Cooling system for an electronic display

A cooling system for an electronic display may include a heat collector plate with internal gas and liquid phase lines. The cooling plate may be thermally isolated together with electronic components of the display within an enclosure of the display, while external lines carry liquid and gas phase refrigerant outside the enclosure to and from the heat collector plate. The external lines may be similar in size to each other and may be connected to the heat collector outside the heat collector plate by a manifold. The heat collector plate contacts a base plate of the electronic display in a thermally conductive relation to transfer heat from electronic components within the display to the gas phase refrigerant. Fans may be included for additional convective heat transfer. A single compressor may be fluidly connected to multiple heat collector plates in respective electronic displays.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention generally relates to heat collector systems, and in particular to heat collector systems for electronic displays.

2. State of the Art

The prior art predominately includes convective heat transfer systems for electronic displays. These systems of the past generally attempt to remove heat from the electronic components in a display through as many sidewalls of the display as possible. In order to do this, the systems of the past have incorporated fans for moving air past the components to be cooled and out of the display. In some cases, the heated air is moved into convectively thermal communication with fins. Some of the past systems have also utilized conductive heat transfer from heat producing components directly to heat conductive housings for the electronics. In these cases, the housings have a large surface area, which is in convective communication with ambient air outside the housings. Thus, heat is transferred convectively or conductively to the housing and is then transferred into the ambient air from the housing by natural convection.

While such heat transfer systems have enjoyed a measure of success in the past, improvements to displays have called for greater cooling capabilities.

DISCLOSURE OF THE INVENTION

The present invention relates to a heat collector plate and cooling system for an electronic display. This invention has many features that are different from those of Applicant's own disclosure in U.S. Pat. No. 5,991,153, issued to Gregory S. Heady et al. Nov. 23, 1999 and entitled “Heat Transfer System for an Electronic Display”, the disclosure of which is incorporated herein in its entirety. However, much of the disclosure of U.S. Pat. No. 5,991,153 provides a background for the improvements of the present invention. Furthermore, the features of the present invention in combination with those of the Applicant's prior patent represent significant and advantageous advances in the art that were not obvious at the time of this invention.

The present invention also has many features that are useable together with the inventions disclosed in Applicant's own disclosure in U.S. patent application Ser. No. 10/823,476, filed Apr. 12, 2004 and entitled “Heat Collector Plate for an Electronic Display”, the disclosure of which is incorporated herein in its entirety.

In particular, cooling devices for electronic displays of the past have generally used convective heat dissipation systems that function to cool an entire interior of the display by one or more fans and fins, for example. This is not adequate in many climates, especially when radiative heat transfer from the sun through a display window becomes a major factor. In many applications and locations 200 Watts or more of power through such a display window is common. Furthermore, the market is demanding larger screen sizes for displays. With increased electronic display screen size and corresponding display window size more heat will be generated, and more heat will be transmitted into the displays. In the past, many displays have functioned satisfactorily with ten or twelve inch screens. Now, many displays are in need of screens having sizes greater than or equal to twelve inches that may require improved cooling systems. For example, some applications call for fifteen inch screens. With increased heat production with the fifteen inch screens and radiative heat transfer from the sun through the display window, heat dissipation systems of the past, (which attempt to cool the entire interior of the display with fins and fans), are no longer adequate.

By the aspects to be described below, the present invention has made consistent cooling possible for electronic displays having screens of sizes greater than or equal to twelve inches. For example, cooling of a fifteen inch screen can be achieved, even in extremely hot climates. The present invention implements insulative materials, improved contact between elements for increased conductive heat transfer, and a two phase refrigerant in conjunction with isolating a volume to be cooled from the compressor and the ambient conditions external to the volume.

In particular, separating the compressor from the electronics has some important advantages. One advantage is that doing so physically separates the heat creating compressor and associated fins from the electronics that the system is trying to cool. Therefore the present invention lessens the opportunity for the heat from the compressor to be returned to the electronic components. Another advantage is that isolation of the compressor from the electronics permits the present invention to be used in applications that have restrictions on how close certain components may be placed to the displays. For example, refrigerant type cooling systems would typically not be approved for gasoline display pumps because of the fire hazards associated with the contactors that switch the cooling system on and off. However, with the present invention, the compressor and associated components can be isolated from a gasoline pump and display. In fact, ideally, a large compressor may be isolated in a canopy or roof. A regulator may control flow through a plurality of lines communicating between the compressor and a corresponding plurality of pumps. Thus, the present invention advantageously opens possibilities of providing effective cooling in gasoline pump displays and other applications.

Convective heat transfer cooling systems of the past used in conjunction with electronic components has the disadvantage of pulling dust in from outside and placing the dust in contact with the components. These components inherently have electrostatically attractive charges, and essentially act as an electrostatic filter that collects the dust. Hence, function and life of the components may be compromised.

A large fluctuation in temperature is common in the non refrigerant cooled devices of the past. Such temperature fluctuation adversely affects the electronic components in these devices. For example, with a 10 degree average temperature fluctuation from a standard 22 degrees C., the life expectancy of a light emitting diode (LED) screen will be cut in half. Thus, with the non refrigerant cooling systems of the past, the life expectancy of an (LED) screen is approximately 18 months. Advantageously, it is believed that the present invention will permit improvement of the life expectancy to a range from approximately 5 years to approximately 7 years.

While sealing off a volume in which the electronic components reside may seem counterintuitive in light of the past convective cooling systems, sealing the volume surrounding the electronics has the advantages of reducing the amount of dust that will collect on the components. Furthermore, sealing a smaller volume that more tightly encloses the electronic components reduces the volume or mass that needs to be maintained at a cool temperature. While electronic displays having screens between ten to twelve inches could be cooled to a degree with the convective heat transfer cooling systems of the past, many screens of sizes greater than or equal to approximately twelve inches require improved cooling capabilities such as those of the present invention. In particular, many applications call for fifteen inch screens. With increased heat production with the screens of larger sizes and radiative heat transfer from the sun through the display window, heat dissipation systems of the past that attempt to cool the entire interior of the display with fins and fans are no longer adequate. On the other hand, it is to be noted that fans may also be implemented with the sealed configurations of the present invention. This may provide the advantage of adding convective heat transfer while isolating the electronic components from external dust. The present invention may be sealed to withstand pressures in a range from approximately plus 3.5 psi absolute to approximately minus 3.5 psi absolute. Sealing to this level equates to providing an enclosure that can withstand 800 pounds of force on a display window that corresponds in size to a 15 inch screen. Such sealing has the advantage of assuring that the enclosure will be protected against entry of external ambient air or moisture.

Whereas the systems of the past attempted to remove heat through all of the sides of the enclosure surrounding the electronic components, the present invention insulates the enclosure as much as possible and removes the heat via a two phase refrigerant fluid to a remote location where the heat is dissipated. For example, if a display screen is included in the electronics that must be viewed through one of the sides, then five sides will be insulated. In the case of no display, all sides (six, in the case of a hexahedron) will be insulated. Parts of any side may be insulated if a full side cannot be insulated.

One or more temperature sensors may be incorporated with the system of the present invention. One temperature sensor may be placed at an upstream end of a liquid phase line within a heat collector plate of the present invention. When this sensor detects a temperature that is too high, it sends a signal that causes the system to prevent liquid from being sent to the compressor. Another temperature sensor may be located at the compressor. The temperature sensor at the compressor may be used to detect a case in which the temperatures are below a predetermined threshold. In this case, the compressor will be turned off until the temperature in the display again requires cooling. Predetermined thresholds may be selected and the system may be configured with a thermostat to advantageously keep an interior of the enclosure at a relatively constant temperature, or at least within a range of acceptable temperatures.

Advantageously, the system associated with the present invention may be implemented as a set of components that can be implemented on existing electronic displays. In this regard, the system may include an enclosure cover for enclosing the heat collector plate in the enclosure. The system may further include internal gas and liquid phase lines inside the heat collector plate and external gas and liquid phase lines extending from the heat collector plate through or around the enclosure cover and to a compressor. The system may include a manifold and appropriate connectors for the lines. The system may include a thermally conductive mastic between the internal gas phase line and the heat collector plate. The system may also include the compressor with any number of compressor associated components. The system may include insulation between the enclosure cover and the heat collector plate, and other insulation. An insulation material may comprise any of a variety of materials including foam. The enclosure cover may likewise comprise an insulative material such an insulative ABS that is also nonflammable. The system may also include fasteners for holding the various components together and for holding the enclosure cover and heat collector plate to the electronics portion of the display. For contacting and conducting heat away from the electronics portion, the system may include a base plate. The heat collector plate may be configured to interface with a particular base plate. Alternatively, a base plate may be configured to interface with a particular electronics display and/or with a particular heat collector plate.

As may be appreciated, any number of system components may be provided as a kit for a particular display or set of displays. Thus, kits may be customized to meet particular servicing needs. For example, a kit may include one or more replacement lines. On the other hand, a kit may include, but is not limited to, any number of components including one or more of all lines, an enclosure cover, enclosure cover insulation, a heat collector plate, and a base plate.

In a simple form, a cooling system for an electronic display, may include a heat dissipater, a compressor, a liquid phase line, and a gas phase line. The system may also include a heat collector thermally connected to each of the liquid phase line and the gas line. A cover may be used to enclose the heat collector within a housing of the electronic display.

The cooling system may further include a base plate thermally coupled to the heat collector, wherein the base plate is adapted for at least one of thermal connection to an electrical component inside the housing or convective heat transfer from air inside the housing. The base plate may include fins to enhance convective heat transfer from circuitry and/or at least one recess to accommodate the electrical component.

The heat collector may be advantageously adapted to be enclosed within the housing on an inside of the cover. In this regard, the heat dissipator would be located on an outside of the cover and would not adapted to be enclosed in the housing. The liquid phase line and the gas phase line would thus traverse the cover. The cover may be adapted for connection to the housing, for enclosing a circuitry of the electronic display, and for enclosing the heat collector in a housing interior. The cover may form a thermal barrier adapted for placement between a housing interior and a housing exterior. The gas phase line and the liquid phase line may pass through the cover. Alternatively, the lines could be routed through a wall of the display housing.

The cooling system may further include insulation on an interior surface of the cover. Pins providing a position indication mechanism may be fixed to the heat collector, traverse the insulation, and extend through the cover. Fasteners may be threaded fasteners, extend through the cover and the heat collector, and engage the display in order to fix the cover on the display. The insulation may have resilient properties so that the fasteners may draw the cover closer to the heat collector and compress the insulation when the fasteners are tightened. At the same time, the position indication mechanism may indicate when the cover is in a fully closed position by a visibly changed physical relationship of the pins relative to other display structure.

The housing associated with the cooling system of the present invention may be adapted to form an enclosure together with the cover. The system may further include insulation adapted for mounting on interior surfaces of the enclosure. The insulation may be adapted to cover generally all of the interior surfaces except for a surface through which a display screen is viewed. The insulation may further be adapted to cover generally all of the interior surfaces of the enclosure.

The cooling system may further include a first sensor in a downstream end of the liquid phase line and a second sensor in a downstream end of the gas phase line to monitor and provide feedback to a thermostat in order to maintain the interior temperature in a preselected range.

The cooling system may further include a plurality of liquid phase lines including the liquid phase line referred to above and a plurality of gas phase lines including the gas phase line referred to above. The liquid phase lines and the gas phase lines may be adapted for thermal connection to a plurality of electronic displays including the electronic display referred to above. Likewise, the cooling system may include a plurality of heat collectors including the heat collector referred to above. The plurality of heat collectors may be thermally connected to respective ones of the plurality of liquid phase lines and to respective ones of the plurality of gas phase lines. The cooling system may also include a plurality of covers including the cover referred to above. The plurality of covers may be adapted for enclosing respective heat collectors of the plurality of heat collectors within a plurality of respective housings including the housing referred to above. In this case, the compressor is a common compressor for the plurality of electronic displays and the compressor is connected to the heat collectors by respective ones of the liquid phase lines, and by respective ones of the gas phase lines. A regulator may be provided in fluid communication with the compressor and the plurality of liquid phase and gas phase lines. The compressor may be located remotely relative to the plurality of heat collectors.

In another simple form of the invention, an electronic display and cooling system may include a housing holding circuitry, a heat collector inside the housing, a gas phase line and a liquid phase line, and a heat dissipater external to the housing. The heat dissipater may be thermally connected to the heat collector by the gas phase line and the liquid phase line.

A base plate may be thermally connected to the circuitry and thermally connected to the heat collector. The base plate may include a thermal conductor configured to interface with the circuitry in a predetermined manner. The circuitry may be a circuitry of a particular electronic display and the base plate may be configured to fit on the circuitry in a thermally conductive condition. The base plate may include fins to enhance convective heat transfer from the circuitry. The base plate may additionally or alternatively include at least one recess to accommodate at least one electrical component of the electronic display. The base plate may not be configured in a form commonly thought to be a plate at all, but may have any configuration that matches the electronic components and heat collector with which it is implemented.

A cover may be connected to the housing and enclose the circuitry and the heat collector in a housing interior. The cover may form a thermal barrier between the housing interior and a housing exterior. The gas phase line and the liquid phase line may traverse the cover. Alternatively, the lines could be routed through a wall of the display housing.

The display and cooling system may also include insulation on an interior surface of the cover as described with regard to the cooling system above. All the features of the cooling system described above are also applicable to the cooling system and display combination of the present invention.

The display and system may further include at least three chambers in a housing interior and a plurality of fan sets in the housing interior. Each fan set may include at least one fan. A first fan set may be positioned to circulate air from a second chamber to a first chamber and back to the second chamber. A second fan set may be positioned to circulate air from the second chamber to a third chamber and back to the second chamber. Thus, excessive heat in the housing interior may be transferred outside of the housing without exposing the circuitry in the housing to dust and moisture from outside the housing.

The at least three chambers and the plurality of fan sets may be positioned and controlled to move heat from areas of higher heat concentration in order to selectively cool overheated locations or to warm overly cool locations. A display component may be wholly inside the display housing. The display component and at least one circuit board may be positioned to at least partially define the first chamber as a front chamber, the second chamber as a center chamber, and the third chamber as a rear chamber. The front chamber may include a portion of the housing between the housing and the display component. The center chamber may include a portion of the housing between the display component and the at least one circuit board. The rear chamber may include a portion of the housing between the at least one circuit board and the housing. In this regard, a plurality of backlighting lamps may be positioned in the center chamber. Furthermore, the heat collector may be positioned in the rear chamber.

The display and system may include sensors as described above. The display and system may also be a first display and system of a plurality of displays with respective systems. Alternatively, the present invention may include a plurality of electronic displays and respective housings. On the other hand, the cooling system may have a plurality of heat collectors in the respective housings fluidly and thermally connected to a common compressor. In this regard, a plurality of liquid phase lines, a plurality of gas phase lines, and a plurality of covers may be provided as described above.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention relate to a cooling system for an electronic display and to combinations of the cooling system and the electronic display. The present invention also relates to a heat collector including a heat collector plate for the cooling system.

As shown inFIG. 1, a heat collector12may be provided in a display15in order to collect and remove excess heat from a compartment18and dissipate the excess heat in a location remote from the compartment18, such as in a housing base21. In the exemplary view ofFIG. 1, the housing base21contains a compressor24. The housing base21will also typically include fins or other heat dissipating components and structure associated with the compressor24.

Advantageously the compartment18is a thermally insulated enclosure. For example, inFIG. 2, a cross section of the display15taken along lines2—2ofFIG. 1shows an alternative embodiment including walls25,26, which may be formed of an insulative ABS material. Alternatively, an insulation material may be placed on interior surfaces of housing walls as will be described in greater detail relative toFIG. 6below. The compartment18may be kept relatively small, and may include only the necessary components for a visual display27and the heat collector12. In the exemplary embodiment ofFIG. 1, the heat collector12includes a heat collector plate28in thermally conductive communication with at least one heat producing electronic component29of the visual display17. Thus, most of the heat transfer from visual display components may be provided by conduction through the heat collector plate28. Fans may also be incorporated to provide additional convective heat transfer as will be described in greater detail relative toFIG. 6.

It is to be understood that the spirit and scope of the present invention includes cooling of displays including, but not limited to LCDs. By way of example and not by way of limitation, the present invention may be used with displays selected from among LCD (including TFT or STN type), light emitting diode (LED), field emitting display (FED), cathode ray tube (CRT), and plasma displays. Furthermore, the present invention may be used with displays of other types including those not yet discovered. In particular, it is contemplated that the present invention may be well suited for use with full color, flat panel LED displays.

Another advantage of the present invention is that the heat collector12is thermally separated from the compressor24. In fact, the compressor24may be located completely remote from the display. For example, a large common compressor could be located in a canopy or in a roof top location remote from one or more displays. This common compressor may be operatively connected to several heat collectors as shown inFIG. 7, as will be described in greater detail below.

FIG. 3Ais a perspective view of the heat collector12. The heat collector12includes the heat collector plate28having a recess39in an upper surface40thereof for receiving a composite gas phase and liquid phase line42therein. The composite line42is connected to a manifold45. The manifold45routes an external liquid phase line48and an external gas phase line51into and out of the composite line42respectively. A mastic54such as a thermal grease may be placed in the recess39to provide good thermal conduction between the composite line42and the heat collector plate28, as shown in the zoomed view at56. A heat collector plate cover57may be placed over the recess39and the composite line42in order to hold the composite line42in place. In an assembled state in which the cover57holds the composite line42in the recess39, the cover57forms an integral part of the heat collector plate28and provides a uniform outer surface for the plate28.

FIG. 3Bis a partial sectional view taken along lines3B—3B ofFIG. 3A. The manifold45has a combined input and output connection59provided by an opening60receiving the composite line42therein. The manifold45also has an output connection63that may be provided by a nipple, for example. The output connection63provides an output opening66. The manifold45also has an input connection69that may be provided by another nipple, for example. The input connection69provides an input opening72. The input connection69receives a liquid phase material73from an external liquid phase line and directs the liquid phase material73through the manifold45and into an internal liquid phase line75. A plug78receives a first end81of the internal liquid phase line75and holds it in place within the manifold45. The plug78also isolates a liquid phase input portion84of the manifold45from a gas phase output portion87thereof. Thus, the liquid phase material73flows into the input portion84of the manifold45and into the first end81of the internal liquid phase line75while a gas phase output portion of the material88flows generally in the opposite direction from a second end96of an internal gas phase line90, back to a first end89of the internal gas phase line, into the gas phase portion87of the manifold45, and out of the output connection63.

As shown inFIG. 3B, the composite line42includes the internal gas phase line90and the internal liquid phase line75disposed inside the internal gas phase line90. Thus, the material73flows into the composite line42via the internal liquid phase line75. When the material73reaches a second end93of the internal liquid phase line, the material flows out of the second end93of the internal liquid phase line75and expands into a gas88in a second end96of the internal gas phase line90.

Thus, the internal liquid phase line75is generally surrounded by a gas phase portion88of the material as it flows out of the heat collector plate28and the manifold45. This arrangement has several advantages. For example, the internal liquid phase line75may be a copper capillary tube, which is relatively fragile. Therefore, placement of the internal liquid phase line75inside the internal gas phase line90has the advantage of protecting the internal liquid phase line75.

Furthermore with the present invention, the liquid phase material73may be brought from the compressor to the manifold in an external liquid phase line48that is substantially the same shape and size as the external gas phase line51. Hence, both the external gas phase line and external liquid phase line may be provided by a universal line. This configuration thus provides greater efficiency in stocking parts, and simplifies installation and replacement of the external lines. Another advantage is provided in that the liquid phase material in the internal liquid phase line75is cooled as it moves from the first end81to the second end93of the internal liquid phase line75.

As can be appreciated, the assembly of the manifold45with the composite line42is facilitated by the configuration of the liquid phase input portion84and the gas phase output portion87of the manifold45. In particular, the manifold45generally forms a shell with recesses in respective liquid phase and gas phase portions84,87for receiving the plug78therein. The plug fits snugly within each of these recesses to form a sealed connection that does not permit escape of the liquid and gas phase material73,88. Thus, when the manifold45is in its assembled configuration, the plug78forms a barrier that prevents the material from escaping and that isolates the liquid phase material73from the gas phase material88.

FIG. 3Cis a perspective view of the heat collector12with an alternative embodiment of a manifold100thereon. The heat collector12includes the heat collector plate27having a recess39in an upper surface40thereof for receiving a composite gas phase and liquid phase line42therein, as described with regard toFIG. 3Aabove. The composite line42is connected to the manifold100. The manifold100routes an external liquid phase line48and an external gas phase line51into and out of the composite line42respectively. The remaining aspects and function of the embodiment ofFIG. 3Care substantially similar to those ofFIG. 3Aas described above.

FIG. 3Dshows an alternative embodiment of the manifold100including a liquid phase portion103and a gas phase portion106. Similar to the embodiment shown and described with regard toFIG. 3A, the manifold100accommodates a plug109. The plug109holds a first end112of an internal liquid phase line115. The plug109also isolates a liquid phase portion118of material from a gas phase portion121of the material. In this embodiment, an input and output connection124for connection with a composite line is provided by an opening127. In order to provide the internal liquid phase line115inside of the internal gas phase line, the internal liquid phase line115has a bend130. This configuration permits an input connection133and an output connection136to lie in closer proximity to the heat collector plate28. Otherwise, the manifold100functions generally similarly to the manifold45shown and described above with regard toFIG. 3B.

FIG. 4Ais a top plan view of the heat collector plate28with the recess39formed therein. The heat collector plate28has first apertures140for receiving first fasteners142, only one of which is shown inFIG. 4A. The first fasteners142attach the heat collector cover57to the heat collector plate28.

The heat collector plate28has second apertures144for receiving second fasteners146, only one of which is shown. The second fasteners146extend through the heat collector plate28and hold the heat collector plate28in a secured condition inside the display15. To this end, the second fasteners146may engage in structure such as a base plate147as shown inFIG. 2. Thus, when the second fasteners146are tightened, the heat collector plate28is drawn into contact with the base plate147and provides thermally conductive contact therewith. In cases in which good thermal contact is still not achieved, a thermal mastic may be disposed between the heat collector plate28and the base plate147.

The base plate147is to be thermally connected to the circuitry of the visual display27and thermally connected to the heat collector28. The base may thus include a thermal conductor configured to interface with the circuitry in a predetermined manner. The circuitry may be a circuitry of a particular electronic display and the base may be configured to fit on the circuitry in a thermally conductive configuration. The base may include fins to enhance convective heat transfer from the circuitry. The base may additionally or alternatively include at least one recess150to accommodate the at least one electrical component29of the electronic display. The heat collector plate may be configured to interface with a particular base. Hence, it is expected that a variety of recesses and other structure will provide a varied contour that meets a particular circuitry configuration in a visual display or other electronic device. Similarly, the heat collector plate may be configured to have a contour that matches a particular base plate of a particular electronic device. Alternatively, a base may be configured to interface with a particular electronics display and with a particular heat collector plate.

The heat collector plate28has third apertures148that fixedly receive third fasteners149in the form of indicator pins. Only one fastener149is shown inFIG. 4A, although several third fasteners149are to be received in respective apertures148throughout the heat collector plate28. The third fasteners149may be configured to extend away from the heat collector plate28far enough to protrude through insulation151and an enclosure cover153as shown inFIG. 2. The enclosure cover153helps to form an enclosure155within the compartment18, as also shown inFIG. 2. The third fasteners149or position indicator pins will protrude out of the enclosure cover153a first distance before the second fasteners146are properly engaged and tightened to secure the heat collector plate28to the display15. Due to its resilient nature, the insulation151acts as a spring that resiliently biases the enclosure cover153away from the heat collector plate28. However, the insulation is compressed during tightening of the second fasteners146and the enclosure cover is moved a distance indicated at157toward the heat collector plate against the bias of the insulation as shown inFIG. 4B.

FIG. 4Bis a sectional view of the enclosure cover153, insulation151, and the heat collector plate28as a unit. As may be appreciated, the cover153may be held to the heat collector plate28by the third fasteners149having larger heads. This sectional view is similar to that ofFIG. 2. However, the enclosure cover153is not attached to the base plate147by the second fasteners146. Therefore, the insulation151is in its expanded state. After the second fasteners146have been properly seated and tightened sufficiently, the position indicating pins149will protrude out of the enclosure cover153to a second distance shown inFIG. 2greater than the first distance shown inFIG. 4B. Thus, the third fasteners149extend in an extended position to the second distance and indicate that the second fasteners146are properly engaged and sufficiently tightened. In this way, the second and third fasteners146,149work together to provide a position indicator mechanism that advantageously enables a user to determine whether the heat collector plate28has been properly installed.

As shown inFIG. 4A, it is to be understood that a large number of first apertures140and corresponding first fasteners142are needed in order to assure that the cover57holds the composite line42in the recess39throughout an entire length of the recess39. Furthermore, the first fasteners142ensure that the composite line42is held in thermal communication with any thermal mastic in the recess39. Thus, proper thermal conduction between the composite line42and the heat collector plate28is assured by the large number of first apertures140and fasteners142. Another requirement is that the cover57(shown inFIGS. 2,3A, and4B) needs to be thick enough to prevent warping or bending of the cover57away from the recess39and the line42therein. Thus, the cover57may comprise a metal plate that has a thickness of approximately ⅛ inch or greater. The cover57may be formed of another material. However, the cover needs to have good heat conduction characteristics when disposed in contact with the base plate147as shown inFIGS. 2 and 4B. Likewise, a large number of second apertures144and second fasteners146is required to assure that the heat collector plate28is held in good thermal contact with the base plate147and/or other elements within the display15. Thus, an exceedingly tight, efficient, and effective heat collector may be provided.

FIG. 2is not a precise sectional view of the embodiment shown inFIG. 1. In particular, the heat collector plate28shown inFIG. 1does not extend as high or as low as does that shown inFIG. 2. Furthermore, the manifold45ofFIG. 1is not shown inFIG. 2. Rather, an input connection166and an output connection169are connected directly to the heat collector plate28for connection with an external liquid phase line181and an external gas phase line183respectively, as shown inFIG. 2. As may be appreciated from the description ofFIGS. 3B and 3Dabove, a manifold for connection with the heat collector plate28of the present invention may take any one of a variety of forms. Furthermore, a manifold may be integrally formed in the heat collector plate so that an input line181and an output line183are combined into a composite line inside the heat collector plate. In this way, additional parts would not be required in order to provide isolation of the liquid and gas phases from each other. Alternatively, isolation of the phases, in a manifold formed integrally with the heat collector plate28, may be provided by a plug similar to those shown inFIGS. 3A and 3b, for example.

It is to be understood that many aspects of the present invention are still upheld with an external capillary input line and a solely gas phase internal line with separate input and output connections directly connected to the heat collector plate. Still further, a composite internal line with separate inlet and outlet opening in the heat collector plate may have a transition at an intermediate position along the composite internal line so that an upstream portion forms an internal liquid phase line and a downstream portion forms an internal gas phase line.

It is also to be noted that the sectional view ofFIG. 2may represent the heat collector plate with a manifold like manifold100ofFIG. 3Dattached along a hidden side thereof. In fact, the embodiments ofFIGS. 1 and 2are not intended to be restrictive in any manner. Rather, the heat collector plate may be provided of any height or width to accommodate any configuration of the manifold within the enclosure cover153. Furthermore, the manifold45/100could be provided outside the enclosure cover153, yet inside the walls25of the display15, as shown in dashed lines inFIG. 2. Still further, the manifold45/100could be located outside the display15altogether, as shown and described with regard toFIG. 6below.

FIG. 5is an exploded perspective view of an alternative embodiment of an electronic display housing190for supporting display electronics in an enclosure193. A base plate196is configured to connect with the electronics in a thermally conductive manner. The base plate196may also include fins199to aid in convective heat transfer from the electronic components to the base plate196. The electronic components may be mounted to an underside of the base plate196. Thus, the base plate and electronic components may be inserted in the housing190as a unit. As shown in the exemplary embodiment ofFIG. 5, a lip202is formed around an outer periphery of the base plate196. This lip202is configured to be supported on a shoulder204on an interior of the housing190. A gasket206may be placed between the lip202and the shoulder204in order to provide insulation and/or sealing of the enclosure193. That is, the gasket206may be provided in order to insulate components within the enclosure193from the housing190and an exterior thereof. Furthermore, the gasket206prevents air and other fluids from entering the enclosure193from outside the housing190.

Fasteners208may be provided in order to hold the base plate196in position on the housing190. A housing cover210is also an enclosure cover in this embodiment. A heat collector plate28may be held on an underside of the housing cover210by position indicator fasteners similar to fasteners149shown inFIG. 4A. Such fasteners may work together with fasteners146to provide a position indicating mechanism similar to that described above. The heat collector plate28has a manifold100associated therewith similar to that shown inFIG. 3D. The manifold100may have an input connection213and an output connection216connected thereto. The input and output connections213,216receive external liquid phase and gas phase lines respectively, as described with regard to the embodiments set forth above.

It is to be understood that the housing cover210may have insulation on an interior surface thereof between the housing cover210and the heat collector plate28as described with regard to the embodiment ofFIG. 2above. In any case, when the housing cover210is properly mounted on the housing190, the housing cover210and the housing190form a uniform electronic display housing with substantially continuous sidewall surfaces. As with the embodiments set forth above the heat collector plate28is in direct contact with the base plate196. Both the base plate196and the heat collector plate28may be formed of a heat conductive material. Therefore, heat may be conducted away from the enclosure193, and the heat producing electronic components therein, and into the two phase refrigerant material as described above.

FIG. 6is a cross-sectional view similar to that shown inFIG. 2. A housing220for supporting an electronic display222, as shown inFIG. 6, incorporates a cooling system223similar to those described with regard to the embodiments ofFIGS. 1–5above. However, the cooling system223further includes fans224,226for active convective heat transfer. The cooling system223ofFIG. 6is analogous to those described above. For example, a heat collector plate28may be held to an enclosure cover230by position indicating fasteners149. Insulation151is disposed between the enclosure cover230and the heat collector plate28. Refrigerant material is circulated through the heat collector plate28via input and output connections233and236that may or may not enter directly into the heat collector plate28. These connections may guide the refrigerant material through a manifold100/45, as described above. An alternative position for a manifold100is shown outside a lower wall239of the housing220. In this configuration, lines to the heat collector plate28can advantageously be changed or repaired without opening the housing220.

The enclosure cover230and heat collector plate28combination is connected to the electronics display via the base plate242. The heat collector plate28is held in thermally conductive contact with the base plate242by fasteners146in a manner substantially similar to that described above.

FIG. 6shows additional insulation245on interior walls of an enclosure248formed by the housing220and the enclosure cover230. As may be appreciated, insulation245may extend over generally all of the interior surfaces of the enclosure including an interior surface of a front wall251except in an area of a display window254. Thus, the enclosure248may be substantially completely thermally isolated from ambient conditions outside of the housing220. Thus, a visual display257such, as an LCD, and associated electronic components260may be protected from the high and low temperature extremes of the ambient air outside of the housing220. Furthermore, the cooling system can be associated with sensors and a thermostat to maintain the enclosure248within a predetermined range of temperatures. This range of temperatures may be set to vary minimally in order to protect the electronic components260and the visual display257and extend their lives.

As shown, a conductive element263and a conductive mastic266are provided to thermally connect the electronic components260to the base plate242. A similar thermal connection could be provided between a visual display257and the base plate242. Power supplies269and272also generate heat. Thus, these electrical components need to be thermally connected to the base plate242as well. If needed, a thermal mastic266may be used to provide a conductive connection therebetween. A bank of back lights275may be used to increase the brightness of the visual display257. These back lights275also generate heat. In order to transfer heat generated by the back lights275, heat conductive brackets278,281and fins284may be used.

In the embodiment shown inFIG. 6, three general chambers are provided in order to enable selective convective heat transfer in accordance with the teachings of the Applicant's own invention shown and described in U.S. Pat. No. 5,991,153. In accordance with the teachings of U.S. Pat. No. 5,991,153, a front chamber287, a middle chamber290, and a rear chamber293are provided. A front fan224and a rear fan226selectively circulate air within the enclosure248through openings295,297,299and300in circuit boards303,306, and309. The different combinations of fan actuation and varying flow patterns within the enclosure248are shown and described in U.S. Pat. No. 5,991,153, which is incorporated herein by reference.

While heat transfer substantially completely by conductive configurations as shown and described with regard toFIGS. 1–5is generally sufficient to maintain the display electronics within an acceptable predetermined range of temperatures, some display electronics may benefit from including the fans and active convective heat transfer shown and described with regard toFIG. 6. Several advantages and specifically beneficial flow patterns are described in the Applicant's patent referred to above.

FIG. 7is a diagrammatic view of a cooling system312in combination with a plurality of electronic displays315. In this embodiment, a compressor318having an associated heat dissipater321compresses and delivers liquid phase refrigerant in a first common line324to a regulator327. The compressor318also receives a gas phase refrigerant in a second common line330. The regulator327delivers liquid phase refrigerant to a plurality of heat collectors333via respective external liquid phase lines336. The heat collectors333absorb heat from individual electronic displays339in accordance with the disclosures set forth above. Hence, the liquid phase refrigerant is converted into a gas phase and returned in respective external gas phase lines342to the compressor318. In most cases, the gas phase refrigerant flow need not be regulated. As indicated by the ellipse at245,248and251, the number of displays may be increased to any practical limit. For example, in a gas station application, a single compressor318may be used in conjunction with twelve to eighteen or more displays339, for example. As may be appreciated, the compressor318and the regulator327could be located in a roof or canopy that covers multiple gasoline pumps. In this way, the compressor and its associated contactor may be isolated from dangerous gas fumes. In this way, the life of electronic displays at gas pumps can be extended while the cooling system312is safe and meets governmental standards for gas stations.

Advantageously, using one compressor in combination with several displays reduces costs associated with multiple compressors that otherwise would be required. Furthermore, the safety requirements of forming a barrier or locating the compressors at a safe distance from the displays is greatly simplified when a single compressor is connected to multiple electronic displays for cooling purposes, such as in gas pump displays, for example.

An advantage of locating the heat dissipation components, including compressor(s), away from the location(s) at which the heat is collected, is that heat transfer back into the compartment18by conduction and/or convection is greatly reduced. Also, the volume to be cooled may also be greatly reduced with the present invention. Therefore, the heat collector12of the present invention is much more efficient and effective in removing heat from the electronic components in one or more display(s) than devices of the past.

It is to be understood that the liquid phase and gas phase lines of the present invention may be formed in any variety of ways including providing preformed lines as has been shown and described above, machining the line(s) directly into the heat collector plate, or molding the plate27to include one or more lines as has been shown and described. The heat collector plate may be formed of any of the variety of materials including, but not limited to, aluminum. For example, there are many plastics which have good heat conductive properties that may be used to form heat collector plates in accordance with the present invention. The heat collector plate may comprise a plurality of components held together by screw or adhesives. Alternatively, the heat collector plate may be molded as a single piece. The two phase material may be any of a variety of refrigerant fluids known or not yet discovered.