JPH01221258A - Positioning device of partially glazed thermal line printed head - Google Patents

Abstract

PURPOSE:To enable a good setting state to be always obtained for either plain paper or card board, by a method wherein a heat radiating plate is divided into two so as to be movable and adjustable, and a head is fixed to an optimum position. CONSTITUTION:After inserting a guide pin 11 buried in a head fixing member 9 into a depressed part 11' provided to a heat radiating plate 3, a printer head is fixed to the fixing member with a screw 13. A head to be fixed, after inserting a guide pin 12 buried in one side of the heat radiating plate into a depressed part 12 of another side of the head radiating plate, being preliminarily fixed with a screw 14 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a printer head positioning device in a printer equipped with a cylindrical platen and a partially glazed thermal line printer head.

[Conventional technology]

In conventional printers, the printer head is made up of a heat generating element and a head heat dissipation plate, and after assembling the printer head with the recesses provided in the head heat dissipation plate set in a fixed relationship with the position of the heat generating element, The printer head is fixed at a predetermined position by being inserted into and fixed to the recess, which is a guide pin embedded in the head fixing member.

[Problem to be solved by the invention]

With conventional printers, the printer head is always fixed in the same position, and even if the printing quality on plain paper (thin paper) is good, when printing on thick paper such as tag paper, the head may not move properly because the paper is thick. Since it is difficult to deform to follow the shape of the heating element, there is a problem in that the efficiency of heat transfer from the head to the paper decreases, making it impossible to obtain good printing quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a positioning device for a partially glazed thermal line printer head so that a good printing condition can always be obtained on both plain paper and thick paper. In other words, in order to improve the print density on thick paper,
Factor 11, as shown in Figure 12, B of the heating element center
It has been found that it is necessary to shift the position of C by a certain amount from the position of C of the platen center.The present invention solves this problem by making the head movable.

[Means to solve the problem]

In order to achieve the above object, in the positioning device of the present invention, the heat sink is divided into two parts and moved.

The head is made adjustable so that it can be fixed at an optimal position. That is, in order to move the guide pin embedded in the head fixing member and the head position by a certain amount from the set value, the heat sink is divided into two parts, and the guide pin is embedded in one of the divided heat sink plates and the recess is provided in the other. Insert the two pieces into place and secure the two pieces together. The amount of this movement is determined by the position of the insertion part of the two sheets, but this is set in advance to achieve the optimal printing condition (.Also, this amount of movement is determined by the position of the insertion part of the two sheets. (Figures 11 and 12),
It is necessary to set two or more types.

In addition, methods for fixing the heat sinks include embedding a guide pin in one of the two heat sinks and providing V grooves on both sides of the other heat sink and fitting them together, or providing a convex portion on one side and attaching the guide pin to the other heat sink. It is also possible to provide a recess for fitting.

Furthermore, in order to set the angle of the fixing member without separating the heat dissipating plate, a convex portion is fixed to the heat dissipating plate by gluing or other method, and this is interposed between the head fixing member and the heat dissipating plate. Good too. In either method, the heat generating part and the cardboard part are in close contact,
This structure provides good thermal conductivity and provides good print density.

By dividing the heat sink into parts and shifting the center of the heating element relative to the platen center 〇, the heating element is made as parallel to the paper as possible to improve heat conduction.
The latter method (FIG. 8) also improves heat conduction by placing the heating element parallel to the paper.

[Effect]

FIGS. 9 and 10 show enlarged cross-sectional views of the vicinity of the partial glaze head heat generating section 6. FIG. That is, in a printer head in which a partial glaze (insulating layer) 5, a resistor 6, a conductor 7, and a protective film 8 are formed in layers on a ceramic substrate 2, the resistor in the portion not covered by the conductor generates heat as a heating element. The positional relationship between the heating element center 8 and the partial glaze center A is not constant, and deviations usually occur during mass production. Conventional printers only print on plain paper.

Even so, good print quality was obtained. However, when printing on thick paper such as tag paper, it was difficult for the paper to follow the shape of the head, resulting in uneven print density.

Therefore, using heads with different amounts of misalignment between the glaze center A and the heating element center 8, with the platen center 〇 fixed, the heating center B is moved in a direction perpendicular to the platen axis (circumferential direction of the platen). 11 and 12 show conceptual diagrams of the results of measuring the optical reflection density (OD value) of the printing surface by printing while moving the printing surface. The OD value of the printing surface is plotted with the vertical axis representing the OD value and the horizontal axis representing the amount of movement of the heat generating element safeter 8 relative to the platen center C. According to Figures 11 and 12, plain paper,
There are places where both cardboard and paper have high OD values. In other words, it can be seen that in order to efficiently transfer heat from the head to the paper, it is sufficient to move the glaze center A and the heating element center B by a certain amount in the circumferential direction of the platen. Divide the plate into two parts, set two or more types of insertion part positions between the heat sinks, and assemble them in advance by combining the insertion parts according to the amount of deviation (by doing so, the center position of the heating element can be adjusted). The platen is moved a certain amount with respect to the center of the platen.

FIG. 8 shows another embodiment in which the same effect as above is achieved by tilting the heating element by a certain amount instead of shifting the center of the heat radiating element. That is, when the convex portion 18 is fixed to the heat sink by adhesive or other method, it is interposed between the head fixing member 9 and the heat sink 60, and the head 19 is tilted by an angle θ with respect to the fixing member 9. , if the platen diameter is 2D, the heating element is D sia with respect to the platen center.
Almost the same effect as when moving by θ was obtained.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 shows a guide pin 11 embedded in the head fixing member 9.
is inserted into the recess 11 provided in the head heat sink 6, and then the printer head is fixed to the fixing member with the screws 16.

The head to be fixed is one which is fixed in advance with screws 14 after inserting the guide pin 12 buried in one side of the heat sink and the recess 12 in the other side.

FIG. 2 shows another embodiment in which two heat sinks are fixed by adhesive instead of using screws.

In FIG. 3, a guide pin 12 is press-fitted between the heat sinks and the two plates are fixed together.

The embodiment shown in FIG.
A guide pin 12 embedded in the other heat sink is inserted into the groove 15 and then fixed with a screw 14. In the embodiment shown in FIG. 5, the heat sinks are fixed together with adhesive.

FIG. 6 shows another embodiment, in which a convex portion 16 provided on one side of the heat sink.
After fitting, the other recess 17 is fixed with a screw 14.

The embodiment shown in FIG. 7 is an example in which the structure shown in FIG. 6 is fixed with adhesive.

The embodiment shown in FIG. 8 shows an example in which a convex portion 18 is fixed on the heat sink at a position interposed between the head fixing member and the heat sink.

〔Effect of the invention〕

As is clear from the above description, the present invention provides the following effects.

By installing the head positioning device according to the present invention, good print quality can be obtained on both plain paper and thick paper, which has been difficult to achieve in the past. Furthermore, since the position of each head is adjusted in advance, even if the head is replaced, good print quality can be obtained without any adjustment, making after-sales service easier.

The method of fixing the two heat sinks can be done in a simple manner, so the cost is not too high.Especially in the sixth embodiment, one is provided with a convex portion and the other is provided with a concave portion for fitting, so the guide pins and Burying process is not required and costs are low.

°・7, Figures 9 and 10 are enlarged cross-sectional views of the vicinity of the head heating element, and Figures 11 and 12 show the concept of the effect that the misalignment of the heating element center glaze center has on the platen center heating element center. A graph showing . 9 and 11 are related, and FIG. 10 and 12 are related.

1...Platen roll, 2...Alumina substrate, 6.6... Heat sink.

5... Partial glaze, 6... Resistor, 7... Conductor, 8... Protective film, 9... Head fixing member, 11... Guide pin, 12... Guide pin between heat sinks, 16...
・Screw, 14...Fixing screw between heat sinks, 15...■Groove.

16... Heat sink convex part, 17... Heat sink recess, 18... Heat sink convex part.

19...Head.

Claims (4)

[Claims] (1) The center of the heating element and the center of the partial glaze do not match and are misaligned.In the positioning device for a partial glaze thermal line printer head, the heat dissipation is performed so that the heating element is in parallel contact with the paper on the platen. A positioning device for a partial glaze thermal line printer head, characterized in that a plate is fixed to a head fixing member. (2) The printer head is fixed to the printer head fixing member by embedding a guide pin in the fixing member of the printer head, providing a recess in the heat dissipation plate that is a part of the printer head, and inserting the guide pin into the recess. The positioning device for a partial glaze thermal line printer head according to claim 1. (3) The head is fixed to the head fixing member after the protrusion 16 is provided on one side of the bisected heat sink and the convex portion is fitted and fixed to the convex portion provided on the other side, and the head is fixed to the head fixing member. Glazed thermal line printer head positioning device. (4) The positioning device for a glazed thermal line printer head according to claim 1, characterized in that the heat sink is not divided into two parts, but the convex portion is fixed on the heat sink at a position where the head fixing member is interposed on the heat sink.