Abstract:
The present invention provides an LED lighting device and a method for verifying the device&#39;s lifespan. The LED lighting device includes multiple LED light sources, a controller configured to keep time for the LED lighting device&#39;s lifespan; a low voltage DC power source configured to supply power; a light intensity sensor configured to capture illuminance data; and a display terminal configured to display received data. Further, the controller records time keeping data based on the illuminance data captured by the light intensity sensor and sends the time keeping data to be displayed on the display terminal.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a continuation in part and claims the priority of Chinese Patent Application No. 201210292622.7 (PCT/CN2012086612) filed on Aug. 16, 2012, the entire content of which is incorporated herein by reference. 
       FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates to the field of light emitting diode (LED) technologies and, more particularly, relates to an LED lighting device that is capable of tracking or monitoring its own lifespan, and relates to a method for verifying the lifespan of the LED lighting device. 
       BACKGROUND 
       [0003]    With the rapid development of new energy-efficient lighting technologies, especially the LED technology, lighting products have become more efficient and durable. Compared with traditional incandescent lamps, the light conversion efficiency of an LED lamp may be 5 to 10 times higher, and the lifespan of an LED lamp may be 30 to 50 times longer. As a result, energy saving improvements have been well received by commercial and individual users. Moreover, innovative financing methods used in energy-saving projects, such as the Energy Management Contract (EMC) mode, attract more and more attention. 
         [0004]    New lighting products such as LEDs have very long lifespans in theory. The lifespan of a lighting product may be defined as the duration during which its light intensity is maintained at, for example, above 70% of the original light intensity. Because there is no practical method to speed up the aging process to measure the lifespan of an LED lighting device, one conventional method is to measure a device&#39;s light intensity after 6,000 hours&#39; aging to estimate its lifespan. Due to the rapid development of new energy-efficient LED technologies, one technology may become obsolete even before its product&#39;s lifespan can be fully tested. For LED manufacturers, this long test time span may cause problems. On the other hand, for LED device users, unless a device consistently fails in a relatively short time, it may be difficult to measure the real lifespan of a device. It may even be harder to compare the lifespan measurements to the claimed lifespan of a lighting product. For example, one product may claim that it has a lifespan of 25,000 hours. If it failed after 20,000 hours of usage, it would be difficult for the user to show a shorter than claimed lifespan. 
         [0005]    As a result, estimating and verifying the lifespan of the new energy-efficient LED devices may be a challenge to device manufacturers and users. The disclosed method and system are directed to solve one or more problems set forth above and other problems 
       BRIEF SUMMARY OF THE DISCLOSURE 
       [0006]    One aspect of the present disclosure provides an LED lighting device that is capable of measuring its own lifespan. The LED lighting device may include a controller configured to keep time for the LED lighting device&#39;s lifespan; a low voltage DC power source configured to supply power; a light intensity sensor configured to capture illuminance data; and a display terminal configured to be connected to the controller. Further, the controller may record time keeping data based on the illuminance data captured by the light intensity sensor and send the time keeping data to be displayed on the display terminal. 
         [0007]    Further, the low voltage DC power source may be connected to the controller. The controller may be a microcontroller or a digital integrated circuit controller. The controller may be connected directly to the display terminal. The display terminal may be placed on the LED lighting device, and the controller may store or send time keeping measurements to the display terminal. The controller includes an internal timing circuit or a timing program. 
         [0008]    In addition, the light intensity sensor may be placed at the luminous zone of the LED lighting device. The controller may capture the illuminance data and convert it into the luminous flux and the luminous flux maintenance factor. The light intensity sensor may be fixed on a substrate/PCB board, which is also used to hold the LED light source. The light intensity sensor may be placed at the center of the substrate/PCB board. 
         [0009]    Moreover, the LED lighting device may include a cup that is placed outside the light intensity sensor and a shading slide that is placed above the light intensity sensor and on top of the LED lampshade. 
         [0010]    Another aspect of the present disclosure provides a method for verifying the lifespan of an LED lighting device. The method includes placing a controller and a low voltage DC power source inside the LED lighting device; measuring the LED lighting device&#39;s lifespan based on illuminance data related to the LED lighting device; transferring data related to the LED lighting device&#39;s lifespan to a display terminal; and displaying the date related to the LED lighting device&#39;s lifespan in real time. 
         [0011]    The method for verifying the lifespan of the LED lighting device may further include recording the illuminance data related to the LED lighting device at pre-set time intervals; transferring the illuminance data related to the LED lighting device to the controller; converting the illuminance data into a luminous flux and a luminous flux maintenance factor; and sending the luminous flux and a luminous flux maintenance factor to the display terminal. 
         [0012]    Moreover, the method may include adding the pre-set interval of time to the lifespan of the LED lighting device when the measured luminous flux maintenance factor is less than a pre-defined value; and measuring an initial light intensity value after the LED device is powered on for 20 to 60 minutes; and measuring another 3 to 5 consequent light intensity values at a time interval of every 20 to 30 minutes. 
         [0013]    In addition, the method for verifying the lifespan of the LED lighting device may include comparing the measured light intensity data to an initial light intensity value to determine a variance; and resetting the initial illuminance value if the variance is less than 10%. Further, the controller and the display terminal may be connected to an external low voltage DC power source. 
         [0014]    Another aspect of the present disclosure provides a system for verifying the lifespan of an LED lighting device. The system may include an LED lighting device with one or more LED light sources; a controller configured to keep time of the LED lighting device lifespan; a light intensity sensor configured to capture illuminance data; and a display terminal configured to be attached to the LED lighting device. The controller may record time keeping data based on the illuminance data captured by the light intensity sensor and send the time keeping data to be displayed on the display terminal. In addition, the system may include a temperature sensor configured to capture the temperature of an LED light source, wherein the display terminal further displays temperature data related to the lifespan of the LED lighting device. 
         [0015]    Embodiments consistent with the present disclosure enable the user to monitor and manage the lifespans of LED lighting devices in real time. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The following drawings are merely examples for illustrative purposes according to various disclosed embodiments and are not intended to limit the scope of the present disclosure. 
           [0017]      FIG. 1  depicts an exemplary LED lighting device configuration consistent with various disclosed embodiments; 
           [0018]      FIG. 2  depicts a schematic diagram of an exemplary micro controller unit (MCU) controller and power supply configuration consistent with various disclosed embodiments; and 
           [0019]      FIG. 3  is a schematic illustrating an exemplary controller module in the LED lighting device consistent with various disclosed embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Reference will now be made in detail to exemplary embodiments of the invention, which are illustrated in the accompanying drawings. Hereinafter, embodiments consistent with the disclosure will be described with reference to drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. It is apparent that the described embodiments are some but not all of the embodiments of the present invention. Based on the disclosed embodiment, persons of ordinary skill in the art may derive other embodiments consistent with the present disclosure, all of which are within the scope of the present invention. 
         [0021]    An exemplary embodiment consistent with the present disclosure is described below.  FIG. 1  illustrates an exemplary embodiment consistent with the present disclosure. The embodiment includes a substrate/PCB board  1 , a lampshade  2 , multiple LED light sources  3 , a controller  4 , a lower voltage DC power supply  6 , a display terminal  7 , a light intensity sensor  8 , a cup  9 , and a shading slide  10 . 
         [0022]    As shown in  FIG. 1 , the substrate/PCB board  1  and the lampshade  2  may be arranged at the upper portion of the LED lighting device. The LED light sources  3  may be fixed on the substrate/PCB board  1 . The controller  4  and the low voltage DC power source  6  may be placed inside the LED lighting device. The controller  4  may be an MCU controller. Further, as shown in  FIG. 1 , the low voltage DC power supply  6  may be connected to the controller  4 . The controller  4  may be connected to a display terminal  7 . The display terminal  7  may be placed on the side of the LED lighting device, and may be an LCD display. In one embodiment, the light intensity sensor  8  may be placed at the luminous zone inside the LED lighting device. The light intensity sensor  8  may be connected to the controller  4 . The light intensity sensor  8  may measure the illuminance of the LED lighting device. The controller  4  may read and convert the illuminance data from the sensor into the luminous flux maintenance factor, and may send the data to the display terminal  7 . The light intensity sensor  8  may be placed at the center of the substrate/PCB board  1 . The cup  9  may be set outside the light intensity sensor  8  to shield direct light from the LED light sources  3 . A shading slide  10  may be placed above the light intensity sensor  8  and on top of the cup  9  to shade the sensor  8  from direct external light. One or more shading slides  10  may be placed at different positions of an LED device to shield light from undesirable light sources that may interfere with the readings of the sensor  8  (e.g., external light). 
         [0023]    Depending on the configuration of the LED lighting device, the light intensity sensor  8  may be placed at different positions with various affiliated structures (e.g., cup  9  and shading slide  10 ) to properly measure the light intensity of the device. Further, multiple light intensity sensors  8  may be place in the LED lighting device to provide more accurate readings of the illuminance or provide back-up coverage. For example, for a more accurate illuminance reading, an LED lighting device may place two sensors in the device and use the average of the two sensors&#39; readings as the measured illuminance value. 
         [0024]    The controller  4  may need a low voltage DC power supply. Often, the LED power supply can also output low voltage DC power. For example, the low voltage DC power source  6  may supply power to the controller  4  directly. If other types of power source are used, as shown in  FIG. 2 , an AC-DC module and a DC-DC module may be needed for voltage conversions. 
         [0025]    When the power is on, the LED light sources  3  may start emitting light. At the same time, the controller  4  may start keeping time. The lifespan time data may be displayed on the display terminal  7  in real time. The controller  4  may have a data protection function, which may keep track of the time data during a power-off period. When the power is turned on again, the controller  4  may resume time keeping. The time keeping functions may keep running until the LED light sources  3  cannot emit sufficient light. The final recorded and displayed duration may be the lifespan of the LED lighting device. 
         [0026]    In one embodiment, the light intensity sensor  8  may take a first light intensity measurement  30  minutes after the LED lighting device is powered on. Then, the sensor may take another three consequent light intensity measurements every 30 minutes. The light intensity measurements may then be compared with an initial light intensity value, which may be provided by the LED manufacturer. If the variance is within 10%, the controller  4  may set the average of these measurements as the initial illuminance value. The sensor  8  may also send this initial illuminance value to the MCU controller  4 . Thereafter, the light intensity sensor  8  may measure light intensity every 30 minutes. In some embodiments, the light intensity sensor  8  may be configured to not take the light intensity readings during the power-off processes. 
         [0027]    As shown in  FIG. 3  the MCU controller  4  may include an oscillating circuit and a reset circuit that may be used to implement the time keeping functions. Further, the MCU controller  4  may be connected to a lower voltage DC power supply  6 , the light intensity sensor  8 , and the display terminal  7 . The controller  4  may retrieve the illuminance measurements from the light intensity sensor  8 , compare the data with the initial illuminance value, convert the illuminance measurement data into the luminous flux and the luminous flux maintenance factor, and send the luminous flux and the luminous flux maintenance factor to the display terminal  7  in real time. 
         [0028]    In one embodiment, when the measured luminous flux maintenance factor is lower than a pre-defined value, the recorded working time by the LED lighting device may be its lifespan. The pre-defined value may be defined based on specific applications. For example, the luminous flux maintenance factor threshold may be set at 70%. For different type of LED lighting devices, the threshold values may be different. 
         [0029]    Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the claims. 
       INDUSTRIAL APPLICABILITY AND ADVANTAGEOUS EFFECTS 
       [0030]    Without limiting the scope of any claim and/or the specification, examples of industrial applicability and certain advantageous effects of the disclosed embodiments are listed for illustrative purposes. Various alternations, modifications, or equivalents to the technical solutions of the disclosed embodiments can be obvious to those skilled in the art and can be included in this disclosure. 
         [0031]    In some embodiments consistent with the present disclosure, other than the light intensity sensors, other sensors may be attached to an LED lighting device to measure other environmental conditions, such as humidity, temperature, etc. The environmental data may also be sent to the controller. The controller may keep track of various environmental conditions, and keep track of the device operation time for these conditions. For example, if an LED lighting device has a 2,000-hour lifespan, the controller may generate data showing that 500 of the 2,000 hours were in a raining environment, 800 of the 2,000 hours were below the freezing temperature, etc. The display terminal may also display lifespan information in combination with environmental information in real time. 
         [0032]    In some embodiments consistent with the present disclosure, sensors may be place next to or may be attached to the LED light sources to measure the temperature of the light sources. The controller may receive the temperature data and keep track of the operation time for various temperature ranges. For example, for an LED device with a 2,000-hour lifespan, the controller may generate data showing the temperature readings for the 2,000 operational hours. 
         [0033]    In other embodiments consistent with the present disclosure, an LED lighting device manufacturer may place a wireless communication module in the LED lighting device. The controller may then send data related to the lifespan data of the LED lighting device through the wireless communication module to other software/hardware modules. For example, the controller may use the wireless module to send the device operation data to an LED lighting device management system. The device management system may then display the data through any type of user interfaces, including an online user interface. The user may then monitor the status of the LED lighting devices remotely to determine whether certain devices need to be replaced or repaired. This type of remote device monitoring can also be used in combination with the on-site monitoring (e.g., through a display terminal on the LED lighting device) to monitor and manage LED lighting devices as needed. 
         [0034]    Embodiments consistent with the present disclosure may use one or multiple sensors to measure light intensity, LED operational conditions, and LED device operational conditions. The controller may keep track of the lifespan data as well as other measures related to operations of the LED lighting device. The controller may send the data related to the LED operations and other conditions to the display terminal to be displayed.