JPH01150566A - Printing apparatus - Google Patents

Abstract

PURPOSE:To prevent the printing inferiority caused by the deformation of a roller shaft, by providing a pressing elastomer taking a mode, wherein a shape is binarily changed by the application of a signal and a head is pressed to the roller shaft under certain constant pressing force, and a mode removing the pressing force to the roller shaft. CONSTITUTION:A pressing elastomer 6 is a coil spring formed of a shape memory alloy and can take two free length values L1, L2 corresponding to the current from a drive signal circuit 13. In the case of L1>L2, the interval between a head support plate 9 and a housing 1 is set so as to become sufficiently larger than L1 and a head 5 is pressed to a roller shaft 3 under proper pressing force against the force of a head return spring 14 to be made printable with respect to roll paper 7. When a printer is not operated, the length of the pressing elastomer 6 becomes L2 and the repulsive force of the spring becomes weak and, therefore, the head 5 revolves around a rotary shaft 10 by the action of the return spring 14 and moves to the position brought into contact with a stopper 15 to be separated from the roller shaft 3. The head 5 is brought into contact with the roller shaft 3 or allowed to be spaced apart therefrom by the control of the drive signal circuit 13.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to various OA
The present invention relates to a printer device widely used in equipment, HA equipment, etc., and particularly relates to a head pressing mechanism thereof.

Conventional printer devices are widely used as note copy output devices for various office automation equipment, and various types have been proposed depending on printing methods. Among them, there is a wide demand for thermal printer devices that utilize heat generated by the head because they operate quietly, have a simple structure, are easy to maintain, and are inexpensive. In this printer device, the head that performs printing is usually pressed against a roller shaft coated with rubber or the like with a predetermined pressure, and heat generated from this pressure and electrical energy applied to the head is used to print. , print a figure, one character, etc. on paper.

Problems to be Solved by the Invention Conventionally, coil springs or leaf springs made of SUS steel or the like have been generally used to press the head, but this method has the following problems. 0 (1) The head is always pressed against the roller shaft by an elastic body, whether printing is in progress or not.
When left unused for a long period of time, the rubber of the roller shaft may partially deform, causing a decline in print quality.

(2) Since the head is always in contact with the printing paper or the roller shaft, moisture in the paper or the rubber component of the roller shaft may deteriorate the insulating layer of the head, reducing the reliability and lifespan of the head.

As described above, the head pressing mechanism of the conventional printer apparatus has problems such as deterioration of print quality due to deformation of the roller shaft and reduction of reliability and life of the head. The present invention aims to provide a printer device equipped with a simple and reliable head pressing mechanism to solve all of these problems.

Means for Solving the Problems In order to achieve the above object, the present invention provides a configuration in which the shape changes binary by applying a signal and presses the head against the roller shaft with a certain pressure force; A pressing elastic body is provided that removes the pressure applied to the cylinder.

Function In the printer device configured as described above, the head is pressed against the roller shaft only when printing is performed on paper in response to a signal, and returns to the shape in which the pressure is released at other times. Therefore, even if the roller shaft is left unused for a long period of time without being printed, problems such as pressurizing and deforming the roller shaft will not occur.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIGS. 1a and 1b are configuration diagrams of a printer device according to an embodiment of the present invention. Further, FIGS. 2A and 2B are detailed operational explanatory diagrams of the head pressing mechanism shown in FIG. 1, and FIG. 3 shows the pressing elastic body shown in FIGS. 1 and 2. Furthermore, Figure 4a
, b are external views showing other embodiments of the pressing elastic body.

In Fig. 1, Fig. 2 a, b, and Fig. 3, 1 is the housing of the printer device, 2 is the motor attached to the housing 1, and 3 is the housing of the printer device.
4 is a belt for transmitting the driving force of the motor 2 to the roller shaft 3, 6 is a head, and 6 is a roller shaft that connects the head 6 to the roller shaft 3 with a prescribed force. Elastic body for pressing, 7 is roll paper, 8 is roll paper 7
It is a holder that holds. As shown in FIGS. 2a and 2b, the head 5 is fixed to a head support plate 9, and the head 5 and the head support plate 9 are installed in the housing 1 so as to freely rotate around a rotating shaft 10. There is. Furthermore, one end of the pressing elastic body 6 is fixed to the housing 1, and the other end is brought into contact with the head support plate 9 at a position facing it. Further, electrodes 11.12 are fixed to both ends of the pressing elastic body 6, and a current is applied by the drive signal circuit 13 through the electrodes 11.12. 15 is a stopper portion provided to protrude from the housing 1, and 14 is a head return spring.

In the head pressing mechanism of the printer apparatus configured as described above, the pressing elastic body 6 is a coil spring made of a shape memory alloy, and the pressing elastic body 6 is a coil spring made of a shape memory alloy, and the pressing elastic body 6 is a coil spring made of a shape memory alloy. The free lengths shown in are Ll and Ll
It can take two values. For example, in the case of Ll>Ll, as shown in FIG. It is possible to apply pressure with an appropriate pressing force against the force of .

In this state, printing on the roll paper 7 becomes possible. When the printer device is not operated, the length of the pressing elastic body 6 becomes Ll as shown in Fig. 2, and the spring repulsive force becomes weak.
Under the action of the return spring 14, the head 5 rotates about the rotating shaft 10 as a fulcrum and moves to a position where it abuts the stopper 16, thereby separating from the roller shaft 3. That is, by controlling the drive signal circuit 13, the head 5 can be brought into contact with or separated from the roller shaft 3.

In the above embodiments, a coil spring-like member was used as the pressing elastic body, but the shape of the pressing elastic body is not limited to this, and is shown in FIGS. 3a and 3b. Similar effects can be expected with the plate spring 6a shape.

Effects of the Invention As described above, in the printer device of the present invention, since the head is brought into contact with the roller shaft only during printing, the reliability of the head is increased and printing defects caused by deformation of the roller shaft can be completely prevented. becomes.

[Brief explanation of the drawing]

Figure 1 4. 2b is a front configuration diagram and a top configuration diagram showing an embodiment of the present invention, FIGS. 2a and 2b are front views explaining the operation of the head pressing mechanism in FIG. 1, and FIG. 3 is a pressing elastic FIGS. 4a and 4b are a perspective view and a front view of another embodiment of the pressing elastic body. 5... Head, 6... Elastic body for pressing. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3/

Claims (1)

[Claims] By applying a signal to a housing, a motor attached to the housing, a roller shaft supported at both ends that rotates due to the drive of the motor, and a head placed parallel to and facing the roller shaft, A printer device whose shape changes in a binary manner and is comprised of a shape that presses the head against the roller shaft with a predetermined pressure, and a pressing elastic body that takes a shape that releases the pressure.