Patent Publication Number: US-2009218259-A1

Title: Paper sheet discriminating apparatus, paper sheet processing apparatus, and paper sheet discriminating method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Applications No. 2008-048415, filed Feb. 28, 2008; No. 2008-070046, filed Mar. 18, 2008; and No. 2008-208537, filed Aug. 13, 2008, the entire contents of all of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a paper sheet discriminating apparatus, a paper sheet processing apparatus, and a paper sheet discriminating method, applied to, for example, a mail processor and configured to discriminate mail pieces by the thickness. 
     2. Description of the Related Art 
     In a mail processor, a plurality of types of mail pieces of different thicknesses that are supplied from a supply section are loaded into a discriminating apparatus and discriminated by the thickness. Thereafter, mail pieces of a desired thickness are conveyed, and sorted and stored in sorting boxes, based on their sorting information. 
     There is a known discriminating apparatus in which a discriminating region is defined by arranging elongated discriminating blades in a cylinder along the inner peripheral surface of a rotating drum with their transverse end portions superposed on one another with gaps between them. 
     In the discriminating apparatus, the discriminating blades are revolved around the center of the discriminating region as the rotating drum rotates, whereby those mail pieces which are thinner than the gaps, among a plurality of mail pieces of different thicknesses in the discriminating region, are passed through the gaps and discriminated (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2000-255761). 
     If a large quantity of mail pieces are loaded in a lump into the discriminating region of the rotary discriminating apparatus described above, the lump of mail pieces cannot be broken even when the discriminating blades are revolved, so that the discrimination is difficult. 
     Conventionally, therefore, the chances of the mail pieces reaching the gaps between the discriminating blades of the discriminating apparatus are increased by increasing the length of the blades or the diameter of the discriminating region. 
     If the discriminating blades or the discriminating region is thus enlarged, however, the apparatus is increased in size and cost and requires a larger installation space. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of these circumferences, and its object is to provide a paper sheet discriminating apparatus, a paper sheet processing apparatus, and a paper sheet discriminating method, capable of increasing the discriminating capacity without increasing the apparatus size and of reducing the installation space as well as the equipment cost. 
     A paper sheet discriminating apparatus according to an aspect of the invention comprises: a rotating drum; a plurality of discriminating blades which are arranged in a cylinder within the rotating drum along an inner peripheral surface thereof, to define a discriminating region which is loaded with a plurality of paper sheets of different thicknesses, transverse end portions of the discriminating blades being superposed with gaps therebetween; a drive device which rotates the rotating drum to revolve the discriminating blades around the center of the discriminating region, thereby causing those paper sheets which are thinner than the gaps, out of the paper sheets of the different thicknesses in the discriminating region, to pass through the gaps; and a control device which performs control to change a rotating state of the rotating drum driven by the drive device. 
     A paper sheet processing apparatus according to another aspect of the invention comprises: a feeding device which supplies a plurality of paper sheets of different thicknesses; a rotating drum provided on the paper-sheet feeding side of the feeding device; a plurality of discriminating blades which are arranged in a cylinder within the rotating drum along an inner peripheral surface thereof, to define a discriminating region which is loaded with the paper sheets of the different thicknesses, transverse end portions of the discriminating blades being superposed with gaps therebetween; a drive device which rotates the rotating drum to revolve the discriminating blades around the center of the discriminating region, thereby causing those paper sheets which are thinner than the gaps, out of the paper sheets of the different thicknesses in the discriminating region, to pass through the gaps; a control device which performs control to change a rotating state of the rotating drum driven by the drive device; a conveying device which conveys the paper sheets delivered from the rotating drum through the gaps between the discriminating blades; and a sorting/storing device which sorts and stores the paper sheets conveyed by the conveying device, based on sorting information concerned. 
     A paper sheet discriminating method according to a further aspect of the invention comprises: arranging a plurality of discriminating blades in a cylinder within a rotating drum along an inner peripheral surface thereof, to define a discriminating region, such that transverse end portions of the discriminating blades are superposed with gaps therebetween, and loading the discriminating region with a plurality of paper sheets of different thicknesses; rotating the rotating drum by means of a drive device to revolve the discriminating blades around the center of the discriminating region, thereby causing those paper sheets which are thinner than the gaps, out of the paper sheets of the different thicknesses in the discriminating region, to pass through the gaps; and performing control to change a rotating state of the rotating drum driven by the drive device. 
     According to the present invention, there are provided a paper sheet discriminating apparatus, a paper sheet processing apparatus, and a paper sheet discriminating method, capable of increasing the discriminating capacity without increasing the apparatus size and of reducing the installation space as well as the equipment cost. 
     Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
         FIG. 1  is an exterior perspective view generally showing a mail processor according to one embodiment of the invention; 
         FIG. 2  is a perspective view showing a letter discriminating apparatus of  FIG. 1 ; 
         FIG. 3  is a side view showing a rotating drum of the letter discriminating apparatus of  FIG. 2 ; 
         FIG. 4  is a front view showing the rotating drum of  FIG. 3 ; 
         FIG. 5  is a view showing an arrangement configuration of discriminating blades of the rotating drum of  FIG. 4 ; 
         FIG. 6  is a block diagram showing a drive control system of the letter discriminating apparatus of  FIG. 2 ; 
         FIG. 7  is a view showing letters loaded in a lump into a discriminating region composed of the discriminating blades of  FIG. 5 ; 
         FIG. 8  is a view showing how the lump of letters is broken in the discriminating region; 
         FIG. 9  is a side view showing a letter discriminating apparatus according to a second embodiment of the invention; 
         FIG. 10  is a front view showing the letter discriminating apparatus of  FIG. 9 ; and 
         FIG. 11  is a view showing a letter discriminating operation of the letter discriminating apparatus of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     First Embodiment 
       FIG. 1  is a general configuration view showing a mail processor as a paper sheet processing apparatus according to one embodiment of the invention. 
     In  FIG. 1 , number  1  denotes a transfer conveyor that conveys a large number of mail letters (hereinafter referred to as letters) as paper sheets to be deposited in a lump. A hopper conveyor  2  for use as a feeding device is provided on the unloading side of the transfer conveyor  1 . The hopper conveyor  2  receives and conveys the letters upward. 
     Provided on the unloading side of the hopper conveyor  2  is a rotary letter discriminating apparatus  3  according to the present invention, which receives letters dropped from the hopper conveyor  2  and discriminates their thicknesses. A takeout device  4  that picks up the letters one by one is disposed on the unloading side of the letter discriminating apparatus  3 . The letters picked up from the takeout device  4  are conveyed along a transfer path. A width discriminating section  6 , hardness discriminating section  7 , thickness detecting section  8 , rejection section  9 , address reading section  10 , switchback section  11 , up-down reversal section  12 , imprinting section  13 , inside-out inversion section  14 , barcode reading section  15 , and sorting/storing section  16  as a sorting/storing device are successively arranged along the direction in which the letters are conveyed. 
     The letters that are loaded in a lump onto the transfer conveyor  1  are delivered onto the hopper conveyor  2  as the conveyor  1  runs. As the hopper conveyor  2  runs, the letters are conveyed upward and loaded into the letter discriminating apparatus  3 . The letters in the letter discriminating apparatus  3  is checked for thickness and delivered in the manner described in detail later. The delivered letters are picked up one by one by the takeout device  4  and conveyed to the width discriminating section  6 , in which they are checked for width. Then, the letters are conveyed to the hardness discriminating section  7 , in which they are checked for hardness. The checked or discriminated letters are fed to the thickness detecting section  8 , in which they are checked for thickness. Those letters which have thicknesses greater than a predetermined thickness are rejected through the rejection section  9 . Those letters which are not rejected are fed to the address reading section  10 , in which addresses thereon are read. Thereafter, the accepted letters are conveyed through the switchback section  11  and the up-down reversal section  12  to the imprinting section  13 , in which they are imprinted. The imprinted letters are fed through the inside-out inversion section  14  to the barcode reading section  15 , in which barcodes thereon are read. Based on the read information, thereafter, the letters are sorted and stored in the sorting/storing section  16 . 
       FIG. 2  is an exterior view showing the rotary letter discriminating apparatus  3 . 
     As shown in  FIGS. 3 and 4 , the letter discriminating apparatus  3  contains a rotating drum  21  therein. Within the drum  21 , a plurality of elongated discriminating blades  22  are integrally arranged along its inner peripheral surface. The discriminating blades  22  are arranged in a cylinder to define a discriminating region  24  with their transverse end portions superposed on one another. As shown in  FIG. 5 , gaps  25  are formed individually at superposed portions of the discriminating blades  22 . Although letters P 1  and P 2  that are thinner than each gap  25  can pass through the gaps  25 , letters P 3  that are thicker than each gap  25  cannot. As shown in  FIG. 4 , moreover, a residual sensor  42  for use as a residual detection device that optically detects the quantity of remaining letters is provided in the discriminating region  24 . 
     A drive motor  28  is connected to the rotating drum  21  through a power transmission mechanism  27 . The drum  21  is rotated counterclockwise by the motor  28 . The discriminating blades  22  are revolved counterclockwise around the center of the discriminating region  24  as the drum  21  rotates. The rotating drum  21  and the discriminating region  24  are tilted so that their letter-receiving side is higher than the non-receiving side. Thus, the letters can be moved along the respective inner bottom surfaces of the blades to the non-receiving side and discharged as the drum  21  rotates. 
     A chute section  30  that guides the letters P 1  and P 2  discharged from the rotating drum  21  is provided on the non-receiving side of the drum  21 . The chute section  30  is underlain by a transfer conveyor  31  for use as a conveying device that conveys the letters P 1  and P 2  toward the takeout device  4 . 
     A chute section  33  that guides the letters P 3  discharged from the discriminating region  24  is provided on the non-receiving side of the region  24 . The chute section  33  is underlain by a storage section  34  that stores the discharged letters P 3 . 
     As shown in  FIGS. 2 and 3 , the hopper conveyor  2  is provided on its top side with a first quantity sensor  36 , such as an ultrasonic sensor, for use as a first measuring device that detects the quantity of letters conveyed by the hopper conveyor  2 . The transfer conveyor  31  is provided on its top side with a second quantity sensor  37 , such as an ultrasonic sensor, for use as a second measuring device that detects the quantity of letters conveyed by the transfer conveyor  31 . 
     As shown in  FIG. 3 , moreover, the hopper conveyor  2  is passed around and between a driving roller  43  and driven rollers  44  and  45 . The driving roller  43  is rotated by the drive motor  46 , whereby the hopper conveyor  2  is run in the direction of the arrow. 
     As shown in  FIG. 6 , the first and second quantity sensors  36  and  37  and the residual sensor  42  are connected to a control section  40  for use as a control device through a transmitter circuit. The control section  40  is connected with the drive motor  28  for the rotating drum  21  and the drive motor  46  for the hopper conveyor  2  through a control circuit. 
     The control section  40  is configured to vary the rotational speed of the drive motor  28 , thereby increasing or reducing the speed of revolution of the discriminating blades  22 , when a predetermined value is exceeded by the detected quantity of letters transmitted from the first quantity sensor  36 , that is, when a large number of letters are detected at a time by the sensor  36 . Under this speed control, a mass of letters loaded at a time into the discriminating region  24  can be jogged to be broken. 
     If a predetermined value is exceeded by the detected quantity of letters transmitted from the second quantity sensor  37 , moreover, the control section  40  concludes that too great a quantity of letters for the discriminating capacity have been loaded into the discriminating region  24 , and stops the discriminating blades  22  from being revolved by the drive motor  28 . 
     Further, the control section  40  is configured to stop the control for varying the rotational speed of the rotating drum  21  when the residual sensor  42  detects remaining letters less than a predetermined quantity. 
     If remaining letters not less than the predetermined quantity are detected by the residual sensor  42 , furthermore, the control section  40  concludes that the loading of the letters from the hopper conveyor  2  is too much, and stops the operation of the drive motor  46  for the hopper conveyor, thereby stopping the loading of the letters. 
     The following is a description of a discriminating operation of the letter discriminating apparatus  3 . 
     First, the rotating drum  21  is rotated by the drive motor  28  to revolve the discriminating blades  22  counterclockwise around the center of the discriminating region  24 . Thereupon, the gaps  25  between the blades  22  are moved forward. As the transfer conveyor  1  and the hopper conveyor  2  run in this state, the plurality of types of letters P 1  to P 3  of different thicknesses are conveyed and loaded into the discriminating region  24 , as shown in  FIG. 7 . 
     After the letters P 1  to P 3  in the discriminating region  24  are dropped onto the discriminating blades  22  that constitute the lower side of the discriminating region  24 , they are obliquely scraped up and conveyed as the blades  22  move. Thereupon, the letters P 1  to P 3  are moved by their own weight toward the gaps  25  between the discriminating blades  22 . The letters P 1  and P 2  that are thinner than the gaps  25  between the blades  22  are delivered from the discriminating region  24  into the rotating drum  21  through the gaps  25 . On the other hand, the letters P 3  that are thicker than the gaps  25  are guided and discharged to the non-receiving side of the discriminating region  24  without passing through the gaps  25 , and are stored into the storage section  34  through the chute section  33 . Thus, the thin letters P 1  and P 2  are discriminated from the thick letters P 3 . 
     If a large quantity of letters are loaded in a lump into the discriminating region  24  for the discrimination, the lump of letters cannot be broken even when the discriminating blades  22  are revolved at a constant speed. In this case, the thin letters P 1  and P 2  are intercepted by the thick letters P 3 , so that the chances of their reaching the discriminating blades  22  are reduced. Consequently, the thin letters P 1  and P 2  cannot pass through the gaps  25  between the blades  22  and may possibly be guided and discharged together with the thick letters P 3  to the non-receiving side of the discriminating region  24 . 
     According to this embodiment, therefore, the quantity of letters loaded into the discriminating region  24  is detected by the first quantity sensor  36 . When the detected quantity exceeds a predetermined value, the control section  40  varies the rotational speed of the drive motor  28 , thereby increasing or reducing the speed of revolution of the discriminating blades  22 . By doing this, a pile of letters in the discriminating region  24  can be jogged to be broken, as shown in  FIG. 8 . Thus, the time before the letters P 1  and P 2  reach the discriminating blades  22  can be shortened, and the chances of their reaching the blades  22  can be increased. In consequence, the thin letters P 1  and P 2  can be securely delivered from the discriminating region  24  into the rotating drum  21  through the gaps  25 . 
     The thin letters P 1  and P 2  delivered into the rotating drum  21  are discharged onto the transfer conveyor  31  through the chute section  30  and conveyed to the takeout device  4 . On the other hand, the thick letters P 3  are discharged from the discriminating region  24  and stored into the storage section  34  through the chute section  33 . 
     If remaining letters not less than the predetermined quantity are detected by the residual sensor  42  during the letter discriminating operation, moreover, the control section  40  concludes that the loading of the letters into the discriminating region  24  by the hopper conveyor  2  is too much, and stops the drive of the drive motor  46  for the hopper conveyor. Thereupon, the travel of the hopper conveyor  2  is stopped, so that the loading of the letters into the discriminating region  24  is stopped. 
     On the other hand, the quantity of letters conveyed to the takeout device  4  by the transfer conveyor  31  is detected by the second quantity sensor  37 . If the predetermined value is exceeded by the quantity of letters detected by the second quantity sensor  37 , the control section  40  concludes that too great a quantity of letters for the discriminating capacity have been loaded into the discriminating region  24 , and stops the drive of the drive motor  28  to stop the revolution of the discriminating blades  22 . 
     If the quantity of remaining letters in the discriminating region  24 , which is detected by the residual sensor  42 , is less than the predetermined quantity, the control section  40  concludes that control for varying the speed of revolution of the discriminating blades  22  is unnecessary, and stops the drive of the drive motor  28  to stop the revolution of the blades  22 . 
     According to the first embodiment, as described above, the speed of revolution of the discriminating blades  22  is increased or reduced if it is detected that the quantity of letters loaded into the discriminating region  24  of the rotating drum  21  is greater than a predetermined quantity, so that the lump of letters in the discriminating region  24  can be jogged to be broken. Thus, the time before the letters P 1  and P 2  reach the discriminating blades  22  can be shortened, and the chances of their reaching the blades  22  can be increased. In consequence, the thin letters P 1  and P 2  can be securely passed through the gaps  25  and discriminated without increasing the size of the apparatus. 
     If remaining letters not less than the predetermined quantity are detected by the residual sensor  42  during the letter discriminating operation, moreover, the control section  40  concludes that the loading of the letters into the discriminating region  24  by the hopper conveyor  2  is too much, and stops the loading of the letters. Thus, the letters cannot be jammed in the discriminating region  24 . 
     If the second quantity sensor  37  detects that the quantity of letters discriminated and delivered toward the takeout device  4  is not less than the predetermined quantity, it is concluded that too great a quantity of letters for the discriminating capacity have been loaded into the discriminating region  24 , and the drive of the drive motor  28  is stopped. Thus, an appropriate quantity of letters can be fed into the takeout device  4 , so that the letters cannot be jammed in a post-processing step. 
     If the remaining letters in the discriminating region  24  are reduced as the discriminating process progresses, moreover, the control of the drive speed of the drive motor  28  is stopped. Thus, useless drive control can be prevented, so that power consumption can be reduced. 
     In the first embodiment described above, the lump of letters is broken by varying the rotational speed of the rotating drum  21 . Alternatively, however, the lump of letters may be broken by intermittently repeating the start and stop of the operation of the rotating drum  21 . 
     Further, the rotational speed of the rotating drum  21  may be changed automatically and periodically instead of performing the speed control for the drum  21  by measuring the quantity of letters using the first quantity sensor  36 . 
     Second Embodiment 
       FIG. 9  is a side view showing a rotary letter discriminating apparatus  50  according to a second embodiment of the invention, and  FIG. 10  is a front view of the apparatus  50 . 
     The letter discriminating apparatus  50  contains a rotating drum  51  therein. Within the drum  51 , a plurality of elongated first discriminating blades  52   a  are integrally arranged along its inner peripheral surface. The discriminating blades  52   a  are arranged in a cylinder to define an inside discriminating region  54   a  with their transverse end portions superposed on one another. As shown in  FIG. 11 , first gaps  55   a  are formed individually at superposed portions of the discriminating blades  52   a . Although letters P 1  and P 2  that are thinner than each first gap  55   a  are allowed to pass through the gaps  55   a , letters P 3  that are thicker than each gap  55   a  are not. 
     Within the rotating drum  51 , moreover, a plurality of elongated second discriminating blades  52   b  are integrally arranged along its inner peripheral surface so as to be situated outside the elongated discriminating blades  52   a . The second discriminating blades  52   b  are arranged in a cylinder to define an outside discriminating region  54   b  with their transverse end portions superposed on one another. As shown in  FIG. 11 , second gaps  55   b  that are narrower than the first gaps  55   a  are formed individually at superposed portions of the discriminating blades  52   b . Although the letters P 1  that are thinner than each second gap  55   b  are allowed to pass through the gaps  55   b , the letters P 2  that are thicker than each gap  55   b  are not. 
     For example, the thick letters P 3  are postal matter of corrugated cardboard, the moderately thick letters P 2  are relatively thick sealed letters, and the thin letters P 1  are postcards. 
     On the other hand, the rotating drum  51  is connected with a drive mechanism  58  for use as a drive device, whereby the drum  51  is rotated counterclockwise. The first and second discriminating blades  52   a  and  52   b  are revolved around the center of the inside and outside discriminating regions  54   a  and  54   b  as the rotating drum  51  rotates. 
     The rotating drum  51  and the inside and outside discriminating regions  54   a  and  54   b  are tilted so that their letter-receiving side is higher than the non-receiving side. Thus, the letters can be moved along the respective inner bottom surfaces of the blades to the non-receiving side and discharged as the drum  51  rotates. 
     A chute section  60  that guides the letters P 1  discharged from the rotating drum  51  is provided on the non-receiving side of the drum  51 . The chute section  60  is underlain by a transfer conveyor  61  for use as a conveying device that conveys the letters P 1  toward the takeout device  4 . 
     Further, a chute section  63   a  that guides the letters P 3  discharged from the inside discriminating region  54   a  is provided on the non-receiving side of the region  54   a . The chute section  63   a  is underlain by a first storage section  64   a  for use as a first storage device that stores the letters P 3 . 
     Furthermore, a chute section  63   b  that guides the letters P 2  discharged from the outside discriminating region  54   b  is provided on the non-receiving side of the region  54   b . The chute section  63   b  is underlain by a second storage section  64   b  for use as a second storage device that stores the letters P 2 . 
     The following is a description of a discriminating operation of the letter discriminating apparatus  50  constructed in this manner. 
     First, the rotating drum  51  is rotated by the drive mechanism  58  to revolve the first and second discriminating blades  52   a  and  52   b  that constitute the inside and outside discriminating regions  54   a  and  54   b , thereby moving the first and second gaps  55   a  and  55   b . As the transfer conveyor  61  and the hopper conveyor  2  run in this state, the plurality of types of letters P 1  to P 3  of different thicknesses are conveyed and loaded into the inside discriminating region  54   a , as shown in  FIG. 11 . After the letters P 1  to P 3  in the inside discriminating region  54   a  are dropped onto the discriminating blades  52   a  that constitute the lower side of the discriminating region  54   a , they are obliquely scraped up and conveyed as the blades  52   a  revolve. Thereupon, the letters P 1  to P 3  are moved by their own weight toward the first gaps  55   a  between the discriminating blades  52   a . Then, the letters P 1  and P 2  that are thinner than the first gaps  55   a  between the discriminating blades  52   a , out of all the letters P 1  to P 3 , are delivered from the inside discriminating region  54   a  to the outside discriminating region  54   b  through the first gaps  55   a . Further, the letters P 3  that are thicker than the first gaps  55   a  are guided and discharged along the discriminating blades  52   a  of the inside discriminating region  54   a  to the exit side, and are stored into the first storage section  64   a  through the chute section  63   a . Thus, the thin letters P 1  and P 2  are first discriminated from the thick letters P 3 . 
     After the letters P 1  and P 2  delivered to the outside discriminating region  54   b  are dropped onto the discriminating blades  52   b  that constitute the lower side of the discriminating region  54   b , they are obliquely scraped up and conveyed as the blades  52   a  revolve. Thereupon, the letters P 1  and P 2  are moved by their own weight toward the second gaps  55   b  between the discriminating blades  52   b . Then, only the letters P 1  that are thinner than the second gaps  55   b  between the discriminating blades  52   b , out of the letters P 1  and P 2 , are delivered from the outside discriminating region  54   b  into the rotating drum  51  through the second gaps  55   b . Further, the letters P 2  that are thicker than the second gaps  55   b  are guided and discharged along the discriminating blades  52   b  of the outside discriminating region  54   b  to the exit side, and are stored into the second storage section  64   b  through the chute section  63   b.    
     The letters P 1  that are delivered from the outside discriminating region  54   b  into the rotating drum  51  are delivered to the transfer conveyor  61  through the chute section  60  and conveyed to the takeout device  4 . 
     According to the second embodiment, as described above, the inside and outside discriminating regions  54   a  and  54   b  are arranged within the rotating drum  51 . 
     After the thick letters P 3  and the letters P 1  and P 2  thinner than the letters P 3  are discriminated in the inside discriminating region  54   a , the moderately thick letters P 2  and the letters P 1  thinner than the letters P 2  are discriminated in the outside discriminating region  54   b . In other words, the letters are discriminated again in the outside discriminating region  54   b  after they are roughly discriminated. Even if a large quantity of letters are loaded in a lump, therefore, they can be discriminated without increasing the size of the discriminating apparatus. Further, the three types of thicknesses of the letters can be discriminated without using a plurality of discriminating apparatuses. 
     Thus, the equipment cost can be reduced, and in addition, the arrangement space can be reduced considerably. 
     The present invention is not limited directly to the embodiments described above, and its components may be embodied in modified forms without departing from the scope or spirit of the invention. Further, various inventions may be made by suitably combining a plurality of components described in connection with the foregoing embodiments. For example, some of the components according to the foregoing embodiments may be omitted. Furthermore, components according to different embodiments may be combined as required. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.