JP5442141B2 - Recording apparatus and recording method - Google Patents

Description

  The present invention relates to a recording apparatus and a recording method, and more particularly to a technique for correcting a conveyance amount error of a recording medium used in an inkjet recording apparatus.

  Conventionally, in an inkjet printer, a high-precision roller with a grindstone coated on a metal shaft has been used as a main conveyance roller, and a DC motor is controlled by position detection means (code wheel and encoder sensor) provided on the shaft. Yes. As a result, the ink jet printer can transport the recording medium (paper) with high accuracy, and realize high image quality of the recorded image. However, relying on the processing accuracy of the transport roller to limit the transport accuracy of the paper has reached its limit, and as a countermeasure against it, recently, eccentric correction of the roller has been implemented.

  Here, the eccentricity correction will be briefly described. When the cross-sectional shape of the conveyance roller is a perfect circle and the central axis and the rotation axis coincide with each other, the roller rotation angle for paper conveyance is uniform. Assuming that, the circumferential length (arc length) when the roller is rotated is constant. Therefore, the conveyance amount of the recording medium conveyed in contact with the roller is always constant. However, when the cross-sectional shape of the transport roller is an ellipse, the transport amount varies depending on the rotational position (rotation phase) of the roller even if the roller is rotated by the same angle. That is, depending on the rotational phase of the roller, an area where the carry amount is larger than the predetermined amount and an area where the carry amount is smaller than the predetermined amount are generated, and the error of the carry amount varies. Thus, in the eccentricity correction, a conveyance amount correction value is acquired for each rotation phase of the roller, and a conveyance amount error that varies according to the rotation phase is corrected. In the following description, the conveyance amount when the roller is rotated by a certain angle is also referred to as a unit conveyance amount.

  On the other hand, with respect to the paper discharge roller disposed on the downstream side of the transport roller, a driven roller called a spur on a star with a sharp tip is used to transport the paper after ink has been applied. A rubber roller, which is an elastic body that does not damage the tip of the spur, is used as the paper discharge roller. At present, the paper conveyance accuracy as high as the conveyance roller cannot be maintained even if the eccentricity correction is performed.

  In particular, a problem regarding the sheet conveyance accuracy is the conveyance amount when the sheet is transferred from the conveyance roller to the discharge roller. That is, the sheet conveyance accuracy when the sheet conveyance is performed by the conveyance roller and the discharge roller (first conveyance operation) to the sheet conveyance state (second conveyance operation) only by the discharge roller. Is a problem. In the transport operation at this time, the first transport operation described above is generally performed due to various factors such as deflection of the roller shaft and instability of the behavior when the sheet is pulled out from the transport roller, in addition to the cause of the deviation in accuracy of the roller. It is known that the conveyance accuracy is lower than in the above state. Therefore, in order to reduce the decrease in the conveyance accuracy at the time of delivery from the conveyance roller to the paper discharge roller, a technique for obtaining the conveyance amount correction value at this time from a test pattern and correcting the conveyance amount at the time of delivery is known. (Patent Document 1).

JP 2005-7817 A Japanese Patent Laid-Open No. 11-188898

  As described above, due to the influence of the eccentricity of the roller, the conveyance amount error varies depending on the rotational phase of the roller. This phenomenon also occurs in the above-described transport operation at the time of delivery, and the transport amount error at the time of delivery varies depending on the rotation phase of the transport roller at the time of delivery and the rotation phase of the paper discharge roller.

  However, in the method of Patent Document 1, the correction value of the conveyance amount at the time of delivery from the conveyance roller to the discharge roller is a fixed value, and the fixed correction value is always used in the conveyance operation at the time of delivery. Carrying amount correction control was performed. For this reason, in the above-described transfer operation at the time of delivery, the rotation phase of the roller is different for each transfer operation, and even if the error in the transfer amount at the time of transfer varies according to the rotation phase, the error cannot be corrected accurately. It was.

  Therefore, the present invention omits the control for adjusting the rotation phase so that the rotation phase of the roller at the time of delivery from the conveyance roller to the discharge roller becomes a predetermined rotation phase, and the adjustment of the rotation phase for shortening the printing time. It is an object of the present invention to provide a recording apparatus and a recording method that can be selected to perform control.

  In order to achieve the above object, the present invention provides a recording apparatus for recording an image on a recording medium transported in a transport direction using a recording head, and is disposed upstream of the recording head in the transport direction. A first transport unit for transporting the recording medium; and a second transport unit disposed downstream of the recording head in the transport direction for transporting the recording medium, From the first transport operation in which the recording medium is transported by the first transport means and the second transport means, the first transport means does not transport the recording medium by the second transport means. A control for adjusting the rotational phase so that the rotational phase of the first and second transport means becomes a predetermined rotational phase when switching to the second transport operation for transporting the recording medium, and adjustment of the rotational phase. Select one of the controls not to be performed Characterized in that it is.

  According to the present invention, control for adjusting the rotation phase so that the rotation phase of the roller at the time of delivery from the conveyance roller to the discharge roller becomes a predetermined rotation phase, and adjustment of the rotation phase for shortening the printing time. It is possible to provide a recording apparatus and a recording method that can be selected by a control that is omitted.

FIG. 3 is a perspective view of a mechanism unit of a recording apparatus applicable to the embodiment of the present invention. FIG. 5 is a cross-sectional view for explaining in detail a conveyance mechanism including a paper feeding unit in the recording apparatus according to the embodiment of the invention. FIG. 4 is a perspective view for explaining in detail a transport mechanism including a paper feeding unit in the recording apparatus of the present embodiment. It is a figure for demonstrating the mechanism which detects the origin in the conveyance roller of embodiment of this invention. It is a figure for demonstrating the mechanism which detects the origin in the conveyance roller of embodiment of this invention. FIG. 4 is a diagram illustrating a state where a carriage in the recording apparatus of the present embodiment is observed from the back side. (A)-(C) are sectional drawings for demonstrating concretely the process in which a lock function acts with the mechanism demonstrated in FIGS. 4-6. It is an electrical block diagram in the recording apparatus of this embodiment. It is a figure for demonstrating the relationship between the conveyance load and conveyance amount in this embodiment. It is a figure explaining the other structural example of the paper discharge part of this embodiment. It is a figure for demonstrating the conveyance amount at the time of delivery in this embodiment. It is a figure explaining the conveyance amount error for every rotation phase of the conveyance roller and paper discharge roller in this embodiment. The figure which shows the conveyance amount error of A section and C section when delivery is performed by the rotational phase of (A)-(C) of FIG. It is a figure which shows the fluctuation | variation of the paper discharge roller in the state of FIG. 13 (A)-(C). It is a figure explaining the correction table which stored the correction value for every rotation phase section in this embodiment. It is a figure explaining the acquisition method of the rotation phase of a roller in conveyance operation at the time of delivery in this embodiment. It is a control flow of delivery amount correction of delivery at the time of a recording operation in the first conveyance amount control. It is a figure of the test pattern which acquires the correction value for every rotation phase space | interval of the conveyance roller and paper discharge roller in this embodiment. FIG. 6 is a diagram for explaining a sheet conveyance state from when a sheet leading edge is detected until the sheet leading edge is caught in a nip of a conveying roller. FIG. 10 is a diagram illustrating a state when the trailing edge of the sheet exits the nip of the conveyance roller with an optimal rotation phase φjust. It is a control flow of delivery amount correction of delivery at the time of a recording operation in the second conveyance amount control. It is a figure explaining the correction value table which stored the correction value for every rotation phase space | interval of a conveyance roller and a paper discharge roller. FIG. 6 is a diagram illustrating a relationship between a recording mode and a conveyance amount control according to the first embodiment. It is a selection flow of conveyance amount control in a 1st embodiment. It is a figure explaining the relationship between the presence or absence of execution of the thinning-out process and the conveyance amount control in the second embodiment. It is a selection flow of conveyance amount control in the second embodiment. It is a selection flow of conveyance amount control in the third embodiment. It is a perspective view of the mechanism part of the recording device applicable to 4th, 5th embodiment. FIG. 30 is a schematic perspective view showing a state when tray recording is performed in the recording apparatus of FIG. 29. FIG. 30 is a cross-sectional view showing a state when tray recording is performed in the recording apparatus of FIG. 29. FIG. 10 is a diagram illustrating a relationship between a recording sheet type and a recording quality, a number of recording passes, and a conveyance amount control according to a fourth embodiment. It is a selection flow of conveyance amount control in the fourth embodiment. It is a selection flow of conveyance amount control in the fifth embodiment.

(First embodiment)
The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a mechanism portion of the recording apparatus according to the present embodiment.

(A) Paper Feed Unit The paper feed unit is a pressure plate 21 on which recording media are stacked, a paper feed roller 28 for feeding recording paper P one by one, a separation roller (not shown) for separating the recording paper P, and a recording medium loading position. A return lever (not shown) or the like for returning to the position is attached to the sheet feeding unit base 20. A movable side guide 23 is movably provided on the pressure plate 21 to regulate the recording medium stacking position. The pressure plate 21 is rotatable about a rotation shaft coupled to the paper feed unit base 20 and is urged toward the paper feed roller 28 by a pressure plate spring (not shown). The paper feed roller 28 has a bar shape with a circular arc in cross section, and feeds it into the apparatus by rotating while contacting the surface of the recording medium. The recording medium hits a nip portion composed of a paper feed roller 28 and a separation roller, is separated at this nip portion, and only the uppermost recording medium is further conveyed to the inside. The rotational force of the paper feed roller 28 is obtained through a drive transmission gear, a planetary gear, or the like from the drive force of a paper feed motor 99 serving as a paper feed drive means. The driving force of the paper feed motor 99 is also transmitted to a cleaning unit described later.

(B) Paper Feeding Unit The main mechanism of the paper feeding unit is attached to the bent sheet metal chassis 11 and the molded chassis 97 and 98. The recording medium sent to the paper feeding unit is guided by a paper guide and a pinch roller holder 30 disposed at the entrance of the paper feeding unit, and is sandwiched between a pair of rollers including a conveyance roller 36 and a pinch roller 37. . The transport roller 36 has a structure in which ceramic fine particles are coated on the surface of a metal shaft, and the metal portions of both shafts are supported by bearing portions attached to the chassis 11. The pinch roller holder 30 holds a plurality of pinch rollers 37 urged against the surface of the conveying roller 36 by a pinch roller spring 31, and the pinch roller 37 abuts on the surface of the conveying roller 36 and follows it. .

  2 and 3 are a cross-sectional view and a perspective view for explaining in detail a transport mechanism including a paper feeding section in the recording apparatus of the present embodiment. The rotational force of the transport roller 36 is obtained by transmitting the driving force of the transport motor 35 made of a DC motor to a pulley gear 361 provided on the shaft of the transport roller 36 via a timing belt 39. A code wheel 362 having slits formed at a pitch of 150 to 360 lpi is directly connected on the same axis of the transport roller 36. The conveyance roller encoder sensor 363 is fixed at the position shown in the figure of the chassis 11 so as to read the number and timing of passage of the slits on the code wheel 362.

  The pulley gear 361 includes a pulley portion and a gear portion, and driving from the gear portion is transmitted to the paper discharge roller gear 404 via the idler gear 45, whereby the paper discharge roller 40 is driven. Further, on the shaft of the paper discharge roller 40, a paper discharge code wheel 402 on which a paper discharge roller encoder 403, which is a position detecting means for detecting the conveyance amount by the paper discharge roller 40, is installed.

  In this embodiment, the rotation ratio between the transport roller 36 and the paper discharge roller 40 is 1: 1. In addition, the transport roller gear 361, the idler gear 45, and the paper discharge roller gear 404, which are drive transmission means to the transport roller 36 and the paper discharge roller 40, are also configured with a rotation ratio of 1: 1. With this configuration, the rotation period of the conveyance roller 36, the rotation period of the paper discharge roller 40, and the rotation period of the transmission gear become equal, and the conveyance amount error caused by the knitting center of the roller also appears at the same period as the roller rotation. .

  Referring again to FIG. 1, when a pair of rollers composed of a conveyance roller 36 and a pinch roller 37 is rotated by the conveyance motor 35, the recording medium sandwiched between these roller pairs is conveyed through the apparatus. The pinch roller holder 30 is provided with an edge sensor for detecting and positioning the leading edge and the trailing edge of the recording medium. By the detection of the edge sensor, the recording medium is attached to the chassis 11 and attached to the recording unit. Positioned on the located platen 34.

(C) Carriage portion On the recording medium supported from below by the platen 34 on the downstream side of the transport roller 36, an image based on the recorded image information is recorded by the recording head 7 mounted on the carriage 50 passing through the upper portion. The

  The carriage 50 is mounted with a recording head 7 and an ink tank 71 for supplying ink thereto, and is movable in a scanning direction indicated by X in the figure, which is a direction intersecting the transport direction. The recording head 7 of the present embodiment applies a voltage pulse to a heater provided at a position corresponding to each discharge port, and uses a pressure change generated by bubble growth or contraction in the generated film boiling to Ink is discharged from the discharge port. However, such a discharge method does not limit the present invention.

  The carriage 50 is supported by a carriage rail 52 and an upper guide rail 111 that extend in a direction orthogonal to the conveyance direction of the recording medium, and its movement direction is guided. The carriage rail 52 is attached to the chassis 11, and the upper guide rail 111 is formed integrally with the chassis 11. Further, the upper guide rail 111 holds the end of the carriage 50 and also serves to maintain a gap between the ejection port surface of the recording head 7 and the recording medium.

  The moving force of the carriage 50 is supplied via a driving force of a carriage motor 54 attached to the chassis 11 via an idle pulley 542 and a timing belt 541 that is stretched and supported by the idle pulley 542. A cord strip 561 in which markings are formed at a pitch of 150 to 300 lpi is stretched in a direction parallel to the timing belt 541, and an encoder sensor (not shown) mounted on the carriage 50 applies the markings while the carriage 50 is moving. Detect. As a result, the current position of the carriage 50 can be detected. The flexible cable 57 electrically connects the carriage substrate on the carriage 50 provided with the encoder sensor and the like to the electric substrate 91 fixed in the apparatus while following the reciprocating movement of the carriage 50. A recording signal for recording by the recording head 7 is transmitted from the electric substrate 91 via the flexible cable 34 and the carriage substrate, and the individual heaters of the moving recording head 7 are driven in accordance with the recording signal, and the platen 34 is moved. Dots are recorded on the recording medium.

(D) Paper Discharge Portion The rotational force of the paper discharge roller 40 is the discharge roller gear directly connected to the paper discharge roller 40 via the idler gear 45 from the gear portion of the pulley gear 361 to which the rotation force of the transport roller 36 is directly connected. This is obtained by transmitting to 404. Referring to FIG. 2 again, a discharge code wheel 402 is installed on the shaft of the discharge roller 40, and the rotation amount of the discharge roller 40 is detected by the discharge roller encoder 403.

  A plurality of spurs are attached to the spur holder 43, and these spurs are pressed toward the paper discharge roller 40 by a spur spring provided with a coil spring in a bar shape. The recording medium on which an image is formed by the recording head 7 is sandwiched between the discharge roller 40 and the nips of the plurality of spurs, conveyed, and discharged.

  The paper discharge unit may be composed of two rollers, and according to this configuration, it is possible to improve the conveyance accuracy of the recording medium.

  FIG. 9 is a diagram for explaining that the relationship between the transport load (hereinafter also referred to as back tension) and the transport amount varies due to the pressing force of the spring on the paper discharge roller 40. The two straight lines shown in the figure indicate the relationship between the back tension and the conveyance amount at different pressing forces.

  Comparing these two straight lines, if the same amount of back tension fluctuation occurs due to component tolerances, variations in the rigidity of the recording medium, etc., when the absolute value of the back tension is smaller than when the back tension is large. Thus, it can be seen that the variation in the transport amount is small.

  FIG. 10 illustrates a configuration of a paper discharge unit provided with a paper discharge assist roller (third transport unit) in addition to the paper discharge roller (second transport unit) in order to suppress the above-described fluctuation in the transport amount as much as possible. FIG. The paper discharge assist roller 41 has a role of canceling the back tension received by the paper discharge roller 40 and is provided at a position upstream of the paper discharge roller 40 in the transport direction. The discharge assist roller 41 is set to have a higher roller peripheral speed than the downstream discharge roller 40 in order to cancel the back tension received by the discharge roller 40. In other words, if the discharge roller 40 and the discharge assist roller 41 have the same rotation ratio, the discharge assist roller 41 is used as a speed increasing system by increasing the diameter of the discharge assist roller 41 with respect to the discharge roller 40. is there. As a result, the back tension received by the paper discharge roller 40 is reduced, and the roller configuration is less affected by the spur spring pressure and the back tension.

  In order to reduce the disturbance of the paper discharge roller 40 due to the conveying force of the paper discharge assist roller 41, the material of the paper discharge roller 40 is rubber, whereas the paper discharge assist roller 41 is a plastic having a small friction coefficient. A roller is used. Further, the paper discharge assist roller 41 also has a role of suppressing the floating of the recording medium at the recording head unit.

  Hereinafter, for the sake of simplicity of explanation, the paper discharge assist roller 41 is omitted, and the description will be made with the configuration of the paper discharge unit including one paper discharge roller 40.

(E) Cleaning unit Returning to FIG. 1, the cleaning unit 60 includes a pump for cleaning the recording head 7, a cap for suppressing the drying of the recording head 7, a blade for cleaning the discharge port surface of the recording head 7, and the like. It is configured. The main driving force of the cleaning unit is obtained by being transmitted from the paper feed motor 99 already described. The cleaning unit 60 is a blade that cleans the face surface of the recording head 7 by a suction operation that sucks unnecessary ink or the like from the recording head 7 by applying a pump while the cap is in close contact with the recording head 7 or movement of the blade. Perform actions and so on.

  4 and 5 are diagrams for explaining a mechanism for detecting the origin in the transport roller (first transport means) of the present embodiment. FIG. 4 is a plan view of the pulley gear 361 on the transport roller 36. 5 shows the case of observing from the back side. The lock ring 4001 is attached to the pulley gear 361, has a circumferential portion 4001a and a concave portion 4001b, and rotates integrally with the transport roller 36. The lock lever 4002 can lock the lock ring 4001 by abutting the lock portion 4002b against the recess 4001b of the lock ring 4001 by rotating around the rotation center 4002a. The lock link lever 4003 is a lever that presses and lifts the lock lever 4002, and the press and lift force between the lock link lever 4003 and the lock lever 4002 is generated by the lock lever spring 4004. The force Ftg for rotating the lock link lever 4003 is generated when the carriage 50 moves to a lock position (the left end portion in FIG. 1) outside the scanning area during recording on the side opposite to the home position.

  FIG. 6 is a diagram illustrating a state in which the carriage 50 in the recording apparatus according to the present embodiment is observed from the back side opposite to that in FIG. A protrusion 50 a is attached to the rear surface of the carriage 50, and the protrusion 50 a comes into contact with the inclined surface 4003 a of the lock link lever 4002 when the carriage 50 moves to the lock position. When a predetermined force Fcr is applied to the inclined surface 4003a of the lock link lever 4002 by such contact, referring to FIG. 4 or FIG. 5 again, Ftg in the direction in which the lock link lever 4003 is rotated in the direction of the arrow in the figure. Occurs.

  FIGS. 7A to 7C are cross-sectional views for specifically explaining a process in which the lock function acts by the mechanism described in FIGS.

  FIG. 7A is a diagram illustrating a state where the carriage 50 is not in the lock position. At this time, since the lock link lever 4003 is not pressed, the lock ring 4001 and the lock ring lever 4002 are separated from each other. During the recording operation, the conveyance roller 36 and the lock ring 4001 are intermittently rotated in the CW direction in the drawing in order to convey the recording medium.

  FIG. 7B shows a state in which the carriage 50 moves to the lock position, the lock link lever 4003 is pressed by the protrusion 50, and a mechanical trigger is applied. Due to the occurrence of Ftg, the lock link lever 4003 rotates, and the lock lever 4002 comes into contact with the circumferential portion 4001 a of the lock ring 4001 by the pressing force of the lock lever spring 4004. At this time, even if the lock lever 4002 receives pressure from the circumferential portion 4001a of the lock ring, the lock lever 4002 can stroke into the lock link lever 4003. Therefore, no damage due to collision occurs between the protrusion 50a of the carriage 50 and the lock link lever 4003. Further, by configuring the lock lever 4002 and the lock link lever 4003 as separate parts as described above, the stroke amount of the lock lever 4003 and the swing amount of the lock link lever 4003 can be set independently.

  FIG. 7C is a view showing a state in which the conveyance roller 36 is further rotated from the state of FIG. 7B and the rotation is locked by the lock ring 4001. When the lock ring 4001 further rotates in the CW direction with the lock lever 4002 in contact with the circumferential portion 4001a of the lock ring 4001, the lock portion of the lock lever 4002 enters the recess 4001b of the lock ring 4001. Then, the subsequent rotation of the lock ring 4001 in the CW direction is hindered. That is, the rotation of the lock ring 4001 and the transport roller 36 is locked. At this time, since the lock ring 4001 is fixed to the pulley gear 361 that transmits the power from the transport motor 35, no rotational force is generated between the transport roller 36 and the pulley gear 361.

  Such a locked state occurs only at one determined position during one rotation of the transport roller 36. Therefore, the position where the conveyance roller is locked in this way can be set as the origin of the phase of the conveyance roller.

  It should be noted that the conveying roller 36 is formed by a conventional method, such as a configuration in which a sensor detects an edge of one cycle / one rotation printed on a code wheel, or a configuration in which an edge of one cycle / one rotation attached to rollers is detected by a sensor. The origin of the phase may be detected.

  FIG. 8 is a block diagram for explaining a control configuration of the recording apparatus of the present embodiment. The CPU 501 controls each mechanism in the apparatus via the controller 502 according to various programs stored in the ROM 504. At this time, the RAM 503 is used as a work area for temporarily storing various data and executing processing. The CPU 501 performs image processing for converting image data received from an externally connected host device into a recording signal that can be recorded by the recording device. Then, various motors 506 are driven via the motor driver 507 or the recording head 7 is driven via the recording head driver 509 to form an image on the recording medium. In the drawing, a motor 506 and a motor driver 507 collectively indicate the transport motor 35, the carriage motor 54, the paper feed motor 99, and the respective drivers that have been previously operated.

  An electrically writable EEPROM 508 stores factory setting values and data to be updated, and this data is used as a control parameter by the controller 502 and the CPU 501. The sensor 505 collectively indicates temperature sensors and encoder sensors installed at various locations in the apparatus, and the above-described transport roller encoder sensor 363 is one of them. The CPU 501 increments the count information detected by the transport roller encoder sensor 363 in the ring buffer of the RAM 503 as needed. When the origin is detected, the origin information is stored in another area of the RAM 503 or the EEPROM.

  Hereinafter, the characteristic configuration of the present embodiment will be described in detail.

  First, a phenomenon in which the conveyance amount error fluctuates during delivery from the conveyance roller 36 to the paper discharge roller 40 will be described. FIG. 11 is a diagram for explaining the conveyance amount at the time of delivery from the conveyance roller 36 to the paper discharge roller 40.

  In the transport operation at the time of delivery, the vicinity of the nip between the transport roller 36 and the pinch roller 37 shown in FIG. 11A is an unstable section for stopping the paper. Therefore, the transport control is performed so as not to stop in this section. Need to do. That is, when the sheet passes through the nip of the conveyance roller 36, the conveyance is started from the upstream side of the nip shown in FIG. 11B and is stopped downstream of the nip shown in FIG. The transport position in this transport operation is transported only by the section A transported by both the transport roller 36 and the paper discharge roller 40, the section B passing through the nip portion, and the paper discharge roller 40. It is divided into C section.

  In addition, since the roller and the discharge roller have eccentricity, even if the rollers are rotated by the same angle, a region where the conveyance amount is large and a region where the conveyance amount is small according to the rotation phase of the roller. Occurs. In the above-described region where the carry amount is large, the carry amount when rotated by a certain angle is larger than the predetermined amount, so the paper carry speed is also increased from the predetermined speed. On the other hand, the conveyance speed becomes small in the region where the conveyance amount is small. As described above, since the conveyance speed varies depending on the eccentricity of the conveyance roller and the discharge roller, a difference in conveyance speed is generated between the conveyance roller and the discharge roller.

  As described above, because a conveyance speed difference occurs between the conveyance roller and the paper discharge roller, when switching from the A section to the C section in the conveyance operation at the time of delivery, the difference is caused by the conveyance speed difference between the conveyance roller and the paper discharge roller. As a result, the transport amount fluctuates. Explaining this, in the state where the paper is being transported by both the transport roller and the paper discharge roller, the pulling force via the paper is caused between the transport roller 36 and the paper discharge roller 40 due to the difference in speed between the two rollers. Or repulsive force is generated. However, when the trailing edge of the sheet passes through the point B, the deflection of the discharge roller 40 due to this force is released. As a result, a transport amount due to a specific factor is generated due to a transport speed difference between the transport roller and the paper discharge roller.

  Of course, in the A section and the C section, an error in the conveyance amount due to the eccentricity of the roller occurs. Since the conveyance amount control by the conveyance roller 36 is dominant in the A section, a conveyance amount error due to the eccentricity of the conveyance roller 36 occurs, and in the C section, a conveyance amount error due to the eccentricity of the paper discharge roller 40 occurs. Therefore, the unit transport amount error (integrated value) in the A section and the unit transport amount error (integrated value) in the C section also need to be considered in correcting the transport amount.

  As described above, the transport amount error fluctuates during the transfer from the transport roller 36 to the paper discharge roller 40 in accordance with the rotation phase of the transport roller and the paper discharge roller in the transport operation during the transfer. Therefore, in correcting the transport amount at the time of delivery from the transport roller to the paper discharge roller, in addition to the transport amount error due to the eccentricity of the A section and the C section, the unit transport amount (transport speed) of the A section and the C section is It is important to correct the transport amount so as to be as equal as possible. It should be noted that in the state where the conveyance roller 36 and the paper discharge roller 40 are both conveying (section A), the conveyance amount control by the conveyance roller 36 is dominant, so this state is simply the conveyance state of the conveyance roller 36. Can be thought of as

  Next, a transport amount error of the recording medium (paper) P caused by a transport speed difference between the transport roller and the paper discharge roller at the time of delivery will be described with reference to FIGS.

  In FIG. 12, the vertical axis represents the conveyance amount error, and the horizontal axis represents the rotation phase of the roller. In the figure, the fluctuation of the conveyance amount according to the rotational phase of the roller in the state (A section) in which the recording medium P is conveyed by both the conveyance roller 36 and the discharge roller 40 is indicated by the solid line, and only the discharge roller 40 is recorded. Conveyance fluctuations corresponding to the rotation phase of the roller in the state of conveying the medium P (section C) are indicated by broken lines. In the figure, the upper side from the center 0 of the vertical axis is a state in which the conveyance speed of the roller is higher than the predetermined speed, and the recording medium is fed more than the predetermined conveyance amount, and the conveyance amount error is positive. Is shown. On the other hand, below the center 0 of the vertical axis, the roller conveyance speed is slower than the predetermined speed, and the recording medium is fed less than the predetermined conveyance amount, and the conveyance amount error is negative. Shows the state.

  FIGS. 13A to 13C are sections A and C when the paper is transferred from the transport roller to the paper discharge roller in the rotational phase of FIGS. The transport amount error is shown. FIGS. 14A to 14C correspond to FIGS. 13A to 13C and illustrate fluctuations of the paper discharge roller 40. FIG.

  FIG. 13A shows the conveyance amount errors in the A section and the C section when the paper is delivered at the rotational phase shown in FIG. In this phase, the transport amount error of the transport roller 36 <the transport amount error of the paper discharge roller 40, that is, the transport speed of the transport roller 36 <the transport speed of the paper discharge roller 40. Becomes a speed increasing system. Therefore, as shown in FIG. 14A, the deflection of the discharge roller 40 that has been bent upstream by the traction force (frictional force) between the discharge roller 40 and the recording medium P is caused after the recording medium P. The end is released at the moment when the end passes through the nip of the conveyance roller 36, and the paper discharge roller 40 moves downstream. Therefore, the amount of paper transport during delivery increases according to the movement of the paper discharge roller 40. In addition to the increase in the carry amount, a value obtained by adding the integral value of the carry amount error in the section A and the integral value of the carry amount error in the section C shown in FIG. This corresponds to an error.

  FIG. 13B shows the conveyance amount error in the A section and the C section when the paper is delivered at the rotational phase shown in FIG. In this phase, the transport amount error of the transport roller 36 = the transport amount error of the paper discharge roller 40, that is, the transport speed of the transport roller 36 = the transport speed of the paper discharge roller 40, so that the paper discharge roller 40 is a constant speed system. . Further, as shown in FIG. 14B, no force is generated through the recording medium due to the speed difference between the paper discharge roller 40 and the conveying roller 36, so that the recording medium P passes through the nip of the conveying roller 36. However, movement of the paper discharge roller due to release of the deflection of the paper discharge roller 40 cannot occur. Therefore, the transport amount of the recording medium P does not change due to the movement of the paper discharge roller. Therefore, a value obtained by adding the integral value of the carry amount error in the section A and the integral value of the carry amount error in the section C in FIG. 13B substantially corresponds to the carry amount error at the time of delivery.

  FIG. 13C shows the transport amount error in the A section and the C section when the paper is delivered at the phase shown in FIG. In this phase, since the transport amount error of the transport roller 36> the transport amount error of the paper discharge roller 40, that is, the transport speed of the transport roller 36> the transport speed of the paper discharge roller 40, the paper discharge roller 40 compared to the transport roller 36. Becomes a deceleration system. Accordingly, as shown in FIG. 14C, the deflection of the discharge roller 40 that has been bent downstream by the traction force (frictional force) between the discharge roller 40 and the recording medium P is caused after the recording medium P. The end is released at the moment when the end passes through the nip of the conveying roller 36, and the paper discharge roller 40 moves upstream. Therefore, according to the movement of the paper discharge roller 40, the conveyance amount of the recording medium P at the time of delivery decreases. In addition to the decrease in the transport amount, a value obtained by adding the integral value of the transport amount error in the section A and the integral value of the transport amount error in the section C shown in FIG. It corresponds to the error.

  In the present embodiment, the first transport amount control and the second transport amount control can be executed as the transport amount control for correcting the transport amount error at the time of delivery described above. Below, this 1st, 2nd conveyance amount control is demonstrated.

[First transport amount control]
First, the first transport amount control, which is one of the transport amount correction control methods in the transport operation during delivery, will be described. The basic procedure of the transport amount correction control method in the transport operation during delivery is to first transport the paper in a state where the rotational phase of the roller is managed, and transport the paper at each rotational phase interval in the A section and the C section. Measure the amount. Next, a conveyance amount correction value for each rotational phase interval of the A section (conveyance roller) and the C section (discharge roller) is calculated from the actual measurement result. Then, in the actual recording operation, a correction value for correcting the conveyance amount in the conveyance operation at the time of transfer from the conveyance amount correction value for each rotation phase interval of the conveyance roller and the discharge roller according to the rotation phase at the time of delivery. Calculate and correct the transport amount of the transport operation at the time of delivery.

  Here, FIG. 22 is a conceptual diagram of eight rotational phase intervals S1 to S8 formed by dividing the roller outer periphery into eight parts, and a correction value table storing correction values for the conveyance amount set for each rotational phase interval. It is shown. In the figure, positions ps1 to ps8 indicate the rotational phase positions of the rollers at which paper conveyance is started in one conveyance operation. Here, both the transport roller 36 and the paper discharge roller 40 divide the outer periphery of the roller into eight, and the transport amount correction is controlled every eight rotation phase intervals S1 to S8. Further, since the rotation phase ratio between the transport roller 36 and the paper discharge roller 40 is equal to 1: 1, both roller rotation phases are managed at the same angle.

  FIG. 18 shows an example of a test pattern that is recorded in order to acquire a conveyance amount correction value for each rotation phase interval between the conveyance roller 36 and the paper discharge roller 40.

  First, a method for obtaining a conveyance amount correction value for each rotation phase interval between the conveyance roller and the discharge roller will be described with reference to FIGS.

  First, the origin of the roller phase is determined by performing the above-described process for detecting the origin of the rotational phase of the roller, so that the rotational phase of the roller can be managed. Then, a test pattern as shown in FIG. 18 is recorded in a state where the rotation phase of the roller can be managed.

  In recording the test pattern, first, a sheet feeding operation is executed from the sheet feeding unit, and the sheet is conveyed until the rotation phase of the conveying roller 36 reaches the position ps1. After the rotation phase of the transport roller reaches the position ps1, the first test pattern 2201 is recorded. After the pattern recording is completed, the conveyance of the sheet is started from the position ps1, and the sheet is conveyed until the rotational phase of the roller reaches the position ps2, and the second test pattern 2202 is recorded. As a result, the pattern interval between the first test pattern 2201 and the second test pattern 2202 corresponds to the unit conveyance amount at the rotational phase interval s1 from the positions ps1 to ps2. Similarly, after the second pattern recording is completed, the conveyance of the sheet is started from the position ps2, and the sheet is conveyed until the rotational phase of the roller reaches the position ps3, and the third test pattern 2203 is recorded.

  The above operation is repeated until the rotational phase of the transport roller 36 returns to the position ps1 again. By repeating such an operation, nine test patterns 2201 to 2209 are recorded.

  Subsequently, in order to perform test pattern recording in the conveyance state of only the discharge roller 40, the sheet is conveyed until the trailing edge of the sheet passes through the nip portion of the conveyance roller 36 and the rotation phase of the discharge roller 40 reaches the position ps1. I do. After the rotational phase of the paper discharge roller reaches the position ps1, the first test pattern 2211 is recorded. Next, the conveyance of the sheet is started from the position ps1, and the sheet is conveyed until the rotation phase reaches the position ps2, and the second test pattern 2212 is recorded. The above operation is repeated until the rotational phase of the paper discharge roller 40 returns to the position ps1 again. As a result, nine test patterns 2211 to 2219 are recorded.

  After the test pattern recording is completed, the pattern intervals of the test patterns 2201 to 2209 and 2211 to 2219 are measured by, for example, a scanner (optical sensor) provided on the carriage 50.

  Here, the pattern intervals from the test patterns 2201 to 2209 correspond to the respective conveyance amounts of the rotation phase intervals S1 to S8 of the conveyance roller 36, and the pattern intervals of the test patterns 2211 to 2219 are the rotation phase intervals S1 to S1 of the paper discharge roller 40. Corresponding to the respective transport amounts of S8. Therefore, by measuring the pattern intervals of the test patterns 2201 to 2209, the conveyance amount errors of the rotation phase intervals S1 to S8 of the conveyance roller 36 can be acquired. Similarly, by measuring the pattern intervals of the test patterns 2211 to 2219, it is possible to acquire the conveyance amount errors of the rotation phase intervals S1 to S8 of the paper discharge rollers.

  Next, the conveyance amount correction value is stored in a correction value storage location prepared for each rotation phase interval of each roller. Specifically, a value obtained by subtracting the measured value from the ideal roller conveyance amount is stored as correction values in SLF1 to SLF8 and SEJ1 to SEJ8 of the correction value table of FIG.

  Through the series of operations described above, the conveyance amount correction value for each rotation phase interval between the conveyance roller 36 and the discharge roller 40 can be acquired.

Next, a method for calculating a conveyance amount correction value at the time of delivery of the roller using a correction value for each rotation phase interval of each roller will be described. As described above, the transport amount at the time of delivery between the transport roller 36 and the paper discharge roller 40 needs to consider the influence of deflection due to the transport speed difference of the rollers in addition to the transport amount error in the A section and the C section. . Therefore, the correction value at the time of delivery is calculated from the following equation using correction coefficients A and B calculated in advance by experiments or the mechanical property values of the rollers.
(Formula 1)
Sk = A ・ SLF + B ・ SEJ
Sk: transport amount correction value in transport operation during delivery SLF: transport amount correction value of transport roller 36 (first correction value)
SEJ: Conveyance amount correction value (second correction value) of the paper discharge roller 40

  That is, in the above equation, the correction value Sk1 at the time of delivery in consideration of a specific conveyance amount error due to a difference in roller conveyance speed in addition to the conveyance amount error in the A section (conveyance roller) and the C section (discharge roller). ~ Sk8 can be calculated. The calculated correction values Sk1 to Sk8 at the time of delivery are stored for each rotation phase section in the correction table shown in FIG.

  Since the correction value is acquired for each of the eight rotation phase intervals for each of the conveyance roller and the paper discharge roller, a maximum of 64 values are calculated as the conveyance amount correction value at the time of delivery. However, in this control, since the rotation ratio between the transport roller 36 and the paper discharge roller is 1: 1, the eight correction values for the transport roller and the paper discharge roller correspond to 1: 1, and correction at the time of delivery is performed. The values are 8 values of Sk1 to Sk8.

  Next, with reference to FIGS. 16 and 17, the conveyance amount correction control at the time of delivery in the actual recording operation will be described. FIG. 16 is a diagram illustrating a method for acquiring the rotational phase of the roller in the transport operation during delivery. FIG. 16A shows a state when the lever 321 provided on the upstream side in the transport direction from the recording head 7 detects the trailing edge of the sheet, and the rotational phase of the roller at that time is φEnd_sns. . FIG. 16B shows a state at the moment when the trailing edge of the sheet exits the nip portion of the conveyance roller, and the rotational phase of the roller at that time is φEnd.

FIG. 17 is a control flow of transport amount correction at the time of delivery in the actual recording operation.
First, referring to FIG. 17, when the actual recording operation is started, the trailing end position of the sheet is detected in step S1701, and the roller rotation phase φEnd_sns at this time is obtained. As shown in FIG. 16, at this time, a distance corresponding to Lend remains until delivery (switching from the A section to the C section). Further, the rotation angle amount of the roller corresponding to the distance Lend is ΔφEnd.

  In step S1701, a conventionally known method for detecting the trailing edge of the paper may be employed. That is, the detection lever 321 (FIG. 16) is configured to move away from the standby position when it contacts the leading edge of the conveyed paper, and to return to the original position when the trailing edge of the paper passes, and the detection lever 321 is set to the standby position. For example, a method of detecting the trailing edge of the sheet by detecting the return.

  Next, in step 1702, based on the rotation phase φEnd_sns and the distance Lend when the trailing edge of the sheet is detected, the rotation phase φEnd of the transfer point is calculated.

  In step S1703, it is determined in which rotation phase section the rotation phase φEnd of the delivery point calculated in the previous step S1702 exists. Here, the following description will be made on the assumption that the rotation phase φEnd at the transfer point exists in the rotation phase section S2.

  Next, in step S1704, the conveyance amount correction value stored in the phase interval at the time of roller delivery obtained in step S1703 is acquired. In this example, the conveyance amount correction value Sk2 corresponding to the rotation phase section S2 is acquired. In the conveyance operation at the time of roller transfer during the actual image recording operation, this correction value is applied to a predetermined conveyance amount (step S1705).

  In the above description, the rotational phase interval at the time of delivery is calculated based on the rotational phase φEnd at the time of detection of the trailing edge of the paper, but it may be always calculated from the phase origin φOrigin. It is also possible to assign a correction value by estimating the rotation phase at the time of transfer from the length information of the recording medium and the print start position information without using the detection information of the paper rear end position.

  In the above description, the conveyance amount correction value at the time of delivery is calculated in advance from the conveyance amount correction value for each rotation phase interval between the conveyance roller and the discharge roller, and the calculated correction value is calculated in the actual recording operation. An appropriate correction value is selected from the stored correction value table. However, it is also possible to acquire up to the conveyance amount correction value for each rotation phase interval between the conveyance roller and the discharge roller, and calculate the correction value on the spot during actual recording according to the rotation phase at the time of delivery. .

  The conveyance amount at the time of delivery of the sheet from the conveyance roller to the discharge roller varies depending on a conveyance amount error due to the eccentricity of the A section and the C section and a conveyance error caused by a difference in roller conveyance speed. That is, the two transport amount errors are both greatly affected by the unit transport amount (transport speed) of the A section (transport roller) and the C section (discharge roller). Accordingly, in correcting the transport amount at the time of delivery, the transport amount is corrected based on the relative relationship between the unit transport amount (transport speed) of the A section (conveyance roller) and the C section (discharge roller). is necessary.

  According to the first transport amount control, since the transport amount at the time of delivery is corrected for each rotation phase based on the difference in unit transport amount (transport speed) between the transport roller and the paper discharge roller, the conventional inherent correction value The paper can be transported with higher accuracy than the case where the above is applied.

[Second transport amount control]
In the first conveyance amount control, a conveyance amount correction value at the time of delivery is obtained in advance for each rotation phase interval of the roller, so that the delivery operation of delivery can be performed at any rotation phase interval during the actual recording operation. This realizes highly accurate transport control with less transport amount error. On the other hand, in the second conveyance amount control, the conveyance amount correction value at the time of delivery is obtained for each rotation phase interval of the roller, and then the rotation phase interval most suitable for the conveyance operation at the time of delivery is determined. In the actual recording operation, the sheet conveyance control is executed so that the conveyance operation at the time of transfer is performed in the optimum rotation phase section.

  Therefore, in the second transport amount control, when the trailing edge of the sheet passes through the nip portion of the transport roller 36, the transport speed between the transport roller and the discharge roller is the same (or closest) at the rotation phase interval, Control is performed so that the transfer operation is performed. That is, in the recording apparatus in which the roller bearings are symmetrically configured with respect to the center in the width direction of the paper, the transport amount of the transport roller 36 and the discharge roller 40 is equal since the center of the paper and the center of the roller coincide. This is because it is optimal to equalize (conveying speed).

  First, a control method for executing a transfer operation at the time of delivery at a desired rotational phase will be described.

  When the sheet is fed from the sheet feeding unit and the leading end is nipped by the conveyance roller, the conveyance operation is performed in a state where the sheet and the conveyance roller 36 do not slip substantially thereafter. Therefore, after the leading edge of the sheet is held between the conveyance rollers, the sheet position and the rotation phase of the conveyance roller can be uniquely managed, and the rotation phase of the transfer can be easily estimated. In other words, the rotational phase at the transfer (point B) can be controlled by adjusting the rotational phase of the roller in which the leading end of the paper after being fed is sandwiched between the nips of the transport roller 36 in consideration of the length of the paper. it can.

  Next, the conveyance control at the time of delivery in the second conveyance amount control will be described with reference to FIGS. FIG. 19 is a diagram for explaining a sheet conveyance state from when the sheet leading edge is detected until the sheet leading edge is caught in the nip of the conveying roller. FIG. 19A shows a state when the lever 321 detects the leading edge of the sheet, and FIG. 19B shows a state when the leading edge of the sheet is caught in the nip of the conveying roller. FIG. 20 shows a state where the trailing edge of the sheet exits the nip of the conveying roller by the optimum rotation phase φjust.

FIG. 21 is a transport control flow at the time of delivery in the main transport amount control.
Referring to FIG. 21, in step S2101, sheet length information Lp is acquired from a printer driver or an input device. Note that paper length information may be acquired using a sensor in the recording apparatus.

  In step S2102, an initial phase (standby stop phase) at which the rotation of the conveying roller 36 is started is calculated based on the acquired sheet length information Lp.

  Next, the transport roller 36 is stopped at the standby stop phase (step S2103), and then the paper feed roller 28 is rotated to start paper feeding (step S2104). In step S2105, the fed paper comes into contact with the lever 321 and rotates the lever 321, and the paper leading edge detection sensor detects the paper leading edge position Ptop. From this point, when the paper feed roller 28 further transports the distance Ptop, it reaches the nip of the transport roller 36. Starting from this point, the conveyance roller 36 starts to rotate (S2106), and until the paper P reaches the nip of the conveyance roller 36, the conveyance roller 36 is rotationally driven and controlled at the conveyance speed of the paper feed roller 28, and conveyance is performed. The sheet P is caught at the nip portion of the roller 36 (S2107). In the second transport amount control, the rotation phase at the time of delivery is determined at this time. Therefore, the rotation phase of the roller at the time of delivery can be set to the optimum phase φjust by the above control.

  Here, a method of calculating the initial phase (standby stop phase) for realizing the transfer operation at the time of delivery with the above optimum phase φjust will be described with reference to FIG.

  The transport amount of the paper feed roller 28 from the time point when the leading edge of the paper P is detected to the time when the transport roller 36 is nipped is Ptop, whereas the transport amount of the transport roller 36 is Ltop which is smaller than Ptop. This is because the conveyance roller 36 is started from a stopped state with respect to the already-operated paper feed roller 28. Here, Ltop can be uniquely calculated when the rotational speed of the paper feed roller 28 and the rotational speed of the transport roller 36 are determined by the recording mode. That is, the conveyance roller 36 may be stopped at a rotation phase that is an amount before the Ltop conveyance amount with respect to the rotation phase of the roller that bites the paper P at the nip.

  The paper P bitten by the transport roller 36 is further transferred from the transport roller 36 to the paper discharge roller 40 when the transport roller 36 is further rotated by the length Lp of the paper (FIG. 20). What is necessary is just to control the phase of the conveyance roller 36 in advance so that the rotation phase of the conveyance roller 36 at this time becomes an optimal rotation phase.

  Therefore, assuming that the optimum phase of the transport roller at the time of delivery is φjust, in order to perform delivery with the rotational phase φjust of the transport roller, the paper P is shifted by a phase difference of (Lp) / (πDr) with the phase difference of (Pp) as a reference. Just bite. Note that Dr is a conveyance execution diameter of the conveyance roller. Furthermore, the phase just before the phase difference of (Lp + Ltop) / (πDr) with the optimum phase φjust as a reference may be set as the standby stop phase of the conveying roller 36. If the standby stop phase of the transport roller 36 is set in consideration of the slip of the roller, the transport control can be performed more strictly.

  As described above, the transfer operation can be performed with the optimum phase φjust, and stable and highly accurate paper conveyance can be realized. Due to manufacturing variations of the recording device, changes over time, and differences in paper types, sudden transfer errors may occur and the transfer operation cannot be performed at the optimum phase φjust. Can do. Further, when the transfer operation cannot be performed at the optimum phase φjust, as described in the first transfer control, by applying a correction value corresponding to the rotation phase at the time of transfer, a transfer amount error at that time can be obtained. Can be reduced.

  Note that the optimum phase φjust varies depending on the axial length of the roller, the setting of the roller, and the like. As described above, when the both-end bearing centers of the rollers coincide with the center of the sheet, the conveyance speeds of the conveyance roller and the discharge roller are the same when the trailing edge of the sheet passes the nip portion of the conveyance roller 36 ( The rotation phase (or the closest) becomes the optimum phase φjust.

  On the other hand, when the discharge assist roller 41 is configured to be accelerated with respect to the discharge roller 40, and the center of both ends of the roller does not coincide with the center of the sheet, the conveyance roller 36 and the discharge roller 40 are conveyed. Even if the speed difference is made equal, the transport amount is not stable. This is because immediately after the sheet passes through the nip, the sheet discharge roller is moved to the downstream side due to the influence of the left-right difference in the roller axial direction due to the deflection of the discharge roller. Such a phenomenon becomes particularly prominent in the configuration in which the discharge assist roller 41 is set to be accelerated relative to the discharge roller 40. In such a case, in relation to the unit conveyance amount of the conveyance roller 36 and the discharge roller 40, a phase in which the conveyance amount of the discharge roller 40 becomes a deceleration system with respect to the conveyance roller 36 is selected, and the discharge roller 40 is preliminarily selected. Is bent downstream. In this way, it is effective to cancel the influence of the above-described deflection release.

  As described above, in the second conveyance amount control, the conveyance operation at the time of delivery can be performed with higher accuracy by setting the optimum phase φjust at the time of roller delivery according to the configuration of the recording apparatus main body.

[Characteristics of this embodiment]
Here, when the first transport amount control and the second transport amount control are compared, in the first transport amount control, it is unclear in which rotational phase section the transport operation at the time of delivery is performed. Depending on the rotational phase interval, sudden transport errors may occur. On the other hand, in the second conveyance amount control, the rotation phase interval most suitable for the conveyance operation at the time of delivery is obtained, and the sheet conveyance control is executed so that the conveyance operation at the time of delivery is performed in this optimum rotation phase section. Therefore, the second transport control can suppress the sudden transport error and stably and highly accurately control the transport.

  However, in the second transport control, the transport roller is rotated after calculating the initial phase (standby stop phase) of the transport roller so that the transport operation at the time of delivery is performed in the optimum rotation phase section. It is necessary to stop at the standby stop phase. Therefore, when the recording operation is performed using the second conveyance amount control, it takes more time for image recording than when the first conveyance amount control is used.

  Therefore, in the present embodiment, the above-described first conveyance amount control and second conveyance amount control are switched according to the recording quality set when image recording is performed. Hereinafter, with reference to FIG. 23, the relationship between the recording mode and the conveyance amount control in the present embodiment will be described.

  First, the recording apparatus of the present embodiment has a configuration in which three recording qualities of “fast”, “standard”, and “beautiful” can be set when recording on plain paper. In these three recording qualities, the number of recording passes in so-called multi-pass recording is different, in which a predetermined area (also referred to as a band) on the recording medium is recorded by scanning a plurality of times. In other words, in “fast”, the number of recording passes is 1 and recording can be performed at high speed, but the recording quality is the lowest. In “clean”, the number of recording passes is 4, and an image with the highest recording quality can be obtained. However, since the number of passes is large, a long recording time is required. “Standard” has two recording passes and is set to obtain standard recording quality and recording speed. The selection of the above recording quality can be arbitrarily set by the user by an operation on an operation unit provided in the recording apparatus or a host connected to the recording apparatus.

  In the present embodiment, in the “fast” mode in which the recording speed is prioritized over the recording quality, the first transport amount control that does not require the process of stopping the transport roller in the standby stop phase is employed. On the other hand, in “standard” and “clean”, recording is performed using the second conveyance amount control, thereby enabling stable and highly accurate conveyance control and realizing image recording with high recording quality. With the above configuration, it is possible to achieve both image recording giving priority to recording speed and image recording with high recording quality by high-accuracy conveyance control.

  FIG. 24 is a flow for selecting the first transport amount control and the second transport amount control of the present embodiment.

  First, the recording data is received at Step 1, and the command portion added to the recording data is analyzed at Step 2. By analysis of the command part in step 2, information on the type of paper on which recording is performed and the designated recording quality is acquired.

  Next, it is determined whether or not the number of recording passes of the recording quality specified in Step 3 is equal to or greater than a predetermined number of passes. Here, since the paper type is plain paper, it is determined whether or not the number of passes is two or more, so that the recording quality “fast” for selecting the first transport amount control is selected, or the second transport amount control is performed. It is determined whether the recording quality is “standard” or “clean”. That is, when the number of recording passes is “standard” of 2 passes and “clean” of 4 passes, the process proceeds to step 4 and the second transport amount control is selected. On the other hand, when the number of recording passes is “fast”, the process proceeds to step 5 and the first transport amount control is selected.

  Subsequently, in step 6, printing is performed by the transport control of either the first transport amount control or the second transport amount control selected in steps 4 and 5.

  As described above, according to the present embodiment, by switching between the first conveyance amount control and the second conveyance amount control according to the designated recording quality, image recording giving priority to the recording speed and high-accuracy conveyance. It is possible to achieve both image recording with high recording quality by control.

(Second Embodiment)
The second embodiment is characterized in that the first transport amount control and the second transport amount control are switched according to whether or not the band boundary thinning process is performed.

  Details of the band thinning process will be described below.

  For example, in recording using plain paper or the like, there is a known problem that black lines are generated and the recorded image is deteriorated in one-pass recording which is efficient for improving the recording speed. This is due to the fact that ink flows from one band to the other band at or near the boundary between adjacent bands (also referred to simply as a connection), particularly in a region where the recording duty is high. That is, since the density becomes high at the band boundary and black streaks are likely to occur, the above-described image deterioration phenomenon occurs.

  With respect to this problem, in Patent Document 2, the print data is thinned out so as to reduce the discharge amount of the predetermined color ink according to the sum of the discharge amount of the predetermined color ink and the discharge amount of the other color ink. A method of performing is disclosed. In this method, by determining the hue of the joint portion from the ink discharge amount of a predetermined color and the multi-color ink discharge amount, and by changing the contents of the thinning process according to the hue, the black stripes are generated. This is to reduce image damage.

  Since such a thinning process requires a plurality of tasks such as dot count of a predetermined area, hue determination, and thinning amount calculation in parallel, a large processing load is imposed on a control system such as an ASIC that controls the recording apparatus main body. Take it. If a task related to the conveyance amount control is added here, in terms of processing load, there may be a case where the recording speed is directly reduced.

  In the case of the above-described first conveyance amount control and second conveyance amount control, the rotation phase interval most suitable for the conveyance operation at the time of delivery is obtained, and the conveyance roller is made to wait in the initial phase. However, the processing load is larger.

  Therefore, in the present embodiment, when the thinning process of the band boundary portion is performed, the processing load is reduced by adopting the first conveyance amount control, and the possibility of a decrease in the recording speed is reduced.

  Hereinafter, the relationship between the execution / non-execution of the thinning process and the switching between the first conveyance amount control and the second conveyance amount control in the present embodiment will be described with reference to FIG. FIG. 25 is a diagram illustrating the relationship among the number of passes for each recording quality, whether or not to perform the thinning process, and the conveyance amount control when recording on plain paper.

  Referring to FIG. 25, when the recording quality is “fast” or “standard”, recording is performed in one pass, but in “standard”, the band boundary thinning process is applied. “Pretty” is 4 passes and does not apply thinning processing of the band boundary. This is because as the number of recording passes increases, the amount of ink applied during one scan decreases, so that the amount of ink flowing into the joint portion is small and black streaks are unlikely to occur.

  As described above, in the present embodiment, the band thinning process is performed only when “standard” is designated among the three recording qualities, so the first transport amount control is selected for “standard”. However, the second transport amount control is selected for “fast” and “clean”.

  Note that black streaks generated at the joint portion are regions corresponding to a plurality of nozzles when the nozzle resolution is 600 dpi to 1200 dpi, and are larger than the error in the conveyance amount due to the eccentricity of the rollers. That is, when the deterioration of the image due to the conveyance error due to the eccentricity of the roller is compared with the deterioration of the image due to the black stripe at the connecting portion between the bands, the latter has a larger influence on the image. Therefore, in the present embodiment, band thinning processing is performed when “standard” recording quality is designated among “fast” and “standard” for performing one-pass recording.

  FIG. 26 shows a sequence for selecting the conveyance amount control in this embodiment.

  First, at Step 1, the recording data is received, and at Step 2, the command portion assigned to the recording data is analyzed. By analysis of the command part in step 2, information on the type of paper on which recording is performed and the designated recording quality is acquired.

  Next, in Step 3, it is determined whether the type of paper on which recording is performed is a paper on which band thinning processing is performed. As described above, the problem of black streaks occurring at the band joints is a problem that is particularly noticeable when recording on plain paper where ink bleeding is likely to occur. On the other hand, black streaks are hardly generated at the joints on papers that are difficult to cause ink bleeding, such as glossy papers. For this reason, band thinning processing may not be necessary for such types of paper. Therefore, in Step 3, if it is determined that the type of the recording medium requires the band thinning process, the process proceeds to Step 4, but if it is determined that the band thinning process is not necessary, the second transport amount control is performed in Step 6. Selected.

  In Step 4, it is determined whether the designated recording quality is the recording quality to be subjected to the band thinning process. In the present embodiment, as described with reference to FIG. 25, when the designated recording quality is “standard”, the process proceeds to Step 5, and the first transport amount control is selected. On the other hand, when the recording quality is “fast” or “clean”, the second transport amount control is selected in Step 6.

  Subsequently, in step 7, recording is executed by the transport control of either the first transport amount control or the second transport amount control selected in steps 5 and 6.

  In the present embodiment, the band thinning process has been described as an example. However, in the other image processes as well, the first and second transport amount controls are switched according to whether or not the image process is executed. It may be.

(Third embodiment)
In the third embodiment, it is determined whether or not image data exists in a predetermined area of the recording paper before the start of recording, that is, whether or not recording is performed before and after the transport operation at the time of delivery. If there is no data to be recorded, printing is performed by the first transport amount control. That is, in this embodiment, if there is no recording data to be recorded in the transition area (area recorded before and after the transport operation at the time of delivery), the first transport amount control is selected. As a result, processing for stopping the conveyance roller at the standby stop phase is omitted, and high-speed recording is realized.

  In this embodiment, if there is no image data in a predetermined area of the recording paper before the start of recording, recording is performed before the start of recording from the recording quality (number of recording passes) and the presence / absence of image processing as in the above-described embodiment. If there is no image data in a predetermined area of the paper, the first transport amount control is selected.

  FIG. 27 shows a selection flow for carrying amount control in this embodiment.

  First, the recording data is received at Step 1, and the command portion added to the recording data is analyzed at Step 2. By analysis of the command part in step 2, information on the type of paper on which recording is performed and the designated recording quality is acquired. Next, in Step 3, it is determined whether the second conveyance amount control is the type of paper to be selected and the recording quality (number of recording passes). If it is determined in Step 3 that the second transport amount control is in a condition to be selected, the process proceeds to Step 4 to analyze the recording data portion in the recording data.

  In Step 5, it is determined from the analysis result of the recording data portion whether or not recording data exists in a predetermined area (transition area). If it is determined in Step 5 that the recording data exists in the transition area, the process proceeds to Step 6 and the second transport amount control is selected.

  On the other hand, if it is determined in Step 3 that the second transport amount control is not in the condition to be selected, or if it is determined in Step 5 that there is no recording data in the transition area, in Step 7, the first transport amount control is performed. Selected.

  Subsequently, in step 8, recording is executed by the transport control of either the first transport amount control or the second transport amount control selected in steps 6 and 7.

(Fourth embodiment)
The fourth embodiment is a recording apparatus capable of recording on a recording sheet and a CD-R or DVD-R (printable disc) that can be recorded on the surface. The first conveyance is performed according to the type of the recording medium. The amount control and the second transport amount control are switched.

  FIG. 28 is an external perspective view showing the configuration of a recording apparatus to which this embodiment can be applied.

  The recording apparatus 100 according to the present embodiment is in the form of a multifunction printer, and a scanner which is a reading apparatus 101 is integrally configured. Reference numeral 102 denotes a viewer, which is a display means for displaying an image read by the scanner, and is a commonly used liquid crystal monitor. Reference numeral 103 is a setting key that can be set by the user. By operating the up / down / left / right keys, an image on the viewer can be arbitrarily moved, enlarged, reduced, or trimmed. Reference numeral 104 denotes a printed matter such as an original or an image such as a photograph. Hereinafter, a CD-R or DVD-R medium that can be recorded on the surface is also referred to as a printable disc.

  Reference numeral 106 denotes a tray, which is devised so that position information of a CD-R or DVD-R that is the electronic information recording medium can be read with high accuracy before recording by an optical sensor (not shown) in the recording apparatus. The tray 106 is provided with a reflecting plate indicating position information, color is changed, or a hole is made to improve reading accuracy.

  29 and 30 are a schematic perspective view and a cross-sectional view showing a state in which tray recording using a tray is performed in the transport mechanism of the recording apparatus, and a recording medium such as a CD-R mounted on the tray. The tray recording to be recorded will be described. When performing tray recording using the tray 226, the paper discharge tray 24 is moved from the normal recording position shown in FIG. 3 to a tray recording position where the tray 226 can be conveyed by a moving mechanism (not shown). Of course, the paper discharge tray 224 is also used to hold recording paper discharged by normal recording.

  At this time, the spur holder 232 is linked to the movement of the discharge tray 224 to the tray recording position, and the discharge rollers on the downstream side and the upstream side until the position where the spur 223 does not contact the printing surface of the recording medium on the tray. It is moved in a direction away from 222a and 222b. Next, a recording medium such as a CD-R is set in the concave portion of the tray 226 with the printing surface up.

  Next, the tray 226 is set at the conveyance start position on the paper discharge tray 224. First, a pair of left and right U-shaped tray guides 225 formed integrally with the paper discharge tray 224 are engaged with rail portions 229 formed on both left and right edges of the tray 226 while the tray 226 is moved. The sheet is inserted into the recording apparatus 100 along the upper surface of the sheet discharge tray 224.

  Along with the insertion of the tray 226, a pressing roller 230 as a first urging member provided on the paper discharge tray 224 rides on the upper surface of the rail portion 229 of the 226. When further inserted, the tray 226 rides on the downstream discharge roller 222a. Here, the apex of the downstream discharge roller 222 a is set higher than the upper surface of the discharge tray 224. The pressing roller 230 as the first urging member is rotatably supported by the pressing roller holder 35 and is urged toward the upper surface of the paper discharge tray 224 by a pressing roller spring 236. Therefore, the tray 226 is pressed against the downstream discharge roller 222a, and the leading end of the tray 226 changes its traveling direction slightly above the horizontal. Thus, a configuration is adopted in which the pressing roller 230 as the first urging member for urging the tray 226 toward the paper discharge roller 222a is disposed downstream of the paper discharge roller 222a.

  When the insertion is further continued, the tip end portion of the tray 226 abuts on a holding rib 231 as a second urging member that is formed integrally with the spur holder 232 and protrudes downward from above in the traveling path of the tray 226. . The contact position between the leading end portion of the tray 226 and the pressing rib 231 is selected in the vicinity of the upstream discharge roller 222 b in the depth direction of the recording apparatus 100. In the width direction, it is selected at the position of the rail portion 229 of the tray 226 located outside the recording sheet during normal recording. In this way, the pressing rib 231 that urges the tray 226 toward the paper discharge roller 222a is arranged between the conveyance roller 208 and the paper discharge roller 222a. The structure arrange | positioned outside is taken.

  Further, in the present embodiment, the holding rib 231 as the second urging member is attached to the spur holder 232 as the driven rotating body support member that supports the spur 223 as the driven rotating body that rotates in contact with the paper discharge roller. It is provided integrally.

  Here, the spur holder 32 as the driven rotor support member is biased in the direction of the downstream discharge roller 222a and the upstream discharge roller 222b by a spring (not shown). Therefore, when the tray 226 is further inserted, the pressing rib 231 rides on the rail portion 229 while curving the tip of the tray 226 slightly downward, so that the tray 26 receives further pressure contact force with respect to the downstream side discharge roller 222a. . When the leading end of the tray 226 reaches a position approximately in the middle between the nip portion of the transport roller 8 and the pinch roller 212 and the upstream discharge roller 222b, the insertion of the tray 226 is stopped. The tray 226 is manually inserted up to the position, and the position of the tray 226 is set as a conveyance start position.

  From the conveyance start position, the tray 226 is conveyed in the upstream direction of normal recording by the reverse rotation of the downstream discharge roller 22a, and is caught in the nip portion of the conveyance roller 208 and the pinch roller 212 that are also reversed. Thereafter, the sheet is conveyed to a recording position by a conveying roller 208, and recording is performed on a recording medium on a tray 226 such as a CD-R tray. Finally, the tray 226 loaded with the recording medium on which recording has been completed is discharged onto the paper discharge tray 224 by the normal rotation of the downstream paper discharge roller 222a.

  Although not described in FIGS. 28 to 30, the basic configuration for realizing the recording operation on the recording paper such as the paper feeding unit and the paper discharging unit is the same as the configuration of the recording apparatus shown in FIG. 1.

FIG. 31 is a diagram showing the selection of the number of recording passes and the conveyance amount control corresponding to the type of recording paper and the recording quality in the present embodiment.
FIG. 31A shows a case where the recording paper is a photographic paper (glossy), and the second transport amount control is selected for any recording quality.
FIG. 31B shows a case where the recording paper is a printable disc, and the first transport amount control is selected for any recording quality.

  As described above, when recording on a printable disc with the recording apparatus of the present embodiment, a mechanism is adopted in which the tray itself is conveyed by a roller while the recording medium (disc) is placed on and held on the tray. For this reason, in the area where the printable disc is recorded, the tray is always transported by a plurality of rollers, so that there is no problem of the transport operation at the time of delivery. Therefore, as shown in FIG. 31 (b), when recording a printable disc, the first conveyance amount control that does not require adjustment of the initial phase of the conveyance roller is set.

  On the other hand, when recording is performed on a recording sheet, there is a transport operation at the time of delivery, and recording is performed before and after the transport operation. Therefore, in the present embodiment, if the recording medium is a sheet, the second transport amount control capable of stably correcting the transport amount error in the transport operation at the time of delivery is selected.

FIG. 32 shows a sequence for selecting the conveyance amount control in this embodiment.
First, the recording data is received at Step 1, the command portion assigned to the recording data is analyzed at Step 2, and based on the analysis result, it is determined whether the recording medium to be selected for the second conveyance amount control at Step 3 To do. That is, if the recording medium is a printable disc, the process proceeds to Step 4 and the first transport amount control is selected. If the recording medium is a sheet, the process proceeds to Step 5 and the second transport amount control is selected.

  In Step 6, recording is performed by the transport control of either the first transport amount control or the second transport amount control selected in Steps 4 and 5.

(Fifth embodiment)
In the fifth embodiment, an example using a copy function which is one of the functions of a multifunction printer will be described. Therefore, the present embodiment is also premised on a configuration in which a copy function is installed like the recording apparatus illustrated in FIGS.

  In the third embodiment described above, whether or not there is image data in the transition area is determined from the recording data, and if there is no data to be recorded, recording is performed by the first conveyance amount control. It was. In contrast, the present embodiment scans a document to be copied and determines whether image data exists in the transition area from the scan result before converting the scanned image data into a print data. It is characterized by.

  FIG. 33 is a selection flow for carrying amount control in the copy function according to this embodiment.

  When the user sets a document to be scanned, sets recording paper, recording quality, etc., and presses the copy button, copying starts. In Step 1, the command of the user setting information data is analyzed, and in Steps 2 and 3, it is determined whether or not the recording paper and recording quality (number of recording passes) require the second transport amount control. At the same time, scanning of the document is started at Step 5, image position determination is performed from the data read at Step 6, and it is determined at Step 7 whether there is image data at a predetermined position (transition region).

  If it is determined in Steps 2 and 3 that the second transport amount control is necessary, and if it is determined in Step 7 that image data exists at a predetermined position, after completion of the image position determination is confirmed in Step 4 In Step 8, the second transport amount control is selected. On the other hand, when it is determined that the second transport amount control is not necessary in any of Steps, the process proceeds to Steps 9 and 10, and the first transport amount control is selected.

  Subsequently, in step 11, recording is performed by the transport control of either the first transport amount control or the second transport amount control selected in steps 8, 9, and 10.

7 Recording Head 36 Conveying Roller 40 Paper Discharge Roller 50 Carriage 100 Recording Device

Claims (10)

A recording apparatus for recording an image on a recording medium conveyed in a conveying direction using a recording head,
A first conveying means disposed upstream of the recording head in the conveying direction, for conveying the recording medium;
A second transport unit disposed downstream of the recording head in the transport direction and configured to transport the recording medium;
From the first transport operation in which the recording medium is transported by the first transport means and the second transport means, the first transport means does not transport the recording medium by the second transport means. A control for adjusting the rotational phase so that the rotational phase of the first and second transport means becomes a predetermined rotational phase when switching to the second transport operation for transporting the recording medium, and adjustment of the rotational phase. One of the controls not to be performed is selected.   The rotation phase is adjusted before the recording medium is transported by the first transport unit so that the recording medium is transported by the first transport unit at a predetermined phase. The recording apparatus according to claim 1.   The recording apparatus according to claim 2, wherein the predetermined phase is calculated based on a length of the recording medium in a conveyance direction.   The recording apparatus according to claim 1, wherein the control for adjusting the rotational phase and the control for not adjusting the rotational phase are performed according to a recording condition.   The recording apparatus according to claim 4, wherein the recording condition is a type of the recording medium.   The recording apparatus according to claim 4, wherein the recording condition is a recording quality for the recording medium.   The recording apparatus according to claim 4, wherein the recording condition is the number of recording passes in multi-pass recording.   5. The recording apparatus according to claim 4, wherein the recording condition is a condition as to whether or not there is data to be recorded before and after the transport operation when switching to the second transport operation.   The recording apparatus according to claim 8, wherein the condition as to whether or not there is data to be recorded before and after the transport operation at the time of switching is determined based on the scanned data. There is a recording method for recording an image on a recording medium conveyed in the conveying direction using a recording head,
The recording medium is transported by both the first transport unit disposed upstream of the recording head in the transport direction and the second transport unit disposed downstream of the recording head in the transport direction. Perform the first transfer operation,
After the recording medium passes through the first conveying means, a second conveying operation is performed in which the recording medium is conveyed by the second conveying means without using the first conveying means,
Control for adjusting the rotation phase so that the rotation phase of the first and second transfer means becomes a predetermined rotation phase when switching from the first transfer operation to the second transfer operation; A recording method characterized by selecting one of the controls that do not perform the adjustment.

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