JP4706460B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus using a drum rotating body.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus is known as an image recording apparatus capable of printing on various recording media represented by plain paper. This ink jet recording apparatus discharges ink, which is a coloring material, directly from a nozzle provided on the surface of the recording head facing the recording medium onto the recording medium, and then lands, penetrates or fixes on the recording medium. A recording apparatus for forming an image. Such an ink jet recording apparatus has very excellent characteristics in terms of process simplicity, quietness during printing, quality of an image recorded on a recording medium, and the like.

  In recent years, among inkjet recording apparatuses, an inkjet recording apparatus in which a recording medium is mounted on a drum rotating body has attracted attention (see, for example, Patent Document 1 and Patent Document 2). The ink jet recording apparatus using the drum rotating body can be aligned with the recording head with high accuracy because it does not convey the recording medium, and can be advantageous in that a high quality image can be formed. Since there is no need for reciprocal movement, there is an advantage of high production efficiency.

  In such an ink jet recording apparatus, only one sub-scanning mechanism for moving the recording head or the like in the sub-scanning direction is provided, and the carriage on which the recording head is mounted has, for example, an ink tank or a damper other than the recording head. Because it is equipped with, it becomes heavy. Further, in order to move such a heavy carriage in the sub-scanning direction at high speed in a short time, it is necessary to use a moving means having a large output, which causes a problem that the transport mechanism becomes large and expensive. is doing.

Therefore, a technique for improving the printing resolution by making the movement in the sub-scanning direction a minute movement in units of dots has been disclosed (for example, see Patent Document 3).
Japanese Patent Laid-Open No. 5-38820 Japanese Patent Laid-Open No. 2000-118065 JP-A-10-138517

  However, as in Japanese Patent Application Laid-Open No. H10-260260, the means for making the movement in the sub-scanning direction finely forms an image continuously in the sub-scanning direction by the same nozzle of the recording head, so that an error occurs in the nozzle missing and the discharge angle. If the nozzle is present, there is a problem that a continuous image defect occurs and a high-quality image cannot be formed.

  In addition, in order to move a heavy carriage at high speed in a short time, a high output moving mechanism is required, which causes a problem of high cost. In addition, if a heavy carriage is moved at high speed in a short time, the entire image recording apparatus is shaken during acceleration / deceleration of the carriage, which has a problem of adversely affecting image formation.

  The present invention has been made in view of the above points, and provides an image recording apparatus capable of forming a high-quality image while ensuring productivity by moving a recording head at high speed in a short time. It is an object to do.

In order to solve such a problem, the invention described in claim 1
A drum rotating body that holds a recording medium on which an image is formed and rotates in the main scanning direction;
A recording head for ejecting photocurable ink onto the recording medium;
In an image recording apparatus comprising a light irradiation device for irradiating light to the ink ,
A first sub-scanning movement mechanism that moves the recording head in a sub-scanning direction orthogonal to the main scanning direction;
At least one second sub-scanning movement mechanism that is disposed downstream of the first sub-scanning movement mechanism in the main scanning direction and moves the light irradiation device in the sub-scanning direction within a predetermined distance from the recording head. and,
A heating device that is disposed upstream of the first sub-scanning movement mechanism in the main scanning direction and heats the recording medium in a non-contact manner;
A float detection sensor that is disposed upstream of the heating device in the main scanning direction and detects the float of the recording medium with respect to the drum rotating body;
It is disposed upstream of the heating device in the main scanning direction and downstream of the floating detection sensor in the main scanning direction, and is pressed against the recording medium to lift the recording medium with respect to the rotating drum. The roller to be eliminated,
It is provided with.

According to a second aspect of the invention, in the image recording apparatus according to claim 1, wherein the first sub-scan moving mechanism causes the intermittent movement of the recording head in a sub-scanning direction when the recording head does not eject ink It is characterized by that.

The invention according to claim 3 is the image recording apparatus according to claim 1 or 2 , wherein the first sub-scanning movement mechanism is driven by a linear motor.

According to a fourth aspect of the present invention, in the image recording apparatus according to any one of the first to third aspects, the second sub-scanning movement mechanism moves continuously.

According to the first aspect of the present invention, since the recording head and the light irradiation device are moved by different sub-scanning movement mechanisms, the weight of the member mounted on one sub-scanning movement mechanism can be reduced. There is an effect that can be done. Further, the weight reduction of the member mounted on the sub-scanning movement mechanism prevents the vibration that occurs when the member is transported by the sub-scanning movement mechanism, and has an effect that a high-quality image can be formed. Furthermore, since the weight of the member mounted on the sub-scanning movement mechanism can be reduced, even if the output of the drive source is small, the cost of the image recording apparatus can be reduced.

According to the second aspect of the invention, since the recording head is intermittently moved when ink is not ejected and the recording head is stopped when ink is ejected, an effect of forming a high-quality image is achieved. .

According to the third aspect of the present invention, since the linear motor is used as the recording head moving mechanism, the recording head can be moved with high positional accuracy in a short time due to the responsiveness of the linear motor. There is an effect that an image of high image quality can be formed.

According to the fourth aspect of the invention, since the light irradiation device is continuously moved, a smaller drive source can be used than when the light irradiation device is moved intermittently, so that the cost can be reduced. Further, by continuously moving the light irradiation device, it is possible to reduce the vibration to the image recording device that occurs when the light irradiation device is transported.

  The configuration of the image recording apparatus according to the present invention will be described below with reference to FIGS. However, the scope of the invention is not limited to the illustrated examples.

  FIG. 1 is a front view showing a schematic configuration of an image recording apparatus 1 as an embodiment of the present invention, and FIG. 2 is a side view showing a schematic configuration of the image recording apparatus 1.

  As shown in FIG. 1, the image recording apparatus 1 is provided with a plate-shaped apparatus mount 2 for fixing members for performing image recording. As shown in FIG. 1, a rotating shaft 3 is provided on the apparatus base 2 so as to extend. The rotating shaft 3 is provided with a cylindrical rotating drum 4 that is a main scanning means and rotates coaxially. The rotating drum 4 holds a recording medium 5 on which an image is formed. The rotating drum 4 is also a holding member for the recording medium 5. Here, the direction in which the rotating shaft 3 extends is defined as a sub-scanning direction Y. An end of the rotating shaft 3 is rotatably supported by a support member 6 erected on the apparatus base 2, and the rotating drum 4 rotates with the rotation of the rotating shaft 3. Here, the circumferential direction in which the rotating drum 4 rotates is defined as a main scanning direction X.

Further, a rod-like stator 7 is provided on the apparatus base 2 so as to extend in the sub-scanning direction Y. Inside the stator 7, a magnet (not shown) is accommodated. A mover 8 formed of an electromagnetic coil is provided on the outer periphery of the stator 7 so as to be movable. When the linear motor 9 is composed of the stator 7 and the movable element 8 and a magnetic field is generated by flowing an electric current through the electromagnetic coil of the movable element 8, a repulsive force and an attractive force generated between the stator 7 and the magnet The mover 8 reciprocates in the sub-scanning direction Y along the stator 7. The linear motor 9 is a first sub-scanning movement mechanism in the present embodiment.
On the mover 8, a head carriage 10 is provided that moves as the mover 8 reciprocates in the sub-scanning direction Y. A recording head 11 that discharges ink of a predetermined process color toward the recording surface of the recording medium 5 is mounted on the head carriage 10. A large number of nozzles (not shown) for ejecting ink are arranged on the surface of the recording head 11 facing the rotating drum 4 (hereinafter referred to as nozzle surface). Each of these recording heads 11 is provided with an element for applying pressure to the internal ink for each nozzle by, for example, a piezo element or a heating element. When these elements are driven, ink is individually supplied from each nozzle. Are discharged as droplets. Thus, in this embodiment, the head carriage 10 on which the recording head 11 is mounted is moved intermittently by the linear motor 9 which is the first sub-scanning movement mechanism.

A ball screw support member 12 extends in the sub-scanning direction Y on the apparatus base 2 on the side opposite to the rotating drum 4 of the stator 7. A ball screw 13 is supported in the ball screw support member 12, and a male screw of the ball screw 13 is screwed with a female screw in the ball screw support member 12.
On the ball screw support member 12, a head control unit holding base 14 that is fitted and movable with the ball screw 13 is provided. A drive motor 15 (see FIG. 3) is connected to the ball screw 13, and the ball screw 13 is rotated by the drive of the drive motor 15 so as to reciprocate the head control unit holding base 14 in the sub-scanning direction Y. Yes. This ball screw 13 is a second sub-scanning movement mechanism in the present embodiment.

A head control unit 16 is fixed to the upper surface of the head control unit holding base 14. The head control unit 16 and the head carriage 10 described above are connected by a cable 17. As a result, the head control unit 16 reciprocates along the head control unit holding base 14 within a predetermined distance of the length of the cable 17.
The head control unit 16 includes an ink intermediate tank 18 that temporarily stores ink discharged from the recording head 11, and a head driver that controls ink discharge of the recording head 11 and driving of a pump (not shown) of the ink intermediate tank 18. A substrate 19 and a head control substrate 20 that controls the rearrangement of the image data are provided.
The ink intermediate tank 18 and the head driver substrate 19 are image forming auxiliary members in the present embodiment, and are held by a head control unit on which the ink intermediate tank 18 and the head driver substrate 19 are mounted by a ball screw 13 that is a second sub-scanning movement mechanism. The stage 14 is continuously moved within a predetermined distance from the recording head 11. The head driver substrate 19 generates and amplifies a drive waveform for ejecting ink from the nozzles, and transmits the drive waveforms to the elements provided for each nozzle described above.

Further, a support member 21 is provided on the apparatus base 2 above the rotating drum 4 so as to extend in the sub-scanning direction Y, and pulleys (not shown) are provided at both ends of the support member 21. And a steel belt is handed over. The support member 21 is a second sub-scanning movement mechanism in the present embodiment.
Further, the support member 21 supports an ultraviolet irradiation device 22 that irradiates the ink discharged from the recording head 11 onto the recording medium with ultraviolet rays, and the ultraviolet irradiation device 22 supplies the ink discharged onto the recording medium 5. Corresponding to the position, it is linearly moved along the support member 21 in the sub-scanning direction Y. The ultraviolet irradiation device 22 is provided with an ultraviolet light source 23. The ultraviolet irradiation device 22 is an image forming auxiliary member in the present embodiment, and is continuously moved within a predetermined distance from the recording head 11 by a support member 21 which is a second sub-scanning movement mechanism.
Note that a known light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a black light, a cold cathode tube, an LED (Light Emitting Diode), or the like can be applied to the ultraviolet light source 23 in the present embodiment. There is no particular limitation.

  A recording medium heating device 24 for heating the recording medium 5 in a non-contact manner is provided between the apparatus base 2 and the stator 7. The recording medium heating device 24 is an image forming auxiliary member in the present embodiment.

  On the upstream side in the main scanning direction X of the ultraviolet irradiation device 22, a photoelectric sensor light emitting unit 25 that irradiates light and a photoelectric sensor light receiving unit 26 that receives light from the photoelectric sensor light emitting unit 25 along the sub-scanning direction Y. The photoelectric sensor light emitting unit 25 and the photoelectric sensor light receiving unit 26 detect the floating or peeling of the recording medium 5 supported by the rotary drum 4. It has become.

  A roller 27 that presses the recording medium 5 is provided between the apparatus base 2, the photoelectric sensor light emitting unit 25, and the photoelectric sensor light receiving unit 26, and lifting or peeling of the recording medium 5 is eliminated by the pressing of the roller 27. It has come to be.

  Next, the control configuration of the image recording apparatus 1 will be described with reference to FIG.

FIG. 3 is a block diagram showing a control configuration of the image recording apparatus 1.
As shown in FIG. 3, the image recording apparatus 1 includes a control unit 28 that controls each unit.

  A rotary drum drive mechanism 29 is connected to the control unit 28, and the control unit 28 controls the rotary drum drive mechanism 29 to rotate the rotary drum 4 at a constant speed in the main scanning direction X. The rotation of 4 is stopped.

Further, the linear motor 9 is connected to the control unit 28, and the head carriage 10 moves intermittently when ink is not ejected from the recording head 11 in accordance with the drive control of the linear motor 9 by the control unit 28. It is like that. The control unit 28 drives and controls the linear motor 9 to stop the head carriage 10 when the recording head 11 mounted on the head carriage 10 is ejecting ink onto the recording medium 5. Further, the control unit 28 drives the linear motor 9 to intermittently move the head carriage 10 in the sub-scanning direction Y and stops it at a predetermined position when ink is not ejected from the nozzles of the recording head 11.
Further, a head driver substrate 19 is connected to the control unit 28, and the timing and amount of ink discharged from the recording head 11 to the recording medium 5 are driven and controlled. In addition, the head driver substrate 19 drives and controls the pump of the ink intermediate tank 18 so that ink is fed from the ink intermediate tank 18 to the recording head 11.

Further, the drive motor 15 is connected to the control unit 28, and the control unit 28 controls the energization to the drive motor 15 to continuously rotate the ball screw 13, whereby the head control unit holding base 14 is moved to the head carriage. Following the 10 continuous movements, the head carriage 10 is continuously moved within a predetermined range.
Further, the head control board 20 is connected to the control unit 28, and the image data is rearranged in accordance with the movement of the head carriage 10 by the control of the head control board 20 by the control unit 28, and the recording head 11. It is discharged from the nozzle.

A support member 21, which is a second sub-scanning movement mechanism, is connected to the control unit 28. The control unit 28 controls energization to the support member 21, so that the ultraviolet irradiation device 22 is discharged onto the recording medium 5. Corresponding to the position of the ink that has been applied, the recording head 11 continuously moves in the sub-scanning direction Y within a predetermined range.
The control unit 28 is connected to an ultraviolet irradiation device 22 that irradiates the recording medium 5 with ultraviolet rays, and the control unit 28 controls the energization of the ultraviolet light source 23 of the ultraviolet irradiation device 22. ing.

  In addition, a recording medium heating device 24 is connected to the control unit 28, and energization of the recording medium heating device 24 is controlled by the control unit 28.

Further, the control unit 28 is connected to the photoelectric sensor light emitting unit 25 and the photoelectric sensor light receiving unit 26, and the control unit 28 drives and controls the light emission of the photoelectric sensor light emitting unit 25 and the light reception of the photoelectric sensor light receiving unit 26. Then, it is determined whether or not the recording medium 5 supported by the rotating drum 4 has floated or peeled off.
Further, the control unit 28 is connected to a roller 27 that presses the recording medium 5 to eliminate floating or peeling, and the control unit 28 controls the driving of the roller 27.

  Next, the operation in this embodiment will be described.

When image data is input from the outside, the control unit 28 holds the recording medium 5 on the rotating drum 4 and drives and controls the rotating drum driving mechanism 29 to rotate the rotating drum 4 in the main scanning direction X at a constant speed. . At this time, the control unit 28 drives and controls the recording medium heating device 24 to heat the recording medium 5 adjacent to the recording medium heating device 24.
In addition, when the rotating drum 4 is rotating, the control unit 28 is driven and controlled by the photoelectric sensor light emitting unit 25 to emit photoelectric light, and is received by the photoelectric sensor light receiving unit 26 to be supported by the rotating drum 4. It is determined whether the recording medium 5 is lifted or peeled off. When it is determined that the recording medium 5 supported by the rotating drum 4 is lifted or peeled off, the control unit 28 drives and controls the roller 27 to press the recording medium 5, and as the rotating drum 4 rotates. The floating and peeling of the recording medium 5 are eliminated.

  When the recording medium 5 is heated to a certain temperature, the control unit 28 drives and controls the linear motor 9 to move the head carriage 10 onto a predetermined position of the recording medium 5 in the sub-scanning direction Y. Then, the control unit 28 stops the head carriage 10 on the rotary drum 4 and causes ink to be ejected from the nozzles of the recording head 11 onto the recording medium 5.

  Further, the control unit 28 causes the head control unit 16 to continuously move in the sub-scanning direction Y within a predetermined distance from the recording head 11 by following the movement of the head carriage 10 in the sub-scanning direction Y. An ink intermediate tank 18 and a head driver substrate 19 are mounted on the head control unit 16. By positioning the ink intermediate tank 18 within a predetermined distance from the recording head 11, fluctuations in the ink pressure resistance in the piping due to the piping distance from the ink intermediate tank 18 to the recording head 11 are reduced, and ink ejection accuracy is reduced. Can be prevented. Further, since the drive waveform for generating ink from the nozzles is generated and amplified in the head driver substrate 19, the head driver substrate 19 is positioned within a predetermined distance from the recording head 11, so that the head driver When the drive waveform is transmitted from the substrate 19 to the recording head 11, it is possible to prevent the drive waveform from becoming dull or adding noise.

  When ink is ejected onto the recording medium 5, the control unit 28 drives and controls the support member 21 and continuously moves the ultraviolet irradiation device 22 so as to be positioned immediately above the recording medium 5 onto which the ink has been ejected. When the ink landed on the recording medium 5 is positioned immediately below the ultraviolet irradiation device 22 as the rotary drum 4 rotates, the control unit 28 drives and controls the ultraviolet irradiation device 22 to transfer the ink from the ultraviolet light source 23 to the recording medium 5. The ink landed on the recording medium 5 is cured by irradiating with ultraviolet rays. As a result, the ink discharged onto the recording medium is fixed.

  The control unit 28 controls the driving of the linear motor 9 when no ink is ejected from the recording head 11 such as when the recording medium 5 does not exist immediately below the recording head 11 due to the rotation of the rotary drum 4. The carriage 10 is intermittently moved in the sub-scanning direction Y and moved to a predetermined position.

  By repeating the above operation, an image is formed by the recording head 11 on the recording medium 5 held on the rotary drum 4.

As described above, in the image recording apparatus 1 according to the present invention, the recording head 11 and the ink intermediate tank 18 and the ultraviolet irradiation device 22 that are image forming auxiliary members are separated from the recording head 11 by using a different sub-scanning movement mechanism. Since it is moved within the distance, there is an effect that the weight of one sub-scanning moving mechanism can be reduced.
As a result, the first sub-scanning mechanism requires only the weight of the recording head 11 that needs to be intermittently moved, so that the recording head 11 is intermittently moved with higher accuracy than when the weight of other image forming auxiliary members is applied. The effect which can be made to move easily is produced. Further, by providing a plurality of sub-scanning movement mechanisms, the image forming auxiliary member that does not need to be moved intermittently is continuously moved, and a driving source having a high driving force is not required, so that the cost can be reduced. There is an effect. Further, by using the continuously moving sub-scanning moving mechanism, it is possible to prevent the vibration generated when the image forming auxiliary member is conveyed and to form a high-quality image.

  In this embodiment, the example in which the recording medium heating device 24 is fixed is shown. However, the present invention is not limited to this, and the recording is performed so as to heat the ink ejected from the recording head by the second sub-scanning mechanism. It may be provided so as to continuously move within a predetermined distance from the head.

1 is a front view showing a schematic configuration of an image recording apparatus according to the present invention. 1 is a side view showing a schematic configuration of an image recording apparatus according to the present invention. It is a block diagram which shows the control structure of the image recording apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image recording device 4 Rotating drum 5 Recording medium 9 Linear motor 10 Head carriage 11 Recording head 13 Ball screw 14 Head control unit holding stand 15 Drive motor 16 Head control unit 17 Cable 18 Ink intermediate tank 19 Head driver substrate 21 Support member 22 UV irradiation Device 24 Recording medium heating device 27 Roller

Claims (4)

A drum rotating body that holds a recording medium on which an image is formed and rotates in the main scanning direction;
A recording head for ejecting photocurable ink onto the recording medium;
In an image recording apparatus comprising a light irradiation device for irradiating light to the ink ,
A first sub-scanning movement mechanism that moves the recording head in a sub-scanning direction orthogonal to the main scanning direction;
At least one second sub-scanning movement mechanism that is disposed downstream of the first sub-scanning movement mechanism in the main scanning direction and moves the light irradiation device in the sub-scanning direction within a predetermined distance from the recording head. and,
A heating device that is disposed upstream of the first sub-scanning movement mechanism in the main scanning direction and heats the recording medium in a non-contact manner;
A float detection sensor that is disposed upstream of the heating device in the main scanning direction and detects the float of the recording medium with respect to the drum rotating body;
It is disposed upstream of the heating device in the main scanning direction and downstream of the floating detection sensor in the main scanning direction, and is pressed against the recording medium to lift the recording medium with respect to the rotating drum. The roller to be eliminated,
An image recording apparatus comprising: The image recording apparatus according to claim 1 , wherein the first sub-scanning movement mechanism intermittently moves the recording head in the sub-scanning direction when the recording head does not eject ink. Wherein the first sub-scan moving mechanism, an image recording apparatus according to claim 1 or 2, characterized in that driven by a linear motor. The second sub-scan moving mechanism, an image recording apparatus according to any one of claims 1 to 3, characterized in that the continuously moving.

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