JPS61279571A - Printer - Google Patents

Abstract

PURPOSE:To obtain a printer extremely simple in construction and capable of recording at high speed, by providing a cam rotated by a motor, a lever having one end in contact with the cam and reciprocated with an intermediate part thereof as a fulcrum, and a carriage connected to the other end of the lever. CONSTITUTION:The lever 8 is reciprocated between D and E with a shaft 9 as a center, thereby reciprocating the carriage 11. During this process, a recording head 18 records on a recording paper 27 according to recording commands outputted from a controlling circuit through a flexible printer base 15. Since the lever 8 functions as a lever with the shaft 9 as a center, the motion between A and B is enlarged in a lever ratio CD:AC with the fulcrum C as a center, resulting in a motion between D and E, whereby the carriage 11 is accelerated by a factor of CD/AC. A tooth part of a partial gear 3 is engaged with a paper- feeding gear 20 for each one revolution of a cam disk 4, namely, each one reciprocation of the carriage 1, so that a paper-feeding roller 24 is rotated through a pinion-gear unit 21, 23, and the paper 27 is fed by a one-line amount while being clamped between the roller 24 and a pinch roller 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer, and more particularly to a printer that performs recording by moving a carriage equipped with a recording head back and forth along a platen.

[Summary of the Disclosure] This specification and drawings describe a printer that performs recording by reciprocating a carriage equipped with a recording head along a platen, and a cam that is rotated by a motor, one end of which is in contact with the cam, and a printer that performs recording by reciprocating a carriage equipped with a recording head along a platen. By providing a lever that rotates reciprocally as a fulcrum and a carriage connected to the other end of this lever, the small amount of movement of one end of the lever is expanded and transmitted to the reciprocating movement of the carry and the carriage, resulting in a simple structure. This paper discloses a technology that enables high-speed recording.

[Prior Art] Various types of printers have been proposed in the past, but these can be broadly classified into line printers and serial printers.

Line printers simultaneously record one line at a time, and serial printers record one character (one digit) at a time.

Furthermore, serial printers can be divided into those that record one character at a time by mounting a type wheel on a carriage, and those that record one character at a time using dots in a dot matrix structure, such as thermal printers and inkjet printers.

The carriage of such serial printers is usually driven by a DC motor or a stepping motor.

In the case of a DC motor, feedback control is performed,
The position of the carriage is constantly detected and this is fed back to control the motor drive. Carriage carry is performed via wires, etc., and carriage return is performed by stopping the motor and connecting the drive system and carriage system. The clutch is turned off and returned to the home position by the tension of the spring, and this position is detected by a position detection means such as a switch and initialized.

-J, when using a stepping motor, it can be controlled relatively easily by open-loop control, but forward and reverse rotation can also be controlled relatively accurately, and the carriage can be moved by forward and reverse rotation of the stepping motor without using a complicated mechanism. The entire system can be configured easily by going back and forth.

Further, there is also known a printer in which one end of a lever rotatably supported in the middle is driven by a cam, a carriage is attached to the other end, and the lever is rotated to perform recording.

[Problems to be solved by the invention] By the way, when a DC motor is adopted, not only does the mechanism become complicated and expensive due to the large number of parts such as clutches, springs, and position detection means, but also because the carriage return is performed using a spring. It has poor responsiveness and is unsuitable for high-speed driving.

Further, since feedback control is performed, the electric circuit becomes complicated and expensive.

On the other hand, when a stepping motor is used, the overall structure is simplified, but even in this case, there is a mechanical limit to high-speed forward and reverse driving due to the inertia of the motor rotor.

Furthermore, although the method of driving the carriage by rotating the lever has the advantage of being relatively simple in structure, it requires a separate drive source from the one that drives the lever to feed the paper, so it requires a large number of parts. However, it has the disadvantage of being complicated and expensive.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a cam rotated by a motor, and a rotating lever that is rotated by the cam using the cam as a fulcrum, A paper feed gear that connects the other end of this lever to the carriage, moves the carriage back and forth along the guide shaft, and transmits the output of the motor that rotates the cam via an intermediate gear. A structure with a paper feed roller is adopted.

[Function] When the structure described above is adopted, the lever is rotated by the cam rotated by the motor, and the lever action of this lever accurately magnifies the relatively small amount of movement of the cam rotation to move the carriage. This makes it possible to drive the carriage without the complicated mechanisms and play required in the past, and at the same time, it is possible to increase the speed to the limit of parts strength and weight reduction.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIGS. 1 and 2 illustrate an embodiment of the present invention, and the reference numeral 1 in the figures is the frame of the printer, which constitutes a fixed part of the apparatus.

A motor 2 is fixed to a part of this frame l,
Nearby, a partially toothed gear 3 and a cam drive gear 4 are coaxially supported.

The cam drive gear 4 meshes with a drive gear 5 fixed to the output shaft of the motor 2.

A cam disk 6 is connected to the cam drive gear 4 via a shaft 4a.
is fixed in an eccentric position.

The cam disk 6 has a cam groove 6a formed on its upper surface.

A cam follower 7 is rotatably fitted into the cam groove 6a.

The cam follower 7 is rotatably supported on one end of the lever 8 via a shaft 7a.

A midway portion of the lever 8 is rotatably supported on the frame side via a shaft 9 at a position closer to the cam follower 7 side.

The end of the lever 8 on the side opposite to the cam follower 7 is connected to the carriage 11 side via a connecting member 10. The connecting member 10 is formed in a cylindrical shape, and the end of the lever 8 is inserted into a hole in the center of the connecting member 10. are slidably fitted.

Further, the connecting member 10 is rotatably supported between the carriage 11 and the slider 12 via a shaft 10a.

The slider 12 is slidably fitted with a guide shaft 13 which is suspended between the left and right side plates of the frame l.

The carriage 11 also has another guide shaft 14 parallel to the guide shaft 13 slidably fitted therein.

In addition, the flexible printed circuit board 1 is mounted on the carriage 11.
Various control @ signals are sent via 5, and carriage 1
Signals etc. from the position detection sensor 6 provided at 1 can be sent to a control circuit (not shown).

Corresponding to this sensor 16, a slit plate 17 for position detection is suspended horizontally between the left and right side plates of the frame l in parallel with the guide shaft 13.14.

This slit plate 17 has a large number of slits formed at a predetermined pitch, and the sensor 16 detects the slits to detect the position of the carriage 11 itself.

Further, as shown in FIG. 1, a recording head 18 is mounted on the carriage 11, and a platen 19 is provided on the frame 1 at a position facing the recording head 18.

Tokoro 1. A paper feed gear 20 is provided in mesh with the partially toothed gear 3, and this paper feed gear 20. ! - A pinion gear 21 is provided coaxially.

This pinion gear 21 meshes with a pinion gear 23 fixed to a shaft 22 arranged parallel to the guide shaft 13, and a paper feed roller 24 is fixed to the shaft 22.

This paper feed roller 24 is connected to the platen 1 as shown in FIG.
It is in contact with a pinch roller 25 provided on the 9 side, and feeds the recording paper 27 by pinching the recording paper 27 guided along the gap 26 between the platen 19 and the frame.

Next, the operation of this embodiment configured as above will be explained.

When the motor 2 is turned on, the cam disk 6 is rotated via the gear 5.4 at a predetermined rotational speed, for example, 300 RPM when recording 5 lines per second.

At this time, the cam disk 6 rotates in a large circle around the shaft 4a, as shown by the dashed line in FIG.

When the cam disk 6 rotates once, the cam follower 7 is forcibly moved along the groove 6a and reciprocates once from the position A to the position B shown in solid line in FIG.

As a result, the lever 8 makes one reciprocating motion about the shaft 9 between the position indicated by the reference numeral in FIG.

During this time, the recording head 18 is connected to the flexible printed circuit board 1.
Recording is performed on the recording paper 27 in accordance with the recording command output from the control a circuit via the control circuit a.

In addition, since the lever 8 also serves as a lever centered on the shaft 9, the lever ratio centered on this fulcrum C, that is, CD
: The movement between A-8 is magnified by the ratio of AC and becomes D-E.
The carriage 11 is accelerated by the amount of CD/AC.

Also, every rotation of the cam disk 4, that is, the carriage 1
For each reciprocation of
0, the paper feed roller 24 is rotated via pinion gears 21 and 23, and the recording paper 27 is held between the pinch roller 25 and fed by one line.

The above operations are repeated to perform sequential recording.

In the above embodiment, a DC motor is used as the motor 2, and a sensor 16 and a slit plate 17 are used as the position detecting means. In this case, the sensor 16 and the slit plate 17 for position detection are not necessary, but if necessary to obtain an initialization signal, the sensor 16 and the slit plate 17 may be used.

Since this embodiment is constructed as described above, it has a structure that includes a cam disc, a lever that is reciprocated by the cam disc, and a carriage that is reciprocated by the lever action of this lever. The relatively small amount of movement at one end is reliably magnified and transmitted to the carriage side, and the carriage is forced to move back and forth, making it possible to increase the speed as much as the strength of the parts and weight reduction allow. , the structure can be simplified.

In the above-mentioned embodiment, a structure using a cam disk was explained as an example of a cam, but for example, a spiral endless groove may be formed on the outer peripheral surface of a cylinder to reciprocate the lever. A cam structure that allows this may be adopted.

[Effects] As is clear from the above description, according to the present invention, a structure including a cam, a lever that is reciprocated by the cam, and a carriage connected to one end of the lever is adopted. Therefore, the carriage can be moved back and forth by an amount corresponding to the lever ratio, and a printer capable of high-speed recording can be obtained with an extremely simple structure.

Further, since the paper is fed by the same drive source as that of the lever, a separate drive source for paper feeding is not required, and the structure is simple and inexpensive.

[Brief explanation of drawings]

Claims (1)

[Claims] In a printer that performs recording by moving a carriage equipped with a recording head back and forth along a platen, there are three components: a cam that is rotated by a motor, a lever that contacts the cam at one end and rotates with its midway as a fulcrum, and this lever. a carriage connected to the other end and a paper feed gear to which the output of a motor for rotating the cam is transmitted via an intermediate gear;
A printer comprising a paper feed roller rotated by the paper feed gear.