JPH0734693Y2 - Ribbon guide mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Utilization of the Invention] The present invention relates to an impact printer using an endless ink ribbon.

[Background of the invention]

In general, an impact printer that uses an endless ink ribbon with a width of 1 inch (hereinafter referred to as ink ribbon) extends the life of the ink ribbon by skewing the ink ribbon with respect to the hammer bank and expanding the area of the ink ribbon passing in front of the hammer bank. ing. Therefore, the left and right ribbon guides that support the skewed ink ribbon are subjected to upward or downward force parallel to the ink ribbon traveling surface from the ink ribbon during traveling. In order to offset this force, the ink ribbon running surface of the ribbon guide has a structure with a certain inclination. However, due to changes in the running state of the ink ribbon that change due to changes in the printing mode during printing, and wear on the running surface, ribbon guides with a certain angle of inclination cannot handle this, and the ink ribbon is biased upward or downward during running. Extending, touching the frame or case, foldback occurs at the top or bottom. For this reason, the foldability of the ink ribbon changes at the upper end and the lower end, resulting in poor folding, resulting in an ink ribbon jam.

[Purpose of device]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, stabilize the operation of this type of printer, improve the reliability of the product, and improve the maintainability.

[Outline of device]

The present invention cuts a cone in a plane parallel to the bottom surface, and when the center of the circle of the bottom surface and the top surface is deviated, that is, when the ribbon guide in the shape of a truncated cone is rotated, the angle between the bottom surface and the side surface that is the ribbon feeding surface is changed. Focusing on the point of continuous change, the ribbon guide is rotated in response to a signal from the ribbon sensor that has detected the deviation of the ink ribbon, and the contact angle of the ink ribbon is changed by changing the contact angle between the ribbon guide and the ink ribbon. The relationship between the ink ribbon, the ribbon sensor, and the ribbon guide is devised so that the feeding position can be corrected and further controlled.

[Example of device]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an ink ribbon running system of a commonly used impact printer. FIG. 2 is a right side view of the ribbon guide mechanism portion which best shows the features of the present invention. FIG. 3 is a perspective view of the ribbon guide, FIG. 4 shows the relationship of the force that the ink ribbon receives from the running surface of the ribbon guide, and FIG. 5 is a control block diagram of the ribbon guide drive motor. In FIG. 2, the ribbon guide 15
0 is directly connected to the gear 180 via the shaft 170, and is linked with the rotation of the drive motor 200 through the gear 190 connected to the drive motor 200. The ribbon guide 150 has a shape as shown in FIG.
As shown in the figure, by interlocking with the drive motor 200, the angle θ between the bottom surface of the ribbon guide 150 and the ribbon traveling surface can be changed steplessly. The relationship between the force that the ink ribbon 10 receives from the ribbon drive rollers 90 and 100 and the angle θ is shown in FIG. 4, where the ink ribbon 10 of the ribbon drive rollers is shown.
When the force of pulling is f _D , fu is the component force of f _D that acts to lift the ink ribbon 10 upward, and is represented by fu = f _Dcos θ. The vertical position of the ink ribbon 10 during traveling is constantly checked by the photosensors 130 and 140, and when it is biased upward or downward, it receives signals from the photosensors 130 and 140 and sends a signal from the control unit to the motor drive unit. Drive motor 200
The angle .theta. Is changed by driving to correct the deviation of the ink ribbon. When the ink ribbon 10 is biased upward, θ is increased and the component force fu is decreased. Inverse ribbon
When 10 is biased downward, decrease θ and increase component force fu. By the above control, the running 10 of the ink ribbon is always directed to the center of the ribbon drive rollers 90 and 100.

In the above embodiment, the ribbon guide mechanism is provided on the ribbon drive rollers 90, 100 side, but it may be provided on the opposite side or both sides. In this case, the shape of the ribbon guide 150 on the opposite side is the upside-down shape of FIG. Further, the drive system of the ribbon guide 10 uses a gear, but a belt may be used.

[Effect of device]

As described above in detail, according to the present invention, since the running position of the ink ribbon can be controlled at all times, the running of the ink ribbon is stable and the ribbon jam can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of an ink ribbon running system of a general impact printer, FIG. 2 is a side view showing an embodiment of the present invention, FIG. 3 is a perspective view of a ribbon guide, and FIG. 4 is a ribbon. Exploded view of the force acting on the ink ribbon at the guide part,
FIG. 5 is a block diagram. In the figure, 10 is an ink ribbon, 20 is a ribbon brake, 30, 50.
Is a ribbon guide, 40 is a hammer bank, 60 is a ribbon roller, 90 and 100 are ribbon drive rollers, 110 is a drive roller motor, 120 is a ribbon pulley, 130 and 140 are photosensors, 150 is a ribbon guide, 170 is a shaft, 180, 190 is a gear and 200 is a drive motor.

Claims (1)

[Scope of utility model registration request] 1. An impact printer using an endless ink ribbon, an ink ribbon sensor for detecting a traveling position of the endless ink ribbon, an inclined truncated cone-shaped ribbon guide, a drive motor for driving the ribbon guide, A ribbon guide mechanism comprising: a control unit that drives the drive motor to correct a position variation of the endless ink ribbon during traveling in response to a detection result of the ink ribbon sensor.