JPH08187876A - Ink jet printer - Google Patents

Abstract

PURPOSE: To provide an ink jet printer which keeps water repellent property of a water-repellence treated surface of an ink discharge nozzle and has excellent discharge stability in a long term reliability of the printer. CONSTITUTION: A water-repellent agent is supplied to a water-repellent agent holding member 6 from a water-repellent agent replenish tank 7 through a tank through hole 8. After an ink on an ink discharge nozzle surface 1 is wiped off by a head wiping pad 5, the ink discharge nozzle surface 1 is coated with the water-repellent agent again by the water-repellent agent holding member 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer which prints on recording paper by ejecting ink from nozzles.

[0002]

2. Description of the Related Art In general, an ink jet printer is used to prevent the deviation of print dot positions and splash due to flight deflection of ejected ink caused by non-uniform accumulation of ink in the vicinity of an ink ejection port of a recording head as the number of prints increases. In many cases, the surface of the nozzle is subjected to a water repellent treatment to prevent ink accumulation. The misregistration and the splash are shown in detail in FIGS. 6 and 7, and the print quality is very bad. Films such as polyimide and polyether are generally used for the nozzle part of the recording head. As the water repellent, CYTOP (Asahi Glass Co., Ltd.) or fluororesin is used for coating or vapor deposition. The way to do is taken.

[0003]

The ink jet printer has a wiping mechanism for wiping off the ink accumulated on the surface of the ink ejection nozzles of the recording head when the power is turned on or at regular intervals. However, hard rubber is usually used in this wiping mechanism, and when the nozzle surface is wiped many times, the water repellent agent coated on the nozzle surface is peeled off due to the friction between the surface and the wiping pad. However, when the printing is repeated to a certain extent, the water repellent agent is almost lost, which causes a problem that the printing quality is deteriorated.

The present invention has been made to solve the above-mentioned conventional problems, and provides an ink jet printer which maintains the water repellency of the surface of an ink ejection nozzle which has been subjected to a water repellent treatment and has excellent long-term ejection stability. With the goal.

[0005]

In order to achieve the above object, the present invention comprises a wiping means for wiping the ink ejection surface of a recording head with a holding member holding a water repellent agent.

[0006]

According to the present invention, the ink ejection surface of the recording head can be recoated with the water repellent by the above-mentioned structure.

[0007]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an inkjet printer according to a first embodiment of the present invention. In FIG. 1, 1 is an ink ejection nozzle surface on which a water repellent treatment of a recording head has been applied, 2 is an ink ejection nozzle port for ejecting ink, 3 is an ink flow channel for supplying ink to the ink ejection nozzle port 2, An ink supply tank that stores ink to be supplied to the ink flow path 3. Further, 5 is a head wiping pad for wiping the ink ejection nozzle surface 1, 6 is a water repellent holding member that holds the water repellent and is in contact with the ink ejection nozzle surface 1, and 7 is a water repellent replenisher that stores the water repellent. Reference numeral 8 denotes a tank through hole for replenishing the water repellent agent from the water repellent agent supply tank 7 to the water repellent agent holding member 6. A polyimide film is used as the nozzle material in which the ink discharge nozzle port 2 is formed, and Cytop is used as the water repellent applied to the surface 1 of the ink discharge nozzle.
p-50 rpm, 20 seconds, 2 step-300 rpm,
It was applied under the condition of 60 seconds. The film thickness of this water repellent is about 10μ.
It was m. After applying the water repellent, the ink ejection nozzle surface 1 is baked at 90 ° C. for 20 minutes to increase the adhesive force of the water repellent. On the other hand, a rubber blade for the head wiping pad 5 was used, and a foamed resin was used for the water repellent agent holding member 6. Further, the foam resin is also stored in the water repellent supply tank 7, and the water repellent is infiltrated into the foam resin. The water repellent holding member 8 is the water repellent replenishing tank 7
Is fixed with an instant curing adhesive.

As an operation, first, the ink discharge nozzle surface 1
In the wiping, the ink ejection nozzle surface 1 is brought into contact with the head wiping pad 5, so that the ink collected on the ink ejection nozzle surface 1 is wiped and the water repellent holding member 6 is brought into contact with the ink ejection nozzle surface 1
It becomes a flow to replenish the water repellent.

(Embodiment 2) FIG. 2 is a schematic view of a main part of an ink jet printer according to a second embodiment of the present invention.
In the second embodiment, the head wiping pad 5 and the water repellent holding member 6 described in the first embodiment are changed to a roller type, and the head wiping pad 9 is a rubber pad having a thickness of 5 mm and a cylinder having a diameter of 8 mm. It is fixed to the suspension 10 with an instant curing adhesive. The water repellent agent holding member 12 also uses the same cylindrical suspension 10, and the foam resin is fixed to the surface. These columnar suspensions 10 are fixed on a water repellent agent replenishment tank 13 by a fixing jig 11. Further, as in the first embodiment, the water repellent agent is replenished from the water repellent agent replenishing tank 13 to the water repellent agent holding member 12 through the tank through hole 14.

In the first embodiment, the ink discharge nozzle surface 1
During wiping or application of the water repellent agent, the head wiping pad 5 and the water repellent agent holding member 6 that come into contact with the ink ejection nozzle surface 1 are fixed, so that the contacting portions are abraded and abrasion powder accumulates. However, in the second embodiment, since the head wiping pad 9 and the water repellent agent holding member 12 are rotating mechanisms, the wiping and the water repellent agent are uniformly applied over a long period of time.
Here, the water repellent agent holding member 12 may be that of the first embodiment.

(Embodiments 3 and 4) Next, FIG. 3 and FIG.
Another shape of the head wiping pad 5 shown in the embodiment of FIG. These show the shape of the head wiping pad 5 as a triangular prism and a cylinder respectively. The triangular head wiping pad 15 shown in FIG. 3 is the third embodiment, and the cylindrical head wiping pad 16 shown in FIG. 4 is the fourth. This is an example.

Using the head wiping pads 5, 9, 15 and 16 of the first to fourth embodiments, magenta and black inks are used, and the ink is 0 at an ambient temperature of 25 ° C.
Wiping was performed 55,000, 10,000, 15,000, and 20,000 times, and printing was performed each time the number of times of wiping was completed, and the printing quality was evaluated. As a print quality evaluation method, the judgment shown in (Table 1) was made based on the positional deviation amount σ of the print dots.

[0013]

[Table 1]

Tables 2 and 3 show the evaluation results of print quality with respect to the number of wipings. 5 shows the wetting angle of the nozzle surface with respect to the number of wipings in Examples 1 and 2 and the conventional example.

[0015]

[Table 2]

[0016]

[Table 3]

As is clear from FIG. 5 and (Table 2) and (Table 3), only the head wiping pad 5 of the conventional example decreases the wetting angle of the ink ejection nozzle surface 1 as the number of wiping increases. It can be seen that the water repellent agent on the surface 1 of the ink ejection nozzle has been stripped off by the head wiping pad 5. As a result, the number of wiping times has deteriorated from 55,000 times in terms of print quality. On the other hand, in the first and second embodiments, the reduction of the wetting angle is smaller than that of the conventional example, and the reduction of the water repellent agent on the ink ejection nozzle surface 1 is suppressed, so that the deterioration of the print quality with respect to the number of wiping is small. In particular, in the first, third and fourth embodiments, the shape of the head wiping pad is the ink ejection nozzle surface 1
The triangular prism shape of the third embodiment having a small contact area with is preferable.
In the following, in the order of the fourth embodiment and the first embodiment, the reduction of the water repellent due to wiping is reduced, and the deterioration of the printing quality is lessened. Therefore, it is preferable that the head wiping pad has a triangular prism shape.

Further, in the second embodiment, the head wiping pad 9 is less worn on the ink ejection nozzle surface 1 than the fixed type because the head wiping pad 9 is a rotary type, and as a result, the reduction of the water repellent agent with respect to the number of wiping is the smallest. Therefore, a printer having excellent long-term reliability of print quality can be realized without deterioration of print quality with respect to the number of wiping.

[0019]

As described above, the present invention is provided with the wiping means for wiping the ink ejection surface of the recording head with the holding member for holding the water repellent agent. Recoating can be performed to prevent the water repellency of the ink ejection surface from decreasing due to an increase in the number of wipings, and to prevent print dot misalignment and splash from occurring due to an increase in the number of wipings to prevent deterioration of print quality. It is possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of essential parts of an inkjet printer according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a main part of an inkjet printer according to a second embodiment of the present invention.

FIG. 3 is a perspective view of a head wiping pad of an inkjet printer according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a head wiping pad of an inkjet printer according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing the wetting angle of the nozzle surface with respect to the number of wipings of the inkjet printers of the first and second embodiments of the present invention and the conventional example.

FIG. 6 is a diagram showing a print dot position shift of a conventional inkjet printer.

FIG. 7 is a diagram showing splash dots of a conventional inkjet printer.

[Explanation of symbols]

 1 Surface of Ink Ejection Nozzle 2 Ink Ejection Nozzle Port 3 Ink Flow Path 4 Ink Supply Tank 5 Head Wiping Pad 6 Water Repellent Retaining Member 7 Water Repellent Replenishing Tank 8 Tank Through Hole 9 Head Wiping Pad 10 Cylindrical Suspension 11 Fixture 12 Water repellent holding member 13 Water repellent replenishing tank 14 Tank through hole 15 Head wiping pad 16 Head wiping pad

Claims (3)

[Claims] 1. An inkjet printer having a recording head, comprising: a holding member for holding a water repellent agent; and wiping means for wiping an ink ejection surface of the recording head with the holding member. Inkjet printer. 2. A wiping means is provided with a water repellent agent supply tank, and a supply means is provided for supplying a water repellent agent from the water repellent agent supply tank to the holding member.
The described inkjet printer. 3. The ink jet printer according to claim 1, wherein the holding member is a rotary type roller.