JPH0249230B2 - WAIYASHIKIDOTSUTOPURINTAHETSUDONOINKUFUCHAKUKIKO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire-type dot printer, and more particularly to an ink-adhering type wire-type dot printer head that prints by depositing ink on the tip of a wire.

Dot printers using wires have been widely used. It is no exaggeration to say that most of these printers use ink ribbons for printing. However, in those using an ink ribbon, since printing is performed via the ink ribbon, the characters become unclear, and the durability of the ink ribbon becomes a problem because printing is performed by striking the ink ribbon. In addition, if the wire diameter is made too thin, the durability of the ribbon will drop significantly due to impact stress, and the weave cannot be made very fine due to textile technology, so the wire diameter used in wire dot printers is limited. This has hindered the use of ultra-fine wires. Furthermore, in order to use an ink ribbon, an additional mechanism called an ink ribbon mechanism is required, which complicates the printer and poses an obstacle to miniaturization.

The present invention has been made in an attempt to provide a structure that can stably and reliably supply an appropriate amount of ink to the printing end surface of the wire even if the wire of a head for a wire type dot printer is operated repeatedly at high speed.

Furthermore, by providing an ink adhesion mechanism that stably supplies and adheres ink to the tip of the wire, the range of use can be expanded to the area of ultra-fine wires, which was not possible with wire-type dot printers using ink ribbons, and printing density can be increased. This was done in an attempt to realize a wire printer capable of printing high quality prints.

Yet another object of the present invention is to achieve a ribbon-less system by reliably and stably adhering ink to the wire printing end face, thereby solving various serious problems that have arisen with the use of conventional ink ribbons. This was done in an attempt to realize a highly reliable wire-type printer by solving problems such as the durability of the ribbon caused by hitting the ribbon, the lifespan of ink, and limitations on wire diameter.

Wire-type dot printers have been widely used in the past. Wire-type dot printers have a great degree of freedom in configuring characters, giving you the flexibility to freely configure character types, fonts, shapes, etc. according to the purpose without changing the printer, and with a limited number of dots. Since characters can be freely configured, printing speed can be increased compared to matrix type printers, and furthermore, it has the advantage of being able to make copies.
However, since printing is performed while striking the ribbon with a thin wire through the ribbon, if the ribbon is struck too many times, the ribbon will be damaged. Also, if the wire itself is used for a long time while striking the ribbon, the tip of the wire will sag, and if the outer periphery of the wire is hardened, the tip of the wire will wear into a concave shape, so it is difficult to strike the ribbon. This has the disadvantage that the stress increases over time, leading to premature breakage of the ribbon. In addition, since the ribbon is fed by a ribbon feeding mechanism attached to the printer, the amount of ribbon is limited, and the ink life of the ribbon is also limited by the length of the ribbon, making it impossible to print with the same ribbon for too long. Furthermore, since there are restrictions on the mounting location of the ribbon feeding mechanism attached to the printer, the printer itself has the disadvantage of becoming larger.

Furthermore, for multi-pin printers that print kanji, for example, by reducing the size of the characters and increasing the print density per mm (how many lines are drawn in 1 mm), the print quality is improved. Attempts are being made to Further, wire dot printers require printing energy above a certain level in order to take advantage of the characteristics of copying. Therefore, as the wire diameter becomes smaller, the stress when striking the ribbon increases, making the ribbon more likely to break. Separately, even in the currently used multi-pin ribbons, it is impossible to create very fine joints due to cloth weaving technology, and if the wire diameter is small relative to the cloth grain, the wire will It will pierce the fabric and cause problems such as wire breakage.
Due to this relationship, when using a ribbon, the bottom diameter of the wire is currently set to be around 0.2 mm, which makes it difficult to print thin, high-density, high-quality prints, and due to the wire diameter. It has the disadvantage of being limited. The present invention was made in order to solve various problems that occur when using such ribbons, and to provide an ink adhesion mechanism that stably and reliably supplies ink directly to the printed end surface of the wire without using a ribbon. It is something.

Currently, many non-impact printers are being offered as printers that do not use ribbons, but they have the disadvantage of not being able to make copies.
The present invention is an attempt to take advantage of the advantage of a wire-type dot printer, which is the ability to make copies, and to provide a boneless printer.

However, some attempts have been made to attach ink directly to the tip of the wire without using an ink ribbon. The conventional technology is Utility Model Publication No. 80628 (1978), Special Publication Publication No. 41-19251 (1973-1925), Publication Publication No.
2652, and US Pat. No. 4,194,846. but,
In the past, I had tried experimenting with the method described above, but by following the high-speed repetitive motion of the wire in a wire dot printer, I was able to adhere an appropriate amount of ink to the print end of the wire, stably, and reliably, resulting in even printing. In order to obtain quality, the specified technical content, structure, etc. are insufficient. The present invention attempts to provide an ink adhesion mechanism in which an appropriate amount of ink is reliably supplied and adhered to the printed end surface of the wire even when the wire is repeatedly operated at high speed.

First, for convenience of explanation, a cross-sectional view of FIG. 1 showing the principle of a wire dot printer head.
I will explain from. 1 is a wire and consists of a wire pin 4 fixed to the wire 1 so as to engage with the printing end surface 1a and the actuating plate 5. 2 is a nose for storing the wires 1, and a guide 2 for guiding the plurality of wires 1 in a predetermined arrangement and shape.
a, 2b, 2c, and a tip guide 3 for guiding the tip of the wire. In the structure shown in a, the arrangement of the tips of the plurality of wires 1 is such that nine wires are arranged in a line as shown in the wire arrangement b. A plunger 6 is fixed to the actuating plate 5. 7 is a drive coil, 8 is a frame made of a magnetic material, and includes a coil core part 8a that attracts the plunger 6 when the drive coil 7 is excited, and a cylindrical joint formed on the outer periphery where a plurality of drive coils are arranged. The iron portion 8b is integrally formed. 9 is a yoke plate made of magnetic material, and has a hole 9 through which the plunger 6 passes.
It has a. 10 is a spacer, 11 is an actuating plate holding lid, and elastic arms 11a formed in a petal shape are provided so that the vicinity of the fulcrum of a plurality of actuating plates 5 arranged on the circumference can be independently pressed. The distal end of the actuating plate 11a has a protrusion 11b that presses down the actuating plate 5, and a protrusion 11c that engages with an actuating plate guide hole 5a provided at the fulcrum of the actuating plate 5. Furthermore, a contact portion 11d for determining the standby position of the actuating plate 5 is provided. The actuating plate 5 has a contact portion 11d at the tip of the actuating plate 5 (the side that engages with the wire pin 4) when the vicinity of the fulcrum is pushed by the elastic arm 11a described above.
It is bent as shown in the figure to create a restoring force that presses against it. 12 is a wire return spring and wire 1
The actuating plate 5 is pushed back to the standby position. 14 is an ink ribbon, 13 is a recording paper, 15
is the platen. The operation of the dot head of this wire printer will be briefly explained. First, when the drive coil 7 is energized in accordance with an external control signal, a magnetic flux flows in a loop shown by a broken line, and the plunger 6 fixed to the actuating plate 5 is attracted. The actuating plate 5 rotates around a fulcrum, and the wire pin 4 engages with the tip.
and push out the wire 1 in the printing direction. The extruded wire 1 hits the ink ribbon 14 and the recording paper 13 against the platen 15 to perform printing. At this time, the ink impregnated in the ink ribbon 14 is transferred onto the recording paper 13. Thereafter, the wire 1 is returned to the standby position by the wire return spring 12, and waits until the next print signal is output. The disadvantages of dot printer heads using this ink ribbon have been discussed above. Next, without using an ink ribbon,
An example of a conventional technique for printing by applying ink directly to the tip of a wire will be explained with reference to FIG. 2, which shows the principle shown in Japanese Utility Model Publication No. 53-2652. Second
The figures show only the ink adhesion mechanism at the tip of the wire dot head, with part a showing the wire in a standby state, and part b showing the wire in a driven state. 21 is a wire, and 22 is a wire tip guide, which is composed of a front guide 22a and a rear guide 22b, between which an ink-impregnated material 23 is arranged, and ink is supplied to the ink-impregnated material 23 through an ink supply pipe 24. 25 is a wire hole through which the wire 21 passes, 26 is recording paper, and 27 is a platen. The wire tip guide 22 is configured such that the wire 21 can slide thereon, and an ink-impregnated material 2 is provided on the sliding surface of the wire tip.
3 is configured so that the wire 21 comes into contact with the wire 21 when it is activated. When in the printing standby state, the wire 21 retreats from the position of the ink-impregnated material 23 as shown in a, and when the wire 21 is activated, it penetrates the ink-impregnated material as shown in b, and when the tip of the wire 21 advances, the ink-impregnated material 23 Ink is supplied from the tip 23 to the printing paper 26 and printing is performed. One of the drawbacks of this ink deposition mechanism is that the tip of the wire retracts behind the ink impregnation material in a standby condition.
In the case of wire-type dot printers, high responsiveness is required for the repeated movements of the wire, so the wire stroke is generally very short, ranging from 0.3 mm to around 1 mm at the longest. If the wire dots are made long, the mechanism for constructing the wire dots becomes extremely difficult, even if high responsiveness of the wires is not required. In addition, since the ink is stored in the ink-impregnated material and the ink adheres to the wire, it follows the high-speed repetitive movement of the wire, and evenly applies ink to the tip of the wire under all operating environmental conditions. Due to the capillary attraction of the ink-impregnated material, it is very difficult to select a suitable material to adhere to the conditions, resulting in problems such as uneven printing and inability to print.
Furthermore, the use of an ink-impregnating material may cause clogging. Furthermore, if pressure is applied only to the ink supply in order to improve the responsiveness of the ink supply, there is a serious drawback in that the ink overflows into the surrounding area. Among the proposed prior art techniques, there are examples in which the ink-impregnating material is disposed near the tip guide, but the above-mentioned drawbacks are also the same. The present invention solves these drawbacks and proposes an ink adhesion mechanism that follows the high-speed movement of the wire and always allows ink to be evenly applied to the tip of the wire.

The description of the present invention will be explained in the third section showing one embodiment of the present invention.
Let's explain from the diagram. FIG. 2A is a cross-sectional view of the ink adhesion mechanism seen from above the dot head, and FIG. 3B is a plan view of the ink adhesion mechanism seen from the print end side. 51 is a wire, 52 is a wire guide that guides the vicinity of the printed end surface of the wire, 53 is a wire rear guide, and 50 is a wire 51 formed between the wire guide 52 and the wire rear guide, and guided by the wire guide 52. d shows a parts diagram (an example of the configuration) of the ink flow path configured to cross the
Shown below. 57 is an ink supply pipe, 58 is an ink supply pipe fixed to the ink supply pipe, and 67 is an ink discharge pipe fixed to the ink discharge pipe 74 (not shown in the drawing, but provided in the same way as the ink supply pipe). Pipe 59 is an ink supply port leading to ink supply pipe 57, and 60 is ink discharge pipe 7.
4, this ink supply port 59
The ink discharge ports 60 are arranged in a direction perpendicular to the wire row in the center of the seven wire arrays, and at substantially symmetrical positions with the wire row sandwiched therebetween. Furthermore, ink bypasses 61 and 62 are provided to connect the ink supply port 59 and the ink discharge port 60 so as to surround the wire row. The ink bypasses 61 and 62 are formed to have a larger width or depth than the ink flow path 50 configured to cross the wire 51 so that ink can easily flow therethrough. Further, the ink coming out of the ink supply port 59 does not directly flow into the ink flow path 50 configured to cross the wire 51, but instead flows into the ink bypass 61, 62 and the ink flow path 50 configured to cross the wire. The ink is configured so as to collide with a wall 66 of the flow path connecting the opening 59, and then branched into the ink flow path 50 configured to cross the ink bypasses 61, 62 and the wire 51.

Gap 6 between wire 51 and wire rear guide 53
3 is a gap 54 between the wire 51 and the wire guide 52
It is set larger than the wire so that the pulsating flow of ink escapes to the rear side of the wire.

56 is a scattered ink collection plate and wire rear guide 5
The wire guide section of No. 3 is arranged through a space 64 from the wire guide section of No. 3. Moreover, this scattered ink collection plate 56
is arranged so as to overlap the rear part of the wire rear guide 53, so that a capillary flow path 68 is formed in the overlapping surface. This capillary channel 68 and the ink discharge port 60
An ink recovery path 65 is provided to connect the two.

Wire guide 5 that guides the tip of the wire 51
A thin ink adjustment and collection groove 69 is provided on the most extreme surface of the wire guide 2, and a part of the groove is connected to the wire guide hole 82 of the wire guide 52. Further, the printed end surface of the wire 51 is waiting between the most extreme surface of the wire guide 52 and the bottom of the ink collection adjustment groove 69. 70 is a wire guide presser.

FIG. 3f shows how the wire guide 52 is connected to the ink flow path 50.
It is a plan view seen from the side. By providing ink supply grooves 80 and 84 having capillary action on the surfaces of the wire guide 52 and the wire rear guide 53 facing the ink flow path 50, the surface of the ink flow path 50 has
Grooves with capillary action are formed. Note that the ink supply grooves 80 and 84 are configured to draw ink in the direction of the wire 51.

The ink adhesion function and effects will be described in detail starting from the ink adhesion mechanism shown in FIG. 3, which shows a specific example of the present invention. First, ink is sent from the ink supply pipe 58,
The ink supply port 59 is reached. Then the ink is
Ink supply port 59 and ink bypass 61, 62
and an ink flow path 5 configured to cross the wire.
The ink flows into the ink bypass 61, 62 and the ink flow path 50 configured to cross the wire, and then reaches the ink discharge port 60. At this time, the main flow of ink flows into the ink bypasses 61 and 62, and the main flow of ink does not directly flow into the ink flow path 50 configured to cross the wire. In addition, since the ink flow path 50, which is configured to cross this wire, is configured as a narrow gap between the wire guide 52 and the wire rear guide 53, the ink is attracted by capillary attraction, and the ink is Bypass 61,6
The ink is also filled by static pressure when the ink flows through the ink. The ink held in the ink flow path 50 configured to cross this wire is further affected by the capillary action of the ink supply groove 80 and the outer diameter of the wire 51.
Due to the capillary action of the gap 54 between the wire guide hole 82 and the wire guide hole 82, the wire 51 is pulled up to the printed end surface (ink is also supplied to the tip when the wire is activated, as will be described later). This wire 5
The ink supplied to the vicinity of the printing end surface of the wire guide 52 enters an ink adjustment and collection groove 69 provided at the most extreme surface of the wire guide 52 and partially connected to the wire guide hole. The surface shape of the ink to be adhered to the printed end surface of the wire 51 is formed between the tip of the wire 51 located between the bottom of the ink adjustment collection groove 69 and the surface of the wire guide 52 and the guide hole of the wire guide 52. The wire 51 serves to ensure that a certain amount of ink always adheres to the printing end surface of the wire 51.

As an example of the supply of ink to the ink adhesion mechanism shown in FIG. 3, which shows a specific example of the present invention, a case will be described in which the ink is supplied by a pump. The flow of ink is as described above, and a method using a pump may include a method of intermittently or continuously feeding a required amount of ink into the ink adhesion mechanism. First, considering the case where ink is sent intermittently,
Naturally, the ink is sent in large pulsating streams. The ink sent to the ink supply port 59 in the form of a pulsating flow first hits the wall surface 66 of the flow path that communicates with the ink bypasses 61 and 62 and the ink flow path 50 configured to cross the wire, and then flows toward the ink bypasses 61 and 62, and only a slight pulsating flow of reduced pressure is transmitted to the ink flow path 50 configured to cross the wire. The effects of this pulsating flow can be prevented to some extent by using an ink-impregnated member, but as mentioned above,
It is difficult to stably deposit an appropriate amount of ink on the tip of the wire following the high-speed movement of the wire, and problems such as clogging of the ink-impregnating material are expected. Returning to the above explanation, it goes without saying that it is better to have no pulsating flow, even the slightest remaining. Third
In the figure, a wire guide 52 and a wire 5 on the front side of an ink flow path 50 configured to cross the wire are shown.
The gap 63 between the wire rear guide 53 and the wire 51 is made larger than the gap 54 between the wire rear guide 53 and the wire 51. With this configuration, the pressure of the pulsating flow that remains is difficult to be transmitted to the tip of the wire and escapes to the rear of the wire. Also, when observing the case where multiple wires are arranged as shown in Figure 3 b and c, it is found that ink flows backward through the gap between the wires according to the pulsating flow of the pump. You can clearly see them escaping. Connect this to the wire rear guide 5
When the gap 63 between the wire 3 and the wire 51 is made small, this phenomenon almost disappears, and a slight pulsating current is observed on the wire printing end face, causing problems such as slight uneven printing when printing is performed.

In the above explanation, the case where the pump that sends ink is operated intermittently was explained, but even when the pump is operated continuously and ink is continuously fed,
It is difficult to keep feeding a constant amount of ink all the time, and it is less than in the case of intermittent feeding, but
Pulsating current still occurs. However, according to the structure of the ink adhesion mechanism of the present invention described above, the pulsating flow of ink can be almost completely resolved.

In the above explanation, an example was given using a pump, but even if the method does not use a pump, if ink is forced into the ink adhesion mechanism, it is difficult to constantly send a constant amount of ink. It will be appreciated that better results can be expected with the method of the invention.

As mentioned above, the dynamic pressure of the ink sent into the ink supply port as a pulsating flow hits the wall, the main flow of the ink is released to the ink bypass, and the ink flow path is configured to cross the wire due to the static pressure and capillary action. By supplying ink to the wire 50, a large pulsating flow of ink can be prevented, and even a small amount of pulsating flow can be prevented from flowing between the front and rear of the ink flow path, which is configured to cross the wire through the gap between the guide hole and the wire. By changing this, it is possible to eliminate the pulsating current that appears on the printing end face, and to supply stable ink to the tip of the wire, thereby providing an ink adhesion mechanism with less uneven printing.

The ink supply port 5 is attached to the ink adhesion mechanism shown in FIG.
9 and the ink discharge port 60, even if ink is fed into the ink adhesion mechanism using a pump or the like, excess ink will pass from the ink supply port through the ink bypasses 61 and 62 and reach the ink discharge port 60. , there is no adverse effect on printing, and there is no adverse effect on the ink in the ink flow path 50 configured to cross the wire. In addition, the ink retention force of the ink flow path 50, which is configured to cross the wire, is configured so that it does not flow as easily as the ink bypass flow path, and is strong due to capillary attraction, so that excess ink within the ink adhesion mechanism is removed. Even if the ink is forcibly discharged from the discharge port 60 with a pump or the like, the ink in the ink flow path 50 configured to cross the wire will not be discharged, and a constant amount of ink will always be stably retained. Become.

Furthermore, by providing ink supply grooves 80 and 84 having capillary action on the surface of the ink flow path 50 so as to face the wire 51, the force with which the ink is drawn around the wire 51 is increased, and the responsiveness of the ink is improved. This has improved the printing process, making it possible to print at high speed and with clarity. In FIG. 3f, the ink supply grooves 80 are provided to correspond to the number of wires, but the shape and number are not limited to this. A similar effect can be obtained by having a groove formed so as to communicate with the guide hole 82.

Further, it is desirable that the shape of the ink supply grooves 80 and 84 is such that the bottom dimension is smaller than the surface dimension, such as a V-shape, so that the capillary action is strong.

FIG. 3g is a plan view of a wire guide 52 seen from the ink flow path 50 side, showing another embodiment of the present invention.
Around the wire guide hole 82, unevenness 83 having capillary action is provided by honing or the like. The operation and effect are similar to those of the ink supply groove 80.

FIG. 3h is a parts diagram of a wire rear guide 53 showing another embodiment of the present invention, in which unevenness 85 having capillary action is provided on the surface facing the ink flow path 50 by honing or the like. The operation and effect are similar to those of the ink supply groove 84.

Note that the surface structure of the ink flow path 50 may be provided on either side of the wire guide 52 or the wire rear guide 53, but as described above, the gap between the wire 51 and the guide hole is better on the wire guide 52. Since it is smaller than the wire rear guide 53, it is preferable to provide the ink supply groove 80 on the wire guide 52 side because the force for drawing ink toward the wire 51 will be stronger.

Here, the printing operation of the wire 51 and the ink adhesion effect of the ink adhesion mechanism will be explained. The printing standby state of the wire 51 is the state shown in FIG. The wire is pulled around the wire 51 by the capillary action of the groove 80, and is further pulled up through the gap 54 between the wire guide hole of the wire guide 52 and the wire 51 by the capillary attraction, and enters slightly beyond the most distal end surface of the wire guide 52. The printed end surface of the wire 51 is reached. Furthermore, the ink that has reached that point also enters the narrow ink adjustment and recovery groove 69 provided on the most distal surface of the wire guide and partially communicating with the guide hole due to the action of capillary attraction. In Fig. 3, for the purpose of explanation, the wires are provided to correspond to the number of wires, but the shape and number are not limited to this. If it has a groove, as mentioned above,
It goes without saying that the effects described later are the same.

When the wire 51 is actuated by a wire driving means as shown in FIG. 1, the ink adhered to the printed end surface of the wire as shown in FIG. The ink is transferred by impact contact with recording paper (not shown) and printing is performed.

As explained above, according to the present invention, a plurality of grooves are provided on the surface wall of the ink flow path formed by the wire guide and the wire rear guide.
The ink supplied to the ink flow path is attracted around the wire guided by the wire guide and is deposited on the tip of the wire by capillary action. Therefore, ink can be supplied to the tip of the wire without interruption, making it possible to perform high-speed printing and clear printing. In addition, the amount of ink supplied to the tip of the wire can be controlled by multiple grooves with capillary action, so a stable amount of ink can always be supplied.
It is possible to correct excess or deficiency in ink supply.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of a wire dot printer. A is a cross-sectional view thereof, and b is a diagram showing a wire arrangement. 1... Wire, 2... Nose, 5... Actuation plate,
6... Plunger, 7... Drive coil, 8...
Frame, 9... Yoke plate, 10... Spacer,
11... Operating plate holding lid, 12... Wire return spring, 13... Recording paper, 14... Ink ribbon, 1
5...Platen. FIG. 2 is a diagram showing an ink adhesion mechanism section showing one principle of the prior art. FIG. 3a is a diagram showing a standby state of the wire. b is a diagram showing a state in which the wire is driven; 21...Wire, 22...Wire tip guide,
22a...Front guide, 22b...Rear guide,
23... Ink impregnating material, 24... Ink supply pipe, 26... Recording paper, 27... Platen. FIG. 3 is a diagram showing a specific example of the present invention. a
is a sectional view of the ink adhesion mechanism seen from above the dot head, b is a plan view of the ink adhesion model seen from the print end side, c is a side sectional view of the ink adhesion mechanism, and d is a parts diagram showing an example of the configuration of the wire rear guide. , e is a model diagram when the wire is in operation, f is a plan view of the wire guide seen from the ink flow path side, g is a plan view of the wire guide showing another embodiment of the present invention seen from the ink flow path side, and h is a main view of the wire guide. FIG. 7 is a parts diagram of a wire rear guide showing another embodiment of the invention. 51... Wire, 52... Wire guide, 53
... Wire rear guide, 50 ... Ink channel configured to cross the wire, 54 ... Gap between wire guide and wire, 56 ... Ink collection plate, 5
7...Ink supply pipe, 58...Ink supply pipe, 59...Ink supply port, 60...Ink discharge port, 61, 62...Ink bypass, 64...Between the wire rear guide and the ink collection plate Space provided, 65... An ink recovery channel that connects the ink discharge port and the ink recovery plate, 66... A wall surface of the channel that connects the ink supply port, the ink bypass, and the ink channel configured to cross the wire, 67 ... Ink discharge pipe, 68 ... Capillary channel between ink collection plate and wire rear guide, 69 ... Ink adjustment collection groove, 70 ... Wire guide presser, 80, 84 ...
Ink supply groove, 82...Wire guide hole, 83,
85...Irregularities having capillary action.

Claims (1)

[Claims] 1. An ink adhesion mechanism for a wire dot printer head that prints by adhering ink to the tip of a wire, which includes a wire, a wire guide having a wire guide hole for positioning and guiding the vicinity of the printing end surface of the wire, and the wire guide. a wire rear guide provided at the rear of the wire, and an ink flow path provided between the wire guide and the wire rear guide for replenishing ink to the tip of the wire; An ink adhesion mechanism for a wire type dot printer head, characterized in that a plurality of grooves are provided on the surface of the ink flow path formed by the guide.