JPS5859871A - High speed printer platen - Google Patents

Abstract

PURPOSE:To reduce noise at printing-time and increase the speed of printing operation, by a method wherein a vibration damping sheet is bonded on part of the outer surface, or the inner surface of a wire dot printer platen cartridge made of the material with great rebound coefficient. CONSTITUTION:The external surface of the body of a platen cartridge 2 is made of materials with great rebound coefficient (e.g., chrome-plated iron pipe). Both ends of the platen cartridge is blocked by end plates by which the cartridge is attached to a printer. In addition, a vibration damping sheet 3 (e.g., lead thin plate or vibration damping alloy sheet) is bonded on the external surface of the body 2. With this method, the wires, when they dot, are speedily rebounded, reducing vibration accompanied by dotting of the wires. The vibration damping sheet 3 may be bonded on the internal surface of the body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a platen for an il [+ speed printer,
! The present invention relates to a platen for high-speed printers that can reduce the noise level during printing and increase the speed of printing.

High-speed printer wires (hereinafter simply referred to as platens), such as the platen of wired dot printers used as output devices for so-called Japanese word processors and computer computers, are destined to collide with dot wires during printing and generate high levels of noise. It has some problems.

As shown in Figure 1, the main body of the platen L is a hollow cylinder to reduce weight and material costs, and when a type hammer or dot wire collides, bending vibrations and the thickness of the side surface of the cylinder This is because complex elastic vibrations including longitudinal vibrations occur, which resonate in the cylindrical portion of the cylinder, resulting in high-level noise.

Conventional platens reduce the noise mentioned above.

The surface of the platen body was coated with rubber having a hardness of 7II3 (for example, hardness: only!), but in reality, this noise-reducing rubber coating was a major hindrance to improving the output speed of the printer. That is, a wired dot printer temporarily prints a dot matrix forming one character. -v constitutes Z- no 1
Hana (The printer head with dot wires arranged in a 1wI pattern is moved by 7 lines of the dot matrix or ! cleverly, and each time the printer head moves, the dot wires are selectively moved to form characters. Although it is necessary to shorten the round trip time of the dot wire in order to increase the output speed of the printer, if the surface of the platen is coated with rubber, this acts as a damper and the bounce of the dot wire is poor. For this reason, the output speed of conventional rubber-coated platens is limited to 10 characters/second.In order to increase the output speed, it is recommended to harden the surface of the platen to improve the bounce of the dot wire. In this case, there was an inconvenience that the noise level would increase this time.

Therefore, the purpose of this Jl@mei is to provide a platen that can satisfy the mutually contradictory demands of increasing printing speed and reducing noise level during printing.

A platen for a high-speed printer according to the present invention that achieves the above object has a vibration damping sheet in close contact with at least one of a part of the outer cylindrical surface or the inner cylindrical surface of a cylindrical main body made of a material with a large coefficient of restitution. It is my special mission to do this.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 1J.

In Figures 1 and 17, the symbol C indicates the main body of the platen, and the main body is made of a material with a large coefficient of repulsion, such as an iron pipe with a chrome-plated outer cylinder surface, and has openings at both ends. It is attached to the printer via an end plate 6, which is attached so as to close the end plate.

On the outer cylinder surface except for the area near the printed surface of the main body section above.

For example, vibration damping sheets such as lead thin plates or damping alloy thin plates)
are adhered with WC adhesive.

The platen according to the embodiment of the present invention configured as described above is capable of quickly repelling the dot wires when a group of dot wires collides through the recording paper for printing. Reduce the interval between

On the other hand, along with the elastic vibration of the body part - front F caused by the collision of the wire dot, the damping sheet J also vibrates as a resonator, but when the damping sheet is made of a high density material such as a lead plate, the damping sheet A force acts on J to keep it in its original position due to inertia, and the vibration energy is converted into thermal energy and reduced.

Furthermore, since the damping sheet (J) attached with adhesive has the same shape as the main body part (J) and is not distorted, the vibration damping effect is also produced by the viscous resistance caused by the relative movement of the two.

Furthermore, the vibration damping sheet J attached so as to cover most of the outer circumferential surface of the main body also functions as a sound insulating material.

Figures 1 and 5 show a modified embodiment of the present invention, in which a vibration damping sheet J is closely adhered to the inner cylindrical surface of the platen main body. When such pressure is applied, there is no change in the shape of the outer peripheral surface of the platen, so another advantage arises that the present invention can be applied to platens such as Japanese typewriters in which recording paper is rotated integrally with the platen. The effects of those shown in Figures 1 and 5 are as shown in Figure 1 and jll! Since it is similar to that shown in FIG. 3, detailed explanation thereof will be omitted.

6 and 7 show other modified embodiments of the present invention,
In this embodiment, a damping sheet J having an annular cross section is filled between an inner cylinder part provided coaxially with the inner side of the main body part 1 and the main body part 1 outside thereof. In other words, if it is attached to the outside of the inner cylinder and formed into a cylindrical shape, the K11lI
A vibration damping sheet J with improved resistance is tightly fitted into the inner cylindrical part of the main body. In this case, the vibration damping effect is similar to that described above, but there is another advantage in that the workability of mounting the vibration damping sheet (J) when assembling the platen is improved.

1 and 9 show still other modified embodiments of the present invention, and FIG. 10 and 11 show further modified embodiments of the present invention, each of which has a main body portion. A presser foot 17j, where fIIkwfrI[I is a part of a circular part and is made of a highly rigid material such as a metal plate, is attached to the outer or inner cylindrical surface of the
Accordingly, the vibration damping sheet J is restrained in close contact with the main body portion and fastened with bolts or screws, and since the effects thereof are the same as those described above, a detailed explanation will be omitted.

As is clear from the above, in the present invention, since the vibration damping sheet is attached to the main body of the platen in close contact,
The elastic vibration of the platen, which is caused by the impact of printing and causes noise, is absorbed by the damping sheet (K), thereby reducing the noise level.

For example, the vibration spectrum of the platen was actually measured for the embodiment shown in FIGS. 1 and 3.

As shown in FIG. 1j, compared to the vibration spectrum of the conventional platen shown by the dashed line, that of the platen according to the present invention shown by the solid line has a significantly lower level in the high frequency region where it is audible to the user's ears. It is clear that the vibrating sheet greatly contributes to reducing the noise level.

In addition, since the printing surface of the platen has a large repulsion coefficient, the colliding dot wires are easily repelled, and the driving and spacing of the dot wires can be shortened, thereby increasing the printing speed.

According to experiments, to, i while keeping the noise level low
It was possible to obtain a printing speed of 0 characters/second.

In the above explanation, it is assumed that the vibration damping sheet is attached only to either the outer circumferential surface or the inner circumferential surface of the platen main body, but it goes without saying that the damping effect will be further improved if it is attached to both. be.

[Brief explanation of drawings]

FIG. 1 is a diagrammatic perspective view showing an example of the structure of a conventional platen, FIG. 2 is a diagrammatic longitudinal cross-sectional view of a platen according to an embodiment-1 of the present invention, and FIG. 3 is a cross-sectional view thereof. Figures 9 to 1/1 are cross-sectional views showing modified embodiments of the present invention, and Figure 12 is a graph showing actual measurement results of the vibration spectrum of the platen, showing an example of the effects of the present invention, with the horizontal axis representing the frequency. , and are shown on the vertical axis, respectively. I...Platen, K...Main body, J...Vibration damping sheet. Thing...the inner cylinder! ... Pressing plate, 6... End plate. , Applicant's representative Inomata Kiyomi 114 2 Mouse 2 times Musi 3 concave 4 sides Tsuji 1 view 88 diagrams Suji 9 times

Claims (1)

[Claims] 1. A damping sheet is closely attached to at least one side of a part of the outer cylindrical surface or the inner cylindrical surface of the cylindrical main body made of a material with a large coefficient of restitution. Platen for high speed printers. (c) The platen for a high-speed printer according to claim 7, wherein the vibration damping sheet is attached to both an outer cylindrical surface and an inner cylindrical surface of the main body. J. The platen for a high-speed printer according to claim 1, wherein the vibration damping sheet is attached to the outer cylindrical surface of the main body excluding the vicinity of the printing surface. The platen for a high-speed printer according to claim 2, wherein the vibration damping sheet is attached to the inner cylinder 11jK of the main body. ! 1! The above vibration damping sheet was attached to the main body using adhesive. A platen for a high-speed printer according to any one of claims 7 to 4, wherein the platen is an image. 6. Claims 1 and 1, characterized in that the damping sheet is installed so as to fill the gap between the main body and an inner cylinder coaxially provided inside the main body. 4. The platen for a high-speed printer according to any one of Items 1 and 4. 7. A high-speed printer according to any one of claims 1 to 3, wherein the damping sheet is fixed by a holding plate whose cross section forms a part of an arc. platen.