JP4816155B2 - Head maintenance method, head maintenance mechanism, printer, and printer system - Google Patents

Description

  The present invention relates to a head maintenance method, a head maintenance mechanism, a printer, and a printer system that maintain a print head having ink nozzles that can eject ink liquid by a cleaning operation.

As an apparatus including a print head having an ink nozzle capable of ejecting an ink liquid, an ink jet printer that performs desired printing on a print medium by ejecting the ink liquid from the ink nozzle can be given.
In such an ink jet printer, when the ink liquid is not ejected from the ink nozzles in a standby state or the like for a certain period of time or longer, the water that is the solvent of the ink liquid evaporates and the viscosity of the ink liquid in the ink nozzle increases. Furthermore, the ink nozzle is clogged, and the ink liquid may not be ejected, or even if it is ejected, the ink liquid may not be the original size or speed, and printing defects may occur (hereinafter referred to as dot missing). ).
Further, depending on the use state of the print head, for example, when the reciprocating movement of the print head is repeatedly performed, the ink meniscus in each ink nozzle may be broken, and as a result, missing dots may occur.

For this reason, in the ink jet printer, when the print head is retracted to the standby position, the ink nozzle of the print head is covered with a cap to prevent an increase in the viscosity of the ink liquid in the ink nozzle.
However, simply covering the print head with a cap during standby or the like cannot prevent an increase in the viscosity of the ink liquid in the ink nozzles when the printing process is not performed over a long period of time. In addition, when the printing process is continuously performed for a long time, the ink meniscus in the ink nozzle may be broken during printing and dot missing may occur.
Therefore, the ink jet printer is provided with a cleaning mechanism that forcibly removes the ink liquid whose viscosity has increased in the ink nozzle or recovers the ink meniscus from being broken.

  The cleaning operation performed by such a cleaning mechanism includes a flushing operation for ejecting ink liquid from the ink nozzle, and an ink suction pump connected to the cap side is driven to suck the ink liquid remaining in the print head. By carrying out for a certain period of time, there is a suction and discharge operation that removes the thickened ink and bubbles in the ink nozzle to the outside and simultaneously supplies a new ink liquid to each ink nozzle. In general, the suction and discharge operation is an operation that requires a longer time than the flushing operation that is a minor cleaning operation.

  In a conventional inkjet printer, the type of cleaning operation is selected according to the elapsed time from the previous cleaning operation at the timing when printing is started, that is, when image data necessary for one scan is accumulated in the print buffer. It is widely known that a print head is cleaned by a selected cleaning operation (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-103802

  By the way, in a conventional printer such as the above-mentioned Patent Document 1, the cleaning operation is performed at the timing immediately before the start of printing. However, the time for actually starting the printing is delayed by the time required for the cleaning operation, and the printing ends. It took a long time to wait, that is, a situation where the throughput was lowered. In particular, when the cleaning operation by the suction and discharge operation is performed, the waiting time until the start of printing is remarkably increased.

  For example, in a printer that prints a coupon issued to a customer at a supermarket cash register or the like, it takes a long time to hand over the coupon to the customer if the cleaning operation by the suction discharge operation is performed before printing. In addition to waiting for the customer, the time required for each customer at the cash register becomes longer, and the efficiency of the cash register work is reduced.

  Therefore, an object of the present invention is to reduce the waiting time at the start of printing by the cleaning operation as much as possible when the cleaning operation is performed on the print head before the start of printing according to the elapsed time from the previous cleaning operation. A head maintenance method, a head maintenance mechanism, a printer, and a printer system.

A head maintenance method according to the present invention capable of solving the above-described problems includes a suction discharge operation for sucking and discharging ink liquid from the ink nozzle to a print head having ink nozzles capable of discharging ink liquid. A head maintenance method in which a cleaning operation is performed before the start of printing in a state where a predetermined time has elapsed since the last cleaning operation was completed,
When an apparatus provided with the print head receives a command periodically received at a predetermined time when the store where the apparatus is installed is out of business hours, the elapsed time since the last cleaning operation was completed It is determined whether or not a determination time set before a predetermined time is reached, and if it is determined that the determination time is exceeded, the cleaning operation is performed.

In addition, a head maintenance mechanism according to the present invention that can solve the above-described problems includes a cleaning mechanism for cleaning a print head having an ink nozzle capable of discharging an ink liquid;
A suction discharge mode drive control circuit for causing the cleaning mechanism to perform a cleaning operation including a suction discharge operation for sucking and discharging ink liquid from the ink nozzle;
A cleaning end timer for measuring an elapsed time from the end of the previous cleaning operation;
An apparatus that is set to activate the suction discharge mode drive control circuit before the start of printing in a state in which the measurement time by the cleaning end timer has passed for a predetermined time, and that includes the print head , when the apparatus is installed shop receives regularly receive instruction at any given time is outside business hours, whether the measured time has become a predetermined time set determination time or more before the And a control unit that is set to activate the suction / discharge mode drive control circuit when it is determined that the time is equal to or longer than the determination time.

  In these head maintenance methods and head maintenance mechanisms, when a predetermined time has elapsed since the end of the previous cleaning operation, a cleaning operation including a suction discharge operation is performed before the start of printing. Further, when the apparatus having the print head receives a command to be received periodically, the elapsed time from the end of the previous cleaning operation is equal to or longer than the determination time set to the time before the predetermined time. If it is longer than the determination time, a cleaning operation is performed. Therefore, when the command is received in a state where the determination time has elapsed since the end of the previous cleaning operation, the cleaning operation is performed without waiting for the next printing start timing, and a predetermined time elapses from the end of the cleaning operation. If it is before, the cleaning operation is not performed at the start of the next printing. That is, even if the state in which the printing operation is not performed continues, the cleaning operation is performed before a predetermined time elapses with a command received periodically as a trigger, and the cleaning operation at the start of printing is not performed. Therefore, it is possible to avoid delaying the timing of actually starting printing by performing the cleaning operation at the start of printing, and the waiting time until the end of printing is reduced, thereby improving the throughput. Further, since the cleaning operation is performed almost every time the determination time elapses, the ink nozzle can be maintained in a good state.

  In the head maintenance method according to the aspect of the invention, it is preferable that the determination time is set to a time before a predetermined interval for receiving the command with respect to the predetermined time.

  In the head maintenance mechanism according to the aspect of the invention, it is preferable that the determination time is set to a time before a predetermined interval for receiving the command with respect to the predetermined time.

  According to these head maintenance methods and head maintenance mechanisms, a regular command is always received after the determination time elapses until the predetermined time elapses, so that the cleaning must be performed before the predetermined time elapses. Since the operation is performed, it is possible to more reliably avoid the cleaning operation before starting printing.

  In the head maintenance method of the present invention, when the elapsed time is determined to be equal to or longer than the determination time, and the cumulative number of cleaning operations is a multiple of a predetermined number, a stronger cleaning operation is performed than when it is not a multiple. It is preferable.

  In the head maintenance mechanism of the present invention, the head maintenance mechanism includes a cleaning cumulative counter that counts the cumulative number of times the suction discharge mode drive control circuit is activated, and the control unit determines that the measurement time is equal to or greater than the determination time, When the cumulative count of the cleaning cumulative counter is a multiple of a predetermined number, it is preferable to provide the suction discharge mode drive control circuit with a stronger cleaning operation setting than when the cumulative count is not a multiple.

  According to these head maintenance methods and head maintenance mechanisms, when the cleaning operation is performed when the command is received and the determination time is exceeded, as described above, when a multiple of a predetermined number, that is, every predetermined number of times, The cleaning operation is stronger than in other cases. Therefore, normally, the ink nozzle state is maintained by performing a moderately strong cleaning operation while suppressing ink consumption, and the ink nozzle state is reset by performing a strong cleaning operation every predetermined number of times. Thus, the ink nozzle can be maintained in a good state.

  In the head maintenance method of the present invention, it is preferable that the strength of the cleaning operation is determined according to the remaining amount of ink supplied to the print head.

  In the head maintenance mechanism of the present invention, it is preferable that the setting of the strength of the cleaning operation to be given to the suction / discharge mode drive control circuit is determined according to the remaining amount of ink supplied to the print head.

  According to these head maintenance methods and head maintenance mechanisms, it is possible to perform a cleaning operation with an optimum strength so that the ink supplied to the print head is not used up.

  In addition, a printer according to the present invention that can solve the above-described problems is characterized by including the head maintenance mechanism according to the present invention.

  According to such a printer, in a situation where a command can be continuously received, a cleaning command including a suction discharge operation can be performed when a regular command is received after the determination time has elapsed since the last cleaning operation was completed. Since the operation is performed, the ink nozzles can be maintained in a good state while avoiding the cleaning operation at the timing before the start of printing. Therefore, it is possible to maintain a high-quality printing state and to improve the throughput by minimizing the waiting time at the start of printing by the cleaning operation.

The printer system according to the present invention which can solve the above problems, have a printer which can communicate with the server according to the present invention described above, the instruction from the server to the printer, the printer is installed The restart command is periodically transmitted at a predetermined time when the store is out of business hours .

  According to such a printer system, the printer managed by the server receives a restart command periodically, and when the restart command is received in a state where the determination time has elapsed, the suction discharge is performed. The cleaning operation including the operation is performed, and the printer is restarted. Since the restart command is set so as to avoid the normal use time zone of the printer, the cleaning operation including the suction and discharge operation is not performed during the normal use time zone of the printer. It is possible to avoid delaying the timing for starting printing.

  According to the head maintenance method, the head maintenance mechanism, the printer, and the printer system according to the present invention described above, the time elapsed from the end of the previous cleaning operation when the command received periodically is received is the predetermined time. If the determination time set before the previous time is exceeded, a cleaning operation including a suction and discharge operation is performed. That is, even if the state in which the printing operation is not performed continues, the cleaning operation is performed before a predetermined time elapses with a command received periodically as a trigger, and the cleaning operation at the start of printing is not performed. Therefore, it is possible to avoid delaying the timing of actually starting printing by performing the cleaning operation at the start of printing, and the waiting time until the end of printing is reduced, thereby improving the throughput. Further, since the cleaning operation is performed almost every time the determination time elapses, the ink nozzle can be maintained in a good state.

Hereinafter, a head maintenance method, a head maintenance mechanism, a printer, and a printer system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1 is an external perspective view of a printer having a head maintenance mechanism for performing a head maintenance method according to an embodiment of the present invention, and FIG. 2 is a state in which the roll paper cover and cartridge cover of the printer shown in FIG. 1 are opened. FIG. 3 is a perspective view of the printer shown in FIG. 2 with the printer case removed, FIG. 4 is a block diagram showing a control system of the printer and printer system shown in FIG. 1, and FIG. 6 is a block diagram for explaining a head maintenance mechanism in the printer shown, and FIG. 6 is a flowchart showing a procedure of a cleaning operation performed by the head maintenance mechanism shown in FIG.

  As shown in FIGS. 1 to 3, the printer 1 of the present embodiment is an inkjet printer that performs color printing on roll paper using a plurality of types of color ink liquids. For example, printing discount coupons for products in a supermarket or the like It is suitable for use in. As shown in FIG. 1, a roll paper cover 5 and an ink cartridge cover 7 are provided on the front surface of a printer case 2 covering the printer body of the printer 1 so as to be freely opened and closed. Further, on the front surface of the printer case 2, a cleaning button 37, a feed switch 38, four display lamps 41 to 44, which are display units, and the power switch 3 are also arranged. The cleaning button 37 is an operation member for manually executing a cleaning process of the print head 21 in order to eliminate problems such as clogging of the print head 21.

  Note that a paper issue port 6 is provided in the upper part of the roll paper cover 5, and printed paper is sent out from the paper issue port 6. In addition, an auto cutter (not shown) is provided inside the paper issuing port 6, and when the portion where the printing of the paper is finished is sent out from the paper issuing port 6, the auto cutter removes a part in the width direction of the paper. It is designed to leave and cut.

When the roll paper cover 5 is opened, as shown in FIG. 2, the paper storage unit 13 that stores the roll paper 11 that is the printing paper is opened, and the paper can be replaced.
When the ink cartridge cover 7 is opened, the cartridge mounting portion 15 is opened as shown in FIG. 2, and the ink cartridge 17 can be attached to and detached from the cartridge mounting portion 15.

  The ink cartridge 17 is a cartridge case 18 that contains a plurality of color ink packs. In the case of the printer 1 of the present embodiment, the ink cartridge 17 is pulled out by a predetermined distance in front of the cartridge mounting portion 15 in conjunction with the operation of opening the ink cartridge cover 7.

  As shown in FIG. 3, a carriage 23 on which a print head 21 is mounted is provided above the paper storage unit 13 in the printer case 2. The carriage 23 is supported by a guide member 25 extending along the width direction of the roll paper 11 so as to be movable in the paper width direction, and the endless belt 26 a extending in the width direction of the roll paper 11 and the endless belt 26 a. The carriage motor 26b for driving the platen 28 can reciprocate in the width direction of the roll paper 11 above the platen 28.

  As shown in the drawing, the upper portion of the cartridge mounting portion 15 is a standby position (home position) of the carriage 23 that reciprocates. Below this standby position, a cap 27 that covers the ink nozzles of the print head 21 exposed on the lower surface of the carriage 23, and the ink in each ink nozzle of the print head 21 is sucked and discarded via the cap 27. An ink suction mechanism 29 is provided. The ink sucked by the ink suction mechanism 29 to become waste liquid is returned to the waste liquid storage section in the ink cartridge 17.

  Each ink pack in the ink cartridge 17 is inserted and connected to the ink supply port of the ink pack when the ink cartridge 17 is mounted on the cartridge mounting portion 15. An ink flow path 31 fixed in the printer case 2 is connected to the ink supply needle of the cartridge mounting portion 15, and one end of a flexible ink tube 33 is connected to the ink flow path 31. The other end of the ink tube 33 is connected to each ink nozzle of the print head 21 via a back pressure adjustment unit 35 provided on the print head 21.

  That is, the ink liquid in each ink pack in the ink cartridge 17 passes from the ink supply needle of the cartridge mounting portion 15 through the ink flow path 31, the ink tube 33, and the back pressure adjustment unit 35 to each ink nozzle on the print head 21. To be supplied. Further, an IC chip for storing data such as the remaining amount of ink and the amount of waste liquid of each color is provided on the side surface of the ink cartridge 17, and a cartridge connection terminal 113 (see FIG. 4) provided in the cartridge mounting portion 15 is provided. The electrical connection with the connection terminal of the IC chip of the ink cartridge 17 is achieved, and the reading / writing of data from the printer control system to the IC chip is enabled.

Next, the control system of the printer 1 will be described.
As shown in FIG. 4, the printer 1 of this embodiment includes a control board 100 to which a cleaning mechanism 59, a data transmission / reception terminal 110, an operation unit 111, a display unit 112, and a cartridge connection terminal 113 are connected. In the printer system 1 </ b> A of the present embodiment, the printer 1 can communicate with the server 200. A plurality of printers 1 may be installed for one server 200.

  The control board 100 is a control unit that comprehensively controls each control mechanism portion of the printer 1. The control board 100 includes a paper conveyance control unit 101, a print control unit 102, a cleaning control unit 50, a command analysis unit 104, a main control unit 105, a reception buffer 106, a communication control unit 107, a status. A transmission unit 108 is connected to be communicable with each other via a bus 109.

  The control board 100 is controlled by activating the firmware read from the ROM, and executes various operations according to various commands from the server 200.

  The paper transport control unit 101 generates a control signal for driving and controlling the transport mechanism of the roll paper 11 in response to various command commands transmitted from the server 200. The transport mechanism is driven according to this control signal and transports the roll paper 11.

  The print control unit 102 is a control unit that controls printing via the print head 21. The print control unit 102 performs ink ejection control from the ink nozzles of the print head 21 provided on the carriage 23, movement operation control of the carriage 23 itself, and the like based on a print instruction and image data sent from the outside.

  The command analysis unit 104 is an analysis unit that analyzes the contents of various control commands sent from the server 200 that is installed outside and connected to the printer 1 so as to be communicable. The analysis result by the command control unit 104 is sent to various control units such as the sheet conveyance control unit 101, the print control unit 102, and the cleaning control unit 50 according to the analysis result. Thereby, each control part performs control according to the received control command.

The main control unit 105 is a signal between the sheet conveyance control unit 101, the print control unit 102, the cleaning control unit 50, the command analysis unit 104, the reception buffer 106, the communication control unit 107, and the status transmission unit 108 provided on the control board 100. Delivery and general control.
The reception buffer 106 is a data storage area in which various commands sent from the server 200 and image data to be printed are temporarily stored.

  The communication control unit 107 is a control unit for performing communication with the server 200 via the data transmission / reception terminal 110. Various commands and data sent from the server 200 are temporarily stored in the reception buffer 106 via the communication control unit 107 and used by various control units and analysis units.

  The status transmission unit 108 generates a status signal indicating the state of the printer 1, and transmits the status signal to the server 200 via the communication control unit 107 and the data transmission / reception terminal 110. The server 200 can grasp the status of the printer 1 by receiving this status signal.

  Further, based on the status signal generated by the status transmission unit 108, display may be performed via the display unit 112, or status information may be output to the roll paper 11.

Next, a head maintenance mechanism 51 including a cleaning mechanism 59 for cleaning the print head 21 and a cleaning control unit 50 for controlling the operation of the cleaning mechanism 59 will be described with reference to FIG.
The head maintenance mechanism 51 performs a cleaning operation on the print head 21 in order to prevent printing defects such as missing dots due to an increase in the viscosity of the ink liquid in each ink nozzle in the print head 21 or breakage of the ink meniscus. Is to implement.

  The head maintenance mechanism 51 includes a cleaning mechanism 59 for cleaning the print head 21 and a cleaning control unit 50. The cleaning control unit 50 controls the normal flushing mode for operating the cleaning mechanism 59 in the normal flushing mode. A circuit 56, a microflushing mode drive control circuit 57 for operating the cleaning mechanism 59 in the microflushing mode, a suction / discharge mode drive control circuit 58 for operating the cleaning mechanism 59 in the suction / discharge mode, and a suction / discharge mode drive control. A cleaning end timer 53 for measuring an elapsed time after the cleaning operation performed by operating the circuit 58 is completed, and a cleaning counter for counting the cumulative number of cleaning operations performed by operating the suction discharge mode drive control circuit 58. In accordance with the set conditions, the ning accumulation counter 54, the memory 55 including an EEPROM, the normal flushing mode drive control circuit 56, the micro flushing mode drive control circuit 57, or the suction / discharge mode drive control circuit 58 are set. And a cleaning main control unit 52 that is selectively activated.

  The cleaning mechanism 59 includes an ink suction mechanism 29 (see FIG. 3) that sucks residual ink in the ink nozzles with an ink suction pump, a wiping mechanism 30 (see FIG. 3) that wipes the tip of the ink nozzles with a wiper blade, and all the ink nozzles. And a flushing mechanism (not shown) for discharging a small amount of ink liquid.

  The cleaning operation in the normal flushing mode by the normal flushing mode drive control circuit 56 does not include the suction discharge process by the ink suction mechanism 29, and performs a normal flushing operation in which a small amount of ink liquid is discharged from all the ink nozzles. .

  The cleaning operation in the micro flushing mode by the micro flushing mode drive control circuit 57 does not include the suction ejection process by the ink suction mechanism 29, and the micro flushing operation in which a smaller amount of ink liquid is ejected from all the ink nozzles than in the normal flushing mode. Is to do.

  The cleaning operation in the suction / discharge mode by the suction / discharge mode drive control circuit 58 is performed by operating the ink suction pump of the ink suction mechanism 29 in order to eliminate problems such as clogging of the ink nozzles in the print head 21. It includes a suction and discharge operation for sucking while discharging a fixed amount of ink from the ink nozzles of the print head 21, and, if necessary, a specified cleaning such as a wiping process for wiping the tip surface of the ink nozzle after the suction and discharge operation Processing is executed. The suction amount of the ink liquid in the suction and discharge operation can be changed according to the degree of clogging of the ink nozzles, the cumulative number of cleanings, and the like.

  The cleaning end timer 53 measures an elapsed time after the cleaning mechanism 59 finishes the previous cleaning operation including the suction discharge operation with respect to the print head 21, and the measurement time is sequentially stored in the memory 55. . Although it is assumed that the printer 1 of the present embodiment is always used with the power on, when the power is turned off, the time information transmitted from the server 200 when the power is turned on again is displayed. Based on the elapsed time stored in the memory 55, the actual elapsed time from the end of the previous cleaning operation is calculated.

  The cumulative cleaning counter 54 counts the cumulative number of times that the cleaning operation has been performed in the suction / discharge mode from when the printer 1 is first turned on, and the cumulative number is the suction amount of ink liquid in the suction / discharge operation, that is, suction. It is referred to by the cleaning main controller 52 when determining the intensity level of the discharge operation. The cumulative number counted by the cleaning cumulative counter 54 is sequentially stored in the memory 55.

  The cleaning main controller 52 selectively activates the normal flushing mode drive control circuit 56, the micro flushing mode drive control circuit 57, or the suction / discharge mode drive control circuit 58 according to the set conditions. As one of the operations, when print data for performing a printing operation is transmitted from the server 200, the normal flushing mode drive control circuit 56 is increased according to the increase in the measurement time by the cleaning end timer 53 at that time. Then, any one of the minute flushing mode drive control circuit 57 and the suction discharge mode drive control circuit 58 is selectively activated in order to cause the cleaning mechanism 59 to perform a pre-printing cleaning operation. The cleaning main control unit 52 is arbitrarily set with a condition for selecting a control circuit to be activated in the pre-printing cleaning operation, and the measurement time by the cleaning end timer 53 is a predetermined time or more. Is set to activate the suction discharge mode drive control circuit 58 to cause the cleaning mechanism 59 to perform a pre-printing cleaning operation including a suction discharge operation. In the present embodiment, the predetermined time is set to 360 hours.

  When the printing operation is performed before a predetermined time, a light cleaning operation by the normal flushing mode drive control circuit 56 or the micro flushing mode drive control circuit 57 is performed before printing in accordance with the measurement time by the cleaning end timer 53. Is to be done. These minor cleaning operations require much shorter time than cleaning operations including suction and discharge operations, and are clearly distinguished from cleaning operations including suction and discharge operations.

  In addition, the cleaning main control unit 52 uses the reception of a restart execution command (restart command) periodically transmitted from the server 200 to the printer 1 as a trigger, and the measurement time by the cleaning end timer 53 is earlier than the predetermined time. It is determined whether or not the determination time set in the time is exceeded, and when the measurement time is determined to be equal to or longer than the determination time, the suction / discharge mode drive control circuit 58 is activated. In this embodiment, the printer 1 is for issuing discount coupons installed in a supermarket, and the restart execution command is issued from the server 200 at a predetermined time at night outside business hours. It is supposed to be sent. That is, the printer 1 is restarted by receiving a restart execution command periodically every 24 hours. For this reason, the determination time is theoretically preferably set to 24 hours before the predetermined time, and if an error in receiving the restart execution command is estimated to be 2 hours and included, the determination time is 26 hours before the predetermined time. This 334 hours may be set as the determination time.

Next, the head maintenance method of this embodiment will be described with reference to the flowchart of FIG.
When a restart execution command is transmitted from the server 200 at a predetermined time in the night when the store where the printer 1 is installed is out of business hours and the printer 1 receives the command, the reception of the restart execution command is triggered. A head maintenance operation sequence is started (step S01). Thereby, the cleaning main control unit 52 first determines whether or not the measurement time (CL elapsed time T1) by the cleaning end timer 53 is equal to or longer than the determination time (334 hours) (step S02).

  If it is determined in step S02 that the time measured by the cleaning end timer 53 is less than the determination time, the head maintenance operation sequence ends (step S03), and the print head 21 is returned to the standby state, and the printer 1 restart processing is performed.

  When it is determined in step S02 that the time measured by the cleaning end timer 53 is equal to or longer than the determination time, the cleaning main control unit 52 performs the suction discharge when the cleaning mechanism 59 performs the cleaning operation including the suction discharge operation. The intensity level of the operation is determined (CL parameter set: step S04). The intensity level of the suction and discharge operation is set according to the cumulative number counted by the cleaning cumulative counter 54 and the ink remaining amount in the ink cartridge 17.

  Next, the IC chip of the ink cartridge 17 is accessed, the remaining amount of ink of each color in the ink cartridge 17 is detected, and the ink consumption amount when the cleaning operation at the intensity level set in step S04 is performed is set to the ink end. Pre-calculation is performed to determine whether or not (pre-CL determination: step S05). In this pre-CL determination, the amount of waste liquid in the ink cartridge 17 is also detected, and whether or not the amount of waste liquid stored in the ink cartridge 17 exceeds an allowable amount when the cleaning operation is performed (waste liquid over) is determined in advance. Perform the calculation.

  After performing the pre-CL determination in step S05, it is determined whether or not an error determination that at least one of ink end and waste liquid over has been made is made (step S06). If it is determined in step S06 that an error has been determined, the carriage 23 is placed at the standby position and the ink nozzles of the print head 21 are covered with the cap 27 (CR lock set: step S09), and the ink end or Error processing for displaying on the display unit 112 (display lamps 41 to 44) that the waste liquid is over is performed (step S10).

  On the other hand, if it is determined in step S06 that there is no error determination, the cleaning main control unit 52 activates the suction / discharge mode drive control circuit 58 with the parameters set in step S04, and the cleaning mechanism 59 performs suction. A cleaning operation including a discharge operation is performed (step S07).

  When the cleaning operation in step S07 is completed, the cleaning main control unit 52 stores the cleaning end time in the memory 55, resets the measurement time (CL elapsed time T1) of the cleaning end timer 53, and sets the count of the cleaning cumulative counter 54 to 1. In addition, the head maintenance operation sequence ends (step S08), and the print head 21 is returned to the standby state.

Here, the CL parameter set sequence in step S04 will be described with reference to FIG. The CL parameter mainly sets the number of steps of the motor that drives the ink suction pump of the ink suction mechanism 29.
As described above, when it is determined in step S02 that the measurement time by the cleaning end timer 53 is equal to or longer than the determination time, the CL parameter setting is started (step S41). First, referring to the cumulative number of cleaning operations counted by the cleaning cumulative counter 54, it is determined whether or not it is a multiple of a predetermined number (8 in the present embodiment) (step S42).

  When it is determined in step S42 that the cumulative number of cleaning operations is not a multiple of 8 (step S42: No), a parameter of cleaning level 1 is set. The cleaning level is the strength of the suction / discharge operation, and the suction / discharge amount (ink consumption) from the print head 21 varies depending on the level. The cleaning level 1 is a level of a normal suction / discharge operation, and a slightly higher suction / discharge operation is set as the cleaning level 2, and a suction / discharge operation performed by closing the choke valve with a stronger negative pressure is set as the cleaning level 3.

  If it is determined in step S42 that the cumulative number of cleaning operations is a multiple of 8 (step S42: Yes), cleaning levels 1 to 3 are set according to the remaining amount of ink. The remaining amount of ink is determined by being classified into five stages of ink statuses 0 to 4, and the ink status 0 is set at the level where the remaining amount of ink is the highest, and thereafter the remaining amount of ink decreases. The ink status 4 is a level at which it is determined that the ink has ended. First, it is determined for each color whether there is an ink corresponding to ink status 2 with relatively little ink remaining (step S43). If there is a color with ink status 2, the parameter of cleaning level 1 is set. (Step S44).

  If it is determined in step S43 that there is no ink status 2 color, it is determined for each color whether or not there is an ink corresponding to ink status 1 with more ink remaining than ink status 2 (step S45). If there is a color of ink status 1, the parameter of cleaning level 2 is set (step S46).

  If it is determined in step S45 that there is no ink status 1 color, the cleaning level 3 parameter is set (step S47).

  As described above, when the cumulative number of cleaning operations is a multiple of a predetermined number, that is, every predetermined number of times, a stronger cleaning operation than other cases is performed according to the remaining amount of ink. Therefore, when the cumulative number is not a multiple of the predetermined number, the ink nozzle state is maintained by performing the cleaning operation with an appropriate strength while suppressing the ink consumption, and the strong cleaning operation is performed every predetermined number of times. Thus, the ink nozzle state is reset, and the ink nozzle is maintained in a good state.

  Even when the cumulative number is a multiple of a predetermined number, a cleaning operation with an appropriate strength is selected according to the remaining amount of ink, so that the ink supplied to the print head 21 can be prevented from becoming an ink end. The cleaning operation with the optimum strength is performed so as not to be used up.

By performing the head maintenance operation sequence described above, when the printer 1 receives a restart command transmitted periodically (every 24 hours) from the server 200, the previous cleaning operation has been completed. It is determined whether or not the elapsed time is equal to or longer than the determination time (334 hours) set to a time before the predetermined time (360 hours). Done. Therefore, if a restart command is received in a state where 334 hours or more have elapsed since the end of the previous cleaning operation, the cleaning operation is performed without waiting for the next printing start timing, and 360 hours have elapsed since the end of the cleaning operation. If it is before, the cleaning operation is not performed at the start of the next printing.
That is, even if the state where the printing operation is not performed continues, the cleaning operation is performed before 360 hours elapses with a restart command received every 24 hours as a trigger, and the cleaning operation at the start of printing is performed. There is no. Therefore, it is possible to avoid delaying the timing of actually starting printing by performing the cleaning operation at the start of printing, and the waiting time until the end of printing is reduced, thereby improving the throughput. Further, since the cleaning operation is performed almost every time the determination time elapses, the ink nozzle can be maintained in a good state.

  In particular, when the printer 1 is used for printing discount coupons for merchandise at a supermarket cash register or the like, a cleaning operation including a suction discharge operation is performed outside business hours. Coupons can be printed and issued without a long waiting time, so that customers do not have to wait, and the time required for each customer at the cash register can be shortened, thereby improving the efficiency of cash register work.

  In addition, it is preferable to automatically perform nozzle check pattern printing before the business start time and confirm that good printing is performed. If printing failure occurs, manual cleaning is performed by pressing the cleaning button 37, and nozzle check pattern printing is performed again to confirm that good printing is performed. For example, if a missing dot occurs in a barcode printed on a coupon, it may cause a barcode reading error, so checking the state of the ink nozzles is effective in maintaining print quality.

1 is an external perspective view of a printer including a head maintenance mechanism for performing a head maintenance method according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state in which a roll paper cover and a cartridge cover of the printer shown in FIG. 1 are opened. FIG. 3 is a perspective view of the printer shown in FIG. 2 with a printer case removed. FIG. 2 is a block diagram showing a control system of the printer and printer system shown in FIG. 1. FIG. 2 is a block diagram for explaining a head maintenance mechanism in the printer shown in FIG. 1. 6 is a flowchart illustrating a procedure of a cleaning operation performed by the head maintenance mechanism illustrated in FIG. 5. 7 is a flowchart showing details of the cleaning parameter set shown in FIG. 6.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 1A ... Printer system, 2 ... Printer case, 3 ... Power switch, 5 ... Roll paper cover, 7 ... Ink cartridge cover, 37 ... Cleaning button, 41 ... Display lamp, 51 ... Head maintenance mechanism, 52 ... Cleaning Main control unit 53 ... Cleaning end timer, 54 ... Cleaning cumulative counter, 55 ... Memory, 56 ... Drive control circuit for normal flushing mode, 57 ... Drive control circuit for minute flushing mode, 58 ... Drive control circuit for suction discharge mode, 59 ... Cleaning mechanism, 200 ... Server

Claims (10)

A cleaning operation including a suction discharge operation for sucking and discharging ink liquid from the ink nozzle for a print head having ink nozzles capable of discharging ink liquid has passed a predetermined time from the end of the previous cleaning operation. A head maintenance method to be performed before starting printing in a state where
When an apparatus provided with the print head receives a command periodically received at a predetermined time when the store where the apparatus is installed is out of business hours, the elapsed time since the last cleaning operation was completed It is determined whether or not a determination time set before a predetermined time is reached, and when it is determined that the determination time is exceeded, the cleaning operation is performed. The head maintenance method according to claim 1,
The head maintenance method according to claim 1, wherein the determination time is set to a time before a predetermined interval for receiving the command with respect to the predetermined time. The head maintenance method according to claim 1 or 2,
A head maintenance method characterized in that when the elapsed time is determined to be equal to or greater than the determination time and the cumulative number of cleaning operations is a multiple of a predetermined number, a stronger cleaning operation is performed than when it is not a multiple. . The head maintenance method according to claim 3,
A head maintenance method, wherein the strength of the cleaning operation is determined in accordance with a remaining amount of ink supplied to the print head. A cleaning mechanism for cleaning a print head having ink nozzles capable of ejecting ink;
A suction discharge mode drive control circuit for causing the cleaning mechanism to perform a cleaning operation including a suction discharge operation for sucking and discharging ink liquid from the ink nozzle;
A cleaning end timer for measuring an elapsed time from the end of the previous cleaning operation;
An apparatus that is set to activate the suction discharge mode drive control circuit before the start of printing in a state in which the measurement time by the cleaning end timer has passed for a predetermined time, and that includes the print head , when the apparatus is installed shop receives regularly receive instruction at any given time is outside business hours, whether the measured time has become a predetermined time set determination time or more before the A head maintenance mechanism comprising: a control unit configured to determine and to start the suction / discharge mode drive control circuit when it is determined that the time is equal to or longer than the determination time. The head maintenance mechanism according to claim 5,
The head maintenance mechanism according to claim 1, wherein the determination time is set to a time before a predetermined interval for receiving the command with respect to the predetermined time. The head maintenance mechanism according to claim 5 or 6,
A cleaning cumulative counter that counts the cumulative number of times the suction discharge mode drive control circuit has been activated;
The control unit determines that the measurement time is equal to or greater than the determination time, and when the cumulative number of cleaning cumulative counters is a multiple of a predetermined number, the cleaning operation is set to be stronger than when it is not a multiple. A head maintenance mechanism provided to a drive control circuit for suction / discharge mode. The head maintenance mechanism according to claim 7,
A head maintenance mechanism that determines the setting of the strength of the cleaning operation to be given to the suction / discharge mode drive control circuit according to the remaining amount of ink supplied to the print head.   A printer comprising the head maintenance mechanism according to any one of claims 5 to 8. A server capable of communicating with the printer according to claim 9;
The printer system according to claim 1 , wherein the command is a restart command periodically transmitted from the server to the printer at a predetermined time when the store where the printer is installed is out of business hours .

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