JP7052376B2 - Inkjet recording device - Google Patents

Description

The present invention relates to an inkjet recording device that records characters and images on a recording medium.

Conventionally, an inkjet recording device having a line head type inkjet head includes a transport unit including a transport belt for transporting sheets, and an inkjet head arranged above the transport unit. While the sheet is conveyed by the transfer unit, ink is ejected from the inkjet head at a predetermined timing, so that characters and images are formed on the sheet.

In such a system, if a deviation occurs between the sheet transport speed and the ink ejection timing, image defects such as image deviation, image elongation, and image shrinkage occur. Therefore, there is known a technique in which the ink ejection timing is determined according to the rotation speed of the driven roller that supports the transport belt from the inside. Patent Document 1 discloses a technique in which an encoder provided on a rotating shaft of a driven roller detects an angular velocity of the rotating shaft, and the speed of a conveyor belt is adjusted according to the angular velocity.

Japanese Unexamined Patent Publication No. 2009-83401

In the technique described in Patent Document 1, when the outer diameter of the driven roller varies, the relationship between the angular velocity detected by the encoder and the circumferential velocity of the conveyor belt becomes different. As an example, when the outer diameter of the driven roller is increased by 0.1%, the circumferential speed of the conveyor belt is increased by 0.1%. On the other hand, the ink ejection timing is determined by the frequency of the pulse plate of the encoder. Therefore, the ink is ejected at a specific timing regardless of the outer diameter of the driven roller. As a result, if the outer diameters of the driven rollers differ by 0.1%, the timing of ink ejection and the circumferential speed of the transport belt will deviate by 0.1%. As a result, as described above, there is a problem that image stretching and image shrinkage occur.

The present invention has been made to solve the above problems, and even if there is an individual difference in the outer diameter of the driven roller that supports the transport belt from the inside, the circumferential speed of the transport belt and ink ejection It is an object of the present invention to provide an inkjet recording apparatus capable of stably controlling timing.

The inkjet recording apparatus according to one aspect of the present invention includes an ink head for ejecting ink and an ink head.
A transport unit, which is arranged so as to face the ink head and transports the sheet so as to allow the ink to be ejected onto the sheet while supporting the sheet, is provided. A transport belt that carries a sheet and orbits along a predetermined circumferential direction, a drive roller that comes into contact with the inner peripheral surface of the transport belt and drives the transport belt in the circumferential direction, and a drive roller that rotates. Corresponds to the angular velocity of the driven roller that generates the rotational driving force to be caused, the driven roller that abuts on the inner peripheral surface of the conveyor belt at a position different from the drive roller and rotates in accordance with the conveyor belt, and the driven roller. The detection unit that detects the angular velocity information to be driven abuts on the inner peripheral surface of the conveyor belt while being urged by the spring member on the downstream side of the drive roller and the upstream side of the driven roller in the circumferential direction of the conveyor belt. A storage unit having a tension roller for adjusting the tension of the conveyor belt and storing outer diameter information regarding the outer diameter of the driven roller, and the angular velocity information detected by the detection unit and stored in the storage unit. A drive roller control unit that controls the drive unit to control the rotation speed of the drive roller based on the outer diameter information of the driven roller, and the angular velocity information detected by the detection unit and stored in the storage unit. A discharge timing control unit that controls the discharge timing of the ink in the ink head based on the outer diameter information of the driven roller.
The transport unit is configured to be replaceable, and includes a unit body in which the actual outer diameter of the driven roller for being stored in the storage unit as the outer diameter information is displayed .

According to this configuration, even if the outer diameter of the driven roller varies (difference between individuals), the transport speed of the sheet transported by the transport belt is set to a predetermined target speed, and the target speed is adjusted. Ink can be ejected from the ink head at an appropriate ejection timing.

In the above configuration, the storage unit stores in advance the reference detection information of the detection unit so that the peripheral speed of the outer peripheral surface of the driven roller having the preset reference outer diameter becomes a predetermined target speed. The drive roller control unit corrects the reference detection information based on the outer diameter information, and the rotation speed of the drive roller so that the angular velocity detection unit detects the corrected reference detection information as the angular velocity information. It is desirable to control.

According to this configuration, the storage unit stores the reference detection information in advance, so that the transfer speed of the transfer belt is appropriately controlled according to the outer diameter of the driven roller.

In the above configuration, the storage unit stores in advance reference ejection timing information for ejecting the ink each time the outer peripheral surface of the driven roller having the reference outer diameter rotates by a predetermined distance, and the ejection timing control is performed. The unit corrects the reference ejection timing information based on the outer diameter information, and ejects the ink in the ink head based on the corrected reference ejection timing information and the angular velocity information detected by the detection unit. It is desirable to control the timing.

According to this configuration, the storage unit stores the reference ejection timing information in advance, so that the ejection timing of the ink head is appropriately controlled according to the outer diameter of the driven roller.

According to the present invention, even if there is an individual difference in the outer diameter of the driven roller that supports the transport belt from the inside, the inkjet recording device that can stably control the circulation speed of the transport belt and the ink ejection timing. Can be provided.

It is sectional drawing which shows the internal structure of the inkjet recording apparatus which concerns on one Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of the periphery of the ink head and the transport unit of FIG. 1. It is a block diagram of the control part of the inkjet recording apparatus which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an internal structure of a printer 1 (inkjet recording device) according to an embodiment of the present invention. In the present embodiment, a printer is exemplified as an inkjet recording device, but the image forming device may be a multifunction device, a copying machine, a facsimile machine, or the like.

The printer 1 includes a device main body 10, a head unit 11 arranged in the device main body 10, a first sheet transport path 101, a second sheet transport path 102, a paper feed cassette 21, and a first paper feed. A unit 22, a paper feed tray 23, a second paper feed unit 24, a resist roller pair 25, a transport roller pair 26, a first transport unit 27, a second transport unit 28, a decaler unit 29, and the like. A paper ejection tray 30, a reversing portion 31, and a double-sided transport path 32 are provided.

The apparatus main body 10 constitutes the appearance of the printer 1 and houses the above-mentioned members and units inside. The paper cassette 21 accommodates a plurality of sheets S inside. The first sheet transport path 101 is a transport path arranged in the lower right portion of the apparatus main body 10. The first paper feed unit 22 feeds the sheet S housed in the paper feed cassette 21 to the first sheet transport path 101. As shown in FIG. 1, other transport roller pairs are arranged in the first sheet transport path 101. The sheet S conveyed through the first sheet transfer path 101 is carried into the resist roller pair 25.

Similarly, the paper feed tray 23 is arranged on the right side surface of the apparatus main body 10, and the sheet S can be placed on the upper surface portion of the paper feed tray 23. The second paper feed unit 24 feeds the sheet S placed on the paper feed tray 23 toward the resist roller pair 25. The resist roller pair 25 adjusts the skew of the sheet S and also adjusts the delivery timing of the sheet S with respect to the first transfer unit 27. The transport roller pair 26 is arranged on the downstream side of the resist roller pair 25 in the transport direction, and transports the sheet S toward the first transport unit 27.

The first transport unit 27 (transport unit) transports the sheet S received from the transport roller pair 26 to the downstream side in the transport direction. The first transfer unit 27 is arranged so as to face the head unit 11. Then, the first transport unit 27 transports the sheet S so as to allow the ink to be ejected onto the sheet S while supporting the sheet S.

The second transport unit 28 further transports the sheet S received from the first transport unit 27 to the downstream side in the transport direction. The decaler unit 29 further transports the sheet S to the downstream side in the transport direction while correcting the curl of the sheet S received from the second transport unit 28.

The second sheet transport path 102 extends along the left side surface of the apparatus main body 10. The sheet S sent out by the decara unit 29 is discharged to the paper output tray 30 via the second sheet transport path 102. The reversing portion 31 is a transport path branched in the middle of the second sheet transport path 102, and is a portion where the sheet S is inverted (switched back) when characters or images are formed on the back surface of the sheet S. .. The sheet S inverted by the inversion unit 31 is carried into the first transfer unit 27 again via the double-sided transfer path 32, the resist roller pair 25 and the transfer roller pair 26.

FIG. 2 is an enlarged cross-sectional view of the periphery of the head unit 11 and the first transfer unit 27 of the printer 1 of FIG.

The head unit 11 has a yellow head unit 11Y, a magenta head unit 11M, a cyan head unit 11C, and a black head unit 11BK, which eject inks of each color. Each of these head units is arranged adjacent to each other along the transport direction of the seat S. Further, these head units are of a known line head type, and have a recording head portion extending along a direction (front-back direction) orthogonal to the transport direction of the sheet S. As a method of ejecting ink ejected from the recording head, a known piezo method, a thermal inkjet method, or the like is applied.

Further, referring to FIG. 2, the first transport unit 27 includes a transport belt 270, a drive roller 271, a first support roller 272, a second support roller 273, a tension roller 274, and a speed detection roller 275 ( It has a driven roller), a belt drive motor 276 (drive unit), an encoder 277 (detection unit), and a suction unit 278.

The conveyor belt 270 orbits along the arrow direction (predetermined circumferential direction) in FIG. 2 and conveys the sheet S. The drive roller 271 is arranged at the left end of the conveyor belt 270 so as to abut on the inner peripheral surface of the conveyor belt 270. The drive roller 271 orbits (drives) the conveyor belt 270 in the circumferential direction by transmitting a moving force to the conveyor belt 270. The first support roller 272 supports the inner peripheral surface of the transport belt 270 at the lower right of the drive roller 271. The second support roller 273 supports the inner peripheral surface of the transport belt 270 on the right side of the first support roller 272. The tension roller 274 supports the inner peripheral surface of the transport belt 270 at the upper right of the second support roller 273. The tension roller 274 is urged to the right by a spring member (not shown) and has a function of adjusting the tension of the conveyor belt 270. The speed detection roller 275 supports (contacts) the inner peripheral surface of the transport belt 270 at a position different from that of the drive roller 271 at the upper left of the tension roller 274. The first support roller 272, the second support roller 273, the tension roller 274, and the speed detection roller 275 each rotate in accordance with the conveyor belt 270. Further, the speed detection roller 275 is used to detect the orbiting speed of the conveyor belt 270. Therefore, the pulse plate 275A is fixed to the rotation shaft of the speed detection roller 275. The pulse plate 275A has a disk shape, and a plurality of slits (not shown) are formed on the side surfaces thereof at intervals in the circumferential direction.

The belt drive motor 276 (drive unit) generates a rotary drive force for rotating the drive roller 271. The belt drive motor 276 is a known stepping motor, and the rotation speed of the drive roller 271 can be adjusted. The belt drive motor 276 is controlled by the motor control unit 501 of the control unit 50 described later.

The encoder 277 is arranged to face the pulse plate 275A of the speed detection roller 275. The encoder 277 has an emission unit that emits detection light and a light receiving unit that receives detection light (not shown). The slit of the pulse plate 275A shields the detection light, so that the encoder 277 outputs a pulse signal according to the rotation angle (angular velocity ω) of the pulse plate 275A. The encoder 277 functions as a detection unit of the present invention that detects angular velocity information (pulse signal) corresponding to the angular velocity of the speed detection roller 275. The suction unit 278 is arranged on the inner peripheral portion of the transport belt 270 and has a fan (not shown). A plurality of holes (not shown) are opened in the transport belt 270, and when the fan of the suction unit 278 rotates, air is sucked through the holes. As a result, the sheet S is attracted to the transport belt 270.

The printer 1 further includes a control unit 50. FIG. 3 is a block diagram of the control unit 50 according to the present embodiment. The control unit 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing a control program, a RAM (Random Access Memory) used as a work area of the CPU, and the like. Further, in addition to the above-mentioned head unit 11, belt drive motor 276, and encoder 277, an input device 40, an image memory 41, an I / F 42, and the like are electrically connected to the control unit 50.

The input device 40 is included in an operation unit (not shown) of the printer 1. The input device 40 receives the outer diameter information of the speed detection roller 275 input by the operator. The input device 40 may be a shipping inspection jig connected to the printer 1 when the printer 1 is manufactured.

The image memory 41 temporarily stores image data for printing given from an external device such as a personal computer. When the printer 1 functions as a copying machine, the image memory 41 temporarily stores image data optically read by a reading device (not shown).

The I / F 42 is an interface circuit for realizing data communication with an external device. For example, the I / F 42 creates a communication signal according to the communication protocol of the network connecting the printer 1 and the external device, and also communicates from the network side. The signal is converted into data in a format that can be processed by the printer 1. The print instruction signal transmitted from the personal computer or the like is given to the control unit 50 via the I / F 42, and the image data is stored in the image memory 41 via the I / F 42.

The control unit 50 calculates the motor control unit 501, the discharge timing control unit 502 (conversion magnification adjustment unit 503, frequency conversion unit 504), the head control unit 505, and the operation by executing the control program stored in the ROM by the CPU. It functions to include a unit 506 and a storage unit 507.

The motor control unit 501 (drive roller control unit) controls the operation of each drive member of the printer 1. In particular, the motor control unit 501 controls the rotational drive (on / off, rotation speed) of the belt drive motor 276. As will be described later, the motor control unit 501 uses the belt drive motor 276 based on the angular velocity information of the speed detection roller 275 detected by the encoder 277 and the outer diameter information of the speed detection roller 275 stored in the storage unit 507. By controlling, the rotation speed of the drive roller 271 is controlled.

The ejection timing control unit 502 controls the ejection timing of the ink of each head unit 11. In particular, the ejection timing control unit 502 determines the ink ejection timing in the head unit 11 based on the angular velocity information of the speed detecting roller 275 detected by the encoder 277 and the outer diameter information of the speed detecting roller 275 stored in the calculation unit 506. Control. The discharge timing control unit 502 includes a conversion magnification adjusting unit 503 and a frequency conversion unit 504.

The conversion magnification adjusting unit 503 determines the conversion magnification to be input to the frequency conversion unit 504 according to the outer diameter information (individual actual outer diameter) of the speed detection roller 275 input from the input device 40 and stored in the storage unit 507. .. If there is no difference between the outer diameters of the speed detection rollers 275 and the outer diameters of all the speed detection rollers 275 match the center value of the design tolerance, the above conversion factor is 1. Actually, since there is an individual difference in the outer diameter of the speed detection roller 275, the conversion magnification is set in order to complement (cancel) the individual difference.

The frequency conversion unit 504 generates a discharge timing signal frequency according to the pulse signal input from the encoder 277. In the present embodiment, it is assumed that the peripheral speed of the outer peripheral surface of the speed detection roller 275 and the transfer speed (movement speed) of the transfer belt 270 are constant, and the outer peripheral surface of the speed detection roller 275 is a predetermined distance (example). The ejection timing signal frequency is set so that the ink is ejected from each head unit 11 when the vehicle is moved by 42 μm). In other words, the frequency determines the pitch between dots in the sub-scanning direction (conveyance direction) of the ink image formed on the sheet S.

The head control unit 505 is electrically connected to the head unit 11, and inputs a head control signal to each head unit 11. The head control signal is set according to the discharge timing signal frequency received from the frequency conversion unit 504. Note that the head control signal is set for each of the main scanning direction and the sub-scanning direction according to the image information.

The calculation unit 506 (drive roller control unit) executes each calculation in the correction operation described later.

The storage unit 507 stores the outer diameter information regarding the outer diameter of the speed detection roller 275 input from the input device 40. Further, the storage unit 507 is an encoder such that the peripheral speed of the outer peripheral surface of the speed detection roller 275 having a preset reference outer diameter (20 mm as an example) becomes a predetermined target speed (628.3 mm / sec as an example). The reference detection information (number of pulses) of 277 is stored in advance. Similarly, the storage unit 507 provides reference ejection timing information (10 kHz as an example) for ejecting ink to the head unit 11 each time the outer peripheral surface of the speed detection roller 275 having the reference outer diameter rotates by a predetermined distance. I remember it in advance.

Next, an example of the processing operation of the control unit 50 according to the present embodiment will be described. As described above, the encoder 277 detects the angular velocity ω of the speed detection roller 275. From the angular velocity ω and the outer diameter D of the speed detection roller 275, the peripheral speed v of the outer peripheral surface of the speed detection roller 275 can be derived (v = D × ω / 2). Therefore, the rotation speed of the drive roller 271 is controlled so that the peripheral speed of the outer peripheral surface of the speed detection roller 275 becomes the preset transport speed of the sheet S (circumferential speed of the transport belt 270). On the other hand, there are individual differences in the outer diameter of the speed detection roller 275. Therefore, in the present embodiment, the calculation unit 506 derives an appropriate rotation speed of the drive roller 271 according to the actual outer diameter of the speed detection roller 275, and the motor control unit 501 drives the belt according to the rotation speed. Controls motor 276.

Specifically, the reference outer diameter of the speed detection roller 275 is 20.00 (mm), and the sheet transfer speed (circumferential speed) of the transfer belt 270 for the printer 1 to satisfy a predetermined printing speed is 628.3 (circumferential speed). mm / sec), the ejection frequency of the head unit 11 for satisfying the printing speed is 10000 (Hz), and the number of pulses for the encoder 277 to detect the pulse plate 275A is 1000 (ppr, the number of pulses per rotation). do.

On the other hand, assuming that the actual outer diameter of the speed detection roller 275 is 20.05 (mm), in order for the sheet transfer speed of the transfer belt 270 to be 628.3 (mm / sec), the encoder from the following equation 1 The desired rotation frequency (number of pulses) of 277 is derived.
628.3 / 20.05 / π × 1000 = 9975 (Hz) ... (Equation 1)

That is, the adjustment ratio (drive adjustment ratio) of the rotation frequency of the encoder 277 (drive roller 271) at the actual outer diameter (20.05 mm) with respect to the rotation frequency of the encoder 277 (drive roller 271) at the reference outer diameter (20 mm) is. It is defined by the following equation 2.
Drive adjustment ratio = standard outer diameter / actual outer diameter ... (Equation 2)

On the other hand, under the same conditions as above, in order for the sheet transfer speed of the transfer belt 270 to be 628.3 (mm / sec), the ejection frequency for determining the ink ejection timing of the head unit 11 is set as described above. It needs to be 10000 (Hz). When the actual outer diameter of the speed detection roller 275 is 20.05 (mm), the desirable rotation frequency is equations 1 to 9975 (Hz). Therefore, in order to obtain a discharge frequency of 10000 (Hz), the reciprocal of the drive adjustment ratio of Equation 2 may be multiplied by the frequency in the case of the reference outer diameter. That is, the adjustment ratio (discharge adjustment ratio) of the discharge frequency of the head unit 11 at the actual outer diameter (20.05 mm) with respect to the discharge frequency of the head unit 11 at the reference outer diameter (20 mm) is defined by the following equation 3. Will be done.
Discharge adjustment ratio = actual outer diameter / standard outer diameter ... (Equation 3)
Therefore, the conversion magnification adjusting unit 503 inputs the above discharge adjustment ratio to the frequency conversion unit 504 as the conversion magnification, so that the frequency conversion unit 504 inputs the discharge timing signal frequency according to the actual outer diameter of the speed detection roller 275. Is generated. As a result, a stable ink image is formed on the sheet S according to an appropriate head control signal input from the head control unit 505 to each head unit 11.

As described above, in the present embodiment, the drive roller control unit composed of the motor control unit 501 and the calculation unit 506 has the angular velocity information (pulse information) detected by the encoder 277 and the speed detection stored in the storage unit 507. Based on the outer diameter information (actual outer diameter) of the roller 275, the belt drive motor 276 is controlled to control the rotation speed of the drive roller 271. Further, the ejection timing control unit 502 controls the ink ejection timing in the head unit 11 based on the angular velocity information detected by the encoder 277 and the outer diameter information of the speed detection roller 275 stored in the storage unit 507. Therefore, even if the outer diameter of the speed detection roller 275 varies (difference between individuals), the transport speed of the sheet S transported by the transport belt 270 is set to a predetermined target speed, and the target speed is adjusted. Ink can be ejected from the head unit 11 at an appropriate ejection timing.

Further, in the present embodiment, the drive roller control unit including the motor control unit 501 and the calculation unit 506 uses the reference detection information for the encoder 277 based on the outer diameter information (20.05 mm) of the speed detection roller 275. Corrected and controls the rotational speed (belt drive motor 276) of the drive roller 271 so that the encoder 277 detects the corrected reference detection information as the angular velocity information. Therefore, by storing the reference detection information in advance in the storage unit 507, the transfer speed of the transfer belt 270 is appropriately controlled according to the outer diameter information of the speed detection roller 275.

Further, the discharge timing control unit 502 including the conversion magnification adjusting unit 503 and the frequency conversion unit 504 corrects the reference discharge timing information (9975 Hz) based on the outer diameter information (actual outer diameter) of the speed detection roller 275. The head unit 11 is controlled to eject ink based on the corrected reference ejection timing information and the angular velocity information detected by the encoder 277. Therefore, by storing the reference discharge timing information in advance in the storage unit 507, the discharge timing of the head unit 11 is appropriately controlled according to the outer diameter information of the speed detection roller 275.

Although the printer 1 according to the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and the modified embodiments exemplified below can be applied.

(1) In the above embodiment, the mode in which the outer diameter information of the speed detection roller 275 is input from the input device 40 to the storage unit 507 has been described. As the outer diameter information, it is desirable that the actual outer diameter of each speed detection roller 275 is described on a predetermined label and attached to the unit main body of the first transport unit 27. In this case, the assembly worker of the printer 1 (first transport unit 27) can store the value of the actual outer diameter of the label in the storage unit 507 by inputting the value of the actual outer diameter of the label from an operation unit (not shown). The actual outer diameter and label may be a known barcode label. Further, the outer diameter information may be directly input to the storage unit 507 from the assembly jig (personal computer) used at the time of manufacturing. Further, it is desirable that the outer diameter information is updated according to the speed detection roller 275 of the new first transport unit 27 even when the first transport unit 27 needs to be replaced after the printer 1 starts to be used. ..

(2) In the above embodiment, the encoder 277 has been described as a detection unit for detecting the angular velocity of the speed detection roller 275, but other angular velocity detection units and devices may be applied. Further, the position of the speed detection roller 275 is not limited to the position shown in FIG. Further, other rollers such as the first support roller 272 may be used as the speed detection roller 275.

1 Printer (inkjet recording device)
10 Equipment main body 101 1st sheet transport path 102 2nd sheet transport path 11 Head unit (ink head)
21 Paper cassette 22 1st paper feed unit 23 Paper tray 24 2nd paper feed unit 25 Resist roller pair 26 Transport roller pair 27 1st paper feed unit (conveyor unit)
270 Conveyance belt 271 Drive roller 272 1st support roller 273 2nd support roller 274 Tension roller 275 Speed detection roller (driven roller)
275A Pulse plate 276 Belt drive motor (drive unit)
277 encoder (detector)
278 Suction unit 28 2nd transfer unit 29 Decala unit 30 Paper output tray 31 Reversing unit 32 Double-sided transfer path 40 Input device 50 Control unit 501 Motor control unit (drive roller control unit)
502 Discharge timing control unit 503 Conversion magnification adjustment unit 504 Frequency conversion unit 505 Head control unit 506 Calculation unit (drive roller control unit)
507 Memory

Claims (3)

An ink head that ejects ink and
A transport unit arranged so as to face the ink head and transporting the sheet so as to allow the ink to be ejected onto the sheet while supporting the sheet.
Equipped with
The transport unit is
A transport belt that carries the sheet and orbits along a predetermined orbital direction,
A drive roller that comes into contact with the inner peripheral surface of the conveyor belt and drives the conveyor belt in the circumferential direction.
A drive unit that generates a rotational driving force that rotates the drive roller, and
A driven roller that comes into contact with the inner peripheral surface of the conveyor belt at a position different from that of the drive roller and rotates in accordance with the conveyor belt.
A detector that detects angular velocity information corresponding to the angular velocity of the driven roller, and
A tension roller that abuts on the inner peripheral surface of the conveyor belt while being urged by a spring member on the downstream side of the drive roller and the upstream side of the driven roller in the circumferential direction of the conveyor belt to adjust the tension of the conveyor belt. When,
Have,
A storage unit that stores outer diameter information regarding the outer diameter of the driven roller, and
A drive roller control unit that controls the drive unit to control the rotation speed of the drive roller based on the angular velocity information detected by the detection unit and the outer diameter information of the driven roller stored in the storage unit. When,
An ejection timing control unit that controls the ejection timing of the ink in the ink head based on the angular velocity information detected by the detection unit and the outer diameter information of the driven roller stored in the storage unit.
Further prepare
The transport unit is an inkjet recording device that is configured to be replaceable and includes a unit body in which the actual outer diameter of the driven roller for being stored in the storage unit as the outer diameter information is displayed . The storage unit stores in advance reference detection information of the detection unit such that the peripheral speed of the outer peripheral surface of the driven roller having a preset reference outer diameter becomes a predetermined target speed.
The drive roller control unit corrects the reference detection information based on the outer diameter information, and determines the rotation speed of the drive roller so that the angular velocity detection unit detects the corrected reference detection information as the angular velocity information. The inkjet recording apparatus according to claim 1, which is controlled. The storage unit stores in advance reference ejection timing information for ejecting the ink to the ink head each time the outer peripheral surface of the driven roller having the reference outer diameter rotates by a predetermined distance.
The ejection timing control unit corrects the reference ejection timing information based on the outer diameter information, and the ejection timing control unit in the ink head is based on the corrected reference ejection timing information and the angular velocity information detected by the detection unit. The inkjet recording apparatus according to claim 2, which controls the ink ejection timing.

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