JP2662273B2 - Image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image forming apparatus having functions such as double-sided image formation and composite image formation.

<Prior Art> Conventionally, an image forming apparatus such as a copying machine having a double-sided image forming function of forming images on both sides of one sheet of paper and a composite image forming function of forming a plurality of images on one side of one sheet of paper. Is provided.

In the above-described image forming apparatus, the sheet once subjected to the image processing is temporarily transferred to the intermediate tray through the second sheet conveying section branched from the discharge side of the first sheet conveying section for supplying and discharging the sheet. After being stored in the image processing unit, the sheet is conveyed again to the image processing unit, and in the case of double-sided image formation,
In the case of forming a composite image, image processing is performed on the same surface as the previous image forming surface.

FIG. 5 is a schematic view of a paper re-feeding section for transporting the paper stored in the intermediate tray to the image processing section again, and the stored paper (P) is addressed to one sheet above the intermediate tray (100). A re-feeding roller (101) for leading out is provided, and a re-feed unit (101) downstream of the intermediate tray (100) for transporting the sheet (P) led out by the re-feeding roller (101) to the image processing unit again. 102) and the intermediate tray (10
A stopper (103) for abutting the leading end of the sheet (P) stored in the intermediate tray (100) and aligning the position of the leading end of the sheet (P) is provided between the sheet feeding unit (0) and the re-sending unit (102). Is provided. The stopper (103) is configured to be rotatable so as to retreat from the sheet lead-out path when the sheet (P) is drawn from the intermediate tray (100).

<Problem to be Solved by the Invention> In the refeeding section having the above configuration, the intermediate tray (10
When the sheet (P) stored in the sheet (P) is drawn out by the paper re-feed roller (101), the sheet (P) is dragged by the uppermost sheet (P), and a plurality of sheets of the lower sheet (P) are moved to the middle. Tray (10
0) (see FIG. 6). Then, in this state, if a paper jam occurs at any position in the paper conveyance path of the image forming apparatus, a series of image processing operations are performed with the paper (P) partially drawn out of the intermediate tray (100). Will be suspended. For this reason, when the stopper (103) returns to the original position after the reset operation, a part of the paper (P) drawn out from the intermediate tray (100) is removed by the stopper (103). Without pushing back, the stopper (103) may get on (see FIG. 7). Therefore, if the original is replaced with the previous original and the image formation is performed again from the beginning after performing the jam processing, when the paper (P) on which the image is formed is conveyed to the intermediate tray (100), P) is led out to the re-sending section (102) side along the paper (P) riding on the stopper (103), and the leading end position of the leading edge of the paper (P) riding on the stopper (103) is reached. If the sheet is located on the near side (upstream side) of the sheet feeding section, there is a problem that the sheet is liable to be multi-fed or jammed in the section when the sheet is fed again.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an image forming apparatus capable of preventing a conveyance trouble such as a double feed of paper or a jam.

<Means for Solving the Problems> According to an image forming apparatus of the present invention for solving the above problems, a detecting means for detecting that the paper accommodated in the intermediate tray is running on the stopper, Transport control means for returning a sheet riding on the stopper to the intermediate tray through the first sheet transport unit and the second sheet transport unit in response to a signal, and an image processing stop control unit for stopping image processing on the sheet Is provided.

<Operation> According to the image forming apparatus having the above configuration, it is determined that the sheet stored in the intermediate tray is running on the stopper.
Detected by the detection means, and based on the detection signal from the detection means, the conveyance control means controls the first paper conveyance unit and the first The sheet can be stored again in the intermediate tray through the second sheet transport unit, and the image processing stop control unit can restrict the image processing from being performed when the sheet passes through the image processing unit.

<Example> Hereinafter, an example will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the entirety of a copying machine as an image forming apparatus according to the present invention.
An optical system (2), an image processing unit (3), a first paper transport unit (4), and a second paper transport unit (1) are provided inside a copier body (1) having a document holder (1) and a document holder (12). 5), an intermediate tray (6), a re-feeding section (7), and the like.

The optical system (2) includes a light source (21), mirrors (22) and (23)
(24), a lens (25), and a mirror (26). A light source (21) exposes an original (not shown) set on the original mounting plate (11) to expose the original (not shown). The reflected light is reflected by mirrors (22) and (23)
(24), lens (25), and mirror (26)
This is for guiding to the image processing unit (3).

The image processing unit (3) includes a charging charger (32) and a developing device (3) around a photosensitive drum (31) rotating in one direction.
3), transfer charger (34), separation charger (35),
And the cleaner (36) are arranged in this order. In the image processing section (3), the reflected light from the document is guided to the surface of the photosensitive drum (31) uniformly charged by the charging charger (32), thereby forming an electrostatic image corresponding to the document image. A latent image is formed, and this electrostatic latent image is developed by a developing device (3
3) The toner image is visualized by 3), and the transfer charger (34)
The toner image is transferred to the surface of the paper (P) by means of, and the paper (P) is separated from the surface of the photoconductor drum (31) by the separation charger (35), and then remains on the surface of the photoconductor drum (31). By collecting the toner with the cleaner (36),
One cycle of the image processing is completed.

The first paper transport unit (4) includes a paper cassette (13a) (1) detachably mounted at a predetermined position of the copier body (1).
3b) or paper feed rollers (41a) (41b) (41) for feeding one sheet of paper (P) from the stacking bypass (14).
c), paper feed path (42a) (42b) (42c), registration roller (43), transport roller (44), transport belt (45), heat fixing device (46), transport roller (47), and discharge The second paper transport unit (5) branches from a switching claw (49) provided between the transport roller (47) and the discharge roller (48). Then, it is guided to the intermediate tray (6) side.

When the image processing is performed only once on the sheet (P), only the sheet conveyance by the first sheet conveying unit (4) is performed, and the image-processed sheet is indicated by an arrow A in the figure. And drain onto the pan (15). Also, on paper (P),
When performing image processing two or more times, such as double-sided image formation and composite image formation, the switching claw (49) is switched so that the paper once image-processed is placed in the second position as indicated by arrow B in the figure. After being sent to the paper transport section (5) and temporarily stored in the intermediate tray (6) as described later, the sheet is supplied to the image processing section (3) by the re-feed section (7) and the registration roller (43).
The image processing is performed again.

The second sheet transport section (5) includes a guide path (50) following the switching claw (49), a transport roller (51), a branch guide plate (53), and a sheet reversing section (54). The paper (P) introduced into the paper transport unit (5) is transported to the intermediate tray (6). At this time, the paper (P) is
By the rotation of 3), the sheet is stored in the intermediate tray (6) in a reversed position through the sheet reversing section (54), or
The sheet is directly stored in the intermediate tray (6) in the same posture without passing through the sheet reversing section (54). After the inverted sheet stored in the intermediate tray (6) is drawn out from the intermediate tray (6), the second image processing is performed on the surface opposite to the first image processing surface ( Double-sided image formation). The sheet (P) stored in the intermediate tray in the same posture is subjected to the second image processing on the same surface as the first image processing surface (composite image formation). The branch guide plate (53)
Is driven by a solenoid.

The paper re-feeding section (7) includes a stopper (72) for abutting the leading end of the paper (P) and a paper re-feeding roller (1) for guiding out the paper (P) stored in the intermediate tray (6) one by one. 73)
The re-feed unit (74) supplies the sheet (P) derived by the re-feed roller (73) to the image processing unit (3).

The stopper (72) has an upright position where the leading end of the sheet (P) supplied to the intermediate tray (6) is abutted, and a down position where the sheet (P) accommodated in the intermediate tray (6) can be led out. (See a solid line and a chain line in FIG. 1), and the rotation is performed by a solenoid (not shown). In addition, the re-sending section (74) includes a conveying roller (74a) (74b) (74c) and a guide path (74d).
(74e) and (74f).

The refeed roller (73) is lifted by a predetermined height by a rotating lever (76) as a lift mechanism so as not to hinder the sheet (P) from being introduced into the intermediate tray (6). Then, when the storage of the sheet (P) is completed, the sheet (P) is brought into contact with the uppermost sheet (P) to derive the sheet (P). At this time, following the topmost sheet to be derived, the leading ends of a plurality of sheets (P) on the lower side are derived. The rotating lever (76) is driven to rotate by a solenoid.

In the copying machine having the above configuration, the stopper (72)
As shown in FIG. 2, a microswitch (75) as a detecting means is provided at the rotating tip of the. The operation lever (75a) of the micro switch (75) protrudes from the upper end of the stopper (72), and when the stopper (72) returns to the upright position, it rides on the stopper (72). When there is a sheet (P) present, a pressing operation is performed by the sheet (P) (see FIG. 3). Therefore, the micro switch (75) can detect that the paper (P) is running on the upper part of the stopper (72).

Further, the copying machine receives the detection signal from the microswitch (75) and converts the paper (P) riding on the stopper (72) into the first paper transport unit (4) without performing image processing. And a control circuit for returning to the intermediate tray (6) again through the second sheet transport section (5).

FIG. 4 is a block diagram showing the above control circuit.
U (90), micro switch (75) connected to the input side of CPU (90), reset switch (91) operated at the end of jam clearing, and electrification connected to the output side of CPU (90) Charger (32), developing device (33), transfer charger (34), branch solenoid (92) (93), paper feed clutch (94), transport clutch (95), (96), stopper solenoid (98), and It consists of a rotating lever solenoid (99). The transfer clutch (95) is connected to the transfer roller (4
4) A clutch for driving (47), the transport belt (45), and the transport roller (51). Transfer clutch (96)
Is a clutch for driving the registration roller (43).
Further, the charging charger (32), the developing device (33), and the transfer charger (34) are connected so that their potentials are controlled by a potential control signal from the CPU (90). Further, the branch solenoid (92) switches the position of the switching claw (49) based on the command signal of the CPU (90), and the branch solenoid (93) switches the branch guide plate (53) based on the command signal of the CPU (90). Switch the position of. Paper feed clutch (9
4) drives the re-feed roller (73) to feed out the paper (P) remaining in the intermediate tray (54), and the stopper solenoid (98) operates the stopper (98) based on the command signal of the CPU (90). 72) is driven to rotate. The rotating lever solenoid (99) is turned on the rotating lever (7) based on a command signal from the CPU (90).
Rotate the 6) to raise and lower the re-feed roller (73).

Hereinafter, a control procedure by the CPU (90) will be described. Now, while the paper (P) is being fed from the intermediate tray (6),
It is assumed that a paper jam occurs at any point in the machine and a series of image processing operations is stopped. Then, the CPU (90) drives the rotation lever solenoid (99), rotates the rotation lever (76), and raises the sheet re-feed roller (73). In this state, the jam processing is performed, and when the reset switch (91) is operated after the completion of the jam processing, the CPU (90) drives the stopper solenoid (98) to move the stopper (72).
Is returned to the upright position. At this time, a part (usually two to three) of the paper (P) whose leading end side is led out from the intermediate tray (6) may not get pushed back to the intermediate tray (6) but ride on the stopper (72). . Then, the micro switch (75) detects the running of the paper (P), and based on the detection signal, the CPU (90) sets the paper feed clutch (94), the transport clutch (95) (96) (97) To drive the paper re-feed roller (73), transport rollers (44), (47), (74
a) (74b) (74c), conveyor belt (45), conveyor roller (5
1) While driving the registration rollers (43), respectively, and driving the branch solenoids (92) and (93), respectively.
The branch pawl (49) is rotated to a position where the first paper transport unit (4) and the second paper transport unit (5) are electrically connected, and the branch guide plate (53) is turned over by the paper (P). It is rotated to a position where it is guided to the intermediate tray (6) without passing through the section (54).
At the same time, the CPU (90) controls the potential of the charging charger (32) to stop the charging of the surface of the photosensitive drum (31), and controls the potential of the developing device (33) to suppress adsorption of toner particles. Then, the potential of the transfer charger (35) is controlled to suppress the toner particles from adhering to the sheet (P). And
The CPU (90) drives the rotary lever solenoid (99) to lower the re-feed roller (73). As a result, the sheet (P) riding on the stopper (72) is not formed in the image processing section (3), and the re-sending section (74), the first sheet transport section (4), and the The sheet is returned to the intermediate tray (6) through the second sheet transport section (5). Then, the absence of the paper (P) running on the stopper (72) is detected by a change in the signal from the microswitch (75), and the rotation lever solenoid (99) is driven to refeed the paper. Raise the roller (73). afterwards,
When a predetermined time has elapsed, the above-described series of processing operations is terminated, and the copying machine is returned to a copy-enabled state.

In this way, the paper (P) riding on the stopper (72) is returned to the intermediate tray (6), so that the paper (P) on which the first image processing has been performed after the jam processing is transferred to the intermediate tray (6). ), The paper (P)
Is drawn out to the re-sending section (74) side along the sheet (P) riding on the stopper (72), causing a double feed of the sheet (P) or jamming at the portion. The point can be eliminated.

In the above procedure, in order not to form an image on the paper (P) being conveyed, the CPU (90) controls all of the charging charger (32), the developing device (33), and the transfer charger (35). Although the potential is controlled, only one or two potentials may be controlled. Also, in the above steps,
By operating the reset switch (91), the stopper solenoid (98) is driven to rotate and return the stopper (72). For example, it is detected that the front cover of the copying machine has been closed after the jam has been cleared. In this way, the stopper (72) may be returned to the rotation, and a series of subsequent processes may be performed.

The image forming apparatus of the present invention is not limited to the above embodiment, and various design changes can be made, for example, the detection means may be constituted by an optical sensor instead of the microswitch (75). it can.

<Effects of the Invention> As described above, according to the image forming apparatus of the present invention, the paper riding on the stopper is again passed through the first paper transport unit and the second paper transport unit without performing image processing. Since the sheet can be accommodated in the intermediate tray, it is possible to prevent the occurrence of paper jam or double feeding of paper in the re-feeding unit when image formation is temporarily stopped and then image formation is performed again. It has the unique effect of being able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the internal structure of a copying machine equipped with a paper re-feeding unit according to the present invention, FIG. 2 is a schematic diagram showing a main part in the vicinity of the paper re-feeding unit, and FIG. FIG. 4 is a block diagram of a control circuit, FIG. 5 is a schematic diagram of a main part showing a conventional example, FIG. 6 is a schematic diagram of a main part showing a re-feeding state, and FIG. FIG. 4 is a schematic diagram of a main part showing a state in which a sheet has been run on a stopper. (3) ... image processing unit, (4) ... first paper transport unit (5) ... second paper transport unit, (6) ... intermediate tray, (7) ... re-feed unit, (72) Stopper, (75) Microswitch as detection means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Morimoto 1-2-28 Tamazuki, Higashi-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. (72) Inventor Mitsuru Adachi 1-2-28 Tamazuki, Higashi-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. (72) Inventor Yasuyuki Hirai 1-2-28 Tamazuki, Higashi-ku, Osaka-shi, Osaka Mita Kogyo Co., Ltd. (72) Inventor Hiroyuki Tsuji 1-2-28 Takuma-ku, Higashi-ku, Osaka, Osaka Mita Kogyo (56) References JP-A-63-127980 (JP, A) JP-A-63-266473 (JP, A) JP-A-63-171722 (JP, A) JP-A-56-162760 (JP, A A)

Claims (1)

(57) [Claims] An image processing section for developing an electrostatic latent image formed on the surface of a photoreceptor by a developing device and transferring the latent image to a sheet, supplying the sheet to the image processing section, A first paper transport unit that transports the paper from the image processing unit, a second paper transport unit that branches from the transport side of the paper transport unit, and transports the paper on which the image processing has been performed once to the intermediate tray; A sheet re-feeding unit for guiding the sheet conveyed to the intermediate tray to the image processing unit, and abutting the leading end of the sheet conveyed to the intermediate tray against the re-feeding unit, and Detecting means for detecting that the sheet stored in the intermediate tray is running on the stopper, and a stopper based on a signal from the detecting means. Ride on Transport control means for returning the paper to the intermediate tray through the first paper transport unit and the second paper transport unit, and image processing stop control means for stopping image processing on the paper. Image forming apparatus.