JP2006103180A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder in which lowering of print speed or degradation of print quality can be suppressed by altering the time up to cap operation when the volume of data of an image to be printed is high. <P>SOLUTION: In an inkjet recorder where a control microcomputer 31 sets a cap time required for a cap unit 19 to move from an open position to a closed position after ink ejecting operation of an inkjet head 11 is stopped, measures the time of stopping operation for ejecting ink from the nozzle array 12 of the inkjet head 11 and moves the cap unit 19 to the closed position when the cap time is reached, the control microcomputer 31 detects the volume of data of an image to be printed and alters the cap time when the volume of data of an image to be printed is high. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus that is used in a copying machine, a printer apparatus, a facsimile apparatus, a multifunction machine, and the like and includes a cap unit that closes an ejection port of an ink jet head.

  Conventionally, the non-impact recording method is advantageous in that noise during recording is small enough to be ignored. Among them, high-speed printing is possible, and printing is performed without performing special fixing processing on plain paper. The ink jet recording method that can perform this is an extremely powerful recording method. Recently, various color recording methods using color inks have been proposed and improved.

  In the conventional ink jet recording method of this type, there is a method in which droplets of a plurality of colors of ink are ejected and adhered to a recording member to perform recording, and have an ejection port for ejecting ink toward the recording member. An inkjet head and a carriage that reciprocates the inkjet head with respect to the recording member are provided.

  On the other hand, in this ink jet recording apparatus, when ink is not ejected, if the nozzle that is the ink ejection port is left in the atmosphere, the ink in the nozzle evaporates, causing thickening and fixing, Since this causes a discharge failure, it is necessary to quickly cap the discharge port so that it does not dry when printing is finished and ink is no longer discharged.

  Normally, the cap sealing operation is performed when a certain cap time (for example, 15 seconds) elapses with the cap opened and the head is not driven. Specifically, after the end of the printing process, after the end of the head recovery operation, or when the power is turned off.

  A cap sealing process for performing the cap sealing operation will be described with reference to FIG. In the cap sealing process (step S91), first, it is determined whether or not ink is being ejected (step S92). If the ink is being ejected, the cap operation is not performed, so the cap time for opening the cap is counted. A timer is initialized (step S94). If it is determined in step S92 that ink is not being ejected, it is determined whether or not the cap is being opened (step S93). If the cap is being opened, the process proceeds to step S95, where a timer is counted and the cap is counted. If not open, the timer is initialized (step S95), and the process is terminated.

  Next, it is determined whether or not the count value of the timer exceeds a preset cap time (step S97), and if it exceeds, the current process is terminated (step S100) and exceeds the cap time. In that case, the inkjet head is raised to the cap position by the carriage to close the ejection port (step S99), and the current process is terminated (step S100).

  However, in such a capping operation, if the print image data input to the printer is intermittent or has a large capacity, it may take time to process the data before executing the printing operation. Then, the end of the data processing is awaited in a state where the discharge port is exposed to the atmosphere and preparations for starting printing are made.

  If time is required for data processing in this way, the capping operation may be performed after the above-described capping time has elapsed, so the operation of opening the cap again when printing resumes and the inkjet head at the printing position The operation of moving to the position is necessary, and the printing time is reduced.

  In order to solve such a problem, in a print recording apparatus having an ink jet type print head, a means for capping the print head and a time from the end of printing by the print head to the start of the capping operation are set. There is an ink jet recording apparatus provided with a time setting means (for example, see Patent Document 1).

  In addition, after interrupting image recording, it is determined whether a recording medium is set in the print area, etc., and the possibility that an image output signal will continue to be sent is determined. There is an ink jet recording apparatus that takes a long waiting time until the cap closing operation is started, and instead performs wiping and preliminary discharge to suppress a decrease in throughput without deteriorating the discharge performance during the standby time ( For example, see Patent Document 2).

  In addition, an inkjet recording apparatus that performs recording using a recording head that discharges ink to form an image on a recording medium, the cap unit covering the ink ejection surface of the recording head after a predetermined time has elapsed after recording interruption, A state detection unit that detects whether or not a recording medium is loaded in the ink jet recording apparatus main body, and a change unit that changes a predetermined time according to the state detected by the state detection unit. There is an ink jet recording apparatus (see, for example, Patent Document 3).

Further, there is a nozzle capping method that measures the time when data transfer is interrupted in the middle of the paper or near the end of the paper, and enters the capping operation when the preset time has elapsed. (For example, refer to Patent Document 4).
Japanese Patent Laid-Open No. 5-84921 JP-A-6-134997 Japanese Patent No. 3101440 JP-A-8-323987

  However, in Patent Document 1, the time from the end of printing to the capping operation can be set, but as the changing means, sensor values such as dip switches, operation panel key operations, temperature sensors, humidity sensors, etc. Therefore, the user feels bothered by the amount of manual operation such as dip switch and panel key operation. In addition, monitoring of sensor values such as a temperature sensor and a humidity sensor cannot know the processing amount of image data, and the cap time cannot be changed according to the amount of image data. For this reason, it is not possible to restart printing promptly or to suppress a decrease in print image quality.

  Also, in Patent Document 2 and Patent Document 3, if the sheet remains in the recording apparatus when the printing process is interrupted, the time until the capping operation is set to be long because the possibility of resuming data reception is high. However, since the processing amount of the image data cannot be known, the capping time cannot be changed according to the image data amount. For this reason, it is not possible to restart printing promptly or to suppress a decrease in print image quality.

  Further, in Japanese Patent Application Laid-Open No. H10-260260, when the transfer of image data is interrupted, the capping operation is performed after a certain time, and particularly when the interruption is performed at the rear end of the paper, the capping operation is performed in a particularly short time. However, the cap time was constant and could not be changed. For this reason, it is not possible to restart printing promptly or to suppress a decrease in print image quality.

  The present invention has been made to solve such a problem, and when the amount of data of an image to be printed is large, the time until the capping operation is changed so as to suppress a decrease in the printing speed, or An ink jet recording apparatus capable of suppressing a decrease in print quality is provided.

  The inkjet recording apparatus of the present invention has an ejection port that ejects at least one color of ink, and ejects ink onto a recording medium from the ejection port, and an ejection port of the inkjet head. A cap unit that moves between a closed position that closes the nozzle and an open position that opens the discharge port, a time measuring unit that measures the time during which the operation of discharging ink from the discharge port of the inkjet head is stopped, and the inkjet head A cap time setting means for setting a cap time, which is a time from when the cap means is located at the closed position to when the cap means is located at the closed position, and a time measured by the time measuring means. When the cap time is reached, the cap means is moved to the closed position. An ink jet recording apparatus including a cap activation unit includes an image data amount detection unit that detects a data amount of an image to be printed, and the cap time setting unit performs printing based on detection information of the image data amount detection unit. The cap time is changed when the amount of image data to be processed is large.

  With this configuration, when the amount of image data to be printed is large, the ink ejection operation by the inkjet head is stopped, and the cap time, which is the time from when the cap means is in the open position to when it is in the closed position, is changed. Therefore, if the amount of image data to be printed is large and it is expected that it will take some time before the printing operation starts from the print ready state, set the cap time long and position the cap means at the closed position. By not shifting to the cap operation to be performed, it is possible to perform a quick resumption of printing while maintaining a state where the discharge port is opened, and it is possible to suppress a decrease in printing speed.

  In addition, when it is expected that it will take time until the printing operation is started from the print preparation state, when the cap time is set short, it is easy to shift to the capping operation, and the ink in the nozzle evaporates. Accordingly, it is possible to suppress the occurrence of ejection failure due to thickening and sticking, thereby suppressing the deterioration of the print image quality.

  Further, the cap time setting means of the ink jet recording apparatus of the present invention is configured to change the cap time when the ink discharge position from the ink jet head is near the front end of the recording medium. With this configuration, when printing near the leading edge of the recording medium, the processing of image data temporarily accumulates and increases, and it takes time to start printing.By changing the cap time at this time, It is possible to suppress a decrease in printing speed or to suppress a decrease in printing quality.

  Further, the cap time setting means of the ink jet recording apparatus of the present invention is configured to change the cap time based on the resolution of an image printed on the recording medium.

  With this configuration, when the resolution of the image to be printed is high, the amount of data of the image to be processed increases. Therefore, by changing the cap time at this time, it is possible to suppress the decrease in the printing speed or to reduce the print quality. Reduction can be suppressed.

  Further, the cap time setting means of the ink jet recording apparatus of the present invention is configured to change the cap time based on an image printing mode.

  With this configuration, the amount of image data to be processed increases depending on the contents of the image data, for example, the printing mode of the image such as the number of interlaces and the number of passes. By changing the cap time at this time, the printing speed can be increased. It is possible to suppress the deterioration or the deterioration of the print quality.

  Further, the cap time setting means of the ink jet recording apparatus of the present invention is configured to change the cap time longer.

  With this configuration, if the amount of image data to be printed is large even if the cap time is changed, and it is expected that it will take time until the printing operation starts from the print preparation state, the cap time is set to be long. By not shifting to the capping operation in which the capping unit is positioned at the closed position, it is possible to suppress a decrease in printing speed by maintaining a state where the discharge port is opened and restarting printing promptly.

  In the ink jet recording apparatus of the present invention, the cap time setting means is configured to change the cap time short.

  With this configuration, when it is expected that it will take time until the printing operation starts from the print preparation state, when the cap time is set short, it is easy to shift to the capping operation, and the ink in the nozzles It is possible to suppress the occurrence of ejection failure due to evaporation to increase the viscosity and adherence, thereby suppressing the deterioration of the print image quality.

  As described above, according to the present invention, when the amount of data of an image to be printed is large, the time until the capping operation is changed to suppress a decrease in printing speed or a decrease in printing quality. An ink jet recording apparatus that can be used can be provided.

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

  1 to 11 are views showing a first embodiment of an ink jet recording apparatus according to the present invention, and this embodiment shows an example in which a jet recording apparatus is mounted on a printer apparatus as an image forming apparatus. . The image forming apparatus is not limited to a printer, but can be applied to a copying machine, a facsimile machine, or a multifunction machine having a plurality of functions such as a copy function and a facsimile function.

  First, the configuration will be described. 1 and 2, the printer apparatus 1 includes a communication circuit 2. This communication circuit 2 is connected to an external device (not shown) such as a personal computer (hereinafter simply referred to as a PC), and receives image data from the PC. Data necessary for printing such as the beginning is received.

  The control circuit 3 controls various devices constituting the printer apparatus 1 to form an image on the recording paper 4 as a recording medium based on the print data received from the PC. A microcomputer (see FIG. 6) is included.

  In addition, a plurality of recording sheets 4 are stored in the sheet feeding tray 5, and the recording sheets 4 are fed from the sheet feeding tray 5 by a sheet feeding roller 6 driven in a clockwise direction by a sheet feeding roller driving motor (not shown). It is supposed to be paper. The recording paper 4 fed by the paper feed roller 6 is transported to a printing position by a transport belt 9 that is moved around by a transport drive roller 7 and a transport driven roller 8.

  A carriage 10 is provided at this printing position, and an inkjet head 11 is mounted on the carriage 10. As shown in FIG. 3, the inkjet head 11 is provided with nozzle rows 12K (black), 12C (cyan), 12M (magenta), and 12Y (yellow) which are ejection openings on the nozzle surface 11a. 12K, 12C, 12M, and 12Y are separated along the main scanning direction A of the recording paper 5.

  The nozzle rows 12K, 12C, 12M, and 12Y are each composed of 192 nozzles. Specifically, the nozzle row 12K includes nozzles 12K-1 to 12K-192, and the nozzle row 12C includes nozzles 12C-1 to 12C-192.

  The nozzle row 12M is composed of nozzles 12M-1 to 12M-192, and the nozzle row 12Y is composed of nozzles 12Y-1 to 12Y-192. These nozzles are separated along the sub-scanning direction B of the recording paper 4. In FIG. 3, the nozzles 12Y-1, 12Y-2, 12Y-3, and 12Y-190, 12Y-191, and 12Y-192 are shown in an enlarged manner, and the other nozzles are numerous. For this reason, illustration is omitted.

  These nozzle rows 12K, 12C, 12M, and 12Y are configured to eject ink from the nozzle openings by driving piezoelectric elements inside the nozzle 12M-1.

  The carriage 10 is held by a carriage drive belt 13, and this carriage drive belt 13 is driven by a carriage drive motor 14 so that the carriage drive belt 13 reciprocates along the main scanning direction A of the recording paper 4. It is supposed to be.

  The conveyance drive roller 7 is connected to a conveyance motor 16 via a conveyance belt 15, and is rotated by driving the conveyance belt 15 around by the conveyance motor 16. 4 is conveyed in the sub-scanning direction B. In order to stably transport the recording paper 4 by the transport belt 9, the recording paper may be electrostatically attracted to the transport belt 9 or may be sucked by air.

  In this way, the transport belt 9 is moved in the sub-scanning direction B of the recording paper 4 and the carriage 10 is moved in the main scanning direction A of the recording paper 4 while moving from the nozzle rows 12K, 12C, 12M, and 12Y to the recording paper 4. By ejecting ink, the image received from the PC is printed on the entire surface of the recording paper 4.

  The printer device 1 is provided with an operation panel 17, and the operation panel 17 is provided with various input keys 17a such as a numeric keypad and a start switch, and inputs for various operations of the printer device 1 are performed by the user. The result is transmitted to the control circuit 3.

  In addition, the printer apparatus 2 is provided with a paper discharge tray 18, which is transported by the transport belt 9 and ejects the recording paper 4 that has been printed, and the discharged recording paper. 4 is accumulated and held.

  A cap unit (cap means) 19 is provided on one side of the carriage 10 in the moving direction. The cap unit 19 is provided corresponding to the nozzle rows 12K, 12C, 12M, and 12Y of the ink jet head 11, and the nozzle unit Dedicated caps 20K, 20C, 20M, and 20Y that cover the rows 12Y, 12C, 12M, and 12Y and isolate them from the outside air are provided.

  As shown in FIGS. 4 and 5, the cap unit 19 includes a cap body 21 and a projecting member 22 projecting downward from the cap body 21, and a cam 23 is always in sliding contact with the projecting member 22. .

  The cam 23 is attached to the rotation shaft 24a of the cap drive motor 24 and is driven to rotate by the cap drive motor 24. The cap unit 19 is rotated by the cam 23 so that the caps 20K, 20C, 20M and 20Y are driven. To close the nozzle rows 12K, 12C, 12M, and 12Y (upward in the movement direction, see FIG. 4) and open positions to open the nozzle rows 12K, 12C, 12M, and 12Y by the caps 20K, 20C, 20M, and 20Y (see FIG. 4). It moves between the lower direction of movement (see FIG. 5).

  Then, by closing the nozzle rows 12K, 12C, 12M, and 12Y with the caps 20K, 20C, 20M, and 20Y, the ink inside the nozzle rows 12K, 12C, 12M, and 12Y is dried and thickened and fixed. It is possible to prevent the ink ejection performance from being deteriorated.

  Also, by opening the nozzle rows 12K, 12C, 12M, and 12Y with the caps 20K, 20C, 20M, and 20Y, the carriage 10 can start scanning the ink-jet head 11, and preparation for starting printing can be performed. .

  FIG. 6 shows a control configuration in the control circuit 3. In FIG. 6, the control microcomputer 31 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a timer, and the like, and detects image data input from the communication circuit 2. Control for printing on the recording surface of the recording paper 4 is performed. In the present embodiment, the control microcomputer 31 constitutes image data amount detection means for detecting the data amount of an image to be printed together with the communication circuit 2.

  The control microcomputer 31 also uses the carriage position detection circuit 32, carriage drive motor drive circuit 33, carry amount detection circuit 34, carry motor drive circuit 35, paper feed roller drive circuit 36, cap drive motor drive circuit based on the image data. The entire printer apparatus 1 is controlled by exchanging signals between the printer 37 and the print control microcomputer 38.

  The carriage position detection circuit 32 detects the position of the carriage 10 and outputs position information to the control microcomputer 31. The carriage position detection circuit 32 is disposed, for example, on the scanning track of the carriage 10. The position of the carriage 10 is detected by counting the number of slits of the encoder sheet with an optical sensor mounted on the carriage 10.

  The carriage drive motor drive circuit 33 drives the carriage drive motor 14 along the main operation direction A by driving the carriage drive motor 14 based on the drive signal according to the movement amount information of the carriage 10 input from the control microcomputer 31. To be moved.

  The carry amount detection circuit 34 detects the carry amount of the carry drive roller 7 and outputs the carry amount information to the control microcomputer 31. The carry amount detection circuit 34, for example, includes the carry drive roller 7. The conveyance amount is detected by counting the number of slits of the rotary encoder sheet attached to the rotary shaft with an optical sensor.

  The conveyance motor drive circuit 35 drives the conveyance motor 16 based on a drive signal corresponding to the conveyance amount information of the conveyance drive roller 7 input from the control microcomputer 31, thereby conveying the conveyance belt via the conveyance drive roller 7. 9 is moved around.

  The paper feed roller drive circuit 36 drives the paper feed roller drive motor based on the paper feed roller drive command signal input from the control microcomputer 31 to rotate the paper feed roller 6 once.

  The cap drive motor drive circuit 37 drives the cap drive motor 24 based on the ascending signal and descending signal of the cap unit 19 input from the control microcomputer 31, thereby causing the cap unit 19 to move between the closed position and the opened position. It is supposed to be moved with.

  The print control microcomputer 38 controls the head drive circuit 39 mounted on the inkjet head 11 based on the ink ejection signal, the carriage 10 position signal, and the recording paper 4 conveyance amount signal input from the control microcomputer 31. The head drive circuit 39 drives the piezoelectric elements provided in the nozzles based on the above-described signals input from the print control microcomputer 38, and supplies ink from the nozzle rows 12K, 12C, 12M, and 12Y. It is designed to be discharged.

  On the other hand, the control microcomputer 31 has a built-in timer, and measures the time during which the operation of ejecting ink from the nozzle rows 12K, 12C, 12M, and 12Y of the inkjet head is stopped. It is composed.

  Further, the control microcomputer 31 sets a cap time which is a time from when the ink ejection operation by the inkjet head 11 stops and when the cap unit 19 is located at the closed position to the closed position. And constitutes a cap time setting means.

  The control microcomputer 31 moves the cap unit 19 to the closed position when the time measured by the timer reaches the cap time, and constitutes a cap activation means.

  The camping time is variable, not fixed, and the control microcomputer 31 changes the cap time when image data to be printed is input from the PC to the communication circuit 2 and the amount of data of the image is large. It is like that.

  Next, the printing process will be described based on the flowchart of FIG. 7 is a print processing program stored in the ROM of the control microcomputer 31 and executed by the CPU.

  In FIG. 7, in the printing process (step S1), first, the cap drive motor 24 is driven to rotate the cam 23 to lower the cap unit 19 to the open position, and the nozzle rows 12K, 12C, 12M, 12Y. Is released (step S2).

  Next, the carriage drive motor 14 is driven to move the carriage from a position facing the cap unit 19 to a position facing the transport belt 9 which is a printing start position (step S3), and then the transport motor 16 is driven to transport the carriage. By rotating the drive roller 7, the conveyor belt 9 is moved by the conveyor drive roller 7 and the conveyor driven roller 8 (step S4).

  Next, after rotating the paper feed roller 6 to feed the recording paper 4 from the paper feed tray 5 and transporting the recording paper 4 to the transport belt 9 (step S5), whether or not the recording paper 4 has reached the printing position. Is determined (step S6).

  If the recording paper 4 has reached the printing position, the drive of the transport motor 16 is stopped (step S7), and then image data is received from the PC by the communication circuit 2 (step S8).

  Next, after the received image data is set in the print control microcomputer 38 to prepare for printing (step S9), the carriage 10 is scanned on the recording paper 4 in order to execute the printing process (step S9). S10).

  Next, ink is ejected from the nozzle rows 12K, 12C, 12M, and 12Y to perform printing on the recording paper 4 (step S11), and it is determined whether or not the main scanning of the carriage 10 is completed (step S12). If the scanning is not finished, ink is ejected (step S11), and if the main scanning is finished, the main scanning of the carriage 10 is stopped (step S13).

  Next, it is determined whether or not printing within one page has been completed (step S14). If printing has not been completed, the conveyance motor 16 is driven to move the recording paper 4 in the sub-scanning direction. (Step 15), the process proceeds to step S6 to perform the printing process for the next line.

  When printing within one page is finished, the driving of the transport motor 16 is stopped (step S16), and then it is determined whether or not the recording paper is discharged to the paper discharge tray 18 (step S17). Here, it is determined whether or not the recording paper 4 is discharged to the discharge tray 18 based on detection information of a discharge sensor (not shown) provided on the discharge tray 18.

  When the discharge of the recording paper 4 is completed, it is determined whether or not printing of all pages has been completed (step S18). If printing of all pages has not been completed, the process proceeds to step S5 and continues. The recording paper 4 to be fed is fed. When all pages have been printed, the conveyance motor 16 is stopped to stop the conveyance belt 9 (step 19) and the printing process is terminated (step S20).

  FIG. 8 is a flowchart of the cap sealing process, which is a cap sealing process program stored in the ROM of the control microcomputer 31 and executed by the CPU.

  In FIG. 8, in the cap sealing process (step S21), it is first determined whether or not ink is being ejected (step S22). If the ink is being ejected, the cap unit 19 is moved to the closed position, and the nozzle row 12K, Since the cap operation for sealing 12C, 12M, and 12Y is not performed, a timer for counting the cap time for closing the cap is initialized (step S24).

  If it is determined in step S22 that ink is not being ejected, it is determined whether or not the cap is being opened (step S23). If the cap is being opened, the process proceeds to step S24 and the timer is counted ( Step S25), the cap time change determination process shown in FIG. 9 is executed (step S26). If the cap is not being opened, the timer is initialized and the process is terminated.

  Next, it is determined whether or not the count value of the timer exceeds a preset cap time (step S27), and if it exceeds, the current process is terminated (step S30) and exceeds the cap time. In this case, after the inkjet head is raised to the closing position by the carriage (step 28), the nozzle rows 12K, 12C, 12M, and 12Y are closed by the caps 20K, 20C, 20M, and 20Y (step S29), and the current processing is performed. Is finished (step S30).

  This cap sealing process is always repeated. When the caps 20K, 20C, 20M, and 20Y are opened for a certain period of time without discharging ink, the caps 20K, 20C, 20M, By abutting 20Y, the ink in the nozzle rows 12K, 12C, 12M, and 12Y is prevented from drying and thickening / adhering, and the ink ejection performance is prevented from deteriorating. .

  Normally, when the printing process proceeds smoothly, the printing process shown in FIG. 7 proceeds without any delay, and the cap sealing operation of FIG. 8 is started when all the printing processes are completed.

  However, if the reception of image data is delayed or there is a large amount of image data, it takes time in step S9 or step S10 in FIG. 7, and as a result, the count value of the timer exceeds the cap time, and the cap sealing operation is activated. There are things to do.

  Therefore, in the cap time change determination process in step S26 of FIG. 8, the cap time change determination process of FIG. 9 is performed to change the cap time. FIG. 9 shows a cap time change determination processing program stored in the ROM of the control microcomputer 31 and executed by the CPU.

  In FIG. 9, the cap time change determination process (step S31) first determines whether the amount of image data received from the PC is larger than a predetermined amount (step S32), and the amount of image data is greater than the predetermined amount. If there are too many, a cap time change flag indicating whether or not to change the cap time is set to "1" (step S33).

  Next, after performing the cap time setting process shown in FIG. 10 (step S34), the cap time change flag is set to “0” in order to reset the cap time (step S35), and the cap time change determination process is ended. (Step S36).

  FIG. 10 is a flowchart of the cap time setting process. FIG. 10 shows a cap time setting processing program stored in the ROM of the control microcomputer 31 and executed by the CPU.

  In FIG. 10, the cap time setting process (step S41) determines whether or not the cap time change flag is “1” (step S42), and determines that the cap time change flag is not “1”. Is set to a standard cap time (step S44). As the standard cap time, for example, a constant value such as 15 seconds is set, or a value such as 15 seconds + k × Δt seconds (k is a coefficient) is set depending on the temperature change Δt.

  If it is determined that the cap time change flag is “1”, the cap time is extended (step S43), and the cap time setting process is terminated (step S45). The extension time is set to a standard cap time × 2 or a value such as a standard cap time + 10 seconds.

  Even if the printing process is interrupted by extending the capping time in this way, the capping operation is performed when the cause is waiting for image data reception or processing, and it is expected to return immediately. Can be delayed. For this reason, when data is received or data processing is completed within the extended time, it is possible to realize prompt resumption of printing without a cap opening operation.

  Further, the cap setting time setting process may be as shown in FIG. The cap time setting process (step S51) in FIG. 11 first determines whether or not the cap time change flag is “1” (step S52) and determines that the cap time change flag is not “1”. Is set to a standard cap time (step S54). As the standard cap time, for example, a constant value such as 15 seconds is set, or a value such as 15 seconds + k × Δt seconds (k is a coefficient) is set depending on the temperature change Δt.

  If it is determined that the cap time change flag is “1”, the cap time is shortened (step S53), and the cap time setting process is terminated (step S55). The extension time is set to a value such as standard cap time ÷ 2 or standard cap time−10 seconds.

  By shortening the cap time in this way, when it is expected that it will take time to receive and process image data when the printing process is interrupted, the nozzle array 12K, By sealing 12C, 12M, and 12Y, it is possible to wait for resumption of printing in a state where drying of the nozzle rows 12K, 12C, 12M, and 12Y is suppressed. As a result, the nozzle state at the time of resuming printing can be maintained well, and the printing quality can be maintained high.

  Whether the capping operation is shortened or extended may be set by the user through the operation panel 17, and when the amount of image data exceeds a certain value, the capping operation is shortened and priority is given to improving the print quality. However, when the amount of image data is equal to or less than a certain value, priority may be given to extending the capping operation and starting a quick printing operation.

  1 to 8 and FIGS. 10 to 13 are views showing a second embodiment of the ink jet recording apparatus according to the present invention, and the basic apparatus configuration is the same as that of the first embodiment.

  In the present embodiment, the control microcomputer 31 constituting the cap time setting means caps when the ink discharge position from the nozzle rows 12K, 12C, 12M, and 12Y of the inkjet head 11 is near the front end of the recording paper 4. It is characterized by changing the time.

  This point will be described based on the flowchart of FIG. FIG. 12 shows a cap time change determination processing program stored in the ROM of the control microcomputer 31 and executed by the CPU, and is executed in step S26 of FIG.

  In FIG. 12, the cap time change determination process (step S61) determines whether or not it is the first scan in the page. If it is the first scan in the page, the processing of the image data immediately after the start of printing. Therefore, it is determined that it will take a long time to start printing, the cap time change plug is set to “1” (step S63), and then the cap time setting process is executed (step S63). S65).

  If it is not the first scan in the page, it is determined whether or not the scan position is near the front end of the recording paper 4 (step S63). If it is determined in step S63 that the scanning position is near the leading edge of the recording paper 4, the processing of image data temporarily increases and the cap time change plug is set to "1" ( If it is determined that the scanning position is not near the leading edge of the recording paper 4 (step S63), a cap time setting process is executed (step S65).

  Next, in order to reset the cap time, the cap time change flag is set to “0” (step S66), and the cap time change determination process is ended (step S67).

  Here, a method of defining the leading end position of the recording paper 4 will be described with reference to FIG. For example, as shown in FIG. 13 (a), the leading end direction is near the leading end of the recording paper 4 from the half position of the entire length of the recording paper 4, or as shown in FIG. The range of the distance (for example, 10 cm for A4 recording paper) is the vicinity of the tip.

  In the present embodiment, when printing near the leading edge of the recording paper 4, the processing of the image data temporarily accumulates and increases, and it takes time to start printing. Therefore, the cap time is extended at this time. Or shortening the printing speed, it is possible to suppress a decrease in printing speed or to suppress a decrease in printing quality.

  FIGS. 1 to 8, FIG. 10, FIG. 11, and FIG. 14 are views showing a third embodiment of the ink jet recording apparatus according to the present invention, and the basic apparatus configuration is the same as that of the first embodiment. is there.

  The present embodiment is characterized in that the capping time is changed based on the resolution of the image that the inkjet head 11 prints on the recording paper 4 by the control microcomputer 31 constituting the capping time setting means.

  This point will be described based on the flowchart of FIG. FIG. 14 shows a cap time change determination processing program stored in the ROM of the control microcomputer 31 and executed by the CPU, and is executed in step S26 of FIG.

  In FIG. 14, the cap time change determination process (step S71) determines whether or not the resolution of the image is high (step S72). If the resolution of the image is high, the amount of image data to be processed is large, and the data Is received, or it takes a long time to start printing, the cap time change plug is set to "1" (step S73), and then the cap time setting process is executed (step S74). .

  Next, in order to reset the cap time, the cap time change flag is set to “0” (step S75), and the cap time change determination process is ended (step S76).

  As described above, in this embodiment, when the resolution of an image to be printed is high, the data amount of the image to be processed increases. At this time, the print speed can be increased or decreased by shortening the cap time. Can be suppressed, or the deterioration of print quality can be suppressed.

  FIGS. 1-8, 10, 11, and 15 are views showing a fourth embodiment of an ink jet recording apparatus according to the present invention. The basic apparatus configuration is the same as that of the first embodiment. is there.

  The present embodiment is characterized in that the cap time is changed based on the printing mode of the image by the control microcomputer 31 constituting the cap time setting means.

  This point will be described based on the flowchart of FIG. FIG. 15 shows a cap time change determination processing program stored in the ROM of the control microcomputer 31 and executed by the CPU, and is executed in step S26 of FIG.

  In FIG. 15, the cap time change determination process (step S81) determines whether or not the number of interlaces, that is, the number of scanning lines in the main scanning direction when drawing one line is greater than a predetermined amount (step S82). When the number of interlaces is larger than the predetermined amount, it is determined that the amount of image data to be processed is large and it takes a long time to start printing, and the cap time change plug is set to “1” ( Step S84), a cap time setting process is executed (Step S85).

  If the number of interlaces is small, it is determined whether the number of passes, that is, whether the number of times the carriage 10 reciprocates to draw one line is greater than a predetermined amount (step S83). If there is too much, it is determined that the amount of image data to be processed is large, and it takes a long time to start printing. After setting the cap time change plug to “1” (step S84), the cap time A setting process is executed (step S85).

  Next, in order to reset the cap time, the cap time change flag is set to “0” (step S86), and the cap time change determination process is ended (step S87).

  As described above, in the present embodiment, when the number of interlaces and passes is large based on the printing mode such as interlace and the number of passes, the amount of image data to be processed increases. By shortening, it is possible to suppress a decrease in printing speed or to suppress a decrease in printing quality.

  As described above, the ink jet recording apparatus according to the present invention suppresses the decrease in the printing speed by changing the time until the cap operation when the amount of data of the image to be printed is large, or the print quality is improved. It has the effect of suppressing the decrease, and is useful as an ink jet recording apparatus or the like that is used in a printer apparatus, a facsimile apparatus, a multi-function machine, etc., and has a cap unit that closes the ejection port of the ink jet head.

1 is a schematic cross-sectional view of a printer apparatus including an inkjet recording apparatus according to first to fourth embodiments of the present invention. It is a schematic longitudinal cross-sectional view of the printer apparatus of 1st-4th embodiment. It is the figure which expanded and displayed some discharge ports of the inkjet head in the 1st-4th embodiment. It is a figure which shows the state which moved the cap unit of 1st-4th embodiment to the obstruction | occlusion position. It is a figure which shows the state which moved the cap unit of 1st-4th embodiment to the open position. It is a block diagram of the control system of the printer apparatus of 1st-4th embodiment. 10 is a flowchart of print processing in the first to fourth embodiments. It is a flowchart of the cap sealing process in the 1st-4th embodiment. It is another flowchart of the cap time change determination process in 1st Embodiment. It is a flowchart of the cap time setting process in 1st-4th embodiment. It is a flowchart of the other cap time setting process in 1st Embodiment. It is a flowchart of the cap time change determination process in 2nd Embodiment. (A) (b) is a figure which shows the front-end | tip position of the recording paper in 2nd Embodiment. It is a flowchart of the cap time change determination process in 3rd Embodiment. It is a flowchart of the cap time change determination process in 4th Embodiment. It is a flowchart of the conventional cap sealing process.

Explanation of symbols

1 Printer device 4 Recording paper (recording medium)
11 Inkjet head 12K, 12C, 12M, 12Y Nozzle row (discharge port)
19 Cap unit (cap means)
31 Control microcomputer (image data amount detection means, timing means, cap time setting means, cap activation means)

Claims (6)

An ink jet head that has a discharge port that discharges ink of at least one color and performs printing by discharging ink from the discharge port to a recording medium;
Cap means for moving between a closed position for closing the discharge port of the inkjet head and an open position for opening the discharge port;
Clocking means for timing the time during which the operation of discharging ink from the discharge port of the inkjet head is stopped;
A cap time setting means for setting a cap time that is a time from when the ink ejection operation by the inkjet head is stopped and when the cap means is located at the closed position to the closed position;
In an ink jet recording apparatus comprising: a cap activation unit that moves the cap unit to the closed position when the time measured by the time unit reaches the cap time.
Image data amount detecting means for detecting the data amount of the image to be printed;
The inkjet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time when the amount of data of an image to be printed is large, based on detection information of the image data amount detection unit. 2. The ink jet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time when an ink discharge position from the ink jet head is near a leading end of the recording medium. The inkjet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time based on a resolution of an image to be printed on the recording medium. The inkjet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time based on an image printing mode. The inkjet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time to be longer. The inkjet recording apparatus according to claim 1, wherein the cap time setting unit changes the cap time to be shorter.

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