JP2009172934A - Printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent ejection failure nozzle detection and recovery operation which are not desired by a user. <P>SOLUTION: It is determined whether ejection failure detection is performed or not based on automatic detection instruction data set by the user (S2). When it is determined that the ejection failure detection is not performed, it is asked to the user whether or not the user wants the ejection failure detection (S3). When it is determined that the ejection failure detection is performed, the ejection failure detection is performed (S5), when the number of prints P after the ejection failure detection performed last time is a predetermined number of prints Pth or more (S4:YES). When an ejection failure nozzle is present (S7:YES), it is determined whether recovery detection is performed or not based on automatic recovery instruction data set by the user (S8). When it is determined that recovery processing is not performed, it is asked to the user whether or not the user wants the recovery processing (S10). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing system, and more particularly to a printing system capable of performing a recovery process of a print head.

  In recent years, development of an ink jet printer using a line head having a printing range equal to or larger than the width of a recording medium has been advanced. In such a line printer, only one nozzle is responsible for printing an extremely narrow area along the conveyance direction of the recording medium. Accordingly, even if the number of defective nozzles causing non-ejection, ejection amount fluctuation, or ejection direction deviation is small, white lines or unevenness are formed on the recording medium, and image quality is greatly degraded. .

  Therefore, in the ink jet recording apparatus disclosed in Patent Document 1, a line type image sensor that reads an image printed on recording paper is provided at a position adjacent to the downstream side in the conveyance direction of the line type print head. . Then, the ejection failure nozzle of the print head is detected based on the image data obtained by the line-type image sensor reading the image printed by the test printing or the practical printing. The recovery operation is performed. As a result, it is possible to accurately detect the ejection failure nozzles and eliminate the ejection failure nozzles.

JP 2006-205742 A

  In the ink jet recording apparatus described in Patent Document 1, when an image is printed by test printing or practical printing, defective ejection of a print head is automatically detected, and when an ejection defective nozzle of the print head is detected, automatically. A predetermined recovery operation is performed. However, with this configuration, for example, even when the user only wants to perform test printing regardless of print quality, the ejection failure nozzle detection operation of the print head is always automatically performed, and the ejection failure nozzle is detected. Then, a predetermined recovery operation is automatically performed. As described above, according to the technique of Patent Document 1, even when the user does not desire, the ejection failure nozzle detection and recovery operation may be performed, and the time until the end of printing becomes longer than necessary, or the ink is discharged. It will be wasted.

  An object of the present invention is to provide a printing system in which defective ejection nozzle detection and recovery operations that are not desired by a user are not performed.

  The printing system of the present invention includes a transport mechanism that transports a recording medium, a print head that discharges liquid toward the surface of the recording medium transported by the transport mechanism, the surface of the recording medium transported by the transport mechanism, or An image sensor capable of imaging a conveyance surface on which a recording medium is placed in the conveyance mechanism, a printing apparatus including a recovery mechanism for performing recovery processing of the print head, and detection of defective ejection of liquid from the print head A first storage means for storing automatic detection instruction data for selectively instructing whether or not the user desires to be automatically performed in a rewritable manner according to a user operation; and the first storage means A first determination is made as to whether or not to detect the ejection failure when the operation history of the printing device meets a first predetermined condition based on the automatic detection instruction data stored in A determination unit; a second determination unit that determines whether or not an operation history of the printing apparatus satisfies the first predetermined condition; and the first determination unit that does not detect the ejection failure. Sometimes, the first inquiry means for inquiring of the user whether or not the user desires to detect the discharge failure, and the discharge failure detection based on the user's response to the inquiry by the first inquiry means. A third determination means for determining whether or not to perform, the first determination means to determine that the ejection failure is detected, and the operation history of the printing apparatus is adapted to the first predetermined condition; and When the third determination means determines that the ejection failure detection is performed, the surface of the recording medium on which the image is recorded by the print head or the conveyance surface on which the image is recorded by the print head is photographed. The image sensor is controlled so as to form an image, and the presence or absence of liquid ejection failure from the print head based on image data obtained by the image sensor imaging the surface or the conveyance surface of the recording medium Detection control means for recognizing the user, and automatic recovery instruction data for selectively instructing whether or not the user wishes to automatically perform the recovery process of the print head in which the ejection failure has occurred, A liquid discharge failure from the print head has occurred based on the second storage means rewritable in response to the operation and the automatic recovery instruction data stored in the second storage means When the detection control means recognizes, the fourth determination means for determining whether or not to perform the recovery process, and when the fourth determination means determines that the recovery process is not performed A second inquiry means for inquiring of the user whether or not the user wishes to perform the recovery process; and whether or not to perform the recovery process based on a user response to the inquiry by the second inquiry means. A fifth determination means for determining, and when the fourth determination means determines that the recovery process is to be performed, and when the fifth determination means determines to perform the recovery process, Recovery control means for controlling the recovery mechanism so as to perform the recovery processing.

  According to the present invention, it is possible for the user to set whether or not the defective ejection of the liquid from the print head is automatically performed, and whether or not the recovery process for the print head in which the defective ejection has occurred is automatically performed. Whether or not the user can set whether or not the recovery process of the print head in which the ejection failure has occurred is not automatically performed. Since the user can select, an operation reflecting the user's intention can be expected. Therefore, ejection failure detection and recovery operations that are not desired by the user are not performed. Therefore, for example, in the case of printing a printed matter that does not cause a problem even if ejection failure occurs in the print head, if the recovery process is not performed, the time until the end of printing is shortened and the liquid is wasted. Unnecessary consumption can be suppressed.

  Further, when the image sensor is deteriorated due to an increase in the number of use and years of use of the printing apparatus, the detection accuracy of the defective ejection nozzle is lowered. In such a case, in a configuration in which a predetermined recovery operation is automatically performed when an ejection failure nozzle of the print head is detected, an unnecessary recovery operation may be performed due to erroneous detection, resulting in wasteful consumption of liquid. It becomes. On the other hand, according to the present invention, when the user determines that the detection accuracy of the ejection failure nozzle by the image sensor is lowered, the print head recovery process is performed only when the user determines that it is necessary. Therefore, it is possible to shorten the time until the end of printing and to suppress wasteful consumption of liquid.

  In the printing system of the present invention, when the fourth determination means determines that the recovery process is not performed, a sixth determination unit determines whether or not the operation history of the printing apparatus meets a second predetermined condition. And further comprising a determination unit, and when the sixth determination unit determines that the operation history of the printing apparatus meets the second predetermined condition, the second inquiry unit performs the recovery process. The recovery control means may control the recovery mechanism to perform the recovery process of the print head without inquiring of the user whether or not the user desires. As a result, even if the user does not wish to execute the recovery process for a long period of time, the recovery process is forcibly performed, so that it is possible to prevent the discharge failure of the print head from further worsening and becoming unrecoverable. Is possible.

  The second predetermined condition is that the number of times that the fifth determination unit continuously determines that the recovery process is not performed after the recovery process of the print head performed previously is a predetermined number of times or more. And the number of recording media recorded after the recovery process of the print head performed last time may be any of a second predetermined number or more. As a result, it is possible to prevent a situation in which printing is continued without performing the recovery process of the print head for a long period of time. Therefore, it is possible to prevent deterioration in print quality.

  The printing system according to the present invention further includes third storage means for storing either the number-of-times data indicating the predetermined number of times or the second number-of-sheets data indicating the second predetermined number of sheets in a rewritable manner according to a user operation. Furthermore, you may provide. Thereby, since the user can set the predetermined number of times or the second predetermined number, an operation reflecting the user's intention more precisely can be expected.

  The first predetermined condition may be that the number of recording media recorded after the previous ejection failure detection is equal to or more than the first predetermined number. As a result, it is possible to prevent a situation in which printing is continued without the user recognizing that a discharge failure has occurred in the print head. Therefore, it is possible to prevent deterioration in print quality.

  The printing system of the present invention may further include a fourth storage unit that stores the first sheet number data indicating the first predetermined number of sheets in a rewritable manner according to a user operation. Thereby, since the user can set the first predetermined number of sheets, an operation reflecting the user's intention more precisely can be expected.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<Schematic configuration of inkjet printer>
As shown in FIG. 1, a printing system 1 according to an embodiment of the present invention includes an inkjet printer 20 including a control unit 14 and a personal computer (PC) 15. The PC 15 has a display 16 and a mouse 17 (see FIG. 4) as a pointing device that is linked to a cursor displayed on the display 16. The control unit 14 and the PC 15 are connected to each other. The ink jet printer 20 is a color ink jet printer having four ink jet heads 2 that respectively eject magenta, cyan, yellow, and black ink. The ink jet printer 20 includes a paper feed mechanism 11 on the left side in FIG. 1 and a paper discharge unit 12 on the right side in FIG.

  Inside the inkjet printer 20, a paper conveyance path is formed through which a paper as a recording medium is conveyed from the paper supply mechanism 11 toward the paper discharge unit 12. The paper feed mechanism 11 is provided with a pickup roller 22. When the pickup roller 22 is rotated by the drive of the pickup motor, the uppermost sheet in the sheet tray 21 is fed out and sent from the left to the right in FIG. A paper transport mechanism is disposed at an intermediate portion of the paper transport path. The paper transport mechanism includes two belt rollers 6 and 7 and an endless transport belt 8 wound around the rollers 6 and 7.

  The outer peripheral surface 8a of the conveyor belt 8 is subjected to silicone treatment and has adhesiveness. A pressing roller 5 is disposed immediately downstream of the sheet feeding mechanism 11 at a position facing the conveying belt 8, and presses the sheet fed from the sheet feeding mechanism 11 against the outer peripheral surface 8 a of the conveying belt 8. Thus, the sheet pressed against the outer peripheral surface 8a is conveyed along the conveying direction B while being held by the adhesive force of the outer peripheral surface 8a. At this time, the belt roller 6 on the downstream side in the paper conveyance direction is given a driving force from the conveyance motor and is rotated clockwise (in the direction of arrow A) in FIG.

  A peeling plate 13 is provided immediately downstream of the conveying belt 8 along the sheet conveying path. The peeling plate 13 is configured to peel the paper held on the outer peripheral surface 8 a of the transport belt 8 from the outer peripheral surface 8 a and send it to the right paper discharge unit 12.

  A substantially rectangular parallelepiped platen 9 is disposed in a region surrounded by the conveyor belt 8. The platen 9 is in contact with the lower surface of the conveyor belt 8 at a position facing the inkjet head 2, that is, on the upper side, and supports the inner side of the conveyor belt 8. As shown in FIG. 1, a predetermined gap is formed between the upper surface of the conveyance belt 8 and the lower surface of the inkjet head 2 by the platen 9.

  FIG. 2 is a partial plan view of the ink jet printer 20. 3 is a cross-sectional view taken along line III-III depicted in FIG. As shown in FIG. 2, each of the four inkjet heads 2 extends in the main scanning direction (the direction perpendicular to the sub-scanning direction and perpendicular to the paper surface of FIG. 1), and the sub-scanning direction (conveyance) (Direction along direction B). That is, the ink jet printer 20 is a line printer in which an ejection area extending in the main scanning direction is formed. As shown in FIGS. 1 and 3, the inkjet head 2 has a head body 3 at the lower end thereof. The head body 3 includes a flow path unit in which a plurality of individual ink flow paths including pressure chambers are formed and an actuator that applies pressure to the ink in the pressure chamber, and has an elongated rectangular parallelepiped shape in the main scanning direction. Have. On the bottom surface of the head main body 3, that is, the discharge surface 3a, a large number of discharge ports having a small diameter, which is one end of the nozzle, are formed side by side.

  As shown in FIGS. 1 and 3, a reservoir unit 10 that temporarily stores ink is fixed to the upper surface of the head body 3. The reservoir unit 10 is longer than the head body 3 and protrudes from both longitudinal sides of the head body 3. In the protruding portion, the reservoir unit 10 is fixed to the frame 4 having a rectangular opening so that the discharge surface 3a is exposed downward from the opening. More specifically, a pair of flanges 4a that support the reservoir unit 10 from the lower side protrude from the opposite sides of the frame 4 toward the inside of the opening. The flange 4 a and both ends of the reservoir unit 10 in the longitudinal direction are fixed with screws 50. The discharge surface 3 a is almost the same height as the bottom surface of the frame 4.

  The head body 3 is parallel to the ejection surface 3a and the portion of the conveyor belt 8 supported by the platen 9 so as to face each other, and a slight gap is formed between the ejection surface 3a and the conveyor belt 8. Is arranged. The gap constitutes a part of the paper transport path. When the paper that is conveyed while being held on the outer peripheral surface 8a of the conveyance belt 8 sequentially passes immediately below the four head bodies 3, ink of each color is ejected toward the upper surface of the paper, that is, the printing surface. Thus, a desired color image is formed on the paper.

  In the present embodiment, an image sensor 201 is attached to the downstream side surface of the inkjet head 2 that is most downstream in the transport direction. Details of the image sensor 201 will be described later.

<Elevating mechanism>
As shown in FIGS. 2 and 3, the frame 4 is supported by a pair of lifting mechanisms 51 provided in the printer 20 so as to be movable in the vertical direction. The pair of lifting mechanisms 51 are arranged on both sides of the four inkjet heads 2 with respect to the sub-scanning direction. Each lifting mechanism 51 includes a head motor 52 as a drive source for moving the frame 4 in the vertical direction, a pinion gear 53 fixed to the shaft of the head motor 52, a rack gear 54 that meshes with the pinion gear 53, and the pinion gear 53. And a guide 56 disposed at a position sandwiching the rack gear 54.

  The head motors 52 included in the elevating mechanism 51 are respectively fixed to the pair of main body frames 1 a of the inkjet printer 20. The pair of body frames 1a are arranged to face each other in the sub-scanning direction. The rack gear 54 extends in the vertical direction, and the lower end thereof is fixed to the side surface of the frame 4. The side surface of the rack gear 54 opposite to the pinion gear 53 is slidably in contact with the guide 56. The guide 56 is fixed to the main body frame 1a.

  When the two head motors 52 are synchronized and the pinion gear 53 is rotated in the forward / reverse direction, the rack gear 54 moves upward or downward. As the rack gear 54 moves, the frame 4 moves up and down with the four inkjet heads 2 in the vertical direction.

  A pair of guide units 59 are disposed on both sides of the frame 4 extending in the sub-scanning direction. Each guide unit 59 includes a bar 58 and a pair of guides 57 sandwiching the bar 58. As shown in FIG. 3, the pair of guides 57 extend in the vertical direction and are respectively fixed to the pair of main body frames 1 b of the inkjet printer 20. The pair of main body frames 1b are arranged to face each other in the main scanning direction. The bar 58 extends in the vertical direction like the guide 57, and is fixed to the side surface of the frame 4 facing the main body frame 1b. The bar 58 is slidably in contact with each of the pair of guides 57.

  The guide unit 59 prevents the ejection surface 3a of the inkjet head 2 from being inclined with respect to the portion of the conveyor belt 8 supported by the platen 9 when the frame 4 is vertically moved by the lifting mechanism 51. That is, even when the frame 4 and the inkjet head 2 are moved up and down in the vertical direction by the lifting mechanism 51, the discharge surface 3 a is always parallel to the upper surface of the platen 9. As a result, the accuracy of ink landing on the paper is improved during printing.

  Usually, the frame 4 is moved by the elevating mechanism 51 and is disposed at a printing position (position shown in FIG. 3) where the four inkjet heads 2 eject ink onto the paper in order to print on the paper. The frame is used only during maintenance of the inkjet head 2 (when purging forcibly ejecting ink from the inkjet head 2, wiping off ink adhering to the ejection surface 3a, and covering the ejection surface 3a with a cap). 4 is moved in the direction of arrow C (upward in the vertical direction) in FIG. 3 by the elevating mechanism 51, and the four inkjet heads 2 are arranged at the head maintenance position above the printing position.

<Image sensor>
The image sensor 201 is attached to the downstream side surface of the inkjet head 2 that is the most downstream in the sub-scanning direction. Therefore, the image sensor 201 can move integrally with the frame 4 and the four inkjet heads 2 by driving the lifting mechanism 51. Since the image sensor 201 is disposed in the gap between the inkjet head 2 and the frame 4 which is the most downstream in the sub-scanning direction, the lower surface of the image sensor 201 is not obstructed by the frame 4 and the outer periphery of the conveyance belt 8. It faces the surface 8a. Further, the image sensor 201 is fixed at a position where the image sensor 201 is focused on the surface of the conveyance belt 8 or the surface of the paper on which the image is formed at the printing position.

  In the present embodiment, the image sensor 201 has an imaging range extending in the main scanning direction. That is, the image sensor 201 is a line type sensor. The imaging range of the image sensor 201 is the same as the printable range of the inkjet head 2 in the main scanning direction. As will be described later, the image sensor 201 recognizes the presence or absence of defective ejection of ink from the inkjet head 2 by capturing an image printed on the paper at the printing position (hereinafter referred to as ejection failure detection). Is used).

<Configuration of maintenance unit>
2 and 3, the maintenance unit 70 for performing the maintenance process, that is, the recovery process for the inkjet head 2 will be described. As shown in these drawings, the maintenance unit 70 is disposed on the left side (retracted position) of the inkjet head 2. The maintenance unit 70 has two trays 71 and 75 that can move horizontally. Among these, the tray 71 has a substantially square box shape opened upward, and includes the tray 75. The tray 71 and the tray 75 are engaged with a later-described concave portion 74b and a convex portion 83a, and when the engagement is released, the two are connected and the two are released. Can be switched.

  When the maintenance unit 70 moves horizontally to the right, the frame 4 moves to the upper head maintenance position (in the direction of arrow C in FIG. 3) in advance, and the maintenance unit is located between the four ejection surfaces 3 a and the conveyor belt 8. A space for 70 is secured. Thereafter, the maintenance unit 70 moves horizontally in the direction of arrow D (the direction along the main scanning direction) in FIG. When the side of the tray 71 far from the inkjet head 2 is opened, and the engagement between the concave portion 74b and the convex portion 83a is released (for example, during the purge operation), the tray 75 is left, leaving the tray 75 Only 71 moves horizontally to the right.

  A waste ink receiving tray 77 is disposed immediately below the retracted position of the maintenance unit 70. The waste ink receiving tray 77 has a size including the tray 71 in a plan view, and even when the tray 71 moves to the right end in FIG. 2, the edge of the tray 71 opposite to the inkjet head 2 overlaps. have. An ink discharge hole 77 a is formed at the end of the waste ink receiving tray 77 that is closer to the inkjet head 2. The ink discharge hole 77a distributes the ink that has flowed from the tray 71 onto the waste ink receiving tray 77 to a waste ink reservoir (not shown).

  In the tray 71, a wiper 72 and a tray 75 are arranged in order from the side close to the inkjet head 2. In the tray 75, four caps 76 having a rectangular planar shape are provided side by side corresponding to each inkjet head 2. Each cap 76 has a longitudinal direction parallel to the longitudinal direction (main scanning direction) of the inkjet head 2 and is arranged at the same pitch as the inkjet head 2 in the sub-scanning direction.

  The cap 76 includes a plate-like member 76b having a rectangular planar shape that is substantially the same size as the ejection surface 3a, and an annular protrusion 76a that protrudes upward from the peripheral edge of the plate-like member 76b. The annular protrusion 76a is made of an elastic material such as rubber, and has a size and a shape facing the peripheral edge of the discharge surface 3a. The cap 76 forms a sealed space when the annular protrusion 76a and the peripheral edge of the discharge surface 3a come into contact with each other. Thus, the cap 76 can cover the ejection surface 3a. Each cap 76 is biased upward while being supported on the bottom surface of the tray 75 by two springs (not shown).

  In addition to the wiper 72, a holding member 74 on which an attachment member 78 is disposed is fixed to the tray 71. The holding member 74 has a U-shaped planar shape. A groove 74a extending along the sub-scanning direction is formed on the upper surface of the portion of the holding member 74 along the sub-scanning direction. An attachment member 78 and a wiper 72 are disposed in the groove 74a. On the other hand, concave portions 74b are formed on the upper surfaces of the two portions extending from the holding member 74 in the main scanning direction.

  The wiper 72 is made of an elastic material such as rubber. The wiper 72 is formed slightly longer than the entire width of the four inkjet heads 2 arranged in parallel, and is fixed to the attachment member 78 so that the longitudinal direction thereof is along the sub-scanning direction. The attachment member 78 has a rectangular parallelepiped shape extending in the same direction as the wiper 72.

  In the vicinity of the left and right sides of the trays 71 and 75, a recess 74b and a hooking member 83 are provided. The hook member 83 extends in the main scanning direction and is rotatable at the center thereof. A convex portion 83 a is formed at the end of the hook member 83 that is closer to the inkjet head 2. When the hook member 83 rotates clockwise in FIG. 3, the convex portion 83a is engaged with the concave portion 74b. Above the maintenance unit 70, contact members 84 are arranged corresponding to the two hook members 83, respectively. The tray 71 and the tray 75 switch between a state in which the tray 71 and the tray 75 are connected and a state in which the connection between the tray 71 and the tray 75 is released depending on whether or not the concave portion 74b and the convex portion 83a are engaged. It is possible.

  The abutting member 84 is supported so as to be rotatable. When the abutting member 84 is rotated clockwise in FIG. 3, one end thereof abuts on the other end 83 b of the hooking member 83. When these contact members 84 are further rotated clockwise, the hook member 83 is rotated counterclockwise, and the engagement between the convex portion 83a and the concave portion 74b is released. On the other hand, when the contact member 84 rotates counterclockwise and moves away from the end portion 83b, the convex portion 83a engages with the concave portion 74b due to the weight of the hook member 83.

  When the maintenance of the inkjet head 2 is not performed, the maintenance unit 70 is stationary at a “retracted position” that does not face the inkjet head 2 as shown in FIGS. 2 and 3. When maintenance is performed, the maintenance unit 70 moves horizontally from the retracted position to the “maintenance position” facing the ejection surface 3 a of the inkjet head 2. At this time, since the frame 4 is disposed at the head maintenance position, the tips of the wiper 72 and the cap 76 do not contact the ejection surface 3a.

  Even during maintenance, during the purge operation, the tray 75 remains and only the tray 71 moves from the retracted position to the maintenance position and receives the discharged ink. When covering the discharge surface 3a with the cap 76, the tray 71 and the tray 75 are connected by the engagement of the concave portion 74b and the convex portion 83a, and the maintenance unit 70 moves to a position where the cap 76 and the discharge surface 3a face each other.

  Each tray 71, 75 is slidably supported by a pair of guide shafts 96a, 96b extending in the main scanning direction. The tray 71 is provided with two bearing members 97a and 97b. The bearing members 97a and 97b protrude from both side surfaces of the holding member 74 in the sub-scanning direction. The tray 75 is provided with two bearing members 98a and 98b. The bearing members 98a and 98b protrude from both side surfaces of the tray 75 in the sub-scanning direction. Further, both ends of the pair of guide shafts 96a and 96b are fixed to the main body frames 1b and 1d, and are disposed parallel to each other between the frames 1b and 1d.

  Here, a horizontal movement mechanism 91 that moves the trays 71 and 75 in the horizontal direction (arrow D direction) along the guide shafts 96a and 96b will be described. As shown in FIG. 2, the horizontal movement mechanism 91 includes a tray motor 92, a motor pulley 93, an idle pulley 94, a timing belt 95, guide shafts 96a and 96b, and the like.

  The tray motor 92 is fixed to an attachment portion 1c formed at an end portion of the main body frame 1b extending in parallel with the sub-scanning direction. The motor pulley 93 is connected to the tray motor 92 and rotates as the tray motor 92 is driven. The idle pulley 94 is rotatably supported by the leftmost main body frame 1d in FIG. The timing belt 95 is disposed in parallel with the guide shaft 96 a and is wound so as to be bridged between the motor pulley 93 and the idle pulley 94. Further, the timing belt 95 is connected to a bearing member 97 a provided on the holding member 74.

  In this configuration, when the tray motor 92 is driven, the timing belt 95 travels as the motor pulley 93 rotates in the forward or reverse direction. As the timing belt 95 travels, the tray 71 connected to the timing belt 95 via the bearing 97a moves along the horizontal direction. When the concave portion 74b of the holding member 74 and the convex portion 83a are engaged, the wiper 72 in the tray 71 and the cap 76 in the tray 75 move together. On the other hand, when the convex portion 83a is not engaged with the concave portion 74b, only the wiper 72 in the tray 71 moves.

<Control system>
Next, the control system of the printing system 1 will be described with reference to FIG. The control unit 14 of the printer 20 includes a CPU (Central Processing Unit) that is an arithmetic processing device, a control program executed by the CPU, and a ROM (Read Only Memory) that stores data used for the control program, and program execution Sometimes it has RAM (Random Access Memory) for temporarily storing data. These function as a detection control unit 32, a recovery control unit 33, a display control unit 34, and the like. An operation button 18 and an LED (light emitting diode) 19 are connected to the control unit 14.

  The detection control unit 32 controls the image sensor 201 to capture a test image printed on a sheet by the inkjet head 2 or a test image printed on the conveyance surface 8a of the conveyance belt 8 when a predetermined condition is satisfied. At the same time, the image sensor 201 recognizes the presence or absence of ink ejection failure from the inkjet head 2 based on the image data obtained by capturing the image. The predetermined condition regarding the detection control unit 32 will be described later.

  The recovery control unit 33 controls the maintenance unit 70 to perform the recovery process of the inkjet head 2 when a predetermined condition is satisfied. The predetermined condition regarding the recovery control unit 33 will be described later.

  The display control unit 34 controls the LED 19 so that the LED 19 lights up or blinks when a predetermined condition is satisfied. The predetermined condition for turning on the LED 19 is different from the predetermined condition for blinking. The predetermined condition regarding the display control unit 34 will be described later. The display control unit 34 and the LED 19 constitute first and second inquiry means.

  When the LED 19 is lit, the user can press the operation button 18 and give a command to the printing system 1 as to whether or not ejection failure detection processing is desired. Similarly, when the LED 19 blinks, the user can press the operation button 18 to give a command to the printing system 1 as to whether or not a recovery process is desired.

  The PC 15 is a CPU (Central Processing Unit) that is an arithmetic processing unit, a ROM (Read Only Memory) and a hard disk that store a control program executed by the CPU and data used in the control program, and data when the program is executed. RAM (Random Access Memory) for temporary storage. These function as the storage unit 41, the determination unit 42, the display control unit 43, and the like.

  The storage unit 41 stores sheet number data indicating the number of printed sheets P after the previous ejection failure detection, number data indicating the number of printed sheets T after the previous recovery process, number data indicating the predetermined number Pth, and predetermined number Tth. The indicated number data is stored. Furthermore, the storage unit 41 has automatic detection instruction data for selectively instructing whether or not the user desires that the ejection failure detection of the ink from the inkjet head 2 is automatically performed, and ejection failure has occurred. The automatic recovery instruction data for selectively instructing whether or not the user desires that the recovery process of the inkjet head 2 is automatically performed is stored. The number data indicating the number of printed sheets P and the number data indicating the number of printed sheets T are incremented by 1 each time printing is performed, and are initialized to zero when ejection failure detection and recovery processing are performed. The other storage contents of the storage unit 41 are stored by operating the input device (for example, by operating the mouse 17 to click a control such as a list box displayed on the display 16 or operating a keyboard (not shown)). The user can write and rewrite.

  The determination unit 42 automatically discharges when the operation history of the inkjet printer 20 meets the first predetermined history condition, that is, when the number of printed sheets P after the previous discharge failure detection is equal to or greater than the predetermined number Pth. Whether or not to perform defect detection is determined based on the automatic detection instruction data stored in the storage unit 41. In addition, when the determination unit 42 determines that the ejection failure is automatically detected, the determination unit 42 determines whether or not the operation history of the ink jet printer 20 meets the first predetermined history condition. Note that the determination unit 42 determines whether or not the ejection failure is automatically detected only when the operation history of the inkjet printer 20 conforms to the first predetermined history condition and then conforms to the first predetermined history condition. This may be determined based on the automatic detection instruction data.

  In addition, when the determination unit 42 determines not to perform discharge failure detection, the determination unit 42 determines whether or not the user desires to perform discharge failure detection. This determination is made by inquiring to the user whether or not it is desired to perform ejection failure detection (lighting of the LED 19 and display of an ejection failure detection processing inquiry image (see FIG. 6) on the display 16 as will be described later). ) Based on the user's response.

  Further, when the detection control unit 32 recognizes that a defective ejection of ink from the inkjet head 2 has occurred, the determination unit 42 determines whether or not to perform the recovery process, and the automatic recovery stored in the storage unit 41. Judgment is made based on the instruction data.

  In addition, when the determination unit 42 determines that the recovery process is not performed when the detection control unit 32 recognizes that the ink ejection failure from the inkjet head 2 has occurred, the operation history of the inkjet printer 20 is recorded. It is determined whether or not the second predetermined history condition is met. Here, the second predetermined history condition is that the number of printed sheets T after the previous recovery process is equal to or greater than the predetermined number Tth. As a modification, the second predetermined history condition is that the number of times R that the determination unit 42 continuously determines that the recovery process is not performed because the user does not desire after the previously performed recovery process is equal to or greater than the predetermined number Rth. It may be that. In this case, instead of adding the number N of prints to the number T of prints, which will be described later, the number of times R determined by the determination unit 42 not to perform the recovery process after the previous recovery process is incremented by one. Similarly to the predetermined number Tth, the predetermined number of times Rth can be written and rewritten to the storage unit 41 by the user.

  Finally, when the determination unit 42 determines that the operation history of the inkjet printer 20 does not meet the second predetermined history condition, the determination unit 42 determines whether the user desires to perform the recovery process. This determination is based on the user's response to an inquiry to the user as to whether or not the recovery process is desired (which is performed by blinking the LED 19 and displaying a recovery process inquiry image (see FIG. 7) on the display 16 as will be described later). Based on.

  The display control unit 43 controls the display 16 so that the ejection failure detection inquiry image shown in FIG. 6 or the recovery process inquiry image shown in FIG. 7 is displayed on the display 16 when a predetermined condition is satisfied. Here, the predetermined condition for displaying the ejection failure detection inquiry image is that determination is made based on automatic detection instruction data unless ejection failure detection is automatically performed. On the other hand, the predetermined condition for displaying the recovery process inquiry image is that it is determined that the operation history of the inkjet printer 20 does not match the second predetermined history condition. The display control unit 43 and the display 16 constitute first and second inquiry means separately from the display control unit 34 and the LED 19.

  The predetermined condition for turning on the LED 19 is the same as the predetermined condition for displaying the ejection failure detection inquiry image, and the predetermined condition for causing the LED 19 to blink is the predetermined condition for displaying the recovery process inquiry image. Is the same. That is, the lighting of the LED 19 and the display of the ejection failure detection processing inquiry image on the display 16 are performed simultaneously, and the blinking of the LED 19 and the display of the recovery processing inquiry image on the display 16 are also performed simultaneously.

  When the ejection failure detection processing inquiry image is displayed on the display 16, the user clicks the YES button or the NO button on the screen with the mouse 17 to instruct the printing system 1 whether or not the ejection failure detection processing is desired. It is possible to give. Similarly, when the recovery process inquiry image is displayed on the display 16, the user clicks the YES button or the NO button on the screen with the mouse 17, and gives an instruction to the printing system 1 as to whether or not the recovery process is desired. It is possible.

  The predetermined condition regarding the detection control unit 32 described above is that the determination unit 42 determines that ejection failure detection is performed based on the automatic detection instruction data, and the operation history of the inkjet printer 20 matches the first predetermined history condition. The determination unit 42 determines that the user has determined that the user has detected the discharge failure, or the determination unit 42 determines that the user desires to perform ejection failure detection. The predetermined condition regarding the recovery control unit 33 is that the determination unit 42 determines that the recovery process is performed based on the automatic recovery instruction data, and the determination unit 42 that the user desires to perform the recovery process. Is one of the judgments.

<Printer operation>
Next, the operation of the printing system 1 according to the present embodiment will be described with reference to the flowchart shown in FIG. The control unit 14 that has started the operation first waits in step S1 to receive a print command including print data (N continuous prints, where N is a natural number of 1 or more) from the PC 15 or other device. To do. When a printing command is received (S1: YES), whether or not ejection failure detection is automatically performed when the number of printed sheets P after the previous ejection failure detection is equal to or greater than the predetermined number Pth in step S2. Is determined based on the automatic detection instruction data stored in the storage unit 41. That is, if the automatic detection instruction data set by the user indicates that the ejection failure detection is automatically performed, it is determined that the ejection failure detection is automatically performed, and the automatic detection instruction data set by the user is If it is not instructed that the ejection failure detection be performed automatically, it is determined that the ejection failure detection is not automatically performed. If it is determined that the ejection failure is not automatically detected (S2: NO), the process proceeds to step S3. If it is determined that the ejection failure is automatically detected (S2: YES), the process proceeds to step S4.

  In step S3, the display control unit 34 controls the display 16 so that the LED 19 is turned on and the display control unit 43 displays the ejection failure detection processing inquiry image shown in FIG. This corresponds to an inquiry to the user regarding whether or not it is desired to perform ejection failure detection. Then, the determination unit 42 determines whether or not to detect ejection failure based on a user response to the inquiry (for example, pressing of an operation button or clicking with a mouse button). If it is determined that ejection failure detection is to be performed (S3: YES), the process proceeds to step S5. If it is determined that the ejection failure detection is not performed (S3: NO), the process proceeds to step S14.

  In step S <b> 4, it is determined whether or not the number of printed sheets P after the previous ejection failure detection is equal to or greater than the predetermined number Pth stored in the storage unit 41. If the number of printed sheets P is equal to or greater than the predetermined number Pth (S4: YES), the process proceeds to step S5. If the predetermined number Pth is not exceeded (S4: NO), the process proceeds to step S14.

  In step S5, the detection control unit 32 controls the image sensor 201 so as to capture a test image printed by the ink ejected from the inkjet head 2 onto the paper, and the image sensor 201 captures the image. Based on the obtained image data, the presence / absence of ink ejection failure (including non-ejection and ejection direction and ejection amount abnormality) from the inkjet head 2 is recognized (in other words, ejection failure detection is performed). Then, the process proceeds to step S6. In step S6, the number of printed sheets P after the previous ejection failure detection is set to 0 and initialized. Then, the process proceeds to step S7.

  In step S <b> 7, the detection control unit 32 determines whether or not the detection control unit 32 has recognized that a discharge failure of the ink from the inkjet head 2 has occurred as a result of performing the discharge failure detection in step S <b> 5. If a discharge failure is recognized (S7: YES), the process proceeds to step S8. If not recognized (S7: NO), the process proceeds to step S14.

  In step S <b> 8, the determination unit 42 determines whether or not to perform recovery processing based on the automatic recovery instruction data stored in the storage unit 41. That is, if the automatic recovery instruction data set by the user indicates that the recovery process of the inkjet head 2 in which the ejection failure has occurred is automatically performed, it is determined that the recovery process is performed, and the user sets If the automatic recovery instruction data does not indicate that the recovery process of the inkjet head 2 in which ejection failure has occurred is automatically performed, it is determined that the recovery process is not performed. If it is determined that the recovery process is to be performed (S8: YES), the process proceeds to step S12. If it is determined not to perform the recovery process (S8: NO), the process proceeds to step S9.

  In step S <b> 9, the determination unit 42 determines whether the number of printed sheets T after the previous recovery process is equal to or greater than the predetermined number Tth stored in the storage unit 41. When the number of printed sheets T after the previous recovery process is equal to or greater than the predetermined number Tth stored in the storage unit 41 (S9: YES), the process proceeds to step S12. If it is not equal to or greater than the predetermined number Tth (S9: NO), the process proceeds to step S10.

  In step S10, the display control unit 34 causes the LED 19 to blink, and at the same time, the display control unit 43 controls the display 16 so that the recovery processing inquiry image shown in FIG. 7 is displayed. This corresponds to an inquiry to the user as to whether or not he / she wishes to perform a recovery process. Then, the determination unit 42 determines whether or not to perform the recovery process based on a user response to the inquiry (for example, pressing of an operation button or clicking with a mouse button). When it is determined that the recovery process is to be performed (S10: YES), the process proceeds to step S12. If it is determined not to perform the recovery process (S10: NO), the process proceeds to step S11.

  In step S11, the number N of prints designated by the print command received in step S1 is added to the number of prints T after the previous recovery process. Then, the process proceeds to step S14.

  In step S12, the recovery control unit 33 controls the maintenance unit 70 to perform the recovery process. And after completion | finish of a recovery process, it progresses to step S13. In step S13, the number of printed sheets T after the previous recovery process is initialized to zero. Then, the process proceeds to step S14.

  Here, the recovery process (that is, maintenance) of the head 2 performed in step S12 will be described below with reference to FIGS. 8 (a) and 8 (b). FIG. 8A is a side view when the frame 4 is moved from the printing position to the head maintenance position, and the tray 71 of the maintenance unit 70 is moved to the maintenance position. FIG. 8B is a side view when the ink attached to the ejection surface 3 a is wiped by the wiper 72.

  When performing a purge operation for recovering the inkjet head 2 that has fallen into a defective discharge, the elevating mechanism 51 moves the frame 4 to the head maintenance position. At this time, the two drive motors 52 are driven in synchronism, and each pinion gear 53 is rotated in the forward direction (clockwise direction in FIG. 3). Then, the rack gear 54 moves upward as the pinion gear 53 rotates. The frame 4 fixed to the rack gear 54 moves upward together with the four inkjet heads 2. When the frame 4 reaches the head maintenance position, the rotation of the drive motor 52 is stopped.

  Thus, a space in which the maintenance unit 70 can be disposed is formed between the ejection surface 3a and the conveyor belt 8. Thus, when the frame 4 is in the head maintenance position, the ejection surface 3a of the inkjet head 2 and the bottom surface of the frame 4 contact the tips of the wiper 72 and the annular protrusion 76a when the maintenance unit 70 moves to the maintenance position. It is in a position that does not.

  Next, the contact member 84 is brought into contact with the end portion 83b of the hooking member 83 to separate the convex portion 83a from the concave portion 74b, and the engagement between the concave portion 74b and the convex portion 83a is released. That is, the connection between the tray 71 and the tray 75 is released. In this state, the timing belt 95 is caused to travel by driving the tray motor 92 of the horizontal movement mechanism 91 so as to move the tray 71 to the maintenance position. Then, as shown in FIG. 8A, the driving of the motor 92 is stopped when the tray 71 reaches the maintenance position.

  Subsequently, a pump (not shown) that forcibly sends the ink in the ink tank to the inkjet head 2 is driven, and a purge operation for discharging ink from the nozzles of the inkjet head 2 into the tray 71 is performed. By this purging operation, the clogging of the nozzle that has caused the ejection failure and the thickening of the ink in the nozzle are eliminated. The ink ejected into the tray 71 moves to the left side in FIG. 8A along the bottom surface of the tray 71 and flows into the waste ink receiving tray 77. Then, the purged ink is discharged from the ink discharge hole 77a of the waste ink receiving tray 77. However, some ink remains as ink droplets on the ejection surface 3a.

  Thereafter, the inkjet head 2 is moved downward by the lifting mechanism 51. At this time, the height of the inkjet head 2 is set such that the tip of the wiper 72 can come into contact with the ejection surface 3 a and the lower surface of the frame 4 when the tray 71 moves to the left side (that is, the retracted position). Then, as shown in FIG. 8B, the tray 71 is moved to the left by the horizontal movement mechanism 91 (that is, the tray 71 is moved from the maintenance position to the retracted position).

  By this operation, the wiper 72 moves in the wiping direction from right to left in FIG. 8B, and the wiping operation of the ejection surface 3a by the wiper 72 is performed. At this time, since the upper end of the wiper 72 is above the lower surface of the frame 4, the wiper 72 comes into contact with the lower surface of the frame 4 and the ejection surface 3 a while being bent, and wipes off ink adhering to the ejection surface 3 a by purging. By executing the series of maintenance operations described above, the ejection failure can be recovered to a normal state.

  In step S14, N consecutive prints designated by the print command received in step S1 are performed. Then, the process proceeds to step S15. In step S15, the number N of prints designated by the print command received in step S1 is added to the number of prints P after the previous ejection failure detection. Then, the process returns to step S1.

  According to the present embodiment described above, the user can set whether or not the ejection failure detection of the ink from the inkjet head 2 is automatically performed, and the recovery process of the inkjet head 2 in which the ejection failure has occurred. The user can set whether or not the ink jetting is automatically performed, and the inkjet head 2 in which the ejection failure has occurred when the recovery process of the inkjet head 2 in which the ejection failure has occurred is not automatically performed. Since the user can select whether or not to perform the recovery process, an operation reflecting the user's intention can be expected. Therefore, ejection failure detection and recovery operations that are not desired by the user are not performed. Therefore, for example, in the case of printing a printed matter that does not cause a problem even if ejection failure occurs in the inkjet head 2, if the recovery process is not performed, the time until the end of printing can be shortened, and the ink It is possible to suppress wasteful consumption.

  In addition, when the image sensor 201 is deteriorated due to an increase in the number of use and years of use of the printer 20, the detection accuracy of defective ejection nozzles is lowered. In such a case, in a configuration in which a predetermined recovery operation is automatically performed when an ejection failure nozzle of the inkjet head 2 is detected, an unnecessary recovery operation may be performed due to erroneous detection, and ink is wasted. It will be. On the other hand, according to the present embodiment, when the user determines that the detection accuracy of the ejection failure nozzle by the image sensor 201 is lowered, the ink jet head 2 is only used when the user determines that it is necessary. Since the recovery process can be performed, it is possible to shorten the time until the end of printing and to suppress wasteful consumption of ink.

  In addition, when the user has set so that the ejection failure detection is automatically performed, the ejection failure detection is automatically performed when the number of printed sheets P after the previous ejection failure detection is equal to or greater than the predetermined number Pth. Therefore, it is possible to prevent a situation in which printing is continued without the user recognizing that an ejection failure has occurred in the inkjet head 2. Therefore, it is possible to prevent deterioration in print quality.

  Furthermore, since the user can set and change the predetermined number Pth in advance, an operation reflecting the user's intention more precisely can be expected.

  In step S9, it is determined whether the number of printed sheets T after the previous recovery process is equal to or greater than the predetermined number Tth. If the number Tth is equal to or greater than the predetermined number Tth, the recovery process is forcibly performed. Therefore, even if the user does not wish to execute the recovery process for a long period of time, the recovery process is forcibly performed. Therefore, it is possible to prevent a situation in which printing is continued without performing the recovery process of the inkjet head 2. Therefore, it is possible to prevent the deterioration of the print quality and to prevent the discharge failure from further worsening and becoming unrecoverable.

  Furthermore, since the user can write and rewrite either the predetermined number Tth or the predetermined number Rth, an operation reflecting the user's intention more precisely can be expected.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made to the above-described embodiments as long as they are described in the claims. It is possible to apply. For example, the stored contents (other than the number of printed sheets P and T) stored in the storage unit 41 can be set using a touch panel or a keyboard, or set by the operation button 18 instead of being set by the user operating the mouse 17. It may be configured to. In step S3, the display control unit 34 controls the LED 19 so that the LED 19 is lit or whether the discharge failure detection process is performed on the display 16 in order to inquire the user whether or not it is desired to detect the discharge failure. The display control unit 43 may control only the display 16 so that the inquiry image is displayed, or may be configured to inquire the user by voice instead of the LED 19 and the display 16. Good. The same applies to step S10.

  In the embodiment described above, the printing system is configured by the printer 20 and the PC 15, but the printing system may be configured by only the printer 20. That is, all the components of the printing system according to the present invention (including the storage unit 41, the determination unit 42, and the display control unit 43 shown in FIG. 4) may be built in the printer 20. Of the components of the printing system according to the present invention, the storage unit 41 may be built in the printer 20. In addition, components other than the printing device may be built in one or a plurality of devices other than the printing device. The recovery mechanism is not limited to that described in the embodiment, and may be a mechanism that performs only the wiping operation of the discharge surface 3a by the wiper 72, or may be another known recovery mechanism.

1 is a diagram illustrating a printing system according to an embodiment of the present invention. FIG. 2 is a partial plan view of the ink jet printer depicted in FIG. 1. It is sectional drawing along the III-III line | wire shown in FIG. 1 is a block diagram of a printing system according to an embodiment of the present invention. 2 is a flowchart showing an operation of the printing system depicted in FIG. 1. It is an example of a display display for inquiring of a user whether or not it is desired to perform ejection failure detection. It is an example of a display display for inquiring of the user whether or not it is desired to perform the recovery process of the inkjet head. FIG. 3 is a side view for explaining a maintenance operation in the ink jet printer depicted in FIG. 1.

Explanation of symbols

1 Printing system 2 Inkjet head (printing head)
3 Head body 3a Discharge surface 4 Frame 8 Conveying belt 8a Outer peripheral surface 14 Control unit 15 PC
16 Display (part of the first and second inquiry means)
18 Operation buttons 19 LED (part of the first and second inquiry means)
20 Inkjet printer (printing device)
32 Detection control unit (detection control means)
33 Recovery control unit (recovery control means)
34 Display control unit (part of the first and second inquiry means)
41 memory | storage part (1st-4th memory | storage means)
42 determination section (first to sixth determination means)
43 Display controller (part of the first and second inquiry means)
51 Elevating mechanism 201 Image sensor

Claims (6)

A transport mechanism that transports a recording medium, a print head that discharges liquid toward the surface of the recording medium transported by the transport mechanism, a surface of the recording medium transported by the transport mechanism, or a recording medium in the transport mechanism An image sensor capable of imaging the transport surface to be mounted, and a printing apparatus including a recovery mechanism for performing recovery processing of the print head;
Automatic detection instruction data for selectively instructing whether or not the user wishes to automatically detect defective discharge of liquid from the print head is stored in a rewritable manner according to a user operation. Storage means,
Based on the automatic detection instruction data stored in the first storage means, a first determination is made as to whether or not to detect the ejection failure when the operation history of the printing apparatus meets a first predetermined condition. Means of judging,
Second determination means for determining whether or not an operation history of the printing apparatus meets the first predetermined condition;
First inquiry means for inquiring of the user whether or not the user desires to perform the discharge defect detection when the first determination means determines not to perform the discharge defect detection;
Third determination means for determining whether to perform the ejection failure detection based on a user response to the inquiry by the first inquiry means;
When the discharge failure detection is performed, the first determination unit determines, and when the operation history of the printing apparatus meets the first predetermined condition, and when the discharge failure detection is performed, the third determination unit. The image sensor is controlled to take an image of the surface of the recording medium on which an image is recorded by the print head or the transport surface of the transport mechanism, and the image sensor controls the surface of the recording medium. Or detection control means for recognizing the presence or absence of liquid ejection failure from the print head based on image data obtained by imaging the transport surface;
Automatic recovery instruction data for selectively instructing whether or not the user wishes to automatically perform the recovery process of the print head in which the ejection failure has occurred can be rewritten according to a user operation Second storage means for storing;
Whether or not to perform the recovery process when the detection control unit recognizes that a liquid ejection failure from the print head has occurred based on the automatic recovery instruction data stored in the second storage unit A fourth determination means for determining whether or not
Second inquiry means for inquiring of the user whether or not the user desires to perform the recovery process when the fourth determination means determines not to perform the recovery process;
Fifth determination means for determining whether or not to perform the recovery processing based on a user response to the inquiry by the second inquiry means;
The recovery is performed so that the recovery process of the print head is performed when the fourth determination unit determines that the recovery process is performed and when the fifth determination unit determines that the recovery process is performed. A printing system comprising a recovery control means for controlling the mechanism. When the fourth determination means determines not to perform the recovery process, the printer further includes sixth determination means for determining whether or not the operation history of the printing apparatus meets a second predetermined condition. ,
Whether or not the second inquiring means wants the user to perform the recovery process when the sixth determining means determines that the operation history of the printing apparatus meets the second predetermined condition 2. The printing system according to claim 1, wherein the recovery control unit controls the recovery mechanism to perform the recovery process of the print head without inquiring of the user.   The second predetermined condition is that the number of times that the fifth determination unit continuously determines that the recovery process is not performed after the recovery process of the print head performed previously is a predetermined number of times or more. 3. The printing according to claim 2, wherein the number of recording media recorded after the recovery process of the print head performed last time is equal to or more than a second predetermined number. system.   The apparatus further comprises third storage means for storing any one of the number-of-times data indicating the predetermined number of times and the second number-of-sheets data indicating the second predetermined number of sheets in a rewritable manner according to a user operation. The printing system according to claim 3.   The first predetermined condition is that the number of recording media recorded after the previous ejection failure detection is equal to or more than the first predetermined number. The printing system described in Crab. 6. The printing system according to claim 5, further comprising a fourth storage unit that stores the first sheet number data indicating the first predetermined number of sheets in a rewritable manner according to a user operation.

Images