3D printers and their control methods

Abstract

This invention discloses a 3D printer and its control method, relating to the field of 3D printing technology. The 3D printer includes a 3D printing module, an ultraviolet light source, and a digital micromirror device. It also includes a cooling supply component, a detection component, and a main control board. The cooling supply component includes a first end and a second end, with the first end connected to the digital micromirror device. The detection component includes a dew point detector and a temperature detector, with the temperature detector connected to the first end. Based on the dew point temperature and the temperature of the first end, the main control board adjusts the cooling supply of the cooling supply component, thereby regulating the temperature of the first end to be higher than the dew point temperature. This reduces the probability of condensation on the digital micromirror device, enabling the printer to maintain high printing accuracy during long-term operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing, in particular to a 3D printer and a control method thereof. BACKGROUND

[0002] The light-curing 3D printing technology is a 3D printing technology that uses a light source such as ultraviolet light to irradiate photosensitive resin to make it quickly solidify and form. It has the characteristics of high precision and good surface quality, and is widely used in the fields of jewelry, medical treatment, model making, etc. During printing, the equipment solidifies the resin layer by layer according to the layered data of the model, and finally stacks to form a complete 3D object. In the process of light-curing 3D printing, there are steps such as resin coating (ultraviolet light source off) and ultraviolet curing (ultraviolet light source on). Therefore, the ultraviolet light source is in an intermittent working state, usually 5-20 seconds on and 5-10 seconds off. DLP (Digital Light Processing) is a common light-curing 3D printing technology, that is, using a projector to project a whole layer of patterns onto the resin surface at one time to realize synchronous solidification of the whole layer, and the printing speed is relatively fast.

[0003] Among them, DMD (Digital Mirror Device) is the core device of digital light processing technology, which mainly realizes projection image by adjusting reflected light. The temperature specification of DMD in the field of 3D printing is 40℃, which is much lower than that in the field of home projection (70℃). At present, the DMD heat dissipation mode is usually that the DMD heat dissipation fin is in contact with the back of the DMD to guide the heat to the heat dissipation fin, and then the heat is guided out by heat exchange between the heat dissipation fin and the air. The image quality obtained by using this heat dissipation mode is not stable, and often appears as a screen after using for a period of time, or even the points do not light, which seriously affects the display quality, thereby seriously affecting the printing accuracy of the 3D printer. SUMMARY

[0004] The main purpose of the present application is to provide a 3D printer and a control method thereof, which aims to solve the technical problem of how to maintain high printing accuracy of the 3D printer in a long-term running state.

[0005] To achieve the above-mentioned purpose, the 3D printer provided by the present application comprises a 3D printing module, an ultraviolet light source and a digital micro-mirror device, the light emitting side of the ultraviolet light source faces the digital micro-mirror device, and the 3D printer further comprises:

[0006] A cold supply assembly, the cold supply assembly comprises a first end and a second end arranged oppositely, and the first end is connected with the digital micro-mirror device;

[0007] a detection assembly, the detection assembly comprising a dew point detection member for detecting ambient temperature and humidity around the DMD to obtain a dew point temperature, and a temperature detection member connected to the first end for detecting temperature of the first end;

[0008] a main control board, the cold supply assembly, the dew point detection member and the temperature detection member being electrically connected to the main control board, the main control board being capable of adjusting the amount of cold supplied by the cold supply assembly so that the temperature of the first end is higher than the dew point temperature.

[0009] In an embodiment, the cold supply assembly comprises a first heat conducting member and a cold supply member connected to each other, the first end being on a side of the first heat conducting member away from the cold supply member, the second end being on a side of the cold supply member away from the first heat conducting member, and the cold supply member being electrically connected to the main control board.

[0010] In an embodiment, the cold supply member comprises a semiconductor refrigeration sheet, the semiconductor refrigeration sheet being connected to the first heat conducting member, the positive and negative poles of the semiconductor refrigeration sheet being electrically connected to the main control board, the semiconductor refrigeration sheet comprising a first state and a second state, the main control board being capable of changing the direction of current of the semiconductor refrigeration sheet so that the semiconductor refrigeration sheet can be switched between the first state and the second state, and the main control board being capable of changing the size of current of the semiconductor refrigeration sheet; when the ultraviolet light source is turned on, the main control board outputs a forward current to the semiconductor refrigeration sheet, the main control board controls the semiconductor refrigeration sheet to be in the first state so that the second end can generate heat and an end of the semiconductor refrigeration sheet away from the second end can generate cold, and the main control board can adjust the size of the forward current to change the amount of cold supplied by the semiconductor refrigeration sheet to the first heat conducting member so that the temperature of the first end is higher than the dew point temperature and the temperature of the DMD is lower than a specified temperature; when the ultraviolet light source is turned off, the main control board outputs a reverse current to the semiconductor refrigeration sheet, the main control board controls the semiconductor refrigeration sheet to be in the second state so that the second end can generate cold and an end of the semiconductor refrigeration sheet away from the second end can generate heat, and the end of the semiconductor refrigeration sheet away from the second end supplies heat to the first heat conducting member so that the temperature of the first end is higher than the dew point temperature and lower than a preset temperature.

[0011] In an embodiment, the 3D printer further comprises a heat dissipation assembly connected to the second end, the heat dissipation assembly being used to reduce the temperature of the second end.

[0012] In an embodiment, the heat dissipation assembly further comprises a second heat conducting member, the second heat conducting member is connected with the second end, and a surface area of a side of the second heat conducting member away from the second end is greater than an area of the second end.

[0013] In an embodiment, the second heat conducting member is connected with the first heat conducting member, so that the second heat conducting member and the first heat conducting member enclose a closed space, and the cold supply member is located in the closed space.

[0014] In an embodiment, the first heat conducting member comprises a heat conducting body and a sealing ring, one side of the heat conducting body is the first end, a side of the cold supply member away from the second heat conducting member and the sealing ring are connected with the other side of the heat conducting body, the sealing ring is annularly arranged at a periphery of the cold supply member, and a side of the sealing ring away from the heat conducting body is connected with the second heat conducting member, so that the heat conducting body, the sealing ring and the second heat conducting member enclose the closed space.

[0015] In an embodiment, the second heat conducting member comprises a bottom plate and a plurality of heat dissipation fins, one side of the bottom plate is connected with the second end, and the other side of the bottom plate is connected with the plurality of heat dissipation fins.

[0016] In an embodiment, the heat dissipation assembly further comprises a heat dissipation fan, the heat dissipation fan is connected with the second heat conducting member, and an air outlet side of the heat dissipation fan faces the second heat conducting member.

[0017] In an embodiment, a first heat conducting layer is filled between the DMD and the first heat conducting member.

[0018] In an embodiment, a second heat conducting layer is filled between the first heat conducting member and the cold supply member.

[0019] In an embodiment, a third heat conducting layer is filled between the second end and the second heat conducting member.

[0020] In an embodiment, the first heat conducting member and the second heat conducting member are both metal heat conducting members.

[0021] In an embodiment, the 3D printer further comprises a capillary pumping member, a side of the first heat conducting member away from the second heat conducting member comprises a mounting area and a capillary pumping area, the DMD and the temperature detecting member are arranged in the mounting area, one end of the capillary pumping member covers the capillary pumping area, the other end of the capillary pumping member is connected with the second heat conducting member, and the capillary pumping member is used to pump condensation generated in the capillary pumping area to the second heat conducting member, so that the condensation can evaporate on the second heat conducting member to reduce the temperature of the second heat conducting member.

[0022] In an embodiment, the dew point detector comprises a temperature and humidity detector, which is arranged on the main control board and electrically connected with the main control board.

[0023] And / or, the temperature detector comprises a thermistor, which is connected with the first end and used for detecting the temperature of the first end.

[0024] The application further provides a control method of a 3D printer, which is applied to the 3D printer and comprises the following steps of:

[0025] controlling the dew point detector to acquire a dew point temperature in real time, and controlling the temperature detector to acquire the temperature of the first end in real time;

[0026] judging whether the ultraviolet light source is turned on or not;

[0027] if yes, controlling the cold supply assembly to output cold to the DMD through the main control board, and adjusting the output amount of the cold in real time according to the dew point temperature and the temperature of the first end, so that the temperature of the first end is higher than the dew point temperature;

[0028] if no, controlling the cold supply assembly to output heat to the DMD through the main control board, so that the temperature of the first end is higher than the dew point temperature.

[0029] In an embodiment, the step of controlling the cold supply assembly to output cold to the DMD through the main control board and adjusting the output amount of the cold in real time according to the dew point temperature and the temperature of the first end comprises the following steps of:

[0030] judging whether the temperature of the first end is higher than the dew point temperature in real time or not;

[0031] if yes, controlling the cold supply assembly to output cold to the DMD through the main control board, and adjusting the output amount of the cold in real time according to the dew point temperature and the temperature of the first end;

[0032] if no, controlling the cold supply assembly to stop outputting cold to the DMD through the main control board.

[0033] In an embodiment, the cold supply assembly comprises a first heat conduction member and a cold supply member which are connected with each other, the cold supply member comprises a semiconductor refrigeration sheet, one side of the first heat conduction member away from the semiconductor refrigeration sheet is the first end, one side of the semiconductor refrigeration sheet away from the first heat conduction member is the second end, and the positive electrode and the negative electrode of the semiconductor refrigeration sheet are electrically connected with the main control board.

[0034] The step of controlling the cold supply assembly to output cold to the DMD by the main control board and adjusting the output amount of the cold according to the dew point temperature and the temperature of the first end in real time comprises:

[0035] The step of outputting a forward current to the semiconductor refrigeration sheet by the main control board and adjusting the size of the forward current according to the dew point temperature and the temperature of the first end in real time, so that the main control board can adjust the amount of cold supplied by the semiconductor refrigeration sheet to the first heat conduction element according to the dew point temperature and the temperature of the first end.

[0036] The step of controlling the cold supply assembly to output heat to the DMD by the main control board comprises:

[0037] The step of outputting a reverse current to the semiconductor refrigeration sheet by the main control board, so that the main control board can control the semiconductor refrigeration sheet to provide heat to the first heat conduction element.

[0038] The technical scheme of the present application acquires the dew point temperature of the environment around the DMD in real time by using a dew point detection element, and acquires the temperature of the first end in real time by using a temperature detection element, and adjusts the amount of cold supplied by the cold supply assembly by the main control board according to the dew point temperature and the temperature of the first end, so as to adjust the temperature of the first end, so that the temperature of the first end and the DMD can be higher than the dew point temperature, thereby reducing the probability of condensation of the first end and the DMD, and further reducing the probability of water droplets generated by condensation falling on the surrounding electronic components and causing damage to the surrounding components, providing a guarantee for the long-term stable operation of the 3D printer, and also enabling the printer to maintain high printing accuracy in a long-term operation state. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0040] Figure 1 The structure schematic diagram of an embodiment of the 3D printer provided by the present application;

[0041] Figure 2 The partial structure schematic diagram of an embodiment of the 3D printer provided by the present application;

[0042] Figure 3 The exploded structure schematic diagram of an embodiment of the 3D printer provided by the present application;

[0043] Figure 4A rear view structural schematic diagram of one embodiment of the 3D printer provided by the present application;

[0044] Figure 5 A flow schematic diagram of the first embodiment of the control method of the 3D printer provided by the present application;

[0045] Figure 6 A flow schematic diagram of the second embodiment of the control method of the 3D printer provided by the present application.

[0046] Explanation of reference numerals:

[0047] 100, 3D printer; 1, ultraviolet light source; 2, digital micromirror device; 3, cold energy supply assembly; 31, first heat conduction member; 311, heat conduction body; 312, sealing ring; 313, mounting area; 314, capillary pumping area; 32, cold energy supply member; 321, semiconductor refrigeration sheet; 33, first end; 34, second end; 4, heat dissipation assembly; 41, second heat conduction member; 411, bottom plate; 412, heat dissipation fin; 42, heat dissipation fan; 51, temperature detection member; 511, thermistor; 6, main control board; 7, closed space; 8, capillary pumping member.

[0048] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0050] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0051] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0052] The light-curing 3D printing technology is a kind of 3D printing technology which uses ultraviolet light and other light sources to irradiate photosensitive resin and make it quickly solidify and form. It has the characteristics of high precision and good surface quality, and is widely used in jewelry, medical treatment, model making and other fields. When printing, the equipment solidifies the resin layer by layer according to the layered data of the model, and finally stacks to form a complete 3D object. There are resin coating (ultraviolet light source off), ultraviolet curing (ultraviolet light source on) and other steps in the light-curing 3D printing process, so the ultraviolet light source is in intermittent working state, usually 5-20 seconds on and 5-10 seconds off. DLP (Digital Light Processing) is a common light-curing 3D printing technology, that is, using a projector to project a whole layer of pattern at one time to the resin surface to realize synchronous curing of the whole layer, and the printing speed is relatively fast.

[0053] Among them, DMD (Digital Mirror Device) is the core device of digital light processing technology, which mainly realizes projection image by adjusting reflected light. The temperature specification of DMD in the field of 3D printing is 40℃, which is much lower than that in the field of home projection (70℃). At present, the DMD heat dissipation mode is usually that the DMD heat dissipation fin contacts the back of the DMD to guide the heat to the heat dissipation fin, and then the heat is guided out by heat exchange between the heat dissipation fin and the air. The image quality obtained by using this heat dissipation mode is not stable, and often appears as a screen after using for a period of time, or even the point is not bright, which seriously affects the display quality, and thus seriously affects the printing precision of the 3D printer.

[0054] The inventor has found that when the existing heat dissipation mode is used to dissipate heat of the DMD, the heat dissipation member for heat exchange with the DMD is prone to condensation if the temperature of the heat dissipation member is lower than the dew point temperature for a long time. The higher the environmental humidity and the lower the cold surface temperature, the greater the risk of condensation. The water droplets generated by condensation may fall on the circuit, components and devices (such as wires, solder joints and control boards) around the refrigeration sheet, causing short circuit, damaging the equipment or causing safety hazards, or affecting the printing accuracy. Long-term condensation can cause oxidation and corrosion of metal parts (such as heat dissipation fins and electrodes), reducing the service life, refrigeration efficiency and printing accuracy of the equipment. At the same time, the condensation on the cold surface of the heat dissipation member will hinder heat exchange and affect the heat exchange efficiency. If the DMD cannot be effectively cooled, the projector will appear a screen with a flower screen when the temperature of the DMD is higher than the specification temperature, and even the point will not be lit, affecting the display quality and reducing the printing accuracy.

[0055] In view of this, the present application provides a 3D printer, which aims to solve the technical problem of how to maintain high printing accuracy of the 3D printer in a long-term running state.

[0056] Please refer to Figures 1 to 3 In an embodiment of the present application, the 3D printer comprises an ultraviolet light source 1 and a digital micromirror device 2, and further comprises a cold supply assembly 3, a heat dissipation assembly 4, a detection assembly and a main control board 6. The cold supply assembly 3 comprises a first end 33 and a second end 34 arranged oppositely, and the first end 33 is connected with the digital micromirror device 2. The heat dissipation assembly 4 is connected with the second end 34, and is used to reduce the temperature of the second end 34. The detection assembly comprises a dew point detection member (not shown in the figure) and a temperature detection member 51. The dew point detection member is used to detect the environmental temperature and humidity around the digital micromirror device 2 to obtain the dew point temperature. The temperature detection member 51 is connected with the first end 33, and is used to detect the temperature of the first end 33. The cold supply assembly 3, the dew point detection member and the temperature detection member 51 are electrically connected with the main control board 6. The main control board 6 can adjust the cold supply amount of the cold supply assembly 3, so that the temperature of the first end 33 is higher than the dew point temperature.

[0057] The technical scheme of the present application acquires the dew point temperature of the environment around the digital micromirror device 2 in real time by using the dew point detection piece, and acquires the temperature of the first end 33 in real time by using the temperature detection piece 51, and adjusts the cold energy supply amount of the cold energy supply assembly 3 according to the dew point temperature and the temperature of the first end 33, so as to adjust the temperature of the first end 33 and the digital micromirror device 2. On the one hand, the temperature of the first end 33 and the digital micromirror device 2 can be higher than the dew point temperature, so as to reduce the probability of condensation of the first end 33 and the digital micromirror device 2, and further reduce the probability of water droplets generated by condensation falling on the surrounding electronic components and causing damage to the surrounding components, thereby prolonging the service life of the equipment, providing a guarantee for the long-term stable operation of the 3D printer, and also enabling the printer to maintain high printing precision in a long-term operation state. On the other hand, the main control board 6 adjusts the temperature of the first end 33, so that the temperature of the first end 33 can be maintained above the dew point temperature, reducing the probability of ice accumulation on the surface of the first end 33, ensuring the heat exchange efficiency of the cold energy supply assembly 3 and the digital micromirror device 2, and providing a guarantee for the long-term operation of the digital micromirror device 2 below the specification temperature, thereby effectively avoiding the occurrence of the situation that the projector is flickering or even not lighting up due to the operation of the digital micromirror device 2 above the specification temperature, so that the printer can maintain high printing precision in a long-term operation state. It should be noted that the cold energy supply assembly 3 can be a semiconductor refrigeration piece 321 or other existing refrigeration structure, which is not limited here; the heat dissipation assembly 4 can be air-cooled by a fan, or can be a water-cooled heat dissipation structure, which is not limited here; the main control board 6, the dew point detection piece and the temperature detection piece 51 are all existing structure, and the cold energy supply assembly 3, the dew point detection piece and the temperature detection piece 51 are electrically connected with the main control board 6 by using the existing connection mode. The 3D printer further comprises a 3D printing module, and the 3D printing module is an existing module.

[0058] Please refer to Figure 2 and Figure 3In an embodiment, the cold supply assembly 3 comprises a first heat conducting member 31 and a cold supply member 32 connected with each other, the first end 33 of the first heat conducting member 31 is away from the cold supply member 32, the second end 34 of the cold supply member 32 is away from the first heat conducting member 31, and the cold supply member 32 is electrically connected with the main control board 6. The cold supply member 32 is connected with the first heat conducting member 31, so that the cold generated by the cold supply member 32 can be rapidly transmitted to the DMD 2 and the temperature detecting member 51 at the first end 33, on the one hand, the temperature of the DMD 2 can be reduced, so that the DMD 2 can operate for a long time below the specification temperature; on the other hand, the temperature detecting member 51 can be used to understand the output of the cold supply member 32, so that the main control board 6 can adjust the output of the cold supply member 32 according to the temperature detected by the temperature detecting member 51 and the dew point temperature, to avoid the temperature of the first end 33 being reduced below the dew point temperature, thereby reducing the generation of condensation.

[0059] In an embodiment, the cold supply member 32 comprises a semiconductor refrigeration sheet 321, the semiconductor refrigeration sheet 321 is connected with the first heat conducting member 31, the positive electrode and the negative electrode of the semiconductor refrigeration sheet 321 are electrically connected with the main control board 6, the semiconductor refrigeration sheet 321 comprises a first state and a second state, the main control board 6 can change the current direction of the semiconductor refrigeration sheet 321, so that the semiconductor refrigeration sheet 321 can be switched between the first state and the second state, and the main control board 6 can also change the current size of the semiconductor refrigeration sheet 321; when the ultraviolet light source 1 is turned on, the main control board 6 outputs a forward current to the semiconductor refrigeration sheet 321, the main control board 6 controls the semiconductor refrigeration sheet 321 to be in the first state, so that the second end 34 can generate heat and the end of the semiconductor refrigeration sheet 321 away from the second end 34 can generate cold, the main control board 6 can adjust the size of the forward current to change the cold supplied by the semiconductor refrigeration sheet 321 to the first heat conducting member 31, so that the temperature of the first end 33 is higher than the dew point temperature and the temperature of the DMD 2 is lower than the specification temperature; when the ultraviolet light source 1 is turned off, the main control board 6 outputs a reverse current to the semiconductor refrigeration sheet 321, the main control board 6 controls the semiconductor refrigeration sheet 321 to be in the second state, so that the second end 34 can generate cold and the end of the semiconductor refrigeration sheet 321 away from the second end 34 can generate heat, and the end of the semiconductor refrigeration sheet 321 away from the second end 34 supplies heat to the first heat conducting member 31, so that the temperature of the first end 33 is higher than the dew point temperature and lower than the preset temperature.

[0060] When the ultraviolet light source 1 is turned on, the digital micro-mirror device 2 generates heat under the irradiation of the ultraviolet light source 1, and if the temperature exceeds the specification temperature, it will cause the projector to appear a screen or even not to light; therefore, the embodiment outputs a forward current to the semiconductor refrigeration sheet 321 through the main control board 6, so that the first end 33 is a cold surface and the second end 34 is a hot surface, the cold surface of the first end 33 exchanges heat with the digital micro-mirror device to reduce the temperature of the digital micro-mirror device, so that it can run below the specification temperature for a long time, and the accuracy of 3D printing is ensured; since the temperature detection piece 51 and the digital micro-mirror device are both located at the first end 33, the temperature of the cold surface and the temperature of the digital micro-mirror device can be known by detecting the value of the temperature detection piece 51, so that the main control board 6 can adjust the current of the semiconductor refrigeration sheet 321 according to the value detected by the temperature detection piece 51, realize the adjustment of the output of the cold surface, and further realize the automatic adjustment of the temperature of the digital micro-mirror device and the first end 33, so that the temperature of the digital micro-mirror device can be maintained below the specification temperature, and the temperature of the first end 33 can be maintained above the dew point temperature, which not only ensures that the digital micro-mirror device can run at a lower temperature for a long time, avoids the phenomenon of reduced printing accuracy caused by the projector appearing a screen or even not lighting due to the temperature of the digital micro-mirror device being higher than the specification temperature, and provides protection for the digital micro-mirror device to have higher display quality; it also ensures that the temperature of the first end 33 can be maintained above the dew point temperature, avoids the phenomenon that water droplets generated by condensation fall to the surrounding electronic devices due to the temperature of the first end 33 being below the dew point temperature for a long time, so that the digital micro-mirror device has a longer service life, and at the same time provides protection for the 3D printer to have a longer service life and better safety.

[0061] When the ultraviolet light source 1 is turned off, the digital micro-mirror device does not generate heat, and at this time, the temperature of the digital micro-mirror device and the first end 33 is low, and there is a risk that the temperature may be lower than the dew point temperature, therefore the main control board 6 outputs a reverse current to the semiconductor refrigeration sheet 321, at this time the first end 33 is a hot surface and the second end 34 is a cold surface, the temperature of the first end 33 rises, and the first end 33 exchanges heat with the digital micro-mirror device, so that the temperature of the digital micro-mirror device also rises, so that the temperature of the first end 33 and the digital micro-mirror device is higher than the dew point temperature, and the generation of condensation is effectively avoided. In this process, the temperature of the first end 33 and the digital micro-mirror device is generally lower than the preset temperature, which is generally 85 degrees Celsius.

[0062] It should be noted that the semiconductor refrigeration technology is a new refrigeration method by direct current. The working principle of the semiconductor refrigeration sheet 321 is that when a piece of N-type semiconductor material and a piece of P-type semiconductor material are connected into a galvanic couple, after the direct current is connected in the circuit, energy transfer can be generated, the current from the N-type element to the joint of the P-type element absorbs heat and becomes the cold end. The joint from the P-type element to the N-type element releases heat and becomes the hot end. The size of heat absorption and heat release is determined by the size of the current and the number of element pairs of N and P semiconductor materials. The inside of the semiconductor refrigeration sheet 321 is a thermoelectric pile composed of hundreds of electrically coupled pairs to enhance the refrigeration effect. The thermal inertia of the semiconductor refrigeration sheet 321 is very small, and the refrigeration and heating time is very fast. In the case of good heat dissipation at the hot end and no load at the cold end, the refrigeration sheet can reach the maximum temperature difference in less than one minute after power-on. The semiconductor refrigeration sheet 321 utilizes the Peltier effect, which is a thermoelectric phenomenon. When the current passes through a closed loop composed of two different conductors (or semiconductors), heat will be absorbed or released at their junction, causing one end to become cold and the other end to become hot. The essence of the Peltier effect is that when carriers (electrons or holes) flow from one material to another, they carry or release energy, resulting in heat absorption or release at the junction. Assuming that the semiconductor refrigeration sheet 321 is powered on, the current direction makes the electrons flow from the low-energy material to the high-energy material. At the junction, the electrons absorb energy (absorb heat from the lattice), causing the end to become cold, and at the other end, the electrons release energy, causing the end to become hot. When the current direction is reversed, the direction of electron movement is opposite to before, and the original "cold end" now becomes the place where electrons release energy, i.e. becomes the hot end, and the original "hot end" now becomes the place where electrons absorb energy, i.e. becomes the cold end. Because the Peltier effect is "directional", the direction of carrier energy transfer changes with the direction of current, so the cold and hot ends will alternate with the reversal of current direction.

[0063] See Figure 2 and Figure 3In an embodiment, the heat dissipation assembly 4 comprises a second heat conduction member 41 connected with the second end 34, and the surface area of the side of the second heat conduction member 41 facing away from the second end 34 is greater than the area of the second end 34. By connecting the second heat conduction member 41 with the second end 34 and making the area of the side of the second end 34 facing away from the semiconductor refrigeration sheet 321 greater than the area of the second end 34, when the second end 34 is the hot surface, the second heat conduction member 41 can be used for heat dissipation. Since the area of the second heat conduction member 41 facing away from the second end 34 is greater than the area of the second end 34 itself, after the second end 34 exchanges heat with the second heat conduction member 41, the temperature of the second heat conduction member 41 rises, and since the second heat conduction member 41 has a larger area in contact with air, the heat dissipation efficiency is higher. Therefore, the present embodiment effectively improves the heat dissipation efficiency of the second end 34 by adding the second heat conduction member 41, thereby providing protection for the normal operation of the semiconductor refrigeration sheet 321, and further enabling the semiconductor refrigeration sheet 321 to output corresponding cooling capacity according to the dew point temperature and the temperature of the first end 33, so as to avoid condensation on the first end 33 and prevent the temperature of the digital micromirror device 2 from being higher than the specified temperature, thereby providing protection for maintaining high printing precision of the 3D printer in a long-term running state.

[0064] In an embodiment, the second heat conduction member 41 is connected with the first heat conduction member 31 to form a closed space 7 with the first heat conduction member 31, and the cooling capacity supply member 32 is located in the closed space 7. By forming the closed space 7 containing the semiconductor refrigeration sheet 321 with the second heat conduction member 41 and the first heat conduction member 31, the semiconductor refrigeration sheet 321 is isolated from the external environment, and it is difficult for the moisture in the external environment to form condensation or ice layer on the cold surface of the semiconductor refrigeration sheet 321 to affect the working efficiency of the semiconductor refrigeration sheet 321, thereby providing protection for the normal operation of the semiconductor refrigeration sheet 321, and further enabling the semiconductor refrigeration sheet 321 to output corresponding cooling capacity according to the dew point temperature and the temperature of the first end 33, so as to avoid condensation on the first end 33 and prevent the temperature of the digital micromirror device 2 from being higher than the specified temperature, thereby providing protection for maintaining high printing precision of the 3D printer in a long-term running state.

[0065] Please refer to Figure 2 and Figure 3In an embodiment, the first heat conducting member 31 comprises a heat conducting body 311 and a sealing ring 312. One side of the heat conducting body 311 is the first end 33. The side of the cold quantity supply member 32 facing away from the second heat conducting member 41 and the sealing ring 312 are connected to the other side of the heat conducting body 311. The sealing ring 312 is annularly arranged around the periphery of the cold quantity supply member 32. The side of the sealing ring 312 facing away from the heat conducting body 311 is connected to the second heat conducting member 41, so that the heat conducting body 311, the sealing ring 312 and the second heat conducting member 41 enclose a sealed space 7. The other side of the sealing ring 312 is sealingly connected to the heat conducting body 311 and the second heat conducting member 41, so that the heat conducting body 311, the sealing ring 312 and the second heat conducting member 41 enclose the sealed space 7. The semiconductor refrigeration sheet 321 is located in the sealing ring 312. One side of the semiconductor refrigeration sheet 321 is connected to the heat conducting body 311, and the other side of the semiconductor refrigeration sheet 321 is connected to the second heat conducting member 41. In this way, the semiconductor refrigeration sheet 321 can exchange heat with the heat conducting body 311 and the second heat conducting member 41, and at the same time, the semiconductor refrigeration sheet 321 is isolated from the external environment, which ensures the normal operation of the semiconductor refrigeration sheet 321. The sealing ring 312 can be sealing foam or sealing rubber ring, and the like, which are not limited herein. In addition, the outer contour of the sealing ring 312 can be circular or square, which are not limited herein. The shape of the inner ring of the sealing ring 312 is matched with the shape of the semiconductor refrigeration sheet 321.

[0066] Referring to Figure 1 and Figure 2 In an embodiment, the second heat conducting member 41 comprises a bottom plate 411 and a plurality of heat dissipation fins 412. One side of the bottom plate 411 is connected to the second end 34, and the other side of the bottom plate 411 is connected to the plurality of heat dissipation fins 412. The plurality of heat dissipation fins 412 are arranged on the side of the bottom plate 411 facing away from the semiconductor refrigeration sheet 321. In this way, the area of the second heat conducting member 41 in contact with air is further increased, so that the heat dissipation efficiency of the second heat conducting member 41 is significantly improved, which ensures that the semiconductor refrigeration member can provide sufficient cold quantity.

[0067] Referring to Figures 1 to 3In an embodiment, the heat dissipation assembly 4 further comprises a heat dissipation fan 42, the heat dissipation fan 42 is connected with the second heat conduction member 41, and an air outlet side of the heat dissipation fan 42 faces the second heat conduction member 41; by increasing the heat dissipation fan, the air flow rate around the second heat conduction member 41 is improved, so that the second heat conduction member 41 can exchange heat with more air in the same time, and the heat dissipation efficiency of the second heat conduction member 41 is further improved, which provides a reliable guarantee for the semiconductor refrigeration piece to provide sufficient cold energy, and then the semiconductor refrigeration piece 321 can output corresponding cold energy according to the dew point temperature and the temperature of the first end 33, so as to avoid the first end 33 from forming condensation and avoid the temperature of the digital micromirror device 2 from being higher than the specification temperature, thereby providing a guarantee for the 3D printer to maintain high printing precision in a long-term running state.

[0068] In an embodiment, a first heat conduction layer (not shown in the figure) is filled between the digital micromirror device 2 and the first heat conduction member 31; wherein the part of the digital micromirror device 2 and the first heat conduction member 31 in contact is not strictly sealed, that is, the actual contact area between the two is smaller than the contact area seen in macroscopy, because the surfaces of the two are difficult to be completely smooth due to the limitation of existing processes, and therefore the gaps are filled by filling the first heat conduction layer between the first heat conduction member 31 and the digital micromirror device 2, so as to expand the area participating in heat exchange between the digital micromirror device 2 and the first heat conduction member 31, and improve the heat exchange effect between the digital micromirror device 2 and the first heat conduction member 31.

[0069] In an embodiment, a second heat conduction layer (not shown in the figure) is filled between the first heat conduction member 31 and the cold energy supply member 32; similarly, the gaps between the first heat conduction member 31 and the cold energy supply member 32 are filled by filling the second heat conduction layer between the first heat conduction member 31 and the cold energy supply member 32, so as to expand the area participating in heat exchange between the cold energy supply member 32 and the first heat conduction member 31, and improve the heat exchange effect between the cold energy supply member 32 and the first heat conduction member 31.

[0070] In an embodiment, a third heat conduction layer (not shown in the figure) is filled between the second end 34 and the second heat conduction member 41; similarly, the gaps between the second end 34 and the second heat conduction member 41 are filled by filling the third heat conduction layer between the second end 34 and the second heat conduction member 41, so as to expand the area participating in heat exchange between the second end 34 and the second heat conduction member 41, and improve the heat exchange effect between the second end 34 and the second heat conduction member 41. The first heat conduction layer, the second heat conduction layer and the third heat conduction layer can be heat conduction gaskets, or heat conduction gels and other heat conduction materials, which are not limited herein.

[0071] In an embodiment, the first heat-conducting member 31 and the second heat-conducting member 41 are both metal heat-conducting members; wherein the first heat-conducting member 31 and the second heat-conducting member 41 are both metal heat-conducting members, because metal has higher heat-conducting efficiency, and by using metal heat-conducting members, the heat-conducting efficiency of the first heat-conducting member 31 and the second heat-conducting member 41 can be effectively improved. In addition, the first heat-conducting member 31 and the second heat-conducting member 41 can be heat-conducting plates or heat-conducting blocks, and the shape thereof is not limited herein.

[0072] Please refer to Figure 4 In an embodiment, the 3D printer further comprises a capillary suction member 8, the side of the first heat-conducting member 31 away from the second heat-conducting member 41 comprises a mounting area 313 and a capillary suction area 314, the digital micromirror device 2 and the temperature detection member 51 are both arranged on the mounting area 313, one end of the capillary suction member 8 covers the capillary suction area 314, the other end of the capillary suction member 8 is connected with the second heat-conducting member 41, and the capillary suction member 8 is used to extract the condensation generated in the capillary suction area 314 to the second heat-conducting member 41, so that the condensation can evaporate on the second heat-conducting member 41 to reduce the temperature of the second heat-conducting member 41. Wherein, the capillary suction member 8 can be a non-woven fabric or a paper towel, and is not limited herein.

[0073] When the ultraviolet light source 1 is turned on, the first end 33 is a cold surface and the second end 34 is a hot surface by the positive current output from the main control board 6 to the semiconductor refrigeration sheet 321, the first end 33 exchanges heat with the digital micromirror device 2, thereby reducing the temperature of the digital micromirror device 2, and the digital micromirror device 2 is maintained below the specification temperature. The temperature of the first end 33 is low due to the output of cold energy to the digital micromirror device 2, and condensation is likely to occur. Although the temperature of the first end 33 can be monitored by the temperature detection member 51, and the temperature of the first end 33 is automatically controlled by the main control board 6 according to the data detected by the temperature detection member 51, so that the temperature of the first end 33 can be maintained above the dew point temperature for a long time, and the probability of condensation is reduced; but the adjustment has a certain delay, that is, when the temperature of the first end 33 is below the dew point temperature, the temperature detection member 51 detects that the temperature of the first end 33 is below the dew point temperature, and the main control board 6 reduces the current of the semiconductor refrigeration sheet 321, so that the temperature of the first end 33 rises above the dew point temperature. This process is not instantaneous, and the temperature of the first end 33 from below the dew point temperature to above the dew point temperature may be accompanied by condensation. The capillary suction member 8 is arranged in the capillary suction area 314 to extract the condensation formed in the capillary suction area 314 to the second heat conduction member 41 by capillary phenomenon. The second heat conduction member 41 exchanges heat with the second end 34, so the second heat conduction member 41 with high temperature can heat the condensation, the condensation absorbs heat and vaporizes, and the heat on the second heat conduction member 41 is taken away, thereby improving the heat dissipation efficiency of the second heat conduction member 41, and effectively avoiding the phenomenon that the condensation gathered on the first end 33 forms water droplets and falls on other electronic components during the process of the first end 33 from below the dew point temperature to above the dew point temperature, so that the 3D printer maintains high printing precision in a long-term running state.

[0074] When the ultraviolet light source 1 is turned off, the first end 33 is a hot surface and the second end 34 is a cold surface by the reverse current output from the main control board 6 to the semiconductor refrigeration sheet 321, and the second end 34 exchanges heat with the second heat conduction plate as a cold surface, thereby reducing the temperature of the second heat conduction plate. Although the second heat conduction plate has a larger area in contact with air than the second end 34 to improve the heat exchange efficiency between the second heat conduction plate and air, but it is still possible that condensation will gather on the second heat conduction plate to form water droplets and fall on other electronic components. Since the capillary suction member 8 is connected to the second heat conduction plate, the capillary suction member 8 will extract the condensation on the second heat conduction member 41 to the capillary suction area 314. Since the first end 33 is a hot surface, the condensation extracted to the first end 33 will be heated and evaporated, thereby reducing the probability of condensation gathering on the second heat conduction plate to form water droplets and fall, and the 3D printer maintains high printing precision in a long-term running state.

[0075] In an embodiment, the dew point detection member comprises a temperature and humidity detector, which is arranged on the main control board 6 and electrically connected with the main control board 6; the temperature and humidity detector is arranged to obtain the temperature and humidity in the environment, so as to obtain the dew point temperature of the current environment, so that the main control board 6 can control the temperature of the first end 33 and the digital micro control device to be above the dew point temperature by the semiconductor refrigeration sheet 321.

[0076] In an embodiment, the temperature detection member 51 comprises a thermistor 511 connected with the first end 33, which is used to detect the temperature of the first end 33. The thermistor 511 is arranged to obtain the temperature of the first end 33, so as to feed back the temperature result to the temperature control chip on the main control board 6, and the temperature control chip adjusts the current of the semiconductor refrigeration sheet 321 according to the temperature result of the thermistor 511, so as to realize the purpose of automatic temperature control.

[0077] The application further provides a control method of the 3D printer, which is applied to the 3D printer. Figure 5 , Figure 5 The control method of the 3D printer provided by the application is shown in the flowchart of the first embodiment; the control method of the 3D printer comprises the following steps.

[0078] S100, controlling the dew point detection member to obtain the dew point temperature in real time, and controlling the temperature detection member to obtain the temperature of the first end in real time;

[0079] Since the dew point temperature of different environments and different times may be different, in order to adapt to the needs of different environments, the dew point detection member is arranged to monitor the dew point temperature of the current environment; similarly, since the temperature of the first end is also real-time changeable, it is affected by the current environment temperature, the temperature of the digital micro control device, the current direction and current size of the semiconductor refrigeration sheet, and the like, so the temperature detection member is arranged to obtain the temperature of the first end in real time.

[0080] S200, judging whether the ultraviolet light source is turned on or not;

[0081] S210, if yes, controlling the cold quantity supply assembly to output cold quantity to the digital micro control device by the main control board, and adjusting the output quantity of the cold quantity in real time according to the dew point temperature and the temperature of the first end; so as to make the temperature of the first end higher than the dew point temperature;

[0082] When the ultraviolet light source is turned on, the digital micromirror device generates heat under the irradiation of the ultraviolet light source, and if the temperature exceeds the specification temperature, the projector will appear to have a screen or even not light up; therefore, the embodiment outputs a forward current to the semiconductor refrigeration sheet through the main control board, so that the first end is a cold surface and the second end is a hot surface, the cold surface of the first end exchanges heat with the digital microcontroller device to reduce the temperature of the digital microcontroller device, so that it can operate below the specification temperature for a long time, ensuring the accuracy of 3D printing; since the temperature detection member and the digital microcontroller device are both located at the first end, the temperature of the cold surface and the temperature of the digital microcontroller device can be known by detecting the value of the temperature detection member, so that the main control board can adjust the current of the semiconductor refrigeration sheet according to the value detected by the temperature detection member, adjust the output of the cold surface, and further automatically adjust the temperature of the digital microcontroller device and the first end, so that the temperature of the digital microcontroller device can be maintained below the specification temperature, and the temperature of the first end can be maintained above the dew point temperature, which not only ensures that the digital microcontroller device can operate at a lower temperature for a long time, avoids the phenomenon of reduced printing accuracy caused by the projector appearing to have a screen or even not light up due to the temperature of the digital microcontroller device being higher than the specification temperature, and provides protection for the digital microcontroller device to have higher display quality; it also ensures that the temperature of the first end can be maintained above the dew point temperature, avoids the phenomenon of water droplets falling to the surrounding electronic devices due to the temperature of the first end being below the dew point temperature for a long time, and makes the digital microcontroller device have a longer service life, while providing protection for the 3D printer to have a longer service life and better safety.

[0083] S220, if not, the main control board controls the cold supply assembly to output heat to the digital micromirror device; so that the temperature of the first end is higher than the dew point temperature.

[0084] When the ultraviolet light source is turned off, the digital microcontroller device does not generate heat, and at this time the temperature of the digital microcontroller device and the first end is low, which may have a risk of being lower than the dew point temperature, therefore the main control board outputs a reverse current to the semiconductor refrigeration sheet, at this time the first end is a hot surface and the second end is a cold surface, the temperature of the first end rises, and the first end exchanges heat with the digital microcontroller device, thereby also raising the temperature of the digital microcontroller device, so that the temperature of the first end and the digital microcontroller device is higher than the dew point temperature, thereby effectively avoiding the generation of condensation. In this process, the temperature of the first end and the digital microcontroller device is generally lower than the preset temperature, which is generally 85 degrees Celsius.

[0085] The dew point detection member obtains the dew point temperature of the ambient environment of the digital micromirror device in real time, the temperature detection member obtains the temperature of the first end in real time, the dew point temperature and the temperature of the first end are used to adjust the cold supply amount of the cold supply assembly by the main control board, so as to adjust the temperature of the first end, on the one hand, the temperature of the first end can be higher than the dew point temperature, so as to reduce the probability of condensation of the digital micromirror device, and further reduce the probability of water droplets generated by condensation falling on the surrounding electronic components and causing damage to the surrounding components, prolong the service life of the equipment, provide a guarantee for long-term stable operation of the 3D printer, and also enable the printer to maintain high printing precision in a long-term running state; on the other hand, the main control board adjusts the temperature of the first end, so that the temperature of the first end can be maintained above the dew point temperature, the probability of ice accumulation on the surface of the first end is reduced, the heat exchange efficiency of the cold supply assembly and the digital micromirror device is ensured, and the long-term operation of the digital micromirror device below the specification temperature is guaranteed, thereby effectively avoiding the occurrence of the situation that the projector is flickering or even not lighting due to the operation of the digital micromirror device above the specification temperature, so that the printer can maintain high printing precision in a long-term running state.

[0086] Please refer to Figure 6 , Figure 6 The flowchart of the second embodiment of the control method of the 3D printer provided by the application is shown in the figure; in an embodiment, the step of adjusting the output amount of the cold by the main control board includes:

[0087] S211, judging whether the temperature of the first end is higher than the dew point temperature in real time;

[0088] S212, if yes, the cold supply assembly is controlled by the main control board to output cold to the digital micromirror device, and the output amount of the cold is adjusted in real time according to the dew point temperature and the temperature of the first end;

[0089] S213, if no, the cold supply assembly is controlled by the main control board to stop outputting cold to the digital micromirror device.

[0090] When the ultraviolet light source is turned on, it is determined in real time whether the temperature of the first end is higher than the dew point temperature. If the temperature of the first end is higher than the dew point temperature, it indicates that the first end is difficult to form condensation, so the main control board can continue to output a forward current to the semiconductor refrigeration piece, and the cooling capacity output of the semiconductor refrigeration piece is adjusted by adjusting the current size, so that the first end can be maintained above the dew point temperature for a long time, and the digital micromirror device can be maintained below the specification temperature for a long time; if the temperature of the first end is lower than the dew point temperature, the main control board stops supplying power to the semiconductor refrigeration piece, so that the semiconductor refrigeration piece stops outputting cooling capacity to the first end. At this time, the digital micromirror device is constantly generating heat under the irradiation of the ultraviolet light source, so the digital micromirror device will cause the temperature of the first end to rise above the dew point temperature, thereby reducing the probability of condensation forming and falling in the form of water droplets in the first end. When the temperature of the first end rises above the dew point temperature, the main control board starts to provide a forward current to the semiconductor refrigeration piece again, thereby realizing automatic temperature control of the first end and the digital micromirror device.

[0091] In an embodiment, the cooling capacity supply assembly includes a first heat-conducting member and a cooling capacity supply member connected to each other, the cooling capacity supply member includes a semiconductor refrigeration piece, a side of the first heat-conducting member away from the semiconductor refrigeration piece is the first end, a side of the semiconductor refrigeration piece away from the first heat-conducting member is the second end, and the positive and negative electrodes of the semiconductor refrigeration piece are electrically connected to the main control board.

[0092] The main control board controls the cooling capacity supply assembly to output cooling capacity to the digital micromirror device, and adjusts the output of the cooling capacity in real time according to the dew point temperature and the temperature of the first end. The step includes:

[0093] S211', the main control board outputs a forward current to the semiconductor refrigeration piece, and adjusts the size of the forward current in real time according to the dew point temperature and the temperature of the first end; so that the main control board can adjust the cooling capacity supply amount of the semiconductor refrigeration piece to the first heat-conducting member according to the dew point temperature and the temperature of the first end.

[0094] The main control board controls the cooling capacity supply assembly to output heat to the digital micromirror device. The step includes:

[0095] S221, the main control board outputs a reverse current to the semiconductor refrigeration piece; so that the main control board can control the semiconductor refrigeration piece to provide heat to the first heat-conducting member.

[0096] When the ultraviolet light source is turned on, the digital micro-mirror device generates heat under the irradiation of the ultraviolet light source, and if the temperature exceeds the specification temperature, the projector will appear to be out of focus or even not light up. Therefore, the embodiment outputs a forward current to the semiconductor refrigeration sheet through the main control board to make the first end a cold surface and the second end a hot surface. The cold surface of the first end exchanges heat with the digital micro-control device to reduce the temperature of the digital micro-control device, so that it can operate below the specification temperature for a long time, ensuring the accuracy of 3D printing. Since the temperature detection member and the digital micro-control device are both located at the first end, the temperature of the cold surface and the temperature of the digital micro-control device can be obtained by detecting the value of the temperature detection member, so that the main control board can adjust the current of the semiconductor refrigeration sheet according to the value detected by the temperature detection member, adjust the output of the cold surface, and automatically adjust the temperature of the digital micro-control device and the first end, so that the temperature of the digital micro-control device can be maintained below the specification temperature, and the temperature of the first end can be maintained above the dew point temperature. This not only ensures that the digital micro-control device can operate at a lower temperature for a long time, avoids the phenomenon of reduced printing accuracy caused by the projector appearing to be out of focus or even not light up due to the temperature of the digital micro-control device being higher than the specification temperature, and provides protection for the digital micro-control device to have higher display quality. It also ensures that the temperature of the first end can be maintained above the dew point temperature, avoids the phenomenon of water droplets falling to the surrounding electronic devices due to the temperature of the first end being below the dew point temperature for a long time, and makes the digital micro-control device have a longer service life, while providing protection for the 3D printer to have a longer service life and better safety. If the temperature of the first end is below the dew point temperature, the main control board stops supplying power to the semiconductor refrigeration sheet to stop the semiconductor refrigeration sheet from outputting cold to the first end. Since the digital micro-mirror device is constantly generating heat under the irradiation of the ultraviolet light source at this time, the digital micro-mirror device will cause the temperature of the first end to rise above the dew point temperature, thereby reducing the probability of condensation and water droplets falling from the first end. When the temperature of the first end rises above the dew point temperature, the main control board starts to supply a forward current to the semiconductor refrigeration sheet, thereby automatically controlling the temperature of the first end and the digital micro-mirror device, and maintaining the temperature of the first end above the dew point temperature for a long time.

[0097] When the ultraviolet light source is turned off, the digital micro-control device does not generate heat, and the temperature of the digital micro-control device and the first end is relatively low, which may be below the dew point temperature. Therefore, the main control board outputs a reverse current to the semiconductor refrigeration sheet, and at this time the first end is a hot surface and the second end is a cold surface. The temperature of the first end rises, and the first end exchanges heat with the digital micro-control device, thereby also raising the temperature of the digital micro-control device, so that the temperature of the first end and the digital micro-control device is above the dew point temperature, thereby effectively avoiding the generation of condensation.

[0098] The above merely describes exemplary embodiments of the present application, and is not intended to limit the protection scope of the present application, and any equivalent structural transformation made according to the technical concept of the present application, or direct / indirect application in other related technical fields, is included in the protection scope of the present application.

Claims

1. A 3D printer comprising a 3D printing module, an ultraviolet light source and a digital micromirror device, a light emitting side of the ultraviolet light source facing the digital micromirror device, characterized in that, The 3D printer further comprises: a cold supply assembly comprising a first end and a second end arranged oppositely, the first end being connected with the DMD; a detection assembly comprising a dew point detector and a temperature detector, the dew point detector being used to detect the ambient temperature and humidity around the DMD to obtain a dew point temperature, and the temperature detector being connected with the first end to detect the temperature of the first end; a main control board, the cold supply assembly, the dew point detector and the temperature detector being electrically connected with the main control board, the main control board being capable of adjusting the cold supply amount of the cold supply assembly according to the dew point temperature and the temperature of the first end, so that the temperature of the first end is higher than the dew point temperature; the cold supply assembly comprises a first heat conducting member and a cold supply member connected with each other, the side of the first heat conducting member away from the cold supply member being the first end, the side of the cold supply member away from the first heat conducting member being the second end, and the cold supply member being electrically connected with the main control board; the cold supply member comprises a semiconductor refrigeration sheet, the semiconductor refrigeration sheet being connected with the first heat conducting member, the positive and negative electrodes of the semiconductor refrigeration sheet being electrically connected with the main control board, and the main control board being capable of changing the current size and direction of the semiconductor refrigeration sheet; when the ultraviolet light source is turned on, the main control board outputs a forward current to the semiconductor refrigeration sheet, the second end can generate heat and the end of the semiconductor refrigeration sheet away from the second end can generate cold, the main control board can adjust the size of the forward current to change the cold supply amount of the semiconductor refrigeration sheet to the first heat conducting member, so that the temperature of the first end is higher than the dew point temperature and the temperature of the DMD is lower than a specification temperature; when the ultraviolet light source is turned off, the main control board outputs a reverse current to the semiconductor refrigeration sheet, the second end can generate cold and the end of the semiconductor refrigeration sheet away from the second end can generate heat, the end of the semiconductor refrigeration sheet away from the second end supplies heat to the first heat conducting member, so that the temperature of the first end is higher than the dew point temperature and lower than a preset temperature; the 3D printer further comprises a heat dissipation assembly connected with the second end, the heat dissipation assembly being used to reduce the temperature of the second end; the heat dissipation assembly comprises a second heat conducting member connected with the second end, the surface area of the side of the second heat conducting member away from the second end being greater than the area of the second end; The 3D printer further comprises a capillary suction member, one side of the first heat-conducting member away from the second heat-conducting member comprises a mounting area and a capillary suction area, the digital micromirror device and the temperature detection member are arranged on the mounting area, one end of the capillary suction member covers the capillary suction area, the other end of the capillary suction member is connected with the second heat-conducting member, and the capillary suction member is used to extract the condensation generated in the capillary suction area to the second heat-conducting member, so that the condensation can evaporate on the second heat-conducting member to reduce the temperature of the second heat-conducting member.

2. The 3D printer of claim 1, wherein, The second heat-conducting member is connected with the first heat-conducting member, so that the second heat-conducting member and the first heat-conducting member form a closed space, and the cold supply member is located in the closed space.

3. The 3D printer of claim 2, wherein, The first heat-conducting member comprises a heat-conducting body and a sealing ring, one side of the heat-conducting body is the first end, the side of the cold supply member away from the second heat-conducting member and the sealing ring are connected with the other side of the heat-conducting body, the sealing ring is annularly arranged on the periphery of the cold supply member, and the side of the sealing ring away from the heat-conducting body is connected with the second heat-conducting member, so that the heat-conducting body, the sealing ring and the second heat-conducting member form the closed space.

4. The 3D printer of claim 1, wherein, The second heat-conducting member comprises a bottom plate and a plurality of heat dissipation fins, one side of the bottom plate is connected with the second end, and the other side of the bottom plate is connected with the plurality of heat dissipation fins. And / or, the heat dissipation assembly further comprises a heat dissipation fan, the heat dissipation fan is connected with the second heat-conducting member, and the air outlet side of the heat dissipation fan faces the second heat-conducting member. And / or, the digital micromirror device and the first heat-conducting member are filled with a first heat-conducting layer. And / or, the first heat-conducting member and the cold supply member are filled with a second heat-conducting layer. And / or, the second end and the second heat-conducting member are filled with a third heat-conducting layer. And / or, the first heat-conducting member and the second heat-conducting member are metal heat-conducting members.

5. The 3D printer according to any one of claims 1 to 4, wherein, The dew point detection member comprises a temperature and humidity detector, the temperature and humidity detector is arranged on the main control board and is electrically connected with the main control board. And / or, the temperature detection member comprises a thermistor, the thermistor is connected with the first end and is used to detect the temperature of the first end.

6. A 3D printing method, characterized by, The 3D printing method adopts the 3D printer according to any one of claims 1 to 5, and the 3D printing method comprises the following steps: controlling the dew point detection member to obtain a dew point temperature in real time, and controlling the temperature detection member to obtain the temperature of the first end in real time; determining whether the ultraviolet light source is turned on; if yes, controlling the cold supply assembly to output cold energy to the digital micromirror device through the main control board, and adjusting the output amount of the cold energy in real time according to the dew point temperature and the temperature of the first end; so that the temperature of the first end is higher than the dew point temperature; if no, controlling the cold supply assembly to output heat to the digital micromirror device through the main control board; so that the temperature of the first end is higher than the dew point temperature.

7. The 3D printing method of claim 6, wherein, The step of controlling the cold supply assembly to output cold energy to the digital micromirror device through the main control board and adjusting the output amount of the cold energy in real time according to the dew point temperature and the temperature of the first end comprises: judging whether the temperature of the first end is higher than the dew point temperature in real time; if yes, controlling the cold supply assembly to output cold to the DMD by the main control board, and adjusting the output of the cold according to the dew point temperature and the temperature of the first end in real time; if no, controlling the cold supply assembly to stop outputting cold to the DMD by the main control board.

8. The 3D printing method of claim 6, wherein, The cold supply assembly comprises a first heat-conducting member and a cold supply member connected with each other, the cold supply member comprises a semiconductor refrigeration sheet, the side of the first heat-conducting member away from the semiconductor refrigeration sheet is the first end, the side of the semiconductor refrigeration sheet away from the first heat-conducting member is the second end, and the positive and negative poles of the semiconductor refrigeration sheet are electrically connected with the main control board; The step of controlling the cold supply assembly to output cold to the DMD by the main control board and adjusting the output of the cold according to the dew point temperature and the temperature of the first end in real time comprises: outputting a forward current to the semiconductor refrigeration sheet by the main control board, and adjusting the size of the forward current according to the dew point temperature and the temperature of the first end in real time; so that the main control board can adjust the amount of cold supplied by the semiconductor refrigeration sheet to the first heat-conducting member according to the dew point temperature and the temperature of the first end; The step of controlling the cold supply assembly to output cold to the DMD by the main control board comprises: outputting a reverse current to the semiconductor refrigeration sheet by the main control board; so that the main control board can control the semiconductor refrigeration sheet to provide heat to the first heat-conducting member.

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