CN221225299U - Projection device - Google Patents

Abstract

The utility model relates to the technical field of projection, in particular to a projection device, which comprises a light machine shell which is arranged in a closed manner, wherein an optical assembly is arranged in the light machine shell, an internal circulation air path is formed in the light machine shell, and heat of air flow flowing along the internal circulation air path is led out of the light machine shell through a semiconductor refrigerator. The projection device adopts a closed heat dissipation structure and adopts the semiconductor refrigerator to actively cool, so that enough cooling capacity can be obtained to cool and dissipate heat of the optical component, the optical component is ensured to work in a proper temperature range, the working stability and the service life of the optical component are ensured, and the projection device is favorable for improving the quality and the brightness of projection images.

Description

Projection device

Technical Field

The present disclosure relates to projection technology, and particularly to a projection apparatus.

Background

An LCD projector is a type of conventional projector that uses an LCD panel as a light modulation device to modulate an illumination beam to obtain an image beam, and then projects the image beam through a lens to form a projection screen. The transmittance of the LCD panel is usually only 5-7%, so that most of the illumination light is absorbed by the LCD panel when passing through the LCD panel, which results in higher temperature rise of the LCD panel and limits the improvement of the brightness of the projection screen.

In order to ensure that the LCD panel can stably work and prolong the service life of the LCD panel, a heat dissipation mechanism is arranged in the projection device to dissipate heat of the LCD panel, the heat dissipation mechanism generally comprises an open structure and a closed structure, the traditional open structure has better heat dissipation effect, but is difficult to effectively prevent dust, impurity dust is adhered to the LCD panel or an optical lens to seriously influence the quality of a projected picture, the LCD panel is in a closed cavity in the traditional closed structure, the dustproof effect is good, but the heat dissipation performance is poor, the heat generated during the working of the LCD panel is difficult to effectively lead out, the working stability of the LCD panel is difficult to ensure, and the brightness of the projected picture is difficult to effectively improve.

Disclosure of utility model

The utility model aims to solve the technical problems and the technical task of improving the prior art, provides a projection device, solves the problems that a heat dissipation mechanism adopted by the projection device in the prior art is difficult to effectively ensure heat dissipation performance and dustproof effect, and limits the improvement of the brightness and the image quality of the picture of the projection device.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

a projection apparatus, comprising:

The optical engine comprises an optical engine shell which is arranged in a closed manner, wherein an optical assembly and an inner fan are arranged in the optical engine shell, an air outlet of the inner fan is adjacent to the optical assembly, and an inner circulation air path is formed in the optical engine shell;

The refrigerating assembly comprises a semiconductor refrigerator, a first heat exchange piece in heat conduction connection with the cold end of the semiconductor refrigerator and a second heat exchange piece in heat conduction connection with the hot end of the semiconductor refrigerator, wherein the first heat exchange piece is arranged in the optical machine shell and is positioned in an internal circulation air path, and the second heat exchange piece is arranged outside the optical machine shell.

The projection device utilizes the semiconductor refrigerator to actively refrigerate, the inner fan is adjacent to the optical component to directly blow the optical component, the cold produced by the semiconductor refrigerator can be effectively utilized to dissipate heat of the optical component, the optical component is ensured to work in a proper temperature range, the working stability and the service life of the optical component are ensured, the brightness of a projection picture is improved in a mode of increasing the brightness of a light source, the projection device adopts a closed radiating structure, the air flow generated by the inner fan only flows along an inner circulating air path of a closed environment, a good dustproof effect is ensured, the effect that the dust adheres to the optical component is influenced on the projection picture quality is effectively avoided, the air flow absorbing the heat of the optical component is changed into low-temperature air flow at the first part of the heat exchange piece through heat exchange, the low-temperature air flow is pumped to the optical component by the inner fan to circularly dissipate heat of the optical component, and the heat absorbed by the first part of the heat exchange piece is radiated outwards from the heat exchange piece connected with the hot end of the semiconductor refrigerator, and the long-lasting stable radiating efficiency is maintained.

Further, the first heat exchange piece and the second heat exchange piece respectively comprise a heat radiation fin and a heat pipe, and the heat radiation fins are in heat conduction connection with the semiconductor refrigerator through the heat pipe. The heat exchange device has the advantages of simple structure, easiness in implementation and large surface area of the heat dissipation fins, and can effectively increase the heat exchange area and improve the heat exchange efficiency, thereby improving the heat dissipation efficiency of the optical component.

Further, the heat pipe of the first heat exchange piece is U-shaped, the bending section of the U-shaped heat pipe is connected with the cold end of the semiconductor refrigerator in a heat conduction mode, and the straight section of the U-shaped heat pipe is connected with the radiating fins. The structure is simplified, and the heat pipe with the U shape realizes the temperature equalizing effect of two traditional heat pipes.

Further, the cold end of the semiconductor refrigerator is connected with the first heat conduction piece in a bonding mode so as to be connected with the first heat exchange piece in a heat conduction mode, the hot end of the semiconductor refrigerator is connected with the second heat conduction piece in a bonding mode so as to be connected with the second heat exchange piece in a heat conduction mode, and the first heat conduction piece and the second heat conduction piece are connected to the optical machine shell in a limiting mode respectively. The heat conduction piece I and the heat conduction piece II can be effectively isolated, heat at the hot end of the semiconductor refrigerator is prevented from being conducted to the cold end through the heat conduction piece II and the heat conduction piece I, stable heat dissipation is guaranteed according to the setting, and the heat dissipation effect of the optical component is guaranteed.

Further, the periphery of the semiconductor refrigerator is wrapped with the heat insulating piece, so that the semiconductor refrigerator is prevented from directly exchanging heat with the outside, condensation and frosting on the semiconductor refrigerator are avoided, and stable and reliable operation of the semiconductor refrigerator is ensured.

Further, the semiconductor refrigerator further comprises a sensor for monitoring the temperature of the cold end or the hot end of the semiconductor refrigerator, the inner fan works according to monitoring information of the sensor, the sensor is easy to arrange and set, the power of the inner fan can be controlled more accurately and stably, and stable operation of the optical component is guaranteed under a proper temperature environment.

Further, the optical component comprises optical devices which are arranged at intervals, a heat dissipation air channel is formed between the optical devices, and an air outlet of the inner fan is opposite to an inlet of the heat dissipation air channel on the optical component;

Or a preset angle is arranged between the air outlet of the inner fan and the inlet of the heat dissipation air duct on the optical assembly, and the preset angle is within a range of plus or minus 10 degrees.

The heat dissipation air duct forms a part of the internal circulation air duct, and air flow can efficiently and smoothly pass through the heat dissipation air duct, so that heat of the optical component is efficiently taken away to ensure that the optical component is at a proper temperature, and the working stability and the service life of the optical component are ensured.

Further, a guide piece with a bending path is arranged at the outlet of the heat dissipation air duct, and the guide piece guides the air flow to the first heat exchange piece. The path length of the internal circulation air path is shortened, so that the air flow can more efficiently circulate, the heat dissipation efficiency and stability are improved, and the influence of heat of the optical component on other components in the optical engine shell due to the heat dissipation to other parts can be avoided.

Further, the optical device comprises an LCD panel, a collimating element and a focusing element, wherein the collimating element is arranged on the light incident side of the LCD panel at intervals, the focusing element is arranged on the light emergent side of the LCD panel at intervals, and a heat dissipation air duct is formed between the collimating element and the LCD panel and between the focusing element and the LCD panel. The collimation element is arranged on the light inlet side of the LCD panel to collimate the illumination light beam and then irradiate the illumination light beam on the LCD panel, so that the uniformity of the modulated image light beam is guaranteed, the focusing element arranged on the light outlet side of the LCD panel focuses the image light beam to the lens to project a projection picture through the lens, the air flow takes away the heat of the LCD panel from the heat dissipation air channels on the two sides of the LCD panel in an efficient manner, the LCD panel is effectively cooled, the long-acting stable operation of the LCD panel is guaranteed at a proper temperature, and the service life and the display effect of the LCD panel are guaranteed.

Further, the FPC end of LCD panel is towards the air outlet place side of interior fan for the IC device on the FPC end can be preferentially with the low temperature air current contact of follow interior fan air outlet output, promotes the heat dissipation cooling effect to the IC device, is favorable to increasing the holistic heat-resisting temperature of LCD panel.

Compared with the prior art, the utility model has the advantages that:

The projection device adopts a closed heat dissipation structure and adopts the semiconductor refrigerator to actively cool, so that enough cooling capacity can be obtained to cool and dissipate heat of the optical component, the optical component is ensured to work in a proper temperature range, the working stability and the service life of the optical component are ensured, and the projection device is favorable for improving the quality and the brightness of projection images.

Drawings

Fig. 1 is a schematic diagram of an internal structure of an optical engine housing of a projection apparatus according to the present utility model;

FIG. 2 is a schematic side view of a projection apparatus according to the present utility model;

FIG. 3 is a schematic view of a partial cross-sectional structure of a refrigeration assembly;

fig. 4 is a schematic partial cross-sectional view of a refrigeration assembly mounted to an optical engine housing.

In the figure:

The light engine comprises a light engine shell 1, a flow guide piece 11, an optical component 2, an LCD panel 21, a collimation element 22, a focusing element 23, heat insulation glass 24, air duct glass 25, a heat dissipation air duct 26, an inner fan 3, a semiconductor refrigerator 4, a first heat exchange piece 41, a second heat exchange piece 42, a first heat conduction piece 43, a second heat conduction piece 44, a heat insulation piece 45, an outer fan 5, a light source 6 and a light source heat dissipation component 7.

Detailed Description

The technical solutions of the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The projection device disclosed by the embodiment of the utility model integrally adopts the closed heat dissipation mechanism, so that a good dustproof effect is ensured, the LCD panel can be efficiently cooled, the LCD panel can be ensured to stably work at a proper temperature, the service life is prolonged, and the brightness of a projection picture is improved.

As shown in fig. 1 and fig. 2, a projection device mainly comprises a refrigeration component and a light machine shell 1 which is arranged in a closed manner, wherein an optical component 2 and an inner fan 3 are arranged in the light machine shell 1, an air outlet of the inner fan 3 is adjacent to the optical component 2, an inner circulation air path is formed in the light machine shell 1, air flow blown out by the inner fan 3 circularly flows along the inner circulation air path, and air flow blown out from the air outlet of the inner fan 3 directly blows the optical component 2, so that the fluidity of the air flow when passing through the optical component 2 is ensured, the air flow velocity loss caused by air flow steering is avoided, and the heat dissipation efficiency of the optical component 2 is improved;

The air flow absorbs the heat of the optical component 2 when passing through the optical component 2 to cool the optical component 2, the temperature of the air flow rises, the heat absorbed by the air flow is led out of the optical machine shell 1 by utilizing the refrigeration component to realize stable circulation heat dissipation of the optical component 2, the refrigeration component comprises a semiconductor refrigerator 4, a first heat exchange piece 41 which is connected with the cold end of the semiconductor refrigerator 4 in a heat conduction way and a second heat exchange piece 42 which is connected with the hot end of the semiconductor refrigerator in a heat conduction way, the first heat exchange piece 41 is arranged in the optical machine shell 1 and is positioned in an internal circulation air path, the second heat exchange piece 42 is arranged outside the optical machine shell 1, the cold end temperature of the semiconductor refrigerator 4 is reduced while the hot end temperature is raised when being electrified, namely the heat of the cold end is actively conducted onto the hot end, thereby obtaining the cold amount in the cold end, the first heat exchange element 41 is in heat conduction connection with the cold end of the semiconductor refrigerator 4, so that heat on the first heat exchange element 41 can be transferred from the cold end of the semiconductor refrigerator 4 to the hot end, namely, the first heat exchange element 41 is at a lower temperature, when the air flow absorbing the heat of the optical component 2 passes through the first heat exchange element 41 along the internal circulation air path, the air flow with high temperature exchanges heat with the first heat exchange element 41, the temperature of the air flow is reduced to become low-temperature air flow, the low-temperature air flow is blown to the optical component 2 under the pumping action of the internal fan 3, the circulating heat dissipation of the optical component 2 is realized, the heat in the air flow is transferred to the first heat exchange element 41, the cold end of the semiconductor refrigerator 4, the hot end of the semiconductor refrigerator 4 and the second heat exchange element 42 are transferred to the second heat exchange element 42 along the direction of the first heat exchange element 41, the second heat exchange element 42 is positioned outside the optical machine shell 1, the heat is continuously radiated outwards from the second heat exchange part 42, so that efficient radiation of the optical component 2 in the closed space is realized, the optical component 2 is ensured to be at a stable proper temperature and is not influenced by dust, the brightness of a projection picture is improved, and the projection picture quality is ensured not to be influenced by dust.

In this embodiment, the first heat exchange member 41 and the second heat exchange member 42 respectively include heat dissipation fins and heat pipes, the heat dissipation fins are connected with the semiconductor refrigerator 4 by heat conduction through the heat pipes, the heat dissipation fins have large surface areas, the heat exchange area can be effectively increased, the heat exchange efficiency is improved, the air flow flowing along the internal circulation air path can be efficiently cooled through the first heat exchange member 41, the cooling capacity produced by the semiconductor refrigerator 4 can be ensured to be efficiently acted on the optical component 2, and the heat is efficiently dissipated outwards through the second heat exchange member 42, so that the problem that the heat is difficult to be effectively discharged and the heat dissipation effect of the optical component 2 is limited is avoided. In order to ensure the sufficiency and the high efficiency of the heat conduction, the first heat conduction member 43 is connected with the first heat conduction member 43 in a fitting way, the first heat conduction member 43 is connected with the first heat exchange member 41 in a heat conduction way, the second heat conduction member 44 is connected with the second heat exchange member 42 in a heat conduction way, the first heat conduction member 43 and the second heat conduction member 44 are made of materials with high heat conductivity such as copper plates, the first heat conduction member 43 is in full fitting contact with the cold end of the first semiconductor refrigerator 4 and in full heat conduction contact with the heat pipe of the first heat exchange member 41, the heat absorbed by the first heat exchange member 41 can be effectively conducted to the cold end of the first semiconductor refrigerator 4, and the second heat conduction member 44 is in full fitting contact with the hot end of the first semiconductor refrigerator 4 and in full heat conduction contact with the heat pipe of the second heat exchange member 42, so that the heat on the hot end of the semiconductor refrigerator 4 can be fully and efficiently conducted to the second heat exchange member 42 to be emitted outwards. The semiconductor refrigerator 4 is a small-sized component, the distance between the first heat conduction piece 43 and the second heat conduction piece 44 is small, in order to enable heat at the hot end of the semiconductor refrigerator to be conducted to the cold end through the second heat conduction piece and the first heat conduction piece, the first heat conduction piece 43 and the second heat conduction piece 44 need to be effectively isolated to avoid heat conduction, specifically, the first heat conduction piece 43 and the second heat conduction piece 44 are respectively and limitedly connected to the optical machine shell 1, the first heat conduction piece 43 and the second heat conduction piece 44 are not in any contact, the optical machine shell 1 is usually a plastic piece with low heat conductivity coefficient, the situation of heat reverse conduction is avoided, and the stability of a heat dissipation effect is guaranteed.

Preferably, as shown in fig. 3, the heat pipe of the first heat exchange member 41 is U-shaped, the bent section of the U-shaped heat pipe is connected with the cold end of the semiconductor refrigerator 4 in a heat conduction manner, the straight section of the U-shaped heat pipe is connected with the heat dissipation fins, the heat pipe with a U-shape realizes the temperature equalizing effect of two traditional heat pipes, the structure is simple and compact, and in particular, the bent section of the U-shaped heat pipe is fully attached to the first heat exchange member 43 on the cold end of the semiconductor refrigerator 4, the sufficiency and the high efficiency of heat conduction are ensured, the straight section of the U-shaped heat pipe is connected with a plurality of heat dissipation fins arranged side by side, ventilation channels are formed between the heat dissipation fins, and air flows pass through the ventilation channels for heat exchange.

In order to make the heat on the second heat exchange member 42 efficiently and outwards emit, the refrigeration assembly further comprises an external fan 5 disposed outside the optical engine housing 1 and matched with the second heat exchange member 42, the air fluidity at the second heat exchange member 42 is enhanced by using the external fan 5, and the heat convection is enhanced to make the heat on the second heat exchange member 42 continuously and stably emit outwards, that is, the heat of the optical assembly 2 is stably and efficiently led out, so that the heat dissipation efficiency of the optical assembly 2 is ensured. The projection device further comprises a light source 6, the heat productivity of the light source 6 is also large when working, therefore, the light source 6 is provided with a light source heat radiation component 7, the light source 6 is embedded on the wall surface of the light machine shell 1, the light source heat radiation component 7 is positioned outside the light machine shell 1, in order to improve the compactness of the structure, the light source heat radiation component 7, the outer fan 5 and the heat exchange piece II 42 are in linear arrangement, namely, the light source heat radiation component 7 is arranged at the air inlet of the outer fan 5, the heat exchange piece II 42 is arranged at the air outlet of the outer fan 5, the outer fan 5 is used for enhancing the air fluidity of the heat exchange piece II 42, and is also used for enhancing the air fluidity of the light source heat radiation component 7, so that the heat radiation effect is effectively improved, the light source heat radiation component 7 also adopts a combined structure of heat radiation fins and heat pipes, and the heat pipes can be conveniently bent and laid by the heat pipes, so that the heat radiation fins with larger volume are compactly laid at proper positions, and the heat radiation fins of the light source heat radiation component 7, the outer fan 5 and the heat radiation fins of the heat exchange piece II 42 are sequentially arranged in a straight line, so that the structure is compact, and the structure is good.

The semiconductor refrigerator 4 is lower in temperature when being electrified and operated, when the environmental humidity is high, the conditions of condensation and frosting are easy to occur on the semiconductor refrigerator 4, and the working stability of the semiconductor refrigerator 4 is affected, therefore, as shown in fig. 4, the periphery of the semiconductor refrigerator 4 is wrapped with a heat insulation piece 45, the semiconductor refrigerator 4 is prevented from being directly contacted with external air, the conditions of condensation and frosting are effectively avoided, the heat insulation piece 45 can be made of foam and other materials, the heat insulation can prevent the condensation and frosting, and the semiconductor refrigerator 4 can also have an anti-collision protection effect, and the semiconductor refrigerator 4 is simple in structure, easy to implement and low in cost. Further, the temperature sensor (not specifically shown in the figure) for monitoring the temperature of the cold end or the hot end of the semiconductor refrigerator 4 is further included, the inner fan 3 works according to the monitoring information of the sensor, and the temperature of the optical component 2 is indirectly monitored by monitoring the temperature of the cold end or the hot end of the semiconductor refrigerator 4, so that the position of the sensor is more convenient to set, and the maintenance is easy. When the temperature of the optical component 2 is stable, the temperatures of the cold end and the hot end of the semiconductor refrigerator 4 are relatively stable, the working power of the inner fan 3 is flexibly and accurately controlled by monitoring the temperature change of the cold end or the hot end of the semiconductor refrigerator 4, the optical component 2 is ensured to stably work in a proper temperature environment, and the rotating speed of the inner fan 3 is favorably controlled.

The optical component 2 comprises optical devices which are arranged at intervals, a heat dissipation air duct 26 is formed between the optical devices, and an air outlet of the inner fan 3 is opposite to an inlet of the heat dissipation air duct 26 on the optical component 2; or a preset angle is formed between the air outlet of the inner fan 3 and the inlet of the heat dissipation air duct 26 on the optical assembly 2, and the preset angle is within the range of plus or minus 10 degrees. The heat dissipation air duct 26 forms a part of an internal circulation air path, and air flow can efficiently and smoothly pass through the heat dissipation air duct 26, so that heat of the optical assembly is efficiently taken away, and the optical assembly is at a proper temperature. The air outlet of the inner fan 3 is adjacent to the heat dissipation air duct 26, and the air outlet of the inner fan 3 is opposite to the inlet of the heat dissipation air duct 26 or has a smaller inclination angle, so that the air flow generated by the inner fan 3 can be led into the heat dissipation air duct 26 and pass through the heat dissipation air duct 26 under the condition of no flow velocity loss, the fluidity of the air flow passing through the optical assembly 2 is enhanced, and the heat dissipation efficiency is further improved.

In this embodiment, the optical device mainly includes an LCD panel 21, a collimating element 22 and a focusing element 23, where the collimating element 22 is disposed at an incident side of the LCD panel 21 at intervals, the focusing element is disposed at an emergent side of the LCD panel 21 at intervals, a heat dissipation air duct 26 is formed between the collimating element 22 and the LCD panel 21 and between the focusing element 23 and the LCD panel 21, and the collimating element 22 and the focusing element 23 specifically adopt fresnel lenses, which are light in structure and small in occupied volume, are parallel to the LCD panel 21 and are distributed at two sides of the LCD panel 21 at intervals, further, a heat insulation glass 24 is disposed between the LCD panel 21 and the collimating element 22, the heat insulation glass 24 is spaced apart from the LCD panel 21 and is spaced apart from the collimating element 22, so that the heat dissipation air duct 26 between the collimating element 22 and the LCD panel 21 is further separated into two paths of heat dissipation air ducts 26, an air duct glass 25 is disposed between the LCD panel 21 and the focusing element 23, and the air duct glass 25 is spaced apart from the LCD panel 21, so that the air duct 26 between the focusing element 23 and the LCD panel 21 is further separated into two paths of heat dissipation air ducts 26 (the optical components for carrying the LCD panel 21 are not shown in fig. and the specific heat dissipation components for carrying the optical device are further improved). Preferably, the inlet of the heat dissipation air duct 26 is disposed on one side of the long side of the LCD panel 21, and the FPC end on the LCD panel 21 is disposed on the long side, so that further, the FPC end of the LCD panel 21 faces one side of the air outlet of the inner fan 3, so that the IC device (integrated circuit) on the FPC end can be preferentially contacted with the low-temperature air flow output from the air outlet of the inner fan, thereby improving the heat dissipation and temperature reduction effects on the IC device and being beneficial to increasing the overall heat-resistant temperature of the LCD panel 21.

Further, the outlet of the heat dissipation air duct 26 is provided with a guiding member 11 with a bent path, the guiding member 11 guides the air flow to the first heat exchange member 41, and the guiding member 11 changes the direction of the air flow to shorten the path length of the internal circulation air path, so that the air flow absorbing the heat of the optical assembly 2 flows to the first heat exchange member 41 more rapidly, and the heat is conducted outwards through the first heat exchange member 41, thereby improving the heat dissipation efficiency. Specifically, the flow guiding member 11 may be an arc wall surface disposed on the optical engine housing 1, and directs the airflow changing flow flowing out from the outlet of the cooling air duct 26 to the first heat exchanging member 41. In this embodiment, the air flow flowing out from the outlet of the heat dissipation air duct 26 is turned 180 ° and then flows through the outside of the focusing element 23, the turned air flow direction is approximately parallel to the heat dissipation air duct 26, the first heat exchange element 41 is disposed at the air inlet of the inner fan 3, the air flow flowing along the inner circulation air path absorbs cold energy at the first heat exchange element 41 to be in a low temperature state, the first heat exchange element 41 is disposed at the air inlet of the inner fan 3 and the optical component 2 is disposed at the air outlet of the inner fan 3, so that the traveling path of the low temperature air flow to the optical component 2 is effectively shortened, the utilization efficiency of the cold energy produced by the semiconductor refrigerator 4 can be improved, the optical component 2 dissipates heat more efficiently, and the first heat exchange element 41 is disposed in the traveling direction of the air flow turned by the guide element 11, so that the whole inner circulation air path is sufficiently short, the traveling path of the air flow is short (the dotted line in fig. 2 indicates the inner circulation air path), the heat of the optical component 2 is prevented from being dissipated to other parts in the optical machine housing 1, and other components are affected, and the heat dissipation effect is better.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that the above-mentioned preferred embodiment should not be construed as limiting the utility model, and the scope of the utility model should be defined by the appended claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the utility model, and such modifications and adaptations are intended to be comprehended within the scope of the utility model.

Claims (10)

1. A projection apparatus, comprising:

The optical engine comprises an optical engine shell (1) which is arranged in a closed manner, wherein an optical assembly (2) and an inner fan (3) are arranged in the optical engine shell (1), an air outlet of the inner fan (3) is adjacent to the optical assembly (2), and an inner circulation air path is formed in the optical engine shell (1);

The refrigeration assembly comprises a semiconductor refrigerator (4), a first heat exchange piece (41) in heat conduction connection with the cold end of the semiconductor refrigerator (4) and a second heat exchange piece (42) in heat conduction connection with the hot end of the semiconductor refrigerator, wherein the first heat exchange piece (41) is arranged in the optical machine shell (1) and is positioned in an internal circulation air path, and the second heat exchange piece (42) is arranged outside the optical machine shell (1).

2. Projection apparatus according to claim 1, characterized in that the first heat exchanger (41) and the second heat exchanger (42) comprise heat radiation fins and heat pipes, respectively, which heat radiation fins are in heat-conducting connection with the semiconductor cooler (4) via the heat pipes.

3. Projection apparatus according to claim 2, characterized in that the heat pipe of the first heat exchanger (41) is U-shaped, the bent section of the U-shaped heat pipe being connected thermally conductively to the cold end of the semiconductor refrigerator (4), the straight section of the U-shaped heat pipe being connected to the heat sink fins.

4. The projection device according to claim 1, wherein the cold end of the semiconductor refrigerator (4) is connected with the first heat conducting element (43) in a fitting manner so as to be connected with the first heat exchanging element (41) in a heat conducting manner, the hot end of the semiconductor refrigerator (4) is connected with the second heat conducting element (44) in a fitting manner so as to be connected with the second heat exchanging element (42) in a heat conducting manner, and the first heat conducting element (43) and the second heat conducting element (44) are respectively connected to the optical machine shell (1) in a limiting manner.

5. Projection apparatus according to claim 1, characterized in that the semiconductor refrigerator (4) is peripherally surrounded by a heat shield (45).

6. Projection apparatus according to claim 1, characterized in that it further comprises a sensor for temperature monitoring of the cold or hot end of the semiconductor refrigerator (4), said inner fan (3) being operated according to the monitoring information of the sensor.

7. The projection device according to claim 1, wherein the optical assembly (2) comprises optical devices arranged at intervals, a heat dissipation air duct (26) is formed between the optical devices, and an air outlet of the inner fan (3) is opposite to an inlet of the heat dissipation air duct (26) on the optical assembly (2);

Or a preset angle is arranged between the air outlet of the inner fan (3) and the inlet of the radiating air duct (26) on the optical assembly (2), and the preset angle is within the range of plus or minus 10 degrees.

8. Projection apparatus according to claim 7, characterized in that a deflector (11) of a curved path is provided at the outlet of the heat dissipation duct (26), said deflector (11) guiding the air flow to the first heat exchange element (41).

9. The projection device of claim 7, wherein the optical device comprises an LCD panel (21), a collimating element (22) and a focusing element (23), the collimating element (22) is disposed at intervals on the light incident side of the LCD panel (21), the focusing element is disposed at intervals on the light emergent side of the LCD panel (21), and a heat dissipation air duct (26) is formed between the collimating element (22) and the LCD panel (21) and between the focusing element (23) and the LCD panel (21).

10. Projection device according to claim 9, characterized in that the FPC end of the LCD panel (21) faces the side of the air outlet of the inner fan (3).