JPH05309909A - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] In a printing device, it is possible at low cost without complicating and increasing the size of the mechanism for adjusting the gap between the platen and the tip of the print head by using power according to the paper thickness of the printing paper. To A carriage 6 is provided with a switching lever 8, a carriage guide shaft 5 eccentrically supported is provided with a gap adjusting gear 12, and the carriage 6 is stopped at a position where the transmission gear 11 and the gap adjusting gear 12 engage. The rotation of the paper feed motor 16 is transmitted to the gap adjusting gear 12 via the transmission gear 11. [Effect] Platen 1 without a motor for gear adjustment
The mechanism for adjusting the gap between the tip of the print head and the print head 7 can be realized at low cost without complicating and increasing the size.

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 32 is arranged in parallel along the axial direction of the platen 31, and a carriage 34 carrying a print head 33 is slidably attached to the shaft 32. Further, the shaft 32 is an eccentric cam 35.
The timing disc 38, which is attached to the frame 36 via the gap adjusting motor 37 and is rotated by the gap adjusting motor 37, and the sensor 39 to adjust the gap between the platen 31 and the print head 33 according to the thickness of the print sheet. It was configured to adjust using power.

[0003]

However, in the above-mentioned printing apparatus, in order to adjust the gap between the platen 31 and the tip of the print head 33 using power in accordance with the paper thickness of the printing paper, a motor dedicated to the gap adjustment is used. Since 37, the timing disk 38, and the sensor 39 are required, there is a drawback that the printing device is complicated and large, and the cost is increased. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to print a gap between a platen and a tip of a print head at a low cost without causing a complicated and large-sized printer. Depending on the thickness of the paper,
An object of the present invention is to provide a printing device that can be adjusted using power.

[0004]

[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 carriage supported by is provided with a switching lever, and the power of the paper feed motor is selectively transmitted by the switching lever to a gap adjusting gear provided on the carriage guide shaft.

[0005]

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 the printing apparatus of the present invention, showing a state in which the switching lever 8 is at the gap adjusting position. FIG. 2 is a partial plan view of the same printer as in FIG. 1 showing the state where the switching lever 8 is at the paper feeding position. FIG. 3 is a side view seen from the left side in FIG. 1 showing a wheel train for paper feed and gap adjustment according to the present invention. The platen 1 is rotatably supported by a side frame 3 by a platen shaft 2, and a platen drive gear 4 for rotating the platen 1 is provided at an end of the platen shaft 2.
Is equipped with. Further, a carriage guide shaft 5 is axially supported by the side frame 3 in parallel along the axial direction of the platen 1,
A carriage 6 is slidably attached to the carriage guide shaft 5. A print head 7, a ribbon 9 and a ribbon mask 10 are mounted on the carriage 6, and a switching lever 8 is further provided. The transmission gear 11 is rotatably supported by the transmission gear shaft 13 and is urged in the direction of the arrow by a spring 14 so that the transmission gear 11 comes into contact with a per degree 15 when not pressed by the switching lever 8. A paper feed motor 16 having a motor gear 17 on the motor frame 19,
An intermediate gear 18 is provided and is attached to the side frame 3 by a column 20.

FIG. 4 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. 5 is a side sectional view of the transmission gear 11 according to the embodiment of the present invention, in which the carriage 6 is arranged in the axial direction of the platen 1.
When is moved, the switching lever 8 arranged on the carriage 6 selectively moves the transmission gear 11 to engage or disengage the gap adjusting gear 12 and the intermediate gear 18, so that smooth engagement can be performed. In addition, both sides of the transmission gear 11 are tapered. For the same reason, the gap adjusting gear 12 and the intermediate gear 18 are also tapered on the side surfaces that engage with the transmission gear 11.

Next, the operation of the printing apparatus thus configured will be described. As shown in FIG. 1, 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 and moves further to the left of the printing range. Switching lever 8 arranged on the carriage 6
Pushes the transmission gear 11 to the left against the spring force of the spring 14, the transmission gear 11 having a taper smoothly engages with the gap adjusting gear 12 having a taper, and stops at the gap adjusting position. When the paper feed motor 16 rotates normally (counterclockwise in FIG. 3), the gap adjusting gear 12 rotates counterclockwise via the motor gear 17 and the transmission gear 11 fixed to the paper feed motor 16. The carriage guide shaft 5 rotates counterclockwise around the eccentric mounting portion 5a to which the gap adjusting gear 12 is fixed, and the protrusion 12a of the gap adjusting gear 12 abuts on the contact portion 19a of the motor frame 19. The paper feed motor 13 loses step due to the contact force and stops. At this time, the platen gap becomes maximum, and the platen gap is held in the maximum state. As shown in FIG. 2, the carriage 6 is moved to the right side, and the switching lever 8 arranged on the carriage 6 is desensitized from the transmission gear 11. The transmission gear 11 is biased to the right by the spring force of the spring 14, and the transmission gear 11 having a taper smoothly engages with the intermediate gear 18 also having a taper, and the contact portion 15 provided on the transmission gear shaft 13 is engaged. Stop at the paper feed position where it abuts. When the paper feed motor 16 rotates in the normal direction at the paper feed position, the platen drive gear 4 is rotated in the normal direction via the motor gear 17, the transmission gear 11, and the intermediate gear 18 fixed to the paper feed motor 16 to load the paper. Next, the carriage 6 is moved to the left again, and the switching lever 8 is moved.
Causes the transmission gear 11 to move to the left, engages with the gap adjustment gear 12, and stops at the gap adjustment position. The transmission gear 11 engages with the motor gear 17 and the gap adjusting gear 12, and the paper feed motor 1
When 6 is rotated in the reverse direction (clockwise in FIG. 3), the gap adjusting gear 12 rotates clockwise through the motor gear 17 and the transmission gear 11. The carriage guide shaft 5 rotates clockwise around the eccentric mounting portion 5a to which the gap adjusting gear 12 is fixed, and the tip 7a of the print head 7 mounted on the carriage 6 has a ribbon 9 and printing paper (not shown). No.), the ribbon mask 10 is pressed and brought into contact with the platen 1, and the paper feed motor 16
Stops due to the contact force and stops, and the platen 1 and the front end 7 of the print head 7 are changed according to the thickness of the print paper (not shown).
The gap between a is set to a predetermined platen gap.
After that, the carriage 6 is moved to the right, and the switching lever 8 provided on the carriage 6 is desensitized from the transmission gear 11. The transmission gear 11 is biased to the right by the spring force of the spring 14, and the transmission gear 11 having a taper smoothly engages with the intermediate gear 18 also having a taper, and the contact portion 15 provided on the transmission gear shaft 13 is engaged. Stop at the paper feed position where it abuts. With the transmission gear 11 set at the paper feed position, the carriage 6 is moved to the print position for printing. When one line is printed, the paper feed motor 1
6 is rotated normally and reversely, the platen drive gear 4 is rotated normally and reversely through the motor gear 17, the transmission gear 11, and the intermediate gear 18 which are fixed to the paper feed motor 16, and the paper is conveyed. Used only to do.

In this way, the carriage 6 is provided with the switching lever 8 and the power of the paper feed motor 16 is switched.
Transmission gear 11 provided for transmission to the gap adjusting gear 12 provided on the carriage guide shaft 5 selectively.
Is engaged with the motor gear 17 and the gap adjusting gear 12, the power of the paper feed motor 16 is transmitted, and the platen 1 is driven by the power according to the paper thickness of the printing paper (not shown).
Since the gap between the tip 7a of the print head 7 and the print head 7 can be adjusted, it is possible to realize an inexpensive printing device without complicating or increasing the size of the gap adjusting mechanism.

Although the present embodiment has been described with reference to the printer among the printing devices, the same effect can be obtained by applying it to other printing devices such as a typewriter.

[0012]

As described above, according to the present invention, the carriage 6 is provided with the switching lever 8, the carriage guide shaft 5 is provided with the gap adjusting gear 12, and the carriage 6 is provided.
Is stopped at a position where the transmission gear 11 and the gap adjusting gear 12 engage with each other by the switching lever 8, so that the power of the paper feed motor 16 is transmitted to the carriage guide shaft 5 eccentrically supported via the transmission gear 11, and the carriage 6 Since the platen 1 can be moved in the direction perpendicular to the axial direction of the platen 1, the gap between the platen 1 and the tip 7a of the print head 7 is automatically adjusted by power according to the thickness of the printing paper (not shown). There is an effect that a printing device that can be realized can be realized at low cost without complicating and upsizing.

[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 partial plan view of a printer showing an embodiment of the present invention.

FIG. 3 is a side view showing a wheel train for paper feeding and gap adjustment according to an embodiment of the present invention.

FIG. 4 is a partial side view of the embodiment of the present invention.

FIG. 5 is a side sectional view of a transmission gear according to an 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 8 Switching Lever 11 Transmission Gear 12 Gap Adjustment Gear 16 Paper Feed Motor 17 Motor Gear 18 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. A printing apparatus comprising: a carriage supported by the carriage; and a switching lever, wherein the power of a paper feed motor is selectively transmitted by the switching lever to a gap adjusting gear provided on the carriage guide shaft.