JPH0111482Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a print position display mechanism for a printer.

FIG. 1 shows an overall schematic diagram of a wire dot printer. A platen 2 is rotatably supported by the frame 1, and is operated to change the line via a gear 3 by a line feed drive motor (not shown). Print media 4
is set on platen 2, and sprocket 5a,
Sent in 5b. Carrier 6 is guide shaft 7
and is guided by the feed screw 8. The feed screw 8 is rotated by a space motor 9 via a belt 10, and this rotation causes the carrier 6 to move onto the platen 2.
space is moved along. A print head 11 is mounted on the carrier 6. Print head 11
is provided with a plurality of printing wires and an electromagnetic mechanism for driving them, and the electromagnetic mechanism is selectively driven in synchronization with the movement of the carrier 6. The ink ribbon cassette 12 contains an ink ribbon 13, which runs between the print head 11 and the print medium 4.

The electromagnetic mechanism for driving the printing wire in the printing head 11 is generally of the open type and the attraction type. For example, in the open type, a permanent magnet and a coil-excited electromagnet are installed in the same magnetic path, and the amateur One end is held, and a printing wire is connected to the other end. Normally, the armature is bent and held by the magnetic attraction force of the permanent magnet, and when printing, the attraction force of the permanent magnet is interrupted by passing current through the coil.
It separates from the magnetic material due to the elastic force of the armature. This operation moves the printing wire toward the platen 2 and performs dot printing. When the current in the coil is cut off, the armature is attracted by the permanent magnet and the printing wire returns to its original position.

By the way, as an indicator for displaying the printing position on the platen, the conventional method of illuminating the platen with a slit or spot-shaped light,
One method is to display an indicator by attaching a transparent plastic indicator with a red line to the print head.

However, an optical system for light irradiation is required. must be installed in a space where the indicator will not collide with the indicator when the carrier is moved. Alternatively, there may be cases where it is difficult to install this method due to the structure of the device.

The present invention was devised in view of the above points, and is a printer that uses a print head to print on a platen supported by a platen shaft and a print medium set on the platen. The present invention provides a print display mechanism for a printer, characterized in that an indicator is rotatably mounted, and a latch is provided that is pressed by a spring against the notch groove that restricts rotation of the indicator.

Examples of the present invention will be described below.

FIG. 2 is a plan view of a printer in which an indicator 14 for displaying the printing position of the present invention is provided on the platen shaft, and FIG. 3 is an explanatory view of the main parts thereof.
is a cross-sectional view in the direction of the platen axis, and b and c are cross-sectional views in the direction perpendicular to the platen axis.

In Fig. 3, 14 is an indicator, 14' is a mark part of the indicator, 15 is a notch groove provided in the indicator 14, 16 is a latch that engages with the groove 15 to stop the rotation of the indicator 14, and 17 is a rotation of the latch 16. The fulcrum 18 is a spring that presses the latch 16 against the indicator 14, 19 is a platen shaft that rotates the platen, and 20 is an inner cover. The latch 16 is pressed against the indicator 14 by a spring 18 and engages a notch 15 in the indicator.

Since the indicator 14 is stopped by a latch 16, the indicator 14 does not rotate even if the platen 2 rotates.

Therefore, it is possible to display the printing position when inserting the slip.

As explained above, the printing position display mechanism of the present invention is achieved by attaching an indicator having a rotatable notch groove with approximately the same diameter as the platen to the platen shaft, and pressing a latch against the notch groove of the indicator to restrict rotation. , the printing position on the platen can be displayed with a simple mechanism.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the printer, FIG. 2 is a plan view of the printer of the present invention, and FIG. 3 is a diagram illustrating the main parts of the indicator section. 1... Frame, 2... Platen, 3... Gear, 4... Print medium, 6... Carrier, 7... Guide shaft, 8... Feed screw, 9... Space motor, 10... Belt, 11 ...print head,
12... Ink ribbon cassette, 13... Ink ribbon, 14... Indicator, 14'... Mark portion, 15... Notch groove, 16... Latch, 17
...Latch rotation fulcrum, 18...Spring, 1
9...Platen shaft, 20...Inner cover.

Claims (1)

[Claims for Utility Model Registration] A platen 2 rotatably supported by a frame 1 via a platen shaft 19, a print head 11 for printing on a print medium 4 set on the platen, and one end of the platen shaft. , a mark section 14' rotatably supported on the platen shaft and for indicating the printing position in the line feed direction.
A printing position display mechanism for a printer, comprising: a disc-shaped indicator 14 having a notch groove 15; and a latch 16 that engages with the notch groove of the indicator and prevents rotation with respect to the frame.