JPH0114436Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an improvement of a platen drive mechanism in a printer.

[Prior art]

Currently, production automation is being carried out in various industrial fields in order to reduce costs, save labor, mass produce, improve quality, etc.

Under these circumstances, efforts are being made to produce printers by automatic assembly.
Manual assembly is still performed because it is necessary to assemble many mechanical parts of different shapes three-dimensionally and compactly.

One of the mechanical parts that is assembled manually is a drive mechanism (hereinafter referred to as LF mechanism) that rotates a platen in a printer.

Because the LF drive motor disposed in the LF mechanism is placed horizontally, the following drawbacks arise.

Generally speaking, automatic assembly is carried out using a "stacking method" in which parts are arranged and assembled using tools that pick up parts one by one, so the tool drive using this stacking method basically consists of three movements: vertical movement, forward/backward movement, and rotation. It consists of axis control, but because the LF drive motor is placed horizontally, the number of axes to control the tool increases compared to a vertically placed one, making the operation more complicated.
There are drawbacks such as a decrease in positioning accuracy and a concomitant decrease in assembly accuracy.

In addition, the increase in the number of axes for controlling the tool makes the control of the tool complicated, which increases troubles in the control system, resulting in poor manufacturing yields.

Furthermore, it also has disadvantages such as an increase in product price due to an increase in assembly time, and a significant increase in maintenance cycles, maintenance time, and maintenance costs for automated equipment including tools.

Conventionally, this places a heavy burden on the tools used for assembly, making automatic assembly difficult.

Furthermore, the structural form of the LF mechanism also has the following drawbacks that hinder automation of assembly.

This is because the driven gear fixed to the platen and the driving gear of the LF drive motor are placed behind the platen, in the horizontal direction opposite to the print head, in order to make the printer thinner and allow the platen to be attached and detached.
Moreover, it is customary to engage below the center of the platen.

As the printing quality of printers increases and the trend toward graphics advances, high precision is required when rotating the platen in forward and reverse directions.
The problem is the meshing play between the drive gear of the LF drive motor and the driven gear of the platen. It is necessary to minimize this play, and in order to reduce this play while performing automatic assembly, the platen must be moved in the opposite direction from the printing head to adjust the engagement. There is a risk that the distance between the print head and the print head will fluctuate and the print quality will deteriorate significantly.

Therefore, in order to move the print head back and forth during automatic assembly to properly adjust the distance between it and the platen, the guide member of the carriage in which the print head is mounted must be adjusted, which is extremely troublesome and difficult. This is a drawback that makes automatic assembly extremely difficult.

[Purpose of invention]

The purpose of the present invention is to solve the conventional drawbacks by making the LF mechanism suitable for automatic assembly.

[Structure of the idea]

In order to achieve the above-mentioned object, the present invention provides a platen drive mechanism in which a drive motor rotationally drives a platen that is rotatably supported so as to face a print head, in which a bevel gear is provided coaxially with the platen, and a bevel gear is provided coaxially with the platen. A flat brushless motor specifically designed for the platen is used as the motor. The flat brushless motor is arranged so that its axial direction is perpendicular to the axial direction of the platen and its rotating shaft faces upward, and a bevel gear meshing with a bevel gear provided coaxially with the platen is connected to the flat brushless motor. The configuration is such that it is directly connected to the rotating shaft of the

Such a configuration facilitates assembly of the platen drive mechanism and the platen, and is effective for automatic assembly.

〔Example〕

An embodiment of the present invention, which is characterized by the above-mentioned object and structure, will be described below with reference to the drawings.

First, the overall outline will be explained with reference to FIG.

FIG. 1 is a schematic overall perspective view of a printer according to an embodiment of the present invention.

1 is a board on which parts to be described later are mounted, 2 is a platen that rotates and forms a printing surface, 3 is a bevel gear to be driven fixed to one end of the platen 2, and 4 is a side frame that rotatably supports the platen 2. , 5 is a LF drive motor using a flat brushless motor that rotationally drives the platen 2, 6 is a driving bevel gear fixed to the motor shaft of the LF drive motor 5, and the bevel gear 6 is the bevel gear of the platen 2. The bevel gear 6 meshes with the bevel gear 3 to drive the platen 2, and as will be explained in a separate drawing to be described later, the bevel gear 6 has an elastic structure so that the teeth can oscillate. This is the LF mechanism that rotationally drives the platen 2.

Reference numeral 7 denotes a space drive motor for the print head, which will be described later. 8, a drive pulley of the space drive motor 7; 9, an idle pulley corresponding to the drive pulley 8; and 10, a print character attached to the drive pulley 8 and the idle pulley 9, which will be described later. Synchro belt that performs head spacing, 11 is synchro belt 1
This is a carriage guide that contains 0 and defines the spacing path of the print head. This is the spacing mechanism.

12 is a print head, 13 is a ribbon cartridge containing an ink ribbon, 14 is a ribbon cartridge guide, and 15 is a print head 12, a ribbon cartridge 13, and a ribbon cartridge guide 14.
The carriage 15 is fixed at a predetermined position on the synchro belt 10 to perform spacing.
16 is a home sensor lever provided on the carriage 15; 17 is a home position sensor for detecting the home sensor lever 16; and 18 is a flat cable for transmitting a signal to the print head 12. This is a carriage mechanism on which a print head 12 and a ribbon cartridge 13 are mounted, and the carriage mechanism has a built-in ribbon shift mechanism.

19 is a ribbon switching motor, 20 is a shift pulley of the ribbon switching motor 19, and 21 is an escape bar. This is coupled to the ribbon shift mechanism.

22 is a power supply section, 23 is a control section, 24 is an external connection connector section, 25 is an operation switch, and 26 is an indicator lamp.

The general structure of the device is as described above, and the LF drive motor 6, like the space drive motor 7, is a flat brushless motor and is placed vertically, so it can be installed instead of being fixed to a conventional side frame, etc. It is very easy to install compared to the horizontal installation, so it is suitable for automatic assembly.Also, when the bevel gear 3 of the platen 2 and the bevel gear 6 of the LF drive motor 5 are engaged, as will be explained later, the LF drive motor Since the bevel gear 6 of the motor 5 has an elastic structure that allows it to swing, it absorbs meshing play and facilitates automatic assembly.

Next, an outline of the printing operation will be described.

The print head 12 receives a print signal from the flat cable 18 so that the platen 2 is shown and starts printing on the print surface formed by wrapping the print medium. At this time, the space drive motor 7 is rotated in synchronization with the print signal to run the synchro belt 10, and while spacing the print head 12 together with the carriage 15, printing of that line is performed.

Thereafter, the LF drive motor 5 is rotated, and the bevel gears 6 and 3 are engaged to rotate the platen 2 to perform a line feed.

The outline of the present invention is as follows, and the LF mechanism, spacing mechanism, carriage mechanism, ribbon shift mechanism, and various control sections explained in FIG. 1 are assembled into a unit and sequentially mounted on the board 1.

Next, each of the above mechanisms will be described in detail based on the drawings.

First, let's talk about the LF mechanism.

FIG. 2 is a side sectional view showing the LF mechanism, FIG. 3 is a perspective view of the driving bevel gear, and 6 is the bevel gear of the LF driving motor 5 using a flat brushless motor.
A hole is provided as shown in FIG. 3, so that the rotating shaft 28
It has elasticity so that it can swing around the center. 27 is a magnetic holder,
28 is a rotating shaft of the LF drive motor 5, and the bevel gear 6, the magnetic holder 27, and the rotating shaft 28 are integrally formed. 29 is a rotating shaft 28 to which the LF drive motor 5 is rotatably attached to the substrate 1.
30 is a rotor magnet fixed to the lower surface of the magnet holder 27, 31 is a magnet 30
A core pole fixed to the substrate 1 to correspond to the
32 is a stator coil arranged on the core pole 31;
3 is a stator coil pattern fixed on the substrate 1 to connect the stator coil 32. The predetermined distance between the stator coil 32 and the rotor magnet 30 is determined by the length of the bearing 29 that supports the rotating shaft 28 of the LF drive motor 5.

In this assembly, when assembling the platen 2 into the side frame 4, the bevel gear 6 of the LF drive motor 5 and the bevel gear 3 of the platen 2 do not mesh immediately, and there is a risk that excessive force will be applied to the meshing part and cause it to break. However, in the present invention, as explained above and shown in FIG. 3, a hollow part is formed in the plane of the bevel gear 6 of the LF drive motor 5 to give it elasticity, so that the excessive force can be absorbed. Damage to parts can be prevented.

In the conventional LF mechanism, the conventional LF drive motor was fixed to the side frame that was perpendicular to the axial direction of the platen 2 using screws, etc., and required bundled wiring. Since the child coil pattern 33 is used, the conventional bundled wiring is not required and the work is done on a flat surface, so the effect on automatic assembly is very large. Further, since the motor is a flat brushless motor, the height of the device does not increase even if it is mounted perpendicularly to the substrate 1.

Next, the spacing mechanism will be described based on FIG.

FIG. 4 is a side sectional view of the spacing mechanism;
34 is a bearing portion of the drive pulley 8; 35 is a stator yoke fixing the bearing portion 34; 36 is a rotor magnet fixed to the lower surface of the drive pulley 8;
7 is a film-like coil pattern arranged from the bottom surface of the substrate 1 to the top surface of the stator yoke 35, and 38 is a fixing device connected to and fixed to the film-like coil pattern 37 so as to correspond to the rotor magnet 36 at a predetermined interval. The space drive motor 7, which is a child coil, is configured in this manner. 39 is an idle pulley shaft, 40 is a carriage guide provided on the board 1, and 41 is a carriage guide 11.
This is a carriage guide pin installed in the

Next, the carriage mechanism will be explained, and then the assembly of the spacing mechanism will be described.

FIG. 5 is a side sectional view of the carriage mechanism;
2 is a rear guide portion of the carriage guide 11, 43
44 is a belt guide of the carriage 15 provided at the bottom of the carriage 15 on the platen 2 side, 45 is a belt hanger facing the belt guide 44, 46 is an upper frame of the printer,
47 is the same bottom frame.

As shown in FIG. 4, in the present invention, a film-like coil pattern 37 is used for the space drive motor 7, so that bundled wiring is not required during assembly, making automatic assembly easier.

During assembly, the idler pulley shaft 39 is press-fitted or installed near one end of the carriage guide 11, and the idler pulley 9 is pushed in from above.

The synchro belt 10 is arranged along the inside longitudinal direction of the box-shaped carriage guide 11, and is wound around the idle pulley 9 even though its teeth do not mesh with each other. The synchro belt 10 is now housed within the carriage guide 11 in a state similar to that shown in FIG. 1, making it easy to assemble the space drive motor 7 into the drive pulley 8.

In this state, instead of immediately wrapping the synchro belt 10 around the drive pulley 8 on the board 1, a jig for assembling a rotatable shaft (no teeth required) is erected at approximately the same position as the drive pulley 8, and the shaft is The other side of the synchro belt 10 is hooked to the belt so that the synchro belt 10 is tensioned to some extent.

Next, as will be explained in detail with reference to FIG. 6, the ribbon cartridge 13, carriage 15, bond drive gear group, etc. are automatically assembled on the axis of the jig, that is, the drive pulley 8 side of the carriage guide 11. In this step, the belt guide 44 and belt hanger 45 of the carriage 15 are engaged with the synchro belt 10 at a position where they can be inserted into the synchro belt 10.

Thereafter, the carriage 15 is slid directly toward the idle pulley 9, and the front guide part 43 and rear guide part 42 of the carriage guide 11 are loosely fitted into the front and rear grooves of the carriage 15.

Here, the assembly jig placed on the drive pulley 8 side is removed and the synchro belt 10 is attached to the drive pulley 8.

Also, at this time, the carriage guide pin 41 is fitted into the carriage guide guide 40 provided on the substrate 1, and the carriage guide 11 is positioned perpendicularly to the axis of the platen 2, and the distance between the printing head 12 and the platen 2 is determined. is also decided.

Next, in order to apply appropriate tension to the synchro belt 10, move the carriage guide 11 toward the left LF drive motor 5 shown in FIG. 1, that is, in the direction of arrow a shown in FIG. 4
1 is tightly attached to the substrate 1.

After that, it can be easily fixed by dipping it together with other electrical parts and soldering it, and it also serves to reinforce the board 1.

Next, the ribbon shift mechanism will be explained based on FIG. 6. FIG. 6 is an exploded perspective view showing a ribbon shift mechanism including a ribbon cartridge and a carriage, and 48 is a ribbon drive pulley of the ribbon cartridge 13, which penetrates to the bottom and projects.

49 is a guide piece protruding from a predetermined outer circumference of the ribbon cartridge guide 14 to accommodate the ribbon cartridge 13; 50 is a latch protruding from both guides 49 with elasticity; 51 is a guide piece for storing the ribbon cartridge 13; A guide hole through which the lower part of the ribbon drive pulley 48 passes, 52 is a mounting portion of a driven shaft to be described later, and 53 is a ribbon cartridge guide 14.
This is a rotating fulcrum for ribbon switching that protrudes from the bottom of the ribbon. The ribbon cartridge 13 is housed in both guide pieces 49 of the ribbon cartridge guide 14, and the lower part of the ribbon drive pulley 48 projects through the guide hole 51 of the ribbon cartridge guide 14.
Both sides are latched with latches 50 to form a single body.

Reference numeral 54 designates a print head storage portion formed by cutting out the carriage 15, 55 designates a print head mounting groove, 56 designates a hole portion for rotatably mounting a driven shaft to be described later, and 5
7 is a lock bar having teeth integrally fixed to the carriage 15 in order to stop unnecessary rotation of the driven shaft; 58 is a pivot guide that supports the rotation of the rotation fulcrum portion 53 of the ribbon cartridge guide 14; and 59 is the lock bar shown in FIG. This is a groove in which a flat cable 18 is attached.

60 is a ribbon drive gear that fits into the lower end of the ribbon drive pulley 48 and rotates, 61 is a pinion arranged on both sides of the ribbon drive gear 60, and 62 is an idle pinion provided between the other pinion 61 and the ribbon drive gear 60. , and these mesh together in series. 63 is a gear guide that rotatably supports the series of ribbon drive gears 60, both pinions 61, and idle pinion 62. The gear guide 63 is attached to the carriage 15 and supports the rotation of each gear together with the carriage 15, and the ribbon drive gear 60 passes through the carriage 15 and meshes with the lower end of the ribbon drive pulley 48 as described above. The ribbon drive gear 60 always rotates in a fixed direction because both pinions 61 including an idle pinion 62 mesh with the lock teeth formed on the rear guide portion 42 of the carriage 11.

64 is a driven shaft for ribbon switching, 65
66 is a rotation determining portion of the driven shaft 64; 67 is a tooth portion that meshes with another fixed portion to prevent rotation due to vibration; 68 is the lower end of the driven shaft 64. Shift pulley 20 shown in FIG.
fit into the groove. 69 is a shift piece that fits into the driven shaft 64, and 70 is a projection of the shift piece that engages with the groove 65. This driven shaft 6
4 is attached by loosely fitting the positioning part 66 into the hole 56 of the carriage 15, and the teeth of the lock bar 57 of the carriage 15 mesh with the teeth 67 of the driven shaft 64 to prevent unnecessary rotation of the driven shaft 64. ing. The mounting portion 52 of the ribbon cartridge guide 14 reaches the ribbon cartridge 13, and one end 68 of the lower portion can be inserted into the groove of the shift pulley 20 in FIG.

This driven shaft 64 is a carriage 15
When the shift pulley 20 reaches the position detected by the home position sensor 17 shown in FIG. 1, one end 68 fits into the groove of the shift pulley 20 and becomes rotatable. However, only when there is a command to switch the ribbon, the escape bar 21 shown in FIG.
Do this by rotating 9. Ribbon switching is performed at an appropriate rotational speed by the lead of the groove 65 of the driven shaft 64, and determines the amount of ribbon shift.
In a normal multicolor ink ribbon, the shift amount for one stage is approximately 5 m/m, and since this is set by the rotation speed of the driven shaft 64, the accuracy of the ribbon shift amount is greatly improved, and the groove portion 65 By changing the lead, the ribbon switching shift amount can be set arbitrarily.

Further, since the thick part A of the gear guide 63 is slightly thicker than each gear, there is no problem with the rotation of the gears. Since the rear guide part 42 is thicker than the other thick part C of the gear guide part 63 and the thick part D of the carriage 15, the rear guide part 42 meshes with the pinion 61 housed in the gear guide 63 and slides. It's becoming possible.

Conventional ribbon switching mechanisms were carried out using plungers, etc., but as the shift amount and number of shifts increased, the size of the plungers became larger and the use of multiple plungers became necessary.Moreover, due to noise problems when the plungers were driven, motors were used recently. A method of mounting the motor on a carriage has been considered, but there were problems such as the difficulty of processing the motor lead wires for wiring.
The present invention solves these problems all at once, making automatic assembly possible.

[Effect of idea]

As explained in detail above, in this invention, the LF drive motor is placed vertically instead of the conventional horizontal one, a flat brushless motor is used, and the driving relationship with the platen is that a bevel gear with an elastic structure is connected to the platen. It has a structure that meshes with the driven bevel gear, and a film-like pattern wiring structure is used for signal input, so that the following effects can be achieved.

The LF drive motor is not mounted horizontally on the side frame as in the past, but is mounted vertically on the board, making it possible to assemble it sequentially on a flat surface, and it also allows for easy automatic assembly as it can be stacked. This is the effect of

In addition, the drive relationship between the platen and the LF drive motor is made of bevel gears with elasticity for the LF drive.
It can absorb the unreasonable force of meshing when assembled, and since the platen is adjusted by moving it in the direction of the platen axis, the printing interval, which is the distance between the print head and the platen, does not change during adjustment, which is a great effect in making automatic assembly very easy. There is also.

Since each wiring is connected by a film-like pattern, automatic assembly is further facilitated.

Due to these effects, the present invention can be very advantageously used in adopting automatic assembly in printers.

[Brief explanation of the drawing]

FIG. 1 is a schematic overall perspective view of a printer according to an embodiment of the present invention, FIG. 2 is a side sectional view showing the LF mechanism,
Figure 3 is a perspective view of the driving bevel gear, Figure 4 is a side sectional view of the spacing mechanism, Figure 5 is a side sectional view showing the carriage mechanism, and Figure 6 explains the ribbon cartridge and ribbon shift mechanism. FIG. 1... Board, 2... Platen, 3... Bevel gear,
5...LF drive motor, 6...Bevel gear, 7...
Space drive motor, 8...drive pulley,
9... Idle pulley, 10... Synchro belt, 11... Carriage guide, 12... Print head, 13... Ribbon cartridge, 14... Ribbon cartridge guide, 15... Carriage,
19... Ribbon switching motor.

Claims (1)

[Claims for Utility Model Registration] A platen drive mechanism in which a drive motor rotationally drives a platen rotatably supported on a substrate so as to face a printing head, a bevel gear being provided coaxially with the platen, the drive motor A flat brushless motor dedicated to the platen is used as the flat brushless motor, and the flat brushless motor is arranged so that its axial direction is perpendicular to the axial direction of the platen and its rotation axis faces upward, and an umbrella is provided coaxially with the platen. A platen drive mechanism characterized in that a bevel gear that meshes with a gear is directly connected to the rotating shaft of a flat brushless motor.