JPH07109075A - Image former - Google Patents

Abstract

PURPOSE:To provide a front loading type image former that forms an image in conveying transfer paper surely to an image forming part even if a special sheet of paper is used as transfer paper, and it is also excellent in operability in addition to being inexpensive in cost. CONSTITUTION:This is a front loading type image former that forms an image by feeding an image forming part to be situated upward, with transfer paper 2 being fed out of a paper feeding part 1 situated downward as curving it at a bend. In this constitution, the image former is provided with a conveying direction selector member 6 set up in at least one bend 5 between a separate part and a resist part 4 being situated in a spot just before the image forming part, a first bypassing route reaching up to the resist part inclusive of the conveying direction selector member and the bend, a second bypassing route 8 to lee connected to an upstream side end of the first byapssing route at one end, and an opening part 9 interconnected to the other end of the second bypassing route. In succession, the conveying direction selector member 6 is selectively switched to the first bypassing route 7 or the second bypassing route side and the transfer paper 2 is fed to the image forming part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming section such as a front-loading type electrophotographic copying machine, facsimile, printer or the like, which is located above a transfer sheet stored under the apparatus while being curved at a curved section. The present invention relates to an image forming apparatus that forms an image by feeding it.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are views showing a method of feeding a transfer sheet to an image forming section in a conventional front loading type electrophotographic copying machine. In this method, a sheet feeding section 101 is configured. Tray 101 on the device body side
The transfer papers 102 loaded on the trays b and the multi-stage tray 101c are transferred from the transfer paper stack 102 on each tray by the separating unit 103 of the separating device adopting the FRR (friction resistance reverse rotation roller) feeding method. The sheets are separated one by one and fed upward, and a pair of relay conveyance rollers 116 forms a registration roller 104a of the registration unit 104 in front of the image forming unit.
Sent to. After that, the image forming transfer section (photosensitive drum 117
The transfer paper 102 on which the toner image on the photoconductor is transferred by a and the transfer device 117b) 117 undergoes fixing by heating and pressurization at the fixing unit 118. Paper feed opening 10 provided on the side wall of the apparatus
9 is provided with a manual feed tray 109a that is pivotally supported so as to be freely openable and closable, and a separation unit 103 as a separation device of the FRR paper feeding system is provided as in the case of the paper feeding unit 101.
The separating unit 103 prevents double feeding of manually fed paper.

After recording an image on one side of the transfer paper 102,
This transfer paper 10 is discharged to the duplex unit and stacked.
In the double-sided mode in which 2 is fed and the image is again recorded on the other side of the transfer sheet 102 by the image forming unit, the transfer sheet 102 having the image recorded on one side is conveyed downward by the switching operation of the switching claw 119. Then, the horizontal conveyance path 1 of the double-sided tray 101a
After passing through 30, the front and back sides are reversed by the forward / reverse rotation roller 131, and the double-sided tray 101 with the image recording surface facing upward.
stacked on a. A transfer sheet with the image recording surface facing up is fed again by a refeed signal from a control unit (not shown), and the transfer roller pair 116 and the registration roller 104a are fed.
The image forming unit such as the image forming transfer unit 117 records an image on the other surface of the transfer paper 102 and the paper is discharged from the paper discharge unit 120.

In conventional front-loading type electrophotographic copying machines, facsimiles, printers, etc., the trays 101a to 101c of the sheet feeding section 101 are stacked in multiple stages to reduce the width direction in order to save space. Therefore, it is necessary to bend the transfer paper 102 when sending it to the image forming unit such as the image forming transfer unit 117. Even in the case of passing through such a curved conveyance path, troubles do not occur particularly in the case of the commonly used transfer paper (55k to 70K) 102. However, when the transfer paper 102 is a thick and strong postcard, a paper for overhead projector (OHP), or a thin special paper such as a paper, the stress on the transfer paper 102 due to the bending is large, and the transfer is not possible or cannot be carried. There was a problem that a state occurred. Therefore, when using the transfer paper 102 having such a large stress, the manual insertion opening 10 is used as described above.
9 is provided and a separate separating device 103 is additionally arranged, and a large number of transfer papers 102 can be fed in a straight path toward an image forming unit such as the image forming transfer unit 117 by manual feeding from a manual feed stand 109a. Has been done.

In these devices and methods, although the transfer paper 102, which is a special paper having a large stress, is rarely used at all times, when it is used, several hundreds of them are collected together, such as a New Year's postcard. It is often passed through. That is, in the past manual feeding of a large number of transfer papers 102, despite having the separating unit 103 of the separating device for the same paper feeding as the trays 101a to 101c of the paper feeding unit 101 independently,
The usage frequency is very low, and the cost for the usage rate is much higher than that of the trays 101a to 101c of the paper feeding unit 101, and as a result, the cost of the entire apparatus is high. Furthermore, the loading capacity of the manual feed stand 109a is at most 5
Since there is a limit of 0 sheets, when it is desired to copy more sheets continuously, it is necessary to set the sheets again and again, which deteriorates the operability.

[0006]

In the above-mentioned conventional front-loading type image forming apparatus, when special paper such as thick paper is used as the transfer paper, there occurs a problem that the transfer is not successful or cannot be carried. If a large number of sheets are manually fed to eliminate them, there is a problem that the cost is high and the operability is deteriorated.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve such a problem. That is, the present invention ensures that even if special paper is used as the transfer paper, the transfer paper is reliably conveyed to the image forming unit to form an image, and the operability is excellent.
It is another object of the present invention to provide a front-loading type image forming apparatus that is smaller and less expensive.

[0008]

In order to achieve the above object, the present invention is directed to a transfer sheet fed from a sheet feeding section located below and separated by a separating section while being bent upward at a bending section. In the front-loading type image forming apparatus that forms an image by feeding the image to the image forming unit, the image forming unit is disposed in at least one curved portion between the separating unit and the resist unit located immediately before the image forming unit. A transport direction switching member, a first detour route including the transport direction switching member, the curved portion, and reaching the registration portion, and a second detour route connected to an upstream end of the first detour route at one end. A transfer direction switching member is selectively switched to the first bypass path side or the second bypass path side, and the transfer paper has the opening portion communicating with the other end of the second bypass path. Image forming unit The transfer means is configured to be fed in, the conveying means for conveying the transfer sheet in both the front and rear directions, the guide direction switching member for preventing the transfer sheet from returning, and the presence / absence of the transfer sheet are detected in the second bypass path. A detection member is provided, a guide member that can be rotationally accommodated or detached is arranged outside the opening, and the transfer paper of the transfer paper is provided between the conveyance unit and the opening in the second bypass path. The presence of detection means for detecting the presence / absence, the paper feeding unit is provided with a plurality of paper feeding trays, and at least one of the trays is loaded with a transfer paper having an image recorded on one side thereof, and then the paper is fed to the image forming unit. Having a double-sided tray for re-feeding,
A detection member for detecting the presence or absence of an image on the transfer paper is arranged at a position immediately downstream of the separation unit, and the first bypass route and the second bypass route are provided near the uppermost stage of the paper feeding unit,
When a jam occurs after the registration section, the conveyance direction switching member is activated to automatically eject the transfer sheet that has stagnated in front of the registration section, and the conveyance means is in the vicinity of the opening. It is characterized in that it is a pair of intermediate rollers and a driven roller which are provided in the above and which are capable of forward and reverse rotation and press the transfer sheet at a predetermined pressure, and are faster than the linear velocity of the relay roller of the curved portion.

[0009]

In the image forming apparatus constructed as described above, the transfer paper is a strong postcard, the overhead projector (OH
Even for special paper such as P), thin paper, long paper, etc., set a large amount in the paper feed section of the front tray, and go to the image forming section via the other detour path different from the normal path. Even if special paper is used as the transfer paper, the transfer paper is surely transferred to the image forming unit to form an image, and the operability is excellent, and the transfer paper is small and the cost is low. It is possible to provide the front-loading type image forming apparatus.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an enlarged view showing a main configuration of an image forming apparatus to which the present invention is applied, and FIG. 2 is an overall configuration explanatory view of a main portion of the image forming apparatus. In FIGS. Double-sided tray 1a, apparatus body side tray 1b, and multi-tiered tray 1
The transfer paper 2 loaded on the paper feed unit 1 including the trays c
Is fed by separating only one of the two transfer sheets stacked on each tray by the separating unit 3 of the FRR (Friction Reverse Roller) feeding type separating device. In the FRR paper feeding method, as is well known, the reverse roller 3b, which is rotationally driven in the direction opposite to the paper feeding direction with a weak torque, is brought into contact with the outer peripheral surface of the paper feeding roller 3a which is rotationally driven in the paper feeding direction. Of the transfer papers that are about to be fed out in two layers, the transfer paper on the reverse roller side is returned to the tray side to separate the multi-feeding papers.

The transfer paper 2 fed from each of the trays 1a, 1b, 1c is moved in the traveling direction by the switching operation of the transfer direction switching member 6 located at the branch portion between the first bypass path 7 and the second bypass path 8. Can be selectively switched. Transport direction switching member 6
The relay roller 5 is provided in the curved portion 5 between the first detour path 7 and
a and the auxiliary roller 5b are arranged to convey the transfer sheet at the nip portion of both rollers, and the relay roller 5a and the auxiliary roller 5b 'are arranged between the conveyance direction switching member 6 and the second bypass path 8. The transfer paper is conveyed at the nip part of the roller.

The transfer paper 2 fed from the double-sided tray 1a is directly placed, or the transfer paper 2 fed from the main body side tray 1b and the multi-stage tray 1c passes through the conveying roller pair 16 and is then arranged on the curved portion 5. Being guided by the carried direction switching member 6
By the cooperation of the relay roller 5a and the auxiliary rollers 5b, 5b ', 5b ", etc., the first detour route 7 or the second detour route 8 connecting the transport direction switching member 6 and the first detour route 7 at one end.
The image is formed by being sent to the registration roller 4a of the registration unit 4 via the above, and sent to the image forming unit such as the image forming transfer unit 17 not shown. The structure of each of the sheet passing patterns A to G will be described in detail below.

The sheet passing pattern A is a case where the commonly used transfer sheets (55k to 70K) 2 stacked on the sheet feeding section 1 are passed. The transfer sheet 2 separated by the separating section 3 made of FRR is turned upward by the conveying direction switching member 6 arranged in the bending section 5 and is guided to the first detour path. The transport direction switching member 6 is
A solid line C position (first detour circuit open position) and a broken line D position (second detour route open position) are rotatable about a fulcrum 6a by a drive device such as a solenoid (not shown). The relay roller 5a is driven by a stepping motor or the like (not shown) and can rotate in the forward and reverse directions. The three auxiliary rollers 5b, 5b ', 5b "in contact with the peripheral surface are synchronized with the rotation direction of the relay roller 5a. In this case, the relay roller 5a rotates in the clockwise direction, and the transfer paper 2 passes through the first detour path 7 and the registration unit 4 rotates.
The image is formed by being sent to the registration roller 4a and sent to an image forming unit such as the image forming transfer unit 17 (not shown).

The paper passing pattern B is for passing the transfer paper 2 as a special paper. This is a case where a thick and strong postcard, a paper for an overhead projector (OHP), a thin paper, a transfer paper 2 such as a long paper, which is stacked on the paper feeding unit 1, is passed. Similar to the paper passing pattern A, the paper feeding unit 1
The transfer sheet 2 stacked on the sheet and separated by the separating section 3 composed of the FRR is guided in the straight direction of the arrow E direction by the conveyance direction switching member 6 arranged in the bending section 5. At this time, the transport direction switching member 6 is manually switched by an operation unit (not shown) or automatically switched by a control unit based on a detection signal from a sheet thickness detection unit (not shown) provided in the sheet feeding unit 1 and thus the fulcrum 6a. Is rotated by a drive device such as a solenoid (not shown) around the center, and is positioned at the position indicated by the broken line D in the figure.

In this case, the relay roller 5a rotates counterclockwise, the transfer paper 2 is guided to the path 8a in the second detour path 8, and the nip portion between the intermediate roller 10a as the conveying means 10 and the driven roller 10b. To reach. Intermediate roller 10a
Are driven by a stepping motor or the like (not shown) and can rotate in the forward and reverse directions. In this case, the intermediate roller 10a
Is rotated counterclockwise, the transfer paper 2 is guided to the path 8b of the second bypass path 8. Further, the transfer paper 2 has an opening 9
In the case of the long paper discharged from the device to the outside of the device, the long paper is held outside the device at the opening 9 by a guide member 13 which also serves as a manual feed table 9a which can be housed or detached. A guide direction switching member 11 as a guide mylar is elastically pressed at its one end to the inner wall of the path before the nip portion between the intermediate roller 10a and the driven roller 10b, and the path 8a in the second bypass path 8 is formed. The transfer sheet conveyed through can be easily passed through the pressure contact portion between the switching member 11 and the inner wall of the path by the conveying force of the rollers 5a and 5b '. Immediately in front of the nip portion between the intermediate roller 10a and the driven roller 10b, a detection means 12 for detecting the passage of the rear end of the transfer sheet is arranged.

Next, when the trailing edge of the transfer paper 2 passes through the guide direction switching member 11 of the guide mylar and is detected by the detecting means 12, a control unit (not shown) reverses the intermediate roller 10a in the clockwise direction to transfer it. The trailing edge of the paper 2 starts at the beginning and returns. However, the guide direction switching member 11 acts on the transfer sheet 2 like a so-called check valve, and prohibits the return to the path 8b. Therefore,
The transfer paper 2 is guided to the path 8c of the second bypass path 8 and is again sent to the registration roller 4a of the registration section 4 by the auxiliary roller 5b ″ there, and sent to the image forming section such as the image forming transfer section 17 not shown. By receiving the image, the image is formed.

Even when the transfer paper 2 is a special postcard such as a strong postcard, a paper for overhead projector (OHP), a thin paper, or a long paper, the second bypass path 8 that does not include a curved portion is used. Since I tried to pass the paper straight through,
Even if a large amount of special paper is set in the paper feed unit 1 of the front tray and continuously fed, it is reliably conveyed to an image forming unit such as the image forming transfer unit 17 not shown. Therefore, according to the image forming apparatus of the present invention, even if the transfer paper 2 is a special paper, the image formation is surely performed without the occurrence of the defective conveyance or the impossible conveyance. Further, since the separation of the transfer paper is carried out collectively by the separating device located in the paper feeding section, there is no need for a separating device dedicated to the manual feed stand 9a as in the prior art, which is compact, low in cost, and further easy to operate. It is also possible to provide an excellent front-loading type image forming apparatus.

Next, the paper passing pattern C is a case where the transfer paper 2 in which the double-sided mode or the composite mode is used is passed. In this case, simply, the double-sided tray 1a of the paper feeding unit 1
Then, it is sufficient to stock the transfer paper 2 having the image recorded on one side. That is, the re-fed transfer sheet 2 may be passed through the sheet passing pattern B in the double-sided mode and the sheet passing pattern A in the composite mode (see FIG. 2). That is, in the double-sided mode, in order to re-feed the transfer sheets stacked on the double-sided tray 1a with the non-recording surface facing upward, it is necessary to reverse and feed the transfer sheets. If the paper is conveyed in the paper passing pattern B, the non-recording surface is fed with the non-recording surface facing the photoconductor surface, so that the image can be formed on the back surface. Further, in the case of the composite mode, since the recording is performed on the recording surface, the sheet passing pattern A may be used.

Next, the sheet passing pattern D is a case where the reused transfer sheet 2 which has been copied is passed on the back side. In this case, the transfer paper 2 has a lower surface of the transfer paper, which is provided immediately downstream of the separation unit 3 and is provided with a detection member 15 for detecting the presence or absence of an image on the surface (the lower surface in the embodiment of FIG. 2) of the transfer paper 2. The presence or absence of an image is detected. The detection result is output to a control unit (not shown) and is processed according to the presence / absence of an image. That is, when the detection member 15 detects the presence of an image on the lower surface of the transfer paper 2, the paper passing pattern B is set and the transfer is performed on the upper surface of the blank paper, while when not detected, the paper passing pattern A is used. Then, the operations of the transport direction switching member 6 and other related members are controlled so that the transfer is performed on the lower surface. Such control is extremely easy. When the detection member 15 for detecting the presence or absence of an image on the upper surface of the transfer sheet 2 is provided, the sheet passing pattern A is used when an image is detected on the upper surface of the transfer sheet 2, and the sheet passing pattern is used when no image is detected. The control is performed so that the pattern B is passed. Therefore,
According to this embodiment, the operator only needs to set the one-sided copied transfer paper in the tray and perform the copying without considering which side is blank.

Next, the sheet passing pattern E is a case where the transfer sheet 2 is discharged when a jam occurs at the downstream side of the resist section 4. The first bypass path 7 and the second bypass path 7 are provided near the uppermost stage of the sheet feeding unit 1.
A bypass path 8 is provided so that when a jam occurs downstream of the registration unit 4, the conveyance direction switching member 6 operates to automatically eject the transfer paper 2 that is stagnant in front of the registration unit 4. That is, as shown in the drawing, a relay sensor 21 is provided for each tray of the paper feeding unit 1, and when the presence of the transfer paper 2 (retention due to jam) is detected by the relay sensor 21, after the jam recovery, The paper passing pattern B is automatically
It is designed to be discharged to the outside of the device by a simple operation. Specifically, for example, when the transfer paper is jammed in front of the transport direction switching member 6, the jammed paper is transported to the registration unit 4 in a switchback manner via the bypass paths 8a, 8b, 8c. If the jam has occurred before the registration unit 4, the jammed paper may be discharged from the opening 9 through the bypass 8c by reversing the roller 5a and the like. Further, when the transfer paper conveyed through the curved portion 5 causes a jam in front of the resist portion 4, after removing the preceding jammed paper, the succeeding paper (the leading end of which is already fed halfway) Are discharged to the opening 9 through the bypass paths 8a and 8b without being conveyed to the resist section 4.

Next, the paper passing pattern F is a case where the transfer paper 2 having a large curl is passed. The transfer paper 2 in this case is a case where a large curl is corrected by passing the paper.
That is, the transfer paper 2 has the intermediate roller 10a and the driven roller 10b that constitute the conveying means 10 provided near the opening 9.
As a result of being pressed by a predetermined light pressure, the conveying force is small and slips, and the intermediate roller 10a and the driven roller 10
The linear velocity of b is set higher than the linear velocity of the relay roller 5a of the bending portion 5. Therefore, the transfer sheet 2 includes the relay roller 5a, the pair of intermediate rollers 10a of the conveying means 10, and the driven roller 10b.
In the state of being nipped across the sheet, the pair of intermediate rollers 10a and the driven roller 10b of the conveying means 10 always slip and are in a pulled state. Therefore, the curl is removed and corrected by a simple operation.

Finally, the sheet passing pattern G is a case where a small number of transfer sheets 2 are passed. A detection unit 14 that detects the presence or absence of the transfer paper 2 is provided between the conveyance unit 10 and the opening 9 in the second bypass route 8. When the transfer papers 2 are set one by one from the opening 9 from the manual feed tray 9a which also serves as the guide member 13 to the conveying means 10 in the same manner as in the normal manual feeding, the space between the pair of intermediate rollers 10a and the driven rollers 10b of the conveying means 10 is set. Since it is pressed with a light pressure, it is set smoothly. The transfer paper 2 is guided to the second detour path 8c of the second detour path 8 by the pair of intermediate rollers 10a of the transporting means 10 which rotates in the clockwise direction in response to the detection signal from the detection means 14, and the auxiliary roller located there. The image is formed by a small device and a simple operation by being sent to the registration roller 4a of the registration unit 4 by 5b and being sent to an image forming unit such as an image forming transfer unit 17 (not shown). .

[0023]

Since the present invention is configured as described above, the transfer paper is a special paper such as a postcard having a strong rigidity, a paper for overhead projector (OHP), a thin paper and a long paper. Even a large amount of paper is set in the paper feed section of the front tray so that it can be reliably conveyed to the image forming section via the other detour path that is different from the normal path. Also, the transfer paper can be reliably conveyed to the image forming unit to form an image, and the operability is excellent, and the image forming apparatus of the front loading type which is small in size and low in cost can be provided. .

[Brief description of drawings]

FIG. 1 is a diagram illustrating a main part of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an overall configuration of a main part including the configuration of FIG.

FIG. 3 is a diagram illustrating an outline of a conventional image forming apparatus.

FIG. 4 is a cross-sectional view of a main part of a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper feeding part, 1a ... Double-sided tray, 1b ... Main body side tray, 1c ... Multistage tray, 2 ... Transfer paper,
3 ... Separation section, 4 ... Registration section, 4a ... Registration roller, 5 ... Curved section, 5a ... Relay roller,
5b ... Auxiliary roller, 6 ... Transport direction switching member, 6
a ... fulcrum, 7 ... 1st detour route, 8 ... 2nd detour route, 8a ... route a, 8b ... route b, 8c ...
..Routes c, 9 ... Openings, 9a ... Bypass, 1
0 ... conveying means, 10a ... intermediate roller, 10b ...
..Driven rollers, 11 ... Guide direction switching member, 12 ...
..Detection means, 13 ... Guide member, 14 ... Detection means, 15 ... Detection member, 16 ... Conveying roller pair, 1
7 ... Image forming transfer section, 18 ... Fixing section, 19 ... Switching claw, 20 ... Paper ejection roller, 21 ... Relay sensor,
101 ... Paper Feeding Unit, 101a ... Double-sided Tray, 10
1b ... main body side tray, 101c ... multi-stage tray,
102 ... Transfer paper, 103 ... Separation section, 104 ...
-Registration part, 104a ... Registration roller, 109
... Aperture, 109a ... Bypass, 116 ...
Conveying roller pair 117 ... Image forming transfer section, 118 ...
Fixing unit, 119 ... Switching claw, 120 ... Paper ejection roller, 121 ... Relay sensor, 130 ... Horizontal conveyance path, 131 ... Forward / reverse rotation roller.

Claims (8)

[Claims] 1. A front loading type in which an image is formed by feeding a transfer sheet fed from a sheet feeding section located below and separated by a separating section to an image forming section located above while curving at a curving section. In the image forming apparatus, the conveying direction switching member disposed in at least one curving portion between the separating portion and the resist portion located immediately before the image forming portion, the conveying direction switching member and the curving portion. Including a first detour route reaching the resist section, a second detour route connected to the upstream end of the first detour route at one end, and an opening communicating with the other end of the second detour route. In addition, the image forming method is characterized in that the transfer direction switching member is selectively switched to the first bypass path side or the second bypass path side to feed the transfer paper to the image forming unit. Dress . 2. A conveying means for conveying the transfer sheet in both the front and rear directions, a guide direction switching member for preventing the transfer sheet from returning, and a detecting means for detecting the presence or absence of the transfer sheet in the second bypass path. The image forming apparatus according to claim 1, wherein the image forming apparatus has a structure. 3. A guide member which can be housed in rotation or detached is arranged outside the opening.
Or the image forming apparatus according to 2. 4. The detecting means for detecting the presence / absence of the transfer paper is arranged between the conveying means and the opening in the second bypass path. Image forming apparatus. 5. The paper feed unit includes a plurality of paper feed trays,
5. The image forming method according to claim 1, wherein at least one of the trays is provided with a double-sided tray for stacking a transfer sheet having an image recorded on one side and re-feeding the transfer sheet to the image forming unit. apparatus. 6. The image forming apparatus according to claim 1, wherein a detection member for detecting the presence / absence of an image on the transfer paper is arranged at a position immediately downstream of the separation unit. 7. The first bypass path and the second bypass path are provided in the vicinity of the uppermost stage of the paper feed section, and when a jam occurs in front of the registration section, the conveyance direction switching member is activated to perform the registration. 7. The image forming apparatus according to claim 1, wherein the transfer sheet stagnating in front of the set is automatically ejected. 8. The conveying means is a pair of intermediate rollers and driven rollers which are provided in the vicinity of the opening and which are capable of forward and reverse rotation and press the transfer sheet at a predetermined pressure. The image forming apparatus according to claim 2, wherein the image forming apparatus is configured to be faster than the speed.