Patent Application
20240286856
Embodiments described herein relate generally to, for example, a paper sheet processing apparatus that stacks and aligns a plurality of paper sheets, an image forming apparatus and methods related thereto.
As a multifunction peripheral having copy function, print function, scan function, and the like, for example, one equipped with a finisher that stacks and binds a predetermined number of sheets after image formation is known. A finisher includes a standby tray, a processing tray, and a stapler.
While the predetermined number of sheets stacked on the processing tray are aligned and stapled, the standby tray causes the next two or three sheets to be stapled to wait above the processing tray. There is a feed member with a paddle between the standby tray and the processing tray. The feed member rotates while the paddle contacts the upper surface of the paper falling from the standby tray to the processing tray, scrapes the paper toward the alignment surface of the stopper at one end of the processing tray, and aligns the edges of the paper against the alignment surface.
If the paper stacked in the standby tray is dropped into the processing tray, the stacking posture of the paper tends to be disturbed. In addition, the stacking posture of the paper on the processing tray tends to vary depending on the paper size, weight, thickness, material, and presence or absence of curls and wrinkles. Therefore, even if the feed member is rotated and an attempt is made to align the edges of the paper against the alignment surface, the edges of the paper may not reach the alignment surface or bounce off the alignment surface and the edges of the paper tend to be unaligned.
In general, according to one embodiment, a paper sheet processing apparatus includes a processing tray, a feed member, a drive unit, a detection unit, and a control unit. The processing tray receives and stacks a plurality of paper sheets. The feed member is rotatably arranged above the processing tray to face the processing tray and includes a paddle that is elastically deformed by being pressed against the paper sheets during rotation to scrape the paper sheets stacked on the processing tray toward an alignment surface by the paddle. The drive unit rotates the feed member. The detection unit is arranged between the feed member and the alignment surface and detects a leading end of the paper sheet being fed toward the alignment surface by the paddle. The control unit controls the drive unit based on a detection result of the detection unit during the period from if the detection unit detects the leading end of the paper sheet to if the paddle separates from the paper sheet and controls the rotation of the feed member so that the leading end of the paper sheet scraped by the paddle is aligned with the alignment surface.
A multifunction peripheral 10 equipped with a finisher 1 according to one embodiment will be described below with reference to the drawings. In the drawings used for the following description, the scale of each part may be changed as appropriate. Also, in the drawings used in the following description, the configuration may be omitted in some cases for the sake of easy understanding of the description.
As shown in
For example, if the operator sets the document D on a paper feed tray 141 of the ADF 14 and sets the presence or absence of stapling, the method of stapling, the number of copies, the paper size, and the like, and then presses the copy start switch, the multifunction peripheral 10 automatically feeds the documents D on the paper feed tray 141 one by one to the document reading position on the document table 121. After reading the document D, the multifunction peripheral 10 automatically discharges the document D at an appropriate timing.
Various data input by the operator can be performed via the control panel of the multifunction peripheral 10 or via an external device such as a personal computer connected to the multifunction peripheral 10.
The multifunction peripheral 10 includes a scanner unit 16, a printer unit 18, cassettes 21, 22, and 23 for paper P, and the like inside the housing 12. The multifunction peripheral 10 also includes a large-capacity feeder 24 containing a large amount of paper of the same size and a manual feed tray 25 on the right wall of the housing 12 in the drawing which will be described later. Further, the multifunction peripheral 10 has the finisher 1 connected to the left wall of the housing 12 in the drawing. The finisher 1 is an example of the paper sheet processing apparatus described in the claims of the present application.
The scanner unit 16 illuminates and scans the document D fed to the document reading position on the document table 121 by the ADF 14, reads and photoelectrically converts the reflected light, and obtains image information of the document
D.
The printer unit 18 operates a laser device 181 based on the image information read by the scanner unit 16 to form an electrostatic latent image on the circumferential surface of a photosensitive drum 182 based on the image information. The printer unit 18 supplies toner to the electrostatic latent image on the photosensitive drum 182 via a developing device 183 to visualize the latent image, and transfers the toner image to the paper P by a transfer charger 184. At this time, the multifunction peripheral 10 feeds the paper P from the cassettes 21, 22, and 23, a large-capacity feeder 24, or the manual feed tray 25.
Further, the multifunction peripheral 10 supplies the paper P onto which the toner image was transferred to a fixing device 185, heats, melts, and then fixes the toner image on the paper P, and discharges the paper to the finisher 1 through a discharge port 20. After passing through the fixing device 185, the multifunction peripheral 10 conveys the paper P, which requires double-sided copying, to a reversing conveying path 26 and reverses the front and back sides of the paper P, and then sends to the fixing region between the photosensitive drum 182 and the fixing device 185 again.
The paper P discharged through the discharge port 20 is an example of paper sheets described in the claims of the present application. Hereinafter, for convenience of explanation, the paper P discharged to the finisher 1 through the discharge port 20 of the multifunction peripheral 10 will be referred to as a paper sheet M.
The finisher 1 stacks and aligns the paper on which images are formed, that is, the paper sheets M discharged through the discharge port 20 of the multifunction peripheral 10, and staples each unit of paper sheets M with the stapler 8, with a predetermined number of stacked paper sheets M as one unit. The stapling process refers to a process of aligning and binding one-side ends of a plurality of stacked paper sheets M.
The finisher 1 includes an entrance roller 2 and an entrance sensor 3 at a position facing the discharge port 20 of the multifunction peripheral 10. The entrance sensor 3 detects the passage of the leading end and the trailing end of the paper sheet M fed into the finisher 1 via the entrance roller 2 in the feeding direction (direction of arrow T in the drawing).
The finisher 1 includes a standby tray 4, a processing tray 6, and a stapler 8. The standby tray 4 stacks and waits for two or three paper sheets M fed in the direction of the arrow T through the entrance roller 2. The processing tray 6 receives the paper sheets M dropped from the standby tray 4 and aligns the trailing ends thereof for stapling. The stapler 8 staples the trailing ends of the paper sheets M stacked and aligned on the processing tray 6. The standby tray 4 and the processing tray 6 are inclined downward toward the trailing ends of the paper sheets M in the feeding direction.
Since the stapling process by the stapler 8 requires a certain amount of processing time, when one unit of the paper sheets M on the processing tray 6 is being stapled, several paper sheets M fed as the next unit are required to stand by at a place different from the processing tray 6. In the present embodiment, if the preceding one unit of paper sheets M is being stapled, two of the next one unit of paper sheets M are made to stand by on the standby tray 4, and the time for stapling the preceding one unit of paper sheets M is ensured.
That is, the first paper sheet M and the second paper sheet M fed in the direction of the arrow T are stacked on the standby tray 4 and after the preceding one unit of stapling is completed, two paper sheets M made to stand by are dropped onto the processing tray 6, and the third and subsequent paper sheets M are directly stacked on the processing tray 6 via the standby tray 4.
As shown in
If the opening and closing trays 401 and 402 are opened to the release position, the paper sheets M stacked on the standby tray 4 drop onto the processing tray 6 due to their own weight. At this time, since the width of the opening formed between the two opening and closing trays 401 and 402 widens toward the upstream side in the feeding direction, if the opening and closing trays 401 and 402 are opened, the trailing ends of the stacked paper sheets M in the feeding direction first fall toward the processing tray 6.
On the upstream side of the standby tray 4 in the feeding direction, there is a paper feed roller 31 that clamps the paper sheets M fed in the direction of the arrow T and feeds the clamped paper sheets M to the standby tray 4, as shown in
As shown in
When stacking the paper sheets M on the standby tray 4, the finisher 1 retracts the standby tray roller 32 upward and lowers the standby tray roller 32 toward the standby tray 4 after stacking the paper sheets M. The finisher 1 rotates the standby tray roller 32 in the reverse direction while keeping the standby tray roller 32 in contact with the paper sheets M stacked on the standby tray 4, and then aligns the paper sheets by abutting the trailing end of the paper sheets M in the feeding direction against a stopper (not shown). After that, the standby tray roller 32 is retracted upward again in order to receive the paper sheet M to be fed next onto the standby tray 4.
The processing tray 6 has a flat mounting surface 61 on its bottom for placing and stacking the paper sheets M dropped from the standby tray 4. The mounting surface 61 is inclined downward toward the upstream side in the feeding direction of the paper sheets M. Under the processing tray 6, there is a conveying mechanism 34 (see
Between the standby tray 4 and the processing tray 6, there are two feed members 40 as partially enlarged in
The feed member 40 acts on the trailing end of the paper sheets M received in the standby tray 4 in the feeding direction. The feed member 40 guides the trailing end of the paper sheet M toward the processing tray 6. Further, the feed member 40 scrapes the vicinity of the trailing end of the paper sheet M dropped onto the processing tray 6 in the direction opposite to the feeding direction.
As shown in
The protruding length of the auxiliary paddle 47 from the rotating body 48 is slightly shorter than the protruding length of the paddle 46. The protruding length of the paddle 46 and the auxiliary paddle 47 is such that the leading end of each paddle at least contacts the mounting surface 61 of the processing tray 6 during the rotation of the feed member 40. The feed member 40 rotates in the direction of arrow R (counterclockwise direction) in the drawing.
The basic operation of the finisher 1 described above will be described below with reference to
First, if the paper sheet M is fed from the multifunction peripheral 10 to the finisher 1, the feed member 40 is on standby while being rotated to the home position shown in
In this state, if the second paper sheet M is fed to the standby tray 4, the second paper sheet M overlaps the first paper sheet M, and the trailing end of the second paper sheet M rides on the receiving portion 42 of the feed member 40. After that, the finisher 1 opens the opening and closing trays 401 and 402, rotates the feed member 40 as shown in
As described above, since the width of the opening between the opening and closing trays 401 and 402 widens toward the upstream in the feeding direction, the trailing end side of the paper sheet M on the standby tray 4 is released from the support first, as shown in
After the paper sheet M drops onto the processing tray 6, if the feed member 40 is further rotated from the state shown in
Also, at this time, the conveying mechanism 34 operates to convey the paper sheets M stacked on the processing tray 6 toward the stopper 50 in cooperation with the scraping operation of the paddle 46. The length of the paddle 46 is such that it can at least be pressed against the processing tray 6 if the feed member 40 is rotated. Therefore, the paddle 46 is pressed against the upper surface of the paper sheet M on the processing tray 6 and is elastically deformed and curved.
After that, as shown in
The leading end of the auxiliary paddle 47 comes into contact with the upper surface of the paper sheet M immediately before the feed member 40 rotates to the position shown in FIG. 8. The auxiliary paddle 47 functions to prevent the paper sheet M from rebounding if the paper sheet M whose leading end m in the abutting direction abuts against the alignment surface 51 of the stopper 50 tries to return in the opposite direction. Further, the auxiliary paddle 47 functions to feed the paper sheet M whose leading end m did not reach the alignment surface 51 of the stopper 50 toward the alignment surface 51.
As described above, if a predetermined number of paper sheets M are stacked on the processing tray 6 and their leading ends m in the abutting direction are aligned, the finisher 1 moves the stapler 8 movably installed along the leading ends m to the stapling position as shown in
Since the paper sheet M fed from the multifunction peripheral 10 to the finisher 1 just underwent image formation, the paper sheet M may be slightly curled due to the application of heat. The degree of curling of the paper sheet M varies depending on the thickness, basis weight, size, and the like of the paper P even if the amount of heat given by the fixing device 185 is the same. In addition, since the finisher 1 needs to drop the paper sheet M from the standby tray 4 to the processing tray 6, the stacking posture of the paper sheets M on the processing tray 6 tends to vary. Therefore, it is difficult to neatly align the leading ends m of all the paper sheets M in the abutting direction with the alignment surface 51 by simply processing all the paper sheets M fed to the processing tray 6 of the finisher 1 in the same manner of rotating the feed member 40 at the same timing and at the same speed. By providing the above-described auxiliary paddle 47, the leading ends m can be aligned with the alignment surface 51 to some extent, but it cannot be said to be sufficient.
On the other hand, the inventors of the present application have proposed that, in order to further improve the alignment of the leading ends m of the paper sheets M on the processing tray 6 of the finisher 1, the rotation speed and the control timing of the feed member 40 are adjusted according to the state of the paper sheets M that dropped onto the processing tray 6. A configuration for controlling the rotation of the feed member 40 and a control method thereof will be described below.
As shown in
The contactor 72 has a shape curved in the direction of the alignment surface 51 toward the mounting surface 61 from a position spaced above the mounting surface 61 of the processing tray 6. The contactor 72 is rotatable with respect to the housing of the finisher 1. The contactor 72 has a contact end 73 near the leading end of rotation, which contacts the upper surface of the paper sheet M during rotation. If the contact end 73 contacts the paper sheet M, the contactor 72 is lifted by the thickness of the paper sheet M and rotates slightly counterclockwise in the drawing.
The magnet 74 can rotate integrally with the contactor 72. The magnet 74 is, for example, disc-shaped and is polarized in a plane including its central axis. The rotating base end portion of the contactor 72 can rotate coaxially with the central axis of the magnet 74. That is, if the leading end m of the paper sheet M reaches the contact end 73 of the contactor 72 and the contactor 72 rotates in the direction in which the contact end 73 moves away from the mounting surface 61, the magnet 74 also rotates by the same angle in the same direction.
The angle sensor 76 faces across the two magnetic poles of the magnet 74 and is fixed to the housing of the finisher 1. The angle sensor 76 detects a change in the direction of the magnetic field that changes due to the rotation of the magnet 74, and detects the rotation angle of the magnet 74, that is, the rotation angle of the contactor 72 from the amount of change. By sufficiently increasing the resolution of the angle sensor 76, slight rotation of the contactor 72 corresponding to the thickness of the paper sheet M can be detected.
For example, if the next paper sheet M is sent to the processing tray 6 in a state where several paper sheets M are stacked on the processing tray 6, the contact end 73 of the contactor 72 is in contact with the upper surface of the uppermost paper sheet M of already stacked several paper sheets M. If a new paper sheet M is fed between the contact end 73 and the contact end 73 from this state, the contactor 72 rotates by the thickness of the paper sheet M. That is, the detection unit 70 can detect the leading end m of the newly fed paper sheet M regardless of the number of paper sheets M already stacked on the processing tray 6. Since the contact end 73 of the contactor 72 moves in an arc shape, strictly speaking, the position in the abutting direction for detecting the leading end m shifts slightly depending on the number of paper sheets M stacked on the processing tray 6.
As shown in
The detection unit 70 detects the leading end m of the paper sheet M that was fed into the processing tray 6 and is being scraped toward the alignment surface 51 by the paddle 46. The memory 82 stores a control table in which the optimal deceleration and deceleration start timing of the feed member 40 with respect to the output value of the detection unit 70 are measured in advance for each thickness, basis weight, and size of the paper P. The optimal deceleration and deceleration start timing of the feed member 40, which were measured in advance for each thickness, basis weight, and size of the paper P, are examples of optimal control values described in the claims of the present application and are the optimal values for aligning the paper sheet M with the alignment surface 51.
The timer 84 measures the time from if the feed member 40 is rotated from the home position shown in
As shown in
The control unit 80 rotates the feed member 40 in ACT 2, and at the same time, starts measuring the time by the timer 84 in ACT 3, and continues measuring the time until the detection unit 70 detects the leading end m of the paper sheet M in ACT 4 (ACT 4; YES) (ACT 5). After that, the control unit 80 acquires the optimal control value from the control table stored in the memory 82 based on the time measured in ACT 5 and the information of the paper P (thickness, basis weight, size, and the like) input in advance (ACT 6), and controls the drive unit 86 according to the control value (ACT 7). The time from if the feed member 40 is rotated until the detection unit 70 detects the leading end m of the paper sheet M includes the information about the position of the leading end m of the paper sheet M dropped onto the processing tray 6 along the abutting direction.
The control of ACT 7 includes control of the rotation speed of the feed member 40 and control of the timing of the control start. For example, if the leading end m of the paper sheet M that dropped onto the processing tray 6 is placed at a position farther from the alignment surface 51 than the designed value, the time measured by the timer 84 in ACT 5 becomes longer than the designed value. In this case, the control unit 80 controls the drive unit 86 so as to decrease the deceleration of the feed member 40 or delay the start timing of deceleration. Further, if the leading end m of the paper sheet M that dropped onto the processing tray 6 is positioned at a position closer to the alignment surface 51 than the designed value, the time measured by the timer 84 in ACT 5 becomes shorter than the designed value. In this case, the control unit 80 controls the drive unit 86 so as to increase the deceleration of the feed member 40 or advance the deceleration start timing. In any case, the control unit 80 controls the rotation of the feed member 40 so that the leading ends m of all the paper sheets M abut against the alignment surface 51 at approximately the same speed and aligned.
The control unit 80 repeats the processes of ACT 1 to ACT 7 until a predetermined number of paper sheets M of one unit are stacked on the processing tray 6 and the leading ends m are aligned, and the leading ends m of the predetermined number of paper sheets M of one unit are aligned (ACT 8; YES), and the process ends. After that, the finisher 1 uses the stapler 8 to staple the leading ends m of the predetermined number of paper sheets M.
As described above, according to the present embodiment, even if the position of the leading end m of the paper sheet M dropped from the standby tray 4 to the processing tray 6 varies in the abutting direction, the leading ends m of all the paper sheets M can be neatly aligned with the alignment surface 51. Therefore, according to the present embodiment, the stapled bundle of paper sheets M is neatly arranged, and the reliability of the finisher 1 can be improved.
Further, according to the present embodiment, the memory 82 stores a control table in which the optimal control values for the feed member 40 are measured in advance according to the thickness, basis weight, size, and the like of the paper P on which the image is to be formed by the multifunction peripheral 10. Then, after the feed member 40 is rotated, the optimal control value based on the time until the detection unit 70 detects the leading end of the paper sheet M is read out from the control table, and the feed member 40 is controlled to rotate. Therefore, regardless of the type of paper P, the leading ends m of the paper sheets M can be neatly aligned before stapling. Further, according to the present embodiment, since the thickness of the paper sheet M can be detected via the detection unit 70, rotation control based on an optimal control value matching the thickness detected by the detection unit 70 is also possible.
Further, as described above, the contact end 73 of the contactor 72 swings to draw an arc track. Depending on the number of the paper sheets M fed to the processing tray 6, the detection unit 70 makes a difference in the position in the abutting direction for detecting the leading end m. For example, the position for detecting the leading end m of the seventh paper sheet M fed on top of the six stacked paper sheets M is the side closer to the alignment surface 51 from the position for detecting the leading end of the second paper sheet M. Therefore, in consideration of this difference, an optimal control value for the feed member 40 corresponding to the number of stacked sheets may be prepared in advance in the control table.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
