JPH068574A - Printer - Google Patents

Abstract

PURPOSE:To automatically and manually control a gap by a method wherein a changeover lever is provided to a carriage to selectively transmit the power of a paper feed motor to the gap control gear provided to a carriage guide shaft by the changeover lever and an adjusting lever is provided to the carriage guide shaft to manually control the gap. CONSTITUTION:A changeover lever 8 is provided to a carriage 6 and a gap control gear 12 is arranged on an eccentrically supported carriage guide shaft 5. By stopping the carriage 6 at a position where a transmission gear 11 and the gap control gear 12 are engaged mutually, the rotation of a paper feed motor 16 is transmitted to the gap control gear 12 through the transmission gear 11 and a gap is manually controlled by the adjusting lever 14 fixed to the carriage guide shaft 15. As a result, a mechanism controlling the gap between the platen l and the leading end of a printing head 7 automatically and manually can be inexpensively realized without using a gap control exclusive motor and being complicated and scaled up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer. 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. 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, adjusts 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 for gap adjustment is used. Since 37, the timing disk 38, and the sensor 39 are required, there is a drawback that the printing apparatus is complicated and large, and the cost is increased.

Further, since the gap between the platen 31 and the tip of the print head 33 is adjusted according to the paper thickness at a specific position of the print paper, the optimum gap cannot be adjusted for print papers such as envelopes where the paper thickness is partially different. However, it had a drawback that it could not be readjusted.

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 printing apparatus. An object of the present invention is to provide a printing apparatus that can adjust the gap according to the paper thickness of the printing paper using power and can also be manually adjusted.

[0006]

[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 on the carriage is provided with a switching lever, and the power of the paper feed motor is selectively transmitted by the switching lever to the gap adjusting gear provided on the carriage guide shaft, and the carriage guide shaft is provided with an adjusting lever for manual adjustment. It is characterized by doing so.

[0007]

The present invention will be described below 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, showing a state in which a switching lever 8 is at a gap adjusting position. FIG. 2 is a partial plan view of the same printer as FIG. 1 showing a state in which the switching lever 8 is at the paper feeding position. FIG. 3 is a side view of the wheel train for paper feed and gap adjustment according to the present invention seen from the left side in FIG. 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. A carriage guide shaft 5 is axially supported by the side frame 3 in parallel with the axial direction of the platen 1,
An adjusting lever 14 is fixed to the carriage guide shaft 5. Carriage 6 to carriage guide shaft 5,
It is slidably attached. 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. Transmission gear 1
1 is rotatably supported by a transmission gear shaft 13 and is urged in the direction of the arrow by a spring 21 to come into contact with 15 degrees per degree when it is not pressed by the switching lever 8.
A paper feed motor 16 having a motor gear 17 and an intermediate gear 18 are arranged on the motor frame 19, and are attached to the side frame 3 by columns 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 clockwise about the rotation center, the carriage 6 guided by the carriage guide shaft 5 approaches the platen 1 and moves backward. 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. 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 constructed 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. The switching lever 8 arranged on the carriage 6 pushes the transmission gear 11 to the left against the spring force of the spring 21, and the transmission gear 11 having the taper smoothly engages with the gap adjusting gear 12 having the taper. , Stop at the gap adjustment position. When the paper feed motor 16 rotates forward (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 on 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 21, and the transmission gear 11 having a taper smoothly engages with the intermediate gear 18 also having a taper, and the abutment portion 15 provided on the transmission gear shaft 13 is provided. It stops at the paper feed position where it abuts against. When the paper feed motor 16 normally rotates at the paper feed position, the platen drive gear 4 is normally rotated 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, the transmission gear 11 is moved to the left side by the switching lever 8, and the transmission gear 11 is moved.
Engages with the gap adjusting gear 12 and stops at the gap adjusting position. The transmission gear 11 engages with the motor gear 17 and the gap adjusting gear 12, and when the paper feed motor 16 is rotated in the reverse direction (clockwise in FIG. 3), the motor gear 17
And the gap adjusting gear 12 rotates clockwise through 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 print head 7 mounted on the carriage 6 is rotated.
Tip 7a of ribbon presses ribbon 9, printing paper (not shown), and ribbon mask 10 to abut platen 1,
6 comes out of step due to the contact force and stops, and the platen 1 and the tip 7 of the print head 7 are adjusted according to the thickness of the print paper (not shown).
The gap between a is set to a predetermined platen gap.
By the way, in the case of printing papers (not shown) having partially different paper thicknesses, for example, in the case of an envelope, the gap between the platen 1 and the tip 7a of the print head 7 is set by the paper thickness of the two overlapped envelopes. Although the platen gap is too narrow in the center of the four sheets, the adjust lever 14 fixed to the carriage guide shaft 5 is rotated clockwise around the eccentric mounting portion 5a to set the proper platen gap. To do. Then move the carriage 6 to the right,
The switching lever 8 arranged at the position is disengaged from the transmission gear 11. The transmission gear 11 is urged to the right by the spring force of the spring 21, and the transmission gear 11 having a taper smoothly engages with the intermediate gear 18 having a taper as well. 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 the printing of one line is completed, the paper feed motor 16 is rotated in the normal and reverse directions, and the platen drive gear 4 is rotated in the normal and reverse directions via the motor gear 17, the transmission gear 11, and the intermediate gear 18 fixed to the paper feed motor 16 to convey the paper. After that, the paper feed motor 16 is used only for feeding paper.

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 used with the power according to the paper thickness of the printing paper (not shown).
Since the gap between the print head 7 and the tip 7a of the print head 7 can be adjusted, and the adjustment lever 14 fixed to the carriage guide shaft 5 can be used for adjustment, the gap adjusting mechanism can be complicated and large. In addition, it is possible to realize an inexpensive printer that can be adjusted manually.

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

[0014]

As described above, according to the present invention, the switching lever 8 is mounted on the carriage 6, the gap adjusting gear 12 is arranged on the carriage guide shaft 5, 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 eccentrically supported carriage guide shaft 5 via the transmission gear 11 and the carriage 6 So that the carriage 6 can be moved in the direction perpendicular to the axial direction of the platen 1, and that the carriage 6 can be moved in the direction perpendicular to the axial direction of the platen 1 even manually by the adjusting lever 14 fixed to the carriage guide shaft 5. As a result, the printing apparatus capable of adjusting the gap between the platen 1 and the tip 7a of the print head 7 automatically and manually according to the thickness of the printing paper (not shown) does not become complicated or large in size, and The effect is that it can be realized at low cost.

[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 feed 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 partial plan view of a conventional printer.

FIG. 6 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 14 Adjust Lever 16 Paper Feed Motor 17 Motor 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 carriage supported by the carriage has 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, and an adjustment lever is provided on the carriage guide shaft for manual operation. A printing device characterized in that it can be adjusted with.