JPH04226368A - Ink supply mechanism of printer - Google Patents

Abstract

PURPOSE:To enable ink in a tank to be supplied surely to a printing head irrespective of its ink surface level. CONSTITUTION:A porous component 60 for impregnation of ink is housed in a tank body 40 and besides, a bottom surface of the porous component 60 is compressed selectively by a tip of an ink supply opening interconnected to a printing head 1 of an ink supply guide 12 or the like. The porous component 60 is compressed in an area near the supply opening, and its average hole diameter becomes smaller than that of other part. Capillary force near the tip of the ink supply guide 12 composing an ink supply component is increased to attract surrounding ink, and ink in the tank is supplied uniformly to the printing head 1 irrespective of the ink surface level.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer that performs recording using ink, and more particularly to an ink supply mechanism for a printer.

0002

2. Description of the Related Art One of the conventionally known ink tank structures is a method of filling the tank with an ink-impregnated member such as a porous material, as shown in FIG. This structure uses the appropriate capillary force of the ink-impregnated member to supply an appropriate amount of ink to the printer head body, while also preventing unintentional ink from flowing out from the tank's air port or ink supply hole. This can be easily achieved.

When using ink from an ink tank having such a structure, the force that moves the ink located far from the ink supply port of the ink tank to the vicinity of the ink supply port is exerted by the capillary tube in the ink impregnation member near the ink supply port. The force increases with the consumption of ink, resulting in a pressure difference between the ink and the ink at a distance from the ink supply port.

0004

[Problems to be Solved by the Invention] However, as is noticeable with porous materials, ink-impregnated members generally suffer from a decrease in the amount of ink impregnated with them, as well as an increase in fluid resistance and problems at various points in the ink path. Partition occurs, making it difficult for ink to flow. Therefore, if the ink becomes difficult to flow before a sufficient pressure difference is created to move the ink,
Ink located far from the ink supply port remains unusable. As described above, conventional ink tanks using ink-impregnated members have disadvantages in that the ink in the tank cannot be used sufficiently and the ink life is short and unstable.

[0005] The present invention solves these problems.
The purpose is to provide an ink supply mechanism for a printer that can efficiently and stably supply ink.

[0006]

[Means for Solving the Problems] An ink supply mechanism for a printer according to the present invention includes an ink tank having an ink supply port;
An ink-impregnated member made of a porous material and housed in the ink tank; and an ink supply guide member that communicates with the recording head, protrudes from an ink supply port of the ink tank, and comes into pressure contact with the ink-impregnated member. It is characterized by

[0007]

According to the above structure of the present invention, since the ink supply guide member is in pressure contact with the ink impregnated member, the pore diameter of the porous material in the pressure contact portion is reduced and the capillary force is increased, so that ink is efficiently collected.

[0008]

[Embodiment] An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a head of an example of an ink-type wire dot printer using the ink supply mechanism of the present invention. The head of this embodiment is a four-color color printer/plotter head, and includes black, red, green, and blue inks, and one wire corresponding to each ink. In a four-color color printer/plotter, one or both of the head and the recording paper are moved so that a wire corresponding to the desired color of the head protrudes at a predetermined position on the recording paper to form dots and draw characters and figures. It has a structure. The gist of the present invention is related to the printing section, and the structure of the entire device will be omitted. Next, the structure of the head of an ink-type wire dot printer using the ink tank of the present invention will be explained with reference to the cross-sectional view of the head in FIG. The head 1 has an ink tank 2 removably disposed above the head 1. The ink tank 2 has a two-piece structure: an ink tank 2b for black ink and a tank 2a for color ink, the interior of which is divided into three parts. An ink impregnating member 60 made of a porous material and filled in the ink tank 2 is impregnated with ink. The ink supply guide 12 has an ink guide groove 12b extending in the axial direction, and the ink impregnation member 60 is in contact with the ink guide groove 12b. The width and depth of the ink guiding groove 12b are set to appropriate values to ensure a stable supply of ink from the ink tank 2. There is a circumferential groove 12a in the front part of the ink supply guide 12, and an ink guiding groove 12b.
It is connected to the inside 12c. A wire guide 13 is incorporated in the circumferential groove 12a, and the combination of the two allows A,
A gap indicated by B is provided. Furthermore, the gap between the wire 11 and the wire guide hole 13a of the wire guide 13 is small, and the ink flows from the ink tank 2 to the ink supply guide 1.
Gap A between the ink guiding hole 12b of No. 2 and the wire guide 13
, B to the tip of the wire 11 by capillary force. The embodiment is a case of a four-color printer/plotter head, and four wires correspond to four colors of ink, respectively. The wire drive device has a coil core 16 around which a coil 17 is wound.
A magnetic circuit is constituted by the yoke 18, the yoke plate 19, and the plunger 15. The movement of the plunger 15 is transmitted to the wire 11 via the clapper 14. The wire driving device described above is covered by a cover 21 and the operating length of the clapper 14 is regulated. During standby, the tip end surface of the wire is deeper than the tip end surface of the wire guide 13, and the wire length is set so that the meniscus of ink formed at the front of the wire guide hole 13a covers the wire tip end surface. Next, the operation will be explained. FIG. 2 shows the state when the coil 17 is energized, and the plunger 15 facing the coil core 16 is attracted. As a result, the clapper 14 to which the plunger 15 is fixed rotates, and the wire 11 engaged at its tip protrudes. The tip end surface of the wire pierces the ink meniscus, causes ink to adhere to the tip end surface, and collides with recording paper (not shown), so that the ink is transferred onto the recording paper. In the wire standby state, the tip end surface of the wire 11 is connected to the wire guide 13.
Since an ink meniscus is formed on the inside of the end surface and in front of the wire tip surface, ink sequentially adheres to the wire tip surface as the wire moves in and out. For details regarding the ink dot printing method, such as the transfer of ink to the wire at the tip of the wire, please refer to the patent application filed by the applicant in 1973.
5-81609, so a detailed description thereof will be omitted. Note that the excess ink on the front surface of the wire guide 13 is drawn by capillary force into the collection groove 13b, which is a narrow groove with a V-shaped cross section provided on the front surface and side surface, so that it does not overflow and stain the recording paper. Reflux to 12. FIG. 3 is a cross-sectional perspective view showing an embodiment of the ink tank of the present invention. The ink tank 2 includes a tank body 40 , a porous member 60 that is an ink-impregnated member filled in a hollow part of the tank body 40 , and a lid 50 . An ink supply port 41 is opened at the front of the bottom surface 40a of the tank body, and an air port 42 is opened at the front wall step 43. The arm portion 12d of the ink supply guide 12 protruding from the printer head body is inserted into the ink supply port 41. A plurality of narrow grooves 45a, 45b, and 45c are provided in the inner stepped portion 44 of the bottom surface 40a of the tank body so as to communicate with the ink supply port 41, and grooves 45a, 45b, and 45c are provided in the arm portion 12d of the ink supply guide 12 of the printer head body. ink guide groove 12
It faces b. Although not shown, the narrow grooves 45a and 45b become one in the middle and guide ink to the narrow groove 12b together with 45c. These tank body bottom parts 40a,
Two types of porous members 61 and 6 having different average pore diameters are provided in a hollow portion surrounded by the side wall portion 40c, the front wall portion 40b, and the tank lid 50.
2, the porous member 62 having a small average pore diameter is arranged in a layered manner in contact with the stepped portion 44 on the bottom surface of the tank body. In the above structure, the capillary force is caused by the porous member 61 having a large average pore diameter;
The ink path is made up of a porous member 62 with a small average pore diameter, a narrow groove 45 for guiding the ink provided on the stepped part of the bottom surface of the tank body, and an ink guiding groove 12b provided on the ink supply guide arm 12d of the printer body, and the ink path becomes larger in this order. It is configured like this. This can be achieved, for example, by setting dimensions as shown below. Average pore diameter of porous member 61: 0.4 mm Porous member 6
Average hole diameter of 2: 0.3mm Groove width of narrow groove 45
0.12 mm Groove width of ink guiding groove 12b: 0.10 mm Next, the operation will be explained. When ink is consumed due to printing, the porous member passes through the ink guide groove 12b of the ink supply guide arm, or both the ink guide groove 12b of the ink supply guide arm and the narrow groove 45 of the step 44 on the bottom of the tank body. The ink in 62 flows into the printer head body. At this time, since the movement of the ink is in the thickness direction of the plate-shaped porous member 62, the amount of movement of the ink within the porous member is small, and there is almost no division of the ink. Furthermore, when the ink in the porous member 62 is consumed, a pressure difference between the ink in the porous member 61 and the porous member 62 immediately occurs due to the difference in average pore diameter, and the same amount of ink as the consumed amount is transferred to the porous member. The porous member 62 is replenished from the member 61 . At this time, the movement of the ink within the porous member 61 is also in the thickness direction, so that the ink is hardly divided. In this way, almost all of the ink in the porous member 61 is consumed while keeping the amount of ink in the porous member 62 almost equal to the state before use, and after that, almost all of the ink in the porous member 62 is also consumed. That will happen. As described above, by adopting the configuration of this embodiment, it is possible to use the ink in the ink tank with almost no remaining ink. FIG. 4 is a perspective view showing another embodiment of the present invention. The other members except the porous member 60 have the same structure as the ink tank of the previous embodiment. The porous member 60 has different thicknesses in its front portion and rear portion, and when the tank body 40 is filled, the front portion is compressed by the tank lid 50. For this reason, even if the porous material has a uniform average pore size, when the tank is filled, the average pore size will be small in the front part near the ink supply port, and the average pore size will continuously increase towards the rear. can be produced. The effect of this embodiment is that the porous member of this embodiment is equivalent to arranging thin plate-like porous materials with slightly different average pore diameters so that the average pore diameters gradually increase from the front to the rear of the ink tank. Therefore, it can be considered in the same way as in the above embodiment. Therefore, ink is consumed from the rear of the porous member, which is far from the ink supply port, and is gradually used up toward the front. In this way, in this example,
Since it is possible to create a state in which the average pore diameters within the porous member are different with only one porous member, the structure has the effect of simplifying the structure.

[0009]

According to the present invention, an ink tank having an ink supply port, an ink-impregnated member made of a porous material housed in the ink tank, and an ink impregnation member that communicates with the recording head and protrudes from the ink supply port of the ink tank. Since the ink supply guide member is in pressure contact with the ink impregnated member, the pore diameter of the porous material in the pressure contact part is reduced and the capillary force is increased, so that the ink is efficiently supplied. This allows stable ink supply.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a printer using an ink supply mechanism according to an embodiment of the present invention.

FIG. 2 is a sectional view of a printer using an ink supply mechanism according to an embodiment of the present invention.

FIG. 3 is a partially cutaway perspective view of an ink supply mechanism according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view of an ink supply mechanism according to another embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view of a conventional ink supply mechanism.

[Explanation of symbols]

1 Head 2 Ink tank 12 Ink supply guide 60 Ink impregnated member

Claims (1)

[Claims] 1. An ink supply mechanism for a printer that supplies ink to a recording head, comprising: an ink tank having an ink supply port; an ink-impregnated member made of a porous material accommodated in the ink tank; An ink supply mechanism for a printer, comprising: an ink supply guide member that communicates with a head, protrudes from an ink supply port of the ink tank, and comes into pressure contact with the ink impregnation member.