JPH0647303B2 - Serial printer - Google Patents

Description

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

(Prior Art) Generally, in a serial printer, a platen, a recording medium, an ink ribbon, and a print head are superposed 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, there is one designed such that the width of the recording medium is wider than the moving range of the print head, and the print head always faces the recording medium and presses 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.
A first recording medium guide that guides both sides of the recording medium, and a movable guide that guides the recording medium from the first recording medium guide to the second recording medium guide. The distance between the both sides of the movable guide is smaller than the moving stroke of the print head or the carriage while surrounding the print head or the carriage. Therefore, when the carriage is at the home position, One of the side edges is located at a position away 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.
Further, when the print head moves to the opposite position, the print head or the carriage abuts on one side of the movable guide in the middle of the movement, and the movable guide also follows this movement to move to the other side of the movable guide. The side guides the vicinity of the opposite side of the recording medium to prevent its rising. Further, when the print head returns to the home position, the print head or the carriage abuts on the other side of the movable guide in the middle thereof, and the movable guide also moves following this movement, so that the movable guide also returns to the home position. It

(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 supported by the carriage 5 while facing the platen 7 supported between the support plates 1a and 1b.
And 1b are reciprocated. Recording medium 8
Is a narrow time card, and is conveyed in a direction (downward in FIG. 1) orthogonal to the moving direction (horizontal direction) of the print head 6. The print head 6 is provided on both sides of the recording medium 8.
Are guided by the first recording medium guides 9 and 9 and the second recording medium guides 10 and 10 which are provided on the substrate 2 so as to face each other, except for the region where M moves. First and second recording medium guides 9, 9 and 1
Nos. 0 and 10 are fixed to the substrate 2 by cutting out a part of their facing surfaces to form an L-shaped cross section. Therefore, the guide grooves 9a, 9a, 10a, 10 are formed between the substrate 2 and
a is formed, and both sides of the recording medium 8 can be guided by this guide groove.

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 U-shape in a plan view, and has a pair of parallel side edges 11a and 11b surrounding the carriage 5 from both sides. A guide for guiding one side edge of the recording medium 8 is provided on this side edge. 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 projecting ends of the drive shafts 12 and 13 that project from the support plate 1a to the right,
A belt 17 is wound around the belt wheels 15 and 16, and the rotation of the drive shaft 12 is transmitted to the drive shaft 13 via the belt 17. Therefore, the drive shafts 12 and 13 rotate at the same rotation speed and in the same direction. Elastic rings 12b and 13b are fitted to the feed rollers 12a and 13a, respectively, and cooperate with pinch rollers 12c and 13c mounted on the back surface of the substrate 2 to record the recording medium, as shown in FIG. 8 feeds are secured.

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.

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 away 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.
Guided by 1a, enter smoothly without rising,
It 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 to the right from the home position shown in the first figure. At this time, since the recording medium 8 is pressed by the print head 6 and the right side edge 11a to prevent the recording medium 8 from floating, clear printing is performed. The distance between the side edges 11a and 11b of the movable guide 11 is
As described above, since it is larger than the width of the carriage 5,
In the initial stage of the movement of the print head 6, the movable guide 11 does not follow the movement of the print head 6 and continues to hold the recording medium 8 with its side 11a. Further, since the distance between the side edges 11a and 11b is smaller than the moving stroke of the print head 6 as described above, the right end of the carriage 5 is the right side edge 11a.
When contacting the inner surface of a and moving further to the right, the movable guide 11 follows this movement. That is, the carriage 5 and the movable guide 11 move integrally to the right. Therefore, as shown in FIG. 2, the print head 6 has the side 1
It stops at the position where 1a contacts the stopper 18. At this time, the left side edge 11b of the movable guide 11 has the first and second sides.
Left guide grooves 9a, 1 of the respective recording medium guides 9, 10
It is located at a position corresponding to 0a. Therefore, this side 11
The left side of the recording medium 8 is pressed by b. After that, the print head 6 reverses and starts moving leftward, that is, toward the home position. Also at this time, similarly to the above, in the initial stage of the movement of the print head 6, the movable guide 11 does not follow, the side edge 11b keeps pressing the recording medium 8, and the left end of the carriage 5 is on the left side edge 11b. When it further contacts the inner surface and moves further, it follows 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, in the above-described embodiment, the movable guide 11 is attached to the guide shaft 3.
Although the structure in which the movable guide 11 is slidably supported is shown, a dedicated member for supporting the movable guide 11 is provided separately from the guide shaft 3 and the drive shaft 12, whereby the movable guide 11 is slidable. It may be configured to support.

(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. Moreover, the movement of the print head is not hindered by the bending of the recording medium. Further, the structure is simple, the operation is stable, and the cost can be reduced.

[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 ... … The right side of the movable guide, 11b …… The left side of the movable guide.

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. Above and below the first and second recording medium guides for guiding both sides of the recording medium, and a movable guide movably provided along the moving direction of the carriage. In order to guide the recording medium from the first recording medium guide to the second recording medium guide, both sides of the movable guide are provided with guide portions of the recording medium, and both sides of the movable guide are provided. The interval is smaller than the moving stroke of the print head or the carriage while surrounding the print head or the carriage. Is at the home position, one side of the movable guide is at a position corresponding to one guide of the first and second recording medium guides located at a position apart from the home position, Is moved to a position opposite to the home position, the other side of the movable guide follows the movement of the carriage or the print head and corresponds to the other guide of the first and second recording medium guides. A serial printer characterized by being moved to a position where