Media supply device

Abstract

To provide a medium supply device which makes substantially constant a slack quantity that a medium has when made to abut on a secondary supply part without lowering efficiency of supply of the medium.SOLUTION: A medium supply device 10 comprises: a primary supply part 11 which conveys a medium loaded on a supply table 14; a secondary supply part 12 which conveys the medium P, having slackened Pa as the medium conveyed by the primary supply part 11 is made to abut, at predetermined conveyance start time; a medium detection sensor 13 which detects the medium P between the primary supply part 11 and secondary supply part 12; and a control part 17 which controls the primary supply part 11 to put conveyance end time of the primary supply part 11 within a predetermined end period and, and also to increase, based upon a conveyance rate η of the medium P, a conveyance quantity of the primary supply part 11 from detection time (time t2) when the medium is detected by the medium detection sensor 13 to conveyance start time of the secondary supply part 12 increases.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a media supply device. [Background technology]

[0002] Conventionally, in order to eliminate the tilt of paper caused by skewing of the paper during transport and to synchronize the printing start position on the printing paper with the image formation start position by the image forming unit, a paper feeding device is known in which the leading edge of the paper transported by the primary paper feed roller is brought into contact with a secondary paper feed roller (registration roller) and stopped temporarily to give slack, and then the paper is transported toward the image forming unit at a predetermined timing.

[0003] Also, an image forming apparatus has been proposed in which a motor that drives a paper feed roller is started, accelerated to a predetermined conveying speed, and then conveys at a constant speed, and starts slow-down control when the paper reaches the vicinity of a registration roller in order to reduce noise (see, for example, Patent Document 1).In this case, the timing of switching between the constant-speed conveying section and the slow-down conveying section is calculated from the timing when a registration sensor provided near the registration roller detects the passage of the leading edge of the paper. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-118888 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when a pickup roller facing a separation plate is used to unwind and transport media such as paper stacked on a supply tray, friction occurs between the media on the supply tray and between the media and the separation plate. Therefore, if the friction between the pickup roller and the media is not sufficiently greater than the friction between the media, the topmost media may not be transported at the desired transport speed. This problem occurs throughout the entire transport path from the supply tray to the secondary supply section (pair of registration rollers). If the pickup roller's transport operation is not properly corrected, the media will not sag enough in the secondary supply section, resulting in poor image quality, such as skewed printing.

[0006] In an image forming apparatus that performs slow-down control as described above, even if the constant-speed conveyance section and the slow-down conveyance section are switched depending on the timing when the media detection sensor (resist sensor) detects the leading edge of the media, the predetermined amount of slack cannot be secured unless the insufficient conveyance speed in the slow-down conveyance section is corrected. Furthermore, adjusting the slow-down conveyance section to secure the amount of slack results in a delay in the timing of sending the media to the image forming unit.

[0007] Here, if the detection time at which the media detection sensor detects the media is earlier than expected, the end time of the subsequent high-speed transport (transport speed before deceleration) can be advanced or the transport end time itself can be advanced to keep the transport time constant; if the detection time is later than expected, the end time of the subsequent high-speed transport can be delayed or the transport end time itself can be delayed to keep the transport time constant, thereby making the transport amount of the primary supply section closer to constant.

[0008] However, for media with low transport rates, transport delays occur even after the media detection sensor detects the media. To make up for the delay before reaching the media detection sensor, the end time of high-speed transport after detection is delayed to maintain a constant transport time, or the end time of transport itself is delayed. Even if this constant transport amount is maintained in the primary supply unit after the detection time, the amount of slack formed after the media reaches the secondary supply unit may be reduced depending on the media transport rate. In this way, if the amount of slack in the media is insufficient, skew cannot be corrected. Alternatively, if an appropriate amount of slack is not formed in the secondary supply unit, transport in the secondary supply unit may become unstable. Furthermore, delaying the end time of transport in the primary supply unit, as described above, may delay the start time of the subsequent transport in the secondary supply unit, or the secondary supply unit may begin transport before the media has even arrived, resulting in a transport error. This results in longer media supply intervals or periods of supply stoppage due to transport errors. This reduces media supply efficiency.

[0009] An object of the present invention is to provide a medium supply device that can keep the amount of slack in the medium caused by the medium hitting a secondary supply section close to constant without reducing the medium supply efficiency. [Means for solving the problem]

[0010] In one aspect, the medium supply device includes a primary supply unit that transports media loaded on a supply table, a secondary supply unit that transports the media that has been bumped and loosened by the impact at a predetermined transport start time, a media detection sensor that detects the media between the primary supply unit and the secondary supply unit, and a control unit that controls the primary supply unit so that the transport end time of the primary supply unit falls within a predetermined end period and so that the transport amount of the primary supply unit is increased from the detection time when the media is detected by the media detection sensor to the transport start time of the secondary supply unit based on the transport rate of the media. [Effects of the Invention]

[0011] According to this aspect, the amount of slack in the medium caused by the medium striking the secondary supply unit can be made nearly constant without reducing the efficiency of medium supply. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an internal structure of a printing device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a control configuration of a medium supply device according to an embodiment. [Figure 3] 1 is an explanatory diagram for explaining an overview of an operation of a medium supplying device according to an embodiment. [Figure 4] 10 is a diagram illustrating the relationship between a primary supply drive unit, a secondary supply drive unit, and an actual medium transport speed in one embodiment. FIG. [Figure 5] FIG. 4 is an explanatory diagram for explaining a transport amount of a primary supply unit according to an embodiment. [Figure 6] 10 is a flowchart illustrating an operation of a primary supply unit according to an embodiment. [Figure 7] 10 is an explanatory diagram for explaining adjustment of a transport amount of a primary supply unit in one embodiment. FIG. [Figure 8] 10(a) to 10(c) are tables for explaining slack amount correction values ​​in one embodiment. [Figure 9] 10(a) to 10(c) are tables for explaining another example of slack amount correction values ​​according to an embodiment. [Figure 10] 10 is a table for explaining another example of the amount of slack after correction according to an embodiment. [Figure 11] 10 is a flowchart illustrating a rotation detection process of a primary supply unit in a modified example of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A medium supplying device according to an embodiment of the present invention will now be described with reference to the drawings.

[0014] FIG. 1 is a diagram showing the internal structure of a printing device 1 according to an embodiment.

[0015] FIG. 2 is a diagram showing the control configuration of the medium supply device 10. As shown in FIG.

[0016] As shown in FIG. 1, the printing device 1 includes a medium supplying device 10, a printing unit 20, and a transport unit 30.

[0017] The medium supplying device 10 shown in FIG. 1 supplies a medium P to a printing unit 20 of a printing apparatus 1. The medium supplying device 10 is disposed integrally with the printing apparatus 1. However, the medium supplying device 10 may also be disposed separately from the printing apparatus 1. Furthermore, the target to which the medium supplying device 10 supplies the medium P is not limited to the printing unit 20 of the printing apparatus 1, but may be other supply destination devices such as a transport device that transports the medium P or a processing device that performs processing other than printing on the medium P. Furthermore, the medium P is, for example, paper (sheets), but may also be other sheet-like media such as film.

[0018] 1, medium supply device 10 includes primary supply unit 11, secondary supply unit 12, medium detection sensor 13, supply table 14, primary supply drive unit 15, and secondary supply drive unit 16. Also, as shown in FIG. 2, medium supply device 10 further includes control unit 17, storage unit 18, and interface 19.

[0019] The primary supply unit 11 has a scraper roller 11a, a pickup roller 11b, a separation plate 11c, and a rotation detection unit 11d (see FIG. 2), and transports the medium P loaded on the supply table .

[0020] The scraper roller 11a picks up and transports the uppermost medium P among the media P stacked on the supply table 14.

[0021] Pickup roller 11b is disposed downstream of scraper roller 11a in the transport direction of medium P, and transports medium P fed out by scraper roller 11a.

[0022] The separation plate 11c is disposed so as to sandwich the medium P between itself and the pickup roller 11b, and prevents double feeding of the medium P. The separation plate 11c is formed of, for example, rubber.

[0023] 2 is, for example, an encoder provided on the drive shaft of pickup roller 11b, and detects the rotation of pickup roller 11b. However, rotation detector 11d is not limited to an encoder as long as it detects the rotation of primary supply unit 11 when medium P is being transported.

[0024] The primary supply unit 11 may also include an air blowing mechanism that blows air to float the medium P, and a conveyor belt that conveys the uppermost medium P that has been floated by the air blowing from the air blowing mechanism. In this way, the primary supply unit 11 may be any unit that conveys the medium P loaded on the supply table 14.

[0025] The secondary supply unit 12 has a pair of registration rollers 12a, 12b. The secondary supply unit 12 is struck by the medium P conveyed by the primary supply unit 11, and conveys the medium P that has become loose due to the abutment at a predetermined conveyance start time (for example, at regular intervals). The conveyance start time of the secondary supply unit 12 may vary depending on factors such as the length of the medium P in the conveyance direction, but it is desirable that the intervals be regular for the same medium P. Note that the secondary supply unit 12 is not limited to having a pair of registration rollers 12a, 12b, and may be any unit that conveys the medium P that has been struck by the medium P conveyed by the primary supply unit 11 and has become loose due to the abutment at the predetermined conveyance start time.

[0026] The medium detection sensor 13 detects the medium P between the primary supply unit 11 and the secondary supply unit 12. The medium detection sensor 13 is, for example, a photoelectric sensor that detects the medium P based on whether or not detection light is blocked by the medium P. The medium detection sensor 13 can also be called a registration sensor because it is the sensor closest to the registration roller pair 12a, 12b on the upstream side of the registration roller pair 12a, 12b in the conveying direction.

[0027] A plurality of sheets of media P are loaded on the supply table 14. The supply table 14 is raised and lowered by driving an elevation drive unit (not shown) based on the detection result of the remaining amount of media P, for example.

[0028] The primary supply driving unit 15 is an actuator such as a motor that drives the scraper roller 11a and the pickup roller 11b.

[0029] The secondary supply driving unit 16 is an actuator such as a motor that drives a driving roller, which is one of the pair of registration rollers 12a and 12b.

[0030] 2 has a processor (e.g., CPU: Central Processing Unit) that functions as an arithmetic processing device that controls the overall operation of the medium supplying device 10. Note that, if the medium supplying device 10 is disposed integrally with the printing device 1 (supply destination device), the control device that controls the overall operation of the printing device 1 may function as the control device 17.

[0031] The storage unit 18 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.

[0032] Interface 19 exchanges various types of information with the control unit of printing device 1 and external devices such as a user terminal. For example, interface 19 receives information such as a request to supply medium P or a request to stop supplying medium P from the control unit that controls the overall operation of printing device 1, and control unit 17 controls the operation of each unit of medium supply device 10 based on this information.

[0033] 1, the printing unit 20 has, for example, a line-head type inkjet head (not shown) for each color used for printing. The printing method of the printing unit 20 may be a printing method other than inkjet printing.

[0034] The transport unit 30 is disposed opposite the printing unit 20 and transports the medium P. For example, the transport unit 30 transports the medium P by a transport belt while holding the medium P by suction.

[0035] The printing device 1 may also be provided with a discharge section for discharging the medium P on which printing has been performed by the printing section 20, an operation panel that functions as an example of an input section and a display section, and the like.

[0036] Next, an outline of the operation of the medium supply device 10 will be described with reference to FIG.

[0037] FIG. 3 is an explanatory diagram for explaining an outline of the operation of the medium supply device 10. As shown in FIG.

[0038] When the primary supply drive unit 15 starts driving under the drive control of the control unit 17 shown in FIG. 2, the scraper roller 11a and the pickup roller 11b transport the uppermost medium P stacked on the supply table 14, as shown in FIG. 3.

[0039] The scraper roller 11a and the pickup roller 11b transport the medium P at a first transport speed V1, and after a predetermined time has elapsed since the leading edge of the medium P is detected (ON) by the medium detection sensor 13, they decelerate and transport the medium P at a second transport speed V2 that is slower than the first transport speed V1.

[0040] The scraper roller 11a and the pickup roller 11b continue to transport the medium P at the second transport speed V2 even when the medium P abuts against the pair of registration rollers 12a and 12b, and then decelerate and stop.

[0041] Here, the scraper roller 11a and the pickup roller 11b are not stopped when the medium P hits the pair of registration rollers 12a, 12b, so slack Pa occurs in the medium P when it hits the pair of registration rollers 12a, 12b, which are stopped.

[0042] 4, the actual transport speed of the medium P, indicated by the thin solid line, is slower than the transport speed of the primary supply unit 11, indicated by the thick solid line (similar to the transport speed of the primary supply drive unit 15 described above), and the transport speed of the secondary supply unit 12, indicated by the thick dashed line (similar to the transport speed of the secondary supply drive unit 16). Note that the transport speed of the primary supply unit 11 (secondary supply unit 12) may vary from the transport speed of the primary supply drive unit 15 (secondary supply drive unit 16), but since they can be viewed as the same, they are considered to be the same.

[0043] Furthermore, the actual transport speed of medium P varies for each medium P. Therefore, in order to keep the transport amount of medium P constant after the detection time when medium P is detected by medium detection sensor 13, it is possible to keep the area A (transport amount of primary supply unit 11) after the detection time shown by the diagonal lines in FIG. 5 constant by, for example, keeping constant the first period D1 (see FIG. 5) during which primary supply unit 11 maintains first transport speed V1 after the detection time even if the detection time is later than expected. The transport amount of primary supply unit 11 can be referred to as the drive amount of primary supply drive unit 15 (the number of rotations in the case of a motor).

[0044] However, even if the transport amount of the primary supply unit 11 after the detection time is kept constant, if the detection time of the medium P is slow, it is expected that delays will occur in the medium P even after the detection time, which may result in a shortage of slack Pa, or the medium P may not even reach the secondary supply unit 12. Furthermore, if the first period D1 during which the first transport speed V1 of the primary supply unit 11 is maintained after the detection time is kept constant even if the detection time is later than expected, the end time of transport by the primary supply unit 11 will be delayed, and the start time of transport by the secondary supply unit 12 will be delayed, or the secondary supply unit 12 may start transporting before the medium P has arrived, resulting in a transport error. Therefore, the lower the transport rate η of the medium P (the longer the detection time), the more preferably the area As for the slack amount correction shown in FIG. 5 can be added to the above-mentioned fixed area A (the transport amount of the primary supply unit 11 can be increased) by, for example, extending the first period D1 during which the primary supply unit 11 maintains the first transport speed V1 after the detection time (period D1+Ds) and shortening the second period D2 during which the primary supply unit 11 maintains the slow second transport speed V2. In other words, the higher the transport rate η of the medium P (the shorter the detection time), the more preferably the transport amount of the primary supply unit 11 can be reduced after the detection time. In this way, the transport amount of the primary supply unit 11 can be adjusted by adjusting the transport speed (the time for maintaining a predetermined speed), which is a parameter that determines the transport amount of the primary supply unit 11. The transport amount of the primary supply unit 11 will be described later. Furthermore, the transport end time of the primary supply unit 11 should preferably be within a predetermined end period. This end period is preferably a period before the specified start time of transport of the secondary supply unit 12 so as not to delay this start time of transport, and more preferably, a period during which the transport time from the start time of transport of the primary supply unit 11, for example at regular intervals, becomes constant.

[0045] Next, the operation of the primary supply unit 11 will be described with reference to FIG.

[0046] FIG. 6 is a flowchart for explaining the operation of the primary supply unit 11.

[0047] FIG. 7 is an explanatory diagram for explaining adjustment of the transport amount of the primary supply unit 11. As shown in FIG.

[0048] First, the control unit 17 shown in Fig. 2 controls the primary supply drive unit 15 to operate the primary supply unit 11, for example, by receiving a supply start signal from a control unit that controls the operation of the entire printing device 1. The flowchart in Fig. 6 shows the control of the control unit 17 focusing on one sheet of medium P.

[0049] First, the control unit 17 starts the primary supply drive unit 15 at an acceleration α1 at time t0 shown in Fig. 7. This causes the primary supply unit 11 to start transporting the medium P (step S1 in Fig. 6). When the primary supply drive unit 15 starts, the control unit 17 receives an encoder signal from an encoder (an example of a drive amount detection unit, not shown) of the primary supply drive unit 15 and starts counting the encoder signal.

[0050] 7, after the conveying speed of the primary supply drive unit 15 (primary supply unit 11) reaches the first conveying speed V1, the control unit 17 controls the primary supply drive unit 15 to maintain the first conveying speed V1 (time t1). As a result, the primary supply unit 11 conveys the medium P at the first conveying speed V1 (step S2). Note that the first conveying speed V1 is, for example, the maximum conveying speed that can be set in the primary supply drive unit 15.

[0051] Next, the control unit 17 determines whether the medium P is detected by the medium detection sensor 13 until the medium P is detected (step S3).

[0052] When the medium P is detected (time t2, step S3: YES), the control unit 17 calculates the switching timing for decelerating the first conveying speed V1 of the primary supply drive unit 15 (primary supply unit 11) to the second conveying speed V2 (step S4). This switching timing will be described later.

[0053] Next, the control unit 17 determines whether the calculated switching timing (time t3) has arrived or not until the switching timing arrives (step S5).

[0054] When the switching timing arrives (time t3, step S5: YES), the control unit 17 drives the primary supply driving unit 15 at the deceleration acceleration α2 (step S6).

[0055] Then, the control unit 17 determines whether the speed reaches the second transport speed V2, which is slower than the first transport speed V1 (at time t4), until it does (step S7).

[0056] When the conveying speed reaches the second conveying speed V2 (time t4, step S7: YES), the control unit 17 controls the primary supply drive unit 15 to maintain the conveying speed at the second conveying speed V2 and convey the medium P (step S8). Note that while the primary supply drive unit 15 maintains the second conveying speed V2, the medium P collides with the secondary supply unit 12 (the pair of registration rollers 12a, 12b).

[0057] Thereafter, at a predetermined deceleration timing (time t5) after medium P hits secondary supply unit 12, control unit 17 drives primary supply drive unit 15 at deceleration acceleration α2 (step S9). Note that medium P continues to be transported even after hitting secondary supply unit 12, causing the above-mentioned slack Pa.

[0058] At a predetermined stop timing (time t6), the control unit 17 stops the primary supply drive unit 15 (step S10). This ends the processing in FIG. 6. Thereafter, the secondary supply unit 12 starts transporting the medium P at a predetermined transport start time. After this transport start time of the secondary supply unit 12, the primary supply unit 11 also starts transporting with a slight delay due to the driving of the primary supply drive unit 15, as shown in FIG. 4. This delay is to allow the secondary supply unit 12 to start transporting earlier in order to eliminate slack Pa in the medium P.

[0059] Furthermore, the control unit 17 activates the primary supply driving unit 15 to transport the next medium P (time t7).

[0060] Next, the calculation of the switching timing (step S4) for decelerating the first conveying speed V1 to the second conveying speed V2 will be described with reference to FIG.

[0061] First, the control unit 17 calculates the conveying rate η (the value obtained by dividing the actual conveying distance by the theoretical conveying distance) based on the count number (number of pulses) of the encoder signal of the primary supply drive unit 15 at the detection time when the medium P is detected by the medium detection sensor 13 and the design value.

[0062] Then, the control unit 17 determines the switching timing so as to increase the conveyance amount of the primary supply unit 11 after the detection time (until the conveyance start time of the secondary supply unit 12) by the slack amount correction values ​​(conveyance amount correction values) X1 to X4 [mm] shown in Figure 8(a) corresponding to the conveyance rate η. These slack amount correction values ​​X1 to X4 may be stored as a table in the storage unit 18.

[0063] As described above, the longer the detection time, the greater the conveyance amount of the primary supply unit 11 (primary supply drive unit 15), so the slack amount correction value X4 for medium P4 with a conveyance rate η of 0.7 or less is the largest, the slack amount correction value X3 for medium P3 with a conveyance rate η greater than 0.7 and less than 0.8 is next largest, the slack amount correction value X2 for medium P2 with a conveyance rate η greater than 0.8 and less than 0.9 is next largest, and the slack amount correction value X1 for medium P1 with a conveyance rate η greater than 0.9 and less than 1 is the smallest. Since the conveyance rate η is unlikely to be 1, in the example of FIG. 8(a), slack amount correction is basically performed.

[0064] 8(a), the slack amount correction values ​​X1 to X4 are determined for each range of the conveyance rate η, which is convenient when an administrator measures the actual amount of slack and determines the slack amount correction values ​​X1 to X4, for example, during maintenance of the medium supply device 10. However, the slack amount correction value may be calculated using a formula that uses the conveyance rate η so that the slack amount correction value increases as the conveyance rate η until the detection time decreases.

[0065] 7, the ratio between the transport rate η of the medium P up to time t2, which is the detection time of the medium detection sensor 13, and the transport rate η of the medium P after time t2 can vary depending on the type of medium P, such as the thickness, size, and material of the medium P, or the environment, such as humidity. For example, if there is a large decrease in the transport rate η before the detection time compared to the rate after the detection time due to large friction between the media P or between the media P and the separation plate 11c immediately after the primary supply unit 11 starts to deliver the media, then if the transport amount after the detection time is increased too much based on the transport rate η before the detection time, the slack Pa will become too large.

[0066] Therefore, in the example shown in Figure 8(b), for media P1 to P4 that are thick paper and for which the decrease in the transport rate η before the detection time is greater than the transport rate after the detection time, the transport amount can be further increased by adding, for example, 2 mm to the slack amount correction value, and in the example shown in Figure 8(c), for media P1 to P4 that are thin paper and for which the decrease in the transport rate η before the detection time is smaller than the transport rate after the detection time, the transport amount can be adjusted by subtracting, for example, 2 mm from the slack amount correction value.

[0067] 9(a) to 9(c) are tables for explaining other examples of slack amount correction values ​​according to the present embodiment.

[0068] FIG. 10 is a table for explaining the amount of slack after correction in the above-mentioned other example.

[0069] In the example of Figure 9(a), the slack amount correction values ​​X1 to X4 are the same as those in the example of Figure 8(a), but the setting examples are as follows: slack amount correction value X1 is 2 mm, slack amount correction value X2 is 6 mm, slack amount correction value X3 is 8 mm, and slack amount correction value X4 is 10 mm.

[0070] If the transport rate η of the medium P up to time t2, which is the detection time of the medium detection sensor 13 shown in Figure 7, is η1, and the transport rate η of the medium P from time t2 onwards until time t6, which is the end time of transport by the primary supply unit 11, is η2, as described above, these transport rates η1 and η2 can vary depending on the type of medium P, such as the thickness, size, and material of the medium P, or the environment, such as humidity.

[0071] As shown in Figure 10, the transport rates η1 and η2 were obtained by actual measurements when the medium P was plain paper, thick paper, and thin paper.The transport rate η1 for plain paper was 0.7, the transport rate η2 for plain paper was 0.75, the transport rate η1 for thick paper was 0.7, the transport rate η2 for thick paper was 0.6, the transport rate η1 for thin paper was 0.65, and the transport rate η2 for thin paper was 0.65.

[0072] One reason why the transport rate η1 (0.65) for thin paper is lower than the transport rate η1 (0.7) for plain paper and thick paper is that, compared to plain paper and thick paper, thin paper is more difficult to peel off the top medium P when stacked on the supply tray 14 shown in Figures 1 and 3 due to sticking to other media P. From the perspective of this sticking, it is thought that thick paper is easier to peel off the top medium P than plain paper, and the transport rate is higher, but in the case of thick paper, because it is heavier than plain paper, the transport rate is lower with the same driving force, and so it is thought that the transport rate is the same as that of plain paper.

[0073] Furthermore, one reason why the transport rate η2 (0.6) for thick paper and the transport rate η2 (0.65) for thin paper are lower than the transport rate η2 (0.75) for plain paper is that, after transport of the medium P begins, the transport rate η2 for plain paper is highest because the configuration of the medium supply device 10, such as the primary supply unit 11, is designed based on plain paper. In the above design, resistance to air and transport members is lowest for plain paper, resulting in a high transport rate, and it can be said that the transport rate is lower for thick paper and thin paper than for plain paper.

[0074] If the transport distance of medium P from when it is detected by medium detection sensor 13 until it reaches secondary supply unit 12 is 30 mm, and the amount of slack formed in medium P is 10 mm, then the transport amount before correction by primary supply unit 11 can be said to be 40 mm from when medium P is detected by medium detection sensor 13. Therefore, when medium P is ideally supplied with transport rates η1 and η2 of 1, medium P advances 40 mm due to transport by primary supply unit 11 from when it is detected by medium detection sensor 13, and the amount of slack becomes 10 mm.

[0075] When the medium P is plain paper, the transport rate η2 is 0.75, so while the transport distance of the primary supply unit 11 is 40 mm, the medium P advances 30 mm from when it is detected by the medium detection sensor 13 through transport by the primary supply unit 11. This 30 mm is the same as the transport distance from when the medium P is detected by the medium detection sensor 13 until it reaches the secondary supply unit 12, so the amount of slack in the medium P is 0, that is, it can be said that the medium P has reached the secondary supply unit 12 but no slack has formed.

[0076] When medium P is cardboard, the transport rate η2 is 0.6, so while the transport distance of primary supply unit 11 is 40 mm, medium P advances 24 mm from when it is detected by medium detection sensor 13 due to transport by primary supply unit 11. This 24 mm is 6 mm shorter than the transport distance of 30 mm from when medium P is detected by medium detection sensor 13 until it reaches secondary supply unit 12, so the amount of slack in medium P is -6 mm, that is, it is located 6 mm before it reaches secondary supply unit 12, and it can be said that no slack is formed.

[0077] When medium P is thin paper, the transport rate η2 is 0.65, so while the transport distance of primary supply unit 11 is 40 mm, medium P advances 26 mm from when it is detected by medium detection sensor 13 due to transport by primary supply unit 11. This 26 mm is 4 mm shorter than the transport distance of 30 mm from when medium P is detected by medium detection sensor 13 to when it reaches secondary supply unit 12, so the amount of slack in medium P is -4 mm, that is, it is located 4 mm before it reaches secondary supply unit 12, and it can be said that no slack is formed.

[0078] Here, regardless of the type of paper (plain paper, thick paper, or thin paper), if the slack correction value when the transport rate η1 shown in Figure 9(a) is 0.7 or less is X4 (10 mm), plain paper with a transport rate η2 of 0.75 will advance an additional 7.5 mm by the correction value after being detected by the medium detection sensor 13, resulting in a slack amount of 7.5 mm. Also, thick paper with a transport rate η2 of 0.6 will advance an additional 6 mm by the correction value after being detected by the medium detection sensor 13, resulting in a slack amount of 0 mm. Also, thin paper with a transport rate η2 of 0.65 will advance an additional 6.5 mm by the correction value after being detected by the medium detection sensor 13, resulting in a slack amount of 2.5 mm.

[0079] Thus, the smaller the transport rate η2 of the type of medium P, the shorter the additional transport distance due to the slack amount correction value. Therefore, the slack amount correction value for thick paper in Figure 9(b) is set to be 8 mm larger than the default slack amount correction values ​​X1 to X4 shown in Figure 9(a). Also, the slack amount correction value for thin paper in Figure 9(c) is set to be 6 mm larger than the default slack amount correction values ​​X1 to X4 shown in Figure 9(a).

[0080] As a result, for thick paper, the amount of slack after correction without taking type into account was 0 mm, whereas the slack correction value after correction taking type into account was an additional 8 mm, and since the conveying rate η2 was 0.6, it was conveyed an additional 4.8 mm by taking type into account, and the amount of slack after correction taking type into account was 4.8 mm.

[0081] In addition, for thin paper, the amount of slack after correction without taking type into account was 2.5 mm, whereas the slack correction value after correction taking type into account was an additional 6 mm, and since the conveying rate η2 was 0.65, it was conveyed an additional 3.9 mm by taking type into account, and the amount of slack after correction taking type into account was 6.4 mm.

[0082] As described above, the amount of slack formed on plain paper, thick paper, and thin paper is 7.5 mm, 0.0 mm, and 2.5 mm, respectively, after slack amount correction without taking type into account, whereas after slack amount correction with type taken into account, the amount is 7.5 mm, 4.8 mm, and 6.4 mm, respectively, resulting in a sufficient amount of slack formed in each case.

[0083] When adjusting the conveying amount of the primary supply unit 11 by using the sum of the above-mentioned slack amount correction values ​​X1 to X4 (±2 mm or +6 or 8 mm) and the initial set slack amount of the medium P as the slack amount, the distance L1 corresponding to the time T1 (first period D1) during which the first conveying speed V1 is maintained after the detection time (time t2) of the medium detection sensor 13 shown in Figure 7 can be expressed as follows.

number

[0084] Furthermore, the distance L3 corresponding to the time T3 (second period D2) during which the second conveying speed V2 is maintained can be expressed as in the following [Equation 2].

number

[0085] In this case, "a", "b", and "c" in [Equation 1] can be expressed as shown in [Equation 3] below.

number

[0086] Furthermore, as shown in FIG. 7, the relationship between the equations in circles 1 to 3 in [Equation 4] holds true.

number

[0087] From the above [Equation 4], the relationship of the following [Equation 5] holds.

number

[0088] By substituting the equation solved for L3 from the equation in circle 3 in [Equation 4] above, L1 can be expressed as [Equation 6] below.

number

[0089] Then, the distance L1 can be expressed as follows:

number

[0090] Once the distance L1 is calculated as described above, the time T1 (first period D1) during which the first conveying speed V1 is maintained after the detection time can also be calculated. Furthermore, the distance L3 in the above equation 2, and therefore the time T3 (second period D2), can also be calculated.

[0091] 7 and Equations 1 to 7 described above are described assuming that time T5, acceleration α1, deceleration acceleration α2, etc. are constant, but these values ​​may be varied as appropriate depending on the desired transport amount of primary supply unit 11. Furthermore, in the present embodiment, the first period D1 (time T1 corresponding to distance L1) during which first transport speed V1 is maintained at the detection time of medium detection sensor 13 and the second period D2 (time T3 corresponding to distance L3) during which second transport speed V2 is maintained at which medium P abuts against secondary supply unit 12 are calculated, but the transport speed of primary supply unit 11 may be adjusted so as not to maintain at least one of first transport speed V1 and second transport speed V2.

[0092] Next, a modification of this embodiment will be described with reference to FIG.

[0093] FIG. 11 is a flowchart for explaining the rotation detection process of the primary supply unit 11 in the modified example.

[0094] The process of this modification starts under the control of the control unit 17 when the control unit 17 stops the primary supply driving unit 15 at a predetermined stop timing (time t6) (step S10) in the flowchart shown in FIG.

[0095] In the above description, an example has been described in which the primary supply unit 11 also starts conveying a little later after the secondary supply unit 12 starts conveying, as shown in FIG. 4. However, in this modified example, after the secondary supply unit 12 starts conveying, the primary supply unit 11 stops conveying the medium P conveyed by the secondary supply unit 12. However, the primary supply unit 11 (scraper roller 11a and pickup roller 11b) rotates as the medium P is conveyed by the secondary supply unit 12.

[0096] As shown in FIG. 11, the control unit 17 controls the primary supply drive unit 15 to stop the transport of the primary supply unit 11 (step S10), and then controls the secondary supply drive unit 16 to start the transport of the secondary supply unit 12 (step S11).

[0097] Thereafter, the control unit 17 determines whether the primary supply unit 11 is rotating in association with the transport of the medium P by the secondary supply unit 12 based on the output signal of the rotation detection unit 11d (step S12). At this time, the control unit 17 may repeat the process of determining whether the primary supply unit 11 is rotating until a time later than the slack elimination period, which will be described later, even if the primary supply unit 11 is not rotating. Here, if the medium P has reached the secondary supply unit 12 through transport by the primary supply unit 11, the primary supply unit 11 rotates in association with the transport of the medium P by the secondary supply unit 12, but if the medium P has not yet reached the secondary supply unit 12 through transport by the primary supply unit 11, the primary supply unit 11 does not rotate in association with the transport of the medium P by the secondary supply unit 12.

[0098] If the rotation detector 11d detects the rotation of the primary supply unit 11 (step S12: YES), the controller 17 determines whether the delay between the rotation detection time (rotation detection start timing) at which the rotation detector 11d detects the rotation of the primary supply unit 11 and the start time of the transport of the secondary supply unit 12 is earlier than the start of the slack elimination period until a predetermined amount of slack in the medium P is eliminated (an example of a period outside the slack elimination period) (step S13). This slack elimination period may be obtained by actual measurement for a medium P having an amount of slack within an allowable range. If the delay between the rotation detection time and the start time of the transport of the secondary supply unit 12 is earlier than the slack elimination period, it can be said that sufficient slack Pa has not been formed in the medium P.

[0099] If the rotation detection unit 11d does not detect rotation of the primary supply unit 11 (step S12: NO), or if rotation is detected but the delay in the rotation detection time is shorter than the slack elimination period (step S13: YES), the control unit 17 controls the secondary supply drive unit 16 to stop the secondary supply unit 12 from transporting the medium P (step S14).The control unit 17 also notifies the user of the error by displaying a message on a display unit such as an operation panel or by outputting a sound from the audio output unit (step S15).

[0100] Furthermore, since it can be said that the transport amount of the primary supply unit 11 was small, the control unit 17 controls the primary supply drive unit 15 (primary supply unit 11) to increase the transport amount of the primary supply unit 11 for the subsequent medium P (step S16). Then, the control unit 17 ends the process shown in FIG.

[0101] In the process of determining whether the delay in the rotation detection time is shorter than the slack elimination period (step S13), if the delay in the rotation detection time is not shorter than the slack elimination period (step S13: NO), control unit 17 determines whether the delay in the rotation detection time, at which rotation detection unit 11d detects the rotation of primary supply unit 11, from the start time of conveyance of secondary supply unit 12 is later than the end of the slack elimination period until a predetermined amount of slack in medium P is eliminated (an example of a period outside the slack elimination period) (step S17).If the delay in the rotation detection time is not longer than the slack elimination period (step S17: NO), it can be said that slack Pa of medium P is the predetermined amount of slack, and control unit 17 therefore ends the process shown in FIG.

[0102] On the other hand, if the delay in the rotation detection time is longer than the slack elimination period (step S17: YES), it can be said that the slack Pa of the medium P is greater than the predetermined amount of slack, and therefore the control unit 17 controls the secondary supply drive unit 16 to stop the transport of the medium P by the secondary supply unit 12 (step S18).The control unit 17 also notifies the user of the error by, for example, displaying a message on a display unit such as an operation panel or by outputting a sound from the audio output unit (step S19).

[0103] Furthermore, since it can be said that the transport amount of the primary supply unit 11 was large, the control unit 17 controls the primary supply drive unit 15 (primary supply unit 11) to reduce the transport amount of the primary supply unit 11 for the subsequent medium P (step S20). Then, the control unit 17 ends the process shown in FIG.

[0104] In the process shown in FIG. 11, when the rotation detection unit 11d does not detect rotation of the primary supply unit 11 (step S12: NO) or when rotation is detected but the delay in rotation detection time is outside the slack elimination period (steps S13, S17: YES), the secondary supply unit 12 stops conveying (steps S14, S18) and the primary supply unit 11 increases or decreases the conveying amount for the subsequent medium P (steps S16, S20). However, when the rotation detection unit 11d does not detect rotation of the primary supply unit 11 (step S12: NO) or when rotation is detected but the delay in rotation detection time is outside the slack elimination period (steps S13, S17: YES), the secondary supply unit 12 stops conveying (steps S14, S18) or the primary supply unit 11 increases or decreases the conveying amount for the subsequent medium P (steps S16, S20) based on only one of the judgment processes, namely when the rotation detection unit 11d does not detect rotation of the primary supply unit 11 (step S12: NO) or when rotation is detected but the delay in rotation detection time is outside the slack elimination period (steps S13, S17: YES), and the other judgment process may be omitted. Alternatively, only one of stopping the transport of the secondary supply unit 12 (steps S14, S18) and increasing or decreasing the transport amount of the primary supply unit 11 for the subsequent medium P (steps S16, S20) may be performed. Alternatively, the increase or decrease in the transport amount of the primary supply unit 11 for the subsequent medium P (steps S16, S20) may be performed by either increasing or decreasing the transport amount.

[0105] In the present embodiment described above, medium supply device 10 includes primary supply unit 11, secondary supply unit 12, medium detection sensor 13, and control unit 17. Primary supply unit 11 transports medium P loaded on supply table 14. Secondary supply unit 12 is struck by medium P transported by primary supply unit 11, and transports medium P in which slack Pa has occurred due to the strike at a predetermined transport start time. Medium detection sensor 13 detects medium P between primary supply unit 11 and secondary supply unit 12. The control unit 17 controls the primary supply unit 11 (primary supply drive unit 15) so that the transport end time (time t6) of the primary supply unit 11 falls within a predetermined end period, and so that the transport amount of the primary supply unit 11 is increased, for example, by slack amount correction values ​​X1 to X4 from the detection time (time t2) when the medium P is detected by the medium detection sensor 13 to the transport start time of the secondary supply unit 12 based on the transport rate η of the medium P.

[0106] If the detection time (time t2) at which the medium detection sensor 13 detects the medium P is earlier than expected, the end time (time t3) of the subsequent high-speed transport (the transport speed before deceleration) can be advanced or the end time (time t6) itself can be advanced to maintain a constant transport time for the subsequent high-speed transport. If the detection time (time t2) is later than expected, the end time (time t3) of the subsequent high-speed transport can be delayed or the end time (time t6) itself can be delayed to maintain a constant transport time for the subsequent high-speed transport. However, since medium P with a low transport rate η continues to be delayed in transport after the detection time (time t2), even if the transport rate of the medium P is not taken into consideration, controlling only the transport time to make up for the delay up to the medium detection sensor 13 may result in a small amount of slack formed after the medium reaches the secondary supply unit 12. Therefore, the skew cannot be corrected due to the reduced slack Pa, and for example, images may be printed at an angle. Alternatively, if an appropriate amount of slack Pa is not formed in the secondary supply section 12, the conveyance of the secondary supply section 12 may become unstable.

[0107] In contrast, in this embodiment, the transport rate of the medium P is taken into consideration by increasing the transport amount of the primary supply unit 11 based on the transport rate η of the medium P (according to the transport situation), and this reduces the variation in the magnitude of the slack Pa caused by a medium P with a late detection time (time t2) continuing to be delayed after the detection time (time t2). Furthermore, by controlling the primary supply unit 11 so that the transport end time (time t6) of the primary supply unit 11 falls within a predetermined end period, it is possible to prevent a transport start time of the secondary supply unit 12 from being delayed or a transport error from occurring when the secondary supply unit 12 starts transporting the medium P before it has reached the secondary supply unit 12, compared to an embodiment in which the transport end time of the primary supply unit 11 is delayed in order to increase the transport amount of the primary supply unit 11. This makes it possible to avoid a longer supply interval for each medium P or a supply stop period due to a transport error. Therefore, according to this embodiment, the amount of slack Pa of the medium P, which is generated by the medium P hitting the secondary supply unit 12, can be made close to constant without reducing the supply efficiency of the medium P. As a result, skew of the medium P can be corrected and the transport of the secondary supply unit 12 can be prevented from becoming unstable.

[0108] In addition, in this embodiment, the control unit 17 increases or decreases the conveying amount of the primary supply unit 11 (primary supply drive unit 15) by adjusting the first period D1 (time T1) during which the first conveying speed V1 of the primary supply unit 11 at the detection time is maintained after the detection time.

[0109] Therefore, the conveying amount of the primary supply unit 11 can be adjusted by simple control, for example, by adjusting the period of the first conveying speed V1 (high-speed conveying), which is the maximum speed of the primary supply unit 11, with a simple configuration that does not use the primary supply drive unit 15 that enables a conveying speed faster than the first conveying speed V1, and within the limited time until the conveying start time of the secondary supply unit 12.

[0110] In addition, in this embodiment, the control unit 17 controls the primary supply unit 11 (primary supply drive unit 15) so that the conveying speed of the primary supply unit 11 becomes a second conveying speed V2 that is slower than the first conveying speed V1 when the medium P is abutted against the secondary supply unit 12, and the control unit 17 increases or decreases the conveying amount of the primary supply unit 11 (primary supply drive unit 15) by adjusting the first period D1 (time T1) and the second period D2 (time T3) during which the primary supply unit 11 maintains the second conveying speed V2.

[0111] Therefore, by simply controlling the period between the first conveying speed V1, which is the maximum speed of the primary supply section 11, and the second conveying speed V2, which is slower than the first conveying speed V1 and can reduce collision noise, the conveying amount of the primary supply section 11 can be adjusted and the collision noise caused by the medium P hitting the surface when slack Pa is formed can be reduced.

[0112] In addition, in this embodiment, the control unit 17 calculates the transport rate η of the medium P based on the transport amount of the primary supply unit 11 from the time when the primary supply unit 11 starts transporting the medium P (time t0) to the detection time (time t2), and determines the first period D1 (time T1) and the second period D2 (time T3) based on this transport rate η.

[0113] Therefore, by determining the first period D1 (time T1) and the second period D2 (time T3) using the transport rate η of the medium P up to the detection time (time t2), the transport amount of the primary supply section 11 can be accurately adjusted, and the amount of slack Pa can be made closer to a constant value.

[0114] In the present embodiment, the control unit 17 determines the first period D1 (time T1) and the second period D2 (time T3) based on the transport rate η and the type of the medium P.

[0115] Even if the ratio of the transport rate η of the medium P varies between the time up to and after the detection time (time t2) of 3, the first period D1 (time T1) and the second period D2 (time T3) can be determined taking that variation into account. Therefore, the transport amount of the primary supply unit 11 can be accurately adjusted, and the amount of slack Pa can be kept close to a constant value.

[0116] Furthermore, in a modification of the present embodiment, medium supply device 10 further includes rotation detection unit 11d, which is an example of a rotation detection unit that detects the rotation of the primary supply unit during transport of medium P. Control unit 17 stops the transport of medium P transported by secondary supply unit 12 by primary supply unit 11 after the transport start time of secondary supply unit 12 (step S10 in FIG. 11). Control unit 17 also stops the transport of medium P transported by secondary supply unit 12 (steps S14 and S18) in at least one of the following cases: when rotation detection unit 11d does not detect the rotation of primary supply unit 11 during transport of medium P transported by secondary supply unit 12 after the transport start time of secondary supply unit 12 (step S12: NO), or when the delay between the rotation detection time at which rotation detection unit 11d detects the rotation of primary supply unit 11 and the transport start time of secondary supply unit 12 is outside the slack elimination period until a predetermined amount of slack in medium P is eliminated (steps S13 and S17: YES).

[0117] This prevents the secondary supply unit 12 from emptying its transport when the rotation detection unit 11d does not detect the rotation of the primary supply unit 11 (when the medium P has not reached the secondary supply unit 12), and prevents the secondary supply unit 12 from transporting the medium P without correcting its skew or with its transport becoming unstable when the delay in the rotation detection time is outside the slack elimination period (when the slack Pa is too large or too small).

[0118] In addition, in a modified example of this embodiment, the control unit 17 increases or decreases the transport amount of the primary supply unit 11 for the subsequent medium P based on the time when the rotation detection unit 11d does not detect the rotation of the primary supply unit 11 during transport of the medium P transported by the secondary supply unit 12 after the transport start time of the secondary supply unit 12 (step S12: NO), or the time when the rotation detection time at which the rotation detection unit 11d detects the rotation of the primary supply unit 11 lags behind the transport start time of the secondary supply unit 12 is outside the slack elimination period until a predetermined amount of slack in the medium P is eliminated (steps S13, S17: YES).

[0119] This prevents the rotation detection unit 11d from not detecting the rotation of the primary supply unit 11 (the medium P has not reached the secondary supply unit 12) or the delay in the rotation detection time from being outside the slack elimination period (the slack Pa is too large or too small) from being repeated for subsequent media P.

[0120] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all of the components shown in the embodiments can be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention. The invention as originally claimed in the present application is described below.

[0121] [Appendix 1] a primary supply unit that transports the media loaded on the supply table; a secondary supply unit that conveys the medium conveyed by the primary supply unit at a predetermined conveyance start time when the medium is struck and loosened due to the strike; a medium detection sensor that detects the medium between the primary supply unit and the secondary supply unit; a control unit that controls the primary supply unit so that a transport end time of the primary supply unit falls within a predetermined end period and so that a transport amount of the primary supply unit is increased from a detection time at which the medium is detected by the medium detection sensor to a transport start time of the secondary supply unit based on a transport rate of the medium; A medium supply device comprising: [Appendix 2] The control unit increases or decreases the conveyance amount of the primary supply unit by adjusting a first period during which a first conveyance speed of the primary supply unit at the detection time is maintained after the detection time. 2. A medium supply device according to claim 1. [Appendix 3] the control unit controls the primary supply unit so that the conveying speed of the primary supply unit becomes a second conveying speed that is slower than the first conveying speed when the medium hits the secondary supply unit; The control unit increases or decreases the conveyance amount of the primary supply unit by adjusting the first period and a second period during which the primary supply unit maintains the second conveyance speed. 3. The medium supply device according to claim 2. [Appendix 4] The control unit calculates the transport rate based on the transport amount of the primary supply unit from the time when the primary supply unit starts transporting the medium to the detection time, and determines the first period and the second period based on the transport rate. 4. The medium supply device according to claim 3. [Appendix 5] The control unit determines the first period and the second period based on the transport rate and the type of the medium. 5. The medium supply device according to claim 4. [Appendix 6] a rotation detection unit that detects rotation of the primary supply unit when the medium is being transported; the control unit stops the transport of the medium transported by the secondary supply unit from the primary supply unit after the transport start time of the secondary supply unit, The control unit stops the conveyance of the secondary supply unit in at least one of the following cases: when the rotation detection unit does not detect rotation of the primary supply unit during conveyance of the medium conveyed by the secondary supply unit after the conveyance start time of the secondary supply unit; and when the delay time between the detection time when the rotation detection unit detects rotation of the primary supply unit and the conveyance start time of the secondary supply unit is earlier or later than a slack elimination period until a predetermined amount of slack in the medium is eliminated. 6. A medium supply device according to any one of claims 1 to 5. [Appendix 7] a rotation detection unit that detects rotation of the primary supply unit when the medium is being transported; the control unit stops the transport of the medium transported by the secondary supply unit from the primary supply unit after the transport start time of the secondary supply unit, The control unit controls the primary supply unit to increase the transport amount of the subsequent medium when, after the transport start time of the secondary supply unit, the rotation detection unit does not detect rotation of the primary supply unit during transport of the medium transported by the secondary supply unit, or when a delay between the detection time at which the rotation detection unit detects rotation of the primary supply unit and the transport start time of the secondary supply unit is shorter than a slack elimination period until a predetermined amount of slack in the medium is eliminated. 6. A medium supply device according to any one of claims 1 to 5. [Explanation of symbols]

[0122] 1 Printing device 10 Media supply device 11 Primary supply section 11a Scraper roller 11b Pickup roller 11c Cutting board 11d Rotation detection unit 12 Secondary supply section 12a, 12b Registration rollers 13 Media detection sensor 14 Supply stand 15 Primary supply drive unit 16 Secondary supply drive unit 17 Control Unit 18 Memory section 19 Interface 20 Printing Department 30 Conveying section D1 1st period D2 2nd period P medium Pa slack V1 First conveying speed V2 Second conveying speed

Claims

1. a primary supply unit that transports the media loaded on the supply table; a secondary supply unit that conveys the medium conveyed by the primary supply unit at a predetermined conveyance start time when the medium is struck and loosened due to the strike; a medium detection sensor that detects the medium between the primary supply unit and the secondary supply unit; a control unit that controls the primary supply unit so that a transport end time of the primary supply unit falls within a predetermined end period and so that a transport amount of the primary supply unit is increased from a detection time at which the medium is detected by the medium detection sensor to a transport start time of the secondary supply unit based on a transport rate of the medium; Equipped with the control unit controls the primary supply unit so that, when the medium strikes the secondary supply unit, the conveying speed of the primary supply unit becomes a second conveying speed that is slower than the first conveying speed at the detection time; the control unit increases or decreases the conveyance amount of the primary supply unit by adjusting a first period during which the primary supply unit maintains the first conveyance speed after the detection time and a second period during which the primary supply unit maintains the second conveyance speed; The control unit calculates the transport rate based on the transport amount of the primary supply unit from the transport start time to the detection time, and determines the first period and the second period based on the transport rate and the transport rate of the medium from the detection time to the transport end time corresponding to the type of medium.

2. A primary supply unit that transports media loaded on a supply table; a secondary supply unit that conveys the medium conveyed by the primary supply unit at a predetermined conveyance start time when the medium is struck and loosened due to the strike; a medium detection sensor that detects the medium between the primary supply unit and the secondary supply unit; a control unit that controls the primary supply unit so that a transport end time of the primary supply unit falls within a predetermined end period and so that a transport amount of the primary supply unit is increased from a detection time at which the medium is detected by the medium detection sensor to a transport start time of the secondary supply unit based on a transport rate of the medium; a rotation detection unit that detects rotation of the primary supply unit when the medium is being transported, the control unit stops the transport of the medium transported by the secondary supply unit from the primary supply unit after the transport start time of the secondary supply unit, The control unit stops the conveyance of the secondary supply unit in at least one of the following cases: when the rotation detection unit does not detect rotation of the primary supply unit during conveyance of the medium conveyed by the secondary supply unit after the conveyance start time of the secondary supply unit; and when a delay time between the rotation detection time at which the rotation detection unit detects rotation of the primary supply unit and the conveyance start time of the secondary supply unit is outside a slack elimination period until a predetermined amount of slack in the medium is eliminated. A medium supply device characterized by:

3. A primary supply unit that transports media loaded on a supply table; a secondary supply unit that conveys the medium conveyed by the primary supply unit at a predetermined conveyance start time when the medium is struck and loosened due to the strike; a medium detection sensor that detects the medium between the primary supply unit and the secondary supply unit; a control unit that controls the primary supply unit so that a transport end time of the primary supply unit falls within a predetermined end period and so that a transport amount of the primary supply unit is increased from a detection time at which the medium is detected by the medium detection sensor to a transport start time of the secondary supply unit based on a transport rate of the medium; a rotation detection unit that detects rotation of the primary supply unit when the medium is being transported, the control unit stops the transport of the medium transported by the secondary supply unit from the primary supply unit after the transport start time of the secondary supply unit, The control unit increases or decreases the transport amount of the primary supply unit for the subsequent medium based on the time when the rotation detection unit does not detect rotation of the primary supply unit during transport of the medium transported by the secondary supply unit after the transport start time of the secondary supply unit, or the time when the rotation detection unit detects the rotation of the primary supply unit's rotation delays from the transport start time of the secondary supply unit is outside a slack elimination period until a predetermined amount of slack in the medium is eliminated. A medium supply device characterized by:

Images