One major problem with conventional light emitting diode (“LED”) light arrays relates to heat, based on the fact that increasing the temperature of a junction increases the current flow and this, in turn, causes increased heating and even higher temperatures, until finally the LEDs will fail. This problem may be partially alleviated, but hot solved, by the use of current limiting resistors and by providing heat sinks with sufficient ventilation to cool the heat sinks. However, the aforementioned problem relating to heat becomes more acute in mass LED displays where individual LEDs are mounted in close proximity to one another and where space may be limited to the point where current limiting resistors cannot be mounted. Mass LED light arrays are needed in applications where an efficient form of illumination is required to replace conventional fluorescent tubes and where illuminated vertical and horizontal LED panels are required. Additionally, mass LED light arrays are needed in creating scalable display screens (such as television screens).
In consideration of the above problems, in accordance with a first aspect, LED panels are provided that are made using a flexible of solid platform in a mesh form, the mesh being constructed from a plurality of conductive strips which themselves act as both electrical and heat conductors. The open mesh construction allows air to circulate freely around the conductor strips of the mesh and around the LED packages mounted on the mesh; thereby, maintaining the whole assembly at a low operating temperature.
In accordance with another aspect of the invention, a multi-layer LED panel structure is provided, with LEDs, e.g., comprising 3 LED chips in 1 package, bonded on a bottom layer. According to this aspect, the bottom layer conducts thermal energy and acts as an electrical ground, while the other layers act as independent buses for individual control of color display, and provide electrical conduction and LED addressing.
In yet another aspect, the present invention is directed to a flexible mesh display device, comprising a first plurality of braided wire conductive strips, arranged in a first direction; a second plurality of braided wire conductive strips, arranged in a second direction such that the first plurality of conductive strips and the second plurality of conductive strips form plural intersections therebetween; and a plurality of light emitting diode (LED) modules, each module forming a pixel of the display device, each of the plurality of LED modules being arranged at one of the plural intersections, each LED module configured to receive display signals from at least one of the braided wire conducting strips and display light in accordance with the received signals.
In another aspect, each of the braided wire conductive strips of each of the first and second plurality of conductive strips has a flattened cross-sectional profile.
In another aspect, the first and second plurality of braided wire conductive strips contact one another at the intersections.
In another aspect, each LED module has a microcontroller and one or more ports, the microcontroller being configured to check a status of at least one of the one or more ports; and, if the status of the port corresponds to a predetermined state, assign the LED module to which the microcontroller belongs to a first display address, and send signals to the microcontrollers of other ones of the LED modules in the display device, the signals assigning respective further display addresses to the other ones of the LED modules in the display device.
In another aspect, the display device further comprises a display memory storing current display information associated with the addresses of the pixels of the display, the information stored in the display memory being accessible by each of the microcontrollers of the LED modules, such that the microcontrollers can retrieve current information for display.
In another aspect, the display device further comprises a display controller, the display controller being configured to update the display information stored in the display memory.
In another aspect, each LED module includes one or more LEDs.
In another aspect, the LEDs in each LED module include red, blue and green LEDs. The one or more LEDs can also be a red, a blue, a green or a white LED.
In another aspect, each LED module is electrically connected to at least one of the conductive strips.
In another aspect, each LED module is electrically connected to at least one of the conductive strips by contacting the at least one conductive strip.
In another aspect, each LED module is electrically connected to at least one of the conductive strips by a lead line from the LED module to the at least one conductive strip.
In yet another aspect, the present invention is directed to a multi-layer display device, comprising a first layer comprising a base layer that conducts at least thermal energy; a second layer, arranged to contact, directly or indirectly, the first layer, the second layer comprising one or more second layer independent buses, arranged in a first direction, for controlling at least one of R, G, and B color control and electrical ground; a third layer, comprising one or more third layer independent buses arranged in a second direction different from the first direction, the third layer independent buses controlling the at least one of R, G, and B color control and electrical ground that are hot controlled by the second layer independent buses; and a plurality of light emitting diode (LED) modules, each module forming a pixel of the display device, each of the plurality of LED modules being mounted on the first layer, each LED module configured to receive display signals from at least one of the second layer independent buses and the third layer independent buses and display light in accordance with the received signals.
In another aspect, the second layer comprises the independent buses for R, G, and B color control, and the third layer comprises the independent buses for electrical ground.
In another aspect, the second layer comprises the independent buses for two of R, G, and B color control, and the third layer comprises the independent buses for electrical ground and the independent buses for color control hot located in the second layer.
In another aspect, each LED module has a microcontroller and one or more ports, the microcontroller being configured to check a status of at least one of the one or more ports; if the status of the port corresponds to a predetermined state, assign the LED module to which the microcontroller belongs to a first display address, and send signals to the microcontrollers of other ones of the LED modules in the display device, the signals assigning respective further display addresses to the other LED modules in the display device.
In another aspect, the display device further comprises a display memory storing current display information associated with the addresses of the pixels of the display, the information stored in the display memory being accessible by each of the microcontrollers of the LED modules, such that the microcontrollers can retrieve current information for display.
In another aspect, the display device further comprises a display controller, the display controller being configured to update the display information stored in the display memory.
In another aspect, each LED module includes one or more LEDs.
In another aspect, the LEDs in each LED module include red, blue and green LEDs. The one or more LEDs can also be a red, a blue, a green or a white LED.
In another aspect, the first, second and third layers are flexible.
In yet another aspect, the present invention is directed to a light emitting diode (LED) device, comprising (a) a plurality of LED modules, each LED module including: one or more LEDs; a microcontroller; and one or more ports, the microcontroller being configured to check a status of at least one of the one or more ports; if the status of the port corresponds to a predetermined state, assign the LED module to which the microcontroller belongs to a first display address, and send signals to the microcontrollers of other ones of the LED modules in the display device, the signals assigning respective further display addresses to the other LED modules in the LED device; and (b) a display memory, coupled to the plurality of LED modules, the display memory storing a current display status for each of the LED modules in the LED device.
The figures are for illustration purposes only and are not necessarily drawn to scale. The invention itself, however, may best be understood by reference to the detailed description which follows when taken in conjunction with the accompanying drawings in which:
According to a first embodiment, a mesh type LED panel is formed using conductive strips that have an insulating substrate bonded to one side of the conductor strip so that a longitudinal strip is isolated from a transverse strip above it While the term display is used generally, it is known in the art that an LED display acts also as an illumination device. Thus, when the term “display” is used, that term is intended in this application to cover the use of LEDs in displays and in illumination devices.
As shown in
An LED package 22 is connected, at each intersection of conductive strips 8 and 20. At each intersection, the LED package 22 is electrically connected to longitudinal conductive strip 20 by solder 24, and to transverse conductive strip 8 by solder 26. As will be appreciated, the invention is not limited to this manner of electrical connection and the connection may be made by any other manner of electrical connection known to those skilled in the art, including, but not limited to welding.
In the embodiment shown in
In the embodiments shown in
The LED light array display device discussed above can also be formed using a flexible mesh, instead of the rigid mesh embodiment shown in
As can be seen from
In the flexible mesh embodiment, each LED package 122 is mounted on the transverse conductor strip 108 by chip, bonding. Placement of the LED chips may be done, e.g., manually or by a pick-and-place machine.
In the embodiment shown in
For example, as shown in
The embodiments illustrated in
As can be seen in
By providing such a four-layer mesh, which can employ any or all of the techniques described above in connection with the single color display embodiments, a color LED light array can be achieved. It is noted that the multi-layer embodiment may used a rigid or a flexible mesh, and may employ any known manner of electrical connection at the intersections, such as, but not limited to, those described above with respect to the embodiments of
The 4-layer structure shown in
Another multi-layer embodiment is illustrated, with respect to
As can be seen in
To achieve display drive, each pixel in the LED light arrays can be assigned an individual address, where each pixel is a LED module that includes a microcontroller and a plurality of LEDs (e.g., three (RGB), or four (RGBW) LEDs).
An example of such an LED module 500 suitable for use in a matrix display, such as those described in connection with the above embodiments, is shown in
As can be seen in
Each LED module 500 preferably comprises a microcontroller 502 that (a) receives data from its own data port and receives commands and graphic signals, (b) performs the processing necessary for the pixel (LED module) on which it is located to participate the dynamic address system, and (c) drives the LED(s) in its own module, with together form a pixel.
The LED modules 500 are preferably connected as follows:
That is, in this example, the microcontroller of the LED module in the bottom right hand corner, upon start up, or reset, for example, or at another time or periodically, cheeks the status of its ports and recognizes the status of the in-ports as having no connection (an open state in the illustrated embodiment). The LED module's microcontroller recognizes, from the status of these ports, that it has position 0, 0 and assigns itself that address. In contrast, the microcontrollers of the other LED modules would, upon checking their in-ports, recognize that they do have a connection, and would therefore not set their own address as 0, 0.
The microcontroller of LED module 0, 0 then starts the dynamic addressing by communicating its position to its neighboring LED modules as No. 0, 0 pixel and assigning thereby its neighbors' addresses as Nos. 0, 1 and 1, 0. The pixels with addresses so assigned then communicate with their succeeding neighbors, in a daisy chain recursion, assigning addresses as shown in
In a preferred embodiment, all of the LED modules 500 share a single data line and each module sends to the remote display memory 506 requests for data (e.g., display-data), which data is changed and refreshed by a display controller 508.
The conventional manner, of handling display boards, by static addressing in which each pixel is pre-assigned a fixed address during manufacture, and is unable to monitor any changes, particularly as to shape or resolution in the display. Because dynamic addressing allows the pixels to reconfigure their addressing based on the signals received at an LED module, it can achieve flexibility as to installation, maintenance and failure detection.
The display controller 508 would, typically be programmed to update the display data in the display memory 506, and each pixel (LED module) picks up its respective data from the display memory 506. A function of the display controller 508 is to change and refresh the display memory. The display memory 506 and display controller 508 would preferably communicate with one another by the use of address bus, 510 and data bus 512, as is known to those skilled in the art.
Although the above description of dynamic addressing of a matrix display is the preferred method, other methods of driving a display using dynamic addressing are possible, such as, but not limited to having the display signals sent by the display controller, for example, received by each LED module, but only acted upon by the LED module haying the address of the display instruction from the controller.
A single-layer mesh LED light array, e.g., one of the arrays shown in
As discussed above, the pixel (LED module) can monitor in real-time the change in shape or in the number of pixels of a display unit, re-assigning its own address according to the changes. With this unique characteristic, a display mesh comprising such pixel (LED modules) can be split into multiple small display units or integrated into a large display unit, while maintaining its structural shape. The microcontroller of each pixel (LED module) can note the changes, e.g., to the state of its ports, independently and re-assign its own address and pick up the data from the corresponding display memory.
Similarly, the pixel (LED modules), using dynamic addressing, can be re-arranged into any desired shape and the displayed image can automatically re-scale to a suitable size without distorting the image. This is in contrast to conventional LED display modules in which the image would be distorted if the module were to be rearranged into another shape without reconfiguring the display controller. Such pixel (LED modules) may be used to create a scalable display screen, such as a scalable television screen. Such a scalable television screen may be split into multiple small television screens displaying different channels or programs.
Illumination
Panels comprising the LED light arrays described in connection with the above embodiments may be constructed in a shape of a square, rectangle, parallelogram, or rhombus, and the pitch of the LEDs may be varied to suit the requirements for the source light intensity. The LED light arrays in accordance with the present invention may be used in standard lighting fittings or lighting displays which required the use of rectilinear lighting modules. For example, the LED light arrays may be arranged as long narrow strips for applications met by fluorescent tubes, or in squares for flush fittings in false ceilings. Alternatively, the LED light arrays may form either part or all of an illuminated ceiling or wall. As shown above in reference to
The two-layer embodiments of the present invention may be used for a fixed single or multicolor use. The multi-layer embodiment of the present invention may have single colored LEDs, or multiple LEDs (e.g., three LEDs in red, blue and green) which may be used for full and variable color applications.
Display Screens
With the dynamic addressing system described above, the multi-layer mesh construction of the LED light arrays may be used in the construction of dynamic display screens including large television screens or “television walls.” Identical individual meshes may be mounted together, the unique address of each pixel (which comprises a microcontroller and a plurality of LEDs (e.g., three (RGB) or four (RGBW) LEDs)) being dynamically assigned.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that the present invention be limited only by the claims and the equivalents thereof.
This utility application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/151,143, filed Feb. 9, 2009, which is hereby incorporated by reference.
Number | Date | Country | |
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61151143 | Feb 2009 | US |