Projection apparatus

A projection apparatus includes a casing, a projection lens, a first and a second light source modules, a first and a second thermal modules respectively thermally coupled to the first and the second light source modules, and a first and a second fans. The casing includes a bottom cover having a first air inlet corresponding to the projection lens, a front cover, a rear cover having a second air inlet, a first and a second side covers, which define an internal space divided into a first and a second areas. The first air inlet is connected to the internal space. A first air outlet of the first side cover and the second air inlet are connected to the first area. The first and the second light source modules, the first and the second thermal modules, and the first and the second fans are disposed in the first area.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Chinese application serial no. 202121491359.5, filed on Jul. 2, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

This disclosure relates to an optical apparatus, and particularly relates to a projection apparatus.

Description of Related Art

With the development of projection technology, users' requirements for the quality of the projected image (e.g., resolution, brightness, and color purity) are increasing, and accordingly, the heat generated by the operation of the light source and light valve is also increasing. In general, in order to improve the brightness or color purity, a common practice is to add other colors of laser diode (LD) light source, such as red laser diode, or other colors of light emitting diode (LED), such as red light emitting diode, resulting in a significant increase in the overall heat generated by the operation of the light source. In detail, the interior of the projection apparatus is equipped with thermal fin and fan, in which the thermal fins are thermally coupled to a heat source (e.g., a light source and a light valve) and the fan is configured to generate forced convection to bring outside cold air into the interior of the projection apparatus. Then, the cold air exchanges heat inside the projection apparatus to form hot air, and the hot air is forcibly exhausted by the fan.

In existing projection devices, the air inlet is located on the rear cover of the casing, while the air outlet is located on the side cover of the casing. To improve the heat dissipation efficiency and light output efficiency, the light source is located in the upstream of the flow field, and the projection lens is located roughly in the middle and downstream of the flow field in contrast. In other words, after the cold air enters from the air inlet to the interior of the casing, the cold air first exchanges heat with the light source to form hot air, and then flows to the air outlet. During the flow of hot air to the air outlet, the hot air flows through the projection lens, resulting in poor heat dissipation and thermal expansion of the projection lens, causing the focal length to drift, thus affecting the image quality. To solve the problem of heat expansion of the projection lens, the design of air inlet in the bottom cover of the casing has been proposed. However, because the bottom cover of the casing is close to the desktop and has a high flow resistance, it is not easy for cold air to enter the interior of the casing from the air inlet of the bottom cover, which has a limited effect on the heat dissipation of the projection lens.

SUMMARY

The disclosure provides a projection apparatus having favorable heat dissipation efficiency and capable of providing favorable image quality.

Other purposes and advantages of the disclosure may be further understood from the technical features disclosed in the disclosure.

In order to achieve one or part or all of the above objectives or other objectives, an embodiment of the disclosure provides a projection apparatus including a casing, a projection lens, a first light source module, a second light source module, a first thermal module, a second thermal module, a first fan, and a second fan. The casing includes a bottom cover, a front cover, a rear cover opposite to the front cover, a first side cover, and a second side cover opposite to the first side cover. The front cover, the rear cover, the first side cover, and the second side cover are disposed around the bottom cover and define an internal space. The projection lens is disposed in the casing. The bottom cover has a first air inlet connected to the internal space and corresponding to the projection lens, and the first air inlet is located between the front cover and the rear cover. An extension line of an optical axis of the projection lens divides the internal space into a first area and a second area. The rear cover has a second air inlet connected to the first area, and the first side cover has a first air outlet connected to the first area. The first light source module, the second light source module, the first thermal module, the second thermal module, the first fan, and the second fan are disposed in the first area. The first light source module is thermally coupled to the first thermal module. The first thermal module is located between the first air inlet and the first fan, and the first fan is located between the first thermal module and the first air outlet. The second light source module is thermally coupled to the second thermal module. The second thermal module is located between the second air inlet and the second fan, and the second fan is located between the second thermal module and the first air outlet.

Based on the above, the embodiments of the disclosure have at least one of the following advantages or effects. According to the embodiments of the disclosure, heat generated during operation of the first light source module and the second light source module is exhausted to outside of the casing through two different heat dissipation ways, thus helping to improve heat dissipation efficiency of the projection apparatus. Furthermore, the heat generated during the operation of the first light source module is transferred to the first thermal module, and then cold air flowing into the first area from the first air inlet of the bottom cover exchanges heat with the first thermal module to form hot air. On the other hand, the heat generated during the operation of the second light source module is conducted to the second thermal module, and then cold air flowing into the first area from the second air inlet of the rear cover exchanges heat with the second thermal module to form hot air. Finally, the hot air is exhausted from the internal space of the casing through the first air outlet of the first side cover. In addition, the cold air flowing into the first area from the first air inlet of the bottom cover cools the projection lens before flowing to the first thermal module. In other words, the projection lens is located upstream of flow field, so the projection lens may be cooled by cold air to avoid thermal expansion, thus improving the quality of the image projected by the projection apparatus.

DESCRIPTION OF THE EMBODIMENTS

FIG.1andFIG.2are schematic views of a projection apparatus according to a first embodiment of the disclosure in two different viewing angles.FIG.3is a schematic top view of the projection apparatus according to the first embodiment of the disclosure. In particular, in order to clearly show internal configuration of a projection apparatus10, a top cover of a casing11is omitted fromFIG.3. Referring toFIG.1toFIG.3, according to this embodiment, the projection apparatus10includes the casing11, a projection lens12, a first light source module13, a second light source module14, a first thermal module15, a second thermal module16, a first fan17, and a second fan18. The projection lens12, the first light source module13, the second light source module14, the first thermal module15, the second thermal module16, the first fan17, and the second fan18are disposed in the casing11.

Specifically, the casing11includes a bottom cover110, a front cover111, a rear cover112opposite to the front cover111, a first side cover113, and a second side cover114opposite to the first side cover113. The front cover111, the rear cover112, the first side cover113, and the second side cover114are disposed around the bottom cover110, and define an internal space115for accommodating the projection lens12, the first light source module13, the second light source module14, the first thermal module15, the second thermal module16, the first fan17, and the second fan18. In more detail, according to this embodiment, the casing11also includes a top cover (not shown), which is disposed opposite to the bottom cover110. The internal space115is defined by the top cover, the bottom cover110, and the first side cover113, the second side cover114, the front cover111, and the rear cover112disposed around the top cover and the bottom cover110. The bottom cover110has a first air inlet110aconnected to the internal space115. The rear cover112has a second air inlet112aconnected to the internal space115, and the first side cover113has a first air outlet113aconnected to the internal space115. In addition, the first air inlet110ais located between the front cover111and the rear cover112, and is also located between the first side cover113and the second side cover114.

The projection lens12is disposed corresponding to the first air inlet110aof the bottom cover110. The projection lens12is approximately located in a middle of the internal space115, and may be a reflective ultra short throw projection lens or other types of projection lenses. Furthermore, an extension line of an optical axis OA of the projection lens12divides the internal space115into a first area115aand a second area115b. A part of the first air inlet110ais connected to the first area115a, and an other part of the first air inlet110ais connected to the second area115b. In addition, the second air inlet112aof the rear cover112and the first air outlet113aof the first side cover113are both connected to the first area115a.

Referring toFIG.1andFIG.3, according to this embodiment, the first light source module13, the second light source module14, the first thermal module15, the second thermal module16, the first fan17, and the second fan18are disposed in the first area115a. The first light source module13and the second light source module14each includes at least one red light emitting element, at least one blue light emitting element, and at least one green light emitting element. To further illustrate, the first light source module13and the second light source module14may each include, for example, at least one red laser diode, at least one blue laser diode, and at least one green laser diode. According to other embodiments, the first light source module13and the second light source module14each includes at least one Red LED, at least one Blue LED, and at least one Green LED. In addition, the at least one red light emitting element, the at least one blue light emitting element, and the at least one green light emitting element included by the first light source module13and the second light source module14may be, for example, a combination of a laser diode and a light emitting diode. The first light source module13is thermally coupled to the first thermal module15, and the second light source module14is thermally coupled to the second thermal module16. Therefore, heat generated during operation of the first light source module13and the second light source module14may be quickly exhausted from the first thermal module15and the second thermal module16, respectively, to avoid overheating that affects light output efficiency and brightness.

The first fan17and the second fan18are configured corresponding to the first air outlet113a. The first thermal module15is located between the first air inlet110aand the first fan17, and the first fan17is located between the first thermal module15and the first air outlet113a. In other words, the first air inlet110a, the first thermal module15, the first fan17, and the first air outlet113aare disposed in sequence. On the other hand, the second thermal module16is located between the second air inlet112aand the second fan18, and the second fan18is located between the second thermal module16and the first air outlet113a. In other words, the second air inlet112a, the second thermal module16, the second fan18, and the first air outlet113aare disposed in sequence.

Referring toFIG.3, the first fan17and the second fan18may be axial fans, and are arranged on one side of the first air outlet113aalong a direction parallel to the optical axis OA of the projection lens12. In addition, a rotation axis RA1of the first fan17is parallel to a rotation axis RA2of the second fan18and perpendicular to the extension line of the optical axis OA of the projection lens12. When the first fan17is running, cold air may enter the internal space115from the first air inlet110a, and flow from below the projection lens12to the first area115a. Then, the cold air exchanges heat with the first thermal module15coupled to the first light source module13to form hot air. After that, the first fan17forces the hot air out of the first area115a, and the hot air is exhausted from the first air outlet113a.

Furthermore, since the projection lens12is configured corresponding to the first air inlet110a, the cold air entering the internal space115from the first air inlet110amay first cool the projection lens12before flowing to the first area115afor heat exchange with the first thermal module15. In other words, the projection lens12is located upstream of flow field, so the projection lens12may be cooled by the cold air to avoid thermal expansion, thus improving quality of an image projected by the projection apparatus10.

On the other hand, when the second fan18is running, the cold air may enter the first area115afrom the second air inlet112aand flow to the second thermal module16. Then, the cold air exchanges heat with the second thermal module16coupled to the second light source module14to form hot air. After that, the second fan18forces the hot air out of the first area115a, and the hot air is exhausted from the first air outlet113a. In other words, the hot air formed after the heat exchange with the second thermal module16does not flow through the projection lens12, but is exhausted directly from the first air outlet113a, thus preventing the projection lens12from being unable to focus due to heat expansion.

Referring toFIG.1andFIG.3, according to this embodiment, the projection apparatus10further includes a first air guider19. The first air guider19is disposed in the first area115aand is located between the first air inlet110aand the first fan17. Furthermore, the first air guider19covers the first thermal module15. When the cold air flows into the first area115afrom the first air inlet110a, the first air guider19may guide the cold air to completely flow through the first thermal module15to improve heat exchange efficiency.

On the other hand, the projection apparatus10further includes a third fan20. The third fan20is disposed in the first area115aand located between the first air inlet110aand the first fan17. Furthermore, the first air guider19covers the third fan20. The third fan20may be an axial fan, and a rotation axis RA3of the third fan20is parallel to the rotation axis RA1of the first fan17. When the third fan20is running, the cold air may enter the internal space115from the first air inlet110a, and is forcedly driven by the third fan20to flow to the first thermal module15.

Driven by the third fan20and guided by the first air guider19, most of the cold air entering the internal space115from the first air inlet110amay flow through the first thermal module15to improve heat exchange efficiency. In addition, after the cold air exchanges heat with the first thermal module15to form hot air, the third fan20drives the hot air to flow to the first fan17. Finally, the first fan17forces the hot air out of the first area115a, and the hot air is exhausted from the first air outlet113a.

Referring toFIG.3, according to this embodiment, the first thermal module15includes a thermal fin set15aand a thermal fin set15bin parallel, and the third fan20is disposed between the thermal fin set15aand the thermal fin set15b. Furthermore, the thermal fin set15ais located between the first air inlet110aand the third fan20, and the thermal fin set15bis located between the third fan20and the first fan17. On the other hand, the thermal fin set15aand the thermal fin set15beach includes multiple thermal fins15c, and the thermal fins15care arranged at intervals along the direction parallel to the optical axis OA of the projection lens12and each of the thermal fins15cis parallel to the rotation axis RA3of the third fan20to reduce flow resistance and improve heat exchange efficiency. The two thermal fin sets15aand15bof the first thermal module15are, for example, connected to the first light source module13through a heat pipe (not shown), and the heat pipe and the two thermal fin sets15aand15b, for example, form a U-shaped structure, and the first thermal module15is, for example, located between the first light source module13and the front cover111.

For example, the first air guider19includes two side walls19a, and the two side walls19aare respectively disposed at two opposite sides of the first thermal module15along a direction perpendicular to the optical axis OA of the projection lens12, and are disposed at two opposite sides of the third fan20. In other words, the two side walls19aare parallel to the rotation axis RA3of the third fan20and parallel to the thermal fins15c, so as to reduce flow resistance and improve heat exchange efficiency. According to another embodiment, the first air guider19is, for example, an inverse-U shaped cover and includes a top surface (not shown) connecting to two side walls19a, so as to have a better air guiding effect.

Referring toFIG.1andFIG.3, according to this embodiment, the projection apparatus10further includes a second air guider21. The second air guider21is disposed in the first area115a, and the second air guider21is connected to the rear cover112corresponding to the second air inlet112a. On the other hand, the second thermal module16includes multiple thermal fins16a, and the thermal fins16aare arranged at intervals along the direction perpendicular to the optical axis OA of the projection lens12, and each of the thermal fins16ais parallel to a direction of an optical axis of the projection lens12. The second air guider21covers the thermal fins16a. When the cold air enters the first area115afrom the second air inlet112a, the second air guider21may guide the cold air to flow through the second thermal module16to improve heat exchange efficiency. In detail, the second air guider21includes two side walls21a. The two side walls21aare respectively disposed at two opposite sides of the second thermal module16along the direction parallel to the optical axis OA of the projection lens12, and are parallel to the thermal fins16a, so as to reduce flow resistance and improve heat exchange efficiency. According to another embodiment, the second air guider21is, for example, an inverse-U shaped cover and includes a top surface (not shown) connecting to the two side walls21a, so as to have a better air guiding effect.

According to this embodiment, the second light source module14is located between the first light source module13and the second air inlet112a, and the second light source module14is closer to the second air inlet112athan the first light source module13is. Furthermore, the heat generated during the operation of the first light source module13is transferred to the first thermal module15, and then, the cold air flowing into the first area115afrom the first air inlet110aexchanges heat with the first thermal module15. In addition, the heat generated during the operation of the second light source module14is conducted to the second thermal module16, and then, the cold air flowing into the first area115afrom the second air inlet112aexchanges heat with the second thermal module16. That is to say, the heat generated during the operation of the first light source module13and the second light source module14is exhausted to outside of the casing11through two different heat dissipation ways, so that both light source modules may achieve a good heat dissipation effect.

Referring toFIG.2andFIG.3, according to this embodiment, the projection apparatus10further includes a digital micromirror device22and a third thermal module23. The digital micromirror device22is disposed in the casing11and is approximately located in the middle of the internal space115. The digital micromirror device22is thermally coupled to the third thermal module23, and the third thermal module23is disposed in the second area115b. Furthermore, the rear cover112further has a third air inlet112bconnected to the internal space115, and the second side cover114has a second air outlet114aconnected to the internal space115. Furthermore, the third air inlet112bof the rear cover112and the second air outlet114aof the second side cover114are both connected to the second area115b, and the third thermal module23is located between the third air inlet112band the second air outlet114a.

According to this embodiment, heat generated by the digital micromirror device22may be quickly exhausted by the third thermal module23. Then, cold air entering the second area115bfrom the third air inlet112bexchanges heat with the third thermal module23to form hot air. After that, the hot air is exhausted from the second area115bthrough the second air outlet114a. Furthermore, the projection apparatus10further includes a fourth fan24and a fifth fan25. The fourth fan24and the fifth fan25are disposed in the second area115b, and are arranged on one side of the second air outlet114a. The fourth fan24and the fifth fan25are located between the third thermal module23and the second air outlet114a, and are configured to force hot air out of the second area115b, and the hot air is exhausted from the internal space115through the second air outlet114a. In addition, the fourth fan24and the fifth fan25may be axial fans and are arranged along the direction parallel to the optical axis OA of the projection lens12. A rotation axis RA4of the fourth fan24and a rotation axis RA5of the fifth fan25are perpendicular to the extension line of the optical axis OA of the projection lens.

When at least one of the fourth fan24and the fifth fan25is running, the cold air may enter the second area115bof the internal space115from the third air inlet112bof the rear cover112and flow to the third thermal module23. Then, the cold air exchanges heat with the third thermal module23to form hot air. After that, the at least one of the fourth fan24and the fifth fan25forces the hot air out of the second area115bthrough the second air outlet114a.

Referring toFIG.2andFIG.3, according to this embodiment, the projection apparatus10further includes a driving circuit26and a power supply27. The driving circuit26and the power supply27are disposed in the second area115bof the internal space115, and are located between the projection lens12and the second air outlet114a. On the other hand, the fourth fan24and the fifth fan25are located between the driving circuit26and the second air outlet114a, or between the power supply27and the second air outlet114a. When the at least one of the fourth fan24and the fifth fan25is running, the cold air may enter the second area115bfrom the third air inlet112b, and flow to the driving circuit26and the power supply27. Then, the cold air exchanges heat with the driving circuit26and the power supply27to form hot air. After that, the at least one of the fourth fan24and the fifth fan25forces the hot air out of the second area115b, and the hot air is exhausted from the internal space115through the second air outlet114a.

FIG.4is a schematic top view of a projection apparatus according to a second embodiment of the disclosure. Referring toFIG.4, a projection apparatus10A according to this embodiment has substantially the same design principles as the projection apparatus10according to the first embodiment, and the main difference are: structural configuration of a second thermal module160and that the projection apparatus10A also includes an auxiliary fan28disposed corresponding to the second thermal module160. Furthermore, the second thermal module160includes a thermal fin set161and a thermal fin set162. The thermal fin set161and the thermal fin set162are both thermally coupled to the second light source module14through a heat pipe (not shown). The thermal fin set161is disposed corresponding to the second air inlet112aand is covered by the second air guider21. In addition, the thermal fin set162is disposed between the second light source module14and the second fan18. In addition, the thermal fin sets161and162are connected to the second light source module14through a heat pipe (not shown), for example.

According to this embodiment, the auxiliary fan28is disposed in the first area115a, and the second air inlet112aand the auxiliary fan28are respectively located at two opposite sides of the thermal fin set161(including multiple thermal fins). The auxiliary fan28may be an axial fan, and a rotation axis RA6of the auxiliary fan28is perpendicular to the rotation axis RA1of the first fan17and the rotation axis RA2of the second fan18. In addition, the second air guider21covers the auxiliary fan28, and the rotation axis RA6of the auxiliary fan28is parallel to the two side walls21aof the second air guider21and the thermal fins of the thermal fin set161to reduce flow resistance and improve heat exchange efficiency. When the auxiliary fan28is running, the auxiliary fan28drives the cold air from the second air inlet112ato flow into the first area115a, and the cold air exchanges heat with the thermal fin set161and the thermal fin set162in sequence. After that, the second fan18forces the hot air out of the first area115athrough the first air outlet113a.

FIG.5is a schematic top view of a projection apparatus according to a third embodiment of the disclosure. Referring toFIG.5, a projection apparatus10B according to this embodiment is a structure of the projection apparatus10disposed in the internal space115, in which the first area115aand the second area115bare left-right reversed relative to what shown inFIG.3.

In summary, the embodiments of the disclosure have at least one of the following advantages or effects. According to the embodiments of the disclosure, heat generated during operation of the first light source module and the second light source module is exhausted to outside of the casing through two different heat dissipation ways, thus helping to improve heat dissipation efficiency of the projection apparatus. Furthermore, the heat generated during the operation of the first light source module is transferred to the first thermal module, and then cold air flowing into the first area from the first air inlet of the bottom cover exchanges heat with the first thermal module to form hot air. On the other hand, the heat generated during the operation of the second light source module is conducted to the second thermal module, and then cold air flowing into the first area from the second air inlet of the rear cover exchanges heat with the second thermal module to form hot air. Finally, the hot air is exhausted from the internal space of the casing through the first air outlet of the first side cover. In addition, the cold air flowing into the first area from the first air inlet of the bottom cover cools the projection lens before flowing to the first thermal module. In other words, the projection lens is located upstream of flow field, so the projection lens may be cooled by cold air to avoid thermal expansion, thus improving the quality of the image projected by the projection apparatus.