JPH026142A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To supply the front of a head with ink from a dummy nozzle and bring ink into contact with a printing nozzle, and to prevent clogging by installing the dummy nozzle to the front of the head and sticking a cap fast to a recessed section so that the dummy nozzle is exposed into the recessed section. CONSTITUTION:The cover 27 of a cap rubber 27 is fast stuck to each of an air vent 16m and dummy nozzles 16a, 16b in the positional relation-ship of a cap rubber 23 and a plate 16, but the cap rubber 22 is not closely attached to printing nozzles 16a-16l, and the recessed section 26 of the cap rubber is faced oppositely. The air vent 16m and a suction port 16n are closed by the cap rubber 22 under the state, thus preventing the evaporation of moisture from a vent tube 18 having high gas permeability and a suction tube 20. The dummy nozzles 16a, 16b are sealed by the cap rubber 22, thus obviating the evaporation of moisture and precipitation and fixing of ink.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet recording apparatus equipped with a recovery means for recovering from printing defects such as clogging of nozzles that cause ink droplets to fly.

[Prior art]

Inkjet recording devices can be roughly divided into two types: one is a method in which ink droplets are ejected continuously and electrically deflected along the way, and the other is a method in which a head with nozzles is moved according to the recording situation and ink droplets are ejected only during printing (on-demand). There is a

Both methods have a configuration in which the ink is ejected from a nozzle installed in the ink chamber, and when in use, there is no particular obstruction to the path from the ink tank to the nozzle, but when not in use or during long periods of rest, etc. , clogging is likely to occur. The main cause of this clogging is that water evaporates from the nozzle, and components of the ink, such as dyes and pigments, solidify and the nozzle holes become clogged.

Conventionally, the following methods have been proposed as means for eliminating this nozzle clogging.

(a) A method that utilizes the property of dyes, pigments, and other components to dissolve easily in water, and supplies a cleaning liquid containing water as a main component to the front surface of the head to dissolve stuck substances.

(b) A method of filling the inside of the cap with a cleaning liquid when attaching the cap to the nozzle part to prevent the formation of solid matter itself.

(C) Method of putting cleaning liquid into the nozzle.

As described above, the conventional clogging eliminating means mainly uses a cleaning liquid.

However, conventional inkjet recording apparatuses require a cleaning liquid supply system, as well as replenishment of the cleaning liquid and disposal of waste liquid. For this reason, the structure becomes complicated, leading to increased costs, and the user's intervention in handling the cleaning liquid impairs operability.

〔the purpose〕

An object of the present invention is to provide an inkjet recording device that can solve these conventional problems and prevent clogging without using a cleaning liquid or complicating the structure.

[Means to achieve the purpose]

The present invention provides a dummy nozzle on the front surface of the head, and a cap having a concave portion brings the dummy nozzle in close contact with the dummy nozzle so that it is exposed in the concave portion, thereby supplying ink from the dummy nozzle to the front surface of the head and bringing the ink into contact with the printing nozzle. It is possible to dissolve the ink stuck inside the printing nozzle and perform a recovery process.

〔Example〕

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

FIG. 1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus according to the present invention.

In FIG. 1, 1 is a base having a U-shaped cross section and includes a left side plate 1a and a right side plate 1b, 2 is a platen roll disposed at the rear of the upper surface of the base 1, and 3 is a center of the platen roll 2. A platen shaft passes through the platen shaft and its both ends are rotatably supported by the left side plate 1a and the right side plate 1b; 4 is a paper feed motor connected to one end of the platen shaft and attached to the right side plate 1b; 5 is a paper feed motor connected to the platen roll 2; A paper pan 7 is used to wrap a sheet such as a recording paper 6, and a solenoid 7 is used to open and close the cap according to the present invention.

Reference numeral 8 denotes a paper press plate that presses the recording paper 6 exposed in the printing section against the platen roll 2 and prevents it from falling toward the print head 15. Reference numeral 9 is a paper press plate that is arranged in parallel in front of the platen roll 2, and has both ends on the left and right sides. A guide shaft 10 fixedly supported by the side plates 1a and 1b is disposed parallel to the guide shaft 9, and is connected to the left and right side plates 1. a, a guide shaft fixedly supported by lb; 11, a carrier movably supported with respect to the guide shafts 9 and 10 and provided with a detection piece 11a protruding from the bottom; 12, a carrier 11 is anchored at one point; a loop-shaped timing belt that moves the carrier 11 in either the left or right direction depending on the rotational direction; 13, a pulley 14 rotatably supported on the base l and supporting one end of the timing belt 12;
15 is a print head mounted on the upper part of the carrier 11; 16 is a plate mounted on the front surface of the print head 15;

17 is a ventilation valve, 18 is ventilation pulp 17 and plate 1
6, 19 is a suction pump, 20 is a suction tube that connects suction pump 19 and plate 16, 21 is an ink cartridge provided on carrier 11 adjacent to head 15, 22 is head 15 in a predetermined position. 23 is a cap holder that holds the cap rubber 22, 24 is a shaft that rotatably supports the cap holder 23, and 25 is a slit. This is a home position detector that detects the position of the carrier 11 when the detection piece 11a enters the slit.

FIG. 2 is a perspective view showing details of the plate 16. 16
a and 16b are dummy nozzles according to the present invention, and 16
C to 161 are printing nozzles.

16m is a vent provided above the dummy nozzle 16a. Further, 16n is a suction port provided on the side near the printing nozzle 161. A ventilation tube 18 is connected to the ventilation port 16m, and a suction tube 2 is connected to the suction port 16n.
0 is connected.

FIG. 3 is a perspective view showing details of the cap rubber 23.

The head-side surface has a recess 26, and a lid 27 that is formed to protrude from the main body surface is provided around the recess 26.

Next, the operation of the embodiment with the above configuration will be explained with reference to FIGS. 4 and 5.

When printing, an operator inserts a recording sheet 6 of a size corresponding to the recording width between the paper pan 5 and the platen roll 2, and sets it in advance so that the leading edge thereof is exposed to a position facing the head 15. Carriage 1 is moved so that head 15 is located at the left end of platen roll 2.
A motor 14 is driven to move the timing heald 12, and the timing heald 12 rotates in accordance with the rotation of the motor 15.

When the head 15 is placed at the printing start position, ink droplets are ejected only from the corresponding nozzles by ink droplet ejection means provided in communication with each of the ten nozzles. Each time one ink droplet flies, the motor 14 rotates and the carrier 11 moves a predetermined distance to the right in FIG. When printing for one line is completed, the carrier 11 is returned to the printing start position, and the next line is printed.

Next, if the printing signal is not transmitted for a certain period of time during normal printing operation, the printing nozzles 16c to 16
It is necessary to put a cap on the container 1 to prevent the ink remaining in the container from sticking. For this reason, in the present invention, if a print signal is not transmitted for a certain period of time or more, the carrier 1
1 is moved to the home position, that is, until the detection piece 11a enters the slit of the home position detector 25, and upon detecting this state, the solenoid 7 is energized and the cap rubber 23 is rotated. This brings the cap rubber 23 into close contact with the plate 16. At this time, the positional relationship between the cap rubber 23 and the plate 16 is as shown in FIG. Ventilation port 16m, dummy nozzle 16a
, 16b are in close contact with the lids 27 of the cap rubber 22, but the cap rubber 22 is not in close contact with the printing nozzles 16a to 16], and their recesses 26 face each other. In this state, since the vent port 16m and the suction port 16n are closed by the cap rubber 22, it is possible to prevent moisture from evaporating from the vent tube 18 and suction tube 20, which have high gas permeability. Further, since the dummy nozzles 16a and 16b are sealed by the cap rubber 22, it is possible to prevent moisture from evaporating and ink from precipitating and sticking. Furthermore, printing nozzles 16c to 16
1 faces the recess 26 and there is nothing in contact with the surface, so
It does not damage the meniscus of the nozzle or damage the nozzle surface.

Next, the recovery operation will be explained.

When turning on the power, after being left unused for a long time, and when ink cartridge 2
1, a recovery operation is executed.

When performing this recovery operation, the solenoid 7 is not energized, the cap rubber 22 is separated from the plate 16, and the positional relationship between the cap rubber 22 and the plate 16 is set as shown in FIGS. 4 to 5. Move the carrier 11 to . After this movement, the solenoid 7 is energized to bring the cap rubber 22 into close contact with the plate 16. At this time, as shown in FIG. 5, the dummy nozzles 16a, L6b, printing nozzles 16C to 161, ventilation port 16m, and suction port 6n face the four parts 26.

In this state, the suction pump 19 is operated, and the cap rubber 2
When negative pressure is generated in the recess 26 of No. 2, the ink inside the nozzle is sucked out (at this time, the ventilation valve 17 is closed). After performing the suction operation for a predetermined time, the ventilation valve 17 is opened ( (Leave the suction pump 19 operating)
Then, the air flows into the recess from the vent 16 and flows to the suction port 16n together with the ink adhering to the nozzle surface. This removes ink residue from the nozzle orifice.

Next, the suction pump 19 is stopped and the solenoid 7 is
The recovery operation is completed by turning off the power supply and separating the cap rubber 22 from the plate 16.

In addition, due to long-term storage, etc., the printing nozzle 16 cm 15
Even if ink is deposited and fixed on the dummy nozzle 16
A to 16b are completely sealed as shown in FIG. 4, and ink does not stick. Then, during suction, dummy nozzle 1
Ink flows out from the printing nozzles 16c and 6a and 16b.
161, the precipitated and hardened ink is dissolved and the printing nozzles 16c to 161 are free from sticking.

In addition, the dummy nozzles 16a and 16b are replaced with the printing nozzle 16C.
By making the diameter larger than 161, the sticking removal effect is further enhanced.

In the above embodiment, an example of the recovery operation using negative pressure suction was shown, but a configuration using pressurization may also be used.

〔effect〕

As is clear from the above description, according to the present invention, the cap can be moved between the position where the dummy nozzle is closed and the position where it is exposed. By supplying ink from a dummy nozzle to dissolve the ink in the printing nozzle, it is possible to prevent clogging of the nozzle without using a cleaning liquid.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of an inkjet recording apparatus according to the present invention, FIG. 2 is a perspective view showing details of the plate 16 surface shown in FIG. 1, and FIG. A perspective view showing the details, FIG. 4 is an explanatory view showing the positional relationship between the cap rubber 22 and the plate 16 during a long period of no recording, and FIG. 5 is an explanatory view showing the positional relationship between the cap rubber 22 and the plate 16 during recovery. It is a diagram. l −・−・・−−−−Base, 2−・・・・・・・
...Platen roll, 7-...
Solenoid, 11 ...--Carrier, 15 ・
・・・・・−・−・Print head, 16−・・−・−・−
---Plate, 16a, 16b--Dummy nozzle, 16C~161--Printing nozzle, 1
6 m --------Vent, 16n--・--・--
------1 Suction port, 18------------- Ventilation tube, 19...--1---- Suction pump, 2
0--Suction tube, 22 Cap rubber, 2
3-...-1-----Cap holder, 20--
−・−−−−−Home position detector, 26 ・・
・・・－・〜・Concave part. Agent Patent Attorney Yasushi Ooto 4 Figure 5 Figure 16 α

Claims (3)

[Claims] (1) A head equipped with a front plate equipped with a printing nozzle that flies ink droplets and mounted on a carrier, and when the head is in a predetermined position, the head is in close contact with the front plate to create a space in front of the printing nozzle. In the inkjet recording apparatus, the inkjet recording device is provided with a recovery means for dissolving ink sticking to the nozzle by generating a negative pressure or pressurization in a space formed by the cap, and a recovery means for dissolving ink sticking to the nozzle. A dummy nozzle communicating with a supply source, a first state where the dummy nozzle is closed by the cap, and a second state where the dummy nozzle is exposed into the space by relatively moving the cap and the head. 1. An inkjet recording apparatus comprising: a control means for controlling the inkjet recording apparatus. (2) The inkjet recording apparatus according to claim 1, wherein the recovery means is operated in the second state. (3) The inkjet according to claim 1, wherein the front cap is provided with an ink suction port that is closed by the cap in the first state and a communication port that communicates with the atmosphere. Recording device.