JPS62113561A - Clogging prevention device of liquid jet recorder - Google Patents

Abstract

PURPOSE:To prevent the generation of clogging due to increased viscosity of an ink even under low-temperature low-humidity circumstances and thereby eliminate the possibility of defective ink discharge by regulating a heating means provided on a capping member on information from a temperature sensing means so as to obtain controlled temperatures which are higher than a lower limit ink discharge temperature and lower than a recording head temperature. CONSTITUTION:The temperature of a capping member are sensed by a temperature sensing element 23, and if said temperature are lower than a recording head temperature, a heating means 20 is actuated. In the meantime, if the temperature are higher, the heating means is stopped. This operation is performed by controlling the turning ON/OFF of a switch 22 through a driver 25. In this way, the temperature of the capping member are regulated to be higher than the lower limit ink discharge temperature TH and lower than the recording head temperature. Consequently, the drying and evaporation of ink inside a nozzle 10 are limited and temperature reduction and viscosity increase are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is for preventing clogging of an inkjet recording device, which prevents clogging of the recording head by attaching a lid member to the recording head when not printing. Regarding equipment.

[Conventional technology]

Generally, in an inkjet recording device, if the nozzle holes of the recording head that eject ink droplets of the recording device are left in the atmosphere, the ink filled in the nozzles will dry, solidify, or increase the concentration of the ink. There is a problem in that the viscosity of the ink increases and so-called clogging occurs, making it impossible to eject ink droplets. Therefore, in order to prevent the orifice surface of the recording head from coming into contact with external air during non-recording times such as before the start of recording or after the end of recording, an apparatus has been proposed in which a crowning member is brought into close contact with the orifice surface.

However, there are two types of ink used in inkjet recording devices, water-based and oil-based, and the factors that increase the viscosity of these inks include the above-mentioned effects of volatile components in the ink and drying. other than,
The viscosity of the ink increases due to the drop in ink temperature, and even if the orifice surface of the print head is sealed with a capping member to prevent the ink from drying out in the nozzles of the print head, the orifice surface of the print head may become capped. If the ink is cooled by the member, ink droplets may not be ejected due to increased ink viscosity.

That is, in general, the temperature dependence of ink viscosity has a characteristic curve that differs depending on the solvent constituting the ink, the concentration of dye contained in the ink, etc., but the viscosity increases as the ink temperature decreases, regardless of whether the ink is aqueous or oil-based. Therefore, if the ink temperature decreases and the ink viscosity increases too much, the ejection power from the inkjet recording head becomes insufficient.

Figure 2 shows the relationship between ink viscosity and ink temperature in the case of water-based ink. If the temperature TA is lower than the ink ejection minimum temperature TH, the ink in the nozzles of the recording head will be cooled, and the ink ejection minimum temperature TH will be lower than the ink ejection minimum temperature TH.
There is a possibility that the ink temperature inside the nozzle becomes as low as 〒8, making it impossible to eject ink droplets.

Therefore, the temperature of the capping member is increased to T', and the ink temperature inside the nozzle is raised to a temperature higher than the lower limit temperature fTs, for example, TB.
' However, if the temperature of the capping member is set higher than the temperature Tc of the recording head, the ink in the nozzle is likely to be evaporated and dried due to the high temperature, resulting in a non-ejection state. Therefore, the appropriate temperature of the capping member needs to be maintained at a temperature lower than the temperature Tc of the recording head, such as TA', for example.

In other words, simply pressing the capping member against the orifice surface of the recording head to seal it will not completely eliminate the clogging of the recording head, and even if the sealing member is sealed, the nozzle will always be clogged. It was necessary to control the ink within an appropriate temperature range.

[Problem that the invention seeks to solve]

In view of the above points, an object of the present invention is to provide a recording head with:
It is an object of the present invention to provide a clogging prevention device for an inkjet recording device jσ, which prevents the volatile components of ink in a nozzle from drying out and prevents ink from being ejected even in a low-temperature environment where ink tends to thicken at low temperatures.

[Means for solving problems]

In order to achieve such an object, the present invention provides a method for preventing clogging of a liquid jet recording device in which a capping member can cover a nozzle hole of a recording head that performs recording by ejecting droplets of recording liquid from a nozzle hole. In the apparatus, a means for heating the crowning member, a means for detecting the temperature of the crowning member, and a heating means for the crowning member are driven based on information from the temperature sensing means for the crowning member, and the heating means for the crowning member is driven. A mold is defined as having a means for controlling the temperature of the mold to a predetermined temperature condition.

[Effect]

In the clogging prevention device configured in this way, the heating means provided on the crowning member is controlled by the information from the temperature detection means.
:Duki Ink I] - By controlling the temperature to be higher than the minimum discharge limit temperature and lower than the recording head temperature, the occurrence of clogging due to viscosity increase is prevented even in a 1 m jilt of low temperature and low humidity, and ink non-discharge. can be prevented from occurring.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

FIG. 1 shows an embodiment of the present invention, where 1 is a carriage on which a recording head 2 is mounted, and 3 is a guide rail that holds the carriage 1 movably. Both ends of an endless belt 4 are connected to the carriage l, which is driven by a drive motor 5 and moves along the recording surface of the recording paper 6. 7 is a roller for feeding the recording paper 6, 8A and 8B are guide rollers, and 9 is a paper feeding motor.

On the other hand, the recording head 2 is provided with a plurality of nozzles IO arranged in a vertical line to eject ink droplets toward the recording paper 6.
A supply tube 12 is connected to the nozzle 10 from an ink tank 11.
Ink 13 is supplied to the nozzle 10 via the flexible cable 12A, and an ink ejection signal is selectively supplied via the flexible cable 12A.

Reference numeral 18 denotes a capping member that is mounted on the orifice surface of the recording head 2 during non-recording, and when the carriage l is moved in the direction of arrow B during non-recording, the capping member 18 is mounted on the orifice surface of the recording head 2.
are pressed together. 19 is an elastic body attached to the crown-wearing side of the cap-wearing member 1, 20 is a heating means for the cap-wearing member 18 (hereinafter referred to as a cap heater), 21 is a power source for heating, and 22 is a switch. . Furthermore, 23 is a temperature detection element, and in this example, by inputting a detection signal from the temperature detection element 23 to a control circuit 24 having a microprocessor, the switch 22 is turned on and off via a driver 25, and the crown M member is turned on and off. This can be done by controlling the temperature of 1B within the temperature range mentioned above.

Next, the operation of the liquid jet recording apparatus and its clogging device constructed as described above will be described. In FIG. 1, during recording, the carriage l is driven and travels in the direction of arrow A from the illustrated recording start position, and each nozzle 10 of the rad 2 is selectively driven to record.
Ink droplets are ejected from the nozzles 10 and adhere to the diagonally lined recording width portion P in the sub-scanning direction of the recording paper 6 facing each nozzle 10, thereby performing recording in a dot matrix pattern. In this way, when the recording of the character is completed, the carriage 1 is driven in the direction of arrow B and returns to the position shown in the figure, and the recording paper 6 is fed in the direction of arrow C by the width of the recording width portion P described above. , the above operation is repeated again.

On the other hand, during non-recording, the carriage 1 is driven in the direction of arrow B from the illustrated position, and the recording head 2 is moved to the crowning member 1.
8, the capping member 18 is displaced in the direction of the arrow by a driving means (not shown), and the member 18 is pressed against the orifice surface of the recording head 2, thereby performing capping. . In this case, the opening 19A formed in the elastic body 19 of the member 18 that is attached to the orifice surface comes into pressure contact with the recording head 2, so that the opening is sealed.

In this case, as mentioned above, if the temperature of the capping member 18 is lower than the lower limit temperature In'TH of the ink ejection limit, the ink 13 at the tip of the nozzle 10 is cooled during sealing, resulting in a non-ejection state. Therefore, in order to increase the temperature of the capping member 18, the heating means 20 of the capping member 18 is controlled based on the signal from the temperature detection element 23.
temperature is set higher than the ink ejection lower limit temperature TH. Furthermore, if the temperature of the capping member 18 is made higher than the recording head temperature ↑C by the heating means 20, the opening 19A of the member 18 may be particularly affected by the large number of nozzles of the recording head 2.
If the volume of the ink in the nozzle must be increased, the evaporation and drying of the ink within the nozzle will be significantly accelerated, resulting in the same non-ejection condition. Therefore, in this example, the temperature of the capping member 18 is detected by the temperature detection element 23, and if the capping member temperature is lower than the recording head temperature, the heating means 20 is operated, and if it is higher, the heating operation is stopped. Turn switch 22 ON and OFF to
is controlled via the driver 25 so that the temperature of the crowning member is higher than the ink ejection lower limit temperature T)l and lower than the recording head temperature, thereby suppressing drying and evaporation of the ink inside the nozzle 10. , and prevents thickening at low temperatures.

Note that if the heating means 20 described above is a self-temperature-controlled heating element whose saturation temperature is between the lower limit temperature for ink ejection and the recording temperature, the switch 22 and temperature detection element 23 as described above may be used. There is an advantage that there is no need to provide one.

〔Effect of the invention〕

As is clear from the above description, according to the clogging prevention device of the liquid jet recording apparatus of the present invention, the heating means and temperature are detected in the capping member attached to the nozzle tip of the recording head to prevent ink from evaporating and drying. The heating means controls the capping member to a temperature higher than the lower limit temperature for ink ejection and lower than the recording head temperature based on information from the temperature detection means. Therefore, it is possible to provide a clogging prevention device for a liquid jet recording device that does not cause ink non-discharge even in low temperature environments and environments where evaporation and dryness are likely to occur.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of the configuration of a clogging prevention device for a liquid jet recording device of the present invention, and Fig. 2 shows the relationship between ink temperature and viscosity in the nozzle in relation to head temperature and crowning member temperature. FIG. l... Carriage 2... Recording head, 3... Guide rail, 4... Endless belt, 5... Drive motor, 6... Recording paper, 7... Roller. 8A, 8B...Guide roller, 9...Paper feed motor, 10...Nozzle. 10A... Orifice, 11... Ink tank, 12... Supply tube, 12A... Flexible cable, 13... Ink, 18... Crown attachment member, 19... Elastic body, 1θA・...Opening portion, 20...Heating means, 21...Power source, 22...Switch, 23...Temperature detection element, 24...Control circuit, 25...Driver. Figure 2

Claims (1)

[Scope of Claims] 1) A clogging prevention device for a liquid jet recording device, in which the nozzle hole of a recording head that performs recording by ejecting droplets of recording liquid from a nozzle hole can be covered with a capping member, means for heating the crowning member; means for detecting the temperature of the crowning member; driving the heating means for the crowning member based on information from the temperature sensing means for the crowning member; 1. A clogging prevention device for a liquid jet recording device, comprising means for controlling the temperature of a member to a predetermined temperature condition. 2) In the clogging prevention device for a liquid jet recording device according to claim 1, the temperature of the crowning member is set to a lower limit temperature at which droplets of the recording liquid can be ejected and a temperature of the recording head. 1. A clogging prevention device for a liquid jet recording device, characterized in that the clogging prevention device is configured to perform control during a period of time.