JPS59150776A - Printer - Google Patents

Abstract

PURPOSE:To enable to reduce the overall size of a printer, by reducing the size of a carriage by removing a drive source for head-up and head-down operations from the carriage, in a thermal transfer type serial printer. CONSTITUTION:A printing head 1 is mounted on the carriage 3, and the position thereof is controlled by a head position controlling shaft 18. The carriage 3 is moved by a carriage-moving screw driven by the first motor. Rotation of the second motor 4 which is a paper-feeding motor is transmitted to a paper-feeding gear 10 connected directly to the first roller 6 or is transmitted to a head position controlling gear 11 connected directly to the shaft 18, through a planetary gear mechanism comprised of the first sun gear 15, a revolving arm gear 8, a planetary gear 16 and the like. The transmission is changed over by a change- over member 12. Accordingly, the size of the carriage and hence the overall size of the printer can be reduced, and cost can be lowered by supplying motive power for head-up and head-down operations from the paper-feeding motor.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to the mechanism of a thermal transfer serial printer. The present invention relates to a printing device used for up-down driving.

(Conventional configuration and its problems) Conventionally, in thermal transfer printers, as shown in Figure 1,
The mainstream is one in which the ink ribbon is stored in a cassette 2 and moves together with the print head 1.

The reason for this is that ink ribbon feeding control is the simplest compared to other methods. However, using a movable cassette like this requires extra space for the cassette to move, so the printer tends to be bulky. A paper feed motor 4, a print head feed motor 5, an ink ribbon feed motor (located in the carriage 3), and a solenoid for pressing and releasing the print head 1 from the platen 6 (also located in the carriage 3). ), it usually consists of three motors and one solenoid, making it difficult to downsize. Therefore, as shown in FIG. 2, there is a printer in which ink ribbon spools 7 are arranged on the left and right, and a print head 1 and a solenoid are left in the carriage 3. Even in this case, the carriage 3 is not very small, and there is a drawback that it is rather difficult to control the feeding of the ink ribbon.

(Object of the Invention) The present invention has been made in view of the conventional problems as described below, and its purpose is to provide a head-up/down drive from a carriage in a thermal transfer serial printer. To provide a printing device in which the printer as a whole is made smaller by removing the power source and reducing the size of the carriage, and furthermore, the power for the head amplifier/reunion is supplied from a paper feed motor to reduce costs. It is in.

(Structure of the Invention) The main parts of the printing device C of the present invention (hereinafter referred to as a printer) are as follows:
A carriage with a print head etc. mounted thereon, a first motor for moving the carriage, a second motor used also for rotating a paper feed roller and driving the print head up and down, and a second motor. It is composed of a planetary gear mechanism and a switching mechanism for switching and transmitting the rotation of the paper feed roller or the feed up/down. Note that in the present invention, the ink ribbon winding mechanism is not directly related, so its explanation will be omitted.

(Explanation of Embodiment) FIG. 3 shows an embodiment of the present invention, and is a plan view of the vicinity of the second motor, which is the main part. Note that the same functional parts as in FIG. 1 are given the same reference numerals. 1 is a print head, which is mounted on the carriage 3 and is connected to the head position control shaft 18.
Its position is controlled by The carriage 3 can be moved left and right by rotation of a carriage moving screw (20 in FIG. 5), and this carriage moving screw is driven by a first motor (not shown). Reference numeral 6 denotes a paper feed roller which holds the recording paper 17 during printing and feeds the recording paper 17 in the direction of arrow C by its rotation when printing is completed. 4 is
In FIG. 1, the second motor is referred to as the paper feed motor, and its rotation is caused by the paper feed gear 10. Alternatively, it can be transmitted to the head position control gear 11 directly connected to the head position control shaft 18. The rotation of the second motor 4 is transmitted to the paper feed gear 1o, and switching between transmitting the rotation to the head position control gear 11 is performed by a switching member 12. In FIG. 3, the switching member 12 is slidable on the head position control shaft 18, but it may be on another shaft. 13t/'i This part is included in a part of the switching part 12 and biases the switching part 12 in the direction of the arrow.
It's Ilbane.

FIG. 4 is an exploded perspective view of the planetary gear mechanism.

15tj: The first sun gear is connected to the motor shaft 4a of the second motor 4. Reference numeral 8 denotes a revolving arm gear rotatably rotatable on a motor shaft, and is located between the second motor 4 and the first sun gear 15. A planetary gear 16 meshes with the first sun gear 15, and three planetary gears are used in the embodiment. The rotation center of the planetary gear 16 is a planetary gear shaft 8a on the revolving arm gear 8. Two rows of teeth are provided on the outer periphery of the revolving arm gear 8, and the head position control gear 11
The one that meshes with this is the revolution arm gear part A, 8c, and the other one is the revolution arm gear part B 8b. 9 is the second sun gear;
Planetary gear] Internal gear part 9cs that meshes with 6 Paper feed gear 10
There is a paper feeding side gear portion 9b that meshes with the paper feed side gear portion 9b, and an external gear portion 9a on the outer periphery. A part of the switching section 12 is provided with teeth 12a, which are connected to the external gear section 9a of the second sun gear 9.
The two gears mesh with the revolution arm gear B 8b, and if either one meshes with the other, that gear will not be able to rotate. Hereinafter, the teeth 12a will be referred to as the fixed portion of the switching member 12.

FIG. 5 shows details of the three carriage parts. 2o is carriage 3
This is a carriage moving screw for moving the paper in parallel with the paper feed roller 6. j8 is a head position control axis, and as shown in FIG. 3, the movement range of the carriage 3 has a square cross section, and the rest is circular. The inside of the carriage 3 is a cavity 3aK.
On the head position control shaft 18 of a, there is a head moving gear 19.
is movable in the axial direction, but the rotation is the same as the axis 18. Reference numeral 1a denotes a rack provided under the print head 1 so as to mesh with the head moving gear 19.

The carriage 3 has a groove 3b so that the print head 1 can move back and forth relative to the paper feed roller 6.

As the head moving gear 190 rotates, it becomes possible to control the position of parts (not shown) related to ink ribbon feeding, including the print head 1 on the carriage 3.

FIG. 3 shows the thermal transfer type serial printer of the present invention during printing. Since the carriage 3 is separated from the switching member 12, the fixed part 12a of the switching member 12, which is biased in the direction of the arrow by the coil spring 13, meshes with the external gear part 9a of the second sun gear 9. The second sun gear 9 cannot rotate. At this time, when the second motor 4 rotates in the direction of arrow A, the rotation of the second motor 4 passes through the sun gear 15 and the planetary gear 16, and since the second sun gear 9 cannot rotate, 8 rotates in the direction of arrow A. This rotation is transmitted to the head position control gear 11, thereby rotating the head movement gear 19 on the head position control shaft 18, and the print head 1 moves in a direction away from the paper feed roller 6.

Similarly, when the second motor 4 rotates in the direction of arrow B when the carriage 3 is separated from the switching member 12, the print head 1 moves closer to the one-sheet feed shimmy 26. This movement of the print head 1 makes it possible to control the position of parts related to the ink ribbon (not shown) as described above. The carriage 3 is moved by rotating a first motor (not shown) using a carriage moving screw 2 shown in FIG.
This can only be achieved by communicating this to 0.

When one line of printing is finished and the carriage 3 approaches the switching member 12, the force of the coil spring 13 is overcome and the switching member 1
2 is pushed in the direction of arrow E. As a result, the fixed part]2'a
is disengaged from the external gear portion 9a of the second sun gear 9 and comes to mesh with the planned arm gear portion B 8b of the revolution arm gear 8. At this time, the revolution arm gear 8 cannot rotate. FIG. 6 shows this state. When the second motor 4 is rotated in the direction of arrow A in this state, the revolution arm gear 8 rotates too much, so the planetary gear 16 only rotates around the planetary gear shaft 8a, and the first sun gear 15 is transmitted to the internal gear portion 9c of the second sun gear 9. At this time, the rotation direction of the second sun gear 9 is in the direction of arrow B. This rotation is carried out via the paper feeding side gear section 9b and the paper feeding gear 1o, and then the paper feeding roller 6.
, and the recording paper 17 is sent in the direction of arrow C.

By repeating the above steps, predetermined characters and other characters can be printed on the recording paper 17. Although a thermal transfer type serial printer has been described as an example, the present invention can also be applied to a thermal serial printer. At this time, the print head 1 only needs to be moved up and down, and the carriage 3
The structure becomes even simpler. Further, in the embodiment, when the carriage is at the printing start position, only when the carriage 3 is pushing the switching member 12 as shown in FIG.
Although it is possible to feed the paper, even in ordinary printers, when printing is finished, the carriage is returned to the printing start position and then the paper is fed, so this often causes problems.

(Effects of the Invention) As explained above, according to the present invention, the following effects can be obtained. In other words, the up/down drive section of the print head, which was conventionally inside the carriage, is now outside, allowing the carriage to be made more compact.Therefore, the load on the first motor, which is the drive source for carriage movement, is reduced, making it more compact. can. In addition, especially in the case of thermal transfer serial printers, it is necessary to operate the ink ribbon on the carriage, so the position of many parts must be controlled, but the drive force is transmitted through the head position control shaft, so the mechanism can be done relatively easily. The drive source for this head position control axis is the same as the second motor, which is also the drive source for paper feeding, so the number of drive sources can be saved, making it possible to downsize the entire printer and reduce costs. can also make a major contribution.

[Brief explanation of the drawing]

1 and 2 are a plan view of the entire conventional thermal transfer type serial printer, respectively. FIG. 3 is a plan view of a main part of an embodiment of the present invention, and FIG. FIG. 5 is an exploded perspective view of a part of the planetary gear mechanism, FIG. 5 is a configuration diagram of the carriage portion, and FIG. 6 is a plan view of the main part for explaining the operation. ■ ・・・・・・Print head, 3 ・・・・・・
...Carriage, 4...Second motor, 6...Paper feed roller, 8...
...Revolving arm gear, 9...Second sun gear, 12...Switching member, 15...
...First sun gear, 16...Planet gear, 17...Recording paper, 18...
Head position control axis, 19... Head movement gear, 20... Carriage movement gear 7. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 4

Claims (3)

[Claims] (1) A print head, a carriage on which the print head is mounted and moves parallel to the paper feed roller, a first motor that drives the carriage, and rotation of the paper feed roller and up/down of the print head. a second motor that drives the second motor; and the driving force of the second motor is switched and transmitted to the paper feed roller when the print head is at the home position, and when the print head leaves the home position. A printing device comprising a switching member that switches and transmits information to the printing head side and a planetary gear mechanism. (2) The planetary gear mechanism includes a first sun gear and a second sun gear.
Consisting of a sun gear, a planetary gear, and a revolving arm gear,
The driving force of the second motor supplied to the first sun gear is taken out to the paper feed roller side through the second sun gear, and a gear portion is provided on the outer periphery of the print head side. The printing device according to item (1), in which the revolving arm gear is determined. (3) The switching member has means for locking the rotation of the second sun gear and the revolving arm gear, and switches either the second sun gear or the revolving arm gear depending on the position of the print head. Lock the first printing device.