JPH0519907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ink dot printer that performs printing by supplying ink to the tip of a recording electrode and causing the ink to fly electrostatically.

BACKGROUND OF THE INVENTION In this type of ink dot printer, focusing on the means for supplying ink to recording electrodes, there is a conventional ink dot printer having a structure in which an ink cartridge is detachably attached to a printer head having recording electrodes therein. An example is shown in FIGS. 5 and 6. An ink bottle 1 in the form of a housing with an open bottom surface is provided. A cap 3 is screwed onto the opening of the ink bottle 1 via a holder 2.
This cap 3 has an outflow hole 4 formed therein.
This outflow hole 4 is hermetically closed by a valve 6 attached to the holder 2 via a spring 5. At the same time, the outflow hole 4 is also covered with a lid 7 from the outside. An ink cartridge 8 is formed here, and the inside of the ink cartridge 8 is filled with ink 9 before use.

On the other hand, an ink tank 10 is formed in the print head, which is not shown in its entirety. This ink tank 10 has a protrusion 11 in its center that pushes up the valve 6.

To attach the ink cartridge 8 having such a configuration to the print head, the lid 7 is removed from the outflow hole 4 and the cap 3 is inserted into the ink tank 10. Then, the valve 6 is pushed up by the protrusion 11, the outflow hole 4 is opened, and the ink 9 in the ink bottle 1 is supplied to the ink tank 10.

Problems to be Solved by the Invention The problems of the conventional technology as described above will be explained with reference to FIGS. 7a, b, and c. ink tank 10
The inner ink surface A substantially corresponds to the position of the lower end of the outflow hole 4, and the ink 9 flows out from the outflow hole 4 as the ink 9 is consumed. Therefore, during printing, the ink 9 is constantly flowing out from the outflow hole 4. Therefore, in order to sufficiently supply the ink 9 to the tip of the recording electrode (not shown), the state in which the ink 9 flows out smoothly from the outflow hole 4 must be maintained.

However, in reality, when the ink surface A in the ink tank 10 is lower than the position of the outflow hole 4,
This has the disadvantage that a film of ink 9 is formed at the outlet of the outflow hole 4, and the ink 9 does not flow out and runs off. The reason for this is that the outflow of the ink 9 from the outflow hole 4 is caused by the inflow of air from the outflow hole 4 into the ink bottle 1, but under the above conditions, it is difficult for air to flow into the ink bottle 1. It is from. In addition, Fig. 7 a, b, c
2 is a schematic diagram showing the drop of the ink liquid level A and the outflow state of the ink 9 over time.

On the other hand, it is also possible to make the ink 9 flow out more smoothly by making the outflow hole 4 larger in diameter. However, even in such a case, the ink 9 still tends to form a film at the exit of the outflow hole 4, making it difficult to obtain a stable outflow state of the ink 9. Moreover,
Each part becomes large in size, making it unsuitable when a plurality of ink cartridges 8 are required, such as when performing multicolor printing.

The present invention has been made in view of the above points, and an object of the present invention is to provide an ink dot printer that can supply ink more stably than an ink cartridge according to the consumption of ink in recording electrodes.

Means for Solving the Problems The present invention provides an ink reservoir that directly or indirectly supplies ink to a recording electrode having ink flowability in the axial direction, and an ink supply pipe whose lower end is in contact with the ink reservoir. A formed ink cartridge was provided, and the lower end of the ink supply pipe was formed in a shape that was not parallel to the ink surface of the ink reservoir.

Function: When the ink surface of the ink reservoir is lower than the lower end of the ink supply pipe, air flows into the ink cartridge more quickly than the ink supply pipe. This is because the lower end of the ink supply tube is inclined with respect to the ink surface, so when the ink surface descends, most of the lower end of the ink supply tube is exposed to the air, and no ink film is formed on this portion. Therefore,
Ink is smoothly supplied to the ink tank from the ink cartridge in response to ink consumption due to printing, which in turn contributes to stable ink supply to the tip of the recording electrode.

Embodiment of the Invention An embodiment of the present invention is shown in FIGS. 1 to 4a,
The explanation will be based on b and c. Two carrier shafts 21 are provided in parallel within the printer body 20. A carrier 22 is slidably held on these carrier shifts 21, and a print head 23 is placed on this carrier 22. A counter electrode 24 is arranged in parallel with the carrier shaft 21 inside the printer main body 20, and a recording paper 25 as a recording medium is guided between the counter electrode 24 and the printing head 22. A tractor 26 is provided for transporting.
Operation knobs 27 are connected to both ends of these tractors 26.

Next, the print head 23 will be explained. The interior of the print head 23 is divided into three chambers, each having an ink tank 28, an ink supply tank 29, and an ink recovery path 30.
Of these, a recording electrode holding hole 31 is formed in a portion communicating with the ink supply tank 29 and the ink recovery path 30, and a recording electrode 32 is fitted and held in this recording electrode holding hole 31. This recording electrode 32
is formed of a member having ink-impregnating properties,
Its surface has been subjected to conductive treatment. A plurality of electrodes are arranged in a row along the longitudinal direction of the counter electrode 24, with the tip thereof facing the counter electrode 24. Further, in the ink supply tank 29 and the ink recovery path 30, an impregnating member 33 having an ink impregnating property is provided which extends upward from the lower surface thereof and comes into contact with the recording electrode 32. Furthermore, a metal rod 35 is provided within the print head 23 for contacting the recording electrode 33 and connecting the recording electrode 32 and a circuit board 34 mounted on the carrier 22.

On the other hand, the ink supply tank 29 and the ink tank 28 are communicated with each other through a through hole 36. Further, a connection hole 37 is provided on the top surface of the ink tank 28.
is formed, and a main body valve 38 is attached to this connection hole 37. This main body valve 38
consists of a valve body 38a and a rod-shaped contact portion 38b protruding from the valve body 38a. These valve bodies 38
Flow grooves 39 are formed in each of the contact portion a and the contact portion 38b. The main body valve 38 is vertically movably held by a guide wall 40 formed in the ink tank 28 with the contact portion 38b facing upward, and is urged upward by a main body spring 41. There is.

An ink cartridge 42 is detachably attached to the print head 23. This ink cartridge 42 has ink 43
An ink supply pipe 45 to be inserted into the connection hole 37 is formed on the lower surface of a container 44 that houses the ink. Here, the lower end of this ink supply pipe 45 forms an inclined surface 45a that is inclined with respect to the horizontal plane. Further, the inside of the ink supply pipe 45 is an ink outflow hole 46, and the container 44 is biased by a spring 47 to form an ink outflow hole 46.
A valve 48 is attached to open and close the valve 6 . This valve 48 has the same structure as the main body valve 38 except that it does not have the abutting portion 38b. Note that the diameter of the contact portion 38b is smaller than the diameter of the ink outflow hole 46, and the ink supply pipe 45 is formed to have a diameter that fits into the connection hole 37. Further, the biasing force of the valve 48 is set to be stronger than the biasing force of the main body valve 38.

In this configuration, the ink 43 in the ink cartridge 42 is supplied to the tip of the recording electrode 32. That is, when the ink supply pipe 45 is fitted into the connection hole 37 and the ink cartridge 42 is attached to the print head 23, the valve 48 comes into contact with the contact portion 38b, and the main body valve 38 and the valve 48 are sequentially opened. . Then, the ink 43 in the ink cartridge 42 flows into the ink tank 28 from the ink outlet hole 46 through the mutual circulation grooves 39, forming an ink reservoir 49. This ink reservoir 49
The ink 43 inside flows into the ink supply tank 29 through the through hole 36, impregnates the impregnation member 33, and is supplied to the recording electrode 32. The ink 43 penetrates into the recording electrode 32 and finally reaches the tip of the recording electrode 32.

On the other hand, at the tip of the recording electrode 32, the ink 4
When the ink 43 in the ink cartridge 42 is consumed, the ink 43 in the ink cartridge 42 is sequentially supplied to the recording electrode 32. At this time, as the ink 43 of the recording electrode 32 is consumed, the ink surface A of the ink reservoir 49 descends, causing the ink 43 in the ink supply pipe 45 to flow into the ink tank 28. The outflow is extremely smooth. The reason for this will be explained based on FIGS. 4a, b, and c. Normally, the ink surface A of the ink reservoir 49 is located near the top of the inclined surface 45a of the ink supply pipe 45. This is because the ink cartridge 42 is in a sealed state except for the ink outlet hole 46.
From this position, the ink surface A gradually descends as the ink 43 is consumed. During this process, the inclined surface 45a of the ink supply tube 45 becomes exposed to the air due to its shape. Therefore, a passage through which air enters the ink tank 42 is formed in the exposed portion. Such air flow is indicated by arrows in Figure 4c. In this way, the ink 43 flows out from the ink cartridge 42 and the air flows in into the ink cartridge 42 continuously, so that the ink 43 flows out smoothly from the ink cartridge 42. Therefore,
The ink 43 is applied well to the tip of the recording electrode 32.
This in turn contributes to maintaining stable printing conditions.

In addition, in actual practice, the lower end of the ink supply pipe 45 may be formed into a section 45b. That is, conceptually, it is sufficient that the ink surface A of the ink reservoir 49 and the lower end of the ink supply pipe 45 are not parallel.

Effects of the Invention The present invention provides an ink reservoir that supplies ink to a recording electrode that has ink flowability in the axial direction, and forms the lower end of the ink supply tube in contact with the ink reservoir in a shape that is not parallel to the ink surface of the ink reservoir. Therefore, when the ink is consumed and the ink surface of the ink reservoir falls, air is drawn into the ink cartridge from the lower end of the ink supply tube that is not parallel to the ink surface, causing ink to flow out from the ink supply tube. Therefore, ink can be well supplied to the tip of the recording electrode, and printing can be stabilized.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional side view of a print head and an ink cartridge showing one embodiment of the present invention, FIG. 2 is a perspective view of the whole, FIG. 3 is a perspective view of the main body valve, and FIG.
Figures a, b, and c are longitudinal cross-sectional side views of the end of the ink supply pipe showing the drop in the ink level in the ink reservoir and the flow of ink from the ink cartridge over time, and Figure 5 is the lower end of the ink supply pipe. FIG. 6 is a vertical side view of an ink cartridge showing a conventional example; FIG. 7 is a vertical side view showing the ink cartridge installed in a print head; 8a, b, and c are longitudinal sectional side views of an ink cartridge schematically showing changes over time in the drop of the ink liquid level in the ink reservoir and the flow of ink from the ink cartridge. 24... Counter electrode, 25... Recording paper (recording body),
32... Recording electrode, 42... Ink cartridge, 43... Ink, 45... Ink supply tube, 4
5a... Inclined surface, 49... Ink reservoir.

Claims (1)

[Scope of Claims] 1. A recording electrode having axial ink flowability disposed opposite to a counter electrode through a recording body,
An ink reservoir is provided that directly or indirectly supplies ink to the recording electrode, and an ink supply tube is formed whose lower end is in contact with the ink reservoir, and an ink cartridge is configured to supply ink from the ink supply tube to the ink reservoir. An ink dot printer characterized in that the lower end of the ink supply pipe is formed in a shape that is not parallel to the ink surface of the ink reservoir. 2. The ink dot printer according to claim 1, wherein the lower end of the ink supply pipe is inclined with respect to the ink surface of the ink reservoir to form an inclined surface.