JPH0952395A - Recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily bring a non-rotational platen and a recording head into uniform pressure contact with each other by providing the non-rotational platen which presses a recording medium relative to the recording head with a predetermined force and whose contact part with the recording medium is subjected to low friction processing. SOLUTION: Rolled recording paper 10 is used as a recording medium, and the recording paper from this rolled recording paper 10 is led to a paper feed mechanism 13 via a guide roll 11 and a thermal head 12. The paper feed mechanism 13 is driven by a motor for transferring paper and transfers the recording paper. While being in loose contact with a fixed platen 14 being a non-rotational platen, the recording medium is pressed with a predetermined force for a recording line of the thermal head 12 to perform low friction processing. By this method, even in the case where the broad thermal head 12 is used, the fixed platen 14 and the thermal head 12 need not be so rigid, and they can be easily brought into uniform pressure contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus in which a recording medium such as a thermal head is sandwiched between a recording medium and a platen and desired recording is performed on the recording medium.

[0002]

2. Description of the Related Art In a conventional recording apparatus of this type, a platen roller is generally used, and a recording sheet is sandwiched between the platen roller and a recording head to perform recording on the recording medium. The platen roller is usually connected to a recording medium transfer motor and is rotatable, and the recording medium is transferred by rotating the platen roller.

[0003]

By the way, such an apparatus has a drawback that a recording medium having a width equal to the width of the recording head must be used. This is because, for example, when a recording medium having a width smaller than that of the recording head is used, the portion of the recording head that does not contact the recording medium comes into contact with the platen roller. This is because the platen roller is rotating at a predetermined speed, and the exposed portion of the recording head is always rubbed by the platen roller, so that the life of the recording head and the platen roller is significantly reduced. .

Further, when a recording head having a wide recording width is brought into pressure contact with a conventional platen roller, the platen roller is bent, and the pressure contact force in the vicinity of the center is reduced, resulting in non-uniform print density. It was Therefore, in order to prevent this bending, the bending rigidity of the platen roller must be increased. This causes an increase in size of the platen roller, hinders downsizing of the apparatus, and has a disadvantage that the pressure contact force of the recording head with respect to the platen roller must be increased. The present invention has been made to improve this point.

[0005]

Therefore, according to the present invention, in the recording apparatus having a non-rotating platen which presses the recording medium transported by the medium transporting means relatively to the recording head with a predetermined force, the non-rotating platen is used. The platen contact portion of the recording medium is treated with low friction.

[0006]

Since the non-rotating platen is used as the platen, even if a recording medium having a small width is used, the exposed portion of the recording head only contacts the non-rotating platen and is not rubbed. Further, the recording paper contact portion of the non-rotating platen is subjected to low friction treatment, whereby the paper can be smoothly fed by the transfer means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the preferred embodiments of the drawings. 1 to 6 each relate to an embodiment of the present invention, FIG. 1 is an explanatory view showing a normal recording state of the first embodiment apparatus, and FIG. 2 is recording on a narrow recording medium of the first embodiment apparatus. FIG. 3 is a configuration diagram of a non-rotating (fixed) platen of the first embodiment device, FIG. 4 is a recording state diagram of the second embodiment device, and FIG. 5 is a non-rotation of the second embodiment device. 6 is a block diagram of the platen, and FIG. 6 is a block diagram of the non-rotating platen of the apparatus of the third embodiment.

Each of the embodiments will be described below. FIG. 1 is a configuration explanatory view showing a normal state of a recording apparatus according to a first embodiment of the present invention, that is, a recording state when a recording medium having a width substantially equal to a width of a thermal head 12 which is a recording head is used.

The roll recording paper 10 is used as a recording medium,
The recording paper from the roll recording paper 10 is fed to the guide roller 1
1. Lead to the paper feed mechanism 13 via the thermal head 12. The recording paper is transferred by driving the paper feed mechanism 13 by a paper transfer motor (not shown). In the figure,
The fixed platen 4, which is a non-rotating platen, is drawn in a slightly floating state, but in an actual recording state, the recording paper is pressed against the recording line of the thermal head 12 with a predetermined force.

By using the fixed platen 4 as described above, it is possible to use recording paper having a narrow width as shown in FIG. In the portion where the recording paper is sandwiched between the thermal head 12 and the fixed platen 14, there is a portion where the thermal head 12 and the fixed platen 14 are in direct contact because the width of the recording paper is small. Even in such a case, by using the fixed platen 14, the both simply maintain the contact state and do not rub each other.

In this case, the recording paper is transported by a paper feeding mechanism 13 provided at the latter stage of the recording section, which is composed of the thermal head 12 and the fixed platen 14. Therefore,
In this recording unit, the recording sheet is brought into contact with the recording line of the thermal head 12 with an appropriate pressing force by the cooperation of the thermal head 12 and the fixed platen 14, and the conveyance of the recording sheet by the sheet feeding mechanism 13 is not hindered. There is a need to.

For this reason, in the first embodiment, the fixed platen 14 has a rounded tip end portion which is substantially in point contact with the printing portion 121 which is the recording line of the thermal head 12. As a result, the contact area of the recording paper brought into pressure contact with the thermal head 12 can be reduced and the transfer of the recording paper is not hindered. By reducing the contact area of the recording paper with respect to the thermal head 12, the pressing force per unit area with respect to a predetermined pressing force can be increased, so that the overall pressing force required for printing can be reduced overall. it can.
Further, since a Teflon sheet or the like is attached to this contact portion of the fixed platen 14 for low friction treatment, this also reduces the obstruction of transport of the recording paper.

In the apparatus of this embodiment, although not shown, the thermal head 12 is fixed to the housing of the apparatus and the fixed platen 4 is supported so as to be vertically movable. Then, when the fixed platen 14 is moved upward, the recording paper can be attached, and when it is moved downward, it contacts the thermal head 12 with an appropriate pressing force. The pressing force can be remarkably reduced as compared with the conventional one in which the recording paper is sandwiched between the recording head and the platen roller to transfer the recording paper. Therefore, the load on the printing unit 121 of the thermal head 12 can be reduced, and the service life can be extended.

Next, a second embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 4 and 5, in this embodiment, a fiber assembly (for example, a metal fiber bundle such as SUS) 142 is provided as the fixed platen 14. In the SUS fiber bundle 142 of this example, each fiber thickness is processed to about 10 to 100 μm. With such a thickness, even a metal fiber shows sufficient flexibility.

Therefore, as shown in FIG. 5, an appropriate pressing force can be generated against the recording paper. In addition, when a recording paper with a small width is used, this fixed platen 1
Even if the fiber bundle of No. 4 directly contacts the printing portion such as the thermal head, the recording head is not destroyed. Further, by using the fiber bundle having sufficient flexibility, the contact portion with the recording paper is oriented in the recording paper transfer direction, and the transferred recording paper can be provided with low friction.

FIG. 6 shows a third embodiment of the present invention in which a sheet bundle (laminate) 143 made of polyethylene film or the like is provided instead of the fiber bundle. Each of these film sheets is laminated at a position corresponding to the recording line of the recording head in a direction traversing the recording paper.
This film is formed by a thin and flexible sheet. As a result, it is possible to provide proper pressing and low friction.

In the above description, the fixed platen has a tapered tip in the first embodiment, and the fixed platen has a flexible shape in the second and third embodiments. The pressure contact force of the recording paper with respect to the recording head is reduced. Accordingly, even when a wide recording head is used, it is not necessary to firmly form the fixed platen and the recording head, and it is possible to easily perform uniform pressure contact without causing problems such as bending.

[0018]

As described above, according to the present invention, since the fixed platen is used as the platen, it is possible to use a narrow recording paper even in the contact type recording system such as the thermal head recording. Further, since the recording paper contact portion of the fixed platen is subjected to the low friction treatment, there is an advantage that it does not hinder the transfer of the recording paper. Further, by reducing the contact area between the recording paper and the recording head, the relative pressure contact force between the recording head and the fixed platen can be reduced, and even if a wide recording head is used, a uniform contact can be easily achieved. Can give pressure. In any of the embodiments of the present invention, since the fixed platen can be manufactured in a lightweight manner, by fixing the recording head to the housing and moving the fixed platen up and down, the mechanism of the apparatus can be simplified. can do.

[Brief description of drawings]

FIG. 1 is a normal recording state diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a state diagram showing recording on recording paper having a small width by the apparatus according to the first embodiment of the present invention.

FIG. 3 is a main part diagram of the device according to the first embodiment of the present invention.

FIG. 4 is a state diagram showing recording on recording paper having a small width by the apparatus of the second embodiment of the present invention.

FIG. 5 is a main part diagram of a second embodiment device of the present invention.

FIG. 6 is a main part diagram of a third embodiment device of the present invention.

[Explanation of symbols]

10: Roll recording paper 12: Thermal head 13: Recording paper transfer mechanism 14: Fixed platen

Claims (2)

[Claims] 1. A recording apparatus having a non-rotating platen which presses a recording medium transported by a medium transporting unit against a recording head with a predetermined force, wherein a recording medium contact portion of the non-rotating platen is subjected to low friction treatment. A recording device characterized by the above. 2. The recording apparatus according to claim 1, wherein the low-friction treatment is configured such that a soft fibrous member or a soft sheet-shaped member is brought into contact with a recording medium at a predetermined pressure.