JP4305560B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus provided with a fixed recording head, and more particularly to prevention of clogging of nozzles from which ink is ejected.

In recent years, in order to increase the recording speed in an ink jet recording apparatus that records ink onto a recording medium by ejecting ink droplets from nozzles, a line type in which a large number of nozzles are arranged over a length longer than the width of the recording medium. An ink jet recording apparatus (hereinafter referred to as a line head type ink jet recording apparatus) provided with a recording head (hereinafter referred to as a line head) has been put into practical use.
In this line head type ink jet recording apparatus, the recording medium is conveyed continuously or intermittently with the recording surface facing the surface on which the nozzles of the line head are formed. Further, the line head selectively ejects ink droplets toward the recording surface of the conveyed recording medium based on information to be recorded from among a large number of arranged nozzles. That is, the line head type ink jet recording apparatus completes the recording on the recording medium only by moving the recording medium in one direction without moving the recording head. Hereinafter, in this specification, an ink jet recording apparatus that completes recording only by moving a recording medium without moving the recording head is collectively referred to as a line head type ink jet recording apparatus.

  In the recording head of the ink jet recording apparatus, not limited to the line head type, the ink solvent evaporates from the nozzle from which the ink droplets are ejected and the viscosity of the ink in the nozzle rises. Or foreign matter may enter the nozzle and the nozzle may become clogged, and the performance of ejecting ink droplets from the nozzle may deteriorate. Therefore, the ink jet recording device performs clogging prevention discharge that discharges ink droplets and prevents clogging regardless of recording before the discharge performance deteriorates due to increase in ink viscosity or clogging in the nozzle. Therefore, it is configured so that good recording quality is maintained.

  In the above-described line head type ink jet recording apparatus, conventionally, a plurality of holes are formed in a transport belt that is passed between a pair of transport rollers and transports a recording medium, and ink droplets are ejected through the plurality of holes. There is known a technique for avoiding that the time required for clogging prevention ejection to complete the recording is prolonged even when recording is continuously performed on the recording medium (for example, see Patent Document 1).

JP 2001-113690 A (Page 6, FIGS. 2 and 3)

  However, in the prior art disclosed in Patent Document 1, a plurality of holes formed in the conveying belt V spanned between the shaft JK1 and the shaft JK2 are formed in the width of the conveying belt V as shown in FIG. Are provided asymmetrically with respect to the center line CL. When a force is applied to the axis JK2 in the direction F shown in FIG. 15B and a tensile load is applied to the conveyor belt V, the conveyor belt V has upper and lower sides as shown in FIG. Deforms asymmetrically with respect to the center line CL. In other words, a meandering phenomenon that the conveying belt rotates while moving in the width direction occurs when the recording medium is conveyed due to the action of a force that deforms the conveying belt V asymmetrically with respect to the center line CL. In addition, in this FIG.15 (b), the shape of the conveyance belt V before giving a tensile load is shown with the dashed-two dotted line.

That is, since the recording medium placed on the conveying belt V also meanders due to this meandering phenomenon, there is an unsolved problem that it is difficult to improve the recording quality of the ink jet recording apparatus.
The present invention has been made to solve the above-described problems, and provides an ink jet recording apparatus that can reduce the meandering of the transport belt and prevent clogging without causing deterioration in recording quality and recording speed. For the purpose.

  In order to solve the above-mentioned problem, the first invention according to the present invention is to apply ink droplets from nozzles onto a recording surface that is opposite to the conveying surface of a recording medium that is placed on a conveying belt and conveyed. An ink jet recording apparatus that performs recording by discharging, wherein a recording area is arranged to face the recording surface and includes a plurality of nozzles arranged in a direction intersecting a conveyance direction of the recording medium. A fixing head having a clogging prevention discharge opening facing the fixed head at a predetermined timing while the conveyor belt makes a round, in the width direction intersecting the conveying direction of the conveyor belt. An inkjet recording apparatus characterized by being formed symmetrically with respect to a center line is provided.

According to the above configuration, the clogging prevention discharge opening of the conveyance belt that faces the fixed head at a predetermined timing while the conveyance belt makes one round is provided symmetrically with respect to the center line in the width direction of the conveyance belt. Therefore, even if a predetermined tensile load is applied to the transport belt, the deformation of the transport belt can be made symmetrical with respect to the center line.
As described above, it is possible to reduce the meandering phenomenon that the conveyance belt rotates while moving in the width direction when the recording medium is conveyed.

According to a second aspect of the present invention, in the first aspect, the clogging prevention discharge opening has a plurality of openings facing a part of the fixed head in a direction intersecting the conveyance direction of the conveyance belt. Further, an ink jet recording apparatus is provided, wherein the ink jet recording apparatus is configured to be arranged over the recording area.
According to the above configuration, the clogging prevention discharge opening of the conveyor belt is configured by arranging a plurality of openings over the recording area. That is, the recording area of the fixed head is divided into a plurality of areas, and the openings are opposed to each of the divided recording areas.

As described above, the area of the opening can be made smaller than the opening area when one clogging prevention discharge opening faces the entire recording area of the fixed head. Therefore, when a predetermined tensile load is applied to the conveyance belt, it is possible to reduce the deformation of the conveyance belt.
In a third aspect based on the second aspect, the fixed head intersects a recording medium transport direction with a plurality of recording heads in which a plurality of nozzles are arranged over a predetermined length. An ink jet recording apparatus is provided, characterized in that the openings are arranged side by side and the opening faces each recording head.

According to the above configuration, since the opening is opposed to each recording head, it is possible to control and implement clogging prevention ejection for ejecting ink droplets regardless of recording, for each recording head.
As described above, it is easier to control clogging prevention discharge compared to the case where a recording area is configured with one fixed head and control is performed for each divided recording area divided to prevent clogging discharge. Become.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1A, which is a plan view, an inkjet recording apparatus 1 according to an embodiment of the present invention includes a gate roller GR, a static electricity applying unit EC, a paper transport unit CV, recording heads HD1 to HD5, A paper discharge unit EJ. In addition, as shown in FIG. 1B, which is a front view, the ink jet recording apparatus 1 includes an ink absorbing portion PD inside a conveyance belt V described later.

Here, the detail of each said structure is demonstrated.
As shown in FIG. 2A, which is a plan view of the paper transport unit CV, the paper transport unit CV includes a drive shaft DS to which power is transmitted from the transport unit drive motor M0, and a drive shaft parallel to the drive shaft DS. A driven shaft FS disposed on the upstream side of the DS, a transport belt V spanning the drive shaft DS and the driven shaft FS, and a bearing that rotatably holds the drive shaft DS and the driven shaft FS in a housing (not shown). BR.

Here, although not shown, the driven shaft FS is applied with a force in the upstream direction in order to apply tension so as not to loosen the conveyor belt V that is passed between the driven shaft FS and the drive shaft DS.
The transport belt V is rotated counterclockwise as viewed in FIG. 1B by the power of the transport section drive motor M0, and the recording paper P placed on the transport belt V is transported in the X direction. Transport to.

As shown in FIG. 2A, the transport belt V is provided with openings WD1 to WD5 corresponding to the recording heads HD1 to HD5. These openings WD1 to WD5 have the same opening shape and area, and are provided in the order of openings WD1 and WD2, openings WD3 and WD5, starting from the opening WD4 from the downstream side in the X direction. ing.
Of these openings WD1 to WD5, the opening WD4 has a center line CL of the width of the conveyor belt V as shown in Y of the opening as shown in FIG. 2B, which is an enlarged view of part C in FIG. The opening portions WD1 and WD2 are adjacent to each other in the Y direction, which is a direction orthogonal to the X direction, with an equivalent distance W1 from the center line CL, and the openings WD3 and WD5 are They are provided adjacent to each other in the Y direction at an equivalent distance W2 from the line CL. That is, the openings WD1 to WD5 are provided symmetrically with respect to the center line CL.

Each of the openings WD1 to WD5 is provided so as to face the recording heads HD1 to HD5 once while the conveyor belt V rotates once by the power of the conveyor drive motor M0.
Further, the paper transport unit CV includes an index sensor IS that outputs an index signal serving as a reference for controlling the rotation of the transport belt V.
The index sensor IS is composed of, for example, an optical sensor including a light emitting element such as a photo interrupter and a light receiving element. The index sensor IS detects an index part ID provided on the transport belt V, and the recording heads HD1 to HD5 perform recording. An index signal is output that triggers the timing of performing clogging and the timing of clogging prevention discharge described later.

As shown in FIG. 1A, the recording heads HD1 to HD5 have recording heads HD3 to HD5 on the downstream side in the X direction of adjacent recording heads HD1 and HD2 with an interval H in the Y direction. The recording heads HD1 and HD2 are alternately arranged in the Y direction with a gap H between the recording heads.
Further, as shown in FIG. 1B, these recording heads HD1 to HD5 are arranged with the nozzles from which ink droplets are ejected facing the recording surface PP of the recording paper P, respectively, on the paper transport section CV. Yes.

Here, the arrangement of nozzles provided in the recording heads HD1 to HD5 will be described. The recording heads HD1 to HD5 are given the same reference numerals for convenience of explanation, but are the same, and here, the recording head HD1 will be described as an example.
3A and 3B are views showing the appearance of the recording head HD1, FIG. 3A is a front view in the A direction in FIG. 1A, and FIG. 3B is a bottom view. In FIG. 3, in order to show the nozzles in an easy-to-understand manner, the size of the nozzles is exaggerated and the number is reduced.

As shown in FIG. 3B, the recording head HD1 includes a yellow nozzle NZY that ejects yellow ink, a magenta nozzle NZM that ejects magenta ink, and a cyan nozzle NZC that ejects cyan ink. And a black nozzle NZK from which black ink is ejected.
The nozzles NZY, NZM, NZC, and NZK for each color are arranged in the X direction and arranged in the Y direction over the arrangement distance LN to form the yellow nozzle row NZYL, the magenta nozzle row NZML, the cyan nozzle row NZCL, and the black The nozzle row NZKL is configured. The arrangement distance LN of these color nozzle rows NZYL, NZML, NZCL, and NZKL is the recording width of the recording head HD1.

  Then, when the recording heads HD1 and HD2 shown in FIG. 1A are translated in the X direction and the recording heads HD1, HD2, HD3, HD4, and HD5 are aligned in the Y direction, as shown in FIG. The nozzle rows NZYL, NZML, NZCL, and NZKL of HD1 to HD5 are aligned in the Y direction to form one nozzle row for each color. In FIG. 4, the recording heads HD1 and HD2 are indicated by two-dot chain lines. Here, the interval H between the recording heads described above is related to the arrangement distance LN of the nozzles H <LN, and the nozzles at the end in the Y direction between the recording heads HD1 and HD2 and the recording heads HD3 to HD5. The positions are set so as to overlap when viewed from the X direction. That is, one nozzle row of each color constitutes a recording area over a distance in which the nozzle arrangement distance LN is aligned in the Y direction by the number of recording heads HD1 to HD5 (here, five).

As the recording heads HD1 to HD5, a recording head that applies ink pressure by a piezoelectric element, a heating element, or the like to eject ink droplets can be employed.
The ink absorbing portion PD absorbs ink by clogging prevention discharge, which will be described later, inside the transport belt V, as shown in FIG. 5 which is a diagram schematically showing a BB cross section in FIG. An ink absorber CT is disposed facing the recording heads HD1 to HD5 with the conveyance path PC of the recording paper P interposed therebetween.

The ink absorber CT is made of a material having a high ability to absorb liquid, such as felt and sponge, and is provided in a case CS disposed on a support plate SJ supported by a housing (not shown). . In FIG. 5, in order to make the configuration easy to understand, the downstream side in the X direction from the drive shaft DS is omitted, and the cross-sectional details of the recording heads HD2 and HD1 are omitted.
Here, the connection of the control of each main part of the inkjet recording apparatus 1 described above will be described.

In addition to the main components described above, the ink jet recording apparatus 1 further includes a paper feeding unit KS that feeds the recording paper P to the gate roller GR as shown in FIG. 6 which is a block diagram.
Further, the inkjet recording apparatus 1 includes a paper feed control unit KSD that controls the paper feed unit KS, a gate roller control unit GRD that controls the gate roller GR, a static electricity application control unit ECD that controls the static electricity application unit EC, and an index. A sensor control unit SD that controls the sensor IS, a motor control unit MD that controls the transport unit drive motor M0, a recording head control unit HDD that controls each of the recording heads HD1 to HD5, and a paper discharge that controls the paper discharge unit EJ A control unit EJD, a recording information storage unit BF that stores recording information from an external device, and an operation command to each of the control units KSD, GRD, ECD, SD, MD, HDD, and EJBD based on the recording information CPU.

Next, the recording operation in the inkjet recording apparatus 1 will be described below.
The inkjet recording apparatus 1 shown in FIG. 1 starts a recording operation when receiving recording information and a recording command from an external device.
When the recording operation is started, the CPU sends a conveyance unit drive command to the motor control unit MD, and the conveyance unit drive motor M0 is counterclockwise by the motor control unit MD when the conveyance belt V is viewed in FIG. The drive is controlled to rotate in the direction.

At the same time or later than this, the CPU sends a paper feed command for instructing the supply of the recording paper P to the gate roller GR to the paper feed controller KSD.
Upon receiving a paper feed command from the CPU, the paper feed control unit KSD controls the paper feed unit KS and supplies the recording paper P one by one from the paper cassette (not shown) in which a plurality of recording papers P are stored to the gate roller GR. Let

When the recording paper P is supplied, the gate roller GR corrects the inclination of the recording paper P with respect to the X direction and the positional deviation in the Y direction.
As shown in FIG. 7, when the index part ID blocks the optical axis between the light emitting element and the light receiving element of the index sensor IS, an index signal is output from the index sensor IS to the CPU.

  When the index signal is input, the CPU starts measuring the time for each of the recording heads HD1 to HD5 to record on the recording paper P, and causes the gate roller control unit GRD to control the driving of the gate roller GR, thereby recording the recording paper. P is sent out to the paper transport unit CV. At this time, it is desirable to place the recording paper P on the transport belt V so as not to close the openings WD1 to WD5 of the transport belt V.

While the recording paper P is sent out to the paper transport unit CV, the static electricity application control unit ECD controls the static electricity application unit EC based on a command from the CPU to charge the recording paper P.
The recording paper P that is charged and has an attracting force to the conveying belt V is applied to the outer peripheral surface of the conveying belt V that is rotated counterclockwise as viewed in FIG. Adsorbed and guided under the recording heads HD1 and HD2.

Then, the CPU sends a first recording command to the recording head controller HDD when it is time to start recording by the recording heads HD1 and HD2 within the measured time.
The recording head control unit HDD controls the recording heads HD1 and HD2 on the basis of the first recording command, on the recording surface PP of the recording paper P that is continuously moved below the nozzle surface NZP by the conveying belt V. Based on the recording information, the first recording is performed by selectively ejecting ink droplets from the nozzles NZY, NZM, NZC, and NZK of each color.

The recording paper P on which the first recording has been performed is further transported by the transport belt V, and is guided to the recording heads HD3 to HD5.
Then, the CPU sends a second recording command to the recording head control unit HDD when the time being measured is the timing for starting recording by the recording heads HD3 to HD5.
Based on the second recording command, the recording head control unit HDD controls the recording heads HD3 to HD5 to perform the second recording in the same manner as in the first recording.

When the second recording is finished, the recording on one recording paper P is finished, and the recording paper P is discharged out of the inkjet recording apparatus 1 by the paper discharge unit EJ controlled by the paper discharge control unit EJD.
Here, when the recording of all of the recording information is completed, the recording operation is completed, and when the unrecorded recording information remains, a new recording paper P is supplied to the gate roller GR at the paper feed timing. The recording operation is continued until the recording of all the recorded information is completed.

Next, clogging prevention discharge processing and operation in the inkjet recording apparatus 1 will be described below. Here, clogging prevention discharge is to prevent clogging by discharging ink droplets from the nozzles regardless of recording before the discharge performance drops due to the increase in ink viscosity or clogging in the nozzles. Done.
This clogging prevention discharge is performed when the user turns on the power of the ink jet recording apparatus 1 or turns on the power when the ink jet recording apparatus 1 is turned on, and when a predetermined time elapses without recording. The operation is started when the CPU starts the clogging prevention discharge process shown in FIG.

First, in step S1, a conveyance unit drive command is output to the motor control unit MD, and the conveyance unit drive motor is output to the motor control unit MD so that the conveyance belt V rotates counterclockwise as viewed in FIG. M0 is controlled and the process proceeds to step S2.
In step S2, it is determined whether or not an index signal is input. If it is determined that the index signal is input (YES), the process proceeds to step S3. If it is determined that the index signal is not input (NO), the index signal is determined. Wait until is entered.

As shown in FIG. 7, when the index part ID blocks the optical axis between the light emitting element and the light receiving element of the index sensor IS, an index signal is output from the index sensor IS to the CPU.
When the index signal is input, the CPU starts a timer in step S3, starts measuring the time required for the openings WD1 to WD5 to face the recording heads HD1 to HD5, and proceeds to step S4. To do.

In this step S4, it is determined whether or not the measured time Ta has reached the predetermined time T1, and if it is determined that it has reached (YES), the process proceeds to step S5 and it is determined that it has not reached (NO). If it does, it will wait until it reaches predetermined time T1.
When the measured time Ta reaches the predetermined time T1 and the opening WD4 is at the timing facing the recording head HD4 as shown in FIG. 9A, in step S5, the CPU controls the recording head. The first clogging prevention discharge command is output to the part HDD, and the process proceeds to step S6.

The recording head control unit HDD controls the recording head HD4 based on the first clogging prevention discharge command, and as shown in FIG. 9B, which is a DD cross-sectional view of FIG. Ink droplets are ejected from the nozzles NZY, NZM, NZC, and NZK of the respective colors toward the ink absorber CT of the ink absorber PD through the part WD4.
Here, the opening shape of each of the openings WD1 to WD5 is set larger than the shape of the nozzle surface NZP of the recording heads HD1 to HD5. In other words, the ink droplets ejected from the nozzles NZY, NZM, NZC, and NZK of the respective colors in a state where the recording heads HD1 to HD5 are opposed to the openings WD1 to WD5, respectively, without adhering to the transport belt V. WD1 to WD5 can be passed. In FIG. 9B, for easy understanding of the configuration, the downstream side in the X direction from the drive shaft DS is omitted, and the cross-sectional details of the recording heads HD3 to HD5 are omitted.

In step S6, it is determined whether or not the measured time Ta has reached the predetermined time T2. If it is determined that the time has reached (YES), the process proceeds to step S7, and it has not reached (NO). If judged, it waits until the predetermined time T2 is reached.
When the measured time Ta reaches the predetermined time T2 and the opening portions WD1 and WD2 face the recording heads HD1 and HD2 as shown in FIG. 10A, in step S7, the CPU Then, the second clogging prevention discharge command is output to the recording head control unit HDD, and the process proceeds to step S8.

As with the recording head HD4, the recording head control unit HDD controls the recording heads HD1 and HD2 and absorbs ink from the nozzles NZY, NZM, NZC, and NZK for each color based on the second clogging prevention discharge command. Ink droplets are ejected toward the body CT.
In step S8, it is determined whether or not the measured time Ta has reached the predetermined time T3. If it is determined that the time Ta has reached (YES), the process proceeds to step S9, and it is determined that it has not reached (NO). Then, it waits until it reaches predetermined time T3.

  As in the case of the recording heads HD1, HD2, and HD4, the measured time Ta reaches the predetermined time T3, and as shown in FIG. 10B, the openings WD3 and WD5 become the recording heads HD3 and HD5. When it is time to face the CPU, in step S9, the CPU outputs a third clogging prevention discharge command to the recording head controller HDD, and proceeds to step S10.

The recording head control unit HDD controls the recording heads HD3 and HD5 on the basis of the third clogging prevention discharge command, similarly to the recording heads HD1, HD2 and HD4, and drops ink droplets toward the ink absorber CT. To discharge.
In step S10, the timer is reset and the process is terminated.
In this clogging prevention discharge process and operation, when the ink droplets are discharged toward the ink absorber CT, the drive of the transfer unit drive motor M0 is controlled to decrease the rotation speed of the transfer belt V, or the transfer is performed. The rotation of the belt V may be stopped.

In the present embodiment, the recording heads HD1 to HD5 correspond to fixed heads, and the openings WD1 to WD5 correspond to clogging prevention discharge openings.
As described above, since the openings WD1 to WD5 are provided symmetrically with respect to the center line CL of the conveyor belt V, even if a tensile load is applied to the conveyor belt V, the conveyor belt V is deformed as shown in FIG. It can be symmetric with respect to the center line CL. Therefore, when the recording medium P is transported, the force for moving the transport belt V in the width direction acts symmetrically with respect to the center line CL, that is, in a direction to cancel each other, and the meandering phenomenon can be reduced. . In addition, in this FIG. 11, the shape of the conveyance belt V before giving a tensile load is shown with the dashed-two dotted line.

  Further, since the clogging prevention discharge opening that allows ink droplets to pass and enables clogging prevention discharge is formed by the openings WD1 to WD5 that face each recording head, the opening is configured with one opening. In comparison, the opening areas of the openings WD1 to WD5 can be reduced. Therefore, when a tensile load is applied to the conveyance belt V, it is possible to reduce the deformation of the conveyance belt V and to suppress a decrease in recording quality. In addition, since it is possible to control clogging prevention discharge for each recording head, it becomes easier to control compared to the case where the recording area composed of one fixed head is divided and controlled. Processing time can be shortened and the circuit configuration can be simplified.

  Further, since the recording heads HD1 to HD5 are arranged so that a part of the recording width LN overlaps between these recording heads when viewed from the X direction, the recording heads HD1 to HD5 have the respective colors at the overlapping positions when viewed from the X direction. Ink droplets can be ejected from the nozzles NZY, NZM, NZC, and NZK. That is, since the ink droplets are ejected by the two recording heads at the recording boundary between the recording heads, it is possible to suppress the unrecorded recording surface PP from being exposed in a streak shape. It becomes.

Further, even if a part of the recording width LN overlaps between the recording heads HD1 to HD5 when viewed from the X direction, the openings WD1 to WD5 facing the clogging prevention discharge openings for each recording head. Therefore, it is possible to suppress an increase in the area of the opening.
In the present embodiment, the openings WD1 to WD5 are provided in the order of the openings WD1 and WD2, and the openings WD3 and WD5 starting from the opening WD4 from the downstream side in the X direction, as shown in FIG. However, the present invention is not limited to this. As shown in FIG. 12, the opening WD4 is provided between the opening WD3 and the opening WD5, and the openings WD3 to WD5 are aligned in the Y direction. Good.

According to this configuration, the arrangement distance in the X direction of the openings WD1 to WD5 can be shortened compared to the case shown in FIG. 2, and the paper transport unit CV can be downsized.
In the present embodiment, the recording heads HD1 to HD5 each provided with a fixed head and each of a yellow nozzle NZY, a magenta nozzle NZM, a cyan nozzle NZC, and a black nozzle NZK that discharge yellow, magenta, cyan, and black ink droplets. However, the present invention is not limited to this. That is, as shown in FIG. 13A, a yellow recording head HDY, a magenta recording head HDM, a cyan recording head HDC, and a black recording head HDK corresponding to each color may be used.

According to this configuration, the area of the nozzle surfaces of the heads Y1 to Y5, M1 to M5, C1 to C5, and K1 to K5 can be reduced. Accordingly, the opening areas of the openings HD1 to HD5 are also correspondingly reduced. It becomes possible to reduce. Therefore, it is possible to reduce the deformation of the transport belt V due to the tension, which can further contribute to the improvement of the recording quality.
In this embodiment, the recording area is configured by the individual recording heads HD1 to HD5. However, the present invention is not limited to this, and the recording area is configured by an integrated recording head HD as shown in FIG. May be.

In this case, clogging prevention discharge can be performed by controlling the integrated recording head HD for each region where the openings WD1 to WD5 face each other.
According to this configuration, the arrangement distance in the X direction of the recording heads HD1 to HD5 can be shortened compared to the case shown in FIG. 1, and the paper transport unit CV can be further downsized.
In the example shown in FIG. 13A described above, the recording heads HDY, HDM, HDC, and HDK for each color have the heads Y1 to Y5, M1 to M5, C1 to C5, and K1 to K5, and the recording width LN. However, the present invention is not limited to this, and as shown in FIG. 14, for example, each of six heads Yi (i = 1 to 6), Mi, Ci Ki may be arranged such that the recording width LN is inclined at a predetermined angle from the Y direction.

  In this case, the openings WD1 to WD3 have a substantially rhombus shape as viewed in FIG. 14, and the opening area is a size that can simultaneously face two of the heads Yi, Mi, Ci, and Ki adjacent to each other in the Y direction. Set to In other words, the opening WD1 faces the heads K1 and K2 of the black recording head HDK at the same timing, and thereafter, sequentially with the rotation of the transport belt V, the heads C1 and C2, the heads M1 and M2, and the heads Y1 and Y2. Facing each other. Similarly, the opening WD2 sequentially faces the heads K3 and K4, the heads C3 and C4, the heads M3 and M4, and the heads Y3 and Y4. The opening WD3 includes the heads K5 and K6, the heads C5 and C6, the heads M5 and M6 and heads Y5 and Y6 are sequentially opposed.

  According to this configuration, the nozzle density in the Y direction in the recording areas of the recording heads HDY, HDM, HDC, and HDK for each color can be increased, the recording image quality can be improved, and the number of openings WD1 to WD3 can be reduced. It becomes possible to do.

1 is an external view showing a main configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 3 is a plan view illustrating a configuration of a paper transport unit according to the embodiment of the present invention. FIG. 3 is a diagram illustrating an appearance of a recording head. FIG. 3 is a diagram illustrating a recording area of the ink jet recording apparatus according to the embodiment of the present invention. Sectional drawing which shows the structure of an ink absorption part. FIG. 3 is a block diagram showing a connection of control of main parts of the ink jet recording apparatus in the embodiment of the present invention. The figure which shows the state which the index sensor of the inkjet recording device in embodiment of this invention detected the index part. FIG. 4 is a diagram illustrating a flow of clogging prevention discharge processing of the ink jet recording apparatus according to the embodiment of the present invention. FIG. 3 is a diagram illustrating clogging prevention discharge of the ink jet recording apparatus according to the embodiment of the present invention. FIG. 4 is a diagram for explaining a flow of clogging prevention discharge operation of the ink jet recording apparatus according to the embodiment of the present invention. The figure explaining the effect of embodiment of this invention. FIG. 6 is a plan view showing another configuration example of the paper transport unit in the embodiment of the present invention. FIG. 9 is a diagram illustrating another configuration example of the recording head. FIG. 10 is a diagram illustrating still another configuration example of the recording head. The figure explaining the subject of a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording device, V ... Conveyor belt, WD1-WD5 ... Opening part, HD1-HD5 ... Recording head.

Claims (3)

An inkjet recording apparatus comprising: a conveyance belt that conveys a recording medium; and a fixed head that is configured by arranging a plurality of recording heads in a direction intersecting a conveyance direction of the recording medium ,
A plurality of openings corresponding to the plurality of recording heads are formed in a part of the transport belt so as to be symmetric with respect to a center line in the width direction of the transport belt,
The plurality of recording heads constituting the fixed head form a plurality of recording head rows extending in a direction intersecting with a conveyance direction of the recording medium,
The plurality of openings form a plurality of opening rows extending in a direction intersecting the conveyance direction of the recording medium,
The number of the opening rows is larger than the number of the recording head rows . The inkjet recording apparatus according to claim 1, wherein the opening is formed so as to face each of the plurality of recording heads . The inkjet recording apparatus according to claim 1, wherein a plurality of fixed heads corresponding to each color are provided .

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