JPH0435977A - Ink ribbon regenerative pad - Google Patents

Abstract

PURPOSE:To hold a sufficient amount of ink and obtain excellent regeneration capability by using a material composed of a polyvinyl formal. CONSTITUTION:An ink ribbon regenerative pad whose material is composed of a polyvinyl formal is formed of a communicating porous member and is so designed as to recover the printing density of an ink ribbon by a method wherein the pad abuts against the ink ribbon to apply ink held by a capillary force to the ink ribbon. Since the polyvinyl formal has a large pore ratio, it can hold a large amount of ink and has a great effect on the movement of ink. The preferable diameter of pores is 200 - 400 mum or so with respect to ink, which is ordinarily used for an ink ribbon, such as, for example, ink comprising an oleic acid as a main solvent and having a viscosity of 100 - 500 cps or so, and the preferable pore ratio is 85% or 90% or more.

Description

Detailed Description of the Invention (Industrial Application Field) By applying ink, which is made of a continuous porous body and is retained by capillary force, by contact with an ink ribbon,
This invention relates to an ink ribbon regeneration pad that restores the print density of an ink ribbon.

(Prior Art) As ink ribbons used in dot printers and the like are used, the print density gradually decreases. However, it would be a waste to throw it away just because the print density has decreased. Therefore,
The six objects being considered for reproduction are exclusively device structures. Preventing the operator's hands from getting dirty
Various efforts have been made to prepare for playback with a single touch, or to automatically end playback even for endless ribbons. Among these are
It also includes matters related to the basic performance of regeneration, such as eliminating excess or deficiency in regeneration.

Here, to give an example of the principle of reproduction, in the attached FIG. 1, reference numeral 1 is an ink ribbon. It is drawn with an awareness of endless things. ink ribbon 1
is sent out from one of the two rollers 2.3 and taken up by the other roller. A pad 4 is arranged between these rollers, and the ink ribbon 1 is inserted into this pad 4.
If tension is applied so as to make contact with the pad 4, the movement of the ink ribbon 1 will rotate the pad 4, and the ink held by the pad 4 will be applied to the ink ribbon 1.

Further, in the attached FIG. 2, the ink ribbon 1 is passed between another roller 5 and the pad 4. Apply tension and pull the ink ribbon 1, thereby rotating the roller 5.At this time, if a force is applied between the roller 5 and the pad 4 in the direction in which they contact each other, the rotation of the roller 5 causes the pad 4 to rotate. The ink ribbon 1 passing between the two also rotates, and ink is applied to the ink ribbon 1 passing between the two. It should be noted that in FIGS. 1 and 2, there is a portion indicated by a chain line, but this is only done in consideration of the fact that ink ribbons are often commercially available as cassettes. In addition to being used in a dedicated playback device, the pad itself can be incorporated into a cassette, for example, or as one of the components of the printer itself.

Now, in both the one shown in FIG. 1 and the one shown in FIG. 2, the ink in the pad 4 is transferred to the ink ribbon 1 by bringing the ink ribbon 1 and the pad 4 into contact with each other. This is possible because the pad retains ink by capillary force. When playing in this way,
When trying to reduce uneven coating, the first thing to consider is to make the pad itself soft to reduce uneven contact. In fact, in the past, many pads were made from "sponge." Here, a typical sponge is a continuous porous body made of polyurethane.

(Problems to be Solved by the Invention) Having a soft pad certainly helps reduce uneven contact. However, the present inventors have found that reducing uneven contact may not always be helpful in reducing uneven coating.

This will be discussed below.

The part of the pad that applies ink to the ink ribbon is a rotating peripheral wall. In other words, ink rapidly moves from the peripheral wall to the ink ribbon. Ink inside the pad moves to the peripheral wall to compensate for ink shortage on the peripheral wall. At this time, if ink is uniformly supplied to one circumferential wall, uneven coating can be suppressed. However, when in contact with the ink ribbon, the peripheral wall portion contracts. It can be said that application is accompanied by squeezing. This contraction then depends on the rotation of the pad. That is, it contracts and recovers periodically in response to rotation. It is thought that ink is replenished from within during this recovery.

Place the compressed sponge next to the wet sponge.
Releasing the compression is like transferring water from a wet sponge to a compressed sponge.

This movement is not always uniform. What has an effect is the weight of the ink itself. In other words, if you play the attached drawing horizontally,
The ink ribbon has its "width" in the vertical direction, but regardless of whether it holds a large amount of ink, the coating density will gradually become thinner in the upper part than in the lower part. .

Further, the softness has a large relationship with the material of the pad, the porosity, the pore diameter, etc. These materials affect the ink retention force. Due to the desire for softness, the ink retention ability is weak, and shading may occur over time due to the ink's own weight.

(Means for solving problems) The material of the pad is polyvinyl formal.

That is, the present invention provides an ink ribbon regeneration pad which is made of a continuous porous body and is configured to restore the print density of the ink ribbon by applying ink retained by capillary force through contact with the ink ribbon. The gist of this invention is an ink ribbon regeneration pad characterized by being made of polyvinyl formal.

The details will be explained below.

Pads don't just have to be hard.

Some ink ribbons have a long total length, for example, 17'm. On the other hand, the pad itself cannot be made that large. The device is unreasonable. Moreover, the pad rotates many times in one playback operation. In addition, considering the reduction in operating time, it is desirable to increase the rotation speed. As a result, a large amount of ink is applied to the ink ribbon on the peripheral wall of the pad many times in a short cycle. The pad is not only hard, but also capable of stably holding a sufficient amount of ink over time to satisfy these conditions, and also allowing the ink to quickly move from the inside to the surrounding wall. It is hoped that it will be possible.

In this regard, polyvinyl formal has a high porosity and can therefore hold a large amount of ink, and also has a preferable pore size that has a large effect on the movement of ink. The ink should be able to sufficiently suppress movement of the ink over time due to its own weight, and should also have sufficient hardness. Here, the preferred pore size varies depending on the type of ink, so it cannot be generally determined, but for example, an ink normally used for ink ribbons, for example, an ink containing oleic acid as the main solvent and having a viscosity of 100 to 500 cp.
For ink of about s, it is about 200 to 400 μm (average). In addition, the porosity is 85% or 90%,
Or it can be something more.

Further, the shape may be other than a cylinder, for example, a polygonal cylinder.

(Example) A continuous porous polyvinyl formal cylindrical body with an average pore diameter of 350 μm, a porosity of 91%, a diameter of 25 m (center hole diameter for shaft center insertion: 5ffI11), and a height of 16 mm was prepared, and this was recycled into an ink ribbon. Ink commercially available as refill ink for pads (mainly oleic acid solvent, viscosity approximately 15
0 cps) and filled with ink from the outer wall surface (excess was removed). When I measured the weight, the amount of ink filled was 6.
．． It was 1g.

In the lost garden pruning Example 1, except that the diameter of the center hole for inserting the shaft center was 15 mm (the pad 4 is marked with a dotted line in the attached Fig. 1, this dotted line part is the center hole). A continuous porous polyvinyl formal columnar body similar to that in Example 1 was prepared and filled with ink under the same conditions as in Example 1. When the weight was measured, the ink filling amount was 5.0
It was g.

In Example 1, the average pore diameter was 250 μm and the porosity was 87.
A continuous porous polyvinyl formal cylindrical body having the same shape as in Example 1 was prepared except that
Ink was filled under the same conditions as in Example 1. When the weight was measured, the ink filling amount was 5.4 g.

In Example 1, the average pore diameter was 300 μm and the porosity was 76.
A continuous porous polyurethane cylindrical body having the same shape as in Example 1 was prepared except that
Ink was filled under the same conditions as above. When the weight was measured, the ink filling amount was 5.7 g.

(Effect of the invention) Regarding the items obtained on each side, the one immediately after ink filling and the 50
An ink ribbon regeneration test was conducted using an ink ribbon that had been left at ℃ for one month. The ink ribbon is a virgin ribbon (endless; length 17 m) that does not contain any ink, the tension is 50 g, and the ink ribbon speed is 10 a.
++/second, and the rotation time is 8 minutes and 30 seconds (the ink ribbon rotates 3 times).

First, in the comparative example which was left at 50° C. for one month, the print density at both ends of the ink ribbon varied in the first test of the ink ribbon. Further, the comparative example immediately after filling with ink also produced shading in the second test. On the other hand, in each of the examples, no shading was observed even in the fourth sample. By the way, when I took a soft X-ray perspective photograph of Example 1, it was found that the ink was present at a substantially uniform depth from the outer wall surface.

There was no significant difference in this whether it was immediately after filling with ink or when it was left at 50'C for one month. Volumetrically small Example 2
This is believed to be the reason why the sample showed good test results similar to the sample of Example 1.

As described above, the pad of the present invention has excellent ink retention properties, is not easily affected by the weight of the ink itself during ink ribbon regeneration or over time, can hold a sufficient amount of ink, and has excellent regeneration ability. You can get it.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams showing the principle of an example of how to regenerate an ink ribbon. 1... Ink ribbon, 2, 3.5... Roller 4.
··pad.

Claims (1)

[Claims] The ink ribbon regeneration pad is made of a continuous porous material and is designed to restore the print density of the ink ribbon by applying ink held by capillary force by contact with the ink ribbon, and the material is polyvinyl. An ink ribbon regeneration pad characterized by being formal.