Media supply device

Abstract

To prevent the occurrence of multiple feeding in a medium supplying device without requiring the user to do any effort. [Solution] The media supply device (1) comprises a loading table (10) on which media (P) are loaded by sequentially replenishing media stacks (PA, PB), supply members (21, 22) that supply media (P) from the loading table (10), a boundary detection unit (60, 70, 80, 44) for detecting the boundary (B) of the media stack (sheet stacks PA, PB), and a control unit (41) that controls the supply members (21, 22) so that the media (P) located at the boundary (B) is supplied at a slower speed than the other media (P).

Description

[Technical Field]

[0001] The present invention relates to a media supplying device that supplies media from a loading platform. [Background technology]

[0002] Conventionally, a method has been known in which a double-feed prevention sheet is interposed between the paper on the paper loading section and the paper to be added when adding paper, in order to prevent a decrease in the friction coefficient on the paper adding surface and thereby reduce the occurrence of double feeds (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-128303 Summary of the Invention [Problem to be solved by the invention]

[0004] At the boundary between stacks of paper, the coefficient of friction fluctuates due to factors such as a weakened adhesion between sheets, making double-feeding more likely to occur as described above. Meanwhile, inserting a double-feed prevention sheet at the boundary between stacks of paper as described above is required every time a stack of paper is replenished, which increases the burden on the user. For example, there are cases where multiple stacks of paper are added to the stacking tray in succession. In this case, a double-feed prevention sheet must be inserted each time a stack of paper is added, further increasing the burden on the user. Furthermore, the number of double-feed prevention sheets also increases.

[0005] An object of the present invention is to provide a medium feeding device that can prevent the occurrence of multiple feeding without requiring any effort from the user. [Means for solving the problem]

[0006] In one embodiment, the media supply device includes a loading tray on which media is loaded by sequentially replenishing stacks of media, a supply member that supplies the media from the loading tray, a boundary detection unit that detects the boundary between the stacks of media, and a control unit that controls the supply member to supply the media located at the boundary at a slower speed than the other media. [Effects of the Invention]

[0007] According to the above aspect, it is possible to prevent the occurrence of multiple feeding without requiring any effort on the part of the user. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a front view showing the paper feeder according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing a control configuration of the paper feeder according to the first embodiment. [Figure 3] 4 is a flowchart illustrating a paper feeding operation in the first embodiment. [Figure 4A] FIG. 1 is an explanatory diagram (part 1) for explaining a paper feeding operation in the first embodiment. [Figure 4B] FIG. 10 is a second explanatory diagram for explaining the paper feeding operation in the first embodiment. [Figure 4C] FIG. 10 is a third explanatory diagram for explaining the paper feeding operation in the first embodiment. [Figure 4D] FIG. 10 is an explanatory diagram (part 4) for explaining the paper feeding operation in the first embodiment. [Figure 4E] FIG. 5 is an explanatory diagram (part 5) for explaining the paper feeding operation in the first embodiment. [Figure 5] 5 is a timing chart showing the paper feed speed of the paper feed roller in the first embodiment. [Figure 6] FIG. 10 is a front view showing a paper feeder according to a second embodiment. [Figure 7] 10 is a flowchart illustrating a paper feeding operation in the second embodiment. [Figure 8]FIG. 10 is a front view showing a paper feeder according to a third embodiment. [Figure 9] 10 is a flowchart illustrating a paper feeding operation in the third embodiment. [Figure 10] FIG. 10 is a diagram showing an operation panel in the fourth embodiment. [Figure 11] 10 is a flowchart illustrating a paper feeding operation in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a medium feeding device according to an embodiment of the present invention will be described with reference to the drawings, taking the paper feeding devices of the first to fourth embodiments as examples.

[0010] First Embodiment FIG. 1 is a front view showing a paper feeder 1 according to the first embodiment.

[0011] FIG. 2 is a block diagram showing the control configuration of the paper feeder 1. As shown in FIG.

[0012] 1, the paper feeder 1 includes a stacking table 10, paper feed rollers 21 and 22, an elevation drive unit 30, and a stacking table height detection unit 60. Also, as shown in FIG. 2, the paper feeder 1 includes a control unit 41, a memory unit 42, an interface unit 43, an operation panel 44, and a paper feed drive unit 50.

[0013] The paper feeder 1 feeds paper P to, for example, an image forming apparatus. The paper feeder 1 may be disposed independently of the image forming apparatus, or may be disposed integrally with the image forming apparatus as a part of the image forming apparatus. The paper feeder 1 may also feed paper P to a device other than the image forming apparatus, or may be disposed integrally with a device other than the image forming apparatus. In this specification, paper P is an example of a medium, and paper feeding is an example of supply. The medium may also be a sheet-like object made of a material other than paper, or an object with a folded portion such as an envelope.

[0014] 1, paper sheets P are loaded onto the loading tray 10 by sequentially replenishing the paper sheet bundles PA and PB (one bundle of paper sheets P). For example, when the remaining amount of paper sheets P on the loading tray 10 is low or has run out, the user may load only one bundle of paper sheets PA and PB onto the loading tray 10, or may load one bundle at a time multiple times in succession.

[0015] The paper feed rollers 21, 22 include the paper feed roller 21 that feeds out the topmost paper sheet P stacked on the stacking tray 10, and the paper feed roller 22 that is positioned downstream of the paper feed roller 21 in the paper feed direction and transports the paper sheet P. The paper feed rollers 21, 22 feed the paper sheets P stacked on the stacking tray 10, for example, by rotating together. The paper feed rollers 21, 22 are an example of a supply member. This supply member is not limited to a roller, but may be another supply member such as a belt. Furthermore, the supply member is not limited to multiple members positioned at different positions in the paper feed direction like the paper feed rollers 21, 22, but may be a single roller, belt, or other member, or multiple rollers, belts, or other members positioned at the same position in the paper feed direction.

[0016] The separation board 23 faces the downstream feed roller 22 of the feed rollers 21, 22 in the paper feed direction, and sandwiches the paper P between the feed roller 22 and the separation board 23, thereby preventing double feeding of the paper P.

[0017] The lifting / lowering drive unit 30 has an actuator such as a motor and a connecting arm that connects the actuator to the stacking table 10, and raises and lowers the stacking table 10. The lifting / lowering drive unit 30 raises the stacking table 10 under the control of the control unit 41 based on, for example, a decrease in the remaining amount of paper P on the stacking table 10 and a decrease in the pressing force of the paper P against the paper feed roller 21. The lifting / lowering drive unit 30 also lowers the stacking table 10 when, for example, replenishing the paper stacks PA and PB.

[0018] The control unit 41 shown in FIG. 2 has, for example, one or more processors (e.g., CPU: Central Processing Unit) that function as an arithmetic processing device that controls the operation of each part of the sheet feeding device 1. This processor reads and executes a predetermined program, for example, from the memory unit 42 or from a storage medium (non-transitory computer-readable recording medium) that is detachable from the sheet feeding device 1. In this way, the control unit 41 (sheet feeding device 1) functions as an example of a computer that executes a program. As will be described in detail later, the control unit 41 controls the sheet feed rollers 21 and 22 so that the sheet P located at the boundary B between the stacks of sheets PA and PB is fed at a slower speed than the other sheets P. Note that when the sheet feeding device 1 is disposed as part of another device such as an image forming device, the control unit, memory unit, interface unit, and operation panel of the other device may also serve as the control unit 41, memory unit 42, interface unit 43, and operation panel 44 of the sheet feeding device 1.

[0019] The storage unit 42 has memories such as a ROM (Read Only Memory), which is a read-only semiconductor memory in which predetermined control programs are pre-recorded, and a RAM (Random Access Memory), which is a semiconductor memory that can be written and read at any time and is used as a working memory area as needed when the processor executes various control programs.

[0020] The interface unit 43 exchanges various information with external devices such as an image forming device and a print control device.

[0021] The operation panel 44 has, for example, a touch panel that accepts input information from the user, operation keys, etc., and functions as an example of an input unit. The operation panel 44 also has a display that displays various information, and functions as an example of a display unit.

[0022] The paper feed drive unit 50 has an actuator such as a single motor that drives the paper feed rollers 21 and 22. Note that the paper feed drive unit 50 drives the paper feed rollers 21 and 22 under the drive control of the control unit 41, and therefore the control unit 41 can be considered to control the paper feed rollers 21 and 22.

[0023] The loading platform height detection unit 60 detects the height of the loading platform 10. For example, the loading platform height detection unit 60 is a motor FG (Frequency Generator) sensor, a potentiometer, a rotary encoder, or the like that detects the height of the loading platform 10 from the drive amount of the lifting drive unit 30, but it may also be a sensor that detects the actual height of the loading platform 10. The loading platform height detection unit 60 is an example of a boundary detection unit that detects the boundary B between the paper stacks PA and PB (medium stacks). In other words, the boundary detection unit includes the loading platform height detection unit 60.

[0024] FIG. 3 and FIGS. 4A to 4E are a flowchart and explanatory diagrams for explaining the paper feeding operation.

[0025] The process of the flowchart shown in FIG. 3 is started by the control unit 41, for example, while the sheet feeding device 1 is stopped from feeding sheets, or when the sheet feeding device 1 is turned on.

[0026] First, the control unit 41 repeatedly determines whether a user replenishing the stack of paper PB has pressed a button for lowering the stack of paper PB on the operation panel 44 until this button is pressed (step S11). Note that instead of determining whether the button for lowering the stack of paper PB has been pressed, a determination may be made as to whether the sheets of paper P on the stack of paper PB have run out by a paper presence / absence detection sensor (not shown) provided on the stack of paper PB.

[0027] When the button to lower the loading platform 10 is pressed (step S11: YES), as shown in Fig. 4A, the control unit 41 detects the height f1 of the loading platform 10 before the lifting / lowering drive unit 30 lowers the loading platform 10 using the loading platform height detection unit 60 (step S12). Here, the height f1 is, for example, the lift distance from the lowest position at the time of replenishment (the distance from the lowest position to the bottom surface of the loading platform 10).

[0028] Next, as shown in FIG. 4B, the control unit 41 controls the lifting / lowering drive unit 30 to lower the loading platform 10 to the lowest position (step S13).

[0029] When stacking tray 10 is lowered to the lowest position, as shown in Fig. 4C, the user adds stack of sheets PB onto the sheets P (stack of sheets PA) remaining on stacking tray 10. Thereafter, control unit 41 controls lifting / lowering drive unit 30 to raise stacking tray 10 so that the topmost sheet P on stacking tray 10 is fed by sheet feed rollers 21 and 22, as shown in Fig. 4D.

[0030] Next, the control unit 41 repeatedly determines whether paper feed by the paper feed rollers 21 and 22 has started until paper feed starts (step S14). The start of paper feed may be determined based on, for example, the timing when the control unit 41 receives a print job, the timing when the stacking table 10 is raised or lowered as described above and paper feed resumes, or the like.

[0031] When paper feeding starts (step S14: YES), the control unit 41 determines whether the height f of the stacking tray 10 has reached "f1±α" (step S15), as shown in Fig. 4E. This "f1±α" is the timing for feeding the paper P located at the boundary B, taking into consideration the height "f1" of the stacking tray 10 before replenishment and the detection tolerance (detection error) "α."

[0032] With regard to "α," not only the topmost sheet P of sheet bundle PA and the bottommost sheet P of sheet bundle PB located at the boundary B between the sheet bundles PA and PB, but also the sheets P adjacent to these may experience fluctuations in the coefficient of friction due to insufficient adhesion of the sheets P at the boundary B. Therefore, it is advisable to treat the several sheets P adjacent to the boundary B as sheets P located at the boundary B in order to perform the low-speed paper feeding described below.

[0033] Furthermore, the time when the friction coefficient is most susceptible to fluctuations may be when feeding the bottom sheet P of the sheet stack PB. Therefore, "α" may be considered only as a positive value, rather than a positive or negative value, as the timing for feeding the remaining one or several sheets P of the sheet stack PB.

[0034] When the height f of the stacking tray 10 reaches "f1±α" (step S15: YES), that is, when it is time to feed the paper P located at the boundary B, the control unit 41 controls the paper feed drive unit 50 to feed the paper P by the paper feed rollers 21, 22 at a slower speed than the other papers P (step S16).

[0035] 5, the low-speed paper feeding is performed by slowing down the speed at which the paper P located at the boundary B (paper P before and after the boundary B) rises to the paper feeding speed (maximum speed) compared to the speed at which the other paper sheets P are fed (see the thick line). Alternatively, the low-speed paper feeding may be performed by slowing down the paper feeding speed compared to the other paper sheets P.

[0036] When the height f of the stacking table 10 does not fall within "f1±α" (step S15: NO), the control unit 41 controls the paper feed drive unit 50 to feed the paper P by the paper feed rollers 21 and 22 at the normal speed (step S17).

[0037] Next, the control unit 41 determines whether paper feeding is complete (step S18). If not complete (step S18: NO), the process is repeated from step S15. If complete (step S18: YES), the process shown in FIG. 3 ends.

[0038] In the first embodiment described above, the paper feed device 1 (media supply device) includes a loading tray 10 on which paper P (media) is loaded by sequentially replenishing paper stacks PA and PB (media stacks), paper feed rollers 21 and 22 (supply members) that feed (supply) paper P from the loading tray 10, a loading tray height detection unit 60 (boundary detection unit) for detecting the boundary B between the paper stacks PA and PB, and a control unit 41 that controls the paper feed rollers 21 and 22 so that paper P located at the boundary B is fed at a slower speed than other paper P.

[0039] In this way, by feeding the paper P located at the boundary B between the paper stack PA and the paper stack PB at a low speed, it is possible to prevent double feeding even if the friction coefficient of the paper P located at the boundary B varies due to insufficient adhesion, etc. Therefore, according to the first embodiment, it is possible to prevent double feeding without requiring any effort from the user. As a result, even paper P that is relatively prone to double feeding, such as thin paper P, can be fed without double feeding. This improves the reliability of the paper feeding device 1. Furthermore, according to the first embodiment, by feeding the paper P located at the boundary B at a low speed, it is possible to prevent other problems, such as empty feeding, in addition to double feeding.

[0040] In addition, in this first embodiment, the paper feeding device 1 further includes a lifting drive unit 30 that raises and lowers the stacking tray 10, the paper feeding rollers 21, 22 feed the topmost sheet of paper P stacked on the stacking tray 10, the boundary detection unit includes a stacking tray height detection unit 60 that detects the height f of the stacking tray 10, and the control unit 41 determines that the sheet of paper P fed by the paper feeding rollers 21, 22 is located at the boundary B between the stacks of paper PA, PB based on the height f of the stacking tray 10 detected by the stacking tray height detection unit 60 reaching the height f1±α of the stacking tray 10 before the stack of paper PB was replenished.

[0041] This makes it possible to identify the sheet P located at the boundary B without identifying the sheet bundles PA and PB themselves. Therefore, it is possible to easily prevent double feeding from occurring.

[0042] Second Embodiment FIG. 6 is a front view showing the paper feeder 2 in the second embodiment.

[0043] The sheet feeding device 2 shown in Fig. 6 can be similar to the sheet feeding device 1 shown in Fig. 1 described above, except that a weight sensor 70 is provided instead of the stacking table height detection unit 60. Therefore, a description of matters that overlap with the first embodiment will be omitted.

[0044] The weight sensor 70 is disposed on, for example, the upper surface of the stacking tray 10, and detects the weight of the paper P stacked on the stacking tray 10. Since the weight of the paper P is an example of the stacking state of the paper P, the weight sensor 70 can be said to be an example of a stacking state detection unit. Like the stacking tray height detection unit 60 of the first embodiment, this stacking state detection unit is also an example of a boundary detection unit for detecting the boundary B between the paper stacks PA and PB (medium stacks). In other words, the boundary detection unit includes a stacking state detection unit (weight sensor 70).

[0045] FIG. 7 is a flowchart for explaining the paper feeding operation in the second embodiment.

[0046] The process of the flowchart shown in FIG. 7 is started by the control unit 41, for example, while the sheet feeding device 2 is stopped from feeding sheets, or when the sheet feeding device 2 is powered on.

[0047] First, the control unit 41 repeatedly determines whether the user replenishing the paper stacks PB and PC has pressed the button for lowering the stacking table 10 on the operation panel 44 until this button is pressed (step S21).

[0048] When the button for lowering the loading platform 10 is pressed (step S21: YES), the control unit 41 controls the lifting / lowering drive unit 30 to lower the loading platform 10 to the lowest position (step S22).

[0049] Then, control unit 41 stores the weight of sheets P on stacker 10 detected by weight sensor 70 in memory unit 42 (step S23). Taking the example of a case where sheets P equivalent to sheet stack PA remain on stacker 10 and sheet stacks PB and PC are replenished twice in total, when stacker 10 descends to the lowest position, control unit 41 first detects weight m1 of sheets P of remaining sheet stack PA with weight sensor 70 and stores this in memory unit 42. When sheet stack PB is replenished onto stacker 10, weight sensor 70 detects weight m2, which is greater than weight m1, and control unit 41 stores weight m2 in memory unit 42. Furthermore, when sheet stack PC or another sheet stack is replenished onto stacker 10, weight sensor 70 detects weight m(n), which is greater than weight m2, and control unit 41 stores weight m(n) in memory unit 42.

[0050] Next, the control unit 41 repeats the determination as to whether the stacking table 10 has risen and paper feed by the paper feed rollers 21 and 22 has started until paper feed starts (step S24).

[0051] When paper feeding begins (step S24: YES), the control unit 41 determines whether the weight m of the paper P on the stacking tray 10 has reached "m(n)±α", ..., "m2±α", or "m1±α" (step S25).

[0052] When the weight m of the paper P on the stacking tray 10 reaches any of "m(n)±α", ..., "m2±α", or "m1±α" (step S25: YES), that is, when it is time to feed the paper P located at the boundary B, the control unit 41 controls the paper feed drive unit 50 to feed the paper P by the paper feed rollers 21 and 22 at a slower speed than the other papers P (step S26).

[0053] On the other hand, when the weight m of the paper P on the stacking tray 10 does not fall under any of "m(n)±α", ..., "m2±α", and "m1±α" (step S25: NO), the control unit 41 controls the paper feed drive unit 50 to feed the paper P at normal speed by the paper feed rollers 21 and 22 (step S27).

[0054] Next, the control unit 41 determines whether the paper feeding is complete (step S28). If it is not complete (step S28: NO), the process repeats from step S25. If it is complete (step S28: YES), the process shown in FIG. 7 ends.

[0055] In the above description, when the stacking tray 10 is lowered to the lowest position (step S22), the control unit 41 stores the weight m of the sheets P detected by the weight sensor 70 in the memory unit 42 (step S23). However, in a mode in which the sheets P on the stacking tray 10 are being fed while pressing the sheet feed rollers 21 and 22 upward, the detected value of the weight m may be different between when the sheets P are being fed (when the stacking tray 10 is raised) and when the stacking tray 10 is lowered to the lowest position, even if the same number of sheets P are loaded. Therefore, the control unit 41 may store the weight m of the sheets P remaining on the stacking tray 10 in the memory unit 42 before the stacking tray 10 is lowered to the lowest position, and may identify the sheets P located at the boundary B based on the weight sensor 70 detecting a weight equal to the weight m during the sheet feeding.

[0056] Furthermore, if the control unit 41 has information on the correspondence between weight m and the number of sheets of paper P, it can convert the increase in weight m when the paper stacks PB and PC are placed on the stack (step S23) into a number of sheets and store this in the memory unit 42, and when that number of sheets are fed, it can determine that the paper P fed by the paper feed rollers 21 and 22 is located at the boundary B.

[0057] In the second embodiment described above, the same effects as those of the first embodiment described above can be obtained, namely, by feeding the paper P located at the boundary B at a slow speed, it is possible to prevent double feeding without requiring any effort from the user.

[0058] In the second embodiment, the boundary detection unit includes a weight sensor 70 (loading state detection unit) that detects the weight (loading state) of the paper P loaded on the loading tray 10. Based on the weight m of the paper P on the loading tray 10 detected by the weight sensor 70, the control unit 41 determines that the paper P fed by the paper feed rollers 21 and 22 is located at the boundary B between the paper stacks PA, PB, and PC.

[0059] This makes it possible to accurately determine which sheet of paper P is located at boundary B using the stacking state, such as the weight m of the sheet of paper P. This makes it possible to more reliably prevent double feeding. Furthermore, by determining boundary B based on the stacking state of the sheets of paper P, it is possible to determine boundary B between each of the sheet bundles PA, PB, and PC, even when the stacking tray 10 is lowered to the lowest position and the sheet bundles PA, PB, and PC are stacked one by one multiple times in succession.

[0060] Third Embodiment FIG. 8 is a front view showing the paper feeder 3 in the third embodiment.

[0061] The sheet feeding device 2 shown in Fig. 8 can be similar to the sheet feeding device 1 shown in Fig. 1 described above, except that an imaging unit 80 is provided instead of the stacking table height detection unit 60. Therefore, a description of matters that overlap with the first embodiment will be omitted.

[0062] The imaging unit 80 may be located at any position, but is preferably located downstream in the paper feed direction of the sheets P stacked on the stacking tray 10. The imaging unit 80 captures images of the sheets P stacked on the stacking tray 10, for example, when the stacking tray 10 is lowered to its lowest position and when the stacking tray 10 is raised and paper is being fed. The control unit 41 determines the height h of the sheets P stacked on the stacking tray 10 based on the image (still image or video) captured by the imaging unit 80. The height h of the sheets P can be determined by identifying shadows that appear at the position of the topmost sheet P through image processing. The stacking state of the sheets P that appears in the image of the sheets P captured by the imaging unit 80 is an example of the stacking state of the sheets P, and the imaging unit 80 is an example of a stacking state detection unit. Similar to the stacking tray height detection unit 60 of the first embodiment, this stacking state detection unit is also an example of a boundary detection unit for detecting the boundary B between the sheet stacks PA and PB (medium stacks). In other words, the boundary detection unit includes a loading state detection unit (image capture unit 80).

[0063] FIG. 9 is a flowchart for explaining the paper feeding operation in the third embodiment.

[0064] The process of the flowchart shown in FIG. 9 is started by the control unit 41, for example, while the sheet feeding device 3 is stopped from feeding sheets, or when the sheet feeding device 3 is powered on.

[0065] First, the control unit 41 repeatedly determines whether the user replenishing the paper stacks PB and PC has pressed the button for lowering the stacking table 10 on the operation panel 44 until this button is pressed (step S31).

[0066] When the button for lowering the loading platform 10 is pressed (step S31: YES), the control unit 41 controls the lifting / lowering drive unit 30 to lower the loading platform 10 to the lowest position (step S32).

[0067] Then, the control unit 41 stores the height h of the sheets P on the stacking tray 10, for example, based on an image captured by the imaging unit 80 (step S33). Taking the example of a case where sheets P equivalent to the sheet stack PA remain on the stacking tray 10 and the sheet stacks PB and PC are replenished twice, when the stacking tray 10 is lowered to the lowest position, the control unit 41 first determines the height h1 of the sheets P of the sheet stack PA based on the image captured by the imaging unit 80 and stores the height h1 in the storage unit 42. When the sheet stack PB is replenished onto the stacking tray 10, the imaging unit 80 captures an image of the sheets P on the stacking tray 10 at a height h2 that is higher than the height h1, and the control unit 41 stores the height h2 in the storage unit 42. When the sheet stack PC or another sheet stack is replenished onto the stacking tray 10, the imaging unit 80 captures an image of the sheets P at a height h(n) that is higher than the height h2, and the control unit 41 stores the height h(n) in the storage unit 42.

[0068] Next, the control unit 41 repeats the determination as to whether the stacking table 10 has risen and paper feed by the paper feed rollers 21 and 22 has started until paper feed starts (step S34).

[0069] When paper feeding begins (step S34: YES), the control unit 41 determines, based on the image captured by the imaging unit 80, whether the height h of the paper P on the stacking tray 10 has reached "h(n)±α", ..., "h2±α", or "h1±α" (step S35).

[0070] When the height h of the paper P on the stacking tray 10 reaches any of "h(n)±α", ..., "h2±α", or "h1±α" (step S35: YES), that is, when it is time to feed the paper P located at the boundary B, the control unit 41 controls the paper feed drive unit 50 to feed the paper P by the paper feed rollers 21 and 22 at a slower speed than the other papers P (step S36).

[0071] On the other hand, when the height h of the paper P on the stacking tray 10 does not fall under any of "h(n)±α", ..., "h2±α", and "h1±α" (step S35: NO), the control unit 41 controls the paper feed drive unit 50 to feed the paper P at normal speed by the paper feed rollers 21 and 22 (step S37).

[0072] Next, the control unit 41 determines whether the paper feeding is complete (step S38), and if it is not complete (step S38: NO), the process repeats from step S35, and if it is complete (step S38: YES), the process shown in FIG. 9 ends.

[0073] In the above description, when the stacking tray 10 is lowered to the lowest position (step S32), the control unit 41 stores the height h of the sheets P based on the image captured by the imaging unit 80 (step S33). However, if the imaging unit 80 captures images of the sheets P both in the paper feeding state and when the stacking tray 10 is lowered to the lowest position, the imaging unit 80 will need to capture images over a wide range. Therefore, the control unit 41 may store the height h of the sheets P remaining on the stacking tray 10 in the memory unit 42 based on the image captured before the stacking tray 10 is lowered to the lowest position, and identify the sheets P located at the boundary B. In this case, the boundary B can be identified, although it is only the boundary B between the stack of sheets PA remaining on the stacking tray 10 and the first replenished stack of sheets PB.

[0074] Furthermore, if the control unit 41 has information on the correspondence between the height h and the number of sheets of paper P (for example, the height per sheet of paper P), it can convert the height of each stack of paper PB, PC when the stacks of paper PB, PC are placed on the stack of paper PB, PC (step S33) into the number of sheets and store this in the memory unit 42, and when that number of sheets are fed, it can determine that the sheets of paper P fed by the paper feed rollers 21, 22 are located at the boundary B.

[0075] In the above description, imaging unit 80 captures images of heights h1, h2, h(n) when replenishing sheet bundles PA, PB, PC, but when sheet bundles PA, PB, PC are loaded on stacking tray 10, it is difficult to load each of the four corners (edges) in exactly the same position, resulting in differences in level between sheet bundles PA, PB, PC. Therefore, control unit 41 may use image processing to identify shadows and the like that are caused by differences in level between sheet bundles PA, PB, PC in the image captured by imaging unit 80 during paper feeding, and determine boundary B between sheet bundles PA, PB, PC.

[0076] In the third embodiment described above, the same effects as those of the first embodiment described above can be obtained, namely, by feeding the paper P located at the boundary B at a slow speed, it is possible to prevent double feeding without requiring any effort from the user.

[0077] In the third embodiment, the boundary detection unit includes an imaging unit 80 (loading state detection unit) that captures (detects) an image (loading state) of the paper P loaded on the loading tray 10. Based on the image (e.g., height h) of the paper P on the loading tray 10 captured by the imaging unit 80, the control unit 41 determines that the paper P fed by the paper feed rollers 21 and 22 is located at the boundary B between the paper stacks PA, PB, and PC.

[0078] This makes it possible to accurately identify the paper P located at the boundary B using the stacking state of the paper P, such as the image of the paper P. This makes it possible to more reliably prevent double feeding. Furthermore, by identifying the boundary B based on the stacking state of the paper P, it is possible to identify the boundary B of each of the paper stacks PA, PB, and PC even when the stacks PA, PB, and PC are stacked one by one multiple times in succession with the stacking tray 10 lowered to the lowest position.

[0079] <Fourth embodiment> FIG. 10 is a diagram showing the operation panel 44 in the fourth embodiment.

[0080] 1 except that the boundary B is determined using the operation panel 44 that acquires input information on the number of sheets in the paper stacks PA and PB instead of the stacking table height detection unit 60. Therefore, a description of matters that overlap with the first embodiment will be omitted.

[0081] As shown in Fig. 10(a), the operation panel 44 has an additional stack number input field 44a, a currently stacked number display field 44b, an add button 44c, and an end button 44d. The operation panel 44 is an example of a sheet count information acquisition unit that acquires input information on the number of sheets in the replenished paper stacks PA and PB. The display contents of the operation panel 44 shown in Figs. 10(a) to 10(c) are displayed on all or part of the operation panel 44, for example, when the stacking table 10 is lowered (during replenishment).

[0082] The number of sheets of the paper stacks PA and PB that have been added by the user is input in the additional stack number input field 44a.

[0083] The current stack number display field 44b displays the number of sheets P stacked on the stacking tray 10, which is managed by the control unit 41. This stack number is managed by adding the number of sheets input in the additional stack number input field 44a and subtracting one sheet each time a sheet P is fed. Note that if the weight sensor 70, the imaging unit 80, or another sensor that detects the sheets P is provided, the control unit 41 can use this sensor to confirm whether the additional stack number has actually been stacked. In this case, even if a discrepancy occurs between the number of sheets detected by the sensor and the additional stack number input in the additional stack number input field 44a, it is preferable to give priority to the additional stack number with higher accuracy.

[0084] The Add button 44c is pressed to confirm the number of sheets entered in the additional stack number input field 44a. For example, as shown in Fig. 10(a), when the Add button 44c is pressed in a state where the current stack number is 30 sheets and 500 sheets have been entered in the additional stack number input field 44a, the operation panel 44 displays 530 sheets in the current stack number display field 44b, as shown in Fig. 10(b). Also, as shown in Fig. 10(b), when the Add button 44c is pressed in a state where the current stack number is 530 sheets and 500 sheets have been entered again in the additional stack number input field 44a, the operation panel 44 displays 1030 sheets in the current stack number display field 44b, as shown in Fig. 10(c).

[0085] The end button 44d is pressed to end the display of the paper stack addition screen on the operation panel 44.

[0086] The operation panel 44, which is an example of a sheet count information acquisition unit, is also an example of a boundary detection unit for detecting the boundary B between the sheet stacks PA and PB (medium stacks), similar to the stacking table height detection unit 60 of the first embodiment. In other words, the boundary detection unit includes a sheet count information acquisition unit (operation panel 44). This sheet count information acquisition unit may be the interface unit 43 (control unit 41) that acquires input information on the number of sheets in the replenished sheet stacks PA and PB from a print control device, a user terminal, or the like.

[0087] FIG. 11 is a flowchart for explaining the paper feeding operation in the fourth embodiment.

[0088] The process of the flowchart shown in FIG. 11 is started by the control unit 41, for example, while paper feeding by the paper feeding device 1 (see FIG. 1) is stopped, or when the paper feeding device 1 is powered on.

[0089] First, the control unit 41 repeatedly determines whether the user who is replenishing the paper stack PB has pressed the button for lowering the stacking table 10 on the operation panel 44 until this button is pressed (step S41).

[0090] When the button for lowering the loading platform 10 is pressed (step S41: YES), the control unit 41 controls the lifting / lowering drive unit 30 to lower the loading platform 10 to the lowest position (step S42).

[0091] Then, the control unit 41 causes the stacking tray 10 to be replenished with paper stacks PA and PB, and stores in the memory unit 42 the current number of sheets loaded (30 sheets) and the number of additional sheets to be loaded (for example, 500 sheets twice) input by the user on the operation panel 44 shown in Figures 10(a) to (c) above as the position of boundary B, which is the position of the additional number of sheets to be loaded (step S43).

[0092] Next, the control unit 41 repeats the determination as to whether the stacking table 10 has risen and the paper feed rollers 21 and 22 have started feeding paper until the paper feed starts (step S44).

[0093] When paper feeding starts (step S44: YES), the control unit 41 determines whether the paper P fed by the paper feed rollers 21 and 22 is paper P located at boundary B (30 sheets±α, 530 sheets±α from the bottom at the time of refilling) (step S45). The determination of whether paper P is paper P located at boundary B may be made, for example, by the control unit 41 subtracting the number of fed sheets from the latest current number of sheets stacked as shown in FIG. 4(c) and checking whether the paper P reaches boundary B.

[0094] If the paper P located at boundary B is being fed by paper feed rollers 21, 22 (step S45: YES), that is, when it is time to feed paper P located at boundary B, control unit 41 controls paper feed drive unit 50 so that paper P is fed by paper feed rollers 21, 22 at a slower speed than other paper P (step S46).

[0095] On the other hand, if the paper P being fed by the paper feed rollers 21 and 22 is not located at the boundary B (step S45: NO), the control unit 41 controls the paper feed drive unit 50 to feed the paper P by the paper feed rollers 21 and 22 at the normal speed (step S47).

[0096] Next, the control unit 41 determines whether the paper feeding is complete (step S48), and if it is not complete (step S48: NO), the process repeats from step S45, and if it is complete (step S48: YES), the process shown in FIG. 11 ends.

[0097] In the fourth embodiment described above, the same effects as those of the first embodiment described above can be obtained, namely, by feeding the paper P located at the boundary B at a slow speed, it is possible to prevent double feeding without requiring any effort from the user.

[0098] In addition, in this fourth embodiment, the boundary detection unit includes an operation panel 44 (number information acquisition unit) that acquires input information on the number of sheets in the replenished paper stacks PA and PB, and the control unit 41 determines that the paper P fed by the paper feed rollers 21 and 22 is located at the boundary B between the paper stacks PA and PB based on the number of sheets in the paper stacks PA and PB acquired by the operation panel 44.

[0099] This makes it possible to accurately determine the paper P located at boundary B using the input information on the number of sheets input by the user who actually replenished the paper P. This makes it possible to more reliably prevent double feeding. Furthermore, by having control unit 41 acquire input information on the number of sheets for each paper stack PA, PB, it is possible to determine boundary B between each paper stack PA, PB even when paper stacks PA, PB are stacked one by one multiple times in succession with stacking tray 10 lowered to the lowest position.

[0100] In the first to fourth embodiments described above, the boundary detection unit has been described as any one of the stacking platform height detection unit 60, the loading state detection unit (weight sensor 70 or imaging unit 80), and the sheet count information acquisition unit (operation panel 44) as an example. However, the boundary detection unit may include two or more of the stacking platform height detection unit 60, weight sensor 70, imaging unit 80, and operation panel 44, and the control unit 41 may determine the boundary B between the sheet stacks PA and PB based on the two or more boundary detection units.

[0101] The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components without departing from the spirit of the invention in the implementation stage. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all the components shown in the embodiments may be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention. Below, some of the inventions described in the specification of this application are additionally noted.

[0102] [Appendix 1] a loading table on which media are loaded by sequentially replenishing media bundles; a supply member that supplies the medium from the loading platform; a boundary detection unit for detecting a boundary between the medium bundles; a control unit that controls the supply member so as to supply the medium located at the boundary at a slower speed than the other medium; A medium supply device comprising:

[0103] [Appendix 2] Further provided is a lifting drive unit that lifts and lowers the loading platform, the supply member supplies the topmost medium stacked on the stacking tray; the boundary detection unit includes a loading platform height detection unit that detects the height of the loading platform, The control unit determines that the medium supplied by the supply member is located at the boundary of the medium stack based on the fact that the height of the loading table detected by the loading table height detection unit has reached the height of the loading table before the medium stack was replenished. 2. A medium supply device according to claim 1.

[0104] [Appendix 3] the boundary detection unit includes a loading state detection unit that detects a loading state of the media loaded on the loading tray, The control unit determines, based on the stacking state detected by the stacking state detection unit, that the medium supplied by the supply member is located at the boundary of the medium stack. 3. The medium supply device according to claim 1 or 2.

[0105] [Appendix 4] the boundary detection unit includes a number information acquisition unit that acquires input information on the number of sheets of the replenished medium bundle, The control unit determines that the medium supplied by the supply member is located at the boundary of the medium bundle based on the number of sheets in the medium bundle acquired by the sheet number information acquisition unit. 4. A medium supply device according to any one of claims 1 to 3. [Explanation of symbols]

[0106] 1,2,3 Paper feeder 10 Loading platform 21,22 Paper feed roller 23 Sabaki board 30 Lifting drive unit 41 Control Unit 42 Storage section 43 Interface section 44 Operation Panel 44a Additional loading quantity input field 44b Current loading number display field 44c Add button 44d Exit button 50 Paper feed drive unit 60 Loading platform height detection unit 70 Weight sensor (loading status detection section) 80 Imaging unit (loading status detection unit) B Boundary P paper PA,PB,PC paper stack

Claims

1. a loading table on which media are loaded by sequentially replenishing media bundles; a supply member that supplies the medium from the loading platform; a boundary detection unit for detecting a boundary between the medium bundles; a control unit that controls the supply member so as to supply the medium located at the boundary at a slower speed than the other medium; A medium supply device comprising:

2. Further provided is a lifting drive unit that lifts and lowers the loading platform, the supply member supplies the topmost medium stacked on the stacking tray; the boundary detection unit includes a loading platform height detection unit that detects the height of the loading platform, The control unit determines that the medium supplied by the supply member is located at the boundary of the medium stack based on the fact that the height of the loading table detected by the loading table height detection unit has reached the height of the loading table before the medium stack was replenished.

2. The medium supply device according to claim 1.

3. the boundary detection unit includes a loading state detection unit that detects a loading state of the media loaded on the loading tray, The control unit determines, based on the stacking state detected by the stacking state detection unit, that the medium supplied by the supply member is located at the boundary of the medium stack.

2. The medium supply device according to claim 1.

4. the boundary detection unit includes a number information acquisition unit that acquires input information on the number of sheets of the replenished medium bundle, The control unit determines that the medium supplied by the supply member is located at the boundary of the medium bundle based on the number of sheets in the medium bundle acquired by the sheet number information acquisition unit.

2. The medium supply device according to claim 1.

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