CN204908027U - Knee pad - Google Patents

Abstract

The utility model relates to a knee protector. A knee pad, comprising a knee pad body and a heating film arranged on the knee pad body, the heating film includes: a first insulating layer; a conductive layer formed on the surface of the first insulating layer; an electrode layer formed on the The surface of the conductive layer is electrically connected to the conductive layer, the electrode layer includes a positive electrode and a negative electrode, and the positive electrode includes a positive bus bar and a plurality of positive inner electrodes extending from the positive bus bar , the negative electrode includes a negative bus bar and a plurality of negative internal electrodes extending from the negative bus bar, the positive internal electrodes and the negative internal electrodes are alternately arranged and spaced from each other; and a second insulating layer is formed on the surface of the electrode layer; the knee pad also includes a connection wire electrically connected to the electrode layer of the heating film. The above-mentioned knee pad has a heating function and can be powered by a lower voltage.

Description

knee pads

technical field

The utility model relates to a knee protector.

Background technique

At present, knee pads are mostly made of materials with good heat resistance such as cotton, velvet or fur to keep the knees warm. When in use, these knee pads cannot release heat by themselves, but rely on accumulating the heat emitted by the human body to keep warm. When used in a cold environment, these knee pads have very limited heat preservation effect on the knees, and it is difficult to resist the external cold. invasion.

Heating knee pads generally have resistance wires installed on the body of the knee pads to generate heat. However, metal heating wires require a higher power supply voltage as resistance wires. Once leakage occurs, it will be life-threatening and dangerous.

Utility model content

Based on this, it is necessary to provide a knee pad with a heating function that can be powered by a lower voltage.

A knee pad, comprising a knee pad body and a heating film arranged on the knee pad body, the heating film includes:

first insulating layer;

a conductive layer formed on the surface of the first insulating layer;

An electrode layer, formed on the surface of the conductive layer and electrically connected to the conductive layer, the electrode layer includes a positive electrode and a negative electrode, and the positive electrode includes a positive bus bar and a bus bar extending from the positive bus bar a plurality of positive internal electrodes, the negative electrode includes a negative bus bar and a plurality of negative internal electrodes extending from the negative bus bar, the positive internal electrodes and the negative internal electrodes are alternately arranged and spaced from each other; and

The second insulating layer is formed on the surface of the electrode layer.

In one of the embodiments, the positive bus bar and the negative bus bar are linear and arranged in parallel, and a plurality of the positive inner electrodes extend from the side of the positive bus bar close to the negative bus bar to all The negative bus bar extends, and a plurality of the negative inner electrodes extend from a side of the negative bus bar close to the positive bus bar to the positive bus bar.

In one of the embodiments, both the positive bus bar and the negative bus bar are arc-shaped and arranged at intervals, and the positive inner electrodes extend from the inner side of the positive bus bar to the inner side of the negative bus bar, so The negative inner electrode extends from the inner side of the negative bus bar to the inner side of the positive bus bar.

In one of the embodiments, the heating film further includes an auxiliary electrode layer disposed between the first insulating layer and the conductive layer, the auxiliary electrode layer is electrically connected to the conductive layer, and the auxiliary electrode layer The layer includes an auxiliary positive electrode and an auxiliary negative electrode, the auxiliary positive electrode includes an auxiliary positive bus bar and a plurality of auxiliary positive internal electrodes extending from the auxiliary positive bus bar, and the auxiliary negative electrode includes an auxiliary negative bus bar and A plurality of auxiliary negative internal electrodes extending from the auxiliary negative bus bar, the auxiliary positive internal electrodes and the auxiliary negative internal electrodes are alternately arranged and spaced apart from each other.

In one of the embodiments, the projection of the auxiliary positive internal electrode and the auxiliary negative internal electrode of the auxiliary electrode layer on the conductive layer is the same as that of the positive internal electrode and the negative internal electrode of the electrode layer on the conductive layer. The projections of the layers are offset from each other.

In one of the embodiments, the heating film further includes a first adhesive layer and a second adhesive layer, the first adhesive layer is disposed between the first insulating layer and the conductive layer, and the second adhesive layer A layer is disposed between the electrode layer and the second insulating layer.

In one of the embodiments, there are multiple positive electrodes, and multiple positive electrodes are connected in series;

And/or, there are multiple negative electrodes, and multiple negative electrodes are connected in series.

In one of the embodiments, the heating element further includes a controller and a wireless communicator, the controller is electrically connected to the electrode layer, and the wireless communicator can receive control instructions and transmit the control instructions to The controller, the controller controls the heating of the heating film according to the control instruction.

another knee pad,

It includes a knee pad body and a heating film arranged on the knee pad body, and the heating film includes:

first insulating layer;

The first electrode layer is formed on the surface of the first insulating layer, the first electrode layer includes a positive electrode, and the positive electrode includes a positive electrode bus bar and a plurality of positive electrode internal electrodes extending from the positive electrode bus bar ,

a conductive layer formed on the surface of the first electrode layer, the conductive layer is electrically connected to the first electrode layer;

The second electrode layer is formed on the surface of the conductive layer and is electrically connected to the conductive layer. The second electrode layer includes a negative electrode, and the negative electrode includes a negative bus bar and extends from the negative bus bar. A plurality of negative internal electrodes, the positive internal electrodes and the projections of the negative internal electrodes on the conductive layer are alternately arranged and spaced from each other; and

The second insulating layer is formed on the surface of the second electrode layer.

In the aforementioned knee pads, since the positive electrode of the electrode layer of the heating film includes a plurality of positive inner electrodes, the negative electrode includes a plurality of negative inner electrodes, and the positive inner electrodes and the negative inner electrodes are arranged alternately, reducing the distance between adjacent inner electrodes, Therefore, the resistance of the conductive layer located between the positive inner electrode and the negative inner electrode is small, so that a lower voltage can be used for power supply, even if a common lithium battery is used for power supply, the purpose of rapid heating can be achieved, so that a lower voltage can be used. voltage supply.

Description of drawings

Fig. 1 is a schematic structural view of a knee pad according to an embodiment;

Fig. 2 is a structural schematic diagram of the heating element of the knee pad in Fig. 1;

Fig. 3 is a structural schematic diagram of the heating film of the heating element in Fig. 2;

Fig. 4 is a schematic structural view of the electrode layer of the heating film in Fig. 3;

Fig. 5 is a structural schematic diagram of a heating film of a knee pad in another embodiment;

Fig. 6 is a structural schematic diagram of a heating film of a knee pad in another embodiment;

Fig. 7 is a structural schematic diagram of a heating film of a knee pad in another embodiment;

8 is a schematic structural view of the electrode layer of the heating film of the knee pad in another embodiment;

9 is a schematic structural view of the electrode layer of the heating film of the knee pad in another embodiment;

Fig. 10 is a schematic structural view of the electrode layer of the heating film of the knee pad in another embodiment;

Fig. 11 is the temperature distribution photo of the heating film of embodiment 1 taken by the infrared thermal imager;

Fig. 12 is a photograph of the temperature distribution of the heating film in Example 2 taken by an infrared thermal imager.

Detailed ways

In order to make the above purpose, features and advantages of the present utility model more obvious and understandable, the specific implementation of the present utility model will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a full understanding of the present invention. However, the utility model can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific implementation disclosed below .

Please refer to FIG. 1 and FIG. 2 at the same time. A knee pad 1 according to an embodiment includes a heating element 10 and a knee pad body 90 .

The heating element 10 includes a heating film 110 , an outer cover 130 , a power supply device 150 , a power switch 170 , and a temperature control device 180 .

The outer cover 130 is sleeved on the heating film 110 , and the heating film 110 is accommodated in the outer cover 130 .

The power supply device 150 , the power switch 170 and the temperature control device 180 are electrically connected to the heating film 110 through connecting wires (not shown in the figure). The material of the outer cover 130 can be cloth, and of course other commonly used materials in the industry, such as far-infrared materials, can also be used.

In the illustrated embodiment, the knee pad body 90 is roughly strip-shaped, the heating film 110 is strip-shaped, and the heating film 110 and the outer cover 130 are fixed on the knee pad body 90 . Certainly, in other embodiments, the knee pad body 90 may also be a sleeve made of elastic material. It should be noted that the knee pad body 90 may further include an inner layer and an outer layer, and the heating film 110 may be directly sandwiched between the outer layer and the inner layer of the knee pad body 90 , and the outer cover 130 may be omitted at this time. Of course, the knee pad 1 may also include other components such as straps or velcro for fixing, which will not be described in detail here.

Referring to FIG. 3 , in the illustrated embodiment, the heating film 110 includes a first insulating layer 112 , a conductive layer 114 , an electrode layer 116 and a second insulating layer 118 stacked in sequence.

The first insulating layer 112 is a base. The material of the first insulating layer 112 is glass or polymer. Preferably, the polymer is PET, PVC, PE, PMMA, PVDF, PANI or PC. Preferably, the thickness of the first insulating layer 112 is 10 μm˜125 μm.

The conductive layer 114 is formed on one side surface of the first insulating layer 112 . The conductive layer 114 is formed of a conductive material. Preferably, the material of the conductive layer 114 is silver, copper, aluminum, graphene, carbon nanotubes, ITO, FTO or AZO. Further preferably, the material of the conductive layer 114 is single-layer graphene or multi-layer graphene. When the material of the conductive layer is graphene, the conductive layer 114 may further contain a dopant, and the dopant is an organic dopant or an inorganic dopant. Preferably, the conductive layer has a thickness of 10 nm to 100 nm.

The electrode layer 116 is formed on the surface of the conductive layer 114 and is electrically connected to the conductive layer 114 .

Referring to FIG. 4 , in the illustrated embodiment, the electrode layer 116 includes a positive electrode 1162 and a negative electrode 1164 . The thickness of the electrode layer 116 is 10 nm to 35 μm.

The positive electrode 1162 includes a positive bus bar 1162 a and a plurality of positive inner electrodes 1162 b extending from the positive bus bar 1162 a.

In the illustrated embodiment, the positive electrode bus bar 1162a is roughly strip-shaped, including a main body (not shown), a connecting portion (not shown), and an extension portion (not shown) connected to the connecting portion. The main body, the connection part and the extension part are all in the shape of a straight line. One end of the connection part is vertically connected to one end of the main body, the other end of the connection part is vertically connected to one end of the extension part, and the main body and the extension part are respectively located on two sides of the connection part.

There are multiple positive internal electrodes 1162b, and the multiple positive internal electrodes 1162b extend from one side of the main body. In the illustrated embodiment, the positive internal electrodes 1162b are straight and perpendicular to the main body of the positive bus bar 1162a. The connection portion between the positive internal electrode 1162b and the positive bus bar 1162a is located on the same side as the main body of the positive bus bar 1162a. The positive inner electrode 1162b has a width of 0.5 mm to 4 mm. The width of the positive bus bar 1162a is much larger than the width of the positive inner electrode 1162b. The width of the positive electrode bus bar 1162a is 6mm˜10mm.

The negative electrode 1164 includes a negative bus bar 1164 a and a plurality of negative inner electrodes 1164 b extending from the negative bus bar 1164 a.

In the illustrated embodiment, the negative electrode bus bar 1164a is roughly strip-shaped, including a main body (not shown), a connecting portion (not shown), and an extension portion (not shown) connected to the connecting portion. The main body, the connection part and the extension part are all in the shape of a straight line. One end of the connection part is vertically connected to one end of the main body, the other end of the connection part is vertically connected to one end of the extension part, and the main body and the extension part are respectively located on two sides of the connection part. The main body of the negative bus bar 1164a and the main body of the positive bus bar 1162a are arranged parallel to each other and at intervals, the positive inner electrode 1162b is located between the main body of the negative bus bar 1164a and the main body of the positive bus bar 1162a, and the positive inner electrode 1162b is far away from the positive bus bar 1162a One end of is spaced from the main body of the negative bus bar 1164a. The connecting portion of the negative bus bar 1164a extends from one end of the main body of the negative bus bar 1164a toward the direction close to the connecting portion of the positive bus bar 1162a, and the connecting portion of the negative bus bar 1164a is substantially flush with the connecting portion of the positive bus bar 1162a.

There are a plurality of negative internal electrodes 1164b, and the negative internal electrodes 1164b all extend from the side of the main body of the negative bus bar 1164a close to the main body of the positive bus bar 1162a, and extend toward the main body of the positive bus bar 1162a, and the ends of the negative internal electrodes 1164b It is spaced apart from the main body of the positive bus bar 1162a. In the illustrated embodiment, the negative inner electrodes 1164b are straight and perpendicular to the main body of the negative bus bar 1164a. Negative internal electrodes 1164b and positive internal electrodes 1162b are arranged alternately and spaced from each other, that is, those adjacent to positive internal electrodes 1162b are all negative internal electrodes 1164b, and those adjacent to negative internal electrodes 1164b are all positive internal electrodes 1162b. Adjacent internal electrodes come from different bus bars. Preferably, in the electrode layer 116, the positive internal electrodes 1162b and the negative internal electrodes 1164b are evenly distributed, that is, the distance between adjacent positive internal electrodes 1162b and negative internal electrodes 1164b is the same, which is 2mm-8mm. The connection portion between the negative inner electrode 1164b and the negative bus bar 1164a is located on the same side of the main body of the negative bus bar 1164a. The negative inner electrode 1164b has a width of 0.5 mm to 4 mm. The width of the negative bus bar 1164a is much larger than the width of the negative inner electrode 1164b. The width of the negative electrode bus bar 1164a is 6mm˜10mm.

The material of the electrode layer 116 is silver, copper, aluminum, platinum, graphene, carbon nanotube, ITO, FTO or AZO. Of course, the electrode layer 116 can also be formed by coating silver paste or copper paste and then solidified. In this case, the electrode layer 116 inevitably contains other materials in the paste. Preferably, the electrode layer 116 and the conductive layer 114 are integrally formed. Preferably, when the material of the conductive layer 114 is graphene, the material of the electrode layer 116 is also graphene, and the electrode layer 116 and the conductive layer 114 are integrally formed. By arranging the electrode layer 116, applying the electrode layer 116 to the conductive layer 114 made of single-layer graphene can make the heating film 110 work at a voltage of ≤ 12V, if the material of the conductive layer 114 is multi-layer graphene , can further reduce the operating voltage.

Further, the positive bus bar 1162a, the positive inner electrode 1162b, the negative bus bar 1164a and the negative inner electrode 1164b of the electrode layer 116 may be made of the same material or different materials.

The second insulating layer 118 is formed on the surface of the electrode layer 116 . The material of the second insulating layer 118 is glass or polymer. Preferably, the polymer is PET, PVC, PE, PMMA, PVDF, PANI or PC. Preferably, the thickness of the second insulating layer 118 is 10 μm˜125 μm.

Please refer to FIG. 1 to FIG. 3 at the same time, the power supply device 150 is electrically connected to the electrode layer 116 of the heating film 110 through a connection wire. The power supply device 150 is used to supply power to the heating film 110 . Specifically, in this embodiment, the power supply device 150 is a portable power source, such as a lithium battery.

Further, the power supply device 150 is also provided with a charging interface 152 for charging.

The power switch 170 is electrically connected to the power supply device 150 and the electrode layer 116 at the same time, and is used to control whether the power supply device 150 supplies power to the electrode layer 116 or not.

The temperature control device 180 is electrically connected to the power supply device 150 and the electrode layer 116 , and is used to control the output voltage of the power supply device 150 to the electrode layer 116 , thereby controlling the heating temperature of the conductive layer 114 .

Please refer to Fig. 1 and Fig. 2 at the same time, the power supply device 150, the power switch 170 and the temperature control device 180 are fixed on the surface of the knee pad body 90, and the connecting wire 140 is arranged inside the knee pad 1 and is invisible to the outside. In other embodiments, the knee pad 1 further includes a control part, and the power supply device 150, the power switch 170 and the temperature control device 180 are all integrated into the control part for easy operation.

The knee pad 1 also includes a controller and a wireless communicator, and the controller is electrically connected to the electrode layer 116 . The wireless communicator can receive the control instruction, and transmit the control instruction to the controller, and the controller controls the heating of the heating film 110 according to the control instruction. Control commands are sent by the control terminal. The control terminal includes at least one of a remote controller, a mobile phone, a tablet computer, a desktop computer and a notebook computer. The control terminal is provided with an infrared transceiver module, a WIFI module or a ZIGBEE module, and the control terminal communicates with the controller through the infrared transceiver module, the WIFI module or the ZIGBEE module. Further, the knee pad 1 is also provided with a temperature sensor electrically connected to the controller, so that the controller can adjust the heating temperature of the heating film according to the received temperature information collected by the temperature sensor. Further, it is also possible to install a corresponding APP on the mobile phone to conveniently control whether the heating film is heated or not and the heating temperature.

Preferably, in order to obtain good temperature uniformity at low voltage, for the special structure of the electrode layer 116, the temperature difference, initial temperature, supply voltage, the distance between the adjacent positive internal electrode 1162b and the negative internal electrode 1164b and The sheet resistance of the conductive layer 114 conforms to the following formula:

T=kU ² /d ² R+t(1)

In formula (1):

t - initial temperature, in °C;

T——The final temperature difference of the heating film, in °C;

U——supply voltage, the unit is V, U≤12V;

d——the distance between adjacent positive internal electrodes 1162b and negative internal electrodes 1164b, in cm, and the distance between adjacent positive internal electrodes 1162b and negative internal electrodes 1164b is calculated according to the distance on one side of the conductive layer;

R——The square resistance of the conductive layer, the unit is Ω/□;

k—constant, the value range is 10-200, the value range of k will be different according to the conduction coefficient between the heating film and the air, and it is inversely proportional to the conduction coefficient between the heating film and the air.

Further, in order to ensure the uniformity of the heating temperature of the knee pad 1, the width and thickness of the positive bus bar 1162a and the negative bus bar 1162b need to consider the current carrying capacity and resistivity of the materials used, and the resistivity should be small enough to reduce the size of the positive bus bar. 1162a and the voltage drop on the negative bus bar 1162b, to ensure that the positive inner electrode 1162b and the negative inner electrode 1164b are arranged at different positions of the positive bus bar 1162a or the negative bus bar 1162b, the difference between the highest voltage and the lowest voltage is not more than 10%, and the current carrying capacity It is determined that the cross-sectional area of the positive bus bar 1162a and the negative bus bar 1162b must be greater than a certain value to ensure that the positive bus bar 1162a and the negative bus bar 1162b will not be burned, and the following formula (2) exists:

n(n+1)lρ _l /WHR＜1/5(2)

in:

n——the interval number generated by the positive inner electrode 1162b and the negative inner electrode 1164b;

ρ ₁ ——Material resistivity of positive bus bar 1162a and negative bus bar 1162b, unit is Ω·m;

l - the length of the positive inner electrode 1162b and the negative inner electrode 1164b, in m;

W——the width of the positive bus bar 1162a and the negative bus bar 1162b, in m;

H——the thickness of the positive bus bar 1162a and the negative bus bar 1162b, in m;

R——the sheet resistance of the conductive layer 114 , the unit is Ω/□.

In the above formula, it is assumed that the positive bus bar 1162a and the negative bus bar 1162b are made of the same material, have the same width and thickness, and the positive inner electrode 1162b and the negative inner electrode 1164b have the same length.

Similarly, the internal electrodes also need to ensure the current carrying capacity and consider that the maximum voltage difference on the same internal electrode does not exceed 10%. There is the following formula (3):

nl ² ρ ₂ /whLR<1/5(3)

in:

n——the interval number generated by the positive inner electrode 1162b and the negative inner electrode 1164b;

l - the length of the positive inner electrode 1162b and the negative inner electrode 1164b, in m;

ρ ₂ ——the resistivity of the material of the positive inner electrode 1162b and the negative inner electrode 1164b, the unit is Ω·m;

w—the width of the positive inner electrode 1162b and the negative inner electrode 1164b, in m;

h——the thickness of the positive inner electrode 1162b and the negative inner electrode 1164b, in m;

L——the length of the positive bus bar 1162a and the negative bus bar 1162b, in m;

R——the sheet resistance of the conductive layer 114 , the unit is Ω/□.

In the above formula, it is assumed that the size of the positive bus bar 1162a and the negative bus bar 1162b are the same, and the material, length, width and thickness of the positive inner electrode 1162b and the negative inner electrode 1164b are the same.

The aforementioned knee pads, by adopting an electrode layer with a special structure, and by arranging the positive internal electrode and the negative internal electrode, reduce the distance between adjacent internal electrodes, thereby making the resistance of the conductive layer between the positive internal electrode and the negative internal electrode Smaller, so that a lower voltage can be used for power supply, even if an ordinary lithium battery is used for power supply, the purpose of rapid heating can be achieved; when the material of the conductive layer 114 is single-layer graphene, a voltage not higher than 1.5V is used for power supply The same heating effect as the traditional heating film can be obtained; by changing the area of the positive bus bar 1162a and the negative bus bar 1164a of the electrode layer, and the distance between the positive inner electrode 1162b and the negative inner electrode 1164b, different heating can be realized power to meet different heating temperature requirements. Using a lower voltage power supply, even if there is a leakage, it will not threaten personal safety at all, the heating time is short, the weight is light, the body feels smooth, there is no problem such as heating wire breakage, and there is no electromagnetic radiation.

When the material of the conductive layer of the knee pad is graphene, the voltage of no more than 7V can be used for power supply, and the temperature can be adjusted through the temperature control device at the same time, and the heating film will emit far-infrared rays that are very consistent with the far-infrared rays naturally emitted by the human body to achieve the therapeutic effect. Purpose.

Please refer to Fig. 5, the structure of the knee pad of another embodiment is substantially the same as that of the knee pad 1, the difference is that in the illustrated embodiment, the heating film 210 of the knee pad includes a first insulating layer 212, a first adhesive layer stacked in sequence 213 , a conductive layer 214 , an electrode layer 216 , a second adhesive layer 217 and a second insulating layer 218 . The conductive layer 214 is bonded to the first insulating layer 212 through the first adhesive layer 213 , and the second insulating layer 218 is bonded to the electrode layer 216 through the second insulating layer 218 . Preferably, the material of the first adhesive layer 213 is ultraviolet curable adhesive, hot melt adhesive or silica gel, and the material of the second adhesive layer 217 is ultraviolet curable adhesive, hot melt adhesive or silica gel.

In the above knee pads, the heating film 210 is prepared by the following steps:

Step S310 , providing a prefabricated board, the prefabricated board includes a base layer for preparing an electrode layer and a conductive layer 214 formed on the surface of the base layer.

Preferably, the base layer is metal foil. The metal foil is copper foil, nickel foil or other metal foil, which is not limited here.

In this step, the conductive layer (such as graphene) is directly grown on the base layer of the provided prefabricated board.

Step S320 , bonding the first insulating layer 212 to the conductive layer 214 of the prefabricated board through the first adhesive layer 213 .

Step S330 , preparing a mask on the surface of the base layer, and etching the base layer, and removing the mask to obtain an electrode layer.

In this step, the pattern of the mask is designed according to the desired pattern of the electrode layer. During the etching process, the prefabricated plate with the mask prepared is placed in the etching solution, and the base layer not protected by the mask is etched away.

Preferably, the etching solution contains substances that can improve the conductivity of the conductive layer 214 .

Step S340 , bonding the second insulating layer 218 to the surface of the electrode layer 216 through the second adhesive layer 217 .

Preferably, the second glue layer 217 and the second insulating layer 218 are provided with through holes corresponding to the positive electrode and the negative electrode of the electrode layer 216 to make lead wires.

The preparation method of the above-mentioned heating film 210 is relatively simple, saving time and material cost. At the same time, the electrode layer is prepared by using metal foil, which has good conductivity and is beneficial to control the uniformity of the temperature of the heating film.

Preferably, the thickness of the first adhesive layer 213 and the second adhesive layer 217 is 25-75 μm.

Please refer to Fig. 6, the structure of the knee pad of another embodiment is substantially the same as that of the knee pad 1, the difference is that in the illustrated embodiment, the heating film 410 of the knee pad includes a first insulating layer 412, a conductive layer 414, The electrode layer 416 , the second adhesive layer 417 and the second insulating layer 418 . The second insulating layer 418 is bonded to the electrode layer 416 through the second insulating layer 418 . Preferably, the material of the second adhesive layer 417 is ultraviolet curing adhesive, hot melt adhesive or silica gel.

In the above knee pads, the heating film 410 is prepared by the following steps:

Step S510 , printing or evaporating on the surface of the conductive layer 144 formed on the surface of the first insulating layer 412 to prepare the electrode layer 416 .

Step S520 , bonding the second insulating layer 418 to the surface of the electrode layer 416 through the second adhesive layer 417 .

Preferably, the second adhesive layer 417 and the second insulating layer 418 are provided with through holes corresponding to the positive electrode and the negative electrode of the electrode layer 416 to make lead wires.

The preparation method of the above-mentioned heating film 410 is relatively simple.

Please refer to FIG. 7 , the structure of the knee pad in another embodiment is substantially the same as that of the knee pad 1 , the difference is that in the illustrated embodiment, the heating film 510 of the knee pad includes a first insulating layer 512 and an auxiliary electrode layer 513 stacked in sequence. , a conductive layer 514 , an electrode layer 516 and a second insulating layer 518 . The auxiliary electrode layer 513 is electrically connected to the conductive layer 514 . The structure of the auxiliary electrode layer 513 is the same as that of the electrode layer 516 . The auxiliary electrode layer 513 includes an auxiliary positive electrode (not shown) and an auxiliary negative electrode (not shown). The auxiliary positive electrode includes an auxiliary positive bus bar and a plurality of auxiliary positive inner electrodes extending from the auxiliary positive bus bar. The auxiliary negative electrode includes an auxiliary negative electrode bus bar and a plurality of auxiliary negative electrode inner electrodes extending from the auxiliary negative electrode bus bar. The auxiliary positive inner electrodes and the auxiliary negative inner electrodes are arranged alternately and spaced apart from each other. Further preferably, the projections of the auxiliary positive internal electrode and the auxiliary negative internal electrode of the auxiliary electrode layer 513 on the conductive layer 514 are staggered from the projections of the positive internal electrode and the negative internal electrode of the electrode layer 516 on the conductive layer.

Please refer to FIG. 8 , the structure of the knee pad in another embodiment is substantially the same as that of the knee pad 1 , the difference is that in the illustrated embodiment, the electrode layer 616 includes a positive electrode 6162 , a first negative electrode 6164 and a second negative electrode 6166 . The first negative electrode 6164 is connected in series with the second negative electrode 6166 . The positive electrode 6162 includes a positive bus bar 6162a and a plurality of positive inner electrodes 6162b extending from the positive bus bar 6162a. There are multiple positive internal electrodes 6162b, and the multiple positive internal electrodes 6162b extend from one side of the positive bus bar 6162a. In the illustrated embodiment, the positive inner electrodes 6162b are straight and perpendicular to the positive bus bar 6162a.

The first negative electrode 6164 includes a first negative bus bar 6164a and a plurality of first negative inner electrodes 6164b extending from the first negative bus bar 6164a. The second negative electrode includes a second negative bus bar 6166a and a plurality of second negative inner electrodes 6166b extending from the second negative bus bar 6166a. Both the first negative bus bar 6164a and the second negative bus bar 6166a are linear, the first negative bus bar 6164a and the second negative bus bar 6166a are all arranged in parallel with the positive bus bar 6162a, and the first negative bus bar 6164a is connected to the second negative bus bar. The bus bars 6166a are located on the same straight line and are spaced apart from each other, and the end of the first negative bus bar 6164a away from the second negative bus bar 6166a is substantially flush with the end of the positive bus bar 6162a, and the second negative bus bar 6166a is far away from the first negative bus bar. One end of the bar 6164a is approximately flush with the other end of the positive bus bar 6162a.

The end of the positive inner electrode 6162b away from the positive bus bar 6162a is close to the first negative bus bar 6164a or the second negative bus bar 6166a, and is spaced apart from the first negative bus bar 6164a or the second negative bus bar 6166a. The first negative internal electrode 6164b extends from the side of the first negative bus bar 6164a close to the positive internal electrode 6162a to the positive internal electrode 6162a and is spaced from the positive internal electrode 6162a, and the first negative internal electrode 6164b is connected to the first negative bus bar The positive inner electrodes 6162b of the strips 6164a alternate. The second negative internal electrode 6166b extends from the side of the second negative electrode bus bar 6166a close to the positive internal electrode 6162a to the positive internal electrode 6162a and is spaced from the positive internal electrode 6162a, and the second negative internal electrode 6166b is connected to the second negative internal electrode 6166b corresponding to the second negative electrode bus bar. The positive inner electrodes 6162b of the strips 6166a alternate.

It should be noted that the first negative electrode 6164 and the second negative electrode 6166 are not limited to be connected in series, and can also be arranged in parallel. There may be multiple positive electrodes, and multiple positive electrodes are connected in series or in parallel. The number of negative electrodes is not limited to two, and may be one or more than two.

Please refer to FIG. 9 , the structure of the knee pad in another embodiment is substantially the same as that of the knee pad 1 , the difference is that in the illustrated embodiment, the positive bus bar 7162 a and the negative bus bar 7164 a of the electrode layer 716 are both linear. The negative bus bar 7162a is spaced apart from the positive bus bar 7164a, and the negative bus bar 7164a extends along the extending direction of the positive bus bar 7162a. The positive inner electrode 7162b bends and extends from the positive bus bar 7162a to the negative bus bar 7164a, and the end of the positive inner electrode 7162b is close to the negative bus bar 7164a and spaced from the negative bus bar 7164a. The negative inner electrode 7164b bends and extends from the negative bus bar 7164a to the positive bus bar 7162a, and the end of the negative inner electrode 7164b is close to the positive bus bar 7162a and spaced from the positive bus bar.

Please refer to FIG. 10 , the structure of the knee pad in another embodiment is substantially the same as that of the knee pad 1, the difference is that in the illustrated embodiment, the positive bus bar 8162a and the negative bus bar 8164a are both arc-shaped and arranged at intervals, and the positive bus bar The bar 8162a and the negative bus bar 8164a are arranged in a circular shape. The positive inner electrode 8162a extends from the inner side of the positive bus bar 8162a to the inner side of the negative bus bar 8162b, and the end of the positive inner electrode 8162b is close to the negative bus bar 8164a and spaced from the negative bus bar 8164a. The negative inner electrode 8164b extends from the inner side of the negative bus bar 8164a to the inner side of the positive bus bar 8162a, and the end of the negative inner electrode 8164b is close to the positive bus bar 8162a and spaced from the positive bus bar. In the illustrated embodiment, both the positive electrode internal electrode 8162b and the negative electrode internal electrode 8164b are linear.

It should be noted that the positive bus bar and the negative bus bar are not limited to the shapes listed in the above-mentioned several embodiments, and may also be in other shapes; the positive inner electrode and the negative inner electrode are not limited to the shapes listed in the above-mentioned several embodiments, It can also be in other shapes, such as curved or wavy, as long as the positive inner electrodes and the negative inner electrodes are arranged alternately, and the distance between the positive inner electrodes and the negative inner electrodes is reduced.

It can be understood that a positive electrode and a negative electrode can also be respectively arranged on both sides of the conductive layer, and the projection of the positive electrode and the negative electrode on the conductive layer is the same as the structure of the conductive layer in the above-mentioned embodiment.

Further description below in conjunction with specific examples.

Example 1:

Please refer to Figure 4 and Figure 5 at the same time, the single-layer graphene is used as the conductive layer of the heating film, and the electrode layer is printed with silver paste.

1. Transfer a layer of graphene on the PET (first insulating layer) with an area of 150mm×150mm and a thickness of 125μm. The graphene has been doped and the square resistance is 250Ω/□;

2. Use screen printing equipment to print the silver paste electrode pattern on the transferred graphene. The shape of the pattern is shown in Figure 4. The distance between the positive inner electrode and the negative inner electrode is 6mm, and the length of the positive inner electrode and the negative inner electrode is 108mm. 1mm, a total of 15 pieces, the width of the positive and negative bus bars is 8mm, and the thickness of the silver paste is 25μm;

3. Bake the printed electrode layer in an oven to solidify the silver paste. The baking temperature is 130°C for 40 minutes.

The initial temperature is room temperature (22°C). In this case, connect the lead wires to the positive and negative electrodes of the electrode layer to the positive and negative electrodes of the 5V power supply. After testing, it can reach a stable state in 60 seconds. At this time, the temperature of the heating film The average temperature can reach about 77.5°C (room temperature is 22°C).

When using 3.7V voltage for power supply, the average heating power of the heating film is about 1500w/m ² .

Preferably, the following steps are further carried out:

4. Lay OCA glue with an area of 150mm×150mm and a thickness of 50μm with PET of the same area;

5. Use laser cutting equipment to open a square hole in the bonded PET/OCA. The size of the hole is 5mm×5mm. The position of the hole should ensure that after the PET/OCA is bonded to the electrode layer, the end of the bus bar is exposed 5mm×5mm the electrode;

6. After aligning the position, attach the PET/OCA to the electrode layer;

7. Make lead wires from the electrodes exposed in the small holes;

In this case, the measured resistance of the heating film is 2.7Ω. Connect the lead wires to the positive and negative electrodes of the 5V power supply respectively. After testing, it can reach a stable state in 60 seconds. Figure 11 shows the heating film taken by an infrared thermal imager The temperature distribution photo shows that the average temperature of the heating film can reach about 66°C (room temperature is 22°C).

The test results show that the average heating power of the heating film is about ^1300w /m2 when the voltage is 3.7V, and the average heating power of the traditional heating film without internal electrodes is about 5w/ ^m2 when the voltage is 3.7V. With the same heating effect as our newly designed heating film, the voltage needs to be increased to about 60V, which has far exceeded the safe voltage of the human body.

Example 2:

In this embodiment, two layers of graphene are used as the conductive layer of the heating film, and the electrode layer is printed with silver paste.

1. Transfer two layers of graphene as the conductive layer on the PET (first insulating layer) with an area of 120mm×120mm and a thickness of 125μm. The graphene has been doped and the square resistance is 120Ω/□;

2. Use screen printing equipment to print the silver paste electrode layer on the transferred conductive layer. The pattern shape is shown in Figure 10. The outer diameter of the bus bar is 96mm, the inner electrode spacing is 6mm, and the width is 1mm. The bus bar width is 8mm, silver Slurry thickness 25μm;

3. Bake the printed electrode pattern in an oven to solidify the silver paste. The baking temperature is 130°C for 40 minutes.

In this case, connect the lead wires to the positive and negative poles of the 5V power supply respectively. After testing, it can reach a stable state in 60 seconds. At this time, the average temperature of the heating film can reach about 137.7°C (initial temperature is room temperature 22°C).

The test results show that using our utility model electrode design scheme, the average heating power of the heating film is about ^3168w /m2 when the power supply is powered by 3.7V.

Preferably, the following steps are further carried out:

4. Lay OCA glue with an area of 120mm×120mm and a thickness of 50μm with PET of the same area;

5. Use laser cutting equipment to open a square hole in the bonded PET/OCA. The size of the hole is 5mm×5mm. The position of the hole should ensure that after the PET/OCA is bonded to the electrode layer, a 5mm×5mm hole is exposed at the end of the bus bar. electrode;

6. After aligning the position, attach the PET/OCA to the electrode layer;

7. Make lead wires from the electrodes exposed in the small holes;

In this case, the measured resistance of the heating film is 2Ω. Connect the lead wires to the positive and negative poles of the 5V power supply respectively. After testing, it takes 40 seconds to reach a stable state. Figure 12 shows the temperature of the heating film taken by an infrared thermal imager. Distribution photos, at this time the average temperature of the heating film can reach about 90.9°C (room temperature is 22°C).

The test results show that the average heating power of the heating film is about ^1300w /m2 when the voltage is 3.7V, and the average heating power of the traditional heating film without internal electrodes is about 5w/ ^m2 when the voltage is 3.7V. With the same heating effect as our newly designed heating film, the voltage needs to be increased to about 60V, which has far exceeded the safe voltage of the human body.

Example 3:

Please refer to Figure 8, the single-layer graphene is used as the conductive layer of the heating film, and the preparation process is as follows:

1. Lay the copper foil with the grown graphene (graphene is doped, the square resistance is 250Ω/□) and the PET with the size of 150mm×300mm and the thickness of 125μm through UV glue, and the size of the copper foil is 140mm×280mm , with a thickness of 25 μm;

2. Curing the UV glue with a wavelength of 365nm and an energy of 1000mJ/cm ² ;

3. Use screen printing equipment to print a peelable mask on the bonded copper foil. The pattern shape is shown in Figure 8. At this time, it is equivalent to dividing the heating film into two, forming two left and right heating films connected in series effect, the actual utilization voltage is halved, the internal electrode spacing is 3mm, the length is 108mm, and the width is 1mm, a total of 32, the bus bar width is 8mm, and the copper foil thickness is 25μm;

4. Bake the printed electrode pattern in an oven to cure the peelable glue. The baking temperature is 135°C for 40 minutes;

5. The baked sample is etched in 30% FeCl ₃ etching solution. After the etching is completed, it is washed with water and dried, and the peelable glue on the electrode surface is peeled off.

In this case, the measured resistance of the heating film is 1.7Ω, and the lead wires are respectively connected to the positive and negative electrodes of the 3.7V lithium-ion battery (1.85V compared to half of the heating film). After testing, the temperature of the heating film can be stabilized after 30S. It reaches about 46°C (room temperature is 22°C).

The test results show that the average heating power of the heating film is about 1521w/m ² when using the electrode design scheme of the utility model and using 3.7V voltage (the voltage actually applied to the two electrodes is 1.85V) for power supply.

Preferably, the following steps are further carried out:

6. Lay OCA glue with an area of 150mm×300mm and a thickness of 50μm with PET of the same area;

7. Use laser cutting equipment to open a square hole in the bonded PET/OCA. The size of the hole is 5mm×5mm. The position of the hole should ensure that after the PET/OCA is bonded to the electrode layer, a 5mm×5mm hole is exposed at the end of the bus bar. electrode;

8. After aligning the position, attach the PET/OCA to the electrode pattern;

9. Make lead wires from the electrodes exposed in the small holes;

The measured resistance of the heating film is 2.5Ω, and the lead wires are respectively connected to the positive and negative electrodes of the 3.7V (actually used voltage is equivalent to 1.85V) lithium-ion battery. After testing, the temperature of the heating film can reach about 45°C after 70S stabilization (room temperature is 22°C), conforming to the formula T=kU ² /d ² R+t (K=151).

Example 4:

In this embodiment, the ITO film is used as the conductive layer of the heating film, and the silver paste is used as the electrode. The pattern design refers to Figure 4. The preparation process is as follows:

1. Use screen printing equipment to print the silver paste electrode pattern on the ITO film with a square resistance of 150mm x 150mm and a square resistance of 150Ω (square resistance 400Ω/□). The shape of the pattern is shown in Figure 4. The distance between the internal electrodes 6mm, length 108mm, width 1mm, a total of 15, bus bar width 8mm, silver paste thickness 25μm;

2. Bake the printed electrode pattern in an oven to solidify the silver paste. The baking temperature is 130°C for 40 minutes.

3. Lay OCA glue with an area of 150mm×150mm and a thickness of 50μm with PET of the same area;

4. Use laser cutting equipment to open a square hole in the bonded PET/OCA. The size of the hole is 5mm×5mm. The position of the hole should ensure that after the PET/OCA is bonded to the electrode layer, a 5mm×5mm hole is exposed at the end of the bus bar. electrode;

5. After aligning the position, attach the PET/OCA to the electrode pattern;

6. Make lead wires from the electrodes exposed in the small holes;

In this case, the measured resistance of the heating film is 5Ω. Connect the lead wires to the positive and negative poles of the 12V power supply respectively. After testing, it can reach a stable state in 55 seconds. At this time, the average temperature of the heating film can reach about 92°C (room temperature is 22°C). °C), conforming to the formula T=kU ² /d ² R+t (K=70).

Example 5:

In this embodiment, the transparent conductive layer adopts single-layer graphene (250Ω/□), and the electrode layer adopts 10 layers of graphene. method, transfer to the 11th layer, stop the transfer, and then etch the top 10 layers of graphene into a patterned electrode layer, or directly grow multi-layer graphene, and then make a patterned electrode layer, the electrode of this embodiment The pattern of the layer is shown in Figure 4, the internal electrode spacing is 3mm, the length is 108mm, and the width is 1mm, a total of 15, the bus bar width is 8mm, and the electrode (10 layers of graphene) is 35nm thick.

In this case, the measured resistance of the heating film is 2Ω. Connect the lead wires to the positive and negative poles of the 1.5V power supply respectively. After testing, it can reach a stable state in 85 seconds. At this time, the average temperature of the heating film can reach about 34°C (room temperature is 22°C), conforming to the formula T=kU ² /d ² R+t (K=120).

Embodiment 6:

In this embodiment, 4 layers of graphene (62.5Ω/□) are used as the conductive layer, and the material of the electrode layer is ITO. The electrode pattern design is shown in Figure 10. The internal electrode spacing is 4mm, the width is 1mm, and there are 16 electrodes in total. The width of the bus bar is 8mm, and the thickness of the silver paste is 25μm.

In this case, the measured resistance of the heating film is 1.6Ω. Connect the lead wires to the positive and negative poles of the 7.5V power supply respectively. After testing, it can reach a stable state in 100 seconds. At this time, the average temperature of the heating film can reach about 103°C (room temperature is 22°C), which conforms to the formula T=kU ² /d ² R+t (K=90).

Embodiment 7:

Example 7 is roughly the same as Example 3, except that the structure of the electrode layer is as shown in Figure 4, the internal electrode spacing is 3mm, the length is 108mm, and the width is 1mm, a total of 115, the bus bar width is 8mm, and the thickness of copper and platinum is 25μm.

In this case, the measured resistance of the heating film is 1.7Ω. Connect the lead wires to the positive and negative poles of the 12V power supply respectively. After testing, it can reach a stable state in 100 seconds. At this time, the average temperature of the heating film can reach about 226°C (room temperature is 22°C), conforming to the formula T=kU ² /d ² R+t (K=32).

Embodiment 8:

Embodiment 8 is roughly the same as Embodiment 1, except that the electrode layer is made of copper foil. The structure of the electrode layer is shown in Figure 10. The internal electrode spacing is 2 mm, the length is 108 mm, and the width is 1 mm. There are 16 bars in total, and the bus bar is 8 mm wide. , copper foil thickness 25μm. The square resistance of the conductive layer made of single-layer graphene is 250Ω/□.

In this case, the measured resistance of the heating film is 2Ω. Connect the lead wires to the positive and negative poles of the 3.7V power supply respectively. After testing, it can reach a stable state in 30 seconds. At this time, the average temperature of the heating film can reach about 143.8°C (room temperature is 22°C), conforming to the formula T=kU ² /d ² R+t (K=89).

Embodiment 9:

In this embodiment, the positive electrode and the negative electrode are separately arranged on both sides of the conductive layer, and the projection of the positive electrode and the negative electrode on the conductive layer is as shown in Figure 4, and the material of the conductive layer adopts single-layer graphene (the square resistance is 250 Ω/□ ), the electrode uses 5-10 layers of graphene or copper foil with a thickness of 10-30 μm, wherein the positive and negative adjacent internal electrode spacing is 4mm, the length is 108mm, and the width is 1mm, a total of 15, and the width of the bus bar is 8mm.

In this case, the measured resistance of the heating film is 2.1Ω. Connect the lead wires to the positive and negative electrodes of the 7.5V power supply respectively. After testing, it can reach a stable state in 30 seconds. At this time, the average temperature of the heating film can reach about 210°C (room temperature is 22°C), which conforms to the formula T=kU ² /d ² R+t (K=134).

Example 10:

Embodiment 10 is roughly the same as Embodiment 3, except that the structure of the electrode layer is shown in Figure 8, the conductive layer is made of 6 layers of graphene (square resistance is 41.6Ω/□), and the electrode layer is made of copper foil. The internal electrode spacing is 3mm, the width is 1mm, and there are 9 electrodes in total, the width of the bus bar is 8mm, and the thickness of the copper foil is 25μm.

In this case, the measured resistance of the heating film is 1.9Ω. Connect the lead wires to the positive and negative poles of the 1.5V power supply respectively. After testing, it can reach a stable state in 30 seconds. At this time, the average temperature of the heating film can reach about 86.3°C (room temperature is 22°C), which conforms to the formula T=kU ² /d ² R+t (K=107).

Example 11:

Embodiment 11 is substantially the same as Embodiment 1, except that different materials are used for the internal electrodes and bus bars, and metal platinum is used as the material for the bus bars and 10-layer graphene is used as the material for the internal electrodes. Single-layer graphene is used as the material of the transparent conductive layer (square resistance is 250Ω/□). The structure of the electrode layer is shown in Figure 4. The electrode spacing in the graphene is 5 mm, the length is 108 mm, and the width is 1 mm. There are 32 bars in total. The bus bar is 8 mm wide and 25 μm thick.

In this case, the measured resistance of the heating film is 1.9Ω. Connect the lead wires to the positive and negative poles of the 12V power supply respectively. After testing, it can reach a stable state in 30 seconds. At this time, the average temperature of the heating film can reach about 243°C (room temperature is 22°C), conforming to the formula T=kU ² /d ² R+t (K=96).

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the utility model, and the description thereof is relatively specific and detailed, but it should not be understood as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (10)

1. A knee pad, characterized in that it comprises a knee pad body and a heating film arranged on the knee pad body, and the heating film includes: first insulating layer; a conductive layer formed on the surface of the first insulating layer; An electrode layer, formed on the surface of the conductive layer and electrically connected to the conductive layer, the electrode layer includes a positive electrode and a negative electrode, and the positive electrode includes a positive bus bar and a bus bar extending from the positive bus bar a plurality of positive internal electrodes, the negative electrode includes a negative bus bar and a plurality of negative internal electrodes extending from the negative bus bar, the positive internal electrodes and the negative internal electrodes are alternately arranged and spaced from each other; and The second insulating layer is formed on the surface of the electrode layer. 2. The knee pad according to claim 1, characterized in that, the positive bus bar and the negative bus bar are linear and arranged in parallel, and a plurality of the positive inner electrodes approach the positive bus bar from the positive bus bar. One side of the negative bus bar extends toward the negative bus bar, and the plurality of negative inner electrodes extend toward the positive bus bar from a side of the negative bus bar close to the positive bus bar. 3. The knee pad according to claim 1, wherein the positive bus bar and the negative bus bar are linear, the negative bus bar and the positive bus bar are arranged at intervals, and the negative bus bar Extending along the extending direction of the positive bus bar, the positive inner electrode bends and extends from the positive bus bar to the negative bus bar, and the negative inner electrode bends from the negative bus bar to the positive bus bar Fold and extend. 4. The knee pad according to claim 1, wherein the positive bus bar and the negative bus bar are both arc-shaped and arranged at intervals, and the positive inner electrode extends from the inside of the positive bus bar to the The inner side of the negative bus bar extends, and the negative inner electrode extends from the inner side of the negative bus bar to the inner side of the positive bus bar. 5. The knee pad according to claim 1, wherein the heating film further comprises an auxiliary electrode layer disposed between the first insulating layer and the conductive layer, and the auxiliary electrode layer is connected to the conductive layer. The auxiliary electrode layer includes an auxiliary positive electrode and an auxiliary negative electrode, and the auxiliary positive electrode includes an auxiliary positive electrode bus bar and a plurality of auxiliary positive electrode internal electrodes extending from the auxiliary positive electrode bus bar. The negative electrode includes an auxiliary negative bus bar and a plurality of auxiliary negative internal electrodes extending from the auxiliary negative bus bar, the auxiliary positive internal electrodes and the auxiliary negative internal electrodes are alternately arranged and spaced from each other. 6. The knee pad according to claim 5, characterized in that, the projection of the auxiliary positive inner electrode and the auxiliary negative inner electrode of the auxiliary electrode layer on the conductive layer is the same as the positive inner electrode and the auxiliary inner electrode of the electrode layer. The projections of the negative internal electrodes on the conductive layer are staggered from each other. 7. The knee pad according to claim 1, wherein the heating film further comprises a first adhesive layer and a second adhesive layer, and the first adhesive layer is arranged on the first insulating layer and the conductive layer In between, the second adhesive layer is disposed between the electrode layer and the second insulating layer. 8. The knee pad according to claim 1, wherein there are multiple positive electrodes, and multiple positive electrodes are connected in series; And/or, there are multiple negative electrodes, and multiple negative electrodes are connected in series. 9. The knee pad according to claim 1, characterized in that, the knee pad further comprises a controller and a wireless communicator, the controller is electrically connected to the electrode layer, the wireless communicator can receive control instructions, and The control instruction is transmitted to the controller, and the controller controls the heating of the heating film according to the control instruction. 10. A knee pad, characterized in that it comprises a knee pad body and a heating film arranged on the knee pad body, and the heating film includes: first insulating layer; The first electrode layer is formed on the surface of the first insulating layer, the first electrode layer includes a positive electrode, and the positive electrode includes a positive electrode bus bar and a plurality of positive electrode internal electrodes extending from the positive electrode bus bar , a conductive layer formed on the surface of the first electrode layer, the conductive layer is electrically connected to the first electrode layer; The second electrode layer is formed on the surface of the conductive layer and is electrically connected to the conductive layer. The second electrode layer includes a negative electrode, and the negative electrode includes a negative bus bar and extends from the negative bus bar. A plurality of negative internal electrodes, the positive internal electrodes and the projections of the negative internal electrodes on the conductive layer are alternately arranged and spaced from each other; and The second insulating layer is formed on the surface of the second electrode layer.