Abstract:
A slack storage assembly for storing optical fibers  11  includes fixed plates  51  disposed in horizontal posture, first movable plates  52  disposed parallel to the fixed plates  51  to be movable toward and away from the fixed plates  51,  and second movable plates  53  disposed parallel to the first movable plates  52  to be movable toward and away from the first movable plates  52.  The optical fibers  11  are fixed as pinched between the fixed plates  51  and first movable plates  52  and between the first movable plates  52  and second movable plates  53.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates an apparatus for storing slacks of optical fibers extending from optical devices. 
     2. Description of the Related Art 
     When connecting optical devices such as semiconductor lasers to an optical system by using optical fibers, for example, longer optical fibers than are necessary for the connection are used in order to obtain excellent characteristics. Consequently, it is necessary to deal with slacks of the optical fibers extending from the optical devices. 
     Conventionally, such slacks are dealt with by simply leaving the optical fibers as they are without supporting them, or by placing the optical fibers on a support member. 
     Where the optical fibers are left as they are without support or placed on a support member, the optical fibers could move and vary the curvature thereof. When the optical fibers move and vary the curvature thereof, variations will occur in the emission pattern of the luminous flux emitted from the optical fibers, to produce an adverse effect upon the light transmission characteristics. 
     Thus, as described in Japanese Patent Publication (Unexamined) No. 1995-63925, optical fibers may be fixed by winding slacks thereof around guide members or the like. In such a case, however, maintainability is poor in time of changing optical devices or optical fibers. 
     SUMMARY OF THE INVENTION 
     The object of this invention, therefore, is to provide a slack storage apparatus for storing slacks of optical fibers, which realizes an improvement in maintainability while preventing movement of the optical fibers to avoid deterioration in transmission characteristics. 
     The above object is fulfilled, according to the present invention, by a slack storage apparatus for storing slacks of optical fibers extending from optical devices, the apparatus comprising a fixed plate disposed in horizontal posture, and at least one movable plate disposed parallel to the fixed plate to be movable toward and away from the fixed plate, wherein, when the movable plate is moved toward the fixed plate, one of the optical fibers is fixedly pinched between the fixed plate and the movable plate. 
     This slack storage apparatus for storing optical fibers is capable of fixedly pinching the optical fibers. Thus, deterioration in transmission characteristics due to movement of the optical fibers is effectively avoided. In addition, the optical fibers may easily be released from the fixed state to realize improved maintainability. 
     In another aspect of the invention, a slack storage apparatus is provided for storing slacks of optical fibers extending from optical devices, the apparatus comprising a plurality of optical fiber fixing units arranged one over another, each of the optical fiber fixing units including a fixed plate disposed in horizontal posture, and at least one movable plate disposed parallel to the fixed plate to be movable toward and away from the fixed plate, wherein, when the movable plate is moved toward the fixed plate, one of the optical fibers is fixedly pinched between the fixed plate and the movable plate. 
     In a further aspect of the invention, a slack storage apparatus is provided for storing slacks of optical fibers extending from optical devices, the apparatus comprising a plurality of optical fiber fixing units arranged one over another, each of the optical fiber fixing units including a fixed plate disposed in horizontal posture, a first movable plate disposed parallel to the fixed plate to be movable toward and away from the fixed plate, a second movable plate disposed parallel to the first movable plate to be movable toward and away from the first movable plate, and a plate moving mechanism for synchronously moving the first movable plate toward the fixed plate and the second plate toward the first movable plate, wherein the optical fibers are fixedly pinched between the fixed plate and the first movable plate and between the first movable plate and the second movable plate. 
     In a still further aspect of the invention, a slack storage apparatus is provided for storing slacks of optical fibers extending from optical devices, the apparatus comprising fixed shafts extending vertically, movable shafts movable vertically and having large diameter portions and small diameter portions arranged alternately, a plurality of fixed plates fixed to the fixed shafts, first movable plates disposed parallel to the fixed plates and corresponding in number to the fixed plates, the first movable plates defining bores smaller than the large diameter portions and larger than the small diameter portions, the small diameter portions extending through the bores, and second movable plates fixed to the movable shafts and corresponding in number to the first movable plates, the second movable plates being parallel to the first movable plates and opposed to the fixed plates across the first movable plates, wherein, with movement of the movable shafts, the optical fibers are fixedly pinched between the fixed plates and the first movable plates and between the first movable plates and the second movable plates, respectively. 
     Other features and advantages of the present invention will be apparent from the following detailed description of the embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of illustrating the invention, there are shown in the drawings several forms which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangement and instrumentalities shown. 
     FIG. 1 is a perspective view of a principal portion of an image recording apparatus including a device supporting assembly; 
     FIG. 2 is an enlarged perspective view of a portion of the image recording apparatus including the device supporting assembly and a slack storage assembly; 
     FIG. 3 is a perspective view, partly broken away, of the slack storage assembly; 
     FIG. 4 is a perspective view, partly broken away, of the slack storage assembly; 
     FIG. 5 is a side view of the slack storage assembly; 
     FIG. 6 is a side view of the slack storage assembly; 
     FIG. 7 is an enlarged fragmentary view of the slack storage assembly; and 
     FIG. 8 is an enlarged fragmentary view of the slack storage assembly. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the present invention will be described hereinafter with reference to the drawings. 
     The construction of an image recording apparatus having an optical fiber slack storage apparatus according to the invention will be described first. FIG. 1 is a perspective view of a principal portion of the image recording apparatus including a slack storage assembly  5  acting as the slack storage apparatus according to the invention. 
     This image recording apparatus is used to record images on a sensitive material  2  mounted peripherally of a drum  1  by emitting a laser beam from an imaging optical system  6 . The apparatus includes a device supporting assembly  4  for supporting numerous semiconductor lasers  3  acting as devices requiring temperature control, and the slack storage assembly  5  for supporting numerous optical fibers  11  optically connecting the semiconductor lasers  3  to the imaging optical system  6 . 
     In this image recording apparatus, the imaging optical system  6  emits a laser beam modulated according to image signals while the drum  1  is rotated by a motor not shown, and a recording head having the device supporting assembly  4 , slack storage assembly  5  and imaging optical system  6  is moved in a direction indicated by an arrow in FIG.  1 . In this way, the laser beam scans the sensitive material  2  to record an image thereon. 
     FIG. 2 is an enlarged perspective view of a portion of the image recording apparatus including the device supporting assembly  4  and slack storage assembly  5  shown in FIG.  1 . FIG. 2 shows only one half of the device supporting assembly  4  and one half of the slack storage assembly  5  provided for the image recording apparatus. The slack storage assembly  5  has a casing  71  to be described hereinafter, which is omitted from FIG.  2 . 
     One half of the device supporting assembly  4  supports a total of 32 semiconductor lasers  3  arranged on right and left side surfaces thereof (only 16 lasers on the right side surface being shown in FIG.  2 ). The device supporting assembly  4  has a top plane closed by a cover  15 , and a rear plane closed by a cover  13 . The cover  13  defines vent openings  14 . 
     Each semiconductor laser  3  is connected at an exit end thereof to one of the optical fibers  11 . The end of each optical fiber  11  remote from the semiconductor laser  3  is connected to a connector  32 . The portion of each optical fiber  11  extending from the semiconductor laser  3  to the connector  32  is fixedly supported by the slack storage assembly  5 . Each connector  32  is connected to an adaptor  31 . These adaptors  31  are connected to optical fibers  12  connected to the imaging optical system  6  (FIG.  1 ). Numeral  39  in FIG. 2 denotes transmission lines for transmitting electrical signals to drive the respective semiconductor lasers  3 . 
     The optical fibers  11  connected to the semiconductor lasers  3  are detached along with the connectors  32  from the adapters  31  when changing or maintaining the semiconductor lasers  3 . Thus, the optical fibers  11  are detachably fixed to the slack storage assembly  5 . The optical fibers  12  connecting the adaptors  31  to the imaging optical system  6  are immovably fixed by a fixing device not shown in FIG.  1 . 
     The construction of the slack storage assembly  5  acting as the slack storage apparatus according to the invention will be described next. FIGS. 3 and 4 are perspective views, partly broken away, of the slack storage assembly  5 . FIGS. 5 and 6 are side views of the slack storage assembly  5 . FIGS. 7 and 8 are enlarged fragmentary views of the slack storage assembly. FIGS. 3,  5  and  7  show a state in which the optical fibers  11  are not fixed. FIGS. 4,  6  and  8  show a state in which the optical fibers  11  are fixed as pinched by fixed plates  51 , first movable plates  52  and second movable plates  53 . 
     Each fixed plate  51 , first movable plate  52  and second movable plate  53 , combined with a fixed shaft unit  61  and a movable shaft unit  65 , constitute a fiber fixing unit. The slack storage assembly  5  includes a plurality of such fiber fixing units arranged one over another inside a casing  71  having an approximately U-shaped section. 
     As shown in FIGS. 7 and 8, each fixed shaft unit  61  has a threaded bore formed at an upper end thereof, and a screw  62  at a lower end for engaging the threaded bore of a next lower fixed shaft unit  61 . Such shaft units  61  are coaxially connected end to end by using the screws  62 , to form two fixed shafts as shown in FIGS. 3 and 4. These shafts are fixed at upper and lower ends thereof to the casing  71 . 
     As shown in FIGS. 7 and 8, each movable shaft unit  65  is in the form of a hollow shaft having a small diameter portion  63  and a large diameter portion  64 . A fixed support rod  66  extends through the movable shaft units  65 . Thus, two movable shafts are formed as shown in FIGS. 3 and 4. These movable shafts are movable up and down relative to the casing  71 . 
     As shown in FIGS. 7 and 8, each fixed plate  51  has bores  57  formed in two corners thereof and having an inside diameter larger than an outside diameter of the screws  62  of the fixed shaft units  61  and smaller than an outside diameter of the fixed shaft units  61 . Thus, the fixed plate  51  is fixed to the fixed shafts as held between the fixed shaft units  61 . Each fixed plate  51  has bores  54  formed in the two other corners thereof and having an inside diameter larger than an outside diameter of the large diameter portions  64  of the movable shaft units  65 . Thus, the fixed plate  51  is freely movable up and down relative to the movable shaft units  65 . 
     As shown in FIGS. 7 and 8, each first movable plate  52  has bores  58  formed in two corners thereof and having an inside diameter larger than the outside diameter of the fixed shaft units  61 . Thus, the first movable plate  52  is freely movable up and down relative to the fixed shaft units  61 . Each first movable plate  52  has bores  55  formed in the two other corners thereof and having an inside diameter larger than an outside diameter of the small diameter portions  63  of the movable shaft units  65 , and smaller than the outside diameter of the large diameter portions  64  of the movable shaft units  65 . Thus, the first movable plate  52  is freely movable up and down only within a region outside the small diameter portion  63  of each movable shaft unit  65 . 
     As shown in FIGS. 7 and 8, each second movable plate  53  has bores  59  formed in two corners thereof and having an inside diameter larger than the outside diameter of the fixed shaft units  61 . Thus, the second movable plate  53  is freely movable up and down relative to the fixed shaft units  61 . Each second movable plate  53  has bores  56  formed in the two other corners thereof and having an inside diameter larger than an outside diameter of the support rods  66  and smaller than the outside diameter of the small diameter portions  63  of the movable shaft units  65 . Thus, the second movable plate  53  is fixed to the movable shafts as held between the movable shaft units  65 . 
     As shown in FIGS. 3 through 6, the second movable plate  53  of the uppermost optical fiber fixing unit has a pulling member  72  attached to the upper surface thereof and defining a pair of bores  73  and  74 . Further, springs  67  are arranged between the second movable plate  53  of the uppermost optical fiber fixing unit and a top plate of the casing  71  for biasing the second movable plate  53  downward. 
     With the slack storage assembly  5  having the above construction, the optical fibers  11  are normally fixed inside the slack storage assembly  5 . When changing or maintaining the semiconductor lasers  3 , the optical fibers  11  are released from the fixed state. 
     To release the optical fibers  11  for changing or maintaining the semiconductor lasers  3 , the second movable plate  53  of the uppermost optical fiber fixing unit is raised, along with the movable shafts including the numerous movable shaft units  65 , against the biasing force of springs  67 , by using the bore  73  of the pulling member  72 . Then, the movable shafts are stopped in place such as by inserting a fixing bar, not shown, into the bore  74  of the pulling member  72 . 
     In this state, as shown in FIG. 7, each second movable plate  53  is raised along with the movable shaft units  65  constituting the movable shafts. Each first movable plate  52  is raised after the lower surface thereof contacts the upper ends of the large diameter portions  64  of the movable shaft units  65 . The fixed plates  51  remain stationary. Thus, as shown in FIGS. 3,  5  and  7 , the fixed plates  51 , first movable plates  52  and second movable plates  53  stop in equidistantly spaced positions. In this state, the optical fibers  11  are released. 
     To reinstate the optical fibers  11  in the normal, fixed state for an image recording operation after the semiconductor lasers  3  are changed or maintained, the pulling member  72  is released. Then, the second movable plate  53  of the uppermost optical fiber fixing unit is lowered, along with the movable shafts including the numerous movable shaft units  65 , by the action of springs  67 . 
     In this state, as shown in FIG. 8, each second movable plate  53  is lowered with the movable shaft units  65  constituting the movable shafts. Each first movable plate  52  descends as a result of loss of the support by the upper ends of the large diameter portions  64  of the movable shaft units  65 . Consequently, as shown in FIGS. 4,  6  and  8 , the fixed plates  51 , first movable plates  52  and second movable plates  53  stop in positions holding the optical fibers  11  between each adjacent pair of fixed plate  51  and first movable plate  52  and between each adjacent pair of first movable plate  52  and second movable plate  53 . 
     In this state, the optical fibers  11  are fixedly pinched, by the action of springs  67 , between each adjacent pair of fixed plate  51  and first movable plate  52  and between each adjacent pair of first movable plate  52  and second movable plate  53 . Thus, the optical fibers are effectively maintained immovable to avoid variations in the curvature thereof which would produce an adverse effect upon the light transmission characteristics. 
     In the above embodiment, two, first and second, movable plates  52  and  53  are used for each fixed plate  51 , and the optical fibers  11  are fixedly pinched between the fixed plate  51  and first movable plate  52  and between the first movable plate  52  and second movable plate  53 . Instead, one movable plate may be used for each fixed plate, with an optical fiber fixedly pinched between the fixed plate and movable plate. 
     In the described embodiment, two optical fibers  11  may be fixed by three plates  51 ,  52  and  53 . The alternative construction noted above fixes each optical fiber with two plates, and thus has a disadvantage of requiring an increased number of plates. 
     Conversely, to fix more optical fibers with fewer plates, an increased number of movable plates may be used for each fixed plate. The optical fibers may be fixedly pinched between these fixed plate and movable plates. 
     However, use of too many movable plates for each fixed plate will bring about an inconvenience that the optical fibers pinched by the movable plates arranged remote from each fixed plate are moved by large extents between the pinched state and released state. 
     The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. 
     This application claims priority benefit under 35 U.S.C. Section 119 of Japanese Patent Application No. 2001-142587 filed in the Japanese Patent Office on May 14, 1997, the entire disclosure of which is incorporated herein by reference.