JPS6411472B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixed head type print head support system.

In the above-mentioned type of thermal dot printer, the heating elements necessary for one line of printing digits are arranged in a horizontal line, and the printing head is considerably horizontally long. For this reason, it is extremely difficult to bring the entire length of the printing head into even contact with the platen, and printing is likely to be shaded in one line.

SUMMARY OF THE INVENTION The present invention aims to improve print quality by providing a support device that allows a fixed print head to be evenly opposed to a platen with a simple configuration.

To explain the example, Fig. 1 and Fig. 2
In the figure, a known thermal printing means 2 is provided on the front surface of a horizontally long head substrate 1. The thermal printing means 2 is in contact with a thermal recording paper 4 fed by a platen 3, and has a large number of heating elements (not shown) necessary for printing one line of printing digits arranged horizontally at minute pitches. They are lined up. On the back side of the head board 1, a pair of mounting plates 5 are attached with screws 6 near the left and right ends.
It is fixed through. Each mounting plate 5 has a bent portion 7 extending rearward at right angles to the head substrate 1, and this bent portion 7 is connected to the arrangement line of the heating elements, that is, the contact line _L1 between the thermal printing means 2 and the platen 3.
(See Figure 4). A support shaft 8 fixed to a frame (not shown) is provided diagonally below the rear of the head board 1.
A pair of support levers 9 are arranged in parallel so as to be independently rotatable. A window hole 10 is formed in the upper part of each support lever 9, into which a part of the bending part 6 is inserted. Each support lever 9 is urged clockwise around the support shaft 8 by a spring 11 (FIG. 2). Therefore, the rear edge 1 of the window hole 10
2 engages with the rear end of the bending portion 7, and the head substrate 1 is pressed toward the platen 3. A front edge 14 of the window hole 9 is loosely fitted into a guide groove 13 formed at the front end of the bending part 7. A vertical bent portion 15 is formed at a lower position of the bending portion 7 at a right angle from the lower edge of the window hole 10, and faces the bending portion 7 in parallel with a distance therebetween. And the bending part 7 and the vertical bending part 15
A compression spring 16 is inserted between the two, and a height adjustment screw 17 is loosely passed through it from the bending part 7 side, and further threaded through the spring 16 to the vertical bending part 15.
An abutment member 18 is arranged at a position that approximately divides the space between the support levers 9 into two. In this embodiment, the receiving member 18 is rotatably received by the support shaft 8, and a support shaft 19 installed between both support levers 9, 9 is connected to a long hole 2 formed in a part of the support member 18.
It passes through 0. A small diameter portion 21 is formed at both ends of the support shaft 19, and the small diameter portion 21 fits into the shaft hole 22 of the support lever 9.
are having fun. A portion 23 of the contact member 18 is in contact with the lower side of the back surface of the head board 1.

When setting the paper, the support levers 9, 9 are moved back as shown in FIG. 3 against the spring force of the spring 11 via a set lever (not shown), and in this state, the recording paper 4 is passed in front of the platen 3. Ru. At this time, the head board 1 is in a semi-restricted state, and the adjustment screw 17
It is possible to rotate around it as shown by the chain line. When the set lever is returned to its original position, the support lever 9,
9 is released and the state shown in FIG. 1 is achieved by the force of the spring 11, and the head substrate 1 is pressed against the platen 3. In FIG. 4, P ₁ and P ₂ are support levers 9,
9 is the pressure application point, and P ₃ is the contact member 18
This is the point of application of pressure. The pressure application points P ₁ and P ₂ are located above the contact line L ₁ between the platen 3 and the head substrate 1 (thermal printing means 2), and the pressure application point P ₃ is located below the line L ₁ . In addition, the pressure application point P ₃ is P ₁ ,
It lies on the perpendicular bisector _L3 of the line segment _L2 connecting _P2 . In other words, the head board 1 is pressed against the platen 3 by pressure from three points P ₁ , P ₂ , and P ₃ , and even if the platen 3 is positioned slightly diagonally due to errors in manufacturing and assembly, the head board 1 is The thermal printing means 2 on the front surface of the substrate 1 is stabilized so as to be in even line contact with the platen 3.
For example, assuming that the platen 3 is installed in an oblique position with the right end side slightly retreating from the left end side, the right support lever 9 will follow this attitude error and move slightly forward of the left support lever 9. I will move on to. This is because the support structure described above does not impair the independent movability of the support levers 9, 9 at all. Conventionally, the head board 1 was rigidly fixed to the support levers 9, 9, so even if the support levers 9, 9 were individually rotatably received on the support shaft 8, the independent movability of the support levers 9, 9 was not possible. The head substrate 1 is restrained by the head substrate 1, and the entire length of the head substrate 1 cannot be evenly contacted with the platen 3, resulting in the head substrate 1 being twisted. Furthermore, if there is a posture error in the platen 3, the contact line of the thermal printing means 2 with respect to the platen 3
There are cases where L ₁ deviates slightly from the arrangement line of the heating elements, but in such a case, turn the adjustment screw 17 to adjust the arrangement line of the heating elements so that it becomes the contact line.

Note that the present invention is specified only by the claims, and various changes can be made without departing from the technical idea thereof. For example, the support lever 9 can be shaped without the window hole 10 as shown in the fifth figure. Further, the shape and support structure of the abutment member 18 can also be changed as appropriate.
For example, the support member 18 may be fixedly installed on the bottom plate (not shown) of the printer. However, a structure in which the abutment member 18 is displaced together with the support lever 9 as in the embodiment has an advantage in that the head board 1 can be easily displaced to the position shown in FIG. 3. Furthermore, in place of the abutment member 18 of the embodiment, a shaft 19 is installed above the support shaft 8, and a disc-shaped abutment member is formed integrally with or separately from the shaft, and this disc-shaped abutment member is attached to the head board 1. It may be made to abut on the lower side of the.

As described in detail above, according to the present invention, even if the head is of a fixed head type and is quite horizontally long, the entire length of the head can be made to face the platen evenly. Print quality can be obtained. Moreover, this has the advantage that even if there is some error in manufacturing and assembly, it can be achieved by simple adjustment. This also significantly reduces the time and labor required for assembly and adjustment, leading to cost reductions.

[Brief explanation of drawings]

The drawings relate to one embodiment of the present invention, and FIG. 1 is a perspective view thereof, FIG. 2 is a sectional side view thereof, FIG. 3 is a sectional side view of the same when the support lever is in the retracted position, and FIG. FIG. 4 is an explanatory view showing the point of application of pressure to the head substrate, and FIG. 5 is a side view showing another embodiment of the support lever. DESCRIPTION OF SYMBOLS 1...Head board, 2...Thermal printing means, 3...Platen, 4...Recording paper, 5...Mounting plate, 7...Bending portion, 8
...Support shaft, 9...Support lever, 15...Vertical bending part, 1
6... Spring, 17... Height adjustment screw, 18... Backing member.

Claims (1)

[Scope of Claims] 1. A pair of mounting plates are fixed at a distance from each other to the back surface of a flat head board having a length necessary for printing one line. A pair of support levers are arranged in parallel so as to be rotatable independently of the support shaft, and the support levers are arranged in parallel so as to be rotatable independently of the support shaft. A vertically bent portion is formed on the lever and faces the bent portion with a space therebetween, a spring is inserted between the bent portion and the vertically bent portion, and the spring is loosely passed through the bent portion. A height adjustment screw for the head board is provided which is screwed into the vertically bent portion, and a contact member is provided which comes into contact with the back surface of the head board at a position that approximately bisects the space between the support levers. A support device for a printing head, characterized in that a position of engagement with the bending portion and a position of contact of the abutment member with the rear surface of the head substrate are located on both sides of a contact line between the platen and the front surface of the head substrate. 2. The print head support device according to claim 1, wherein the support member is supported by the support shaft and a support rod installed between the support levers.