JPS6216182A - Printer - Google Patents

Abstract

PURPOSE:To contrive a marked reduction of abnormal sounds or noise, a smoother turning of a cam plate, efficient use of a ribbon and a lower running cost, by a system wherein a cam plate is provided with two kinds of cam grooves for printing and correction in correspondence with rotating directions, and is controlledly turned foward and reversely so that a cam follower pin is positioned alternately in two printing cam grooves. CONSTITUTION:In continuous printing, the cam plate 23 is turned forward and reversely so that the cam follower pin 3 is positioned alternately in the first cam groove 23a and in the second cam groove 23b. A printing ribbon 8 is vertically moved in such a range that an upper half 8a and a lower half 8b thereof in the width direction are alternately opposed to a printing position. Only forward rotation is transmitted to a ribbon-feeding mechanism under the function of a one-way clutch 13, so that the ribbon is not taken up at the time of reverse rotation, when the cam follower pin 3 is positioned from the second cam groove 23b into the first cam groove 23a. Accordingly, the upper half 8a and the lower half 8b of the ribbon are alternately used for printing, and the ribbon is taken up one time per two strokes of printing operation.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention includes a printing ribbon and an erasing tape, and is configured to selectively lift them up to a printing position by a single cam plate. It relates to printing devices such as printers and type-likes.

[Conventional technology]

A conventional general printing device of this type has a configuration as shown in FIGS. 4 and 5. That is, the ribbon lift cam plate 1 rotated by a ribbon drive motor (not shown) consisting of a stamping motor is rotated around the rotation axis 2 of the cam plate 1, as shown in FIG. A circular first cam groove 1a for continuous printing with a predetermined radius (inner diameter) R1, and a first cam groove 1a with a predetermined curvature from the base position (referred to as the home position or initial point) lb. 1a, and a second cam groove 1c for single character printing connected to the first cam groove 1a.
A third cam groove 1d for erasing is connected to the third cam groove 1d, and a first cam groove 1a is formed at a predetermined curvature from the third cam groove 1d.
A fourth cam groove 1e for return communication is provided.

Then, when a key touch operation for printing is performed,
The ribbon drive motor drives the cam plate l as shown in Fig. 5.
The cam follower pin 3 is rotated forward by an angle of 75° in the direction of the arrow, and the cam follower pin 3 is inserted into the second cam groove 1 as shown by the broken line arrow in the figure.
c, as shown in Figure 6, set the HO position (base position 1b).
) to the H1 position. The ribbon cartridge holder 5 of the lever mechanism connected via the pin 3 of the cam follower 4 is rotated in the direction of the arrow C from the ho position to the h1 position shown in FIG. 4 using the lift support shaft 6 as a fulcrum. The printing ribbon 8 stored in the printing cartridge 7 set on the printing cartridge 5 is lifted up to a specified printing position corresponding to the hammer 9.

During the above-mentioned lift-up operation, the driving side head gear 10 fixed to the rotating shaft 2, the passive side head gear 12 meshed with this and held on the base plate 1), and the rotation of this head gear 12 are connected to the one-way clutch 13. A driving side gear 14 that is transmitted via a driving side gear 14 and a passive side gear 15 that meshes with the driving side gear 14 and is held on the base ill.
The ribbon drive plate 16, which is integrated with the driven gear 15, is rotated by the ribbon lift mechanism section, which is comprised of the following, and the printing ribbon 8 is wound up by a predetermined ribbon feed amount.

After the ribbon 8 is wound up, the hammer solenoid 17
is energized and the hammer 9 is projected forward (to the right in FIG. 4), and the hammer 9 strikes the print surface of the print wheel 18, causing the ink on the ribbon 8 to wrap around the platen 19 and retain the print. It is attached to the paper 20 and printed.

Here, when only one character is printed, the cam plate 1 is reversely rotated in the direction of arrow B in FIG. 5 until a zero signal is output from the ribbon sensor (not shown), and the printing ribbon 8 is also It is lifted down in the direction of arrow D in Figure 4 and returns to its original state. At this time, the reverse rotation of the drive motor is not transmitted to the ribbon drive plate 16 by the one-way clutch 13, and the ribbon 8 is not wound.

On the other hand, when printing is performed continuously, the cam plate 1 is
The cam follower pin 3 continues to be rotated intermittently at a predetermined rotation angle in the direction of the arrow, and continues to follow the circular first cam groove 1a with a radius R1 as shown by the dashed-dotted line arrow in FIG. 3 is held at the height of Hl as shown in FIG. 6, and the printing ribbon 8 is also held at the printing position without being lifted down. At this time, since the drive motor rotates in the forward direction, the printing ribbon 8 is also wound up every printing operation. Further, when the cam follower pin 3 is located at the intersection 1f of the first cam groove 1a and the third cam groove 1d, the pin 3 is attached to the fan-shaped guide portion of the cam auxiliary plate 21 having a radius of approximately R1. By coming into contact with the top, the third cam groove 1d
It follows the first cam groove 1a without falling.

In addition, when erasing erroneously printed characters is performed, the cam plate 1 is rotated 120 degrees in the direction of the arrow B, and the cam follower pin 3 follows the third cam groove 1d and rotates as shown in FIG.
By moving the ribbon cartridge holder 5 downward to the 2 position, the ribbon cartridge holder 5 is rotated to the h2 position in FIG. It is lifted amplified and faces the hammer 9, and this hammer 9 erases the erasing tape 2.
2 is struck through the print wheel 18, and the ink of the printed characters is lifted off and erased.

Thereafter, the cam plate 1 is rotated in the direction of arrow B until a zero signal is output from the ribbon sensor, and the pin 3 returns to the base position 1b following the cam displacement curve shown by the two-dot chain line in FIG. 22 is also lifted down as is clear from FIG. During this erasing operation, since the drive motor is driven in reverse rotation, the one-way clutch 13 does not take up the ribbon 8, and the erasing tape 22 is moved by a crank mechanism (not shown) according to the amount of displacement of the lift amplifier. ) is activated, and a take-up reel (not shown) rotates to take up a certain amount.

(Problems to be Solved by the Invention) However, the printing device has various problems as described below. That is, since the first cam groove 1a for continuous printing is circular, an intersection 1f is created between the first cam groove 1a and the third cam groove 1d for erasing.
A cam auxiliary plate 2I is required to prevent the cam follower pin 3 from falling into the third cam groove 1d at the intersection 1f during continuous printing. If the radius is the same as the groove 1a, the cam follower pin 3 will not slide smoothly.On the other hand, if the radius is too small than the radius R1 of the first cam groove 1a, the ribbon 8 will drop slightly from the printing position each time, resulting in extremely High processing accuracy is required. Also, during the erasing operation, the Nikam follower pin 3 crosses the intersection I.
A pressing mechanism is required to always press the cam follower pin 3 against the inner surface of each cam groove so that it does not enter the first cam groove 1a at the position f, which increases the cost. Moreover, by providing the pressing mechanism, the pin 3 enters the fourth cam groove 1e during continuous printing and the pin 3 enters the first cam groove 1a during the process of returning to the original state after the completion of the erasing operation. In order to prevent this from entering, it is necessary to form steps 1g and 1h in the depth of the cam groove at two locations, and these steps 1g and 1h are the source of abnormal sounds and noise.

Furthermore, since the widthwise central portion of the ribbon 8 is lifted up to a height position facing the hammer 9, the widthwise side edge portions of the ribbon 8 are not used for printing, and the ribbon 8 Running costs are high due to the large amount of wasted parts.

(Means for Solving the Problems) The present invention has been made in view of the various problems of the conventional art.The present invention has been made in view of the above-mentioned various problems in the conventional art. In a printing device in which a mechanism is driven and a ribbon cartridge holder of a lever mechanism connected via a pin of a cam follower is selectively rotated between a printing position and an erasing position by forward and reverse rotation of the cam plate, The cam plate has a circular arc shape with a radius corresponding to lifting up the upper half in the width direction of the printing ribbon to the printing position, and the printing groove is connected from the base position in the normal direction corresponding to the normal rotation direction. a second cam groove for printing, which is connected in the forward direction from the first cam groove in an arc shape with a radius corresponding to lifting the lower half of the width direction of the printing ribbon to the printing position; cam groove and
a third cam groove for erasing extending from the base position in a reverse direction corresponding to the reverse rotation direction and communicating with the base position without intersecting both the first and second cam grooves; A one-way clutch is provided that transmits only the forward rotation of the plate to the ribbon feed mechanism, and the cam is arranged such that the cam follower pin is alternately located in the first cam groove and the second cam groove during continuous printing operations. It is an object of the present invention to provide a printing device having a configuration in which a control signal for rotating a plate in forward and reverse directions is given to the drive motor, thereby solving various conventional problems at once. It is.

(Function) With the above configuration, during continuous printing operation, the cam plate is aligned so that the cam follower pins are alternately located in the first cam groove and the second cam groove. Since the printing ribbon is rotated, the upper and lower halves in the width direction are alternately moved up and down within the range facing the printing position, and only forward rotation is transmitted to the ribbon feed mechanism by a one-way clutch. Therefore, during reverse rotation when the cam follower pin is positioned from the second cam groove to the first cam groove, no ribbon winding operation is performed. Therefore, printing is performed by alternately using the upper half and lower half in the width direction of the ribbon, and the ribbon is wound up once for every two printing operations.

(Implementation I!17) A preferred embodiment of the present invention will be described in detail below.

In FIG. 1 and FIG. 2, the same or equivalent parts are given the same reference numerals. And cam f! 23 is
Radius R1 corresponding to lifting up the upper half 8a of the printing ribbon 8 in the width direction to the character position facing the hammer 9
) and an arcuate first cam groove 23a for printing at an angle θ1.
and an angle θ2 having a radius R12 corresponding to lifting the plate half 8b of the printing ribbon 8 in the width direction to the printing position.
The arc-shaped second cam groove 23b for printing and both ends of the arc-shaped portion of the angle θ3 having the same radius R2 as the existing one intersect with both the first and second cam grooves 23a and 23b, respectively. A third cam groove 23C for erasing is communicated with the base position 23d with a predetermined curvature, and a first cam groove 23 with a predetermined curvature in the forward direction (opposite to the forward rotation direction) from the base position.
a, the fourth cam groove 23e communicates with the first cam groove 2
The fifth cam groove 23b communicates with the second cam groove 23b in the positive direction from 3a.
The cam auxiliary plate 21 is removed, and the cam plate 23 is moved so that the cam follower pin 3 is alternately positioned in the first cam groove 23a and the second cam groove 23b during continuous printing operation. 4 to 6 in that the rotation is controlled in the forward and reverse directions within the range of θ4 shown in FIG.
This is different from the conventional printing device shown in the figure. .

The operation of the embodiment apparatus configured as described above will be explained with reference to FIG.

When a key touch operation for printing is performed, the ribbon drive motor is driven by a print command signal, and the cam plate 23 is rotated forward by 90 degrees in the direction of arrow A, and the cam follower pin 3 is rotated as shown in FIG. The ribbon cartridge holder 5 is rotated in the direction of arrow C from the ho position to the h1) position shown in FIG. 1, and the upper half 8a of the printing ribbon 8 is lifted up to the printing position. The ink on the upper half 8a of the ribbon 8 is transferred and printed onto the printing paper 20 by the same operation as in the conventional example described above.

At this time, since the cam plate 23 is rotating in the forward direction, the ribbon drive plate 16 is rotated via the one-way clutch 13, and the ribbon 8 is wound up by a specified length.

Note that the cam follower pin 3 is prevented from entering the third cam groove 23c due to the step 23g.

If the next print command signal is not output within the specified time, that is, if only one character is printed one-on-one, the cam plate 23 is rotated in the direction of arrow B and returns to its original state as shown in Figure 2. do. At this time, since the cam plate 23 is rotating in the opposite direction, the rotational force is cut off by the one-way clutch 13, so that the ribbon 8 is not wound up. On the other hand, when the second printing command signal is output within the specified time, the cam plate 2
3 is further rotated forward in the direction of arrow A, and the cam follower pin 3
is located in the second cam groove 23b following the first cam groove 23a to the fifth cam groove 23f, and as shown in FIG.
3, the ribbon cartridge holder 5 is rotated to the h12 position, and the lower half 8b of the printing ribbon 8 is lifted up to the printing position. At this time, the ribbon 8 is wound up by the forward rotation of the cam plate 23. Furthermore, when the third printing command signal is output within the specified time, the cam plate 23 is reversely rotated in the direction of arrow B, and the cam follower pin 3 is positioned from the second cam groove 23b to the first cam groove 23a. , the upper half 8a of the ribbon 8 again corresponds to the printing position. At this time, since the cam plate 23 is rotating in the opposite direction, the ribbon 8 is not wound up. Thereafter, if the print command signal continues to be output within the specified time after printing, the same forward and reverse rotation operations of the cam plate 23 as described above are repeated. That is, every time a printing operation is performed twice using the lower half 8b and upper half 8a of the ribbon 8, one winding operation of the ribbon 8 is performed, and when the printing operation is stopped or completed, It is immediately lifted down to its original state.

If an operation to delete incorrectly printed characters is performed,
The cam plate 23 is reversely rotated by 135° in the direction of arrow B, the cam follower pin 3 is moved down to the height position H2 as shown in FIG. The erasing tape 22 is rotated in the direction of the arrow C from the hO position to the h2 position in Fig. 1, and the erasing tape 22 is lifted up to the printing position and is opposed to the hammer 9, which presses the erasing tape 22 through the print wheel 18. The ink of the incorrectly printed characters is lifted off and erased. After that, the cam plate 23 continues to be rotated in the direction of arrow B until the ribbon sensor outputs a zero signal, and the cam follower pin 3
As shown in FIG. 3, the cam groove returns to the base position 23d sequentially following the third cam groove 23C to the fourth cam groove 23e.

In the embodiment, as is clear from FIGS. 2 and 3, the first cam groove 23a is located at an angle of 90° to 1° from the base position 23d.
The second cam groove 23 . Since b is similarly set within the range of angle θ2 from 180° to 210°, the winding amount of the ribbon 8 (ribbon feeding amount) corresponds to the size of the printed characters, symbols, etc. to be printed. The angle θ4 can be arbitrarily set within the range of angle θ4 shown in FIG. Further, the rotational drive of the cam plate 23 and the drive of other mechanisms are all controlled by control signals from the controller CPU.

(Effects of the Invention) As explained above, according to the printing device of the present invention, the cam plate has two types of cam grooves, one for printing and one for erasing, corresponding to the rotational direction, and the cam groove for printing is annular. Zuni, 2
Since the cam plate is controlled to rotate forward and reverse so that the cam follower pins are alternately positioned in the cam grooves for printing, there is no intersection between the cam grooves for printing and erasing on the cam plate. Both the cam auxiliary plate and the pressing mechanism for pressing the cam follower pin into pressure contact with the inner surface of the cam groove, which require extremely high machining accuracy, are unnecessary, and costs can be significantly reduced. Further, since a pressing mechanism is not required and the step portion between the cam grooves is reduced, abnormal sounds and noises are significantly reduced, and the cam plate rotates smoothly, improving reliability.

Furthermore, two types of printing cam grooves are provided so that the upper and lower halves of the ribbon in the width direction are used alternately for printing.
In addition to increasing the printing capacity of the ribbon cartridge, the ribbon can be used efficiently without waste, and running costs can be reduced. In addition, the existing one-way clutch, which is provided to prevent ribbon winding during erasing operations, can be replaced with a mechanism that winds the ribbon once every two printing operations during printing operations by reverse rotation of the cam plate. Since it has a rational structure that can be used to prevent ribbon winding, there is no need to add a special mechanism and there is an advantage that it can be manufactured at low cost.

[Brief explanation of drawings]

1 to 3 show an embodiment of the printing device of the present invention, FIG. 1 is a right side view, FIG. 2 is an enlarged view of the cam plate, FIG. 3 is an explanatory diagram of the operation of the cam follower pin, and FIG. Figure 4 and subsequent figures show a conventional printing device, with Figure 4 being a right side view, Figure 5 being an enlarged view of the cam plate, and Figure 6 being an explanatory diagram of the operation of the cam follower pin. 3...Cam follower pin 4...Cam follower 5.
... Ribbon cartridge holder 6 ... Support shaft 8 ... Printing ribbon 8a
, 8b... Upper and lower half parts of the ribbon 9... Hammer 13... One-way clutch 16... Ribbon drive plate 22... Erasing tape 23... Cam plate
23a...First cam groove 23b...Second cam groove 23C...Third cam groove 23d...Base position

Claims (1)

[Claims] (1) The ribbon lift cam plate is rotated by driving the drive motor by key touch operation, and the ribbon feed mechanism is also driven, and the forward and reverse rotation of the cam plate causes a lever connected to the pin of the cam follower. In a printing device in which a ribbon cartridge holder of the mechanism is selectively rotated between a printing position and an erasing position, the cam plate has a radius corresponding to lifting up the upper half of the printing ribbon in the width direction to the printing position. a first cam groove for printing that has an arc shape and communicates in a positive direction corresponding to the forward rotation direction from the base position, and a lower half of the printing ribbon in the width direction that is lifted up to the printing position. a second cam groove for printing, which has a circular arc shape with a radius of a third cam groove for erasing that communicates with the base position without intersecting both cam grooves of No. 2, and a one-way clutch that transmits only the forward rotation of the cam plate to the ribbon feed mechanism; A control signal is applied to the drive motor to rotate the cam plate forward and reverse so that the cam follower pin is alternately located in the first cam groove and the second cam groove during a printing operation. printing device.