JP2011068100A - Printing apparatus, and printing method - Google Patents

Abstract

An object of the present invention is to optimize overlay while taking into account actual behavior of a carriage and behavior of a feeding operation.
A first driving unit that controls driving of a carriage, a second driving unit that controls a feeding operation, and a variation that acquires a variation factor that affects the first driving unit and the second driving unit. Element acquisition means, time acquisition means for acquiring the actual time required for the carriage in the previous pass to start printing and the actual time required for the end of the feed operation in correspondence with the variable elements, and the acquired variable elements It has behavior prediction means for predicting each time in the current pass based on the acquired real time, and drive control means for optimizing the overlay based on the predicted time.
[Selection] Figure 5

Description

  The present invention relates to a printing apparatus and a printing method for controlling behavior of a recording medium feeding operation and carriage operation.

  2. Description of the Related Art Conventionally, in a printing apparatus, for the purpose of improving throughput during printing, the feeding operation and the carriage operation are overlapped so that printing is started with the carriage positioned in a predetermined area immediately after the feeding operation is completed. That is, when printing for one pass is completed, the motor is driven to perform a feeding operation, and the carriage motor (CR motor) is driven at a predetermined timing during the feeding operation to start the carriage movement. This is a process in which the carriage is positioned in the printing area and printing is started simultaneously with the end of the feeding operation.

  In order to perform superposition, it is necessary to set the drive timing of the carriage in accordance with the feed amount of the motor. Therefore, in the conventional printing apparatus, the carriage drive timing is set in advance using a table, and the carriage is driven in accordance with the drive schedule stored in the table (see, for example, Patent Document 1).

  Further, in actual superposition, the acceleration value or speed of the carriage may change, and the carriage may not reach a predetermined position at the end of the feeding operation, and a waiting time may occur before printing is started. . For this reason, a printing apparatus that optimizes overlay by taking the speed or acceleration of the carriage into account is also disclosed (for example, see Patent Document 2).

JP 2004-90431 A Japanese Patent Laid-Open No. 2001-232882

  In the conventional overlay optimization, only the behavior of the carriage is considered, and the behavior of the feeding operation is not considered. Therefore, even if only the change in the behavior of the carriage is taken into account, it is difficult to optimize the overlay when the feeding operation does not follow the target behavior.

  The present invention has been made in view of the above problems, and an object of the present invention is to optimize the overlay while taking into consideration the actual behavior of the carriage and the behavior of the feeding operation.

  In order to solve the above-described problems, according to the present invention, there is provided a printing apparatus that performs superposition for starting printing by controlling the position of a carriage in accordance with a feeding operation of a recording medium, and controls the driving of the carriage. 1 driving means, second driving means for controlling the feeding operation, fluctuation element obtaining means for obtaining a fluctuation element affecting the first driving means and the second driving means, and the fluctuation element Corresponding to the time acquisition means for acquiring the actual time until the carriage starts printing in the previous pass and the actual time required to complete the feeding operation, the acquired variable element, and the acquired Behavior prediction means for predicting the time required for the carriage to start printing and the time required for the feed operation to end in the current pass based on the actual time; Set the drive timing of the carriage on the basis of time, it is constituted with a drive control means for optimizing the overlay.

In the invention configured as described above, the fluctuation element acquisition means acquires the fluctuation elements that affect the first driving means and the second driving means, and the time acquisition means corresponds to the fluctuation elements in the previous time. The real time until the carriage in the pass starts printing and the real time required for the feeding operation are acquired, and the behavior predicting means is based on the obtained variation factor and the obtained real time, The time required for the carriage to start printing and the time required for the feeding operation to end are predicted, and the control means sets the carriage drive timing based on the predicted time to optimize the overlay. .
Therefore, it is possible to optimize the overlay while considering the behavior of the carriage driving and feeding operation, and the throughput of the printing apparatus can be improved.
Furthermore, since only the drive timing of the carriage is adjusted, for example, it is not necessary to improve the performance of the first drive control unit such as increasing the speed of the carriage in accordance with the behavior of the carriage, and the control according to the present invention without increasing the cost. It can be performed.
Here, the pass means that the carriage prints a predetermined line by one movement in the main scanning direction.

The drive control means classifies the time at which the second drive means finishes the feeding operation into a time for sending the recording medium to a predetermined position and a time for completely stopping the recording medium, The driving timing of the carriage may be adjusted based on the time and the time required for the carriage to finish printing.
In the invention configured as described above, it is possible to consider the behavior including the stop of the sheet during the feeding operation, and it is possible to optimize the overlay in more detail.

Further, the time acquisition means measures an actual time until the carriage starts printing in the previous pass and an actual time required to complete the feeding operation, and updates the actual time according to the measurement result. It is good also as a structure acquired while.
In the invention configured as described above, since the real time is updated for each path, it is possible to perform the optimization of the superimposition more reflecting the behavior of the previous path.

When the actual time of the previous pass is reflected in the behavior of the current pass, there is no need to acquire a variable element that does not change between the previous pass and the current bus. For this reason, the variation factor acquisition unit may acquire only a variation factor that varies for each path.
In the invention configured as described above, the number of variable elements to be acquired can be reduced.

Further, as an example of a method for acquiring a variation factor, the variation factor acquisition unit may acquire only a variation factor that most affects the behavior of the first drive unit and the second drive unit.
There are various variable factors that affect the carriage behavior and feed operation, but only the ones that most affect the drive and feed operations of the carriage are obtained to predict the behavior. Thus, it is possible to optimize the overlay while reducing the processing load.

Further, the first drive means starts the carriage drive after a stop stabilization time after the end of the previous pass printing, and the drive control means sets the carriage drive timing to the stop stabilization time. In the case of eroding, the drive of the carriage may be started after the stop stabilization time.
In the invention configured as described above, the present invention can be applied to a configuration in which driving is started after the carriage is stopped for a predetermined time.

When the CR reciprocates with an endless belt, the endless belt is stretched by a driving pulley directly connected to the CR motor and a driven pulley not directly connected to the CR motor. Therefore, the acceleration followability of the carriage changes depending on whether the endless belt is directly driven by the driving pulley or indirectly driven via the driven pulley. Therefore, the carriage may be configured to perform printing while reciprocating in the main scanning direction, and the drive control unit may be configured to change the drive timing in accordance with the direction in which the carriage moves.
In the invention configured as described above, even when acceleration followability differs depending on the moving direction of the CR, the overlay can be optimized in more detail by setting the drive timing in consideration of this acceleration delay. Can do.

  Further, the present invention can be applied not only to the invention of products but also to a printing method using superposition.

1 is a block configuration diagram showing a configuration of a printing apparatus 100. FIG. It is a side view which shows the inside of a printing apparatus. 2 is a block configuration diagram showing a configuration of a DC unit 40. FIG. 3 is a block configuration diagram showing an acceleration control unit 41. FIG. 6 is a diagram illustrating a driving schedule for CR and paper feeding in the printing apparatus 100. FIG. It is a table | surface explaining the list of the fluctuation elements which the fluctuation element acquisition part 41a acquires as an example. 6 is a flowchart for explaining measurement in the printing apparatus. It is a figure for demonstrating the relationship between the parameter | index acquired in measurement, and load (tau) '. It is a graph which shows the relationship between the acceleration time and distance in each variable element. 4 is a flowchart for explaining processing executed by an acceleration control unit 41. It is a flowchart explaining the flow in which the DC unit acquires the behavior of the CR motor 92 and the PF motor 81 in a predetermined path (previous path). FIG. 11 is a flowchart in which the DC unit optimizes the superimposition of the current pass based on the actual behavior measured in the flow shown in FIG. 10. It is a flowchart explaining the process which the control calculating part 41b performs in step S16.

Embodiments of the present invention will be described below in the following order with reference to the drawings.
(1) First embodiment:
(2) Second embodiment:
(3) Other embodiments:

(1) First embodiment:
=== Summary of Invention ===
FIG. 1 is a block configuration diagram illustrating a configuration of the printing apparatus 100. FIG. 2 is a side view showing the inside of the printing apparatus. As shown in the drawing, a carriage 91 (hereinafter referred to as CR) is mounted inside the printing apparatus 100. The CR 91 is attached to an endless belt 93 stretched by a driving pulley 94 and a driven pulley 95, and the print head 30 is disposed below the CR 91. An ink cartridge for supplying ink to the print head 30 is detachably attached to the upper portion of the CR 91. In addition, a carriage motor 92 (hereinafter referred to as a CR motor 92) for driving the CR 91 is mounted on the back side of the printing apparatus 100. The CR motor 92 drives the driving pulley 94, thereby causing the endless belt 93 to move. Power is transmitted and the CR 91 is reciprocated in the main scanning direction. Therefore, a first driving means is realized by the CR motor 92 and a driving mechanism (not shown).

  In addition, inside the printing apparatus 100, a paper feeding unit 83 including a PIC roller 83a for taking out paper from the paper tray TR and intermediate rollers 83b and 83c, and a paper fed by the paper feeding unit 83 are sub-scanned. And a PF roller 82 for feeding paper in the direction. A PF motor 81 is mounted on the lower end side of the printing apparatus 100, and the PF motor 81 is connected by a gear (not shown) and functions as power for the PF roller 82 and the paper feed unit 83. Therefore, the second driving unit is realized by the PF motor 81 and the PF roller 82. In the present embodiment, the CR motor 92 and the PF motor 81 are described as DC motors, but are not limited thereto.

  Further, the printing apparatus 100 detects the behavior of the host IF 51, the CPU 52, the ASIC 53, the DC unit 40, the PF driver 54, the CR driver 55, the encoder 60 that detects the behavior of the CR 91, and the behavior of the PF roller 82. A rotary encoder 70 and a memory 56 (not shown) including a ROM, a RAM, and an EEPROM are included. The ASIC 53 is connected to the host PC via the host IF 51 and realizes transmission / reception of various data transmitted from the host PC. The ASIC 53 controls printing resolution and driving of the print head 30 based on print data transmitted from the host PC.

  The CPU 52 controls the overall driving of the printing apparatus 100 and sets the driving schedule of the CR motor 92 and the PF motor 81 and the printing schedule of the print head 30 based on the print data received from the host PC via the host IF 51 and the ASIC 53. The CPU 52 controls the drive of the storage head via the head driver according to the various schedules set. Further, the CPU 52 outputs a command signal based on the drive schedule to the DC unit 40.

  FIG. 3 is a block configuration diagram showing the configuration of the DC unit 40. The DC unit 40 controls the CR motor 92 via the CR driver 55 based on the command signal, and controls the PF motor 81 via the PF driver 54. The DC unit 40 includes an acceleration control unit 41 and a timer 42 that control an acceleration period and a deceleration period of each motor, a PID control unit 43 that controls a speed of each motor in a constant speed period, an acceleration control unit 41 and PID control. The PWM control unit 44 that outputs a signal to each driver based on the duty signal DXP output from the unit 43 is a main component.

  The acceleration control unit 41 controls the acceleration of the CR motor 92 and the PF motor 81 when a command command is output from the CPU 52. At this time, every time the acceleration control unit 41 receives an interrupt signal from the timer 42, the acceleration control unit 41 integrates a predetermined duty signal DXP and outputs it to the PWM control unit 44. The PID control unit 43 includes a proportional element (P), an integral element (I), and a differential element (D), and a CR motor 92 and a PF based on pulse signals output from the encoder 60 and the rotary encoder 70. The moving speed, moving direction, and position of the motor 81 are calculated, a predetermined duty signal DXP is integrated based on the deviation from the target speed, and output to the PWM controller 44.

  FIG. 4 is a block configuration diagram showing each block of the acceleration control unit 41 according to the first embodiment. The acceleration control unit 41 includes a variation factor acquisition unit (variation factor acquisition unit) 41a, a control calculation unit (drive control unit) 41b, and a behavior calculation unit (behavior prediction unit) 41c. Here, the variation factor acquisition unit 41a acquires a variation factor that affects the behavior of the CR 91 and the paper feed. The variable element will be described later. Further, the behavior calculation unit 41c predicts the CR 91 and the paper feeding behavior according to the actual behavior of the CR 91 and the paper feeding actually measured in the previous pass, and the obtained variation factor. Then, the control calculation unit 41b sets the drive start timing of the CR 91 based on the predicted CR 91 and paper feeding behavior.

=== Description of superposition ===
FIG. 5 is a diagram illustrating a driving schedule for CR and paper feeding in the printing apparatus 100. Hereinafter, “overlay” in the printing apparatus 100 and conventional problems will be described with reference to FIG. In FIG. 5, the horizontal axis represents time t, and the vertical axis represents CR91 or paper feed speed. FIG. 5A shows a driving schedule for CR 91 and paper feed set by the target table stored in the memory 56. On the other hand, FIG. 5B shows an actual CR 91 and paper feed driving schedule as an example.

  When a print command is input from the CPU 52 to the DC unit 40, the DC unit 40 drives the PF motor 81 to feed the paper to a predetermined position. When the paper reaches a predetermined position, the paper sensor detects the paper, and the DC unit 40 stops the PF motor 81. At this time, the paper feed drive schedule changes from the previous pass end time in the acceleration period, constant speed period, and deceleration period according to the target table, and after reaching the target position at time t2, passes through the stop stabilization time and passes through time t3. Stop at. In addition, the movement distance in each period can be represented by the area in the drive schedule shown in FIG. 5, and the distance is preset.

  Further, the driving schedule of the CR 91 changes from the previous pass printing end time in the deceleration period, the stop period, and the acceleration period according to the target table. Further, the DC unit 40 drives the CR motor 92 when the PF motor 81 reaches the position EPp at the time t0 so that the CR 91 can start printing at the paper feed end time t3, and causes the CR 91 to reach the speed Vc at the time t3. To achieve superposition.

ここで、図４（Ａ）に示すように、印刷開始時間Ｔ１は、ＣＲの駆動開始時刻ｔ０から印刷を開始するまでに要する時間をいう。また、位置到達時間Ｔ２は、紙送りにおける時刻ｔ０から目標位置に到達するまでの時間をいう。そして、停止安定時間Ｔ３は、紙送り（ＰＦモーター８１）が目標位置に到達してから速度が０になるまでの時間をいう。 As shown in FIG. 5A, in the superposition, the time required for the CR 91 to start printing (hereinafter referred to as the printing start time T1) and the time when the paper in paper feeding reaches the target position. The relationship between the time required (hereinafter referred to as position arrival time T2) and the time required for the paper to stop and stabilize (hereinafter referred to as stop stabilization time T3) is expressed by the following (formula 1). It is prescribed by using.

Here, as shown in FIG. 4A, the print start time T1 is the time required from the CR drive start time t0 to the start of printing. The position arrival time T2 is the time from the time t0 in the paper feed until the target position is reached. The stop stabilization time T3 is the time from when the paper feed (PF motor 81) reaches the target position until the speed becomes zero.

  The driving schedule for CR91 and paper feed is set in advance so that superposition can be realized by the target table. However, the acceleration delay of the CR motor 92 and the deceleration advance of the PF motor 81 occur, and the target superposition cannot always be realized. That is, as shown in FIG. 4B, when the CR 91 does not follow the target acceleration value during the acceleration period, or when the paper feed is completed earlier than the target time in the paper feed, the CR 91 is stopped after the paper feed is stopped. Waiting time Tw occurs until printing starts (t3-t4), and the throughput of the printing process is lowered.

  Therefore, in the present invention, the actual behavior of CR91 and paper feeding in a predetermined pass is acquired by measurement, and the behavior in the subsequent pass is predicted based on the acquired actual behavior. Then, the overlay is optimized based on the predicted value in a later pass. That is, the CR 91 and the paper feed behavior are predicted from the actual behavior of the CR 91 and the paper feed measured in the previous pass in consideration of the variation factors of the current pass. Then, the driving timing of the CR 91 is adjusted based on the predicted value to optimize the overlay. In the present invention, since only the driving timing of the CR 91 is adjusted, for example, it is not necessary to perform speed control for increasing the speed of the CR 91 in accordance with the behavior of the CR 91, so there is no need to improve the performance of the CR motor 92 or the PF motor 81. Overlay can be optimized without increasing costs.

ここで、（式２−１）は、ＣＲモーター９２の加速期間での力の関係を示す。また、（式２−２）はＰＦモーター８１の減速期間での力の関係を示す。そして、（式２−３）は、ＰＦモーター８１の停止安定期間での力の関係を示す。θ”（ｔ）はモーターの回転加速度、θ’（ｔ）はモーターの回転速度、θ（ｔ）はモーターの回転距離、Ｊは慣性モーメント、Ｄは速度係数、Ｋは、ばね係数、τはモーターが発生させるトルク、τ’は負荷、τ”は紙送りの停止後、逆転をしようとする力を示す。また、各係数の添え字ｃは，ＣＲモーター９２に関するものを、ｐはＰＦモーター８１に関するものを、ｐｓは停止安定に関するものを示す。例えば、慣性モーメントＪは質量ｍの物体が回転半径ｒで回転している場合Ｊ＝ｍｒ２となるが、ＣＲ９１にインクを積載するオンーキャリッジ方式の印刷装置では、印刷処理毎にインク重量ｍが変化するため、右辺が一定であればＣＲモーター９２にかかる慣性モーメントＪが変動し各項の値も変化する。 === Variable factors ===
The variable element acquisition unit 41a acquires a variable element that affects the behavior of CR and PF. The relationship of the force which acts on a motor can be represented by the following (Formula 2-1) (Formula 2-2) (Formula 2-3) using the equation of motion.

Here, (Equation 2-1) shows a force relationship during the acceleration period of the CR motor 92. Further, (Equation 2-2) shows the relationship of force during the deceleration period of the PF motor 81. And (Formula 2-3) shows the relationship of force in the stop stable period of the PF motor 81. θ ″ (t) is the rotational acceleration of the motor, θ ′ (t) is the rotational speed of the motor, θ (t) is the rotational distance of the motor, J is the moment of inertia, D is the speed coefficient, K is the spring coefficient, and τ is Torque generated by the motor, τ ′ is a load, and τ ″ is a force for reverse rotation after the paper feed is stopped. Further, the subscript c of each coefficient is related to the CR motor 92, p is related to the PF motor 81, and ps is related to stop stability. For example, the moment of inertia J is J = mr2 when an object having a mass m is rotated at a rotation radius r. However, in an on-carriage type printing apparatus in which ink is loaded on the CR 91, the ink weight m is increased for each printing process. Therefore, if the right side is constant, the moment of inertia J applied to the CR motor 92 varies and the value of each term also changes.

  In the present embodiment, the following elements are used as variable elements that affect the behavior of each motor. FIG. 6 is a table illustrating a list of variable elements acquired by the variable element acquisition unit 41a41a as an example. In FIG. 6, each element of the ink weight m, the motor torque τ, the load τ ′, and the reverse rotation τ ″ after the stop is shown as a variable element. In addition to the list of the variable elements, FIG. The main factors of each variable element and the acquisition method are described below.

  The ink weight m indicates the weight of ink loaded on the CR 91 in the on-carriage CR 91. Therefore, the value changes for each path. As described above, the ink weight m is a variable that affects the value of the moment of inertia J of the CR 91. As an ink weight acquisition method, a value stored in an ink counter provided in an ink case is read, or indirectly according to an ink supply amount.

  The motor torque τ is a force generated by the motor based on electric power, and is calculated by multiplying the torque constant Kt by the current I. Furthermore, it is known that the motor torque τ varies according to the temperature around the motor. Therefore, in order to acquire the motor torque, the value of the motor torque τ may be acquired from the torque constant Kt set in each period of the CR motor 92 and the PF motor 81 and the current I flowing through each motor. Then, the ambient temperature is measured by a thermistor mounted inside the printing apparatus 100, and the value of the motor torque τ is acquired using a table indicating the relationship between the temperature and the motor torque. Moreover, since the heat quantity W can be calculated using the internal resistance R and the current I using W = R * I2, in addition to using the thermistor, the heat quantity is calculated using the current flowing through the motor. It may be.

  The load τ ′ is a force that counteracts the driving of the motor when the motor generates the motor torque τ and performs the driving. As the load τ ′, there are a load that changes due to a temperature change such as a driving resistance of a motor, and a load that changes according to the resistance of the printing apparatus 100. Furthermore, some PF motors 81 change due to the paper type, paper size, and paper state (conveyance path) of the paper to be fed.

  For the load τ ′ that changes according to the temperature change and tolerance, an index indicating the load is acquired by measurement, and then a value is acquired using a table indicating the relationship between the index and the load τ ′. The measurement is a process executed when the printing apparatus 100 is turned on, when an ink tank is replaced, or when a predetermined number of sheets are printed. Details thereof will be described later. The paper type and paper size of the paper to be fed are set after the paper type is set on the driver, the paper type sensor or paper size sensor in the printing apparatus 100 is used, and the paper type and load τ. Get a value using a table showing the relationship with '.

  The load τ ′ resulting from the sheet state is a load that occurs to react to the motor torque τ in the process in which the sheet fed to the sheet feeding unit is conveyed by the PF roller 82. For example, as illustrated in FIG. 2, when the PF roller 82 transports the sheet with the leading end of the sheet nipped by the intermediate roller 83 b, the load τ ′ on the PF motor 81 increases. On the other hand, when the leading edge of the sheet exceeds the intermediate roller 83b and the nip by the intermediate roller 83b is released, the load τ 'on the PF motor 81 decreases. Therefore, in order to obtain the load τ ′ that changes due to the paper state, the position of the paper in the paper feed is detected by a sensor mounted inside the apparatus, and the relationship between the detected paper position and the load τ ′ is determined. What is necessary is just to acquire a value from the table shown.

The reverse rotation τ ″ after stopping is a phenomenon in which the PF roller reverses after the paper feed in the PF motor 81 is completed, and occurs due to the mechanical structure and the paper state. In addition, the reverse rotation after the stop includes the PF roller and the intermediate roller. As an example, a value (Tasf / Tpf) obtained by dividing the torque Tasf of the intermediate roller 83b by the torque Tpf of the PF roller 82 can be used as a value indicating the ease of reverse rotation of the PF roller 82. The value of the ease of reverse rotation is acquired by the reverse rotation detection measurement, and the value is acquired based on a table that defines the relationship between the acquired value and the reverse rotation torque after stopping.
Then, as a method for acquiring the value of reverse rotation after stop due to the paper state, a table showing the relationship between the paper position during paper feeding and the reverse rotation torque after stop is used, as with the motor torque τ due to the paper state. To get the value. The reverse rotation detection measurement is executed when the printing apparatus 100 is turned on, when the ink tank is replaced, or when the number of printed sheets reaches a predetermined number, and is calculated from the current value flowing through each motor.

=== About Measurement ===
The measurement will be described below. FIG. 7 is a flowchart for explaining measurement in the printing apparatus. FIG. 8 is a diagram for explaining the relationship between the index acquired in the measurement and the load τ ′. The measurement is a process executed when the printing apparatus is turned on, when the ink tank is replaced, or when a predetermined number of sheets are printed. In FIG. 7, the measurement is described using the PF motor 81 as an example, but the process is the same for the CR motor 92.

  First, the PF motor 81 is activated (step S1), and the acceleration control unit 41 accelerates the PF motor 81 until the rotation speed approaches the target speed Vp1. Next, when the rotational speed of the PF motor 81 approaches Vp1, the process shifts to control by the PID control unit 43 (step S2), and constant rotational driving is performed at the target rotational speed Vp1. At this time, the output signal DXI of the integration element of the PID control unit 43 becomes a constant value.

  When the difference between the rotation speed of the PF motor 81 and the target rotation speed Vp1 falls below a predetermined value and the output signal value DXI becomes a predetermined value, the output signal value DXI is sampled at a predetermined interval (step S3). Thereafter, when the PF roller rotates once, sampling of the output signal DXI is terminated (step S4).

  Then, the sampled N output signals DXI are divided by the length of the recording period, and an average value DXIavr1 of the output signal of the integration element corresponding to the load of the PF motor 81 in the constant speed period at the target rotational speed Vp1 is calculated. (Step S5).

  Next, with respect to Vp2 different from the target rotational speed Vp1, the processing of step S1 to step S5 is performed in the same manner, and the average of the output signals of the integration elements according to the load of the PF motor 81 in the constant speed period at the target rotational speed Vp2 The value DXIavr2 is calculated. The calculated DXIavr1 at the target rotational speed Vp1 and DXIavr2 at the target rotational speed Vp2 are stored in a predetermined memory.

  Hereinafter, the relationship between the driving load and the output value of the integral element will be described with reference to FIG. It is known that the average values DXIavr1 and DXIavr2 of the output signals of the integration elements obtained by the measurement increase as the driving load of the PF motor 81 increases. Therefore, the average values DXIavr1 and DXIavr2 of the output signals of the integration elements are indexes indicating the driving load of the PF motor 81. Therefore, if a table defining the relationship between the integration element output signal average value DXIavr and the load τ ′ is created, PF based on the average value DXIavr1 or DXIavr2 of the integration element output signal obtained by the measurement is used. It becomes possible to acquire the load τ ′ of the motor 81. The measurement has been described above.

=== About Behavior Calculation Unit ===
The behavior calculation unit 41c measures the behavior of the CR 91 and the paper feed at the time of executing the predetermined pass, and predicts the behavior of the CR 91 and the paper feed of the subsequent pass based on the measured value of the behavior and the fluctuation element. The behavior calculation unit 41c measures the behavior of the CR 91 and the paper feed when executing a predetermined pass, and updates the prediction table indicating the relationship between the actual measurement time and the movement distance based on the actual measurement value. Then, the behavior calculation unit 41c predicts the behavior of CR and paper feeding in accordance with the updated prediction table and the acquired variation factors.

  FIG. 9 is a graph showing the relationship between acceleration time and distance in each variable element. For example, if the value of the ink weight m as a variable element changes, the moment of inertia also changes accordingly, so the acceleration time A1 required to reach a certain rotational distance changes. Therefore, the prediction table defines the acceleration time A1 of CR91, the deceleration time B1 of paper feed, and the stop stabilization time C1 in each variable element. The prediction table includes a first table that predicts the behavior of the CR 91 and second and third tables that predict the behavior of paper feeding. Further, the value of the prediction table is updated every time printing is performed for each pass. The initial value of each prediction table is acquired by a theoretical value using an equation of motion, actual measurement data, or process acquisition, and is stored in the memory 56.

  The first table defines the acceleration time when the CR moves a predetermined distance, and the value is stored for each variable element. That is, in the first table, the movement distance of the CR 91 and the acceleration time A1 of the CR 91 corresponding to this movement distance are stored for each variable element. Therefore, when the variable elements are the ink weight m, the motor torque τ, and the load τ ′, the first table is set by using the value of each variable element and the moving distance as reference values. Here, the moving distance is a distance that the CR 91 moves to start printing, and is a value set in advance for each paper type.

  The second table shows the relationship between the paper feed amount of the PF roller 82 and the time required to achieve this paper feed amount. Like the first table, the second table corresponds to each variable element and the feed amount. The value is stored. And the 3rd table shows the stop stable time in paper feeding, and the value is set up according to each variation factor. The stop stabilization time is a value corresponding to one of the values in accordance with the torque τ "of reverse rotation after stop, which is a variable factor.

  Here, as a variation factor for referring to the values of each table, a variation factor that changes the CR 91 or a paper feeding behavior that is most affected may be set. For example, the ink weight m is a value that changes the moment of inertia J of the motor, but the change of the moment of inertia J can be considered as the most influential element that changes the behavior of the motor. On the other hand, the motor torque τ and the load τ ′ do not vary greatly in each path. Therefore, in CR91, only the ink weight m may be used as a variable element as a variable element. In the paper feed, only the motor torque τ and the load τ ′ are variable factors, but a value obtained by subtracting the load τ ′ from the motor torque τ may be used as a paper feed variable factor. Here, it is possible to achieve a balance between the prediction accuracy and the reduction of the processing load or the memory used by using only the variable element that most affects the behavior of the motor.

=== Regarding the Control Calculation Unit ===
The control calculation unit 41b adjusts the CR drive timing according to the prediction result to optimize the overlay. The control calculation unit 41b calculates the driving timing of the CR 91 that is optimally superimposed from the CR 91 predicted by the behavior calculation unit 41c and the paper feeding behavior, and updates the driving schedule of the CR 91.

=== About optimization of superposition ===
Hereinafter, a method for optimizing the overlay of the printing apparatus according to the present embodiment will be described with reference to FIGS. FIG. 10 is a flowchart illustrating a flow in which the DC unit 40 acquires the behavior of the CR motor 92 and the PF motor 81 in a predetermined path (previous path). FIG. 11 is a flowchart in which the DC unit 40 optimizes the superimposition of the current pass based on the actual behavior measured in the flow shown in FIG.

  Hereinafter, a method for measuring the behavior of the CR 91 and the paper feeding in the previous pass will be described with reference to FIG. It is assumed that the time measurement by the acceleration control unit 41 is performed using a timer (not shown). First, the variable element acquisition unit 41a acquires a variable element of a pass to be printed (previous pass) (step S11). The variable element acquisition unit 41a acquires the variable elements in the path to be executed from now on for each of CR91 and paper feed.

  The behavior calculation unit 41c measures the time required to move the distance Lc that the CR 91 moves before starting printing (step S12). That is, when the CR 91 starts accelerating, the encoder 60 outputs a detection pulse. The behavior calculation unit 41c analyzes this detection pulse and measures the time required for the CR 91 to move to the printing position after starting driving. Then, the acceleration time from the start of driving of the CR 91 until reaching the printing position is stored as the acceleration time A1. Since the moving distance Lc varies depending on the paper to be printed, the distance Lc is acquired in advance through a value set by the driver.

  The behavior calculation unit 41c measures the time required to feed the paper by a predetermined length (step S13). That is, when the PF roller 82 is controlled to decelerate from the predetermined speed Vp at time t0 and the paper feeding operation is executed, a detection pulse is output from the rotary encoder 70. When the paper feed is completed, the paper sensor detects the leading edge of the paper and outputs a detection signal. Therefore, the behavior calculation unit 41c analyzes the detection pulse output from the rotary encoder 70, and measures the time required to feed the paper from the time t0 to the target position. In addition, the behavior calculation unit 41c stores the above time as the deceleration time B1.

  The behavior calculation unit 41c measures a stop stabilization time in paper feeding (step S14). That is, the behavior calculation unit 41c monitors the detection pulse output from the rotary encoder 70, and measures the time from when the PF motor 81 reaches the target position until the speed becomes completely zero. The behavior calculation unit 41c stores the time from when the sheet reaches the target position until it completely stops as the stop stabilization time C1.

  The behavior calculation unit 41c updates the prediction table (step S15). The behavior calculating unit 41c updates the first to third tables based on the variation factor acquired in step S1 and the relationship between the distance and time measured according to the variation factor. The processing of the acceleration control unit 41 in the previous pass has been described above.

  Next, with reference to FIG. 11, the optimization of the overlay in the current pass will be described. The variable element acquisition unit 41a predicts each time in the current pass according to the following flow from the acceleration time A1, the deceleration time B1, and the stop stabilization time C1 measured in the previous pass.

  The fluctuation element acquisition unit 41a acquires CR91 and paper feed fluctuation elements in the current pass (step S21). Here, load τ ′ (related to temperature, tolerance, paper type and paper size), reverse rotation after stop (related to mechanical structure) is not measured in conjunction with the path in the first place, Since it can be assumed that there is no change compared to the previous pass, it is not acquired with the current pass. Therefore, in step S21, all or any of the ink weight m, the motor torque τ, the load τ ′ (related to the paper state), and the reverse rotation after stop (related to the paper state) are acquired as the variable elements.

  The behavior calculation unit 41c predicts the acceleration time A1 of the CR 91 in the current pass based on the prediction table (step S22). The behavior calculation unit 41c refers to the first table updated during the previous pass, and acquires the acceleration time A1 in the current pass of CR91 from the value corresponding to the variation factor of the current pass acquired in step S12.

  The behavior calculation unit 41c predicts the paper feed deceleration time B1 in the current pass based on the reference table (step S23). The behavior calculation unit 41c refers to the second table updated during the previous pass, and acquires the paper feed deceleration time B1 in the current pass from the value corresponding to the fluctuation element of the current pass acquired in step S12. .

  The behavior calculation unit 41c predicts the stop stabilization time C1 of the current pass based on the reference table (step S24). The behavior calculation unit 41c refers to the third table updated during the previous pass, and acquires the paper feed stop stabilization time in the current pass from the value corresponding to the variation factor of the current pass acquired in step S12. .

  Based on the times A1, B1, and C1 in the current pass acquired in steps S22 to S24, the control calculation unit 41b acquires the driving timing of the CR 91 that optimizes the overlay (step S25). FIG. 12 is a flowchart illustrating the process executed by the control calculation unit 41b in step S25. The control calculation unit 41b subtracts the paper feed deceleration time B1 and the stop stabilization time C1 in the current pass from the CR acceleration time A1 in the current pass (step S161).

  The control calculation unit 41b subtracts the time calculated in step S161 from the target driving start time t0 of the CR motor 91 to calculate the driving start time t0 'of the CR motor 92 (step S162). If the calculated drive start time t0 'does not erode in the CR91 stop stabilization time (step S163), the control calculation unit 41b calculates the position of the PF roller 82 at this time (step S164). For example, the position of the PF is obtained based on the second table in the prediction table. Here, the stop stable time of the CR 91 is a time required until the CR 91 is completely stopped after being decelerated.

On the other hand, when the calculated drive start time t0 ′ erodes the CR91 stop stabilization time (step S163), the control calculation unit 41b determines the position EPp of the PF roller 82 at the time after the CR91 stop stabilization time has elapsed. Is calculated (step S165).

  Returning to FIG. 11, the control calculation unit 41b stores the calculated position EPp of the PF roller 82 in the memory 56, and updates the driving schedule of the CR 91 (step S26). The overlay optimization according to the first embodiment has been described above.

  As described above, in this embodiment, since the behavior of the current pass is predicted based on the behavior of the previous pass and the overlay is optimized, deviations such as measurement errors can be absorbed and the overlay is more accurately performed. Can be optimized. Further, if each value stored in the prediction table is increased by superimposing printing, it is possible to realize superimposition more optimally according to the amount of information.

(2) Second embodiment:
In the configuration in which the printing apparatus 100 performs printing in accordance with the reciprocation of the CR 91, the acceleration of the CR 91 may change depending on the movement direction. As shown in FIG. 1, the CR 91 reciprocates by an endless belt 93, and this endless belt 93 is stretched by a driving pulley 94 directly connected to the CR motor 92 and a driven pulley 95 not directly connected to the CR motor 92. . Therefore, the case where the endless belt 93 is directly driven by the driving pulley 94 (hereinafter referred to as direct pulling) and the case where the endless belt 93 is driven indirectly via the driven pulley 95 (hereinafter referred to as driven pulling). )), The acceleration followability of CR91 changes. That is, in the driven pull, the endless belt 93 is driven via the driven pulley 95, so that the acceleration followability of the CR 91 is worse than the direct pull, and the printing start time of the CR 91 is delayed. Therefore, when the moving direction of the CR 91 is the driven pulling direction, the driving timing may be set in consideration of the acceleration delay of the CR 91 according to the moving direction in addition to the adjustment according to the first embodiment. With the above configuration, overlay can be optimized in more detail.

  Further, in a printing apparatus that performs printing in accordance with the reciprocation of the CR 91, the driving timing may be set in accordance with a direction (following pulling) in which acceleration followability is poor.

(3) Other embodiments:
The above-described prediction of the behavior of the CR 91 and the prediction of the paper feeding behavior are not only performed using the prediction table, but only the behavior of the CR 91 is performed using the prediction table, for example, and the actual measurement is performed for the paper feeding. A value may be used.

  Needless to say, the present invention is not limited to the above embodiments. That is, the mutually replaceable members and configurations disclosed in the above embodiments are applied by changing their combinations as appropriate. The members and configurations disclosed in the examples can be replaced with the members and configurations interchangeable with each other as appropriate, and the combination thereof is changed and applied. It is one of the present invention that a person skilled in the art can appropriately substitute the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments based on the above, and change the combination to apply. It is disclosed as an example.

DESCRIPTION OF SYMBOLS 30 ... Print head, 40 ... DC unit, 41 ... Acceleration control part, 41a ... Fluctuation element acquisition part, 41b ... Control calculating part, 41c ... Behavior calculating part, 42 ... Timer, 43 ... PID control part, 44 ... PWM control part 52 ... CPU, 53 ... ASIC, 54 ... PF driver, 55 ... CR driver, 56 ... Memory, 60 ... Encoder, 70 ... Rotary encoder, 81 ... PF motor, 82 ... PF roller, 83 ... Paper feed unit, 83a PIC roller, 83b Intermediate roller, 83c Intermediate roller, 91 Carriage, 92 CR motor, 93 Endless belt, 94 Drive pulley, 95 Driven pulley, 100 Printing device

Claims (8)

In accordance with a recording medium feeding operation, a printing apparatus that performs superposition for starting printing by controlling the position of a carriage,
First driving means for controlling the driving of the carriage;
Second driving means for controlling the feeding operation;
A fluctuation element acquisition means for acquiring a fluctuation element that affects the first driving means and the second driving means;
Corresponding to the variable element, time acquisition means for acquiring an actual time until the carriage starts printing in a previous pass and an actual time required for the feed operation to end;
Behavior prediction for predicting the time required for the carriage to start printing and the time required for the feed operation to end in the current pass based on the acquired variation factor and the acquired actual time Means,
And a drive control unit configured to set the drive timing of the carriage based on the predicted time and optimize the overlay.   The drive control means classifies the time at which the second drive means finishes the feeding operation into a time for sending the recording medium to a predetermined position and a time for completely stopping the recording medium. The printing apparatus according to claim 1, wherein the drive timing of the carriage is adjusted based on a time required for the carriage to finish printing.   The time acquisition unit measures an actual time until the carriage starts printing in the previous pass and an actual time required for the feeding operation to be completed, and acquires the actual time while updating it according to the measurement result. The printing apparatus according to claim 1, wherein the printing apparatus is a printing apparatus.   4. The printing apparatus according to claim 1, wherein the variable element acquisition unit acquires only a variable element that varies for each pass. 5.   5. The printing apparatus according to claim 1, wherein the variable element acquisition unit acquires only a variable element that most affects the carriage and the feeding operation. 6. The carriage is controlled to start acceleration after a stop stabilization period after the end of printing for the previous pass,
6. The overlay controller according to claim 1, wherein when the set drive timing of the carriage erodes during the stop stable period, the overlay control unit starts driving after the stop stable period. The printing apparatus as described in any one of. The carriage is configured to perform printing while reciprocating in the main scanning direction,
The printing apparatus according to claim 1, wherein the superimposing control unit is configured to change a driving timing according to a direction in which the carriage moves. In accordance with a recording medium feeding operation, a printing method for performing superposition for controlling printing of a carriage and starting printing,
A variable factor acquisition step of acquiring a variable factor affecting the first driving unit for controlling the driving of the carriage and the second driving unit for controlling the feeding operation;
Corresponding to the variable element, a time acquisition step of acquiring an actual time until the carriage starts printing in the previous pass and an actual time required until the feed operation is completed;
A behavior prediction step of predicting a time until the carriage starts printing in the current pass and a time until the feeding operation ends based on the acquired variation factor and the acquired actual time. When,
And a superposition control step of setting the carriage driving timing based on the predicted time and optimizing the superposition.

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