JPH02151444A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the clogging and rusting of a nozzle by arranging a fixing apparatus using a heater as a heat source at a position set to the rear stage of a head and not opposed to the head. CONSTITUTION:The recording paper passing a roller 4 is carried to the opposed surface of a head 1 and, at the same time, ink droplets fly from a nozzle 2 corresponding to recording data to be adhered to and absorbed by the surface of the recording paper to perform recording. The recording paper after the finish of recording is successively sent to the part above a heating plate 5. The heating plate 5 is formed using a metal plate painted black and heated by a heater 6 held to a current supply state immediately after printing or before then. The non-recording surface of the recording paper is brought into contact with the heating plate 5 and the drying of the ink dot absorbed by the surface of the recording paper is performed. Since a drying position is set above the head 1, high temp. steam caused by drying is not brought into contact with the head and the closure of the orifice of the nozzle is not generated. The effect of the generation of steam caused by heating or a heating unit on the head part can be excluded and high-grade recording can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and more particularly to an inkjet recording device that performs recording by ejecting ink droplets from nozzles of a head according to recording information.

[Conventional technology]

Recording devices such as printers and facsimiles can be classified into thermal types, wire dot types, inkjet types, etc. depending on the recording method.

Among these, the inkjet method (inkjet recording device) supplies ink to a recording head that has at least one fine orifice (or nozzle) and drives an energy generator provided in the orifice based on print data. , causing the ink in the orifice to expand and contract, causing ink droplets to fly from the tip of the orifice,
The ink droplets are attached to a sheet such as paper or a thin plastic plate to form a dot pattern.

This type of inkjet recording apparatus conventionally uses special paper whose surface is coated with silica or the like to improve ink absorption.

In recent years, improvements in inks have made feathering (bleeding into paper) less likely to occur even when using plain paper with poor ink absorbency. By the way, there is a relative relationship between the feathering of ink on the paper surface and the fixing speed (drying time).

Therefore, in order to increase the fixing speed, it is common practice not only to improve the ink but also to equip the recording apparatus with an auxiliary drying means such as a heater.

That is, a method is used in which heating of the recording paper is started at the moment when the ink droplets land on the paper surface, or even before that moment.

[Problem that the invention seeks to solve]

However, in such conventional inkjet recording apparatuses, the distance between the nozzle surface of the head and the paper is 0.
If fixing is performed by heating and drying immediately after printing or before printing, the ink moisture and paper moisture vapor generated by this process will adhere to the head surface, causing nozzle clogging due to dew condensation. It has been demonstrated that it causes rust, etc., and has been found to be undesirable.

In addition, radiant heat from the heater increases the temperature of the head,
There is also the problem that it affects the ejection conditions of ink/1Ii (especially when using bubble jet) and impairs the stability of the image.

On the other hand, inkjet recording apparatuses include those in which the nozzle surface of the head coincides with a horizontal surface, and those in which the nozzle surface is attached at an angle to the horizontal surface. Among these, in the former configuration, wetting caused by ink tends to accumulate around the nozzle, and the nozzle opening is blocked with ink droplets or a film, which tends to cause ink droplets to fail to be ejected.

Furthermore, when the head is tilted, the paper must be tilted in the printing section, which causes the image density to be lower on the upper side of the solid printing section of the paper than on the lower side, resulting in density unevenness. This is because the surface tension of the ink and the interfacial tension with the paper decrease as the temperature rises, and the ink tends to accumulate on the lower side of the solid due to gravity).

Therefore, when there is no heater, even if the paper path is inclined, density unevenness hardly occurs and there is no problem.

An object of the present invention is to provide an ink shared recording device that can solve the problems of the prior art and can solve various problems caused by heater energization immediately after printing or before printing, such as nozzle clogging and rusting. It is to be.

[Means to solve the problem]

The present invention achieves the above object by disposing a fixing device using a heater as a heat source at a position downstream of the head and not facing the head.

Further, in order to prevent density unevenness due to ink flowing down on the paper surface, it is desirable that at least a portion of the heating member of the fixing device that contacts the recording medium be horizontal or inclined.

[Function] By configuring as in claim 1, the vapor evaporated from the paper and ink due to the heating of the fixing device is discharged outside the device without touching the head surface, and no dew condensation occurs on the head surface.

By configuring as in claim 2, the dripping of ink dots on the paper surface can be reduced to zero or minimized, and the occurrence of density unevenness due to differences in ink thickness caused by dripping can be prevented.

〔Example〕

The present invention will be specifically described below with reference to FIGS. 1 to 5.

FIG. 1 is a side view showing an embodiment of an inkjet recording apparatus according to the present invention.

In FIG. 1, ■ is a head equipped with a plurality of nozzles 2;
3 is a path through which the recording paper passes, 4 is a roller that conveys the recording paper to the printing position, 5 is a heating plate disposed horizontally at the bottom of the path after the head 1, and 6 is disposed below the heating plate 5. This is a heater installed.

The head 1 is arranged above the inclined surface of the path 3. Further, the heating temperature by the heater 6 is, for example, 50 degrees Celsius to 9 degrees Celsius.
Set to 0 degrees. The heating plate 5 and heater 6 constitute a fixing device.

In the above configuration, the recording paper that has passed through the roller 4 is
At the same time as the ink is transported to the opposite surface of the head 1, ink droplets are ejected from the nozzle 2 according to the recording information, and the ink droplets are attached to and absorbed by the surface of the recording paper, thereby performing recording.

The recording sheets on which recording has been completed are sequentially fed to the upper part of the heating plate 5. The heating plate 5 is made of a black-painted metal plate or the like, and is heated by a heater 6 that is energized immediately after printing or even longer.

The non-recording surface of the recording paper comes into contact with the processing plate 5, and the ink dots absorbed on the paper surface are dried.

Since the drying position is located above the head 1, high-temperature steam accompanying drying does not come into contact with the head 1, and the nozzle opening is not clogged. The generated high-temperature steam is naturally exhausted out of the machine from the top by hot air flow. Instead of natural flow, it may be forcibly discharged using a motor fan or the like.

Although the heating plate 5 and the heater 6 are arranged horizontally, they may be inclined within 45 degrees, preferably within 25 degrees. With this angle, even if unfixed ink adheres to the surface of the recording paper, there is no risk that the ink will move on the surface of the paper.

FIG. 2 shows a second embodiment of the present invention, in which the path 3 is formed into a "U" shape, the head L is arranged on the vertical plane, and the heating plate 5 and heater 6 are arranged below the upper horizontal plane. It was designed to be set up. By doing so, the path length can be shortened.

In this case, the head 1 is arranged vertically, but as described above, it may be inclined at an angle of 45 degrees or less.

FIG. 4 shows a fourth embodiment of the present invention, in which the total length of the heating plate 5 is lengthened, and a heating section 5a for removing residual moisture and a heating section 5b for fixing that is continuous with the heating section 5a and has a predetermined inclination are arranged. It was designed to be set up. After the recording is completed by the head 1, the moisture contained in the recording paper is first evaporated by the heating section 5a for removing residual moisture, and then the recording paper is fixed by the heating section 5b for fixing.

FIG. 5 shows a fifth embodiment of the present invention, in which heat can be applied by a heater 6 to the surface of a recording medium without using a heating plate. For this reason, a heater 6 is provided above the position where the recorded recording paper passes, and a fan motor 7 is provided above the heater 6. The cold air generated by the fan motor 7 is blown by the heater 6 to become hot air, and is blown onto the ink-attached surface of the recording paper to dry it.

Note that the recording paper after fixing is divided into a, b, as shown in FIG.
, c may be discharged.

With the above configuration, it is possible to prevent the occurrence of one-degree unevenness due to ink dripping due to temperature rise or ink dripping due to decrease in paper surface tension and interfacial tension. Note that the heating plate needs to be longer than the required length. This is to ensure that sufficient heating is carried out, and that the added unfixed portion has a high solubility, and a large amount of /8 quality particles are concentrated, so that uneven fixing will not occur as the paper moves. It is also effective in preventing wrinkles from forming on the recording paper due to temperature non-uniformity.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

In the ink jet recording apparatus according to claim 1, the fixing device using a heater as a heat source is provided at a position downstream of the head and not facing the head, thereby eliminating the influence of steam generation due to heating and heating elements on the head section. It is possible to perform high-quality recording.

In the inkjet recording apparatus according to the second aspect, at least a part of the heating member in contact with the recording medium of the fixing device is made horizontal or inclined, so that the ink dots immediately after recording are prevented from dripping onto the paper surface, and density unevenness is prevented. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an embodiment of the inkjet r-1+h recording apparatus according to the present invention, and FIGS. 2 to 5 show second to fifth embodiments of the inkjet r-1+h recording apparatus according to the present invention. FIG. i--1--・--1-Head, 2-11111-
-Nozzle, 3-----Path, 5--Heating plate, 6--Heater, 7-Fan motor.

Claims (2)

[Claims] (1) In an inkjet recording device that performs recording by ejecting ink droplets from a nozzle of a head to a recording medium according to recording information, a fixing device using a heater as a heat source is installed at a position downstream of the head and not facing the head. An inkjet recording device characterized in that: (2) The inkjet recording apparatus according to claim 1, wherein at least a portion of the heating member in contact with the recording medium of the fixing device is horizontal or inclined.