Patent Publication Number: US-2015084546-A1

Title: Dimming Control System

Description:
INCORPORATION BY REFERENCE 
     The present invention claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2013-195741 filed on Sep. 20, 2013. The content of the application is incorporated herein by reference in their entirety. 
     FIELD 
     Embodiments described herein relate generally to a dimming control system to perform dimming control of a luminaire. 
     BACKGROUND 
     Hitherto, there is a dimming control system to perform dimming control of a luminaire for a stage, a studio or the like. In this dimming control system, a host equipment transmits dimming data in order to obtain a directed lighting state as stage lighting, and a luminaire receiving the dimming data performs dimming control of a lighting load. 
     The communication protocol with the specified data frame structure in compliance with the DMX standard (DMX512/1990; United States Institute for Theatre Technology (USITT) standard) is often adopted for transmission of the dimming data. 
     Besides, in recent years, the RDM (Remote Device Management) standard is also adopted as an extension of the DMX standard. In the RDM standard, a host equipment transmits an inquiring command, and a luminaire receiving this command replies luminaire information to the host equipment. The time of three DMX packets is specified for the inquiry, and next dimming data in compliance with the DMX standard can not be transmitted during the inquiry and reply. 
     As stated above, when the host equipment acquires the luminaire information of the luminaire, the next dimming data in compliance with the DMX standard can not be transmitted during the inquiry and reply. Thus, there is a fear that the real-time property of light change required for staged dimming can not be secured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a dimming control system of an embodiment. 
         FIG. 2  is a structural view showing an example of data frames of a communication protocol adopted in the dimming control system. 
         FIG. 3  is a structural view showing another example of the data frames. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a dimming control system includes a luminaire and a host equipment. The luminaire receives dimming data transmitted using data frames based on a specified communication protocol, and performs dimming control of a lighting load. The host equipment uses the data frames to transmit the dimming data, and uses a part of the data frames to transmit a command to request luminaire information of the luminaire. 
     By this, while the real-time property of staged dimming is secured, the luminaire information from the luminaire is acquired. 
     Hereinafter, an embodiment will be described with reference to  FIG. 1  to  FIG. 3 . 
     As shown in  FIG. 1 , a dimming control system  10  includes a host equipment  11 , luminaires  12  as plural terminals, and a communication line  13  to sequentially connect the plurality of luminaires  12  in series to the host equipment  11  so as to enable communication. 
     The host equipment  11  is, for example, a dimming operation table, and includes an operation input part  16  including, for example, a feeder and to enable operation input, a communication part  17  to communicate with the luminaire  12  through the communication line  13 , and a control part  18  including communication control and to control the host equipment  11 . 
     The luminaires  12  are various luminaires including, for example, a horizon light and a spot light used for the lighting of a stage or a studio. 
     The luminaire  12  includes a lighting load  21 , a communication part  22  to communicate with the host equipment  11  through the communication line  13 , a sensor part  23  to acquire luminaire information, and a control part  24  to control the luminaire  12 . 
     The lighting load  21  uses, for example, a light source such as an LED. 
     The sensor part  23  detects luminaire information including temperature of the lighting load  21 , short circuit of the lighting load  21 , electric leakage, and other abnormalities. 
     The luminaire  12  includes ID information intrinsic to each of the luminaires  12 , and a channel is arbitrarily set as an intrinsic address for dimming control. A storage part of the control part  24  stores the ID information and the channel information. 
     In the dimming control system  10 , a communication protocol corresponding to, for example, the DMX standard is adopted. The host equipment  11  transmits dimming data, and the luminaire  12  receives the dimming data of its own channel and performs dimming control of the lighting load  21 . The host equipment  11  and the luminaire  12  are communicable with each other, and the luminaire  12  can transmit data to the host equipment  11 . 
       FIG. 2  and  FIG. 3  show an example of data frames of the communication protocol adopted by the dimming control system  10 . In the DMX standard, a packeted control signal is generated, and the unit of the packet is called a frame. One frame includes 8 bits, the first frame is a start code to specify the kind of the data, and the remaining frames 1 to 512 are data frames. Channels 1 to 512 are allocated to the data frames, and the dimming data is stored for each of the channels 1 to 512. For example, since one channel includes 8 bits, dimming control of 256 gradations can be performed. Further, a start bit and a stop bit as signals for start and stop are added to the first and last of the dimming data of one channel. Accordingly, the dimming data of one channel is sandwiched between the start bit and the stop bit. 
     Besides, among the channels 1 to 512, all channels are seldom used, that is, the number of the luminaires  12  is often smaller than 512. Thus, among the channels 1 to 512, for example, a data frame of a lower channel is often not used. Incidentally, according to the setting of channels of the luminaires  12 , there is a case where a data frame of a higher or medium channel is not used. 
     The host equipment  11  uses the data frame of the unused channel, and transmits command information requesting the luminaire information to the luminaire  12 . For example, when channels including seven lower channels 506 to 512 are not used, the data frames of the channels 506 to 512 are allocated to the command to request the luminaire information of the luminaire  12 . The command is ID information of the luminaire  12 . 
     The luminaire  12  confirms whether or not its own ID information is included in the data frames. When its own ID information is included in the data frames, immediately after the transmission completion of the data frames from the host equipment  11  is confirmed, that is, immediately after the stop bit of the last data frame is confirmed, the luminaire transmits the luminaire information detected by the sensor part  23  to the host equipment  11 . 
     The host equipment  11  sets a reply waiting time for receiving the reply from the luminaire  12  in a period from immediately after the transmission of the data frame, that is, from immediately after the stop bit of the last data frame to the transmission of the next data frame. The reply waiting time is a time in a range where a human being can not recognize the change of light, for example, about 10 ms. 
     As shown in  FIG. 2 , in the reply waiting time, the output from the host equipment  11  is caused to have a low level, so that the host equipment  11  can receive the signal (indicated by a broken line in  FIG. 2 ) of the luminaire information replied from the luminaire  12 . Besides, as shown in  FIG. 3 , the output from the host equipment  11  in the reply waiting time may be caused to have a high level. In this case, the luminaire  12  side is connected to the signal ground to achieve a low level and transmits the signal (indicated by a broken line in  FIG. 3 ) of the luminaire information, so that the host equipment  11  can receive the luminaire information replied from the luminaire  12 . 
     Next, the operation of the dimming control system  10  will be described. 
     The host equipment  11  transmits the dimming data to the respective luminaires  12  in accordance with the communication protocol corresponding to the DMX standard, so that the directed lighting state as the stage lighting can be obtained. 
     Each of the luminaires  12  receives the dimming data of its own channel among the dimming data transmitted from the host equipment  11 , and performs dimming control of the lighting load  21 . 
     Besides, when transmitting the dimming data, the host equipment  11  uses the data frames of the unused channels, and transmits the ID information of the specific luminaire  12  from which the luminaire information is requested. 
     When the specific luminaire  12  confirms that its own ID information is included in the data frames transmitted from the host equipment  11 , the luminaire transmits the luminaire information detected by the sensor part  23  to the host equipment  11  immediately after the completion of dimming data transmission is confirmed, that is, immediately after the stop bit of the last data frame is confirmed. 
     The host equipment  11  receives the luminaire information replied from the luminaire  12  in the reply waiting time from immediately after the dimming data transmission, that is, from immediately after the stop bit of the last data frame to the next dimming data transmission. By this, the host equipment  11  can acquire and confirm the state of the luminaire  12 . 
     Besides, at each time of dimming data transmission, the host equipment  11  changes and transmits the ID information of the luminaire  12  from which the luminaire information is requested, so that the host equipment can acquire the luminaire information of the luminaire  12  from which the luminaire information can be requested. 
     As stated above, the host equipment  11  uses a part of the data frames to transmit the dimming data and can transmit the command to request the luminaire information of the luminaire  12 . Thus, the time for receiving the reply from the luminaire  12  has only to be secured before the next dimming data is transmitted, and the time till the next dimming data transmission can be shortened. Thus, while the real-time property of staged dimming is secured, the luminaire information from the luminaire  12  can be acquired. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.