JPS60116485A - Printer - Google Patents

Abstract

PURPOSE:To enable positioning with high accuracy, by a method wherein a platen facing a printing head is fitted onto side frames fitted to guide shafts so that the platen can be rotated, in an impact-type printer. CONSTITUTION:A printer 16 provided with a plurality of printing heads 15 is fitted to two parallel guide shafts 12, 13 supported by left and right base frames 11, through a head carriage 14 so that it can be moved. The side frames 17 are provided on the outside of the base frames 11, and are supported by fitting it to ends of the guide shaft 12 and an eccentric cam 18 provided at an end of the guide shaft 13, and the platen 20 is rotatably fitted onto the side frame 17. The platen 20 can be positioned relatively to the heads 15 and a gap therebetween can be set, with only the guide shafts 12, 13 as references, the construction is simple, and the printer can be easily assembled.

Description

[Detailed description of the invention] Technical field The present invention relates to an impact printer.

BACKGROUND ART This type of impact printer has the advantages of being low in price, highly reliable, low in running cost, and reliable printing, and is widely used as a peripheral device for word processors, personal computers, and the like.

In this impact type printer, in order to maintain uniform print quality, it is necessary to keep the gap between the paper surface and the print head, or in other words, the gap between the platen and the print head, accurate and constant.

However, in conventional printers of this type, two guide shafts, a platen, etc. are directly attached to a frame provided on a base plate, and a printing device equipped with a print head is supported on these two guide shafts via a head carriage. I was doing it. Therefore, the gap between the platen and the print head is determined depending on the mounting accuracy of the guide shaft and platen to the frame. Therefore, if you want to create the gap accurately, it is necessary to adjust the individual members such as the guide shaft and platen. It was necessary to accurately align and attach it to the frame. As a result, positioning and setting the gap between the platen and the print head have become extremely troublesome and troublesome. Furthermore, since the individual members are directly aligned and assembled to the frame, the assembly is complicated and troublesome.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an inexpensive printer in which the gap between a platen and a print head can be easily set with high precision, and the printer is simple in structure and easy to assemble.

In order to achieve the above object, the present invention includes a printing device having a print head movably attached to two guide shafts supported by a base frame via a head carriage, and a printing device that is attached to the guide shafts. The print head is characterized in that a platen facing the print head is rotatably mounted on the side frame.

Therefore, the gap between the platen and the print head can be easily set with high precision.

1. It is extremely easy to assemble, as all you have to do is assemble each member in sequence with the guide shaft as a reference.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2 show the main parts of a printer according to the present invention, in which a pair of base frames 1 are mounted on a base plate 10.
1, 1.1 are placed parallel to each other at intervals. Two parallel guide shirts 1-12.13 are supported between this base frame 11.11.

A head carriage 14 constituting a printing mechanism is inserted and supported in the guide shirt 1'2.18 so as to be movable within a certain range in the axial direction. The head carriage 14 includes a printing device 16 having a plurality of printing heads 15 in the printing line direction.
are integrated.

Base frame 11. ．． A side frame 17 is provided on one side of the frame 11. Side frame 17°17 is
The guide shaft 12 is located in the middle on the negative side (front side in the figure).
A total of seven frames 11.11 are fitted and supported on shaft ends protruding from the frame 11.11. Furthermore, a cam groove 171 into which the eccentric cam 18 provided at the shaft end of the guide shaft 13 is fitted is formed at one end of the side frame 17.17.

A platen 20 is supported on the side frames 17, 17. That is, a receiving groove 172 is formed in the upper part of the side frame 17°170- side, and the receiving grooves 172, 17
The shaft ends of a central shaft 21 protruding from both sides of the platen 20 are rotatably fitted and supported by the shaft ends of the central shaft 21 . Thereby, the platen 20 is mounted on the guide shaft 12.18 via the side frame 17.17, facing the print head 15.

Reference numeral 22 denotes a paper guide installed between the base frames 11 and 11, which has a certain clearance between it and the platen 20 and guides the fed paper, which is the print medium, along the circumferential surface of the platen 20. It is designed to guide you. At the bottom of the paper guide 22, openings 23 are provided at multiple locations in the longitudinal direction.
. . , the pressure rollers 24 . . . sandwich and press the paper against the platen 20. The pressure rollers 24 are arranged along the longitudinal direction of the leaf spring body 25, and the shaft portions 241 protruding on both sides of the rollers 24 are arranged along the longitudinal direction of the leaf spring body 25.
It is rotatably supported in a recess 251 formed in the. One side of the leaf spring body 25 is placed on a wall 26 erected on the base plate 10 and is held on the wall 26 through engagement between the mounting hole 252 and the support piece 261. In addition, the other sides are notches 2 formed on the circumferential surface of the guide shaft 12.
It is supported on 7. By appropriately rotating the guide shaft 12 by external operation, the plate spring body 25 swings up and down about one side as a fulcrum at an angle corresponding to the step between its circumferential surface and the notch 27, and the pressure rollers 24... sandwich the paper and bring it into pressure contact with the platen 20, and then separate it from there.

The paper is inserted between the platen 20 and the paper guide 22 from the rear side in FIG.
At zero rotation, the paper is guided by the paper guide 22 along its circumferential surface and sequentially sent to the front side. A printing hammer (not shown) is provided on the front side of the printing head 15 of the printing device 16, and it hits the back of the selected printing head to print on the paper on the platen 20. .

In assembling the printer configured as described above, first, the head carriage 14 equipped with the printing device 16 is inserted into the guide shaft 13 and supported, and the support frames 141 provided on the front surface of the head carriage 14 are inserted into the guide shaft 12 by the notch 27. Support the insertion while avoiding. Next, guide shaft 1
2.18 is supported between the base frames 11.11, and the side frames 17.17 are attached to the shaft ends thereof as described above. After that, the guide shaft 12 and the wall part 2
A leaf spring body 2 with a pressure roller 24 attached between 6
5 is installed, and the paper guide 22 is fitted between the base frames 11 and 11 from above. Next, the platen 20 is attached to the upper part of the side frame 11.11 through the receiving groove 172.
When the printer is attached, the printer is assembled as shown in FIGS. 1 and 3. According to this, the printer can be assembled by sequentially stacking each member around the guide shaft 12.18, making the assembly easy and also easily automating and mechanizing the assembly using an automatic assembly machine, etc. be able to. In addition, the platen 20 is connected via the side frames 1.1, 1.1
Since the print head 15 of the platen 20
The positioning and setting of the gap 100 can be performed using only the guide shaft 12, 13 as a reference. Therefore, positioning between the platen 20 and the print head 15 can be easily and accurately performed. Therefore, the platen 20 and the print head 15
The gap 100 can be easily obtained with higher precision than in the past. Moreover, since it is only necessary to attach the side frame 17.17 to the guide shaft 12.18 and the platen 20 to the upper part of the side frame 14.14, the structure is simple and the manufacturing cost can be reduced. can. Still, it is easy to assemble and can be done easily.

Then, when the guide shaft 13 is externally operated via an adjustment lever or the like and rotated to a desired angle, the side frame 1
7.17 is an eccentric cam 1 centered on the guide shaft 12
The platen 20 swings upward or downward depending on the amount of eccentricity of the print head 8, and accordingly, the platen 20 approaches or moves away from the print head 15, and the gap 100 therebetween changes. This creates a gap 10 between the paper mounted on the platen 20 and the print head 15.
0 can be adjusted appropriately depending on the thickness of the paper, etc.

The present invention is applicable not only to line printers shown in the embodiments, but also to serial type printers, and not only to printers whose paper feeding method uses a friction feed method using pressure rollers, but also to other types of printers. Of course, the present invention can also be applied to printers using bin feed or tractor feed methods.

[Brief explanation of the drawing]

1 is a perspective view of essential parts of a printer according to the present invention, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a side view of FIG. 1. 11.11...Base frame. 12.18... Guide shaft. 15・・・・・・・・・・・・Print head. 9-16・・・・・・・・・・・・Printing device. 14・・・・・・・・・・・・ Head carriage. 17.17... Side frame. 20・・・・・・・・・・・・Platen. -10-

Claims (1)

[Claims] (1) In a printer that prints on paper fed along a platen by striking the print head, the printing device, which is equipped with the print head on two parallel guide shafts supported by a base frame, can be moved via a head carriage. A printer characterized in that the platen is rotatably mounted on a side frame attached to the guide shaft so as to face the print head.