JPH0684091B2 - Paper ejection mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a paper ejection mechanism, and more particularly, to a paper ejection for reciprocating a paper for overprinting a plurality of colors in a color printer using single-cut sheets. Regarding the mechanism.

[Prior Art] In a conventional paper discharge mechanism of a color printer, two rollers corresponding to the upper and lower sides sandwich the paper and feed the paper in the forward direction. However, when the next color is overprinted, the paper is reversed. It is retreating once. When the paper is retracted, the discharge roller has a reverse rotation prevention mechanism to prevent the discharged paper from being caught in the stacker. When the paper is retracted, the upper and lower two rollers have an opening / closing mechanism that is opened and closed by a drive source such as a solenoid. There is.

[Problems to be solved by the invention]

However, such a conventional paper discharge mechanism as described above requires a pair of upper and lower rollers, a driving source and a driving circuit for opening and closing, which causes a cost increase and a lack of reliability. .

[Means for solving problems]

In the paper discharge mechanism of the present invention, one side of the pair of upper and lower discharge rollers is removed and the remaining roller is a discharge roller having a rubber roller provided at a constant interval on the discharge roller shaft, and one of the paper guides provided above the discharge roller When the paper is running in the forward direction, the paper pressing piece is placed inside the outer circumference of the rubber roller so that the paper is ejected by generating frictional force between the paper and the rubber roller, and reverses when the paper is running in the reverse direction. The prevention mechanism prevents the frictional force from escaping from the outer peripheral surface of the rubber roller that has been stopped, and allows the paper to run smoothly in the reverse direction, preventing abnormal noise when the paper is running backwards, and wrapping the discharged paper in the stacker section. It is configured so that the prevention of functional disorders such as can be realized with an inexpensive configuration.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the present invention, and FIG.
It is an AA perspective view shown in a figure.

1 and 2, the platen 1 rotates in the forward direction during printing and in the reverse direction when the paper is retracted. The sheet driving rollers 2 and 3 are mounted in front of and behind the platen 1, and the sheet 7 runs without slack of the sheet 7. The paper 7 being printed is reciprocated back and forth above the stacker 5 by the discharge roller 4.

The paper guide 6 guides the paper 7 to the discharge roller 4, and the push rod 8 can be swung left and right by a center pin 9 provided on the paper guide 6. The push rod 8 pushes the paper 7 against the discharge roller 4 while the paper 7 is being fed in the forward direction, and therefore the rotation is blocked by the stopper 10.

The print head 11 is fixed to a head support 12 and can move up and down around a rotary hinge 13. During printing, the platen 1 is pressed by the pressure spring 14, and printing is performed on the paper 7 via the ink ribbon 15. When the paper 7 is run in the reverse direction, the solenoid 16 is driven counterclockwise and the print head
11 and Platen 1 are separated and Platen 1 is reversed.

Next, the push rod 8 which is a main component of the present invention
The operation of will be described.

When paper 7 is fed in the forward direction due to the start of printing operation,
The push rod 8 is pushed counterclockwise by the tip of the sheet 7 and rotates. When the push rod 8 is rotated by a certain amount, the movement of the push rod 8 is restricted by the stopper 10. At this time, the push rod 8 is positioned so as to fit into the discharge roller 4 and the paper 7
Is pressed against the discharge roller 4.

As a result, a frictional force is generated between the discharge roller 4 and the sheet 7 due to the stiffness of the sheet 7, and the sheet 7 is discharged in the forward direction.

Next, the paper 7 is retracted in the opposite direction to perform the overprinting of the second color. At this time, a reverse rotation preventing one-way clutch (not shown) is mounted on the shaft of the discharge roller 4 so that the discharged paper 7'is not caught, so the discharge roller 4 does not rotate in the reverse direction. When the paper 7 is retracted in the opposite direction, the push rod 8 rotates clockwise, the above-mentioned frictional force is removed, and the paper 7 can be fed smoothly.

〔The invention's effect〕

The paper discharge mechanism of the present invention generates a frictional force between the discharge roller and the paper by the push rod that is pushed and rotated by the paper while the paper is being fed in the forward direction, and normally discharges the paper in the stacker direction to perform overlapping printing. When the paper is fed in the reverse direction, the push rod rotates in the reverse direction by the paper, eliminating the force that presses the paper against the discharge roller and eliminating the frictional force, so that there is no abnormal noise in the paper in the reverse direction. Since the sheet can be smoothly fed, there is an effect that the sheet can be fed with an inexpensive structure.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, and FIG.
It is an AA perspective view shown in a figure. 1 ... Platen, 2, 3 ... Paper drive roller, 4 ... Ejection roller, 5 ... Stacker, 6 ... Paper guide, 7, 7 '
...... Paper, 8 ...... Push rod, 9 ...... Center pin,
10 …… Stopper, 11 …… Print head, 12 …… Head support, 13 …… Rotary hinge, 14 …… Pressure spring, 15…
… Ink ribbon, 16… Solenoid.

Claims (1)

[Claims] 1. A paper feeding mechanism for feeding paper in both forward and reverse directions to perform overprinting,
A discharge roller for discharging the printed paper to the paper stacker, and the paper is pressed in the forward direction while the paper is being discharged in the forward direction to generate a frictional force between the paper and the paper. And a push rod that rotates in forward and reverse directions depending on the sheet to be removed.