JPH0284350A - Thermal head printing pressure balance device - Google Patents

Abstract

PURPOSE:To certainly apply sharp printing to a label by mounting a control means due to screw-nut to the pivot of a bracket supporting the thermal head elastically energized to a platen roller at least on one side of said shaft. CONSTITUTION:A thermal head 41 is fastened to a support member 44A on one side thereof by a fastener 43a such as a rivet and indirectly mounted on the bracket 43 fastened to a support member 44B on the other side thereof to be made rotatable on a pivot 45. One end of the bracket 43 supporting the thermal head 41 is directly fixed to the support member 44A and the other end thereof is fixed to the support member 44B through an adjusting nut 48 as an adjusting means and, by the fine adjustment of the adjusting nut 48, the non-uniformity of the printing pressure to a label continuous body 1 generated by the irregularity of the processing accuracy of a part (thermal head 41 or platen roller 42) and the error of the assembling accuracy of said part are corrected.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is an automatic label pasting machine capable of automatically pasting labels with desired printing onto articles conveyed by a conveyor or the like. The present invention relates to a printing pressure balance device for a thermal head for making clear prints on a body.

(Prior art) This type of continuous label is printed while being held between a thermal head and a platen roller, but there may be variations in the accuracy of the parts of the thermal head or platen roller, or errors in the assembly accuracy of both parts. (Generally about 0.05m/m)
As a result, the platen roller and thermal head do not come into contact with each other in parallel, making clear printing impossible. To explain this using the conceptual diagram shown in FIG. 5, when the thermal head (101) is set to the platen roller (100),
The clarity of printing on the label continuous body (102) which is held between these two members and printed on is ideal when both members are in a parallel state as shown in (a).

However, in general, there are many cases where one side of the thermal head (lot) is tilted compared to the other side, as shown in (b) and (c). That is, on the downward side of the slope, the gap is small, the printing pressure is large, and the print is dark. On the other hand, on the upper side of the slope, the gap is large, the printing pressure is small, and the print becomes thin.

Therefore, clear printing cannot be performed due to uneven printing pressure on the label continuous body (102). A thin spacer is interposed on one side of the gap to equalize the printing pressure.

(Invention or Section WU to be solved) The spacer used as a balance for printing pressure is interposed between the thermal head and its supporting member (bracket), so it is troublesome to insert the spacer. There are problems in that it takes time and requires skill to adjust the printing pressure.

Therefore, in the apparatus of the present invention, it is an object of the present invention to provide a balance adjustment apparatus that can easily and reliably equalize the printing pressure balance and obtain clear printing on a continuous label body without using this spacer. do.

(Means for Solving the Problems) As a printing pressure balance device for a thermal head of the present invention, a support member 44 is provided on one side of the fulcrum shaft 45 of the thermal head 41 which is disposed opposite to the platen roller 42 and is elastically biased. An adjustment nut 48 is attached to the adjustment nut 48, and the adjustment nut 48 is used to finely adjust uneven printing pressure when printing on the label continuous body 1 caused by uneven component precision or assembly precision error. It is designed to provide clear printing.

(Function) Referring to the general view of FIG. 1, the continuous label body 1 wound around the supply reel IO passes through a guide roller 19, is suspended by a tension roller 16 that moves up and down, and then is suspended by a tension roller 16 that moves up and down.
0, 21, 22, etc., the thermal head 41 is pressed against the platen roller 42 via the label sensor 23.
This leads to a printing section 40 consisting of. When inserting the label, the thermal head 41 is separated from the platen roller 42,
It is necessary to form a label passage in this portion to facilitate label insertion.

Specifically, in FIG. 2, by rotating the opening/closing lever 50 of the thermal head 41 in the time direction, the thermal head 4 is brought into pressure contact with the platen roller 42 by the cam 52.
1, by operating the opening/closing lever 50 clockwise, the bracket 4 is opened by the action of the cam 52 connected to the opening/closing lever 50.
3 rotates clockwise about its fulcrum shaft 45 against the elasticity of the spring 46, causing the label passage 5 to become raised, and the label passage 5
1 can be formed.

In this way, the tip of the label continuous body 1 is connected to this label passage 51.
Then, by operating the opening/closing lever 50 in the opposite direction, the continuous label l is clamped between the platen roller 42 and the thermal head 41 by the action of the spring 46. do.

Next, referring to FIG. 1, the leading end of the label continuous body l which has completed label setting passes through the adjusting member 70 and reaches the label sticking member 71 having the turning bin 26. Peel off piece 2 and apply it with roller 72
With this, a label piece is affixed to the article being conveyed by a conveyor or the like.

Here, referring to FIG. 2, the printing unit 40, that is, the label continuous body l held in pressure contact between the thermal head 41 and the platen roller 42 has a printing pressure of either large or small on either side in the width direction. This results in an uneven and poor condition. This uneven state occurs due to variations in parts such as the thermal head or platen roller.

Thus, this uneven printing pressure can be eliminated by tightening or loosening the adjustment screw 48, and the uneven printing pressure can be eliminated on the label continuous body 1.
Printing for a# is applied.

Specifically, as shown in the cross-sectional view of FIG.

One side of the bracket 43 that supported the thermal head 41 is a fastening body 43a, which is directly fixed to a support member 44A rotatably disposed on the fulcrum shaft 45.
On the other side, a screw shaft 47,
It is fixed via an adjustment seat 48 and a fixing nut 49,
2Xi! By setting the position where the adjusting nut 48 and the fixing nut 49 sandwich the other side of the bracket 43,
The parallel balance of the thermal head 41 with respect to the platen roller 42 is maintained.

Specifically, on the other side of the bracket 43 of the thermal head 41, a threaded shaft 47 is implanted in the support member 44 of the fulcrum shaft 45. A through hole 43b drilled in the bracket 43 is loosely fitted into the screw shaft 47, the adjustment nut 48 is hinged to the upper part of the bracket 43, and a fixing nut 49 is screwed to the lower part thereof. It is the composition.

Thus, when adjusting the balance by pushing down the thermal head 41, it is sufficient to first loosen the fixing nut 49, push it down to the desired position, and then tighten the adjusting nut 48 downward. Conversely, if you want to adjust the balance by pushing up the thermal head 41, first loosen the adjusting nut 48 and push it up to the desired position, then tighten the fixing nut 49 upwards. This achieves a stable balance of the printing pressure of the thermal head 41 against the platen roller 42.

(Example) A printing pressure balance device for a thermal head in an automatic label pasting machine of the present invention shown in FIGS. 1 to 3 will be described.

First, to explain the overall outline with reference to FIG. 1 showing the overall configuration, a supply reel is wound around a continuous label body 1 consisting of label pieces 2 temporarily attached at equal intervals on a tape-shaped mount 3. The lO is fixedly held on the boss 11 of the printer 4 by a support arm 12 fixedly attached to the bracket 5 of the printer 4.

The continuous label body l wound around this supply reel 10 passes through a guide roller 19 and is suspended by a tension roller 16 that moves up and down. Here, the fulcrum 13 of the supply reel IO and the fulcrum 15 of the tension roller 16 are eccentric, and a label feeding means having a braking function by frictional contact is provided between the peripheral edge of the supply reel IO and the tension roller 16. Next, the label continuum l is guided by the guide roller 20°21
．． 22, etc., and passes through a label sensor 23 to a printing unit 40 consisting of a thermal head 41 which is placed opposite to a platen roller 42 related to the apparatus of the present invention and is in pressure contact. The specific configuration, operation, and effects of this device are shown in Figures 2 to 4.
This will be described later with reference to the drawings.

Desired printing is performed on the label piece 2 of the label continuous body 1 that has reached the printing section 40. Next, the continuous label l passes through a label peeling position adjustment member 70 equipped with a pair of turning rollers 24 and 2S, and reaches the turning pin 26. Thus, the means for transporting the label continuous body l is one that transmits the rotational drive of the motor 6 mounted on the bracket 5 to the pulling roller 53, and is pulled by the pulling roller 53 and the pressure roller 54.

The continuous label body 1 has reached the turning pin 26.

At this point, the label piece 2 is
The label is peeled off, and a label is pasted by a pasting roller 72 onto the article that is loaded on a conveyor or the like and transported. In this pasting, the label pasting member 71 is pushed down, and this operation is performed when the label pasting member 71 receives the protruding action of the plunger 74 due to the excitation of the solenoid 73.

Next, the continuous label body after the label pieces 2 have been pasted on the article is formed into a tape-like backing paper 3, and the tape-like backing paper 3 is sandwiched by the pressure contact force of the pressure roller 54 via the guide roller 27.2B, and the tape-like backing paper 3 is held by the pressure contact force of the pressure contact roller 54, and It is wound onto a take-up reel 30 via a roller 53.

Next, the platen roller 42 and thermal head 41 of this device
The configuration of the printing section 40 of this apparatus, which is constructed in combination with the following, will be explained with reference to FIGS. 2 to 4.

First, as shown in FIGS. 2 and 4, a printing unit 40 prints desired information such as a bar code, serial number, date of manufacture, price display, etc. on the label piece 2 of the label continuum l. It is composed of a platen roller 42 and a thermal head 41 which are arranged in a facing relationship. This thermal head 41 has one side fixed to a support member 44A with a fixing member 43a such as a screw, and the other side attached to a bracket 43 indirectly fixed to a support member 44B. Can rotate. Specifically, in FIG. 2, when the opening/closing lever 50 is operated clockwise, the bracket 43 is pushed up by the action of the cam 52, and the thermal head 41 rotates clockwise to form the label passage 51. Usually, the bracket 43 is biased counterclockwise by a spring 46 interposed in the support member 44B, so that the thermal head 41 is elastically biased toward the platen roller 42.

Furthermore, adjustment means is provided only on one side of the plane of the bracket 43 that supports the thermal head 41. That is, the adjustment nut 48 as the adjustment means is
It clamps the bracket 43 in cooperation with the fixing nut 49, and is screwed onto a screw shaft 47 fixed to a support member 44A rotatably disposed on the fulcrum shaft 45.

Next, referring to FIG. 3, as described above, the thermal head 4
One side of the bracket 43 that supported the support member 44
A, and the other side is fixed to a support member 44B via an adjustment nut 48 or the like as an adjustment means,
Fine adjustment of this adjustment nut 48 can cause variations in the processing accuracy of the parts (thermal head 41 or platen roller 42), as well as uneven printing pressure on the label continuous body l caused by errors in the assembly accuracy of these parts. It equalizes the

Specifically, the other side of the bracket 43 of the thermal head 41 has a support member 44B rotatably disposed on the fulcrum shaft 45.
It will be fixed to a screw shaft 47 fixed to. A through hole 43b formed in the bracket 43 is loosely fitted into this screw shaft 47, the adjustment nut 48 is screwed into the upper part of the bracket 43, and the fixing nut 4 is screwed into the lower part of the adjustment nut 48.
9 is screwed on. That is, the thermal head 4
The first bracket 43 exhibits a state of being held between a screw body and a nut.

Thus, when adjusting the balance by pushing down the thermal head 41, it is sufficient to first loosen the fixing nut 49, push it down to the desired position, and then tighten the adjustment screw 48 downward. Conversely, if you want to adjust the balance 7A by pushing up the thermal head 41, first loosen the adjusting nut 48 and push it up to the desired position, then tighten the fixing nut 49 upwards. Thus, the printing pressure of the thermal head 41 can be stably balanced.

In the embodiment, the fixing nut 49 is disposed below the adjusting nut 48, but the fixing nut 49 is not limited thereto, and the same purpose of balance adjustment can be achieved by using an elastically biased spring washer.

Further, these adjustment means may also be provided on the support member 44A side.

(Effects) As described above, the printing pressure balance device of the present invention includes an adjustment means using a screw and nut on at least one side of the fulcrum shaft 45 of the bracket supporting the elastically biased thermal head 41 on the platen roller 42. Because of the configuration, platen roller 4
The uneven printing pressure during printing on the continuous label body held between the thermal head 2 and the thermal head 41 can be equalized by fine adjustment of this adjustment means, which has the advantage of ensuring clear printing on the label. have

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the feeding, printing, label peeling, label pasting, and winding of a continuous label body equipped with the printing pressure balance device of the present invention, and Fig. 2 is the Ifrg of the printing pressure balance of the present invention.
s side view, FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2, FIG. 4 is a plan view of FIG. 2, and FIG. (a) shows the parallel state, and (b) and (c) show the inclined state. l...Label continuum 2...Label piece 3...
Tape-shaped mount 40... Printing section 41... Thermal head 42... Platen roller 43... Bracket 44A, 44B... Support member 45... Fulcrum shaft 46... Spring 47... Screw Shaft 48...Adjusting nut 49...Fixing nut 50...Opening/closing lever

Claims (1)

[Claims] In a thermal head that is supported by the tip of a bracket rotatably disposed on a fulcrum shaft so as to be able to approach and separate from a platen roller, at least one side of the base end connected to the fulcrum shaft is threaded. - A printing pressure balance device that is connected via nut means, and is capable of maintaining parallelism of the thermal head with respect to the platen roller by adjusting the positional relationship with the fulcrum shaft by the means. .