JP2007301464A - Recording apparatus and coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus and a coating apparatus in which the progress of the thickening of a coating agent is suppressed, the coating agent containing dust such as paper powder is never applied again on a recording medium and use of the coating agent is small. <P>SOLUTION: An external tub 105 provided with a filter 112 to be press-contacted with a coating roller 71A is provided to cover a coating tub 101 and the coating agent collected in the external tub 105 is recovered into a tank 103 based on the information from a remaining quantity detecting unit 113 provided in the tank 103. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a coating apparatus including a processing unit that applies a liquid different from ink to a recording medium.

  Conventionally, typical recording methods of a recording apparatus include an inkjet method, a wire dot method, a thermal method, a sublimation method, a thermal transfer method, an electrophotographic method, a silver salt photography method, and the like. Each of these methods is roughly classified into a serial type and a full line type as a recording method. In a serial type recording apparatus, after a recording medium is set at a predetermined position, recording is performed by a recording head mounted on a carriage that scans in the main scanning direction along the recording medium. Recording is performed in a desired range of the recording medium by repeating the operation of feeding a predetermined amount of paper in the sub-scanning direction after the recording head finishes recording for one line and then recording the next line. . On the other hand, in a full-line type recording apparatus that performs recording only by sub-scanning in which the recording medium is transported in the transport direction, the recording medium is set at a predetermined recording position, and one line of recording is performed continuously. A fixed amount of paper feed (pitch feed) is performed. Then, an image is recorded on the entire recording medium.

  Among the above recording methods, the ink jet method has an advantage that high-quality recording can be performed on various recording media with relatively simple means and configuration. However, even in the ink jet system, depending on the characteristics of the ink and the recording medium, the ink may not be favorably absorbed by the recording medium or may not be favorably colored, which may lead to a decrease in recording quality. For example, when ink is ejected onto a polyethylene terephthalate (PET) sheet in order to create a transmissive original, the ink is difficult to be absorbed by the recording medium, and it may bleed and a suitable image quality may not be obtained. Conversely, when ink is ejected onto paper with large irregularities such as drawing paper, the ink permeates into the paper and a suitable color development may not be obtained. In order to improve these problems, a recording medium (hereinafter also referred to as coated paper) in which a liquid for forming an ink receiving layer is previously applied on the surface of the recording medium is known.

  However, these coated papers may apply more liquid than necessary to the recording surface in order to cope with as many recording devices and recording modes as possible, and may be more expensive than ordinary paper. Also, if you want to express various textures, you have to prepare their special papers. Furthermore, since these coated papers deteriorate in quality due to moisture absorption, it is necessary to pay attention to the humidity during storage.

  As a technique for solving these problems, a recording apparatus having a coating processing unit that applies a coating agent for holding ink on a recording medium recording surface is conventionally known. In this recording apparatus, a coating agent that absorbs or develops ink is applied to a recording medium recording surface by a suitable amount before recording, and then ink-jet recording is performed on a portion where the liquid is applied, thereby forming a suitable image. Can be obtained. As described above, a recording apparatus having a processing (hereinafter also referred to as preprocessing) portion for applying a coating agent on a recording surface in advance before recording includes a device (Patent Document 1) for applying the coating agent to the entire recording medium. There is an apparatus (Patent Document 2) that applies a coating agent only to a portion of a recording medium where recording is performed.

  In addition, a recording medium recorded by the inkjet method is relatively inferior in robustness as compared with a recording medium recorded by another recording method. For example, until the ejected ink is dried or absorbed by the recording medium, the fixability of the ink on the recording surface of the recording medium is poor and easily transferred to an object in contact therewith. In addition, even after the ink is dried or absorbed by the recording medium, if water is attached to the recording surface, the ink may bleed or flow out. Furthermore, since the recording surface after recording is in a state in which the color material is exposed and adhered on the recording medium, the color may be changed by ozone, fluorescent light, sunlight, or the like. On the other hand, as an improvement measure regarding such a point, there is a case where a color material using a pigment is used. In that case, the gloss may differ depending on the bronze phenomenon, the recording density, and the ink color.

  In order to solve such a problem, a method for protecting ink after recording by applying a coating agent such as an overcoat agent on the recording surface after ejecting the ink onto the recording medium is known. As described above, a recording apparatus having a processing (hereinafter also referred to as post-processing) portion for applying a coating agent to a recording surface after recording includes a device having a roller pair or the like to apply the coating agent to the entire recording surface ( Patent Document 3).

Here, each coating agent used for pre-processing and post-processing is demonstrated.
In general, many coating agents used as pretreatments react with discharged ink to maintain color development. Therefore, the coating agent has conventionally been easy to react with water-based ink and often contains a solvent. As an example, Japanese Patent Application Laid-Open No. H10-228561 pre-treats a recording medium using a polymer solution such as carboxymethyl cellulose, polyvinyl alcohol, or polyvinyl acetate, and then discharges the ink to a portion where the polymer solution is adhered. How to do is described. Patent Document 5 discloses an ink jet recording method in which an image recording promoting liquid containing a compound that insolubilizes a dye in ink is attached to a recording medium, and then ink is ejected and recorded on a portion where the image recording promoting liquid is attached. Are listed.

  Moreover, many coating agents used as post-treatments are absorbed on the recording surface in order to improve the glossiness of the recorded matter and to improve the weather resistance. Therefore, it is not necessary that the coating agent used in the pretreatment is easily reactive with water-based ink. For example, Patent Document 3 and Patent Document 6 describe that oil-based silicone oil, wax, fats and oils, and the like are used particularly when water resistance is given to a recorded matter.

  FIG. 1 is a side view showing a coating agent application unit in a conventional recording apparatus. The coating agent 123 is stored in the tank 119. First, the coating agent 123 in the tank 119 is pumped up by the supply roller 122. The spread coating agent 123 is then transferred to the transport roller 120 and further transferred to the coating roller 118, the amount of the coating agent is adjusted by the thin film roller 121, and is applied to the recording medium 125 provided in the coating roller 101. The

  By using such a method, it is possible to apply the coating agent to the recording medium 125, and the coating agent can reduce bleeding of the recording result and color bleed (bleeding between colors), thereby improving image quality. .

JP 07-156538 A Japanese Patent No. 2675001 JP 2003-93940 A JP-A-56-89595 Japanese Patent Laid-Open No. 8-20161 JP 2003-25559 A

  However, in the image recording apparatus having the configuration in which the coating agent 123 is applied in this way, the coating agent 123 transferred to each roller increases in viscosity by touching the outside air during the transportation process, evaporating, volatilizing, drying, etc. Furthermore, it sometimes fixed and precipitated. In this case, not only does the amount of application to the recording medium fluctuate, but in some cases it may become impossible to apply. Moreover, when the contact portion between the rollers is filled with the thickening agent, the rotational torque of the rollers is extremely increased and the rollers do not rotate. In order to prevent this, a motor that generates more torque than necessary must be provided.

  Further, there is a possibility that the coating agent 123 may flow out from the gap of the coating basket due to the rollover of the recording device or the like. In addition, it is also conceivable that the coating agent 123 that has been applied to the recording roller 125 and remains without being applied to the recording medium 125 is mixed with the coating agent 123 in the tank 119 again. The coating agent 123 remaining without being applied is often thicker than the coating agent 123 in the tank 119 and often contains paper dust or other dust. . When the thickened and contaminated coating agent 123 containing paper powder or the like is mixed in the tank 119, if the amount of the coating agent 123 in the tank 119 is small, the coating agent 123 in the tank 119 As the viscosity increases, the content of dust such as paper dust increases and the coating agent 123 deteriorates. In addition, it is conceivable to collect and discard the contaminated coating agent containing paper dust and the like before returning to the tank 119. In this case, the consumption of the coating agent 123 increases. Running costs will increase.

  Therefore, the present invention provides a recording apparatus and a coating apparatus that suppresses the progress of thickening of the coating agent, prevents the coating agent containing dust such as paper dust from being applied again to the recording medium, and consumes less coating agent. Objective.

  Therefore, the recording apparatus of the present invention includes an application unit capable of applying the liquid supplied from the tank to the recording medium, a recording unit capable of recording an image on the recording medium before or after the liquid is applied, A recovery means for recovering the liquid that has not been applied to the recording medium from the application means into the tank; a control means for controlling the application operation of the application means in accordance with a change in the viscosity of the liquid in the tank; It is characterized by providing.

  Further, the coating apparatus of the present invention includes a coating unit capable of coating the liquid supplied from the tank to the coating medium, and a collecting unit for collecting the liquid that has not been coated on the coating medium from the coating unit into the tank. And control means for controlling the application operation of the application means in accordance with a change in the viscosity of the liquid in the tank.

  The recording apparatus and the coating apparatus of the present invention have a function of collecting the coating agent discharged from the tank, and when collecting, remove foreign matters such as paper dust contained in the coating agent by a filter, Furthermore, it collect | recovers, after confirming the residual amount of the coating agent in a tank. As a result, the coating agent in the tank can be prevented from becoming a predetermined viscosity or more without being mixed with a foreign substance, so that the state of the coating agent can always be kept good. Furthermore, the consumption of the coating agent can be reduced by the recovery function.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a perspective view showing a recording unit of the ink jet recording apparatus according to the embodiment of the present invention. The recording head 205 has a nozzle (not shown) and is detachably mounted on the carriage 204. The recording head 205 has an electrothermal converter (not shown), and the electrothermal converter generates heat energy, thereby recording ink by ejecting ink from an ink ejection port (not shown) of the nozzle. The carriage 204 reciprocates along a guide shaft 203 having a central axis coaxial with the main scanning direction Y. A recording medium 202 such as recording paper or a plastic thin plate is supported by a platen 206 so as to form a flat recording surface facing the surface of the recording head 205 having the ink discharge ports, and is rotated by the rotation of the paper feed roller 201. It is conveyed in the scanning direction X.

  FIG. 3 is a schematic block diagram of the control system of the recording apparatus to which the present invention is applicable. In the figure, a CPU 300 executes control processing of the operation of the recording apparatus, data processing, and the like. The ROM 301 stores programs such as those processing procedures, and the RAM 302 is used as a work area for executing these processes. Ink is ejected from the recording head 205 when the CPU 300 supplies drive data and drive control signals of an electrothermal transducer (not shown) to the head driver 205A. The CPU 300 receives information from the remaining amount detection unit 113 and the like, and controls the carriage motor 303 via the motor driver 303A, and controls the PF motor 304 via the motor driver 304A. It is carried out.

  FIG. 4 is a cross-sectional view showing a coating portion of the recording apparatus of the present embodiment. In the figure, a recording unit that forms an image on the recording medium 202 by an ink jet method with a recording head 205, and a roller pair 71A, 71B that applies the coating agent 110 to the recording medium 202 prior to the recording operation as a pretreatment, The coating process part containing the mass 100 is shown. The coating agent 110 is stored in the tank 103 and is supplied to the coating basket 101 through the supply path 102 by the supply pump 106. Then, the coating agent 110 is supplied from the coating basket 101 to the porous body 100. At this time, the amount of the coating agent 110 supplied to the porous body 100 is controlled by the supply pump 106 so as to be larger than the amount finally applied to the recording medium 202. In this way, the influence of the supply amount of the coating agent 110 that varies depending on the pulsation of the supply pump, the temperature and humidity, the deterioration of the coating agent 110, the viscosity increase, and the like does not reach the coating amount on the recording medium 202. .

  Here, the air communication valve 107 provided in the tank 103 is provided to perform gas-liquid exchange when the coating agent 110 is discharged from the tank 103. In addition, a remaining amount detection unit 113 that detects the remaining amount of the coating agent 110 inside the tank 103 is provided in the tank 103. Furthermore, in the application processing unit, application roller pairs 71A and 71B are provided in a rotatable state. The porous body 100 is pressed against the application roller 71A. As a result, the coating agent 110 supplied to the porous body 100 is transferred to the coating roller 71A. As described above, a larger amount of coating agent 110 than the amount applied to the recording medium 202 is supplied to the porous body 100, so that a larger amount of coating agent than the amount applied to the recording medium 202 is also applied to the coating roller 71 </ b> A. 110 is transferred. The excessively transferred coating agent 110 is scraped off to an appropriate amount by the coating amount regulating member 109 as the post-transfer coating roller 71A rotates. The coating agent 110 scraped off at this time is dropped into an outer casing 105 provided so as to cover the coating basket 101 and is collected in the tank 103 through the collection path 104. The pump 111 is used for this series of collections, but is configured to be collected in the tank 103 by actively using gravity.

  In such a configuration, the recording medium 202 is fed and conveyed in the direction of the arrow L1 in the drawing from a sheet feeding cassette or the like (not shown), and an appropriate amount of the coating agent 110 is recorded by the nip portion of the coating rollers 71A and 71B in the conveyance process. It is applied to the recording surface of the medium 202. The width of the application roller 71A is wider than the width of the recording medium 202. Therefore, the coating material 110 supplied to the portion other than the width of the recording medium 202 on the coating surface of the coating roller 71 </ b> A is scraped off by the cleaning member 108. At this time, the coating agent 110 scraped off is also collected in the tank 103 in the same manner as the coating agent 110 scraped off by the coating amount regulating member 109 described above. Thereafter, the recording medium 202 passes through the U-shaped path L2 and is conveyed in the direction of arrow L3 (X). Then, recording is performed by the recording head 205 in the recording unit.

  In the recording apparatus having the above-described configuration, it is desirable that the material of the coating roller 71A has a relatively high affinity with the coating agent 110 and has a low affinity for impurities such as dust. Therefore, in this embodiment, epichlorohydrin rubber having a wall thickness of about 5 mm and a rubber hardness of 30 ° is suitable for the application roller 71A having an outer diameter of 40 mm.

  The porous body 100 can hold a predetermined amount of the coating agent 110, has durability against friction with the coating roller 71 </ b> A, and has a chemical resistance because the coating agent 110 is acidic. Therefore, in this embodiment, a sponge obtained by foaming polypropylene is used.

  The application regulating member 109 was a plate-like rubber blade having a relatively high hardness. For the application regulating member 109, a metal plate such as stainless steel may be used. Since the cleaning member 108 easily adheres dust such as paper dust due to its function, a rubber blade whose surface is coated with fluorine is used.

  A filter 112 is provided at the connecting portion between the outer casing 105 and the collection path 104 to filter out dust such as paper dust contained in the coating agent 110 when the coating agent 110 dropped on the outer casing 105 is collected. In addition, the coating agent 110 that does not contain paper dust or the like is collected in the tank 103.

  In this way, the coating agent 110 transferred to the coating roller 71A and then collected is collected in the tank 103 while the dust such as paper dust is removed and the viscosity is increased. When the thus thickened coating agent 110 is collected, the viscosity of the coating agent 110 in the tank 103 gradually increases. When the thickened coating agent 110 is collected in the tank 103, there is no problem when there is a sufficient amount and viscosity of the coating agent 110 to dilute the thickened coating agent 110. However, when the recovered coating agent 110 cannot be diluted to a predetermined viscosity, a predetermined amount of the coating agent 110 cannot be applied to the recording medium 202.

  It has been found that the appropriate coating amount of the coating agent applied to the recording medium in order to improve the ink absorption or color development is from 0.1 g to 0.2 g. Here, in the coating unit of the recording apparatus of FIG. 4, the coating amount in the case of a coating agent thickened by evaporation with respect to the coating amount when a coating agent having a standard viscosity of 3 cp is applied to an A4 size recording medium. FIG. 5 shows the result of investigating how much the value changes.

  Therefore, comparing the above results with the appropriate coating amount, it was found that the viscosity of the coating agent must be maintained at 15 cp or less. That is, if the viscosity of the coating agent is 15 cp or less, an appropriate amount of the coating agent can be applied to the recording medium.

  Furthermore, the change in the viscosity when the coating agent was thickened by touching the outside air during recording was examined. When recording was continuously performed by the recording apparatus of the present embodiment in an environment of a temperature of 30 ° C. and a humidity of 10% RH, the coating agent 110 collected in the outer casing 105 was recorded when 20 sheets of recording were completed. The viscosity was found to be 20 cp. Considering the fact that the viscosity of the coating agent becomes too high even if it is collected in the tank 103 and diluted in the tank 103, the coating agent in the outer casing 105 is removed every at least 20 sheets of recording. It was made to collect.

  FIG. 6 shows a state where the outer collar 105 is pressure-bonded to the application roller 71A in the application unit of the recording apparatus of the present embodiment. This crimping operation is performed by a vertical mechanism 114 provided outside the outer casing 105. When the recording is completed before the recording reaches 20 sheets, the outer casing 105 is pressed against the application roller 71A by the up-and-down mechanism 114 as shown in FIG. Prevents evaporation. As a result, the coating agent 110 that accumulates in the outer casing 105 does not have a viscosity of 20 cp or more.

  FIG. 7 is a graph showing the relationship between the remaining amount of the coating agent 110 in the tank 103 and the viscosity when recording is performed by the method described above. It can be seen that the remaining amount of the coating agent 110 in the tank 103 which was 1000 g at the beginning of the recording decreases as recording is performed, and the viscosity of the coating agent 110 increases as the remaining amount decreases. It can be read that the remaining amount of the coating agent 110 is 28 g when the viscosity of the coating agent 110 is 15 cp, which is a viscosity at which an appropriate amount of the coating agent can be applied to the recording medium. That is, when recording is performed with the remaining amount of the coating agent 110 in the tank 103 being 28 g or less, sufficient coating agent 110 is not applied, and the recording quality is lowered. Therefore, when the remaining amount detection unit 113 detects that the remaining amount of the coating agent 110 in the tank 103 has reached 28 g, the recording operation is stopped until the tank is replaced with a new tank.

  With the configuration as described above, a sufficient amount of the coating agent 110 can be applied to the recording medium, the progress of the thickening of the coating agent is suppressed, and the coating agent containing dust such as paper powder is provided. It was possible to realize a coating unit of the recording apparatus that is not coated again on the recording medium and consumes less coating agent.

  In the present embodiment, the configuration in which the coating process is performed before recording has been described. However, the present invention is not limited to this and may be applied to post-processing after recording.

  In this embodiment, since the positional relationship between the application roller 71A and the outer casing 105 is vertical, the vertical mechanism 114 is used to press the outer casing 105 against the application roller 71A. However, the present invention is not limited to this. It is not a thing. In other words, the positional relationship between the application roller 71A and the outer casing 105 can be any positional relationship as long as the outer casing 105 can be pressed against the application roller 71A and the outer casing 105 can receive the dripping coating agent. Also good.

  In the present embodiment, the coating agent 110 in the outer casing 105 is collected every time 20 sheets are recorded. However, the present invention is not limited to this. It is desirable to change.

  In the present embodiment, the application unit in the ink jet recording apparatus is shown. However, the present invention is not limited to this, and the present invention may be applied to other recording systems (such as a thermal transfer system), or may be used as a single application apparatus. Good.

  In this embodiment, the present invention is applied to a serial type recording apparatus, but it can also be applied to a full line type recording apparatus.

  In the present embodiment, the recording operation is stopped when the remaining amount detecting unit 113 detects that the remaining amount of the coating agent 110 in the tank 103 has reached 28 g. Operation (for example, display of warning, generation of warning sound, etc.) may be used.

It is a side view which shows the coating agent application part in the conventional recording device. FIG. 3 is a perspective view showing an image forming area of the recording apparatus according to the embodiment of the invention. FIG. 2 is a schematic block configuration diagram of a control system of a recording apparatus to which the present invention can be applied. It is sectional drawing which shows the application part of the recording device of embodiment of this invention. FIG. 5 is a table showing the relationship of the coating amount per recording medium when the viscosity of the coating agent is changed. It is a figure of the state which crimped the outer collar to the application roller in the application part of the embodiment of the present invention. It is the figure showing the relationship between the residual amount of the coating agent in a tank, and a viscosity.

Explanation of symbols

71A coating roller 71B coating roller 100 porous body 101 coating basket 103 tank 104 recovery path 105 outer casing 109 coating regulating member 110 coating agent 112 filter 123 coating agent 125 recording medium 201 paper feed roller 202 recording medium 205 recording head

Claims (16)

An application means capable of applying the liquid supplied from the tank to the recording medium;
Recording means capable of recording an image on the recording medium before or after the liquid is applied;
Recovery means for recovering the liquid that has not been applied to the recording medium from the application means into the tank;
Control means for controlling the application operation of the application means in accordance with a change in the viscosity of the liquid in the tank;
A recording apparatus comprising: Detecting means for detecting the remaining amount of the liquid in the tank;
The recording apparatus according to claim 1, wherein the control unit controls the application unit according to a viscosity of the liquid associated with a remaining amount detected by the detection unit.   3. The recording according to claim 1, wherein the control unit stops the application operation of the liquid by the application unit when the viscosity of the liquid in the tank exceeds a reference value. 4. apparatus.   The recording apparatus according to claim 1, wherein the coating unit includes a coating roller capable of transferring the liquid attached to an outer peripheral surface to the recording medium.   The recording apparatus according to claim 1, wherein the application unit includes a porous body that supplies the liquid supplied from the tank to an outer peripheral surface of the application roller.   The said collection | recovery means is equipped with the braid | blade for scraping off the said liquid from the outer peripheral surface of the said application roller, The said liquid scraped off with the said blade is collect | recovered to the said tank, The Claim 1 thru | or 5 characterized by the above-mentioned. A recording apparatus according to any one of the above.   The recording apparatus according to claim 6, wherein the collection unit collects the scraped coating agent at a predetermined interval.   The recording apparatus according to claim 6, wherein the collecting unit collects the coating agent that has been scraped off for each predetermined number of recording sheets.   The said collection | recovery means has a filter which can isolate | separate the said liquid and a foreign material in the collection path | route of the said liquid that has been scraped off. Recording device. Application means capable of applying the liquid supplied from within the tank to the application medium;
A recovery means for recovering the liquid that has not been applied to the application medium from the application means into the tank;
Control means for controlling the application operation of the application means in accordance with a change in the viscosity of the liquid in the tank;
A coating apparatus comprising: Detecting means for detecting the remaining amount of the liquid in the tank;
The said control means controls the said control means according to the viscosity of the said liquid matched with the detection residual amount of the said detection means, The coating device of Claim 10 characterized by the above-mentioned.   12. The application according to claim 10, wherein the control unit stops the application operation of the liquid by the application unit when the viscosity of the liquid in the tank exceeds a reference value. apparatus.   The coating apparatus according to claim 10, wherein the coating unit includes a coating roller capable of transferring the liquid attached to an outer peripheral surface to the coating medium.   14. The coating apparatus according to claim 10, wherein the coating unit includes a porous body that supplies the liquid supplied from the tank to the outer peripheral surface of the coating roller.   15. The recovery unit includes a blade for scraping off the liquid from an outer peripheral surface of the coating roller, and the liquid scraped off by the blade is recovered in the tank. The coating apparatus in any one of. The said collection | recovery means has the filter which can isolate | separate the said liquid and a foreign material in the collection path | route of the said liquid that has been scraped off. Coating device.

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