JP2005059304A - Ink jet recording apparatus and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To run out of ink during printing when a large amount of ink is consumed except for a recording operation such as a suction recovery process or a preliminary ejection process in order to maintain image quality when an ink remaining amount in an ink tank is small. There are problems such as the recorded image being blurred and the number of recordable images being reduced.
Ink is ejected in accordance with print data, the remaining amount of ink in an ink tank set in a recording head 3 that performs a recording operation is managed, and a standby time of the recording head 3 after printing is started is set. In addition, the ink from the recording head 3 is ejected at a predetermined timing to perform the cleaning operation (suction recovery or preliminary ejection) of the recording head 3, but when the remaining amount of ink in the ink tank falls below a certain value, The amount of ink discharged in the cleaning operation is reduced.
[Selection] Figure 9

Description

  The present invention relates to an image recording method and an image recording apparatus, and relates to, for example, an ink jet recording apparatus that records characters and images on a recording medium by ejecting ink droplets from recording nozzles according to print data.

  Examples of the recording apparatus such as a printer, a copying machine, and a facsimile include a recording apparatus that records an image by forming a dot pattern based on image information on a recording medium such as paper or a plastic thin plate. Such recording apparatuses include various recording system recording apparatuses such as an ink jet system, a wire dot system, a thermal system, and a laser beam system. In recent years, high-speed recording, high image quality (high resolution) ), Low noise is required. As a recording apparatus that meets these requirements, there is an ink jet recording apparatus (ink jet recording apparatus). In this ink jet recording apparatus, an ink (recording liquid) droplet discharged from the discharge port of a recording head is attached to a recording medium to form an image. Further, since recording can be performed in a non-contact manner, a stable image can be recorded on a wide range of recording media.

<Ink consumed by non-printing operations in inkjet printers>
In such an ink jet printer, ink is consumed in addition to image recording in order to maintain the image quality to be recorded. For example, it is necessary to perform suction recovery to remove bubbles in the recording head, or to discharge ink at regular intervals even during non-printing in order to prevent the discharge nozzles from drying.

  However, if the remaining amount of ink is low and ink is consumed for purposes other than recording in order to maintain image quality, the ink will run out during printing, and the recorded image will fade, reducing the number of recordable images. Problems occur.

  In such an ink jet recording apparatus, when the remaining amount of ink is reduced, control for prohibiting the recovery operation when the remaining amount of ink is reduced for the purpose of reducing the amount of ink used other than printing. Has been proposed.

  Japanese Patent Laid-Open No. 05-169668 proposes an ink discharge recovery device that monitors the remaining amount of ink during a period of recovery operation of the ink discharge capability and stops the ink suction operation when the ink amount becomes less than a specified value. Has been.

  Japanese Patent Application Laid-Open No. 09-300645 discloses an ink tank detection sensor that detects the presence or absence of an ink tank, an ink remaining amount detection sensor that detects the remaining amount of ink in the ink tank, and a suction mechanism that makes the ink suction amount variable. There has been proposed an ink ejecting apparatus that includes a drive circuit and controls the suction mechanism drive circuit based on the ink tank detection sensor and the ink remaining amount detection sensor to stop the suction operation when the ink becomes less than a predetermined amount. .

  Japanese Patent Application Laid-Open No. 2000-296627 includes an ink storage unit, a cleaning unit, a determination unit, and a control unit, and compares the remaining amount of ink in the ink storage unit with the amount of ink used for cleaning during cleaning. Cleaning is performed only when it is determined that cleaning is possible, and when it is determined that cleaning cannot be performed, the ink tank is replaced without cleaning, and this makes it necessary to replace the tank immediately after cleaning. Printing devices have been proposed that prevent this from happening.

However, the prohibition / interruption of the recovery operation based on the remaining ink amount can prevent running out of ink during cleaning and wasteful tank replacement, but does not increase the amount of ink that can be used for printing, and therefore the number of printable sheets. The problem arises that is no different from the conventional.
JP 05-169668 A Japanese Patent Laid-Open No. 09-300645 JP 2000-296627 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its feature is to provide a simple control inkjet recording apparatus that increases the amount of ink that can be used for printing while minimizing the effect on image quality. It is in.

In order to solve the above problems, an ink jet recording apparatus according to the present invention is an ink jet recording apparatus that discharges a plurality of types of ink in accordance with print data and records the print data on a recording medium. A recording head that discharges ink in response to the recording operation, a management unit that manages a remaining amount of ink in an ink tank set in the recording head, and a standby time that sets a standby time of the recording head after printing is started Setting means;
A cleaning unit that discharges ink from the recording head at a predetermined timing to clean the recording head, and a discharge amount of the ink of the cleaning unit is reduced when the remaining amount of ink becomes a predetermined value or less. Cleaning control means for controlling.

  The ink jet recording apparatus according to the present invention manages the remaining amount of ink in the ink tank, and changes the cleaning operation of the recording head when the remaining amount of ink falls below a certain value. This makes it possible to reduce the amount of ink to be printed and to increase the number of printable sheets.

  First, a basic configuration of an ink jet recording apparatus that is commonly applied to each embodiment and a block diagram of a control configuration thereof will be described with reference to FIGS.

  In each embodiment, the ink jet recording apparatus may be simply referred to as a recording apparatus or a printing apparatus.

  Further, in this specification, “recording” and “printing” (sometimes referred to as “printing”) include not only the formation of significant information such as characters and figures, but also whether it is significant or insignificant. Regardless of whether or not it has been made obvious so that it can be perceived in the above, it also represents a case where an image, a pattern, a pattern or the like is widely formed on a recording medium or the medium is processed.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Furthermore, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly in the same way as the definition of “recording (printing)” above. It represents a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing an ink (for example, solidification or insolubilization of a colorant in ink applied to the recording medium).

  Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port or a liquid channel communicating with the ejection port and an element that generates energy used for ink ejection.

<Example of basic configuration of inkjet recording apparatus>
First, a schematic configuration diagram of a main part of an ink jet recording apparatus to which the present invention can be applied will be described.

  FIG. 1 is an external perspective view showing an outline of the configuration of an ink jet recording apparatus 1 which is a typical embodiment of the present invention.

  As shown in FIG. 1, an ink jet recording apparatus (hereinafter referred to as a recording apparatus) transmits a driving force generated by a carriage motor M1 to a carriage 2 on which a recording head 3 that performs recording by discharging ink according to an ink jet system is mounted. 4, the carriage 2 is reciprocated in the direction of arrow A, and for example, a recording medium P such as recording paper is fed through a paper feeding mechanism 5 and conveyed to a recording position. Recording is performed by ejecting ink onto the recording medium P.

  Further, in order to maintain the state of the recording head 3 satisfactorily, the carriage 2 is moved to the position of the recovery device 10 and the ejection recovery process of the recording head 3 is intermittently performed.

  In addition to mounting the recording head 3 on the carriage 2 of the recording apparatus 1, an ink cartridge 60 for storing ink to be supplied to the recording head 3 is mounted. The ink cartridge 60 is detachable from the carriage 2.

  As shown in FIG. 2, the recording head 3 of this example constitutes a recording head cartridge 30 together with an ink cartridge 60 that stores ink. As the ink cartridge 60, for example, black, light cyan, light magenta, cyan, magenta, and yellow ink tanks independent of each color are prepared in order to enable photographic-tone high-quality color recording. Although four color ink tanks are drawn in FIG. 1 and six color ink tanks are drawn in FIG. 2, either of them can be applied in this embodiment.

  Now, the carriage 2 and the recording head 3 can achieve and maintain a required electrical connection by properly contacting the joint surfaces of both members. The recording head 3 applies energy according to a recording signal to selectively eject ink from a plurality of ejection ports for recording. In particular, the recording head 3 of this embodiment employs an ink jet system that ejects ink using thermal energy, and includes an electrothermal transducer to generate thermal energy, which is applied to the electrothermal transducer. Electric energy is converted into thermal energy, and ink is ejected from the ejection port by utilizing pressure changes caused by bubble growth and contraction caused by film boiling caused by applying the thermal energy to the ink. The electrothermal transducer is provided corresponding to each of the ejection ports, and ink is ejected from the corresponding ejection port by applying a pulse voltage to the corresponding electrothermal transducer in accordance with the recording signal.

  As shown in FIG. 1, the carriage 2 is connected to a part of the driving belt 7 of the transmission mechanism 4 that transmits the driving force of the carriage motor M <b> 1, and slides in the direction of arrow A along the guide shaft 13. It is designed to be freely guided and supported. Accordingly, the carriage 2 reciprocates along the guide shaft 13 by forward and reverse rotations of the carriage motor M1. A scale 8 is provided for indicating the absolute position of the carriage 2 along the moving direction of the carriage 2 (the direction of arrow A). In this embodiment, the scale 8 uses a transparent PET film on which black bars are printed at a necessary pitch, one of which is fixed to the chassis 9 and the other is supported by a leaf spring (not shown). Yes.

  Further, the recording apparatus 1 is provided with a platen (not shown) facing the discharge port surface where the discharge port (not shown) of the recording head 3 is formed, and the recording head 3 is driven by the driving force of the carriage motor M1. At the same time as the carriage 2 loaded with is reciprocated, recording is performed over the entire width of the recording medium P conveyed on the platen by giving a recording signal to the recording head 3 and discharging ink.

  Further, in FIG. 1, 14 is a conveyance roller driven by a conveyance motor M2 to convey the recording medium P, 15 is a pinch roller that abuts the recording medium P against the conveyance roller 14 by a spring (not shown), and 16 is a pinch. A pinch roller holder 17 that rotatably supports the roller 15 is a conveyance roller gear fixed to one end of the conveyance roller 14. Then, the transport roller 14 is driven by the rotation of the transport motor M2 transmitted to the transport roller gear 17 through an intermediate gear (not shown).

  Further, reference numeral 20 denotes a discharge roller for discharging the recording medium P on which an image is formed by the recording head 3 to the outside of the recording apparatus, and is driven by transmitting the rotation of the transport motor M2. . The discharge roller 20 abuts on a spur roller (not shown) that presses the recording medium P by a spring (not shown). Reference numeral 22 denotes a spur holder that rotatably supports the spur roller.

  Furthermore, as shown in FIG. 1, the recording apparatus 1 includes a desired position (for example, a home position) outside the reciprocal movement range (outside the recording area) for the recording operation of the carriage 2 on which the recording head 3 is mounted. A recovery device 10 for recovering the ejection failure of the recording head 3 is disposed at a position corresponding to the position).

  The recovery device 10 includes a capping mechanism 11 for capping the ejection port surface of the recording head 3 and a wiping mechanism 12 for cleaning the ejection port surface of the recording head 3, and interlocks with the capping of the ejection port surface by the capping mechanism 11. Ink recovery such as forcibly discharging ink from the discharge port by suction means (suction pump or the like) in the recovery device, thereby removing ink or bubbles having increased viscosity in the ink flow path of the recording head 3 Processing (also referred to as suction recovery processing) is performed.

  In addition, by discharging ink that does not contribute to image recording from the ink discharge port toward the cap of the capping mechanism, a recovery process (both discharge recovery process or preliminary discharge) is performed in order to maintain a good ink discharge state of the recording head 3. Say).

  Further, when the recording operation is not performed, the ejection port surface of the recording head 3 is capped by the capping mechanism 11 to protect the recording head 3 and to prevent ink evaporation and drying. On the other hand, the wiping mechanism 12 is disposed in the vicinity of the capping mechanism 11 and wipes ink droplets adhering to the ejection port surface of the recording head 3.

  The capping mechanism 11 and the wiping mechanism 12 can keep the ink ejection state of the recording head 3 normal.

  As shown in FIG. 1, the carriage 2 is provided with a carriage cover for guiding the recording head 3 to a predetermined mounting position on the carriage 2. Further, the carriage 2 is provided with a head set lever 23 that engages with a tank holder of the recording head 3 to set the recording head 3 at a predetermined mounting position. The head set lever 23 is provided so as to be rotatable with respect to a head set lever shaft positioned at the upper part of the carriage 2. (Not shown) is provided. With the spring force, the head set lever 24 is mounted on the carriage 2 while pressing the recording head 3.

<Control Configuration of Inkjet Recording Apparatus (FIG. 3)>
FIG. 3 is a block diagram showing a control configuration of the recording apparatus shown in FIG.

  As shown in FIG. 3, the controller 600 includes an MPU 601, a program corresponding to a control sequence to be described later, a required table, a ROM 602 storing other fixed data, a control of the carriage motor M1, a control of the transport motor M2, and a recording. A special purpose integrated circuit (ASIC) 603 that generates a control signal for controlling the head 3, and a RAM 604, an MPU 601, an ASIC 603, and a RAM 604, which are provided with image data development areas and program execution areas, are connected to each other. A system bus 605 for transferring data, and an A / D converter 606 for inputting analog signals from the sensor group described below, A / D converting them, and supplying digital signals to the MPU 601 and the like.

  In FIG. 2, reference numeral 610 denotes a computer (or a reader for image reading, a digital camera, etc.) serving as a supply source of image data, and is collectively referred to as a host device. Image data, commands, status signals, and the like are transmitted and received between the host apparatus 610 and the recording apparatus 1 via an interface (I / F) 611.

  Further, reference numeral 620 denotes a switch group, which instructs activation of a power switch 621, a print switch 622 for instructing printing start, and a process (recovery process) for maintaining the ink ejection performance of the recording head 3 in a good state. For example, a recovery switch 623 for receiving a command input from the operator. Reference numeral 630 denotes a position sensor 631 such as a photocoupler for detecting the home position h, a temperature sensor 632 provided at an appropriate location of the recording apparatus for detecting the environmental temperature, and the like. It is a sensor group.

  Further, 640 is a carriage motor driver that drives a carriage motor M1 for reciprocating scanning of the carriage 2 in the direction of arrow A, and 642 is a conveyance motor driver that drives a conveyance motor M2 for conveying the recording medium P.

  The ASIC 603 transfers drive data (DATA) of the printing element (ejection heater) to the printing head while directly accessing the storage area of the RAM 602 during printing scanning by the printing head 3.

<Remaining amount management by main unit dot count>
4 to 9 are diagrams for explaining the first embodiment of the present invention that can be applied to the above-described ink jet recording apparatus. First, the flow from the start to the end of printing will be described with reference to FIGS.

  First, FIG. 4 is a diagram for explaining a process of a series of operations of printing command → paper feeding → printing → paper ejection → standby → capping.

  FIG. 4 is a schematic diagram for explaining from printing to capping after printing is completed. FIG. 4A is a schematic diagram illustrating a carriage, a cap, and a recording unit that are waiting for printing. In the standby recording apparatus, the head portion is protected by a cap as shown in FIG. 4 in order to prevent drying of the ink discharge portion of the recording head. When a printing command is sent from this state to the recording apparatus, it is determined whether suction recovery is necessary, and if necessary, the inside of the cap is set to a negative pressure to perform ink suction recovery. If it is determined that it is not necessary, as shown in FIG. 4B, the cap is removed from the carriage, and the carriage 2 can move to the recording unit. In this state, the recording medium is fed from the automatic supply unit to the recording unit, and the recording preparation is completed.

  FIG. 4C is a diagram illustrating a state in which the carriage 2 moves and recording is performed by the recording unit. A recording operation in which ink is ejected from the recording head 3 based on recording data while the recording head 3 is scanned in the main scanning direction together with the carriage 2 by the carriage (CR) motor M1, and a line feed (LF) motor (conveyance motor) M2 By repeating the transport operation for transporting a predetermined amount of paper in the sub-scanning direction, images are sequentially recorded on the paper.

FIG. 4D shows a state in which image recording has been completed and the sheet has been discharged. The carriage 2 waits for the next print command at a position facing the cap. At this time, in order to prevent the recording head from drying, ink is discharged (preliminary discharge) at regular intervals in the cap or toward the ink absorber. As shown in FIG. 4E, when a certain time elapses, it is determined that printing will not be performed for a while, and the head is capped again.
<Explanation of remaining ink management>
5 to 8 are flowcharts (remaining amount counting method) for managing the amount of ink used in the printing apparatus.

  With reference to FIG. 5, management of the amount of ink used at the time of suction recovery will be described.

  First, when the suction recovery is instructed, the suction recovery process starts. In step S101, the type of suction recovery is set according to various conditions such as the elapsed time from the previous suction recovery and the number of print dots. Here, it is assumed that the suction A is 0.1 g, the suction B is 0.2 g, and the suction C is 0.4 g. For example, C, which is a suction amount as much as possible, is set if the elapsed time from the previous suction recovery is long.

  Subsequently, in step S102, suction recovery is performed according to the suction type set in step S101, and in step S103, the ink amount used in the current suction recovery is set. In this case, the used ink amount may be calculated each time, or a set value determined in advance for each suction type may be used. The set ink amount is added to the recovery counter, and the suction recovery ends.

  Next, management of the amount of ink used during preliminary ejection will be described with reference to FIG.

  First, when preliminary ejection is instructed, the type of preliminary ejection is set in step S201 according to the application. Here, 10 discharges are performed as the preliminary discharge A, 500 discharges as the preliminary discharge B, and 2000 discharges as the preliminary discharge C. After performing preliminary ejection according to the preliminary ejection type set in step S202, in step S203, the ink amount used in the current preliminary ejection operation is set. As in the suction recovery, the used ink amount may be calculated each time, or a preset value determined in advance for each preliminary ejection type may be used. In step S204, the set ink amount is added to the preliminary ejection counter, and the preliminary ejection ends.

  FIG. 7 is a flowchart showing a process for measuring the amount of ink used in printing.

  First, at the start of printing, the “printing ink amount measurement routine” is started. In step S301, the printing operation is actually performed. In step S302, the amount of ink used in printing is calculated every line or every time printing is performed for a predetermined printing unit. In step S303, the calculated ink amount is added to the print counter. This series of operations is repeated until printing is completed.

  FIG. 8 is a flowchart showing a process for managing the remaining amount of ink.

  Ink remaining amount calculation is performed at the end of printing or soft power OFF processing. In step S401, the “ink remaining amount counter” is read. In step S402, the value of “recovery counter” is read. In step S403, the value of “preliminary discharge counter” is read, and in step S404, the value of “print counter” is read.

  In step S405, the ink consumption is calculated based on the counter values of “recovery”, “preliminary ejection”, and “printing” (for example, the number of counters × the amount of ink ejected once). In step S 406, a process of subtracting the ink consumption from the “ink remaining amount” to make a new “ink remaining amount” is performed. In step S407, the obtained “ink remaining amount” is written in the ink remaining amount counter. In step S408, the “recovery”, “preliminary discharge”, and “printing” counters are cleared and reset, and the ink remaining amount calculation sequence is performed. Exit.

  Here, it is assumed that the remaining ink counter is recorded in an EEPROM provided on the main body substrate. EEPROM is a type of non-volatile memory that does not lose its memory even if power is not supplied from the outside. It is a kind of ROM that can electrically erase and write contents. Information about the remaining amount is retained.

  The basic operation for managing the remaining ink amount has been described above. This embodiment is also based on this basic operation, and the features of this embodiment will be described in detail below.

  FIG. 9 is a flowchart for explaining suction recovery in the recording apparatus to which the present invention is applied. The main feature of the present embodiment is that the suction amount is reduced (for example, 0.1 g → 0.05 g) when the ink remaining amount is equal to or less than a predetermined value.

  First, when suction recovery is instructed, the type of suction recovery is set according to various conditions in step S501. Regarding this type, A, B, and C described above can be applied. In step S502, the remaining ink amount is compared with a preset value. If the remaining ink amount is equal to or greater than the set value, the process proceeds to step S503. If the remaining ink amount is equal to or less than the set value, the process proceeds to step S504. In step 503, the suction amount is set to a normal value (for example, 0.1 g). In step S504, since the ink remaining amount is equal to or less than the set value, the suction amount is set to half of the normal value (for example, 0.05 g).

  Next, in step S505, suction recovery is performed according to the set suction conditions. In step S506, the ink amount used for the suction is set. In step S507, the amount of ink used in the recovery counter (value calculated based on the amount of ink used) is added, and the suction recovery sequence ends.

  Here, the normal ink suction amount set in step S503 is set so that there is no problem in image quality in any state of the recording apparatus. On the other hand, in step S504, since the suction amount is set to be smaller than usual, there is a possibility that some images may be disturbed. However, in exchange for the possibility of image distortion, the ink consumption is reduced, and it becomes possible to postpone the serious problem that the ink runs out and printing cannot be used at all. The present invention has the advantage that there is no problem in the printing process even if it is somewhat delayed.

  As described above, the above configuration makes it possible to reduce the amount of ink consumed in the recovery of suction depending on the remaining amount of ink, and to increase the amount of ink that can be used for printing.

  In the above-described embodiment, the suction amount is set to be halved when the ink remaining amount is equal to or less than a certain value. However, the method for setting the suction amount is not limited to this. For example, when a suction sequence of 0.03 g is prepared as the suction amount A ′ and the remaining ink amount is equal to or less than the set value, suction A is suction A ′, suction B is suction A, and suction C is suction B. It is also possible to reduce the amount of suction using the setting.

  The feature of this embodiment is that when the remaining amount of ink is equal to or less than a predetermined value, processing for increasing the preliminary ejection interval (for example, 3 seconds → 10 seconds) is performed.

  10 and 11 are diagrams for explaining a second embodiment of the present invention that can be applied to the above-described ink jet recording apparatus.

  First, the basic operation of the preliminary ejection process will be described with reference to FIG. FIG. 10 is a flowchart for explaining processing from printing to capping after printing.

  When printing is instructed, printing processing is performed in step S601. In step S602, it is determined whether there is print data to be continuously printed. If there is print data, the process returns to step S601 to continue printing. If there is no print data, the process advances to step S603 to set a standby preliminary discharge interval Ty. In step S604, a standby time Tw is set. In step S606, the standby timer is reset and then started.

  In step S606, a preliminary ejection operation is performed while the recording head 3 is on standby. In step S607, the preliminary ejection timer is reset, and the preliminary ejection interval timer is started. In step S608, it is determined whether or not the preliminary ejection timer has reached the preliminary ejection interval Ty. If it has been reached, the process returns to step S606 to perform standby preliminary ejection. If the preliminary ejection timer is less than the preliminary ejection interval Ty, the process proceeds to step S609, where the presence or absence of print data is determined. If there is print data, the process returns to step S601 to start printing. If there is no print data, it is determined in step S610 whether or not the standby timer has reached the standby time Tw. If it is determined in step S610 that the standby time Tw has not been reached, the process returns to step S608 to perform preliminary discharge at the preliminary discharge interval Ty until the standby time Tw is reached. If the standby timer reaches the standby time in step S610, the process proceeds to step S611, where capping processing is performed, and the printing sequence ends.

  FIG. 11 is a flowchart for explaining processing from printing to capping after printing according to the present invention, in which the basic operation of the preliminary ejection and capping described above is improved.

  When printing is instructed, a printing process is performed in step S701. Subsequently, in step S703, it is determined whether there is print data to be continuously printed. If there is print data, the process returns to step S701 to continue printing. If there is no print data, the process proceeds to step S703. These operations are the same as the basic operations of FIG. In step S703, it is determined whether the remaining amount of ink is equal to or greater than a set value. If the remaining ink amount is equal to or greater than the set value, the standby preliminary discharge interval Ty is set to the normal 3 seconds in step S704. If the remaining ink amount is less than the predetermined set value, the preliminary ejection interval Ty is set to 10 seconds longer than normal in step S705. When the process of step S704 or S705 ends, the process proceeds to step S707.

  In step S706, the standby time Tw is set. After the standby time is set, the standby timer is reset in step S707 and then restarted. In step S708, preliminary ejection is performed during the standby time. When the preliminary discharge is started, the timer is started again after the preliminary discharge interval timer is reset in step S709.

  In step S710, the preliminary ejection timer and the preliminary ejection interval Ty are compared. If the preliminary ejection interval Ty has been reached, the process returns to step S708, and the standby preliminary ejection is continued. If it is determined in step S710 that the preliminary ejection timer has not reached the preliminary ejection interval Ty, the process proceeds to step S711, and the presence / absence of print data is determined. If there is print data, the process returns to step S701 to start printing. If there is no print data, it is determined in step S712 whether or not the standby timer has reached the standby time Tw. If the standby timer has not reached the standby time Tw, the process returns to step S710, and preliminary discharge is performed at the preliminary discharge interval Ty until the standby time Tw is reached. If the standby timer has reached the standby time Tw, the process proceeds to step S713, a capping process is performed, and the printing sequence is completed. The series of processing flow in the latter half is the same as the basic operation described above.

  Here, the normal preliminary ejection interval set in step 704 is set so that there is no problem in image quality in any state of the recording apparatus. On the other hand, in step S705, a pre-discharge interval that is longer than normal is set, so that there is a possibility that some images may be disturbed. However, the ink consumption is reduced in exchange for the possibility of image disturbance, which makes it possible to postpone the serious problem that the ink runs out and printing is faint and cannot be used at all.

  In this embodiment, since the preliminary discharge interval is normally 3 seconds, 20 preliminary discharges are performed during the standby time of 60 seconds. However, when the present invention is applied, when the remaining amount of ink decreases. Since only 6 preliminary ejections are required, the amount of ink consumed by the preliminary ejection is 30% (6 times / 20 times) than usual.

  When a print command is received from the capping state, it takes extra time until the first sheet is printed by a cap open operation or the like, compared to printing from the standby state. In order to avoid this, when the standby time is extended from 60 seconds, the amount of ink consumed by preliminary ejection also increases, and the effectiveness of the present invention is further increased.

  In this embodiment, in order to reduce the amount of ink consumed by the preliminary ejection, the setting of the standby preliminary ejection interval is changed when the remaining amount of ink is equal to or less than the set value. The control for reducing the amount of ink generated is not limited to this. For example, the number of preliminary ejections is usually 10 while the number of ink remaining is less than the set value, the number is reduced to 3 It may be good that the standby time Tw is normally 60 seconds, but is set to 10 seconds when the remaining ink amount is not more than the set value.

  A feature of the present embodiment is that a process of reducing the standby time is performed when the remaining amount of ink is a predetermined value or less. The remaining amount management is performed, for example, in a memory of an ink cartridge (ink tank).

  FIG. 12 is a diagram for explaining the present embodiment which can be applied to the above-described ink jet recording apparatus.

  In the first and second embodiments, the method of managing the remaining ink amount with the main body EEPROM has been described. However, the present invention does not limit the management location of the remaining ink amount. As an example, a case where an EEPROM is installed in the ink cartridge 60 and the remaining amount of ink is managed will be described. Control that has a memory in the ink cartridge 60 and manages the remaining amount of ink has been widely known, and it is easy to manage the remaining amount of a tank in a specific ink cartridge even when the ink cartridge 60 is detached. There are advantages, such as.

  FIG. 11 is a schematic diagram of an ink cartridge 60 used in this embodiment. FIG. 3 is a view when the ink cartridge 60 in FIG. 2 is viewed from a direction B in FIG. 2. Reference numeral 61 denotes a protrusion for fixing the ink cartridge 60 to the recording head 3, and performs positioning when the ink cartridge is attached to the recording head 3. Reference numeral 62 denotes a substrate on which an EEPROM for managing the remaining amount of ink used in this embodiment is mounted, 63 is an electrode for reading and writing to the EEPROM, and 64 is an EEPROM. When the electrode 63 is attached to the recording head 3, the electrode 63 comes into contact with an electrode (not shown) on the recording head provided at the opposite position, and the electrode of the recording head is connected to the main body via the electrode provided on the carriage 2. And have electrical connection.

  Next, a print standby operation in the recording apparatus to which the present invention is applied will be described with reference to FIG.

  When printing is instructed, printing is executed in step S801. Subsequently, in step 802, it is determined whether there is data to be continuously printed. If there is print data, the process returns to step S801 to continue printing. If there is no data to be continuously printed, the process proceeds to step S803, where it is determined whether or not the remaining amount of ink is greater than or equal to a predetermined set value.

  If it is determined in step S803 that the remaining amount of ink is greater than or equal to a certain value, the process proceeds to step S804, and a normal standby time Tw is set. On the other hand, if it is determined in step S803 that the remaining amount of ink is less than a certain value, the process proceeds to step S812 to perform capping without performing preliminary ejection processing during standby, and the print standby operation is terminated.

  After the standby time Tw is set in step S804, the process proceeds to step S805, where the preliminary ejection interval Ty is set. In step S806, after the standby timer is reset, the standby timer is started again. By the processing in steps S807 to S811, preliminary ejection is repeated at the preliminary ejection interval Ty during the standby time Tw.

  If it is determined in step S811 that the standby time has passed, the process proceeds to step S812, where capping is performed and the print standby operation ends.

  This makes it possible to reduce the amount of ink consumed by the preliminary ejection when the remaining amount of ink is less than a certain value. As described above, when a print command is received from the capping state, it takes extra time until the first sheet is printed by a cap open operation or the like, compared to printing from the standby state. However, in this embodiment, in exchange for this problem, it is possible to postpone a serious problem that the ink is used up and the printing is faint and cannot be used at all. Usually, since the standby time is 60 seconds and the preliminary ejection interval is 3 seconds, 20 preliminary ejections are performed during the standby time of 60 seconds. However, when the present invention is applied, the ink remaining amount decreases. In this case, since the preliminary ejection during standby is not performed, the amount of ink consumed by the preliminary ejection can be significantly reduced.

  In the present invention, an example in which capping is performed immediately when the remaining amount of ink is less than a certain value has been described. However, the control for changing the standby time is not limited to this. For example, instead of performing capping immediately, the setting of the standby time may be changed, and capping may be performed after 20 seconds.

  In the first embodiment, the suction amount of the suction recovery process is reduced according to the ink remaining amount. In the second embodiment, the time interval of the preliminary ejection process is increased according to the remaining ink amount. In the third embodiment, the preliminary ejection process is performed according to the remaining ink amount. Processing for determining whether or not to perform is performed.

  In the fourth embodiment, the amount of ink consumed can be significantly reduced more appropriately by combining the cleaning processes of these three recording heads 3. As for the combination, the configuration of the first embodiment and the configuration of the second embodiment, the configuration of the first embodiment, and the configuration of the third embodiment are considered preferable. By this combination, a synergistic effect of ink reduction can be expected.

  Further, when the configuration of the second embodiment and the configuration of the third embodiment are combined, the processing shown in FIG. 14 is performed. The description of the operation of the present embodiment is omitted because it overlaps with the description of the first to third embodiments.

  In FIG. 14, first and second set values are provided when determining the remaining ink amount. The first set value is used in step S903, and the second set value is used in step S904. The first set value is smaller than the second set value.

  That is, if the remaining amount of ink is smaller than the first set value in step S903, the process proceeds to step S915 without performing the subsequent process, for example, the preliminary ejection process (prohibition), and the capping operation is performed and the printing is performed. Processing ends.

  If the ink remaining amount is greater than or equal to the first set value in step S903, it is further determined in step S904 whether the ink remaining amount is greater than or equal to the second set value. If the remaining ink amount is equal to or greater than the second set value, the preliminary ejection interval is set to 3 seconds, for example, in step S905, and if it is equal to or less than the second set value, the preliminary ejection interval is set to, for example, 10 seconds in step S906. Is done. Since other operations are the same as those in the third embodiment, description thereof is omitted.

Thus, by providing two set values (threshold values) for the remaining amount of ink, it is possible to perform very flexible processing depending on the remaining amount of ink.
<Other implementations of the present embodiment>
A feature of the present invention is that it provides a system or apparatus with a storage medium storing software program codes for realizing the functions of the embodiments, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium in the storage medium. It can also be realized by reading and executing the program code. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying such program code, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM Etc. can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code. A case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

  Furthermore, after the program code read from the storage medium is written to the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the function is based on the instruction of the program code. This includes a case where the CPU or the like provided in the expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  In the above embodiments, the liquid droplets ejected from the recording head have been described as ink, and the liquid stored in the ink tank has been described as ink. However, the container is not limited to ink. Absent. For example, a treatment liquid discharged to the recording medium may be accommodated in the ink tank in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

  The above embodiment includes means (for example, an electrothermal converter or a laser beam) that generates thermal energy as energy used to perform ink ejection, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.

  As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. When the drive signal is pulse-shaped, the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve the discharge of the liquid (ink) with particularly excellent responsiveness, which is more preferable.

  As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, the liquid path, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an opening that absorbs a pressure wave of thermal energy is discharged to a plurality of electrothermal transducers A configuration based on Japanese Patent Laid-Open No. 59-138461 disclosing a configuration corresponding to each part may be adopted.

  Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration or a configuration as a single recording head formed integrally may be used.

  In addition to the cartridge type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being mounted on the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.

  In addition, it is preferable to add recovery means, preliminary means, and the like for the recording head to the configuration of the recording apparatus described above because the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.

  Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.

  In the embodiments described above, the description is made on the assumption that the ink is a liquid. However, even if the ink is solidified at room temperature or lower, it may be softened or liquefied at room temperature, or In the ink jet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that it is in the stable discharge range. Any ink may be used as long as it is liquid.

  In addition, it is solidified in a stand-by state in order to actively prevent temperature rise by heat energy as energy for changing the state of ink from the solid state to the liquid state, or to prevent ink evaporation. Ink that is liquefied by heating may be used. In any case, by applying heat energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case of using ink having the property of being liquefied for the first time. In such a case, the ink is held as a liquid or solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260, It is good also as a form which opposes with respect to an electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.

In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like as well as an image output terminal of an information processing device such as a computer or a separate apparatus, and a transmission / reception function are provided. It may take the form of a facsimile machine.

1 is an external perspective view showing an outline of a configuration of an ink jet recording apparatus to which the present invention is applied. 1 is a perspective view of a recording head used in an ink jet recording apparatus to which the present invention is applied. 1 is a block diagram illustrating a configuration of a control circuit of an ink jet recording apparatus to which the present invention is applied. It is a figure which shows the mode of operation | movement of the recording head at the time of printing in an inkjet recording device. It is a flowchart which shows the flow of the basic process for managing the amount of ink consumption at the time of suction | recovery recovery. It is a flowchart which shows the flow of the basic process for managing the ink consumption at the time of preliminary discharge. It is a flowchart which shows the flow of the basic process for managing the ink consumption at the time of printing. It is a figure which shows the flow of the basic process for managing the amount of ink consumption. It is a figure which shows the flow of the recovery operation | movement in Example 1. FIG. It is a figure which shows the flow of basic operation | movement from printing to capping. FIG. 10 is a diagram illustrating a flow of operations from printing to capping in the second embodiment. FIG. 6 is a diagram of an ink cartridge in Example 3. FIG. 10 is a diagram illustrating a flow of operations from printing to capping in the third embodiment. It is a figure which shows the flow of operation | movement from printing to capping in Example 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Carriage 3 Recording head 60 Ink cartridge 600 Controller 601 MPU
602 ROM
603 ASIC
604 RAM
605 System bus 605 A / D converter 610 Host device 611 Interface

Claims (12)

An inkjet recording apparatus that ejects a plurality of types of ink according to print data and records the print data on a recording medium,
A recording head that discharges ink according to the print data and performs a recording operation;
Management means for managing the remaining amount of ink in the ink tank set in the recording head;
A standby time setting means for setting a standby time of the recording head after printing is started;
Cleaning means for cleaning the recording head by discharging ink from the recording head at a predetermined timing;
Cleaning control means for controlling to reduce the ejection amount of the ink used in the cleaning means when the ink remaining amount becomes a certain value or less;
An ink jet recording apparatus comprising:   The cleaning unit performs a suction recovery process as a cleaning operation of the recording head, and the cleaning control unit is controlled to reduce the amount of ink used in the suction recovery process when the remaining amount of ink becomes a predetermined value or less. The inkjet recording apparatus according to claim 1, wherein:   The cleaning unit performs a preliminary ejection process during the standby time as the cleaning operation of the recording head, and the cleaning control unit sets the interval of the preliminary ejection process when the remaining ink amount becomes a predetermined value or less. 3. The ink jet recording apparatus according to claim 1, wherein the ink discharge amount is reduced by setting the amount to a long period of time as compared with a case where the amount is a predetermined value or more.   3. The cleaning unit according to claim 1, wherein the cleaning unit performs a preliminary ejection process during the standby time as a cleaning operation of the recording head, and the cleaning control unit controls the standby time after printing to be changed. The ink jet recording apparatus described.   The cleaning means performs a preliminary ejection process during the standby time as a cleaning operation of the recording head, and the cleaning control means controls to prohibit the preliminary ejection process when the ink remaining amount is equal to or less than a predetermined value. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is an ink jet recording apparatus.   2. The cleaning unit according to claim 1, wherein the cleaning unit performs a preliminary ejection process during the standby time as a cleaning operation of the recording head, and the cleaning control unit controls to change the number of preliminary ejections after printing. 2. An ink jet recording apparatus according to 2.   The cleaning unit performs a preliminary ejection process as a cleaning operation of the recording head, and the cleaning control unit prohibits the preliminary ejection process when the ink remaining amount is equal to or less than a first set value, and further performs the ink remaining process. When the amount is not less than the first set value and not more than the second set value, the predischarge process interval is controlled to be longer than when the remaining ink amount is not less than a certain value. The inkjet recording apparatus according to claim 1, wherein   The ink jet recording apparatus according to any one of claims 1 to 7, wherein the management unit manages the remaining amount of ink with a memory provided in the main body of the ink jet recording apparatus.   The ink jet recording apparatus according to claim 1, wherein the management unit manages a remaining amount of ink with a memory provided in the ink tank. A method for controlling an ink jet recording apparatus that discharges a plurality of types of ink according to print data and records the print data on a recording medium,
A management step of managing the remaining amount of ink in an ink tank set in a recording head that discharges ink according to the print data and performs a recording operation;
A standby time setting step for setting a standby time of the recording head after printing is started;
A cleaning step of cleaning the recording head by discharging ink from the recording head at a predetermined timing;
A cleaning control step of controlling the ink discharge amount in the cleaning step to be reduced when the ink remaining amount becomes a predetermined value or less;
A method for controlling an ink jet recording apparatus, comprising:   A program for causing an inkjet recording apparatus to execute the control method for an inkjet recording apparatus according to claim 10.   A computer-readable storage medium storing the program according to claim 11.

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