JPS6184253A - Bubble discharge device of inkjet recorder - Google Patents

Abstract

PURPOSE:To permit a bubble discharge with a simple constitution and to reduce costs by integrally constructing a carriage on which an ink cartridge built-in head is installed and driven, and a bubble discharge pump and by making the reciprocating motion of the carriage discharge the bubbles. CONSTITUTION:Pertaining to an ink jet recorder of 'on-demand' type, a carriage 17 on which an ink cartridge built-in head is mounted and driven thereon and a bubble discharge pump 15 are integrally constructed. At the time of bubble discharge the bubble discharge pump 15 is actuated by the reciprocating motion of the carriage 17, and the ink from the ink bag 3 of the ink cartridge 2 to the head body 1 is designed to return to the bag 3. The ink jet head 1, the ink cartridge 2 and the bubble discharge pump 15 are made integrally and no tubing is used for piping, resulting in less inclusion of bubbles from outside, and therefore, jet is stabilized, and in addition, a circulation of ink is used for discharge of the generated bubbles, causing no consumption of ink, and further, the driving force of the bubble discharge pump comes from an excess driving power of the carriage, and no additional driving means is required. The costs are, therefore, reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bubble ejecting device in an on-demand inkjet recording device.

The ink supply system to the heads in conventional on-demand inkjet recording devices uses tubes for piping, but air passes through the walls of the tubes at a constant rate. When the solubility of air in the tube reaches saturation, bubbles are generated due to temperature changes, etc. Therefore, an air bubble evacuation pump is installed between the head and the ink tank, and when necessary, the nozzle is covered with a cap, the pump is activated, and the ink is forcibly circulated between the ink tank and the nozzle, and the air bubbles inside the head are removed from the ink tank. However, the pump for discharging bubbles installed in the ink supply system from the ink tank to the head is not driven during printing, and the valve must be kept open, so a means for that purpose must be provided. To avoid this, you need another ink tank,
Furthermore, the driving means for the pump is often required separately, which increases the cost (Japanese Patent Laid-Open No. 56-758
Publication No. 66).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to enable air bubbles to be discharged from an on-demand inkjet head integrated with an ink cartridge with a simple configuration.

[Father] In order to achieve the above object, the present invention integrally forms a gear ridge for mounting and driving an ink cartridge-integrated head and an air bubble ejection pump, and when air bubbles are ejected, the air bubble ejection pump is activated by reciprocating movement of a carriage. This is characterized in that when activated, the ink from the ink bag of the ink cartridge to the head body flows into the ink bag at a rate of 1M.

Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a schematic configuration diagram of an integrated ink cartridge type head to which a bubble discharge device according to the present invention is added, and a partially transparent view of a discharge flow path.

In Figure 1, 1 is the head body, which is a short pipe (not shown) made of a slightly non-permeable material (metal such as stainless steel, thick resin) without using any tubes. It is integrally connected to the ink cartridge 2 near the bottom surface. 3 is an ink bag housed in the cartridge. The ink cartridge-integrated head is placed and fixed on a carriage 17 that is integrated with a bubble evacuation pump main body 15 made of a rotary pump, tube pump, or the like. This carriage is pulled by a carriage drive wire 18 and slides on the slide rail 16. When air bubbles are discharged, the reciprocating movement of the carriage is used to rotate the pinion gear 22 on the rack 21 fixed to the printer housing, and this rotation is applied to the shaft 23. gear 24
．． Input gear 25. The information is transmitted to the pump through the pump drive input shaft 26 (details will be described later).

Due to the action of this pump, head main body 1 - pump 15 -
The ink is circulated between the ink cartridge 2 and the head main body 1, and the discharged air bubbles contained in the ink collected in the ink cartridge are floated and trapped above the ink bag 3 so as not to be sent to the head. In this case, if the ink bag 3 is bellows-shaped, ink is likely to be accumulated and trapped at the peak of the chevron. Ink circulation occurs when air bubbles are detected by an air bubble detector (not shown) or when there is a printing defect.

This is done only when signs of failure appear, and not at the time of printing. To explain this ink circulation path in detail, the action of the pump main body 15 causes the ink to flow through the pump 15.
→ Pump outlet flow path 10 in the carriage - Ink loading flow path 11 in the head - Ink bag 3 - Ink bag output flow path 12 in the head - Lower common liquid chamber 6 - Ink supply flow path 7 - Upper common liquid chamber ( bubble collection chamber) 5-downward flow bubble evacuation channel 8-carry;

It circulates from the internal pump inlet channel 9 to the pump 15.

Normally, during printing, ink from the ink bag 3 flows through the lower common liquid chamber 6 - the common ink flow path 7 - the multi-nozzle 4 and is ejected. There are two ink connection ports between the head body 1 and the ink cartridge 2 and between the head body 1 and the carriage 17. In particular, between the head and the carriage, the connection joint pipe 13 must be inserted into the carriage side circle 14. The ink is received and handed over. Also, if the balance between ink inflow and ejection into the nozzle 4 (liquid chamber) is lost, dripping from the nozzle and air bubbles are likely to occur, so the resistance value should be set so that the flow path fluid resistance 19.20 is sufficiently lower than that of the nozzle. is set, and the suction and discharge balance with the pump is maintained. Therefore, there is no need to take the trouble to cover the nozzle when discharging air bubbles. The upper common liquid chamber 5 is intended for collecting and discharging air bubbles, so its upper wall is tapered upward and connected to the air bubble discharging channel 8 .

FIG. 2 shows the drive mechanism of the bubble evacuation pump, with (A) showing the overall configuration, and (B) and (C) showing details of the rank and pinion gear parts, respectively. Note that the same reference numerals as in FIG. 1 indicate the same contents.

In FIG. 2, the reciprocating movement of the carriage 17 causes the pump 1 to
5, the pump drive input gear 25 always rotates in the same direction on the outward and return trips of the carriage. That is, a rotating (oscillating) member 30 is provided, and in the white arrow (return path) in the figure, the rotation of the pinion 22 is transmitted from the shaft 23 to the gear 24 to the gear 24' to the gear 29 to the imposto gear and the gear 25. On the outward path (black arrow), the rotation is transmitted as follows: gear 24 - reverse rotation - forward rotation conversion gear 27 - gear 28 -> input gear 25, and input gear 25 always rotates in the same direction. A slip ring 31 frictionally engages with the central shaft 23 and is fixed to the rotating member 30. 32 is a suction solenoid plunger for engaging the pinion gear 22 with the rack 21;
It is attached to a holding member 33 fixed to 7. 3
4 is a compression spring, 35 is an E-ring, and plunger 3
2 is inactive, the rack 21 and pinion gear 22 are disengaged. Note that the shaft 26 and the plunger are screwed together, and between the rotating member 30 and the holding member 33,
A slip surface is formed between the slip ring 31 and the shaft 26. The rack 21 and pinion gear 22 are shown in figure (C
), the start side of the mating is tapered and incompletely geared to facilitate mating. When engaging, the carriage is moved at low speed and then the plunger is pulled. In this way, we are able to reduce costs by using a simple small plunger and gears without using a separate motor for driving the bubble evacuation pump, and furthermore, without having to mount a heavy motor on the carriage, we can use a lightweight carriage. The remaining drive force of the carriage is used to operate the bubble evacuation pump.

As mentioned above, according to the present invention, the inkjet head, ink cartridge, and bubble evacuation pump are integrally formed, and no tube is used for piping, so there is less air bubbles mixed in from the outside, and as a result, jetting is improved. It is stable, and since the ink is circulated to discharge generated bubbles, there is no ink consumption.Furthermore, the bubble discharge pump is driven using the remaining driving force of the carriage, so no separate driving means is required. Cost reduction can be achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an integrated ink cartridge head equipped with a bubble ejecting device according to the present invention and a partially transparent view of the ejection channel, and FIG. 2 is a diagram showing the drive mechanism of the bubble ejecting pump. ) is an overall configuration diagram (B), and (C) is a diagram showing details of the rank and pinion gear parts. 1...Head body, 2...Ink cartridge, 3
... Ink bag, 4... Nozzle, 5... Two-part common liquid chamber, 6... Lower common liquid chamber, 7... Ink supply channel, 8... Discharge channel, 15 ...Pump body, 16...
・Slide rail. 17... Carriage, 21... Rack, 22...
Pinion gear, 25...Input gear 226...
Input shaft, 32...plunger.

Claims (4)

[Claims] (1) A carriage for mounting and driving an ink cartridge-integrated head and a bubble ejection pump are integrally formed, and when air bubbles are ejected, the air bubble ejection pump is operated by the reciprocating movement of the carriage, and the ink bag of the ink cartridge is moved from the head body. 1. A bubble discharge device for an inkjet recording device, characterized in that the ink is circulated to an ink bag. (2) The head body includes a lower common liquid chamber, a flow path, a nozzle part, and an upper common liquid chamber that communicate with each other in sequence, and the lower common liquid chamber is connected to an outlet flow path of an ink bag provided in the head. The inkjet recording apparatus according to claim 1, wherein the upper common liquid chamber has an upper wall tapered upward and is connected to a bubble discharge channel. bubble evacuation device. (3) An ink bag inlet channel, in which a pump inlet channel and a pump outlet channel are provided in the carriage, the pump inlet channel is connected to the bubble discharge channel, and a pump outlet channel is provided in the head. Claim No. 1 characterized in that it is connected to (
A bubble discharge device in an inkjet recording apparatus according to item 1) or item (2). (4) The pump inlet channel and pump outlet channel of the carriage are connected to the bubble discharge channel and the ink bag inlet channel in the head by inserting a connecting joint pipe into the O-ring on the carriage side. A bubble ejecting device in an inkjet recording apparatus according to claim (3), wherein the bubble ejecting device is