JP4712835B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus, and more particularly to a recording medium pretreatment means effective for an inkjet image recording method. Specifically, before applying a pretreatment liquid for improving image quality. The present invention relates to an image recording apparatus provided with a treatment liquid coating apparatus.

  In recent years, inkjet printers are rapidly spreading due to advantages such as low noise, low running cost, and easy colorization. However, when recorded on plain paper, in addition to initial quality problems such as bleeding, density, color tone, and show-through, there were problems related to image robustness such as water resistance and weather resistance. Proposals have been made.

  As a means for solving these problems, when an image is formed with ink, a recording material in which a material for fixing the dye in the ink is fixed on the surface of the recording material, such as plain paper, or a white pigment or the like on the surface. Patent Documents 1 to 4 disclose that a recording material coated with a water-soluble polymer is used. However, this method requires the purchase of special paper that has been pre-coated, so there is the inconvenience that it is not possible to freely use paper that is close to you, and there is a problem with the ease of writing with a pencil or pen. there were.

  Further, Patent Document 5 discloses that ink permeability is increased by adding a surfactant or the like to ink in order to suppress bleeding at a color boundary such as a two-color overlapping portion. This method is effective for resolving bleeding at the color boundary such as the two-color overlapped area and smearing (image contamination due to contact after printing) because the ink penetrates the recording paper at a high speed. The image cannot be resolved. Furthermore, although a method of adding a volatile solvent to the ink is disclosed in Patent Document 6, the same effect as that of the permeable ink can be obtained, but the nozzle is likely to be clogged. In addition, in order to improve water resistance and light resistance, the use of ink containing a pigment as a colorant has also increased, but it is difficult to maintain the reliability around the nozzle such as clogging with an ink containing a pigment, Further, when high color reproducibility such as a photographic image or CG is required, there is a problem that cyan and magenta color development is insufficient and a satisfactory image cannot be obtained.

  Therefore, in order to solve such a problem, Patent Document 7 discloses that a polymer solution such as carboxymethyl cellulose, polyvinyl alcohol, polyvinyl acetate or the like is sprayed on the recording material in advance, and then the polymer solution adheres to the part. An ink jet recording method for printing by ejecting ink has been proposed. However, although this method can improve the sharpness of the printed image, it is not effective to improve the drying property of the printed image, and the effect of improving the image quality in the color image is not so recognized. Also, there is a patent on an ink jet recording method in which an image recording acceleration liquid containing a compound that insolubilizes a dye in the ink is deposited on a recording material by an ink jet method, and then the ink is ejected and printed on a portion where the image recording acceleration liquid is adhered Although disclosed in References 8 to 10 and the like, this method has a large amount of moisture adhering at the two-color overlapping portion, so that bleeding at the color boundary cannot be sufficiently suppressed, and ink show-through is large. There's a problem. Furthermore, there is a problem that cockling (waving) of the recording material occurs. In addition, since the image recording acceleration liquid is sprayed with an inkjet head, there are restrictions on the viscosity and surface tension of the liquid in order to obtain stable injection, and there are restrictions on the nozzle diameter and composition of the liquid in order to prevent clogging. There was a problem that conditions were added and the degree of freedom was significantly reduced.

As a method for solving this problem, Patent Document 11 (hereinafter referred to as a conventional example) discloses a method of applying to the entire paper surface using a roller. FIG. 2 is a schematic sectional view showing a configuration in which a coating material is applied to a recording medium using a roller in a conventional example. In the figure, a recording medium 63 is wound around a platen roller 61 rotated by a motor or the like (not shown) with a presser chuck 62. A coating material 65 is accommodated in the coating unit 64, and the coating material 65 is thinned on the roller surface of the coating roller 69 by the stirring / supply roller 66 and the transport / thinning rollers 67, 68. The coating roller 69 is rotated while being pressed onto the recording medium 63 wound around the rotating platen roller 61, and the coating material 65 is applied to the surface of the recording medium 63. At the same time, the inkjet head 70 performs recording by discharging ink onto the surface of the recording medium 63 coated with the coating material 65. As described above, according to the conventional method in which the pretreatment liquid for improving the image quality is previously applied to the recording area by the application roller, the liquid having a relatively high viscosity is thinly applied as compared with the method of spraying using the ejection head. It is excellent in that image bleeding and color bleeding can be further reduced.
JP-A-56-86789 JP-A-55-144172 JP 52-53012 A JP-A-56-89594 JP 55-65269 A JP-A-55-66976 JP-A-56-89595 JP-A-64-63185 JP-A-8-20159 Japanese Patent Laid-Open No. 8-20161 JP 7-156538 A

  However, not all paper types require pretreatment with a coating roller. The pretreatment by the application roller is mainly applied to the plain paper in order to eliminate the above-mentioned problems, and the pretreatment is usually unnecessary for paper types such as coated paper, glossy paper, and OHP. When such a paper type is conveyed through the pretreatment application roller, if the speed of the application roller is low, the processing ability and the processing speed are reduced, and the pretreatment liquid is wasted. It is not preferable from an environmental point of view. Further, since the rigidity of the recording material is reduced due to the application of the pretreatment liquid, cockling (waving) of the recording material occurs while the recording material is conveyed to the recording area where recording is performed, and a jam occurs. There is a problem that occurs.

  The present invention is intended to solve these problems, and can be printed on a paper that does not require coating without being subjected to a coating process so that the processing capability is not reduced, and a paper reversing structure is formed to reduce the size. It is an object of the present invention to provide a high-speed image recording apparatus that can be configured with a compact mechanism that can prevent the occurrence of jam while being planned.

  In order to solve the above problem, an application roller that applies a pretreatment liquid, which is a liquid containing a compound that insolubilizes the colorant in the recording liquid, to a recording area of the recording medium, and a counter roller that faces the application roller In the image recording apparatus of the present invention, the pretreatment liquid coating means includes the pretreatment liquid coating means and the image recording means for recording an image in the recording area of the recording medium by discharging the recording liquid. An application process path for applying the liquid and an application unnecessary path not applied are provided, and the image recording means is pulled out from the paper feeding unit and applies the pretreatment liquid, and then reverses upward through the application process path. The recording medium that has been transported in the direction of the paper feeding unit and coated with the pretreatment liquid is a guide plate provided on each of the front and back surfaces of the recording medium, and is used from above. It is characterized in that is guided to toward the sheet feed unit direction. Therefore, it is possible to provide an image recording apparatus that has a simple configuration and does not waste the pretreatment liquid with respect to a recording medium that does not require application of the pretreatment liquid, and can increase the speed by not performing the application process. . In addition, it is possible to provide an image recording apparatus that can be configured with a compact mechanism capable of preventing the occurrence of jam while reducing the size by forming a paper reversing structure.

  Furthermore, by having a roller pair at the exit end of the guide plate, the recording material after passing through the guide plate can be reversed and conveyed toward the paper feed unit without jamming.

  In addition, the recording medium coated with the treatment liquid is once transported upward and then pressed downward, and then recording is performed by the image recording means, so that the recording material can be reliably reversed without jamming. .

  According to the image recording apparatus of the present invention, the application process path for applying the pretreatment liquid to the recording medium by the pretreatment liquid application unit and the application unnecessary path for non-application are provided. After applying the pretreatment liquid withdrawn from the paper unit, the recording medium is turned upside down through the application process path and recorded on the recording medium, and the pretreatment liquid is applied. The recording medium is guided by guide plates provided on both the front and back surfaces of the recording medium, so as to be directed in the direction of the paper feeding unit from vertically above. Therefore, even during intermittent conveyance during printing, the application roller rotates at a constant speed by a separate drive from the pair of conveyance rollers, so that there is no waviness or uneven image quality due to application unevenness, and application conditions by the application roller can always be kept constant. . In addition, it is possible to provide an image recording apparatus that has a simple configuration and does not waste the pretreatment liquid with respect to a recording medium that does not require application of the pretreatment liquid, and can increase the speed by not performing the application process. In addition, it is possible to provide an image recording apparatus that can be configured with a compact mechanism capable of preventing the occurrence of jam while reducing the size by forming a paper reversing structure.

  FIG. 1 is a cross-sectional view showing a configuration of an image recording apparatus according to an embodiment of the present invention. In FIG. 1, the image recording apparatus 1 according to the present embodiment mainly includes a paper supply unit 10, a pretreatment liquid coating unit 20, and an image recording unit 30. The paper supply unit 10 includes a paper supply roller 12 that sends out the paper 11. The pretreatment liquid application unit 20 contains a pretreatment liquid 22 that contains a pretreatment liquid 22 that is a liquid containing a colorant and a compound that insolubilizes the colorant in a recording liquid composed of a solvent that disperses or dissolves the colorant. A tank 21, a pumping roller 23 that stirs and pumps the pretreatment liquid 22, a film thickness control roller 24 that controls the pumped pretreatment liquid 22 to have a uniform film thickness, and a coating roller 25. A counter roller 26 that applies the pretreatment liquid 22 to the conveyed paper 11, a sensor 27 that detects markings such as coloring and holes on the back surface of the paper that does not require coating, and a coating process path (in the drawing) Each path is configured by a turnable switching claw 28 that switches a paper conveyance path to an application unnecessary path (indicated by arrow B in the figure) and a conveyance roller pair 29 in the application unnecessary path. Carrying paper It is configured to include a guide plate 42 for guiding the. The image recording unit 30 includes a recording head mounted on a transport roller 31 to 33 that transports the transported paper 11 to a recording area of a recording head 37 described later, and a carriage 35 that moves along the guide rod pair 34. 37, a pair of discharge rollers 38 and 39 for discharging the recorded paper 11, a pair of conveying rollers 40 for guiding the paper 11 from the coating unit 20 to the image recording unit 30, and a blade 41. It is configured.

Next, a series of image recording operations in the image recording apparatus 1 of the present embodiment having such a configuration will be described with reference to FIG.
First, the paper 11 stored in the paper feed unit 10 is sent out by the paper feed roller 12. At that time, the marking applied to a predetermined position on the back surface of the paper 11 is detected by the sensor 27. As a result of detection, if the paper 11 needs to be applied, for example, plain paper, the switching claw 28 is indicated by a broken line in the figure. Rotate to a position to guide the paper 11 to the coating process path. At this time, the pretreatment liquid 22 in the pretreatment liquid tank 21 of the pretreatment liquid coating unit 20 is pumped up by the pumping roller 23, and is controlled to have a uniform film thickness on the roller surface of the coating roller 25 by the film thickness control roller 24. ing. Then, the pretreatment liquid 22 is uniformly and thinly applied to the recording area of the paper 11 by the application roller 25 and the counter roller 26. The recording area of the paper 11 is coated with the pretreatment liquid 22 by the pretreatment liquid coating unit 20, and is guided by the guide plate 42 and conveyed outside from the coating unnecessary path while being on the upper side and vertically from the recording head. Guide to 37 recording areas. Therefore, the paper 11 whose pretreatment liquid 22 has been applied and the rigidity of the paper itself has been reduced can prevent jamming due to cockling (waving) . Thereafter, the sheet 11 is first pushed downward vertically by the conveying roller pair 40 provided at the front end portion of the guide plate 42 so as to be further reversed by the blade 41 and the conveying rollers 31 to 33. Then, the paper 11 is sent to a recording area having a recording head 37 positioned in a direction reverse to the feeding direction of the paper 11 sent out from the paper feeding unit 10. Thereafter, the carriage 35 reciprocates along the guide rod pair 34 based on the image signal, and recording is sequentially performed on the recording area of the paper 11 on which the pretreatment liquid 22 is applied by the recording head 37 mounted on the carriage 35. The paper is discharged to the discharge portion by the discharge roller pair 38 and 39.

  On the other hand, if the result detected by the sensor 27 is a sheet such as OHP or glossy film that does not require coating on the sheet 11, the sheet 11 is guided to the coating-unnecessary path at a position where the switching claw 28 is indicated by a solid line in the figure. Then, while being guided and conveyed by the guide plate 42, it is guided from the upper side to the recording area where the recording head 37 is located from the upper side. Further, the paper 11 is first pushed downward vertically by the conveying roller pair 40 provided at the front end portion of the guide plate 42 so as to be further reversed by the blade 41 and the conveying rollers 31 to 33. Then, the paper 11 is sent to a recording area having a recording head 37 positioned in a direction reverse to the feeding direction of the paper 11 sent out from the paper feeding unit 10. Thereafter, the carriage 35 reciprocates along the guide rod pair 34 based on the image signal, and the recording head 37 mounted on the carriage 35 sequentially records on the recording area of the paper 11 and is discharged by the discharge roller pairs 38 and 39. Discharged to the department.

  Although the present embodiment is an example in which a marking indicating the necessity / unnecessity of applying the pretreatment liquid is applied to a predetermined position on the back surface of the paper 11 and the path is switched by detecting the marking with a sensor. It is not necessary, and it goes without saying that the same effect can be obtained even if the operator switches the switching claw with a control signal for selecting a plain paper or the like that requires application in a host device such as a personal computer. Further, the switching claw may be switched by a control signal in a cancel mode in which application is not required forcibly according to an operator's instruction. Further, in order to avoid the occurrence of paper jam at the switching claw without providing the switching claw, each paper feeding unit for storing the paper for each paper type may be provided corresponding to the coating process path and the coating unnecessary path.

  The recording method of the present invention is not limited to the ink jet method described in the above embodiment. Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and substitutions can be made within the scope of the claims.

It is sectional drawing which shows the structure of the image recording apparatus which concerns on this invention. It is a schematic sectional drawing which shows the structure of the pre-processing liquid application part in a prior art example.

Explanation of symbols

1; image recording apparatus; 10; paper supply unit;
11; paper, 12; paper feed roller, 20; pretreatment liquid application unit,
21; Pretreatment liquid tank, 22; Pretreatment liquid, 23; Pumping roller,
24; film thickness control roller; 25; coating roller; 26; counter roller;
27; Sensor, 28; Switching claw, 29, 40;
30; Image recording unit, 31-33;
34; guide rod pair; 35; carriage; 36; recording unit;
37; recording head, 38, 39; discharge roller pair,
41; blade, 42; guide plate.

Claims (3)

A pretreatment liquid coating means including a coating roller for coating a recording medium of a recording medium with a pretreatment liquid that contains a compound that insolubilizes the colorant in the recording liquid, and a counter roller facing the coating roller; In an image recording apparatus having image recording means for recording an image in a recording area of the recording medium by discharging a liquid,
An application process path for applying the pretreatment liquid to the recording medium by the pretreatment liquid application means and an application unnecessary path for not applying are provided,
The image recording means is applied to the recording medium which is pulled out from the paper feed unit and applies the pretreatment liquid and then reverses upward through the application process path and is conveyed toward the paper feed unit. To record,
The recording medium coated with the pretreatment liquid is guided by guide plates provided on both the front and back surfaces of the recording medium so as to be directed in the direction toward the sheet feeding unit from vertically above. Image recording device . The apparatus according to claim 1, characterized in that it comprises a pair of rollers on the outlet side distal end portion of the front Symbol guide plate. Before the treatment liquid has been applied recording medium, the conveyed coating process path once upward after passing through, according to claim 1 or from thereafter pressed downward and performing recording by said image recording means 2. The image recording apparatus according to 2.

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