JPH05338315A - Printer - Google Patents

Abstract

PURPOSE:To obtain a mechanism wherein a gap between a platen and a tip of a printing head is regulated by using motive power according to a thickness of printing paper in a printer at a low cost by making the mechanism neither complicated nor large-sized. CONSTITUTION:A transmission gear 11 is borne with a carriage 6, and a gap regulation gear 12 is arranged to a carriage guide shaft 5. By stopping the carriage 6 at an engaging position of the transmission gear 11 with the gap regulation gear 12, rotation of a paper feed motor is transmitted to the gap regulation gear 12 via the transmission gear 11. Therefore, a mechanism wherein a gap between a platen 1 and a tip of a printing head 7 is regulated without a gap regulation exclusive use motor can be realized at a low cost by making the mechanism neither complicated nor large-sized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device. More specifically, it relates to a gap adjusting mechanism between the platen and the tip of the print head.

[0002]

2. Description of the Related Art Conventionally, as a means for adjusting the gap between the platen and the front end of the print head by using power in accordance with the thickness of the printing paper, there is known one disclosed in JP-A-63-84962. Has been. The contents disclosed therein are shown in FIGS. 6 and 7. A shaft 22 is arranged in parallel along the axial direction of the platen 21, and a carriage 24 carrying a print head 23 is slidably attached to the shaft 22. The shaft 22 is an eccentric cam 25.
The timing disc 28, which is attached to the frame 26 via the gap adjusting motor 27 and is rotated by the gap adjusting motor 27, and the sensor 29, adjusts the gap between the platen 21 and the print head 23 according to the thickness of the print sheet. It was configured to make adjustments using power.

[0003]

However, in the above-mentioned printing apparatus, in order to adjust the gap between the platen and the tip of the print head by using power according to the paper thickness of the printing paper,
Gap adjustment dedicated motor and timing disc,
Since a sensor is required, the printing device becomes complicated and large,
It had the drawback of increasing costs.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the cost between the platen and the tip of the print head at a low cost without causing a complicated and large-sized printer. It is an object of the present invention to provide a printing device capable of adjusting the gap using power in accordance with the thickness of the printing paper.

[0005]

[Means for Solving the Problems] In order to solve the above problems,
The printing apparatus of the present invention is a printing apparatus having a platen supported by a side frame and a carriage guide shaft eccentrically supported by the side frame in parallel with the platen. The transmission gear is rotatably supported by the carriage supported by
It is characterized in that the power of the paper feed motor is selectively transmitted to a gap adjusting gear provided on the carriage guide shaft via a transmission gear.

[0006]

The present invention will now be described based on the illustrated embodiments.

FIG. 1 is a partial plan view of a printer showing an embodiment of a printing apparatus of the present invention, and FIG. 2 is a side view seen from the left side in FIG. 1 showing a wheel train for paper feeding and gap adjustment of the present invention. is there. The platen 1 is rotatably supported by the side frame 3 by a platen shaft 2, and at the end of the platen shaft 2,
A platen drive gear 4 for rotating the platen 1 is provided. A carriage guide shaft 5 is axially supported by the side frame 3 in parallel to the axial direction of the platen 1, and a carriage 6 is slidably attached to the carriage guide shaft 5. A print head 7, a ribbon 8 and a ribbon mask 9 are mounted on the carriage 6, and a support gear 10 axially supported by the carriage 6 is used as a rotation axis to transmit a transmission gear 11
Is supported. A paper feed motor 13 having a motor gear 14 and an intermediate gear 15 are arranged on the motor frame 16, and are attached to the side frame 3 by columns 17.

FIG. 3 is a partial side view of the embodiment of the present invention seen from the left side in FIG.
Is rotatably attached to the side frame 3 by the attachment portion 5a, and the gap adjusting gear 12 is fixedly provided at the end of the attachment portion 5a. Since the mounting portion 5a is eccentric with respect to the carriage guide shaft 5, when the mounting portion 5a is rotated in the clockwise direction, the carriage 6 guided by the carriage guide shaft 5 comes close to the platen 1 and is reversed. When it is rotated counterclockwise, the carriage 6 guided by the carriage guide shaft 5 moves away from the platen 1.
By rotating the gap adjusting gear 12 in this manner, the gap between the platen 1 and the tip 7a of the print head 7 (hereinafter referred to as the platen gap) can be varied.

FIG. 4 is a side sectional view of the transmission gear 11 according to the embodiment of the present invention. The transmission gear 11 is mounted on the carriage 6, and when the carriage 6 moves in the axial direction of the platen 1, the motor gear 14, and Since the gap adjusting gear 12 is engaged or disengaged, the left side surface of the transmission gear 11 is tapered so that smooth engagement can be performed.

FIG. 5 is a side sectional view of the gap adjusting gear 12 according to one embodiment of the present invention. The gap adjusting gear 12 is tapered on the side engaging with the transmission gear 11.
Further, the projection 12a is provided, and the projection 12a and the contact portion 3a of the side frame 3 are arranged so that the platen gap becomes maximum.

Next, the operation of the printing apparatus thus configured will be described. In response to a loading command from a computer (not shown) or an operation panel (not shown), the carriage 6 slides along the carriage guide shaft 5, moves further to the left of the print range, and has a tapered gap adjusting gear 12. , The transmission gear 11 also having a taper on the motor gear 14 smoothly engages,
Stop at the engage position. When the paper feed motor 13 rotates forward (counterclockwise in FIG. 2), the gap adjusting gear 12 rotates counterclockwise via the motor gear 14 and the transmission gear 11 fixed to the paper feed motor 13. The carriage guide shaft 5 rotates counterclockwise around the eccentric mounting portion 5a to which the gap adjusting gear 12 is fixed, so that the protrusion 12a of the gap adjusting gear 12 abuts on the hitting portion 3a of the side frame 3. Then, the paper feed motor 13 steps out against the contact force and stops. At this time, the platen gap becomes maximum,
At the maximum platen gap, the carriage 6 is moved, the transmission gear 11 is disengaged with the motor gear 14 and the gap adjusting gear 12, and the paper is loaded. Next, the carriage 6 is moved again, the transmission gear 11 is engaged with the motor gear 14 and the gap adjusting gear 12, and the predetermined platen gap is set. After that, the carriage 6 is moved to the print position, and thereafter, the paper feed motor 13 is used only for feeding the paper.

By engaging the transmission gear 11 mounted on the carriage 6 with the motor gear 14 and the gap adjusting gear 12 as described above, the power of the paper feed motor 13 is transmitted, and the thickness of the printing paper (not shown) is reduced. Since the gap between the platen 1 and the tip 7a of the print head 7 can be adjusted by using the corresponding power, it is possible to realize an inexpensive printing device without complicating and increasing the size of the gap adjusting mechanism.

Although the present invention has been described with respect to the printer among the printing devices, the same effect can be obtained with other printing devices such as a typewriter.

[0014]

As described above, according to the present invention, the transmission gear 11 is mounted on the carriage 6, the gap adjusting gear 12 is arranged on the carriage guide shaft 5, and the carriage 6 is attached to the transmission gear 11 and the carriage guide shaft. By stopping at the engagement position of No. 5, the power of the paper feed motor 13 is transmitted via the transmission gear 11, the gap adjusting gear 12 is rotated, and the carriage 6 can be moved in the direction perpendicular to the axial direction of the platen 1. Therefore, the platen 1 and the front end 7a of the print head 7 are automatically adjusted according to the paper thickness of the print paper (not shown).
There is an effect that a printing device capable of adjusting the gap between them using power can be realized at low cost without complicating or increasing the size.

[Brief description of drawings]

FIG. 1 is a partial plan view of a printer showing an embodiment of a printing apparatus of the present invention.

FIG. 2 is a side view showing a wheel train for paper feeding and gap adjustment according to an embodiment of the present invention.

FIG. 3 is a partial side view of the embodiment of the present invention.

FIG. 4 is a side sectional view of a transmission gear according to an embodiment of the present invention.

FIG. 5 is a side sectional view of the gap adjusting gear according to the embodiment of the present invention.

FIG. 6 is a partial plan view of a printer showing a conventional example.

FIG. 7 is a partial side view of a conventional printer.

[Explanation of symbols]

 1 Platen 2 Platen Shaft 3 Side Frame 4 Platen Drive Gear 5 Carriage Guide Shaft 6 Carriage 7 Print Head 11 Transmission Gear 12 Gap Adjustment Gear 13 Paper Feed Motor 14 Motor Gear 15 Intermediate Gear

Claims (1)

[Claims] 1. A printing apparatus having a platen supported by a side frame and a carriage guide shaft eccentrically supported by the side frame in parallel with the platen, wherein a print head is mounted and slidable on the carriage guide shaft. The transmission gear is rotatably supported by the carriage supported by
The power of the paper feed motor is selectively passed through the transmission gear,
A printing apparatus, which transmits to a gap adjusting gear provided on the carriage guide shaft.