JP2010046944A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer in which print quality is improved by correctly examining whether or not the printer is in the state that an ink can be normally discharged from nozzles of printer head. <P>SOLUTION: The printer P comprises: a position sensor 42 for detecting a predetermined height position of a printer head 31 which is vertically moved by a gap adjustment part 33; a control unit 90 for controlling vertical movement of a subplaten 61 via a subplaten lifting mechanism 80 so that a distance between a discharge opening plane of the printer head 31, which is moved along a guide rail 32 to the upper position of a test medium T supported by the subplaten 61 based on the predetermined height position of the printer head 31 detected by the position sensor 42, and the surfaces of the test medium T becomes a predetermined distance; and an inspection means which checks nozzle function of the printer head 31 based on a fixed state of an ink which is discharged from the discharge opening plane of the printer head 31 with the predetermined distance and deposited on the surfaces of the test medium T. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printer apparatus having a function of checking whether ink is accurately ejected from nozzles formed on a printer head.

  2. Description of the Related Art Conventionally, a printer apparatus (inkjet printer) that performs printing by ejecting ink from nozzles formed on the lower surface of a printer head while moving the printer head relative to the print medium and attaching the ink to the print medium in a desired pattern It has been known. In such a printer device, the ink solidifies in the nozzles of the printer head, causing nozzle clogging, or dust adhering to the surface of the print medium is attached to the nozzle openings due to the adhesive force of the ink. Sometimes. As a result, the ink cannot be ejected accurately from the nozzle toward the print medium, the ink lands at a position different from the desired position on the print medium surface, and characters or lines printed on the print medium surface are printed. There is a possibility that a missing dot in which no ink dot exists in a part of the figure may cause a printing defect.

Therefore, as a technique for checking the nozzle function before printing on the surface of the print medium, for example, Patent Document 1 discloses a technique in which the printer head is moved from the nozzles arranged on the lower surface of the printer head while moving the printer head over the test medium supported by the sub-platen. A technique is disclosed in which the ejected ink is landed on the surface of a test medium, and whether or not there is a missing dot based on a test pattern (dot arrangement) printed on the surface of the test medium is disclosed. According to such a configuration, since the nozzle function of the printer head can be checked in advance before printing on the print medium, if it is determined in advance that the nozzle function is abnormal, printing from the nozzle is By performing a flushing operation that discharges irrelevant ink and discharging ink solidified in the nozzle at once, the function of the nozzle can be restored to a normal state, and the occurrence of printing defects can be prevented in advance. .
JP 2002-172804 A

  By the way, the printer apparatus as described above has a structure capable of printing on the surface of various types of print media ranging from thin to thick, and the printer head has a structure that matches the thickness of the print medium to be printed. By adjusting the position height, the distance between the lower surface of the printer head in which the ejection opening surfaces of the nozzles are lined up and the surface of the print medium supported by the platen facing it is appropriately adjusted to the target gap. It is like that. However, when checking the nozzle function, the print medium to be printed and the test medium used for checking the nozzle function are different in thickness, material, etc., and therefore the printer in which the gap between the print medium and the print medium is properly adjusted If the test pattern is printed on the test medium by the head, the distance between the lower surface of the printer head and the surface of the test medium may be too close or too far away. Therefore, it has been difficult to land the ink accurately at the desired position. Therefore, even if the presence / absence of missing ink dots is inspected based on the test pattern printed on the test medium in this manner, the quality of the nozzle function cannot be accurately inspected. There was a problem that the quality deteriorated.

  The present invention has been made in view of such a problem, and accurately checks whether or not the ink is normally ejected from the nozzles of the printer head, thereby preventing printing defects from occurring. Accordingly, an object of the present invention is to provide a printer apparatus with improved print quality.

  In order to achieve the above object, a printer apparatus according to the present invention includes a print medium support portion (for example, the platen 10 in the embodiment) that supports a print medium, and a guide rail that is provided above the print medium support portion. A printer head that is reciprocally attached to a member and ejects ink from a discharge opening surface of a nozzle formed downward, and a head lifting mechanism that moves the printer head up and down relative to the print medium support (for example, implementation) A printer head which is moved up and down to a predetermined height by a head lifting mechanism according to the thickness of the print medium supported by the print medium support section, along the guide rail member. In a printer device configured to perform printing by ejecting ink from nozzles onto the surface of a print medium while moving A test medium support section (for example, sub-platen 61 in the embodiment) that is provided below the guide rail member adjacent to the print medium support section and supports the test medium, and a support section that holds the test medium support section so as to be movable up and down. An elevating mechanism (for example, the sub-platen elevating mechanism 80 in the embodiment) and detection means for detecting a predetermined height position of the printer head moved up and down by the head elevating mechanism (for example, the position sensor 42 and the arithmetic processing unit 95 in the embodiment). And a discharge opening surface of the printer head moved to a position above the test medium supported by the test medium support along the guide rail member based on the predetermined height position of the printer head detected by the detection means The test is performed via the support lifting mechanism so that the distance from the surface of the test medium is a predetermined distance. The movement control means (for example, the raising / lowering movement control unit 94 and the arithmetic processing unit 95 in the embodiment) that controls to move the medium support unit up and down is separated from the discharge opening surface of the printer head by a predetermined distance. It comprises inspection means (for example, the optical sensor 70 and the image processing unit 96 in the embodiment) for checking the nozzle function of the printer head from the ejection state of ink landed on the surface.

  In the printer apparatus according to the present invention, the guide rail member is disposed near one end side in the relative movement direction of the printer head, and abuts against the discharge opening surface of the printer head moved near the one end side. A maintenance unit that performs predetermined maintenance; and a cap lifting mechanism that holds the maintenance unit so as to be movable up and down with respect to the printer head. It is preferable to detect a predetermined height position of the printer head based on the height position in contact with the opening surface.

  Further, the cap raising / lowering mechanism is configured such that the maintenance unit can be moved up and down by a rotational driving force of a drive motor (for example, the cap drive motor 56 in the embodiment), and the detection unit is configured to discharge the maintenance unit from a predetermined reference position. It is preferable to detect the predetermined height position of the printer head based on the drive control amount of the drive motor corresponding to the moving distance that moves up and down to the contact position with the surface.

  In the printer device according to the present invention configured as described above, when the nozzle function of the printer head is checked by the inspection unit, the height is adjusted according to the thickness of the print medium supported by the print medium support unit. A predetermined height position of the printer head is detected by the detecting means, and based on the detected height position of the printer head, a predetermined gap between the surface of the test medium to be checked and the discharge opening surface of the printer head is determined. The movement control means is configured to control to move the test medium support part up and down via the support part raising / lowering mechanism so as to be separated from each other. According to this configuration, the ink ejected from the nozzle of the printer head is accurately landed on a desired position on the surface of the test medium, and the quality of the nozzle function of the printer head is accurately inspected from the ejected state of the landed ink. This improves the reliability of the nozzle function check. Therefore, it is possible to improve the printing quality by preventing the occurrence of printing defects.

  Further, in the above printer apparatus, a maintenance unit that performs a predetermined maintenance by contacting the discharge opening surface of the printer head is provided, and the detection unit is configured to detect the height of the maintenance unit that contacts the discharge opening surface of the printer head. A configuration for detecting a predetermined height position of the printer head is preferable. In such a configuration, the printer head is maintained at a predetermined height position from the contact position between the maintenance unit and the printer head, for example, while performing maintenance such as sucking excess ink or dust on the printer head. It can be detected accurately and efficiently.

  Further, the detection means detects the predetermined height position of the printer head based on the drive control amount of the drive motor corresponding to the distance that the maintenance unit moves up and down from the predetermined reference position to the contact position with the discharge opening surface. It is preferable to do. When configured in this manner, the height position of the printer head can be detected with a simple and inexpensive configuration.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As an example of an ink jet printer to which the present invention is applied (hereinafter referred to as a printer apparatus), a schematic configuration of a printer apparatus P of a type in which one of XY two axes moves a print medium and the other one moves a printer head. 1 is shown in FIG. 1, and a cross-sectional view taken along line II-II in FIG. 1 is shown in FIG. In the following description, the arrow directions shown in the drawings will be referred to as up and down, left and right, and front and rear directions.

  As schematically shown in FIGS. 1 and 2, the printer device P is formed in a substantially rectangular parallelepiped shape with its outer peripheral portion covered with a cover 9, and is called a frame 8 serving as a mounting base for each mechanism and a medium. A printing unit 3 that performs a predetermined operation such as printing on a sheet-like print medium M such as a vinyl chloride sheet; a feed-out mechanism 4 that sends the raw print medium M wound in a roll shape to the print unit 3; The winding mechanism 5 that winds up the printing medium M that has been drawn by the printing unit 3, the maintenance unit 50 and the nozzle function check unit 60 that are provided adjacent to the left side of the printing unit 3, and the operation of each part of the printer device P And a control unit 90 for controlling.

  The printing unit 3 includes a platen 10 that supports the printing medium M, a medium moving mechanism 20 that moves the printing medium M supported by the platen 10 back and forth, and is supported above the platen 10 so as to be movable left and right. A carriage 30 that holds the printer head 31 and a carriage moving mechanism 45 that relatively moves the carriage 30 left and right with respect to the print medium M supported by the platen 10 are provided.

  The platen 10 is disposed on the frame 8, and a media support surface 11 that horizontally supports the print medium M is formed on the upper surface of the left and right belt-like drawing areas formed by the printer head 31.

  The media moving mechanism 20 is provided so as to be rotatable about a rotation shaft extending in the left and right directions, and has a cylindrical feed roller 21 provided with an upper peripheral surface exposed to the media support surface 11 of the platen 10, and a feed roller 21. A roller driving motor 23 for rotationally driving the roller, a timing belt 22 stretched between a driven pulley coupled to the shaft end of the feed roller 21 and a driving pulley coupled to the shaft end of the roller driving motor 23, respectively. A plurality of roller assemblies 25 each having a pinch roller 26 that is rotatable in the front-rear direction and disposed at predetermined intervals on the left and right above the feed roller 21 are mainly configured.

  The roller assembly 25 is configured to be displaceable between a clamp position where the pinch roller 26 is elastically engaged with the feed roller 21 and an unclamp position where the pinch roller 26 is spaced above the feed roller 21. By rotating the roller drive motor 23 in a state in which the roller assembly 25 is set to the clamp position and the print medium M is sandwiched between the upper and lower rollers 26 and 21, the print medium M corresponds to the rotation angle of the feed roller 21. The sheet is conveyed back and forth at a feed amount corresponding to the feed amount, that is, the drive control amount output from the control unit 90 to the roller drive motor 23. In FIG. 1, both the state where the roller assembly 25 is set at the clamp position and the state where the roller assembly 25 is set at the unclamp position are shown.

  The carriage 30 is supported by a guide rail 32 that is attached to the frame 8 so as to be movable in the right and left direction and extends in parallel to the feed roller 21. The guide rail 32 is a support rail of a linear motion bearing also referred to as a linear motion guide or a linear guide, and the carriage 30 is fixed to a slide block (not shown) fitted and supported by the guide rail 32, thereby the carriage. 30 is supported above the platen 10 so as to be slidable left and right, and is driven by a carriage moving mechanism 45 described below. The guide rail 32 that guides the slide movement of the carriage 30 extends to above the nozzle function check unit 60 and the maintenance unit 50, and the carriage 30 is positioned above the nozzle function check unit 60 and the maintenance unit 50. It can be moved to an upper position (capping position).

  Here, an enlarged front view of the vicinity of the carriage 30 is shown in FIG. As shown in FIG. 3, the carriage 30 is provided with a gap adjusting unit 33 for appropriately adjusting the distance between the lower surface of the printer head 31 and the printing target surface of the printing medium M to a predetermined gap. The gap adjusting unit 33 is an optimal distance for printing processing between the carriage lifting mechanism 34 that moves the carriage 30 up and down relative to the printing medium M, and the lower surface of the printer head 31 and the printing target surface of the printing medium M ( The carriage raising / lowering mechanism 34 is, for example, a feed that moves the carriage 30 up and down along a slide rail 36 that extends vertically by rotating the feed handle 35. It consists of a screw mechanism.

  The presentation mechanism 37 is a frame member 38 provided on the right side surface of the carriage 30, a rod 39 supported by the frame member 38 so as to be movable up and down, and a rod 39 provided on the rod 39 and moved downward with respect to the frame member 38. In order to restrict the position where the lower end of the rod 39 abuts against the print medium M is a position where a predetermined gap between the printer head 31 and the print medium M is presented, the rod 39 is restricted from moving below the position. A rod spring 41 that biases the stopper 40a and the rod 39 upward with respect to the frame member 38, and a rod 39 that is provided on the rod 39 and is biased upward by the rod spring 41 with respect to the frame member 38 has a constant height. The lower stopper 40b and the like for restricting the further movement. Thus, the carriage 30 is moved downward by the carriage lifting mechanism 34 in a state where the rod 39 is moved downward against the urging force of the rod spring 41 until the upper stopper 40a hits the upper end of the frame member 38. By bringing the lower end portion of the rod 39 into contact with the print target surface, the distance between the lower surface of the printer head 31 and the print target surface of the print medium M can be appropriately adjusted so as to be a predetermined gap. ing.

  As shown in FIG. 1, the carriage moving mechanism 45 includes a driving pulley 46 and a driven pulley 47 provided near the left and right side ends of the guide rail 32, a carriage driving motor 48 that rotates the driving pulley 46, and a driving pulley 46. And an endless belt-like timing belt 49 that is stretched around the driven pulley 47, and the carriage 30 is connected and fixed to the timing belt 49. The rotation of the carriage drive motor 48 is controlled by the control unit 90, and the carriage 30 is moved left and right by a feed amount corresponding to the drive control amount output from the control unit 90 to the carriage drive motor 48.

  The printer head 31 is provided on the lower surface side of the carriage 30 facing the medium support surface 11 of the platen 10, and the gap adjustment unit 33 determines the printer head 31 according to the thickness of the print medium M supported by the platen 10. Appropriate adjustment is performed so that the lower surface is separated from the print target surface of the print medium M by a predetermined gap. There are various arrangements for the arrangement of the printer head 31, and an appropriate arrangement can be used. In this embodiment, however, a number of nozzles each ejecting fine ink particles are arranged in a straight line in the front-rear direction. A head configuration in which two rows are formed in parallel and four printer heads 31 are arranged on the left and right to arrange a total of eight nozzle rows is illustrated. A discharge opening surface of a nozzle for discharging ink particles is formed on the lower surface of the printer head 31.

  Adjacent to the left side of the printing unit 3 configured in this manner, a maintenance unit 50 for maintaining a state in which ink is normally ejected from the nozzles of the printer head 31 and a test pattern printed on the test medium T. A nozzle function check unit 60 for checking the quality of the nozzle function of the printer head 31 is provided.

  As shown in FIG. 1, the maintenance unit 50 includes a cap body 51 in which a plurality of rubber caps 52 arranged on the left and right sides at the same interval as the plurality of printer heads 31 are disposed, and the cap body 51 is moved up and down with respect to the printer head 31. And the like. When the carriage 30 is moved to the left end portion (cap position) of the guide rail 32 by the carriage moving mechanism 45, the rubber cap 52 faces the printer head 31 vertically. It is like that.

  Here, the schematic diagram which shows the state of the raising / lowering operation | movement of the maintenance unit 50 is shown in FIG. As shown in FIG. 4A, the cap elevating mechanism 53 resists the urging force of the cap spring 54 for applying the urging force for moving the cap main body 51 downward to the cap main body 51. An eccentric cam 55 that moves the cap body 51 upward, a cap drive motor 56 that rotationally drives the eccentric cam 55, and the like. The cap body 51 is always urged downward from the cap spring 54 so that the bottom surface of the cap body 51 and the outer peripheral portion of the eccentric cam 55 come into contact with each other. The main body 51 is moved up and down by a movement amount corresponding to the rotation angle of the eccentric cam 55 (a drive control amount output from the control unit 90). For this reason, as shown in FIG. 4B, the printer head 31 is moved to the cap position above the maintenance unit 50 by the carriage moving mechanism 45, and the cap body 51 is moved to a predetermined height (head sealing) by the cap lifting mechanism 53. The discharge opening surface on the lower surface of the printer head 31 is covered with a rubber cap 52 and sealed. Thereby, it is possible to prevent the ink facing downward from the nozzles of the printer head 31 from drying. Further, the discharge opening surface of the printer head 31 sealed by the rubber cap 52 is set to a negative pressure by a suction pump (not shown) or the like to suck (remove) ink or dust that has been dried, and to supply ink. By being filled with newly supplied ink (not shown), the ink is normally ejected from the nozzles of the printer head 31.

  The position sensor 42 detects whether or not the cap body 51 is positioned at a head sealing position where the lower surface (discharge opening surface) of the printer head 31 can be sealed by the rubber cap 52. The position sensor 42 includes a transmissive photosensor 43 provided on the left side surface of the carriage 30 and a plate-shaped shielding plate 44 provided so as to protrude upward from the upper surface of the cap body 51. It is detected that the cap body 51 is positioned at a head sealing position where the lower surface of the printer head 31 can be sealed by blocking the detection light by the shielding plate 44. From the position sensor 42, a detection signal indicating whether or not the cap body 51 is located at the head sealing position is output to the control unit 90.

  Further, on the right side of the cap body 51, a first lower limit detection sensor 59 including a limit switch or the like for detecting the lowest position (reference position) of the lifting and lowering movement of the cap body 51 by the cap lifting mechanism 53 is provided. Yes.

  Here, FIG. 5 shows a side cross-sectional portion of the nozzle function check unit 60 in the VV portion in FIG. The nozzle function check unit 60 discharges the sub platen 61 that supports the test medium T, the test medium movement mechanism 63 that supplies the test medium T onto the sub platen 61, and discharges the test medium T from the sub platen 61, and the printer head 31. In addition, an optical sensor 70 and a sub-platen 61 for detecting dot dropout of ink droplets landed on the print target surface of the test medium T (a state in which no ink dot is present where an ink dot should be present) and the like are provided in the printer head 31. On the other hand, it is mainly composed of a sub-platen lifting mechanism 80 that moves up and down.

  The sub platen 61 is provided side by side on the left side of the platen 10, and a substantially rectangular test medium support surface 62 that horizontally supports a portion to be printed on the test medium T is formed on the upper surface of the sub platen 61.

  The test medium moving mechanism 63 includes a roll support unit 64 that feeds the unprocessed test medium T wound in a roll shape, a winding unit 65 that winds up the test medium T after test pattern printing, and a cylindrical shape that extends to the left and right. The feed roller 66, an electric motor (not shown) that rotationally drives the feed roller 66, a pressing roller 67 that is rotatably provided above the feed roller 66, and the like. The test medium T is fed to the feed roller 66 and the pressing roller 67. The test medium T is transported back and forth at a feed amount corresponding to the rotation angle of the feed roller 66 (drive control amount output from the control unit 90). .

  The optical sensor 70 includes a light emitting element 71 and a light receiving element 72 disposed above a path through which the test medium T discharged from the printing area on the sub platen 61 passes by the test medium moving mechanism 63, and is emitted from the light emitting element 71. The inspection light to be reflected is reflected by the test medium T on which the test pattern is printed and is received by the light receiving element 72. The image of the test pattern captured by the light receiving element 72 is photoelectrically converted into an image signal, and the test pattern dot missing printed on the surface of the test medium T by the control unit 90 electrically connected to the light receiving element 72 is imaged. This can be detected by processing, and thereby, the quality of the nozzle function of the printer head 31 can be checked. The periphery of the light emitting element 71 and the light receiving element 72 is covered with a separator 73 provided in the sub-platen 61 and having an opening 74 through which the test medium T passes, so that intrusion of ambient light is prevented.

  The sub platen elevating mechanism 80 includes a sub platen spring 81 for applying an urging force for moving the sub platen 61 downward to the sub platen 61, an eccentric cam 82 for moving the sub platen 61 up against the urging force of the sub platen spring 81, and an eccentricity. A sub-platen drive motor 83 that rotationally drives the cam 82 is formed. The sub platen 61 is always urged downward from the sub platen spring 81 so that the bottom surface of the sub platen 61 and the outer peripheral portion of the eccentric cam 82 are in contact with each other. By rotating the sub platen drive motor 83, the sub platen 61 is rotated. The eccentric cam 82 is moved up and down by a movement amount corresponding to the rotation angle (a drive control amount output from the control unit 90). Therefore, the sub platen 61 is moved up and down by the sub platen elevating mechanism 80 in accordance with the height position of the printer head 31, so that the space between the lower surface of the printer head 31 and the printing target surface of the test medium T supported by the sub platen 61. The distance can be adjusted to the optimum distance for test pattern printing.

  Further, on the right side of the sub platen 61, a second lower limit detection sensor 84 including a limit switch for detecting the lowest position (reference position) of the vertical movement of the sub platen 61 by the sub platen lifting mechanism 80 is provided.

  A schematic block diagram of the printer apparatus P is shown in FIG. The control unit 90 includes a ROM 91 in which a control program for controlling the operation of each unit of the printer device P is written, a RAM 92 for temporarily storing a processing program for drawing on the printing medium M, a printing program read from the RAM 92, and an operation panel 97. A control unit 93 that performs arithmetic processing on the input operation signal and the like and controls the operation of each unit according to the control program, a display panel that displays the operation state of the printer device P, and the operation panel 97 provided with various operation switches are provided. And moving the print medium M back and forth by the medium moving mechanism 20, moving the carriage 30 left and right by the carriage moving mechanism 45, and controlling ink ejection from each nozzle of the printer head 31.

  By the way, since the print medium M to be used for printing in the printer apparatus P and the test medium T for checking the nozzle function are different in thickness, material, etc., the printer head 31 in which the gap with the print medium M is appropriately adjusted is used. If the test pattern is printed on the test medium T, the ink cannot be landed accurately on the desired position of the test medium T. As a result, the test pattern is printed on the test medium T. Thus, there is a problem that even if the presence or absence of missing dots is checked, accurate determination cannot be made. Therefore, in the printer apparatus P, the lower surface of the printer head 31 and the print target surface of the test medium T are constant regardless of the height at which the printer head 31 whose gap is appropriately adjusted according to the print medium M is located. Thus, the control unit 93 of the control unit 90 is configured to control the operation of each unit.

  The control unit 93 of the control unit 90 includes an up / down movement control unit 94 for controlling a predetermined operation of the nozzle function check unit 60 and the maintenance unit 50, an arithmetic processing unit 95, an image processing unit 96, and the like.

  The up-and-down movement control unit 94 outputs a drive pulse signal for rotating the motor based on the operation signal input from the operation panel 97, and the up-and-down movement of the cap body 51 by the rotational drive of the cap drive motor 56 and the sub-platen drive. The sub platen 61 is controlled to move up and down by the rotation of the motor 83. Further, the up / down movement control unit 94 receives the ON signal from the first lower limit detection sensor 59 to stop the downward movement of the cap body 51 by the cap drive motor 56 at the lowest position (reference position), or the second By receiving the ON signal from the lower limit detection sensor 84, the sub platen drive motor 83 is controlled to stop the descending movement of the sub platen 61 at the lowest position (reference position), and the detection signal from the position sensor 42 is received. Then, control is performed to stop the upward movement of the cap body 51 by the cap drive motor 56 at a predetermined head sealing position for sealing the lower surface of the printer head 31.

  The arithmetic processing unit 95 calculates the height at which the lower surface of the printer head 31 whose height has been adjusted by the gap adjusting unit 33 is calculated. Specifically, when the detection signal is received from the position sensor 42 because the cap body 51 is positioned at a predetermined head sealing position, the arithmetic processing unit 95 causes the cap lifting mechanism 53 to lower the lowermost position (reference position) of the cap body 51. Position) to a predetermined head sealing position, that is, the amount of rotation of the cap drive motor 56 from when the OFF signal is received by the first lower limit detection sensor 59 to when the detection signal is received by the position sensor 42 The position of the cap body 51 is calculated from the movement distance corresponding to the (drive control amount), and thereby the position of the lower surface of the printer head 31 that is sealed by the upper surface of the cap body 51 (rubber cap 52) in the same plane. The height can be determined.

  Further, the arithmetic processing unit 95 is used to print the height information of the lower surface of the printer head 31 obtained as described above, the thickness of the test medium T stored (set) in the RAM 92 in advance, and test pattern printing. The standard distance is separated from the lower surface of the printer head 31 in test pattern printing based on the information on the standard distance (gap) between the lower surface of the optimum printer head 31 and the printing target surface of the test medium T. The optimal height at which the test media support surface 62 of the sub platen 61 should be positioned is calculated, and is necessary for the vertical movement from the lowest position (reference position) of the sub platen 61 to the optimal height position by the sub platen lifting mechanism 80. A rotation amount (drive control amount) of the sub platen drive motor 83 according to the distance is calculated. Based on the rotation amount (drive control amount) of the sub platen drive motor 83 obtained by the arithmetic processing unit 95, the elevation movement control unit 94 outputs a drive pulse signal corresponding to this drive control amount to the sub platen drive motor 83, Control is performed to move the sub platen 61 up and down relative to the printer head 31 to a position of the optimum height for test pattern printing.

  The image processing unit 96 performs image processing on the ejection state of the ink ejected on the test medium T based on the image signal of the test pattern input from the optical sensor 70, and the test pattern drawn on the test medium T Is checked for missing dots. As a result, it is possible to check the quality of the nozzle function of the printer head 31, and to prevent the occurrence of dot omission in some of the characters, figures, images, etc. drawn on the print medium M by the printer head 31 in advance. Can do.

  The overall configuration of the printer device P has been described above. Hereinafter, the operation of each component member when printing is performed on the print medium M using the printer device P will be described.

  The print medium M is attached to the printer device P so as to be conveyed on the platen 10 from the rear to the front, and is conveyed forward while being sandwiched between the upper and lower rollers 21 and 26. At this time, the distance between the lower surface of the printer head 31 that ejects ink and the printing target surface of the printing medium M is appropriately adjusted by the gap adjusting unit 33 so as to have a predetermined gap corresponding to the thickness of the printing medium M. The Then, ink is ejected from the nozzles of each printer head 31 while moving the carriage 30 back and forth along the guide rails 32 with respect to the print medium M located on the platen 10 in a desired pattern. Adhere to. Next, after the print medium M is conveyed forward by a predetermined pitch, ink is repeatedly ejected while the carriage 30 is reciprocated left and right again. The printed print medium M is transported forward and taken up by the take-up mechanism 4 so that a series of printing on the print medium M in the printer device P is performed.

  The operation of each component when performing printing on the print medium M has been described above, but the operation of each component when performing the nozzle function check of the printer head 31 will be described below. As described in the prior art, for example, when the ink hardens in the nozzles of the printer head 31 and nozzle clogging occurs, the ink is not normally ejected from the printer head 31 and the printing medium M There is a risk that missing dots may occur in some of the characters, figures, images, etc. drawn on the screen, resulting in poor printing. In order to prevent such printing defects from occurring, the nozzle function is checked. The nozzle function check is preferably performed at a stage before printing on the print medium M in order to prevent printing defects on the print medium M. In the following description, the nozzle function is checked in advance. An example will be described.

  When checking the nozzle function, first, the sub platen 61 that supports the test medium T and the cap body 51 of the maintenance unit 50 are positioned at their lowest positions. Then, the carriage 30 is moved left and right by the carriage moving mechanism 45 so that the printer head 31 is positioned at an upper position facing the print target surface of the print medium M supported by the platen 10. Next, in order to make the height position of the printer head 31 correspond to the print medium M to be printed after the nozzle check, the rod 39 is held in the lower position where the upper stopper 40a hits the upper end of the frame member 38 in the presentation mechanism 37. The entire carriage 30 is moved downward by the carriage lifting mechanism 34 until the lower end portion of the rod 39 contacts the printing target surface of the printing medium M, so that the lower surface of the printer head 31 and the printing target surface of the printing medium M are moved. Proper adjustment is made so that the distance between the two becomes the desired gap.

  After the gap adjustment of the printer head 31 is performed, the carriage 30 is moved to the capping position above the maintenance unit 50 by the carriage moving mechanism 45 and the cap main body 51 of the maintenance unit 50 is moved up by the cap lifting mechanism 53. . Along with the upward movement of the cap body 51, when the detection light of the photosensor 43 provided on the printer head 31 reaches a position where the shielding plate 44 provided on the cap body 51 blocks, the cap body 51 is moved to a predetermined position. The position sensor 42 (photo sensor 43) detects the position at the head sealing position, and the up / down movement control unit 94 of the control unit 90 detects the upward movement of the cap body 51 at the head sealing position based on the detection signal. Control to stop. As a result, the rubber cap 52 of the cap body 51 is sealed so as to cover the lower surface of the printer head 31 at the head sealing position, thereby preventing drying of the ink in the vicinity of the ejection opening surface of the printer head 31, By removing the excess ink, dust and the like, it is possible to maintain a state where ink is normally ejected from the nozzle.

  At this time, the calculation processing unit 95 of the control unit 90 calculates the amount of movement until the cap body 51 reaches the head sealing position by the cap lifting mechanism 53 based on the rotation amount (drive control amount) of the cap drive motor 56. Then, the height at which the lower surface of the printer head 31 is located is calculated from the obtained movement amount. For this reason, the height position of the lower surface of the printer head 31 can be efficiently detected with a simple configuration.

  Further, the arithmetic processing unit 95 determines the test medium supported by the sub platen 61 based on the information such as the height of the lower surface of the printer head 31 thus obtained and the thickness of the test medium T preset in the RAM 92. The height at which the sub platen 61 should be positioned is calculated from the lower surface of the printer head 31 so that the print target surface of T becomes the optimum gap for test pattern printing, and the sub platen 61 has the above height from the lowest position (reference position). A rotation amount (drive control amount) of the sub platen drive motor 83 is calculated according to the distance necessary to move to the position. Then, when the sub platen drive motor 83 is rotationally controlled by a feed amount corresponding to the rotation amount (drive control amount) obtained by the arithmetic processing unit 95, the sub platen 61 is moved upward via the eccentric cam 82, and the test is performed. Adjustment is performed so that the printing target surface of the medium T and the lower surface of the printer head 31 are positioned at a target distance. Thereby, even if the height at which the printer head 31 is positioned varies according to the thickness of the print medium M to be printed, the sub-platen 61 that supports the test medium T is adjusted to a desired height position accordingly. By performing the control, the interval between the lower surface of the printer head 31 and the printing target surface of the test medium T is appropriately adjusted to an optimum distance for test pattern printing, so that the ink landing position on the test medium T is adjusted. It is prevented from becoming unstable.

  Next, ink is ejected from the nozzles of each printer head 31 while the carriage 30 is reciprocated left and right along the guide rail 32 with respect to the test medium T, whereby ink is applied to the test medium T in a desired test pattern. Let it land. Thereafter, the test medium T on which the test pattern is printed is discharged forward from the printing area of the sub platen 61 by the test medium moving mechanism 63, passes through the opening 74 of the separator 73, and is disposed on the left and right in the separator 73. The light is sent to a position below the light emitting element 71 and the light receiving element 72. Then, the inspection light from the light emitting element 71 is reflected by the test medium T on which the test pattern is printed, and the reflected light is received by the light receiving element 72, whereby an image of the test pattern is captured. Then, based on the image signal photoelectrically converted by the light receiving element 72, the image processing unit 96 of the control unit 90 determines the presence or absence of missing dots in the test pattern printed on the test medium T, and whether the nozzle function of the printer head 31 is good or bad. Is checked.

  At this time, as described above, when the test pattern is printed on the test medium T, the sub-platen 61 that supports the test medium T is controlled to be adjusted to a desired height position. Since the ink to be ejected can be accurately landed on the test medium T, it is possible to accurately check the quality of the nozzle function.

  When the optical sensor 70 confirms the presence or absence of missing dots in the test pattern printed on the test medium T, the nozzle function check ends. As a result, if it is found that there is an abnormality in the nozzle function, the maintenance unit 50 removes ink or dust that is drying and solidifying at the nozzles of the printer head 31, or is related to printing from the nozzles. Ink is discharged (flushing) or the like to recover the state where ink can be normally discharged from the nozzle. On the other hand, if it is confirmed that the nozzle function is normal, then the carriage 30 is moved to the right along the guide rail 32 from the capping position above the sub-platen 61 and printing on the print medium M is started. Let

  According to the printer device P configured in this way, when the nozzle function of the printer head 31 is checked, the height at which the printer head 31 is positioned with the gap adjusted according to the thickness of the print medium M to be printed. Accordingly, the sub-platen 61 that supports the test medium T is controlled to move up and down so that the distance between the print target surface of the test medium T to be checked and the lower surface of the printer head 31 is properly adjusted. As a result, the ink ejected from the printer head 31 can be accurately landed on the test medium T, the test pattern can be printed, and the quality of the nozzle function of the printer head 31 can be checked accurately. Can be prevented, and the printing quality of the printer device P can be improved.

  In the above-described embodiment, the gap adjusting unit 33 is exemplified by the carriage elevating mechanism 34 using the manual feed screw mechanism and the presentation mechanism 37 that presents the predetermined gap by manual adjustment of the rod 39. For example, the carriage raising / lowering mechanism may be an electric type, and the presentation mechanism may be an electronic type such as a detection sensor.

  In the embodiment described above, as an example of the ink jet printer, a printer apparatus of a type in which one of the XY two axes moves the print medium and the other one moves the printer head is shown. The present invention can be similarly applied to other inkjet printers, for example, a printer apparatus of a head moving type in which the X-axis carriage and the Y-axis carriage move in the XY direction with respect to a table holding a print medium.

1 is a schematic diagram illustrating a schematic configuration of a printer device according to the present invention as viewed from the front. It is side surface sectional drawing which showed the II-II part in FIG. It is a schematic diagram which shows the carriage periphery in the said printer apparatus by front view. 2A and 2B are schematic diagrams illustrating a state of a lifting / lowering operation of a maintenance unit in the printer apparatus, where FIG. 3A illustrates a state positioned at a reference position, and FIG. 4B illustrates a state positioned at a head sealing position. It is side surface sectional drawing which showed the VV part in FIG. FIG. 2 is a schematic block diagram of the printer apparatus.

Explanation of symbols

M print medium P printer device T test medium 10 platen (print medium support section)
30 Carriage 31 Printer head 32 Guide rail (guide rail member)
33 Gap adjustment part (head lifting mechanism)
42 Position sensor (detection means)
50 Maintenance Unit 53 Cap Lifting Mechanism 56 Cap Drive Motor (Drive Motor)
60 Nozzle function check unit 61 Sub-platen (test medium support part)
70 Optical sensor (inspection means)
80 Sub-platen lifting mechanism (supporting mechanism lifting mechanism)
90 Control unit 93 Control unit 94 Elevation movement control unit (movement control means)
95 Arithmetic processing part (detection means, movement control means)
96 Image processing unit (inspection means)

Claims (3)

A print medium support for supporting the print medium;
A printer head that is attached to a guide rail member provided above the print medium support portion so as to be reciprocally movable, and that ejects ink from an ejection opening surface of a nozzle formed downward;
A head lifting mechanism for moving the printer head up and down relative to the print medium support unit;
The print medium is moved along the guide rail member while the printer head moved up and down to a predetermined height position by the head elevating mechanism according to the thickness of the print medium supported by the print medium support section. In a printer configured to perform printing by discharging ink from the nozzles on the surface of
A test medium support part which is provided below the guide rail member adjacent to the print medium support part and supports a test medium;
A support lifting mechanism for holding the test medium support movably up and down;
Detecting means for detecting the predetermined height position of the printer head moved up and down by the head lifting mechanism;
Based on the predetermined height position of the printer head detected by the detection means, the printer head moved to a position above the test medium supported by the test medium support along the guide rail member. A movement control means for performing control to move the test medium support part up and down via the support part lifting mechanism so that a distance between the discharge opening surface and the surface of the test medium is a predetermined distance;
Inspection means for checking a nozzle function of the printer head from an ejection state of ink ejected from the ejection opening surface of the printer head at a predetermined distance and landed on the surface of the test medium. A printer apparatus. Maintenance that is arranged in the vicinity of one end side in the relative movement direction of the printer head with respect to the guide rail member and performs predetermined maintenance by contacting the discharge opening surface of the printer head moved in the vicinity of the one end side. Unit,
A cap lifting mechanism for holding the maintenance unit movably up and down with respect to the printer head;
The detection means detects the predetermined height position of the printer head based on a height position at which the maintenance unit moves up and down by the cap lifting mechanism and contacts the discharge opening surface of the printer head. The printer apparatus according to claim 1, wherein the printer apparatus is configured as described above. The cap lifting mechanism is configured to be movable up and down by the rotational driving force of a drive motor.
The detection means is configured to detect the predetermined amount of the printer head based on a drive control amount of the drive motor according to a moving distance in which the maintenance unit moves up and down from a predetermined reference position to a contact position with the discharge opening surface. The printer apparatus according to claim 2, wherein the printer is configured to detect a height position of the printer.

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