JPH04128074A - Drive mechanism of printer - Google Patents

Abstract

PURPOSE:To perform the contact and separation driving of a printing head and the taking-up driving of an ink ribbon by an inexpensive and simple structure by forwardly and reversely rotating one drive motor to forwardly and reversely rotate a shaking gear. CONSTITUTION:At first, it is explained that a printing head 7 is brought into contact with a platen 2 to be brought to a head-down state from a head-up state. In this case, when a shaking gear 28 is rotationally driven in a counterclockwise direction by driving a motor, a shaking plate 29 is shaken in the counterclockwise direction and a head-down gear 30 is meshed with a cam gear 33 and the engaging pin 35 of the shaking plate 29 is engaged with the head-down cam groove 36a of the cam gear 33, through a shaking part 36c. By this mechanism, the cam gear 33 is rotated in the counterclockwise direction and a head contact and separation cam lever 40 gradually guides the contact and separation driving pin 42 thereof from the large diameter part of the contact and separation driving cam groove 39 of the cam gear 33 toward the small diameter part thereof, that is, from the outside to the inside and the shaking plate is shaken in the clockwise direction around a support shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer drive mechanism, and particularly to a drive mechanism for driving a print head of a printer toward and away from a platen, and for winding an ink ribbon during printing. This invention relates to a printer drive mechanism.

[Conventional technology]

FIG. 5 shows a conventional general printer, in which a flat platen 2 is disposed approximately in the center of a frame 1 of the printer so that its printing surface is approximately vertical. A carriage shaft 3 is disposed below the front side of the platen 2 of the frame 1 in parallel with the platen 2. Further, a seven-lunge-shaped guide portion 4 is formed on the front edge of the frame 1, and a rack 5 is formed on the inner edge of this guide portion 4. A carriage 6 is attached to the carriage shaft 3 and the guide section 4, and this carriage 6 is attached to the rack 5.
By driving a motor meshed with the carriage shaft 3 and the guide section 4, the carriage shaft 3 can freely reciprocate along the carriage shaft 3 and the guide section 4. A print head 7 is attached to the tip of the carriage 6 so as to face the platen 2. An ink ribbon is stored on the top surface of the carriage 6, and the ink ribbon is connected to the print head 7 and the platen. A guiding ribbon cassette (not shown) is attached between the two.

Further, a paper insertion port 8 is formed at the rear of the platen 2 to transport paper (not shown) to the front of the platen 2, and the paper insertion port 8 is provided with a paper insertion port 8 for transporting the paper at a predetermined speed. A paper feed roller 9 is provided. Below this paper feed roller 9, a pressure roller 10 that is in pressure contact with this paper feed roller 9 is disposed at the rotation point, and a sheet of paper is placed between the paper feed roller 9 and this pressure roller 10. Insertion port 8
It is designed to nip and convey the paper inserted from there.

FIG. 6 shows a conventional carriage drive mechanism and print head drive mechanism in such a printer. Inside the carriage 6, there is a carriage drive motor 1.
1 is provided, and the output shaft 12 of this carriage WpvJ motor 11 is meshed with the rack 5 via a gear 13. The carriage 6 can freely reciprocate along the carriage shaft 3 by forward and reverse rotation of the carriage drive motor 11.

Further, a fixing member 14 for a print head 7 is pivotally attached to the platen 2 side of the carriage 6 via a fulcrum 15. It is said that it can move towards and away from the opponent. One end 17a of a cam follower 17 as a driven joint, which is formed in a bell crank shape and is rotatable about a fulcrum 16, is in contact with the fixing member 14 of the print head 7, and the other end is in contact with the fixing member 14 of the print head 7. The portion 17b is slidably engaged with an endless cam groove 19 of a cam member 18 as a driving joint. An output pinion 23 of a print head up/down motor 22 mounted on the carriage 6 is meshed with a gear 20 integrally formed on the outer periphery of the cam member 18 via a transmission gear 21. The cam member 18 is rotated by the rotation of the motor 22, and the cam follower 17 is rotated with the rotation of the cam member 18. The rotation of the cam follower 17 causes the fixed member 14 to be pressed against one end 17a of the cam follower 17. The printing head 7 is moved forward and backward relative to the platen 2, and the print head 7 presses the ink ribbon and recording paper against the platen 2, and releases the pressure.

Further, a motor 25 that drives an ink ribbon take-up revolving bin 24 for winding up an ink ribbon (not shown) is also provided on the carriage 6 separately from the motor 22 for up and down printing. Output binion 25a
A take-up gear 27, which is provided coaxially with the ink ribbon take-up bod 24, is engaged with the ink ribbon take-up bod 24 via a transmission gear 26. Further, a sensor (not shown) is provided for detecting the up and down of the print head 7, and this sensor controls the operation of the ink ribbon winding motor 25 in response to the up and down of the print head 7. It's about to be controlled.

In the conventional printer, paper is inserted through the paper insertion slot 8, the paper is sandwiched between the paper feed roller 9 and the pressure roller 10, and the paper feed roller 9 is driven to rotate. is conveyed at a predetermined speed in a direction orthogonal to the moving direction of the carriage 6. On the other hand, the print head up/down motor 22 is driven to press the print head 7 against the paper with a predetermined pressure contact force, and in this state, the carriage drive motor 11 is driven to move the carriage 6. and driving the print head 7 based on a desired print signal while driving the ribbon take-up motor 25 to rotate the take-up bobbin 24 to take up the ink ribbon in the ribbon cassette.
This is to perform desired printing on the paper.

[Problem to be Solved by the Invention] However, in the drive mechanism of the conventional printer, a motor 22 for moving the print head up and down to drive the print head 7 toward and away from the platen 2, and a motor 22 for driving the print head to take up and wind the ink ribbon. Motor 2 for winding the ink ribbon
5 are provided separately from each other, which increases the size and weight of the carriage 6, and requires electric circuits for two types of drive motors, which complicates the structure of the printer and makes the device This has the problem of causing an increase in size. Furthermore, each drive motor 22.
In order to properly operate the print head 25, a sensor for detecting the contact/separation position of the print head 7 described above is required, which results in a complicated circuit and an increase in manufacturing cost.

The present invention has been made in view of these points, and it is possible to drive the print head toward and away from the printer and to drive the ink ribbon to take up the ink ribbon at low cost and with a simple structure, thereby making it possible to downsize the device. The purpose of this invention is to provide a driving mechanism for a printer.

[Means to solve the problem]

In order to achieve the above object, the printer drive mechanism according to the present invention has a printer drive mechanism that drives the print head of the printer toward and away from the platen, and drives the take-up bobbin to rotate. A rocking gear that is rotated in forward and reverse directions by rotational drive is provided, and a cam gear that drives the print head toward and away from the printer is provided near the rocking gear, and the rocking gear is configured to rotate the rocking gear in the opposite direction. A rocking plate is attached to the rocking plate, and a head-down gear and a head-up gear are attached to the rocking plate, which mesh with the rocking gear and selectively mesh with the cam gear. The present invention is characterized in that a ribbon winding gear is attached which meshes with the moving gear and meshes with the winding gear of the winding bobbin.

[For production]

According to the present invention, by rotating one drive motor forward and backward to rotate the rocking gear forward and backward, the rocking plate is rocked, and the head-down gear and the head-up gear are selectively attached to the cam gear. At the same time, the ribbon winding gear is engaged with the winding gear of the winding bobbin, thereby driving the printing head toward and away from the platen and driving the winding bobbin in a normal winding manner. Because it is inexpensive and has a simple structure, it is possible to miniaturize the device.Furthermore, there is no need for sensors to detect the contact/separation position of the print head, the circuit is simple, and manufacturing costs are significantly reduced. It is something that can be done.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

FIGS. 1 to 3 show an embodiment of the drive mechanism of the printer according to the present invention. A movable gear 28 is disposed, and a movable plate 29 is disposed on the upper surface side of the movable gear 28.
It is arranged to be able to swing freely around a. Further, on one side of the swing plate 29, a head-down gear 30 and a head-up gear 31 that are meshed with the swing gear 28 are provided.
are each rotatably attached, and the rocking plate 2
On the other side of 9, a ribbon winding gear 32 is rotatably attached. Also, near the attachment side of the head-down gear 30 and the head-up gear 31 of the swing gear 28, the head-down gear 30 and the head-up gear 31 are mounted, respectively, by the swing of the swing plate 29. A cam gear 33 that is selectively engaged is rotatably disposed near the attachment side of the ribbon winding gear 32 of the swing gear 28, and the swing of the swing plate 29 causes the ribbon winding to be carried out. A winding gear 34 of a winding bobbin with which the winding gear 32 is engaged is rotatably disposed.

A retaining pin 35 is provided on the swing plate 29 at a position corresponding to the upper surface of the cam gear 33 to protrude downward, and as shown in FIG. A head-down cam 136a, through which the engagement pin 35 is guided when the gear 30 is in mesh with the cam gear 33, is formed on the center side, and is located on the outer periphery of the head-down cam 1I36a. A head-up cam groove 36b is formed in which the engaging pin 35 is guided when the head-up gear 31 is in mesh with the cam gear 33. The head-down cam groove 368 and the head-up cam groove 36b communicate with each other via a swinging portion 36c. Further, on the outer peripheral surface of the cam gear 33, a notch is formed to the inside of the teeth of the cam gear 33, and a down intermittent part 37 is formed to engage the head down gear 30 and disable rotation transmission, and the head up gear 31 The lower surface of the cam gear 33 is provided with a spiral-shaped approaching/separating driving cam WA.
39 is formed.

The carriage also includes a cam lever 4 for approaching and separating the head.
0 is arranged so as to be swingable around a support shaft 41,
A contact/separation drive pin 42 that is engaged with the contact/separation drive cam 39 of the cam gear 33 is attached to one end of the head contact/separation cam lever 40, and the other end of the head contact/separation cam lever 40 A print head 7 is attached to the section.

Next, the operation of this embodiment will be explained.

First, a case will be described in which the print head 7 is moved from the head-up state shown in FIG. 1 to the head-down state by bringing the print head 7 into contact with the platen 2 as shown in FIG. 2.

In this case, when the motor is driven to rotate the swing gear 28 in the counterclockwise direction in FIG. At the same time, the engagement pin 35 of the swing plate 29 passes through the swing portion 36C and is engaged with the down cam groove 368 of the cam gear 33. As a result, the cam gear 33 is rotated counterclockwise, and accordingly, the head contact/separation drive cam lever 40 moves the contact/separation drive pin 42 from the large diameter portion of the contact/separation drive cam groove 39 of the cam gear 33 to the small diameter portion. By being guided gradually from the outside to the inside toward the end, it is swung in the FRi1 direction about the support shaft. As shown in FIG. 2, when the cam gear 33 rotates approximately once and the head down gear 30 is engaged with the down intermittent portion 37 of the cam gear 33, the rotational force of the pinion is transmitted to the cam gear 33. The cam gear 33 is stopped. In this state, the contact/separate drive pin 42 is located at the smallest diameter side of the contact/separate drive cam 39, so that the head contact/separation drive cam lever 40 is positioned closest to the print head 7.
The printing head 7 is held at the 9th position close to the platen 2, and the print head 7 is pressed against the platen 2 with strong force.

Further, as shown in FIG. 3, since the head-down gear 30 is located in the down-intermittent part 37 of the cam gear 33, the bed-down gear 30 enters inside the teeth of the cam gear 33, thereby causing rocking. The plate 29 is further swung counterclockwise than when it engages with the cam gear 33,
A front bong winding gear 32 is meshed with a winding gear 34.

The rotational force of the swing gear 28 rotates the winding gear 34, which rotates a winding bobbin (not shown) to wind up the ink ribbon.

Simultaneously with the start of winding of the ink ribbon, the print head 7 is driven while driving the carriage in the carry direction.
Desired printing is performed by energizing each heating element based on a desired printing signal.

Next, a case will be described in which the print head 7 is moved away from the platen 2 (not shown) from the head-down position shown in FIG. 3 to the head-up position as shown in FIG.

In this case, by driving the motor in the opposite direction to when the head is down and rotating the swing gear 28 clockwise in FIG. 2, the swing plate 29 is swinged clockwise, and the head The up gear 31 is engaged with the cam gear 33, and the ribbon winding gear 32 is engaged with the winding gear 3.
4, and the engaging pin 35 of the swing plate 29 connects to the up cam groove 36b of the cam gear 33 via the swing part 36c.
&: Engaged. As a result, the cam gear 33 is rotated clockwise, and accordingly, the head contact/separation driving cam lever 40 has its contact/separation drive pin 42 gradually guided from the inside to the outside by the contact/separation drive cam groove 39 of the cam gear 33. As a result, it is swung counterclockwise around the support shaft. Then, as shown in FIG.
3, the rotational force of the pinion is no longer transmitted to the cam gear 33, and the cam gear 33 is stopped. In this state, the contact/separate drive pin 42 is located at the outermost side of the contact/separate drive cam W439, so that the print head 7 is separated from the platen 2.

Therefore, in this embodiment, a single drive motor is used to drive the print head 7 toward and away from the platen 2, and also to drive the winding bobbin to take up the winding bobbin, which is inexpensive and has a simple structure. The device can be made smaller, and there is no need for a sensor υ for detecting the contact/separation position of the print head, the circuit is simple, and the manufacturing cost can be significantly reduced.

Note that the present invention is not limited to the above embodiments,
Various changes can be made as necessary.

C. Effects of the invention] As described above, the printer drive mechanism according to the present invention has the following effects:
Since a single drive motor drives the print head toward and away from the platen and drives the take-up bobbin to take up the winding bobbin, it is inexpensive and has a simple structure, making it possible to downsize the device and reduce manufacturing costs. This effect can be significantly reduced.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the printer drive device of the present invention, in which FIG. 1 is a plan view showing the head-up state, FIG. 2 is a plan view showing the head-down state, and FIG. 3
4 is a plan view of the cam gear, FIG. 5 is a perspective view of a conventional general printer, and FIG. 6 is a conventional print head contact/separation drive and ink. FIG. 2 is a cross-sectional view that does not show a ribbon winding drive device. 7... Print head, 28... Rocking gear, 29...
Rocking plate, 30... Gear for head down, 31... Gear for head up, 32... Gear for ribbon winding, 3
3... Cam gear, 34... Winding gear, 35...
Engagement pin, 36... cam groove, 39... cam groove for contact/separation drive, 40... cam lever for head contact/separation, 42...
Pin for contact/separation drive.

Claims (1)

[Claims] In the drive mechanism of the printer, which drives the print head of the printer toward and away from the platen, and drives the take-up bobbin to rotate, a swing gear is provided which is rotated in forward and reverse directions by the forward and reverse rotation of one drive motor. , a cam gear for driving the print head toward and away from the oscillating gear is disposed near the oscillating gear, and a oscillating plate that oscillates as the oscillating gear rotates is attached to the oscillating gear. A head-down gear and a head-up gear are attached to the plate, which mesh with the swing gear and selectively mesh with the cam gear, and which mesh with the swing gear and mesh with the winding gear of the winding bobbin. A printer drive mechanism characterized in that a ribbon winding gear is attached.