Recording system

Abstract

The present invention provides a recording system capable of reducing the possibility of deterioration of the alignment of the medium on the loading tray. The recording system (1) comprises: a first discharge unit for discharging the medium on which the ink is ejected and recorded; a loading tray for loading the medium (P) discharged by the first discharge unit; a lifting mechanism (78) for lifting the loading tray; a control unit (25) for controlling the lifting mechanism (78); and an estimation unit (51) for estimating the weight of the medium (P) loaded on the loading tray, wherein the control unit (25) controls the lifting action of the loading tray according to the weight of the medium estimated by the estimation unit (51).

Description

Technical Field

[0001] The present invention relates to recording systems. Background Art

[0002] In the past, a structure has been disclosed in which the weight of a sheet bundle formed on a processing tray is estimated, and if the sheet bundle is estimated to be heavy, a sheet moving unit is controlled so as to increase the conveying force per unit time when conveying the sheet bundle compared to when the sheet bundle is estimated to be light. According to this structure, even when the sheet bundle is heavy, the sheet bundle can be reliably discharged to the stacking tray.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-137518 Summary of the invention

[0004] However, in the conventional literature, only the discharge performance of the sheet bundle formed on the processing tray is considered, and there is no description on the processing of the sheet bundle after discharge.

[0005] Regarding sheets with images formed by an inkjet printer, the weight of the sheet stack becomes a problem even after being ejected onto a stacking tray. Sometimes the movable stacking tray cannot be properly controlled due to the weight of the sheet stack, resulting in a technical problem of deterioration in sheet alignment.

[0006] The recording system comprises: a discharge section that discharges a medium on which a liquid is ejected and recorded; a loading section that loads the medium discharged by the discharge section; a lifting section that lifts and lowers the loading section; a control section that controls the lifting section; and an estimation section that estimates the weight of the medium loaded on the loading section, wherein the control section controls the lifting and lowering action of the loading section based on the weight of the medium estimated by the estimation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a cross-sectional view of the recording system according to the first embodiment.

[0008] Figure 2 It is a block diagram of a recording unit and a post-processing device according to the first embodiment.

[0009] Figure 3 It is a perspective view of the medium loading device according to the first embodiment.

[0010] Figure 4A It is a side view of the upper surface detection sensor according to the first embodiment.

[0011] Figure 4B It is a side view of the upper surface detection sensor according to the first embodiment.

[0012] Figure 5AThis is a flowchart of the lifting and lowering operation of the lifting and lowering mechanism according to the first embodiment.

[0013] Figure 5B This is a flowchart of the lifting and lowering operation of the lifting and lowering mechanism according to the first embodiment.

[0014] Figure 6 This is a flow chart of the lifting and lowering operation of the lifting and lowering mechanism according to the second embodiment.

[0015] Figure 7 This is a flow chart of the lifting and lowering operation of the lifting and lowering mechanism according to the third embodiment.

[0016] Figure 8 This is a flow chart of the lifting and lowering operation of the lifting and lowering mechanism according to the fourth embodiment.

[0017] Description of Reference Numerals

[0018] 1…recording system, 2…recording unit, 3…intermediate unit, 5…post-processing device, 10…printer unit, 11…scanner unit, 12…medium storage box, 13…discharge tray after recording, 14…box storage unit, 19…operation unit, 20…line head, 21…supply path, 22…first discharge path, 23…second discharge path, 24…reversal path, 25…control unit, 30…receiving path, 31…first switching path, 32…second switching path, 33…merging path, 35…forking part, 36…merging part, 39…medium loading device, 40…loading tray, 40a…base part, 40b…extending part, 41…receiving part, 42…end binding part, 43…first conveying path , 45…second conveying path, 46…punching processing unit, 47…post-processing unit, 48…processing tray, 49…upper tray, 51…inference unit, 52…storage unit, 53…receiving unit, 62…first discharge unit, 63…second discharge unit, 75…guide frame, 76…driving belt, 77A, 77B…lifting guide, 78…lifting mechanism, 79…transmission shaft, 80…upper surface detection sensor, 81…mark, 81a…front end portion, 81b…inspected portion, 82…photointerrupter, 83…rotating shaft, 90…lower limit sensor, 91…light emitting unit, 92…light receiving unit, D…fork portion, P…medium, T1…first threshold value, T2…second threshold value, T3…third threshold value, Z…weight. DETAILED DESCRIPTION

[0019] 1. First Implementation

[0020] First, the first embodiment is described. As an example, Figure 1 The recording system 1 shown is from Figure 1 The recording unit 2, the intermediate unit 3 and the post-processing device 5 are provided in order from the right side to the left side.

[0021] The recording unit 2 records on the conveyed medium P. The intermediate unit 3 receives the recorded medium P from the recording unit 2 and delivers it to the post-processing device 5, and mainly performs the function of turning over the medium P and promoting the drying of the medium P. The post-processing device 5 is provided with an end binding unit 42, which performs an end binding process of bundling the recorded medium P in the recording unit 2 and binding the ends.

[0022] The recording unit 2, the intermediate unit 3, and the post-processing device 5 are described in detail below in this order.

[0023] In the XYZ coordinate system of each figure, the X direction is the device depth direction, the Y direction is the device width direction, and the Z direction is the device height direction. The X direction, the Y direction, and the Z direction are orthogonal to each other.

[0024] In the depth direction of the device, when distinguishing between the front and the back, the front is called the +X direction, and the back is called the -X direction. In the width direction of the device, when distinguishing between the left and the right, the left is called the +Y direction, and the right is called the -Y direction. In the height direction of the device, when distinguishing between the top and the bottom, the top is called the +Z direction, and the bottom is called the -Z direction.

[0025] The recording unit 2 is configured as a multifunction device including a printer unit 10 and a scanner unit 11, and the printer unit 10 includes a line head 20 as a recording unit for recording on a medium P. In the present embodiment, the line head 20 is configured as a so-called inkjet recording head that ejects ink as an example of liquid onto the medium P for recording.

[0026] A cassette storage section 14 having a plurality of media storage cassettes 12 is provided at the bottom of the printer section 10. The media P stored in the media storage cassettes 12 are conveyed to the recording area of ​​the line head 20 through a supply path 21 indicated by a solid line, and a recording operation is performed. The media P recorded by the line head 20 is conveyed to either a first discharge path 22 or a second discharge path 23. The first discharge path 22 is a path for discharging the media P to a post-recording discharge tray 13 provided above the line head 20, and the second discharge path 23 is a path for conveying the media P to the intermediate unit 3.

[0027] exist Figure 1 In FIG. 1 , the first discharge path 22 is indicated by a dotted line, and the second discharge path 23 is indicated by a dashed line. The second discharge path 23 extends in the +Y direction of the recording unit 2 and delivers the medium P to the receiving path 30 of the adjacent intermediate unit 3 .

[0028] In addition, the recording unit 2 has Figure 1The reversing path 24 is indicated by a two-dot chain line in the figure, and is configured to enable double-sided recording, which enables recording on the first side of the medium P and then reversing the medium P to record on the second side. In addition, each of the supply path 21, the first discharge path 22, the second discharge path 23, and the reversing path 24 is provided with one or more roller pairs (not shown) as an example of a unit for conveying the medium P.

[0029] The recording unit 2 is provided with a control unit 25 for controlling the actions related to conveyance or recording of the medium P in the recording unit 2. In addition, the recording system 1 is configured such that the recording unit 2, the intermediate unit 3, and the post-processing device 5 are mechanically and electrically connected to each other, and the medium P can be conveyed from the recording unit 2 to the post-processing device 5. In addition, the control unit 25 in this embodiment can control various actions in the intermediate unit 3 and the post-processing device 5 connected to the recording unit 2.

[0030] The recording unit 2 includes an operation unit 19, and is configured to be able to input various settings and execution commands related to various processes in the recording unit 2, the intermediate unit 3, and the post-processing device 5 through the operation unit 19. In addition, the operation unit 19 includes a display panel (not shown), and is configured to be able to display various information on the display panel.

[0031] Furthermore, when an external computer (not shown) is connected to the recording system 1 , various settings or execution commands similar to those performed by the operation unit 19 can be performed in the external computer.

[0032] Next, use Figure 2 The control structure is explained with a block diagram.

[0033] The recording unit 2 includes a control unit 25, a storage unit 52, and a receiving unit 53. The receiving unit 53 receives a recording command for instructing execution of recording and recording data for indicating the contents of recording from the outside.

[0034] The control unit 25 is composed of a processor and the like, operates according to the control program stored in the storage unit 52, and controls the line head 20 to perform recording according to the recording data received by the receiving unit 53. In addition, the control unit 25 has an estimation unit 51 as a functional block realized by the control program. The estimation unit 51 estimates the weight of the medium P according to the recording data received by the receiving unit 53. The storage unit 52 is composed of a semiconductor memory and the like, stores the control program, and stores the weight of the medium P in an unrecorded state, and the like.

[0035] In addition, the post-processing device 5 includes a post-processing unit 47 and a medium loading device 39, which will be described in detail below. The medium loading device 39 includes a lifting mechanism 78, an upper surface detection sensor 80, and a lower limit sensor 90. The upper surface detection sensor 80 includes a light interrupter 82 in which a light emitting element and a light receiving element are integrally formed, and the lower limit sensor 90 is configured to include a light emitting unit 91 and a light receiving unit 92. In addition, the post-processing unit 47 includes a punching processing unit 46 and an end binding unit 42. The control unit 25 of the recording unit 2 is configured to be able to control the post-processing unit 47 and the lifting mechanism 78.

[0036] Next, the intermediate unit 3 will be described. Figure 1 The intermediate unit 3 shown in the figure delivers the medium P received from the recording unit 2 to the post-processing device 5. The intermediate unit 3 is arranged between the recording unit 2 and the post-processing device 5. The medium P conveyed in the second discharge path 23 of the recording unit 2 is received by the intermediate unit 3 from the receiving path 30, and then the medium P is conveyed to the post-processing device 5. It should be noted that the receiving path 30 is Figure 1 Indicated by double dotted line.

[0037] In the intermediate unit 3, there are two conveying paths for conveying the medium P. The first conveying path is from the receiving path 30 through Figure 1 The first switching path 31 shown by the midpoint line is a path for conveying to the merging path 33. The second conveying path is from the receiving path 30 through Figure 1 The second switching path 32 indicated by the two-dot chain line is a path for conveying the fluid to the merging path 33 .

[0038] The first switching path 31 is a path for switching the medium P to the direction of arrow A2 after receiving the medium P in the direction of arrow A1. The second switching path 32 is a path for switching the medium P to the direction of arrow B2 after receiving the medium P in the direction of arrow B1.

[0039] The receiving path 30 branches into a first switching path 31 and a second switching path 32 at a branching portion 35. The branching portion 35 is provided with a shutter (not shown) for switching the conveyance destination of the medium P to either the first switching path 31 or the second switching path 32.

[0040] The first switching path 31 and the second switching path 32 merge at the merging portion 36 . Therefore, no matter whether the medium P is fed from the receiving path 30 to the first switching path 31 or the second switching path 32 , the medium P can be delivered to the post-processing device 5 through the common merging path 33 .

[0041] The intermediate unit 3 receives the medium P from the recording unit 2 to the receiving path 30 with the recording surface closest to the line head 20 facing upward, but the medium P is bent and reversed at the merging path 33 with the recording surface closest to the line head 20 facing downward.

[0042] Therefore, the medium P in a state where the most recent recording surface faces downward is delivered from the intermediate unit 3 in the +Y direction to the first conveyance path 43 of the post-processing device 5 .

[0043] Furthermore, in each of the receiving path 30 , the first switching path 31 , the second switching path 32 , and the merging path 33 , one or more roller pairs (not shown) are arranged as an example of a unit that transports the medium P.

[0044] When recording is performed continuously on a plurality of media P in the recording unit 2 , the media P entering the intermediate unit 3 are alternately conveyed to the conveyance path through the first switching path 31 and the conveyance path through the second switching path 32 . This can increase the throughput of media conveyance in the intermediate unit 3 .

[0045] In addition, in the case of a structure that ejects liquid (specifically ink) onto a medium P for recording as in the line head 20 of the present embodiment, if the medium P is wetted during processing in the subsequent post-processing device 5, friction on the recording surface or poor alignment of the medium P may occur.

[0046] By delivering the recorded medium P from the recording unit 2 to the post-processing device 5 via the intermediate unit 3 , the conveyance time of the recorded medium P to the post-processing device 5 can be prolonged, and the medium P can be dried further before reaching the post-processing device 5 .

[0047] Next, the post-processing device 5 will be described. Figure 1 The post-processing device 5 shown in the figure includes a receiving portion 41 for receiving the medium P from the intermediate unit 3 at the lower part in the −Y direction. The medium P conveyed in the merging path 33 of the intermediate unit 3 enters the post-processing device 5 from the receiving portion 41 .

[0048] The post-processing device 5 includes an end stapling unit 42 that processes the medium P received from the receiving unit 41 .

[0049] The post-processing device 5 includes a first conveying path 43 that conveys the medium P received from the receiving unit 41 to the end stapling unit 42 .

[0050] The end binding unit 42 is a component that performs an end binding process for binding an end portion of the medium P, such as a corner portion of one side of the medium P or a side portion of one side of the medium P. As an example, the end binding unit 42 is configured to include a binding machine.

[0051] In addition, the post-processing device 5 includes a punching unit 46 that performs a punching process on the medium P received from the receiving unit 41. The punching unit 46 is provided at a position close to the receiving unit 41 of the first conveying path 43 through which the medium P received by the post-processing device 5 passes, and is configured to perform a punching process upstream of the first conveying path 43. In addition, the medium P received from the receiving unit 41 may be punched by the punching unit 46 or may not be punched.

[0052] The medium P received from the receiving unit 41 can pass through Figure 1 The first conveying path 43 shown in the figure conveys the medium P to the processing tray 48. In the processing tray 48, the medium P is stacked on the processing tray 48 in a manner that the rear ends in the conveying direction are aligned. If a predetermined number of medium P sheets are stacked on the processing tray 48, the rear ends of the medium P can be end-stapling processed by the end stapling unit 42. The post-processing device 5 includes a first discharge unit 62 as a discharge unit that discharges the medium P in the +Y direction. In addition, the post-processing device 5 includes a second discharge unit 63 described later in addition to the first discharge unit 62, and is configured to be able to discharge the medium P from these.

[0053] The medium P processed by the end stapling unit 42 is discharged from the first discharge unit 62 to the outside of the housing of the post-processing device 5 by a discharge unit (not shown) and then loaded on the loading tray 40 as a loading unit constituting the medium loading device 39 .

[0054] The loading tray 40 is provided to protrude in the +Y direction from the post-processing device 5. In the present embodiment, the loading tray 40 includes a base portion 40a and an extension portion 40b, and the extension portion 40b is configured to be receivable in the base portion 40a.

[0055] An upper tray 49 is provided on the upper part of the post-processing device 5, and the medium P is discharged from the second discharge unit 63 to the upper tray 49 by a discharge unit (not shown). A second conveying path 45 is provided between the forked portion D in the middle of the first conveying path 43 and the second discharge unit 63, and the medium P received from the receiving unit 41 can be discharged to the upper tray 49 via the second conveying path 45 without passing through the end binding unit 42.

[0056] Next, the medium loading device 39 included in the post-processing device 5 will be described.

[0057] Figure 31 is a diagram showing the overall structure for raising and lowering the loading tray 40 in the medium loading device 39, and includes an elevating guide 77A located at a position offset in the -X direction relative to the loading tray 40, and an elevating guide 77B located at a position offset in the +X direction relative to the loading tray 40. The elevating guides 77A and 77B are based on a guide frame 75 extending in the Z-axis direction, and a plurality of structural elements are assembled on the guide frame 75.

[0058] The lifting guides 77A and 77B are provided with a driving belt 76 along the Z-axis direction, and the loading tray 40 is pulled in the ascending direction and the descending direction by the driving belt 76. In addition, in the present embodiment, the ascending direction of the loading tray 40 is the +Z direction, and the descending direction is the -Z direction. In addition, the X-axis direction is the width direction of the loading tray 40.

[0059] In the lifting guides 77A and 77B, a lifting mechanism 78 as a lifting part is provided at the lower side of the lifting guide 77A. The lifting mechanism 78 has a motor as a driving source, and the driving belt 76 is driven by the motor to lift the loading tray 40. In addition, a transmission shaft 79 is provided between the lifting guide 77A and the lifting guide 77B, and the power of the lifting mechanism 78 is transmitted to the lifting guide 77B side through the transmission shaft 79. In the present embodiment, a stepping motor is used as the motor of the lifting mechanism 78, but a motor of other types such as a DC motor may also be used. In the present embodiment, the control unit 25 controls the lifting mechanism 78 to lift the loading tray 40.

[0060] An upper surface detection sensor 80 is provided above the loading tray 40 of the medium loading device 39. Figure 3 Illustration omitted.

[0061] like Figure 4A and Figure 4B As shown in FIG. 1 , the upper surface detection sensor 80 is configured to detect the position of the upper surface of the medium P loaded on the loading tray 40. More specifically, the upper surface detection sensor 80 detects the upper surface of the medium P when the medium P is loaded on the loading tray 40, and detects the upper surface of the loading tray 40 itself when the medium P is not loaded on the loading tray 40. Hereinafter, both the upper surface of the loading tray 40 itself and the upper surface of the medium P loaded on the loading tray 40 are referred to as the upper surface of the medium P on the loading tray 40.

[0062] As described above, the control unit 25 controls the lifting mechanism 78 to lift the stacking tray 40. The control unit 25 controls the lifting mechanism 78 using the detection result of the upper surface detection sensor 80 to keep the distance between the upper surface of the medium P on the stacking tray 40 and the first discharge unit 62 constant.

[0063] The upper surface detection sensor 80 includes a flag 81 and a photointerrupter 82. The flag 81 is configured to be able to swing around a rotation axis 83. The flag 81 includes a front end portion 81a that contacts the upper surface of the medium P on the loading tray 40 and a detected portion 81b detected by the photointerrupter 82.

[0064] The control unit 25 can understand the state of the flag 81 based on the detection result of the photointerrupter 82 .

[0065] The front end portion 81a is configured to be able to swing to an entry position onto the loading tray 40 by rotating around the rotation shaft 83 (see Figure 4A ) and the retreat position from the loading tray 40 (refer to Figure 4B ).

[0066] The front end portion 81a moves to the entry position after the medium P is discharged onto the stacking tray 40, and moves to the retreat position before the subsequent medium P is discharged. At the entry position, the front end portion 81a abuts against the upper surface of the medium P on the stacking tray 40, and rotates as the stacking tray 40 is raised or lowered.

[0067] The control unit 25 raises and lowers the stacking tray 40 as the medium P is discharged from the first discharge unit 62, and determines the standby position based on the detection result of the upper surface detection sensor 80. The standby position here refers to the position of the stacking tray 40 receiving the medium P discharged from the first discharge unit 62, that is, the height of the stacking tray 40.

[0068] Next, a standby position determination operation for determining the standby position of the loading tray 40 will be described.

[0069] First, when the medium P is loaded on the loading tray 40 , the control unit 25 moves the front end 81 a of the upper surface detection sensor 80 to the entry position and contacts the upper surface of the medium P. The control unit 25 obtains the detection result of the photointerrupter 82 when the upper surface detection sensor 80 contacts the upper surface of the medium P.

[0070] When the detection signal of the photointerrupter 82 is ON, that is, when the photointerrupter 82 detects the detected portion 81 b , the control unit 25 does not change the position of the loading tray 40 .

[0071] On the other hand, when the detection signal of the photointerrupter 82 is OFF, that is, when the photointerrupter 82 does not detect the detected portion 81 b, the control unit 25 lowers the position of the stacking tray 40. This is because it can be determined that the distance between the upper surface of the medium P on the stacking tray 40 and the first discharge unit 62 is narrowed by the stacking of the medium P.

[0072] In the process of lowering the loading tray 40 downward, the detection signal of the photointerrupter 82 is switched from OFF to ON, and then switched from ON to OFF. The control unit 25 stops the lowering of the loading tray 40 in response to the switching from ON to OFF.

[0073] Then, the control unit 25 raises the loading tray 40 until the detection signal of the photointerrupter 82 changes from OFF to ON, and stops the raising of the loading tray 40 when the detection signal changes to ON. The above is the standby position determination operation.

[0074] In this way, the control unit 25 performs a standby position determination action consisting of a lowering action to lower the loading tray 40 and an ascending action to ascend the loading tray 40 according to the detection result of the upper surface detection sensor 80, so as to maintain the upper surface of the medium P on the loading tray 40 at a predetermined position, that is, a predetermined height.

[0075] By this standby position determination operation, the distance between the upper surface of the medium P on the loading tray 40 and the first discharge unit 62 is maintained substantially constant, and the possibility of deterioration of alignment when the medium P is discharged can be reduced.

[0076] Here, as the upper surface detection sensor 80 for detecting the upper surface of the medium P on the loading tray 40 , a sensor composed of a mark 81 and a photointerrupter 82 is used, but the present invention is not limited thereto, and other sensors may be used for upper surface detection.

[0077] return Figure 3 The medium loading device 39 is provided with a lower limit sensor 90. The lower limit sensor 90 is a transmission type sensor including a light emitting unit 91 provided in the lifting guide 77A and a light receiving unit 92 provided in the lifting guide 77B.

[0078] The lower limit sensor 90 is provided below the lifting guides 77A and 77B, and is configured to be able to detect that the loading tray 40 has reached the lower limit position based on the light receiving state of the light receiving unit 92 .

[0079] The upper surface detection sensor 80 detects the upper surface of the medium P on the loading tray 40 so that the upper surface of the medium P is arranged at a predetermined position.

[0080] In other words, as the number of media P loaded on the loading tray 40 increases, the position of the loading tray 40 moves downward.

[0081] Therefore, as the medium P is discharged onto the stacking tray 40, the stacking tray 40 moves downward, and finally blocks the light from the light emitting unit 91. As a result, the light receiving unit 92 cannot receive the light from the light emitting unit 91, and the detection result of the lower limit sensor 90 changes. The control unit 25 determines that the stacking tray 40 has reached the lower limit position based on the change in the detection result. In other words, it is determined that the medium P on the stacking tray 40 has reached the upper limit of the stacking.

[0082] In this way, the upper limit of the stacking tray 40 is monitored based on the detection result of the lower limit sensor 90. Here, the upper limit of the stacking tray 40 is monitored by the lower limit sensor 90, but the upper limit may be monitored by counting the number of media P discharged onto the stacking tray 40.

[0083] In this manner, the upper limit of the medium P loaded on the loading tray 40 is monitored by a predetermined method, and the loading tray 40 is configured to operate under the monitoring.

[0084] However, when recording is performed using an inkjet printer such as the recording unit 2 of the present embodiment, the above-mentioned method of monitoring the upper limit of the loading is sometimes not sufficient. When recording is performed on the medium P using an inkjet printer, the weight of the medium P in the unrecorded state plus the weight of the ink is the weight of the medium P. In other words, the more ink is ejected from the medium P, the heavier the weight of the medium P. Therefore, when the amount of ink is large and the heavy medium P is excessively loaded on the loading tray 40, a load is also applied to the lifting mechanism 78 that lifts and lowers the loading tray 40, and the lifting and lowering action of the loading tray 40 may not be properly controlled. As a result, the distance between the upper surface of the medium P on the loading tray 40 and the first discharge portion 62 changes, and the alignment may be deteriorated. In addition, there is a possibility that the lifting mechanism 78 of the loading tray 40 is damaged, or a load exceeding the assumed load is applied, resulting in abnormal noise.

[0085] Therefore, in the present invention, the weight of the medium P is estimated taking into account the weight of the ink ejected onto the medium P, and the loading tray 40 is controlled. This can reduce the deterioration of the alignment of the medium P on the loading tray 40, and can reduce the damage of the lifting mechanism 78 or the generation of abnormal noise.

[0086] The weight of the medium P hereinafter refers to the weight of the medium P taking into account the weight of the ink ejected onto the medium P. The weight of the medium P not taking into account the weight of the ink ejected onto the medium P refers to the weight of the medium P in an unrecorded state.

[0087] The estimation unit 51 is used to estimate the weight of the medium P loaded on the loading tray 40. The estimation unit 51 estimates the amount of ink ejected onto the medium P by the line head 20, and estimates the weight of the ink based on the amount of ink. Then, the weight of the medium P is estimated by adding the weight of the ink to the weight of the medium P in an unprinted state.

[0088] Specifically, in order to estimate the weight of ink ejected by the printer unit 10, the estimation unit 51 refers to the recording data received by the receiving unit 53. Then, the number of dots of ink used for recording is acquired from the recording data.

[0089] The estimation unit 51 calculates the weight of the ink ejected to the medium P by multiplying the number of dots of ink used for recording by the weight of the ink per dot, and estimates the weight as the weight of the ink. At this time, the weight of the ink per dot may be set individually according to the size of the dot.

[0090] When double-sided recording is performed, the weight of the ink is calculated for each of the front and back surfaces, and the sum of the weights is estimated as the weight of the ink.

[0091] Then, the estimation unit 51 estimates the weight of the medium P as the weight of the medium P by adding the weight of the ink to the weight of the medium P in the unrecorded state.

[0092] The weight of the medium P in the unrecorded state here varies depending on the paper type or paper size, so it is preferable to change the weight of the medium P in the unrecorded state according to the paper type or paper size of the recorded medium P. In this case, the weight of the medium P in the unrecorded state may be estimated by using only one of the paper type or paper size of the medium P.

[0093] The estimation unit 51 can estimate the total weight of the media P on the loading tray 40 by estimating the weight of each medium P and adding the weights of the media P each time the media P is loaded on the loading tray 40. Hereinafter, the total weight of the media P loaded on the loading tray 40 is referred to as the weight of the media P on the loading tray 40.

[0094] The control unit 25 controls the lifting and lowering operation of the loading tray 40 based on the weight of the medium P on the loading tray 40 estimated by the estimation unit 51 .

[0095] Here, when it is determined that the weight of the medium P loaded on the loading tray 40 is about to reach or has reached a threshold value, the control unit 25 limits the lifting and lowering of the loading tray 40. In this embodiment, the limitation of the lifting and lowering operation means prohibiting the lifting and lowering operation.

[0096] Thus, the stacking tray 40 does not move when a load greater than expected is applied, thereby reducing the possibility that the lifting and lowering of the stacking tray 40 cannot be appropriately controlled and the alignment of the media P on the stacking tray 40 is deteriorated.

[0097] In addition, it is possible to reduce the possibility of the lifting mechanism 78 being damaged or abnormal noise being generated before the upper limit of the loading of the loading tray 40 is reached.

[0098] Below, according to Figure 5A and Figure 5B The specific operations are described in detail with reference to the flowchart.

[0099] When the user instructs to start recording and the receiving unit 53 receives the recording instruction and the recording data of the job corresponding to the recording instruction, the estimation unit 51 obtains the recording data received by the receiving unit 53 (step S101). Then, the recording data of the next medium P discharged from the first discharge unit 62 is obtained from the acquired recording data (step S102). The estimation unit 51 estimates at least one of the paper type and paper size from the recording data, and estimates the weight of the medium P in the unrecorded state by referring to the storage unit 52 (step S103).

[0100] After estimating the weight of the medium P in the unrecorded state, the estimation unit 51 estimates the weight of the ejected ink based on the recorded data (step S104). Then, the weight of the medium P is estimated by adding the weight of the ink acquired in step S104 to the weight of the medium P in the unrecorded state acquired in step S103 (step S105). Then, the control unit 25 discharges the medium P onto the loading tray 40 (step S106). Then, the estimation unit 51 calculates the weight of the medium P on the loading tray 40 by adding the weight of the medium P acquired in step S105 to the weight of the medium P discharged onto the loading tray 40 (step S107).

[0101] Here, the control unit 25 determines whether the weight of the medium P on the loading tray 40 calculated by the estimation unit 51 in step S106 is equal to or greater than a threshold value (step S108 ).

[0102] When it is determined in step S108 that the weight of the medium P on the stacking tray 40 is greater than the threshold value, the control unit 25 performs a lowering operation of the stacking tray 40 until the stacking tray 40 reaches the lower limit, that is, until the lower limit sensor 90 detects the stacking tray 40 (step S112). During this lowering operation, the control unit 25 counts the time until the stacking tray 40 reaches the lower limit, and uses the count value.

[0103] This operation is an operation for grasping the position of the stacking tray 40, and is an operation for confirming whether the user has taken away the medium P on the stacking tray 40. When the user has taken away the medium P on the stacking tray 40, the stacking tray 40 is raised by the standby position determination operation, and the number of sheets of the medium P that can be stacked on the stacking tray 40 is also increased. However, since the control unit 25 makes a judgment based on the estimation result of the estimation unit 51, it may be mistakenly judged that the weight of the medium P on the stacking tray 40 is greater than the threshold value. Therefore, the control unit 25 judges whether the user has taken away the medium P on the stacking tray 40 by performing an operation for grasping the position of the stacking tray 40. Specifically, when the count value is greater than a predetermined value, that is, when the stacking tray 40 has dropped downward by more than the expected amount, the control unit 25 judges that the user has taken away the medium P, and changes the threshold value of the weight of the medium P. At this time, the threshold value of the weight of the medium P may be changed according to the count value. The threshold value after the change when the count value is greater than the predetermined value may be greater than the threshold value after the change when the count value is less than the predetermined value. On the other hand, when the count value is smaller than the predetermined value, it is determined that the user has not removed the medium P, and the threshold value is not changed.

[0104] Then, the control unit 25 determines whether the count value is greater than a predetermined value (step S113). If the count value is less than the predetermined value, it is determined that the user has not taken the medium P. Then, the control unit 25 restricts the lifting and lowering of the stacking tray 40 (step S115), and stops recording (step S116). Then, the user is notified that the medium P cannot be discharged onto the stacking tray 40 (step S117).

[0105] On the other hand, when it is determined in step S108 that the weight of the medium P on the loading tray 40 is not equal to or greater than the threshold, the process proceeds to step S109 .

[0106] If it is determined in step S113 that the count value is greater than the predetermined value, that is, if it is determined that the user has taken the medium P, the control unit 25 changes the threshold value of the weight of the medium P (step S114). Specifically, the threshold value is increased to allow additional medium P to be accepted, and the process proceeds to step S109.

[0107] In step S109, the control unit 25 performs a standby position determination operation for the stacking tray 40. As described above, as the standby position determination operation, the control unit 25 raises and lowers the stacking tray 40 based on the detection result of the upper surface detection sensor 80, and keeps the distance between the first discharge unit 62 and the upper surface of the medium P on the stacking tray 40 constant.

[0108] After the standby position determination operation of the stacking tray 40 is performed, the control unit 25 determines whether the stacking tray 40 has reached the lower limit based on the detection result of the lower limit sensor 90 (step S110). Here, when it is determined that the stacking tray 40 has reached the lower limit, the control unit 25 restricts the lifting and lowering operation of the stacking tray 40 (step S115) and stops recording (step S116). Then, the control unit 25 notifies the user that the medium P cannot be discharged onto the stacking tray 40 (step S117).

[0109] On the other hand, if it is determined in step S110 that the loading tray 40 has not reached the lower limit, the control unit 25 determines whether the job has ended (step S111). If the job has ended, the operation ends. If the job has not ended, the process returns to step S102 and the subsequent media P are processed in the same manner.

[0110] In this way, the control unit 25 determines whether the weight of the medium P on the stacking tray 40 is greater than or equal to the threshold value, and when it is determined that the weight is greater than the threshold value, the control unit 25 restricts the lifting and lowering operation of the stacking tray 40 .

[0111] Thus, the stacking tray 40 is not moved with a load greater than expected, thereby reducing the possibility that the lifting and lowering of the stacking tray 40 cannot be properly controlled and the alignment of the media P on the stacking tray 40 is degraded.

[0112] In addition, it is possible to reduce the possibility that the lifting mechanism 78 is damaged or abnormal noise is generated before the upper limit of the loading of the loading tray 40 is reached.

[0113] In addition, the predetermined value to be compared with the count value until the stacking tray 40 reaches the lower limit is preferably determined based on the number of mediums P stacked on the stacking tray 40 and the amount of ink ejected onto the medium P.

[0114] In the case of a medium P recorded by an inkjet printer, the medium P absorbs ink and curls. The degree of curling varies depending on the amount of ink ejected onto the medium P.

[0115] Therefore, the height of the medium P loaded on the loading tray 40 changes according to the number of sheets of the medium P and the amount of ink ejected to the medium P. In other words, when the upper surface position of the medium P on the loading tray 40 is fixed, the distance from the loading tray 40 to the lower limit sensor 90 changes according to the number of sheets of the medium P and the amount of ink ejected to the medium P.

[0116] Therefore, by changing the predetermined value according to the number of mediums P on the loading tray 40 and the amount of ink ejected onto the medium P, it is possible to more accurately determine whether the user has taken away the medium P.

[0117] In addition, instead of the amount of ink ejected onto the medium P, the printing rate (printing ratio) of the medium P that can be calculated from the recording data may be used.

[0118] When a stepping motor is used as the motor of the lifting mechanism 78 , it is also possible to determine whether the user has taken the medium P by using the number of steps until the stacking tray 40 blocks the light of the light emitting unit 91 as a count value.

[0119] Furthermore, the limitation of the lifting and lowering operation includes not only limiting the lifting and lowering operation when the loading tray 40 is lifted and lowered, but also limiting only the lifting operation of the loading tray 40 .

[0120] When performing the raising operation to raise the loading tray 40 and the lowering operation to lower the loading tray 40, the raising operation causes a greater load on the lifting mechanism 78. In the lowering operation, the load applied to the lifting mechanism 78 is smaller than that in the raising operation.

[0121] Therefore, by allowing the descending operation, the medium P can be continuously discharged, and the lifting mechanism 78 can be appropriately controlled, so that the deterioration of the alignment can be reduced, and the damage or abnormal noise of the lifting mechanism 78 can be reduced.

[0122] 2. Second Implementation

[0123] Next, the second embodiment will be described. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and duplicate descriptions are omitted.

[0124] The second embodiment is similar to the first embodiment in that when the weight of the medium P on the stacking tray 40 reaches a threshold or more, the lifting and lowering of the stacking tray 40 is restricted. However, the operation before the lifting and lowering is restricted is different from the first embodiment.

[0125] In the second embodiment, when the weight of the medium P on the stacking tray 40 reaches or exceeds a threshold value, the control unit 25 determines the remaining number of sheets that can be stacked, and discharges the medium P from the first discharge unit 62 according to the remaining number of sheets that can be stacked.

[0126] The remaining number of sheets that can be loaded is the number of media P that can be discharged onto the loading tray 40 . By discharging the remaining number of sheets that can be loaded onto the loading tray 40 , it is determined that the weight of the media P on the loading tray 40 has reached the upper limit.

[0127] Furthermore, the threshold value in the second embodiment may be different from the threshold value in the first embodiment.

[0128] In this configuration, when a few media P are left on the loading tray 40, the control unit 25 can determine whether the weight of the media P loaded on the loading tray 40 has reached the upper limit. Therefore, when recording a plurality of media P in one job, it is possible to prevent recording from being stopped in the middle of the job.

[0129] At this time, the remaining number of sheets that can be loaded is preferably determined based on the assumed maximum weight per sheet of the medium P. The assumed maximum weight per sheet refers to the weight of the medium P when the maximum number of dots that can be punched is punched into the medium P.

[0130] Here, the value obtained by dividing the remaining stowable weight at the stage where the weight reaches or exceeds the threshold value by the assumed maximum weight per sheet is defined as the remaining stowable number of sheets.

[0131] In this way, since the remaining number of sheets that can be loaded is determined based on the assumed maximum weight per sheet of the medium P, the weight of the medium P on the loading tray 40 does not exceed the upper limit.

[0132] Below, according to Figure 6 The specific operations are described in detail with reference to the flowchart.

[0133] Since steps S101 to S117 are the same as those in the first embodiment, the description will start from step S121. When the count value is less than the predetermined value in step S113, the control unit 25 determines the remaining number of sheets of medium P that can be discharged to the loading tray 40 (step S121). Then, the subsequent medium P is discharged (step S122), and the number of discharged sheets is incremented (step S123).

[0134] Then, the control unit 25 performs a standby position determination operation for the loading tray 40 (step S124 ), and determines whether the loading tray 40 has reached the lower limit (step S125 ).

[0135] When it is determined in step S125 that the loading tray 40 has reached the lower limit position, the control unit 25 restricts the lifting and lowering operation of the loading tray 40 (step S115 ), prohibits recording (step S116 ), and notifies the user (step S117 ).

[0136] When it is determined in step S125 that the stacking tray 40 has not reached the lower limit position, the control unit 25 determines whether the number of sheets of the medium P discharged onto the stacking tray 40 has reached the remaining number of sheets that can be stacked (step S126). Then, when it is determined that the number of sheets of the medium P discharged onto the stacking tray 40 has reached the remaining number of sheets that can be stacked, the process proceeds to step S115. When it is determined that the number of sheets of the medium P discharged onto the stacking tray 40 has not reached the remaining number of sheets that can be stacked, the process returns to step S122 and the same operation is repeated.

[0137] The media P discharged onto the loading tray 40 in step S126 refers to the number of media P discharged onto the loading tray 40 after the remaining number of sheets is set. In other words, it refers to the number of media P discharged onto the loading tray 40 after the weight of the media P on the loading tray 40 reaches a threshold value or more.

[0138] Thus, the loading tray 40 is not moved with a load greater than expected applied to it, and the lifting mechanism 78 can be appropriately controlled. Therefore, the deterioration of the alignment of the medium P on the loading tray 40 can be reduced, and damage or abnormal noise of the lifting mechanism 78 can be reduced.

[0139] Furthermore, since the loading tray 40 does not operate in a state where an unexpected load is applied to the loading tray 40 , the possibility that the loading tray 40 does not operate properly and the alignment of the medium P on the loading tray 40 is deteriorated can be reduced.

[0140] 3. Third Implementation

[0141] Next, the third embodiment will be described. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and duplicate descriptions are omitted.

[0142] The third embodiment is similar to the first and second embodiments in that the control of the loading tray 40 is changed when the weight of the medium P on the loading tray 40 reaches or exceeds a threshold value, but the control method is different from the first and second embodiments.

[0143] In the present embodiment, the control unit 25 can change the rotation speed of the motor of the lifting mechanism 78 when the weight of the medium P on the loading tray 40 reaches or exceeds a threshold value.

[0144] Specifically, when the weight of the medium P on the loading tray 40 reaches a threshold value or more, the control unit 25 reduces the rotation speed of the motor. In other words, the control unit 25 makes the rotation speed of the motor slower when the weight of the medium P on the loading tray 40 reaches a threshold value or more than the rotation speed of the motor slower than when the weight of the medium P on the loading tray 40 is less than the threshold value.

[0145] The motor can increase the torque by reducing the rotation speed, so the lifting mechanism 78 can be properly controlled even when a load greater than expected is applied to the loading tray 40. Therefore, the deterioration of the alignment of the medium P on the loading tray 40 can be reduced, and damage or abnormal noise of the lifting mechanism 78 can be reduced.

[0146] Below, according to Figure 7 The specific operations are described in detail with reference to the flowchart.

[0147] Steps S101 to S117 are the same as those of the first embodiment, but are different from the first embodiment in that step S131 is implemented.

[0148] When the count value is smaller than the predetermined value in step S113 , the control unit 25 reduces the speed of the motor of the lifting mechanism 78 in step S131 .

[0149] This can reduce the deterioration of the alignment of the medium P on the loading tray 40 and reduce the damage or abnormal noise of the lifting mechanism 78 .

[0150] In the present embodiment, it is not necessary to reduce the rotation speed of the motor in both the lowering operation and the raising operation of the loading tray 40 , and the rotation speed of the motor may be reduced only in the raising operation.

[0151] This is because, when a load greater than an assumed load is applied to the loading tray 40 , a greater load is applied to the motor in the raising operation than in the lowering operation.

[0152] Therefore, the control unit 25 may reduce the rotation speed when the loading tray 40 is performing the ascending operation, and may not reduce the rotation speed when the loading tray 40 is performing the descending operation.

[0153] This can reduce the load on the motor and reduce the reduction in throughput.

[0154] In the present embodiment, the lifting speed of the stacking tray 40 may be set to a plurality of levels, and the lifting speed of the stacking tray 40 , that is, the rotation speed of the motor may be changed according to the weight of the medium P on the stacking tray 40 .

[0155] Specifically, as shown in Table 1, when the weight Z of the medium P on the stacking tray 40 is less than the first threshold value T1, the lifting speed is set to the first speed in both the lifting operation and the lowering operation. In addition, when the weight Z of the medium P on the stacking tray 40 is greater than the first threshold value T1 and less than the second threshold value T2, the lifting speed is set to the second speed. In addition, when the weight Z of the medium P on the stacking tray 40 is greater than the second threshold value T2 and less than the third threshold value T3, the lifting speed is set to the third speed.

[0156] The lifting speed becomes slower as the lifting speed changes to the first speed, the second speed, and the third speed. That is, the lifting speed can be reduced in stages as the weight Z of the medium P on the loading tray 40 increases.

[0157] Thus, the rotation speed of the motor can be changed according to the load applied to the loading tray 40 , so that the load applied to the motor can be reduced while reducing the reduction in throughput.

[0158] Table 1

[0159]

[0160] In addition, as shown in Table 2, the rotation speed of the motor may be changed according to the weight Z of the medium P on the loading tray 40 only during the ascending operation of the loading tray 40 .

[0161] This can reduce the load on the motor and reduce the reduction in throughput.

[0162] Table 2

[0163]

[0164] 4. Fourth Implementation

[0165] Next, a fourth embodiment will be described. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and duplicate descriptions are omitted.

[0166] The fourth embodiment is similar to the first to third embodiments in that the control of changing the loading tray 40 when the weight of the medium P on the loading tray 40 reaches a threshold or more, but the control method is different from the first to third embodiments.

[0167] In the present embodiment, the control unit 25 can change the driving current of the motor of the lifting mechanism 78 when the weight of the medium P on the loading tray 40 reaches or exceeds a threshold value.

[0168] Specifically, when the weight of the medium P on the loading tray 40 reaches or exceeds the threshold value, the control unit 25 controls the driving current flowing to the motor to increase. In other words, the control unit 25 controls the driving current flowing to the motor to be greater when the weight of the medium P on the loading tray 40 reaches or exceeds the threshold value than when the weight of the medium P on the loading tray 40 is less than the threshold value.

[0169] As the driving current flowing through the motor increases, the torque also increases, so the lifting mechanism 78 can be appropriately controlled even when a load greater than expected is applied to the loading tray 40. Therefore, it is possible to reduce the deterioration of the alignment of the medium P on the loading tray 40, and reduce damage or abnormal noise of the lifting mechanism 78.

[0170] Below, according to Figure 8 The specific operations are described in detail with reference to the flowchart.

[0171] Steps S101 to S117 are the same as those of the first embodiment, but are different from the first embodiment in that step S141 is implemented.

[0172] When the count value is smaller than the predetermined value in step S113 , the control unit 25 increases the drive current flowing to the motor of the lifting mechanism 78 in step S141 .

[0173] This can reduce the deterioration of the alignment of the medium P on the loading tray 40 and reduce the damage or abnormal noise of the lifting mechanism 78 .

[0174] In addition, in the present embodiment, the current value flowing through the motor may be set in a plurality of stages, and the driving current flowing through the motor may be changed according to the weight of the medium P on the loading tray 40 .

[0175] Specifically, as shown in Table 3, when the weight Z of the medium P on the loading tray 40 is less than the first threshold value T1, the current value of the driving current is set to the first current value in both the ascending action and the descending action. In addition, when the weight Z of the medium P on the loading tray 40 is greater than the first threshold value T1 and less than the second threshold value T2, the current value is set to the second current value. In addition, when the weight Z of the medium P on the loading tray 40 is greater than the second threshold value T2 and less than the third threshold value T3, the current value is set to the third current value.

[0176] The current value increases as it changes to the first current value, the second current value, and the third current value. That is, the driving current can be changed in stages as the weight Z of the medium P on the loading tray 40 increases.

[0177] Thus, the torque of the motor can be changed according to the load applied to the loading tray 40 , so that the load applied to the motor can be reduced while reducing the reduction in throughput.

[0178] Table 3

[0179]

[0180] In addition, as shown in Table 4, the driving current of the motor may be changed according to the weight Z of the medium P on the loading tray 40 only during the raising operation of the loading tray 40 .

[0181] This can reduce the load on the motor and reduce the reduction in throughput.

[0182] Table 4

[0183]

[0184] In the fourth embodiment, the problem may be dealt with by increasing the current limit value instead of increasing the drive current flowing to the motor.

[0185] Next, modifications of the embodiment will be described.

[0186] In the first to fourth embodiments described above, the estimation unit 51 is configured as a functional block in the control unit 25 , but may be configured by hardware different from the control unit 25 .

[0187] In the first to fourth embodiments, the weight of the medium P is estimated and the lifting mechanism 78 is controlled by the control unit 25 provided in the recording unit 2, but the present invention is not limited to this method. For example, a loading control unit having the same function as the control unit 25 may be arranged inside the medium loading device 39, and the weight of the medium P is estimated and the lifting mechanism 78 is controlled by the loading control unit. Figure 5A , Figure 5B , Figure 6 , Figure 7 , Figure 8 Alternatively, a post-processing control unit having the same function as the control unit 25 may be arranged outside the medium loading device 39 inside the post-processing device 5, and the weight of the medium P and the control of the lifting mechanism 78 may be estimated by the post-processing control unit. In these cases, the information required for estimating the weight of the medium P, such as the recording data, may be obtained via the recording unit 2 or directly obtained from the outside. In addition, in this case, the estimation unit 51 for estimating the weight of the medium P may be arranged inside the loading control unit or the post-processing control unit or may be arranged outside.

[0188] When calculating the weight of ink, the weight of ink is calculated based on the number of ink dots and the weight of ink per dot. However, the weight of ink may also be calculated based on the printing rate of recorded data.

[0189] Specifically, the number of dots of ink impressed on the medium P may be calculated from the printing rate, and the weight of the ink may be calculated by multiplying the number of dots calculated from the printing rate by the weight of the ink per dot.

[0190] In the first to fourth embodiments, when the weight of the medium P on the loading tray 40 reaches a threshold or more, the discharge destination of the medium P may be changed from the loading tray 40 to another tray and recording may be continued without interrupting recording by the line head 20 .

[0191] In the first to fourth embodiments, the timing of calculating the weight of the medium P loaded on the loading tray 40 may be earlier than the timing of discharging the medium P onto the loading tray 40 .

[0192] When the weight of the medium P loaded on the loading tray 40 is calculated in advance and the calculated weight of the medium P on the loading tray 40 is equal to or greater than a threshold value, the discharge of the medium P originally scheduled to be discharged to the loading tray 40 may be prohibited.

[0193] In addition, at this time, the discharge of the corresponding medium P may not be prohibited, but the discharge destination of the medium P may be changed from the loading tray 40 to another tray and recording may be continued.

[0194] It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention described in the claims, and these modifications are also included in the scope of the present invention.

Claims

1. A recording system, characterized in that: have: A discharge unit that discharges the medium on which the liquid is ejected and recorded; a loading portion for loading the medium discharged through the discharge portion; A lifting part, which enables the loading part to be lifted and lowered; a control unit that controls the lifting unit; and an estimating unit for estimating a weight of a medium loaded on the loading unit, The control unit controls the lifting and lowering operation of the loading unit according to the weight of the medium estimated by the estimation unit. When the weight of the medium estimated by the estimation unit is equal to or greater than a threshold value, the control unit determines the remaining number of sheets that can be loaded on the loading unit after the weight reaches or exceeds the threshold value. The control unit limits the lifting and lowering operation when the number of media discharged by the discharge unit after reaching or exceeding the threshold value reaches the remaining number of media that can be loaded.

2. The recording system according to claim 1, characterized in that The estimation unit estimates the weight of the medium placed on the placement unit based on the weight of the medium before the liquid is ejected and the amount of the liquid ejected onto the medium.

3. The recording system according to claim 1 or 2, characterized in that: The control unit limits the lifting and lowering operation when the weight of the medium estimated by the estimation unit is equal to or larger than a threshold value.

4. The recording system according to claim 1 or 2, characterized in that: The remaining number of sheets that can be loaded is determined based on the assumed maximum weight of each medium.

5. The recording system according to claim 1 or 2, characterized in that: The recording system includes an upper surface detection sensor capable of detecting an upper surface of the medium loaded on the loading portion. The control unit performs a descending action of lowering the stacking unit and an ascending action of ascending the stacking unit after the descending action according to the detection result of the upper surface detection sensor, so as to keep the upper surface of the medium stacked on the stacking unit at a predetermined position. The control unit limits the ascending operation when the weight of the medium estimated by the estimation unit is equal to or larger than a threshold value.

6. The recording system according to claim 1 or 2, characterized in that: The lifting part has a motor as a driving source, The control unit is capable of changing the rotation speed of the motor according to the weight of the medium estimated by the estimation unit. The rotation speed of the motor when the weight of the medium estimated by the estimating unit is greater than or equal to a threshold value is set lower than the rotation speed of the motor when the weight of the medium estimated by the estimating unit is less than the threshold value.

7. The recording system according to claim 6, characterized in that The recording system includes an upper surface detection sensor capable of detecting an upper surface of the medium loaded on the loading portion. The control unit performs a descending action of lowering the stacking unit and an ascending action of ascending the stacking unit after the descending action according to the detection result of the upper surface detection sensor, so as to keep the upper surface of the medium stacked on the stacking unit at a predetermined position. The control unit makes the rotation speed of the motor during the ascending action lower when the weight of the medium estimated by the estimation unit is greater than the threshold value than when the weight of the medium estimated by the estimation unit is less than the threshold value.

8. The recording system according to claim 1 or 2, characterized in that: The lifting part has a motor as a driving source, The control unit is capable of changing the driving current of the motor according to the weight of the medium estimated by the estimation unit. The driving current of the motor when the weight of the medium estimated by the estimating unit is greater than a threshold value is set to be greater than the driving current of the motor when the weight of the medium estimated by the estimating unit is less than the threshold value.

9. The recording system according to claim 8, characterized in that The recording system includes an upper surface detection sensor capable of detecting an upper surface of the medium loaded on the loading portion. The control unit performs a descending action of lowering the stacking unit and an ascending action of ascending the stacking unit after the descending action according to the detection result of the upper surface detection sensor, so as to keep the upper surface of the medium stacked on the stacking unit at a predetermined position. The control unit makes the driving current of the motor during the ascending action greater than the driving current of the motor during the ascending action when the weight of the medium estimated by the estimation unit is greater than the threshold value, compared with when the weight of the medium estimated by the estimation unit is less than the threshold value.

10. The recording system according to claim 3, characterized in that The recording system comprises: an upper surface detection sensor capable of detecting an upper surface of the medium loaded on the loading portion; and a lower limit sensor capable of detecting that the stowage portion is at the lower limit, The control unit performs a descending action of lowering the stacking unit and an ascending action of ascending the stacking unit after the descending action according to the detection result of the upper surface detection sensor, so as to keep the upper surface of the medium stacked on the stacking unit at a predetermined position. When the weight of the medium estimated by the estimation unit is greater than the threshold value, the control unit lowers the loading unit to a position detectable by the lower limit sensor. The lifting and lowering operation of the loading section is controlled based on the count value until the loading section is detected by the lower limit sensor.

11. The recording system according to claim 10, characterized in that When the count value is less than a predetermined value, the control unit does not change the threshold value. When the count value is equal to or greater than the predetermined value, the control unit increases the threshold value.

12. The recording system according to claim 11, characterized in that The predetermined value is determined based on the number of media and the amount of liquid ejected onto the media.

Images