1. Field of the Disclosure
Embodiments disclosed herein generally relate to a light-emitting display architecture. More specifically, embodiments disclosed herein relate to an improved light-emitting display architecture with pixel nodes for use in various industries.
2. Background Art
Display units for entertainment, architectural, and advertising purposes have commonly been constructed from numbers of light-emitting elements, such as light-emitting diodes (“LEDs”) or incandescent lamps mounted onto flat panels. These light-emitting elements may be selectively turned on-and-off to create patterns, graphics, and video displays for both informational and aesthetic purposes. It is well known to construct these displays of tiles or large panels, each containing several light-emitting elements, which may be assembled in position for an entertainment show or event, or as an architectural or advertising display. Examples of such systems are disclosed in U.S. Pat. Nos. 6,813,853, 6,704,989, 6,677,918, and 6,314,669.
Large video displays used in advertising, sports, and other public video applications are built using a combination of plastic housing and structural components. These video displays generally house a circuit board containing light-emitting diodes, power distribution, and driver electronics. The assemblies are well known and may be supplied as single pixels, as described by Yoksza et al in U.S. Pat. No. 5,410,328, multiple pixel strips, as disclosed by Masanobu Miura in U.S. Pat. No. 5,268,828, and multi pixel modules, as described by Matsumura et al in U.S. Pat. No. 5,785,415. Modifications and refinements of these basic designs are well known and may include the substitution of surface mount emitters for through-hole emitters.
Recently, lighting technology has been applied to create large displays with similar functionality to earlier single pixel displays created by traditional video companies. These low-resolution displays are sometimes used with higher resolution screens and are controlled by the same media servers of the higher resolution screens. As such, many of these systems use communication schemes based on a standard lighting protocol, such as the standard lighting protocol DMX 512, or on a proprietary system such as those disclosed within U.S. Pat. Nos. 6,016,038 and 6,166,496. Addressing in the DMX 512 protocol is normally limited because this protocol requires addressing at each individual fixture. Thus, proprietary protocols along with dip switches or remote boxes have been used for larger installations in order to set addresses. This arrangement may not be ideal for very large installations with large numbers of pixel nodes.
Additionally, the systems used for these large displays are commonly more distributed with components decentralized in order to increase flexibility. For instance, in
Further, low-density video display systems are often made overly complicated by the requirement to either physically address each individual pixel or to physically address pixels in large groups using a central distribution box. A system where each pixel is individually addressed is more adaptable and elegant because the cabling system may be more flexible. Further, a system with a central distribution box is more easily maintained because an employee may change a faulty pixel without having to understand or learn the addressing system.
All video display systems require large numbers of light-emitting elements or pixels acting independently and, thus, have a requirement for the distribution of large amounts of continually changing data. Prior art systems have most commonly used systems based on a shift register design with input driven either directly by computer derived data or video signals. Such large systems are typically not robust or fault tolerant and are subject to interference and failure. In a standard shift register based driver system, the failure of a single driver may cause the loss or failure of an entire string of pixels.
As displays are increasingly used in architectural installations where access for maintenance may be difficult and expensive (or even virtually impossible in the case of a system embedded in a glass window), the need for extreme reliability increases. Accordingly, there exists a need for a light-emitting display driver architecture that improves upon these prior art displays for continued development and success within the various light-emitting industries.
In one aspect, embodiments disclosed herein relate to a light-emitting display driver architecture. The driver architecture includes a wire interface, a host controller electrically connected to the wire interface, and a first pixel node and a second pixel node connected to the wire interface in parallel. The first pixel node and the second pixel node each include a communication unit electrically connected to the wire interface, a control unit electrically connected to the communication unit, a driver electrically connected to the control unit, and a light-emitting element electrically connected to the driver.
In another aspect, embodiments disclosed herein relate to a method of supplying power and data to a light-emitting display driver architecture. The method includes transmitting a power signal and a data signal from a host controller through a wire interface to a first pixel node and a second pixel node connected in parallel across the wire interface, and extracting data from the data signal with the first pixel node based upon a fixed unique ID corresponding to the first pixel node. The method further includes controlling a driver and a light-emitting element of the first pixel node based upon the extracted data.
In yet another aspect, embodiments disclosed herein relate to another light-emitting display driver architecture. The driver architecture includes a first pixel node and a second pixel node each having a light-emitting element, and a frame having a first pixel location and a second pixel location. The first pixel location and the second pixel location each have a fixed unique ID. The first pixel node is disposed at the first pixel location, thereby acquiring the fixed unique ID of the first pixel location, and the second pixel node is disposed at the second pixel location, thereby acquiring the fixed unique ID of the second pixel location.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
Specific embodiments of the present invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures may be denoted by like reference numerals for consistency.
In one aspect, embodiments disclosed herein relate to a light-emitting apparatus with at least two pixel nodes connected in parallel. The pixel nodes each include functional units that enable communication, controlling, and driving of a light-emitting element located in each pixel node. In another aspect, embodiments disclosed herein relate to functional units and a light-emitting element disposed within a highly integrated circuit. In yet another aspect, embodiments disclosed herein relate to a wire interface. The wire interface enables data signals and power signals to be sent between pixel nodes and host controllers. In another aspect, embodiments disclosed herein relate to a frame having a plurality of pixel locations, in which the pixel locations enable data signals and power signals to be sent to specific pixel nodes disposed within the frame.
Referring now to
Further, the host controller 305 may also provide a power signal (not shown) along the wire interface 307. This power signal may then be used to power the pixel nodes 303 and elements (e.g., functional units 308) thereof. As such, a power supply (not shown) may be included within the host controller 305 to provide the power signal, or may be a separate from the host controller 305. In another embodiment, multiple power supplies may be electrically connected in different locations of the light-emitting display driver architecture 301. For simplicity within this description, the host controller 305 will provide the power signal in the remaining embodiments, but a person of ordinary skill in the art will appreciate, as discussed above, that this arrangement could vary.
Continuing with
Because the pixel nodes 303 are connected in parallel to the wire interface 307 to the host controller 305, the pixel nodes 303 are not dependent on neighboring pixel nodes 303 for any reason. For example, if any one of the pixel nodes 303 may catastrophically fail, be purposely turned off, be taken out, or for any other reason generally stop functioning, the remaining pixel nodes 303 in the light-emitting driver architecture 301 may continue to function as intended. This may, therefore, provide advantages over more typical arrangements, such as a daisy chain arrangement (i.e., series arrangement). In the other arrangements, if any one node stops functioning, or begins functioning incorrectly, any associated or neighboring nodes may be affected and, in some cases, also cease to function correctly. Further, the parallel arrangement of the pixel nodes 303 may also allow for a single data signal to be sent from a host controller 305. This may allow for simple wiring within the wire interface 307, thereby making the wire interface 307 less burdensome and less error prone. Furthermore, because only a single data signal may be propagating on the wire interface 307 from a host controller 305, any multi-signal interference may be reduced, if not all together avoided.
As shown above, each pixel node 303 may comprise the functional units 308 of the communication unit 309, the control unit 311, the driver 313, and the light-emitting element 315. As such, the communication unit 309 may communicate (i.e., send and/or receive data signals) with the host controller 305 or other pixel nodes 303, and the control unit 311 may control and process received data signals into control signals. The control signals from the control unit 311 may then control the driver 313 to drive (i.e., selectively turn on-and-off, vary light color or intensity) the light-emitting element 315. This arrangement of the functional units 308 within the pixel nodes 303 may allow for the host controller 305 to provide a single data signal along the wire interface 307. As such, this greatly decreases the complexity of the host controller 305. Further, with each node 303 having this arrangement of the functional units 308, each pixel node 303 may have the capability to operate independent of all other pixel nodes 303.
Those having ordinary skill in the art will appreciate that, although embodiments disclosed herein are only shown with one light-emitting element disposed on and electrically connected to each pixel node, the invention is not so limited. In other embodiments, multiple light-emitting elements, such as multiple LEDs, may be disposed on each pixel node. In such a case, the LEDs may emit different colors, such as red, green, and blue, as is common for a pixel node comprised of LEDs.
Further, the pixel node 303 may contain the functional units 308 within an integrated circuit, such as a highly integrated circuit. For example, the integrated circuit may be an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a complex programmable log device (CPLD), system-on-chip (SOC) design, or any other integrated circuit well known in the art. The integrated circuit having the functional units 308 allows each pixel node 303 to be very compact, dense, and small. As a benefit, the light-emitting element 315 within the pixel node 303 may then be a larger portion of the overall pixel node 303. Further, the use of this integrated circuit may allow for each pixel node to be placed within very close proximity while still providing the benefit of a simple wire interface. Those having ordinary skill in the art will appreciate that not all of the functional units need be included within the integrated circuit. Rather, benefits from using the integrated circuit may be seen by incorporating at least one of the functional units, such as a larger or more complex functional unit, within the integrated circuit.
Furthermore, the pixel nodes may also be placed a greater distance from each other because no longer are they limited by the distance to any of the global functional units. For example, in the prior art, a light-emitting display driver architecture may only incorporate one driver and one control unit to control all of the pixel nodes and light-emitting elements of the architecture. As such, it may be expensive and impractical to boost the signals from both the driver and the control unit, in addition to any other data signals and power signals, along the path from one pixel node to the next pixel node. However, by incorporating the functional units, as shown in
As such, including the functional units within the pixel node into an integrated circuit may allow for a simpler design process of the light-emitting display driver architecture. For example, the amount and/or complexity of the data sent between the host controller and the pixel nodes is reduced, thereby reducing or eliminating any need for internal data buss lines for communication.
In one embodiment, when a single data signal is sent from the host controller 305 along the wire interface 307, each pixel node 303 may be configured to extract a portion of the data signal from the wire interface 307 corresponding to each pixel node 303. As such, this may possible because each pixel node 303 has a unique address associated with each pixel node 303. The unique address corresponds to a specific portion of the data signal that the host controller 305 is broadcasting along the wire interface 307. Therefore, in one embodiment, the communication unit 309 of the pixel node will enter a listening mode in which the communication unit 309 reads, or listens to, the data signal that is propagating from the host controller 305 on the wire interface 307. Upon reading data from the data signal that corresponds to the pixel node 303, the communication unit 309 will extract or relay the corresponding data portion to the remainder of the pixel node 303, such as the control unit 311 of the pixel node 303, so that the pixel node 303 may process the data signal portion and drive the light-emitting element 315 according to the data signal.
In one embodiment, the unique address is assigned to the pixel node 303 based on a discovery process mode for the host controller 305. In this mode, the host controller 305 may send a request to all, or a selection, of the pixel nodes 303, thereby requesting that each pixel node 303 return a pixel node signal containing a fixed unique identification (ID) of the pixel node 303 (discussed further below). In another embodiment, when a pixel node 303 is positioned or installed within the light-emitting display driver architecture 301, the pixel node 303 may then send the pixel node signal along the wire interface 307 to the corresponding host controller 305. As such, the host controller 305 may then send back to the pixel node 303 the unique address, thereby enabling the pixel node 303 to extract the associated data portion from the data signal that the host controller 305 broadcasts on the wire interface 307.
Referring now to
Further, rather than defining the fixed unique ID with a local storage unit connected to the pixel node, the fixed unique ID 417 may be defined by a physical feature of the pixel node. For example, the pixel node may have a unique radio frequency identification, a unique reflective surface (e.g., bar code), a unique resistor, a unique capacitance value, a unique groove or bump structure, or any other well known physical feature known in the art that may identify the pixel node. The physical feature may then be detected by a functional unit electrically connected to the pixel node whenever the fixed unique ID is used for identification.
Further, the fixed unique ID may be defined by a physical feature of the pixel location which is identified by the pixel node. This may provide the advantage that all pixel nodes may be manufactured completely identically and interchangeably. Referring now to
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In
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Further, those having ordinary skill in the art will appreciate that other physical features may be used to define the fixed unique ID at the pixel locations. For example, in one embodiment, each pixel location may include a conductor with a path to a Ground. A variance in electrical characteristics of an internal circuit may then be used to define the fixed unique ID of the pixel location. Further, in another embodiment, each pixel location may include a physical indentation system to define the fixed unique ID. The indentations may be bumps, perforations, grooves, a raised area on a flat surface, any combination thereof, or any other indentations known in the art. Furthermore, the pixel locations may include metal slugs that the pixel node is capable of detecting using signal processing techniques known in the art. Furthermore still, the pixel locations may include magnetic elements that the pixel node is capable of detecting, such as by using signal processing techniques known in the art, including, but not limited to, Hall Effect sensors. Furthermore still, the pixel locations may include a small infra-red (IR), ultra-violet (UV), or visible light emitter to illuminate a unique pattern at the pixel location. An IR receiver included within the pixel node may detect the unique pattern illuminated to determine a fixed unique ID from the IR emitter at the pixel location.
In another embodiment, the host controller may then store the fixed unique IDs in a routing record. The routing record may then be used to map the wiring of the display architecture. The routing record may be used for trouble shooting and to enable the system to route around any problems, such as catastrophic driver failures and cut or disconnected cables.
Referring now to
Regardless, when the host controller 1105 sends the data signal, the data signal is split into a two components (e.g., the D+ and D− components) and sent over the two wires 1135 and 1137. The pixel node 1103 then may receive a difference between the two components, thereby acquiring the data signal. In such a configuration, the pixel node 1103 may ignore the power signal (e.g., the V+ and V− components) with respect to Ground to provide a tolerance for a Ground offset. As such, minor changes in Ground potential between the host controller 1105 and the pixel node 1103 may not affect the data signal being received by the pixel node 1103. For example, when grounding, the wires 1135 and 1137 may have the same impedance to Ground, so any interfering fields or currents may induce the same voltage in both wires 1135 and 1137. Because the pixel node 1103 may only receive or read the difference between the wires 1135 and 1137 when acquiring the data signal, the wire interface 1107 may not be affected. In a similar embodiment, the pixel node 1103 may be sending a pixel node data signal using differential signaling, in which the host controller 1105 may be receiving the differential pixel node data signal.
In
All three wires 1137, 1139, and 1141 are electrically connected to the host controller 1105 and the pixel nodes 1103 are connected in parallel across the three wires 1137, 1139, and 1141. This embodiment may also use differential signaling for the data signal, in which the D+ and the V+ signal are sent on individual wires 1139 and 1141. This may be useful when accommodating for a more powerful or noisy V+ component of the power signal.
In
In
As described above, the pixel nodes may include functional units such as the communication unit, the control unit, the drive unit, and the light-emitting element. However, in another embodiment, as shown in
Further, another embodiment may include an additional storage unit for the additional functional unit 1248. This additional storage unit may, for example, store data to be displayed by the corresponding pixel node. This may also allow the host controller to offline upload data to the pixel units. Thus, the data does would not have to be uploaded all in real time. Also, if there is data that is frequently reused, the data may be stored in the storage unit and, rather than transferred from the host controller multiple times, may simply send a command to pull the reusable data from the additional storage unit of the pixel node. Thus, such an additional storage unit may provide the advantage of saving bandwidth and allowing offline data transfers.
Referring now to
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The MCU 1555 and/or additional functional units 1548 within the pixel node 1503 may also produce control signals to control drivers 1513. The outputs from the drivers 1513 may then be used to control other functional units of the pixel node 1503, such as light-emitting elements connected to the driver 1513. Further, the MCU 1555 and/or additional functional units 1548 may be provided with inputs 1551, thereby allowing data signals from the functional units 1548 of the pixel node 1503, or external sensor units, to be routed back to the MCU 1555. As such, the MCU 1555 may require logic and/or further functional units disposed within the MCU 1555 or electrically connected thereto, such as Read-only-Memory (ROM), Flash Memory, Random Access Memory (RAM), Frequency Oscillators (OSC), Arithmetic Logic Units (ALU), Digital Signal Processors (DSP), Input/Output circuitry (I/O), Analogue to Digital converters (ADC), Digital-to-Analogue converters (DAC), Temperature Sense elements (TEMPSENSE), Pulse Width Modulation outputs (PWM), in addition to any other elements known in the art.
Similarly still,
Further, in this embodiment, a communication unit 1753 is connected across the data wires 1741 and 1745 to extract the data signal for a state machine logic unit 1761. The state machine logic unit 1761 then controls the reception of the data signal from the data wires 1741 and 1745 and parses it into actions. For example, the state machine logic unit 1761 may identify the start of a message, interpret the command code, execute the required command, and restore itself in readiness to receive the next message. Because of the basic operations of the state machine logic unit 1761, the state logic unit may be replaced by an MCU. For example, the state machine logic unit 1761 performs functions similar to the MCU 1555 of
Referring now to
In such an embodiment, the controller 1975 may be capable of recognizing and routing around failures of any of the switches 1967, 1969, 1971, and 1973 or light-emitting elements 1915 and 1916. For example, if the controller 1975 recognizes that switch 1973 has failed in the open position, then controller 1975 will open switch 1969 and close switch 1971. Switch 1967 may then be opened and closed by controller 1975 to allow current to pass through light-emitting element 1916 as required. Alternatively, if the controller 1975 recognizes that switch 1973 has failed in the closed position, then controller 1975 will open switches 1967 and 1971. Switch 1969 may then be opened and closed by controller 1975 to allow current to pass through light-emitting element 1915 as required. Alternatively still, if the controller 1975 recognizes that light-emitting element 1915 has failed, then controller 1975 will open switches 1973 and 1969 and close switch 1971. Accordingly, switch 1967 may then be opened and closed by controller 1975 to allow current to pass through light-emitting element 1915 as required. As such, controller 1975 may reconfigure the redundant circuit arrangement to compensate for failure in either the opened or closed position of any of the switches 1967, 1969, 1971, and 1973, or failure of either of the light-emitting elements 1915 and 1916.
Those having ordinary skill in the art will appreciate that other schematics and layouts may be constructed to achieve a redundant circuit arrangement as explained herein. For example, rather than having the light-emitting element arranged in a redundant circuit arrangement, any one of the possible functional units, or combination of the functional units, may be arranged in a redundant circuit arrangement. Further, switches 1967, 1969, 1971, and 1973 are here shown diagrammatically as simple switches. However, those having ordinary skill in the art will appreciate that the switches 1967, 1969, 1971, and 1973 may be constructed as any type of switch known in the art, such as metal-oxide-semiconductor field-effect transistors (MOS-FETs).
For example,
Another embodiment may use junction points and provide a wire interface with redundant connectivity. Thus, the light-emitting display driver architecture may take advantage of the redundant connectivity of the wire interface and the fixed unique IDs to close any gaps in the data distribution by providing alternate data paths on an active basis during operation of the display. This active redundancy may also provide multiple data signal inputs from multiple host controllers to the wire interface as opposed to the one-in, one-out topology. Thus, failures of data distribution may be mitigated and the display may continue to operate.
In another embodiment, a wire interface topology is chosen such that no single link, wire, or pixel node, is critical to the overall connectivity of the system allowing the use of the fixed unique IDs to enable routing around the failure of any single element. Such an embodiment may further provide protection against multiple simultaneous failures of individual data paths or nodes. In another embodiment, the host controller may dynamically monitor pixel nodes, and/or specific functional units within each pixel nodes (e.g. drivers), and bypass a failed pixel node or functional unit.
Referring now to
In addition to the above discussed benefits and advantages, embodiments of the present disclosure may provide for one or more of the following advantages. First, embodiments disclosed herein may provide for a light-emitting display driver architecture having a three wire interface (V+D+, V−D−, Ground), rather than the legacy four-wire interface. This may enable the data signal and power signal to be sent over the same wires. Further, differential data signaling may be used in such an embodiment to reduce radio frequency interference (RFI), electromagnetic interference (EMI) emission, and noise sensitivity.
Further, embodiments disclosed herein may provide for a light-emitting display driver architecture having the pixel nodes connect in parallel on the wire interface. This arrangement may help avoid any propagation of errors within the light-emitting display driver architecture. The parallel structure may also be coupled with the bidirectional signaling (host controller-to-pixel node, pixel node-to-host controller, pixel node-to-pixel node) to enable communication in both directions between the host controller and the pixel nodes.
Furthermore, embodiments disclosed herein may provide for a light-emitting display driver architecture having multiple pixel nodes share a common set of functional units. For example, in an embodiment in which a flash memory of a MCU is shared between multiple pixel nodes, the flash memory may provides non-volatile storage of pixel node parameters and may store non-volatile pixel node history data (e.g. black box) and/or power up data (e.g. customer logo).
Finally, embodiments disclosed herein may provide for a light-emitting display driver architecture that has a plurality of functional unit combinations and integrations. Having such a plurality of functional units may allow for the pixel nodes to perform multiple internal functions, including: reset; test pattern; accept unique serial number; self addressing (set relative address in node string array); node monitoring; node aging calculation and monitoring and compensation; node calibration; data demultiplexing from ordered data set in multi-node data field of message; fault monitoring; temperature monitoring; system verification (loop back messaging to controller); video frame sync timing reference (e.g. VSYNC); and video pixel data (e.g. an ordered sequence of data describing pixel node values.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
This application claims benefit, under 35 U.S.C. § 119, of U.S. Provisional Application Ser. No. 60/812,660, filed on Jun. 9, 2006 and entitled “Driver Architecture for Light Emitting Displays” in the name of Jeremy Hochman, David Main, Nils Thorjussen, Christopher Varrin, and Matthew Ward. This application also claims benefit of U.S. Provisional Application Ser. No. 60/848,988, filed on Oct. 3, 2006 and entitled “Multi-Drop Distributed Node Micro-Controller Architecture” in the name of David Main. This application also claims benefit of U.S. Provisional Application Ser. No. 60/892,378, filed on Mar. 1, 2007 and entitled “Robust Addressing System for Large, Pixel Based, Displays” in the name of Matthew Ward. This application also claims benefit of U.S. Provisional Application Ser. No. 60/896,788, filed on Mar. 23, 2007 and entitled “Display with Interactive Pixels” in the name of David Main and Christopher Varrin. The disclosures of these U.S. Provisional Applications are incorporated herein by reference in their entirety.
Number | Date | Country | |
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60812660 | Jun 2006 | US | |
60848988 | Oct 2006 | US | |
60892378 | Mar 2007 | US | |
60896788 | Mar 2007 | US |