JP2018161882A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately determine rubbing between a head and the medium to be recorded.SOLUTION: A recording device moves a carriage in a scanning direction when it is determined that a medium to be recorded is not located in a region where the medium can oppose to the carriage and stores an abnormal position on a scale in a storage section on the basis of a detection result of an index formed in the scale during the moving. When a detection position on the scale of a detection section is located on a position other than the abnormal position during printing, it is determined that rubbing is generated between a head and the medium to be recorded when corresponding speed becomes a value slower than a first threshold in a speed parameter value related to a speed of the carriage. When the detection position is located at the abnormal position, it is determined that rubbing is generated between the head and the medium to be recorded when the corresponding speed becomes a value slower than a second threshold corresponding to a speed slower than the first threshold in the speed parameter value.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a recording apparatus.

  Patent Document 1 discloses a serial type ink jet printer that ejects ink from a head onto paper while moving a carriage on which the head is mounted in the scanning direction as an example of a recording apparatus. In the ink jet printer of this Patent Document 1, the current value corresponding to the deviation between the carriage speed detected by the linear encoder and the carriage target speed is applied to the carriage drive motor with feedback control. The drive motor is controlled.

  By the way, so-called cockling that absorbs ink discharged from the head and the paper undulates, or deformation of the paper such as paper curl due to ink absorption causes friction between the paper and the head during the movement of the carriage. There is. When such rubbing occurs, the head may be damaged or the paper may be jammed.

  Therefore, in the inkjet printer described in Patent Document 1, in the feedback control of the carriage drive motor, if the carriage speed is delayed from the target speed due to rubbing, the current value applied to the drive motor becomes larger than usual. When the current value exceeds a predetermined threshold value, it is determined that rubbing has occurred.

JP 2010-184443 A

  Here, the linear encoder that detects the speed of the carriage is usually provided along the scanning direction, and a scale on which an index is formed at predetermined intervals, and an index that is mounted on the carriage and formed on the scale are detected. It has a detection part. The linear encoder detects the speed of the carriage while the detection unit reads the index on the scale while the carriage is moving. In such a linear encoder, when an abnormality such as dirt or scratches occurs on the scale, it becomes difficult for the detection unit to accurately read the index on the scale. As a result, the carriage speed detected by the linear encoder may be slower than the actual speed. In this case, in the ink jet printer described in Patent Document 1, when the carriage speed detected by the linear encoder is slower than the target speed due to dirt on the scale, although there is actually no rubbing, There is a possibility of misjudging that rubbing has occurred.

  An object of the present invention is to provide a recording apparatus that can accurately determine rubbing between a head and a recording medium.

In order to solve the above problems, a recording apparatus according to the present invention includes a head having a nozzle for discharging a liquid, a carriage on which the head is mounted, and a carriage drive that reciprocates the carriage in a predetermined scanning direction. And a scale provided along the scanning direction and having an index formed at predetermined intervals, and an encoder mounted on the carriage and having a detection unit for detecting the index formed on the scale; A storage unit, and a control unit. The control unit is configured to determine whether the recording medium is located in an area that can face the carriage, and to perform the medium position determination process and the medium position determination process. When it is determined that the recording medium is not located in an area that can face the carriage, the carriage driving unit is moved so that the carriage moves in the scanning direction. An abnormal position detection that generates abnormal position information including an abnormal position on the scale based on a detection result of the index by the detection unit during the movement of the carriage and stores the abnormal position information in the storage unit And when the recording medium is determined to be located in an area where the recording medium can face the carriage, the carriage is moved at a target speed in the scanning direction. The carriage drive unit is controlled based on a speed parameter value related to the speed of the carriage acquired from the detection result of the index, and the head is controlled to discharge liquid from the nozzle to a recording medium based on image data. During the printing process for printing an image on the recording medium and the control of the carriage drive unit in the printing process, When the detection position on the scale of the detection unit is a position other than the abnormal position of the abnormal position information stored in the storage unit, the speed parameter value acquired at that time is If the corresponding speed is a slow value compared to the first threshold value corresponding to a speed slower than the target speed, it is determined that rubbing has occurred between the head and the recording medium, and the printing process During the control of the carriage drive unit, when the detection position on the scale of the detection unit is the abnormal position of the abnormal position information stored in the storage unit, the speed parameter value acquired at that time However, if the corresponding speed is slower than the second threshold corresponding to the speed slower than the first threshold, the rubbing that determines that rubbing has occurred between the head and the recording medium. Judgment processing can be executed.

  According to the present invention, when the detected position is an abnormal position, the head and the recording target are recorded using the second threshold value corresponding to a speed slower than the first threshold value used when the detected position is a position other than the abnormal position. Judgment is made on the rubbing that occurs with the medium. As described above, by using different threshold values for the abnormal position on the scale and the position other than the abnormal position, the speed parameter value acquired based on the detection result of the index by the detection unit is reduced due to the abnormality on the scale. However, it is possible to accurately determine the rubbing that occurs between the head and the recording medium.

1 is a schematic vertical sectional view of an ink jet printer. It is a schematic plan view of an ink jet printer. (A) is a figure which shows arrangement | positioning of the scale of an encoder and a detection sensor, (b) is a figure which shows the state which the detection sensor has opposed to the permeation | transmission area | region, (c) is a figure where a detection sensor is a non-transmission area | region. It is a figure which shows the state which has opposed. (A) is a figure which shows a pulse signal when dirt is not adhering to a scale, (b) and (c) are figures which show a pulse signal when dirt is adhering to a scale. (A) is a block diagram showing the electrical configuration of the printer, and (b) is a diagram for explaining thresholds relating to paper rubbing and jamming at abnormal positions and positions other than abnormal positions. It is explanatory drawing explaining the fall factor of the carriage speed acquired based on the detection result by a detection sensor, (a) is a figure when a paper rubbing is a fall factor, (b) is a fall factor of jam. FIG. It is explanatory drawing explaining the fall factor of the carriage speed acquired based on the detection result by a detection sensor, (a) is a figure when the stain | pollution | contamination on a scale is a fall factor, (b) is paper rubbing and It is a figure when the stain | pollution | contamination on a scale is a reduction factor. It is a flowchart which shows operation | movement of an inkjet printer. It is a flowchart which shows operation | movement of an inkjet printer. It is a flowchart which shows operation | movement of the inkjet printer which concerns on a modification. It is a flowchart which shows operation | movement of the inkjet printer which concerns on a modification.

  Hereinafter, the inkjet printer 1 will be described as an example of a recording apparatus. In the following description, as shown in FIG. 1 and FIG. As illustrated in FIG. 1, the printer 1 includes a feeding unit 2, a printer unit 3, a control device 100, and the like.

  The feeding unit 2 includes a paper feed tray 51 on which a paper P that is a recording medium is placed, and a pickup roller 52 provided above the paper feed tray 51. The pickup roller 52 takes out the paper P one by one from the paper feed tray 51 when the paper feed motor 53 (see FIG. 5A) is driven under the control of the control device 100. The paper P taken out by the pickup roller 52 is sent out along the guide 54 and supplied to the printer unit 3.

  As shown in FIG. 2, the printer unit 3 includes a carriage 4, an ink jet head 5 (hereinafter, head 5), a transport mechanism 6, an encoder 7, a cap 8, a flushing receptacle 9, and the like. The carriage 4 is supported by two guide rails 11 and 12 extending in the left-right direction. The two guide rails 11 and 12 are arranged at intervals in the front-rear direction. Pulleys 13 and 14 are provided at both ends of the upper surface of the guide rail 12 in the left-right direction. An endless belt 15 made of a rubber material is wound around the pulleys 13 and 14. The carriage 4 is attached to a portion of the belt 15 located between the pulley 13 and the pulley 14. A carriage motor 16 is connected to the right pulley 13. Then, when the carriage motor 16 is rotated forward and backward, the pulleys 13 and 14 rotate, so that the belt 15 travels, and the carriage 4 reciprocates with the horizontal direction as the scanning direction. At this time, the left pulley 14 rotates as the belt 15 travels.

  The head 5 is mounted on the carriage 4 and reciprocates in the scanning direction together with the carriage 4. The lower surface of the head 5 is a nozzle surface 10a (see FIG. 1) on which a plurality of nozzles 10 for ejecting ink are formed. Further, in the head 5, an actuator including an ink flow path communicating with the plurality of nozzles 10, and a plurality of driving elements that apply pressure to the ink in the ink flow paths and discharge the ink from the plurality of nozzles 10, respectively. And. The actuator is not limited to a specific configuration, but, for example, a piezoelectric actuator having a piezoelectric element that pressurizes ink using deformation due to the inverse piezoelectric effect of the piezoelectric layer can be suitably used as the driving element. In addition, you may employ | adopt the heat generating element for generating a bubble in an ink with a heat | fever as a drive element.

  Further, in order to print an image on the paper P, the head 5 has four types of ink ejection volume (volume of ink droplets) that can be ejected from the nozzle 10 within one ejection cycle (large droplet, medium droplet, small droplet, Non-discharge). Therefore, what can be expressed by the dots formed on the paper P are four levels of density corresponding to the ink ejection amount. As described above, the printer 1 can perform four gradation printing on the paper P. The ejection cycle is the time required for the head 5 to move by a unit distance corresponding to the scanning direction resolution.

  The transport mechanism 6 includes a platen 41 and two transport rollers 42 and 43. The platen 41 is disposed below the carriage 4 and at a position that can face the carriage 4. The width of the platen 41 in the left-right direction is longer than the width in the left-right direction of the paper P, and supports the paper P from below during printing.

  The two conveying rollers 42 and 43 are arranged at the front and rear so as to sandwich the platen 41. The two transport rollers 42 and 43 are rotationally driven in synchronization by the transport motor 37 (see FIG. 5A) under the control of the control device 100, and the paper P sent from the feeding unit 2 is fed. Then, the sheet is conveyed to an area A above the platen 41 that can face the carriage 4 (refer to FIG. 1; hereinafter, an opposed area A). A rotary encoder 40 (see FIG. 5A) that outputs a pulse signal corresponding to the rotation of the transport roller 42 is installed on the rotation shaft of the transport roller 42. The control device 100 controls the conveyance of the paper P based on the pulse signal of the rotary encoder 40.

  Further, as shown in FIG. 1, a paper sensor 38 is disposed on the upstream side of the transport rollers 42 and 43 in the transport direction. The sheet sensor 38 detects whether or not the sheet P exists at the detection position, with the position in the transport direction upstream of the transport rollers 42 and 43 in the transport path of the sheet P as a detection position. The control device 100 determines whether or not the paper P is positioned in the facing area A based on the detection result of the paper sensor 38 and the control content for the transport motor 37. Specifically, the control device 100 determines that the transport amount of the paper P by the transport rollers 42 and 43 based on the pulse signal of the rotary encoder 40 after the paper sensor 38 detects the leading edge of the paper P is the paper sensor 38. Is the first point in time when the leading edge of the paper P reaches the counter area A. Further, the transport amount of the paper P by the transport rollers 42 and 43 based on the pulse signal of the rotary encoder 40 from the first time point is the length of the facing area A (carriage 4) in the transport direction and the length of the paper P. The point in time when the total length in the transport direction is reached is the second point in time when the trailing edge of the paper P has left the facing area A. Then, it is determined that the sheet P is located in the facing area A from the first time point to the second time point.

  Further, a paper sensor 39 is disposed on the downstream side of the transport rollers 42 and 43 in the transport direction. The sheet sensor 39 detects whether or not the sheet P exists at the detection position, with the position in the conveyance direction downstream of the conveyance rollers 42 and 43 in the conveyance path of the sheet P as a detection position. The control device 100 determines the jam of the paper P based on the pulse signal of the rotary encoder 40 and the detection results of the paper sensors 38 and 39. Specifically, in the control device 100, the pulse number of the pulse signal of the rotary encoder 40 counted from the time when the paper sensor 38 detected the paper P has reached a value corresponding to the conveyance distance between the paper sensors 38 and 39. Nevertheless, if the paper sensor 39 does not detect the paper P, it is determined that a jam has occurred.

  The encoder 7 is a transmissive linear encoder, and includes a scale 21 and a detection sensor 22 as shown in FIGS. 2 and 3. The scale 21 is disposed on the upper surface of the guide rail 12 and extends in the scanning direction over the movable range of the carriage 4. In addition, as shown in FIG. 3A, a plurality of transmissive regions 21a and non-transmissive regions 21b are alternately arranged on the scale 21 along the scanning direction. The region widths in the scanning direction of each of the transmissive regions 21a are all the same, and the region widths in the scanning direction of each of the non-transmissive regions 21b are also the same. That is, on the scale 21, the plurality of transmission regions 21a are formed at predetermined intervals (region width of the non-transmission region 21b) along the scanning direction, and the plurality of non-transmission regions 21b are predetermined intervals along the scanning direction. It is formed for each (area width of the transmission area 21a). The transmissive region 21a is a region that transmits light, while the non-transmissive region 21b is a region that does not transmit light.

The detection sensor 22 is mounted on the carriage 4 and includes a light emitting element 26 and a light receiving element 27. The light emitting element 26 and the light receiving element 27 are arranged so as to sandwich the scale 21 in the front-rear direction. The light emitting element 26 irradiates light toward the light receiving element 27. The light receiving element 27 receives the light emitted from the light emitting element 26. The detection sensor 22 detects the transmission region 21a and the non-transmission region 21b using the position on the scale 21 between the light emitting element 26 and the light receiving element 27 as a detection position.

  Specifically, as shown in FIG. 3B, when the detection position of the detection sensor 22 is the transmission region 21a, the light emitted from the light emitting element 26 transmits through the transmission region 21a and receives the light receiving element. 27 receives light. On the other hand, as shown in FIG. 3C, when the detection position of the detection sensor 22 is the non-transmissive region 21b, the light emitted from the light emitting element 26 is blocked by the non-transmissive region 21b and received. The element 27 is not reached. Therefore, when the detection position of the detection sensor 22 is moved by moving the carriage 4 in the scanning direction, the light receiving element 27 receives light from the light emitting element 26 and does not receive light from the light emitting element 26. The state is repeated alternately.

  As shown in FIG. 4A, the detection sensor 22 has a potential of V1 when the light receiving element 27 does not receive light from the light emitting element 26, and when the light receiving element 27 receives light from the light emitting element 26. A pulse signal whose potential is V2 (V2 <V1) is output. That is, the pulse signal output from the detection sensor 22 indicates that the detection sensor 22 detects the non-transmission region 21b when the potential is V1, and the detection sensor 22 indicates the transmission region 21a when the potential is V2. Indicates that it is detected. Although details will be described later, in the present embodiment, the control device 100 acquires the speed of the carriage 4 (hereinafter also referred to as the carriage speed Vcr) based on the detection result of the detection sensor 22.

  As shown in FIG. 2, the cap 8 is disposed on the right side of the platen 41, and correspondingly, in the printer 1, the carriage 4 can be moved to a standby position where the nozzle surface 10 a faces the cap 8. It has become. The cap 8 can be moved in the vertical direction by an elevating mechanism (not shown). When the carriage 4 is positioned at the standby position, when the cap 8 is moved upward and brought close to the head 5, the cap 8 comes into close contact with the nozzle surface 10 a and the plurality of nozzles 10 are covered with the cap 8. Note that the cap 8 is not limited to being in close contact with the nozzle surface 10a. For example, when the head 5 has a frame disposed so as to surround the nozzle surface 10a, the cap 8 is in close contact with the frame. The nozzle 10 may be covered by this. In the printer 1, when printing is not performed, the carriage 4 is positioned at the standby position, and the plurality of nozzles 10 are covered with the cap 8. Thereby, drying of the ink in the nozzle 10 is prevented.

  The flushing receptacle 9 is disposed on the left side of the platen 41. Correspondingly, in the printer 1, the carriage 4 can be moved to the flushing position where the nozzle surface 10a faces the flushing receptacle 9. When the carriage 4 is positioned at the flushing position, the ink is ejected from each nozzle 10 to perform the flushing that discharges the thickened ink in each nozzle 10. The flushing position does not necessarily have to be a position where the nozzle surface 10a faces the flushing receptacle 9. For example, when flushing is performed while the carriage 4 is moving, the movement of the carriage 4 is dependent on the speed of the carriage 4. It may be a position in front of the flushing receptacle 9 in the direction.

As shown in FIG. 5A, the control device 100 includes a CPU (Central Processing Unit) 1
01, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a nonvolatile memory 104, an oscillation circuit 105, an ASIC (Application Specific Integrated Circuit) 106, and the like. The ROM 102 stores programs executed by the CPU 101, various fixed data, and the like. The RAM 103 temporarily stores data (image data and the like) necessary for executing the program. The nonvolatile memory 104 stores abnormal position information, which will be described later. The oscillation circuit 105 outputs a clock signal having a predetermined frequency. The ASIC 106 is connected to various devices or driving units of the printer 1 such as the head 5, the detection sensor 22, the carriage motor 16, the conveyance motor 37, the paper sensor 38, the touch panel 99, and the communication interface 110.

  The CPU 101 executes various processes for controlling operations of the head 5, the carriage motor 16, and the like via the ASIC 106 by executing programs stored in the ROM 102. In the following description, it is assumed that various processes are performed by the CPU, but the control apparatus 100 may include a plurality of CPUs, and the processes may be shared by the plurality of CPUs. The control device 100 may include a plurality of ASICs, and the processing may be shared by the plurality of ASICs. Alternatively, the processing may be performed by one ASIC alone. Hereinafter, processing executed by the CPU 101 in accordance with a program stored in the ROM 102 will be described.

  When the CPU 101 receives a print command from the external device 200 such as a PC via the communication interface 110, the CPU 101 controls the head 5, the carriage motor 16, the transport motor 37, and the like, and relates to the image data stored in the RAM 103. A printing process for printing an image on the paper P is executed.

  Specifically, when receiving a print command, the CPU 101 first generates ejection data by performing image processing such as known error diffusion processing (quantization processing) on the image data stored in the RAM 103. . This ejection data is 4-gradation data corresponding to four types of ejection amounts of ink that can be ejected from the nozzle 10 within one ejection cycle. Also. The CPU 101 controls the pickup roller 52 and the transport motor 37 to transport the paper P from the paper feed tray 51 toward the facing area A. Thereafter, the CPU 101 determines whether or not the paper P is located in the facing area A based on the detection result of the paper sensor 38 and the like. When it is determined that the paper P is located in the facing area A, the CPU 101 starts a printing process related to the generated ejection data. In this printing process, the CPU 101 performs ejection processing for ejecting ink from the nozzles 10 based on ejection data during one movement (also referred to as a pass) of the carriage 4 in the scanning direction, and paper P by the transport mechanism 6. Is alternately performed with a conveying process for conveying the predetermined amount forward.

  In the discharge process for printing one pass, the CPU 101 determines the current carriage speed Vcr acquired based on the detection result of the detection sensor 22 and the target speed so that the carriage 4 moves at a constant speed at the target speed. The movement of the carriage 4 is controlled by feedback control based on the deviation. In the printer 1, a plurality of speeds can be set as the target speed of the carriage 4. The CPU 101 selects any one of the speeds of the plurality of stages according to a print instruction (an instruction related to the resolution in the scanning direction of an image to be printed on the paper P included in the print instruction), a print range in a pass, and the like. One speed is set as a target speed, and the carriage motor 16 is controlled so that the carriage 4 moves at a constant speed at the target speed during the discharge process.

  By the way, when the paper P absorbs ink, paper deformation such as cockling and curling occurs. When such paper deformation occurs, when printing in subsequent passes, as shown in FIG. 6A, the paper P and the nozzle surface 10a of the head 5 rub against each other during movement of the carriage 4 (see FIG. 6A). Hereinafter, paper rubbing) may occur. If the movement of the carriage 4 is continued in the state in which the paper rubbing has occurred, it causes ink ejection failure or jamming due to the damage of the nozzle surface 10a.

  Therefore, when moving the carriage 4, the CPU 101 acquires a carriage speed Vcr that is the current speed of the carriage 4, and determines whether paper rubbing has occurred based on the carriage speed Vcr. When the CPU 101 determines that paper rubbing has occurred, the CPU 101 performs processing for stopping the movement of the carriage 4 and the like. Details will be described below.

In the ejection process, as described above, the CPU 101 controls the carriage motor 16 so as to move the carriage 4 at the target speed. During this control, the carriage 4 moves roughly at the target speed, although it is somewhat affected by motor fluctuations. However, when the paper rubbing occurs, the carriage speed Vcr is significantly lower than the target speed due to the frictional force between the nozzle surface 10a and the paper P. Therefore, when the carriage speed Vcr acquired during the control of the carriage motor 16 is slower than a predetermined threshold value (hereinafter referred to as the first threshold value), it can be determined that paper rubbing has occurred. The first threshold value is a value corresponding to a speed slower than the target speed, and the difference between the target speed and the first threshold value is larger than the speed decrease due to the motor fluctuation. For example, when the carriage speed Vcr varies about 5% due to motor fluctuations with respect to the target speed, the first threshold value is set to a value of 90% of the target speed.

  The carriage speed Vcr can be calculated by the following equation 1. In Equation 1, W is the area width in the scanning direction of one non-transmissive area 21b, and F is the frequency of the clock signal output from the oscillation circuit 105. Further, CK is the number of clock signals output from the oscillation circuit 105 while the detection sensor 22 is detecting one non-transmissive region 21b.

Vcr = W / (CK / F) (Equation 1)
In the above formula 1, the region width W and the frequency F are fixed values that are determined in advance. Therefore, the carriage speed Vcr can be calculated by obtaining the clock number CK. For this clock number CK, the period from the time when the potential of the pulse signal output from the detection sensor 22 rises from V2 to V1 to the time when the potential falls from V1 to V2, that is, the potential of the pulse signal becomes V1. It can be obtained by counting the clock of the clock signal output from the oscillation circuit 105 during the holding period (hereinafter also referred to as V1 holding period). As described above, it is possible to determine the sheet rubbing by acquiring the carriage speed Vcr based on the detection result of the detection sensor 22 while the carriage 4 is moving. The carriage speed Vcr is acquired every time the potential of the pulse signal output from the detection sensor 22 falls from V1 to V2.

  In addition, as shown in FIG. 6B, when the paper P is deformed so as to be lifted upward, the paper 4 may collide with the side surface of the paper P and the carriage 4 during the movement of the carriage 4 to cause a jam. When such a jam occurs, the carriage speed Vcr is much lower than when the paper is rubbed. Therefore, the CPU 101 determines that a jam has occurred when the carriage speed Vcr acquired based on the detection result of the detection sensor 22 is slower than the third threshold corresponding to the speed slower than the first threshold. The third threshold is set to a value that is 30% of the target speed, for example.

  Incidentally, the scale 21 may be abnormal due to ink stains or the like in part of the scale 21. For example, when a jam occurs, a removal operation for removing the jammed paper is performed by the user. In the course of this removal operation, the ink may adhere to the scale 21 and become dirty. In addition, so-called borderless printing may be performed in which ink is ejected from the nozzle 10 over a range wider than the length of the paper P in the scanning direction and printing is performed over the entire length of the paper P in the scanning direction. Normally, when the ink is ejected from the nozzle 10, only the energy required to land the ink on the upper surface of the paper P supported by the platen 41 is added to the ink. In FIG. 5, a part of the ink ejected from the nozzle 10 in the range outside the paper P in the scanning direction is misted without landing on the platen 41. The mist ink may adhere to the scale 21 and become dirty.

  As described above, when an abnormality occurs due to dirt or the like adhering to the scale 21, the pulse signal output from the detection sensor 22 is different from the pulse signal that should be output based on this detection sensor 22. The acquired carriage speed Vcr may be slower than the actual speed. This will be specifically described below.

  When the dirt-attached portion is the non-transmissive region 21b, the non-transmissive region 21b is originally a region that blocks light, and therefore, a pulse output from the detection sensor 22 due to the stain on the non-transmissive region 21b. The signal does not differ from the pulse signal that should be output.

  On the other hand, when the part to which the dirt is attached is the transmission region 21a, the light emitted from the light emitting element 26 is blocked by the dirt of the transmission region 21a and does not reach the light receiving element 27. As a result, due to the contamination of the transmission region 21a, the pulse signal output from the detection sensor 22 is different from the pulse signal that should be output originally.

  For example, as shown in FIG. 4B, in the transmissive region 21a, when dirt that is connected to only one of the adjacent non-transmissive regions 21b adheres, the detection position of the detection sensor 22 is one non-transmissive region. In addition to the period in 21b, the potential is held at V1 during the period in which the detection position is in the dirty portion.

  Further, as shown in FIG. 4C, when dirt is attached to the entire transmission region 21a, in addition to the period in which the detection position of the detection sensor 22 is in one non-transmission region 21b, one non-transmission region, In addition, the potential is held at V1 during a period in one transmission region 21a to which dirt is attached.

  As described above, when dirt is attached to the transmission region 21a of the scale 21, the V1 holding period in which the potential is held at V1 becomes longer than the period in which the detection position of the detection sensor 22 is in one non-transmission region 21b. As a result, the number of clocks CK acquired during the V1 holding period is larger than the number of clocks counted during the period in which the detection position of the detection sensor 22 is in one non-transmissive region 21b. That is, the number of clocks CK in Equation 1 is larger than the actual value. On the other hand, in the above formula 1, the region width W for the non-transmissive region 21b is a fixed value. For this reason, when the number of clocks CK is larger than the actual value, the carriage speed Vcr calculated using the equation 1 becomes slower than the actual speed. As a result, as shown in FIG. 7A, when the carriage speed Vcr is less than the first threshold value even though no paper rubbing has occurred, the CPU 101 erroneously determines that paper rubbing has occurred. Become. As a result, the movement of the carriage 4 is stopped and the printing process is unnecessarily interrupted, so that the usability of the printer 1 is deteriorated.

  Therefore, in this embodiment, in order to solve this problem, the CPU 101 generates abnormal position information regarding the abnormal position on the scale 21 and stores it in the nonvolatile memory 104 before the printing process. Execute.

  In addition, when the detection position of the detection sensor 22 is a position other than the abnormal position during the control of the carriage motor 16 in the printing process, the CPU 101 determines paper rubbing using the first threshold, and the detection position is the abnormal position. In this case, a rubbing determination process for determining sheet rubbing is performed using a second threshold different from the first threshold. The second threshold value is a threshold value that is smaller than the first threshold value and larger than the third threshold value. Moreover, the threshold value setting process which sets these 1st threshold value-3rd threshold value is performed. Hereinafter, these processes will be described in detail.

  In the abnormal position detection process, when the CPU 101 determines that the paper P is not located in the facing area A, the CPU 101 controls the carriage motor 16 to move the carriage 4 at a constant speed in the scanning direction. The moving range of the carriage 4 at this time is a range from the standby position to the flushing position. Then, based on the detection result of the detection sensor 22 during the movement of the carriage 4, abnormal position information including an abnormal position on the scale 21 and a speed reduction rate described later corresponding to the abnormal position is generated for each abnormal position. . This will be specifically described below.

  During the abnormal position detection process, since the paper P is not located in the facing area A, the carriage speed Vcr does not become slow due to paper rubbing, and the carriage 4 is kept at a constant speed at substantially the same speed as the set target speed. Will move. Therefore, when there is no dirt on the scale 21, as shown in FIG. 4A, the lengths of the V1 holding periods are all the same, and the detection sensor 22 is one non-transmissive region. This is the same as the period during which 21b is detected. Therefore, the carriage speed Vcr calculated by substituting the number of clocks CK acquired in each V1 holding period as a variable in the above equation 1 is substantially the same as the set target speed.

  On the other hand, as shown in FIGS. 4B and 4C, when dirt connected to the non-transmissive area 21 b is attached to any of the transmissive areas 21 a on the scale 21, this transmissive area on the scale 21. The positions of the dirt portion 21a and the non-transmissive region 21b are abnormal positions. When the detection position of the detection sensor 22 has this abnormal position, the V1 holding period is longer than when the detection position is a position other than the abnormal position, and the number of clocks CK acquired in this V1 holding period is also large. Become more. Therefore, the carriage speed Vcr calculated by substituting this clock number CK as a variable in the above equation 1 is slower than the set target speed. Therefore, the CPU 101 determines that the current detection position of the detection sensor 22 is an abnormal position on the scale 21 when the calculated carriage speed Vcr is slower than a predetermined threshold. The threshold value is a speed slower than the target speed by taking into account an error due to disturbance such as the motor fluctuation.

  The current detection position of the detection sensor is obtained by counting the number of non-transmissive areas 21b detected by the detection sensor 22 from the standby position of the carriage 4. The non-volatile memory 104 stores a count value indicating the number of detected non-transmissive areas 21b detected by the detection sensor 22 from the standby position of the carriage 4. When the carriage 4 moves to the left along the scanning direction, the CPU 101 stores the non-transmissive region 21b in the nonvolatile memory 104 every time the non-transmissive region 21b is detected by the detection sensor 22 (the potential rises from V2 to V1). The stored count value is incremented by one. On the other hand, the CPU 101 sets the count value stored in the non-volatile memory 104 to 1 each time the detection sensor 22 detects the non-transmissive area 21b when the carriage 4 moves to the left along the scanning direction. Count down. Thereby, the current detection position of the detection sensor 22 can be acquired.

  As described above, the CPU 101 determines an abnormal position on the scale 21. Further, the CPU 101 calculates a rate of speed reduction due to dirt at the abnormal position from the carriage speed Vcr acquired corresponding to each abnormal position. Specifically, the ratio of the acquired carriage speed Vcr when the target speed is 100 is defined as a speed reduction rate. Then, the CPU 101 generates abnormal position information including the abnormal position and the speed decrease rate corresponding to the abnormal position for each abnormal position, and stores it in the nonvolatile memory 104. Note that the speed control of the carriage 4 during the abnormal position detection process is also performed by feedback control based on the deviation between the target speed and the carriage speed Vcr acquired based on the detection result of the detection sensor 22. Here, if the acquired carriage speed Vcr is slower than the actual speed due to contamination on the scale 21, the feedback control cannot be performed appropriately. Therefore, when the acquired carriage speed Vcr is slower than the predetermined threshold, the acquired carriage speed Vcr may not be used as a parameter for feedback control.

When the carriage 4 moves with acceleration / deceleration, the carriage speed Vcr largely fluctuates due to a large motor fluctuation or the like. Therefore, when abnormal position information is generated based on the detection result of the detection sensor 22, The accuracy may be low. On the other hand, when the carriage 4 is controlled to move at a constant speed, the variation in the carriage speed Vcr is small. For this reason, the accuracy can be improved by controlling the carriage 4 to move at a constant speed and generating the abnormal position information based on the detection result of the detection sensor 22 as in the present embodiment. . In the present embodiment, the target speed of the carriage 4 set in the abnormal position detection process is the fastest speed among a plurality of settable speeds. Thereby, the time which an abnormal position detection process requires can be shortened.

  In the threshold setting process, the CPU 101 sets the first threshold and the third threshold according to the target speed of the carriage 4 during the ejection process of the printing process. For example, as described above, a value of 90% of the target speed is set as the first threshold value, and a value of 30% of the target speed is set as the third threshold value. Further, the CPU 101 sets a second threshold value for each abnormal position on the scale 21 based on the target speed of the carriage 4 during the ejection process and the abnormal position information stored in the nonvolatile memory 104. For example, the second threshold value for a certain abnormal position is set to a value of 90% of the value obtained by multiplying the target speed by the speed reduction rate corresponding to the certain abnormal position. The method for setting the second threshold value is not limited to this. For example, the relationship between the speed reduction rate and the second threshold value corresponding to each target speed is stored in the ROM 102 by a table or a calculation formula. These may be used to set the second threshold based on the speed decrease rate acquired in the abnormal position detection process.

  When setting the second threshold value for each abnormal position, if the second threshold value is smaller than the third threshold value, the range of the stain is large on the scale 21, and the paper rubbing is accurately determined. Therefore, an error screen may be displayed on the touch panel 99. Or, exceptionally, the third threshold value may be set to be smaller than the second threshold value only for this abnormal position. As described above, by setting the first to third threshold values in accordance with the target speed of the carriage 4, it is possible to accurately determine paper rubbing and jamming. Further, by setting the second threshold value for each abnormal position based on the speed reduction rate, it is possible to determine the sheet rubbing more accurately.

  In the rubbing determination process, as shown in FIGS. 5B and 6A, the CPU 101 stores the detection position of the detection sensor 22 in the nonvolatile memory 104 during the control of the carriage motor 16 in the printing process. If it is a position other than the abnormal position in the abnormal position information, it is determined that sheet rubbing has occurred when the carriage speed Vcr acquired at that time is less than the first threshold and greater than or equal to the third threshold. When the detection position of the detection sensor 22 is an abnormal position during the control of the carriage motor 16 in the printing process, the CPU 101 obtains the carriage speed Vcr acquired at that time as shown in FIG. If it is less than the second threshold corresponding to the abnormal position and greater than or equal to the third threshold, it is determined that paper rubbing has occurred. This determination of the presence or absence of sheet rubbing is performed every time the carriage speed Vcr is acquired. As shown in FIG. 5B, when the acquired carriage speed Vcr is less than the third threshold value, the CPU 101 determines that a jam has occurred regardless of the detection position of the detection sensor 22.

  Hereinafter, a series of operations of the printer 1 will be described with reference to FIGS. 8 and 9. At the start of the operation flow in FIG. 8, it is assumed that the carriage 4 is positioned at the standby position and the sheet P does not exist on the transport path including the facing area A.

  As shown in FIG. 8, when the CPU 101 receives a print command from the external device 200 or the like (S1: YES), it is before the conveyance of the paper P to the facing area A, and thus the paper P is positioned in the facing area A. The abnormal position detection process is executed (S2). Specifically, the CPU 101 controls the carriage motor 16 to move the carriage 4 from the standby position to the flushing position at a constant speed with the maximum speed that can be set as the target speed. Then, abnormal position information is generated based on the detection result of the detection sensor 22 during the movement of the carriage and stored in the nonvolatile memory 104.

  Next, the CPU 101 executes a flushing process for causing the head 5 to perform flushing (S3). Thereby, the ink thickened in the nozzle 10 can be discharged. Then, the CPU 101 generates ejection data from the image data stored in the RAM 103 (S4). Next, the CPU 101 controls the pickup roller 52, the conveyance motor 37, etc., and conveys the paper P in the paper feed tray 51 to the facing area A (S5). Since the sheet P is transported to the facing area A by the process of S5, the CPU 101 determines that the sheet P is located in the facing area A.

  Then, the CPU 101 sets the first and third thresholds according to the target speed of the carriage 4 set in the next discharge process, and the target speed of the carriage 4 and the abnormality stored in the nonvolatile memory 104. Based on the position information, a threshold value setting process for setting a second threshold value for each abnormal position is executed (S6). Thereafter, the CPU 101 starts an ejection process related to printing for one pass (S7). That is, the carriage motor 16 is controlled to start the movement of the carriage 4 in the scanning direction, and the head 5 is controlled to start the ejection of ink from the nozzles 10 based on the ejection data. During the control of the carriage motor 16, the detection position of the detection sensor 22 and the carriage speed Vcr are acquired based on the detection result by the detection sensor 22. As described above, the speed control of the carriage 4 during the ejection process is performed by feedback control based on the deviation between the target speed and the carriage speed Vcr acquired based on the detection result of the detection sensor 22. Is called. However, when the detection position of the detection sensor 22 on the scale 21 is an abnormal position, the carriage speed Vcr acquired at that time is slower than the actual speed. As a result, there is a possibility that the speed control of the carriage 4 during the ejection process cannot be performed appropriately. Therefore, when the detection position of the detection sensor 22 on the scale 21 is an abnormal position, the acquired carriage speed Vcr may not be used as a parameter for feedback control. Alternatively, feedback control may be performed after correcting the acquired carriage speed Vcr with reference to the speed decrease rate of the abnormal position information corresponding to the abnormal position stored in the nonvolatile memory 104.

  Next, the CPU 101 determines whether or not the acquired carriage speed Vcr is less than a third threshold value (S8). If it is determined that the carriage speed Vcr is greater than or equal to the third threshold (S8: NO), the CPU 101 determines that no jam has occurred and proceeds to the process of S9. On the other hand, if it is determined that the carriage speed Vcr is less than the third threshold (S8: YES), the CPU 101 determines that a jam has occurred, and proceeds to the process of S30.

  In the process of S9, the CPU 101 refers to the abnormal position information in the nonvolatile memory 104 to determine whether or not the current detection position of the detection sensor 22 is an abnormal position (S9). If it is determined that the detected position is a position other than the abnormal position (S9: NO), the CPU 101 determines whether the acquired carriage speed Vcr is less than the first threshold (S10). If it is determined that the carriage speed Vcr is equal to or higher than the first threshold value (S10: NO), the CPU 101 determines that no sheet rubbing has occurred, and proceeds to the process of S12. On the other hand, if it is determined that the carriage speed Vcr is less than the first threshold (S10: YES), the CPU 101 determines that paper rubbing has occurred, and proceeds to the process of S35.

  If it is determined in step S9 that the detected position is an abnormal position (S9: YES), the CPU 101 determines whether the acquired carriage speed Vcr is less than the second threshold (S11). If it is determined that the carriage speed Vcr is equal to or higher than the second threshold (S11: NO), the CPU 101 determines that no sheet rubbing has occurred and proceeds to the processing of S12. On the other hand, if it is determined that the carriage speed Vcr is less than the second threshold (S11: YES), the CPU 101 determines that paper rubbing has occurred, and proceeds to the process of S35.

  In the processing of S12, the CPU 101 determines whether or not the ejection processing (printing for one pass) has been completed. If it is determined that the discharge process has not ended (S12: NO), the process returns to S8 to continue the discharge process. On the other hand, if it is determined that the ejection process has been completed (S12: YES), it is determined whether printing on one sheet of paper P has been completed (S13). When it is determined that printing on one sheet of paper P has not been completed (S13: NO), the CPU 101 controls the transport motor 37 to transport the paper P forward by a predetermined amount (S14). In order to execute the pass printing, the process proceeds to S6. On the other hand, when it is determined that the printing on one sheet of paper P has been completed (S13: YES), the CPU 101 controls the transport motor 37 to transport the printed paper P forward to face the opposite area A. Then, it is determined whether or not all the printing related to the received print command has been completed (S16). If it is determined that printing has been completed (S16: YES), the CPU 101 controls the carriage motor 16 to move the carriage 4 to the standby position, and then proceeds to S1.

  On the other hand, if it is determined that the printing has not yet been completed (S16: NO), it is determined whether or not the printing of the image on the paper P performed immediately before was borderless printing (S17). If it is determined that it is not borderless printing (S17: NO), the CPU 101 proceeds to the process of S5 to execute the printing of the next paper P. On the other hand, when it is determined that the printing is borderless printing (S17: YES), the CPU 101 executes an abnormal position detection process on the assumption that there is a possibility that a new stain has occurred on the scale 21 (S18). Thereby, the abnormal position information stored in the nonvolatile memory 104 is updated. Thereafter, the CPU 101 proceeds to the process of S5 to execute the printing of the next paper P.

  As shown in FIG. 9, in the process of S <b> 30 performed when it is determined that a jam has occurred, the CPU 101 controls the carriage motor 16 to stop the carriage 4. Then, the CPU 101 displays a screen indicating that a jam has occurred on the touch panel 99 (S31). Thereafter, the user removes the jammed paper. Then, when an input indicating that the removal work is completed is received from the user via the touch panel 99 (S32: YES), the CPU 101 may have a new stain on the scale 21 during the removal work. Then, an abnormal position detection process is executed (S33). Thereby, the abnormal position information stored in the nonvolatile memory 104 is updated. Thereafter, the CPU 101 proceeds to the process of S5 in order to execute the printing based on the same ejection data with the new paper P again.

  In the process of S <b> 35 that is performed when it is determined that paper rubbing has occurred, the CPU 101 controls the carriage motor 16 to stop the carriage 4. Then, the CPU 101 waits for a predetermined time (S36), and then controls the transport motor 37 to discharge the printed paper P from the facing area A (S37). Here, when the reason for the deformation of the paper P comes from the fact that the paper P has absorbed the ink, if the paper P is kept waiting for a while in this state, the paper P is lifted, and as a result, the paper P is separated from the nozzle surface 10a. . Therefore, as described above, by waiting for a predetermined time before discharging the paper P from the facing area A, it is possible to prevent the paper from rubbing between the paper P and the nozzle surface 10a when the paper P is discharged. can do.

  Next, the CPU 101 again generates ejection data from the same image data so that the ejection amount of ink ejected per sheet P is smaller than the ejection data used in the previous printing process ( S38). For example, by changing the threshold value in the quantization process, the ratio of ejecting medium drops or large drops of ink is lowered, while the ratio of ejecting small drops of ink is increased. Thereafter, in order to execute printing based on the generated ejection data on a new sheet P, the process proceeds to S5. In this way, by changing to ejection data with a small ejection amount of ink ejected per sheet of paper P, the degree to which the paper P is deformed by the ink ejected from the nozzles 10 during reprinting is suppressed. Can do. As a result, it is possible to suppress paper rubbing during reprinting.

  As described above, according to the present embodiment, when the detection position of the detection sensor 22 is an abnormal position, the second threshold corresponding to a speed slower than the first threshold used when the detection position is a position other than the abnormal position is set. Used to determine paper rubbing. As described above, by using different threshold values for the abnormal position on the scale 21 and the position other than the abnormal position, the carriage speed Vcr acquired based on the detection result of the detection sensor 22 is reduced due to the contamination on the scale 21. Even so, it is possible to accurately determine the sheet rubbing.

  Further, since the movement of the carriage 4 from the standby position for the flushing process performed before the printing process to the flushing position also serves as the movement of the carriage in the abnormal position detection process, the carriage 4 is moved only for the abnormal position detection process. There is no need to move it anew.

  In addition, after borderless printing or after jamming, there is a possibility that dirt is newly attached to the scale 21, and therefore an abnormal position detection process is executed before the next printing is performed. As a result, paper rubbing can be accurately determined during the next printing. Although not shown in the flowcharts of FIGS. 8 and 9, the CPU 101 determines that the jam of the paper P has occurred based on the pulse signal of the rotary encoder 40 and the detection results of the paper sensors 38 and 39. Also, the abnormal position detection process is executed before the next printing.

  In the embodiment described above, the carriage motor 16 corresponds to a “carriage driving unit”. The detection sensor 22 corresponds to a “detection unit”, and the non-transmissive region 21b corresponds to an “index”. The nonvolatile memory 104 corresponds to a “storage unit”. The flushing receptacle 9 corresponds to a “liquid receptacle”. The carriage speed Vcr acquired based on the detection result of the detection sensor 22 corresponds to the speed parameter value. The speed reduction rate corresponds to “speed information”. The paper sensors 38 and 39 and the rotary encoder 40 correspond to a “jam detection unit”.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the processing after the CPU 101 determines that paper rubbing has occurred (S10: YES, S11: YES) may be as shown in FIG. 10 (a) and FIG. 10 (b). Hereinafter, these modifications will be described.

  First, the modification shown in FIG. 10A will be described. When the CPU 101 determines that paper rubbing has occurred, the CPU 101 controls the carriage motor 16 to move the carriage 4 in the direction opposite to the traveling direction of the carriage 4 when the paper rubbing is determined until it is outside the platen 41. (S41). Since the head 5 and the paper P are not in contact until the paper rubbing is determined, even if the carriage 4 is moved in the direction opposite to the traveling direction as in the process of S41, the head 5 and the paper There is little possibility of paper rubbing with P.

  Thereafter, the CPU 101 performs the processing of S42 and S43 similar to S37 and S38 described above, and then proceeds to the processing of S5 in order to execute printing based on the generated ejection data on a new sheet P. As described above, also in the present modification, it is possible to prevent the head 5 from being damaged by the paper rubbing after the paper rubbing is determined.

Next, a modification shown in FIG. 10B will be described. In this modified example, even if the CPU 101 determines that paper rubbing has occurred, if the printing of the pass has not been completed, the CPU 101 continues to perform unless jamming occurs. Specifically, if the CPU 101 determines that paper rubbing has occurred, the CPU 101 determines whether printing for one pass has been completed (S51). If it is determined that printing for one pass has not been completed (S51: NO), printing is continued, and it is determined whether the acquired carriage speed Vcr is less than the third threshold value (S52). If it is determined that the carriage speed Vcr is greater than or equal to the third threshold (S52: NO), the process returns to S51. On the other hand, if it is determined that the carriage speed Vcr is less than the third threshold (S53: YES), it is determined that a jam has occurred, and the process proceeds to S53.

  If it is determined in step S51 that printing for one pass has been completed (S51: YES), it is determined whether printing on one sheet of paper P has been completed (S53). If it is determined that printing on one sheet of paper P has been completed (S53: YES), the process proceeds to S15. On the other hand, if it is determined that printing on one sheet of paper P has not been completed (S53: NO), the CPU 101 waits for a predetermined time (S54), and then controls the carry motor 37. Then, the paper P is conveyed forward by a predetermined amount (S55), and the process proceeds to S6 to execute the next pass printing. As described above, when it is determined that paper rubbing has occurred, printing for the next pass is started after waiting for a predetermined time. That is, when it is determined that paper rubbing has occurred, the printing start timing of the next pass is delayed as compared with the case where it is not determined that paper rubbing has occurred. As a result, at the printing start timing of the next pass, the sheet P is lifted by the amount of waiting for the predetermined time, so that the possibility of paper rubbing during printing of the next pass can be reduced. In addition, even if it is determined that paper rubbing has occurred, the printing process is continuously executed, so the time required for the printing process can be shortened.

  Hereinafter, another modified example will be described. As described above, the speed control of the carriage 4 is performed by feedback control based on the deviation between the current carriage speed Vcr acquired based on the detection result of the detection sensor 22 and the target speed. For this reason, when the detection position of the detection sensor 22 crosses the abnormal position, the CPU 101 erroneously determines that the speed of the carriage 4 has decreased below the target speed, and moves the carriage motor 16 so that the speed of the carriage 4 increases. Control. For this reason, the actual speed of the carriage 4 becomes higher than the target speed. Thereafter, the speed of the carriage 4 (acquired carriage speed Vcr) converges to the target speed by feedback control. In this process, the speed of the carriage 4 fluctuates up and down around the target speed. At this time, the fluctuation range of the speed fluctuation of the carriage 4 is larger as the target speed of the carriage 4 during the ejection process is higher. Therefore, when the target speed is high, the carriage speed Vcr acquired based on the detection result of the detection sensor 22 may be less than the first threshold due to the speed fluctuation of the carriage 4. That is, even when the detection position of the detection sensor 22 is a position other than the abnormal position, the actual speed of the carriage 4 (carriage speed Vcr) is caused by dirt on the scale 21 within a predetermined range before and after the abnormal position. ) May be less than the first threshold. As a result, there is a possibility that it is erroneously determined that paper rubbing has occurred although paper rubbing has not occurred.

  Therefore, in this modification, when a speed (second speed) that is less than a predetermined speed threshold is set as the target speed of the carriage 4 during the discharge process among the settable speeds, the rubbing determination process Is performed with the same processing contents as in the above embodiment. On the other hand, when the speed (first speed) lower than the speed threshold is set as the target speed of the carriage 4 during the ejection process, the processing content of the rubbing determination process is changed.

  Specifically, when the detection position of the detection sensor 22 is a position other than the abnormal position of the abnormal position information stored in the nonvolatile memory 104, the CPU 101 is in a predetermined range before and after the abnormal position. When the carriage speed Vcr acquired at that time is less than the second threshold and greater than or equal to the third threshold, it is determined that paper rubbing has occurred. That is, when the acquired carriage speed Vcr is less than the first threshold value and greater than or equal to the second threshold value, it is not determined that paper rubbing has occurred. More specifically, in the operation of the printer 1, as shown in FIG. 11, the process of S60 is executed instead of the process of S9 described above. In the process of S60, the CPU 101 determines whether or not the current detection position of the detection sensor 22 is within an abnormal position or a predetermined range before and after the abnormal position. When it is determined that the detected position is a position other than the abnormal position and is outside the predetermined range before and after the abnormal position (S60: NO), the process proceeds to S10. On the other hand, if it is determined that the detected position is within the abnormal position or the predetermined range before and after the abnormal position (S60: YES), the process proceeds to S11.

  As described above, it is possible to reduce the possibility of erroneously determining that the paper is rubbed due to the speed fluctuation of the carriage 4 caused by the stain on the scale 21. When the detection position of the detection sensor 22 is within a predetermined range before and after the abnormal position regardless of the target speed of the carriage 4 during the ejection process, the CPU 101 determines that the carriage speed Vcr acquired at that time is the second speed. If it is less than the threshold and greater than or equal to the third threshold, it may be determined that paper rubbing has occurred.

  Hereinafter, other modifications will be described.

  In the above-described embodiment, the detection sensor 22 is configured to detect the non-transmissive region 21b of the encoder 7 as an index, but may be configured to detect the transmissive region 21a as an index. The encoder 7 is a so-called transmissive linear encoder. However, the encoder 7 is not limited to this, and may be a reflective linear encoder. In this case, the non-transmissive area 21b is changed to a non-reflective area that does not reflect light, and the transmissive area 21a is changed to a reflective area that reflects light. Then, by arranging both the light emitting element 26 and the light receiving element 27 of the detection sensor 22 on the front side or the rear side of the scale 21, it is possible to output a pulse signal from the detection sensor 22 as in the above-described embodiment. is there. Furthermore, the encoder may be a non-optical encoder, and for example, a magnetic encoder may be used. In this case, the non-transmissive region 21b described above may be a magnetic region, and the transmissive region 21a may be a non-magnetic region.

  Further, the target speed of the carriage 4 in the abnormal position detection process does not need to be a maximum speed that can be set, and may be another speed that can be set. Further, the scale 21 may be divided into a plurality of divided regions in the scanning direction, and abnormal position information may be generated in units of the divided regions in the abnormal position detection process. For example, each divided area is divided so as to have a plurality of non-transmissive areas 21b. If any of the carriage speeds Vcr acquired in the divided area is lower than a predetermined threshold, the entire divided area may be set as an abnormal position. In addition, when the stain | pollution | contamination on the scale 21 straddles two adjacent division areas, the whole division area is good also as these 2 division areas as an abnormal position. As described above, by generating abnormal position information in units of divided areas, the storage capacity when storing abnormal position information in the nonvolatile memory 104 can be reduced. In the abnormal position detection process, the carriage 4 is moved over the range from the standby position to the flushing position. However, the movement range during the abnormal position detection process is not particularly limited to this. Therefore, in the abnormal position detection process, only the abnormal position information corresponding to the movement range in which the carriage 4 is moved among the abnormal position information stored in the nonvolatile memory 104 may be updated.

  Further, the abnormal position information may be information having only the abnormal position. In this case, the second threshold value is not set for each abnormal position but may be set to a uniform value according to the target speed. Further, the speed information included in the abnormal position information does not need to be a speed decrease rate, and may be a carriage speed Vcr corresponding to the abnormal position, for example.

  In the above-described embodiment, the carriage speed Vcr is acquired based on the detection result of the detection sensor 22, but may be a speed parameter value related to the carriage speed Vcr instead of the carriage speed Vcr itself. For example, instead of calculating the carriage speed Vcr, the clock number CK acquired during the V1 holding period may be acquired as the speed parameter value. In this case, the speed parameter value increases as the speed of the carriage 4 decreases. Therefore, in the first to third threshold values, the first threshold value has the smallest value and the third threshold value has the largest value.

  In the above-described embodiment, when it is determined that paper rubbing has occurred, the ejection amount of ink ejected per sheet P during reprinting is reduced by changing the ejection data. However, it is not particularly limited to this. For example, the ink discharge amount may be reduced by adjusting the drive voltage for the drive element included in the actuator of the head 5.

  In the above-described embodiment, it is determined whether or not the paper P is positioned in the facing area A based on the detection result of the paper sensor 38, but the present invention is not limited to this. For example, a sensor that can directly detect whether or not the paper P is located in the facing area A is provided, and whether or not the paper P is located in the facing area A is determined based on the detection result of the sensor. Good.

  In the above-described embodiment, the first threshold value is set to a value of 90% of the target speed, but is not limited to this. For example, when executing the abnormal position detection process, the CPU 101 detects the carriage speed Vcr having the slowest speed among the carriage speeds at a plurality of positions determined to be other than the abnormal position. Then, the CPU 101 may set the first threshold value to a value that is 90% of the slowest carriage speed Vcr.

  The carriage speed Vcr slightly fluctuates at a position other than the abnormal position when the carriage 4 comes into contact with a small foreign object or the like on the guide rails 11 and 12. The CPU 101 sets the first threshold on the basis of the slowest carriage speed Vcr so that the CPU 101 does not mistakenly determine that sheet rubbing has occurred based on such variation in the carriage speed Vcr. As a result, it is possible to prevent the CPU 101 from erroneously determining paper rubbing. Note that the slowest carriage speed Vcr is slower than the target speed.

1 Printer (recording device)
4 Carriage 5 Inkjet head 7 Encoder 21 Scale 21b Non-transmissive region (index)
22 Detection sensor (detection unit)
101 CPU (control unit)
104 Non-volatile memory (storage unit)

Claims (16)

A head having a nozzle for discharging liquid;
A carriage on which the head is mounted;
A carriage driving unit for reciprocating the carriage in a predetermined scanning direction;
A scale provided along the scanning direction and having an index formed at predetermined intervals; and an encoder mounted on the carriage and having a detection unit for detecting the index formed on the scale;
A storage unit;
A control unit;
With
The controller is
Medium position determination processing for determining whether or not the recording medium is positioned in an area that can face the carriage;
When the medium position determination process determines that the recording medium is not located in an area that can face the carriage, the carriage drive unit is controlled so that the carriage moves in the scanning direction, and the carriage moves. An abnormal position detection process including generating abnormal position information including an abnormal position on the scale based on a detection result of the index by the detection unit, and storing the abnormal position information in the storage unit;
When the medium position determination process determines that the recording medium is located in an area that can face the carriage, the index of the detection unit is set so that the carriage moves at a target speed in the scanning direction. Controlling the carriage driving unit based on a speed parameter value related to the speed of the carriage acquired from the detection result, and controlling the head to discharge liquid from the nozzle to a recording medium based on image data; A printing process for printing an image on a recording medium;
During the control of the carriage drive unit in the printing process, when the detection position on the scale of the detection unit is a position other than the abnormal position of the abnormal position information stored in the storage unit, When the speed parameter value acquired in step S3 is slower than the first threshold value corresponding to a speed slower than the target speed in the printing process, the speed parameter value is set between the head and the recording medium. It was determined that rubbing occurred,
Acquired when the detection position on the scale of the detection unit is the abnormal position of the abnormal position information stored in the storage unit during the control of the carriage driving unit in the printing process. When the speed parameter value is a value corresponding to a slower speed than the second threshold value corresponding to a speed slower than the first threshold value, rubbing has occurred between the head and the recording medium. Rubbing judgment processing to judge,
The recording apparatus characterized by being able to execute. The controller is
During the printing process, the carriage driving unit is controlled to stop the movement of the carriage when the rubbing judgment process determines that rubbing has occurred between the head and the recording medium. The recording apparatus according to claim 1. The controller is
During the printing process, when it is determined that rubbing has occurred between the head and the recording medium by the rubbing determination process, the carriage travels in a direction opposite to the traveling direction when it is determined that the rubbing has occurred. The recording apparatus according to claim 1, wherein the carriage driving unit is controlled so that the carriage moves. The controller is
During the printing process, if it is determined that rubbing has occurred between the head and the recording medium by the rubbing determination process, the path of the carriage in the scanning direction when it is determined that rubbing has occurred. Printing is performed continuously, and the printing start timing of the next pass is compared with the case where it is not determined that rubbing has occurred between the head and the recording medium by the rubbing determination processing. The recording apparatus according to claim 1, wherein the recording apparatus is delayed. The controller is
In the abnormal position detection process, the speed parameter value corresponding to the abnormal position is also acquired based on the detection result of the index by the detection unit, and the speed corresponding to the abnormal position is added to the abnormal position. Generating the abnormal position information including speed information on the parameter value, and storing it in the storage unit;
further,
A first setting process for setting the second threshold value for each abnormal position is performed based on the speed information corresponding to the abnormal position of each of the abnormal position information stored in the storage unit. The recording apparatus as described in any one of Claims 1-4. The controller is
In the abnormal position detection process, the carriage driving unit is controlled so that the carriage moves at a constant speed in the scanning direction, and the abnormality is detected based on the detection result of the index by the detection unit during the movement of the carriage. The recording apparatus according to claim 1, wherein position information is generated. The controller is
A plurality of speeds can be set as a target speed when the carriage driving unit is controlled to move the carriage at a constant speed in the scanning direction.
The controller is
In the abnormal position detection process, the highest speed among the plurality of speeds is set as a target speed, and the carriage driving unit is controlled to move the carriage at a constant speed in the scanning direction. The recording apparatus according to any one of claims 1 to 6. The controller is
A plurality of speeds can be set as a target speed when the carriage driving unit is controlled to move the carriage at a constant speed in the scanning direction.
The controller is
In the printing process, any one of the plurality of speeds is set as a target speed, and the carriage driving unit is controlled so that the carriage moves at a constant speed in the scanning direction. ,
further,
The second setting process for setting the first threshold value and the second threshold value is executed according to a target speed of the carriage set in the printing process. The recording device described in 1. The controller is
In the rubbing determination process, during the control of the carriage drive unit in the printing process, the detection position on the scale of the detection unit is a position other than the abnormal position of the abnormal position information stored in the storage unit. Even when there is a certain value within a predetermined range before and after the abnormal position, when the speed parameter value acquired at that time is a value corresponding to a slower speed than the second threshold, The recording apparatus according to claim 1, wherein rubbing is determined between the recording medium and the recording medium. The controller is
A first speed and a second speed slower than the first speed can be set as a target speed when the carriage driving unit is controlled to move the carriage at a constant speed in the scanning direction.
The controller is
In the printing process, one of the first speed and the second speed is set as a target speed, and the carriage driving unit is controlled so that the carriage moves at a constant speed in the scanning direction. Is what
further,
In the rubbing judgment process,
Only when the target speed of the carriage set in the printing process is the first speed,
During the control of the carriage drive unit in the printing process, even when the detection position on the scale of the detection unit is a position other than the abnormal position of the abnormal position information stored in the storage unit, When the velocity parameter value acquired at that time is within a predetermined range before and after the position, and the corresponding velocity is slower than the second threshold value, between the head and the recording medium. The recording apparatus according to claim 1, wherein it is determined that rubbing has occurred. A platen capable of facing the carriage and supporting a recording medium;
A cap located outside the platen in the scanning direction and capable of covering the nozzle of the head;
A liquid receiver positioned opposite to the cap with respect to the platen in the scanning direction;
With
The controller is
When the carriage is positioned at a flushing position where the liquid can be discharged from the nozzle to the liquid receiver, the head can be controlled to perform a flushing process for discharging the liquid from the nozzle to the liquid receiver.
further,
The controller is
When the carriage is positioned at a standby position facing the cap, when the print process execution command is received, before the print process,
The carriage drive unit is controlled to move the carriage from the standby position to the flushing position, and the abnormal position information is generated based on the detection result of the index by the detection unit during the movement of the carriage. The abnormal position detection process stored in the storage unit is executed, and the flushing process is executed after the carriage is positioned at the flushing position by the abnormal position detection process. The recording apparatus according to any one of 1 to 10. The controller is
In the printing process, when the head is controlled to discharge the liquid from the nozzle over a range wider than the length of the recording medium in the scanning direction, before the printing process is executed next. The recording apparatus according to claim 1, wherein the abnormal position detection process is executed. It further includes a jam detection unit for detecting a jam,
The controller is
13. The abnormal position detection process is executed before the next printing process when it is determined that a jam has occurred based on the jam detection unit. The recording device according to item. The controller is
During the printing process, if the rubbing judgment process determines that rubbing has occurred between the head and the recording medium, the printing process is stopped, and then the same image as the canceled printing process. The new printing process based on data is performed by reducing the ejection amount of the liquid ejected from the nozzles per recording medium. Recording device. The controller is
15. The abnormal position detection process, wherein the scale is divided into a plurality of divided areas each having a plurality of the indices, and the abnormal position information is generated in units of the divided areas. A recording apparatus according to claim 1. The controller is
During the control of the carriage drive unit in the printing process, the speed parameter value acquired from the detection result of the index of the detection unit is compared with a third threshold value corresponding to a speed slower than the second threshold value. The recording apparatus according to any one of claims 1 to 15, wherein it is determined that a jam has occurred when a speed at which the recording is performed is a slow value.

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