Patent Application
20190327865
Exemplary embodiments of the present invention relate generally to assemblies for electronic displays.
Electronic displays have grown in popularity not only for indoor use, but also for outdoor use. One exemplary application, without limitation, is the digital out of home market where the electronic displays are increasingly replacing the use of static posters. The use of electronic displays is advantageous because they allow images to be changed quickly as well as permit the use videos and interactive displays, among other benefits. Such displays may be used for advertisements, public announcements, information, wayfinding, and the like.
Such outdoor, and some indoor, displays are sometimes encased in a housing to protect them from environmental conditions. The housing may be designed to resist, mitigate, manage, control, or prevent water, precipitation, dust, and air contaminant intrusion, vandalism, tampering, wind, temperature changes, solar loading, extreme temperatures, and the like. Oftentimes, these displays are placed outdoors where they are subject to extreme temperatures, drastic temperature changes, and significant solar loading. If the temperature inside the housing gets too high or too low the electronic displays and related components may be damaged. As such, the temperature inside the housing must be maintained at acceptable levels. In order to maintain the temperature inside the housings at acceptable levels, a number of gas pathways are generally placed through the housing. Sometimes, a combination of open loops carrying ambient air and closed loops carrying circulating gas are used.
Over time, the market has demanded increasingly larger displays. These larger displays have correspondingly larger surface areas and often require correspondingly larger, in size or number, gas pathways to maintain the temperature in the housing. As the dimensions of these displays and corresponding gas pathways have increased, the potential for the displays to bow outwardly has increased. This is because, typically, the displays are mostly unsupported. The displays are generally mounted along their perimeter so illumination from the backlight is permitted to reach the entirety of the display, among other considerations. Thus, a large section of the display is not directly mounted to a housing or other stabilizing or supporting structure, which may allow bowing of the display. Additionally, the asymmetrical temperature loading of various layers and components of the display may contribute to such display bowing. Further still, some displays have a gap between the electronic display itself and a cover panel located in front of the electronic display. As the electronic display bows towards the cover panel, the gap between the cover panel and the display may be narrowed and a resulting venturi effect may be created. The venturi effect may increase the bowing forces.
Such bowing can cause damage to the display, distortion of the displayed image, and may disrupt airflow through the open and closed loops. In some cases, the electronic display may bow outwardly enough that it contacts the cover panel. This may not only interrupt normal thermal management but may also result in significant heat transfer from the solar loaded cover panel to the electronic display. This may rapidly cause permanent damage to the display. Therefore, what is needed is a system and method for reducing or combating bow in an electronic display.
Additionally, display assemblies comprising a backlight sometimes have a sealed cavity for the backlight. As the illumination devices and other components of the backlight generate heat, heat can become trapped in this cavity. Because the cavity may be completely or partially sealed, the heat may build up and cause damage to components of the assembly. Therefore, what is needed is a system and method for removing heat from the backlight cavity.
The present invention is a system and method for reducing or combating bow in an electronic display. The present invention is also a system and method for removing heat from the backlight cavity. The present invention provides a first gas pathway through first gas pathways between a cover panel and an electronic display and an additional flow path through a backlight cavity located in the space between the electronic display and a backlight. The flow of air through the backlight cavity removes heat from the backlight cavity generated by the illumination devices or other components.
The amount or speed of airflow through the first gas pathway and the backlight cavity may be controlled so as to create a pressure drop in the backlight cavity as compared to the first gas pathway. This pressure drop may result in forces which tend to pull the electronic display away from the cover panel, thereby reducing or eliminating the bowing. In particular, a support or a bracket may be used to create an entrance gap and exit gap into and out of the backlight cavity. In this way the amount or speed of airflow through the backlight cavity may be controlled. The entrance gap may be smaller than the exit gap. In exemplary embodiments, an angled section may extend from the distal end of the bracket located near the exit gap. The angled section may extend towards the side of the housing to restrict the flow of air from the first gas pathway into a second gas pathway located behind the backlight. The constriction of this air may create a venturi effect, creating a low-pressure zone near the angled section to pull circulating gas through the backlight cavity.
In addition to the features mentioned above, other aspects of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments, wherein like reference numerals across the several views refer to identical or equivalent features, and wherein:
Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, specific details such as detailed configuration and components are merely provided to assist the overall understanding of these embodiments of the present invention. Therefore, it should be apparent to those skilled in the art that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
Regardless, a rear plate 32 may be located behind the backlight 30. The rear plate 32 may be located behind, spaced apart from, and substantially parallel to the backlight 30. A first gas pathway 22 may be located in the space between the rear surface of the cover panel 12 and the front surface of the electronic display 14. This space may also be referred to as the LCD cavity herein. The first gas pathway 22 may be configured to receive circulating gas 24. The circulating gas 24 may travel through the first gas pathway 22 and into a second gas pathway 26 located behind the backlight 30.
The second gas pathway 26 may be located in the space between the rear plate 32 and the rear of the housing 16. The second gas pathway 26 may comprise a heat exchanger 28 and an electronics cavity 30, though such is not required. The heat exchanger 28 may be any type of heat exchanger 28. The heat exchanger 28 may be mounted to the rear plate 32, though any location is contemplated. In exemplary embodiments, the heat exchanger 28 occupies a first portion of the second gas pathway 26 and the electronics cavity 34 occupies a second portion where various electronic components may be located. The heat exchanger 28 may also be part of a second open loop pathway. These various electronic components may be used to operate the display assembly 10. After traveling through the second gas pathway 26, the circulating gas 24 may return to the first gas pathway 22, thus creating a closed loop. Stated another way, the closed loop may encircle the electronic display 14. One or more closed loop fans 35 may be placed along the closed loop so as to control the speed and amount of circulating gas 24 pass through the closed loop, or through the first gas pathway 22 or the second gas pathway 26. In exemplary embodiments, the closed loop fan 35 may be located between the heat exchanger 28 and the electronics cavity 34, though any location is contemplated.
In exemplary embodiments, a corrugation layer 38 may be located between the rear surface of the backlight 30 and the front surface of the rear plate 32. The corrugation layer 38 may be configured to receive ambient air 44. The space between the rear plate 32 and the backlight 30 may define a first open loop channel 37. The ambient air 44 may also flow through the heat exchanger 28 (the second open loop pathway). Ambient air 44 may enter the assembly 10, pass through the first or second open loop pathways and then exit the assembly 10, thus creating an open loop. One or more open loop fans 33 may be placed along the open loop to control the amount or speed of ambient air 44 flowing through the open loop, or through the corrugation layer 38 or the heat exchanger 28.
A backlight cavity 36 may be located in the space between the rear surface of the electronic display 14 and the front surface of the backlight 30. A portion of the circulating gas 24 may be separated from the remainder of the circulating gas 24 and travel into or through the backlight cavity 36. This portion of the circulating gas 24 may also be referred to herein as the backlight cavity gas 25. The backlight cavity gas 25 that exits the backlight cavity 36 may be rejoined with the circulating gas 24. The backlight cavity 36 may be framed on the sides, at least in part, by supports 47. In exemplary embodiments, a first supports 47 is located on the side of the backlight cavity 36 which receives the backlight cavity gas 25 and a second support 47 is located on the side of the backlight cavity 36 where the backlight cavity gas 25 exits the backlight cavity 36.
The supports 47 may extend from the rear surface of the electronic display 14 to support various components, such as but not limited to, a diffuser, optical films, a transparent sheet, or the like, located between the electronic display 14 and the backlight 30. The supports 47 may be spaced apart from the backlight 30 or the electronic display 14 at one or more locations to define an entrance gap and an exit gap for the backlight cavity gas 25 to enter or exit the backlight cavity 36, respectively. In other exemplary embodiments, the supports 47 may comprise a number of aperture which define the entrance gap and the exit gap. As will be explained in greater detail herein, the backlight cavity gas 25 may be maintained at a lower pressure relative to the circulating gas 24 traveling through the first gas pathway 22, though such is not required.
In exemplary embodiments, the pressure of the backlight cavity gas 25 may be kept relatively low by controlling the amount or speed of the backlight cavity gas 25 permitted to enter and exit the backlight cavity 36. The amount or speed of the backlight cavity gas 25 may be controlled, at least in part, by the dimensions and/or shape of the backlight cavity 36. In exemplary embodiments, the gap between the supports 47 and the front surface of the backlight 30 may be sized and configured to control the amount or speed of the backlight cavity gas 25 allowed to enter and exit the backlight cavity 36. In exemplary embodiments, the gap between the support 47 located at the entrance to the backlight cavity 36 may be smaller than the gap between the support 47 located at the exit of the backlight cavity 36 to reduce the pressure of the backlight cavity gas 25.
Alternatively, or in addition, the amount or speed of air permitted to enter and exit the backlight cavity 36 may be controlled by brackets 48. In exemplary embodiments, a first bracket 48 is located on the side of the backlight cavity 36 which receives the backlight cavity gas 25 and a second bracket 48 is located on the side of the backlight cavity 36 where the backlight cavity gas 25 exits the backlight cavity 36. The brackets 48 may be substantially shaped as an upside-down “L” and may extend from either edge of the electronic display 14 so as to also frame the backlight cavity 36. The gap between the bracket 48 and the surrounding structure, including but not limited to, the backlight 30 and the corrugation layer 38, may be sized and configured to control the amount or speed of the backlight cavity gas 25 allowed to enter and exit the backlight cavity 36. In exemplary embodiments, the gap between the bracket 48 located at the entrance to the backlight cavity 36 may be smaller than the gap between the bracket 48 located at the exit of the backlight cavity 36 to reduce the pressure of the backlight cavity gas 25.
In exemplary embodiments, some or all of the brackets 48 may comprise an angled section 49 extending from an end thereof. This angled section 49 may be angled, oriented, sized, shaped, and otherwise configured to likewise to control the amount or speed of the backlight cavity gas 25 allowed to enter and exit the backlight cavity 36. In exemplary embodiments, the angled section 49 may only be located on the exit of the backlight cavity 36 to assist in reducing the pressure of the backlight cavity gas 25.
In exemplary embodiments, the angled section 49 may extend towards the side of the housing. The angled section 49 may extend into the flow of circulating gas 24 passing from the first gas pathway 22 into the second gas pathway 26. The angled section 49 may disrupt a portion of such flow and instead permit said backlight cavity gas 25 to rejoin the remainder of the circulating gas 26. As the angled section 49 may restrict the flow of circulating gas 24 passing from the first gas pathway 22 into the second gas pathway 26, the angled section 49 may create a venturi effect and result in a lower pressure area near the exit of the backlight cavity 36. This lower pressure area may force or encourage the backlight cavity gas 25 to enter, flow through, and exit the backlight cavity 36. This may affect the relatively pressure of the backlight cavity gas 25 and the resulting forces on the electronic display 14. The angle of the angled section 49 may be engineered and adjusted to provide a desirable flow through the backlight cavity 36 and resulting force on the electronic display 14.
The amount or speed of the circulating gas 24 permitted to enter and exit the backlight cavity 38 (the backlight cavity gas 25) may be predetermined to account for anticipated bowing of the electronic display 14. Indeed, the amount or speed of the backlight cavity gas 25 may determine the pressure of the backlight cavity gas 25, and thus the resulting force on the electronic display 14. For example, without limitation, enough resulting force may be desirable to substantially cancel out the bowing of the electronic display 14. However, too much resulting force may compress the electronic display 14, resulting in image distortion and/or damage to the electronic display 14. In exemplary embodiments, a pressure difference between 0-0.5 psi between the circulating gas 24 flowing through the first gas pathway 22 and the backlight cavity gas 25 may be desirable, though any relative pressures are contemplated. For example, without limitation, the supports 47, the brackets 48, and the angled section 49 may be sized to create a predetermined relative pressure drop. Similarly, the angle of the angled section 49 may be selected to create a predetermined relative pressure drop. It is contemplated that other control devices may be used to control the amount or speed of the backlight cavity gas 25 such as, without limitation, fans, structural obstructions, diffusers, filters, throttles, valves, flow splitters, or the like.
As can be seen in both
As can be seen, the pressure of the backlight cavity gas 25 located in the backlight cavity 38 is relatively low as compared to the pressure of the circulating gas 24 located in the first gas pathway 22 along the entirety of the first gas pathway 22. The resulting pressure drop may create forces which counteract the bowing of the electronic display 14 that may otherwise occur, leading to decreased or eliminated bowing as shown in this figure. It is notable that while the pressure differential (here, a relative pressure drop) between the data points in the backlight cavity 36 and the corresponding data points in the first gas pathway 22 may be relatively small, when multiplied by the number of square inches in the corresponding electronic display 14, the resulting forces can be significant.
A first exit gap 45 may be located between the support 47 and the rear plate 32. In exemplary embodiments, the second exit gap 43 may be located between a distal end of the support 47 and the front surface of the rear plate 32. A second exit gap 43 may be located between the bracket 48 and the housing 16. Alternatively, or in addition the second exit gap 43 may be located between the angled section 49 and the housing 16. In exemplary embodiments the portion of the housing 16 defining the second exit gap 43 may be a sidewall of the housing 16 which also defines a portion of the electronics cavity 34. The first exit gap 45 and the second exit gap 43 may permit the backlight cavity gas 25 to escape the backlight cavity 36 and rejoin the remainder of the circulating gas 24.
A second entrance gap 41 may be located between the support 47 and the rear plate 32. In exemplary embodiments, the second entrance gap 41 may be located between a distal end of the support 47 and the front surface of the rear plate 32. A first entrance gap 39 may be located between the brackets 48 and the housing 16. In exemplary embodiments the portion of the housing 16 defining the first entrance gap 39 may be a sidewall of the housing 16 which also defines a portion of the electronics cavity 34. The second entrance gap 41 and the first entrance gap 39 may permit a portion of the circulating gas 24 (i.e., the backlight cavity gas 25) to separate from the remainder of the circulating gas 24 and enter the backlight cavity 36.
As previously described, in exemplary embodiments the first entrance gap 39 is smaller than the second exit gap 43. In exemplary embodiments the second entrance gap 41 is smaller than the first exit gap 45. However, any size first entrance gap 39, second exit gap 43, second entrance gap 41, and first exit gap 41 is contemplated.
Although the flow of the ambient air 44 and the circulating gas 24 may be shown and described herein with respect to particular directions and orientations, it is contemplated that the ambient air 44 and the circulating gas 24 may flow in other directions. For example, without limitation, ambient air 44 and circulating gas 24 shown as flowing clockwise may flow counter-clockwise, when shown flowing vertically from top to bottom may flow from bottom to top, when shown flowing horizontally from right to left may flow from left to right, when shown flowing vertically may flow horizontally, when shown flowing horizontally may flow vertically, and the like.
Any embodiment of the present invention may include any of the optional or preferred features of the other embodiments of the present invention. The exemplary embodiments herein disclosed are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. Having shown and described exemplary embodiments of the present invention, those skilled in the art will realize that many variations and modifications may be made to the described invention. Many of those variations and modifications will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.
This application is a continuation of U.S. non-provisional patent application Ser. No. 15/964,258 filed Apr. 27, 2018, which claims the benefit of U.S. provisional patent application Ser. No. 62/491,123 filed Apr. 27, 2017, the disclosures of all of which are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 62491123 | Apr 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15964258 | Apr 2018 | US |
| Child | 16502515 | US |
