JPH0410062Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printer that forms dots by bringing a wire into contact with and separating from a recording medium to transfer ink held at the tip of the wire to the recording medium.

Conventionally, as shown in FIG. 1, a wire holding member 1 that is moved relative to a recording medium, a bearing 2 having a hole 2a provided at the tip end of this wire holding member 1, and this bearing 2 are provided. an ink reservoir 4 for storing ink 3 provided in the wire holding member 1 so as to communicate with the hole 2a of the bearing 2;
a and a wire 5 disposed in the ink reservoir 4 so as to be able to reciprocate in the direction of the recording medium; the wire 5 is brought into contact with and separated from the recording medium, and the ink 3 held at the tip of the wire 5 is transferred to the recording medium; A printer is known in which the bearing 2 has a flat front end surface.

In this printer, the ink 3 in the ink reservoir 4 is moved between the wire 5 and the hole 2a of the bearing 2 due to surface tension.
It oozes out from the gap with the wall and is supplied to the tip of the wire 5. The amount of ink 3 supplied to the tip of the wire 5 is determined approximately by the size of the gap between the wire 5 and the wall of the hole 2a of the bearing 2. For example, ink 3
If the tip end surface of the wire 5 is slightly behind the tip end surface of the bearing 2 as shown in FIG. is maintained, and the amount of ink 3a at the tip of the wire 5 in this case is appropriate. However, if the tip of the ink 3 protrudes outward from the tip of the bearing 2 as shown in FIG.
As shown in the figure, ink 3 is held at the tip of the wire 5 when the wire 5 moves toward the recording medium.
The amount of a is too large.

In conventional printers, the amount of ink supplied to the tip of the wire 5 is adjusted by the size of the gap between the wire 5 and the wall of the hole 2a of the bearing 2, and since the tip surface of the bearing 2 is flat, the wire 5 and hole 2 of bearing 2
When the gap with the wall a is larger than the reference value, the ink 3 protrudes from the tip end of the bearing 2 as shown in FIGS. 3 and 4, so the amount of ink 3a supplied to the tip of the wire 5 increases. There is a drawback that it is too much.

An object of the present invention is to provide a printer that can overcome the above-mentioned drawbacks.

The present invention is characterized in that the distal end of the bearing, which is disposed within the hole so that the wire can be reciprocated, protrudes from the distal end surface of the wire holding part and is formed in the shape of a dome or a truncated cone.

The present invention will be explained in detail below with reference to FIGS. 5 to 8.

In FIG. 5, reference numeral 6 indicates a platen, and a recording medium 7 such as paper is placed so as to be in contact with this platen 6. Wire holding member 8 faces this recording medium 7 and is spaced apart from it at a predetermined interval.
are arranged to be movable in the horizontal direction. A bearing 9 made of a hard material is provided at the tip of the wire holding member 8. This bearing 9 has a hole 9a formed therein as shown in FIG. Above bearing 9
The tip protrudes from the tip surface of the wire holding member 8 and is formed into a dome shape. An ink reservoir 10 is provided in the wire holding member 8 so as to communicate with the hole 9a of the bearing 9, and ink 11 is stored in the ink reservoir 10. In addition,
The ink reservoir 10 may be filled with an ink-impregnated member such as felt. A wire 12 is connected to the recording medium 7 in the hole 9a of the bearing 9 and the ink reservoir 10.
It is arranged so that it can move back and forth in the direction of.

The rear end of the wire 12 is fixed to the lower end of an armature 13 shaped like a leaf spring. The upper end of this armature 13 is fixed to a support 14. An electromagnet 15 is arranged near the middle part of the armature 13, and a permanent magnet 16 is placed in contact with the rear end of the iron core 15a of the electromagnet 15.
is located. Coil 15 of the electromagnet 15
b is connected to the image signal current supply circuit 17. When no current is supplied to the coil 15b, the armature 13 is attracted by the magnetic force of the iron core 15a magnetized by the permanent magnet 16 and is in contact with the tip of the iron core 15a. The electromagnet 15, permanent magnet 16 and support body 14 are held by a holder 18 fixed to the wire holding member 8.

The image signal current supply circuit 17 causes the coil 1 to
When the image signal current is supplied to the coil 15
The current flowing through b creates a magnetic field in the opposite direction to the magnetic field formed in the iron core 15a magnetized by the permanent magnet 16, thereby weakening the magnetic force acting on the armature 13. For this reason, iron core 15
The armature 13, which is in contact with the tip of the armature a, moves in the direction of the recording medium 7 due to its elastic force.
As the armature 13 moves, the wire 12 moves in the direction of the recording medium 7, that is, the arrow a in FIG.
direction and comes into contact with the recording medium 7. At this time, the ink 1 held at the tip of the wire 12
1a is transferred to the recording medium 7 to form ink dots.

Next, when the supply of image signal current to the coil 15b is cut off, the armature 13 is attracted by the magnetic force of the iron core 15a magnetized by the permanent magnet 16, moves, and comes into contact with the tip of the iron core 15a. As the armature 13 moves, the wire 12 also moves away from the recording medium 7 and stops with its tip located in the hole 9a of the bearing 9.

The ink 11 in the ink reservoir 10 is supplied to the wire 1
2 and the wall of the hole 9a of the bearing 9, it oozes out to the tip of the wire 12 due to surface tension. The amount of ink supplied to the tip of the wire 12 is determined approximately by the size of the gap between the wire 12 and the wall of the hole 9a of the bearing 9. If the gap between the wire 12 and the wall of the hole 9a of the bearing 9 is large, the ink coming out from the hole 9a to the front end of the bearing 9 will flow downward because the tip of the bearing 9 is formed in a dome shape. Therefore, wire 12
The amount of ink 11a supplied to the tip of is maintained at an appropriate value.

Note that the tip of the bearing 9 may be formed into a truncated cone shape. Further, as shown in FIG. 8, the tip of the bearing 9 may be formed into a truncated cone shape, and a liquid absorbing member 19 may be provided on the tip surface of the bearing 9. Furthermore, the distal end of the bearing 9 may be formed into a dome shape and the liquid absorbing member 19 may be provided on the distal end surface of the bearing 9.
When the liquid absorbing member 19 is provided on the tip surface of the bearing 9,
It is possible to more effectively prevent ink from protruding from the front end surface of the bearing 9 and accumulating due to surface tension.

While moving the wire holding member 8 in the horizontal direction with respect to the recording medium 7, the wire 1 is held against the recording medium 7.
After one line of recording is performed by selectively contacting and separating the wires 2 and 2, the wire holding member 8 is returned to the other end of the recording medium 7, and the recording medium 7 is moved upward or downward, and the above-mentioned procedure is again performed. Recording is performed in the same manner as described above, and by repeating this recording operation, recording is performed over the entire surface of the recording medium 7.

Note that a plurality of wires 12 may be arranged in the vertical direction on the wire holding member 8. Further, a plurality of wires 12 are attached to the wire holding member 8 over the entire width of the recording medium 7 in a direction perpendicular to the moving direction of the recording medium 7.
The recording medium 7 is arranged in a row or in a plurality of rows, and while the wire holding member 8 is stationary, the recording medium 7 is moved intermittently or continuously in a direction perpendicular to the row direction of the wires 12. However, the wires 12 may be selectively brought into contact and separated from each other. Furthermore, the wire driving means for reciprocating the wire 12 may be composed of a plunger type solenoid, a spring, or the like.

The printer of the present invention can supply an appropriate amount of ink to the tip of the wire even when the gap between the wire and the hole wall of the bearing is larger than a reference value.

[Brief explanation of the drawing]

Figures 1 to 4 are partially cutaway front views showing the main parts of a conventional printer, Figure 5 is a diagram showing the configuration of the printer of the present invention, and Figures 6 and 7 are main points of the printer of the present invention. FIG. 8 is a partially cutaway front view showing main parts of another embodiment of the printer of the present invention. 7... Recording medium, 8... Wire holding member, 9...
... Bearing, 9a... Hole, 10... Ink reservoir, 11
...ink, 12...wire, 13...armature, 15...electromagnet.

Claims (1)

[Scope of utility model registration request] A wire holding member that is moved relative to a recording medium, a bearing having a hole provided in the wire holding member, and an ink reservoir portion for storing ink provided in communication with the hole of the bearing. , a wire disposed in the bearing and the ink reservoir so as to be movable back and forth in the direction of the recording medium; and the wire is brought into contact with and separated from the recording medium to transfer the ink held at the tip of the wire to the recording medium. wire driving means, wherein the bearing has a tip end protruding from the front end surface of the wire holding member and is formed in a substantially dome shape or a substantially truncated cone shape.