown by (U3), and then the unit U1 including the fixing device 77 is provided. In the direction of arrow W1. In this embodiment,
The transfer device 75 and the separation device 76 are excluded from the pull-out unit U2 on the paper feed side including the registration roller 82, and the transfer device 75 and the separation device 76 remain in the image forming apparatus during the jam processing. Even with such a configuration, the vicinity of the transfer position T is largely opened by pulling out the units U1 and U2 and opening the door DR, so that the jammed recording paper P can be easily removed.

[0074]

According to the first, third, or sixteenth aspect of the present invention, even in an image forming apparatus provided with an additional paper feed unit where the paper feed path tends to be short, the stop when the additional paper feed unit runs out of recording material. In the control, unnecessary image formation on the image carrier is prevented from being performed, and it is possible to prevent an increase in load on the cleaning device due to removal of toner forming an unnecessary image and waste of toner. In addition, it is possible to prevent early deterioration of the image carrier.

According to the second, ninth and tenth aspects of the present invention, in the image forming apparatus provided with an additional paper supply unit on the paper discharge side of the image forming apparatus from which the recording material on which the image is formed is discharged, In the stop control when the recording material is exhausted, unnecessary image formation is prevented from being performed on the image carrier, and the load on the cleaning device is increased by removing the toner forming the unnecessary image. And waste of the toner can be prevented, and early deterioration of the image carrier can be prevented.

According to the fourth and eleventh aspects of the present invention, in a color image forming apparatus for forming an image on a photoreceptor and transferring the image from the photoreceptor to a recording material, a stop when the recording material is exhausted in the additional paper supply unit. In the control, the unnecessary image formation on the image carrier is prevented from being performed, and the increase in the load on the cleaning device and the waste of the toner due to the removal of the toner forming the unnecessary image can be prevented. This makes it possible to prevent the image carrier from being deteriorated early.

According to the fifth and twelfth aspects of the present invention, in a color image forming apparatus for transferring an image formed on a photoreceptor to an intermediate transfer member and then transferring the image from the intermediate transfer member to a recording material, In the stop control when the recording material runs out, unnecessary image formation is prevented from being performed on the image carrier, and the load on the cleaning device due to the removal of the toner forming the unnecessary image is increased. It is possible to prevent waste of toner and prevent early deterioration of the image carrier.

According to the invention of claims 6, 7, 13, and 14,
By arranging a plurality of image forming means opposite to the image carrier, even in an image forming apparatus in which the distance from the first image forming position to the transfer position is long, the recording material is no longer present in the additional paper supply unit. During the stop control, unnecessary image formation is prevented from being performed on the image carrier, thereby preventing an increase in load on the cleaning device and waste of toner due to removal of toner forming an unnecessary image. This makes it possible to prevent the image carrier from being deteriorated early.

According to the eighth and fifteenth aspects of the present invention, when an additional paper feeding unit is provided in an image forming apparatus having a double-sided image forming function, the image forming apparatus performs the image control in the stop control when the additional paper feeding unit runs out of recording material. Unnecessary image formation on the carrier is prevented, and it is possible to prevent an increase in load on the cleaning device and waste of toner due to removal of toner forming unnecessary images. In addition, early deterioration of the image carrier can be prevented.

According to the seventeenth aspect of the present invention, since the fixing means is pulled out in the moving direction of the recording material, the recording material jammed in the apparatus is bent or broken in an accordion state by the drawing, making it difficult to remove the recording material. Is solved, and the jam processing is facilitated.

According to the eighteenth and twenty-third aspects of the present invention, the transport path for transporting the recording paper to the transfer position is taken out along the transport direction, so that the recording material jammed in the apparatus is bent or broken in an accordion state. Inconveniences such as difficulty in removal are eliminated and jam clearance is facilitated.
Jam processing for removing the recording material jammed at the time of the transfer position becomes easy.

According to the nineteenth aspect, the recording material conveyance path near the transfer position is greatly opened, so that the jam processing is extremely easy.

According to the twentieth aspect of the present invention, the jam processing can be easily performed in the image forming apparatus provided with the paper discharge path for guiding the recording paper passing through the fixing means.

According to the twenty-first aspect of the present invention, it is easy to remove a jam when a recording material is jammed in the sheet discharging path.

According to the twenty-second aspect, the jam in the fixing unit and the jam in the paper discharge unit after fixing can be separately processed, so that the jam processing is further facilitated.

According to the twenty-fourth aspect, the transfer device is pulled out together with the transport path for transporting the recording material to the transfer position. Therefore, the transport path near the transfer position is greatly opened, and the jam processing becomes extremely easy.

According to the twenty-fifth aspect of the invention, it is easy to remove a jam in the transport path for transporting the recording material to the transfer position.

According to the twenty-sixth aspect of the present invention, in an image forming apparatus for forming an image on a photoreceptor and transferring the image from the photoreceptor to a recording material, the recording material jammed in the apparatus is bent or broken in an accordion state. Thus, the inconvenience such as the difficulty of removal is eliminated, and the jam processing is facilitated.

According to the twenty-seventh aspect of the present invention, in an image forming apparatus for transferring an image formed on a photoreceptor to an intermediate transfer member and then transferring the image from the intermediate transfer member to a recording material, the recording material jammed in the apparatus may have an accordion. Inconveniences, such as being bent or broken in a state and making it difficult to remove, are eliminated, and jam clearance is facilitated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration of an image forming apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a diagram showing a configuration of an image forming apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a diagram showing a configuration of a color image forming apparatus according to Embodiment 4 of the present invention.

FIG. 5 is a diagram illustrating a configuration of a color image forming apparatus according to Embodiment 5 of the present invention.

FIG. 6 is a diagram showing a configuration of an image forming apparatus according to Embodiment 6 of the present invention.

FIG. 7 is a diagram showing a configuration of an image forming apparatus according to Embodiment 7 of the present invention.

FIG. 8 is a diagram illustrating the relationship between the timing of image formation on the image carrier and the timing of sheet feeding.

[Explanation of symbols]

 1, 50, 61 Photoconductor 2, 51, 62 Charging device 3, 52, 63 Exposure device 4, 53, 64 Developing device 5, 65 Transfer device 6 Separation device 7 Fixing device 8 Cleaning device 20, 82 Registration roller 30 Paper feed Table 31 First unloading unit 32 Second unloading unit 41 Delivery roller 42, Separation and conveyance roller 43 Separation roller A Image forming apparatus main body B Additional paper feed unit U1, U2, U3 Unit P Recording material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/01 G03G 15/01 N 3F048 15/16 15/16 3F100 15/20 101 15/20 101 3F343F Terms (reference) 2H028 BA06 BA09 BA16 2H030 AA06 AA07 AB02 AD05 BB02 BB23 BB42 BB71 2H032 BA09 BA15 BA23 2H033 AA29 AA37 BA06 BA10 BB01 BB28 2H072 AA02 AA22 AA32 AB01 AB15 BA13 3A01 BA01 DA01 BA01 3F343 FA02 FB01 FC08 GA01 GB01 GC01 GD01 HA37 HB08 JA01 KB03 MA23 MA56

Claims (27)

[Claims] 1. An image carrier, an image forming means arranged to face the image carrier and forming an image on the image carrier, and transferring an image formed on the image carrier to a recording material Transfer means, fixing means for fixing an image transferred to a recording material, paper supply means for supplying a recording material to a transfer position formed by the transfer means, and main body paper supply section for supplying a recording material to the paper supply means An additional paper supply unit having an additional paper supply unit for storing a recording material, and an additional paper supply unit for unloading the recording material from the additional paper supply unit; Is provided substantially in parallel with the main body paper supply unit. The additional paper supply unit paper supply unit is a first discharge unit that discharges a recording material from the additional paper supply unit recording material storage unit. A second transporting device that transports the recording material toward the paper feeding unit while substantially reversing the transport direction. Image forming apparatus characterized by having parts and the recording material presence detection means provided in the vicinity of the first discharge section. 2. The image forming apparatus main body according to claim 1, wherein a reversing conveyance section for substantially reversing the recording material from the second unloading section and conveying the recording material toward the sheet feeding means is provided in the image forming apparatus main body. Image forming apparatus. 3. The method according to claim 1, further comprising: determining a paper feed based on a detection result of the recording material presence / absence detection unit, based on a detection result of the recording material presence / absence detection unit, rather than an image movement time from the image forming position of the image forming unit to the transfer position. 3. The image forming apparatus according to claim 1, wherein a time required to reach the transfer position is longer. 4. The image forming apparatus according to claim 1, wherein said image bearing member is made of a photoreceptor, and has a plurality of said image forming means for forming a plurality of images on said photoreceptor. The image forming apparatus as described in the above. 5. The photoconductor, the photoconductor, an electrostatic latent image forming device, a developing device for developing an electrostatic latent image to form an image on the photoconductor, and the photoconductor. 4. The image forming apparatus according to claim 1, further comprising a plurality of image forming units having a transfer unit configured to transfer an image formed on the intermediate transfer body. 5. 6. A paper feed is determined based on a detection result of the recording material presence / absence detection unit, based on a moving time of an image from an image formation position of a leading image formation unit of the plurality of image formation units to the transfer position. 6. The image forming apparatus according to claim 4, wherein a time from when the recording material is fed to when the recording material is fed to the transfer position is longer. 7. The image forming apparatus according to claim 1, wherein said image bearing member has a belt shape. 8. An image forming apparatus according to claim 1, further comprising a back-side paper feeding means for forming an image on one side and inverting the recording material having passed through said fixing means, and conveying the recording material to said paper feeding means.
8. The image forming apparatus according to claim 7. 9. An image carrier, an image forming means arranged to face the image carrier and forming an image on the image carrier, and transferring the image formed on the image carrier to a recording material Transfer means, fixing means for fixing an image transferred to a recording material, paper supply means for supplying a recording material to a transfer position formed by the transfer means, and main body paper supply section for supplying a recording material to the paper supply means An image forming apparatus main body comprising: an additional paper supply unit for storing a recording material; an additional paper supply unit for discharging a recording material from the additional paper supply unit; and the additional paper supply unit. A recording material presence / absence detecting unit provided near the paper feeding unit, an additional paper feeding unit provided substantially in parallel with the main body paper feeding unit, and the recording medium is ejected by the additional paper feeding unit. After substantially reversing the conveying direction of the recording material, An image forming apparatus characterized in that a reverse conveying portion supplied to the image forming apparatus main body. 10. A method according to claim 1, further comprising: determining a paper feed based on a detection result of a recording material presence / absence detecting unit, rather than an image moving time from the image forming position of the image forming unit to the transfer position; The image forming apparatus according to claim 9, wherein a time required to reach the transfer position is longer. 11. An image according to claim 9, wherein said image bearing member is made of a photoreceptor, and has a plurality of said image forming means for forming a plurality of images on said photoreceptor. Forming equipment. 12. The image bearing member comprises an intermediate transfer member,
A photoconductor, an electrostatic latent image forming unit, a developing unit that develops an electrostatic latent image to form an image on the photoconductor, and a transfer unit that transfers an image formed on the photoconductor to the intermediate transfer body. The image forming apparatus according to claim 9, further comprising a plurality of the image forming units. 13. A paper feed is determined based on a detection result of the recording material presence / absence detecting means, based on a moving time of an image from an image forming position of a leading image forming means of the plurality of image forming means to the transfer position. After that, the recording material is fed,
The image forming apparatus according to claim 11, wherein a time required to reach the transfer position is longer. 14. The image forming apparatus according to claim 9, wherein said image bearing member has a belt shape. 15. An image forming apparatus according to claim 1, further comprising a back-side sheet feeding means for turning over the recording material having an image formed on one side thereof and passing through said fixing means, and transporting the recording material to said sheet feeding means.
15. The image forming apparatus according to any one of claims 14 to 14. 16. A recording material storing means for storing a recording material, and a first material for unloading the recording material in the recording material storing means in a first direction.
An additional sheet feeding device, comprising: a carry-out unit and a second carry-out unit that reverses the recording material from the first carry-out unit and delivers the material in a second direction substantially opposite to the first direction. 17. An image carrier, an image forming unit arranged to face the image carrier, and forming an image on the image carrier, and transferring the image formed on the image carrier to a recording material. An image forming apparatus comprising: a transfer unit; and a fixing unit that conveys a recording material conveyed from a transfer position formed by the image carrier and the transfer unit substantially horizontally and fixes an image on the recording material. An image forming apparatus, wherein the fixing unit is provided so as to be able to be taken out in a direction along a moving direction of the recording material passing through the fixing unit. 18. An image carrier, an image forming means arranged to face the image carrier and forming an image on the image carrier, and transferring the image formed on the image carrier to a recording material An image forming apparatus comprising: a transfer unit; and a fixing unit that conveys a recording material conveyed from a transfer position formed by the image carrier and the transfer unit and fixes an image on the recording material. An image having a transport path including a substantially horizontal paper feed path for supplying a recording material, wherein the transport path is provided so as to be able to be taken out in a direction substantially opposite to a moving direction of the recording paper. Forming equipment. 19. The image forming apparatus according to claim 17, further comprising a door that opens and closes in a direction substantially perpendicular to the moving direction of the recording material and opens the vicinity of the transfer position. . 20. The fixing unit is taken out integrally with the fixing unit.
The image forming apparatus according to any one of claims 17 to 19, further comprising a paper discharge path that guides and discharges the fixed recording material. 21. The image forming apparatus according to claim 20, wherein said paper discharge path is openable after being taken out. 22. A sheet discharging path for guiding a recording material after fixing and discharging the sheet, wherein the sheet discharging path is arranged so that the fixing unit can be taken out after the sheet discharging path is retracted. 20. The image forming apparatus according to claim 17, further comprising: 23. The image forming apparatus according to claim 18, wherein the conveying path includes a sheet feeding unit that conveys a recording material to the transfer position in synchronization with image formation on the carrier. Item 10. The image forming apparatus according to item 1. 24. The image forming apparatus according to claim 18, wherein the transport path includes the transfer unit. 25. The transport path according to claim 18, wherein at least a part of the transport path is openable after being taken out.
25. The image forming apparatus according to any one of items 24 to 24. 26. The image forming apparatus according to claim 17, wherein said image bearing member is made of a photoreceptor, and has a plurality of said image forming means for forming a plurality of images on said photoreceptor. The image forming apparatus as described in the above. 27. The image bearing member comprises an intermediate transfer member,
A photoconductor, an electrostatic latent image forming unit, a developing unit that develops an electrostatic latent image to form an image on the photoconductor, and a transfer unit that transfers an image formed on the photoconductor to the intermediate transfer body. The image forming apparatus according to any one of claims 17 to 26, further comprising a plurality of the image forming units provided.