JPS5913997B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device that prints characters on a print head onto printing paper on a platen via an ink ribbon.

The applicant has already proposed a printing device in which the distance between the print head and the platen is shortened in order to increase the printing speed.

In such a printing device, when the print head swings back to the neutral position after the printing impact operation is completed, the distance between the print head and the platen is short, so the printed characters cannot be observed or the characters may fall onto the platen. 1 when necessary to deal with malfunctions such as problems with the printer's printing paper equipment.
The above problem is solved by moving the 0 print head from the neutral position to a retracted position further away from the platen. In this way, when the print head swings back after the printing impact operation is completed, it can be selectively stopped at either the neutral position or the retracted position on the trajectory extension 15 of the swing return movement further away from the platen. In a printing device with a mechanism, the ink ribbon interposed between the platen and the print head must be at least a predetermined distance from the platen when the print head is in the retracted position, and the print head must be at least a predetermined distance away from the platen.
When in the upright position, it is required to be in a position advanced in the direction of the platen so as not to engage with the print head. An object of the present invention is to provide a printing device as described above, which is equipped with an ink ribbon position movement mechanism that moves the ink ribbon 25 forward or backward toward the platen in conjunction with the swinging movement of the print head. .

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic road view of an embodiment of the present invention, FIG. 2 is a schematic side view of an embodiment of the present invention, and FIG.
- ■ direction arrow view. As shown in Figure 1, the platen 5
A print head 8 and an ink ribbon cartridge 6 are arranged facing each other, and the ink ribbon T is held in a tensioned state by tying 35 knots at both ends of the cartridge 6, and is wound onto a ribbon spool (not shown) inside the cartridge 6. 9 is a lever for moving the ribbon.

An embodiment of the structure of the moving mechanism for the ribbon moving lever 9 will be described with reference to FIGS. 2 and 3. The printing head 8 facing the platen 5 on which the printing paper 22 is attached has a pair of bowl-shaped type foils 24, 241 with type groups 23, 23 around them.
Consisted of. Print head 8 is rotatably mounted on hammer bracket 10 and slidably in the vertical direction. Hammer bracket 10 is pivotally connected to support member 18 by shaft 21 (FIG. 3). This support member 18 is fixed to a carrier (not shown) that slides along the platen 5 (perpendicular to the drawing). The hammer bracket drive motor for printing impact operation installed on this carrier (
A fan-shaped gear 12 is connected to an output shaft 13 (not shown), and a gear 11 that meshes with this is connected to a shaft 21 on the hammer bracket side.
shared and fixed. The lever 9 for moving the ribbon is the shaft 19
is pivotally connected to the support member 18 by. This ribbon moving lever 9 is connected to a carrier 17 via links 15 and 16. A pivot shaft 20 connecting both links 15 and 16 also functions as a driven wheel of the cam mechanism, and is fitted into a cam groove 14 formed in the gear 11. Next, the operation of the printing device having the above configuration will be explained. Figure 2 shows the state of the print head 8 during printing, and the print head 8 is connected to the platen 5.
It is in contact with the side. Thereafter, in order to return the print head to its original position, a hammer bracket drive motor (not shown) rotates, causing the sector gear 12 and the gear 11 to rotate as indicated by arrows C and D. When the printing head 8 swings and rotates in the direction of arrow E about the shaft 21 (FIG. 3) as the gear 11 rotates and returns to its neutral position, the pivot 20 of the link 15 moves into the cam groove 14.
Reach part A of. At this time, if the cam groove 14 is formed on the circumference around the shaft 21, the position of the pivot shaft 20 will not change during the return from the printing impact position to the neutral position, and therefore the ribbon moving lever 9 will not be driven. When the sector gear 12 and the gear 11 further rotate in the directions of arrows C and D in order for the print head 8 to perform a retracting operation, the pivot shaft 20 of the link 15 moves from part A to part B within the cam groove 14. Therefore, the link 15 moves to the left in FIG. 2, so that the ribbon moving lever 9 rotates about the shaft 19 in the direction of arrow F. Therefore, the ink ribbon (not shown) stretched in front of the ribbon moving lever 9 (on the platen side) moves in a direction away from the platen due to its own tension as the ribbon moving lever 9 moves. That is, in FIG. 1, the print head is indicated by the dotted line 8? At the print position shown, the ink ribbon moves to the position shown by the dotted line 77/.The ribbon moving lever is at the forward position shown by the solid line, and when the print head is at the neutral position shown by the solid line, the ink ribbon moves to the position shown by the solid line 7. The ribbon moving lever remains at the forward position, and when the printing head further swings to the retracted position indicated by the dashed line 8', the ribbon moving lever moves to the rear position (away from the platen).
The ink ribbon reaches a point (indicated by a dashed-dotted line 9'), and at the same time, the ink ribbon also moves backward as shown by a dashed-dotted line 7/. As described above, by using the cam mechanism, the ink ribbon can be moved forward or backward in the direction of the platen in conjunction with the swinging movement of the print head, and when the print head is retracted, the ink ribbon is moved back to perform printing. Characters can be observed, printing paper can be inserted smoothly, and when the print head is in the neutral position, the ink ribbon can be advanced toward the platen and disconnected from the print head. Note that the drive mechanism for the ribbon moving lever is not limited to a cam mechanism; it may be directly linked to the movement of the hammer bracket and provided with a stopper to prevent it from coming into contact with the platen, or a hammer bracket drive motor may be used. It may also be linked to

Further, in order to ensure the movement of the ink ribbon, a vertical groove may be provided at the upper end of the ribbon moving lever, and the ink ribbon may be inserted into this vertical groove.

[Brief explanation of the drawing]

FIG. 1 is a schematic top view of an embodiment of the present invention, FIG. 2 is a schematic side view of the embodiment of the present invention, and FIG. 3 is a view taken along the - direction arrow in FIG. 5... Platen, 7... Ink ribbon, 8... Printing head, 9... Ribbon moving lever, 22... Printing paper .

Claims (1)

[Claims] 1. A print head equipped with a large number of characters and capable of swinging motion performs a printing impact operation against the printing paper on a platen via an ink ribbon, and when the print head swings back to the neutral position after this impact action is completed, Furthermore, in a printing device having a mechanism capable of selectively stopping the ink ribbon at either one of the retracted positions on the trajectory extension of the oscillating movement away from the platen, a ribbon moving lever is provided for moving the ink ribbon forward or backward toward the platen. The lever moves in conjunction with the swinging movement of the print head, so that when the print head is in a neutral position or in a printing impact operation, the lever is in an advanced position close to the platen, and when the print head is in a retracted position, it is in a retracted position away from the platen. A printing device characterized by: