JPH0338350A - Thermal line printer - Google Patents

Abstract

PURPOSE:To easily detach a coil spring connecting a main body frame and a thermal line head substrate by providing at least one of said main body frame and a portion of said substrate in contact with said spring with a recessed portion of a smaller width than said spring. CONSTITUTION:There are provided a groove 24 and a head adjusting plate 23 in a thermal head substrate 20 so as to easily detach a spring 22. The head adjusting plate 23 is adjusted so that a predetermined distance is kept between a head of the thermal head substrate 20 and a printing paper, and fixed by a screw 25. One end of the ring-shaped spring 22 is positioned above the groove 24 where a part of the spring 22 does not fall inside the groove 24, and moreover within an area surrounded by a hook shaped section of the head adjusting plate 23. One end of an instrument 26 is inserted into the groove 24 in the gap between the spring 22 and head adjusting plate 23. Then, the instrument 26 is inclined to be inserted into the bottom portion of the spring 22. If the instrument 26 is pressed towards a direction shown by an arrow around fulcrum of an upper end of the head adjusting plate 23, the spring 22 is compressed, with raising the instrument 26. Accordingly, the spring 22 can be easily detached.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a thermal line printer.

2. Description of the Related Art A conventional thermal line printer will be described with reference to the drawings.

FIG. 3 shows a perspective view (FIG. 3a) and a side view (FIG. 3b) of a conventional thermal line printer.

In Figure 3, 1 is the recording paper, 2 is the main body frame, 3 is the paper feed roller, 4 is the thermal line head board with a heat sink on the back side, 5 is the main body frame side plate, and 6 is the paper feeder during printing. A stepping motor, 7 a drive gear for driving the paper feed roller 3, 8 a phototransistor for detecting the presence or absence of recording paper 1, 9 a coiled spring that presses the thermal line head board 4, 10 a thermal line head board This is a head adjustment plate that adjusts the position of 4.

The operation of the thermal line printer will be explained based on FIG. After the recording paper 1 is inserted into the printer along the shape of the main body frame, the recording paper 1 is moved between the paper feed roller 3 and the thermal line head board 4 by the rotation of the paper feed roller 3.
caught between. At this time, the thermal line head board 4 is pressed against the recording paper 1 and the paper feed roller 3 with uniform pressure by a coiled spring 9 fixed to the side plate 5 of the main body frame. After that, the thermal line head board 4 prints on a predetermined line on the recording paper 1, and furthermore, the driving gear 7 directly connected to the paper feed roller 3 feeds the paper one step by the stepping motor 6, and the thermal line head board 4 prints on a predetermined line. conduct. Desired printing is performed by repeating these operations.

FIG. 4 shows an enlarged view (FIG. 4a) and a side view (FIG. 4b) of the coiled spring that presses the thermal line head board 4.

A coil-shaped spring 9 is fixed to the thermal line head substrate 4 side with a key-shaped head adjustment plate 10 so as not to move. A coiled spring 9 is attached to the side plate 5 of the main body frame.
In order to fix the main body lane 9, it is prevented from shifting. At this time, the protrusion of the convex portion is smaller than the inner diameter of the coil of the coiled spring 9.

Problems to be Solved by the Invention However, with the above-mentioned conventional configuration, it is difficult to easily remove the thermal line head for maintenance such as removing print scum from the recording paper attached to the thermal line head or replacing the thermal head. cannot, also
If you try to remove it forcibly, the spring may be damaged or the thermal line head board may be damaged. The present invention is intended to solve these problems, and aims to enable the coil spring that connects the main body frame and the thermal line head board to be easily removed.

Means for Solving the Problem In order to achieve this purpose, the thermal line printer of the present invention has a main body frame and a main body frame.
It is characterized by providing a recessed portion.

Effect By providing a recess in the part where the spring comes into contact in this way,
Spring removal becomes easier.

Example Below, an example of the present invention will be described. I will explain while doing so.

An enlarged view (Fig. 1 a) and a plan view thereof (Fig. 1
Figure b) is shown.

In FIG. 1, 20 is a thermal head board, 21 is a main body frame side plate, 22 is a coiled spring, 23 is a head adjustment plate, 24 is a groove for facilitating the removal of the spring 22, and 25 is a head adjustment plate 23. This is a screw that fixes the

The story structure of this example will be explained with reference to FIG.

The thermal head substrate 20 is provided with a groove 24 and a head adjustment plate 23 to facilitate the removal of the spring 22. This head adjustment plate 23 is adjusted so that the head of the thermal head board 20 maintains a predetermined distance from the printing paper, and is fixed with screws 25. Here, the trenches were dug 2 meters wide and 5 holes deep.

One end of the ring-shaped spring 22 is located above this groove 24 and at a position where a part of the ring-shaped spring 22 does not fall into the groove 24, and further within the area surrounded by the hook-shaped area of the head adjustment plate 23. will be placed in

The ring-shaped spring 22 used in this example had a diameter of 5 mm and a spring height of 1 mm.

The other end of the ring-shaped spring 22 is pressed and fixed by the main body frame side plate 21. A burring portion is formed by pressing the main body frame side plate 21 at the portion where the ring-shaped spring 22 is fixed. A spring is fitted into this purling part and fixed.

FIG. 2 shows a cross section of the spring portion when the coiled spring 22 is removed.

The structure of FIG. 2 is the same as that of FIG. 1, and 26 is a tool for removing the coiled spring 22.

The operation for removing the coiled spring 22 will be explained.

A metal rod with a diameter of 1.5 nua and a length of 5 cm was used as a tool 26 for removing the coiled spring 22 (hereinafter referred to as a removal tool).

First, a coiled spring 22 in contact with the thermal head board
One end of the removal tool 26 is inserted into the groove 24 in the gap between the head adjustment plate 23 and the head adjustment plate 23, and the removal tool 26 is inserted diagonally so as to fit into the bottom of the coiled spring 22.

Thereafter, by using the top end of the head adjustment plate 23 as a fulcrum and pushing the removal tool 26 in the direction of the arrow using a lever principle, the coiled spring 22 is easily compressed and becomes in a floating state. At the same time, the coiled spring 22 can be easily removed by inserting the removal tool 26 into the bottom of the coiled spring 22 and then lifting the removal tool 26. or the thermal line head board 20.

Note that although an embodiment of a coil-shaped spring has been described here, a rod-shaped spring or a three-dimensional spring can also be removed in the same manner.

Although a cylindrical metal rod was used here as the tool for taking out the coiled spring, it is also possible to use a tool that can be partially inserted into the groove, or a tool made of a material such as wood or plastic.

Note that here, the coiled spring 22 is connected to the head adjustment plate 23.
Although the coiled spring 22 has a structure surrounded by , the coiled spring 22 can be easily removed even without a head adjustment plate by inserting a removal tool 26 into the groove 24 and lifting it up.

Effects of the Invention As described above, the present invention includes a main body frame, a spring attached to the main body frame, a thermal line head board pressed by the spring, and a part with a width narrower than the width of the spring in the area in contact with the spring. By providing the recess, the spring can be easily removed without damaging the spring or the thermal line head board.

[Brief explanation of drawings]

Fig. 1 is a diagram illustrating the state of the coiled spring that presses the thermal line head in an embodiment of the present invention, and Fig. 2 is a diagram illustrating the state of the coiled spring when removing the coiled spring in the embodiment of the present invention. A cross-sectional view, FIG. 3 is a diagram illustrating a conventional thermal line printer, and FIG. 4 is a diagram illustrating a coiled spring that presses down a thermal line head of a conventional thermal line printer. 20... Thermal line head board, 21...
...Body frame side plate, 22...Coil-shaped spring, 23...Head adjustment plate, 24...
... Groove, 25 ... Screw, 26 ... Coiled spring removal tool.

Claims (1)

[Claims] A main body frame, a spring attached to the main body frame, and a thermal line head board that is pressed against the print medium by the spring, and a width of the spring is provided on at least one of the main body frame and the part of the board that is in contact with the spring. A thermal line printer characterized by providing a concave portion with a narrower width.