JPH05301412A - Printing apparatus - Google Patents

Abstract

PURPOSE:To attempt both to miniaturize furthermore an apparatus and to decrease the manufacturing cost by bringing driving sources such as motors having been provided individually together. CONSTITUTION:A label printing apparatus is provided with a rack 13 fixed on the main body of the apparatus and a carriage case 27 moving reciprocally along the rack 13. In addition, in the carriage case 27, a small gear 21 and a large gear intermeshed with the rack 13 and rotated forwardly and reversely, a follower plate 23 being frictionally hooked with the large gear, a thermal head 28, an arm 26 being inclined by rotation of the follower plate 23, and a coil spring 29 are provided and projecting and retreating of the thermal head 28 is performed by utilizing the rotating force of the small gear 21 being rotated forwardly and reversely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing a character string input in advance on a specific paper such as a label sheet or a postcard in which a plurality of labels are arranged.

[0002]

2. Description of the Related Art As a printing mechanism of a conventional printing apparatus, there is widely known one that reciprocates a carriage equipped with a print head and the like during printing. The carriage is equipped with a mechanism for projecting and retracting the print head. With the movement of the carriage, the print head is projected outside the carriage when printing is performed, and the carriage moves without printing. In this case, the projecting print head is retracted, and the printing process is continuously performed over a plurality of lines while repeating this operation. Also,
This carriage also serves as a cassette holder for mounting the ribbon cassette of the ink ribbon, and therefore the carriage also has a winding shaft for winding the ink ribbon.

[0003]

In such a conventional printing apparatus, a carriage motor is used as a drive source for moving the carriage, and an electromagnetic solenoid or the like is used as a drive source for projecting and retracting the print head. Further, for winding the ink ribbon, a motor for rotating and driving the above-described winding shaft is separately provided.

However, providing a large number of drive sources such as a motor in this way not only requires an extra installation space, but also causes an increase in manufacturing cost.

The present invention has been made to solve such a problem, and by integrating drive sources such as motors that are individually installed, further miniaturization of the device and reduction in manufacturing cost can be achieved. The purpose is to reduce.

[0006]

A printer according to the present invention comprises a rack fixed to the main body of the apparatus and arranged in a direction orthogonal to the inserting direction of paper, and a support base reciprocating along the rack. And a support base driving means for driving the support base. In addition, the support base is mainly composed of a print head that prints on paper, a pinion gear that meshes with the rack and rotates forward and backward with the reciprocating motion of the support base, a pinion gear, or a gear that works in conjunction with this pinion gear. A gear is provided coaxially with this main gear, and a driven plate that frictionally engages the side surface of this main gear with a constant frictional force is provided. It is characterized in that the driven plate for driving drives the projection and the retraction of the print head.

Further, the main support of the printer is further supported by a driven plate, and as the driven plate rotates relative to the main gear, the main gear is engaged with the main gear. It is also possible to provide a planetary gear that rotates on the outer periphery of the vehicle and a take-up shaft that winds the ink ribbon, in which the rotating planetary gear contacts and meshes with each other, and a rotational force is applied by the planetary gear.

With such a structure, when the support is moved forward along the rack, the print head is projected by the forward rotation of the driven plate and the planetary gear is engaged with the winding shaft. Further, when the support base moves back along the rack, the print head is retracted and the planetary gear is disengaged from the winding shaft by the reverse rotation of the driven plate.

[0009]

[Operation] When the support base starts to move when printing is performed,
The pinion gear meshed with the rack or the main gear as a gear interlocking with the pinion gear also rotates. The driven plate rotates in the positive direction integrally with the main gear under the presence of a constant frictional force, and the rotational force causes the print head to project.
The main gear continues to rotate with the movement of the support, but the driven plate is restricted from rotating after the print head is projected. At this time, a force against the frictional force between the driven plate and the main gear acts, and the driven plate starts sliding with respect to the main gear.

When the support base starts moving in the opposite direction, the driven plate rotates in the opposite direction together with the main gear, and the rotational force causes the print head to retract. Although the main gear continues to rotate with the movement of the support base, the rotation of the driven plate is restricted again after the print head is retracted. At this time, a force against the frictional force with the main gear acts on the driven plate, and the driven plate stops at that position and starts sliding with respect to the main gear.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A label printing apparatus for printing a label as a printing apparatus according to the present invention will be described below with reference to the accompanying drawings.

1 to 3 show the appearance and internal mechanism of the label printing apparatus 1. A label printing device (hereinafter referred to as a device) 1 is a device that prints on each of a large number of labels 4a arranged regularly on a label sheet 4, and is composed of an upper half body 2 and a lower half body 3. An insertion port 5 for the label sheet 4 is formed in the middle. In the upper half 2 of the device 1,
A large number of keys 6 into which characters and the like can be input are arranged, and a display portion 7 formed of a liquid crystal panel for displaying a predetermined number of characters, the number of lines, or input characters and the like is arranged above the keys 6. The lower half 3 is formed with an insertion opening 5 and a feeding path 11 extending rearward from the insertion opening 5, and a guide for guiding the inserted label sheet 4 on the upper surface of the feeding path 11. A roller 9 is provided. Further, behind the guide roller 9, there are provided paper feed rollers 8 which are rotationally driven by a sheet feed motor 16 and which feed the inserted label sheet 4, at a total of three places, and printing is performed behind them. The printing unit 20 is provided.

The lower portion of the printing unit 20 is the label sheet 4
Helical shaft 1 arranged in a direction orthogonal to the insertion direction of
The rotation of the carriage motor 14 is transmitted to the spiral shaft 12 through the gear train 15, and the printing unit 20 reciprocates along the rotating spiral shaft 12. .. A rack 13 is installed above the printing unit 20 in parallel with the spiral shaft 12. The teeth of the rack 13 are formed on the lower side so as to face the printing unit 20,
As described later in detail, the gears in the printing unit 20 are
It is in a state of meshing with. A thermal head 28 formed of a dot array capable of printing one character, for example, projects from the lower portion of the printing unit 20, and a rubber platen 17 is provided on the lower half 3 of the thermal head 28. is doing.

The printing section 20 also functions as a cassette holder for mounting a ribbon cassette (not shown) of an ink ribbon.

Here, the printing operation of the apparatus 1 will be schematically described. First, the apparatus 1 has a guide side wall 18 formed on the left side of the insertion port 5, and the label sheet 4 is inserted from the insertion port 5 while abutting the left side of the label sheet 4 against the side wall 18. This is because the mechanism for performing the printing process is based on the front end (front left corner) of the left side of the label sheet 4 into which the device 1 is inserted. The label sheet 4 is positioned by bringing it into contact with.

When the label sheet 4 is inserted through the insertion port 5 in this manner, the label sheet 4 is sent to the rear side by the paper feed roller 8 inside the apparatus, and when the label sheet 4 reaches the predetermined position, the printing section 20 is reached. Printing is executed. When the printing unit 20 moves from the left end of the apparatus 1 which is the reference position of the printing process to the right side, the thermal head 28 is projected along with the movement in this direction, and the printing unit 20 returns to the initial position. Therefore, when moving toward the left end (initial position), the thermal head 28 is retracted along with the movement in this direction.

After all the printing is completed and a predetermined character string is printed on each label 4a, the label sheet 4 is ejected from the paper ejection port 10 on the back surface.

Here, the mechanism of the printing unit 20 which mechanically drives the thermal head 28 in accordance with such movement will be described in detail.

First, the internal structure of the printing unit 20 is shown in FIGS.

The printing portion 20 has an outer shell portion formed as a carriage case 27, and inside thereof, a small gear 21 as a pinion that meshes with the rack 13 described above, and a small gear 21 that meshes with and interlocks with the small gear 21. And a driven plate 23 disposed on one side surface of the large gear 22 coaxially with the large gear 22 for frictionally engaging with the large gear 22 with a constant friction force. ing. This driven plate 23 is a large gear 2
When the driven plate 23 is externally applied with a force that opposes this frictional force, the driven plate 23 stops at that position and starts sliding with respect to the large gear 22. This is a so-called clutch mechanism (see FIG. 5).

Further, the outer periphery of the large gear 22 is provided with a planetary gear 24 which meshes with the large gear 22 and rotates around the outer periphery thereof. The planetary gear 24 is integrally supported by a driven plate 23. There is. Therefore, the planetary gear 24 is driven by the large gear 2 as the driven plate 23 slides with respect to the large gear 22.
The outer circumference is rotated while meshing with 2.

Further, a winding shaft 25 for winding the ink ribbon is disposed adjacent to the large gear 22 and the driven plate 23, and the gear portion 25a at the base end portion thereof is a rotating planetary gear. The structure is such that it abuts and meshes with 24. The winding shaft 25 and the gear portion 25a at the base end are frictionally engaged with each other with a constant friction force.

A V-shaped locking piece 23a is formed on the side surface of the driven plate 23 so as to project therefrom.
Inside the character groove, an arm 2 rotatable about the base end 26a is provided.
The front end of 6 is engaged. Further, the arm 26 is engaged with the projecting engagement portion 28'a on the upper part of the head member 28 'which is integrated with the thermal head 28, and the tilting of the arm 26 causes the head member 28' to move up and down, which results in the thermal. The head 28 is projected and retracted. In addition,
A coil spring 29 is in contact with the upper end of the head member 28 ', and the coil spring 29 exerts a reaction force on the carriage case 27 to constantly press the head member 28' downward.

Next, the operation of each constituent element of the printing unit 20 thus configured will be described. First, when printing is performed as described above, the printing unit 20 that was initially in the state of FIG. 4B is moved in the direction indicated by arrow A in FIG. Then, along with this movement, the small gear 21, the large gear 22, and the driven plate 23 rotate in the direction shown in the figure, and the planetary gear 24 also rotates around the outer periphery of the large gear 22 accordingly. Since the V-shaped locking piece 23a is also tilted by the rotation of the driven plate 23, the pressing force of the coil spring 29 causes the head member 28 to rotate.
′ Moves downward and causes the thermal head 28 to project. At this time, the arm 26 is also pressed by the protruding engagement portion 28'a and tilts downward about the base end portion 26a (FIG. 4A). As the rotation further progresses, the planetary gear 24 comes into contact with the gear portion 25a of the winding shaft 25, and the driven plate 23 is prevented from further rotation. As a result, a force against the frictional force acts on the driven plate 23, and the driven plate 23 thereafter stops at that position and starts sliding with respect to the large gear 22. After that, the printing unit 20 continues to move, but the rotation of the small gear 21 is transmitted to the gear unit 25a via the large gear 22 and the planetary gear 24. As a result, the ink ribbon take-up shaft 25 continues to rotate until the movement of the printing unit 20 is stopped.

Next, since this movement is stopped and the printing section 20 returns to the initial position, the movement is started in the direction indicated by the arrow B in FIG. 4 (b). With this movement, the small gear 21 and the large gear 2
2 and the driven plate 23 rotate in the opposite direction to the above, as shown in FIG. 4B, and the planetary gear 24 also rotates the outer periphery of the large gear 22 in the opposite direction to that described above as a result. By this rotation, the meshing of the planetary gear 24, which has meshed with the gear portion 25a of the winding shaft 25, is released, and the rotation of the winding shaft 25 is stopped. At the same time, the V-shaped locking piece 23a is also tilted by the rotation of the driven plate 23, and the head member 28 'is pushed upward via the arm 26 against the pressing force of the coil spring 29, and the thermal head 28 is used as a reference. Retract to position.
When the rotation further progresses, a part of the driven plate 23 comes into contact with the locking portion 27a of the carriage case 27 to prevent further rotation. As a result, a force against the frictional force acts on the driven plate 23, so that the driven plate 23 stops at that position thereafter, and the large gear 22
Begins to slide against. On the other hand, due to this frictional force, the locking piece 23a of the driven plate 23 continues to push up the arm 26 and the head member 28 'upward against the pressing force of the coil spring 29, and the printing unit 20 causes the arrow A in FIG. This state is maintained until the movement starts again in the direction of.

In this way, the printing unit 20 causes the thermal head 28 to project and rotates the ink ribbon take-up shaft 25 during the forward movement for printing, and returns the thermal head 28 to the original position during the backward movement. It has a mechanism for reversing and stopping the rotation of the winding shaft 25 to interrupt the winding of the ink ribbon. Moreover, this mechanism uses the rotational force of the small gear 21 that meshes with the rack 13 as a drive source when the printing unit 20 moves in mesh with the rack 13 to perform all mechanically.

In the embodiment described above, the pressing force of the coil spring 29 is used when the thermal head 28 is projected, but the coil spring 29 is designed to have a large rotatable angle. Alternatively, the arm 26 can be pressed downward by the locking piece 23a of the driven plate 23 to tilt the arm 26, and the thermal head 28 can be projected.

Further, in this embodiment, an example in which the driven plate is frictionally engaged with the large gear as one of the gears interlocking with the small gear has been shown, but the small gear as the pinion gear is changed by changing the design of the gear train. However, it is also possible to directly frictionally engage the driven plate.

[0029]

As described above, according to the printing apparatus of the present invention, the support base for supporting the print head or the like is moved along the rack, the pinion gear is meshed with the rack, and the pinion gear or A gear that interlocks with this pinion gear is used as a main gear, and a driven plate is frictionally engaged with this main gear, and a mechanism that uses forward / reverse rotation of this driven plate to project and retract the print head is adopted. ..

Therefore, by moving the support base by the support base drive means, it is possible to drive the protrusion and retreat of the print head, so that another drive source dedicated to drive the print head is not required, and the apparatus is further improved. In addition to reducing the size of
The manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a printing apparatus according to the present invention.

FIG. 2 is a perspective view showing an internal mechanism of the printing apparatus.

FIG. 3 is a perspective view showing an internal mechanism of the printing apparatus.

FIG. 4A and FIG. 4B are plan views showing the internal mechanism of the printing unit.

FIG. 5 is a schematic perspective view showing a main part of a gear mechanism arranged in a printing unit.

[Explanation of symbols]

1 ... Label printing device, 4 ... Label sheet (paper), 13
... rack, 14 ... carriage motor (support base driving means), 20 ... printing unit, 21 ... small gear (pinion gear),
22 ... Large gear (main gear), 23 ... Follower plate, 24 ... Planetary gear, 25 ... Winding shaft, 27 ... Carriage case (support base).

Claims (2)

[Claims] 1. A rack fixed to an apparatus main body and arranged in a direction orthogonal to a sheet insertion direction, a support base reciprocating along the rack, and a support base drive means for driving the support base. The support base includes a print head that prints on the sheet, and the rack that meshes with the print head.
A pinion gear that rotates in the reverse direction, and the pinion gear or a gear that interlocks with this pinion gear as the main gear, is arranged coaxially with respect to this main gear, and with a constant frictional force against the side surface of this main gear. A driven plate that frictionally engages is provided, and a driven plate that rotates forward / reversely following the main gear,
A printing apparatus which drives the protrusion and the retreat of the print head. 2. The main gear is further supported on the support base by the driven plate, and the driven plate is meshed with the main gear as the driven plate rotates relative to the main gear. A planetary gear that rotates around the outer periphery of the ink-jet printer, and a planetary gear that abuts and meshes with the rotating planetary gear, and a rotational force is applied by the planetary gear. When moving forward along the rack, the print head is projected by forward rotation of the driven plate, and the planetary gears are meshed with the take-up shaft. 2. The printer according to claim 1, wherein, when moving, the print head is retracted and the planetary gear is disengaged from the winding shaft by reverse rotation of the driven plate.