Patent Publication Number: US-8988001-B2

Title: Lamp and illumination system and driving method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 99133096, filed on Sep. 29, 2010. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a lamp and an illumination system and a driving method thereof, and more particularly, to a light emitting diode (LED) lamp and an illumination system and a driving method thereof. 
     2. Description of Related Art 
     In the past 20 years, people have been working hard on the development of new illumination sources. It is specified in the “Rainbow Project” funded by the European Union (EU) that a new illumination source should satisfy such four conditions as high efficiency, low power consumption, zero pollution, and close resemblance to natural light. Because a light emitting diode (LED) possesses aforementioned characteristics and is far superior to conventional illumination sources (for example, incandescent lamp and fluorescent lamp), the LED is widely considered a green light source in the 21 st  century and adopted for replacing incandescent lamp and fluorescent lamp as a leading product in the illumination source market. 
     Generally speaking, an LED lamp with a dimming function directly emits light according to a pulse width modulation (PWM) signal generated by a dimmer. To be specific, a driver in the LED lamp directly drives the LEDs according to the PWM signal generated by the dimmer. Besides, a frequency of the driving signal generated by the driver in the LED lamp according to the PWM signal generated by the dimmer for driving the LEDs is equal to a frequency of the PWM signal generated by the dimmer. 
     However, because the PWM signals generated by dimmers from different manufacturers have different but fixed frequencies (usually fall within a range of 100 Hz-1 KHz), if the selected dimmer generates a PWM signal of a low but fixed frequency (for example, 100 Hz), flickering of the light source provided by the LED lamp is easily detected by the human eye (this is because the frequency of the PWM signal generated by the dimmer is very close to the frequency range detectable to the human eye). 
     On the other hand, if the selected dimmer generates a PWM signal of a high but fixed frequency (for example, 1 KHz), signal interference between different components of the driver in the LED lamp is greatly increased, and the complexity in designing an electromagnetic-interference-free (EMI-free) circuit is greatly increased (this is because the frequency of the PWM signal generated by the dimmer not only interferes with the signal transmission between different components of the driver in the LED lamp but also increases the overall EMI index of the LED lamp). 
     Additionally, the Taiwan Patent No. M381241, M371263, and 1297819, the Taiwan Patent Publication No. 201019008, and the U.S. Pat. Nos. 7,560,677 and 7038399 disclose techniques for driving an LED lamp. 
     SUMMARY OF THE INVENTION 
     Accordingly, the invention provides a light emitting diode (LED) lamp and an illumination system and a driving method thereof, wherein problems in conventional techniques are effectively resolved. 
     Additional aspects and advantages of the invention will be set forth in following description. 
     According to an embodiment of the invention, a lamp including a lighting unit, a conversion unit, and a driver is provided. The conversion unit is capable of receiving an input pulse width modulation (PWM) signal and converting the input PWM signal into an output PWM signal, wherein a frequency of the input PWM signal and a frequency of the output PWM signal are different. The driver is coupled between the lighting unit and the conversion unit. The driver is capable of receiving the output PWM signal and generating a driving signal to drive the lighting unit according to the output PWM signal. 
     According to another embodiment of the invention, an illumination system including a dimmer and a lamp is provided. The dimmer is capable of providing an input PWM signal. The lamp is coupled to the dimmer. The lamp is capable of receiving the input PWM signal and provides a light beam according to an output PWM signal related to the input PWM signal, wherein a frequency of the input PWM signal and a frequency of the output PWM signal are different. 
     According to yet another embodiment of the invention, a method for driving an LED lamp is provided. In the method, an input PWM signal is provided. The input PWM signal is converted into an output PWM signal, wherein a frequency of the input PWM signal and a frequency of the output PWM signal are different. A driving signal is generated to drive the LED lamp according to the output PWM signal. 
     In embodiments of the invention, the frequency of the output PWM signal has a fixed specific value. 
     In summary, the embodiment or embodiments of the invention may have at least one of the following advantages. In embodiments of the invention, the driver in the LED lamp generates the driving signal for driving the lighting unit (i.e., LEDs) according to the output PWM signal, and the frequency of the driving signal is equal to the frequency of the output PWM signal instead of the frequency of the input PWM signal. Thus, the problems of conventional techniques may be effectively resolved by appropriately adjusting the frequency of the output PWM signal (for example, to 300 Hz) (in foregoing embodiments, because the frequency of the output PWM signal exceeds a range recognizable to human eyes, the output PWM signal does not interfere with signal transmission between various elements in the driver of the LED lamp or increase the overall electromagnetic interference (EMI) of the LED lamp). 
     Other objectives, features and advantages of the invention will be further understood from the further technological features disclosed by the embodiments of the invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a diagram of an illumination system according to an embodiment of the invention. 
         FIG. 2  is a diagram of a lamp in  FIG. 1 . 
         FIG. 3  is a diagram of a built-in lookup table in a conversion unit according to an embodiment of the invention. 
         FIG. 4  is a flowchart of a method for driving a light emitting diode (LED) lamp according to an embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS. 
     It is to be understood that other embodiment may be utilized and structural changes may be made without departing from the scope of the invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. 
     Referring to both  FIG. 1  and  FIG. 2 , an illumination system  100  includes a dimmer  101  and a lamp  103 . The lamp  103  includes a conversion unit  201 , a driver  203 , and a lighting unit  205 . The lighting unit  205  may be a light emitting diode (LED) module including a plurality of LEDs (not shown). Thereby, the lamp  103  is an LED lamp. 
     In the embodiment, the dimmer  101  provides an input pulse wide modulation (PWM) signal PWM_I in response to user operations. The lamp  103  is coupled to the dimmer  101 . The lamp  103  receives the input PWM signal PWM_I from the dimmer  101  and provides a light beam according to an output PWM signal PWM_O related to the input PWM signal PWM_I, wherein a frequency of the input PWM signal PWM_I and a frequency of the output PWM signal PWM_O are different, and the frequency of the output PWM signal PWM_O has a fixed specific value (will be explained thereinafter). 
     To be specific, the conversion unit  201  receives the input PWM signal PWM_I from the dimmer  101  and converts the input PWM signal PWM_I into the output PWM signal PWM_O. In the embodiment, regardless of what the frequency of the input PWM signal PWM_I provided by the dimmer  101  is (for example, any frequency between 100 Hz and 1 KHz), the frequency of the output PWM signal PWM_O provided by the conversion unit  201  remains at aforementioned fixed specific value (for example, 300 Hz, however, not limited thereto). Besides, the driver  203  is coupled between the conversion unit  201  and the lighting unit  205 . The driver  203  receives the output PWM signal PWM_O from the conversion unit  201  and generates a driving signal DS to drive LEDs in the lighting unit  205  according to the output PWM signal PWM_O. 
     In the embodiment, the conversion unit  201  has a built-in lookup table LUT (as shown in  FIG. 3 ), and the conversion unit  201  obtains the output PWM signal PWM_O from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  and provides the output PWM signal PWM_O to the driver  203 . In other words, the duty cycle PWM_O_D of the output PWM signal PWM_O provided by the conversion unit  201  is determined by the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101 . 
     To be specific, the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is fixed to a second predetermined value when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is greater or smaller than a first predetermined value. 
     For example, the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is fixed to 100% when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is smaller than 5% (inclusive). Besides, the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is fixed to 0% when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is greater than 95% (inclusive). 
     On the other hand, the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  and the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  have an equation relationship when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is between two predetermined values. 
     For example, the equation relationship between the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  and the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is expressed as following equation 1 when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is between 5% (not inclusive) and 95% (not inclusive):
 
PWM —   O   —   D =(96%−PWM —   I   —   D )×(100/91)  Equation 1.
 
     Thus, the duty cycle PWM_O_D of the output PWM signal PWM_O obtained by the conversion unit  201  from the lookup table LUT according to the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  (10%) is 94.5% (i.e., (96%−10%)×(100/91)) when the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is 10%. The values of the duty cycle PWM_I_D of the input PWM signal PWM_I and the duty cycle PWM_O_D of the output PWM signal PWM_O in other cases may be deduced accordingly. 
     As described above, the conversion unit  201  obtains an output PWM signal PWM_O having a duty cycle PWM_O_D of 50.5% (i.e., (96%−50%)×(100/91)) and a fixed frequency of 300 Hz from the lookup table LUT of the conversion unit  201  and provides the output PWM signal PWM_O to the driver  203  when the dimmer  101  provides an input PWM signal PWM_I having a duty cycle PWM_I_D of 50% and a frequency between 100 Hz and 1 KHz in response to a user operation. Thereby, the driver  203  generates a driving signal DS to drive LEDs in the lighting unit  205  according to the output PWM signal PWM_O (for example, by enhancing the driving capability of the output PWM signal PWM_O). 
     Namely, the driver  203  in the lamp  103  generates the driving signal DS for driving the lighting unit  205  (i.e., the LEDs) according to the converted output PWM signal PWM_O, and the frequency of the driving signal DS is equal to the frequency of the converted output PWM signal PWM_O instead of the frequency of the input PWM signal PWM_I. Thus, aforementioned problems in the conventional techniques may be effectively resolved by appropriately designing the frequency (for example, 300 Hz, but not limited thereto) of the output PWM signal PWM_O (in foregoing embodiment, because the frequency of the output PWM signal PWM_O is over the frequency range detectable by the human eye, signal transmission between various components of the driver  203  in the lamp  103  is not interfered, and the overall electromagnetic-interference (EMI) index of the lamp  103  is not be increased). 
     Additionally, in an actual application, the duty cycle of the input PWM signal PWM_I provided by the dimmer  101  varies in response to user&#39;s operations. Taking a rotary dimmer  101  as an example, because the rotation speed of the dimmer  101  is not fixed (namely, could be changed every now and then) but is controlled by a user, and the input PWM signal PWM_I received by the conversion unit  201  and the driving signal DS generated by the driver  203  have similar response curves and may produce a response difference, flickering may be produced in the light beam provided by the lamp  103  if the rotation speed of the dimmer  101  controlled by the user is too slow. On the other hand, if the rotation speed of the dimmer  101  controlled by the user is too fast, slow response and long adjustment time may be produced in the light beam provided by the lamp  103 . 
     Accordingly, in other embodiments of the invention, the conversion unit  201  further controls the driver  203  to delay or accelerate the generation of the driving signal DS according to the variable quantity of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101 . Thus, the conversion unit  201  controls the driver  203  to delay the generation of the driving signal DS when the conversion unit  201  determines that the variable quantity of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is smaller than a specific predetermined value. Otherwise, the conversion unit  201  controls the driver  203  to accelerate the generation of the driving signal DS. 
     For example, the conversion unit  201  determines that the rotation speed of the dimmer  101  controlled by the user is too slow and accordingly controls the driver  203  to generate the driving signal DS in a delayed manner when the conversion unit  201  determines that the variable quantity of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is smaller than 10% (i.e., the variation of the duty cycle PWM_I_D of the input PWM signal PWM_I provided at a previous time and at the current time by the dimmer  101 , but not limited thereto). Accordingly, the response curve of the driving signal DS generated by the driver  203  is different from the response curve of the input PWM signal PWM_I received by the conversion unit  201  and is smoother. Thus, no flickering is produced in the light beam provided by the lamp  103  even if the rotation speed of the dimmer  101  controlled by the user is too slow. 
     Contrarily, the conversion unit  201  determines that the rotation speed of the dimmer  101  controlled by the user is too fast and accordingly controls the driver  203  to generate the driving signal DS in an accelerated manner when the conversion unit  201  determines that the variable quantity of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  is greater than 10%. Accordingly, the response difference between the input PWM signal PWM_I received by the conversion unit  201  and the driving signal DS generated by the driver  203  is effectively reduced. Thus, slow response or long adjustment time may not be produced in the light beam provided by the lamp  103  even if the rotation speed of the dimmer  101  controlled by the user is too fast. 
     Moreover, in an actual application, the dimmer  101  may be rotated by the user to a position making the duty cycle PWM_I_D of the input PWM signal PWM_I received by the conversion unit  201  to fall on a threshold (for example, 50.9% to 51%). In this case, the conversion unit  201  looks up in the lookup table LUT of the conversion unit  201  by alternatively using the input PWM signal PWM_I having the duty cycle PWM_I_D of 50% and 51% and accordingly alternatively provides the output PWM signal PWM_O having the duty cycle PWM_O_D of 49.4% (corresponding to the input PWM signal PWM_I having the duty cycle PWM_I_D of 50%) and 50.5% (corresponding to the input PWM signal PWM_I having the duty cycle PWM_I_D of 51%) to the driver  203 . As a result, the light beam provided by the lamp  103  becomes unstable. 
     Accordingly, in other embodiments of the invention, the conversion unit  201  further detects the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101 . The conversion unit  201  obtains the output PWM signal PWM_O from the lookup table LUT in the conversion unit  201  according to a same duty cycle and provides the output PWM signal PWM_O to the driver  203  when the conversion unit  201  detects that the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  remains the same duty cycle for a predetermined number of times. 
     For example, the conversion unit  201  obtains the output PWM signal PWM_O having a duty cycle PWM_O_D of 50.5% (i.e., (96%−50%)×(100/91)) from the lookup table LUT of the conversion unit  201  according to the input PWM signal PWM_I having a duty cycle PWM_I_D of 50% and provides the output PWM signal PWM_O to the driver  203  when the conversion unit  201  detects that the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  remains 50% for five continuous times (not limited thereto). 
     Contrarily, when the conversion unit  201  detects that the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  does not remain the same duty cycle for the predetermined number of times, the conversion unit  201  determines a stable duty cycle according to a variation pattern of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101 , and the conversion unit  201  then obtains the output PWM signal PWM_O from the lookup table LUT of the conversion unit  201  according to the stable duty cycle and provides the output PWM signal PWM_O to the driver  203 . 
     In the embodiment, the variation pattern of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  may indicate that the duty cycle PWM_I_D of the input PWM signal PWM_I changes from large to small or from small to large. Besides, the stable duty cycle determined by the conversion unit  201  is greater than the duty cycle PWM_I_D of the input PWM signal PWM_I when the variation pattern of the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  indicates that the duty cycle PWM_I_D of the input PWM signal PWM_I changes from large to small. Otherwise, the stable duty cycle determined by the conversion unit  201  is smaller than the duty cycle PWM_I_D of the input PWM signal PWM_I. 
     For example, the conversion unit  201  determines the stable duty cycle based on whether the duty cycle PWM_I_D of the input PWM signal PWM_I previously provided by the dimmer  101  changes from a duty cycle PWM_I_D greater than 51% to a duty cycle PWM_I_D between 50.9 and 51% or changes a duty cycle PWM_I_D smaller than 50% to a duty cycle PWM_I_D between 50.9 and 51% when the conversion unit  201  detects that the duty cycle PWM_I_D of the input PWM signal PWM_I provided by the dimmer  101  does not remain the same duty cycle for five continuous times (for example, the duty cycle PWM_I_D changes between 50.9% and 51%). 
     To be specific, assuming that the conversion unit  201  determines that the duty cycle PWM_I_D of the input PWM signal PWM_I previously provided by the dimmer  101  changes from a duty cycle PWM_I_D greater than 51% to a duty cycle PWM_I_D between 50.9 and 51%, the conversion unit  201  determines a stable duty cycle of 51% and obtains an output PWM signal PWM_O having a duty cycle PWM_O_D of 49.4% (i.e., (96%−51%)×(100/91)) from the lookup table LUT of the conversion unit  201  to provide to the driver  203 . 
     Additionally, assuming that the conversion unit  201  determines that the duty cycle PWM_I_D of the input PWM signal PWM_I previously provided by the dimmer  101  changes from a duty cycle PWM_I_D smaller than 50% to a duty cycle PWM_I_D between 50.9 and 51%, the conversion unit  201  determines a stable duty cycle of 50% and obtains an output PWM signal PWM_O having a duty cycle PWM_O_D of 50.5% (i.e., (96%−50%)×(100/91)) from the lookup table LUT of the conversion unit  201  to provide to the driver  203 . 
     Accordingly, in the embodiment, even though the dimmer  101  is rotated by the user to a position that makes the duty cycle PWM_I_D of the input PWM signal PWM_I received by the conversion unit  201  falls on a threshold (for example, between 50.9% and 51%), the conversion unit  201  looks up the lookup table LUT of the conversion unit  201  according to the input PWM signal PWM_I having a duty cycle PWM_I_D of 50% or 51%, so that the light beam provided by the lamp  103  may be stabilized. 
     A method for driving an LED lamp is provided based on the embodiments described above, as illustrated in  FIG. 4 . The LED lamp driving method in the embodiment includes following steps. 
     An input PWM signal is provided (step S 401 ). 
     Whether the duty cycle of the input PWM signal remains a same duty cycle for a predetermined number of times is determined (step S 403 ). 
     If the duty cycle of the input PWM signal remains the same duty cycle for the predetermined number of times, the same duty cycle is determined (step S 405 ). Otherwise, a stable duty cycle is determined (step S 407 ). Herein the stable duty cycle is determined according to a variation pattern of the duty cycle of the input PWM signal, wherein the stable duty cycle is greater than the duty cycle of the input PWM signal when the variation pattern indicates that the duty cycle of the input PWM signal changes from large to small, and the stable duty cycle is smaller than the duty cycle of the input PWM signal when the variation pattern indicates that the duty cycle of the input PWM signal changes from small to large. 
     After determining the same/stable duty cycle, whether the same/stable duty cycle is greater than a first predetermined value (for example, 95% (inclusive), but is not limited thereto) or smaller than a second predetermined value (for example, 5% (inclusive), but is not limited thereto) is determined (step S 409 ). 
     When the same/stable duty cycle is greater than the first predetermined value or smaller than the second predetermined value, the input PWM signal is converted (for example, by looking up the lookup table according to the duty cycle of the input PWM signal) to obtain the output PWM signal having its duty cycle fixed to a third predetermined value (step S 411 ), wherein a frequency of the input PWM signal and a frequency of the output PWM signal are different, and the frequency of the output PWM signal has a fixed specific value (for example, 300 Hz, but is not limited thereto). Otherwise, whether the same/stable duty cycle is between a fourth predetermined value and a fifth predetermined value (for example, between 5% (not inclusive) and 95% (not inclusive), but is not limited thereto) is determined (step S 413 ). 
     When the same/stable duty cycle is between the fourth predetermined value and the fifth predetermined value, the input PWM signal is converted (for example, by looking up the lookup table according to the duty cycle of the input PWM signal) to obtain an output PWM signal (step S 415 ). Herein the duty cycle of the output PWM signal and the duty cycle of the input PWM signal have an equation relationship. If the duty cycle of the input PWM signal is indicated as PWM_I_D, and the duty cycle of the output PWM signal is indicated as PWM_O_D, the equation relationship may be expressed as: PWM_O_D=(96%−PWM_I_D)×(100/91). When the same/stable duty cycle is not between the fourth predetermined value and the fifth predetermined value, whether the same/stable duty cycle is greater than the first predetermined value or smaller than the second predetermined value is determined again (step S 409 ). 
     After obtaining the output PWM signal, a variable quantity of the duty cycle of the input PWM signal is determined (step S 417 ). 
     If the variable quantity of the duty cycle of the input PWM signal is smaller than a sixth predetermined value, a driving signal is generated according to the output PWM signal in a delayed manner to drive the LED lamp (step S 419 ). If the variable quantity of the duty cycle of the input PWM signal is greater than the sixth predetermined value, the driving signal is generated according to the output PWM signal in an accelerated manner to drive the LED lamp (step S 421 ). 
     In summary, the embodiment or embodiments of the invention may have at least one of the following advantages. According to foregoing embodiments of the invention, a driver in a lamp generates a driving signal DS for driving a lighting unit (i.e., LEDs) according to a converted output PWM signal PWM_O, and the frequency of the driving signal DS is equal to the frequency of the output PWM signal PWM_O instead of the frequency of the input PWM signal PWM_I. Thus, the problems in the conventional techniques may be effectively resolved by appropriately designing the frequency (for example, 300 Hz) of the output PWM signal PWM_O (in an embodiment of the invention, because the frequency of the output PWM signal is over a frequency range detectable by the human eye, signal transmission between various components of the driver in the lamp is not interfered, and the overall EMI index of the lamp is not increased). 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. Moreover, these claims may refer to use “first”, “second”, etc. following with noun or element. Such terms should be understood as a nomenclature and should not be construed as giving the limitation on the number of the elements modified by such nomenclature unless specific number has been given. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.