JPS63441Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a wire dot printer.

BACKGROUND OF THE INVENTION As is well known, the print head of a wire dot printer is equipped with a plurality of print wires that are moved forward and backward at high speed by an electromagnetic drive. In general, in wire dot printers, the printing wire is driven at high speed in very short cycles, so compared to other types of printers such as type wheel type or type ball type, the gap between the print head and the platen (this gap (when the recording medium is inserted) is set much smaller.

On the other hand, in this type of printer, stacked sheets are sometimes used as a recording medium, for example, when issuing a slip. This stacked paper is made by stacking a plurality of sheets of non-carbon paper, for example, and the edges on both sides are bound with fasteners so as not to shift. The fastener part is approximately twice as thick as the other part (marked area).

The printing head is scanned from side to side by a pulse motor or the like, but this type of pulse motor has uneven speed when started. For this reason, in this technical field, a run-up section of the printing head is often provided so that the printing operation is started from a position where the rotation of the pulse motor is stable. In such a case, the home position of the printing head (a position shifted to the left by the run-up section from the printing start position) is a position that approximately corresponds to the fastener of the printing paper. Therefore, when the print head is in the home position, the frictional load on the fastener of the paper inserted into the narrow gap between the platen and the print head becomes large.
This sometimes caused jamming of the printing paper and poor paper feeding.

Purpose of the invention The purpose of the invention is to ensure smooth head scanning and to prevent jamming of the printing paper when using copy printing paper for simultaneous printing on multiple sheets.

Means for Achieving the Object In order to achieve the above object, in the present invention, a recess is provided in the front surface of the platen at least at a position where the fastener portion of the left edge portion faces.

Embodiments Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

In FIG. 1, a well-known wire dot type printing head 4 is mounted on a carriage 3 which is slidably supported by two guide shafts 1 and 2. A paper guide 5 is attached to the front of the print head 4.
Furthermore, a guide pulley 6 is rotatably attached. An ink ribbon 8 is wound around a guide pulley 6, a guide pulley 7 rotatably mounted on a carriage 3, and the front end surface of the print head 4. In front of the print head 4, there is a platen 9 in the form of an elongated prismatic column with a slight gap between the front end surface and the print head 4.
is installed, and the printing paper 10 is fed upward through this narrow gap.

The printing paper 10 is, for example, a copy printing paper made by stacking multiple sheets of non-carbon paper, and usually such printing paper has paper in the middle of the perforation 11, as shown in FIGS. 3 and 4. A fastener 12 is formed to prevent displacement, and this fastener portion is approximately twice as thick as the other portions. The position of this fastener 12 is the home position of the printing head 4 (a position shifted to the left by the run-up section from the printing start position, that is, the position shown in the first figure).
The position approximately corresponds to .

Therefore, in the present invention, a recess 13 is formed in the front surface of the platen 9 at a position corresponding to the home position of the print head 4, in other words, at a position corresponding to the fastener 12 of the paper 10, as shown in the first figure. be. Therefore, during paper feeding, the fastener 12 of the paper 10 passes through a gap that is locally widened by the recess 13.

Effects of the Invention According to the wire dot printer of the present invention described above, the fastener 12 is not strongly pinched between the platen 9 and the front surface of the print head 4 even when the print head 4 is located at the home position. . For this reason, jamming of the printing paper 10 and poor paper feeding will not occur, and the printing head 4 can be smoothly moved from the home position.

Note that the recess 13 is formed by at least the left fastener 1 of the printing paper 10 because the print head 4 is not normally moved to the right fastener.
The above effects can be sufficiently achieved simply by providing the parts at positions corresponding to the second part.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention,
FIG. 1 is a plan view thereof, FIG. 2 is a sectional view of the main part of the platen, FIG. 3 is a front view of the main part of the overlapping printing paper, and FIG. 4 is a sectional view taken along the line of FIG. 3. 4...Print head, 9...Platen, 10...
Printing paper, 12...fastener, 13... recess.

Claims (1)

[Claims for Utility Model Registration] In a wire dot printer consisting of a wire dot type print head that scans from side to side and a platen arranged opposite to this print head, a gap between the print head and the platen. When the printing medium to be inserted into the platen is for simultaneous printing of multiple sheets stacked on top of each other and bound by fasteners at both side edges, at least the left side edge is attached to the front surface of the platen. A recess is provided at a position where the fastener portions of the parts face each other. A wire dot printer characterized by: