JP2010111092A - Inkjet recording device and inkjet recording system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set an appropriate stirring condition corresponding to an ink sedimentation state. <P>SOLUTION: This inkjet recording system includes a stirring condition determination sequence for determining the stirring condition in accordance with manufacturing time of an ink tank. For example, it is determined whether or not M months or more have passed since manufacturing of the ink tank of pigment Cyan ink (S30), and a value A indicating the degree of the sedimentation state of the pigment Cyan ink is determined (S31, S32). The degree of the sedimentation state indicates that the pigment is more easily sedimented as the number becomes larger, and stirring frequency is determined so that it becomes larger as the number becomes larger. Thus, since stirring is performed by using the appropriate stirring condition with respect to the individual ink tank, images with high quality can be obtained without performing excessive stirring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording system having a stirring means for stirring ink in an ink tank.

  An ink jet recording apparatus performs recording by ejecting ink droplets from fine ejection ports provided in an ink jet head (recording head) and landing the ink droplets on a recording medium. Conventionally, dye inks using dyes as colorants have been mainly used for inks used in ink jet recording.

  On the other hand, a pigment ink using a pigment having excellent light resistance and weather resistance as compared with a dye as a coloring material has been put into practical use. Since the pigment is dispersed without being dissolved in the ink, the pigment ink has a property that the pigment particles easily settle in the ink. When an ink tank containing pigment ink is left for a long period of time, pigment particles gradually settle in the ink tank, and a layer having a high pigment concentration and a dark color (hereinafter referred to as a sedimented ink) is generated at the bottom of the ink tank. . When recording is performed using this ink tank, areas with different densities are formed in the recorded image due to the precipitated ink, and density unevenness occurs.

  In order to suppress such sedimentation of the pigment ink, a method is known in which the ink is periodically stirred by a stirring means provided in the ink tank (see Patent Document 1).

In this patent document 1, a moving body is provided inside the ink tank, and the moving body is periodically moved before the printing operation at intervals shorter than the period in which sedimentation occurs to stir the precipitated ink, thereby reducing image quality deterioration due to density unevenness. Is disclosed.
JP-A-9-309212

  However, in periodic stirring, stirring may not be performed even if sedimentation occurs, or excessive stirring may be performed. This will be described below.

  The sedimentation of the pigment as described above occurs not only when the ink tank is left to stand after being mounted on the ink jet recording apparatus, but also between the time when the ink tank is manufactured and the time when the ink tank is mounted on the ink jet recording apparatus.

  When time elapses after the pigment ink is injected into the ink tank, the pigment particles are aggregated to generate pigment particles having a large particle size, which are settled. FIG. 11 shows the number of coarse particles having a particle diameter of 0.5 μm or more generated in the ink tank after one month and two months from the production. Thus, it can be seen that the coarse particles increase as time elapses from the date and time when the ink tank is manufactured. In other words, the pigment ink that has passed since it was injected into the ink tank has a large number of pigment particles having a certain particle size larger than the pigment particles immediately after being injected into the ink tank. Larger particles have a faster settling rate than smaller particles, so the more pigment particles with larger particles, the longer it takes for the pigment concentration region to affect the image quality due to the sedimentation of the pigment particles. Shorter.

  Further, it has been experimentally found that when large pigment particles are generated, the sedimentation speed does not return to the original value even if mechanical stirring is performed. An ink tank having a long elapsed time since the pigment ink was injected into the ink tank has a shorter time until image quality deterioration occurs even if the settled pigment particles are agitated than an ink tank having a short elapsed time.

  As described above, since the settling speed of the pigment ink varies depending on the elapsed time from the manufacture of the ink tank, in the configuration in which periodic stirring is performed as in Patent Document 1, stirring is not performed even if settling occurs, or excessively. The case where agitation is performed will arise.

  An object of the present invention is to obtain a high-quality recorded image without excessive stirring by setting the stirring conditions according to the settling state of each ink tank.

  The present invention has been made in view of this point, and in an ink jet recording apparatus that performs recording by discharging ink supplied from an ink tank, stirring means for stirring ink in the ink tank, and the ink tank An agitation condition determining unit that determines the agitation condition after mounting on the apparatus main body, and the agitation condition determining unit determines the agitation condition based on information relating to an elapsed time from the manufacturing time of the ink tank to the installation. It is characterized by.

  Another aspect of the present invention is an ink jet recording system including an ink jet recording apparatus that performs recording by discharging ink supplied from an ink tank and a host device for controlling the ink jet recording apparatus. A stirring means for stirring the ink tank and a stirring condition determining unit for determining a stirring condition after the ink tank is mounted on the apparatus main body, and the stirring condition determining unit is an elapsed time from the manufacturing time of the ink tank to the mounting. The agitation conditions are determined based on information regarding the above.

  According to the present invention, it is possible to obtain a high-quality recorded image without excessive stirring by setting the stirring conditions according to the settling state of each ink tank.

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

<Inkjet recording apparatus>
FIG. 1 is a perspective view showing an ink jet recording apparatus main body applied in the present embodiment in a state where an exterior portion is removed and an internal mechanism is exposed. The recording apparatus main body according to the present embodiment includes a paper feed unit, a paper transport unit, a paper discharge unit, a carriage unit, a cleaning unit, and an exterior unit.

  The paper feeding unit separates the recording media stacked on the pressure plate M2010 one by one and feeds them to the recording unit. The paper transport unit includes a roller pair including a transport roller M3060 that sandwiches and transports the fed recording medium toward a recording area by the recording head, and a pinch roller M3070 provided opposite to the transport roller M3060, and a driving source of the transport roller M3060. A transfer motor E0002 and the like.

  The paper discharge unit includes a paper discharge roller M3100 for discharging the recording medium from the recording area and a plurality of spur rollers (not shown) that cooperate with the paper discharge roller M3100.

  The carriage unit is a carriage M4000 on which the cartridge H1000 and the ink tank H1900 can be mounted. The carriage M4000 is supported by a guide shaft M4020 and a guide rail M1011. The guide shaft M4020 guides and supports the carriage M4000 in a direction (X direction in the drawing) orthogonal to the recording medium conveyance direction (Y direction in the drawing). . The carriage M4000 reciprocates in the X direction via a timing belt M4041 stretched by two pulleys M4042 by the driving force of the carriage motor E0001 attached to the chassis M1010.

  In an area where a recording head H1001 (see FIG. 2) to be described later performs recording, the conveyed recording medium is supported from below, so that the distance between the recording medium surface and the ejection port surface of the recording head is kept constant. A platen M3040 is provided.

  When an image is recorded on the recording medium in the above configuration, the recording position in the Y direction is positioned by conveying the recording medium by the roller pair including the conveying roller M3060 and the pinch roller M3070. Further, the carriage M4000 is moved in the X direction by the carriage motor E0001 to position the recording head H1001. The positioned recording head H1001 ejects ink to the recording medium in accordance with the recording signal from the electric control board E0014. In the recording apparatus of the present embodiment, the recording scan in which the carriage M4000 moves in the X direction while the recording head H1001 performs recording, and the conveyance operation in which the recording medium is conveyed in the Y direction by the conveyance roller M3060 are intermittently repeated. Thus, image recording is performed on the recording medium.

  The cleaning unit has a cap (not shown) that covers the ejection port surface of the recording head H1001 during suction or non-recording, and performs a recovery operation of the recording head. The recovery operation in the present embodiment includes suction and preliminary discharge. In the suction, after the cap covers the ejection port surface of the recording head H1001, the suction motor M5000 draws out ink from the nozzles of the recording head and discharges the ink in the ink tank. Preliminary ejection is performed by ejecting ink into the cap. In addition, preliminary discharge receiving means may be provided separately from the cap, and preliminary discharge may be performed by discharging ink to the preliminary discharge receiving means.

<Recording head and ink tank>
FIG. 2 is a perspective view for explaining the configuration of the cartridge H1000 of the present embodiment.

  The cartridge H1000 in this embodiment includes a recording head H1001, an ink tank H1900, an ink tank mounting unit, and an ink supply unit from the ink tank H1900 to the recording head. The cartridge H1000 is detachably mounted on the carriage M4000. Each of the ink tanks H1900 is provided with a ROM (H1002) that records information about the ink tank manufacturing time as information about the ink sedimentation status. The information related to the ink tank manufacturing time may be information indicating the date when the ink tank was manufactured, or may be information indicating the time when ink was injected into the ink tank. Further, at least one of the ink tanks H1900 contains pigment ink.

  FIG. 3 shows the internal configuration of the ink tank H1900. The ink tank H1900 is attached to the carriage M4000 in the direction A in the drawing. The scanning direction of the carriage M4000 is a direction perpendicular to the paper surface, and stirring plates 20A and 20B capable of reciprocating in this direction are attached inside the ink tank H1900. The stirring operation is performed by repeating the reciprocating operation of the stirring plates 20A and 20B accompanying the reciprocating scanning of the carriage M4000.

  In this embodiment, the cartridge H1000 is mounted on the carriage M4000. However, as shown in FIG. 4, a mode in which the ink tank 302 is stationary and ink is supplied to the recording head 300 by the supply pipe 301 may be used. . 4 shows a form in which the stirring plate 303 is reciprocated from the outside of the ink tank 302 to stir, but the stirring form may be a form of stirring by a rotor rotating by an external magnetic field or a circulation configuration in the ink tank 302. It is also possible to use a form in which the mixture is stirred by circulation.

  In FIG. 2, a plurality of color ink tanks, at least one of which is pigment ink, is mounted. However, the present invention is not limited thereto, and may be, for example, single color pigment ink.

<Configuration of control system of inkjet recording apparatus>
FIG. 5 is a block diagram for explaining a control configuration of an ink jet recording system including the ink jet recording apparatus and the host device of the present embodiment.

  Reference numeral 200 denotes a controller (control unit) that controls the entire apparatus by acquiring information from each mechanism in the apparatus and transmitting a command. In addition to the CPU 201, the controller 200 includes a ROM 203 that stores various programs and a RAM 205 that is used as a work area for the CPU 201. The controller 200 functions as an agitation condition determination unit for determining the agitation condition using the agitation condition determination table stored in the ROM 203 and information relating to the manufacturing timing of the ink tank.

  The host device 210 connected to the outside of the recording apparatus main body preferably functions as a supply source of image data, and is preferably in the form of a computer that creates and processes image data and controls the recording apparatus. Image data, other commands, status signals, and the like are transmitted / received to / from the controller 200 via the interface (I / F) 212. In the recording apparatus of this embodiment, the image data transmitted from the host apparatus 210 to the controller 200 is a multi-value signal of 600 ppi (pixels / inch; reference value), and the recording data that the recording head H1001 records on the recording medium is It is a binary signal of 1200 dpi. That is, when executing recording, the controller 200 converts a multi-value signal of 600 ppi into a binary signal of 1200 dpi.

  The head driver 240 is a driver for driving the electrothermal transducer (discharge heater) 25 of the recording head H1001 in accordance with binary recording data. The carriage motor driver 250 is a driver for driving the carriage motor E0001 that moves the carriage M4000, and the conveyance motor driver 270 is a driver for driving the conveyance motor E0002 that conveys the recording medium in the conveyance direction.

  In addition, the recording apparatus is provided with a timer 280 so that the recording operation command standby time and the elapsed time from the previous stirring operation can be measured.

  In this embodiment, the controller 200 in the recording apparatus functions as the stirring condition determination unit. However, the present invention is not limited to this, and the printer driver of the host device 210 functions as the stirring condition determination unit. Form may be sufficient.

<Stirring timing>
Next, the timing for stirring in the present embodiment will be described. Ink agitation is performed at the timing of the end of the recording operation and the standby of the recording command after the ink tank is installed.

  In this embodiment, when recording is not performed within a predetermined waiting time after the recording operation is completed, stirring is performed based on a stirring condition determination table shown in FIG. A stirring condition determination sequence performed at the end of the recording operation will be described with reference to FIG. Thereafter, the recording operation command standby state is entered, and stirring is performed based on the stirring condition determination table shown in FIG. A stirring condition determination sequence performed during the recording command standby will be described with reference to FIG.

  First, in FIG. 6, after the recording operation is completed, the presence / absence of a recording operation command is determined (S1), and a standby time corresponding to the time when there is no recording operation command is measured (S2). When a recording operation command is input within a predetermined waiting time, this sequence is terminated and the recording operation is started again. When a predetermined waiting time has elapsed without inputting a recording operation command, an elapsed time from the previous stirring operation is calculated (S3). Then, the number of stirrings is determined based on the stirring condition determination table (see FIG. 10A) and the elapsed time calculated in S3 (S4), and stirring is performed (S5). After stirring, a cap closing operation is performed to cover the discharge port surface of the recording head with a cap, and the sequence is terminated (S6). Thereafter, the apparatus shifts to a recording command standby state.

  In this way, when the cap closing operation of FIG. 6 is completed, the mode shifts to the power saving mode of FIG. 7 (S10). The presence / absence of a recording operation command is determined (S11). If there is a recording operation command, this sequence is terminated. If there is no recording operation command, it is determined whether or not the elapsed time from the previous stirring exceeds a predetermined time (S12). When the predetermined time has elapsed, the mode shifts to the normal power mode (S13), and the cap open operation is performed (S14). Thereafter, an interval for stirring is determined based on the stirring condition determination table (see FIG. 10B) corresponding to the previously determined condition 0 or condition 1, and stirring is performed (S15). After stirring, the cap closing operation is performed again (S16), and the process returns to the beginning of the sequence (S10).

<Agitation condition determination sequence>
A sequence for determining the stirring condition based on information indicating the manufacturing time of the ink tank, which is a feature of the present embodiment, using the ink jet recording apparatus having the above-described configuration will be described. The agitation condition is determined by the agitation condition determination unit when the ink tank is attached to the apparatus main body such as when the ink tank is replaced. At this time, agitation conditions at the end of the above-described recording operation and at the time of waiting for a recording command are determined based on information on the ink tank manufacturing time stored in the ROM of the ink tank.

  Hereinafter, the case where the pigment Cyan and the pigment Magenta are used as the pigment ink will be described. In FIG. 8, when the stirring condition determination sequence is executed, first, the sedimentation state information reading sequence (S20) shown in FIG. 9 is performed. Since the ease of sedimentation varies depending on the type of pigment ink, in the present embodiment, as shown in FIG. 9, a threshold value for determining the degree of sedimentation for each pigment ink is provided.

  In FIG. 9, it is determined whether or not the elapsed time since the manufacture of the ink tank of the pigment Cyan ink has passed M months or more (S30), and a value A representing the degree of the settling state of the pigment Cyan ink is determined (S31, 32). ). The degree of the sedimentation condition indicates that the larger the number, the more easily the pigment settles, and the shorter the time from stirring until the density unevenness occurs (hereinafter, the degree of sedimentation condition is expressed as bad). Next, it is determined whether the elapsed time from the manufacture of the ink tank of the pigment Magenta ink has passed N months or more (S33). Then, the value B is determined by determining the degree of sedimentation (S34, S35). Then, in order to match the stirring condition to the ink tank having the worst sedimentation condition, the maximum value of values A and B is determined as the value of the stirring condition J (S36).

  When the stirring condition J value is determined in FIG. 9 and the sedimentation state information reading sequence (S20) in FIG. 8 is completed, it is determined whether the J value is 0 or 1 (S21), and the value of stirring condition 0 or stirring condition 1 is determined. And finishes (S22, 23).

  As the stirring conditions determined in this way, detailed conditions are set in the stirring condition determination table. The stirring condition determination table will be described with reference to FIG.

  First, as described above, the timing of agitation is when the recording operation ends and when a recording command is awaited. In this example, two parameters, the elapsed time from the previous stirring and the number of stirrings, are used as parameters for optimally stirring.

  At the end of the recording operation, as shown in FIG. 10A, under the stirring condition 0, the elapsed time from the previous stirring is 30 times up to 72 hours, 60 times from 72 to 144 hours, and 144 to 216 hours. Is stirred for 120 times and 240 times for 216 hours or more. On the other hand, in the stirring condition 1, the elapsed time from the previous stirring is 60 times up to 48 hours, 120 times from 48 to 96 hours, and 240 times stirring for 96 hours or more. Thus, the elapsed time from the manufacturing time of the ink tank is longer and the settling condition is worse, that is, the stirring condition 1 is set to increase the number of times of stirring in the elapsed time shorter than the stirring condition 0.

  When waiting for a recording command, as shown in FIG. 10B, stirring is performed 240 times every 216 hours under stirring condition 0, and 240 times every 96 hours under stirring condition 1. Also in this case, as in FIG. 10A, the stirring condition 1 in which the sedimentation condition is worse is set so that the stirring is performed at a time interval shorter than the stirring condition 0.

<Other embodiments>
In the embodiment described above, the number of times of stirring and the time interval for stirring are set as the stirring conditions. However, the conditions to be set are not limited to these, and any conditions that can change the stirring effect may be used. For example, the stirring time, the stirring speed, the stirring acceleration, or the like may be set as the stirring conditions. That is, the worse the sedimentation condition, the longer the stirring time, or the greater the stirring speed and stirring acceleration, so that the stirring conditions according to the sedimentation condition can be set.

  In the above-described embodiment, two stirring speeds and the time interval for stirring are set as the stirring conditions set according to the information related to the manufacturing timing of the ink tank, but only one of them may be set. . In short, the stirring conditions set in accordance with the information related to the ink tank manufacturing time may include at least one of the time interval for stirring, the number of times of stirring, the time for stirring, the stirring speed, and the stirring acceleration. .

  Further, in the sedimentation status information reading sequence in FIG. 9, only one threshold for the elapsed time from the manufacture for determining the sedimentation status of the ink tank is provided, but a plurality of thresholds can be set. It is also possible to set three or more types of stirring conditions by setting a plurality of threshold values.

  In the present embodiment, the information regarding the ink tank manufacturing time is stored in the ROM of the ink tank, but the present invention is not limited to this. In the present invention, it suffices if information relating to the manufacturing time can be acquired, and the information may be acquired from a host computer or the user may directly input the information.

It is a perspective view which shows the inkjet recording device applied by embodiment of this invention in the state which removed the exterior part and exposed the internal mechanism. It is a perspective view for demonstrating the structure of a cartridge. It is a perspective view for demonstrating the internal structure of the ink tank applied by embodiment of this invention. 1 is a schematic view of a cartridge stationary ink jet recording apparatus. FIG. It is a block diagram for demonstrating the structure of control in the inkjet recording device applied by embodiment of this invention. It is a flowchart explaining the stirring timing at the time of the printing applied by embodiment of this invention. It is a flowchart explaining the stirring timing at the time of the printing standby applied by embodiment of this invention. It is a flowchart explaining the stirring condition determination sequence applied in embodiment of this invention. It is a flowchart explaining the sedimentation condition reading sequence applied in the embodiment of the present invention. It is a stirring condition determination table applied in the embodiment of the present invention. It is a graph explaining that the number of coarse particles having a large particle diameter increases as time passes from the date and time when the ink tank is manufactured.

Explanation of symbols

E0201 CPU
E0202 ROM
H1000 Cartridge H1001 Recording head H1900 Ink tank H1901 ROM
M4000 carriage

Claims (6)

An inkjet recording apparatus that performs recording by discharging ink supplied from an ink tank,
A stirring means for stirring the ink in the ink tank;
A stirring condition determining unit for determining stirring conditions after mounting the ink tank on the apparatus main body,
The ink jet recording apparatus, wherein the stirring condition determining unit determines the stirring condition based on information related to an elapsed time from the manufacturing time of the ink tank to mounting.   2. The ink jet recording apparatus according to claim 1, wherein the stirring condition includes at least one of a time interval for stirring, the number of times of stirring, a time for stirring, a stirring speed, and a stirring acceleration.   3. The ink jet recording apparatus according to claim 1, wherein the stirring condition determination unit determines a stirring condition at the end of the recording operation and a stirring condition at the time of waiting for the recording operation command.   2. The ink jet recording apparatus according to claim 1, wherein the stirring condition is such that the longer the elapsed time indicated by the information, the shorter the time interval for performing the stirring.   2. The ink jet recording apparatus according to claim 1, wherein the stirring condition is such that the number of times of stirring increases as the elapsed time indicated by the information increases. An inkjet recording system including an inkjet recording apparatus that performs recording by discharging ink supplied from an ink tank, and a host device for controlling the inkjet recording apparatus,
A stirring means for stirring the ink in the ink tank;
A stirring condition determining unit for determining stirring conditions after mounting the ink tank on the apparatus main body,
The ink jet recording system, wherein the stirring condition determining unit determines the stirring condition based on information relating to an elapsed time from the manufacturing time of the ink tank to mounting.

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