Plane thermal printing head capable of preventing static accumulation

Abstract

The utility model relates to the technical field of thermal printing manufacturing, in particular to an anti-static accumulation planar thermal printing head which is reasonable in structure and reliable in work, and is characterized in that a static conductive electrode is also arranged on a heating substrate for the thermal printing head; the static conductive electrode is arranged on the edge of the surface of the substrate on the paper outlet side of the heating substrate for the thermal printing head and arranged in the main printing direction or the auxiliary printing direction, the static conductive electrode is connected with the GND end of the PCB, and the protection layer comprises an insulation protection layer covering the surfaces of the heating resistor body, part of the common electrode and individual electrodes. Compared with the prior art, static electricity generated during friction between the thermal printing medium and the surface of the thermal printing head is accumulated, the problem of static electricity damage is reduced, meanwhile, the static electricity conducting electrode, the circuit board GND and the metal heat dissipation plate are conducted to form an electricity release channel, and the static electricity conducting electrode is not prone to being damaged by static electricity generated during friction between the static electricity conducting electrode and the metal heat dissipation plate. And electrostatic protection can also be realized on the printer mainboard.

Description

Technical field:

[0001] The utility model relates to the technical field of thermal printing manufacturing, in particular to a flat thermal printing head with reasonable structure and reliable operation and anti-static accumulation. Background technology:

[0002] As is known to all, a planar thermal print head needs to set a heating resistor and a wire electrode connected thereto on the thermal print head heating substrate, so as to use the wire electrode to power the heating resistor. In order to avoid damage to the above-mentioned electrical components, the heating resistor and the wire electrode surface are usually provided with a protective layer, and the protective layer first includes an insulating protective layer to prevent the unexpected electrical connection between the heating resistor and the electrode wire. In the actual printing process, the insulating protective layer directly contacts and rubs with the printing medium, which will generate static electricity. Since the generated static electricity has no release channel, it will cause the accumulation of static electricity on the surface of the thermal print head, affecting the printing quality and the service life of the product. To solve this problem, the prior art mainly reduces the accumulation of static electricity by adding a conductive protective layer on the upper surface of the insulating protective layer. Such a conductive protective layer contains particles made of conductive materials, which can form a conductive path during the accumulation of static electricity, and through the extension of the conductive protective layer, for example, it is recorded in the patent document CN216942356U that the accumulated charge is released by connecting the conductive protective layer with the metal heat sink in the thermal printing device.

[0003] However, during continuous printing, as the printing time increases, the amount of accumulated charge increases. Although the accumulated charge release path established in the above patent document can release the accumulated static electricity to a certain extent, the metal heat sink of the thermal printing device does not have a grounding structure, resulting in the inability to completely release the accumulated static electricity on the protective layer. Once there are hole defects in the protective layer during the sintering process, the accumulated charge can easily travel along the tiny conductive path in the conductive protective layer along the hole defects to form an unexpected electrical connection with the heating resistor and the electrode wire under the protective layer, causing product failure or shortening of service life. Summary of the invention:

[0004] The utility model aims at the shortcomings and deficiencies in the prior art and proposes a flat thermal print head which has a reasonable structure and high reliability and can prevent static electricity accumulation.

[0005] The utility model achieves this through the following measures:

[0006] A planar thermal print head for preventing static electricity accumulation is provided with a heating substrate for the thermal print head, a control IC and a PCB circuit board. The heating substrate for the thermal print head is provided with an underglaze layer, and the surface of the underglaze layer is provided with a common electrode, an individual electrode and a heating resistor, and a protective layer is provided on the surface of the heating resistor and part of the common electrode and the individual electrode. It is characterized in that the heating substrate for the thermal print head is also provided with a static electricity conductive electrode, which is arranged at the edge of the substrate surface on the paper output side of the heating substrate for the thermal print head and is arranged along the main printing direction or along the sub-printing direction. The static electricity conductive electrode is connected to the GND end of the PCB circuit board, and the protective layer includes an insulating protective layer covering the surface of the heating resistor and part of the common electrode and the individual electrode, and also includes a conductive protective layer covering the insulating protective layer and the surface of the static electricity conductive electrode.

[0007] The utility model provides that the static conductive electrode is arranged at the edge of the heating substrate for the thermal print head along the main printing direction, or the static conductive electrode is arranged at the edge of the heating substrate for the thermal print head along the main printing direction and the auxiliary printing direction.

[0008] The utility model is also provided with a metal heat sink, the thermal print head is fixed on the metal heat sink with a heating substrate, and the static-conducting electrode is also connected with the metal heat sink via a conductive resin.

[0009] In the utility model, a sealing glue protective layer is provided at the junction of the PCB circuit board and the heating substrate for the thermal print head, and the connection between the static conductive electrode and the GND end on the PCB circuit board is realized through a conductive resin layer. Further, a conductive resin layer for connecting the static conductive electrode and the GND end on the PCB circuit board is provided at the junction of the PCB circuit board and the heating substrate for the thermal print head, and the conductive resin layer and the sealing glue protective layer are located on the same straight line; further, the conductive resin layer located on the same straight line as the sealing glue protective layer extends to the metal heat sink to simultaneously realize the connection between the static conductive electrode and the metal heat sink and the GND end on the PCB circuit board, which can be realized by providing a gap at the junction of the PCB circuit board and the heating substrate for the thermal print head, and arranging the conductive resin layer to simultaneously cover the ground end of the static conductive electrode, the GND end on the PCB circuit board, and fill the GND end and the ground end of the static conductive electrode.

[0010] The height of the conductive resin layer of the utility model does not exceed the height of the packaging glue protective layer, so that the conductive resin layer has no contact with the printing rubber roller in the printer body, that is, the thermal printing medium on the upper side of the conductive resin layer does not contact the printing rubber roller.

[0011] In the utility model, one end of the common electrode is connected to the heating resistor along the auxiliary printing direction, and the other end of the common electrode is connected to the printing power supply; one end of the individual electrode is connected to the heating resistor along the auxiliary printing direction, and the other end of the individual electrode is connected to the control IC, and the control IC is configured on a PCB circuit board or a heating substrate for a thermal print head; the control IC is also packaged and protected by a packaging glue protective layer; a socket connected to the printer body is also provided on the PCB circuit board.

[0012] The width d of the static conductive electrode of the utility model is not less than 0.1 mm.

[0013] In order to prevent the adverse effects caused by static electricity accumulation on the surface of the thermal print head, the utility model sets a static electricity conductive electrode so that the conductive protection layer on the surface of the heating substrate of the thermal print head is connected with the metal heat sink and the GND signal on the PCB circuit board through the conductive resin layer, thereby establishing a rapid charge release channel, so that the charges accumulated on the surface of the conductive protection layer can be effectively released along the conductive path; because the static electricity conductive electrode is connected with the GND of the circuit board and the metal heat sink, a static electricity release channel is formed, so the printer mainboard can also be protected from static electricity.

[0014] Compared with the prior art, the utility model reduces the static electricity accumulation generated when the thermal printing medium and the surface of the thermal print head rub against each other, and reduces the problem of static electricity damage. At the same time, since the static electricity conductive electrode is connected with the GND of the circuit board and the metal heat sink, a static electricity release channel is formed, so the printer mainboard can also be protected from static electricity. The anti-static ability of the thermal print head in the continuous printing process is continuously guaranteed, and the printing quality of the thermal print head is not affected, and the service life of the thermal print head is guaranteed. Description of the drawings:

[0015] Attached Figure 1 The utility model is a schematic diagram of the structure of the conductive electrostatic electrode.

[0016] Attached Figure 2 yes Figure 1 Schematic diagram from another angle.

[0017] Attached Figure 3 yes Figure 2 A partial enlarged schematic diagram of the middle S region.

[0018] Attached Figure 4 It is a schematic diagram of the arrangement position of the conductive electrostatic electrode in the utility model.

[0019] Attached Figure 5 It is a schematic diagram of the paper feeding state during the printing process of the utility model.

[0020] Figure numerals: heating substrate 1 for thermal print head, metal heat sink 2, packaging glue protective layer 3, PCB circuit board 4, connector 5, heating resistor 6, static conductive electrode 7, conductive resin layer 8, insulating protective layer 9, conductive protective layer 10, GND pad 11, printing rubber roller 12, thermal printing medium 13. Specific implementation method:

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] Example:

[0023] This example provides a Figure 1 , 2 The flat thermal print head for preventing static accumulation shown in the figure comprises a metal heat sink 2, on which a heating substrate 1 and a PCB circuit board 4 are arranged, the heating substrate 1 comprises an insulating substrate, on the surface of the insulating substrate a base glaze layer is arranged, on the surface of the base glaze layer a common electrode and an individual electrode are arranged, a heating resistor 6 is arranged between the common electrode and the individual electrode along the main printing direction, as a heating element for generating Joule heat, a protective layer is covered on the surface of the heating resistor 6 and part of the individual electrodes, the common electrode and the static conductive electrode 7, one end of the common electrode is connected to the heating resistor 6 along the secondary printing direction, and the other end thereof is connected to a printing power source;

[0024] One end of the individual electrode is connected to the heating resistor 6 along the secondary printing direction, and the other end is connected to the control IC, which is configured on the PCB circuit board 4 or the heating substrate 1; Figure 3 As shown, a packaging glue protective layer 3 is used to package and protect the connection between the heating substrate of the thermal print head and the PCB circuit board 4, and the control IC is also packaged and protected by the packaging glue protective layer 3; a socket 5 connected to the printer body is also provided on the PCB circuit board 4. The above structure belongs to the prior art and will not be described in more detail here.

[0025] In order to prevent static electricity accumulation on the surface of the thermal print head, an insulating protective layer 9 is covered on the surface of the heating resistor 6 and some individual electrodes and the common electrode, and a conductive protective layer 10 is covered on the insulating protective layer 9. In this example, a static electricity conductive electrode 7 is provided on the edge substrate surface of the paper output side of the heating substrate 1 along the main printing direction and along the auxiliary printing direction (the main printing direction is perpendicular to the auxiliary printing direction), and the conductive protective layer 10 covers the upper surface of the static electricity conductive electrode 9. The static electricity conductive electrode 7 is connected to the GND signal on the PCB circuit board 4, and the conductive resin layer 8 is connected to the static electricity conductive electrode 7. That is, the conductive protective layer 10 on the surface of the heating substrate 1 is connected to the metal heat sink 2 and the GND pad 11 of the PCB circuit board 4 through the conductive resin layer 8, and the height of the conductive resin layer 8 is not higher than the height of the packaging glue protective layer 3;

[0026] As attached Figure 3 , Figure 5 As shown, the conductive resin layer 8 has no contact with the printing roller 12 in the printer body, that is, the thermal printing medium 13 in the conductive resin layer 8 does not contact the printing roller 12; the conductive protective layer 10 is continuous or discontinuous. Figure 5 As shown, since the conductive resin layer 8 connects the conductive protective layer 10 on the surface of the heating substrate 1 with the metal heat sink 2, the static electricity generated by the friction between the thermal printing medium 13 and the heating substrate 1 can be released during continuous printing. Compared with the original specification product without the conductive resin layer 8, the static voltage on the surface of the heating substrate 1 can be reduced by more than 30%, so that the static electricity will not accumulate too high to break down and damage the print head. At the same time, during continuous printing, since the static electricity conductive electrode is connected with the circuit board GND and the metal heat sink, a static electricity release channel is formed, so the printer mainboard can also be protected from static electricity. The height of the conductive resin layer 8 is not higher than the height of the packaging glue protective layer 3. In this way, the conductive resin layer 8 has no contact with the printing rubber roller 12. When performing thermal printing, it can be ensured that the conductive resin layer 8 will not be worn by the thermal printing medium 13, and the static electricity release ability and printing quality will not be affected.

[0027] The utility model can prevent the accumulation of static electricity generated when the thermal printing medium and the surface of the thermal print head rub against each other during continuous printing, reduce the problem of static electricity damage, and at the same time, because the static electricity conductive electrode is connected with the GND of the circuit board and the metal heat sink, a static electricity release channel is formed, so the printer mainboard can also be protected from static electricity. The antistatic ability of the thermal print head in the continuous printing process is continuously guaranteed, and the printing quality of the thermal print head is not affected, thereby ensuring the service life of the thermal print head.

Claims

1. A planar thermal print head for preventing static electricity accumulation, comprising a heating substrate for the thermal print head, a control IC and a PCB circuit board, wherein the heating substrate for the thermal print head is provided with an underglaze layer, a common electrode, an individual electrode and a heating resistor are provided on the surface of the underglaze layer, and a protective layer is provided on the surface of the heating resistor and part of the common electrode and the individual electrode, characterized in that: The heating substrate for the thermal print head is also provided with an electrostatic conductive electrode, which is arranged at the edge of the substrate surface on the paper output side of the heating substrate for the thermal print head and is arranged along the main printing direction or along the secondary printing direction. The electrostatic conductive electrode is connected to the GND end of the PCB circuit board. The protective layer includes an insulating protective layer covering the heating resistor and part of the common electrode and the surface of the individual electrode, and also includes a conductive protective layer covering the insulating protective layer and the surface of the electrostatic conductive electrode.

2. The anti-static accumulation planar thermal print head according to claim 1, characterized in that: The electrostatic conductive electrode is arranged at the edge of the heating substrate for the thermal print head along the main printing direction, or the electrostatic conductive electrode is arranged at the edge of the heating substrate for the thermal print head along the main printing direction and the auxiliary printing direction.

3. The anti-static accumulation planar thermal print head according to claim 1, characterized in that: A metal heat sink is also provided, the thermal print head is fixed on the metal heat sink by a heating substrate, and the electrostatic conductive electrode is also connected to the metal heat sink via a conductive resin.

4. The anti-static accumulation planar thermal print head according to claim 3, characterized in that: A packaging glue protection layer is provided at the joint between the PCB circuit board and the heating substrate for the thermal print head, and the connection between the static-conducting electrode and the GND terminal on the PCB circuit board is realized through a conductive resin layer.

5. The anti-static accumulation planar thermal print head according to claim 4, characterized in that: The conductive resin layer used for connecting the electrostatic conductive electrode and the GND end on the PCB circuit board is arranged at the junction of the PCB circuit board and the heating substrate for the thermal print head, and the conductive resin layer and the packaging glue protection layer are located on the same straight line.

6. The anti-static accumulation planar thermal print head according to claim 5, characterized in that: The conductive resin layer located on the same straight line as the packaging glue protective layer extends to the metal heat sink to simultaneously realize the connection between the electrostatic conductive electrode and the metal heat sink and the GND terminal on the PCB circuit board. A gap is provided at the junction of the PCB circuit board and the heating substrate for the thermal print head, and the conductive resin layer is arranged to simultaneously cover the ground terminal of the electrostatic conductive electrode, the GND terminal on the PCB circuit board, and fill the GND terminal and the ground terminal of the electrostatic conductive electrode.

7. The anti-static accumulation planar thermal print head according to claim 4, characterized in that: The height of the conductive resin layer does not exceed the height of the packaging glue protective layer, and the conductive resin layer has no contact with the printing rubber roller in the printer body.

8. The anti-static accumulation planar thermal print head according to claim 1, characterized in that: One end of the common electrode is connected to the heating resistor along the auxiliary printing direction, and the other end of the common electrode is connected to the printing power supply; one end of the individual electrode is connected to the heating resistor along the auxiliary printing direction, and the other end of the individual electrode is connected to the control IC, and the control IC is configured on the PCB circuit board or the heating substrate for the thermal print head; the control IC is also encapsulated and protected by a protective layer of encapsulation glue; a socket connected to the printer body is also provided on the PCB circuit board.

9. The anti-static accumulation planar thermal print head according to claim 1, characterized in that: The width d of the electrostatic conductive electrode is not less than 0.1 mm.

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