Patent Application
20060044524
The present invention relates to the field of beam projectors, and more particularly to a system and method for cooling a beam projector.
Beam projectors are used in media presentation environments such as business meetings, home theaters and the like. In general, the beam projector has taken the place of overhead projectors, slide projectors, and other devices used for showing visual presentations. For example, it is common in a meeting to connect a laptop or other computing system to a beam projector and then project a media presentation that everyone in the room can observe (e.g., slideshow, video, real-time data, or the like). In most multimedia type rooms, the beam projector is mounted on the ceiling and hardwired to an outlet on the wall and a user connects their laptop with the hardwiring to utilize the beam projector.
However, multimedia rooms are cost prohibitive. Therefore, an office building may have a few multimedia rooms but generally not all the meeting rooms will be multimedia rooms. Additionally, in the non-multimedia rooms, it may also be necessary to view a visual presentation. Therefore, a presenter may carry a portable beam projector to ensure that they will be able to show the visual presentation even if they do not have access to a multimedia room.
Portable beam projectors also provide the ability for a presenter to hold a meeting in a location other than the multimedia room or even the office building. For example, the presentation may be shown at the back room of a coffee shop, a restaurant, or any location that has a power outlet.
However, one drawback of a portable beam projector is the cooling time after the beam projector is turned off. For example, a standard beam projector requires a long time delay (many minutes) of fan operation after shutdown to allow bulb and optics to cool. For a mounted beam projector hardwired to the building power, this may not be a concern. However, for a portable beam projector, it means that the presenter must wait a long time delay (many minutes) after the visual presentation ends before he can unplug and pack-up the portable beam projector.
Beam projectors, both mounted and portable, also require an amount of cooling during their operation. Specifically, the light-generating source of the beam projector gets extremely hot and requires a fan to provide the cooling to maintain the life of the bulb. However, when the fan is operational, noise from the fan is loud enough to interfere with conversations. This problem is even more pronounced when teleconferencing or video-conferencing is used during the presentation. In that case, the fan may provide negative feedback to the conferencing microphone causing disrupted reception for the off-site personnel.
A system and method for cooling a beam projector. The system includes a fluid reservoir proximal to a light-generating source of the beam projector, a heat pipe coupled with the fluid reservoir and a thermal mass coupled with the heat pipe. The fluid reservoir adapted for storing a low energy state fluid that changes to a higher energy state fluid when it absorbs a heat energy generated by the light-generating source. The heat pipe adapted for transmitting the higher energy state fluid. The thermal mass adapted for receiving and dissipating the heat energy released from the higher energy state fluid when it returns to a low energy state fluid.
Reference will now be made in detail to the alternative embodiment(s)s of the present invention, a system and method for cooling a beam projector. While the invention will be described in conjunction with the alternative embodiment(s), it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.
Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.
With reference now to
Referring still to
Beam projector assembly 100 also includes a passive cooling system 150. In one embodiment, passive cooling system 150 includes a fluid reservoir 120, a heat pipe 125 and a thermal mass 130. In one embodiment, fluid reservoir 120 is proximal to the light-generating source 115. In
The heat from the light-generating source 115 is established with a low energy state fluid (e.g., a liquid) in the fluid reservoir 120 resulting in a portion of the low energy state fluid in the fluid reservoir 120 to change into a higher energy state fluid (e.g., a gas or vaporizing fluid). The higher energy state fluid is then carried along the heat pipe 125 which is coupled with the fluid reservoir 120. When the higher energy state fluid reaches the end of heat pipe 125, the higher energy state fluid returns to the low energy state by releasing the heat energy to the thermal mass 130. In so doing, the thermal mass 130 receives the heat generated by light-generating source 115 and utilizes standard heat sink methods (e.g., conduction and radiation of the heat over the surface area of the thermal mass 130) to dissipate the heat received from the higher energy state fluid.
In beam projector assemblies not having a passive cooling system 150, the post utilization cooling time may require many minutes of additional cooling prior to unplugging the beam projector assembly 100 (referred to herein as pack time). However, as will be described in detail herein, the utilization of embodiments of the present passive cooling system 150 reduces the pack time of the beam projector assembly 100 to less than a minute. Although such times are provided here, embodiments of the invention may provide results that are more or less than the times stated herein. However, in each embodiment, the pack time is reduced when the passive cooling system 150 is utilized.
With reference now to
With reference now to
Use and Operation
The following is a detailed description of the use and operation of the present system and method for cooling a beam projector. With reference again to
In general, sufficiently cooled refers to the temperature at which the light-generating source 115 will not be damaged if the cooling systems were to stop operation. The method used for cooling light-generating source 115 to a sufficient temperature may be controlled by the type of fluid utilized in passive cooling system 150. For example, as is well known in the art, the volatility of a fluid provides a direct relationship between the vapor point of the fluid and the temperature of the light-generating source 115.
In operation, the beam projector assembly 100 is connected to a power source, for example, plugged into a wall outlet. The light-generating source 115 generates a beam of light 117 which is the “projection” seen by those watching the presentation. While the light-generating source 115 is operational, heat is also generated as a by-product and the heat generated by the light-generating source 115 must be dissipated or the light-generating source 115 will fail. Moreover, damage to the light-generating source 115 even to include the reduction of life span of the light-generating source 115 is not desirable due to the prohibitive cost associated with buying a replacement light-generating source 115.
In order to dissipate the heat, a passive cooling system 150 is used to remove the heat from the light-generating source 115. In general, the fluid reservoir 120 is filled with a fluid in a low energy state (e.g., a liquid) having a vapor point that is within the tolerances of the operating temperature of light-generating source 115. Therefore, when light-generating source 115 reaches the vapor point temperature, the low energy state fluid in the fluid reservoir 120 begins to change to a higher energy state fluid (e.g., a gas) thereby transferring, via the heat energy of vaporization, the heat away from the light-generating source 115. As is well known in thermodynamics, as long as a portion of the fluid in the fluid reservoir 120 remains in the low energy state (e.g., liquid form), the temperature of the fluid reservoir will remain at or below the vapor point temperature of the fluid.
The higher energy state fluid generated in the fluid reservoir 120 then traverses along the heat pipe 125 toward the thermal mass 130. The heat energy contained in the higher energy state fluid is then released to the thermal mass 130 when the higher energy state fluid (e.g., gas) returns to a lower energy state fluid (e.g., liquid) state. In so doing, the heat generated by the light-generating source 115 is transferred from the light-generating source 115 to the thermal mass 130. In one embodiment, the heat pipe 125 is made from any number of materials known in the art to provide a path for the higher energy state fluid to reach the thermal mass 130. In one embodiment, thermal mass 130 is a heat sink. Additionally, in one embodiment thermal mass 130 contains ducting, fins, or the like to increase the surface area of thermal mass 130. In addition, thermal mass 130 and/or heat pipe 125 may be formed from a thermally conductive metal such as aluminum, copper, gold, or the like.
Therefore, by utilizing the passive cooling system 150, the beam projector assembly 100 may be operated without a cooling fan and the associated fan noises. In addition, since the cooling system 150 is passive, there is no need to wait for the beam projector assembly 100 to cool prior to pack up. Therefore, pack time is reduced since there is no need to keep the beam projector assembly 100 plugged in after the presentation is complete.
With reference now to
Cooling fan 210 is used to provide additional airflow to the light-generating source 115. In one embodiment, the cooling fan 210 has a thermal switch that turns on the cooling fan 210 if the temperature of the light-generating source 115 reaches a certain temperature. Therefore, the cooling fan 210 may be intermittent. That is, the cooling fan 210 will remain inactive until the thermal switch is tripped at which point the cooling fan 210 will activate. Then, when the temperature of the light-generating source 115 is lowered, the thermal switch will trip again and the cooling fan 210 will be deactivated. In so doing, even though the active cooling system (e.g., fan 210) is used, the overall noise of the beam projector assembly 200 is reduced since the fan 210 is of low speed or intermittent type. Moreover, the cooling fan 210 may act as a backup system to ensure that a problem with the passive cooling system 150 (or optional cooling system 248) does not result in a loss of light-generating source 115. In another embodiment, a plurality of cooling fans 210 is present.
With reference now to
Cooling fan 310 of
With reference now to
Therefore, after a user completes a presentation, the user may simply pack-up the beam projector 400 without keeping the unit plugged in to the primary power source to power the cooling fans 210 and/or 310. In so doing, a user's pack time is more efficiently utilized and the light-generating source 115 is not damaged by early removal from the primary power source. In another embodiment, the battery 410 will provide sufficient power to operate the fans 210 and/or 310 until the light-generating source 115 is sufficiently cooled in the case of a power loss during operation. Thus, the passive cooling system 150 and battery 410 are also valuable components of a mounted beam projector assembly as well as a portable beam projector assembly.
With reference now to
With reference still to
For example, as described in detail herein, the fluid reservoir 120 is proximal to the light-generating source 115 of the beam projector 400, a heat pipe 125 is connected with the fluid reservoir 120 and a thermal mass 130 is connected with the heat pipe 125. The fluid reservoir 120 stores a low energy state fluid (e.g., a liquid) that changes to a higher energy state fluid (e.g., a gas) when the fluid absorbs heat energy generated by the light-generating source 115. The heat pipe 125 then transmits the higher energy state fluid. The thermal mass 130 receives and dissipates the heat energy which is released from the higher energy state fluid when it returns to a low energy state in the proximity of the thermal mass 130.
In another embodiment, a second optional passive cooling system 248 includes a heat pipe 245 fixedly coupled with the fluid reservoir 120 and a thermal mass 240 fixedly coupled with the heat pipe 245. Thereby providing a plurality of both thermal masses and heat pipes. Furthermore, a low speed fan 310 may be utilized in conjunction with the passive cooling system 150 and/or 248 thereby providing increased airflow to the thermal mass 130 (and/or optional thermal mass 240) coupled with the heat pipe 125 (and/or optional heat pipe 245).
Referring still to
In one embodiment, a battery 410 is provided for powering the active cooling system when the beam projector assembly 400 is unplugged from a primary power source. The battery 410 may be used to power the cooling fan 210, cooling fan 310, or both cooling fan 210 and cooling fan 310. In addition, in order to maintain a charged battery 410, in one embodiment, battery 410 is recharged when the beam projector assembly 400 is plugged into a primary power source (e.g., an AC outlet).
Thus, embodiments of the present invention provide, a method and system for cooling a beam projector. Additionally, embodiments provide a method and system for cooling a beam projector which reduces the pack time of the beam projector by remaining operational without connection to a main power source (e.g., a wall outlet). Embodiments of the present invention further provide reduced fan noise without adversely affecting the lamp life of the light-generating source.
While the method of the embodiment illustrated in flow chart 500 shows specific sequences and quantity of steps, the present invention is suitable to alternative embodiments. For example, not all the steps provided for in the methods are required for the present invention. Furthermore, additional steps can be added to the steps presented in the present embodiment. Likewise, the sequences of steps can be modified depending upon the application.
The alternative embodiment(s) of the present invention, a method and system for cooling a beam projector, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.
