Recording device and control method for recording device

Abstract

To control output of a motor in holding control of holding the motor at a stop position, more properly than before.SOLUTION: A recording device comprises: recording means that performs recording on a sheet; conveying means that conveys the sheet to a recording position where the recording means performs recording; a motor that drives the conveying means; and control means that controls rotation of the motor. The control means can execute holding control of holding the motor at a stop position. The control means determines a first output value that is an output value from the motor in the holding control, in accordance with a second output value that is an output value from the motor at the time before the motor stops at the stop position.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a recording apparatus and Recording device control method By law Regarding. [Background technology]

[0002] Inkjet printers, one example of a recording device, perform recording by repeatedly conveying a sheet a predetermined distance and ejecting ink onto the sheet using a printhead. In such recording devices, when stopping a sheet being conveyed, an external force in the opposite direction to the conveying direction may be applied to conveying members such as conveying rollers due to twisting or resistance of components of the conveying mechanism. This force may then cause the stopped sheet to return in the opposite direction. To mitigate this phenomenon, Patent Document 1 discloses controlling the current value flowing through the motor that drives the conveying mechanism so that the motor stops at a target stop position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-273559 Summary of the Invention [Problem to be solved by the invention]

[0004] The motor output required to stop the motor in the stopped position can vary depending on the magnitude of the external force mentioned above. Therefore, depending on the magnitude of the external force, the motor output may be insufficient to stop the motor in the stopped position, causing the motor to rotate in the reverse direction. Also, depending on the magnitude of the external force, the motor output may be excessive, causing the motor to rotate further forward from the stopped position.

[0005] The present invention provides a technique for controlling the output of a motor more appropriately than ever before during holding control for holding the motor at a stopped position. [Means for solving the problem]

[0006] According to one aspect of the present invention, a recording means for recording on a sheet; a conveying means for conveying a sheet to a recording position by the recording means; a motor for driving the conveying means; a control means for controlling the rotation of the motor; Equipped with the control means is capable of executing a holding control to stop the rotating motor at a target position and hold the motor at the stop position, The control means determining a first output value, which is an output value of the motor during the holding control, according to a second output value, which is an output value of the motor before the motor is stopped at the stop position; updating the target position to a current position based on the fact that the rotation speed of the motor has become equal to or less than a threshold value during execution of the holding control; A recording device is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique for controlling the output of a motor more appropriately than ever before during holding control for holding the motor at a stopped position. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the internal structure of a recording apparatus according to an embodiment. [Figure 2] 2 is a cross-sectional view of a feeding section and a conveying section of the recording apparatus of FIG. 1. [Figure 3] FIG. [Figure 4] 10(a) and 10(b) are diagrams for explaining the structure of the separation section. [Figure 5] 10(a) to 10(c) are diagrams illustrating the structure of the separation section. [Figure 6] FIG. [Figure 7] FIG. 2 is a schematic diagram of a conveying section and a conveying path. [Figure 8] FIG. 2 is a block diagram showing the control configuration of the printing apparatus. [Figure 9] FIG. 3 is a diagram illustrating a control configuration of a conveyor motor. [Figure 10] 10 is a flowchart showing an outline of a recording operation. [Figure 11] FIG. 10 is a diagram for explaining a conveying operation for each pass in a printing operation. [Figure 12] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 13] 10A is a diagram showing an example of a change in speed when switching from feed control to hold control, and FIG. 10B is a diagram showing an example of a change in PWM value when switching from feed control to hold control. [Figure 14] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 15] 10A and 10B are diagrams illustrating a comparison between a case where the holding control of the present embodiment is executed and a case where the holding control is not executed. [Figure 16] 10A and 10B are diagrams illustrating a further comparison between a case where the holding control of the present embodiment is performed and a case where it is not performed. [Figure 17] 10 is a flowchart showing a continuous feeding operation in the recording apparatus. [Figure 18] 10 is a graph showing changes in the speed and PWM value of a carry motor. [Figure 19] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 20] FIG. 2 is a block diagram showing the control configuration of the printing apparatus. [Figure 21] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 22] 1 is a perspective view showing an overview of a recording apparatus according to an embodiment. [Figure 23] FIG. [Figure 24] FIG. 3 is a cross-sectional view of the feeding section in the width direction. [Figure 25] FIG. 2 is a cross-sectional view in a direction parallel to the sheet stacking surface of the pressure plate. [Figure 26] FIG. [Figure 27]FIG. 2 is a perspective view of a drive unit provided in a feeding unit. [Figure 28] FIG. 10 is a diagram showing an example of a feeding drive table of a drive motor. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] <1. First embodiment> <1.1. Recording device configuration> <1.1.1. Overview> 1 is a perspective view showing the internal structure of a recording apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a feeding unit 2 and a conveying unit 5 of the recording apparatus 1 shown in FIG.

[0011] The recording device 1 performs recording on a sheet. In this embodiment, the recording device 1 is a serial inkjet recording device that performs recording by ejecting ink onto a sheet. The recording device 1 includes a feed unit 2, a conveyance unit 5, a conveyance motor 6 (see FIG. 6), a recording unit 7, and a discharge unit 8.

[0012] The feeding unit 2 and the conveying unit 5 convey sheets (recording media). The feeding unit 2 includes a pickup roller 111. The conveying unit 5 includes a conveying roller 51, a discharge roller 53, and a pair of intermediate rollers 3 (see FIG. 7). The feeding unit 2 and the conveying unit 5 will be described in detail later.

[0013] The recording unit 7 performs recording on the conveyed sheet. For example, the recording unit 7 includes a recording head 71 (see FIG. 8) capable of ejecting ink, and a carriage 72 (see FIG. 8) that mounts the recording head 71 and can move back and forth in a scanning direction (the width direction of the sheet that intersects with the conveyance direction). For example, by moving the recording head 71 in the scanning direction by the carriage 72, it is possible to perform recording at any position in the width direction of the sheet.

[0014] The sheet on which recording has been performed in the recording unit 7 is discharged from the discharge unit 8. The discharge unit 8 includes a discharge tray 81. The sheet on which recording has been performed in the recording unit 7 is discharged to the discharge tray 81 by discharge rollers 53 of the conveying unit 5, which will be described later.

[0015] The conveying motor 6 transmits its driving force to the conveying rollers 51, the discharge rollers 53, the intermediate rollers 3a, and the rollers of the feeding unit 2 via a gear train 37 (see FIG. 6). That is, the conveying motor 6 drives each of the rollers that convey the sheet. For example, the conveying rollers 51 and the pickup roller 111 are driven by the same conveying motor 6.

[0016] In this embodiment, a sheet transport path CP is formed in the recording apparatus 1. The transport path CP is a path that runs from the feeding unit 2 through the conveying unit 5 to the discharging unit 8. This will be described in detail later. In the following, the feeding unit 2 side of the transport path CP will be referred to as the upstream side in the transport direction, and the discharging unit 8 side will be referred to as the downstream side in the transport direction. The driving direction of the transport motor 6 when the transport rollers 51 rotate to transport the sheet downstream in the transport direction may be referred to as the forward direction, and the driving direction of the transport motor 6 when the transport rollers 51 rotate to transport the sheet upstream in the transport direction may be referred to as the reverse direction.

[0017] <1.1.2. Configuration of the feeding section> Please also refer to Figure 3. Figure 3 is a perspective view of the feeding unit 2. The feeding unit 2 feeds (conveys) sheets to the conveying unit 5. The feeding unit 2 includes a cassette 100, a pickup roller unit 110, and a separating unit 120.

[0018] The cassette 100 can store multiple stacked sheets. In this embodiment, the cassette 100 is provided at the bottom of the housing of the recording apparatus 1. More specifically, the cassette 100 is provided below the recording unit 7. The cassette 100 includes a stacking unit 101 for stacking sheets and left and right side guides 102a and 102b for guiding the widthwise sides of the sheets. The side guides 102a and 102b align the left and right sides of the sheets. The side guides 102a and 102b are adjustable in position according to the width of the sheets and are configured to face both sides of the sheets and move in tandem in the directions of arrows A1 and B1, which move toward each other, and in the directions of arrows A2 and B2, which move away from each other. This aligns the sheets so that their centers in the width direction (X direction in the figure) are always at a fixed position. The stacking unit 101 is also movable in the directions of arrows Y1 and Y2, and is operated by the user. For example, sheets are stacked (set) when the stacking portion 101 is pulled out to the maximum in the Y2 direction.

[0019] The pickup roller unit 110 is a unit for feeding (conveying) sheets. The sheets stacked in the cassette 100 are fed to the conveying section 5 by a pickup roller 111 included in the pickup roller unit 110. The pickup roller unit 110 is disposed above the stacking section 101. The pickup roller unit 110 includes a pickup roller 111, a pickup arm 112, and a drive shaft 113.

[0020] The pickup roller 111 is provided on the conveying path CP upstream of the conveying roller 51 in the conveying direction, and conveys the sheet along the conveying path CP. The pickup roller 111 also conveys the sheet stacked on the stacking unit 101 to the conveying path CP.

[0021] The pickup arm 112 is rotatable around a drive shaft 113 in the directions of arrows C1 and C2 depending on the stacking height of the sheets stacked on the stacking section 101. A pickup roller 111 that feeds the uppermost sheet is provided at the tip of the pickup arm 112. A driving force from the conveyance motor 6 is transmitted to the pickup roller 111 via the drive shaft 113 and an idler gear (not shown). The pickup roller unit 110 is also provided with a biasing member (not shown) that biases the pickup arm 112 in the direction of arrow C1. When the pickup roller unit 110 is in a standby state, the biasing member presses the pickup roller 111 against the sheet with a predetermined biasing force. The pickup roller 111 is positioned so as to abut against the sheet at the center of the sheet in the width direction.

[0022] The separator 120 separates the top sheet from the other sheets among the sheets stacked on the stacker 101. FIGS. 4(a) to 5(c) are diagrams illustrating the structure of the separator 120. The separator 120 is disposed on the downstream side of the stacker 101 in the sheet feeding direction (the arrow Y1 side). The separator 120 is provided with an inclined surface member 121 and a separation piece 122. The inclined surface member 121 has an inclined surface that forms an obtuse angle with respect to the sheet feeding direction (the arrow Y1 direction) so as to apply a predetermined separation resistance force to the sheets. A plurality of arc-shaped protrusions 122a are formed continuously at a predetermined pitch in the vertical direction on the upper surface of the separation piece 122 (FIG. 4(b)). Valleys 122b are formed between the protrusions 122a. The separation piece 122 is movable in the directions of arrows Y1 and Y2 along a guide portion 123 provided on the inclined surface member 121 (FIGS. 5(a) and 5(b)). In the standby state, as shown in FIG. 5(a), the separation piece 122 abuts against Y-direction abutment surfaces 125a and 125b of the inclined surface member 121 due to the biasing force of the biasing member 124 in the direction of arrow Y2, and protrudes from the inclined surface member 121 in the direction of arrow Y2. During sheet feeding, the separation piece 122 is pressed by the sheets on the stacking unit 101, and moves in the direction of arrow Y1. Meanwhile, when the position pressed by the sheets is low, the separation piece 122 rotates about the guide portion 123 as shown in FIG. 5(b), due to the frictional resistance between the guide portion 123 and the separation piece, and the position pressed by the biasing member 124 and the sheets. Furthermore, when the pressed position is high, the separation piece 122 moves in parallel in the Y1 direction as shown in FIG. 5(c).

[0023] <1.1.3. Structure of the transport unit> 6 and 7 will be referred to in addition to Fig. 1 and Fig. 2. Fig. 6 is a perspective view of the conveying section 5. Fig. 7 is a schematic view of the conveying section 5 and the conveying path CP.

[0024] The conveying section 5 includes a conveying roller 51, a pinch roller 52, a discharge roller 53, and a spur 54. and , and an intermediate roller pair 3.

[0025] The conveying roller 51 conveys the sheet along the conveying path CP. The conveying roller 51 also conveys the sheet to a recording position by the recording unit 7. The pinch roller 52 is provided opposite the conveying roller 51. The discharge roller 53 and the spur 54, which face each other, discharge the sheet onto the discharge tray 81. The intermediate roller pair 3 is made up of intermediate rollers 3a and 3b, which face each other. The intermediate roller 3a is provided between the conveying roller 51 and the pickup roller 111 on the conveying path CP.

[0026] As described above, in this embodiment, the conveying motor 6 drives various rollers that constitute the feeding unit 2 and the conveying unit 5. In other words, a single drive source is used to convey sheets in the recording device 1. Furthermore, the pickup roller 111, the intermediate roller 3a, the conveying rollers 51, and the discharge rollers 53 are all rotated by a drive train that is connected to the conveying motor 6 as a drive source. This will be described in detail below.

[0027] The conveying roller 51 and the discharge roller 53 are connected to the conveying motor 6 by a gear train 37, and when the conveying motor 6 drives the conveying roller 51 in the direction of arrow A in the figure, the conveying roller 51 and the discharge roller 53 each rotate in a direction to convey the sheet downstream in the conveying direction. When the conveying motor 6 drives the conveying roller 51 in the direction of arrow B in the figure, the conveying roller 51 and the discharge roller 53 each rotate in a direction to convey the sheet upstream in the conveying direction.

[0028] The conveying roller 51 and the input gear 33 of the feeding unit 2 are connected by a gear train (not shown), and when the conveying roller 51 rotates in the direction of the arrow A, the input gear 33 of the feeding unit 2 rotates in the direction of A in Fig. 6, i.e., in the direction for performing the feeding operation. When the conveying roller 51 rotates in the direction of the arrow B, the input gear of the feeding unit 2 rotates in the direction of B in Fig. 6, i.e., in the direction for performing the feeding preparation operation. The drive amount of the conveying motor 6 is detected by a conveying encoder 813 (see Fig. 8), and the speed and drive amount of the conveying motor 6 are controlled by performing various controls such as PID control.

[0029] Next, a description will be given of the sheet transport path CP of the recording apparatus 1. The sheet fed by the pickup roller 111 of the feeding section 2 passes through the point CP in FIG. With lines The sheet passes through the conveying path CP shown in FIG. 1, is first guided by the inclined surface member 121 and the U-turn member 131, and is conveyed to the intermediate roller pair 3. The sheet further conveyed by the intermediate roller pair 3 is guided by the pinch roller holder 55 and the guide portion 56, and is fed to the conveying roller 51.

[0030] The sheet fed to the transport rollers 51 undergoes skew correction and other operations before being transported to a recording position by the recording unit 7. The recording unit 7 records on the sheet that has been transported to the recording position. The sheet transported from the transport rollers 51 is guided by a platen 58 and a spur base 59, and then reaches the discharge rollers 53. During the recording operation, the sheet is transported by the transport rollers 51, the discharge rollers 53, or both, and after the recording operation is completed, the sheet is discharged onto a discharge tray 81 by the discharge rollers 53. The platen 58 also guides the sheet so as to maintain a constant distance between the sheet transported to the recording unit 7 and the nozzles.

[0031] In this embodiment, the curved section CP1 of the conveying path CP is formed by the inclined surface member 121 and the U-turn member 131. That is, the inclined surface member 121 and the U-turn member 131 are an example of a path forming member that forms the curved section CP1 of the conveying path CP. In this embodiment, the section CP1 forms a reversing path that reverses the traveling direction of the sheet.

[0032] An edge detection lever 57 is also provided on the pinch roller holder 55. When the sheet passes through the conveying path CP, the edge detection lever 57 is rotated to detect the leading and trailing edge positions of the sheet. That is, the sheet is detected at a detection position on the conveying path. For example, if the edge detection lever 57 detects the leading edge position of the sheet during a feeding operation and detects the trailing edge position during a recording operation or a discharging operation, the actual length of the sheet can be measured based on the amount of drive of the conveying motor 6 required to detect the leading and trailing edge positions. Note that, although an example is shown here in which the edge of the sheet is mechanically detected by the edge detection lever 57, the edge of the sheet may also be detected optically by a photosensor or the like.

[0033] When performing the continuous feeding operation described later, after the trailing end of the preceding sheet passes the pickup roller 111, the subsequent sheet is fed by the pickup roller 111 at a predetermined interval due to a delay in the gear train or the like, thereby performing the continuous feeding operation.

[0034] <1.1.4. Control Configuration> FIG. 8 is a block diagram showing the control configuration of the recording device 1. The control unit 802 comprehensively controls the recording device 1. The control unit 802 is, for example, a CPU (Central Processing Unit). The storage unit 803 includes a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The ROM stores various programs. The RAM provides a system work memory for the CPU acting as the control unit 802 to operate, and is also used to temporarily store various data. For example, the CPU acting as the control unit 802 reads out a program stored in the ROM included in the storage unit 803 from the RAM included in the storage unit 803 and executes it, thereby realizing various functions of the recording device 1. The non-volatile storage unit 804 is, for example, an HDD (Hard Disk Drive), and stores various programs, data, etc.

[0035] The operation unit 805 accepts operation inputs from the user. The operation unit 805 may include, for example, a touch panel or hard keys. For example, the control unit 802 controls the operation of the recording device 1 in accordance with the operation content of the operation unit 805 by the user, i.e., the instruction content. The control unit 802 can also accept instructions regarding the operation of the recording device 1 from an input device 801 such as a PC or smartphone. Furthermore, the display unit 806 displays various types of information.

[0036] The control unit 802 also acquires the detection results of the edge detection lever 57, the stacking detection sensor 808, and the conveyance encoder 813, and controls the conveyance motor 6 and the recording unit 7 based on these detection results. The control unit 802 controls the operation of the conveyance motor 6, thereby driving various rollers included in the feeding unit 2 and the conveyance unit 5. The stacking detection sensor 808 detects the stacking state of sheets in the stacking unit 101. The conveyance encoder 813 detects the drive amount of the conveyance motor 6.

[0037] An overview of the control of the carry motor 6 will now be given. In this embodiment, the carry motor 6 is a DC motor, and the control unit 802 controls the DC motor using a PWM value. For example, the control unit 802 controls the power (PWM value) supplied to the carry motor 6 in accordance with load fluctuations so that the carry motor 6 rotates at a target rotation speed. At this time, the control unit 802 adjusts the PWM value based on the difference between the actual rotation speed of the carry motor 6 based on the detection result of the carry encoder 813 and the target rotation speed of the carry motor 6. Furthermore, in a continuous feeding operation described below, the control unit 802 switches the drive control of the carry motor 6 in accordance with the position of the sheet S2 at the start of the conveying operation.

[0038] FIG. 9 is a diagram showing the control configuration of the carry motor 6. In this embodiment, the control unit 802 controls the carry motor 6 by servo control. For example, the control unit 802 reads out and executes a program stored in the storage unit 803, thereby realizing the functions of a target position generation unit 301, a PID (Proportional-Integral-Differential) calculation unit 302, a PWM (Pulse Width Modulation) generation unit 303, a speed information calculation unit 304, and a position information calculation unit 305. Alternatively, a dedicated circuit that functions as each unit may be provided. 9 The servo control shown in is merely an example, and other control modes may also be used.

[0039] The target position generation unit 301 generates, for each servo control, a target position that gradually increases with time up to the target stop position of the conveyance motor 6. The target position is, for example, the position at which recording by the recording head 71 starts on the sheet 201.

[0040] PID calculation unit 302 calculates the energy to be applied to the motor by PID calculation from the target position generated by target position generation unit 301, the motor speed obtained from speed information calculation unit 304, and the motor position obtained from position information calculation unit 305. In servo control, a method using PID calculation that performs calculations on a proportional term P, an integral term I, and a differential term D is common.

[0041] The PWM generation unit 303 calculates a PWM value to be set in the motor driver 104 from the calculation result of the PID calculation unit 302. The PWM value is the time ratio of the pulse width between on and off within a predetermined time, and ranges from 0% to 100%. The larger the PWM value, the greater the power supplied to the motor.

[0042] The speed information calculation unit 304 calculates the rotation speed of the carry motor 6 from the rotation angle of the carry motor 6 based on the detection result of the carry encoder 813 and the time measurement value of a timer or the like built into the recording apparatus 1.

[0043] The position information calculation unit 305 accumulates the rotation angle of the carry motor 6 based on the detection result of the carry encoder 813 and calculates the position information of the carry motor 6 .

[0044] In this way, using the detection results of the conveyance encoder 813, the speed information calculation unit 304 calculates the speed of the conveyance motor 6, and the position information calculation unit 305 calculates the position information of the conveyance motor 6. The conveyance encoder 813 is made up of an optical sensor having a light-emitting unit that emits light and a light-receiving unit that receives light, and a code wheel with a hole that transmits light. The code wheel is attached coaxially with the rotation axis of the conveyance motor 6. The encoder may also be configured to detect the physical rotation of the conveyance roller 51.

[0045] <1.2. Recording operation overview> FIG. 10 is a flowchart showing an outline of the recording operation in the recording device 1.

[0046] In S101, the control unit 802 receives a recording instruction from the user via the operation unit 805 or the input device 801.

[0047] In S102, the control unit 802 performs a feeding operation. The control unit 802 drives the feeding unit 2 by the conveying motor 6 to feed the uppermost sheet of the sheets stacked in the stacking unit 101 to the conveying unit 5. In S103, the control unit 802 performs a recording operation by the recording unit 7 on the sheet conveyed to the conveying unit 5. Here, the recording head 71 performs a recording operation for one pass while moving in the width direction of the sheet.

[0048] In S104, the control unit 802 determines whether or not the next printing is to be performed by the next printing unit 7. The next printing here refers to one more pass of printing that is to be performed after the sheet on which one pass of printing has been performed in S103 has been fed a predetermined amount. pathIf printing is to be performed on the entire printing area of ​​the sheet, the process proceeds to S105, otherwise the process proceeds to S107. For example, the control unit 802 proceeds to S107 if printing is to be performed on the entire printing area of ​​the sheet.

[0049] In S105, the control unit 802 executes a continuous feeding determination operation. As will be described in detail later, when the control unit 802 determines that a continuous feeding operation should be performed, the control unit 802 conveys the sheet being recorded and the subsequent sheets using the conveyance motor 6, which is a common drive source. On the other hand, when the control unit 802 determines that a continuous feeding operation should not be performed, the control unit 802 conveys only the sheet being recorded.

[0050] In S106, the control unit 802 executes a printing operation on the sheet. Here, as in S103, the printing head 71 performs a printing operation for one pass while moving in the width direction of the sheet.

[0051] After the printing operation in S106, the control unit 802 returns to S104. That is, the control unit 802 repeats S104 to S106 to print over the entire printing area of ​​the sheet.

[0052] In S107, the control unit 802 performs a discharge operation. The control unit 802 drives the discharge roller 53 by the conveyance motor 6 to discharge the printed sheet onto the discharge tray 81. Thereafter, the control unit 802 ends the printing operation. 10 Although the printing operation for one sheet is shown, the control unit 802 repeats this flowchart until printing of all pages included in the printing job is completed.

[0053] If the control unit 802 detects an abnormality with the edge detection lever 57, the stack detection sensor 808, the conveyance encoder 813, or the like during execution of the above flow, it displays an error message and / or instructions to the user on the display unit 806. Examples of the content of the error include a paper jam error, an out-of-paper error, and an out-of-ink error.

[0054] FIG. 11 is a diagram illustrating the conveying operation for each pass in the printing operation. By repeating the processing of the flowchart in FIG. 10, the control unit 802 repeatedly conveys the sheet 201 as a sheet and prints on the entire printing area of ​​the sheet 201 across the width of the print head 71, thereby performing printing on the entire printing area of ​​the sheet 201. First, at timing t_1, the conveying unit 5 conveys the sheet 201 so that the leading edge of the sheet 201 in the conveying direction falls within the printing width of the print head 71. Then, the print head 71 prints on the printing area 701 (S103). Thereafter, at timing t_2, the conveying unit 5 conveys the sheet 201 so that the upstream edge of the printing area 701 in the conveying direction at timing t_1 is positioned at the downstream edge of the printing width of the print head 71 (S105). Then, the print head 71 prints on the printing area 702 (S106). Furthermore, at timing t_3, the conveying unit 5 conveys the sheet 201 so that the upstream end of the recording area 702 at timing t_2 in the conveying direction is positioned at the downstream end of the recording width of the recording head 71 (S105). Then, the recording head 71 performs recording on the recording area 703 (S106). By repeating this operation, it is possible to perform recording on the entire recording area of ​​the sheet 201.

[0055] <1.3. Conveyance control (feed control and holding control)> <1.3.1. Return of sheet when transport stops> When the sheet 201 is repeatedly conveyed and stopped for each recording width during the recording operation as described above, a force (reaction force) in the opposite direction to the conveying direction may be applied to the sheet. This reaction force may be generated, for example, when a force in the opposite direction to the conveying direction is applied to the rollers of the conveying unit 5 due to twisting of a drive transmission member that transmits the drive of the conveying unit 5, or when the sheet 201 is stopped due to resistance of a member of the conveying unit 5. This reaction force may cause the stopped sheet 201 to return in the opposite direction to the conveying direction. If the sheet 201 is returned, there is a risk that the area on the sheet 201 where recording is desired and the area where recording is actually performed will not match in the conveying direction. This may cause a decrease in recording quality. Therefore, in this embodiment, conveyance control is performed using the following process to prevent the stopped sheet 201 from being returned in the opposite direction to the conveying direction.

[0056] <1.3.2. Example of transport control processing> FIG. 12 is a flowchart showing an example of processing performed by the control unit 802 in the transport control. 9 The conveyance control of the sheet 201 is performed by controlling the conveyance motor 6 at regular intervals by the servo control. In this embodiment, the conveyance control includes feed control for conveying the sheet 201 a predetermined distance and hold control for stopping the sheet at a target position and holding the sheet at that position. In other words, the control unit 802 can execute feed control and hold control. Furthermore, this flowchart shows the flow until recording by the recording head 71 on one sheet 201 is completed.

[0057] In S401, the control unit 802 executes feed control of the sheet 201. For example, the control unit 802 executes the servo control of FIG. 10 at each control cycle of the conveyance motor 6 to operate the conveyance motor 6, thereby conveying the sheet 201, such as paper, to a recording position. For example, the feed control can be executed when conveying the sheet 201 from the cassette 100 to a recording start position below the recording unit. Also, for example, the feed control can be executed when conveying the sheet 201 by a distance equivalent to one pass of the recording head 71 during recording processing.

[0058] In S402, the control unit 802 acquires a PWM value Pt. The control unit 802 acquires the current PWM value of the carry motor 6 as the PWM value Pt. The control unit 802 stores the acquired PWM value Pt in a storage area of ​​the storage unit 803. Note that if the PWM value Pt has already been stored in the storage unit 803, the control unit 802 updates the value stored in the storage unit 803 to the currently acquired value.

[0059] In S403, the control unit 802 determines whether the sheet 201 has reached the end position of the feed control. If the end position has been reached, the control unit 802 proceeds to S404, and if not, returns to S401. The end position of the feed control is a position different from the target stop position described below, and specifically, is a position a predetermined distance before the target stop position. However, a configuration can also be adopted in which the end position of the feed control and the target stop position (before update) described below are set to the same position.

[0060] Furthermore, in this embodiment, steps S401 to S403 are repeated until the sheet 201 reaches the end position of the feed control. Therefore, the control unit 802 proceeds to S404 in a state in which the PWM value Pt of the conveying motor 6 at the time when the sheet 201 reaches the end position of the feed control is stored in the storage unit 803. Note that the control unit 802 may repeat S401 and S403 until the sheet 201 reaches the end position of the feed control, and execute S402 at the time when the sheet 201 reaches the end position of the feed control. In other words, the order of S402 and S403 may be reversed.

[0061] In S404, the control unit 802 executes hold control for the sheet 201. The hold control is control for stopping the rotating conveyance motor 6 at a target position and holding the conveyance motor 6 at the stop position. When conveying the sheet 201, a force in the direction opposite to the conveyance direction may be applied to the conveyance rollers 51 due to external forces such as resistance of components of the conveyance mechanism. Therefore, if servo control is terminated after the sheet 201 reaches the stop position, the conveyance motor 6 may be returned from the stop position in the reverse direction (the rotation direction opposite to that when conveying the sheet 201 in the conveyance direction). Therefore, in this embodiment, by executing hold control to control the conveyance motor 6 even after the stop position is reached, the position of the conveyance motor 6 is prevented from being returned due to an external force. As will be described in detail later, in this hold control, the control unit 802 determines the PWM value of the conveyance motor 6 according to the PWM value Pt acquired in S402, thereby controlling the conveyance motor 6 with an appropriate output value that takes into account the external force acting on the conveyance rollers 51.

[0062] In S405, the control unit 802 checks whether recording has been completed for the entire recording range of the sheet 201, and if so, proceeds to S406; if not, returns to S401. That is, the control unit 802 alternately executes feed control and hold control until recording has been completed for the entire recording range of the sheet 201. In other words, after the end of feed control, hold control is executed for the period until the start of the next feed control.

[0063] In S406, the control unit 802 ejects the sheet 201 from the recording apparatus 1 after the printing has been completed.

[0064] According to the process described above, the holding control is performed, and the sheet 201 can be conveyed intermittently by a predetermined distance while suppressing the return of the sheet 201 due to the reverse rotation of the conveying motor 6 when it is stopped.

[0065] <1.3.3. Determining the motor output value in holding control> Next, a description will be given of the determination of the output value of the carry motor 6 in the hold control, which is a feature of this embodiment. Figures 13(a) and 13(b) are diagrams showing an example of changes in speed and PWM value when switching from feed control to hold control.

[0066] The transport operation in feed control is divided into an acceleration section in which the transport motor 6 accelerates each transport roller of the transport section 5, a constant speed section in which the transport motor 6 rotates at a constant speed, and a deceleration section in which the transport motor 6 decelerates. Note that Figs. 13(a) and 13(b) show the deceleration section and holding control of the feed control. Also, the PWM value of the transport motor 6 during feed control is set to the PWM value shown in Figs. 13(a) and 13(b) so that the actual rotation position or rotation speed of the transport motor 6 matches the command rotation position or rotation speed. 9 The PID calculation unit 302 calculates the PID and the PWM generation unit 303 generates the PWM.

[0067] At this time, the PID calculation unit 302 performs calculations so that the conveyance motor 6 rotates at the commanded rotation speed while taking into account the drive load of the conveyance mechanism itself and the conveyance load of the sheet being conveyed. The results are shown in Figures 13(a) and 13(b). The conveyance load of the sheet being conveyed has characteristics that vary depending on the contact state between the conveyance guide and the sheet within the conveyance path. In other words, the drive load required by the motor at the end of the deceleration section varies depending on the position of the conveyed sheet, and therefore varies for each pass. Therefore, the PWM value of the conveyance motor 6 required at the end of the feed control also varies.

[0068] On the other hand, as mentioned above, when the feed operation ends, the carry motor 6 may be rotated in the reverse direction by an external force. More specifically, this external force occurs when the torsion of a drive transmission member (not shown), which drives while dragging a drive load, is released toward the carry motor 6 when the motor stops. This fluctuation is particularly significant when the carry roller 51 connected to the carry motor 6 is further connected to an upstream carry member, such as the intermediate roller 3a or the pickup roller 111. This fluctuation can cause the PWM value when transitioning from feed control to hold control to deviate from the PWM value required to hold the carry motor 6. For example, if the PWM value of the carry motor 6 during hold control is set to a constant value, depending on the magnitude of the external force, the motor torque may be insufficient, causing the motor to rotate in the reverse direction, or excessive motor torque may cause the motor to rotate in the forward direction.

[0069] Therefore, in this embodiment, the conveying motor 6 is rotated at the command speed at the end of the feed control. Turned over The PWM value at the start of the holding control is adjusted based on the PWM value required to hold the paper. This brings the PWM value of the carry motor 6 closer to an appropriate PWM value according to the external force at that time, making it possible to prevent the motor from rotating in the reverse direction or excessively in the forward direction.

[0070] Specifically, the PWM value Pt at the end position of the feed control is subtracted by a constant value Pd to set the PWM value Pi at the start of the hold control. That is, the initial PWM value Pi of the hold control is set as follows: Pi=Pt-Pd (formula 1) However, Pd>0 The PWM value Pt increases as the external force applied to the carry motor 6 at the end of the feed control increases, and therefore the initial PWM value Pi also increases as the external force applied to the carry motor 6 at the end of the feed control increases. Therefore, by determining the initial PWM value Pi for the hold control in accordance with the final PWM value Pt, the output value of the carry motor 6 during the hold control can be determined more appropriately. This makes it possible to prevent the motor from rotating in reverse due to insufficient motor torque or rotating forward due to excessive motor torque during the hold control. In other words, the motor output during the hold control, which holds the motor at a stopped position, can be controlled more appropriately than before.

[0071] In this embodiment, an example has been shown in which the initial PWM value Pi is determined by subtracting a constant value Pd from the PWM value Pt when the end position of the feed control is reached. However, the initial PWM value Pi may also be determined by dividing the PWM value Pt by a constant value Pd2. That is, Pi=Pt / Pd2 (formula 2) However, Pd2>1 That is, an initial PWM value Pi smaller than the PWM value Pt may be determined by performing a predetermined calculation on the PWM value Pt. For example, in this embodiment, the initial PWM value Pi is calculated by subtracting a constant value Pd from the PWM value Pt, but the value subtracted from the PWM value Pt may vary depending on the type, size, thickness, basis weight, etc. of the sheet.

[0072] Furthermore, in this embodiment, the control unit 802 acquires the PWM value of the carry motor 6 when the end position of the feed control is reached as the PWM value Pt at the end of the feed control. However, other methods can be used to acquire the PWM value Pt. For example, the control unit 802 may acquire, as the PWM value Pt, the average value of the PWM values ​​generated by the PWM generation unit 303 over a predetermined number of control cycles until the end position of the feed control is reached. In other words, the PWM value Pt at the end of the feed control may be based on PWM values ​​over a predetermined period including the end of the feed control. Furthermore, the PWM value Pt at the end of the feed control may be acquired so that the load acting on the carry motor 6 during the hold control can be determined based on the transport load acting on the carry motor 6 during the feed control.

[0073] <1.3.4. Specific examples of retention control> Next, the retention control will be further described. Fig. 14 is a flowchart showing an example of processing by the control unit 802, and shows a specific example of S404 (retention control) in Fig. 12.

[0074] In S501, the control unit 802 initializes parameters used in the hold control. In this way, the control unit 802 initializes the target position every time hold control is executed. In this embodiment, the parameters to be initialized are the target stop position pos_t, the number of consecutive stops cnt_c, and the number of hold control continuations cnt_k.

[0075] The target stop position pos_t is a target stop position in the hold control, and is initialized to a value obtained by adding a predetermined value to the end position of the feed control used in S403 of FIG. 12. The target stop position pos_t is used in the hold servo control in S508, which will be described later. The number of consecutive stops cnt_c is the number of times the motor continues to have a rotation speed below the threshold, and is initialized to 0. The number of consecutive stops cnt_c is used in S505 and S506, which will be described later. The number of hold control continuations cnt_k is the number of times the hold state continues, and is initialized to 0. The number of hold control continuations cnt_k is used in S503, which will be described later.

[0076] In S502, the control unit 802 performs holding servo control based on the target stop position pos_t calculated in S501. Here, control for one control cycle is performed to position the carry motor 6 at the target position.

[0077] In S503, the control unit 802 determines whether or not the end condition of the holding servo control is satisfied. If satisfied, End the process If not, proceed to S504. In this embodiment, if any one of the following three conditions, condition A, condition B, or condition C, is met, it is determined that the end condition of the retention control is met. When the next feed control command is received (Condition A) When the difference between the current motor position and the target stop position is greater than or equal to the threshold value th_p (Condition B) When the continuous operation time of the holding control is equal to or greater than the threshold th_k (Condition C) Each condition will be explained below.

[0078] Condition A is a condition for performing the next feed control. When an instruction for the next feed control is received, the holding control is ended and the feed control for the next transfer is started.

[0079] Condition B is a condition for preventing the hold control from interfering with an operation such as removing the sheet 201 when such an operation occurs. Because the hold control is a control for maintaining the rotational position of the motor, when the hold control is activated, it may be difficult to remove the sheet 201. In this embodiment, when the current position pos_n, the target position p_t, and the threshold th_p satisfy the following formula 3, it is determined that an external force greater than the external force thought to be the cause of returning the stop position (for example, a force attempting to pull out the sheet 201) has been received, and the hold control is terminated. Furthermore, the threshold th_p is a value set based on the external force expected during transport, and when the hold control is normally activated, the following formula 3 is not satisfied. pos_t>pos_n + th_p (Formula 3) In this way, when the stopped carry motor 6 rotates by the threshold value th_p or more, the control unit 802 ends the holding control even before the start of the next feed control.

[0080] Condition C is a condition for preventing the hold control from continuing even if an abnormality or the like occurs in the device. The hold control in this embodiment is a process for applying power to the motor. Therefore, without condition C, even if an abnormality or the like occurs in the device, if the above-mentioned conditions A and B continue not to be satisfied, power will continue to be applied to the motor, increasing the load on the motor. In this embodiment, if the hold control continuation count cnt_k and the threshold th_k satisfy the following formula 4, it is determined that normal hold control is not being performed, and the hold control is terminated. Furthermore, the threshold th_k is a value that does not satisfy the following formula 4 when the hold control is operating normally. Therefore, for example, the threshold th_k is set to be longer than the period during which the carriage 72 and the print head 71 perform one pass of printing operation. cnt_k>th_k (Formula 4) In this way, if the stop state of the carry motor 6 continues for a predetermined time or longer, the control unit 802 ends the holding control even before the start of the next feed control.

[0081] As described above, in a normal state, the control unit 802 ends the holding control based on an instruction to start the next feed control. On the other hand, when a predetermined condition is satisfied, the control unit 802 ends the holding control even before the start of the next feed control.

[0082] In S504, the control unit 802 determines whether the rotation speed of the carry motor 6 is equal to or less than the threshold value th_s, and if it is equal to or less than the threshold value th_s, the process proceeds to S505, and if it is not equal to or less than the threshold value th_s, the process proceeds to S510. That is, if the rotation speed spd_n of the carry motor 6 and the threshold value th_s satisfy the following formula 5, the control unit 802 proceeds to S505, and if not, the process proceeds to S510. spd_n≦th_s (Equation 5) Here, the control unit 802 makes this determination to determine whether the carry motor 6 is (substantially) stopped. Therefore, the threshold value th_s is set to a value close to 0 or to 0 so that it can be determined that the carry motor 6 is stopped.

[0083] In S505, the control unit 802 updates the number of consecutive stops cnt_c using the following formula 6. cnt_c=cnt_c+1 (Formula 6)

[0084] In S506, the control unit 802 determines whether the number of consecutive stops cnt_c is equal to or greater than a threshold value th_c. If it is equal to or greater than the threshold value th_c, the process proceeds to S507; if it is not equal to or greater than the threshold value th_c, the process proceeds to S502. The threshold value th_c is a value that can be used to determine that the carry motor 6 has stopped. That is, the control unit 802 can determine that the carry motor 6 has stopped when the state in which the rotation speed is equal to or less than the threshold value th_s continues for a predetermined period of time. If the number of consecutive stops cnt_c is less than the threshold value th_c, the state in which the rotation speed of the carry motor 6 is equal to or less than the threshold value th_s has not continued long enough to determine that the carry motor 6 has stopped, and therefore servo control continues.

[0085] In S507, the control unit 802 updates the target stop position pos_t. That is, the control unit 802 updates the target stop position pos_t to the current position where the carry motor 6 has been stopped (where the rotational speed is equal to or less than the threshold value th_s) for a predetermined period of time. The position where the carry motor 6 has been stopped is considered to be a position where the driving force of the carry motor 6 is balanced with the external force during conveyance. Therefore, if it is determined in S506 that the number of consecutive stops cnt_c is equal to or greater than the threshold value th_c, it can be considered that the drive force of the carry motor 6 is balanced with the external force and has stopped. In this way, the control unit 802 updates the target position to the current position based on the rotational speed of the carry motor 6 while the hold control is being performed.

[0086] Note that updating the target stop position pos_t in this step may result in a difference between the target stop position pos_t before the update and the actual stop position. However, by setting the servo control parameters so that the feed control reaches the feed control end position in the feed control of S401 and stops the feed motor 6 at a gentle speed, the difference between the actual stop position and the target stop position pos_t becomes small enough to not affect the recording results. In other words, the control unit 802 may decelerate the rotation speed of the carry motor 6 to a threshold value or less in the feed control before transitioning to the hold control.

[0087] In S508, the control unit 802 performs holding servo control (holding control) based on the target stop position pos_t updated in S507. Here, control is performed for one control cycle to position the carry motor 6 at the target position. However, due to the steps up to this point, the carry motor 6 is already stopped at the updated target stop position pos_t, which is a position that balances with the external force during carry. Therefore, the control unit 802 performs servo control to hold the position of the carry motor 6 at the updated target stop position pos_t. At this time, the control unit 802 controls the drive of the carry motor 6 using the initial PWM value Pi determined by the above-mentioned equation 1. Note that the initial PWM value Pi can be determined at a predetermined timing. For example, the control unit 802 may determine (update) the initial PWM value Pi at the timing when the PWM value Pt is acquired in S402 of FIG. 12. Furthermore, for example, the control unit 802 may determine (update) the initial PWM value Pi based on the PWM value Pt stored in the storage unit 803 at the timing of parameter initialization in S501.

[0088] In S509, the control unit 802 determines whether or not the termination condition of the holding control is satisfied. If the termination condition is satisfied, End the process If not, the process returns to S508. The process in this step is the same as S503. Furthermore, through S508 and S509, the position of the carry motor 6 is maintained at the updated target stop position pos_t until the termination condition is met.

[0089] On the other hand, when the process proceeds from S504 to S510, the control unit 802 updates the number of consecutive stops cnt_s to 0. That is, since it was determined in S504 that the motor was not stopped, the number of consecutive stops cnt_s is set to 0 and counting is started again.

[0090] 15(a) and 15(b) are diagrams showing a comparison between a case where the holding control of this embodiment is executed and a case where it is not executed.

[0091] FIG. 15(a) shows the change in motor position over time when the hold control of this embodiment is not performed, i.e., when the stop position is returned by an external force. When motor control ends after reaching the feed control end position, the conveyance motor 6 rotates a predetermined amount by inertia and then stops temporarily. However, an external force may cause the conveyance motor 6 to return from that stop position. When the rotation position of the conveyance motor 6 is returned in this manner, the sheet 201 moves backward in the opposite direction to the conveyance direction. As a result, printing may be performed at a position on the sheet 201 that is different from the intended printing position, resulting in an undesired printing result. For example, in FIG. 11, the area printed at timing t_1 and the area printed at timing t_2 may overlap in the conveyance direction. This overlap may result in streaks. In this way, if the conveyance motor 6 does not stop at the desired stop position in the recording device 1, degradation of the image quality of the printed product may occur.

[0092] 15(b) is a diagram showing the change in motor position over time when holding control is performed in this embodiment. The position where the motor remains stopped for the threshold value th_c is the position where the external force during conveyance is balanced. Therefore, by performing holding servo control with this position as the updated target stop position pos_t, the rotational position of the conveyance motor 6 can be maintained without the conveyance motor 6 rotating in the reverse direction.

[0093] 16(a) and 16(b) are diagrams showing a further comparison between the case where the holding control of this embodiment is performed and the case where it is not performed.

[0094] 16(a) shows a case where the hold control of this embodiment is not executed, and the deviation between the current position of the carry motor 6 and the target stop position is fed back to the position control of the carry motor 6 so that the carry motor 6 stops at the target stop position. In this case, when the carry motor 6 stops beyond the target stop position, the carry motor 6 is controlled to rotate in the reverse direction to stop the carry motor 6 at the target stop position. The reverse rotation of the carry motor 6 may cause the sheet 201 to bend. Alternatively, the repeated forward and reverse rotation of the carry motor 6 may cause backlash in the power transmission system.

[0095] FIG. 16(b) is a partially enlarged view of FIG. 15(b), showing the change in motor position over time when the hold control of this embodiment is performed. In this embodiment, even if the carry motor 6 exceeds the target stop position, the target position is updated to the point at which the carry motor 6 stops. Therefore, the hold control operates to maintain the current position at which the carry motor 6 is stopped. This makes it possible to suppress the reverse rotation of the carry motor 6 as shown in FIG. 10(a).

[0096] As described above, according to this embodiment, by executing hold control when the carry motor 6 is stopped, it is possible to suppress rotation of the carry motor 6 in the direction opposite to the carry direction due to an external force. Then, by updating the target stop position pos_t to the current position based on the rotation speed of the carry motor 6 while the hold control is being executed, it is possible to suppress rotation of the carry motor 6 in the direction opposite to the carry direction due to the control. Therefore, in the stop operation of the carry motor 6 for carrying the sheet 201, it is possible to suppress rotation in the direction opposite to the carry direction.

[0097] In this embodiment, by performing holding control with an output (PWM value) according to the external force during conveyance, more specifically near the end of feed control, it becomes possible to improve stopping accuracy during conveyance without the conveyance motor 6 rotating in the opposite direction to the conveyance direction.

[0098] In the present embodiment, a method for updating the target stop position in the hold control is exemplified. However, it is sufficient that the initial PWM value Pi is determined based on the PWM value Pt, and the hold control method at that time, more specifically, the method for moving the sheet from the end position of the feed control to the target stop position is not limited to the above-described method.

[0099] <1.4. continuous Application of initial PWM value Pi during holding control in feeding operation> The initial PWM value Pi in the above-described hold control can be applied to a continuous feeding operation. In this embodiment, the continuous feeding operation refers to an operation in which the transport operation of the sheet being recorded (hereinafter, sometimes referred to as sheet S1) and the transport (feed) operation of the next sheet (hereinafter, sometimes referred to as sheet S2) are performed in parallel. This continuous feeding operation allows the recording operation of sheet S2 to proceed quickly after the recording operation of sheet S1 is completed, thereby shortening the time required to record on multiple sheets.

[0100] On the other hand, in a continuous feeding operation, the torque required during feeding may vary depending on the position of the sheet S2 on the conveying path CP. For example, when viewed from the direction shown in FIG. 7, when the leading edge of the sheet S2 in the conveying direction is located in a curved section of the conveying direction, the torque required may be relatively larger than when the leading edge is located in a straight section. If the required torque is large, the conveying motor 6 may experience a torque shortage, which may reduce the accuracy of conveying control or stop the drive of the conveying motor 6. Therefore, in this embodiment, the continuous feeding operation is performed while suppressing the occurrence of a torque shortage according to the following flowchart. Then, the initial PWM value Pi is applied in the maintenance control during this continuous feeding operation.

[0101] <1.4.1. Example of processing by the control unit in continuous feeding operation> FIG. 17 is a flowchart showing the continuous feeding operation in the recording apparatus 1. 10 1 shows a specific example of the process of S105.

[0102] In S201, the control unit 802 determines whether the conditions for performing the continuous feeding operation are met, and if so, proceeds to S203; if not, proceeds to S202. For example, depending on the size, thickness, material, basis weight, and conveying speed during printing of the sheet, the torque required to convey a single sheet may be large, making it inappropriate to perform the continuous feeding operation. Therefore, the control unit 802 determines whether to perform the continuous feeding operation based on information such as the sheet size, type, and conveying speed setting during printing acquired from the printing job or setting information of the recording device 1 stored in the memory unit 803, etc.

[0103] In S202, the control unit 802 cuts off the transmission of drive force from the conveyance motor 6 to the pickup roller 111. After that, the control unit 802 proceeds to S206. That is, the control unit 802 switches from a transmission state in which drive force is transmitted from the conveyance motor 6 to the pickup roller 111 to a non-transmission state in which drive force is not transmitted from the conveyance motor 6 to the pickup roller 111.

[0104] In S203, the control unit 802 identifies the leading edge position of the succeeding sheet S2. In this embodiment, the control unit 802 identifies the leading edge position of the succeeding sheet S2 using the detection result of the edge detection lever 57. Specifically, the control unit 802 identifies the leading edge position of the sheet S2 based on the leading edge position of the sheet S1 identified by the edge detection lever 57, the length of the sheet S1 in the conveying direction, and the distance between the rear edge of the sheet S1 and the leading edge of the sheet S2 in the conveying direction.

[0105] More specifically, the control unit 802 first obtains the transport amount d1 of the sheet S1 after the leading edge of the sheet S1 is detected by the edge detection lever 57 from the detection result of the transport encoder 813. Then, the control unit 802 calculates the distance L1 from the detection position of the edge detection lever 57 to the trailing edge of the sheet S1 from the transport amount d1 and the sheet length lp. The length lp can be obtained from, for example, a setting value included in the recording job.

[0106] The relationship between the conveyance amount d1, length lp, and distance L1 is expressed as L1 = lp - d1. Using this relationship and the delay amount pp of the gear train described above, the distance L2 from the edge detection lever 57 to the leading edge of the sheet S2 can be expressed as L2 = lp - d1 + pp. With this configuration, the leading edge position P of the sheet S2 can be identified without providing a sensor or the like in the predetermined area A1.

[0107] In S204, the control unit 802 determines whether the stop position P of the leading edge of the sheet S2 is located in the predetermined area A1, and if so, proceeds to S205, otherwise proceeds to S206.

[0108] In this embodiment, the predetermined area A1 is an area based on the sheet transport load. More specifically, the predetermined area A1 is an area where the transport load becomes relatively high during the sheet feeding operation. Specifically, the predetermined area A1 in this embodiment is an area between the pickup roller 111 and the pair of intermediate rollers 3. This is because, when the inclined surface member 121 and the U-turn member 131 are present on the transport path CP from the pickup roller 111 to the pair of intermediate rollers 3 as in this embodiment, the sheet transport load becomes high in the curved section formed by these members. In this regard, in this embodiment, it can be said that the curved section formed by the path forming members such as the inclined surface member 121 and the U-turn member 131 is set as the predetermined area A.

[0109] The area where the transport load is high is not limited to this, depending on the arrangement and number of various rollers and transport guide members. Also, there may be multiple areas where the transport load is high.

[0110] Whether the stop position P of the leading end of the sheet S2 is located in the predetermined area A1 can be determined as follows. That is, let the distance from the end detection lever 57 to the intermediate roller pair 3 be the distance Ps1, and the distance from the end detection lever 57 to the pickup roller 111 be the distance Ps2. At this time, when the distance L2 from the end detection lever 57 to the leading end of the sheet S2 satisfies Ps1 < L2 < Ps2, it can be determined that the stop position is in the predetermined area A1.

[0111] In S205, the control unit 8*2 changes the feed drive table. For example, the control unit 8*2 changes the feed drive table to one with a low acceleration.

[0112] Figure 28 shows an example of the feed drive table. Here, Table 1 is the table used when the continuous feeding operation is not performed or when the leading end position of the sheet S2 is outside the predetermined area A1 even when the continuous feeding operation is performed. Also, Table 2 is the table used when the continuous feeding operation is performed and the leading end position of the sheet S2 is in the predetermined area A1. The control unit 8*2 changes the feed drive table from Table 1 to Table 2. The rotational speed of the conveyance motor 6 during constant-speed rotation in Table 2 is the same as that in Table 1, but the acceleration is set to be smaller than that in Table 1. That is, when the leading end of the sheet S2 is located in the predetermined area A1, the control unit 8*2 switches the drive control of the conveyance motor 6 so that the acceleration of the conveyance motor 6 is smaller than when it is not in that case.

[0113] Here, the control unit 802 changes the acceleration of the conveying motor 6. However, it is sufficient if the drive (output) of the conveying motor 6 is controlled so as to be more limited when the leading edge of the sheet S2 is located in the predetermined area A1 than when the leading edge is not located in the predetermined area A1. For example, the control unit 802 may switch the drive control of the conveying motor 6 so that the rotation speed of the conveying motor 6 is lower when the leading edge of the sheet S2 is located in the predetermined area A1 than when the leading edge is not located in the predetermined area A1. Note that the rotation speed here is the rotation speed during constant rotation after acceleration. Alternatively, the control unit 802 may switch the drive control of the conveying motor 6 so that both the acceleration and rotation speed of the conveying motor 6 are lower when the leading edge of the sheet S2 is located in the predetermined area A1 than when the leading edge is not located in the predetermined area A1.

[0114] In S206, the control unit 802 performs the feeding and conveying operation. Here, if the conditions for performing the continuous feeding operation are not satisfied (S201: No), the transmission of drive to the pickup roller 111 is cut off (S202), so only the conveying operation of the preceding sheet S1 is performed. Also, if the conditions for performing the continuous feeding operation are satisfied (S201: Yes) and the leading edge of sheet S2 is located in the predetermined area A1 (S204: Yes), the feeding drive table is changed and the continuous feeding operation is performed. In other words, the continuous feeding operation is performed with the drive of the conveying motor 6 restricted. Also, if the conditions for performing the continuous feeding operation are satisfied (S201: Yes) and the leading edge of sheet S2 is not located in the predetermined area A1 (S204: No), the continuous feeding operation is performed without changing the feeding drive table. In other words, the continuous feeding operation is performed with the drive of the conveying motor 6 not restricted. Thereafter, the control unit 802 ends the flowchart.

[0115] As described above, in this embodiment, the drive control of the conveying motor 6 is switched depending on the position of the succeeding sheet S2. Therefore, it is possible to perform a continuous feeding operation while suppressing the occurrence of a torque shortage of the conveying motor 6. In other words, it is possible to more effectively control the drive sources that drive the multiple conveying means.

[0116] <1.4.2. Application of initial PWM value Pi according to external force during continuous feed drive> If the above-described continuous feeding operation is performed with a single conveying motor 6, the load when feeding the following sheet S2 will be dragged along when performing feed control for the preceding sheet S1. In other words, in the holding control after feed control for the preceding sheet S1, the fluctuation of the external force applied to the conveying motor 6 will also depend on the position of the following sheet S2 in the conveying path.

[0117] Specifically, when the leading edge of the trailing sheet S2 is located in the conveying area A1, the external force (returning force) becomes large. In particular, when the leading edge of the trailing sheet S2 approaches the deceleration area of ​​the leading sheet S1 at a position where it is caught between the protrusions 122a of the separation piece 122, the external force (returning force) becomes large near the end of the feed control depending on the rigidity of the sheet. Also, when the leading edge of the trailing sheet S2 approaches the U-turn exit of the conveying path and the curvature of the trailing sheet S2 becomes large, and the leading sheet S1 approaches the deceleration area, the external force (returning force) becomes large near the end of the feed control depending on the rigidity of the sheet.

[0118] Therefore, in this embodiment, the conveying motor 6 is rotated at the command speed at the end of the feed control in the conveying area A where the load is high and these phenomena occur. Turn over The PWM value at the start of the holding control is adjusted based on the PWM value required to hold the paper. This brings the PWM value of the carry motor 6 closer to an appropriate PWM value according to the external force at that time, making it possible to prevent the motor from rotating in the reverse direction or excessively in the forward direction.

[0119] Specifically, the initial PWM value Pi for the holding control can be determined based on the above-mentioned formula 1 (or formula 2).

[0120] In addition, when the leading end of the subsequent sheet S2 is not located in the conveyance area A, the PWM value at the end of the feed control becomes relatively low. In such a case, if the result of subtracting a constant value from the PWM value Pt based on Equation 1 causes the initial PWM value Pi to fall below 0, the output value of the conveyance motor 6 in the holding control may be set to zero, and the same control may be executed.

[0121] Also, the constant value Pd in Equation 1 may be changed depending on whether the leading end of the subsequent sheet S2 is located in the conveyance area A or not. Further, the constant value Pd when the leading end of the subsequent sheet S2 is not located in the conveyance area A may be made smaller than the constant value Pd when it is located in the conveyance area A. Alternatively, when the leading end of the subsequent sheet S2 is not located in the conveyance area A, the application of the initial PWM value Pi based on Equation 1 may not be executed.

[0122] Furthermore, depending on the type of the sheet to be conveyed, the speed during conveyance, the ON / OFF setting of the continuous feeding operation, etc., in the case of conveyance where it is difficult to receive an external force, the initial PWM value Pi of the holding control may be changed to a second value Pi2 (<Pi1). Alternatively, in the case of conveyance where it is difficult to receive an external force, the application of the initial PWM value Pi may not be carried out.

[0123] <1.5. PWM value adjustment control during load fluctuation> Subsequently, the adjustment control during load fluctuation during deceleration will be described. In the continuous feeding operation, during the deceleration operation or stop operation of the preceding sheet, the leading end of the subsequent sheet may be caught between the protrusions 122a of the separation piece 122. In this case, depending on the rigidity of the sheet, the leading end of the subsequent sheet may come out of the protrusion 122a near the end part of the feed control. When the leading end of the subsequent sheet comes out of the protrusion 122a, the conveyance load of the conveyance motor 6 may suddenly become lighter.

[0124] 18 is a graph showing changes in the speed and PWM value of the conveying motor 6 when the leading edge of the following sheet leaves the separation piece 122 at timing F while the preceding sheet is decelerating. The vertical axis represents the speed and PWM value of the conveying motor 6, and the horizontal axis represents time. Region A is the acceleration region, region B is the constant speed region, and region C is the deceleration region.

[0125] Graph P shows the command speed during feed control of the preceding sheet. As mentioned above, if normal feed control is maintained (adjustment control OFF) in which fluctuations in the load of the following sheet affect the feed control of the preceding sheet during feed control, the speed of the conveying motor 6 will increase suddenly due to the PWM value just before the load becomes lighter. After that, the control unit 802 reduces the PWM value by servo control to bring the conveying motor 6 closer to the commanded speed, but the speed does not decrease by the time the target position is reached, and the speed at the end of the feed control remains high.

[0126] Under these circumstances, if the initial PWM value Pi is calculated from the PWM value Pt at the end of the feed control based on Equation 1, a deviation occurs in the force resisting the external force (return force). In some cases, the inertial force of the mechanism may cause the target position to be significantly exceeded, resulting in the target position being updated to that position. The reduction in load during feed control may not only be caused by the leading edge of the sheet slipping out of the protrusion 122a, but may also be caused by the shape of the conveying path or the shape and structure of the components forming the conveying path.

[0127] Therefore, in this embodiment, the PWM value is adjusted as follows. That is, in the deceleration region related to the end region of the feed control, if the speed difference Vd between the target speed and the actual speed becomes larger than a predetermined value, it is determined that a sudden load release has occurred and the PWM value has become excessive, and a process is performed to subtract a fixed value Pc from the PWM value (adjustment control ON). That is, if the speed difference Vd becomes larger than a predetermined value, Predetermined value The output value of the conveying motor 6 is made smaller than in the following cases. regionEven if a load fluctuation occurs, it is possible to appropriately shift to holding control. A specific processing example will be described below.

[0128] 19 is a flowchart showing an example of a process for adjustment control during load fluctuations. This flowchart can be executed in parallel with, for example, S401 to S403 in FIG.

[0129] In S901, the control unit 802 checks whether the feed control has entered the deceleration region (region C), and if it has entered, proceeds to S902, and if it has not entered (if it is in the acceleration region or constant speed region), repeats the check of S901.

[0130] In S902, the control unit 802 determines whether the rotation position of the carry motor 6 has reached the feed control end position, and if so, ends the flow chart, and if not, proceeds to S903.

[0131] In S903, the control unit 802 calculates the speed difference Vd between the target speed and the actual speed of the carry motor 6, and determines whether the speed difference Vd is greater than or equal to the threshold value Th Vd The control unit 802 checks whether the speed difference Vd exceeds the threshold value Th Vd If it exceeds the threshold, the process proceeds to S904, otherwise the process ends.

[0132] In S904, the control unit 802 subtracts the value Pc from the PWM value for the next control cycle.

[0133] According to the above process, the control unit 802 reduces the PWM value of the carry motor 6 when there is a large error between the target speed and the actual speed of the carry motor 6 during the deceleration section of the feed control. This allows the control unit 802 to appropriately control the speed of the carry motor 6 when a load fluctuation occurs during the deceleration section of the feed control (particularly when the load becomes lighter) (graph Q2). Furthermore, when performing the above process of determining the initial PWM value Pi for the holding control based on the PWM value Pt at the end of the feed control, it is possible to prevent the initial PWM value Pi from becoming larger than necessary.

[0134] 2. Second embodiment The following describes a recording device 800 according to the second embodiment. Note that the same elements as those in the first embodiment are denoted by the same reference numerals and descriptions thereof will be omitted.

[0135] In the first embodiment, the recording device 1 has a paper feed port that feeds the sheet to a reverse conveying path (a curved conveying path). In particular, in response to load fluctuations caused by a sheet being fed through the reverse conveying path, an example is shown in which an initial PWM value Pi for the hold control is determined based on a PWM value Pt at the end of a feed control region.

[0136] In contrast, the recording apparatus 800 of the second embodiment has two paper feed ports and a mechanism for switching between the first and second paper feed ports and a recovery mechanism. Specifically, a first transport path is provided for transporting a sheet set in the front tray to the recording position via the first paper feed port and a reverse transport path, and a second transport path is provided for transporting a sheet set in the rear tray to the recording position via the second paper feed port and a transport path from the rear side. Here, the first transport path corresponds to the transport path CP of the first embodiment. The second embodiment differs from the first embodiment in that holding control is performed taking into account differences in load fluctuations due to the differences in these transport paths. Compared to the first embodiment, this embodiment allows for a larger number of sheets to be stacked, and also allows for two types of sheets to be stacked, thereby improving the sheet compatibility of the recording apparatus.

[0137] <2.1. Control configuration> Figure 20 is a block diagram of the control configuration of the recording apparatus 800. Here, the differences from the configuration shown in Figure 8 of the first embodiment will be mainly explained. In this embodiment, a transport / recovery motor 822 is provided instead of the transport motor 6. The transport / recovery motor 822 operates the transport unit 810 and recovery unit 818 with a single motor by switching the destination of the driving force transmitted by a drive switching unit 817.

[0138] The conveying unit 810 conveys sheets. The conveying unit 810 includes a print conveying unit 815, a discharge unit 816, a front feed unit 830, and a rear feed unit 840. For example, the print conveying unit 815 may include a conveying roller 51, an intermediate roller 3a, etc. The discharge unit 816 may include a discharge roller 53, etc. The front feed unit 830 may include a pickup roller 111, etc. The rear feed unit 840 may include a roller for feeding a sheet set in the rear tray to the second conveying path, etc. The conveying unit 810 is provided with a drive switching mechanism 823. The drive switching mechanism 823 is configured to selectively switch between power connection and power disconnection to the front feed unit 830 and the rear feed unit 840. The recovery unit 818 may perform recovery processing for the recording head 71. The recording device 800 may perform a recording operation according to the flowchart shown in FIG. 10.

[0139] <2.2. Example of transport control processing> FIG. 21 is a flowchart showing an example of processing performed by the control unit 802 in transport control.

[0140] In S2101, the control unit 802 determines whether the drive force of the transport / recovery motor 822 is transmitted to the transport unit 810, and if it is the transport unit 810, the process proceeds to S2102, and if not, the process proceeds to S2113.

[0141] In S2104, the control unit 802 checks the paper feed method, and if front paper feed is specified, proceeds to S2103, and if rear paper feed is specified, proceeds to S2109. S2103 to S2106 are the same as S401 to S404 in FIG. 12. S2109 to S2112 are also the same as S401 to S404 in FIG. 12. However, in this embodiment, the calculation methods for the initial PWM value of the hold control used in S2106 and S2112 are different. Specifically, the PWM value Pt required at the end of the feed control is subtracted by a constant value Pva in S2106, and by a constant value Pvb in S2112, and these values ​​are used as the initial PWM value of the hold control. That is, the initial PWM value of the hold control is Pia=Pt-Pva (formula 7) or, Pib = Pt - Pvb (Equation 8) Let it be so.

[0142] When the conveyance path includes a curved path such as a reverse conveyance path, the external force generated on the conveyance member such as the conveyance roller tends to be larger compared to the case where such a path is not included. Therefore, in front paper feeding, the paper feeding of the subsequent sheet is larger than that in rear paper feeding, and the twist of the driving part becomes larger, so the initial PWM value tends to be larger. Thus, by setting Pia < Pib, the initial PWM value can be appropriately set according to the external force generated on the conveyance member such as the conveyance roller. load When the control unit 802 proceeds from S2106 or S2112 to S2107, it checks whether recording has ended for the entire recording range of the sheet. If it has ended, it proceeds to S2108; otherwise, it returns to S2102. S2107 corresponds to S405 in FIG. 12. S2108 is the same process as S406 in FIG. 12. After S2108, the control unit 802 ends the flowchart.

[0143] On the other hand, when proceeding from S2101 to S2113, the control unit 802 executes recovery control. For example, the control unit 802

[0144] executes a drawing process. At this time, the conveyance / recovery motor 822 drives the suction pump included in the recovery unit 818. , suck At S2114, the control unit 802 determines whether the recovery control has ended. If it has ended, it ends the flowchart; otherwise, it returns to S2113.

[0145]

[0146] ​According to this embodiment, the control unit 802 executes hold control when the destination of the drive force of the transport / recovery motor 822 transmitted by the drive switching unit 817 is the transport unit 810. On the other hand, the control unit 802 does not execute hold control when the destination is a mechanism different from the transport unit 810 (here, the recovery unit 818). As a result, by executing hold control in transport operations that require greater motor stopping accuracy, it is possible to suppress a decrease in stopping accuracy. On the other hand, by not executing hold control in operations that require relatively less motor stopping accuracy, it is possible to reduce the power consumption of the motor. In other words, it is possible to ensure both motor stopping accuracy and power consumption reduction.

[0147] In this embodiment, different initial PWM values ​​are used in the hold control depending on whether the paper feed method is front feed or rear feed, which allows the initial PWM value to be determined appropriately depending on the transport load caused by the difference in the transport path.

[0148] 3. Third Embodiment 22 is a perspective view showing an overview of a recording device 900 according to the third embodiment. In the following, elements that are the same as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0149] The recording device 900 includes a feeding section 902 that separates and feeds sheets one by one, a conveying section 5 that conveys the sheets fed by the feeding section 902, a recording section 7, a conveying motor 6 (not shown), and a discharge section 8 that discharges and stacks sheets on which recording has been completed by the recording section 7.

[0150] 3.1. Structure of the feeding section Fig. 23 is a perspective view of the feeding section 902. Fig. 24 is a cross-sectional view in the width direction of the feeding section 902. The feeding section 902 is made up of a stacking section 21, a feeding / separating section, and a driving section.

[0151] The stacking unit 21 is configured to include a tray 23, a pressure plate 24, side guides 25a and 25b, and a stacking detection unit 26. The pressure plate 24 is a pressure plate that applies a conveying force to the sheets. It is urged to rotate toward the feed roller 22 by a pressure plate spring (not shown), and a cam provided in the drive unit presses the pressure plate 24, causing it to rotate in a direction away from the feed roller 22. This urging and separating action causes the sheet to be fed.

[0152] When the feeding unit 902 is not feeding sheets, i.e., in a standby state, the pressure plate 24 is fixed at a predetermined position away from the feeding roller 22. At this predetermined position, a gap sufficient to stack multiple sheets is secured between the feeding roller 22 and the pressure plate 24.

[0153] Figure 25 is a cross-sectional view of the pressure plate 24 in a direction parallel to the sheet stacking surface. The side guides 25a and 25b are slidably attached to the pressure plate 24, and rack portions 252 provided on the side guides 25a and 25b are connected to side guide gears 253, thereby linking the movements of the side guides 25a and 25b. The side guide gear 253 is biased perpendicular to the direction of rotation by a side guide spring (not shown). This allows the side guides 25a and 25b to operate only when they receive a certain level of operating force, and they can be fixed so that they do not move accidentally when the pressure plate 24 is biased or separated, vibrations from the drive source occur, or the user transports the recording device.

[0154] After a plurality of sheets are stacked in the gap between the feeding roller 22 and the pressure plate 24, the side guides 25a and 25b are moved to adjust the width of the sheets so that the regulating surfaces 251a and 251b of the side guides 25a and 25b regulate the width direction of the sheets. Orthogonal The movement in the sheet width direction is restricted, so that the device can accommodate any sheet width within a predetermined width range, and can stably feed sheets of different widths.

[0155] The stacking detection unit 26 is composed of a stacking detection lever 261 and an optical sensor 263. The stacking detection lever 261 is rotatably disposed on the upper part of the pressure plate 24 and is urged toward the pressure plate 24 by a stacking detection spring 264. The stacking detection lever 261 is molded from a material that is opaque to infrared rays, and when a flag portion 262 passes between the light-emitting and light-receiving portions of the optical sensor 263, the output of the optical sensor 263 changes, making it possible to detect the position of the stacking detection lever 261. When no sheets are stacked in the stacking unit 21, the flag portion 262 is located outside the light-emitting and light-receiving portions of the optical sensor 263 and the sensor detection is turned OFF. When sheets are stacked in the stacking unit 21, the tip of the stacking detection lever 261 comes into contact with the stacked sheets, causing the stacking detection lever to rotate, thereby positioning the flag portion 262 between the light-emitting and light-receiving portions of the optical sensor 263 and turning ON the sensor detection. This makes it possible to determine whether or not sheets are stacked on the stacking section 21.

[0156] Next, the configuration of the feeding / separating section will be described. The stacked sheets are pressed against the feeding roller 22 by the operation of the pressure plate 24 described above. The feeding roller 22 is rotated at the same time as the sheets are pressed against it, and the uppermost sheet of the sheets in contact with the feeding roller 22 is conveyed by the frictional force of the feeding roller 22. Because the feeding roller 22 feeds the sheets by frictional force, it may be made of a material such as rubber with a high friction coefficient, such as EPDM, or urethane foam.

[0157] Here, since the frictional force between the feed roller 22 and the top sheet is often greater than the frictional force between the top sheet and the sheet immediately below it, only the top sheet is often conveyed. However, there are cases where the feed roller 22 pulls out multiple sheets at once, for example, when there are burrs on the edge of the sheets that are created when the sheets are cut, when sheets stick together due to static electricity, or when sheets with a very high surface friction coefficient are used.

[0158] In such a case, only the top sheet is separated by a separation roller 27 equipped with a torque limiter. The separation roller 27 is pressed against the feed roller 22 so as to abut on the downstream side in the conveying direction from the point where the feed roller 22 and the sheet first come into contact with each other.

[0159] Here, the configuration of the separation roller 27 will be described. Figure 26 is an exploded perspective view of the separation roller unit. The separation roller 27 is fixedly attached to a clutch cylinder 272, and a clutch shaft 273 is rotatably housed inside the clutch cylinder 272. A clutch spring 271 is wound around the clutch shaft 273, and one end of the winding of the clutch spring 271 is engaged with the clutch cylinder 272.

[0160] With this configuration, when the separation roller 27 and the clutch cylinder 272 are rotated in the direction of the arrow in the figure with the clutch shaft 273 fixed, the clutch spring 271 wound around the clutch shaft 273 is released from the clutch shaft 273. When the separation roller 27 and the clutch cylinder 272 rotate by a predetermined angle, the clutch shaft 273 and the clutch spring 271 slide relative to each other, thereby maintaining a predetermined torque.

[0161] The surface of the separation roller 27 is made of rubber, urethane foam, or the like so as to have a friction coefficient similar to that of the feed roller 22. The separation roller 27 is rotatably supported by a separation roller holder 274, which is a separation means holding member, via a clutch cylinder 272 and a clutch shaft 273, and is pressed against the feed roller 22 by a separation roller spring 275.

[0162] With this configuration, when no sheet is interposed between the feeding roller 22 and the separating roller 27, the separating roller 27 rotates in accordance with the rotation of the feeding roller 22.

[0163] When one sheet falls between feed roller 22 and separation roller 27, the frictional force between feed roller 22 and the sheet is greater than the frictional force between separation roller 27, which rotates at a predetermined torque, and the sheet, and therefore the sheet is conveyed while rotating separation roller 27. However, when two sheets fall between feed roller 22 and separation roller 27, the frictional force between feed roller 22 and the sheet on the feed roller 22 side becomes greater than the frictional force between the sheets. Also, the frictional force between the sheet on the separation roller 27 side and separation roller 27 becomes greater than the frictional force between the sheets, and therefore slippage occurs between the sheets. As a result, only the sheet on the feed roller 22 side is conveyed, and the sheet on the separation roller 27 side stops in place as separation roller 27 does not rotate and is not fed.

[0164] Next, the configuration of the double-feed prevention unit will be described. As described above, even if about two sheets enter the nip between the feed roller 22 and the separation roller 27, they can be separated. However, there are cases where more sheets enter, or where two sheets enter and after only the sheet on the feed roller 22 side has been fed, an attempt is made to feed the next sheet in succession while leaving one sheet near the nip. In such cases, there is a possibility that multiple sheets will be fed at the same time, which is known as double feeding. To prevent this, a double-feed prevention unit is provided.

[0165] The double feed prevention unit has a return lever 28, which is inserted into the sheet transport path when setting a sheet or when waiting to record, to prevent the leading edge of the sheet from accidentally entering too far into the feeding unit. The return lever 28 is configured to be released after the start of the feeding operation and retracted from the sheet transport path, so that the return lever 28 does not interfere with the progress of the sheet during feeding.

[0166] When the separation operation is completed, the return lever 28 begins to return the sheet in the separation nip due to the action of a cam provided on the control gear 31. At that time, the release cam 32 also moves the front-stage regulating member, that is, the front-stage regulating holder 29, and the separation roller holder 274 equipped with the separation roller 27, in a direction away from the feed roller 22. The movement of the front-stage regulating holder 29 and the separation roller holder 274 away from each other makes it possible to perform the sheet returning operation by the return lever 28 with a small force.

[0167] After completing the sheet returning operation, the return lever 28 rotates once to a position where it is retracted from the sheet transport path, and after the feeding from the feeding section 902 is completed, it returns to the standby position again.

[0168] Next, the configuration of the drive unit will be described. Figure 27 is a perspective view of the drive unit. The drive unit includes an input gear 33, intermediate gears 34 and 35, a control gear 31, a release cam 32, and a roller gear 36. The control gear 31 rotates in conjunction with the release cam 32, rotating from its initial standby position, or in the direction of the arrow, to the paper-passing position. Between the standby position and the paper-passing position, the release cam 32 pushes down or releases a follower (not shown), causing it to rotate, thereby lifting or lowering the pressure plate 24 and retracting or returning the return lever 28. The drive force is then transmitted from the control gear 31 to the roller gear 36, causing the feed roller 22 to rotate. The control gear 31 further rotates in the direction of the arrow from the paper-passing position to the standby position. Between the paper-passing position and the standby position, the drive force from the control gear 31 to the roller gear 36 is released by the missing-tooth gear 31a. The return lever 28 also moves from the return position to the standby position. In this way, when the control gear 31 rotates once in the direction of the arrow in the figure, a series of feeding operations of the feeding section 902 is performed once.

[0169] The feeding unit 902 is connected to the conveying motor 6 by a gear train (not shown), and is driven by the driving force input by the input gear 33 to rotate the control gear 31 via intermediate gears 34 and 35. The intermediate gears 34 and 35 have a latch mechanism inside the two-stage gear, and the two-stage gears are connected and can operate when rotating in one direction, but are not connected when rotating in the opposite direction, so that the output-side stage gear rotates freely relative to the input-side gear.

[0170] The control gear 31 is composed of a gear with missing teeth made up of multiple stages. When the input gear 33 drives in the direction indicated by the arrow A in the figure, the drive is transmitted to the missing tooth portion 31b of the control gear 31 via the intermediate gear 34, causing the control gear 31 to rotate in the direction indicated by the arrow. The missing tooth portion 31b of the control gear 31 is located in the rotational portion from the standby position to the paper passing position described above. As a result, the control gear 31 rotates from the standby position to the paper passing position in response to the drive from the input gear 33 in the direction indicated by the arrow A. After reaching the paper passing position, the missing tooth gear 31b disengages from the intermediate gear 34 and the control gear 31, cutting the drive connection between them and preventing the control gear 31 from rotating any further. At this time, the latch mechanism described above prevents the intermediate gear 35 from transmitting drive to the stepped gear, and therefore drive is not transmitted to the missing tooth gear 31c of the control gear 31.

[0171] When the input gear 33 drives in the direction of arrow B in the figure, the drive is transmitted to the toothless portion 31c of the control gear 31 via the intermediate gears 34 and 35, and the control gear 31 rotates in the direction of the arrow in the figure. The toothless portion 31c of the control gear 31 is located in the rotational portion from the paper passing position to the standby position described above. As a result, in response to the drive from the input gear 33 in the direction B, the control gear 31 rotates from the paper passing position to the standby position, and after reaching the standby position, the drive connection between the intermediate gear 35 and the control gear 31 is cut off by the toothless gear 31c disengaging, and the control gear 31 does not rotate any further. The latch mechanism described above prevents the drive of the intermediate gear 34 from being transmitted to the stepped gear, so the drive is not transmitted to the toothless gear 31b of the control gear 31.

[0172] In this way, the drive unit provided in the feeding unit performs a series of feeding operations from the standby position to the sheet passing position by rotating the input gear 33 in direction A, and then performs a feeding preparation operation from the sheet passing position to the standby position by rotating the input gear 33 in direction B. When driven by the rotation amount in direction B required for the feeding preparation operation, the distance by which the conveying roller 51 conveys the sheet upstream in the conveying direction is defined as L1.

[0173] <3.2. Description of the load when reconnecting missing teeth and application of the initial PWM value Pi> In this embodiment, when the input gear is driven in the direction A and the control gear 31 rotates to the sheet passing position, the missing tooth gear 31c, which was at an angle where it did not transmit power (a portion with no teeth), is reconnected to drive halfway through. This is because, after the sheet is fed, the control gear 31 may rotate in the direction B during skew correction in the conveying roller unit, so it is necessary to disconnect it once. To ensure smooth reconnection, the meshing portion of the missing tooth gear 31c is configured to be elastically deformable in the radial direction.

[0174] After the sheet is fed, the missing tooth gear 31c is reconnected while feed control is being performed. At this time, if feed control is stopped while the tooth tip of the elastic portion of the missing tooth gear 31c is in contact with the intermediate gear 35, a reaction force is generated in the drive transmission system, and a force (external force) acts to return the conveyance motor 6. This force to return the conveyance motor 6 varies depending on the contact state between the gears when the conveyance motor 6 is stopped, so the PWM value when transitioning to hold control may deviate from the PWM value required to hold the conveyance motor 6. This may result in insufficient motor torque causing the motor to rotate in the reverse direction, or excessive motor torque causing the motor to rotate in the forward direction.

[0175] Therefore, in this embodiment, the conveying motor 6 is driven at the command speed at the end of the feed control. rotate The PWM value at the start of the holding control is adjusted based on the PWM value required to maintain the paper feed speed. This brings the PWM value of the carry motor 6 closer to an appropriate PWM value according to the external force at that time, making it possible to prevent the motor from rotating in the reverse direction or excessively in the forward direction.

[0176] Specifically, the same control as in the first embodiment can be applied. That is, with respect to the PWM value Pt at the end position of the feed control, the value obtained by subtracting a constant value Pd is used as the initial PWM value Pi of the holding control. That is, the initial PWM value Pi of the holding control is Pi = Pt - Pd (Equation 1) However, Pd > 0 may be used. Alternatively, the value obtained by dividing the PWM value Pt by a constant value Pd2 may be used as the PWM value Pi at the start of the holding control. That is, Pi = Pt / Pd2 (Equation 2) However, Pd2 > 1 may be used.

[0177] Also, in the region other than the contact region between this missing tooth gear 31 c and the intermediate gear 35, when the PWM value at the end of the feed control is low and the value obtained by subtracting a constant value from the PWM value Pt falls below 0, the output value of the conveyance motor 6 in the holding control may be set to zero and the same control may be executed. In the region other than the contact region between this missing tooth gear 31 c and the intermediate gear 35, a second lower value Pd2 may be used as the constant value Pd to be subtracted.

[0178] Also, in the region other than the contact region between this missing tooth gear 31 c and the intermediate gear 35 (that is, when the external force applied to the conveyance motor 6 is relatively small), it may not be necessary to execute the application of the initial PWM value Pi based on the PWM value Pt.

[0179] Furthermore, depending on the type of the sheet to be conveyed, the speed during conveyance, the ON / OFF setting of the continuous feeding operation, etc., in the case of conveyance where it is difficult to receive an external force, the initial PWM value Pi of the holding control may be changed to a second value Pi2 (<Pi1). Alternatively, in the case of conveyance where it is difficult to receive an external force, it may not be necessary to apply the initial PWM value Pi.

[0180] <4. Other Embodiments>

[0181] Whether or not the initial PWM value Pi of the hold control is applied can be switched as appropriate. For example, depending on the type of sheet to be conveyed and the speed at which it is conveyed, if the sheet is not likely to be subjected to external forces, the initial PWM value Pi of the hold control may not be applied.

[0182] For example, information associating the type of sheet with whether or not to apply the initial PWM value Pi for the hold control may be stored in the storage unit 803. Then, when receiving an instruction for conveyance control, the control unit 802 may acquire information about the type of sheet 201 and compare it with the information stored in the storage unit 803 to determine whether or not to apply the initial PWM value Pi based on the PWM value Pt in the hold control. The recording apparatus 1 may be configured to be able to accept information about the type of sheet 201 from an input unit such as a touch panel or hard keys.

[0183] Furthermore, for example, the recording apparatus 1 may set the rotation speed of the conveying motor 6 during conveyance control in accordance with the size or type of the sheet, or information input by the user, etc. Then, the initial PWM value Pi based on the PWM value Pt may be applied only when the rotation speed is equal to or greater than a threshold value.

[0184] Furthermore, in the above embodiment, a serial inkjet printer is exemplified as the recording device 1, but the features of the above embodiment can be appropriately applied to other conveying devices that sequentially convey sheets by a predetermined amount.

[0185] Furthermore, in the above embodiment, when the leading edge of the sheet S2 is located in the predetermined area A1, the control unit 802 switches the drive control of the carry motor 6 so that the acceleration of the carry motor 6 is smaller than when the leading edge is not located in the predetermined area A1. This prevents the drive load of the carry motor 6 from becoming too large. On the other hand, if the drive of the carry motor 6 is restricted more than necessary, this may lead to a decrease in the efficiency of the printing operation. Therefore, the control unit 802 may relax the restriction on the drive of the carry motor 6 according to the PWM value that is currently restricted.

[0186] For example, when recording on multiple sheets, the control unit 80228 Check the PWM values when performing drive control of the conveyance motor 6 according to Table 2 of 28 for a plurality of times (for example, 1 to 3 times). Then, when the maximum value of the checked PWM values is less than or equal to the threshold value, the control unit 802 may change the acceleration of the conveyance motor 6 to a3 (a2 < a3 < a1) when the sheet S2 is in the predetermined area A1. Thereby, the drive control of the conveyance motor 6 can be appropriately switched according to the margin with respect to the load of the conveyance motor 6. Further, a plurality of tables with different accelerations may be further prepared, and the table may be selected according to the checked PWM values.

[0187] In addition, when the drive of the conveyance motor 6 is restricted by the rotational speed, the control unit 802 may relax the restriction by increasing the rotational speed.

[0188] Also, in the above embodiment, the length lp of the sheet S1 obtained from the set values and the like included in the recording job is used. As another aspect, for the first plurality of sheets, the length lp obtained from the set values and the like included in the recording job may be used, and for the subsequent sheets, the length lp as the measurement result for the first plurality of sheets may be used. The measurement of the length lp of the sheet can be performed by obtaining the rotation amount of the conveyance motor 6 by the conveyance encoder 813 while the end detection lever 57 is detecting the sheet, and converting the rotation amount of the conveyance motor 6 into the conveyance amount of the conveyance roller 51.

[0189] In the above embodiment, the leading edge position of sheet S2 is identified based on the position of sheet S1. However, the method for identifying the leading edge position of sheet S2 can be changed as appropriate. For example, a sensor for detecting a sheet may be provided in a predetermined area A1, and the leading edge position of sheet S2 may be identified as being in the predetermined area A1 based on the detection result of the sensor. As an example, sensors for detecting a sheet may be provided at the upstream and downstream ends of the predetermined area A1. Then, the control unit 802 may determine that the leading edge of sheet S2 is located in the predetermined area A1 during the period from when the sensor at the upstream end detects sheet S2 to when the sensor at the downstream end detects sheet S2. Alternatively, the leading edge position of sheet S2 may be identified based on the detection result of an encoder or the like that detects the rotation angle of pickup roller 111.

[0190] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0191] <5. Notes> The above-described embodiment discloses at least the following recording apparatus, control method for the recording apparatus, and conveyance apparatus.

[0192] (Item 1) a recording means for recording on a sheet; a conveying means for conveying a sheet to a recording position by the recording means; a motor for driving the conveying means; a control means for controlling the rotation of the motor; Equipped with the control means is capable of executing a holding control for holding the motor at a stop position, the control means determines a first output value, which is an output value of the motor during the holding control, according to a second output value, which is an output value of the motor before the motor is stopped at the stop position. A recording device characterized by:

[0193] (Item 2) Item 1. The recording device according to item 1, the conveying unit conveys the sheet downstream in the conveying direction by rotating the motor in a first rotation direction; The first output value is smaller than the second output value and is an output value in a direction in which the motor rotates in the first rotation direction. A recording device characterized by:

[0194] (Item 3) Item 1 or 2: A recording device according to any one of items 1 and 2, the first output value is the second output value minus a first predetermined value; A recording device characterized by:

[0195] (Item 4) Item 1 or 2: The recording device according to any one of items 1 to 2, The first output value is the second output value divided by a second predetermined value. A recording device characterized by:

[0196] (Item 5) 5. The recording device according to any one of items 1 to 4, the control means updates the target position for stopping the motor to a current position based on the rotation speed of the motor during execution of the holding control. A recording device characterized by:

[0197] (Item 6) 6. The recording device according to any one of items 1 to 5, the control means is capable of performing feed control for controlling the rotation of the motor so that the conveying means conveys the sheet by a predetermined distance; The second output value is the output value of the motor when the feed control ends. A recording device characterized by:

[0198] (Item 7) Item 6. The recording device according to item 6, the control means executes the holding control for a period from the end of the feed control until the start of the next feed control. A recording device characterized by:

[0199] (Item 8) 8. The recording device according to any one of items 1 to 7, The conveying means is a first roller provided in a conveying path for conveying the sheet to a recording position of the recording means; a second roller that is provided upstream of the first roller in the conveying path and that conveys a sheet; Including, the motor drives the first roller and the second roller; A recording device characterized by:

[0200] (Item 9) Item 8. The recording device according to item 8, a switching means for switching between a transmission state in which a driving force is transmitted from the motor to the second roller and a non-transmission state in which a driving force is not transmitted from the motor to the second roller, the control means determines the first output value in accordance with the second output value when the switching means is in the transmission state. A recording device characterized by:

[0201] (Item 10) 10. The recording device according to any one of items 8 to 9, the control means is capable of performing feed control for controlling the rotation of the motor so that the conveying means conveys the sheet by a predetermined distance; The control unit is capable of performing a conveying operation of conveying a second sheet following the first sheet by the second roller in parallel with conveying a first sheet by the first roller as the feed control. A recording device characterized by:

[0202] (Item 11) Item 11. The recording device according to item 10, when a difference between a target rotation speed and an actual rotation speed of the motor becomes larger than a predetermined value in a deceleration section of the motor in the feed control during the execution of the conveying operation, the control means reduces the output value of the motor compared to when the difference is equal to or smaller than the predetermined value. A recording device characterized by:

[0203] (Item 12) 12. The recording device according to any one of items 10 to 11, The conveying path further includes a path forming member that forms a curved section between the second roller and the first roller. A recording device characterized by:

[0204] (Item 13) Item 13. The recording device according to item 12, The curved section is a section that forms a reversing path that reverses the traveling direction of the sheet. A recording device characterized by:

[0205] (Item 14) 14. The recording device according to any one of items 12 to 13, Further provided is a loading section for loading sheets, the second roller is a pickup roller that conveys the sheet stacked on the stacking unit to the conveying path, the path forming member includes a separation portion that separates the top sheet stacked on the stacking portion from other sheets, The separating unit includes an inclined surface member that forms an inclined surface on the conveying path, and a protrusion that can hook a leading edge of a sheet conveyed along the inclined surface. A recording device characterized by:

[0206] (Item 15) 15. The recording device according to any one of items 1 to 14, a first stacking section for stacking sheets; a second stacking section for stacking sheets, the control means changes a method of determining the first output value according to the second output value between a case where the sheet is transported from the first stacking unit to the transport path and a case where the sheet is transported from the second stacking unit to the transport path. A recording device characterized by:

[0207] (Item 16) Item 16. The recording device according to item 15, At least one of a conveying path from the first stacking unit to a recording position by the recording means and a conveying path from the second stacking unit to the recording position includes a reversing path that reverses the traveling direction of the sheet. A recording device characterized by:

[0208] (Item 17) 17. The recording device according to any one of items 1 to 16, wherein the motor is controlled by servo control. A recording device characterized by:

[0209] (Item 18) a recording means for recording on a sheet; a conveying means for conveying a sheet to a recording position by the recording means; a motor that drives the conveying means, Executing a holding control to hold the motor at a stop position; determining a first output value that is an output value of the motor in the holding control according to a second output value that is an output value of the motor before the motor is stopped at the stop position; Including, A control method comprising:

[0210] (Item 19) a conveying means for conveying a sheet; a motor for driving the conveying means; a control means for controlling the rotation of the motor; Equipped with the control means is capable of executing a holding control for holding the motor at a stop position, the control means determines a first output value, which is an output value of the motor during the holding control, according to a second output value, which is an output value of the motor before the motor is stopped at the stop position. A conveying device characterized by:

[0211] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0212] 1: Recording device, 5: Conveying unit, 6: Conveying motor, 7: Recording unit, 802: Control unit

Claims

1. a recording means for recording on a sheet; a conveying means for conveying a sheet to a recording position by the recording means; a motor for driving the conveying means; a control means for controlling the rotation of the motor; Equipped with the control means is capable of executing a holding control to stop the rotating motor at a target position and hold the motor at the stop position, the control means determines a first output value, which is an output value of the motor during the holding control, according to a second output value, which is an output value of the motor before the motor stopped at the stop position, and updates the target position to a current position when the rotation speed of the motor becomes equal to or less than a threshold value during execution of the holding control. A recording device characterized by:

2. 2. The recording device according to claim 1, the conveying unit conveys the sheet downstream in the conveying direction by rotating the motor in a first rotation direction; the first output value is smaller than the second output value and is an output value in a direction in which the motor rotates in the first rotation direction; A recording device characterized by:

3. 2. The recording device according to claim 1, the first output value is the second output value minus a first predetermined value; A recording device characterized by:

4. 2. The recording device according to claim 1, the first output value is the second output value divided by a second predetermined value; A recording device characterized by:

5. 2. The recording device according to claim 1, the control means is capable of performing feed control for controlling the rotation of the motor so that the conveying means conveys the sheet by a predetermined distance; the second output value is the output value of the motor when the feed control is terminated. A recording device characterized by:

6. 6. The recording device according to claim 5, the control means executes the holding control for a period from the end of the feed control until the start of the next feed control. A recording device characterized by:

7. 2. The recording device according to claim 1, The conveying means is a first roller provided in a conveying path for conveying a sheet to a recording position of the recording means; a second roller that is provided upstream of the first roller in the conveying path and that conveys the sheet; Including, the motor drives the first roller and the second roller; A recording device characterized by:

8. 8. The recording device according to claim 7, the control means is capable of performing feed control for controlling the rotation of the motor so that the conveying means conveys the sheet by a predetermined distance; the control unit is capable of performing a conveying operation of conveying a second sheet following the first sheet by the second roller in parallel with conveying a first sheet by the first roller as the feed control; A recording device characterized by:

9. 9. The recording device according to claim 8, when a difference between a target rotation speed and an actual rotation speed of the motor becomes larger than a predetermined value in a deceleration section of the motor in the feed control during the execution of the conveying operation, the control means reduces the output value of the motor compared to when the difference is equal to or smaller than the predetermined value. A recording device characterized by:

10. 9. The recording device according to claim 8, The conveying path further includes a path forming member that forms a curved section between the second roller and the first roller. A recording device characterized by:

11. 11. The recording device according to claim 10, The curved section is a section that forms a reversing path that reverses the traveling direction of the sheet. A recording device characterized by:

12. 11. The recording device according to claim 10, Further provided is a loading section for loading sheets, the second roller is a pickup roller that conveys the sheet stacked on the stacking unit to the conveying path, the path forming member includes a separation portion that separates the top sheet stacked on the stacking portion from other sheets, The separating unit includes an inclined surface member that forms an inclined surface on the conveying path, and a protrusion that can hook a leading edge of a sheet conveyed along the inclined surface. A recording device characterized by:

13. a recording means for recording on a sheet; a first roller for transporting the sheet to a recording position of the recording means; a second roller that is provided upstream of the first roller in the conveying direction and that conveys the sheet; a motor that drives the first roller and the second roller; a control means for controlling the rotation of the motor; a switching means for switching between a transmission state in which a driving force is transmitted from the motor to the second roller and a non-transmission state in which a driving force is not transmitted from the motor to the second roller, the control means is capable of executing a holding control for holding the motor at a stop position, the control means determines a first output value, which is an output value of the motor during the holding control, in accordance with a second output value, which is an output value of the motor before the motor stopped at the stop position, at least when the switching means is in the transmitted state. A recording device characterized by:

14. a first stacking section for stacking sheets; a second stacking section for stacking sheets; a recording unit for recording on a sheet supplied from the first stacking unit or the second stacking unit; a conveying means for conveying a sheet to a recording position by the recording means; a motor for driving the conveying means; a control means for controlling the rotation of the motor; the control means is capable of executing a holding control for holding the motor at a stop position, the control means determines a first output value, which is an output value of the motor during the holding control, in accordance with a second output value, which is an output value of the motor before the motor is stopped at the stop position; the control unit changes a method of determining the first output value according to the second output value depending on whether the sheet is transported from the first stacking unit to the transport path or the sheet is transported from the second stacking unit to the transport path. A recording device characterized by:

15. 15. The recording device according to claim 14, At least one of a conveying path from the first stacking unit to a recording position by the recording means and a conveying path from the second stacking unit to the recording position includes a reversing path that reverses the traveling direction of the sheet. A recording device characterized by:

16. 2. The recording apparatus according to claim 1, wherein the motor is controlled by servo control. A recording device characterized by:

17. a recording means for recording on a sheet; a conveying means for conveying a sheet to a recording position by the recording means; a motor that drives the conveying means, Stopping the rotating motor at a target position and executing a holding control to hold the motor at the stop position; determining a first output value, which is an output value of the motor during the holding control, according to a second output value, which is an output value of the motor before the motor is stopped at the stop position; updating the target position to a current position based on the fact that the rotation speed of the motor has become equal to or less than a threshold value during execution of the holding control; Including, A control method comprising:

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