JPS5934205Y2 - fax machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile device with uniform print density and constant paper feed amount.

FIG. 1 is a side cross-sectional view of the area surrounding a conventional platen roller in a facsimile machine, and FIG. 2 is a front view, in which 1 is a platen roller, 2 is a print head, 3 is printing paper, and 4 is a pressing spring. The platen roller 1 is coated with rubber or the like to improve the adhesion between the print head 2 and the print paper 3, and is applied with pressure by a spring 4.

The printing paper 3 is fed by rotating the platen roller 1 or by being pulled by another roller, belt, etc. (not shown).

However, with this structure, there is a problem that the platen roller is bent by the pressure of the spring, reducing the pressing force at the center and worsening the adhesion between the print head and the printing paper.In order to reduce the bending, the platen roller is When the diameter is increased, the pressing force per unit area on the platen roller decreases, and therefore, when the total pressure is increased, the deflection of the platen roller also increases, resulting in uneven printing.

In addition, regarding the feeding of printing paper, if the printing paper is fed with a platen roller, the amount of distortion of the covering material may change due to fluctuations in the pressing force of the platen roller, changes in the rubber material, etc., and the machining accuracy of the outer diameter of the platen roller may be affected. There is a drawback that the radius of rotation changes due to grass trees, etc., and as a result, the feed amount of the printing paper is not constant.

The present invention solves the above-mentioned drawbacks by providing a bank up roller in contact with the platen roller, applying pressure to the platen roller through the bank up roller, and rotating the platen roller by the rotation of the bank up roller. An object of the present invention is to provide a facsimile device that can reduce the diameter of a platen roller, eliminate flexure, and print evenly by feeding the printing paper, and can keep the feeding amount of the printing paper constant. That is.

FIG. 3 is a side sectional view showing an embodiment of the present invention, and FIG. 4 is a front view thereof, in which 1 is a platen roller, 2 is a print head, 3 is printing paper, 4 is a suppressing spring, and 5 is a front view. It is a metal bank unroller.

One or more bank up rollers 5 are provided so as to be in contact with the platen roller 1, and are connected to a drive device (not shown).

In this configuration, the back amplifier roller 5 is pressurized by the pressing spring 4, and the platen roller 1 is pressurized by the bank amplifier roller 5, and its bearing can move up and down. It is designed to absorb deformation of the covering material around the outer periphery of the platen roller 1 due to fluctuations.

Further, the plurality of bank amplifier rollers 5 are configured to rotate in the same direction, and the platen roller 1 rotates in the opposite direction to the backup roller 5 according to the circumferential speed of the backup roller 5 to feed the printing paper 3. It has become.

In the above configuration, since the backup roller 5 pressed by the suppressing spring 4 presses the entire length of the platen roller 1, the diameter of the platen roller 1 can be reduced.

The smaller the diameter, the higher the pressing force per unit area, so the total pressure applied to the backup roller 5 can be reduced.
Therefore, the platen roller 1 hardly bends, making it possible to apply a uniform pressing force, and even during printing for a long time, stable printing density can be obtained, and even printing can be performed.

In addition, the circumference of the backup roller 50 and the printing paper are in a pair relationship regardless of the pressing force and the diameter of the platen roller 1, and the diameter of the bank unroller 5 made of metal has sufficient accuracy, so the printing paper 3 The feed amount can be kept constant.

According to the present invention, a bank up roller is provided in contact with the platen roller, the backup roller is pressed to apply pressure to the platen roller, and the bank up roller is rotated to cause the platen roller to rotate and print paper. Since it has a feeding structure, it is possible to perform stable printing without unevenness and to keep the feeding amount of printing paper constant.

Also, since the bank unroller is provided, the diameter of the platen roller can be made thinner, thereby increasing the pressing force per unit area, so the total pressure can be reduced and therefore a large pressing force is not required. This is extremely effective when printing long or wide characters.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the side I around the conventional platen miller;
The drawings are a front view of FIG. 1, FIG. 3 is a side sectional view of the vicinity of the platen roller of the present invention, and FIG. 4 is a front view of FIG. 3. 1...Platen roller, 2...Print head, 3...
- Printing paper, 4...pressing spring, 5...bank up roller.

Claims (1)

[Scope of Claim for Utility Model Registration] l In a facsimile machine in which a platen roller that requires pressure per unit area is arranged on the print head and printing is performed by bringing the printing paper into close contact with the print head using the platen roller, the platen roller Install one or several bank amplifier rollers so that they come into contact with the paper and do not come into contact with the printing paper.
A facsimile machine characterized in that the bank up roller is pressed by a spring to apply pressure to the platen roller. 2. The facsimile machine according to claim 1, wherein the bank up roller is connected to a drive device, and the bank up roller is driven to rotate the platen roller.