Abstract:
A clean-room monitoring device for monitoring the interior of a clean-room having a floor in which a removable cover such as a grating or a non-porous cover is disposed, includes: a monitoring camera which captures an image of the removable cover; a monitor which detects the existence of an opening exposed when the removable cover is removed, based on an image signal obtained from the monitoring camera, detects the presence of a workman approaching the opening if it is detected that the opening exists, and outputs a warning signal if the workman is detected; and a warning generator which receives the warning signal from monitor and issues a warning.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation Application of PCT International Application No. PCT/JP2013/004102, filed Jul. 2, 2013, which claimed the benefit of Japanese Patent Application No. 2012-153760, filed Jul. 9, 2012, the entire content of each of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a clean-room monitoring device and a method for monitoring a clean-room. 
       BACKGROUND 
       [0003]    In the related art, e.g., in a semiconductor manufacturing line configured to manufacture semiconductor devices, a number of semiconductor manufacturing apparatuses have been arranged in a clean-room under a clean atmosphere. Inside the clean-room, a down flow of clean air is formed to flow from the ceiling toward the floor of the clean-room. Thus, dust found in the clean-room is allowed to be discharged out of the clean-room. 
         [0004]    In order to form a down flow in such clean rooms, a grating having a number of apertures is placed in the floor of the clean-room. A space in which the down flow is distributed is placed below the grating. The grating can be removed. A workman can, for example, enter the space below the grating to perform work when the grating is removed. 
         [0005]    However, since an opening is exposed in the floor when the grating is removed, there is a potential danger that the workman may fall into the space through the opening. To avoid this danger, attempts have been made to warn the workman by setting up a pylon or barricade tapes around the opening when the grating is removed. In addition, in order to prevent workmen from falling into openings on construction sites and so on, there has been proposed a device for supporting baseboards on or around such openings. 
         [0006]    In such a device, a warning sign for a workman was provided by setting up a pylon or barricade tapes around the opening when the grating in the clean-room was removed. However, a pylon or barricade tapes may not be promptly set up right after removing the grating and the workman may not be aware of the existence of the opening at that time. Thus, an accident where the workman could fall into the opening is possible at that time. In addition, even if a pylon or barricade tapes are set up, the workman may not be aware of the existence of the pylon or barricade tapes. Thus, there is another possibility of an accident occurring where the workman could fall into the opening. 
       SUMMARY 
       [0007]    The present disclosure provides some embodiments of a clean-room monitoring device and a clean-room monitoring method capable of preventing a workman from falling into an opening exposed when a removable cover for the opening (for example, a porous cover including a grating or a non-porous cover) is removed. 
         [0008]    According to one embodiment of the present disclosure, there is provided a clean-room monitoring device for monitoring the interior of a clean-room having a floor in which a removable cover is disposed, including: a monitoring camera which captures an image of the removable cover; a monitor which detects the existence of an opening exposed when the removable cover is removed, based on an image signal obtained from the monitoring camera, detects the presence of a workman approaching the opening if it is detected that the opening exists, and outputs a warning signal if the workman is detected; and a warning generator which receives the warning signal from the monitor and issues a warning. 
         [0009]    According to another embodiment of the present disclosure, there is provided a clean-room monitoring method for monitoring the interior of a clean-room having a floor in which a removable cover is disposed, including: capturing an image of the removable cover by means of a monitoring camera; detecting the existence of an opening exposed when the removable cover is removed, based on the captured image obtained from the monitoring camera in the step of capturing; detecting the presence of a workman approaching the opening if it is detected that the opening exists in the step of detecting the existence of the opening; and issuing a warning if the workman is detected approaching the opening in the step of detecting the presence of the workman approaching the opening. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure. 
           [0011]      FIG. 1  is a view illustrating a general configuration of a clean-room monitoring device according to one embodiment of the present disclosure. 
           [0012]      FIGS. 2 and 3  are views for illustrating an example of an installation state of the clean-room monitoring device. 
           [0013]      FIG. 4  is a flow chart illustrating a clean-room monitoring operation. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. 
         [0015]      FIG. 1  is a block diagram illustrating a general configuration of a clean-room monitoring device according to one embodiment of the present disclosure. Referring to  FIG. 1 , a clean-room monitoring device  100  includes a monitor  101  implemented with a computer or the like, a monitoring camera  102  such as a digital camera or the like, and a warning generator  103  configured to generate a warning with light, a warning signal and so on. The warning generator  103  includes, for example, a revolving light, a speaker configured to emit a warning sound, etc. 
         [0016]    Referring to  FIG. 2 , monitoring cameras  102  are installed on the top surface of semiconductor manufacturing apparatuses  110  arranged in the clean-room. The monitoring cameras  102  capture an image of the floor (for example, including a removable cover such as a grating or a non-porous cover) of the clean-room from above. In the floor of the clean-room, a removable cover may be disposed through which a down flow of clean air formed from the ceiling toward the floor is introduced into a space below the floor. In some embodiments, the removable cover may be a grating or any other type of cover with at least one pore through which a down flow of clean air from the ceiling toward the floor is introduced into the space below the floor. In some other embodiments, the removable cover may be a non-porous cover that may be disposed to cover a pore or aperture formed on the floor. In such case, the down flow of clean air from the ceiling toward the floor may be introduced into the space below the floor through a gap between the removable cover and the pore on the floor or some other type of a ventilation mechanism. Depending on the type of clean-room, the height of the space below the removable cover is, for example, 1 to 5 meters. Therefore, it could be very dangerous when a workman falls into the space in the floor of the clean-room. 
         [0017]    The monitoring cameras  102  are provided to capture the image of the floor (removable cover) in passages formed between the semiconductor manufacturing apparatuses  110 . In the example shown in  FIG. 2 , passages  111  in which the workman can pass through surround the semiconductor manufacturing apparatuses  110 . Four monitoring cameras  102  are arranged to image the passages  111  all around the semiconductor manufacturing apparatuses  110 . 
         [0018]    As shown in  FIG. 3 , a plurality of the semiconductor manufacturing apparatuses  110  is arranged in the clean-room. The monitoring cameras  102  are installed in the semiconductor manufacturing apparatuses  110  in such a manner that removable covers in all passages in the clean-room can be seen by one of the monitoring cameras  102 . It is shown in the example of  FIG. 3  that the warning generators  103  are arranged in the semiconductor manufacturing apparatuses  110 . However, the warning generators  103  may be arranged in places other than the semiconductor manufacturing apparatuses  110 . 
         [0019]    In the example of  FIG. 3 , some of the removable covers are removed and an opening  113  is exposed in the floor. The monitor  101  analyzes image signals from the monitoring cameras  102  and monitors whether or not the opening  113  is exposed in the clean-room. 
         [0020]    As described above, the monitoring cameras  102  are installed in such a manner that the removable covers in all passages in the clean-room can be seen by one of the monitoring cameras  102 . Therefore, when any removable covers is removed in the passages  111  in the clean room, any one of the monitoring cameras  102  can detect the removal, thereby detect that the opening  113  is exposed. 
         [0021]    The monitoring cameras  102  may be installed in places other than the semiconductor manufacturing apparatuses  110 , such as the ceiling or walls of the clean-room. In addition, the monitoring cameras  102  may be used in combination with the monitoring cameras  102  arranged in areas other than the semiconductor manufacturing apparatuses  110 , such as the ceiling or walls of the clean-room. 
         [0022]    Next, an operation of the clean-room monitoring device  100  will be described with reference to a flow chart of  FIG. 4 . 
         [0023]    Upon starting a clean-room monitoring operation by the clean-room monitoring device  100 , the monitor  101  receives an image signal for the floor (removable cover) of an imaged passage  111  from each monitoring camera  102  (Step S 301 ). 
         [0024]    Next, the monitor  101  analyzes the image signal received from each monitoring camera  102 . Then, the monitor  101  determines whether or not the removable cover is removed from the floor of the passage  111  and whether there exists a section where an opening  113  is exposed in the passage  111  (Step S 302 ). 
         [0025]    If it is determined that there are no sections where an opening  113  is exposed in the passage  111 , the monitor  101  determines whether to terminate the monitoring process of the passage  111  (Step S 305 ). If it is determined that the process is not to be ended, the operation at Step  5301  is repeated. If it is determined that the process is to be ended, the process for monitoring is ended. 
         [0026]    On the other hand, if it is determined in Step  5302  that the removable cover is removed and the opening  113  is exposed in the passage  111 , the monitor  101  determines whether or not a workman approaches the opening  113  (Step S 303 ). 
         [0027]    If it is determined that no workman approaches the opening  113 , the monitor  101  determines whether to terminate the monitoring process (Step S 305 ). If it is determined that the process is not to be ended, the operation from Step  5301  is repeated. If it is determined that the monitoring process is to be ended, the process for monitoring is ended (Step S 306 ). 
         [0028]    If it is determined that a workman approaches the opening  113 , a warning signal is outputted from the monitor  101  to the warning generator  103  to issue a warning with light, warning sound or the like (Step S 304 ). The warning from the warning generator  103  allows the workman approaching the opening  113  to be alerted to an imminent dangerous situation, thereby preventing the workman from falling into the opening  113 . 
         [0029]    Next, the monitor  101  determines whether to terminate the process (Step S 305 ). If it is determined that the process is not to be ended, the operation from Step S 301  is repeated. If it is determined that the process is to be ended, the process for monitoring is ended. 
         [0030]    As described above, in the clean-room monitoring device and the clean-room monitoring method according to this embodiment, when a removable cover in the clean-room is removed to expose an opening  113  in the floor of the clean-room, the opening  113  is automatically detected and a warning is issued when a workman approaching the opening  113  is detected, thereby calling to the attention of the workman an imminent danger. Accordingly, even in a case where a pylon or barricade tapes around the opening  113  is not set up, the workman is alerted to perceive the existence of the opening  113 . Thus, it is possible to prevent the workman from falling into the opening  112  exposed when the removable cover is removed. 
         [0031]    According to the present disclosure, it is possible to provide a clean-room monitoring device and a clean-room monitoring method capable of preventing a workman from falling into an opening exposed when a removable cover for the opening is removed. 
         [0032]    It is to be understood that the present disclosure is not limited to the disclosed embodiment but various modifications can be made. 
         [0033]    The clean-room monitoring device and the clean-room monitoring method of the present disclosure can be utilized in the manufacture of substrates for semiconductor devices and flat panel displays, solar cell panels and so on and thus has industrial applicability.