Light source module with light combining system, fans and ducts

A light source module adapted to a projector includes a light source, a light combining system, a first cooling fan, a second cooling fan, a first guide duct and a second guide duct. The light source includes a first light emitting device and a second light emitting device. The light combining system is disposed between the first light emitting device and the second light emitting device. The first cooling fan is disposed on the first light emitting device. The second cooling fan is disposed on the second light emitting device. The first guide duct is connected to the first cooling fan and guides a cooling airflow provided by the first cooling fan to the second light emitting device. The second guide duct is connected to the second cooling fan and guides a cooling airflow provided by the second cooling fan to the first light emitting device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Chinese application serial no. 201410334724.X, filed on Jul. 15, 2014. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The invention relates to a light source module, and particularly relates to a light source module adapted to a projector.

Related Art

A projector is a display device capable of producing images at anytime anywhere. An imaging principle of the projector is to convert an illumination beam produced by a light source into an image beam via a light valve, and the image beam is projected onto a screen or a wall through a lens to form an image. With progressing of projection technique and reduction of manufacturing cost, use of the projector has gradually expanded from commercial use to domestic use.

Generally, the projector has a light source module for providing light beams required for image projection. In order to satisfy a demand on high brightness of the projector, some projectors are installed with a plurality of light emitting devices in order to improve a light intensity of the light source module, and when number of the light emitting devices of the projector is increased, the number of cooling fans is also increased in order to respectively cool down the light emitting devices. Under restriction of a limited configuration space of the light source module in the projector, a guide duct of each cooling fan is required to be over bended in order to guide a cooling airflow to each of the light emitting devices. However, a flow rate of the cooling airflow has a loss due to the over bending, and a heat dissipation rate is accordingly decreased due to such design. On the other hand, if the air output of the cooling fan is increased in order to solve the above problem, the cooling fans may produce excessive noise to bother the user during the operation.

China Patent Publication No. CN102540674 discloses a projection apparatus, in which two fans are used to dissipate heat of a single lamp. The heat inside the lamp is concentrated at a top side of the lamp, and airflow intensities of the two fans can be adjusted, such that the intensity of the airflow at the top side of the lamp is higher than that of the airflow at a bottom side of the lamp, by which a temperature difference between the top side and the bottom side of the lamp is decreased. China Utility Model Patent No. CN202522834 discloses a cooling device of a projector, in which two fans are used to dissipate heat of a single bulb. The heat is concentrated at a high temperature section above a lighting tube of the bulb, and a flow rate of the fan corresponding to the high temperature section can be adjusted to a larger value. U.S. Patent Publication No. US20080231812 discloses an image projecting section having two light source devices, where heat of each light source is dissipated by two fans.

SUMMARY

The invention is directed to a light source module, which is provided with dual light sources and has good cooling efficiency.

Other objects and advantages of the invention can be further illustrated by the technical features broadly embodied and described as follows.

In order to achieve one or a part of or all of the objects or other objects, an embodiment of the invention provides a light source module, which is adapted to a projector. The light source module includes a light source, a light combining system, a first cooling fan, a second cooling fan, a first guide duct and a second guide duct. The light source includes a first light emitting device and a second light emitting device. The light combining system is disposed between the first light emitting device and the second light emitting device. The first cooling fan is disposed on the first light emitting device. The second cooling fan is disposed on the second light emitting device. The first guide duct is connected to the first cooling fan and guides a cooling airflow provided by the first cooling fan to the second light emitting device. The second guide duct is connected to the second cooling fan and guides a cooling airflow provided by the second cooling fan to the first light emitting device.

According to the above descriptions, the embodiment of the invention has at least one of the following advantages. In the embodiment of the invention, the first cooling fan is disposed on the first light emitting device and the first cooling fan is used to dissipate heat of the second light emitting device. The second cooling fan is disposed on the second light emitting device and the second cooling fan is used to dissipate heat of the first light emitting device. In this way, in case that the first light emitting device and the second light emitting device are disposed opposite to each other, the first guide duct connected to the first cooling fan is capable of guiding the cooling airflow provided by the first cooling fan to the second light emitting device via a relatively small bending degree, and the second guide duct connected to the second cooling fan is capable of guiding the cooling airflow provided by the second cooling fan to the first light emitting device via a relatively small bending degree. Thus, loss of a flow rate of the cooling airflow due to over bending is decreased, so as to improve heat dissipation capability of the light source module.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1is a side view of a light source module according to an embodiment of the invention.FIG. 2is a top view of the light source module ofFIG. 1. Referring toFIG. 1andFIG. 2, the light source module100of the embodiment is adapted to a projector, and is used for providing light beams required by images projected by the projector. The light source module100includes a light source110and a light combining system120, the light source110includes a first light emitting device110aand a second light emitting device110b. The light combining system120is disposed between the first light emitting device110aand the second light emitting device110b, and combines the light emitted by the first light emitting device110aand the light emitted by the second light emitting device110b. The light combining system120includes at least one light combining prism. In other embodiments, the light combining system120may include other suitable light combining elements, for example, a beam splitter, relay lenses, a light condensing lens, etc., however, the invention is not limited thereto.

The light source module100further includes a first cooling fan130a, a second cooling fan130b, a first guide duct140aand a second guide duct140b. The first cooling fan130ais disposed on the first light emitting device110a, and the second cooling fan130bis disposed on the second light emitting device110b. The first guide duct140ais connected to the first cooling fan130aand guides a cooling airflow F1provided by the first cooling fan130ato the second light emitting device110b, and the second guide duct140bis connected to the second cooling fan130band guides a cooling airflow F2provided by the second cooling fan130bto the first light emitting device110a. In the embodiment, the first guide duct140ahas a first bending section142abending towards the second light emitting device110b, and the second guide duct140bhas a second bending section142bbending towards the first light emitting device110a. The first cooling fan130aand the second cooling fan130bare, for example, a sirocco fan, a silent fan, an axial flow fan, or other fans suitable for providing the cooling airflow, however, the invention is not limited thereto.

In case that the first light emitting device110aand the second light emitting device110bare disposed opposite to each other as shown inFIG. 1andFIG. 2, the heat of the second light emitting device110bis dissipated by the first cooling fan130adisposed on the first light emitting device110a, and the heat of the first light emitting device110ais dissipated by the second cooling fan130bdisposed on the second light emitting device110b. Thus, the first guide duct140acan guide the cooling airflow F1provided by the first cooling fan130ato the second light emitting device110bvia a smaller bending degree of the first bending section142a, and the second guide duct140bcan guide the cooling airflow F2provided by the second cooling fan130bto the first light emitting device110avia a smaller bending degree of the second bending section142b.

In this way, loss of flow rates of the cooling airflow F1and the cooling airflow F2due to over bending is decreased, so as to improve heat dissipation capability of the light source module100. Therefore, it is unnecessary to excessively increase the air output of the first cooling fan130aand the second cooling fan130bin order to improve the cooling capability of the light source module100, so as to avoid excessive noise produced when the first cooling fan130aand the second cooling fan130bare working.

For example, bending angles of the first bending section142aand the second bending section142bare less than 90 degrees, such that the cooling airflow F1and the cooling airflow F2can be more smooth. In other embodiments, the bending angles of the first bending section142aand the second bending section142bcan be preferred in the range of 25 to 50 degrees or other suitable angle ranges; the invention is not limited thereto.

In the embodiment, a beam emitted by the first light emitting device110aand a beam emitted by the second light emitting device110bare respectively transmitted to the light combining system120along a first optical axis A1and a second optical axis A2, and the beam emitted by the first light emitting device110aand the beam emitted by the second light emitting device110bare transmitted along a third optical axis A3(shown inFIG. 2) after combined by the light combining system120, where the first optical axis A1and the second optical axis A2are perpendicular to the third optical axis A3. The first guide duct140aand the second guide duct140bare not located on the first optical axis A1, the second optical axis A2and the third optical axis A3. The beam emitted by the first light emitting device110a, the beam emitted by the second light emitting device110band the beam combined by the light combining system120are not blocked by the first guide duct140aand the second guide block140b, either. Thus, light emitting of the light source module100is not impeded.

Referring toFIG. 2, the first light emitting device110ahas a first portion P1and a second portion P2, the second light emitting device110bhas a third portion P3and a fourth portion P4, where the first portion P1and the second portion P2are respectively aligned to the third portion P3and the fourth portion P4, the first optical axis A1is located between the first portion P1and the second portion P2, and the second optical axis A2is located between the third portion P3and the fourth portion P4. The first cooling fan130ahas a first air outlet132a, and the second cooling fan130bhas a second air outlet132b. The first air outlet132aof the first cooling fan130ais located on the first portion P1and is connected to the first guide duct140a. The second air outlet132bof the second cooling fan130bis located on the fourth portion P4and is connected to the second guide duct140b. According to such configuration, the first guide duct140aand the second guide duct140bare misaligned and are not interfered with each other.

In the embodiment, the first light emitting device110ais, for example, a high pressure mercury lamp and includes a first lampshade112aand a first light emitting element114a. The second light emitting device110bis, for example, a high pressure mercury lamp and includes a second lampshade112band a second light emitting element114b. The first light emitting element114aand the second light emitting element114bare respectively disposed in the first lampshade112aand the second lampshade112b. In other embodiments, the first light emitting device110aand the second light emitting device110bcan be other suitable type of light emitting devices such as light emitting diodes (LEDs), laser light sources, etc., however, the invention is not limited thereto.

In detail, the first lampshade112aand the second lampshade112brespectively have a first opening end H1and a second opening end H2, where the first opening end H1and the second opening end H2all face the light combining system120. The light combining system120is located between the first opening end H1and the second opening end H2, such that the beams emitted by the first light emitting element114aand the second light emitting element114bcan respectively pass through the first opening end H1and the second opening end H2to reach the light combining system120. Moreover, the first guide duct140aextends from the first cooling fan130ato the second opening end H2, and the second guide duct140bextends from the second cooling fan130bto the first opening end H1, such that the cooling airflow F1provided by the first cooling fan130aand the cooling airflow F2provided by the second cooling fan130bare respectively guided by the first guide duct140aand the second guide duct140bto dissipate the heat inside the first lampshade112aand the heat inside the second lampshade112b. In the embodiment, the first cooling fan130ais disposed at a side of the first lampshade112a, and the second cooling fan130bis disposed at a side of the second lampshade112b, however, the first cooling fan130aand the second cooling fan130bcan be respectively assembled with the first light emitting device110aand the second light emitting device110bthrough other components according to space configuration requirements, the invention is not limited thereto.

FIG. 3is a top view of a light source module according to another embodiment of the invention. In the light source module200ofFIG. 3, configurations and functions of a light source210, a first light emitting device210a, a first lampshade212a, a first light emitting element214a, a second light emitting device210b, a second lampshade212b, a second light emitting element214b, a light combining system220, a first guide duct240aand a second guide duct240bare similar to configurations and functions of the light source110, the first light emitting device110a, the first lampshade112a, the first light emitting element114a, the second light emitting device110b, the second lampshade112b, the second light emitting element114b, the light combining system120, the first guide duct140aand the second guide duct140b, and details thereof are not repeated.

The differences between the light source module200and the light source module100is that the position of the first cooling fan230ais different to the position of the first cooling fan130a, such that an air outlet232aof the first cooling fan230ais located at a second portion P2′ of the first light emitting device210aother than a first portion P1′ of the first light emitting device210a, and the position of the second cooling fan230bis different to the position of the second cooling fan130b, such that an air outlet232bof the first cooling fan230bis located at a third portion P3′ of the second light emitting device210bother than a fourth portion P4′ of the second light emitting device210b. According to the above configuration, the first guide duct240aand the second guide duct240bare misaligned and are not interfered with each other. In other embodiments, the position of the first cooling fan230aon the first light emitting device210aand the position of the second cooling fan230bon the second light emitting device210bcan be changed according to actual requirements; the invention is not limited thereto.

It should be notice that the number of the cooling fans is not limited by the invention, which is described below with reference ofFIG. 4.FIG. 4is a side view of a light source module according to still another embodiment of the invention. In the light source module300ofFIG. 4, configurations and functions of a light source310, a first light emitting device310a, a first lampshade312a, a first light emitting element314a, a second light emitting device310b, a second lampshade312b, a second light emitting element314b, a light combining system320, a first cooling fan330a, a first air outlet332a, a second cooling fan330b, a second air outlet332b, a first guide duct340a, a second guide duct340b, a cooling airflow F1′ and a cooling airflow FT are similar to configurations and functions of the light source110, the first light emitting device110a, the first lampshade112a, the first light emitting element114a, the second light emitting device110b, the second lampshade112b, the second light emitting element114b, the light combining system120, the first cooling fan130a, the first air outlet132a, the second cooling fan130b, the second air outlet132b, the first guide duct140a, the second guide duct140b, the cooling airflow F1and the cooling airflow F2, and details thereof are not repeated.

The differences between the light source module300and the light source module100is that the light source module300further includes a third cooling fan350a, a fourth cooling fan350b, a third guide duct360aand a fourth guide duct360b. The first cooling fan330aand the third cooling fan350aare respectively located at two opposite sides of the first light emitting device310a, and the second cooling fan330band the fourth cooling fan350bare respectively located at two opposite sides of the second light emitting device310b. The third guide duct360ais connected to the third cooling fan350aand guides a cooling airflow F3provided by the third cooling fan350ato the second light emitting device310a, and the fourth guide duct360bis connected to the fourth cooling fan350band guides a cooling airflow F4provided by the fourth cooling fan350bto the first light emitting device310b.

According to the above description, in the light source module300of the embodiment, besides that the first cooling fan330a, the second cooling fan330b, the first guide duct340aand the second guide duct340bare disposed at a top side S1of the light source310for providing cooling airflows to blow upper sections of the first light emitting device310aand the second light emitting device310b, the third cooling fan350a, the fourth cooling fan350b, the third guide duct360aand the fourth guide duct360bare further disposed at a bottom side S2of the light source310for providing cooling airflows to blow lower sections of the first light emitting device310aand the second light emitting device310b, where the top side and the bottom side of the light source, the upper sections and lower sections of the light emitting devices are defined according to gravity direction. Configurations and functions of the third cooling fan350aand the third air outlet352athereof, the fourth cooling fan350band the fourth air outlet352bthereof, the third guide duct360aand the fourth guide duct360bare similar to configurations and functions of the first cooling fan330aand the first air outlet332athereof, the second cooling fan330band the second air outlet332bthereof, the first guide duct340aand the second guide duct340b, by which heat dissipation efficiency of the light source module300is further improved.

According to the above description, in case that the upper sections of the first light emitting element314aand the second light emitting element314bhave higher temperature due to rising of hot air, the air output of the first cooling fan330aand the second cooling fan330blocated at the top side S1of the light source310can be set to be greater than the air output of the third cooling fan350aand the fourth cooling fan350blocated at the bottom side S2of the light source310, so as to improve the heat dissipation efficiency at the upper sections above the first light emitting element314aand the second light emitting element314b. In other embodiments, the air output of the first cooling fan330a, the second cooling fan330b, the third cooling fan350aand the fourth cooling fan350bcan be adjusted according to an actual orientation of the light source module300, so as to evenly dissipate heat of peripheral areas of the first light emitting element314aand the second light emitting element314b.

In summary, the embodiments of the invention have at least one of the following advantages. In the embodiments of the invention, the first cooling fan is disposed on the first light emitting device and the first cooling fan is used to dissipate heat of the second light emitting device, and the second cooling fan is disposed on the second light emitting device and the second cooling fan is used to dissipate heat of the first light emitting device. In this way, in case that the first light emitting device and the second light emitting device are disposed opposite to each other, the first guide duct connected to the first cooling fan is capable of guiding the cooling airflow provided by the first cooling fan to the second light emitting device via a relatively small bending degree, and the second guide duct connected to the second cooling fan is capable of guiding the cooling airflow provided by the second cooling fan to the first light emitting device via a relatively small bending degree. Thus, loss of a flow rate of the cooling airflow due to over bending is avoided, so as to improve heat dissipation capability of the light source module. In this way, it is unnecessary to excessively increase the air output of the first cooling fan and the second cooling fan in order to improve the heat dissipation capability of the light source module, so as to avoid excessive noise produced when the first cooling fan and the second cooling fan are working.