JP3334727B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus. More specifically, the present invention relates to a transfer type ink jet recording apparatus that records an ink image on a recording sheet by transferring an ink image formed on a transfer medium based on recording data to a recording sheet as a recording medium.

[0002]

2. Description of the Related Art A transfer type ink jet printer is characterized in that high quality recording can be obtained regardless of the quality of recording paper. As such a transfer-type ink jet printer, configurations described in U.S. Pat. No. 4,538,156, U.S. Pat. No. 5,099,256, and JP-A-62-22849 are known.

In these apparatuses, an ink jet recording head (hereinafter, referred to as a recording head) having a plurality of nozzles is provided on a cylindrical transfer medium via a gap. The recording step includes a writing step of writing an ink image on the transfer medium, and a transfer step of transferring the ink image onto the recording paper by bringing a recording paper as a recording medium into contact with the transfer medium and pressing it from behind. .

[0004]

In these apparatuses, air bubbles and foreign matter flow into the recording head.
When an irregular ejection operation failure occurs and an ejection operation failure occurs, the ejection failure tends to continue until the recovery operation of the print head is performed. Particularly, in a transfer type ink jet recording apparatus capable of high-quality recording regardless of paper quality, there is a problem that image quality is significantly degraded when a discharge operation failure occurs in a recording head, which causes waste of recording paper and loss of recording data. there were.

[0005] The present invention has been made from this viewpoint,
SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus capable of preventing recording paper waste and loss of recording data and performing stable recording .

[0006]

In the present invention for [Means for Solving the Problems] To achieve the above object, an ink jet recording head for forming an ink image on the transcription medium by selectively discharging the ink droplets from the nozzles, the recording a transfer medium carrying an ink image formed by the ink droplets from the head, and transfer means for transferring the ink image to the recording medium is brought into contact with the transfer medium, or in Ranaru ink jet recording apparatus, the serial <br / > a storage unit that holds recording data, and removing means for removing the untransferred ink image of the transfer medium, a detection means for detecting an ink droplet discharge failure of said recording head based on the ink image of the transfer medium, wherein Recovery means for recovering the ink droplet ejection failure of the recording head, and interrupting the printing when the detection means detects the ink droplet ejection failure of the recording head. From actuates the serial recovery means the removal means, and so as to print the print data of said storage means again.

[0007]

According to the above method, during the recording operation, the recording data is held by the storage means, and the operation state of the recording head is monitored. A method of removing the ink image and recovering the recording head is performed, and a predetermined recording can be performed with the recording data held thereafter.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described in accordance with embodiments.

FIG. 1 is a perspective view of an ink jet printer according to a first embodiment. On the transfer drum 1 as a transfer medium, there is a recording area 20 corresponding to one page of the recording paper 5 as a recording medium. A carriage 1 is provided around the transfer drum 1.
6, a light irradiation device 4 as a heating unit, a cleaning blade 9 as a removing unit, and a backup roller 3 are arranged. The transfer drum 1 is driven to rotate in the direction of arrow A by a rotation drive device 17. The carriage 16 reciprocates in the arrow D direction by the carriage swinging means 15.

The recording head 2 is supplied with ink from an ink container 84 via a supply tube 85. The ink container 84 is in communication with the atmosphere during the recording operation, and
When the ink is discharged, air flows in and the inside of the container is maintained at the atmospheric pressure. During the recovery operation, the pressure is increased by forcibly pumping the air into the ink container 84 by the pressure pump 83 to increase the pressure to eject ink or foreign matter or bubbles mixed therein from the nozzles of the recording head 2, thereby causing malfunctioning nozzles. To recover.

The transfer drum 1 is formed by laminating fluorosilicone rubber as a surface layer around an aluminum tube which is a good heat conductor. It is desirable that the surface layer has a property that the ink image is easily peeled off. The fluorosilicone rubber used in this example has low surface energy, high releasability, milky white color, and high light reflectivity.

The light irradiating device 4 is made of a bright aluminum plate for condensing the light of the heater lamp 41 composed of a rod-shaped halogen lamp on the transfer drum 1 and irradiates the outer peripheral surface of the transfer drum 1 with light to carry an ink image carried thereon. Is heated and dried.

The backup roller 3 is an aluminum metal roller, and can be controlled to move in the direction of arrow E by a load device 31, and is pressed against the transfer drum 1 in a transfer step of transferring the ink image on the transfer medium to the recording medium. Configuration. In the transfer step, the transfer drum 1 is pressed by the transfer drum 1 via the recording paper 5 as a recording medium and is rotated in the direction of arrow B.

The ink is obtained by dispersing a pigment in pure water as an ink solvent together with additives such as an emulsion and a surfactant. Specifically, 3 wt% of carbon black as a pigment, 8 wt% of a styrene-acryl copolymer emulsion as an emulsion, 8 wt% of glycerin as a humectant, and polyvinylpyrrolidone 6 as a water-soluble resin.
The ink was prepared by adding 1 wt% of a surfactant, 1 wt% of a surfactant, and several wt% of a preservative or the like.

The cleaning blade 9 is a urethane rubber plate, and is driven to rotate in the direction of arrow H by a blade swinging device 14. At this time, the edge portion of the cleaning blade 9 is in contact with the outer peripheral surface of the transfer drum 1, and the transfer drum 1 is rotated to remove the ink image on the transfer drum 1.

As shown in the sectional view of FIG. 2, the recording head 2, the recording head driving circuit 12, the line sensor 11, the light source 10, and the ink ejected from the nozzles during the recovery operation of the recording head are received on the carriage 16, Carriage 1
6 has a cover member 87 that leads to a collection container 86 through a garter groove 88 formed in the container 6. The cover member 87 rotates to the position indicated by the solid line in FIG. 2 while the recording head 2 moves in the direction of arrow C during the recovery operation. FIG. 2 during recording operation
As shown by a broken line therein, the recording head 2 moves to a position close to the transfer drum 1 and the cover member 87 is accommodated below the recording head 2. The recording head 2 is an ink jet recording head using a piezoelectric element. A plurality of nozzles arranged on a straight line parallel to the axis of the transfer drum 1 are arranged at equal intervals on the front surface of the recording head 2 facing the transfer drum 1. Have in Q. The ink droplets are selectively arranged at grid points on the transfer drum 1 to form a predetermined ink image. When the lattice spacing is P, the nozzle spacing of the recording head 2 is set so as to have a relationship of Q = P × N (N is an integer). The print data is taken into a memory 60 as a storage means, and transmitted to a print head drive circuit 12 via a control circuit 61 so as to discharge the print data to a predetermined grid point in the print area 20. The recording head drive circuit 12 applies a predetermined electric signal to the piezoelectric element of the recording head 2 connected by the signal line 13,
An ink droplet ejection operation is performed.

In the light source 10, a light emitting element 71 driven by a light source driving circuit 70 is formed in a line at a position corresponding to a nozzle. Light from the light emitting element 71 is focused on the transfer medium by the lens 72. The line sensor 11 is the transfer medium 1
A light receiving element 73 for detecting the upper ink droplet and receiving the light reflected by the transfer medium 1 is provided in a line shape. The output of the light receiving element 73 is sent to a detection circuit 74, which detects the presence or absence of an ink droplet on the transfer medium 1. When ink droplets are present, carbon black in the ink mainly absorbs light, so that the amount of light reflection is lower than when the ink droplets are not present. Thus, the presence or absence of the ink droplet is detected.
If there is no ink droplet at a predetermined grid point corresponding to the print data, it is detected that the print head 2 is malfunctioning.
Therefore, the operation state of the recording head 2 can always be monitored.

Next, the operation will be described. The recording operation includes two steps, a writing step of forming an ink image on the transfer drum 1 and a transfer step of transferring one page of the ink image formed on the transfer drum 1 to recording paper.

First, the first step, the step of forming an ink image on the transfer drum 1, will be described. The ink image is formed based on the recording data held in the memory 60. FIG. 7 illustrates the image forming process. When the nozzle pitch is Q (however, Q
= N * P), and in order to briefly describe the scanning method of the apparatus of the present embodiment, the integer N will be described as 4 here. In this case, an ink image is formed on the recording area 20 of the transfer drum 1 at a predetermined lattice interval P by four rotations of the transfer drum.
The recording head continuously moves at a constant speed so that the recording head moves by P in the direction of arrow D per rotation of the transfer drum 1. The plurality of nozzles provided at intervals Q form an ink image while moving in the direction of arrow D. A portion written by each nozzle by one rotation of the transfer drum 1 is a hatched portion 601. When the moving amount of the recording head 2 reaches Q (more precisely, QP) or more, the entire area is scanned. In this manner, ink droplets are selectively ejected from a plurality of nozzles of the recording head 2 based on the recording data, and a predetermined ink image is recorded on the transfer drum 1.

On the other hand, the operation state of the recording head 2 is constantly monitored during this writing process, and the presence or absence of a discharge operation failure is detected.

If the predetermined writing process is completed without detecting an operation failure, the process proceeds to a second process, a transfer process. In the transfer step, the transfer drum 1 carrying one page of the ink image in the recording area 20 passes through the light irradiation device 4, receives the light irradiation, heats the ink image, evaporates the ink solvent, and sets the dry state. An ink image is obtained. This ink image reaches a contact portion with the backup roller 3 as it rotates. The backup roller 3 is brought into contact with the transfer drum 1 at this timing, and the recording paper 5 is sent to the contact portion. Pressure is applied to the recording paper 5 by the backup roller 3, and the ink image on the transfer drum 1 is transferred to the recording paper 5.
Is transferred to

After the transfer step, the cleaning blade 9
Is brought into contact with the transfer medium, and the transfer drum 1 is rotationally driven to remove the transfer residual ink image, and the process proceeds to the next ink image forming step.

Next, an operation in the case where an operation failure is detected before the end of the writing step will be described.

At this time, when a malfunction is detected, the writing process is stopped, the recording head 2 is moved in the direction shown by the arrow C in FIG. 2, and the cover member 87 is moved to the position shown by the solid line in FIG. Rotate. Thereafter, the ink container 84 is pressurized by the pressurizing pump 83, and the ink, the foreign matter mixed therein, and bubbles are ejected from the nozzles, thereby recovering the malfunctioning nozzles.

Further, the ink image on the transfer medium is removed by rotating the cleaning blade 9 in contact with the transfer drum 1.

Thereafter, based on the recording data held in the memory 60, the writing process is started again.

According to the present embodiment, a malfunction of the recording head 2 can be detected by detecting ink droplets constituting an ink image on the transfer medium. In the case of a malfunction, before the transfer to the recording medium is performed, the removal of the ink image on the transfer drum 1 and the recovery of the recording head 2 are performed, and thereafter, the predetermined recording is performed using the retained recording data. Thus, waste of recording paper and loss of recording data can be prevented, and a stable recording operation can be performed. Further, in the present embodiment, the writing process is stopped as soon as an operation failure occurs, and the recovery process is performed. Therefore, the present embodiment has a feature that a required time can be saved and ink consumption can be reduced.

Next, a second embodiment will be described with reference to FIGS. FIG. 3 is a perspective view of the ink jet printer of the present embodiment, and has a storage area 20 and a band-shaped test area 21 provided outside the storage area 20 on the outer periphery of the transfer drum 1. In the storage area 20, an ink image to be recorded on a recording medium is formed. In the test area 12, an ink image pattern for detecting the operation state of the recording head 2 is formed.
In the present embodiment, ink droplets are ejected from all the nozzles so as to fill all of the grid points in the test area 12 with ink droplets.
The ink image pattern thus formed is hereinafter referred to as a solid image.

Guide shafts 61 and 62 are provided above the recording head 2.
Has a carriage 34 guided to the carriage. On the carriage 34, a density detecting device 7 for detecting the light reflection density of the solid image of the test area 21 on the transfer medium 1 and a suction means 8 for recovering the ejection failure of the recording head 2 are mounted. Carriage 3
4 can be moved by the moving device 30 along the axial direction of the transfer medium 1.

The density detecting device 7 detects the optical density of the solid image in the test area 12 of the transfer medium 1, and as shown in the sectional view of FIG. And a light receiving element 73 for receiving the light reflected from the transfer medium 1. The output of the light receiving element 73 is sent to the detection circuit 74 to detect whether the solid image of the test area 12 on the transfer medium 1 has a predetermined reflection density.

The suction member 8 is biased by a spring in the direction of arrow F and presses the front surface of the recording head 2 when the recording head 2 comes to the retracted position. The suction member 8 has a suction pipe 89 inside and a pipe 91 connected to the suction pipe 89. The suction pump 90 supplies ink from the recording head 2 or foreign matter mixed into the ink.
The bubbles are sucked out and collected in the collection container 86. This allows
A malfunctioning nozzle with foreign matter mixed therein is recovered. Structures other than the above are the same as those in the first embodiment, and a description thereof will be omitted.

Next, the operation will be described.

In the writing step, an ink image is formed by ejecting ink droplets to predetermined positions of the lattice points based on the recording data held in the memory in the recording area 20. On the other hand, ink droplets are continuously ejected from all the nozzles in the test area 21, and a solid band-shaped solid image extending in the axial direction of the transfer drum 1 is formed in this area. If a malfunction nozzle exists, a portion corresponding to the malfunction nozzle becomes a strip-shaped blank portion extending in the circumferential direction in the test area 12.

After forming the ink image for one predetermined page, the carriage 34 scans in the axial direction of the transfer drum 1 at the timing when the test area 21 arrives, and the density detector 7 detects the solid image of the test area 21. Detect optical density. If there is a nozzle with an ejection failure, the surface layer of the transfer drum 1 is exposed at a portion corresponding to the nozzle, and the light reflectance is high. As a result, the presence and position of the malfunction nozzle can be detected. Therefore, if the resolution of the density detecting device 7 is substantially equal to the nozzle interval Q (= P × N) of the recording head, practically sufficient detection accuracy can be obtained. When a malfunction nozzle is detected, the carriage 34 is moved to the position of the malfunction nozzle to move the print head 2 backward. Suction member 8
Is deflected by a spring in the direction of arrow F as shown in FIG. 2, so that the ink is sucked from the front surface of the recording head 2 as the recording head 2 retreats, and the malfunction nozzle is recovered. Other operations are the same as those of the first embodiment, and the description is omitted.

In this embodiment, since the operation density of the recording head 2 is detected by detecting the reflection density of the solid image in the test area 21 provided on the transfer medium, the detection device can be configured at low cost. Have. Further, in order to detect the reflection density of a solid image, which is a collection of ink droplets, the present embodiment is suitable for a case where an ink having a low light absorption rate is used, such as an ink used for a color inkjet recording apparatus. Detection accuracy can be obtained.
Further, the present invention can be easily applied to use the reflection density detected from the solid image for correction of an increase or decrease in the amount of ink ejected from the recording head 2.

Next, a third embodiment will be described with reference to FIGS. FIG. 5 is a perspective view of the ink jet printer of the present embodiment. The transfer drum 1 is made of a transparent glass having an outer periphery continuous with the transfer drum 1, and has a prism 51 having a light emission area at a portion corresponding to the test area 21. Transparent glass has good solid image removability due to its smooth surface properties.

As shown in FIG. 6, the density detecting device 7 causes light from the light emitting element 71 to enter the prism 51 in a substantially vertical direction, and further emits light substantially perpendicularly to the lower surface of the solid image to enter the light receiving element 73. In this embodiment, a white halogen lamp bulb was used as the light emitting element 71 and a Cds cell was used as the light receiving element 73.

In this embodiment, the presence or absence of a malfunction nozzle is detected by detecting the light transmission density of the solid ink image in the test area 21. The presence or absence of a malfunctioning nozzle is detected from the difference in light transmission density between when a solid image is carried and when a predetermined ink droplet is not ejected due to malfunction. Other configurations and operations are the same as in the second embodiment, and a description thereof will be omitted.

According to the present embodiment, light is incident and emitted vertically through the test area 21 and the light transmission density of the solid image is detected, whereby the defective operation of the recording head 2 is more efficiently performed. Can be detected. Further, the detection can be performed even when the surface layer of the transfer drum 1 is made of a material having low light reflectance (for example, a material exhibiting black color).

[0040]

As described above, according to the present invention, in the present invention, the storage means for holding the recording data, the removing means for removing the untransferred ink image on the transfer medium, and the recording head based on the ink image on the transfer medium are used. A detection unit for detecting an ink droplet ejection failure; and a recovery unit for recovering the ink droplet ejection failure of the recording head. When the detection unit detects the ink droplet ejection failure of the recording head, printing is interrupted. Since the data in the storage unit is printed again after the recovery unit and the removal unit are operated, it is possible to prevent waste of the recording paper and loss of the recording data, and to perform stable recording.

[Brief description of the drawings]

FIG. 1 is a perspective view of an inkjet printer according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a detection unit used in the ink jet printer according to the first embodiment of the present invention.

FIG. 3 is a perspective view of an ink jet printer according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a detecting unit used in an ink jet printer according to a second embodiment of the present invention.

FIG. 5 is a perspective view of an ink jet printer according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a configuration of a detecting unit used in an ink jet printer according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating an operation of an ink image forming process on the transfer drum 1 of the ink jet printer according to the first embodiment of the present invention.

[Explanation of symbols]

 1: transfer drum (transfer medium) 2: recording head 3: backup roller 4: light irradiation device 5: recording paper (recording medium) 7: density detector 8: suction member 9: cleaning blade (removal means) 10: light source 11 : Line sensor 16: Carriage 20: Recording area 21: Test area 51: Prism 60: Memory (storage means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/01 B41J 2/18 B41J 2/185 B41J 29/17 B41J 29/46

Claims (5)

(57) [Claims] 1. A by selectively discharging ink droplets from the nozzles
An ink jet recording head for forming an ink image on the transcription medium, the transfer medium carrying an ink image formed by the ink droplets from the recording head, thereby recording medium in contact with the transfer medium is transferred to said ink image a transfer unit, or in Ranaru ink jet recording apparatus, a storage means for holding a record data, and removing means for removing the untransferred ink image of the transfer medium, the recording head based on the ink image of the transfer medium Detecting means for detecting an ink droplet ejection failure, and recovery means for recovering the ink droplet ejection failure of the recording head, wherein when the detection means detects the ink droplet ejection failure of the recording head, printing is performed. After suspending and operating the recovery means and the removal means, the storage means
An inkjet recording device that prints print data again. 2. The ink jet recording apparatus according to claim 1, wherein said detecting means comprises means for detecting an optical characteristic of an ink image on said transfer medium. 3. A selectively eject ink droplets from the nozzles
Transfer and ink jet recording head for forming an ink image on the transcription medium, the transfer medium carrying an ink image formed by the ink droplets from the recording head, the ink image by contacting the record medium to the transfer medium a transfer unit for, if the Ranaru ink jet recording apparatus, a storage means for holding a record data, and removing means for removing the untransferred ink image of the transfer medium, the outer on said transfer medium, and transfer recording area detecting means for detecting an ink droplet discharge failure of said recording head based on the ink image formed on, and a recovery means for recovering the ink ejection failure of the recording head, the recording head by said detecting means When an ink drop ejection failure is detected, the ink jet printer prints recording data in the storage unit after operating the recovery unit and the removal unit. Recording device. 4. The method according to claim 1, wherein the detecting unit is configured to detect whether
4. The ink jet recording apparatus according to claim 3, wherein the ink jet recording apparatus is constituted by optical means for detecting the light reflection density of the ink image formed outside the transfer recording area . 5. An ink jet recording apparatus according to claim 3, wherein a transparent area is formed in a part of said transfer medium, and said detecting means comprises optical means for detecting light transmittance of said transparent area.