JP4484586B2 - Recording apparatus and cueing position control method of recording apparatus - Google Patents

Description

  The present invention relates to a recording apparatus and a cueing position control method of the recording apparatus, and more particularly to control of a cueing position in a recording apparatus having a servo-controlled motor for each of a paper feeding unit and a conveying unit.

  2. Description of the Related Art Conventionally, in a recording apparatus such as a printer, a recording medium feeding operation and a conveying operation are different in order to enable a parallel operation or to distribute a load on a motor and realize a high function and a high speed. A configuration using a motor is known.

  Further, in order to achieve both quietness and high speed, an increasing number of recording apparatuses use a DC motor that has a quiet driving sound and does not step out. However, the DC motor needs to be feedback controlled (servo control) based on the signal of the encoder as the position detection means, and the encoder is also required when using the DC motor, so that the cost tends to increase.

  For this reason, although the driving time during recording is relatively long and a DC motor is often used for driving and conveying operations of the carriage, in a recording apparatus using a separate motor for the paper feeding operation, A pulse motor is generally used for a paper feeding operation in which the driving time is relatively short.

  In such a recording apparatus provided with different drive sources (motors) for feeding operation and conveying operation, in order to shorten the time until the start of recording, a register for correcting skew feeding of the sheet is used. If the take-up operation is omitted and the paper fed by the paper feed roller is directly bitten into the transport roller to cue the recording paper (hereinafter referred to as “no registration”), the connection between the paper feed operation and the transport operation is Exists.

  Usually, the paper feed roller of the paper feed unit is set so as to pick up the paper and send a distance longer than the distance to the nip of the transport roller, and has a fixed transport amount. On the other hand, the conveyance amount at the time of cueing of the conveyance roller changes according to the image pattern to be recorded. For this reason, when the cueing is performed without a registration, the stop timings of the paper feed roller and the conveyance roller are not equal. In order to grasp the position of the recording paper in the registration-free cueing, it is necessary to switch from the recording paper position grasping by the paper feeding operation to the recording paper position grasping by the conveying operation during the cueing operation.

  On the other hand, in the cueing operation in which the registration operation is performed, the conveyance roller is stopped at the end of the recording paper registration operation loop, and the cueing amount can be managed only by the rotation amount of the conveyance roller from this state.

As a method of cueing without registration, when a pulse motor is used for paper feeding operation, a paper position detecting means is installed between the paper feeding roller and the conveying roller, and the recording paper being fed Counting of the pulse of the pulse motor for paper feed operation is started from the leading edge detection position, and the paper conveyance amount is calculated from the output of the encoder of the DC motor for conveyance with reference to the time when the count time reaches a predetermined time. A method is disclosed in Japanese Patent Laid-Open No. 2002-037483 (Patent Document 1).
JP 2002-037483 A

  However, the above-described registrationless cueing method employs a pulse motor for paper feeding operation and performs open loop control, but employs a DC motor and performs closed loop control using feedback control (servo control). This cannot be applied as it is, and the error of the cue amount when there is no cash register fluctuates.

  In the first place, the servo control is to perform control so as to follow the command value (ideal profile). For this reason, in a configuration in which separate motors that are servo-controlled by individual position detection signals are used as driving sources for paper feeding operation and conveyance operation, the position of the control target (paper) driven by the motor is ideal. Since the profile follows the profile with a time delay, there is a difference between the ideal position and the actual position at a certain time. Further, the difference in position also occurs due to disturbances such as mechanical load fluctuations.

  Therefore, if the cue processing applied to the pulse motor is applied to a servo-controlled motor (DC motor) as it is, the difference (deviation) between the above-mentioned assumed position and the actual position becomes the deviation of the cue amount as it is. The recording start position is misaligned.

  That is, since the conveyance amount of the paper feed motor is managed by time, if the speed fluctuation occurs in the paper feed motor, a positional deviation occurs.

  In addition, mass production of recording devices causes some variation between individual products due to part tolerances and manufacturing process errors, but this cue amount is not an exception and is somewhat different between individual products. Variation will occur. However, no attempt has been made to suppress this variation.

  The present invention has been made in view of the situation as described above. In the recording apparatus that has separate servo motors for paper feeding and conveyance and servo-controls each motor, the registration operation is not performed. Even in the case of recording, it is an object to suppress variations in the cueing amount and accurately control the recording start position.

In order to achieve the above object, a recording apparatus as one aspect of the present invention includes a stacking unit that stacks a plurality of recording media,
A paper feed roller, and a paper feed motor that drives the paper feed roller and is servo-controlled based on the rotation amount of the paper feed roller, and picks up the recording media stacked on the stacking means one by one A paper feed means for feeding paper by the paper feed roller;
A conveyance roller, a pinch roller provided opposite to the conveyance roller, and a conveyance motor that drives the conveyance roller and is servo-controlled based on a rotation amount of the conveyance roller , and feeds paper by the paper feeding unit Conveying means for nipping the recorded recording medium between the conveying roller and the pinch roller and conveying the recording medium to a recording area;
A leading edge detecting means provided in a conveying path from the stacking means to the conveying means, for detecting passage of the leading edge of the recording medium;
A first conveying distance of the recording medium from the position where the tip is discovered in the recording medium by said front edge detecting means to a predetermined position, and the control based on the rotation amount of the feed roller, from the predetermined position of the recording area By controlling the second conveyance distance of the recording medium to the recording start position based on the rotation amount of the conveyance roller, the position from the position where the leading edge of the recording medium is detected by the leading edge detection unit to the recording start position is determined. and a control means for conveying the recording medium in succession,
The predetermined position is
A nip position or a nip position, which is defined in a conveyance path between a position where the leading edge of the recording medium is detected by the leading edge detection means and the recording area, and is nipped by the conveyance roller and the pinch roller Is defined on the recording area side .

The recording layer h paper cueing position control method as another aspect of the present invention that achieves the above object comprises driving a stacking means for stacking a plurality of recording media, a paper feed roller, and the paper feed roller, A paper feed motor that is servo-controlled based on the rotation amount of the paper feed roller, and picks up recording media stacked on the stacking means one by one and feeds the recording medium by the paper feed roller; A conveyance roller, a pinch roller provided opposite to the conveyance roller, and a conveyance motor that drives the conveyance roller and is servo-controlled based on the rotation amount of the paper supply roller, and is supplied by the paper supply unit. A conveying means for nipping the paper-recorded recording medium between the conveying roller and the pinch roller and conveying the recording medium to a recording area, and a conveying path from the stacking means to the conveying means are provided to pass the leading edge of the recording medium. detection A front end detecting unit that provides a cue position control method for a recording apparatus provided with,
A first conveying distance control step of controlling based on the first conveyance distance of the recording medium from the position where the tip is discovered in the recording medium to a predetermined position, the rotation amount of the paper feed roller by said front edge detecting means,
By controlling the second conveyance distance of the recording medium from the predetermined position to the recording start position of the recording area based on the rotation amount of the conveyance roller, the leading edge of the recording medium is detected by the leading edge detection unit. second possess a conveying distance control step of performing the position continuously conveying the recording medium to the recording start position,
The predetermined position is
A nip position or a nip position that is defined in a conveyance path between a position where the leading edge of the recording medium is detected by the leading edge detection means and the recording area, and the recording medium is nipped by the conveyance roller and the pinch roller Is defined on the recording area side.

  In this case, since both the first transport distance and the second transport distance are controlled based only on the rotation amount of the roller, the speed fluctuation of the motor is compared with the case where the control is performed based on the speed and time. It is possible to control the recording start position of the recording medium without being affected by the above.

  Therefore, even when the registration operation is not performed, it is possible to suppress the variation in the conveyance amount by the conveyance roller and accurately control the recording start position.

  The predetermined position may be after the nip position where the recording medium starts to be nipped by the conveyance roller and the pinch roller in the conveyance path to the recording area.

  You may comprise so that at least any one of a 1st conveyance distance and a 2nd conveyance distance can be changed according to the inputted correction value. In this case, the correction value is preferably obtained from the recording result of a predetermined test pattern. Moreover, it is preferable to provide a non-volatile storage means for storing the correction value.

  A DC motor is preferably used as the paper feed motor and the transport motor.

  The above object can also be achieved by a computer program that causes a computer apparatus to execute the cueing position control method of the recording apparatus, and a storage medium that stores the program.

  According to the present invention, since both the first transport distance and the second transport distance are controlled based only on the rotation amount of the roller, the speed of the motor is compared with the case where the control is performed based on the speed and time. It is possible to control the recording start position of the recording medium without being affected by fluctuations.

  Therefore, even when the registration operation is not performed, it is possible to suppress the variation in the conveyance amount by the conveyance roller and accurately control the recording start position.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the components described in the following embodiments are merely examples, and are not intended to limit the scope of the present invention only to them.

  In this specification, “recording” (sometimes referred to as “printing”) is not only for forming significant information such as characters and figures, but also for human beings visually perceived regardless of significance. Regardless of whether or not it has been manifested, it also represents a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or the medium is processed.

  The “recording medium” includes not only recording paper used in general recording apparatuses but also a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. It shall represent.

  Furthermore, in the present specification, the “encoder” detects the amount of rotation or movement of a mechanism portion driven by a motor or the like, and a pattern attached to the motor or the mechanism portion driven by the motor, A sensor that detects the pattern, for example, a pulse signal (pulse signal) is output from the sensor each time a predetermined amount of rotation or movement of the mechanism part, and the mechanism part or driven is counted by counting the signal. The rotation amount and the movement amount of the body can be calculated, and the shape of the pattern, the detection method of the sensor, and the shape of the output signal are not particularly limited. In the specification, “an encoder output (signal)” means an output (signal) from a sensor.

  In the embodiments described below, a recording apparatus using an inkjet recording method will be described as an example.

<First Embodiment>
FIG. 1 is a perspective view showing a state where a cover of a recording apparatus as a first embodiment of the recording apparatus according to the present invention is removed, FIG. 2 is a perspective view of FIG. 1 viewed from the back side, and FIG. It is a side view which shows a conveyance system.

  The printer according to this embodiment includes (A) an automatic paper feeding unit, (B) a paper feeding unit, (C) a paper discharge unit, (D) a carriage unit, and (E) a cleaning unit. Therefore, the outline of each of these parts will be sequentially described.

(A) Automatic Paper Feed Unit The automatic paper feed unit has a configuration in which a pressure plate 1 for stacking recording paper and a paper feed roller 33 for feeding recording paper are attached to the base 2. A movable side guide 3 is movably provided on the pressure plate 1 to restrict the recording paper stacking position. The pressure plate 1 is rotatable about an axis coupled to the base 2 and is urged against the paper feed roller 33 by a pressure plate spring (not shown).

  The recording paper is conveyed to a nip portion composed of a paper feed roller 33 and a separation roller (not shown) by a driving force of a paper feed motor 32 that is a DC motor. The fed recording paper is separated at the nip portion, and only the uppermost recording paper P is conveyed. Here, feedback control is performed based on rotation amount (speed) information of the paper feed roller 33 obtained by reading the number of lines of the paper feed encoder scale 34 fixed to the transmission gear of the paper feed roller 33 by the paper feed encoder sensor 35. To control the rotation of the paper feed motor 32, which is a DC motor. For this purpose, a counting means for counting the number of lines of the paper feed encoder scale 34 is provided.

(B) Paper Feed Unit The paper feed unit has a transport roller 4 for transporting the recording paper and a paper edge position detection sensor 36. The transporting roller 4 is provided with a driven pinch roller 5 in contact therewith. The pinch roller 5 is held by a pinch roller guide 6 and is pressed against the conveying roller 4 by being urged by a pinch roller spring (not shown), thereby generating a recording sheet conveying force. Further, a recording head cartridge 7 that forms an image based on image information is provided on the downstream side of the conveying roller 4 in the recording sheet conveying direction. (Hereinafter, conveyance is also called LF (line feed).)
The transport encoder sensor 28 is fixed to the transport encoder sensor holder 29 and is attached to the chassis 12. The driving force of the transport motor 25 is transmitted to the transport roller gear 27 press-fitted and fixed to the transport roller 4 via the transport timing belt 30. Based on the rotation amount (speed) information of the transport roller 4 obtained by reading the number of lines of the transport encoder scale 26 inserted into the transport roller 4 and fixed to the transport roller gear 27 by the transport encoder sensor 28, feedback control is performed. The recording paper is conveyed by controlling the rotation of the conveyance motor 25 which is a DC motor. For this purpose, a counting means for counting the number of lines of the transport encoder scale 26 is provided. The recording paper fed to the paper feeding section is guided by a pinch roller guide 6 and a paper guide 37 (not shown in FIGS. 1 and 2) and sent to a pair of rollers of a transport roller 4 and a pinch roller 5. At the time of recording, the recording paper is conveyed on the platen 8 by rotating the roller pairs 4 and 5.

(C) Carriage part The carriage part has a carriage 9 on which the recording head cartridge 7 is detachably mounted. The carriage 9 holds the guide shaft 10 for reciprocating scanning in the direction intersecting the recording paper conveyance direction and the guide rail 11 for maintaining the gap between the recording head cartridge 7 and the recording paper by holding the upper rear end of the carriage 9. Is supported by. The guide shaft 10 and the guide rail 11 are attached to the chassis 12.

  The carriage 9 is driven via a timing belt 14 by a carriage motor 13 which is a DC motor attached to the chassis 12. The timing belt 14 is stretched and supported by an idle pulley 15. Further, the carriage 9 is provided with a flexible cable 17 for transmitting a head signal from the electric board 16 to the recording head cartridge 7. The carriage 9 is equipped with a linear encoder (not shown) for detecting the position of the carriage, and the position of the carriage 9 can be detected by reading the number of lines of the linear scale 18 attached to the chassis 12. it can. The signal of the linear encoder 18 is transmitted to the electric board 16 through the flexible cable 17 and processed.

  In the above configuration, when an image is formed on the recording sheet, the recording sheet is conveyed by the conveying roller pairs 4 and 5 to the row position (position in the conveying direction of the recording sheet) where the image is formed, and the carriage motor 13; By feedback control using a linear encoder, the carriage 9 is moved to a row position for image formation (a position that intersects the conveyance direction of the recording paper), and the recording head cartridge 7 is opposed to the image formation position. Thereafter, the recording head cartridge 7 ejects ink toward the recording paper according to a signal from the electric substrate 16 to form an image.

(D) Paper Discharge Unit A spur (not shown) is in contact with the paper discharge roller 19 so that the paper discharge unit can rotate following the paper discharge roller 19. Drive from the transport roller gear 27 is transmitted to the paper discharge roller 19 via a paper discharge transmission gear 31 and a paper discharge roller gear 20. With the above configuration, the recording paper that is driven and has an image formed thereon by the carriage unit is conveyed while being sandwiched between the nip between the paper discharge roller 19 and the spur, and is discharged to a paper discharge tray (not shown).

(E) Cleaning unit The cleaning unit includes a pump 24 that cleans a path to each nozzle (discharge port) of the recording head cartridge 7, a cap 21 that suppresses drying of the recording head cartridge 7, and the recording head cartridge 7. A wiper 22 for cleaning the face surface of the motor and a PG motor 23 as a drive source.

(Control configuration)
FIG. 4 is a block diagram illustrating a control configuration of the printer configured on the electric board 16.

  In the figure, reference numeral 401 denotes a printer control CPU of the printer apparatus, which controls printing processing using a printer control program, printer emulation, and recording font stored in the ROM 402.

  A RAM 403 stores decompressed data for recording and data received from the host. Reference numeral 404 denotes a recording head (representing the recording head of the recording head cartridge 7 as a block), reference numeral 405 denotes a motor driver for driving a motor, reference numeral 406 denotes a printer controller, access control of the RAM 403, data exchange with a host device, and motor driver. Send control signal to. Reference numeral 407 denotes a temperature sensor composed of a thermistor or the like, which detects the temperature of the printer apparatus.

  The CPU 401 reads out information such as an emulation command sent from the host device to the printer device from the I / O data register in the printer controller 406 while performing mechanical / electrical control of the main body by the control program in the ROM 402, Is written to the I / O register and I / O port in the printer controller 406 and read out.

(Position servo system)
FIG. 5 is a schematic diagram for explaining a position control system of a general DC motor, and shows a method for applying position servo. Here, as a representative example, a position servo for a conveyance motor (also referred to as an LF motor) will be described, but the control for the paper feed motor 32 is also the same.

  In the present embodiment, the position servo is used in the acceleration control region, the constant speed control region, and the deceleration control region. The DC motor is controlled by a technique called PID control or classical control, and the procedure will be described below.

  First, the target position to be given to the control object is given in the form of an ideal position profile 6001. In the apparatus of the present embodiment, this corresponds to the absolute position where the recording sheet conveyed by the LF motor should reach at the corresponding time. This position information changes as time progresses. By performing additional value control on the ideal position profile, the apparatus of the present embodiment is driven.

  The device is equipped with 6005 encoder sensors to detect the physical rotation of the motor. The encoder position information converting means 6009 is a means for obtaining absolute position information by adding the number of slits detected by the encoder sensor, and the encoder speed information converting means 6006 is a signal of the encoder sensor and a clock built in the printer. From this, the current driving speed of the LF motor is calculated.

  A numerical value obtained by subtracting the actual physical position obtained by the position information conversion means 6009 from the ideal position profile 6001 is transferred to the position servo feedback process 6002 and later as a position error that is insufficient with respect to the target position. . Reference numeral 6002 denotes a position servo major loop, and generally means for performing a calculation related to the proportional term P is known.

  As a result of the calculation in 6002, a speed command value is output. This speed command value is passed to 6003 and subsequent speed servo feedback processes. The minor loop of the speed servo is generally a means that performs a PID calculation for calculating the proportional term P, the integral term I, and the differential term D.

  In the apparatus of the present embodiment, in order to improve the followability when a nonlinear change in the speed command value occurs and to prevent the adverse effect of the differential operation during the follow-up control, a method generally called a differential leading form is shown. The encoder speed information obtained in 6006 is subjected to a differential operation in 6007 before taking the difference from the speed command value obtained in 6002. This method itself is not the subject of the present invention, and depending on the characteristics of the system to be controlled, it may be sufficient to perform the differential operation in 6003.

  In the minor loop of the speed servo, the numerical value obtained by subtracting the encoder speed information from the speed command value is passed to the PI operation circuit 6003 as a speed error that is insufficient with respect to the target speed, and the energy to be given to the DC motor at that point is determined. , And a method called PI calculation. The motor driver circuit receiving it changes the duty of the applied voltage using, for example, means for changing the pulse width of the applied voltage (hereinafter referred to as “PWM (Pules Width Modulation) control”) while the motor applied voltage is constant. Then, the current value is adjusted, the energy given to the DC motor 6004 is adjusted, and the speed control is performed.

  The DC motor that rotates by being applied with a current value performs physical rotation while being affected by disturbance 6008, and its output is detected by an encoder sensor 6005.

(Speed servo system)
FIG. 6 is a schematic diagram for explaining a speed control system of a general DC motor, and shows a method for applying speed servo. In the apparatus of this embodiment, the speed servo is used in the positioning control area. The DC motor is controlled by a technique called PID control or classical control, and the procedure will be described below.

  First, the target speed desired to be given to the controlled object is given in the form of 7001 ideal speed profile. In the apparatus of this embodiment, this is the ideal speed at which the recording paper should be conveyed by the LF motor at the corresponding time, and is the speed command value at the corresponding time. As time progresses, this speed information changes. By performing additional value control on this ideal speed profile, the apparatus of this embodiment is driven.

  In the speed servo, a means for performing a PID calculation for calculating a proportional term P, an integral term I, and a differential term D is generally used. In the apparatus of the present embodiment, in order to improve the followability when a nonlinear change in the speed command value occurs and to prevent the adverse effect of the differential operation during the follow-up control, a method generally called a differential leading form is shown. The encoder speed information obtained in 6006 is subjected to a differential operation in 7003 before taking the difference from the speed command value obtained in 7001. This method itself is not the subject of the present invention, and depending on the characteristics of the system to be controlled, it may be sufficient to perform the differential operation in 7002.

  In the speed servo, the numerical value obtained by subtracting the encoder speed information from the speed command value is passed to the PI calculation circuit 7002 as a speed error that is insufficient with respect to the target speed, and the energy to be given to the DC motor at that time is calculated using the PI calculation. It is calculated by the method called. The motor driver circuit that has received it uses, for example, PWM control to change the duty of the applied voltage, adjust the current value, adjust the energy applied to the 6004 DC motor, and perform speed control.

  The DC motor that rotates by being applied with a current value performs physical rotation while being affected by disturbance 6008, and its output is detected by an encoder sensor 6005.

(Cue operation)
In the following, the recording paper cueing operation in the configuration as described above will be described.

  FIG. 7 is a flowchart of the cueing operation in the present embodiment, and FIGS. 8A to 8D are diagrams for explaining each operation state. FIG. 8A shows an initial state. 8A to 8D, each part shape is expressed in a simplified manner, and the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals.

  The main portion will be described again. Reference numeral 33 denotes a paper feed roller, which is driven based on a position signal from a paper feed encoder (35: not shown in this figure) (32: not shown in this figure). Is rotated by. The rotation amount of the paper feed roller 33, that is, the movement amount of the recording paper P conveyed by the paper feed roller 33 is detected by a position signal (pulse count number) of the paper feed encoder sensor. Reference numeral 4 denotes a transport roller, which is rotated by a transport motor (25: not shown in this figure) driven based on a position signal from a transport encoder sensor (28: not shown in this figure). The rotation amount of the transport roller 4, that is, the movement amount of the recording paper P transported by the transport roller 4 is detected by the count number of the pulsed position signal output from the transport encoder sensor.

  In the initial state shown in FIG. 8A, when a recording command is received from the host, the driving of the paper feed roller is started (step S1001), and the uppermost recording paper P is picked up.

  The recording paper P separated from the paper stack 39 is conveyed by the rotation of the paper feed roller 33, and the front edge of the paper is detected by the paper edge position detection sensor 36. The paper position detection sensor 36 is a photo-interrupter type sensor, and the paper position detection lever 38 that has shielded the light receiving slit 36-a in the initial state is pushed and rotated by the leading edge of the paper, as shown in FIG. 8B. In addition, the leading edge of the recording sheet is detected when the light receiving slit 36-a is in the transmissive state (step S1002).

  With this position as a reference, counting of the rotation amount of the paper feed roller, that is, the movement amount of the recording paper P is started by a position signal from the paper feed encoder 35 (step S1003). The distance from the recording paper leading edge detection position to the nip between the conveying roller 4 and the pinch roller 5 is LP. This LP is a constant and is obtained in advance by design values or product measurements.

  Further, when the leading edge of the recording paper P reaches the leading edge detection position, the driving of the conveying roller 4 is started (step S1004). The timing for starting the driving of the conveying roller 4 is not particularly limited to this timing.

  Next, the process waits until the rotation amount of the paper feed roller 33, that is, the position count value reaches LP, and when it is determined that the position count value becomes equal to the value corresponding to LP (FIG. 8C, step S1005), the recording sheet. It is considered that the front end of P has reached the position of the nip between the conveying roller 4 and the pinch roller 5 (determination), and the rotation amount of the conveying roller 4, that is, the recording paper P is determined by the position signal from the conveying encoder 28 based on this timing. The movement amount is counted (step S1006).

  Here, the distance from the nip arrival position to the recording start position is PTOP. This PTOP is a variable that is set by calculation based on a predetermined distance from the nip position between the conveying roller 4 and the pinch roller 5 to the recording area of the recording head cartridge, the write data position of the recording image on the recording paper, and the length of the margin at the leading edge. It is.

  When the count value becomes a value corresponding to PTOP while managing the rotation amount of the conveyance roller 4, that is, the movement amount of the recording paper P, by counting the pulse-shaped position signal output from the conveyance encoder sensor 28 (FIG. 8D), the conveyance roller 4 is stopped (step S1007). Thereafter, the driving of the paper feed roller 33 that has been performing the paper feed operation is terminated (step S1008). Note that the stop timing of the paper feed roller is not limited to this, and changes according to the recording start position of the image data to be recorded.

  As described above, the timing of detecting the leading edge of the recording paper by the paper edge position detection sensor 36 is used as a trigger to start counting the rotation amount of the paper feed roller (encoder position signal). Then, using the timing at which the rotation amount of the paper feed roller reaches a value corresponding to the distance LP as a trigger, counting of the rotation amount of the transport roller (encoder position signal) is started. Then, the conveyance motor is controlled to rotate until the rotation amount of the conveyance roller reaches a value corresponding to the recording start position at the leading edge of the recording paper (a value corresponding to PTOP).

  With the above operation, the registrationless cueing operation of this embodiment is completed. As is apparent from the above description, during the operation of the present embodiment, processing is performed based only on position information without using speed information and time information obtained from the output signals of the encoders. That is, since processing is performed based only on the physical position of LP, the calculated position of PTOP, and the count value of the encoder position signal, it is assumed that a speed difference or speed fluctuation has occurred between the paper feed roller 33 and the transport roller 4. However, the effect does not affect the cueing amount.

  Here, counting of the position signal of the transport encoder 28 is started at the nip arrival position in the above description. This is because the position signal of the transport encoder sensor 28 is counted from the count of the position signal of the paper feed encoder sensor 35 before the nip arrival position. When the count is changed, position management based on the rotation amount of the transport roller 4 is performed in a state where the recording paper P is not held between the transport rollers 4, and a speed deviation occurs between the paper feed roller 33 and the transport roller 4. This is because the error appears as an error in the cueing amount.

  On the other hand, when the position signal count of the paper feed encoder sensor 35 is changed to the position signal count of the transport encoder sensor 28 after reaching the nip, the recording paper P is already held by the transport roller 4, and the recording paper The leading end position of P is a position that substantially corresponds to the rotation amount of the transport roller 4. In this case, the leading end position of the recording paper P is affected by the speed fluctuation of the paper feed roller 33 after being held between the transport rollers 4, but unlike the conditions before the nip described above, The recording paper P itself reduces the speed deviation of the transport roller 4. That is, each roller is difficult to rotate independently, and the recording paper P already nipped by the conveyance roller 4 follows the movement of the conveyance roller 4 having a strong conveyance force, so that an error caused by the paper supply roller 33 is suppressed. To work.

  As can be seen from the above, the switching timing from the position signal count of the paper feed encoder sensor 35 to the position signal count of the transport encoder sensor 28 satisfies the necessary condition if it is after the nip arrival, Is most preferred.

  As described in the servo control above, time information and speed information are not required in feedback control that has a control delay with respect to the target motion profile and that causes fluctuations from the target motion profile due to disturbance. Processing improves the positioning accuracy dramatically. In particular, the mechanical configuration (load and disturbance) of the paper feed roller 33 and the transport roller 4 is usually inevitably different, and it is difficult to maintain a synchronized operation, so the necessity is clear.

  Note that the paper feed roller 33 does not necessarily serve as a paper feed, but also serves as a transport roller for transporting paper to the transport roller 4, and the present invention can be applied when the paper feed roller also serves as the transport roller. It is obvious. In addition, when the distance between the paper feed roller 33 and the transport roller 4 is long and the paper cannot be transported to the transport roller 4 only by the paper feed roller 33, the intermediate roller is used in this configuration even in the configuration in which the transport intermediate roller is added. It does not depart from the present invention to fall within the category of paper rollers.

  Comparing the cueing operation of the present embodiment with the conventional cueing operation, the conventional cueing operation does not manage the transport amount of the recording paper P by the paper feed roller 33 by position, but only by time management. Therefore, if the assumed position and the actual roller (paper) transport amount are different, that is, if a mismatch between the assumed motion profile and the actual motion profile occurs, the speed deviation is the cue amount. However, according to the cueing operation according to the present embodiment, it is possible to suppress the variation in the cueing amount of the paper by the conveying roller and accurately control the recording start position.

<Second Embodiment>
Hereinafter, a second embodiment according to the present invention will be described. The second embodiment is also a recording apparatus similar to the first embodiment. In the following description, the description of the same parts as the first embodiment is omitted, and the characteristic of the second embodiment is described. The explanation will focus on the part.

  In the first embodiment, the value of the distance LP from the recording sheet leading edge detection position to the nip arrival position is a constant, and the value PTOP of the distance PTOP from the nip arrival position to the recording start position is a variable of a predetermined value and a set value. However, in the second embodiment, these values are determined based on actually measured values.

  Generally, in mass production at a factory, the constant parts of LP and PTOP vary due to component tolerances and assembly process errors. As factors of fluctuation of the LP value, the sheet edge position detection sensor 36, the sheet edge position detection sensor lever 38, the paper guide 37, the conveying roller 4, the pinch roller 5 positioning accuracy (part accuracy), and the PTOP constant value are as follows. The positioning accuracy (component accuracy) of the conveying roller 4, the pinch roller 5, the platen 8, the recording head cartridge 7, etc. is affected. In the first embodiment, there is no influence of the operation fluctuation in each recording apparatus, and only the fluctuation due to the position accuracy affects the cueing amount. However, in this embodiment, errors in such components and manufacturing processes are further performed. The purpose is also to cancel.

  In the present embodiment, at the time of shipment from the factory, for example, a predetermined recording mode is set, a test pattern 901 as shown in FIG. 9 is recorded on the recording paper P, and the leading end position of the recording paper P is recorded from the recorded test pattern 901. And the recording start position is measured, this value is compared with an ideal distance (design value), and the difference is reflected as a correction value in the constant part of LP or PTOP. In other words, when D is longer than the ideal value (correction value is +), subtraction is performed, and when D is shorter than the ideal value (correction value is −), addition is performed, thereby correcting variations in individual recording apparatuses. It is.

  The difference (correction value) from the measured D value or ideal value is preferably stored in a non-volatile storage means (such as EPROM) in the main body. As described above, since the cueing operation of the present embodiment does not depend on the speed, the correction value does not need to be changed depending on the driving speed, and the correction value acquired at a certain speed can be applied under all conditions. .

  In addition, a test pattern as shown in FIG. 10 may be recorded instead of the test pattern shown in FIG. 9, and a portion cut off at the leading end of the recording may be visually determined to input a correction value. The test pattern 101 in FIG. 10 is composed of a straight line having a constant inclination and a plurality of straight lines drawn downward from the straight line at a predetermined interval. Each straight line drawn downward has a numerical value from −4 to 4 Each is recorded correspondingly.

  In the illustrated example, the solid line portion is recorded on the recording paper P, and the broken line portion is a pattern that protrudes outside the recording paper P and is not recorded. Here, a numerical value (-1 in this figure) located at the boundary between the leading edge of the recording paper P and the inclined straight line is set as a correction value, and the difference from the reference numerical value (for example, 0 in the figure) is the LP value. Alternatively, the same effect as described above can be obtained by storing in a non-volatile storage means (such as EPROM) in the main body so as to be reflected in the constant part of PTOP.

  Note that the test pattern is not limited to the patterns shown in FIGS. 9 and 10, and may be any pattern that can directly or indirectly measure the cueing amount of the recording paper. Furthermore, it is possible to provide means capable of directly or indirectly measuring values related to component tolerances and mounting errors without recording a test pattern, and updating the constant portion based on the obtained values. .

  The timing at which such test pattern recording and correction based on the test pattern are performed is not limited at the time of factory shipment, and may be appropriately performed by a user or a service person as needed. As a method (interface) for inputting the correction value, a jig used by a factory or a service person may be used, or a key operation of a printer driver or a storage device may be used. Any recording apparatus that actually records, etc., and corrects based on the result to cancel errors due to individual recording apparatus parts and attachments are included in the scope of this embodiment. It will be understood.

<Other embodiments>
In the above description, an example in which the present invention is applied to a serial type ink jet recording apparatus has been described. However, the present invention is not limited to this, and a configuration in which a sheet feeding operation and a conveying operation are controlled by different motors. For example, it can be applied to a full-line type recording apparatus.

  Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even when applied to a system composed of a plurality of devices (for example, a host computer, interface device, reader, printer, etc.). You may apply.

  Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in the.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowchart described above (shown in FIG. 7).

FIG. 3 is a perspective view of a mechanism unit of the recording apparatus according to the first embodiment of the invention. It is the perspective view which looked at the mechanism part of FIG. 1 from the back side. FIG. 2 is a side view illustrating a conveyance driving unit of the recording apparatus in FIG. 1. FIG. 2 is a block diagram illustrating a control configuration of the recording apparatus in FIG. 1. It is a schematic diagram explaining the position control system of the DC motor in 1st Embodiment of this invention. It is a schematic diagram explaining the speed control system of the DC motor in 1st Embodiment of this invention. It is a flowchart of the registration-free cueing operation in the first embodiment of the present invention. It is a schematic diagram which shows the initial state of FIG. FIG. 8 is a schematic diagram illustrating a paper leading edge position detection state in FIG. 7. It is a schematic diagram which shows the nip position arrival state of FIG. It is a schematic diagram which shows the cue position arrival state of FIG. It is a figure which shows the example of the test pattern in the 2nd Embodiment of this invention. It is a figure which shows another example of the test pattern in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure plate 2 Paper feed base 3 Side guide 4 Conveyance roller 5 Pinch roller 6 Pinch roller guide 7 Recording head cartridge 8 Platen 9 Carriage 10 Guide shaft 11 Guide rail 12 Chassis 13 Carriage motor 14 Timing belt 15 Idle pulley 16 Electric board 17 Flexible cable 18 Linear Scale 19 Paper Discharge Roller 20 Paper Discharge Roller Gear 21 Cap 22 Wiper 23 PG Motor 24 Pump 25 Carrying Motor 26 Carrying Encoder Scale 27 Carrying Roller Gear 28 Carrying Encoder Sensor 29 Carrying Encoder Sensor Holder 30 Carriage Timing Belt 31 Paper Discharge Transmission Gear 32 Feeding Paper motor 33 Paper feed roller 34 Paper feed encoder scale 35 Paper feed encoder sensor 36 Recording paper edge detection sensor 37 Page Par guide 38 Recording paper edge detection sensor lever 39 Recording paper stack P Recording paper

Claims (7)

A loading means for loading a plurality of recording media;
A paper feed roller, and a paper feed motor that drives the paper feed roller and is servo-controlled based on the rotation amount of the paper feed roller, and picks up the recording media stacked on the stacking means one by one A paper feed means for feeding paper by the paper feed roller;
A conveyance roller, a pinch roller provided opposite to the conveyance roller, and a conveyance motor that drives the conveyance roller and is servo-controlled based on a rotation amount of the conveyance roller , and feeds paper by the paper feeding unit Conveying means for nipping the recorded recording medium between the conveying roller and the pinch roller and conveying the recording medium to a recording area;
A leading edge detecting means provided in a conveying path from the stacking means to the conveying means, for detecting passage of the leading edge of the recording medium;
A first conveying distance of the recording medium from the position where the tip is discovered in the recording medium by said front edge detecting means to a predetermined position, and the control based on the rotation amount of the feed roller, from the predetermined position of the recording area By controlling the second conveyance distance of the recording medium to the recording start position based on the rotation amount of the conveyance roller, the position from the position where the leading end of the recording medium is detected by the leading end detection unit to the recording start position is determined. and a control means for conveying the recording medium in succession,
The predetermined position is
A nip position or a nip position that is defined in a conveyance path between a position where the leading edge of the recording medium is detected by the leading edge detection means and the recording area, and the recording medium is nipped by the conveyance roller and the pinch roller A recording apparatus characterized in that the recording apparatus is defined on the recording area side . The control means includes
Counting the rotation amount of the paper feed roller is triggered by the detection of the front edge of the recording medium by the front edge detection means, and the rotation amount count of the paper feed roller becomes a value corresponding to the first transport distance. The recording apparatus according to claim 1, wherein counting of the rotation amount of the transport roller is started using this as a trigger . Before SL control means, at least one of the first transport distance and the second transport distance, claim 1, characterized in that it is configured to change in accordance with the correction value or two The recording device described in 1.   The recording apparatus according to claim 3, wherein the correction value is obtained from a recording result of a predetermined test pattern.   The recording apparatus according to claim 3, further comprising a nonvolatile storage unit that stores the correction value.   The recording apparatus according to claim 1, wherein the paper feed motor and the transport motor are DC motors. A stacking unit configured to stack a plurality of recording media; a sheet feeding roller; and a sheet feeding motor that drives the sheet feeding roller and is servo-controlled based on a rotation amount of the sheet feeding roller. a sheet feeding means for feeding paper by said paper feed roller a stacked recording medium are picked up one by one, conveying roller, a pinch roller disposed opposite to the conveying roller, and drives the conveyor rollers, wherein A conveyance motor that is servo-controlled based on the rotation amount of the sheet feeding roller, and conveys the recording medium fed by the sheet feeding unit to the recording area by being sandwiched between the conveyance roller and the pinch roller. A cueing position control method for a recording apparatus, comprising: and a front end detecting unit provided in a transport path from the stacking unit to the transport unit and detecting the passage of the front end of the recording medium,
A first conveying distance control step of controlling based on the first conveyance distance of the recording medium from the position where the tip is discovered in the recording medium to a predetermined position, the rotation amount of the paper feed roller by said front edge detecting means,
By controlling the second conveyance distance of the recording medium from the predetermined position to the recording start position of the recording area based on the rotation amount of the conveyance roller, the leading edge of the recording medium is detected by the leading edge detection unit. second possess a conveying distance control step of performing the position continuously conveying the recording medium to the recording start position,
The predetermined position is
A nip position or a nip position that is defined in a conveyance path between a position where the leading edge of the recording medium is detected by the leading edge detection means and the recording area, and the recording medium is nipped by the conveyance roller and the pinch roller A cueing position control method for a recording apparatus, wherein the cueing position control method is defined on the recording area side .

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