JPH068603A - Switching apparatus of ink ribbon - Google Patents

Abstract

PURPOSE:To switch a ribbon without using a driving source exclusive for a ribbon lift by providing an intermittent mechanism and an engaging means for stopping the rotation of an intermittent gear between a driving gear and a lift cam. CONSTITUTION:When an ink ribbon cassette 7 mounted on a carriage 2 in the movable manner in the vertical direction is to be lifted, a trigger solenoid 35 is excited and a plunger 36 is attracted against a returning spring 21. A notch part of a trigger lever 20 is separated from a projecting part of a lift intermittent gear 16, and at the same time, the carriage 2 is moved to mesh the lift intermittent gear 16 with a lift transmission gear 14. At this time, the lift intermittent gear 16 is rotated in accordance with the rotation of a lift friction gear. Meanwhile, when the excitation of the trigger solenoid 35 is shut and the carriage 2 is moved to mesh the notch part of the trigger lever 20 with the projecting part of the lift intermittent gear 16, the rotation of the lift intermittent gear 16 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output device for printing and printing, and more particularly to an ink ribbon switching device for a printer having an ink ribbon cassette mounted on a carriage.

[0002]

2. Description of the Related Art Conventionally, as an ink ribbon switching mechanism, one disclosed in JP-A-63-254089 has been known. FIG. 13 is a plan view showing a conventional ink ribbon switching device. According to this, when the carriage 2 is controlled to move beyond the print area, the switching levers 101 and 102 are pushed and slid to the left and right, and the ink ribbon cassette lift cam 103 is rotated in one direction to lift. The lever 104 is moved up and down to execute the ink ribbon switching, and the switching lever is pushed and slid to the left and right until the requested ink ribbon is selected. Sliding beyond the print area. The distance was about a dozen millimeters.

[0003]

However, in the above-mentioned prior art, when switching the ink ribbon, the switching lever has to be pushed and slid to the left and right at a position where the carriage exceeds the printing area. There has been a problem in that the outer carriage needs to have a moving space of ten or more millimeters on each of the left and right sides, and the entire printer becomes large. Further, there is a problem in that the carriage must be moved to the outside of the printing area for ribbon switching, and throughput at the time of ribbon switching is reduced.

The present invention has been made in view of the above-mentioned drawbacks, and there is no movement space of the carriage outside the printing area, and the ink ribbon switching operation can be performed anywhere regardless of the position of the carriage, thus simplifying the apparatus. ,Miniaturization,
The purpose is to improve throughput.

[0005]

In order to solve the above-mentioned problems, an ink ribbon switching device of the present invention comprises a carriage which reciprocates along an output medium, and an ink ribbon cassette which is mounted on the carriage and can move in the vertical direction. ,
An intermittent gear having a lift cam that lifts the ink ribbon cassette, a gear that rotates according to the movement of the carriage, and a tooth portion that meshes with the gear and a neutral portion that does not mesh with the drive gear, and an intermittent gear that is coaxial with the intermittent gear. A friction gear, which is rotatably supported with a certain friction against the gear, and an engagement / disengagement means for selectively stopping the rotation of the intermittent gear in a state where the neutral portion of the intermittent gear and the gear oppose each other. It is characterized in that a mechanism for driving the means is provided.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic plan view of an embodiment in which the present invention is applied to a printer. FIG. 2 shows a side view of FIG. 1 viewed from the right side. First, 2 is a carriage, 3 is a platen opposite to the carriage 2, 4 is printing paper fed by the platen 3, 5
Is a print head mounted on the carriage 2, and 7 is an ink ribbon cassette in which an ink ribbon interposed between the print head 5 and the printing paper 4 is mounted.

In the printer shown in the figure, the carriage 2 having the print head 5 is moved in the print digit direction by a print signal from the host computer, and is struck by a wire inside the print head 5, and wound on the platen 3 via an ink ribbon. The above-mentioned wire is struck on the mounted printing paper 4 to print characters and the like.

The carriage 2 moves in the print digit direction on a drive shaft arranged in parallel with the platen 3. The ink ribbon storage portion of the ink ribbon cassette 7 is mounted on the carriage 2 on the operator side (the lower side in FIG. 1) that abuts the rear of the print head 5.

Reference numeral 7b is a rotation center shaft for vertically moving the tip end portion of the ink ribbon cassette 7, and the ink ribbon cassette 7 is rotatably supported about the rotation shaft 7b.

FIG. 3 is a side view of the wheel train showing a winding mechanism for the ink ribbon and a ribbon lift mechanism for vertically shifting the ink ribbon cartridge 7. The ribbon winding mechanism and the ribbon lifting mechanism will be described with reference to FIGS. 1 and 3. 23 is a carriage 2 in which rack gears are toothed
, A planetary gear 9 configured to mesh with the guide plate 23, a planetary lever 10 supported to swing the planetary gear 9 left and right, and a ribbon 13 meshing with the planetary gear 9. A transmission gear, 11 is a ribbon transmission gear that also meshes with the planetary gear 9, 12 is a ribbon driven gear that meshes with the ribbon transmission gear 11, and 8 is an ink ribbon 7a.
Is a ribbon drive gear and a drive shaft for winding. When the carriage 2 moves in the X'direction, the planet gears 9 rotate counterclockwise (hereinafter referred to as CCW). Planet lever 10 is C
The planetary gear 9 rotates to CW and meshes with the ribbon transmission gear 13, so that the ribbon transmission gear 13 rotates clockwise (hereinafter referred to as CW) to rotate the ribbon drive gear 8 to CCW. When the carriage 2 moves in the X direction, the planet gear 9 rotates CW. The planetary lever 10 rotates to CW, the planetary gear 9 meshes with the ribbon transmission gear 11, and the planetary gear 9 rotates to CW. As a result, the ribbon transmission gear 11
Rotates to CCW. The ribbon driven gear 12 connected to the ribbon transmission gear 11 rotates to CW and the ribbon drive gear 8 to CCW. Therefore, the ribbon drive gear 8 always rotates CCW regardless of the moving direction of the carriage 2.

Next, the ribbon lift mechanism will be described.
Reference numeral 14 is a lift transmission gear, 15 is a lift friction gear, 16 is an intermittent lift gear, 17 is a lift cam gear for sliding the lift lever 18 up and down, and 19 is a home position detection sensor 2 fixed to the lift lever 18.
5, a ribbon position blocking plate, and 20 is a trigger lever for fixing the lift intermittent gear 16 at a predetermined position, with a center of rotation as a fulcrum.
Reference numeral 21 is a return spring that can swing in the W or CCW direction, which gives a tension force to the trigger lever 20, and 35 is a trigger solenoid.

Next, the operation will be described with reference to FIGS. 4, 5 and 6. FIG. 4 is a wheel train plan view showing the intermittent gear mechanism during printing. The lift transmission gear 14 connected to the ribbon drive gear 8 rotates to CW and the lift friction gear 15 always rotates to CCW. The neutral portion 16e of the intermittent lift gear 16 does not form a gear and does not receive the driving force of the lift transmission gear 14. In addition, the lift intermittent gear 1
6 is fitted in the notch 20a of the trigger lever 20 and the protrusion 16a of the intermittent lift gear 16 and does not rotate during printing. In this state, the lift friction gear 15 connected to the lift transmission gear 14 rotates while exerting a constant frictional force on the lift intermittent gear 16.

When the ink ribbon cassette 7 is lifted, the trigger lever 20 is rotatably fixed as shown in FIG. 1 and the plunger 36 of the trigger solenoid 35 is supported so that the trigger lever 20 can swing. By exciting the trigger solenoid 35, the plunger 36 is attracted against the tension of the return spring 21. When a color print command is input here, the trigger solenoid 35
Is excited, the notch 20a of the trigger lever 20 is removed from the protrusion 16a of the lift intermittent gear 16, and at the same time, the carriage 2 is operated to lift the lift intermittent gear 16
Meshes with the lift transmission gear 14. As shown in FIG. 5, the lift friction gear 15 rotates CCW, and the disc spring 2
A frictional force is exerted by the load of 2 and the lift intermittent gear 16 is C
Rotate to CW. Next, when the trigger solenoid 35 is de-energized and the carriage 2 is moved by a predetermined amount, the lift intermittent gear 16 rotates 1/4 and the protrusion 16 of the lift intermittent gear 16 is rotated.
The notch portion 20a of the trigger lever 20 is re-entered in b,
The rotation of the lift intermittent gear 16 stops. Even if the carriage 2 is moved by a predetermined amount or more as shown in FIG. 6, the second neutral portion 16f of the lift intermittent gear 16 and the lift transmission gear 1
4 is opposite. At the same time, the protrusion 16b of the intermittent lift gear 16 does not fall into the notch 20a of the trigger lever 20 to rotate the intermittent lift gear 16 by the trigger lever 20. Therefore, the lift cam gear 17 is 1 /
Stop at 4 turns. FIG. 7 is a development view of the cam portion of the lift cam gear 17. In the state described above, the lift lever 18
Stops at the portion B in FIG. 7 and raises the ink ribbon cassette 7 by one step to execute the ribbon lift. If this operation is performed twice, the lift cam gear 17 makes 1/2 rotation, if it is performed 3 times, it makes 3/4 rotation, and if it is made 4 times, it makes one rotation. Lift cam gear 17 is 1 /
After every four rotations, the lift lever 18 moves the lift cam gear 17
Using the cam part formed on the guide as a guide,
Part, B part, C part, D part, and the lift lever 18 is moved up and down to lift the ink ribbon cassette 7 in four stages.

In this embodiment, depending on the stepped cam deviation position of the lift cam 17, the A part (black), B part (cyan), C
Part (magenta) and D part (yellow). The number of rotations of the lift cam gear 17 is controlled so that a predetermined color ink ribbon can be selected by sending a signal for energizing the trigger solenoid 35 and a signal for moving the carriage 2 in accordance with the required selection color of the ink ribbon 7a. It

The color home detection operation will now be described. The ribbon position must be detected when the power of the printer is input. Therefore, in the present embodiment, the ribbon position shield plate 1 attached to the lift lever 18 with the lift lever 18 in the position A (black) of the lift cam 17 is used.
As indicated by the solid line 9 in FIG. 3, it is set so as to come to the lowest point. When the carriage 2 is moved in the X'direction in this state, the ribbon position shield plate 19 enters the gap 25a of the position detection sensor 25. FIG. 2 is a diagram showing the positional relationship of the ribbon position shield plate 19 with respect to the position detection sensor 25.

The home position return detection of the carriage 2 is executed by the protrusion 2a formed on the carriage 2 entering the gap 25a of the position detection sensor 25 by moving the carriage 2 in the X'direction.

In this embodiment, the embodiment using the plunger type trigger solenoid 35 has been described.
As the type of solenoid, for example, an open type solenoid can also be used.

[0019]

As is apparent from the above description, according to the ribbon switching device of the present invention, the intermittent mechanism and the engaging / disengaging means for stopping the rotation of the intermittent gear are provided between the drive gear and the lift cam. Therefore, ribbon switching can be performed without using a drive source dedicated to the ribbon lift. Therefore, the apparatus can be downsized and the cost can be reduced, and since the space for moving the carriage outside the printing area is not required, the apparatus can be simplified, downsized, and the throughput can be improved.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a ribbon switching device showing an embodiment of the present invention.

FIG. 2 is a side view showing the positional relationship between the lift lever and the sensor at the color home position of the embodiment of FIG.

FIG. 3 is a development view of a train wheel side surface in the embodiment of FIG.

FIG. 4 is a plan view of a train wheel showing an intermittent mechanism during printing (standby) of the present invention.

FIG. 5 is a train wheel plan view showing a trigger input state of the intermittent mechanism of the present invention.

FIG. 6 is a plan view of a train wheel showing an operation of the intermittent mechanism of the present invention.

FIG. 7 is a development explanatory view of a lift cam that shifts a lift lever of the present invention in four stages.

FIG. 8 is a plan view showing a conventional ink ribbon switching device.

[Simple explanation of symbols]

 2 carriage 3 platen 4 printing paper 5 printing head 7 color ink ribbon cassette 8 ribbon drive gear 9 planet gear 10 planet lever 11 ribbon transmission gear 12 ribbon driven gear 13 ribbon transmission gear 14 lift transmission gear 15 lift friction gear 16 lift intermittent gear 17 lift Cam gear 18 Lift lever 19 Ribbon position shield plate 20 Trigger lever 21 Return spring 22 Disc spring 23 Guide plate 25 Position detection sensor 28 Base frame 35 Trigger solenoid 36 Plunger 101 Switching lever right 102 Switching lever left 103 Lifting cam 104 Lift lever

Claims (1)

[Claims] 1. A carriage that reciprocates along an output medium, an ink ribbon cassette that is mounted on the carriage and can move in the vertical direction, a lift cam that lifts the ink ribbon cassette, and a rotation that follows the movement of the carriage. An intermittent gear that includes a gear and has a tooth portion that meshes with the gear and a neutral portion that does not mesh; and a friction gear that is rotatably supported on the intermittent gear coaxially with the friction gear with a certain friction. Selectively engaging and disengaging means for stopping rotation of the intermittent gear in a state where the neutral portion of the intermittent gear and the gear are opposed to each other, and a mechanism for driving the engaging and disengaging means. Ink ribbon switching device.