JPS6354553B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer that can perform two operations, head feeding and paper feeding, with a single drive source.

The basic mechanism of a conventional serial printer is shown in FIG. In Fig. 1, 1 is a print head, 2 is a drive source for horizontal head feed, 3 is a printing paper, 4 is a drive source for paper feed, and 5 is a platen. Printing is performed on printing paper 3 while being fed in the left and right direction by source 2,
After printing one line, the paper feeding drive source 4 rotates the platen 5 to feed the printing paper 3, completing one cycle of operation. Therefore, one operating cycle requires two
This method has the disadvantage that two drive sources are required, and the control circuits for those drive sources are also complicated.

Furthermore, Japanese Patent Application Laid-open No. 48-95128 discloses that a solenoid clutch and a differential gear mechanism are used to select a combination of gears so that the printing head reciprocates from side to side and the printing paper can be fed in one continuous dot feed or in rapid feed. A high speed printer configured as shown in FIG. The print head is moved by a cylindrical cam or drive shaft, and the print paper with a manual paper feed knob is fed by a pin feed unit or paper feed drive shaft, which is connected to the same drive source by a gear train, and the print head is moved by a gear train. Moves and feeds printing paper.

However, it requires a large number of complicated parts, such as a solenoid clutch and a differential gear mechanism, and in addition, manual feeding of printing paper requires complicated and heavy operations such as a solenoid clutch, a differential gear mechanism, and a gear train. I will let you do it.

It is an object of the present invention to eliminate these drawbacks and, in particular, to provide a printer equipped with a mechanism for manually feeding printing paper with good operability.

FIG. 2 shows an embodiment of the present invention, in which 6 is a drive source, 7 is a lead screw shaft, 1 is a print head, 8 is a reduction gear, 9 is a deformation gear, 10 is a platen gear, 5 is a platen, 3 is a printing paper, 11 is a detent spring, and 12 is a manual paper feed knob.

To operate this, first the drive source 6 is driven to rotate the lead screw shaft 7.
The lead screw shaft 7 has a screw groove in a closed loop, and if the drive source 6 is rotated in one direction, the print head 1 is caused to repeat horizontal reciprocating motion.

The rotation speed of the lead screw shaft 7 is controlled by the gear at the end of the shaft and the reduction gear 8.
The deceleration gear 8 is decelerated at a gear ratio such that the deceleration gear 8 rotates once during the stroke of one line of printing, and the rotation is changed to the deformation gear 9.
to communicate. The deformation gear 9 meshes with the platen gear 10 to rotate the platen 5, but the deformation gear 9 has only a partial number of teeth so as to rotate the platen 5 by the angle necessary for line feed. Print head 1
During printing, the deformation gear 9 and the platen gear 10 do not mesh with each other, but when the printing head 1 finishes printing and reaches the end of the printing paper, both gears mesh, and a line feed is performed for each line printed. The above operations allow the print head to be fed laterally and the print paper to be fed.Additionally, there are a detent spring 11 and a manual paper feed knob 12 as auxiliary mechanisms that assist in the above operations. The detent spring 11 is used as a pawl for stopping the platen gear 10 in order to prevent the platen 5 from freely rotating due to the tension of the printing paper 3, etc., and at the same time to prevent misalignment between the deformation gear 9 and the platen gear 10. It is being Manual paper feed knob 12
is provided so that the printing paper 3 can be replaced and continuous paper can be fed even when the drive source 6 is stopped. However, the operation of the manual paper feed knob 12 is easy when the deformation gear 9 and the platen gear 10 are not engaged, but if the gears happen to be engaged, a large load is applied and the operation becomes difficult. To avoid this, between the reduction gear 8 and the deformation gear 9,
A square claw kamiai clutch is provided for the kamiai.

FIG. 3 is an explanatory diagram of the Kami-eye clutch mechanism, in which 13 is a square pawl of a reduction gear, 14 is a square pawl of a deformation gear, 9 is a deformation gear, and 10 is a platen gear.
Power from the drive source is transmitted to the platen gear 10.
When attempting to turn the gear in the direction of the arrow, the square pawl 13 of the reduction gear presses against the square pawl 14 of the deformation gear, as shown in FIG. 3A. If it becomes necessary to turn the manual paper feed knob when the deformation gear 9 and the platen gear 10 are engaged as shown in FIG. By this amount, the deformable gear 9 rotates out of the meshing state, and the manual paper feed knob can be easily operated.

That is, when the printing head 1 reaches the edge of the printing paper, the deformation gear 9 and the platen gear 10 mesh with each other.
The state shown in FIG. 3A is reached. If you try to feed the paper in this state, turn the manual paper feed knob 12 and turn the platen gear in the direction of the arrow.
The screws rotate and come out of the meshed state, resulting in the state shown in FIG. 3A. In this state, as is clear from FIG. 2, the platen gear 10 only engages with the detent spring 11, and the manual paper feed knob 12 can be turned smoothly.

Furthermore, when the printing head 1 stops at a position other than the edge of the printing paper, the deformation gear 9 and the platen gear 10 do not mesh with each other, resulting in a situation similar to that shown in FIG. I can do it.

Note that the deformation gear 9 and the platen gear 10 are just examples for explanation, and parallel shaft gears such as helical gears and helical gears can be used.

As explained above, the present invention moves the print head and feeds the print paper having a manual paper feed knob by using the same drive source connected by a square claw eye clutch or a deformed gear. The simple structure makes it possible to reduce the number of parts, and in particular, the cooperative action of the square claw clutch and the deformable gear makes it possible to obtain a mechanism for manually feeding printing paper with good operability.

[Brief explanation of drawings]

FIG. 1 is a basic structural diagram of a conventional serial printer device, and FIG. 2 is an explanatory diagram of a mechanism of an embodiment of the present invention.
FIG. 3 is an explanatory diagram of the operation of the square claw kami-eye clutch with play. 1...Print head, 2...Drive source for horizontal head feed, 3...Print paper, 4...Drive source for paper feed, 5...
...Platen, 6... Drive source, 7... Lead screw shaft, 8... Reduction gear, 9... Deformation gear, 10... Platen gear, 11... Detent spring, 12... Manual paper feed knob, 13 …
...Square claw of reduction gear, 14...Square claw of deformed gear.

Claims (1)

[Scope of Claims] 1. In a serial printer in which a print paper feeding means having a manual paper feed knob and a print head moving means are connected to the same drive source by a gear train, the feeding means is provided with a manual paper feed knob. The moving means consists of a parallel shaft gear provided integrally with the platen, and a detent spring that presses the tooth groove of the parallel shaft gear to prevent free rotation of the platen.The moving means is a drive that rotates in one direction. and a lead screw shaft that is connected to the drive source and that moves the print head back and forth along the platen using a screw groove formed in a closed loop, and a gear train that reduces the rotation of the lead screw shaft. The gear, the first square pawl provided integrally with the reduction gear, and the parallel shaft gear are provided with partial teeth that do not mesh with each other while the printing head is printing, but that mesh with each other when the printing head reaches the edge of the printing paper. deformed gear and
It is provided integrally with the deformed gear and is engaged with the first square pawl by rotating the lead screw shaft in one direction or by rotating the manual paper feed knob in the printing paper feeding direction to release the engagement. A serial printer comprising a second square claw provided with play.