JP2010260268A - Recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording device capable of adjusting a platen gap, while reducing a load applied to components. <P>SOLUTION: A printer includes: a recoding head 21 executing recording processing for a recording medium P; a support part 30a supporting the recording medium P, when the recording processing is executed; a carriage 19 holding the recording head 21 and a reflection type sensor 29 and configured to be displaceable in a displacement direction Z where a separation distance from the support part 30a is changed; a PG motor for displacing the carriage 19; a part to be reflected 36 in which the separation distance in the displacement direction Z is prescribed with respect to the support part 30a; and a CPU performing the drive control of the PG motor, based on a detection value when the part to be reflected 36 of the reflection type sensor 29 is a reflection target. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus capable of adjusting a platen gap.

  2. Description of the Related Art Conventionally, in a recording apparatus such as a printer, a platen gap for changing a separation distance (a platen gap) between the recording head and the platen in order to maintain a constant distance (paper gap) between the recording head and the recording medium. An adjustment mechanism was provided (for example, Patent Document 1).

  In an ink jet printer as a recording apparatus disclosed in Patent Document 1, ink droplets are ejected from a recording head held by a carriage onto a recording medium while relatively moving while maintaining a distance from the recording medium. . Therefore, in order to suppress the drop in the landing position of the liquid droplets and the decrease in printing accuracy, when performing recording processing on recording media having different thicknesses, the paper gap can be reduced by changing the platen gap. I tried to keep it constant.

  The platen gap adjusting mechanism includes a cam fixed to the shaft end of the guide shaft that supports the carriage, a fixed pin (cam follower) that supports the guide shaft via the cam, and a motor for rotating the guide shaft. It was equipped with. Then, by rotating the cam together with the guide shaft by driving the motor, the carriage and the recording head are moved up and down to switch the platen gap in a plurality of stages.

Japanese Patent Laid-Open No. 2004-314591

  By the way, in the platen gap adjustment, a reference phase for rotating the cam is set, and the amount of rotation from the reference phase to the platen gap at each stage is specified. Conventionally, as described in Patent Document 1 as the second embodiment, the cam is provided with a protrusion, and the protrusion is brought into contact with the fixed pin to restrict the rotation of the cam. Therefore, it is common to detect the reference phase when rotating the cam.

  However, since the motor is driven for a predetermined time in a state where the rotation of the cam is restricted at the time of applying, there is a problem that a large load is applied to the components such as the cam and the protrusion every time the platen gap is adjusted. was there.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a recording apparatus capable of performing platen gap adjustment while reducing the load applied to the components.

  In order to achieve the above object, a recording apparatus of the present invention includes a recording head that performs a recording process on a recording medium, a support unit that supports the recording medium during the execution of the recording process, the recording head, and the reflection head. A carriage configured to hold a mold sensor and be displaceable in a displacement direction in which a separation distance with respect to the support portion changes, a drive source for displacing the carriage, and the support portion in the displacement direction And a control unit that performs drive control of the drive source based on a detection value in which the reflection target of the reflective sensor is a reflection target.

  According to this configuration, the platen gap can be adjusted based on the detection value that reflects the reflected portion of the reflective sensor. Thereby, since it is not necessary to apply each time the platen gap is adjusted, the platen gap can be adjusted while reducing the load applied to the components.

  The recording apparatus of the present invention further includes a support member that supports the recording medium when the recording process is performed, and the carriage is configured to be movable in a main scanning direction intersecting the displacement direction. On the movement path in the main scanning direction, a recording area in which the recording head performs the recording process and a non-recording area outside the recording area are set. In the main scanning direction, the support unit The reflection member is provided at a position corresponding to the non-recording area of the support member, while being provided at a position corresponding to the recording area of the support member.

  According to this configuration, since the reflected portion is provided at a position corresponding to the non-recording area of the support member, it can be avoided that the reflected portion interferes with the recording medium and interferes with the recording process. Contamination of the reflection part due to the recording process can be suppressed. Moreover, since the reflected part is provided in a part of the support member provided with the support part, the separation distance between the reflected part and the support part can be defined by the support member alone.

In the recording apparatus of the present invention, the reflection type sensor is an optical sensor provided to detect a width of the recording medium in the main scanning direction.
According to this configuration, since the reflection type sensor for detecting the platen gap can be used also as the optical sensor for detecting the width of the recording medium in the main scanning direction, it is necessary to provide a sensor dedicated to adjusting the platen gap. There is no.

The recording apparatus of the present invention includes a plurality of the reflected portions having different separation distances from the support portion in the displacement direction.
According to this configuration, even when the carriage is displaced such that the separation distance with respect to the support portion changes in a plurality of steps, it is possible to obtain a detection value with the reflected portion corresponding to each step as a reflection target.

  In the recording apparatus of the present invention, a cam surface and a protrusion that are fixed to a shaft end of a guide shaft that is rotated in accordance with driving of the drive source, and whose distance from the axis of the guide shaft changes, are formed on the guide shaft. And a cam follower that supports the guide shaft via the cam, and the carriage supported by the guide shaft by the drive source is in the displacement direction. A platen gap adjusting device capable of switching a platen gap, which is a separation distance between the recording head and the support portion, in a plurality of stages, and a setting state of the platen gap based on the detected value. Storage means for storing a threshold value to be referred to in order to determine whether or not the carriage is configured such that the protrusion is in contact with the cam follower to rotate the guide shaft. Is disposed at the reference position in the displacement direction when it is braking, the control means, the carriage on the basis of the detection values detected by the state of being arranged in the reference position, to re-setting of the threshold.

  According to this configuration, the control unit can always reset the threshold value with a predetermined frequency while determining the setting state of the platen gap based on the detection value. Therefore, it is possible to appropriately adjust the platen gap while reducing the load on the components.

In the recording apparatus of the present invention, the control unit resets the threshold value when the recording process is executed in a prescribed processing amount.
According to this configuration, since the threshold value can be reset every time the recording process is executed, the platen can be appropriately adjusted while suppressing the influence of the deterioration of the reflective sensor and the contamination of the reflected part. Gap adjustment can be performed.

1 is a perspective view illustrating a schematic configuration of an ink jet printer according to an embodiment. FIG. 3 is a cross-sectional view for explaining a support member and a recording head in the embodiment. The side view which shows a cam. The graph which shows the relationship between the rotation amount of PG motor, and the change of a platen gap. The graph which shows the threshold value referred in order to determine the setting state of a platen gap. 1 is a block diagram illustrating an electrical configuration of an ink jet printer according to an embodiment. Explanatory drawing about platen gap adjustment of the 1st pattern. Explanatory drawing about the platen gap adjustment of a 2nd pattern. Explanatory drawing about the platen gap adjustment of a 3rd pattern.

  Hereinafter, an embodiment in which the present invention is embodied in a printer which is a kind of recording apparatus will be described with reference to FIGS. In the following description, when referring to “front-rear direction”, “left-right direction”, and “up-down direction”, the direction indicated by an arrow in each figure is used as a reference.

  As shown in FIG. 1, the printer 11 includes a main body frame 12. A set unit 13 on which a recording medium P such as recording paper can be set is provided on the back side of the main body frame 12. In the main body frame 12, a PF motor 14 used for transporting the recording medium P and drive rollers 15 and 16 rotated by the PF motor 14 are accommodated. Each of the driving rollers 15 and 16 is rotated with the driving of the PF motor 14 while the recording medium P is sandwiched between driven rollers (not shown) provided above the driving rollers 15 and 16, respectively. The recording medium P is transported in the forward direction, which is the sub-scanning direction Y.

  Long grooves 17 extending in the vertical direction are formed in the left and right side walls of the main body frame 12. In addition, a rod-shaped guide shaft 18 that extends in the left-right direction and whose shaft end is loosely inserted into the long groove 17 is installed on the main body frame 12. A carriage 19 is supported on the guide shaft 18 so as to be capable of reciprocating in the left-right direction.

  An ink cartridge 20 containing ink is detachably mounted on the carriage 19, and a recording head 21 that performs recording processing on the recording medium P is held on the lower surface side thereof. The lower surface 21a of the recording head 21 is provided with a plurality of nozzle openings (not shown) that can eject ink stored in the ink cartridge 20 downward.

  The carriage 19 is connected to a CR motor 25 provided on the back side of the pulley 22 via an endless timing belt 24 stretched between the pair of pulleys 22 and 23. The carriage 19 is moved in the left-right direction as the main scanning direction X as the CR motor 25 is driven.

  A maintenance unit 26 is disposed at the bottom near the right side in the main body frame 12. The position where the maintenance unit 26 is disposed is on the movement path of the carriage 19 in the main scanning direction X, and is a home position where the recording process on the recording medium P is not performed. That is, on the movement path of the carriage 19 in the main scanning direction X, a recording area in which the recording head 21 executes a recording process and a non-recording area outside the recording area are set. The carriage 19 is moved to the home position when the power is turned off or during printing standby, and maintenance processing such as cleaning of the recording head 21 is performed by the maintenance unit 26.

  On the left side of the maintenance unit 26, a platen 27 is fixed as a support member that supports the recording medium P when the recording process is executed. Then, a recording process is performed by alternately performing a conveying process for conveying the recording medium P in the sub-scanning direction Y by a predetermined distance and a printing process for ejecting ink from the nozzle openings of the recording head 21 that moves along the main scanning direction X. A recording process for the medium P is executed.

Next, a mechanism for detecting the movement position of the carriage 19 in the main scanning direction X will be described.
The printer 11 is provided with a control device 100 (see FIG. 6) for controlling the recording process and a linear encoder 101 (see FIG. 6) for detecting the movement position and movement speed of the carriage 19 in the main scanning direction X. Yes. The linear encoder 101 includes a scale 28 made of a light shielding material and a CR sensor (not shown) as an optical sensor as components.

  As shown in FIG. 1, the scale 28 is disposed in the main body frame 12 so as to extend along the main scanning direction X, and the CR sensors are light sources disposed so as to face each other with the scale 28 interposed therebetween. A portion (not shown) and a light receiving portion (not shown) are mounted on the carriage 19.

  A plurality of slits (not shown) are formed in the scale 28 at regular intervals along the main scanning direction X. The light receiving unit of the CR sensor outputs a high output value when receiving light emitted from the light source unit, and outputs a low output value when not receiving light emitted from the light source unit. Yes. Therefore, when the carriage 19 moves in the main scanning direction X at the time of detection by the CR sensor, the slits of the scale 28 are intermittently disposed between the light source unit and the light receiving unit, so that a high output value and a low output are periodically generated. A pulse signal in which a value appears is obtained.

  The control device 100 calculates the moving speed of the carriage 19 based on the frequency of the pulse signal output from the CR sensor, and detects the position of the carriage 19 in the main scanning direction X based on the count value of the number of pulses. In addition, the control device 100 performs movement control of the carriage 19 in the main scanning direction X based on these calculation results and detected positions.

Next, the reflection type sensor provided in the printer 11 will be described.
In the printer 11, recording processing is performed on a plurality of types of recording media P having different widths and thicknesses. Therefore, the printer 11 includes a paper width sensor for detecting the width of the recording medium P in the main scanning direction X.

  As shown in FIG. 2, the reflective sensor 29 as a paper width sensor is an optical sensor having a light source unit 29 a and a light receiving unit 29 b, and on the lower surface side of the carriage 19, on the left side of the recording head 21, the recording head 21. It is provided to line up. The reflective sensor 29 receives reflected light of light emitted downward from the light source unit 29a by the light receiving unit 29b, and detects a detection value V (voltage value) corresponding to the intensity of the reflected light received by the light receiving unit 29b. Output to the control device 100.

  Then, the detection is performed by the reflection type sensor 29 while moving the carriage 19 in the main scanning direction X in the recording region, and the control device 100 changes the reflection target based on the detection value V, that is, at both ends of the recording medium P. The width of the recording medium P is calculated by detecting the position.

  In the printer 11, white recording paper having a high reflectance is often used as the recording medium P. Therefore, the detection is performed so that the reflectance on the platen 27 side is clearly lower than the reflectance of the recording medium P. The accuracy is improved. Specifically, the platen 27 is provided with a rib 30 having a support portion 30a for supporting the recording medium P and a bottom portion 31 lower than the rib 30, and the reflectance is longer because the reflection distance is longer than the support portion 30a. The bottom 31 that is lowered is the reflection target of the reflective sensor 29. The surface of the rib 30 and the bottom 31 of the platen 27 is a dark color (for example, black) with low reflectivity.

  Thereby, the reflectance of the platen 27 is reduced, and the detection value V is clearly different between the case where the recording medium P is a reflection target and the case where the platen 27 is a reflection target. Then, by performing a printing process according to the calculated width of the recording medium P, ink adheres to the platen 27 and the conveyed recording medium P is not contaminated.

Next, a platen gap adjustment mechanism provided in the printer 11 will be described.
As shown in FIG. 1, the printer 11 displaces the carriage 19 in a displacement direction Z (vertical direction perpendicular to the main scanning direction X and the sub-scanning direction Y) in which the separation distance of the platen 27 from the support portion 30a changes. A platen gap adjusting device (hereinafter referred to as “PG adjusting device”) 32 is provided. When the recording process is performed on the recording medium P having a different thickness, the carriage 19 is displaced in the displacement direction Z according to the thickness of the recording medium P by the PG adjusting device 32.

  In other words, the platen gap PG (see FIG. 2), which is the distance between the lower surface 21a of the recording head 21 and the support portion 30a of the platen 27, is switched in a plurality of stages by the PG adjusting device 32, whereby the recording head 21 and the recording medium P (Referred to as “paper gap PaG” hereinafter, see FIG. 2).

  The PG adjustment device 32 includes a cam 33, a cam follower 34, and a PG motor 35 (see FIG. 6) as a drive source for displacing the carriage 19. The cam 33 is disposed outside the left and right side walls of the main body frame 12 while being fixed to the shaft end of the guide shaft 18. The cam follower 34 protrudes from the outer surfaces of the left and right side walls of the main body frame 12 at a position below the guide shaft 18 and supports the guide shaft 18 via the cam 33. The PG motor 35 is a stepping motor that rotates based on a control signal output from the control device 100 provided in the printer 11.

  As shown in FIG. 3, the cam 33 has a cam surface 33 a in which the distance from the axis of the guide shaft 18 continuously changes along the circumferential direction, and projections 33 b and 33 c in the circumferential direction of the guide shaft 18. It is formed along. The cam surface 33a has four stable regions S (S1, S2, S3, S4) in which the distance from the axis increases stepwise along the circumferential direction from the protrusion 33b to the protrusion 33c. Transition regions T (T1, T2, T3) for continuously connecting the stable regions S are alternately formed.

  The guide shaft 18 is supported by the main body frame 12 in a state where the cam surface 33 a of the cam 33 is in contact with the outer peripheral surface 34 a of the cam follower 34. Further, the shaft end of the guide shaft 18 is loosely inserted into a long groove 17 extending in the vertical direction provided above the cam follower 34 on the left and right side walls of the main body frame 12. As a result, the guide shaft 18 is allowed to be displaced in the vertical direction while being restricted from being displaced in the horizontal direction.

  Therefore, when the guide shaft 18 is rotated with the driving of the PG motor 35, the cam 33 rotates with respect to the cam follower 34, whereby the guide shaft 18 and the carriage 19 are displaced in the vertical direction. Yes. As shown in FIG. 4, the guide shaft 18 is rotated while each transition region T of the cam 33 is in contact with the outer peripheral surface 34a of the cam follower 34, whereby the carriage 19 is displaced in the vertical direction, and the platen gap PG is switched to a plurality of stages. Further, when the stable regions S1 to S4 of the cam 33 are in contact with the outer peripheral surface 34a of the cam follower 34, the platen gap PG is set to PG1 to PG4 in ascending order.

  The PG motor 35 can be driven to rotate in both forward and reverse directions, and the guide shaft 18 rotates in the plus direction, which is clockwise when viewed from the right side, as the PG motor 35 is rotated forward. The carriage 19 is displaced upward. On the other hand, as the PG motor 35 is driven in reverse rotation, the guide shaft 18 rotates in the negative direction, which is counterclockwise when viewed from the right side, and the carriage 19 is displaced downward.

  When the protrusion 33c contacts the cam follower 34 when the guide shaft 18 rotates in the plus direction and the rotation of the cam 33 is restricted, the carriage 19 has an upper end position where the platen gap PG becomes PG4. Placed in. On the other hand, when the protrusion 33b contacts the cam follower 34 when the guide shaft 18 is rotated in the minus direction, the carriage 19 is in a lower end position where the platen gap PG becomes PG1. Placed in. In the present embodiment, this lower end position is a reference position in the displacement direction Z of the carriage 19.

  In the following description, the state where the protrusions 33b and 33c are brought into contact with the cam follower 34 so that the rotation of the cam 33 is restricted is referred to as “adjustment”, and the rotation phase of the cam 33 at this application is determined. Is referred to as the “degree position”. Whether the rotation of the cam 33 is restricted is determined based on whether the current value of the PG motor 35 has reached a predetermined threshold value.

  That is, by applying the cam 33 to the cam follower 34, the position of the carriage 19 in the displacement direction Z, that is, the current setting state of the platen gap PG can be confirmed. In addition, the platen gap PG can be switched by adding or subtracting the number of driving steps of the PG motor 35 according to the rotation direction with the contact position as a reference.

  Note that the amount of rotation of the PG motor 35 when switching the platen gap PG is defined based on rotation phases R1 to R4 (see FIG. 4) set as representative positions of the stable regions S1 to S4. Further, when the carriage 19 is disposed at the reference position in the displacement direction Z, the cam 33 has a state in which R1 set as a representative phase of the stable region S1 of the cam surface 33a is in contact with the outer peripheral surface 34a of the cam follower 34. Become.

  By the way, when the cam 33 is applied, a large physical load is applied to the cam 33 and the cam follower 34. In order to reduce such a load, the printer 11 is provided with a platen gap detection mechanism described below.

  The platen gap detection mechanism includes the reflected portion 36 (36a, 36b, 36c, 36d), the reflective sensor 29, and the control device 100 shown in FIG. Each reflected portion 36 is provided at a position corresponding to the non-recording area of the platen 27 in the main scanning direction X. In addition, each of the reflected portions 36 is defined with a separation distance in the displacement direction Z with respect to the support portion 30 a provided at a position corresponding to the recording area of the platen 27.

  Specifically, the height of the reflected portion 36a in the displacement direction Z is equal to the support portion 30a of the rib 30. The separation distance (height difference) between the support portion 30a and the reflected portions 36b, 36c, and 36d is equal to the difference (height difference) between PG2, PG3, and PG4 with respect to PG1, respectively. That is, the platen 27 includes a plurality of reflected portions 36a to 36d having different separation distances from the support portion 30a in the displacement direction Z so as to correspond to the respective stages PG1 to PG4 of the platen gap PG set in a plurality of stages. Is provided.

  The platen 27 is dark so that the reflectance is lower than that of the recording medium P. On the other hand, each of the reflected portions 36 increases the reflectance in order to detect the reflection distance more accurately. Mirror finish is applied. Therefore, when the reflective sensor 29 detects each reflected portion 36 as a reflection target, a detection value V corresponding to the separation distance to each reflected portion 36 is output.

  Further, when the recording medium P is a reflection target of the reflective sensor 29, the reflectance can be changed due to the difference in the surface state even when the reflection distance is equal. On the other hand, by making each of the reflected parts 36 subjected to the same mirror finish to be reflected by the reflective sensor 29, the change in the reflection distance can be accurately captured based on the detection value V.

  The control device 100 stores threshold values A1 to A4, B1 to B4, C1 to C4, D1 to D4, and V1 set by actual measurement shown in FIG. The threshold values A1 to A4 are threshold values corresponding to PG1 to PG4 when the reflected portion 36a of the reflective sensor 29 is a reflection target, and the threshold values B1 to B4 are the reflected portion 36b of the reflective sensor 29 as a reflection target. This is a threshold value corresponding to PG1 to PG4. The threshold values C1 to C4 are threshold values corresponding to PG1 to PG4 when the reflection target 36c of the reflective sensor 29 is a reflection target, and the threshold values D1 to D4 are the reflection target 36d of the reflection sensor 29 as a reflection target. This is a threshold value corresponding to PG1 to PG4.

  The threshold values A1 to A4, B1 to B4, C1 to C4, and D1 to D4 have a predetermined proportional relationship, and A1 = B2 = C3 = D4 = V1, A2 = B3 = C4, A3 = B4. B1 = C2 = D3 and C1 = D2. Further, when referring to each threshold value to determine the setting state of the platen gap PG based on the detection value V, each threshold value has a predetermined width, and whether or not the detection value V is included in the range. You may make it determine.

  The reflective sensor 29 held by the carriage 19 is similarly displaced in the displacement direction Z as the carriage 19 is displaced in the displacement direction Z. Therefore, the current platen gap PG can be detected by comparing the detection value V when each of the reflected portions 36 of the reflective sensor 29 is a reflection target and the corresponding threshold value. Further, if the carriage 19 is displaced in the displacement direction Z while performing detection by the reflective sensor 29, it can be determined whether or not the target platen gap PG has been reached based on the detection value V of the reflective sensor 29. .

Next, the electrical configuration of the printer 11 will be described.
As shown in FIG. 6, the control device 100 provided in the printer 11 includes a PF motor 14, a CR motor 25, a PG motor 35, and a recording head 21 as an output system, and a linear encoder 101 and a reflective sensor as an input system. 29 is electrically connected. The control device 100 includes a CPU 50, ROM 51, and RAM 52 as control means, a nonvolatile memory 53 as storage means, motor drive circuits 54, 55, and 56, a head control unit 57, a CR counter 58, and a PG counter 59. Are connected to each other via a bus 60.

  The CPU 50 controls the drive of the PF motor 14, the CR motor 25, and the PG motor 35 via the motor drive circuits 54, 55, and 56, and drives and controls the recording head 21 via the head control unit 57. Perform droplet ejection control.

  The CR counter 58 counts the number of pulses (pulse edge) of the pulse signal output from the linear encoder 101. Specifically, when the carriage 19 reaches the end of the movement path on the home position side (right side) along the main scanning direction X, the CR counter 58 is reset. When the carriage 19 moves leftward, the value of the CR counter 58 is added. When the carriage 19 moves rightward, the value of the CR counter 58 is subtracted. Therefore, the CPU 50 is configured to perform movement control of the carriage 19 while grasping the position of the carriage 19 in the main scanning direction X from the count value of the CR counter 58.

  The PG counter 59 is reset when the carriage 19 is disposed at the reference position in the displacement direction Z. After this resetting, the PG counter 59 adds or subtracts the number of driving steps of the PG motor 35 according to the rotation direction. The CPU 50 is configured to grasp the position of the carriage 19 in the displacement direction Z, that is, the setting state of the platen gap PG, from the count value of the PG counter 59.

  The ROM 51 stores a control program executed by the CPU 50 and the like. The RAM 52 temporarily stores calculation results of the CPU 50 and various data to be processed by executing the control program. In the rewritable nonvolatile memory 53, thresholds A1 to A4, B1 to B4, C1 to C4, D1 to D4, which the CPU 50 refers to in order to determine the setting state of the platen gap PG based on the detection value V. V1 is stored. The nonvolatile memory 53 stores the current setting state of the platen gap PG.

Next, platen gap adjustment in the printer 11 will be described.
In the printer 11, the setting state of the platen gap PG can be grasped from the count value of the PG counter 59. However, when the printer 11 is started up or reset, it is forcibly terminated due to an error such as a paper jam or illegal processing, for example, and the count value of the PG counter 59 may not match the actual platen gap PG.

  Therefore, in the printer 11, the platen gap PG is normally detected based on the detection value V with the reflected portion 36 of the reflective sensor 29 as a reflection target, and after matching with the value of the PG counter 59, The platen gap PG is switched. That is, the CPU 50 controls the driving of the PG motor 35 based on the detection value V that reflects the reflected portion 36 of the reflective sensor 29 as a reflection target.

  Then, platen gap adjustment based on the detection value V, that is, detection and switching of the platen gap PG can be performed by the following three patterns. In the platen gap adjustment of each pattern, the current setting state of the platen gap PG stored in the nonvolatile memory 53 is PG1, and a case where this is switched to PG3 will be described as an example.

  First, the platen gap adjustment of the first pattern for determining the setting state of the platen gap PG with reference to the threshold values A1 to A4 while setting the reflected portion 36a as a reflection target of the reflective sensor 29 will be described.

  In adjusting the platen gap of the first pattern, first, the carriage 19 is moved in the main scanning direction X as shown by a solid line in FIG. 7 in order to arrange the reflective sensor 29 at a position facing the reflected portion 36a. Then, the detection value V obtained with the reflected portion 36a of the reflective sensor 29 as a reflection target is compared with the threshold value A1, and it is confirmed that the current platen gap PG is PG1.

  Subsequently, in order to switch the platen gap PG to PG 3, the carriage 19 is displaced in the displacement direction Z by driving the PG motor 35 while performing detection by the reflective sensor 29. Then, the detected value V is compared with the threshold value A3, and when the detected value V = A3, the driving of the PG motor 35 is stopped (a state indicated by a two-dot chain line in FIG. 7). Thereby, the switching of the platen gap PG to PG3 is completed.

  That is, in the platen gap adjustment of the first pattern, the platen gap PG is switched based on the change according to the reflection distance of the detection value V obtained by using one reflected portion 36a as a reflection target. Therefore, the reflection target is not limited to the reflected portion 36a, and any one reflected portion 36 may be provided.

  Next, platen gap adjustment of the second pattern for determining the setting state of the platen gap PG with reference to the threshold value V1 while setting the reflected portions 36a to 36d as reflection targets of the reflective sensor 29 will be described.

  In adjusting the platen gap of the second pattern, first, as shown by a solid line in FIG. 8, the carriage 19 is mainly used to arrange the reflective sensor 29 at a position facing the reflected portion 36a corresponding to the current platen gap PG. Move in the scanning direction X. Then, the detection value V for reflecting the reflected portion 36a of the reflective sensor 29 is compared with the threshold value V1 (= A1) to confirm that the current platen gap PG is PG1.

  Incidentally, when the current platen gap PG is PG2, the reflective sensor 29 is arranged at a position facing the reflected portion 36b corresponding to PG2, and the reflected portion 36b of the reflective sensor 29 is set as a reflection target. The detected value V to be compared is compared with the threshold value V1 (= B2) to confirm that the current platen gap PG is PG2.

  Subsequently, the carriage 19 is moved in the main scanning direction X as indicated by a two-dot chain line in FIG. 8 in order to dispose the reflective sensor 29 at a position facing the reflected portion 36c corresponding to the target platen gap PG.

  Thereafter, in order to switch the platen gap PG to PG3, the PG motor 35 is driven to displace the carriage 19 in the displacement direction Z while performing detection by the reflective sensor 29. Then, the detected value V is compared with the threshold value V1 (= A1 = C3), and the driving of the PG motor 35 is stopped when the detected value V = V1 (state indicated by a dotted line in FIG. 8). Thereby, the switching of the platen gap PG to PG3 is completed.

  That is, in the platen gap adjustment of the second pattern, after changing the reflection target to the reflected portions 36a to 36d corresponding to each stage of the platen gap PG based on the fact that the detection value V becomes equal if the reflection distance is equal, The carriage 19 is displaced until the detection value V = V1.

Next, the platen gap adjustment of the third pattern that combines the first pattern and the second pattern will be described.
In adjusting the platen gap of the third pattern, first, the carriage 19 is moved in the main scanning direction X as shown by a solid line in FIG. 9 in order to arrange the reflective sensor 29 at a position facing the reflected portion 36a. Then, the detection value V for the reflection target 36a of the reflective sensor 29 is compared with the threshold value A1, and it is confirmed that the current platen gap PG is PG1.

  Subsequently, in order to switch the platen gap PG to PG 3, the carriage 19 is displaced in the displacement direction Z by driving the PG motor 35 while performing detection by the reflective sensor 29. Then, the detected value V is compared with the threshold value A3, and when the detected value V = A3, the driving of the PG motor 35 is stopped (a state indicated by a two-dot chain line in FIG. 9).

  Next, the carriage 19 is moved in the main scanning direction X as shown by a dotted line in FIG. 9 in order to place the reflective sensor 29 at a position facing the reflected portion 36c corresponding to the target platen gap PG. Then, the detection value V for the reflection target 36c of the reflective sensor 29 is compared with the threshold value A1 (= C3), and when it is confirmed that the detection value V = A1, the PG3 of the platen gap PG is reached. Switching is complete.

  That is, in the platen gap adjustment of the third pattern, after switching the platen gap PG in the same way as the first pattern, the platen gap PG is based on the fact that the detection value V becomes equal if the reflection distance is the same as in the second pattern. Check whether the gap PG has been switched correctly.

Next, threshold resetting will be described.
The respective threshold values set corresponding to PG1 to PG4 are reset at a predetermined timing in consideration of deterioration or contamination of the reflective sensor 29 and the reflected portion 36. That is, the CPU 50 performs the threshold value by the following procedure when the recording process is executed in a predetermined specified amount, for example, whenever a recording process is performed on a predetermined number of recording media P or when an error occurs. Reset the settings.

  In resetting the threshold, first, as a placement step, the carriage 19 is moved in the main scanning direction X, and the reflective sensor 29 is placed at a position facing the reflected portion 36a. Further, as a reference position detecting step, the projection 33b of the cam 33 is applied to the cam follower 34 to place the carriage 19 at the reference position, and the platen gap PG is set to PG1. Then, as the first threshold value setting step, the detection value V detected by using the reflected portion 36a of the reflective sensor 29 with the carriage 19 placed at the reference position as a reflection target is reset as a new threshold value A1.

  Next, the CPU 50 calculates A2 to A4 based on the proportional relationship of the thresholds A1 to A4 and the reset threshold A1, and resets these as new thresholds. Alternatively, the threshold values A2 to A4 are also reset based on the detection value V in order to correct the change in the proportionality factor accompanying the deterioration of the reflective sensor 29.

  In this case, after the first threshold setting step, the projection 33c of the cam 33 is applied to the cam follower 34, or the platen gap PG is switched to PG4 based on the number of driving steps of the PG motor 35. After that, as a second threshold setting step, the detection value V for the reflection target 36d of the reflective sensor 29 as a reflection target is reset as a new threshold A4.

  Then, A2 and A3 may be calculated based on the proportional relationship from A1 and A4 reset based on the detection value V, and A2 and A3 may also be reset based on the detection value V. That is, after the second threshold setting step, as the intermediate threshold setting step, the platen gap PG is switched from PG1 to PG2 and PG3 based on the number of driving steps of the PG motor 35, and the reflective sensor 29 in each switching state is switched. The detection value V is reset as new threshold values A2 and A3.

Then, the CPU 50 stores the reset threshold values A <b> 1 to A <b> 4 in the nonvolatile memory 53, whereby the resetting of the threshold values is completed.
Also, the threshold values B1 to B4, C1 to C4, and D1 to D4 can be reset similarly to the threshold values A1 to A4. That is, the reflection type sensor 29 is disposed at a position facing the reflected portions 36b, 36c, 36d, and the threshold value B1 is based on the detection value V detected in a state where the carriage 19 is disposed at the reference position by the application. , C1 and D1 are reset. Thereafter, the threshold values B2 to B4, C2 to C4, and D2 to D4 are reset based on the number of driving steps of the PG motor 35 or the proportional relationship.

  However, since not all threshold values are referred to in platen gap adjustment, only necessary threshold values may be reset. For example, when the platen gap adjustment of the first pattern is performed, it is sufficient to reset only the threshold values A1 to A4 that are referred to.

  In resetting the threshold value of the second pattern, it is sufficient to reset the threshold value at least as V1 = A1. However, the thresholds B2, C3, and D4 may be reset in addition to the threshold A1 in order to confirm that there is no abnormality in each reflected portion 36.

  In this case, after obtaining the threshold value A1 by probing, the reflective sensor 29 is arranged at a position facing the reflected portion 36b, and the platen gap PG is switched to PG2 based on the number of driving steps of the PG motor 35. The detection value V detected using the reflected portion 36b of the reflective sensor 29 as a reflection target may be reset as the threshold B2.

  Similarly, after resetting the threshold value B2, the reflective sensor 29 is disposed at a position facing the reflected portion 36c, and the platen gap PG is switched to PG3 based on the number of driving steps of the PG motor 35, so that the reflective sensor 29 The detection value V with the reflected portion 36c as a reflection target may be reset as the threshold C3. Further, the reflective sensor 29 is arranged at a position facing the reflected portion 36d, the platen gap PG is switched to PG4 based on the number of driving steps of the PG motor 35, and the reflected portion 36c of the reflective sensor 29 is reflected. The detected value V may be reset as the threshold value D4.

  By comparing the threshold values A1, B2, C3, and D4 reset in this way, if any of A1, B2, C3, and D4 that should be equal to each other has a significantly different value, it corresponds. There is a possibility that the reflectance has changed due to foreign matters adhering to the reflected portion 36. In other words, the reflected portions 36a to 36d can be inspected by resetting the thresholds A1, B2, C3, and D4.

According to the embodiment described above, the following effects can be obtained.
(1) The platen gap PG can be adjusted based on the detection value V that reflects the reflected portion 36 of the reflective sensor 29 as a reflection target. Thereby, since it is not necessary to apply each time the platen gap is adjusted, the platen gap can be adjusted while reducing the load applied to the components.

  (2) Since the reflected portion 36 is provided at a position corresponding to the non-recording area of the platen 27, it can be avoided that the reflected portion 36 interferes with the recording medium P and hinders the recording process. Contamination of the reflected portion 36 due to the recording process can be suppressed. Further, since the reflected portion 36 is provided on a part of the platen 27 provided with the support portion 30a, the separation distance between the reflected portion 36 and the support portion 30a can be defined by the platen 27 alone.

  (3) Since the reflective sensor 29 for detecting the platen gap PG can also be used as an optical sensor for detecting the width of the recording medium P in the main scanning direction X, a sensor dedicated to adjusting the platen gap is provided. There is no need.

  (4) Even when the carriage 19 is displaced so that the separation distance with respect to the support portion 30a changes in a plurality of steps, the detection value V can be obtained by using the reflected portions 36a to 36d corresponding to the respective steps as reflection targets. .

  (5) Normally, the CPU 50 can determine the setting state of the platen gap PG based on the detection value V, and reset the threshold value with a predetermined frequency. Therefore, it is possible to appropriately adjust the platen gap while reducing the load on the components.

  (6) By resetting the threshold every time the recording process is performed with the specified processing amount, the platen gap is appropriately adjusted while suppressing the influence of deterioration of the reflective sensor 29, contamination of the reflected portion 36, and the like. It can be carried out.

  (7) In adjusting the platen gap of the first pattern, it is only necessary to provide one reflected portion 36, so that the apparatus can be realized with a simple configuration. Further, since the threshold value corresponding to each stage of the platen gap PG can be changed by software, the platen 27 having the reflected portion 36a is shared by a plurality of types of printers 11 having different setting patterns of the platen gap PG. Can be used. Furthermore, since the threshold value can be arbitrarily set, the present invention can also be applied to the case where the platen gap PG is changed to an arbitrary value without steps.

  (8) In the platen gap adjustment of the second pattern, the platen gap PG can be adjusted by referring to one threshold value V1. Therefore, the platen gap is appropriately adjusted even when, for example, the light emission capability of the light source unit 29a of the reflective sensor 29 is reduced or the proportionality coefficient of a plurality of threshold values corresponding to each reflected portion 36 is changed due to contamination of the light receiving unit 29b. It can be carried out. Further, since the platen gap PG can be adjusted even if V1 is an arbitrary value different from A1, B2, C3, and D4, the frequency of allocation can be further reduced.

  (9) In the platen gap adjustment of the third pattern, after switching the platen gap PG based on the detection value V with the reflected portion 36a of the reflective sensor 29 as a reflection target, the other reflected portion 36 is reflected. Since it is confirmed that the target platen gap PG has been switched to the target, the platen gap can be adjusted more reliably.

The above embodiment may be changed to another embodiment as described below.
The displacement direction Z is not limited to the vertical direction, and the distance from the platen 27 may be changed by, for example, displacing the carriage 19 in an oblique direction or a horizontal direction.

  The timing for resetting the threshold value can be arbitrarily set. For example, printing is performed every 800 sheets of paper as the recording medium P in borderless printing, and every 1000 sheets of paper as the recording medium P in printing with margins. It can also be set according to the method. Alternatively, the resetting interval may be shortened according to the usage period of the printer 11.

It is not necessary to store all threshold values A1 to A4, B1 to B4, C1 to C4, D1 to D4 in the nonvolatile memory 53, and only necessary threshold values may be stored.
-The cam 33 is good also as a structure which is not provided with the projection part 33c.

The carriage 19 may be arranged at the reference position in the displacement direction Z when the protrusion 33c contacts the cam follower 34 and the rotation of the guide shaft 18 is restricted.
The reflection part 36 may be provided on a member different from the platen 27.

The platen gap may be adjusted using only one of the patterns.
When only the platen gap adjustment of the first pattern is performed, it is not necessary to provide a plurality of the reflected portions 36.

The reflection part 36 may be provided in the recording area. In that case, interference with the recording medium P can be avoided by providing the reflected portion 36 on the bottom 31.
The platen gap PG can be set to any plurality of stages, not limited to four stages. Also in this case, the platen gap adjustment based on the detection value V can be performed by providing the reflected portion 36 according to each stage of the platen gap PG.

The reflective sensor 29 is not limited to an optical sensor, and may be a magnetic sensor, for example.
The reflective sensor 29 may not be used as a paper width sensor, but may be a sensor dedicated to platen gap adjustment.

The printer 11 may be provided with a mechanism for measuring the thickness of the recording medium P, the thickness of the recording medium P may be automatically measured, and the corresponding platen gap PG may be automatically set.
In the above embodiment, the recording apparatus is embodied as an ink jet printer. However, the present invention is not limited to this, and other recording apparatuses (printing apparatus, copying apparatus, etc.) such as a dot impact type printer in which a change in the paper gap affects the printing accuracy. And a FAX machine and a multi-function machine equipped with a combination of these apparatuses). Furthermore, a liquid ejecting apparatus that ejects or ejects liquid other than ink may be employed, and can be used for various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. . In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in the state when the substance is in a liquid phase, such as a liquid state with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a coloring material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface light emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid as a sample used as a precision pipette, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these injection devices.

  A1 to A4, B1 to B4, C1 to C4, D1 to D4, V1 ... threshold, P ... recording medium, PG ... platen gap, V ... detected value, X ... main scanning direction, Y ... displacement direction, 11 ... recording device As a printer, 18 ... guide shaft, 19 ... carriage, 21 ... recording head, 27 ... platen as a support member, 29 ... reflection type sensor, 30a ... support part, 32 ... platen gap adjusting device, 33 ... cam, 33a ... Cam surface, 33b, 33c ... projection, 34 ... cam follower, 35 ... PG motor as drive source, 36, 36a, 36b, 36c, 36d ... reflected portion, 50 ... CPU as control means, 53 ... storage means As a non-volatile memory.

Claims (6)

A recording head for performing a recording process on the recording medium;
A support unit that supports the recording medium during the execution of the recording process;
A carriage configured to hold the recording head and the reflective sensor, and to be displaceable in a displacement direction in which a separation distance from the support portion changes;
A drive source for displacing the carriage;
A reflected portion in which a separation distance in the displacement direction is defined with respect to the support portion;
A recording apparatus comprising: a control unit configured to perform drive control of the drive source based on a detection value in which the reflection target of the reflection type sensor is a reflection target. A support member that supports the recording medium when the recording process is performed;
The carriage is configured to be movable in a main scanning direction that intersects the displacement direction, and on the movement path of the carriage in the main scanning direction, a recording area in which the recording head executes the recording process; A non-recording area outside the recording area is set,
In the main scanning direction, the support portion is provided at a position corresponding to the recording area of the support member, and the reflection portion is provided at a position corresponding to the non-recording area of the support member. The recording apparatus according to claim 1. The recording apparatus according to claim 2, wherein the reflective sensor is an optical sensor provided to detect a width of the recording medium in the main scanning direction. 4. The recording apparatus according to claim 1, further comprising a plurality of the reflected portions having different separation distances with respect to the support portion in the displacement direction. 5. A cam surface and a protrusion that are fixed to a shaft end of a guide shaft that is rotated in accordance with the driving of the drive source and change in the distance from the axis of the guide shaft are formed along the circumferential direction of the guide shaft. Cams,
A cam follower that supports the guide shaft via the cam;
Platen gap adjustment that can switch the platen gap, which is the separation distance between the recording head and the support portion, in a plurality of stages by displacing the carriage supported by the guide shaft in the displacement direction by driving the drive source Equipment,
Storage means for storing a threshold value to which the control means refers to determine the setting state of the platen gap based on the detection value;
The carriage is disposed at a reference position in the displacement direction when the protrusion is in contact with the cam follower and the rotation of the guide shaft is restricted,
5. The control unit according to claim 1, wherein the control unit resets the threshold value based on the detection value detected in a state where the carriage is disposed at the reference position. The recording device according to one item. The recording apparatus according to claim 5, wherein the control unit resets the threshold when the recording process is executed in a predetermined processing amount.

Images