JPH0624110A - Ribbon guide supporting device - Google Patents

Abstract

PURPOSE:To offer an ribbon guide supporting device which enables an ink ribbon and paper to travel smoothly and improves the durability of a print head and the ink ribbon. CONSTITUTION:A ribbon guide 8 which holds a ribbon mask 6 having a window 7 facing the tip of a print head 4 is provided and through-holes 12 and 13 are drilled in the ribbon guide 8 perpendicularly intersecting with the axis of a platen 1. A carrier 3 is provided with penetrating pins 11 having a specified outside diameter which allows the pins 11 to penetrate through the through-holes 12 and 13 with a specified clearance. Thereby, both the ribbon mask 6 and the ribbon guide 8 are displaced by the pressures imposed by an ink ribbon 14 and paper 18, so that the clearances between the print head 4 and the ribbon mask 6 and between the ribbon mask 6 and the platen 1 are kept constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon guide supporting device used in a serial printer.

[0002]

2. Description of the Related Art Conventionally, a ribbon guide for holding a ribbon mask formed of a thin metal plate is attached to a carrier on which a print head is mounted, and the paper fed to the front surface of a platen and the tip of the print head are pulled out. A ribbon mask is used to separate the ink ribbon from the
There is a serial printer in which the ink of an ink ribbon is transferred to a sheet through a window opened in the center of a ribbon mask by driving a print head. Since the ribbon mask needs to be a thin plate for separating the paper from the ink ribbon and for bringing the ink ribbon into contact with the paper in the central window, it is generally formed on the ribbon guide after being formed independently. It is assembled and attached to the carrier by this ribbon guide. Further, this type of printer is equipped with a print gap adjusting device that sets the print gap between the platen and the print head by adjusting the distance between the platen and the carrier according to the thickness of the paper. Is common.

[0003]

Ribbon masks and ribbon guides, in addition to the dimensional tolerances of the parts themselves in manufacturing,
Tolerances are also required for both mounting positions. Further, a tolerance is required between the carrier and the ribbon guide to regulate the error in the mounting position. Therefore, due to the accumulation of these tolerances, variations occur in the gap between the tip of the print head and the ribbon mask and the gap between the ribbon mask and the platen. Further, since the ribbon guide that holds the ribbon mask is fixed to the carrier, even if the print gap between the print head and the platen is adjusted according to the thickness of the paper, the ribbon guide is held between the tip of the print head and the platen. It does not correct the positional deviation of the ribbon mask. As a result, when the gap between the ribbon mask and the print head is too small, the running property of the ink ribbon is deteriorated. As a result, the durability of the dot pin and the ink ribbon is impaired, such as the dot pin being broken due to the ink ribbon being caught by the dot pin of the print head, or the ink ribbon fraying. On the other hand, if the ribbon mask is too close to the platen, there is a problem in that the passage of the paper becomes poor and the running property of the carrier is affected. In order to suppress such variations, it is necessary to tighten manufacturing tolerances or add another adjusting mechanism. In this case, there is a drawback that the cost becomes extremely high.

[0004]

According to the present invention, a carrier having a print head mounted thereon is reciprocally movable along a platen, and a ribbon formed of a thin plate having a window facing the tip of the print head. A ribbon guide for holding the mask is provided, an insertion hole orthogonal to the axis of the platen is formed in the ribbon guide, and an insertion shaft having an outer diameter dimension is inserted into the insertion hole with a predetermined play. It is provided on the carrier.

[0005]

Since the insertion shaft of the carrier is inserted into the insertion hole of the ribbon guide with a certain amount of play, the ribbon mask can be displaced together with the ribbon guide by the pressure between the ink ribbon and the paper. In a state where the pressure acting between the ink ribbon and the pressure acting between the ribbon mask and the paper are balanced, and the print head and the platen face each other with a print gap corresponding to the thickness of the paper being opened. The gap between the tip of the print head and the ribbon mask can be set to a value corresponding to the thickness of the ink ribbon, and the gap between the ribbon mask and the platen can be set to a value corresponding to the thickness of the paper. This makes it possible to smoothly run the ink ribbon and the paper and improve the durability of the print head and the ink ribbon. Moreover, the manufacturing cost can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a vertical side view, in which 1 is a platen, and a print head 4 is fixed to a clamp 5 on a carrier 3 slidably fitted to a carrier shaft 2 parallel to the platen 1. It is installed in. Reference numeral 6 is a ribbon mask formed of a thin metal plate, and a window 7 facing the tip of the print head 4 is formed at the center of the ribbon mask 6. Reference numeral 8 is a ribbon guide made of synthetic resin for holding the ribbon mask 6.

FIG. 1 is a vertical sectional front view. As shown in FIG. 1, columns 3 for holding both sides of a square tube-shaped nose 9 of the print head 4 are formed on the carrier 3, and cross-sections are formed on both sides. A circular insertion shaft 11 is erected. Further, on both sides of the ribbon guide 8, insertion holes 12 and 13 to be fitted into the insertion shaft 11 are formed. One insertion hole 12 is circular, while the other insertion hole 13 is an oval-shaped hole that is long along the longitudinal direction of the platen 1, and the diameter of the insertion hole 12 and the minor diameter of the insertion hole 13 are as described above. The size is determined so that the insertion shaft 11 can be fitted with a play of 0.1 to 0.2 mm in the direction orthogonal to the axis of the platen 1. Guide grooves 15 for guiding the ink ribbon 14 are formed on both sides inside the ribbon guide 8 with the nose 9 of the print head 4 interposed therebetween. These guide grooves 15 are provided at the end 16 on the platen 1 side.
Is close to the nose 9 and is inclined so as to spread in a V shape as it goes rearward. The ribbon mask 6 has bending pieces 17 on both sides that bend inward from the outside, and the bending masks 17 are maintained in a fixed state by locking the bending pieces 17 at the corners on both sides of the ribbon guide 8.

In such a configuration, the gap between the carrier 3 and the platen 1 is adjusted by operating the print gap adjusting device (not shown), and the print gap between the tip of the print head 4 and the platen 1 is the paper 18. Adjusted according to thickness. In FIG. 2, S ₁ is the print gap. The paper 18 is inserted between the platen 1 and the ribbon mask 6, and the ink ribbon 14 is passed through the guide groove 15 and guided to the tip of the print head 4.

Here, the insertion holes 12, 1 of the ribbon guide 8
Since there is a play of 0.1 to 0.2 mm between the insertion shaft 11 of the carrier 3 and the carrier shaft 3, the ribbon guide 8 and the ribbon mask 6 are displaced by 0.1 to 0.2 mm in the direction orthogonal to the platen 1. To be allowed. As a result, the ribbon mask 6 can be displaced together with the ribbon guide 8 by the pressure of the ink ribbon 14 and the paper 18.
Thereby, the pressure acting between the ribbon mask 6 and the ink ribbon 14 and the pressure acting between the ribbon mask 6 and the paper 18 can be balanced. As a result, when the print gap S ₁ is adjusted according to the thickness of the paper 18, the gap S ₂ between the tip of the print head 4 and the ribbon mask 6 becomes a value commensurate with the thickness of the ink ribbon 14. The gap S ₃ between the ribbon mask 6 and the platen 1 is set to a value corresponding to the thickness of the paper 18. Therefore, the running of the ink ribbon 14 and the paper 18 can be made smooth, and the durability of the print head 4 and the ink ribbon 14 can be improved.

Further, the guide groove 15 formed on both sides inside the ribbon guide 8 has its end portion 16 close to the nose 9, so that the contact length between the ribbon mask 6 and the ink ribbon 14 can be shortened. it can. As a result, the pressure that the ribbon mask 6 receives from the ink ribbon 14 can be reduced. Also in this respect, the paper 18 can be smoothly passed between the platen 1 and the ribbon mask 6. When the plate thickness of the ribbon mask 6 is t, S ₁ is t and S
It is the sum of ₂ and S ₃ .

As described above, only by displacing the ribbon guide 8, a gap S ₂ between the tip of the print head 4 and the ribbon mask 6 and a gap S between the ribbon mask 6 and the platen 1 are formed.
_{Since 3} can be controlled, it is not necessary to regulate the manufacturing tolerances of the individual components such as the carrier 3, the ribbon guide 8 and the ribbon mask 6 and the tolerances of the mounting dimensions of the three members more than necessary, thus reducing the manufacturing cost. Can be lowered.

In the above embodiment, the two insertion shafts 11 having a circular cross section are erected on the carrier 3, but one insertion shaft having a polygonal cross section may be provided on the carrier 3. In this case, the same purpose can be achieved by forming one insertion hole in the ribbon guide 8 corresponding to the cross section of the insertion shaft.

[0013]

As described above, according to the present invention, since the insertion hole is formed in the ribbon guide for holding the ribbon mask and the insertion shaft which is inserted with a predetermined play in the insertion hole is provided in the carrier, the ink ribbon is formed. The pressure between the ribbon mask and the paper can displace the ribbon mask together with the ribbon guide, which balances the pressure acting between the ribbon mask and the ink ribbon with the pressure acting between the ribbon mask and the paper. Then, in a state where the print head and the platen face each other with a print gap corresponding to the thickness of the paper opened, the gap between the tip of the print head and the ribbon mask is set to a value corresponding to the thickness of the ink ribbon, The gap between the ribbon mask and the platen can be set to a value corresponding to the thickness of the paper, which allows the ink ribbon and the paper to run smoothly, It is possible to improve the durability of the ink ribbon, moreover, has the effect of such the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional side view.

FIG. 3 is an exploded perspective view.

[Explanation of symbols]

 1 Platen 3 Carrier 4 Print Head 6 Ribbon Mask 7 Window 8 Ribbon Guide 11 Insertion Shaft 12, 13 Insertion Hole

Claims (1)

[Claims] 1. A carrier on which a print head is mounted is provided so as to be reciprocally movable along a platen, and a ribbon guide for holding a ribbon mask formed of a thin plate is provided having a window facing the tip of the print head. An insertion hole is formed in the ribbon guide, the insertion hole being orthogonal to the axis of the platen, and the carrier is provided with an insertion shaft having an outer diameter dimension that is inserted into the insertion hole with a predetermined play. Ribbon guide support device.