JPH034532Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an improvement of a serial printer using a bail roller.

In serial printers, it is difficult to print high quality unless the printing paper is in close contact with the platen. Therefore, a method is used in which a bail roller that can move forward and backward toward the platen is used to bring the printing paper into close contact with the platen. Generally adopted. In this case, the bail roller is retracted from the platen until the set printing paper passes the bail roller, and then moves toward the platen to press the printing paper against the platen surface and bring it into close contact.

[Conventional technology]

The main parts of this type of conventional serial printer are explained in the third section.
As shown in the figure. In the figure, 1 is a platen, 2 is a paper guide, 3 is a top cover, and 4 is a bail roller drive mechanism. The bail roller drive mechanism 4 includes a bail lever 6 that is rotatably supported by a support shaft 5, a bail roller 7 that is rotatably supported by the bail lever 6, and a spring that biases the bail lever 6 in the direction of the arrow. (force means) 8 and an electromagnetic mechanism (drive means) 9 connected to the bail lever 6.

Next, the procedure for setting printing paper in this printer will be explained.

When the leading edge of printing paper 11, which is transported in the direction of arrow A by a paper feeding device such as sprocket 10, reaches paper passage sensor (detection means) 12, sensor 12 detects this and activates electromagnetic mechanism 9. Then, the plunger 9a of the electromagnetic mechanism 9 moves in the direction of arrow B, which causes the bail lever 6 to rotate counterclockwise against the biasing force of the spring 8, and the bail roller 7, which was in pressure contact with the platen 1, Evacuate from platen 1. Then print paper 1
1 is subsequently transferred and guided by the paper guide 2 and enters between the paper guide 2 and the platen 1, and the platen 1 rotates in the clockwise direction shown by the arrow, and the pressure roller 13a presses against the platen 1.
13b. When the printing paper 11 is transferred a predetermined amount after being detected by the sensor 12 and its leading edge passes the bail roller 7, the electromagnetic mechanism 9 stops operating, and the bail lever 6 returns to its original position by the biasing force of the spring 8. A bail roller 7 brings the printing paper 11 into close contact with the platen 1.

These operations are automatically performed simply by pressing the paper set switch, and printing on the printing paper 11 thus set is performed by a printing means such as a printing head (not shown). The printing paper 11 is moved to the platen 1 every time one line of printing is completed.
After the specified printing is completed, the cut edge 14 of the top cover 3 is
is cut at a predetermined position.

[Problem that the invention attempts to solve]

As mentioned above, conventional automatic paper setting involves returning the bail lever and letting the bail roller bring the printing paper into close contact with the printer (bail roller closed). It is desirable that the printing start position be located at the cutter edge of the print head.

However, if the printing paper is transported until the leading edge reaches the paper cut position without being held down by the bail roller, the leading edge of the printing paper hits the top cover, causing a transport failure. In addition, to solve this problem, it is possible to transport the printing paper to such an extent that the leading edge does not hit the top cover and then close the bail roller. This is not a good idea as it requires adjustment work to transport the paper until it reaches the paper cut position.

[Means for solving problems]

The purpose of the present invention is to provide a printing paper setting mechanism that can solve the above-mentioned problems.As a means for this purpose, the printing paper that is supplied when setting the paper is transported and set, and the set printing paper is A paper feeding mechanism that feeds paper into a new line when printing, a bail roller that is energized by an energizing means and presses against the platen to bring the printing paper into close contact with the platen, and a leading end of the printing paper that is fed toward the platen when paper is set. a detecting means for detecting the bail roller at a predetermined position; a driving means that operates for a predetermined period of time in response to a detection signal from the detecting means to retract the bail roller from the platen against the urging force of the urging means; In a serial printer equipped with a top cover equipped with a cutter edge for cutting paper, the drive means stops operating when the print paper is set when the leading edge of the print paper reaches between the bail roller and the cutter edge, and the drive means stops the paper feed. The mechanism is then configured to rotate again until the leading edge of the printing paper reaches the cutting edge.

[Effect]

By adopting the above configuration, the leading edge of the printing paper fed when paper is set passes the bail roller which has been retracted from the platen, and is brought into close contact with the platen by the bail roller.Then, the leading edge of the printing paper is brought into close contact with the platen by the platen which continues to rotate. It is moved until it reaches the print position and is set at the print start position.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is an explanatory diagram of the operation of the serial printer according to the present invention, in which 21 is a bail roller and 22 is a printing head. Note that the same reference numerals are given to members having the same configuration as the conventional one.

The bail roller 21 is rotatably supported at the tip of a bail lever 23 whose base is rotatably supported by a support shaft, and the bail lever 23 is connected to an electromagnetic mechanism as in the past, although detailed illustrations are omitted. and is biased clockwise by a spring. When paper is not set, the bail roller 21 is in pressure contact with the platen 1.

When the paper set switch is pressed during paper setting, the printing paper is fed toward the platen 1 and the platen 1 starts rotating. When the leading edge of the printing paper 11 fed toward the platen 1 reaches the paper passage sensor 12, the sensor 1
2 detects this and activates the electromagnetic mechanism. As a result, the bail lever 23 rotates counterclockwise against the biasing force of the spring, and the bail roller 21, which was in pressure contact with the platen 1, retreats from the platen 1. Thereafter, the printing paper 11 is continuously transported and guided by the paper guide 2 and enters between the paper guide 2 and the platen 1, and then the platen 1 rotates clockwise and a pressure roller (not shown) presses against the platen 1. transported between.
After the leading edge of the printing paper 11 is detected by the sensor 12, the printing paper 11 is transferred by a predetermined amount and when the leading edge reaches the position shown in FIG. . As a result, the bail lever 23 returns to its original position as shown by the chain line in FIG. The platen 1 starts rotating again after a predetermined period of time has elapsed, and stops when the leading edge of the printing paper 11 being transported thereby reaches the cutting edge 14.

The above operation is automatically performed by simply pressing the paper set switch, and the printing paper 11 is set at the printing start position where the leading edge is located at the cutter edge 14. In this case, however, the bail roller 21 that has been retracted from the platen is The leading edge of the printing paper is connected to the bail roller 2.
1 and cutter edge 14, move forward and press the printing paper against the stopped platen 1, then rotate the platen 1 again to transfer the printing paper again, position it at the printing start position, and set it. Because it is curved, it is possible to solve the conventional problem of the leading edge of the printing paper hitting the top cover.

Figure 2 is a time chart showing the above operation in comparison with the conventional one, and Figure 2 a shows the conventional one and the second one.
Figure b shows the invention.

[Effect of idea]

As described above, according to the present invention, it is possible to automatically set the printing paper, and it also solves the conventional problem of the leading edge of the printing paper hitting the top cover and causing transport failure. Is possible.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the serial printer according to the present invention. Figure 1 is an explanatory diagram of the operation of the serial printer, and Figures 2 a and b are comparative explanations of the operation of each part of the present invention with the conventional one. This is a time chart. FIG. 3 is a side view of essential parts of an example of a conventional serial printer. In the figure, 1 is a platen, 2 is a paper guide, 3 is a top cover, 8 is a spring (energizing means), 9 is an electromagnetic mechanism (driving means), 11 is printing paper, 12
14 is a cutter edge, 21 is a bail roller, 22 is a print head,
23 is a bail lever.

Claims (1)

[Scope of Utility Model Registration Claim] A paper feeding mechanism that transports and sets the supplied printing paper and feeds the set printing paper into a new line when printing, and a paper feed mechanism that is activated by an activation means to press the printing paper against the platen and press the printing paper against the platen. a bail roller brought into close contact with the platen; a detection means for detecting the leading end of the printing paper fed towards the platen at a predetermined position when paper is set; A printing paper set for setting printing paper in a serial printer comprising a driving means for retracting the printing paper from the platen against the urging force of the pushing means, and a top cover having a cutter edge for cutting the printing paper at an end thereof. When the printing paper setting switch is operated, the driving means temporarily stops operating when the leading edge of the printing paper reaches between the bail roller and the cutter edge, and the paper feeding mechanism then stops operating. A serial printer characterized in that the printer is configured to rotate again until the leading edge of the printing paper reaches the cutting edge.