Patent Publication Number: US-2016232839-A1

Title: Electroluminescent status display

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/114,023, filed on Feb. 9, 2015, the entire content of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Conventional status displays, e.g., for electronic equipment such as a computing or storage device, often include little more than one or more relatively small light-emitting diodes (LEDs), which may provide a binary status indicator (e.g., on/off, active/inactive, error/no error, etc.). Alternatively, a status display may include a somewhat larger liquid crystal display (LCD) or screen for status information, but an LCD display or screen is more expensive and is usually still relatively small compared to the equipment being monitored. 
     The relatively small size of such conventional status displays makes them hard to see, notice or interpret from a distance, e.g., from across an equipment room or at the end of a row of equipment racks or peering through windows into an equipment room. Abnormal conditions may not be noticed immediately, and may require a technician to inspect the status display at a closer distance (e.g., within five feet of the equipment). Furthermore, the relatively plain nature of the status display makes them appear to be relatively nondescript to a casual observer. Criticality of a critical alarm may be comprehended less quickly. 
     Therefore, what is needed is an improved status display that can help overcome the shortfalls of the conventional art. 
     BRIEF SUMMARY 
     Embodiments in accordance with the present disclosure provide an improved equipment status display by use of one or more electroluminescent displays. Embodiments further include a system and method to use such an improved equipment status display. 
     Embodiments in accordance with the present disclosure provide a system to provide an electroluminescent status display, the system including a sensor configured to detect a condition, a driver circuit to generate a control signal when the condition is detected by the sensor, and an electroluminescent display coupled to the driver circuit to receive the control signal, wherein the control signal controls light from the electroluminescent display. 
     Embodiments in accordance with the present disclosure provide a method to provide an electroluminescent status display, the method including sensing a condition by use of a sensor, generating a control signal by use of a driver circuit when the condition is sensed by the sensor, and emitting electroluminescent light by use of an electroluminescent display coupled to the driver circuit, wherein the control signal controls emission of the electroluminescent light. 
     The preceding is a simplified summary of embodiments of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various embodiments. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components, and wherein: 
         FIG. 1  illustrates a schematic layer diagram of a conformal electroluminescent emitter as known in the art; 
         FIG. 2  illustrates a functional block diagram of an electroluminescent status display system in accordance with an embodiment of the present disclosure; 
         FIG. 3  illustrates a perspective view of a rack-mountable electronic equipment in accordance with an embodiment of the present disclosure; and 
         FIG. 4  illustrates a method in accordance with an embodiment of the present disclosure. 
     
    
    
     The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. Optional portions of the figures may be illustrated using dashed or dotted lines, unless the context of usage indicates otherwise. 
     DETAILED DESCRIPTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments or other examples described herein. In some instances, well-known methods, procedures, components and circuits have not been described in detail, so as to not obscure the following description. Further, the examples disclosed are for exemplary purposes only and other examples may be employed in lieu of, or in combination with, the examples disclosed. It should also be noted the examples presented herein should not be construed as limiting of the scope of embodiments of the present invention, as other equally effective examples are possible and likely. 
     As used herein, the term “module” refers generally to a logical sequence or association of steps, processes or components. For example, a software module may comprise a set of associated routines or subroutines within a computer program. Alternatively, a module may comprise a substantially self-contained hardware device. A module may also comprise a logical set of processes irrespective of any software or hardware implementation. 
     Electroluminescence (EL) is a known characteristic of certain materials that enables the material to emit light in response to an electrical field. Electroluminescent light may have a relatively vibrant and uniform color that is difficult to achieve by other lighting technologies such as LED backlighting. Electroluminescent displays may also be very thin, thus being amenable to low-profile applications (i.e., thin applications) and flexible applications. Electroluminescent displays are also known to have very fast transition times, and appear to a human to turn on or off instantaneously. 
     At a sub-atomic level, electroluminescence is caused by radiative recombination, also known as spontaneous emission. During radiative recombination, an applied alternating electrical current causes phosphorescent substances to emit photons. EL does not require heat to produce light, meaning that an electroluminescent apparatus is safe, efficient, long lasting, and cool to the touch. 
     Embodiments in accordance with the present disclosure use one or more EL displays to help overcome shortfalls in the background art of equipment status displays, and provide an improved equipment status display. For example, an electroluminescent display allows for embodiments having a relatively larger size of status display compared to the conventional art. Such embodiments would be easier and quicker to see, notice or interpret from a distance, e.g., from across an equipment room or at the end of a row of equipment racks or peering through windows into an equipment room. Abnormal conditions would be noticed more quickly, without necessarily needing a technician to inspect the status display at a closer distance. Furthermore, the relatively eye-catching nature of the status display makes them appear to be highly noticeable to an observer, technician, or the like. Criticality of a critical alarm may be comprehended more quickly. 
     If lights within an equipment room have been dimmed, e.g., to save energy, an electroluminescent display may provide improved visibility in a dimly-lit space. 
     An electroluminescent apparatus as known in the art may be formed by applying various layers of materials as conformal coatings to an object by use of processes known in the art. For example, an electrically conductive base backplane film layer is applied upon a substrate. A dielectric film layer is applied upon the backplane film layer, then a phosphor film layer is applied upon the dielectric film layer. An electrode film layer is applied upon the phosphor film layer using a substantially transparent, electrically conductive material. An electrically conductive bus bar may be applied upon the electrode film layer. A spray conformal coating process may be used to apply at least some of the layers. The electroluminescent phosphor is excitable by an electrical field established across the phosphor film layer such that the device emits electroluminescent light upon application of an electrical charge between the backplane film layer and at least one of the electrode film layer and the bus bar. 
     Embodiments in accordance with the present disclosure may provide both functional and aesthetic benefits by use of a conformal coating electroluminescent display. For example, a conformal coating electroluminescent display may be formed or shaped in an arbitrary shapes (e.g., to reproduce a symbol or graphic such as a trademarked logo), thus providing an aesthetic benefit in addition to a functional benefit. 
       FIG. 1  illustrates a schematic layer diagram of an electroluminescent emitter  10  as known in the art. EL emitter  10  may include a substrate  12 , a primer layer  14 , an electrically conductive backplane electrode layer  16 , a dielectric layer  18 , a phosphor layer  20 , a substantially transparent, electrically conductive top electrode  22 , a bus bar  24  and an optional encapsulating layer  26 . 
     Substrate  12  may be a select surface of any suitable target item upon which EL emitter  10  is to be applied. Substrate  12  may be conductive or non-conductive, and may have any desired combination of convex, concave and reflexed surfaces. 
     Primer layer  14  is a non-conductive film coating applied to substrate  12 . Primer layer  14  serves to electrically insulate substrate  12  from subsequent conductive and semi-conductive layers, discussed further below. Primer layer  14  also preferably promotes adhesion between substrate  12  and subsequent layers. 
     Conductive backplane  16  is a film coating layer that is preferably masked over primer layer  14  to form a bottom electrode of EL emitter  10 . 
     Dielectric layer  18  is an electrically non-conductive film coating layer comprising a material possessing high dielectric constant properties encapsulated within an insulating polymer matrix having relatively high permittivity characteristics (i.e., an index of a given material&#39;s ability to transmit an electromagnetic field). Dielectric layer  18  serves two functions. Firstly, dielectric layer  18  provides an insulating barrier between backplane layer  16  and the superimposed semi-conductive phosphor  20 , top electrode  22  and bus bar  24  layers. In addition, because of the unique electromagnetic polarization characteristics of the dielectric materials, dielectric layer  18  serves to enhance the performance of the electromagnetic field generated between the backplane  16  and top electrode  22  layers when an alternating current (AC) signal  28  is applied between the backplane and the top electrode. 
     Phosphor layer  20  is a semi-conductive film coating layer comprised of a material (e.g., metal-doped Zinc Sulfide (ZnS)) encapsulated within a highly electrostatically permeable polymer matrix. When excited by the presence of an alternating electrostatic field generated by AC signal  28 , the doped ZnS absorbs energy from the field, which it in turn re-emits as a visible-light photon upon returning to its ground state. 
     Top electrode  22  is a film coating layer that is preferably both electrically conductive and generally transparent to light. 
     Bus bar  24  provides a relatively low-impedance strip of conductive material, usually comprised of one or more of the materials usable to produce as conductive backplane  16 . Bus bar  24  is typically applied to the peripheral edge of the lit field. 
     Encapsulating layer  26  is preferably an electrically insulating material applied over the EL emitter  10  stack-up, thereby protecting EL emitter  10  from external damage. Encapsulating layer  26  is also preferably generally transparent to light emitted by the lower layers of EL emitter  10 , and is preferably chemically compatible with any envisioned topcoating materials for the target item of substrate  12  that provide a mechanism for chemical and/or mechanical bonding with topcoating layers. Encapsulating layer  26  may be comprised of any number of aqueous, enamel or lacquer-based products. 
     Embodiments in accordance with the present disclosure provide a relatively large EL display on a visible major surface of an electronic equipment. A visible surface includes a surface that would be visible during normal use. For example, if the electronic equipment is a rack-mounted computing or storage module having a visible major surface in a front direction of the rack, an EL display may be provided at least on the front surface of the module. Alternatively, the EL display may be provided on the rack itself, e.g., on a surface near the top of the rack, or on a portion of the rack adjacent to the side of the electronic equipment. 
     The EL display may be relatively large compared to display indicators of the known art, and/or compared to the size of the visible major surface. For example, the EL display may cover substantially the entire visible major surface, or more that a predetermined percentage of the major surface (e.g., more than 50%, more than 75%, more than 90%, etc.). More than one EL display may be used to cover the visible major surface, in order to provide separate status indicators. If more than one EL display is disposed on the visible major surface, a small portion of the visible major surface between adjacent EL displays may not be covered by one or more layers of the EL displays, forming gaps in those layers between adjacent EL displays. For example, a gap may exist in top electrode layer  22  in order to provide electrical isolation between adjacent EL displays. On the other hand, other layers such as primer layer  14  may extend across the entire visible major surface, including locations between adjacent EL displays. 
     Embodiments in accordance with the present disclosure may allow electronic equipment such as a computer system or a component thereof to provide quick visual identification of a condition (e.g., an error condition that warrants further attention, or a healthy condition that does not require immediate attention). The condition may be reflective of the status of a hardware component such as a circuit board (e.g., overheating, power supply failure, excessive CPU usage, etc.), or of a computer object (e.g., an anomalous state in a finite-state machine such as an intrusion detection, an anomalous state of data such as over-limit or under-limit conditions, and so forth). More generally, the condition may be indicative of hardware and/or software and/or an object-oriented representation of a portion of the system, and may be indicative of a degree of criticality (e.g., critical, warning and healthy). 
     In contrast to status indicators of the known art that use a small LED to act as an indicator of system status, embodiments in accordance with the present disclosure allow light and color alteration or morphing of, but not limited to, the entire front of a system. Embodiments may further indicate status by modulation of the electroluminescent display, e.g., by blinking an EL display on/off, or bright/dim, change colors, etc. 
     Embodiments in accordance with the present disclosure provide an additional benefit by providing enhanced aesthetics to cover the look of a computer or computer object. 
     An EL display may be applied to electronic equipment in a variety of ways. For example, an entire front-facing bezel (and potential other areas) of a system may have applied thereupon a single or multi-layer EL coating, while obtaining electrode power from but not limited to the computer system board (e.g., motherboard), system power supply, or alternate power sources in order to enable proper illumination and color transitioning. During certain events, the illuminated area or areas may morph on/off or change color. 
     Alternatively, if it desired to provide multiple colors to indicate multiple conditions (e.g., green, yellow and red to indicate good, marginal and failure, respectively), separate EL displays on separate portions of the major surface may be provided. Furthermore, because of the relatively larger size affordable by EL displays, the shape of the EL display itself may also be adapted to help indicate the type of condition to be indicated. For example, a red EL display to indicate a critical condition may be shaped like an octagon order to suggest a stop sign. In other examples, an entire front of a system can glow a red color, thus making the system very noticeable and identifiable in a large data center. 
       FIG. 2  illustrates a functional block diagram of an EL display system  200  in accordance with an embodiment of the present disclosure. System  200  includes electronic equipment such as processor  201  or data storage device  203 , which are being monitored by status sensor  205 . Additional electronic equipment or components thereof (not illustrated in  FIG. 2 ) may be monitored, such as transceivers, power supplies, and so forth. Status sensors  205  may sense and report error conditions or lack of error conditions. Error conditions may include hardware errors (e.g., power supply failure, hot spots, over-voltage or under-voltage conditions, etc.), or software errors (e.g., fault conditions such as stack or buffer overflows, timeout or race conditions, high system resource utilization, etc.), or other errors (e.g., anomalous finite-state machine state), or any combination of such errors. 
     Status sensor  205  may include one or more of a hardware-type sensor, a software-based sensor, or an environmental sensor. Examples of hardware-type sensors may include a thermistor for an over-temperature monitor, a fan failure sensor, an over-voltage or under-voltage sensor, etc. Examples of a software-based sensor may include a watchdog timer, a monitoring daemon, an operating system task manager monitor, etc. Examples of an environmental sensor may include an ambient temperature or humidity monitor, a moisture sensor, a vibration sensor, etc. 
     Status sensor  205  may further include a sensor processor and a sensor memory to support sensing function or obtaining sensor readings. For example, if a polling process is used to gather readings from sensors, the sensor processor may be used to control the polling and the sensor memory may be used to store polled readings. Similarly, if an interrupt-driven process is used, the sensor processor may be used to respond to and handle an interrupt request. 
     Optionally, status sensor  205  may also be responsive to an external data signal  211  from an external source. For example, if a central monitoring center or operations center determines that an electronic equipment needs attention, a signal may be sent to status sensor  205  associated with the electronic equipment. In that circumstance, status sensor  205  would detect the presence of external data signal  211  and then cause an EL display on the electronic equipment to change state. 
     Status sensor  205  changes state when a monitored condition occurs or when in response to external data signal  211 . A change of state may be indicated by, e.g., lighting up if normally off, turning off if normally on, changing color or intensity, or changing some other visible aspect such as blinking if not normally blinking, and so forth. 
     Status sensor  205  may be coupled to EL driver  207 , which may accept logical control signals from status sensor  205  (e.g., whether or not an error condition exists) and generate hardware signals to drive one or more EL displays  209 . Hardware signals may include lines of appropriate voltage and frequency to drive EL display  209  (e.g., the AC signal  28  of  FIG. 1 ). EL display  209  may be disposed on a surface of the electronic equipment in order to provide the desired functionality and aesthetic design. A dedicated EL driver  207  may be provided for each EL display  209  that is to be controlled independently. For an EL display  209  capable of being on or off, being “on” may be considered to be an active state of EL display  209 . 
     Multiple status sensors  205  may be provided, e.g., a dedicated sensor for at least some monitored conditions. However, when driving EL driver  207 , at least some sensory conditions may be mapped (i.e., combined) in order to drive a single EL display  209 . For example, all hardware faults may be combined to drive a single EL display  209  that represents the presence of any of the monitored hardware faults. Such mappings may be static, or may be provisionable by the sensor processor. 
       FIG. 3  illustrates a perspective view of a rack-mountable electronic equipment  300  in accordance with an embodiment of the present disclosure. Electronic equipment  300  includes a major front surface  301 , which has disposed thereupon EL displays  303 ,  305 . EL displays  303 ,  305  may be formed from the conformal electroluminescent emitter of  FIG. 1 . Major front surface  301  may be used as substrate  12  for EL displays  303 ,  305 . 
     EL displays  303 ,  305  may provide different colors to provide indication of different conditions. For example, EL display  303  may be green when lit to provide an indication of good status, and EL display  305  may be red when lit to provide an indication of an error status. Shapes of EL displays  303 ,  305  may be selected to provide a desired aesthetic or functionality. For example, EL display  305  may be shaped functionally like a stop sign to indicate an error condition. EL display  303  may have a different shape, such as a shape that evokes function (e.g., a shape like a disk drive to indicate a state of health of a storage system) (not illustrated), or may have a fanciful shape such as a name or logo of a manufacturer, or a decorative shape. EL display  305  may be shaped aesthetically like a logo of the manufacturer of electronic equipment  300  or a component within (e.g., “SymbolicIO™ inside”). EL display  305  also may have dual purposes of functionality and aesthetics. 
     Electronic equipment  300  may further include an optional set of status or controls  307  for any information that cannot be easily conveyed by EL displays  303 ,  305  (for example, if any textual information such as a port number needs to be indicated). 
       FIG. 4  illustrates a method  400  in accordance with an embodiment of the present disclosure. Method  400  begins at step  401 , at which monitoring of hardware, software, and/or the environment takes place. Step  401 , once it commences, is ordinarily an ongoing and/or substantially continuous process that may continue indefinitely. This may include a polling process or an interrupt-driven process. 
     Next, method  400  transitions to step  403 , at which a change in status is detected. Until a change in status has in fact been detected (except for a control signal as described below), method  400  may remain in step  401 . Step  403  may further include detecting what kind or type of monitored status has changed, e.g., a hardware status, a software status, or an environmental status. The change in status may represent a binary change in status (e.g., above a threshold or below a threshold), or alternatively a change in status may represent a change in a monitored analog or multilevel (greater than two levels) parameter (e.g., a temperature change). The magnitude of the change in the analog or multilevel parameter may be compared to a threshold by use of the sensor processor. For example, a 5 degree change in temperature may not be sufficient to raise an alarm, but a 20 degree change may be sufficient to raise an alarm. 
     Next, method  400  transitions to step  407 , at which driving signals (e.g., AC signal  28 ) for an electroluminescent status display may be generated. Status may be indicated by a change in the driving signals, e.g., activate driving signals to indicate the start of a monitored status condition, or deactivating driving signal to indicate the end of a monitored status condition. Fault conditions may be mapped (i.e., combined) to drive a lesser number of EL displays. For example, all fault conditions may be mapped to one EL driver for hardware faults and one EL driver for software faults. 
     Optionally, method  400  may include step  405 , at which an external data signal (e.g., external data signal  211 ) may be detected. The external data signal may be a signal that is intended to cause or stimulate a change in status of an EL display. 
     Next, method  400  transitions to step  409 , at which an EL status display is changed, based upon the EL driving signals from step  407 . 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the present invention may be devised without departing from the basic scope thereof. It is understood that various embodiments described herein may be utilized in combination with any other embodiment described, without departing from the scope contained herein. Further, the foregoing description is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. Certain exemplary embodiments may be identified by use of an open-ended list that includes wording to indicate that the list items are representative of the embodiments and that the list is not intended to represent a closed list exclusive of further embodiments. Such wording may include “e.g.,” “etc.,” “such as,” “for example,” “and so forth,” “and the like,” etc., and other wording as will be apparent from the surrounding context. 
     No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the terms “any of” followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include “any of,” “any combination of,” “any multiple of,” and/or “any combination of” multiples of the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. 
     Moreover, the claims should not be read as limited to the described order or elements unless stated to that effect. In addition, use of the term “means” in any claim is intended to invoke 35 U.S.C. §112, ¶6, and any claim without the word “means” is not so intended.