JPS5849196B2 - printer printing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing mechanism of a printer, such as a thermal printer or an electric discharge rupture printer, which has a prink head that slides in a pressed state against a platen and printing paper, and particularly relates to the shape of the platen.

FIG. 1 shows an example of a printing mechanism of a conventional printer, in which a printer head 1 is held by a printer head holder 3 and constitutes a printer head unit, and the printer head holder 3 is guided by a guide rod 6 and is By rotating the screw shaft 5 forward and backward, it reciprocates in both directions of arrows A and B.

Further, the feed screw shaft 5 is fitted into the frame 8, and the guide rod 6 is loosely fitted into the elongated hole 8-1 of the frame 8, freely rotating around the feed screw shaft 5, and is applied with force in the direction of arrow F by the elastic member 4. In response to this, the printer head 1 is pressed down against the platen 2 via the printing paper γ, and prints on the printing paper 7.

Here, in this type of mechanism, the platen 2 and the printer head 1 are always in a pressed state, so the pressing force greatly impedes the insertion of the printing paper 7 when the printer is in a standby (stopped) state, and can also cause paper jams. It had some drawbacks.

An object of the present invention is to create a gap between the platen supporting printing paper and the printer head by providing a convex portion on the platen at the position of the printer head in the standby (stopped) state of the printer. The purpose is to reduce the load when inserting printing paper in the (stopped) state and eliminate paper jams.

Another object of the present invention is to reduce the time it takes for the printer head to return to the standby position by consuming the inertial energy immediately before the printer head enters the standby state on a cam surface provided on the platen.

FIG. 2 shows the printing mechanism of the printer according to the present invention.

A convex portion 2-1 and an inclined cam 2-2 are provided in a portion of the platen 2 that does not face the printing paper 7.

Furthermore, in Figures 3 and 4, printer head 1 and platen 2 are shown.
, showing a cross-sectional view of the printer head holder 3 and the printing paper 1,
Convex portion 2- of printer head holder 3 facing platen 2
A chamfer 3-1 is provided at the corner on the 1 side.

The normal printing operation of the printing mechanism of such a printer will be explained with reference to FIGS. 2 and 3.

In FIG. 2, the printer head 1 is pressed against the platen 2 by an elastic member 4, and the printer head 1 is held by a printer head holder 3 to constitute a printer head unit, and the printer head holder 3 is a guide rod. 6 and driven by a motor (not shown) etc., the feed screw shaft 5 slides back and forth in both directions of arrows A1 and B, and the range of the reciprocating sliding is between C and C in FIG. do.

In Fig. 3, in the direction of arrow A or B, or in the direction of arrow A
, B Printing is performed on the printing paper 7 held between the platen 2 and the printer head 1 during reciprocating sliding in both directions, and the printable range is the reciprocating sliding range C' of the printer head printing section 1-1. be.

(c=c') Next, the operation of shifting from the normal printing operation to the standby (stop) state will be explained with reference to FIGS. 3 and 4.

In FIG. 3, it is assumed that the printer head holder 3 slides in the direction of arrow A and then enters a standby (stopped) state.

Figure 4 shows a cross-sectional view of the printing mechanism of the printer in the standby (stopped) state. In order to ensure the sliding range C', one drive of the reciprocating sliding is cut off after sliding the reciprocating sliding range C, so even if a means such as a stop control circuit is used for the motor of the drive source, D due to inertial energy. >C
becomes.

Therefore, by actively using inertial energy to move the printer head 1 or the printer head holder 3 onto the convex portion 2-1 via the inclined cam 2-2, the printer head 1 and the printing paper 7 are faced to each other. The printer head 1, which was in contact with the printing paper 7 in a pressed state, is separated from the printing paper 7 by widening the gap E between the printing paper 7 and the platen 2, thereby improving the ease of inserting the printing paper 7 in the standby (stopped) state. In addition, by consuming inertial energy, the stopping time for transitioning from the normal operating state to the standby (stopped) state can be shortened without using stopping distance control for the drive source.

Furthermore, this stopping time can be adjusted by the height of the convex portion 2-1 of the platen 2, the shape of the inclined cam 2-2, and the friction coefficient of the sliding portion.

The above is an example of the present invention, and the reciprocating movement of the print head is performed once.
It is not limited to the feed screw shaft 5 which is driven by forward and reverse rotation of the drive device, but also the helical grooves 9 that intersect as shown in FIG.
Even if the drive means always has the same reciprocating sliding range by using the feed screw shaft 9 which has a unidirectional rotation and reciprocatingly slides, the convex portion 2-1 of the platen 2 can be made longer. By widening the gap E between the platen 2 and the printer head 1 during paper feeding, this can be used to reduce the paper feeding load.

Furthermore, if the convex portions 2-1 of the platen 2 are provided at both ends of the platen 2 as shown in FIG. ), the object of the present invention can still be achieved.

As explained above, the present invention does not limit the feeding means of the printer head 1, the number, location, and shape of the convex portions 2-1 of the platen 2, the mounting position of the elastic member 4, etc.

As explained above, the present invention is designed to release the pressing force between the printer head and the platen that holds the printing paper while the printer is in the standby (stopped) state by the reciprocating sliding movement of the printer head unit. This has the advantages of improving the ease of inserting printing paper, shortening the time the printer is stopped from operating, and having an extremely simple structure.

[Brief explanation of the drawing]

FIG. 1 is an example of a printing mechanism of a conventional printer, FIG. 2 is an example of a printing mechanism of a printer according to the present invention, and FIGS. 3 and 4 are cross-sectional views of the vicinity of the platen according to the present invention. . 1... Printer head (constituting printer head holder 3 and printer head unit), 2...
...Platen, 2-1...Protrusion, 2-2...
... Slope cam 3 ... Print head holder, 4 ... Elastic member, 5 ... Feed screw shaft, 6 ... Guide rod, 7 ... ...Printing paper, 8.
·····flame. FIG. 5 is a perspective view showing another embodiment of the platen according to the present invention. FIG. 6 is a plan view showing another embodiment of the printing mechanism of the printer according to the present invention.

Claims (1)

[Scope of Claims] 1. A holder on which the print head is mounted in a printer that prints on recording paper by moving the print head back and forth along a platen and pressing the print head against the platen at least during printing; and the holder. a recording paper located between the print head and the platen; and a recording paper that presses the recording paper while the print head moves in a digit direction when the printer is driven. and a cam surface that releases the pressure of the print head in the printing direction via the recording paper and releases the connection between the print surface and the print head when the printer is on standby. A printing mechanism for a printer, comprising: a platen; and a spring member that biases the holding body to press the print head toward the platen.