JPH03258554A - Ink jet printer - Google Patents

Abstract

PURPOSE:To prevent the air bubbles taken in a needle from entering a head module without worsening the flow of an ink and make system reducible in size by providing a connecting body with a needle and locating an ink chamber and a filter downstream an ink passage from the needle. CONSTITUTION:A connecting body 2 having an ink passage formed therein is provided to introduce the ink from an ink cartridge 1 to a head module 3 and this connecting body 2 is provided therein with an ink chamber 2f in communication with one end of the ink passage and having an air bubble collecting part the upper part thereof. A filter 8 is provided at a boundary part between the ink passage and the ink chamber 2f and a nozzle 10 having a communication hole to introduce therethrough the ink from the ink cartridge 1 to the ink chamber 2f is fixed to the connecting body 2 at the position opposite to the lower part of the ink chamber. Since, in this way, the ink chamber 2f and the filter 8 are located downstream the ink passage from the needle 10, the air bubbles are trapped by the filter 8, sent upward and collected at the upper part of the ink chamber 2f.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inkjet printer equipped with a filter mechanism that traps ink dust, air bubbles, and the like.

[Prior Art] Conventionally, a filter mechanism for trapping ink dust, air bubbles, etc. in an inkjet printer was disclosed in Japanese Patent Application Laid-Open No. 63-153
As in Japanese Patent Publication No. 146, there is a mechanism in which an ink outlet is provided that protrudes from the underside of the ink tank, and this ink outlet has a structure in which filters are provided at regular intervals between a rubber stopper and the ink outlet. As in Japanese Patent No. 62-257857, there is a device in which a filter device is provided in a flow path pipe connecting an ink cartridge and a print head.

[Problem to be solved] However, in the former case, when the needle is inserted into the rubber stopper and the ink is taken out, air bubbles taken into the ink tank when the needle is inserted rises and are trapped by the filter. There were issues with problems such as blocking the ink flow, and air bubbles taken in from the needle when the needle was inserted flowing directly into the head module.

Moreover, in the latter case, since the filter device is provided independently and separately, there is a problem that the entire printer system becomes large and the cost increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet printer that does not impair the flow of ink, prevents air bubbles taken into the needle from entering the head module, and allows the overall system of the printer to be miniaturized. .

[Means for Solving the Problems] In order to achieve the above object, an inkjet printer of the present invention includes a connecting body in which an ink flow path for guiding ink from an ink cartridge to a head module is formed, and a connecting body provided in the connecting body. an ink chamber that communicates with one end of the ink flow path and has an air bubble reservoir at the upper end; a filter that is provided at the boundary between the ink flow path and the ink chamber; The ink chamber has a communicating hole leading to the ink chamber, and a needle fixed to the connecting body at a position opposite to the lower part of the ink chamber.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in the first diagram, an ink cartridge 1. Connecting body 2 and head module 3
are combined.

The ink cartridge 1 houses an ink bag 5 containing ink, and the opening of the ink bag 5 is connected to a septum 6. The septum 6 has a rubber portion 6a at the front. The ink cartridge 1 is detachably mounted on a carriage (not shown) by a predetermined means, and when the ink cartridge 1 is mounted, a needle 10, which will be described later, is inserted into the rubber portion 6a.

As shown in Figures 1 to 4, the connecting body 2 integrally forms the entire ink flow path that leads ink from the ink cartridge 1 to the head module 3, and is made of chemical-resistant and white-colored material such as polyethylene or polypropylene. It is made by integrally molding a material with good light reflectivity. The ink supply pipe 3a of the head module 3, which will be described later, is located above the septum 6 of the ink cartridge 1. Therefore, in order to guide the ink of the ink cartridge 1 to the head module 3, the connecting body 2 has a first pipe extending upward. Ink passage chamber 2
a and a second ink passage chamber 2b in which a meandering ink groove is formed.

The first ink passage chamber 2a has a linear ink groove 2 on the front side.
The needle 10 is attached to the rear surface of the connecting body 2 through the filter mechanism 7 at the lower end, and the upper end is connected to the second ink passage chamber 2b by a communication passage 2j extending toward the rear surface. It's communicating.

The filter mechanism 7 is as shown in Figure 5.6, and the first ink passage chamber 2a has a mounting hole 2e for the filter 8 on the bottom surface 2d of the ink groove 2c, and a hole 2e with a circular cross section and a predetermined width for trapping air bubbles, etc. Ink chamber 2f and needle 10 installation port 2g
is formed, the filter attachment hole 2e and the ink chamber 2f are on the same axis, and the diameter of the ink chamber 2f is sufficiently larger than the diameter of the communication hole 10a opened inside the needle 10, and the ink chamber The lower end of 2f coincides with the lower end of the communication hole 10a of the needle. The filter 8 is made of, for example, nylon,
A mesh made of resin fibers such as Teflon or vinylon, or metal fibers such as stainless steel, or a metal plate with many holes are used, and the hole size is 0°5 in either case. The thickness is preferably about 50 μm. The filter 8 is fixed to the connecting body 2 by heat welding to the mounting hole 2e, or the filter 8 is integrated into the connecting body 2 by insert molding so that a gap larger than the hole of the filter 8 does not occur. do. The needle 1o is attached to the mounting port 2g, and as shown in the third figure, there is a communication hole 10a in the front part.
A horizontal hole 10b communicating with is opened.

A first transparent flexible sheet 11 is fixed to the front surface of the first ink passage chamber 2a. The fixed part is the cross-hatched part in FIG. 4, and as shown in the figure, the flexible sheet 11 is attached to the ink groove 2 of the first ink passage chamber 2a.
The flexible sheet 11 is fixed to the front end surface of the side wall forming part c, but in the left side part, the flexible sheet 11 is not fixed to the inside of the fixed part, although it is at the same height as the front end surface. A portion 2k of the side wall (hereinafter referred to as a protrusion) on which the adhesive sheet 11 can freely approach and separate is left. The first flexible sheet 11 is made of a thin film of a chemically resistant material such as polyethylene or polypropylene, is flexible and transparent, and is fixed by heat welding, ultrasonic welding, or the like. A flexible sheet 11 is attached to the protruding portion 2 as shown in Fig. 1.3°4.
A photoreflector 12 is provided opposite to. The photoreflector 12 has a part that emits light and a part that receives light, and the difference in light is compared, and when the difference in light becomes small, it is detected that the ink has run out.

The second ink passage chamber 2b has a large recess 2m with a circular cross section carved into the rear surface, and a communication passage 2j is provided at the lower end of the recess 2m to serve as an ink inlet, and a pair of ink discharge ports are provided approximately at the center of the recess 2m. 2q is provided. In addition, in the recessed portion 2m, a convex portion 2p having the same height as the rear end surface is integrally formed with the connecting body 2 in order to define a meandering and bilaterally symmetrical ink groove 2r that communicates the ink inlet and the ink outlet. It has an impressive shape.

The ink groove 2r once reaches the vicinity of the upper end of the recess 2m along the side surface of the recess 2m, descends from there in the circumferential direction of the recess 2m, once descends below the ink discharge port 2q, and from there rises to drain the ink. It has reached the discharge port 2q. In the ink groove 2r, a portion 2s near the upper end of the recess 2m is a place where air bubbles in the ink are trapped and prevented from reaching the ink discharge port 2q.

Each of the pair of ink discharge ports 2q has a discharge pipe 2t on the front side.
is formed.

On the rear end surface of the side wall forming the recess 2m, a second flexible sheet 13 is fixed to the peripheral edge of the recess 2m, as shown by cross hatching. The material, fixing method, etc. of the flexible sheet 13 are the same as in the case of the first flexible sheet 11.
The explanation will be omitted here.

As shown in the first figure, in the head module 3, a pair of ink supply pipes 3a protruding from the rear surface are connected to a discharge pipe 2t by a connecting member 14, and the ink supply pipes 3a are communicated with an ink reservoir 3b. The inks are separated into the respective piezoelectric element action chambers 3c and are ejected from respective nozzles (not shown) formed in two vertical rows in the nozzle portion 3d. A piezoelectric cord 3e is provided on the outer surface of the head module 3, corresponding to each piezoelectric element action chamber 3c.

Next, the effect will be explained.

The ink cartridge 1 is mounted on the carriage, and the needle 10 and septum 6 are connected. When using the plink for the first time, ink is sucked from the nozzle portion 3d by an ink suction means (not shown) or the like.

Then, the air and the like in the coupling body 2 and the head module 3 are sucked out, and the ink in the ink bag 5 is filled into the head module 3 via the needle 10.

When the priming sequence finishes filling the head module 3 with ink, the carriage moves from the home position to the recording position and prints according to the print signal. At this time, when there is a sudden change in the carriage, such as when the -th line finishes printing and the carriage moves to the first position of the next line, the connector 2. Pressure fluctuations occur in the ink inside the head module 3 and the like. However, since the rear surface of the second ink passage chamber 2b and the front surface of the first ink passage chamber 2a of the connecting body 2 are formed of the second flexible sheet 13 and the first flexible sheet 11, , this flexible sheet 1
3 and 11 move according to the fluctuations in the pressure waves, the fluctuations in the pressure waves are absorbed. Therefore, unevenness in ink ejection from the nozzle portion 3d due to the generation of pressure waves within the ink is prevented, and uniform and highly accurate ink ejection becomes possible.

Air bubbles in the ink stored in the ink bag 5,
Dust and the like enter the connecting body 2 side from the needle 10 as the ink is used. However, due to the presence of filter 8,
Air bubbles, dirt, etc. are trapped there. Furthermore, the air bubbles rise along the filter 8 and accumulate above the ink chamber 2f.
It comes off from the part of the filter 8 facing the communication hole 10a of the needle 1°. Therefore, there is no possibility that the flow of ink is blocked by air bubbles surrounding the filter portion, resulting in poor ink flow, or that air bubbles are pushed by the ink flow and pass through the filter 8. In addition, air bubbles that have passed through the filter 8 and dissolved in the ink may be removed from the first ink passage chamber 2.
Air bubbles accumulated and generated in the ink passage chamber a or the second ink passage chamber 2b are formed into a linear ink groove 2c and a meandering ink groove 2r.
, and accumulates at the upper end 2s of the four parts 2m. Therefore, clean ink without bubbles, dust, etc. is supplied to the head module 3, and ink discharge failure, nozzle clogging, etc. are prevented.

Next, when the ink in the ink bag 5 runs out, a negative pressure is generated in the ink, and the ink between the protrusion 2 and the first flexible sheet 11 flows toward the ink groove 2C, and the ink is removed from the protrusion. Since the portion appears white, the amount of light received by the photoreflector 12 increases, and it is detected that the ink is running out.

Therefore, the ink cartridge 1 is removed and a new ink cartridge 1 is installed. At this time, air gets mixed into the needle 10, but since the filter 8 is provided in front of the second needle 10, the air is blocked by the filter 8, and the connecting body 2. Air is prevented from entering the head module 3. When replacing the ink cartridge 1 with the carriage 2, it is not possible to use a large ink cartridge, so the priming sequence that sucks out a large amount of ink cannot be performed frequently, but the filter 8 installed in front of the needle traps air bubbles. Since the air bubbles are stored in the upper part of the ink chamber 2f, there is a very low possibility that the air bubbles will flow to the head module 3 even if the priming sequence is not performed. Therefore, after replacing the ink cartridge 1, printing work can be performed immediately.

Although the above embodiment describes an inkjet printer using a piezoelectric element 3e, the present invention is applicable to various types of inkjet printers such as those using a bubble jet.

[Effects] In the present invention, a needle is provided in the connecting body, and an ink chamber and a filter are provided downstream of the needle in the ink flow path. Therefore, air bubbles are trapped by the filter, rise up, and accumulate above the ink chamber. It does not impede the flow of ink and prevents air bubbles taken into the needle from entering the head module. Furthermore, since the needle and filter are provided in the connecting body that guides ink from the ink cartridge to the head module, it is possible to downsize the entire printer system.

[Brief explanation of drawings]

Figures 1 to 6 show one embodiment of the present invention.
The figure shows the head module on the carriage. FIG. 2 is a rear view of the connecting body; FIG. 3 is a cross-sectional view taken along line A-A in FIGS. 2 and 4; FIG. 4 is a front view of the connecting body section, FIG. 5 is an enlarged view of section B in FIG. 3, and FIG. 6 is a diagram of the filter section viewed from direction C in FIG. 5. DESCRIPTION OF SYMBOLS 1... Ink cartridge, 2... Connecting body, 2f... Ink chamber, 2 k ・ 3 ・ ・ 8 ・ 10 ・ 0a ・Protrusion part, ・Head module, ・Filter, ◆・Needle, ・・Communication hole. I”d

Claims (1)

[Scope of Claims] A connecting body in which an ink channel is formed to guide ink from the ink cartridge to the head module; an ink chamber having a reservoir, a filter provided at a boundary between the ink flow path and the ink chamber, and a communication hole for guiding ink from the ink cartridge to the ink chamber, and a lower part of the ink chamber. and a needle fixed to the connecting body at a position opposite to the needle.