JPH06127044A - Serial impact printer - Google Patents

Abstract

PURPOSE:To provide a serial impact printer such that projections are easily provided to a platen and sharp printing can be performed by utilizing the projections. CONSTITUTION:Two rows of coil-shaped projections 22 are provided to the surface on the side of a printing head 2 of a platen 6. The projections 22 are constituted of springs each having a thickness slightly larger than the diameter of each of printing wires 24 and arranged so that the respective ridge parts of the springs correspond to the arrangement of the tip parts of the printing wires 24. That is, the ridge parts exposed from the surface of the platen 6 are so arranged as to serve as individual wire receiving parts 25 for the printing wires. Gap parts 26 are formed between the individual wire receiving parts 25 and the individual wire receiving parts protrude from the surface of the platen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial impact printer in which a print head runs along the surface of a print medium, and more particularly, an improvement of a platen which is arranged to face the print head with the print medium sandwiched therebetween. Regarding

[0002]

2. Description of the Related Art Conventionally, impact printers have been used for printing on a copy-type printing paper set of a large number of sheets of pressure-sensitive paper such as carbon paper. In such a method of use, it has been desired that a clear print can be performed on all the leaves of a large number (for example, about 10 sheets) of print paper.

However, in order to clearly print on a large number of copy-type printing sheets, there are the following two problems. One is a problem in that the printing paper of the uppermost layer is perforated when printing with a strong striking force in order to perform printing with sufficient density on the printing paper of the lowermost layer. Another problem is that the lower the printing paper is, the more dispersed the striking force is transmitted, so that the printed characters are easily blurred.

To solve these problems, for example, as shown in Japanese Patent Publication No. 56-41429, etc., an ultrasonic vibration oscillator is installed on a platen which is arranged so as to face the print head with a print sheet interposed therebetween. Techniques have been proposed for connecting and vibrating the platen at high frequencies.

[0005]

However, even in the apparatus disclosed in the above publication, although it is effective in increasing the print density, there is no effective effect in the other problem, and the lowermost layer is not effective. It was not possible to print clearly without blurring the printing paper.

As a countermeasure against this, a method of processing the platen surface facing the print head and providing a long plate-like projection extending in the lateral direction of the platen surface can be considered. However, in this case, although there is an advantage that the printing becomes clearer than in the conventional example, there is a problem that it takes a lot of time and labor to manufacture since the projection is formed by cutting the surface of the platen.

Further, if this protrusion is simply provided,
Depending on the shape of the protrusion, the striking force is not always concentrated enough, and it may not be possible to realize extremely clear printing.
The present invention solves the above-mentioned problems, and provides a serial impact printer in which it is easy to provide a protrusion on the platen, and moreover, it is possible to perform clear printing using this protrusion. To aim.

[0008]

In order to achieve this object, the invention of claim 1 includes a print head having a plurality of print wires and running along the surface of a print medium, and the print medium. A serial impact printer including a platen, which is arranged so as to face the print head and is capable of running in the same direction as the print head in synchronization with the print head, wherein the print wire is separate from the platen. A gist of a serial impact printer is characterized in that a wire receiving portion which is hit by is attached to the platen facing surface side of the platen corresponding to the printing wire.

According to a second aspect of the present invention, a print head having a plurality of print wires and running along the surface of the print medium is disposed so as to face the print head with the print medium sandwiched therebetween. A serial impact printer comprising: a platen capable of traveling in the same direction as the print head in synchronization with the print head, wherein a wire receiving portion that is hit by the print wire is provided on a surface of the platen facing the print head. SUMMARY OF THE INVENTION A gist of a serial impact printer is characterized in that it is provided so as to project toward the print head side corresponding to each of the print wires, and a gap portion is provided between each wire receiving portion.

Further, according to the invention of claim 3, a print head having a plurality of print wires and running along the surface of the print medium, is arranged to face the print head with the print medium sandwiched therebetween. A serial impact printer comprising: a platen capable of running in the same direction as the print head in synchronization with the print head, wherein a print wire separate from the platen is provided on a surface of the platen facing the print head. A wire receiving portion that is hit is attached, and further, each wire receiving portion is provided with an individual wire receiving portion that protrudes toward the print head side corresponding to each of the print wires,
A gist of a serial impact printer is characterized in that a gap portion is provided between each of the individual wire receiving portions.

[0011]

According to the invention of claim 1, since the wire receiving portion which receives the impact of the printing wire is attached to the surface of the platen facing the print head separately from the platen, it is compared with the conventional platen cut. Thus, the ease of forming the wire receiving portion and the degree of freedom in mounting are improved.

According to the second aspect of the present invention, wire receiving portions are provided so as to correspond to the respective print wires on the surface of the platen facing the print head, and the wire receiving portions are provided between the wire receiving portions. A gap is provided. Therefore, when the print wire hits the print medium, the print medium is sandwiched between the print wire and the wire receiving portion, and the striking force of the print wire is hardly dispersed, and the print wire and the individual print wires are not dispersed. Concentrated in an extremely small area between the opposing wire receiving portions, clear printing is performed at the position where the printing wire is hit.

Further, according to the invention of claim 3, claim 1
Also, since both of the configurations of claim 2 are provided, the wire receiving portion can be easily attached, and clear printing can be performed.

[0014]

Embodiments of the serial impact printer embodying the present invention will be described below with reference to the drawings. Figure 1
2 is a perspective view showing the vicinity of the print head and platen of the printer according to the first embodiment, FIG. 2 is a sectional view of the same, FIG. 3 is a front view of the platen, and FIG. 4 (a) is a projection provided on the platen surface. 4 is a plan view of the portion, FIG.
(C) is explanatory drawing which shows the side surface.

As shown in FIGS. 1 and 2, in the printer 1 of this embodiment, a print head 2 is mounted on a carriage 5 supported by a main guide shaft 3 and a sub guide shaft 4, so that a predetermined size is obtained. It is provided so as to reciprocate in the axial direction at a position facing the print surface of the print medium P at the print position. On the other hand, the platen 6 is connected to the frame 8 via the leaf spring 7.
Supported by the main guide shaft 9 together with the frame 8.
When the print head 2 is mounted on the carriage 11 supported by the sub guide shaft 10, the print medium P is sandwiched therebetween.
Is provided so as to be reciprocally movable in the axial direction at a position opposed to. The shafts 3, 4, 9 and 10 are arranged in parallel.

The carriage 5 on which the print head 2 is mounted and the carriage 11 on which the platen 6 is mounted are moored to the timing belts 12 and 13 at positions corresponding to each other. The timing belts 12 and 13 are stretched between drive rollers 15 and 16 of the same diameter fixed to a drive shaft 14 extending in a direction orthogonal to the main guide shafts 3 and 9, and rollers (not shown) corresponding to these. Has been done. This allows the print head 2 and the platen 6 to move in the same direction with the print head 2 and the platen 6 constantly facing each other. The drive shaft 14 is connected to a drive mechanism from a motor (not shown), and a pair of paper feed rollers 17a, 17b and 18a, 18b are provided upstream and downstream in the transport direction of the print medium P. There is.

The print head 2 includes a flexible substrate 19
Is connected, and print information from a control device (not shown) is sent to the print head 2 via the flexible substrate 19. The print head 2 is provided with a plurality of print units (not shown), and a print wire 24 (FIG. 4) for printing the print medium P on this print unit.
And a piezoelectric element for each print wire 24, and a motion transmission mechanism that magnifies the expansion / contraction displacement of this piezoelectric element and transmits it to the print wire.

As shown in the platen 6 in FIG. 3, a laminated piezoelectric element 20 is disposed on the surface of the leaf spring 7 opposite to the platen 6. The piezoelectric element 20 is configured to expand and contract in the direction of the platen 6 in response to the applied alternating voltage of several kHz from the ultrasonic flow region.

Further, as shown in FIG. 4, the surface 6a (platen surface) of the platen 6 on the print head 2 side has an outer diameter of about 1.3.
Two rows of mm-shaped coil-shaped protrusions (wire receiving portions) 22 are provided. The protrusion 22 is composed of a spring having a thickness (about 0.28 mm) slightly larger than the diameter of the print wire 24, and each mountain portion of the spring corresponds to the arrangement of the tip of the print wire 24. It is arranged like. That is, the mountain portion exposed from the platen surface is arranged to be the individual wire receiving portion 25 for each print wire 24. Therefore, a gap portion 26 of, for example, about 0.28 mm is formed between the individual wire receiving portions 25, and the individual wire receiving portion 25 is, for example, about 0.
13 mm protruding. Further, as shown in FIG. 5, the protrusion 22 is formed separately from the platen 6,
It is mounted in a fixing groove 28 formed on the platen surface and fixed with epoxy resin or the like.

The platen 6 is made of stainless steel or the like, while the protrusions 22 are made of a material harder than the platen 6, such as tungsten or ceramic zirconia, which has excellent durability. Is suitable. Further, the printer 1 is provided with a control circuit (not shown) that detects the amount and quality of the print medium P by a sensor (not shown), and determines whether or not to apply vibration to the platen 6 by this. There is. Then, for example, in the case where the print medium P is a multi-sheet set in which the next and subsequent sheets are carbon paper, it is determined that it is necessary to apply vibration to the platen 6, and a voltage is applied to the piezoelectric element 20. It is configured.

Next, the printing operation of the printer 1 thus constructed will be described with reference to FIGS. As shown in FIG. 2, the print medium P includes a pair of paper feed rollers 17a located upstream (lower side in the drawing) in the paper transport direction.
It is sent to a predetermined printing position by 17b. Then, the desired print wire 24 of the print head 2 prints by hitting the print medium P sent to the predetermined print position via the ink ribbon IR. As a result, during printing, the printing medium P is sandwiched by a large pressure in a small area between the tip of each printing wire 24 and the individual wire receiving portion 25. When the uppermost leaf of the print medium P is plain paper and the next leaf and below is carbon paper, the uppermost leaf is printed by the ink ribbon IR, but the following leaf and below is made of carbon by the impact force of the print head 2. A copy is available.

A control circuit (not shown) is used for printing.
When it is determined that the platen 6 needs to be vibrated, an AC voltage is applied to the piezoelectric element 20. As a result, the piezoelectric element 20 expands and contracts in the direction of the platen 6 and imparts vibration to the platen 6 via the plate spring 7.
The frequency of this vibration is appropriately set so that the vibration is applied once to several times while the print wire is in pressure contact with the print medium P.

On the other hand, the drive shaft 14 is rotated by a motor (not shown) in synchronization with the transmission of print information from a host computer (not shown), and the drive rollers 15 and 16 are rotated in accordance with the rotation. As a result, the carriage 5 having the print head 2 runs on the surface of the print medium P via the timing belt 12, and following this movement, the carriage 11 having the platen 6 causes the timing belt 13 to move.
It travels on the back surface of the print medium P via. The moving speeds are exactly the same because the drive rollers 15 and 16 have the same diameter. Therefore, while the platen 6 is vibrated by the piezoelectric element 20, the print head 2 runs along the surface of the print medium P. In synchronism with this, the print medium P is sandwiched and the rear surface of the print medium P is run. When the printing of one line is completed, the print medium P is conveyed by a predetermined length by the pair of paper feed rollers 18a and 18b located downstream (upper side in the figure) in the conveying direction.

As described above, in this embodiment, since the protrusion 22 is a coil-shaped member formed separately from the platen 6, it is only necessary to put the protrusion 22 in the fixing groove 28 and bond it. It has the remarkable feature that its formation is very simple. Further, since the gap portion 26 is provided between the individual wire receiving portions 25, the impact area is smaller than that of the gap portion 26.
Will be very small as specified in. Therefore, the striking force of the printing wire 24 is hardly dispersed and is concentrated on an extremely small area between each printing wire 24 and the individual wire receiving portion 25 facing it, and the striking position of the printing wire 24 is sharp. Printing is performed.

Further, since the vibrating force of the platen 6 is applied as necessary, clear printing quality can be obtained over the entire leaf of the print medium even when the print medium of a multi-sheet set is printed at the same time. Moreover, since the impact force of the print head 2 can be suppressed, noise during printing can be reduced. Further, by selectively vibrating the platen 6, it is possible to reduce the printing energy cost.

Next, the second embodiment will be described with reference to FIGS.
It will be described based on. The printer of this embodiment is the first
The present example is substantially different from the example in that the platen is not provided with a piezoelectric element and the configuration of the protrusions on the platen surface is substantially the same as the other points, and only the difference will be described in detail.
6 is a front view of the platen, FIG. 7 (a) is a plan view of the protrusion, FIG. 7 (b) is its cross section, and FIG. 7 (c) is its side view.

As shown in FIG. 6, a platen 31 having a substantially T shape.
The protrusions 32 are provided in two rows on the platen surface 31a at the tip of the. The protrusion 32 is a columnar member having a diameter of about 0.8 mm formed separately from the platen 31, and as shown in FIG. 7, the fixing groove 3 formed on the platen surface 31a.
It is mounted inside 3 and fixed with epoxy resin or the like. The upper side of the protrusion 32 is cut out so as to correspond to the print wire, and a large number of individual wire receiving portions 34 are formed, and gaps 35 are formed between the individual wire receiving portions 34. . As the material of the projection 32, cemented carbide can be used in addition to tungsten and ceramic zirconia.

With this structure, the same effect as that of the first embodiment can be obtained, and the projection 3 is formed by cutting the column.
Since 2 is formed, there is an advantage that it is strong and durable. Next, a third embodiment will be described with reference to FIG. The printer according to the present embodiment is substantially different from the printer according to the second embodiment in the configuration of the projecting portion on the platen surface, and is substantially the same as the printer according to the second embodiment, and only the difference will be described in detail. Note that FIG.
FIG. 8A is an explanatory view showing a disassembled state of the protrusion, and FIG. 8B is an explanatory view showing the assembled state.

As shown in FIG. 8, the projecting portion 42 comprises a base portion 43 and a spherical individual wire receiving portion 44. The individual wire receiving portion 44 is fitted into a fixing hole 45 provided in the base portion 43, and is made of resin or the like. Adhesive fixed. The protrusion 4
2 itself is fixed with resin in a fixing groove provided on a platen surface (not shown), or is directly joined to the platen surface by brazing or the like.

With such a structure, the same effects as those of the above-described respective embodiments can be obtained, and since the individual wire receiving portion 44 has a spherical shape, it is not necessary to cut and form the gap portion 46, and at the time of impact. The impact area is extremely small,
There is an advantage that the print quality is improved.

Next, a fourth embodiment will be described with reference to FIGS.
A description will be given based on 0. The printer according to the present embodiment is substantially different from the printer according to the third embodiment in the configuration of the projecting portion on the platen surface, and is substantially the same as the printer according to the third embodiment, and only the difference will be described in detail. In addition, FIG. 9A shows the disassembled state of the protrusion,
FIG. 9B is an explanatory diagram showing the assembled state,
FIG. 10 is a front view of the protrusion on the platen surface.

As shown in FIGS. 9 and 10, the projection 52 is plate-shaped, and a plate-shaped base member 53, a spherical individual wire receiving portion 54, and a plate-shaped guide member having a large number of guide holes 55 formed therein. And 56. The individual wire receiving portion 54 is
The head portion 54a is arranged so as to be exposed from the guide hole 55, sandwiched between the base portion 53 and the guide member 56, and fixed with resin or the like.

In particular, in this embodiment, as shown in FIG. 10, the individual wire receiving portions 54 are arranged in a diamond shape, and the guide member 56 is provided with guide holes 55 in a diamond shape in accordance with the arrangement. There is. The protrusion 52 itself is directly joined to the surface of the platen 57 with resin or the like.

With such a structure, the same effects as those of the above-described respective embodiments can be obtained, and the individual wire receiving portions 54 can be freely arranged and can be easily formed. Next, a fifth embodiment will be described with reference to FIGS. 11 and 12. The printer according to the present embodiment is substantially different from the printer according to the fourth embodiment in the configuration of the protrusions on the platen surface, and is substantially the same as the printer according to the fourth embodiment. Therefore, only the difference will be described in detail. Note that FIG. 11A is a front view of the protrusion, and FIG.
12A is a plan view thereof, FIG. 12A is a front view of the platen to which the protrusion is attached, and FIG. 12B is a side view thereof.

As shown in FIG. 11, the protrusion 62 is plate-shaped and comprises a plate-shaped base 63 and individual wire receiving portions 64 arranged in a diamond shape. The individual wire receiving portion 64 is a pin-shaped member, is fitted into a mounting hole 66 provided in the base portion 63 in a diamond shape, is fixed with resin or the like, and protrudes from the surface of the base portion 63.

Further, as shown in FIG. 12, the protrusion 62 itself is directly joined to the surface of the platen 67 with resin or the like. Even with such a configuration, the same effects as those of the above-described respective embodiments can be obtained, and since the individual wire receiving portion 64 has a pin shape and can be fitted into the mounting hole 66 of the base portion 63, its manufacture is easy. There are advantages.

The present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be implemented in various modes within the scope of the gist of the present invention.

[0038]

As described above, according to the invention of claim 1,
Since the wire receiving part that receives the impact of the printing wire is attached to the platen facing surface side of the platen separately from the platen, it is easier to form the wire receiving part as compared with the conventional platen that is cut. There is a remarkable effect that the degree of freedom in mounting is improved.

Further, according to the second aspect of the invention, the wire receiving portions are made to protrude from the surface of the platen facing the print head so as to correspond to the respective print wires, and a gap is provided between the wire receiving portions. Since it is provided, when printing, the striking force of the printing wire is hardly dispersed, it is concentrated in an extremely small area between each printing wire and the wire receiving part, and the striking position of the printing wire is extremely high. There is an advantage that clear printing is performed.

Further, according to the invention of claim 3, there is an effect that the wire receiving portion can be easily attached and extremely clear printing can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a serial impact printer according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the serial impact printer according to the first embodiment.

FIG. 3 is a front view showing the platen of the first embodiment.

FIG. 4 is an explanatory diagram showing a protrusion of the first embodiment.

FIG. 5 is an explanatory diagram showing a method of fixing the protrusion of the first embodiment.

FIG. 6 is a front view showing a platen according to a second embodiment.

FIG. 7 is an explanatory diagram showing a protrusion of the second embodiment.

FIG. 8 is an explanatory diagram showing a protrusion of the third embodiment.

FIG. 9 is an explanatory diagram showing a protrusion of the fourth embodiment.

FIG. 10 is a plan view showing a protrusion of a fourth embodiment.

FIG. 11 is an explanatory view showing a protrusion of the fifth embodiment,
11 (a) is a front view thereof, and FIG. 11 (b) is a plan view thereof.

FIG. 12 is an explanatory view showing a platen of a fifth embodiment, FIG. 12 (a) is its front view, and FIG. 12 (b) is its plan view.

[Explanation of symbols]

2 ... Print head 6, 31, 57 ... Platen 6a, 31a ... Platen surface 22, 32, 42, 5
2, 62 ... Projection portion 24 ... Printing wire 25, 34, 44, 54, 64 ... Individual wire receiving portion 26, 35, 46 ... Gap portion P ... Print medium

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akira Ninomiya 15-1 Naeshiro-cho, Mizuho-ku, Nagoya, Aichi Prefecture Brother Industries, Ltd.

Claims (3)

[Claims] 1. A print head having a plurality of print wires and running along the surface of a print medium, and a print head disposed opposite to the print head with the print medium sandwiched therebetween, in synchronization with the print head. A serial impact printer comprising: a platen capable of traveling in the same direction as the print head, wherein a wire receiving portion, which is separate from the platen, for receiving the impact of the print wire, is provided on a surface of the platen facing the print head. , A serial impact printer, which is attached corresponding to the printing wire. 2. A print head having a plurality of print wires and running along the surface of a print medium; and a print head disposed opposite to the print head with the print medium sandwiched therebetween, in synchronization with the print head. A serial impact printer comprising: a platen capable of traveling in the same direction as the print head, wherein a wire receiving portion that is hit by the print wire is provided on each of the print wires on a surface of the platen facing the print head. Correspondingly, the serial impact printer is characterized in that it is provided so as to project toward the print head side and a gap is provided between each wire receiving portion. 3. A print head having a plurality of print wires and running along the surface of a print medium; and a print head disposed opposite to the print head with the print medium sandwiched therebetween, in synchronization with the print head. A serial impact printer comprising: a platen capable of traveling in the same direction as the print head, wherein a wire receiving portion, which is separate from the platen, is formed on the surface of the platen facing the print head, the wire receiving portion being hit by the print wire. The wire receiving portion is provided with individual wire receiving portions protruding toward the print head side corresponding to the print wires, and a gap portion is provided between the individual wire receiving portions. A serial impact printer characterized by that.