JPH0940302A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate necessity of reducing the number of stages of a paper feeding cassette even in the case of mounting a stacking part for double-side image formation by providing a second paper feeding cassette in a dead space between a conveying means and the stacking part. SOLUTION: A conveying path part 29 serving as a conveying means for conveying paper at the time of double-side copying is provided on the upper side in a case 50. A plurality of carrier rollers 30 are disposed in the conveying path part 29, along a paper conveying direction. A unit 3A is provided below the conveying path part 29, and this unit 3A is provided with a stacking part 45 for stacking paper discharged from the conveying path part 29 and fed through a switching gate 51, a guide 53 and a discharge roller 54. An auxiliary paper feeding cassette 66 serving as a second paper feeding cassette is provided in a dead space between the stacking part 45 and the conveying path part 29, integrally with the stacking part 45. Paper feeding function can thereby be added without making a device large-sized.

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 applied as an electronic copying machine, for example.

[0002]

2. Description of the Related Art Some image forming apparatuses of this type are capable of forming images on both sides of a sheet. The paper is supplied from a paper feed cassette and sent to an image transfer section between the photoconductor and the transfer charger, where the image is transferred to one surface side thereof. The paper with the image transferred to this one side is temporarily
After being accumulated in the stack section (accumulation section), it is taken out from the stack section and inverted, and is sent to the image transfer section again, and the image is transferred to the other surface side and discharged to the sheet discharge tray.

In the type in which both the stack section and the paper feed cassette are incorporated in the apparatus main body and pulled out from the front side of the apparatus main body, when the stack section is attached, the stack section has at least the same size as the paper feed cassette. Therefore, it is necessary to reduce the number of paper feed cassettes by one.

[0004]

However, reducing the number of stages of the paper feed cassette by one stage impairs the commerciality in the diversification of the paper size. Especially,
In the case where the paper feed cassette is provided with two stages as standard equipment, if the number of paper feed cassette stages is reduced by one by mounting the stack section, only one paper feed cassette is provided.

Therefore, when two sheet feeding cassettes are required, a sheet feeding cassette device must be separately mounted, and the size of the apparatus main body is increased by one cassette and the cost is increased. There was an inconvenience. Therefore, in the present invention, even if the stacking unit for double-sided image formation is mounted,
An object of the present invention is to provide an image forming apparatus that does not need to reduce the number of paper feed cassette stages.

[0006]

In order to solve the above-mentioned problems, the present invention provides a device main body having an image transfer section for transferring an image onto a sheet, and a first sheet feeding apparatus for feeding the sheet. A paper cassette, a first feeding means for feeding the paper supplied from the first paper feeding cassette to the image transfer section, and transferring the image to the one side, and an image transferred to the one side by the image transfer section. Conveying means for conveying the sheets, a stacking section for accumulating the sheets conveyed by the conveying means provided in parallel with the conveying means at a predetermined interval, and taking out the sheets accumulated in the accumulating section, the image Second feeding means for feeding the image to the transfer portion to transfer the image to the other surface side, a second paper feeding cassette provided in a space between the conveying means and the stacking portion for feeding the paper, and The paper supplied from the paper cassette Formed by and a third feed means for transferring an image on one side is sent to the serial image transfer unit.

According to a second aspect of the present invention, there is provided an apparatus main body having an image transfer section for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette. To the image transfer section for transferring an image to one surface side, a conveying means for conveying the sheet having the image transferred on the one surface side by the image transfer section, and a predetermined interval with respect to the conveying means. A stacking unit that is provided in parallel and stacks the sheets that are transported by the transporting unit; and a sheet that is stacked on the stacking unit and is sent to the image transfer unit to transfer the image to the other surface side. A feed unit, a second paper feed cassette provided in the space between the transport unit and the stacking unit for feeding paper, and a paper feed unit that intersects with the transport unit and feeds paper from the second paper feed cassette. Send it to the image transfer section ; And a third feed means for transferring the image on the side formed by.

According to a third aspect of the present invention, an apparatus main body having an image transfer portion for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette. To the image transfer section for transferring an image to one surface side, a conveying means for conveying the sheet having the image transferred on the one surface side by the image transfer section, and a predetermined interval with respect to the conveying means. A stacking unit that is provided in parallel and stacks the sheets that are transported by the transporting unit; and a sheet that is stacked on the stacking unit and is sent to the image transfer unit to transfer the image to the other surface side. A feed unit, a second paper feed cassette provided in the space between the transport unit and the stacking unit for feeding paper, and a paper feed unit that intersects with the transport unit and feeds paper from the second paper feed cassette. Send it to the image transfer section Third feeding means for transferring the image to the surface side, and a sheet which is provided at the intersection of the third feeding means and the conveying means and which is conveyed by the conveying means and the third feeding means. And a guide means for selectively guiding the sheet.

According to a fourth aspect of the present invention, an apparatus main body having an image transfer section for transferring an image onto a sheet, a mounting table on which the apparatus main body is mounted, and a mounting table provided inside the mounting table to supply the sheet. The first paper feed cassette and the paper supplied from the first paper feed cassette are sent to the image transfer unit through a first communication port that connects the apparatus main body and the mounting table, and an image is displayed on one surface side. A first feeding means for transferring, a conveying means for conveying a sheet on which an image is transferred on one surface side in the image transfer section, and a conveying means provided in parallel with the conveying means at a predetermined interval. A stacking unit that stacks the sheets to be stacked, and a second feeding unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit through the first communication port to transfer the image to the other surface side. , The space between the transport means and the stacking unit And a second paper feed cassette that supplies paper to the image transfer unit via a second communication port that connects the paper supplied from the second paper feed cassette to the apparatus main body and the mounting table. A third feeding means for transferring an image to the one feeding side is provided.

According to a fifth aspect of the present invention, there is provided an apparatus main body having an image transfer section for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette. To the image transfer section for transferring an image to one surface side, a conveying means for conveying the sheet having the image transferred on the one surface side by the image transfer section, and a predetermined interval with respect to the conveying means. A second stacking unit, which is provided in parallel and stacks the sheets transported by the transporting unit; A feed unit, a second paper feed cassette provided in the space between the transport unit and the stacking unit for feeding paper, and a paper feed unit that intersects with the transport unit and feeds paper from the second paper feed cassette. Send it to the image transfer section A third feeding means for transferring an image to the surface side, the third feeding means for feeding the image from the intersecting portion to the image transferring portion, the conveying means, and the route connecting the intersecting portions. The operation of the means is stopped.

According to the first to fifth aspects of the invention, the second paper feed cassette is provided in the dead space between the conveying means and the accumulating section, so that the size of the apparatus is not increased.
Enable to add paper feeding function.

Further, according to a third aspect of the present invention, the guide means is provided at the intersection of the third feeding means and the conveying means, and the sheet conveyed by the conveying means by the guide means and the third feeding means. By selectively guiding the sheets to be fed, it is possible to satisfactorily accumulate the sheets in the stacking unit or feed the sheets to the image transfer unit.

According to a fifth aspect of the present invention, the operation of the third feeding means is stopped by stopping the operation of the third feeding means when the paper is full in the route connecting the intersection, the image transfer portion, the conveying means and the intersection. The sheets sent from the second paper feed cassette do not collide with the sheets sent to the stacking unit, and the sheets can be stacked well.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 2 is an external view showing the overall configuration of the electronic copying apparatus. In the figure, reference numeral 1 denotes an apparatus main body, an automatic document feeder 2A is provided on the upper surface of the apparatus main body 1, and a paper discharge tray 4 is provided on one side.

The apparatus body 1 is a housing (mounting table) 5 of the sheet feeding apparatus.
0 is mounted on the upper surface. A unit 3A and first paper feed cassettes 3B and 3C are arranged in the housing 50 so that the unit 3A can freely move in and out.

FIG. 3 is a diagram showing the internal structure of the electronic copying apparatus. A scanner section 5 is provided on the upper side of the apparatus main body 1. The scanner unit 5 is provided with first and second carriages 6 and 7 so as to be movable. The first carriage 6 is provided with an exposure lamp 8 and a first reflection mirror 9. Second and third reflection mirrors 10 and 11 are arranged on the second carriage 7. An optical lens 13 and a light receiving element 14 are arranged in the optical path of the reflected light reflected by the third reflecting mirror 11.

A sheet conveying path 15 is horizontally provided below the scanner section 5. A registration roller 22, an image forming unit 17, a conveyance belt 27, a fixing unit 18, a feed roller 28, a gate 19 and a discharge roller 20 are sequentially arranged in the paper conveyance path 15 along the paper conveyance direction. There is.

The image forming means 17 rotatably includes a photosensitive drum 31 as an image carrier, and a peripheral portion of the photosensitive drum 31 is a charging charger 32 as a charging means sequentially in the rotation direction. Exposure unit 33, developing device 3
4, transfer, peeling charger 35a, 35b, further,
A cleaner 36 is provided.

Reference numeral 39 is a polygon mirror for scanning the information light. The light scanned by the polygon mirror 39 is sent to the exposure unit 33 via the optical system 40. The developing device 34 accommodates a two-component developer composed of toner and carrier and rotatably includes a developing roller 62 for supplying the developer.

The fixing means 18 comprises a heat roller 41,
The heat roller 41 and the press roller 42 are in contact with each other. FIG. 1 shows the inside of a housing 50 of the paper feeding device.

A transport path unit 29 as a transport unit for transporting a sheet at the time of double-sided copying is provided on the upper side of the housing 50. In the transport path unit 29, a plurality of sheets are transported along the transport direction of the sheet. A roller 30 is provided. The sheet conveyed by the sheet conveying path 15 in the apparatus main body 1 is selectively guided to the sheet discharge tray 4 side or the conveying path section 29 side via the guide 52 by the rotation of the gate 19. ing. The unit 3A is provided below the transport path unit 29. The unit 3A is a stacking unit 4 as a stacking unit that stacks the sheets discharged from the transport path unit 29 and sent through the switching gate 51 as the guide unit, the guide 53, and the discharge roller 54.
5 are provided. In the stack portion 45, there are a rear end guide 59 and a width guide 60 that guide the sheets according to the size.
Are arranged. The stacking capacity of the stack part 45 is 10 to 10.
It is 50 sheets.

The stack portion 45 is provided with a rotatable pressing member 55, and a take-out roller 56 for pressing the paper by the pressing member 55. The take-out roller 56 has a half-moon shape and also has a function of separating the paper. A paper feed roller 57 is provided in the takeout direction of the paper taken out by the takeout roller 56. A separation roller 58 is pressed against the paper feed roller 57. The separating roller 58 has a function of using the idling force of the winding of the spring as a brake, and when two or more sheets are fed into the nip portion between the sheet feeding roller 57 and the separating roller 58, the coefficient of friction between the sheet and the rubber of the roller is reduced. Due to the difference
It has a separating function of feeding only the lowermost sheet in contact with the sheet feeding roller 57. The paper fed by the paper feed roller 57 is sent to the paper feed port 62 provided on the upper surface of the housing 50 via the guide 61. The paper feed port 62 has a receiving port 63 provided on the bottom surface of the apparatus body 1.
Is communicated to. The receiving port 63 is connected to the feed roller 65 via a guide 64. Paper feed port 62 and receiving port 6
The first communication port is constituted by 3.

The first paper feed cassettes 3B and 3C are also provided.
The paper inside is taken out by the pick-up roller 23, and the taken-out paper is separated one by one by the paper feed roller 24 and the separation roller 25 and sent out to the vertical conveyance path 55. A pair of feed rollers 16 is arranged in the vertical conveyance path 55 so as to correspond to each of the paper feed cassettes 3B and 3C.

By the way, an auxiliary paper feed cassette 66 is provided in the space between the transport path section 29 and the stack section 45.
Is integrally provided with the stack portion 45 to form the unit 3A.

The paper feed cassette 66 can store a maximum of 200 to 250 sheets of paper. Paper cassette 6
A push-up member 67 is provided in the interior of 6, and is pushed upward by a spring (not shown) to be pressed against the pickup roller 68. The paper is taken out by the rotation of the pickup roller 68.

A paper feed roller 70 is provided in the takeout direction of the paper taken out by the pickup roller 68. A separation roller 71 is pressed against the paper feed roller 70. The separating roller 71 has a function of using the idling force of a spring as a brake, and when two or more sheets are fed into the nip portion between the sheet feeding roller 70 and the separating roller 71, the sheet and the surface rubber portion of the roller 71 are separated from each other. Due to the difference in friction coefficient, it has a separating function of feeding only the lowermost sheet in contact with the sheet feeding roller 70. The paper fed by the paper feed roller 70 is transferred to the housing 5 via the switching gate 51.
The paper is fed to the paper feed port 72 provided on the upper surface of the sheet. The paper feed port 72 communicates with a receiving port 73 provided on the bottom surface of the apparatus body 1. The receiving port 73 is connected to the feed roller 65 via a guide 74. The paper feed port 72 and the receiving port 73 form a second communication port.

When images are formed on both sides of the paper fed from the auxiliary paper feed cassette 66, when the paper is continuously fed, the paper intersects at the switching gate 51,
Since it interferes, control is performed at the following timing.

In the embodiment, the main body feeding speed is set as follows. Process speed: 125 mm / sec, Paper feed speed: 350 mm / sec Number of processed sheets A ₄ Horizontal size: 25 sheets / minute Paper distance: 90 mm Paper path distance from switching gate 51 to registration roller 22: 221 mm (A) Registration roller Paper path distance from 22 to the switching gate 51 via the image transfer unit 17a and the transport path 29 ... 1074 mm (B) Here, it is calculated how many sheets of paper fit within the size of B.

In the case of A ₄ landscape, the length is 210 mm, and if the paper gap of 90 mm is added, it becomes 300 mm. Therefore, even if 3 sheets are inserted within the size of B, the leading edge of the first sheet is switched. It will not be applied to the gate 51.

Further, since the A ₄ lateral size is shorter than the A dimension, one sheet can fit in the A dimension. This gives A
_In case of ₄ sizes, 4 sheets from the paper feed cassette 66
It is possible to stack the sheets on the stack 45 after feeding and forming an image on one side.

However, when four or more sheets are continuously formed on both sides, four sheets are stacked on the stack 45 in one cycle.
That is, when the trailing edge of the fourth sheet passes through the switching gate 51, the sheet feeding from the sheet feeding cassette 66 is started.

In the case of the longest LD, the length is 43
Since it is 2 mm, for the same reason, two pieces will fit in the B dimension. Since it will not fit within the size of A, 2
Stacks of more than one sheet will be stacked in a two-sheet cycle.

Further, when considering a short size, for example, A ₄ width, if the cassette sheet feeding speed is 380 mm / sec or more within the time when 90 mm of paper passes through the switching gate 51,
It is possible for the paper in the paper feed cassette 66 to pass through the switching gate 51 within the time between normal continuous copy papers.

Therefore, at the time of image formation, the original is set on the automatic original feeder 2A and the copy button is turned on. As a result, the original is sent and set on the original placing table 2, the exposure lamp 8 is turned on, and the first and second carriages 6 and 7 are moved. As a result, the original is scanned with light, and the reflected light reflected from the original by this scanning is received by the light receiving element 14 via the first to third reflecting mirrors 9 to 11 and the optical lens 13, and the image is read. The read image is sent to the polygon mirror 39 as information light via a transmission system (not shown). Polygon mirror 3
The information light sent to the laser beam 9 is scanned by the rotation of the polygon mirror 39 and is applied to the photosensitive drum 31 via the optical system 40. The surface of the photosensitive drum 31 is the charging charger 3
It is uniformly charged by 2 and an electrostatic latent image of the original is formed. This electrostatic latent image is sent to the developing device 34 by the rotation of the photoconductor drum 31, toner is supplied, and is visualized.

On the other hand, at this time, the paper feed cassette 3B,
Paper is supplied from 3C or the auxiliary paper feed cassette 66. The sheet picked up by the pickup roller 23 from the sheet feeding cassettes 3B and 3C is fed by the sheet feeding roller 24, and the vertical conveyance path 55, the supply port 62, and the receiving port 63.
The image is transferred to the guide 64 via the (first communication port) and further to the image transfer unit 17a via the feed roller 65 and the registration roller 22 to transfer the image.

The sheet taken out from the auxiliary sheet feeding cassette 66 is guided through a switching gate 51 (shown by a broken line), a supply port 72 and a receiving port 73 (second communication port) to a guide 74.
Then, the image is transferred to the image transfer portion 17a via the feed roller 65 and the registration roller 22, and the image is transferred.

The sheet on which the image is transferred is peeled from the photosensitive drum 31 by the action of the peeling charger 35b, and is fed between the heat roller 41 and the press roller 42 of the fixing means 18 by the traveling of the conveying belt 27 to heat it. And it is pressurized and fixed. The sheet on which the image is fixed is discharged to the sheet discharge tray 4 via the feed roller 28, the gate 19, and the sheet discharge roller 20.

Further, during double-sided copying, the sheet is sent to the conveying path 29 via the guide 52 by the rotation of the gate 19 and is accumulated in the stack section 45 via the switching gate 51 (shown by a solid line).

The collected sheets are taken out by the take-out roller 56, and then sent to the guide 64 through the paper feed roller 57, the guide 61, the supply port 62, the receiving port 63 (first communication port), and further, The image is transferred to the image transfer portion 17a via the feed roller 65 and the registration roller 22, and the image is transferred to the back side.

The sheet on which the image is transferred is peeled off from the photosensitive drum 31 by the action of the peeling charger 35b, and is fed between the heat roller 41 and the press roller 42 of the fixing means 18 by the traveling of the conveying belt 27 to heat it. And it is pressurized and fixed. The sheet on which the image is fixed is discharged to the sheet discharge tray 4 via the feed roller 28, the gate 19, and the sheet discharge roller 20.

As described above, the second paper feed cassette 6 is placed in the dead space between the transport path 29 and the stack portion 45.
Since 6 is provided, without increasing the size of the device,
A paper feeding function can be added, and downsizing and cost reduction can be achieved.

[0042]

As described above, the present invention has the following features.
Since the second sheet feeding cassette is provided in the dead space between the conveying means and the accumulating section, the sheet feeding function can be added without increasing the size of the apparatus, and the size and cost can be reduced. Can be reduced.

Further, according to a third aspect of the present invention, the guide means is provided at the intersection of the third feeding means and the conveying means, and the sheet conveyed by the conveying means by the guide means and the third feeding means. Since the guided sheets are selectively guided, the sheets can be favorably accumulated in the accumulating section or sent to the image transfer section.

According to a fifth aspect of the present invention, the operation of the third feeding means is stopped when the paper is full in the route connecting the intersection, the image transfer portion, the conveying means and the intersection. The sheets sent from the second paper feed cassette do not collide with the sheets sent to the stacking unit, and the sheets can be stacked well.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is an external perspective view showing an electrophotographic apparatus including the sheet feeding device of FIG.

FIG. 3 is a configuration diagram showing the inside of the electrophotographic apparatus of FIG.

[Explanation of symbols]

 P ... Paper 17a ... Image transfer unit 1 ... Device main body 3B, 3C ... First paper feeding cassette 24 ... Paper feeding roller (first feeding means) 29 ... Conveying path (conveying means) 45 ... Stacker (stacking portion) 57 ... Paper feeding roller (second feeding means) 66 ... Second paper feeding cassette 70 ... Paper feeding roller (third feeding means)

Claims (5)

[Claims] 1. An apparatus main body having an image transfer section for transferring an image to a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette for the image transfer section. A first feeding means for transferring an image to the one side of the feeding, a conveying means for conveying the sheet having the image transferred on the one side in the image transfer section, and a parallel arrangement with a predetermined interval with respect to the conveying means. A stacking unit that stacks the sheets that are transported by the transport unit, and second transporting unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit to transfer the image to the other surface side; A second paper feed cassette provided in the space between the means and the stacking unit to feed the paper, and the paper fed from the second paper feed cassette to the image transfer unit to transfer the image to one surface side. The third feeding means, Image forming apparatus characterized by Bei was. 2. An apparatus main body having an image transfer section for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette for the image transfer section. A first feeding means for transferring an image to the one side of the feeding, a conveying means for conveying the sheet having the image transferred on the one side in the image transfer section, and a parallel arrangement with a predetermined interval with respect to the conveying means. A stacking unit that stacks the sheets that are transported by the transport unit, and second transporting unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit to transfer the image to the other surface side; A second paper feed cassette provided in the space between the means and the stacking unit to feed the paper; and a paper feed from the second paper feed cassette, which intersects with the carrying unit, and feeds the paper to the image transfer unit. Transfer the image to the one side An image forming apparatus comprising: a third feeding unit configured to: 3. An apparatus main body having an image transfer section for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette for the image transfer section. A first feeding means for transferring an image to the one side of the feeding, a conveying means for conveying the sheet having the image transferred on the one side in the image transfer section, and a parallel arrangement with a predetermined interval with respect to the conveying means. A stacking unit that stacks the sheets that are transported by the transport unit, and second transporting unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit to transfer the image to the other surface side; A second paper feed cassette provided in the space between the means and the stacking unit to feed the paper; and a paper feed from the second paper feed cassette, which intersects with the carrying unit, and feeds the paper to the image transfer unit. Transfer the image to the one side Third feeding means for making the sheet, and a sheet provided at the intersection of the third feeding means and the conveying means and conveyed by the conveying means, and the third sheet.
An image forming apparatus comprising: a guide unit that selectively guides a sheet fed by the sheet feeding unit. 4. An apparatus main body having an image transfer portion for transferring an image onto a sheet, a mounting table on which the apparatus main body is mounted, and a first paper feed cassette provided inside the mounting table for supplying the sheet. And a sheet fed from the first sheet feeding cassette to the image transfer section through a first communication port that connects the apparatus body and the mounting table to each other, and a first feed that transfers an image to one surface side. Means, conveying means for conveying the paper on which the image is transferred to the one surface side in the image transfer section, and the sheets conveyed by the conveying means are provided in parallel with the conveying means at a predetermined interval and are accumulated. A stacking unit, a second feeding unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit through the first communication port to transfer the image to the other surface side; Paper in the space between A second paper feed cassette to be supplied, and a paper supplied from the second paper feed cassette is sent to the image transfer unit via a second communication port that connects the apparatus main body and the mounting table, and an image is displayed on one surface side. An image forming apparatus comprising: a third feeding unit that transfers the image. 5. An apparatus main body having an image transfer section for transferring an image onto a sheet, a first sheet feeding cassette for feeding the sheet, and a sheet fed from the first sheet feeding cassette to the image transfer section. A first feeding means for transferring an image to the one side of the feeding, a conveying means for conveying the sheet having the image transferred on the one side in the image transfer section, and a parallel arrangement with a predetermined interval with respect to the conveying means. A stacking unit that stacks the sheets that are transported by the transport unit, and second transporting unit that takes out the sheets stacked in the stacking unit and sends the sheets to the image transfer unit to transfer the image to the other surface side; A second paper feed cassette provided in the space between the means and the stacking unit to feed the paper; and a paper feed from the second paper feed cassette, which intersects with the carrying unit, and feeds the paper to the image transfer unit. Transfer the image to the one side A third feeding unit for causing the image transfer unit, the conveying unit from the intersection, and further, when the sheet is full in a route connecting the intersection, the third feeding unit is provided.
An image forming apparatus characterized in that the operation of the feeding means is stopped.