JPH0647304B2 - Serial printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer in which a print head reciprocates, and more particularly to a serial printer suitable as a time recorder using a narrow recording medium such as a time card. is there.

(Prior Art) Generally, in a serial printer, a platen, a recording medium, an ink ribbon, and a print head are stacked in this order, and the print head moves left and right relative to the recording medium.

As a first example, when a narrow recording medium such as a time card is used and printing is performed to the full width, the print head passes through a paper guide for guiding the recording medium such as a card. It is desirable to provide up to a part. However, since the dot impact type print head faces the platen with a minute gap, it is difficult to provide a paper guide up to a region through which the print head passes.
Therefore, in the first conventional example, the paper guide is interrupted in the area where the print head passes.

A second example is one in which a paper guide is provided up to the passage area of the print head. In this configuration, a complicated mechanism that allows the paper guide to retract to the rear of the platen when the print head passes is added. ing.

As a third example, the width of the recording medium is made wider than the moving range of the print head, and the print head is designed so as to always face the recording medium and press the rising of the recording medium.

(Problems to be Solved by the Invention) Among the above-mentioned conventional techniques, in the first example, the card as a recording medium is lifted from the platen, and the card catches on the print head or moves when the print head moves. Or, the movement of the print head is obstructed, or the card is stained with ink, which causes trouble.

In the second example, the number of parts increases, the configuration becomes complicated, and the cost increases.

In the third example, the width of the card has to be made wider than necessary, and there is a problem that it is uneconomical because left and right unprintable portions remain.

Therefore, an object of the present invention is to provide a serial printer which, when a narrow recording medium such as a time card is used, has a very simple structure and is capable of smoothly inserting and ejecting the recording medium and capable of clear printing. is there.

(Means for Solving Problems) A feature of the present invention is that the carriage moves above and below an area where the carriage moves.
First and second recording medium guides for guiding both sides of the recording medium, and a movable guide for guiding the recording medium from the first recording medium guide to the second recording medium guide,
The movable guide and the carriage or the print head are connected to each other by a means for interrupting the connecting force. The distance between the both sides of the movable guide surrounds the print head or the carriage and It is smaller than the moving stroke of the head or the carriage. Therefore, when the carriage is at the home position, one side of the movable guide is located at a position apart from the home position. When the carriage moves to the position opposite to the home position, the other side of the movable guide follows the movement of the carriage or the print head. Then, it moves to a position corresponding to the other guide of the first and second recording medium guides.

(Operation) When the print head is located at the home position, one side of the movable guide guides a side farther from the home position of the recording medium to prevent the print head from floating.
In the initial stage of the movement of the print head, the print head is connected to the movable guide via the disconnecting means, so that the movable guide moves along with the movement of the print head and guides across the recording medium. When the movable guide moves together with the print head by a predetermined distance, the movable guide comes into contact with a stopper provided on one side of the printer body and becomes immovable, so that the print head is disengaged from the connecting means by its moving force. However, the other side of the feasible guide guides the vicinity of the opposite side of the recording medium to prevent its floating. Then, when it reaches the final movement position on the side opposite to the home position, it is connected to the movable guide again via the disconnecting means. After that, when returning to the home position, the movable guide is connected to the print head and moves integrally while traversing the recording medium at the beginning of the movement, as in the case of reaching the final movement position from the home position. Comes into contact with a stopper provided on the other side of the printer body, so that the print head is disengaged from the movable guide and is reconnected when it reaches the home position.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, a serial printer support plate 1
A substrate 2 and two guide shafts 3 and 4 are supported between a and 1b. By the guide shafts 3 and 4, the carriage 5
Is supported so that it can reciprocate left and right. Carriage 5
A print head 6 is mounted on the top. Print head 6
Is to reciprocate between the support plates 1a and 1b by the carriage 5 while facing the plante 7 supported between the support plates 1a and 1b. The recording medium 8 is
The time card has a narrow width and is conveyed in a direction (downward in FIG. 1) orthogonal to the moving direction (left-right direction) of the print head 6. On both sides of the recording medium 8, the first recording medium guides 9 and 9 and the second recording medium guides 9 and 9 are provided on the substrate 2 so as to face each other in the upper and lower portions except the region where the print head 6 moves. Guided by 10, 10.
First and second recording medium guides 9, 9 and 10, 1
In 0, a part of the facing surface is cut out and its cross section is L
It is fixed to the substrate 2 in a letter shape. For this reason, guide grooves 9a, 9a, 10a, 10a are formed between the substrate 2 and the guide grooves so that both sides of the recording medium 8 can be guided.

The movable guide 11 is supported by the guide shaft 3 and the drive shaft 12 so as to be slidable along the moving direction of the carriage 5. The movable guide 11 has a planar U-shape, and has a pair of parallel side edges 11a and 11b that surround the carriage 5 from both sides, and one side edge of the recording medium 8 guides the side edges. A part is formed and guides the recording medium 8 from the first recording medium guide 9, 9 toward the second recording medium guide 10, 10. Movable guide 1
The distance between the pair of opposite side edges 11a and 11b of 1 is
It is set to be larger than the width of the carriage 5 and smaller than the moving stroke of the carriage 5.

Drive shafts 12 and 13 are rotatably supported by the support plates 1a and 1b. Feed rollers 12a and 13a for feeding the recording medium 8 downward are fixed to the drive shafts 12 and 13, respectively. A drive gear 14 is fixed to a protruding end of the drive shaft 12 protruding leftward from the support plate 1b, and the drive force is transmitted from a drive source (not shown) to rotationally drive the drive shaft 12. . Belt wheels 15 and 16 are fixed to the protruding ends of the drive shafts 12 and 13 that project rightward from the support plate 1a, and a belt 17 is wound between the belt wheels 15 and 16.
The rotation of the drive shaft 12 via the belt 17 causes the drive shaft 13 to rotate.
Be transmitted to. Therefore, the drive shafts 12 and 13 rotate at the same rotation speed and in the same direction. In addition, the feed roller 12
Elastic rings 12b and 13b are fitted in the a and 13a, respectively, and cooperate with the pinch rollers 12c and 13c mounted on the back surface of the substrate 2 to cooperate with the recording medium 8 as shown in FIG.
Is sure to send.

Stoppers 18 and 19 are fixed to the inner surfaces of the support plates 1a and 1b. The movable guide 11 is attached to the stoppers 18 and 19.
The outer surfaces of the side edges 11a and 11b of the
The moving range of the movable guide 11 is restricted.

Between the carriage 5 and the movable guide 11, the disconnecting means 2 is provided.
0 is provided. The structure of the disconnecting means 20 will be described. The permanent magnets 21a and 21b are provided on both sides of the carriage 5.
Is stuck. Further, L-shaped magnetic bodies 22a and 22b that can be coupled to the permanent magnet by a magnetic attraction force are fixed to the sides 11a and 11b facing the permanent magnet. Permanent magnets 21a, 21b and magnetic bodies 22a, 2
The magnetic attraction with 2b is weak, and only the force required to follow the movement of the extremely lightweight movable guide 11 carriage 5 is given as the attraction.

Next, the operation will be described.

As shown in FIG. 1, the recording medium 8 is inserted from above with the print head 6 in the home position. Both sides of the recording medium 8 are guided by the guide grooves 9a, 9a of the first recording medium guides 9, 9 to enter. At this time, one side (right side) 11a of the movable guide 11 is located at a position corresponding to a guide located at a position apart from the home position of the carriage 5 among the first and second recording medium guides 9 and 10. Therefore, in the area where the print head 6 moves, the right side of the recording medium 8 is the side 1 of the movable guide 11.
It is guided by 1a, smoothly enters without floating, passes through a sensor (not shown), and is guided to the guide grooves 10a, 10a of the second recording medium guides 10, 10. When printing is performed on the recording medium 8 stopped at a predetermined position, the print head 6 starts moving rightward from the home position shown in FIG.
The movable guide 11 follows the movement of the carriage 5 because it is connected to b by a magnetic attraction force. That is,
The carriage 5 and the movable guide 11 move integrally to the right. At the time of this printing, the recording medium 8 is pressed by the print head 6 and the right side edge 11a to prevent the recording medium 8 from rising, so that clear printing is performed. Since the distance between the both sides 11a and 11b of the movable guide 11 is smaller than the moving stroke of the print head 6 as described above,
The movement of the movable guide 11 together with the print head 6 causes the side 11a of the movable guide 11 to contact the stopper 18. Therefore, the movable guide 11 cannot move further to the right. Further, as described above, the distance between the both sides 11a and 11b of the movable guide 11 is larger than the width of the carriage 5, so that after the side 11a abuts the stopper 18 on the right side, only the print head 6 is further Move to the right,
Therefore, due to this moving force, the permanent magnet 21b becomes magnetic.
Then, the print head 6 moves further to the right without following the movable guide 11 and stops in a state where the permanent magnet 21a is in contact with the magnetic body 22a, as shown in the second illustration. At this time, the left side edge 11b of the movable guide 11 holds down the left side edge of the recording medium 8. Then, the print head 6 reverses and starts moving toward the left home position. At this time, similarly to the above, in the initial stage of the movement of the print head 6, the movable guide 11 has the magnet 21
After the movable guide 11 comes into contact with the left stopper 19, the permanent magnet 21a is magnetized by the moving force of the print head 6 after the movable guide 11 contacts the left stopper 19. The print head 6 moves away from the suction force of the body 22a and stops at the home position shown in FIG. In this way, the movable guide 11 guides the recording medium 8 when the recording medium 8 is inserted and ejected and when the print head 6 is moved.

The movable guide 11 can be designed so as to surround the print head 6.

Further, the disconnecting means 20 may be provided between the print head 6 and the movable guide 11. Magnet 21
It is not limited to the connecting / disconnecting means 20 composed of a and 21b and the magnetic bodies 22a and 22b. For example, a leaf spring having a locking portion bent in a dogleg shape at the tip is fixed to one side,
The same effect can be obtained by forming a locking concave portion for locking the locking portion on the other side and setting the mechanical coupling force between the locking portion and the locking concave portion to the same magnitude as above.

Further, in the above-described embodiment, the movable guide 11 is slidably supported by the guide shaft 3 and the drive shaft 12, but the movable guide 11 is supported separately from the guide shaft 3 and the drive shaft 12. A dedicated member may be provided, and the movable guide 11 may be slidably supported thereby.

(Effect of the invention) Since the present invention is provided with a movable guide, even when a narrow recording medium such as a time card is used, the recording medium can be smoothly inserted and ejected, and the floating of the recording medium can be prevented. It can be prevented and stable and clear printing can be performed. Further, the movement of the print head is not hindered by bending of the recording medium. Further, the structure is simple, the operation is stable, and the cost can be reduced. Further, even if the movable guide is extremely lightweight, the movable guide can be prevented from moving due to the influence of inclination or vibration by providing the disconnecting means, and stable operation without displacement can be obtained. .

[Brief description of drawings]

1 and 2 are front views of the main parts, and FIG. 3 is FIG. 1 II.
It is a sectional view taken along the line I-III. 5 ... Carriage, 6 ... Print head, 7 ... Platen, 8 ... Recording medium, 9 ... First recording medium guide, 10 ... Second recording medium guide, 11 ... Movable guide, 11a ... ... right side of the movable guide, 11b ... left side of the movable guide, 20 ... disconnecting means.

Claims (1)

[Claims] 1. A carriage that reciprocates opposite a platen, a print head mounted on the carriage, a recording medium that is conveyed in a direction orthogonal to the moving direction of the carriage, and an area where the carriage moves. First and second recording medium guides for guiding both sides of the recording medium above and below, a movable guide movably provided along the moving direction of the carriage, the movable guide and the carriage or the above. The movable guide guides the recording medium from the first recording medium guide to the second recording medium guide. The movable guide is provided between the print head and any one of the print heads. To this end, both sides of the movable guide are provided with guide portions of the recording medium, and the distance between the both sides of the movable guide is equal to the print head or Encloses the carriage and is smaller than the moving stroke of the print head or the carriage. When the carriage is at the home position, one side of the movable guide is located at a position apart from the home position. When the carriage is at a position corresponding to one of the first and second recording medium guides and the carriage has moved to a position opposite to the home position, the other side of the movable guide is Alternatively, it follows the movement of the print head and moves to a position corresponding to the other guide of the first and second recording medium guides, and the connecting / disconnecting means includes the movable guide and the carriage or the print head. When one of them is connected with a predetermined connecting force, the movable guide follows the movement of the print head, and Serial printers when subjected to forces exceeding a serial connection force, characterized in that the movable guide is a departure from the print head.