TWI457267B - Conveyance device, printing device, and conveyance method - Google Patents

Description

Transport device, printing device, and transport method

The present invention relates to a device for transporting a sheet material to a processing position by two sets of rolls, and the like, and more particularly to a conveying apparatus which can eliminate a back tension acting on a downstream side roll without expanding the scale of the apparatus.

Conventionally, in a device such as a printer, it is a device that processes a sheet medium such as paper and needs to transport the sheet. The transport apparatus generally includes, for example, an upstream side roller that supplies the medium to a transport path from a portion where the sheet medium is stored, and a downstream side roller that performs printing on the transport medium along the transport path. The location of the processing is carried.

In such a transfer apparatus, it is necessary to accurately control the supply of the medium to be transported with high quality, and it is necessary to accurately control the supply speed of the medium from the downstream side roller. However, there is a problem in that it is difficult to control the back side roll when there is a back tension which is stretched from the upstream side.

Therefore, as a technique for overcoming this problem, a proposal as disclosed in Patent Document 1 below has been proposed. In this document, it is proposed to advance the driving timing of the upstream side roller and increase the amount of transportation.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-56367

However, in the method described in the above Patent Document 1, the advancement is due to the above The method of increasing the drive timing or the amount of conveyance is fixedly determined regardless of the situation. Therefore, there is a problem in that appropriate control is always performed in accordance with the changed transport state. For example, the force applied to each roller or the conveying force changes due to the wear of the rollers or the storage of the medium (the diameter of the roller when the medium is rolled), and so is always performed at a fixed value. In the control, there is a problem that the medium is not slack between the upstream side roller and the downstream side roller, or vice versa, causing friction with the member in the conveying path, and is generated on the downstream side roller. Anti-tension. Further, there is a problem that it is necessary to increase the scale of the apparatus so that the slack does not disappear and the slack is always maintained, and the member is not slackened until the medium comes into contact with the member in the transport path.

Accordingly, an object of the present invention is to provide a device for transporting a sheet to a processing position by two sets of rolls, and to eliminate a reverse tension acting on a downstream side transfer device without expanding the scale of the apparatus.

In order to achieve the above object, an aspect of the present invention provides a conveying apparatus comprising: an upstream side roller that feeds a sheet-shaped processed medium to a conveying path; and a downstream side roller that supplies the fed medium to a processing position; And a control unit that controls driving of the upstream side roller and the downstream side roller to transport the medium to be processed at a constant speed; and the control unit is based on the upstream side roller and the downstream side roller at the time of the previous conveyance operation The specific information determines the start timing of the upstream side roller and the downstream side roller at the start of the transport operation. The specific information refers to the behavior of the upstream side roller and the downstream side roller at the time of the last transfer operation until the above-mentioned constant speed is reached. And driving information of the upstream roller and the downstream roller at the above fixed speed.

Further, in the above aspect of the invention, preferably, the activation timing is determined such that a start timing of the downstream side roller is delayed with respect to the upstream side roller.

Further, in the above aspect of the invention, the information indicating the behavior until the constant speed is reached is a time from the start of the upstream roller and the downstream roller to the constant speed.

Further, in the above aspect of the invention, the information indicating the behavior until the constant speed is reached is started from the start of the upstream side roller and the downstream side roller. The amount of the medium to be processed is transferred by each of the upstream roller and the downstream roller until the time required for the constant speed is reached. Further, the present invention is characterized in that the driving information at the time of the constant speed is information indicating the magnitude of the power required to drive the upstream side roller and the downstream side roller.

Further, in the above aspect of the invention, preferably, the information indicating the behavior up to the constant speed, the driving information at the constant speed, and the above-described information are displayed in advance for each type of the processed medium. Information on the relationship between the start timings.

Further, in the above aspect of the invention, the medium to be processed is supplied to the upstream side roller in a state of being held in a roll shape.

In order to achieve the above object, another aspect of the present invention provides a printing apparatus comprising the above-described conveying apparatus, and the above processing position The processed media performs printing.

In order to achieve the above object, still another aspect of the present invention is a conveying method of a conveying apparatus, comprising: an upstream side roller that feeds a sheet-shaped processed medium to a conveying path; and a downstream side roller that sends the conveying unit The medium is supplied to the processing position; and the control unit controls driving of the upstream roller and the downstream roller to transport the processed medium at a constant speed; and the control unit is based on the upstream of the previous transfer operation The specific information of the side roller and the downstream roller determines the start timing of the upstream roller and the downstream roller at the start of the transport operation. The specific information is information indicating the behavior of the upstream side roller and the downstream side roller at the time of the constant speed at the time of the previous conveyance operation, or the driving information of the upstream side roller and the downstream side roller at the constant speed.

Further, in the above aspect of the invention, the information indicating the behavior until the constant speed is reached is the time from the start of the upstream roller and the downstream roller until the constant speed is reached, or The above-described upstream side roller and the downstream side roller are transported by the upstream roller and the downstream roller until the time required for the constant speed to be reached from the start of the upstream roller The amount of media being processed.

Further, in the above aspect of the invention, the driving information at the constant speed is information indicating the magnitude of the power required to drive the upstream roller and the downstream roller.

Further objects and features of the present invention will become apparent from the embodiments of the invention described below.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, this embodiment does not limit the technical scope of the present invention. In the drawings, the same or similar components are denoted by the same reference numerals or reference numerals.

Fig. 1 is a schematic configuration diagram showing an embodiment of a printing apparatus to which the conveying apparatus of the present invention is applied. The printer 2 shown in Fig. 1 is a printing apparatus according to an embodiment of the present invention, and the printing apparatus transports the paper 26 of the printing medium to the printing by the paper feed roller 29 (upstream side roller) and the conveyance roller 30 (downstream side roller). The printing process is executed at the position, and the driving start timing of the two rolls is determined based on the behavior at the start of driving of the two rollers in the previous transfer operation in each transfer operation, and the slack of the paper 26 between the two rolls is always maintained. For fixing.

As shown in FIG. 1, the printer 2 is a device that performs a printing process by receiving an instruction from a host device 1 such as a computer. Here, as an example, the roll paper 25 is used as the paper 26, and the paper 26 is continuously conveyed. The printing device is printed.

Fig. 1 schematically shows a schematic configuration of a printer 2, and the printer 2 includes a printing system that performs printing processing on the paper 26 and a transport system that carries the paper 26.

The printing control unit 21 is provided with a print control unit 21 that receives a print instruction from the main unit 1 and issues a print command to the head unit 23 in accordance with the instruction, and requests the conveyance control unit 22 of the transport system to use the paper 26 . Transfer. The head 23 performs a printing process on the paper 26 that moves at a specific speed between the head portion 23 and the platen 24 in accordance with the printing instruction.

In the transport system, as shown in FIG. 1, the transport control unit 22 makes a roll paper The paper 26 held in the storage place of the printing medium is conveyed to the head portion 23 along the conveyance path 33, and thereafter, the conveyance operation of discharging from the printer 2 via the paper discharge roller 32 is performed.

In order to convey the paper to the head portion 23, a paper feed roller 29 (upstream side roller) and a conveyance roller 30 (downstream side roller) driven by the respective motors (27A and 27B) are included. On the two rolls, the driven rolls (28A and 28B) are placed at positions facing each other with the paper 26 interposed therebetween with a pressure applied to the side of the paper 26.

The paper feed roller 29 has a function of supplying the paper 26 held as the roll paper 25 to the conveyance path 33, and is rotated by the torque of the motor 27A transmitted through the speed reducer, and by being combined with the driven roller 28A. The paper 26 is moved by the friction between the squeezing papers 26.

The transport roller 30 has a function of transporting the paper 26 supplied by the paper feed roller 29 to the position of the head 23, which is a printing position, and rotates by the torque of the motor 27B transmitted through the speed reducer, and by The paper 26 is moved by the frictional force between the paper 26 pressed together with the driven roller 28B.

Encoders 31A and 31B are provided in the paper feed roller 29 and the conveyance roller 30, respectively, and the number of rotations of the two rollers detected by the above is notified to the conveyance control unit 22.

The conveyance control unit 22 shown in FIG. 1 controls a part of the conveyance system, and controls the conveyance operation of the paper 26 based on an instruction from the print control unit 21. In particular, the paper feed roller 29 and the conveyance roller 30 are controlled to be driven and stopped, and the paper 26 to be conveyed to the printing position is satisfactorily executed. The printer 2 has characteristics in the driving and stopping control of the paper feed roller 29 and the conveyance roller 30, and the details thereof will be described below.

Although not shown, the transport control unit 22 includes a CPU (Central Processing). Unit, central processing unit), ROM (Read Only Memory), RAM (Random Access Memory), NVRAM (Non-Volatile Random Access Memory, non-volatile random access memory) The above-described processing executed by the transport control unit 22 is mainly executed by the CPU in accordance with the program stored in the ROM.

In the above-mentioned RAM, each of the drive data required for the processing, and the drive data required for the conveyance and stop control of the paper feed roller 29 and the conveyance roller 30, and the following waiting time ΔT are stored in the memory. this. The drive drive data stored in the memory includes the drive start time of the paper feed roller 29 and the transport roller 30, the transport speed, and the Duty value of the motor 27 (here, the amount of current supplied to the motor 27). .

Further, in the above NVRAM, the relationship information useful for determining the waiting time ΔT is stored in advance. Information about this relationship is described below.

Further, the transport system including the paper feed roller 29, the transport roller 30, and the transport control unit 22 corresponds to the transport device of the present invention.

The printer 2 having the configuration described above has characteristics in the conveyance control of the paper 26, and the details thereof will be described below.

As described above, in the printer 2, the printing process is performed on the paper 26 conveyed at a specific (fixed) speed. When the printing process is started, the conveyance control unit 22 controls the conveyance speed of the paper feed roller 29 and the conveyance roller 30 to rapidly reach the specific speed, and maintains the conveyance speed until the end of the printing process, and the printing process ends. Then, the conveyance control unit 22 stops the two rollers. This transport operation and transport processing are repeatedly executed each time the printing process is executed.

Further, when the paper 26 is initially set, the conveyance control unit 22 is configured to The paper 26 controls the two rollers in such a manner that a fixed slack (for example, slack as shown in FIG. 1) is generated between the paper feed roller 29 and the conveyance roller 30, and the paper 26 is conveyed to a specific position in advance. In order to prevent the back tension from acting on the conveyance roller 30 as described above, the paper 26 can be always fed from the conveyance roller 30 to the printing position at a constant speed.

Further, the paper feed roller 29 receives the force for extracting the paper 26 from the roll paper 25 located on the upstream side as the back tension. Therefore, the paper feed roller 29 generally receives the back tension of the transport roller 30 during the conveyance of the paper 26.

Therefore, at the start of each of the above-described transfer operations, the paper feed roller 29 tends to take time until the specific speed is reached. FIG. 2 is a view showing an example of the behavior of the paper feed roller 29 and the conveyance roller 30 at the start of the conveyance operation. In the figure, the horizontal axis indicates the elapsed time (T) after the start of driving, and the vertical axis indicates the transport speed (V) of each roller. Moreover, the curve A of the graph indicates the behavior of the paper feed roller 29, and the curve B indicates the behavior of the transport roller 30.

As described above, since the back tension is larger than the conveyance roller 30 and acts on the paper feed roller 29, as shown in FIG. 2, the paper feed roller 29 (curve A) reaches the target speed at the specific speed. Slow down. Therefore, there is a difference in the amount of paper conveyed by the two rolls until the two rolls reach the above specific speed. In the example shown in Fig. 2, a difference in conveyance amount (?L) corresponding to the area formed between the curve B and the curve A is generated.

Therefore, when the two rolls are simultaneously started at the start of the above-described transfer operation, the transfer roller 30 transports the difference corresponding to the conveyance amount difference (ΔL) until the two rolls reach a specific speed and are controlled by the same conveyance amount. A lot of quantity. This situation may result in a decrease in the slack of the paper 26 described above, and may also be guided by the difference in the amount of conveyance. Causes the relaxation to disappear.

Therefore, the conveyance control unit 22 of the printer 2 performs control for keeping the slack generated in the initial state substantially constant in the respective conveyance operations. Hereinafter, the specific control content will be described.

FIG. 3 is a flowchart illustrating the procedure of processing executed by the transport control unit 22. Hereinafter, the control content of the above-described transfer operation will be described with reference to Fig. 3 . In addition, this control is based on the fact that the difference in the conveyance amount at the start of the drive is eliminated by delaying the start timing of the conveyance roller 30, and is based on the fact that the remaining amount of the roll paper 25 is clearly indicated. The start timing is determined by the drive data during the transfer operation. Further, as the driving data, the difference in the conveyance amount between the paper feed roller 29 and the conveyance roller 30, the difference in the conveyance amount until the paper feed roller 29 and the conveyance roller 30 are raised, and the difference in the conveyance amount between the paper feed roller 29 and the conveyance roller 30, respectively A method of achieving a difference in Duty value between each of the paper feed roller 29 and the transport roller 30 after reaching the above specific speed.

In each of the transport operations, the transport control unit 22 receives the paper transport start instruction from the print control unit 21 (step S1), and acquires the value of the waiting time ΔT held in the RAM (step S2). The waiting time ΔT is a waiting time for delaying the start timing of the transport roller 30 described above, and is determined after the end of each transport operation and held in advance for information for the next transport operation. That is, the waiting time ΔT is a value determined at the time of the last transfer operation, and a specific determination method will be described below. Further, when the printer 2 is activated and is in the initial transfer operation, a preset value held in advance in the NVRAM is obtained. Moreover, the value of the waiting time ΔT determined at the time of each transport operation can also be stored in the above NVRAM, which was obtained from there.

Further, the conveyance control unit 22 starts the driving of the paper feed roller 29 after the above instruction (step S3). In other words, the motor 27A is started, and thereafter, the control is continued such that the conveyance speed of the paper feed roller 29 is the target specific speed. Further, the conveyance control unit 22 performs drive control of the paper feed roller 29 and the conveyance roller 30 by PID (Proportion Integration Differentiation) control based on the detection results of the encoders 31A and 31B.

Then, after the start of driving of the paper feed roller 29, the conveyance control unit 22 waits for the waiting time ΔT obtained (step S4), and then starts driving of the conveyance roller 30 (step S5). In other words, the motor 27B is started, and thereafter, the control is continued such that the conveyance speed of the conveyance roller 30 becomes the target specific speed.

Thereafter, when the paper feed roller 29 and the conveyance roller 30 reach the above-described specific speed, the control of the constant speed drive is continued for both rollers (step S6).

When the conveyance control unit 21 receives the stop instruction of the conveyance (step S7), the conveyance control unit 22 performs control to stop the driving of the paper feed roller 29 and the conveyance roller 30 (step S8). In this control, the two rolls may be controlled to rapidly change the speed to 0. However, it is preferable to perform the control for stopping the rolls so that the conveyance amounts of the two rolls in the transfer operation become the same. . Thereby, the slack of the paper 26 between the paper feed roller 29 and the conveyance roller 30 at the start of the conveyance operation is maintained.

When the two rollers are stopped in this manner and the conveyance operation is completed, the conveyance control unit 22 determines the waiting time in the next conveyance operation based on the driving state of the paper feed roller 29 and the conveyance roller 30 during the conveyance operation. △T and remember in The previously held value is deleted in the above RAM (step S9).

The waiting time ΔT is used to overcome the difference in the amount of conveyance caused by the difference between the behavior of the paper feed roller 29 and the conveyance roller 30 at the start of driving, so it is possible to determine the behavior based on the start of driving of the two rollers. Waiting time △T method. Specifically, as described above, as one method, the waiting time ΔT is obtained from the difference in rise time between the paper feed roller 29 and the conveyance roller 30.

Figure 4 is a diagram for explaining the waiting time ΔT. 4(A) is the same as the graph shown in FIG. 2, and shows the temporal change in speed when the paper feed roller 29 and the transport roller 30 start driving at the same time, and the rise time difference corresponds to ΔT1 here. That is, the rise time difference is a time difference required for each roller from the start of driving to the specific speed at which the target is reached.

Fig. 4(B) shows the temporal change in the transport speed of the paper feed roller 29 and the transport roller 30 when the control of the printer 2 is performed based on Fig. 3 . The driving of the conveying roller 30 shown by the curve B is started as described above, and the driving delay of the paper feed roller 29 shown by the curve A is delayed by the waiting time ΔT. Therefore, until the time when both of the two rolls reach the specific speed of the target (T3 in the figure), the amounts of the two rolls are substantially the same (the areas of ΔL1 and ΔL2 are substantially the same). In the conveyance operation, the slack of the paper 26 is kept substantially constant.

The above-mentioned rise time difference ΔT1 and the waiting time ΔT can be said to be substantially proportional. Therefore, the proportional coefficient k1 of ΔT=k1×ΔT1 is determined in advance by experiments, and the information is previously recorded as the relationship information. NVRAM. Therefore, in this method, the time from the start of driving to the arrival of the specific speed is determined for each of the paper feed roller 29 and the conveyance roller 30. (In the example shown in FIG. 4(B), TA and TB are obtained, ΔT1 is calculated based on the difference, and the proportional coefficient k1 as the relationship information is used, and ΔT=k1×ΔT1 is used. The relationship is determined by the waiting time ΔT.

Further, each of the drive data stored in the RAM is used for the determination of the waiting time ΔT, and the data is appropriately acquired and memorized by the transport control unit 22. Further, the conveyance speed of the paper feed roller 29 and the conveyance roller 30 and the corresponding duty value of the motor 27 (here, the amount of current supplied to the motor 27) are memorized at specific time intervals.

The second method is a method of determining the waiting time ΔT based on the difference ΔL between the paper feed roller 29 and the conveyance roller 30 until the conveyance amount is increased. In this case, the difference between the transport amount ΔL and the waiting time ΔT may be said to be substantially proportional. Therefore, the proportional coefficient k2 of ΔT=k2×ΔL is determined in advance by experiments, and the information is used as the above. Relational information is pre-memorized in NVRAM. Therefore, in this method, the paper feed roller 29 and the conveyance roller 30 are each obtained from the start of the driving and the time from the start of the driving of the paper feed roller 29 to the above-described specific speed (Fig. 4(B) In the TA), the amount of the transport paper 26 is calculated, and ΔL is calculated based on the difference therebetween, and the waiting time ΔT is determined based on the relationship of ΔT = k2 × ΔL using the proportional coefficient k2 as the relationship information.

In the example shown in FIG. 4(B), the conveyance amount in the acceleration of the paper feed roller 29 is the conveyance amount from the time T1 to T3, and the conveyance amount in the acceleration of the conveyance roller 30 is from T2 to T4. The amount of conveyance is calculated as ΔL based on the difference between the conveyance amounts.

Next, the third method will be described. This method utilizes the difference in Duty value of each of the motor 27 of the paper feed roller 29 and the transport roller 30 after reaching the above specific speed. ΔD calculates the difference between the behavior of the paper feed roller 29 and the conveyance roller 30 at the start of driving. That is, the waiting time ΔT is determined based on the Duty value difference ΔD described above.

Fig. 5 is a view showing an example of the duty value of the motors 27A and 27B over time. The Duty value indicates the amount of current supplied to each motor 27 in a relative value, and indicates that the larger the value, the larger the force to be applied to the roller.

Fig. 5 shows the Duty values of the motors 27A (curve A) and 27B (curve B) from the start of driving of the paper feed roller 29 and the conveyance roller 30. Usually, since a large force is required at the time of starting, the Duty value is a mountain shape as shown in Fig. 5, and becomes a substantially fixed Duty value after reaching the target speed.

As for the two rolls to be controlled to the same target speed, the larger the duty value means the larger the load (the power required for driving), that is, the greater the back tension applied to the paper feed roller 29. Therefore, the above-described rising delay at the start of driving can be calculated from the Duty value difference. Therefore, in this method, the waiting time ΔT is determined based on the Duty value difference. Further, since the Duty value is largely fluctuated and unstable during the control at the start of driving, the used Duty value difference uses a stable period of time after reaching the above specific speed (for example, the period shown in P of FIG. 5). The Duty value difference is ΔD.

In this case, since the Duty value difference ΔD and the waiting time ΔT can be said to be substantially proportional, the ratio coefficient k3 of ΔT=k3×ΔD is determined in advance by experiments, and the information is used as The above relationship information is memorized in NVRAM. Therefore, in this method, a representative Duty value of each of the rollers after the paper feed roller 29 and the conveyance roller 30 reach the specific speed is obtained, and ΔD is calculated based on the difference, and the ratio as the relationship information is used. The coefficient k3 determines the waiting time ΔT based on the relationship of ΔT = k3 × ΔD.

Furthermore, the representative Duty value can be set to an average of a plurality of Duty values detected within a predetermined time.

Furthermore, among the three methods, here, the relationship between the information (ΔT1, ΔL, ΔD, collectively referred to as ΔX) for determining the waiting time and the waiting time ΔT is linear. However, the relationship may be set to a function f of ΔT=f(ΔX). In this case, the function f is also set in advance and recorded in advance as relationship information.

When the waiting time ΔT is determined in this manner and stored in the RAM, and the value is updated (step S9), the control processing for one series of the transfer operation is ended, and thereafter, the same processing is repeatedly executed.

Further, since the information (ΔT1, ΔL, ΔD) for determining the waiting time differs from the waiting time depending on the type of the paper 26, etc., it is also possible to use each of the printers 2 The above relationship information is prepared in advance by using paper.

As described above, in the transport system of the printer 2 of the present embodiment, the start timing of the transport roller 30 is appropriately delayed based on the behavior at the time of the previous transport operation, that is, based on the previous situation. Therefore, the conveyance delay at the start of the start of the paper feed roller 29 can be appropriately eliminated, and the slack of the paper 26 between the paper feed roller 29 and the conveyance roller 30 can be kept constant without change during the conveyance operation. As a result, even if the conveyance condition such as the remaining amount of the roll paper 25 changes, the back tension acting on the conveyance roller 30 can be eliminated, and the paper 26 can be accurately supplied from the conveyance roller 30 to the printing position to improve the printing quality.

Further, since the slack that is initially set is substantially not changed, there is no excessive slack and the paper 26 is in contact with the member of the transport path, and there is no need to eliminate the space in the transport path. on The device is expanded by the reverse tension.

Moreover, this conveying method can function more effectively in the apparatus using the roll paper 25 which has a back tension which acts to the paper feed roller 29 and is easy to change.

Further, since the waiting time ΔT of the transport roller 30 is determined by using appropriate indexes, accurate control can be performed.

Further, as described above, by preparing the above-described relationship information for each type of paper and performing control, more accurate control can be performed.

Further, in the present embodiment, the printing medium is paper, but the sheet medium is not limited thereto.

The scope of the present invention is not limited to the above-described embodiments, and the invention described in the claims and the equivalents thereof.

1‧‧‧Main device

2‧‧‧Printer

21‧‧‧Print Control Department

22‧‧‧Transportation Control Department

23‧‧‧ head

24‧‧‧Press

25‧‧‧Roll paper

26‧‧‧ paper

27A‧‧‧Motor

27B‧‧‧Motor

28A‧‧‧ driven roller

28B‧‧‧ driven roller

29‧‧‧Feed roller

30‧‧‧Transport roller

31A‧‧‧Encoder

31B‧‧‧Encoder

Fig. 1 is a schematic configuration diagram showing an embodiment of a printing apparatus to which the conveying apparatus of the present invention is applied.

FIG. 2 is a view showing an example of the behavior of the paper feed roller 29 and the conveyance roller 30 at the start of the conveyance operation.

FIG. 3 is a flowchart illustrating the procedure of processing executed by the transport control unit 22.

4(A) and 4(B) are diagrams for explaining the waiting time ΔT.

Fig. 5 is a view showing an example of the duty value of the motors 27A and 27B over time.

1‧‧‧Main device

2‧‧‧Printer

21‧‧‧Print Control Department

22‧‧‧Transportation Control Department

23‧‧‧ head

24‧‧‧Press

25‧‧‧Roll paper

26‧‧‧ paper

27A‧‧‧Motor

27B‧‧‧Motor

28A‧‧‧ driven roller

28B‧‧‧ driven roller

29‧‧‧Feed roller

30‧‧‧Transport roller

31A‧‧‧Encoder

31B‧‧‧Encoder

Claims (18)

A conveying device comprising: an upstream side roller that sends a sheet-shaped processed medium to a conveying path; a downstream side roller that supplies the fed medium to a processing position; and a control unit that controls the upstream side roller and The downstream side roller is driven to transport the medium to be processed at a constant speed, and the control unit determines the transport operation based on the specific information of the upstream roller and the downstream roller during the previous transport operation. The start timing of the upstream side roller and the downstream side roller at the beginning. The conveying device of claim 1, wherein the specific information indicates information on behaviors of the upstream side roller and the downstream side roller reaching the constant speed at the time of the previous conveying operation. The transport apparatus according to claim 1, wherein the specific information is drive information at the time of the constant speed of the upstream side roller and the downstream side roller at the time of the last transport operation. The transport apparatus of claim 1, wherein the determining the timing of the activation is such that a start timing of the downstream side roller is delayed with respect to the upstream side roller. In the conveying apparatus of claim 2, the information indicating the behavior until the constant speed is reached is the time from the start of the upstream side roller and the downstream side roller until the constant speed is reached. The conveying device of claim 2, wherein the information indicating the behavior of reaching the constant speed is required to be started from the start of the upstream side roller until the constant speed is reached from the start of the upstream side roller and the downstream side roller. By the time, each of the upstream side roller and the downstream side roller is moved The amount of the above processed media is sent. The conveying device of claim 3, wherein the driving information at the constant speed is information indicating a magnitude of power required to drive the upstream roller and the downstream roller. The transport apparatus of claim 2, wherein the information indicating the behavior up to the constant speed, the driving information at the constant speed, and the information indicating the relationship between the start timings are held in advance for each type of the processed medium . The transport apparatus of claim 3, wherein the information on the relationship between the drive information at the constant speed and the start timing is held in advance for each type of the processed medium. The conveying apparatus of claim 1, wherein the medium to be processed is supplied to the upstream side roller in a state of being held in a roll shape. A printing apparatus comprising the conveying apparatus according to any one of claims 1 to 10, wherein printing is performed on the processed medium at the processing position. A transport method comprising: an upstream roller that feeds a sheet-shaped processed medium to a transport path; and a downstream roller that supplies the fed media to a processing position And a control unit that controls driving of the upstream roller and the downstream roller to transport the processed medium at a constant speed; the transport method is characterized in that the control unit is based on the upstream of the previous transport operation The specific information of the side roller and the downstream roller determines the start timing of the upstream roller and the downstream roller at the start of the transport operation. The method of transferring the request item 12, wherein the specific information indicates information on behaviors of the upstream side roller and the downstream side roller reaching the constant speed at the time of the previous transport operation. The transfer method of claim 12, wherein the specific information is drive information at the time of the constant speed of the upstream side roller and the downstream side roller at the time of the last transfer operation. The transfer method of claim 12, wherein the determining of the start timing is such that the start timing of the downstream side roller is delayed with respect to the upstream side roller. The transfer method of claim 13, wherein the information indicating the behavior until the constant speed is reached is from the start of the upstream side roller and the downstream side roller to the time until the constant speed is reached. The method of conveying the item of claim 13, wherein the information indicating the behavior of reaching the constant speed is required from the start of each of the upstream side roller and the downstream side roller, after the upstream side roller is self-starting until reaching a constant speed The amount of the medium to be processed is transferred by each of the upstream roller and the downstream roller until the time. The transport method of claim 14, wherein the driving information at the constant speed is information indicating a magnitude of power required to drive the upstream roller and the downstream roller.