Patent Application
20250206556
The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2023-216688, filed on Dec. 22, 2023. The above applications are hereby expressly incorporated by reference, in these entireties, into the present application.
The present disclosure relates to a method, apparatus, and program for feeding sheets that cause sheets to float by supplying air, then suctioning and conveying an uppermost sheet to feed the sheet, and a learning model.
Conventional sheet feeding devices that supply paper to printing equipment, etc., that supply air to a plurality of sheets of paper which are loaded on a loading table to cause them to float, and then suction and convey the topmost sheet to supply the sheet, are known.
Japanese Unexamined Patent Publication No. 2023-61933, for example, proposes a method for determining control parameters in a sheet feeding device based on paper property information for a sheet feeding device such as that described above.
However, although paper property information is used to adjust control parameters in the method disclosed in Japanese Unexamined Patent Publication No. 2023-61933, the actual flotation state of sheets is not taken into consideration. Therefore, control parameters which are set may not always be optimal, and there is a risk that empty feed or multi-feed will occur.
The present disclosure has been developed in view of the foregoing circumstances. The present disclosure provides a method, an apparatus, and a program for supplying sheets, and a learning model that can adjust control parameters more optimally and prevent the occurrence of empty feed and multi-feed.
A sheet feeding apparatus of the present disclosure is equipped with: a loading table on which a plurality of sheets are loaded, a flotation air supply unit that causes the sheets to float by supplying air toward the edge surfaces of the plurality of sheets which are loaded on the loading table, a suction conveying unit that suctions and conveys the topmost sheet among the plurality of sheets which are caused to float by the supply of air, an image capturing unit that captures an image of a flotation state of the plurality of sheets which are caused to float by the supply of air, a control parameter adjusting unit that adjusts control parameters of the flotation air supply unit based on information on the flotation state obtained from the image captured by the image capturing unit, and a control unit that controls the flotation air supply unit based on the control parameters adjusted by the control parameter adjusting unit.
According to the sheet feeding apparatus of the present disclosure, since an image of the flotation state of a plurality of sheets which are caused to float by the supply of air is captured and the control parameters of the flotation air supply unit are adjusted based on the information on the flotation state of the sheets obtained from the captured image, more optimal adjustment of control parameters can be made in consideration of the actual flotation state of the sheets, thereby preventing the occurrence of empty feed and multi-feed.
An air sheet feeding system that employs an embodiment of a sheet feeding apparatus of the present disclosure will be described in detail hereinafter with reference to the attached drawings. The air sheet feeding system of the present embodiment is characterized by the adjustments to control parameters which are employed for air sheet feeding. First, the air sheet feeding system as a whole will be described.
The air sheet feeding system 100 in the present embodiment has a sheet feeding apparatus 1 and a control apparatus 2, as illustrated in
As illustrated in
In addition, as illustrated in
A plurality of sheets of paper P are loaded on the loading table 10. The loading table 10 is raised and lowered in the vertical direction by the loading table elevation drive unit 91 illustrated in
The suction conveying unit 20 is equipped with a conveyor belt 21 and pulleys 22 and 23 over which the conveyor belt 21 is hung. One of the pulleys 22, 23 is a drive pulley and the other is a driven pulley. The drive pulley is rotated by the suction conveying drive unit 92 illustrated in
The conveyor belt 21 is provided with a number of through holes to allow suction air A1, which is suctioned by the suctioning mechanism 30 described below, to pass through.
Two suction conveying units 20 are arranged in the center region of the width direction (the left to right direction in
The suctioning mechanism 30 draws suction air A1 upward from an area enclosed by the conveyor belt 21 of the suction conveying unit 20 through the plurality of through holes in this conveyor belt 21. As a result, the suctioning mechanism 30 causes the topmost sheet of paper P1 of the plurality of sheets of paper P loaded on the loading table 10 to be suctioned to the suction conveying unit 20.
The conveying mechanism 50 has a roller pair. The roller pair may have one drive roller and one driven roller, or both may be driven rollers. The drive roller of the conveying mechanism 50 conveys the sheets of paper P in the conveyance direction D and supply it to the paper conveyance path of a printing device (not illustrated) by the conveyance drive unit 93 rotating the drive rollers.
The conveyance sensor 51 is provided in the vicinity of a downstream side of the conveying mechanism 50. The conveyance sensor 51 detects the sheets of paper P which are conveyed by the conveying mechanism 50. The conveyance sensor 51 detects whether the sheets of paper P have arrived at a normal timing.
The main flotation air supply unit 71 is located downstream of the plurality of sheets of paper P which are loaded on the loading table 10 in the conveyance direction D, and blows main flotation air A3 diagonally upward to cause about 10 sheets of paper P including the topmost sheet of paper P1, for example, to float.
The main flotation air supply unit 71 is equipped with a fan 71a and a shutter 31. The fan 71a generates the main flotation air A3 by being driven to rotate. The shutter 31 switches between shielding and supplying the main flotation air A3.
The shutter body 31a oscillates (rotates) in both the clockwise and the counterclockwise directions within a range of 45 degrees, for example, with the rotating shaft member 31c as the axis of rotation, by being driven by the shutter drive unit 94 illustrated in
The shutter body 31a has, for example, four vane sections 31a-1. These four vane sections 31a-1 are provided at equal intervals (e.g., 90 degrees apart) in the direction of rotation of the shutter body 31a.
The aperture member 31b is, for example, a disc-shaped plate. The aperture member 31b has, for example, four through holes 31b-1 to allow the main floating air A3 to pass therethrough. The four through holes 31b-1 are provided at equal intervals (e.g., 90 degrees apart) in the direction of rotation of the shutter body 31a, similar to the vane sections 31a-1.
The shutter body 31a oscillates (moves) between a shielding position at which the vane sections 31a-1 cover the through holes 31b-1 to shield the main flotation air A3 illustrated in
The main separation air supply unit 72 is located downstream of the plurality of sheets of paper P which are loaded on the loading table 10 in the conveyance direction D and blows main separation air A4 diagonally upward to separate the topmost sheet of paper P1 from a second from topmost sheet of paper P2.
The main separation air supply 72 is equipped with a fan 72a. The fan 72a generates main separation air A4 by being driven to rotate.
The side flotation air supply units 81 are respectively provided on the right and left sides of the plurality of sheets of paper P which are loaded on the loading table 10 in the width direction, (only the right side is illustrated in
Each of the side flotation air supply units 81 is equipped with a fan 81a and a shutter 81b. The fan 81a generates the side flotation air A5 by being driven to rotate. The shutter 81b has the same configuration as the shutter 31 and is driven by the shutter drive unit 94 to switch between shielding and supplying the side flotation air A5.
The side separation air supply units 82 are respectively provided on the right and left sides of the plurality of sheets of paper P which are loaded on the loading table 10 in the width direction, and blows side separation air A6 to separate the topmost sheet of paper P1 from the second from the top sheet of paper P2.
Each of the side separation air supply units 82 is equipped with a fan 82a and a flow channel 82b for side separation air A6 supplied by the fan 82a.
The sheet detecting sensor 64 is a sensor that detects the passage of the sheets of paper P. The sheet detecting sensor 64 has a transmissive optical sensor, for example. The sheet detecting sensor 64 detects the arrival of the sheets of paper P transported by the suction conveying unit 20 and detects the thickness of the transported sheets of paper P, thereby detecting multi-feed of the sheets of paper P.
The image capturing unit 40 captures images of the downstream (front) end face of the sheets of paper P which are loaded on the loading table 10 in the conveyance direction, thereby capturing images of the flotation state of the loaded sheets of paper P. The image capturing unit 40 has an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor and an imaging optical system, for example. The image capturing unit 40 is installed at a height and has an angle of view that enables imaging of the flotation state of the loaded sheets of paper P and the downstream end of the suction conveying unit 20.
The image capturing unit 40 of the present embodiment captures images at 60 fps during the time it takes to suction and convey one sheet of paper P from the loading table 10 until the sheet of paper P is detected by the conveyance sensor 51, for example, and outputs the captured image to the control apparatus 2.
The control unit 61 controls the operation of the entirety of the sheet feeding apparatus 1. The control unit 61 is equipped with a CPU (Central Processing Unit), a semiconductor memory such as a ROM (Read Only Memory) and a RAM (Random access memory), storage such as a hard disk, and a communication I/F.
The control unit 61 controls the operations of each of the units illustrated in
The loading table elevation drive unit 91 has an actuator such as a motor that raises and lowers the loading table 10.
The suction conveying drive unit 92 has an actuator such as a motor that rotates the drive pulley, which is one of the pulleys 22 and 23 of the suction conveying unit 20. The conveyance drive unit 93 has an actuator such as a motor that rotates the drive rollers of the conveying mechanism 50.
The shutter drive unit 94 has an actuator such as a motor that rotates the shutter 31 and the shutter 81b.
Next, the operation of the sheet feeding apparatus 1 will be described.
When starting sheet feeding, the control unit 61 opens the shutter 31 to enable supply of the main flotation air A3. The control unit 61 also starts driving the suctioning mechanism 30, the main flotation air supply unit 71, the main separation air supply unit 72, the side flotation air supply unit 81, and the side separation air supply unit 82.
Thereby, the main flotation air A3 and side flotation air A5 are caused to blow from the main flotation air supply unit 71 and the side flotation air supply unit 81, and the main separation air A4 and the side separation air A6 are caused to blow from the main separation air supply unit 72 and side separation air supply unit 82. In addition, a suction holding force is generated in the through holes of the conveyor belt 21.
A plurality of sheets of paper P at an upper portion of a bundle of sheets of paper are lifted from the bundle by the flotation air currents of the main flotation air A3 and the side flotation air A5, and the topmost sheet of paper P among them is held by suction on the conveying surface of the conveyor belt 21.
Meanwhile, the main separation air A4 and the side separation air A6 are fed between the topmost sheet of paper P and the second from topmost sheet of paper P and flow toward the upstream side.
In this state, the control unit 61 closes the shutter 31. Thereby, the blowing of the flotation airflow of the main flotation air A3 is ceased. As a result, the main separation air A4 and side separation air A6 separate the topmost sheet P from the second from topmost and lower sheets of paper P, and the second from topmost and lower sheets of paper P drop.
Next, the control unit 61 causes the suction conveying drive unit 92 to drive the suction conveying unit 20 to convey the sheet of paper P.
The control unit 61 then opens the shutter 31 to cause the sheets of paper P to float for a next sheet of paper P to be fed.
By repeating the above operations, the sheets of paper P are sequentially fed out from the sheet feeding apparatus 1 to the printing device.
During this sheet feeding operation, the control unit 61 controls the raising of the loading table 10 in response to the decrease in the sheets of paper P which are loaded on the loading table 10 due to the sheets of paper being fed out.
Next, the control apparatus 2 will be described.
The control apparatus 2 obtains the captured images taken by the image capturing unit 40 of the sheet feeding apparatus 1, adjusts the control parameters of the main flotation air supply unit 71 (in the present embodiment, the duty ratio of the drive voltage of the fan 71a) based on the captured images, and outputs the adjusted control parameters to the control unit 61 of the sheet feeding apparatus 1. The control unit 61 of the sheet feeding apparatus 1 controls the main flotation air supply unit 71 based on the control parameters output from the control apparatus 2.
Specifically, the control apparatus 2 is equipped with an image recognition unit 80 and a control parameter adjusting unit 83.
The image recognition unit 80 obtains a captured image taken by the image capturing unit 40 of the sheet feeding apparatus 1, and obtains information on the flotation state of the sheets of paper P in the sheet feeding apparatus 1, based on the captured image. The image recognition unit 80 of the present embodiment obtains, as information on the flotation state, the position of the floating sheets of paper P, the number of the floating sheets of paper P, the state of suction to the suction conveying unit 20, the state of occurrence of two sheets floating in an overlapped state and three sheets floating in an overlapped state, the shifted state of the sheets of paper P, and the scattered state of the sheets of paper P. It is not necessary to obtain all of these pieces of flotation state information, but at least one of them should be obtained.
The image recognition unit 80 detects the edges of the sheets of paper P from the captured image.
The image recognition unit 80 obtains information on the position of the second from topmost sheet of paper P next to the topmost sheet of paper P that is suctioned by the suction conveying unit 20 as the position of the floating sheets of paper P.
Specifically, the position of the second from the top sheet of paper P described above is detected from each of a plurality of captured images which are captured while one sheet of paper P is being fed, and the average of the positions is obtained as information on the position of the floating sheets of paper P.
As information on the number of sheets of floating paper P, an average value of the number of sheets of floating paper P detected in each of the aforementioned plurality of captured images is obtained.
As for the state of suction to the suction conveying unit 20, information indicating whether the topmost sheet of paper P is suctioned onto the suction conveying unit 20 is obtained. In the present embodiment, whether a sheet of paper P is suctioned on the suction conveying unit 20 is detected by detecting a through hole of conveyor belt 21 from a captured image at the downstream end of the suction conveying unit 20. Specifically, in the case that a through hole of the conveyor belt 21 is detected in a captured image, information indicating that the sheet of paper P is not suctioned by the suction conveying unit 20 is obtained, and in the case that no through hole of the conveyor belt 21 is detected in a captured image, that is, in the case that the through holes are blocked by the sheet of paper P, information indicating that the sheet of paper P is suctioned by the suction conveying unit 20 is obtained.
The occurrence status of two sheets floating in an overlapped state and three sheets floating in an overlapped state is obtained from the captured images. Specifically, the total number of detections in an area where two sheets are floating in an overlapped state (TWO PLY FLOTATION) and in an area where three sheets are floating in an overlapped state (THREE PLY FLOTATION) are obtained.
The shifted state of sheets of paper P refers to a fluttered state of the plurality of sheets of paper P which are loaded in the loading table 10. The fluttered state of sheets of paper P is the fluttered state of each sheet of paper P which is caused to float by the flotation air, and if the amount of flutter is large, the captured image will be blurred, precluding detection of the edge of each sheet of paper P.
The image recognition unit 80 obtains, as information on the shifted state of the sheets of paper P, the presence or absence of captured images in which the edge of each sheet of paper P is undetectable due to the blurring described above.
The scattered state of sheets of paper P refers to a state of scattering of the plurality of sheets of papers P which are caused to float by the flotation air. Specifically, an average sheet spacing and a variation in sheet spacing are obtained as the scattered state of sheets of paper P.
The control parameter adjusting unit 83 adjusts the control parameters of the main flotation air supply unit 71 based on the aforementioned flotation state information obtained from the captured image by the image recognition unit 80, information on the detection of multi-feed by the sheet detecting sensor 64, information on the arrival of the sheets of paper P to the conveyance sensor 51, and paper quality information of the sheets of paper P. In the present embodiment, the control parameter to be adjusted is the duty ratio of the drive voltage that drives the fan 71a of the main flotation air supply unit 71, as described above.
Information on whether multi-feed is detected is obtained as the information on the detection of multi-feed. Information on whether the timing at which the sheets of paper P are detected by the conveyance sensor 51 is faster (early) or slower (undelivered) than a normal timing is obtained as the information on the arrival of the sheets of paper P to the conveyance sensor 51. Information on the size of the sheets of paper P and the type of the sheets of paper P is obtained as the paper quality information of the sheets of paper P. The paper quality information of the sheets of paper P is obtained, for example, from a setting input by the user. Alternatively, the paper quality information of sheets of paper P may be obtained from a print job.
The control parameter adjusting unit 83 has a learning model which is obtained by reinforcement learning the relationship between predetermined control parameters of the main flotation air supply unit 71 and the results of sheet feeding including the flotation state information, the multi-feed information, and the arrival information of the sheets of paper P obtained from the captured image when paper was fed using the predetermined control parameters, as well the paper quality information of sheets of paper P. The information on the flotation state obtained from the captured image, the sheet feeding result, and the paper quality information of the sheets of paper P are environmental parameters for the reinforcement learning, and are summarized in
When the reinforcement learning is performed, a reward is given to a learning model. The reward is determined by determining whether the environmental parameters illustrated in
Next, the method of adjusting the control parameters of the sheet feeding apparatus 1 using the learning model described above will be described with reference to the flowchart illustrated in
First, when a print start command is set and input by a user, the sheet feeding apparatus 1 operates as described above, the sheets of paper P are caused to float, and sheet feeding is initiated (S10). At this time, preset initial values are used as control parameters.
Then, the flotation state of the sheets of paper P is imaged by the image capturing unit 40 of the sheet feeding apparatus 1 (S12), and the captured image is input to the image recognition unit 80 of the control apparatus 2, which obtains the information on the flotation state from the captured image. After a sheet of paper is fed, the information on the flotation state, the paper quality information of the sheets of paper P, and the information on the result of feeding the sheet of paper are input to the control parameter adjusting unit 83 as environmental parameters (S14).
The control parameter adjusting unit 83 inputs the input environmental parameters to the learning model, obtains the amount of control parameter adjustment (S16), and outputs the control parameters with the adjustment amount added to the sheet feeding apparatus 1.
The control parameter adjusting unit 83 also obtains a reward based on the environmental parameters (S18). At this time, if the reward is negative (S20, YES) and if the reward is positive but this is the first time that the reward is positive (S22, NO), the control parameter adjusting unit 83 continues to adjust the control parameters by repeating the processes from S12 to S18 after the next paper feed is conducted to continuously perform the adjustment of the control parameters.
Meanwhile, if positive rewards are obtained twice in a row (S20, NO, S22, YES), the control parameter adjusting unit 83 terminates the control parameter adjustment process (S24) and the sheet feeding apparatus 1 continues to use the same control parameters to feed paper.
Note that in the present embodiment, the adjustment process for control parameters is terminated when positive rewards are obtained twice in a row, as described above. However, if positive rewards are not obtained twice in a row after 10 adjustment processes, for example, the adjustment process may be terminated after 10 adjustments.
In addition, in the present embodiment, the drive voltage of the main flotation air supply unit 71 is adjusted as a control parameter, but the present disclosure is not limited to such a configuration, and other factors that affect the flotation state of the sheets of paper P, such as the timings at which the shutter 31 is opened and closed, for example, may be included in the control parameters.
The control apparatus 2 is equipped with a CPU, semiconductor memory such as ROM and RAM, storage such as a hard disk, and a communication I/F. An embodiment of a sheet feeding program of the present disclosure is installed in the semiconductor memory or hard disk of the control apparatus 2, and the sheet feeding program is executed by the CPU to perform the control parameter adjustment process described above.
In the present embodiment, the control parameter adjustment process is realized by the sheet feeding program, but the present disclosure is not limited to such a configuration, and some or all of the functions or control may be realized by hardware such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other electric circuits.
According to the above embodiment of the air sheet feeding system 100, an image of the state of a plurality of sheets of paper being caused to float by air supply is captured, and the control parameters of the main flotation air supply unit 71 are adjusted based on the information on the flotation state obtained from the captured image, such that more optimal control parameters can be adjusted in consideration of the actual flotation state of the sheets of paper P. Therefore, the control parameters can be adjusted more optimally, taking into account the actual flotation state of the sheets of paper P, and the occurrence of empty feed and multi-feed can be prevented.
At least one of the information on the flotation state, the position of the floating sheets of paper P, the number of floating sheets of paper, the state of suction to the suction conveying unit, the shifted state of the sheets of paper, and the scattered state of the sheets of paper is obtained, such that the control parameters can be adjusted with higher precision.
In addition, because the control parameters are adjusted based on the information on the flotation state obtained from the captured images and the sheet feeding results, the control parameters can be adjusted to reflect the results of sheet feeding as well.
Further, the control parameters are adjusted based on the flotation state information obtained from the captured images and the paper quality information of the sheets of paper P, and the sheet feeding results. Therefore, it is possible to adjust the control parameters according to the paper quality information of the sheets of paper P.
Still further, the control parameters are adjusted using a learning model which is obtained through reinforcement learning of the relationship between predetermined control parameters and the flotation state information obtained from the captured image when the paper is fed using the control parameters. Therefore, the adjustment of the control parameters is performed automatically, which means that no special skills are required to conduct the adjustment.
Still yet further, the learning model is trained by a reward determined based on at least one of the flotation state information and the sheet feeding results, which reduces the time required to adjust the control parameters, thereby reducing equipment downtime.
In addition, the adjustment of control parameters is terminated when positive rewards are obtained consecutively by the same control parameters, which allows for more efficient adjustment of control parameters.
The present disclosure is not limited to the above embodiment, but may be embodied by transforming the components to an extent that it does not depart from the spirit and scope thereof at the implementation stage. Also, various embodiments may be formed by appropriate combinations of the plurality of components disclosed in the above embodiment. For example, all of the components which are disclosed in the embodiment may be combined as appropriate. It is, of course, possible to make various modifications and applications within a scope that does not depart from the spirit and scope of the disclosure.
The following items are further disclosed with respect to the present disclosure.
A sheet feeding apparatus of the present disclosure is equipped with: a loading table on which a plurality of sheets are loaded, a flotation air supply unit that causes the sheets to float by supplying air toward the edge surfaces of the plurality of sheets which are loaded on the loading table, a suction conveying unit that suctions and conveys the topmost sheet among the plurality of sheets which are caused to float by the supply of air, an image capturing unit that captures an image of a flotation state of the plurality of sheets which are caused to float by the supply of air, a control parameter adjusting unit that adjusts control parameters of the flotation air supply unit based on information on the flotation state obtained from the image captured by the image capturing unit, and a control unit that controls the flotation air supply unit based on the control parameters adjusted by the control parameter adjusting unit.
In the sheet feeding apparatus of Item 1, the control parameter adjusting unit may obtain at least one of a position of the floating sheets, a number of floating sheets, a state of suction to the suction conveying unit, a shifted state of the sheets, and a scattered state of the sheets as information on the flotation state.
In the sheet feeding apparatus of Item 1 or Item 2, the control parameter adjusting unit may adjust the control parameters based on the information on the flotation state obtained from the captured image and the results of sheet feeding.
In the sheet feeding apparatus of any of Items 1 through 3, the control parameter adjusting unit may adjust the control parameters based on the information on the flotation state obtained from the captured image, sheet quality information, and the results of sheet feeding.
In the sheet feeding apparatus of any of Items 1 through 4, the control parameter adjusting unit may adjust the control parameters using a learning model obtained by prior reinforcement learning of the relationship between predetermined control parameters and the flotation state information obtained from the captured image when sheet feeding was performed using the predetermined control parameters.
In the sheet feeding apparatus of Item 5, it is preferable for the learning model to be trained by rewards which are determined based on at least one of the flotation state and the result of sheet feeding.
In the sheet feeding apparatus of Item 6, it is preferable for the control parameter adjusting unit to terminates adjustment of the control parameters when positive rewards are obtained consecutively by the same control parameters.
A sheet supply method of the present disclosure comprises causing a plurality of sheets of paper which loaded on a loading table to float by supplying air toward edge surfaces of the sheets, and suctioning and conveying the topmost sheet of the plurality of floating sheets, capturing an image of a flotation state of the plurality of sheets of paper by supplying the air, adjusting control parameters of an flotation air supply unit that supplies the air based on information on the flotation state obtained from the captured image, and controlling the flotation air supply unit based on the adjusted control parameters.
A sheet supply program of the present disclosure causes a computer to execute the steps of causing a plurality of sheets of paper which loaded on a loading table to float by supplying air toward edge surfaces of the sheets, and suctioning and conveying the topmost sheet of the plurality of floating sheets, capturing an image of a flotation state of the plurality of sheets of paper by supplying the air, adjusting control parameters of an flotation air supply unit that supplies the air based on information on the flotation state obtained from the captured image, and controlling the flotation air supply unit based on the adjusted control parameters.
A learning model of the present disclosure is a learning model which is employed when adjusting control parameters of a flotation air supply unit of the sheet feeding apparatus of Item 1, and is obtained by reinforcement learning a relationship between predetermined control parameters and information on a flotation state obtained from a captured image captured by an image capturing unit of the sheet feeding apparatus when a sheet is fed employing the predetermined parameters.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-216688 | Dec 2023 | JP | national |
