JPH07241983A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To make an ink jet recording apparatus free from influence by ambient temperature and kinds of media on which recording is made. CONSTITUTION:The apparatus is composed of a coating device 2 for coating a medium on which recording is made with a coating material before the recording is made on the recording medium with recording ink, a heating device 1 that applies heating beforehand to the coating material, a temperature control device 3 that controls the heating device 1, and a recording device 4 that makes recording in accordance with recording signals 5. Therefore, the coating can be made under a stabilized condition, and high-definition ink jet recording can be made constantly as printing is made on a film made by uniform coating. The high-definition ink jet recording is also available regardless of kind of medium on which the recording is made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus using an ink jet recording system for recording by ejecting and adhering ink droplets on a recording medium, and in particular, it is affected by the type of recording medium and environmental temperature. The present invention relates to an inkjet recording device that enables stable and high-quality printing to be obtained.

[0002]

2. Description of the Related Art Ink jet recording methods include various recording ink ejection methods such as an electrostatic suction method, a method of applying a mechanical vibration or displacement to a recording ink by using a piezoelectric element,
Recording is performed by generating and flying small droplets of the ink by a method of heating and foaming the recording ink and utilizing the pressure, and attaching some or all of them to a recording medium such as paper. The ink jet recording apparatus using this ink jet recording system is attracting attention as a recording apparatus that generates less noise and can perform high-speed printing, high-quality printing, and multicolor printing.

In such an ink jet recording apparatus, in order to prevent bleeding or flow of the recording ink adhering to the recording medium due to the ink jet recording and impairing the printing quality, it is necessary to use an inorganic pigment on the base paper. Inkjet paper coated with a layer made of a special material that is porous and has a large water absorption capacity and that adsorbs coloring components in the recording ink, and an inkjet special film whose surface is specially treated to prevent the recording ink from flowing. A dedicated recording medium such as the one described above was used.

[0004]

However, there is a problem that high-quality print recording cannot be performed in the ink jet recording system unless such a limited recording medium is used. Furthermore, if a user who handles the inkjet recording apparatus mistakenly uses a different type of recording medium, not only high quality print recording cannot be performed due to bleeding of the recording ink, but also the recording apparatus flows due to the flow of the recording ink. There was a problem of causing fatal pollution inside.

Therefore, the present invention solves the above-mentioned problems and enables high-quality ink jet recording without being affected by the type of recording medium used and the ambient temperature.

[0006]

In order to solve the above-mentioned problems, the ink jet recording apparatus of the present invention applies a coating material onto a recording medium before recording with recording ink on the recording medium. A coating means for coating, a heating means for preheating the coating material, a temperature control means for controlling the heating means, and a recording means for recording according to a recording signal are provided, and the type of recording medium to be used and To realize an inkjet recording apparatus capable of high-quality inkjet recording regardless of the environmental temperature.

[0007]

By providing the coating means, heating means, temperature control means and recording means as described above, the coating material can be coated on the recording medium before recording with the recording ink is performed. .

[0008] The coating material is a material containing a resin material having a characteristic of appropriately absorbing or appropriately compatibilizing the recording ink, and is a substance that is melted by a liquid or heat. The viscosity η of the liquid is expressed by the following equation, and the viscosity decreases exponentially with increasing temperature. The reverse is also true.

[0009]

[Equation 1]

By heating the coating material to a desired temperature in advance, the viscosity of the coating material can be kept substantially constant or below a certain value to adjust the coating conditions. As a result, a uniform coating film can be formed on the recording medium without being affected by the temperature of the environment in which the apparatus is installed, and image recording with recording ink can be performed with the type of recording medium used and the installation of the device. High quality ink jet recording can be performed without being affected by the temperature of the environment.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing the arrangement of an ink jet recording apparatus according to the present invention. FIG. 2 is a schematic diagram of the inkjet recording apparatus of the present invention. FIG. 3 is an explanatory view for explaining the operations of the temperature control means and the heating means of the ink jet recording apparatus according to the present invention. FIG. 4 is an experimental example showing the relationship between temperature and viscosity. FIG. 5 is a sectional view showing a section of the coating means.

In FIG. 1, the heating means 1 comprises a heater and an infrared lamp. As the heater, for example, a sheath heater, a ceramic heater, or a silicon rubber heater is used.
In particular, the silicon rubber heater is preferable because it can uniformly heat the entire liquid by wrapping it around a container containing the coating liquid.

The coating means 2 is composed of various ink jet heads such as a spray, an ink jet recording head using the vibration force of a piezoelectric element, and a bubble jet head using film boiling. In particular, a spray using high-pressure gas such as LP gas or diethyl ether or compressed air is preferable because the restriction by the coating material is loose and a coating material having high viscosity can be used.

The temperature control means 3 has the function of detecting the temperature and the function of controlling the ON / OFF of the heating means or the strength of the heating according to the detected temperature. The temperature is detected by a temperature sensor.
Bimetal thermostat, thermocouple, thermistor, etc. are used.
The heating means 1 is controlled by converting the temperature from the characteristic value measured by the temperature sensor, for example, the variation amount of the resistance value, and determining whether or not the temperature is a desired temperature. Then, when there is a large difference between the desired temperature and the measured temperature, the temperature is adjusted to the desired temperature range by heating strongly and finely adjusting the temperature. Examples of the temperature control means 3 include a combination of a comparator and a relay, a temperature sensitive reed switch, a CPU, and the like. When the temperature change is not rapid or the set temperature range is wide, it is preferable to control by the CPU.

The recording means 4 is a known ink jet head such as an ink jet recording head using the vibration force of a piezoelectric element or a bubble jet head using film boiling.
In FIG. 2, reference numeral 8 denotes a recording medium, which is a coated paper, a small amount of special paper, a PPC paper, an OHP film, or the like. A platen roller 9 is rotated by a motor or the like (not shown). The reference numeral 10 designates a carrier, on which the coat means 2 and the recording means 4 are fixed. Reference numeral 11 denotes a lead screw, which scans the carrier 10 by rotating. 1
Reference numeral 2 is a guide rail that slides the carrier 10. 1
Reference numeral 3 denotes a housing, in which the platen roller 9, the lead screw 11 and the like are arranged. Reference numeral 14 is a pipe for supplying the coating material to the coating means 2.

In FIG. 3, 18 is a silicon rubber heater. Reference numeral 19 is a container for storing the coating material. The container 19 only needs to transfer heat to the coating material 20, and is made of glass, plastic, metal or the like. It is important for the container 19 to efficiently transfer heat, and metal is preferable, and aluminum is particularly preferable. 21 is an air intake. Reference numeral 14 is the pipe described above. Although not shown, a temperature sensor is attached to the tip of the pipe 14 in the container 19 and measures the temperature of the coating material just before being supplied to the coating means 2.

In FIG. 5, reference numeral 23 is a needle for adjusting the discharge amount of the coating material. By pushing the needle 23 toward the outlet 24, the flow path of the coating material 20 is closed and the coating is stopped. The flow path is opened by pulling the needle, a negative pressure is generated by the gas 25 being blown, and the coating material 20 is discharged from the blowing port 24.

The temperature and the viscosity have the relationship described above.
As an example, FIG. 4 shows the relationship between temperature (° C.), viscosity (cps), and concentration (% by weight) when the coating material 20 is an aqueous solution of partially saponified polyvinyl alcohol having an average degree of polymerization of 1800. By increasing the temperature or decreasing the concentration, the viscosity of the coating material 20 can be lowered. For example, if the pressure of the gas 25 and the structure of the spray shown in FIG.
The amount of the coating material 20 discharged per unit time is determined by the viscosity of 0. When the viscosity is high, the liquid amount is small, and when the viscosity is low, the liquid amount is large. When the environmental temperature is low and the temperature of the coating material 20 is low, the viscosity increases and the coating liquid amount decreases. As a result, problems such as uneven coating and insufficient amount of coating occur, which leads to deterioration of image quality. In order to solve this problem, the coating material 2 is used in advance.
0 is heated to the desired temperature to reduce viscosity and ensure coating operation.

At a gas pressure of 0.3 to 0.4 kgf / cm ² , coating failure occurs unless the coating material 20 has a viscosity of less than 5. However, by heating 2% by weight of the coating material 20 to about 20 ° C. or higher and 4% by weight of the coating material 20 to about 80 ° C.,
A stable coating can be realized with a low gas pressure of 0.3 to 0.4 kgf / cm ² . Similarly, at a gas pressure of 4.0 to 4.8 kgf / cm ² , coating failure will occur unless the coating material 20 has a viscosity of less than 50. However, 6 wt% coating material 20 is approximately 4
Above 0 ° C, about 8% by weight of coating material 20 is about 75
By heating to ℃, 4.0 to 4.8kgf / c
A stable coating can be achieved with a gas pressure of m ² . As described above, by heating the coating material 20, a higher concentration of the coating material 20 can be coated without causing coating failure. The high-concentration coating material 20 has an advantage that it can suppress the problem of wrinkles and curls which occur when paper fibers are coated with water to absorb moisture, and can be coated at high speed.

Needless to say, the coating can be performed without being affected by the environmental temperature and without causing coating defects. next,
With regard to the present embodiment, first, a detailed operation will be described with reference to FIGS.

In preparation for the printing operation, first, the temperature control means 3
Reads the temperature of the coating material 20 with a temperature sensor (not shown). Then, the temperature control means 3 determines whether or not the read temperature is within the desired temperature range, and if it is within the desired temperature range, outputs the operation permission signal 6 to the coating means 2 and the recording means 4. If the temperature is outside the desired temperature range, the temperature control means 3 outputs the heating signal 7 to the heating means 1. The heating means 1 heats the container 19 according to the heating signal 7. The temperature control means 3 monitors the temperature of the container 19 at any time, and when the temperature recovers within a desired range, the heating signal 7 suspends the heating, and the coating means 2 and the recording means 4 receive the operation permission signal 6. Output.

Next, as the platen roller 9 rotates in the direction of arrow 15, the recording medium 8 wound around the platen roller 9 is conveyed in the direction of arrow 15. still,
The platen roller 9 aligns the desired recording start position with the positions of the recording means 4 and the coating means 2, and suspends the conveyance. Further, the lead screw 11 is rotated to move the carrier 10 to the home position 16 to prepare for recording.

The recording means 4 and the coating means 2 which are permitted to operate by the operation permitting signal 6 start to operate. In accordance with the operation permission signal 6, the coating unit 2 pulls the needle 23, ejects the coating material 20, and coats the recording medium 8. The recording unit 4 also ejects recording ink onto the recording medium 8 in response to the recording signal 5. Along with this, the lead screw 11 rotates, and the carrier 10 moves on the lead screw 11 and the guide rail 12 in the main scanning direction of arrow 17. Thereby, the coating means 2 and the recording means 4
While moving in the main scanning direction of the arrow 17, the recording medium 8
Further, the recording means 4 forms an image such as a character, a line drawing or a pattern on the coating material. Then, when scanning for one line is completed, the needle 23 is returned, the coating operation is temporarily interrupted, the lead screw 11 is rotated in the direction opposite to that at the time of recording, and the carrier 10 is returned to the home position 16. Further, the platen roller 9 is rotated in the direction of the arrow 15, and the recording medium 8 wound around the platen roller 9 is conveyed by one line to prepare for the start of recording of the next line.

By repeating the above operation, the recording material 8 can be coated with the coating material 20, and recording can be performed with the recording ink. This makes it possible to realize high-quality recording without being affected by the temperature of the environment and without being limited by the type of recording medium.

In the present embodiment, the recording means 4 is described as one mono-color recording, but the present invention is also applied to an ink jet recording apparatus having the recording means 4 for yellow, magenta, cyan and black by the same method. Applicable. (Embodiment 2) An embodiment of the present invention will be described with reference to FIGS. 1 and 3 to 6.

FIG. 6 is a schematic view of the ink jet recording apparatus of the present invention. Other drawings are the same as those in the first embodiment, and the description thereof will be omitted. In FIG. 6, reference numeral 8 denotes a recording medium, such as coated paper, micro-coated special paper, PPC paper, and O paper.
HP films and the like. A platen roller 9 is rotated by a motor or the like (not shown). The reference numeral 10 designates a carrier, on which the coat means 2 and the recording means 4 are fixed. 11
Is a lead screw, and scans the carriage 10 by rotating. Reference numeral 12 is a guide rail, which is a carriage 1.
Slide 0. Reference numeral 13 denotes a housing, which is a platen roller 9
The lead screw 11 and the like are provided. Reference numeral 14 is a pipe for supplying the coating material to the coating means 2. Reference numeral 30 is a cross-flow fan for drying the coating material discharged onto the recording medium 8.

The detailed operation of this embodiment will be described below. In preparation for the printing operation, first, the temperature control means 3 reads the temperature of the coating material 20 with a temperature sensor (not shown). Then, the temperature control means 3 determines whether or not the read temperature is within the desired temperature range, and if it is within the desired temperature range, outputs the operation permission signal 6 to the coating means 2 and the recording means 4. If the temperature is outside the desired temperature range, the temperature control means 3 outputs the heating signal 7 to the heating means 1. The heating means 1 heats the container 19 according to the heating signal 7. The temperature control means 3 monitors the temperature of the container 19 at any time, and when the temperature recovers within a desired range, the heating signal 7 suspends the heating, and the coating means 2 and the recording means 4 receive the operation permission signal 6
Is output.

Next, when the platen roller 9 rotates in the direction of arrow 31, the recording medium 8 wound around the platen roller 9 is conveyed in the direction of arrow 31. still,
The platen roller 9 has a desired recording start position and the coating means 2
Adjust the position of and suspend the transport. The coating means 2 is installed so as to be offset from the recording means 4 by one line in the direction opposite to the paper feeding direction. In addition, the lead screw 11
Is rotated to move the carrier 10 to the home position 16 to prepare for recording.

The coat means 2 permitted to operate by the operation permission signal 6 starts its operation. Further, the cross flow fan 30 for drying the coating material 20 also rotates. The cross flow fan 30 is the coating material 20.
It is possible to expect a higher image quality improving effect by drying the image recording medium and then recording with the recording ink.

In accordance with the operation permission signal 6, the coating means 2 pulls the needle 23 and discharges the coating material 20,
The recording surface is coated on the recording medium 8. The cross flow fan 30 is constantly rotating during the coating operation to dry the coated coating material 20. Then, the lead screw 11 rotates in accordance with the coating operation, and the carrier 10 moves to the lead screw 11
And moves on the guide rail 12 in the main scanning direction of arrow 17. As a result, the coating unit 2 coats the recording medium 8 while moving in the main scanning direction of the arrow 17. Then, when scanning for one line is completed, the needle 23 is returned, the coating operation is temporarily interrupted, the lead screw 11 is rotated in the direction opposite to that at the time of recording, and the carrier 10 is returned to the home position 16. Further, the platen roller 9 is rotated in the direction of arrow 31, and the recording medium 8 wound around the platen roller 9 is conveyed by one line. As a result, the coating means 4 is coated on the first line,
The coating means 3 is aligned with the second line to prepare for the next scan.

Next, the temperature control means 3 reads the temperature of the coating material 20 with a temperature sensor (not shown). Then, the temperature control means 3 determines whether or not the read temperature is within the desired temperature range, and if it is within the desired temperature range,
The operation permission signal 6 is output to the coating means 2 and the recording means 4.

The recording means 4 and the coating means 2 which are permitted to operate by the operation permitting signal 6 start to operate. In accordance with the operation permission signal 6, the coating unit 2 pulls the needle 23, ejects the coating material 20, and coats the second line of the recording medium 8. Further, the recording means 4 has a recording signal 5
Accordingly, the recording ink is ejected on the first line coated on the recording medium 8. Along with this, the lead screw 11 rotates, and the carrier 10 moves to the lead screw 1
1 and the guide rail 12 are moved in the main scanning direction of arrow 17. As a result, the coating means 2 and the recording means 4 are separated by the arrow
The coating means 2 coats the recording medium 8 while moving in the main scanning direction of 7, and the recording means 4 forms images such as characters, line drawings, and patterns on the coating material coated by pre-scanning. Then, when scanning for one line is completed, the needle 23 is returned, the coating operation is temporarily interrupted, the lead screw 11 is rotated in the direction opposite to that at the time of recording, and the carrier 10 is returned to the home position 16. Further, the platen roller 9 is rotated in the direction of the arrow 31, the recording medium 8 wound around the platen roller 9 is conveyed by one line, and the recording start of the next line is prepared.

By repeating the above operation, the recording material 8 is coated with the coating material 20, and recording with the recording ink can be performed thereon. This makes it possible to realize high-quality recording without being affected by the temperature of the environment and without being limited by the type of recording medium.

In the present embodiment, the temperature of the coating material 20 was monitored every scan, but if the coating material has a high specific heat and the temperature hardly changes in one scan, the temperature may be monitored every few scans. good. Furthermore, in (Embodiment 1) and (Embodiment 2), the form in which the coating material is supplied from the outside of the housing is shown, but the present invention is not limited to this. For example, a container of coating material can be housed inside the housing.

[0036]

As is apparent from the above description, according to the present invention, in the ink jet recording apparatus for recording the image on the recording medium by ejecting the recording ink according to the recording signal, the recording ink is formed on the recording medium. Prior to recording, a coating means for coating the recording medium with a coating material, a heating means for heating the coating material, a temperature control means for controlling the heating means, and recording according to the recording signal. By having the recording means to do so, the coating material can be warmed to the desired temperature before the recording operation. As a result, the coating material can always be coated on the recording medium under the same conditions without being affected by the temperature of the environment, and the viscosity of the coating material increases at low temperatures, resulting in non-coating or non-uniform coating. , Can be solved.
Therefore, coating can be performed under stable conditions, and printing on a uniform coating film enables high-quality inkjet recording at all times. Further, high quality ink jet recording is possible without being limited to the type of recording medium used.

Furthermore, since a coating material which is solid at room temperature or which has a high viscosity and cannot be coated is heated to melt and lower in viscosity, the recording medium can be coated.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an inkjet recording apparatus according to the present invention.

FIG. 2 is a schematic diagram of an inkjet recording apparatus of the present invention.

FIG. 3 is an explanatory diagram illustrating operations of a temperature control unit and a heating unit in the inkjet recording apparatus of the present invention.

FIG. 4 is an example showing a relationship between temperature and viscosity in a coating material.

FIG. 5 is a cross-sectional view showing a cross section of coating means in the inkjet recording apparatus of the present invention.

FIG. 6 is a schematic diagram of an inkjet recording apparatus of the present invention.

[Explanation of Codes] 1 heating means 2 coating means 3 temperature control means 4 recording means 8 recording medium 9 platen roller 10 transport table 11 lead screw 12 guide rail 13 housing 14 pipe 18 heater 19 container 20 coating material 21 air intake port 23 Needle 24 Outlet 30 Cross Flow Fan

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Sato 6-31-1, Kameido, Koto-ku, Tokyo Seiko Electronics Industry Co., Ltd.

Claims (2)

[Claims] 1. An ink jet recording apparatus for recording an image on a recording medium by ejecting recording ink according to a recording signal, before recording on the recording medium with the recording ink. A coating means for coating the medium with a coating material, a heating means for warming the coating material, a temperature control means for controlling the heating means, and a recording means for recording according to the recording signal. Inkjet recording device. 2. The ink jet recording apparatus according to claim 1, wherein the coating material heated by the heating means is kept at an arbitrary temperature of 20 ° C. to 80 ° C. by the temperature control means.