JPH0820143A - Printing equipment - Google Patents

Abstract

(57) [Summary] [Purpose] A simple structure is used as the power source for pressing and separating the platen and print head. [Structure] The paper feed roller 9 and the motor 10 are connected by a first gear train 21, and the first gear train 21 and the planetary gear 25 are connected to a second gear train.
The gear train 22 is connected. The planet gear 25 is the third gear 22.
Rotate around c. The planetary gear 25 and the platen 8 are connected. The motor 10 rotates the paper feed roller 9 forward and backward, and the platen 8 is pressed against or separated from the print head in conjunction with the forward and reverse rotation of the paper feed roller 9. The printing head of the platen 8 can be pressed and separated by the power source of the paper feed roller 9, and the power source of the platen is unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head and a print head for printing with a recording paper sandwiched between platens.

[0002]

2. Description of the Related Art A word processor or a personal computer has a built-in printer for printing on recording paper by thermal transfer or the like. In these printers, when the recording paper is set between the print head and the platen, the platen needs to be separated from the print head. 7 and 8 show a conventional printing apparatus which performs such an operation.

In these figures, a print head 100, a platen 110, and a paper feed roller 120 are provided inside the apparatus main body.
And are arranged. The print head 100 is attached to one end of the head arm 140. The head arm 140 is attached to a head attachment member 150, which constitutes a part of a lid (not shown) of the device body, via a shaft 160 so as to be rotatable in forward and reverse directions. Print head 10
0 is pressed against the platen 110 by the clockwise rotation of the head arm 140 (see FIG. 8), while the platen 110 is rotated by the counterclockwise rotation of the head arm 140.
(See FIG. 7). Then, in the contact state with the platen 110, the recording paper 200 and the ink ribbon 210
Is pressed against the platen 110 to perform printing on the recording paper 200, and when the recording paper 20 is separated from the platen 110, the recording paper 20 is placed between the print head 100 and the platen 110.
It is possible to set 0. The press contact and separation of the print head 100 are performed by rotation of the cam plate 170, which will be described later.

The paper feed roller 120 is arranged at a position close to the platen 110, is connected to a motor (not shown), and rotates in forward and reverse directions. The paper feed roller 120 sandwiches the recording paper 200 between it and the nip roller 180, and discharges the printed recording paper 200 by its clockwise rotation, while discharging the recording paper 200 to be set by its counterclockwise rotation. Supply in the direction of the print head 100.

In addition to the above configuration, a pin 140a is attached to the end of the head arm 140 on the side opposite to the print head 100, and a cam plate 170 facing the pin 140a is provided in the apparatus body. A cam groove 190 into which the pin 140a is inserted is formed in the cam plate 170. The shape of the cam groove 190 is set so that the head arm 140 rotates in the forward and reverse directions by the rotation of the cam plate 170.
The rotation of 40 causes the print head 100 to come into pressure contact with or separate from the platen 110. Here, the cam plate 170
Needs to rotate separately from the rotation of the paper feed roller 120, and is driven by a motor (not shown) different from the motor of the paper feed roller 120.

The ink ribbon 210 is mounted in the main body of the apparatus while being housed in the ribbon cassette 220. The ribbon cassette 220 has a rewind roll 240 and a take-up roll 250 rotatably attached to a cassette case 230 thereof. The ink ribbon 210 is wound around these rollers 240 and 250, and the rewind roll 240 is wound. The recording paper 200 is pulled out from the recording medium and travels so as to be wound around the winding roll 250, and printing is performed on the recording paper 200 during this traveling. In this case, the ribbon cassette 220 is attached to the apparatus main body from the lateral direction (the penetrating direction in the drawing), and the print head 100 enters through the opening 260 on the upper surface of the apparatus main body to be in the illustrated state.

In the conventional printing apparatus having the above-described structure, first, the motor for driving the cam plate 170 is activated to operate the cam plate 1
70 rotates, and the state shown in FIG. 7 is obtained. In this state, the cam groove 190 of the cam plate 170 pulls down the pin 140a, which causes the head arm 140 to rotate in the counterclockwise direction and the print head 100 to move away from the platen 110, thereby forming a gap therebetween. For this state,
The recording paper 200 is inserted from the paper feed roller 120 in the direction of the arrow X and manually or driven by a motor.
The recording paper 200 is inserted into the print head 100 and the platen 110 by rotating 0. As a result, the recording paper 200
Is complete.

Following this, the motor for driving the cam plate 170 is operated to rotate the cam plate 170 by 90 degrees. As a result, the state shown in FIG. 8 is obtained. In this state, the cam groove 190 pulls up the pin 140a, which causes the head arm 140 to rotate in the clockwise direction and the print head 100 to come into pressure contact with the platen 110 to be in a printable state. In synchronization with the start of printing by the print head 100, the paper feed roller 120 is driven by a motor to rotate in a counterclockwise direction, and a moving force in the arrow Y direction is applied to the recording paper 200. As a result, the printed recording paper 200 is ejected.

[0009]

Since the conventional printing apparatus has a structure in which the print head 100 is pressed against and separated from the platen 110 by the rotation of the cam plate 170, the cam plate 170 is separated from the paper feed roller 120. Need to rotate.

Therefore, it is necessary to dispose a drive source such as a motor for rotating the cam plate 170 separately from the motor for driving the paper feed roller 120. In addition, it is necessary to provide a head arm 140 for moving the print head 100. As a result, the number of parts is large and the structure and its control are complicated. Further, since the cam plate 170 has the cam groove 190,
There is a problem in that the molding needs to be performed with high precision and the molding is troublesome.

The present invention has been made in consideration of the above circumstances, and the press contact and separation between the platen and the print head can be performed with a simple structure with a small number of parts. An object of the present invention is to provide a printing device that does not require a head arm or the like.

[0012]

A printing apparatus according to the present invention comprises a print head for printing on a recording sheet, a platen for pressing the recording sheet against the print head when the printing head prints on the recording sheet, and the printing apparatus. A paper feed roller that rotates in the forward and reverse directions to supply and discharge recording paper to the head,
The platen is separated from the print head in conjunction with the rotation of the paper feed roller in one direction, and the platen is brought into pressure contact with the print head in conjunction with the rotation of the paper feed roller in the other direction. It is characterized by

In the printing apparatus having this structure, the interlocking means interlocks with the forward and reverse rotations of the paper feed roller to move the platen so that the platen is pressed against and separated from the print head. Then, while the platen is brought into pressure contact with the print head to be in a printable state on the recording paper, the separation of the platen from the print head enables the setting of the recording paper. Therefore, it is not necessary to provide an independent drive source separate from the paper feed roller to press and separate the platen and the print head.

According to the present invention, it is possible to provide a stopper for restricting the operation of the platen, which presses and separates from the print head, within a certain movement range, which can prevent interference between the platen and other members. No damage.

The interlocking means according to the present invention includes a first gear train for transmitting rotation in the forward and reverse directions to the paper feed roller, and the first gear train.
And a planetary gear that meshes with the second gear train and moves within a certain range as the second gear train rotates. The platen and the platen can be integrally moved. In this interlocking device, the second gear train is driven by the driving of the first gear train, and the planetary gear is moved by the driving of the second gear train,
The platen presses or separates from the print head. Therefore,
The cam groove, which is difficult to mold, is not required, and the manufacturing is easy.

[0016]

1 to 6 show an embodiment of the present invention.
In this embodiment, as shown in FIG. 6, a device main body 1 and a lid body 2 which rotates about a support shaft 3 to open and close are provided. A print head 4 is attached to the lid body 2 via a head attaching member 7 described later, and a side surface of the device body 1 is formed with an inlet / outlet 5 for inserting / removing a ribbon cassette 30 described later. In this configuration, the ribbon cassette 30 is set in or taken out from the device main body 1 through the doorway 5 from the direction of penetrating the paper surface.

FIG. 1 shows a state in which the recording paper 6 is set with the ribbon cassette 30 attached to the apparatus body 1. The print head 4 is attached to a lower end portion of a mounting piece 7a that integrally hangs from a head mounting member 7 that forms a part of the lid body 2 (see FIG. 6). The print head 4 enters the ribbon cassette 30 by the closing operation of the lid body 2 and contacts the ink ribbon 31 in the ribbon cassette 30.

In the illustrated example, the ribbon cassette 30 includes a cassette case 33 having an opening 32 through which the print head 4 advances and retracts, and a rewinding roll 34 and a winding roll 35 rotatably attached to the cassette case 33. I have it. Ink ribbon 31 is for these rolls 3
It is stretched around 4, 35 and runs in the direction of the winding roll 35. At this time, the print head 4 prints on the recording paper 6. In order to perform this traveling, the ribbon cassette 30
The device body 1 is provided with a take-up shaft (not shown) that engages the take-up roll 35 by the mounting and rotates the roll 35 in the winding direction of the ink ribbon 31.

When printing on the recording paper 6 by the print head 4, the platen 8 contacts the print head 4 and presses the ink ribbon 31 and the recording paper 6 against the print head 4 as shown in FIG. Therefore, the platen 8 is attached to the print head 4
Is arranged in the device body 1 so as to be located below. The platen 8 is brought into pressure contact with or separated from the print head 4 by an interlocking means 20 described later.

At the time of printing, the recording paper 6 is indicated by an arrow B in FIG.
Is conveyed in the direction. A paper feed roller 9 is arranged downstream of the platen 8 in the conveyance direction of the recording paper 6. The paper feed roller 9 is rotated in the forward and reverse directions by a rotational force transmitted from a motor 10 (see FIG. 2) as a drive source provided in the apparatus body 1. 1 and 4, 1
Reference numeral 1 denotes a nip roller that sandwiches the recording paper 6 with the paper feed roller 9. When the paper feed roller 9 rotates counterclockwise with the recording paper 6 sandwiched with the nip roller 11, the recording paper 6 is rotated. 6 is conveyed in the direction of arrow B, and is discharged (see FIG. 4). The platen 8 is pressed against and separated from the print head 4 by transmitting the forward and reverse rotations of the paper feed roller 9 through the interlocking mechanism 20.

2 and 5 show the interlocking mechanism 20. Reference numeral 10 is a motor that rotates the paper feed roller 9 forward and backward as described above. The motor 10 and the paper feed roller 9
A first gear train 21 is provided between the first gear train 2 and
A second gear train 22 is arranged between 1 and the platen 8. The first gear train 21 is the output gear 10a of the motor 10.
A first gear 21a that meshes with the first gear 21a and a second gear 21b that meshes with the first gear 21a are provided. On the other hand, the paper feed roller 9 has a driven gear 23 attached to its roller shaft 9a for integrally rotating the paper feed roller 9, and the driven gear 23 meshes with the second gear 21b. . In each of the first gear 21a and the second gear 21b in the first gear train 21, the gear to which the rotational force is transmitted from the upstream side has a large diameter, and the gear to transmit the rotational force to the downstream side has a small diameter. A two-stage gear is used, whereby the first gear train 21 decelerates the rotation of the motor 10 and transmits it to the paper feed roller 9.

Next, the second gear train 22 in the interlocking means 20 has a first gear 22a that meshes with the first gear 21a of the first gear train 21, and a second gear 22a that meshes with the first gear 22a.
The gear 22b and the third gear 22c that meshes with the second gear 22b are provided. Also in each of the gears 22a, 22b, 22c in the second gear train 22, the gear for transmitting the rotational force from the upstream side has a large diameter and the gear for transmitting the rotational force to the downstream side has a small diameter. Is used,
The rotational force is gradually reduced and transmitted to the downstream side. The third gear 22 in the second gear train 22
A planetary gear 25 is meshed with c.

The planetary gear 25 is connected to the bearing portion 22d of the third gear 22c by the arm 26 to form a third gear.
The meshed state with the gear 22c is maintained, and the third gear 2
The rotation of 2c causes the third gear 22c to act as a sun gear and moves around it. Reference numerals 13 and 14 are stoppers for restricting the movement of the planetary gear 25 within a certain area. The stoppers 13 and 14 are arranged at positions where the arm 26 abuts.
The planetary gear 25 is restricted from further moving upward, and the arm 26 is contacted with the stopper 14, so that the planetary gear 25 is restricted from moving downward.

FIG. 3 shows the planetary gear 25 and platen 8 assembly. The planetary gear 25 has a gear shaft 27,
The platen 8 is attached to the gear shaft 27. The platen 8 has a gear shaft 27 penetrating the planetary gear 2
5, the gear shaft 27 merely attaches the platen 8 and the gear shaft 27 and the platen 8 are not engaged with each other. Therefore, the gear shaft 2
The rotational force of 7 is not transmitted to the platen 8, and the platen 8 only rotates following the rotation of the gear shaft 27.

By assembling the platen 8 to the planetary gear 25 in this way, the platen 8 moves with the movement of the planetary gear 25, so a connecting member for moving is provided between the planetary gear 25 and the platen 8. There is no need, the structure is simple, and the assembly can be made with a small number of parts.

In the above structure, when setting the recording paper 6, the motor 10 is driven counterclockwise as shown in FIG. As a result, the paper feed roller 9 moves to the first gear train 21.
It rotates in the clockwise direction via (see FIG. 1). The rotational force of the paper feed roller 9 is transmitted to the third gear 22c of the second gear train 22 in conjunction with the rotation of the paper feed roller 9. This third gear 2
A planetary gear 25, which is connected to the gear 22c by an arm 26, meshes with 2c, and the planetary gear 25 rotates clockwise around the third gear 22c by the rotation of the third gear 22c (see FIG. 2). ). As a result, the platen 8 also integrally moves in the same direction and is separated from the print head 4 (see FIG. 1). The movement of the platen 8 and the planetary gear 25 is stopped by the arm 26 coming into contact with the stopper 14, and further movement is restricted. For this reason, these do not interfere with the surrounding members, and the damage can be prevented. FIG. 1 shows such a state. Since the paper feed roller 9 continues to rotate in the counterclockwise direction, the recording paper 6 is conveyed in the direction of arrow A and inserted between the print head 4 and the platen 8, Set.

When printing is to be performed after setting the recording paper 6, the motor 10 is driven clockwise as shown in FIG. As a result, the paper feed roller 9 rotates counterclockwise, and the rotational force is transmitted to the second gear train 22 in conjunction with the rotation of the paper feed roller 9. Therefore, the third gear 22c of the second gear train 22 rotates clockwise. Therefore, the platen 8 integrally rotates in the same direction and comes into pressure contact with the print head 4. FIG. 4 shows such a state, and the print head 4
When a print signal is input to the recording paper 6, printing is performed on the recording paper 6, and the recording paper 6 is sequentially fed out by the rotation of the paper feed roller 9. Even in this case, since the stopper 13 stops the platen 8 and the planetary gear 25 from moving more than necessary, it is possible to prevent interference with surrounding members.

In this embodiment, the paper feed roller 9 is used.
The platen 8 is linked to the rotation of the print head 4 in the forward and reverse directions.
Since the platen 8 is driven into contact with and separated from, the drive of the platen 8 can be shared with the drive of the motor 10 of the paper feed roller 9. Therefore, the drive source can be a single system, the structure thereof can be simplified, and the control is facilitated. Further, since it is not necessary to move the print head 4 and a transmission member for moving the print head 4 is not required, the number of parts can be significantly reduced, and the manufacturing is easy.

The present invention is not limited to the above embodiment,
Various modifications are possible. For example, the interlocking member 20 may be a single-system gear train instead of a two-system gear train. In this case, a large-diameter gear is provided on the downstream side, and the driven gear 23 on the paper feed roller 9 side and the planetary gear 25 on the platen 8 side are meshed with this gear to prevent interference. Further, the paper feed roller 9 may be rotated by an endless transmission member such as a chain or a belt.

[0030]

According to the present invention, the platen is pressed against and separated from the print head in conjunction with the forward and reverse rotations of the paper feed roller. Therefore, the pressure contact and separation of the platen can be performed by the drive source of the paper feed roller. , The drive source is a single system. Therefore, the number of parts is reduced, the structure is simplified, and control and assembly are omitted.

Further, according to the present invention, by providing the stopper for restricting the movement of the platen within a certain area, it is possible to prevent the platen from moving more than necessary and prevent interference with surrounding members. Further, according to the present invention, the interlocking means is provided with a planetary gear, and the platen is moved by the planetary gear, whereby the assembling of these is facilitated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a first embodiment of the present invention when separating a platen.

FIG. 2 is a side view showing an operating state of the interlocking device when the platen is separated.

FIG. 3 is a perspective view of a main part of an assembly of a platen and a planetary gear.

FIG. 4 is a cross-sectional view of a main part when the platen is pressure-welded.

FIG. 5 is a side view showing an operating state of the interlocking device when the platen is pressed.

FIG. 6 is a side view showing the overall configuration of the device.

FIG. 7 is a sectional view of a main part of a conventional device.

FIG. 8 is a cross-sectional view of essential parts showing the operation of the conventional device.

[Explanation of symbols]

 4 print head 6 recording paper 8 platen 9 paper feed roller 10 motors 13, 14 stopper 20 interlocking means 21 first gear train 22 second gear train 25 planetary gear

Claims (4)

[Claims] 1. A print head for printing on a recording paper, a platen for pressing the recording paper against the print head when the print head prints on the recording paper, and supply and discharge of the recording paper to the print head. To rotate the paper feed roller in the forward and reverse directions, and to move the platen away from the print head in conjunction with the rotation of the paper feed roller in one direction, and to rotate the paper feed roller in the other direction. And a interlocking device that presses the platen against the print head. 2. The printing apparatus according to claim 1, further comprising a stopper for restricting an operation of pressing and separating the platen with respect to the print head within a predetermined movement range. 3. The first interlocking device transmits a rotation in forward and reverse directions to the paper feed roller, a second gear train connected to the first gear train, and the second gear train. 2. The printing apparatus according to claim 1, further comprising: a planetary gear that meshes with a gear train and moves within a certain range as the second gear train rotates, wherein the platen moves together with the planetary gear. 4. The printer according to claim 3, wherein the planetary gear of the interlocking means is attached to the same shaft as the platen.