Abstract:
A fishing reel for winding a fishing line includes a reel unit, a spool, a handle, a tension detection section, a temperature detection section, a detected tension correction section, and a corrected tension output section. The spool is rotatably attached to the reel unit and configured to wind the fishing line thereon. The handle is mounted to the reel unit, and configured to rotate the spool. The tension detection section is configured to detect tension applied on the fishing line by converting the tension into an electric signal. The temperature detection section is disposed to detect temperature of the tension detection section. The detected tension correction section is configured to correct the tension after being detected on the basis of the temperature of the tension detection section after being detected. The corrected tension output section is configured to output the tension after being corrected by the detected tension correction section.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Japanese Patent Application No. 2010-145183 filed on Jun. 25, 2010, the entirety of which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fishing reel, particularly to a fishing reel attached to a fishing rod for winding and releasing a fishing line. 
         [0004]    2. Background Art 
         [0005]    The fishing reels generally include a reel unit, a spool rotatably attached to the reel unit, and a handle for rotating the spool. The spool is attached onto a spool shaft supported by the reel unit, whereas the handle is fixedly attached onto a handle shaft while being disposed in parallel to the spool shaft. Japanese Laid-open Patent Application Publication No. JP-A-2005-270017 describes one of the well-known fishing reels of the aforementioned type. The fishing reel of the publication further includes, for instance, a star drag, a drag mechanism, and a torque sensor. The start drag is attached onto the handle shaft. The drag mechanism, such as a lever drag, is attached onto the spool shaft for braking rotation of the spool. The torque sensor detects torque applied on the drag mechanism. Tension applied on the fishing reel can be herein calculated using tension applied on the drag mechanism (i.e., the tension detected by the torque sensor). Therefore, an angler can reliably grasp tension applied on the fishing line, which is a current fishing condition in real time including information regarding whether or not a fish bites, a pulling level of a fish and the like, by displaying the tension applied on the fishing line on a display unit of a fishing information display device or a display unit of a counter case disposed on the top of the reel unit, for instance. 
         [0006]    According to the well-known fishing reels, the tension on the fishing line is detected by the torque sensor provided for detecting the toque applied on the drag mechanism. In general, the drag mechanism is configured to brake rotation of the spool by contact friction when a plurality of drag plates is abutted to the spool. However, the drag plates are heated due to increase in contact friction thereof in some cases, for instance, when a fish pulls the fishing line quite strongly during activation of the drag mechanism. When the drag mechanism is thus heated, the torque sensor disposed in the vicinity of the dram mechanism increases its temperature. Accordingly, the torque sensor can detect torque imprecisely. Such an imprecisely detected torque value results in a large difference between an actual tension value and a calculated tension value calculated based on the detected toque value. In other words, there are high chances that an angler cannot precisely grasp the tension applied on the fishing line. 
         [0007]    In view of the above, the present invention addresses a need to produce a fishing reel for allowing an angler to precisely grasp the tension applied on the fishing line. 
       SUMMARY 
       [0008]    The foregoing objects can basically be attained by providing a fishing reel including a reel unit, a spool, a handle, a tension detection section, a temperature detection section, a detected tension correction section, and a corrected tension output section. The spool is rotatably attached to the reel unit, and is configured to wind the fishing line thereon. The handle is mounted to the reel unit, and is configured to rotate the spool. The tension detection section is configured to detect tension applied on the fishing line by converting the tension into an electric signal. The temperature detection section is disposed in a vicinity of the tension detection section, and disposed to detect temperature of the tension detection section. The detected tension correction section is configured to correct the tension after being detected on the basis of the temperature of the tension detection section after being detected. The corrected tension output section is configured to output the tension after being corrected by the detected tension correction section. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Referring now to the attached drawings which form a part of this original disclosure: 
           [0010]      FIG. 1  is a perspective view of a fishing reel adopting an exemplary embodiment of the present invention; 
           [0011]      FIG. 2  is a cross-sectional view of the fishing reel; 
           [0012]      FIG. 3  is an enlarged cross-sectional side view of a left part of the fishing reel; 
           [0013]      FIG. 4  is an enlarged cross-sectional view of a torque sensor of the fishing reel; 
           [0014]      FIG. 5  is a plan view of a display unit of the fishing reel; 
           [0015]      FIG. 6  is a plan view of a fishing information display device; 
           [0016]      FIG. 7  is a control block diagram of the fishing reel; 
           [0017]      FIG. 8  is a control flowchart of a detected tension correction calculation output processing of the fishing reel; 
           [0018]      FIG. 9  is a plan view of a fishing information display device of another exemplary embodiment; and 
           [0019]      FIG. 10  is a plan view of a display unit of the fishing information display device of another exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0020]    As illustrated in  FIGS. 1 and 2 , a fishing reel  100  adopting an exemplary embodiment of the present invention is a large dual-bearing reel for trolling. The fishing reel  100  includes a tubular reel unit  1 , a spool shaft  2 , a spool  3 , and a handle  4 . The spool shaft  2  is rotatably attached to the center part of the reel unit  1 . The spool  3  is supported by the spool shaft  2  while being allowed to rotate but prevented from axially moving. The handle  4  is disposed lateral to the reel unit  1 . Further, the fishing reel  100  includes a rotation transmission mechanism  6 , a lever drag mechanism  7 , and an anti-reverse mechanism  9  in the inside of the reel unit  1 . The rotation transmission mechanism  6  is configured to transmit rotation of the handle  4  to the spool  3 . The lever drag mechanism  7  is configured to brake rotation of the spool  3  in a fishing line release direction. The anti-reverse mechanism  9  is configured to prevent rotation of the spool  3  in the fishing line release direction. 
         [0021]    The reel unit  1  includes a first side plate  10  (a left side plate), a second side plate  10  (a right side plate) and a reel body  12 . Each of the first and second side plates  10  and  11  is a closed end tubular member made of metal. The reel body  12  is a perforated tubular member made of metal. The first and second side plates  10  and  11  are concentrically joined to the both axial ends of the reel body  12  by a socket joint. Under the condition, the first and second side plates  10  are fixed to the reel body  12  by a plurality of fixation screws. The first and second side plates  10  and  11  support the both axial ends of the spool shaft  2  with roughly the center parts thereof for allowing the spool shaft  2  to rotate. 
         [0022]    A pair of harness lugs  13  is attached to the top of the reel unit  1  at a predetermined interval for connecting the fishing reel to a single or plurality of reel harnesses. Specifically, one of the harness lugs  13  is disposed between the first side plate  10  and the reel body  12 , whereas the other of the harness lugs  13  is disposed between the second side plate  11  and the reel body  12 . On the other hand, a fishing rod attachment portion  14  is disposed on the bottom of the reel body  12  for attaching the fishing reel to a fishing rod. 
         [0023]    As illustrated in  FIGS. 1 to 3 , a box-like counter case  70  is disposed on the top of the first side plate  10  of the reel unit  1 . The counter case  70  includes a display unit  79  and an operating unit  77  on the top surface thereof. The display unit  79  is configured to display the information of depth where a terminal tackle is positioned in the water (i.e., terminal tackle water depth information, corresponding to fishing line length), information of tension applied on the fishing line (i.e., corrected torque), information of release speed of the terminal tackle, and the like. The operating unit  77  is disposed on the front side of the display unit  79  for allowing an angler to execute a switching operation of the display contents displayed by the display unit  79 . 
         [0024]    As illustrated in  FIGS. 2 and 3 , an attachment board  10   a  with a roughly disc shape is attached and fixed to the inside of the first side plate  10  of the reel unit  1 . A variety of components are disposed on the attachment board  10   a.  For example, such components include: a control unit  73  (see  FIG. 7 ) configured to execute a variety of controls, a storage unit  78  (see  FIG. 7 ) storing a variety of information, a below-mentioned spool sensor  71  (see  FIG. 7 ), a lead switch forming a part of a spool counter  72  (see  FIG. 7 ), a board temperature sensor  69  (see  FIG. 7 ) for detecting the temperature of a below-mentioned sensor board of the attachment board  10   a,  and a backup battery. As illustrated in  FIGS. 2 to 4 , a detection coil  75   b  of a below-mentioned torque sensor  75  and a holder case  75   c  for holding a temperature sensor  76  are further attached to the attachment board  10   a.  As illustrated in  FIG. 4 , the holder case  75   c  is a roughly cylindrical case member through which the spool shaft  2  penetrates. The holder case  75   c  is attached and fixed to the attachment board  10   a  by an attachment screw  10   c  screwed into a screw hole  10   b  formed in the attachment board  10   a.    
         [0025]    As illustrated in  FIG. 2 , the spool shaft  2  is rotatably supported by the first and second side plates  10  and  11  through a pair of a bearing  31   a  (left side bearing) and a bearing  31   b  (right side bearing) disposed onto the both axial ends of the spool shaft  2 . Further, the spool  3  is rotatably supported by two bearings  32   a  and  32   b  disposed onto the spool shaft  2 . The bearings  32   a  and  32   b  are separated from each other while being disposed between the bearings  31   a  and  31   b  in the axial direction. Specifically, the bearings  32   a  and  32   b  are disposed in the both axial ends of the spool  3 . As illustrated in  FIGS. 2 and 3 , a ratchet wheel  50 , which will be described below, of the anti-reverse mechanism  9  is abutted to the right side of an inner race of the bearing  31   a  disposed onto the left axial end of the spool shaft  2 . On the other hand, a friction disc  26 , which will be described below, of the lever drag mechanism  7  is abutted to the left side of an inner race of the left-side bearing  32   a  supporting the spool  3 . As illustrated in  FIGS. 3 and 4 , a tubular member  2   a  with a tube-like shape is attached onto the outer periphery of the spool shaft  2  while being axially interposed between the ratchet wheel  50  of the anti-reverse mechanism  9  and the friction disc  26  of the lever drag mechanism  7 . Further, a magnetostrictive element  75   a  of the torque sensor  75  is attached onto the outer periphery of the tubular member  2   a.  The detection coil  75   b  of the torque sensor  75  and the temperature sensor  76  are disposed on the outer peripheral side of the tubular member  2   a  where the magnetostrictive element  75   a  is attached, while being held by the holder case  75   c  attached and fixed to the attachment board  10   a . A pair of a cap member  2   b  (left side cap member) and a cap member  2   c  (right side cap member), respectively having a closed end tubular shape, is disposed onto the both axial ends of the tubular member  2   a  as intervening members. Specifically, the cap member  2   b  is attached onto the left axial end of the tubular member  2   a  while the left end thereof abuts to the right end of the ratchet wheel  50  of the anti-reverse mechanism  9 . In other words, the cap member  2   b  functions as an intervening member for preventing the left end of the tubular member  2   a  from directly making contact with the right end of the ratchet wheel  50  of the anti-reverse mechanism  9 . On the other hand, the cap member  2   c  is attached onto the right axial end of the tubular member  2   a  while the right end thereof abuts to the left end of the friction disc  26  of the lever drag mechanism  7 . In other words, the cap member  2   c  functions as an intervening member for preventing the right end of the tubular member  2   a  from directly making contact with the left end of the friction disc  26  of the lever drag mechanism  7 . 
         [0026]    As illustrated in  FIG. 2 , the spool  3  includes a bobbin trunk  3   a  and a pair of flanges  3   b  integrally formed with the axial ends of the bobbin trunk  3   a.    
         [0027]    As illustrated in  FIG. 2 , the handle  4  is fixed onto a protruding end of a tubular handle shaft  5  disposed in parallel to and below the spool shaft  2 . The handle shaft  5  is rotatably supported by the reel unit  1  through two bearings  33   a  and  33   b . The bearings  33   a  and  33   b  are disposed below a boss  11   a  while being axially separated from each other. 
         [0028]    As illustrated in  FIG. 2 , the rotation transmission mechanism  6  includes a speed change mechanism configured to switch handle rotation speed between a high speed and a low speed. As illustrated in  FIG. 2 , the rotation transmission mechanism  6  includes a first gear  16 , a second gear  17 , a third gear  18 , a fourth gear  19 , an engaging piece  20 , two compression springs  21   a  and  21   b,  and an operating shaft  22 . The first gear  16  is used for winding the fishing line at a high speed, whereas the second gear  17  is used for winding the fishing line at a low speed. The first and second gears  16  and  17  are both rotatably supported onto the handle shaft  5  of the handle  4 . The third gear  18  is meshed with the first gear  16 , whereas the fourth gear  19  is meshed with the second gear  17 . Under the condition, the third and fourth gears  18  and  19  are rotatably attached onto the spool shaft  2 . The engaging piece  20  is configured to couple the handle shaft  5  to either the first gear  16  or the second gear  17  and transmit rotation therefrom to a coupled one of the first and second gears  16  and  17 . The compression springs  21  and  21   b  are disposed on the both axial sides of the engaging piece  20  for positioning the engaging piece  20 . The operating shaft  22  is configured to set the engaging piece  20  to be in a predetermined position. The operating shaft  22  protrudes to the outside from the handle shaft  5  while penetrating through the inside of the handle shaft  5 . The protruding end (i.e., the right end) of the operating shaft  22  includes a slide-type stopper  23  disposed in the handle  4 . 
         [0029]    When the operating shaft  22  is pressed leftwards in the rotation transmission mechanism  6  with the aforementioned structure in  FIG. 2 , the engaging piece  20  is disposed in the second gear  17  and rotation of the handle  4  is transmitted to the fourth gear  19  through the second gear  17 . The spool shaft  2  and the spool  3  thereby rotate at a low speed. When the slide-type stopper  23  is slid for pulling the operating shaft  22  rightwards in  FIG. 2 , on the other hand, the engaging piece  20  is disposed in the first gear  16  and rotation of the handle  4  is transmitted to the third gear  18  through the first gear  16 . The spool shaft  2  and the spool  3  thereby rotate at a high speed. 
         [0030]    As illustrated in  FIG. 2 , the lever drag mechanism  7  includes a brake disc  25 , the friction disc  26 , and a moving mechanism  29 . The brake disc  25  is attached to the left side of the spool  3 . The friction disc  26  is disposed on the left side of the brake disc  25  while being opposed thereto. The moving mechanism  29  is configured to reciprocate the spool  3  and the brake disc  25  in the axial direction of the spool shaft  2 . 
         [0031]    As illustrated in  FIGS. 2 and 3 , the brake disc  25  is a washer-like disc member made of, for instance, stainless. The brake disc  25  is attached to the end surface of the left-side flange  3   b  of the spool  3  by a plurality of attachment pins disposed at predetermined intervals along the circumferential direction thereof. The brake disc  25  is prevented from rotating with respect to the spool  3  but is allowed to move at a predetermined distance in the axial direction of the spool  3  for making contact with or separating away from the spool  3 . 
         [0032]    As illustrated in  FIGS. 2 and 3 , the friction disc  26  is opposed to the brake disc  25 . The friction disc  26  is attached onto the spool shaft  2  while being movable in the axial direction of the spool shaft  2 . A friction plate  26   a  is fixed to the friction disc  26  surface opposed to the brake disc  25  by screws. For example, the friction plate  26   a  is a ring plate made of abrasion resistant material such as carbon graphite, fiber reinforced resin or the like. The right end surface of the inner periphery of the friction disc  26  is abutted to the inner race of the bearing  32   a  disposed in the inner periphery of the spool  3  through a coil spring  47  of the moving mechanism  29 . On the other hand, the left end surface of the inner periphery of the friction disc  26  is abutted to the ratchet wheel  50  of the anti-reverse mechanism  9  through the cap member  2   c,  the tubular member  2   a,  and the cap member  2   b.  The ratchet wheel  50  is fixedly (non-rotatably) attached to the outer peripheral surface of the cap member  2   b . The ratchet wheel  50  is abutted to the inner race of the bearing  31   a.  The outer race of the bearing  31   a  is abutted to the first side plate  10 . The friction disc  26  is thereby prevented from moving outwards in the axial direction of the spool shaft  2  (i.e., leftwards in  FIG. 2 ). Further, the fiction disc  26  is prevented from rotating in the fishing line release direction by the ratchet wheel  50 . The anti-reverse mechanism  9  is a claw type mechanism and includes the ratchet wheel  50  and a ratchet claw  51 . The ratchet wheel  50  includes saw teeth on the outer periphery thereof. The ratchet claw  51  is disposed on the outer peripheral side of the ratchet wheel  50  for locking the saw teeth with the tip thereof. The ratchet claw  51  is pivotably attached to the inner surface of the first side plate  10 . The ratchet claw  51  is urged for locking the saw teeth by a tension spring. 
         [0033]    As illustrated in  FIGS. 2 and 3 , the outside of the friction disc  26  is covered with a drag cover  41 . The drag cover  41  is made of, for instance, aluminum alloy for achieving good heat radiation. The drag cover  41  includes a cover body  41   a  and an attachment portion  41   b.  The cover body  41  is a saucer-like member having a circular opening in the center thereof. The attachment portion  41   b  is a ring member integrally formed with the outer peripheral surface of the cover body  41   a.  The cover body  41   a  includes a space in the inside thereof for containing the friction disc  26  and the brake disc  25 . Further, a plurality of magnets, which form a part of a spool sensor  71  (see  FIG. 7 ) and the spool counter  72  (see  FIG. 7 ), is attached to the left surface of the cover body  41   a  while being opposed to a lead switch forming a part of the spool sensor  71  and the spool counter  72 . The attachment portion  41   b  is fixed to the end surface of the flange  3   b  of the spool  3  by arbitrary fixation means such as a plurality of screws. The drag cover  41  is configured to unitarily rotate with the spool  3 . 
         [0034]    As illustrated in  FIG. 2 , the moving mechanism  29  includes a brake operating lever  45 , a press mechanism  46 , and the coil spring  47 . The brake operating lever  45  is pivotably disposed in the reel unit  1 . The press mechanism  46  is configured to press and move the spool  3  and the brake disc  25  leftwards in  FIG. 2  in conjunction with a clockwise pivot of the brake operating lever  45 . The coil spring  47  is configured to urge the friction disc  26  for moving the spool  3  and the brake disc  25  rightwards in  FIG. 2  in conjunction with a counterclockwise pivot of the brake operating lever  45 . The coil spring  47  is attached onto the outer periphery of the spool shaft  2  in a compressed state while being interposed between the friction disc  26  and the bearing  32   a  disposed in the inner periphery of the spool  3 . The coil spring  47  is configured to urge the friction disc  26  and the spool  3  in opposite directions. 
         [0035]    As illustrated in  FIG. 2 , the brake operating lever  45  is attached to the reel unit  1  while being pivotable between a brake release position and a maximum brake position. When pivoted in the clockwise direction, the brake operating lever  45  is set to be in the brake release position. When pivoted in the counterclockwise direction, on the other hand, the brake operating lever  45  is set to be in the maximum brake position. The brake operating lever  45  includes a lever portion  45   a  and a knob portion  45   b.  The lever portion  45   a  is pivotably attached onto the boss  11   a.  The knob portion  45   b  is fixed to the front end of the lever portion  45   a.  The base end of the lever portion  45   a  is non-rotatably held by a first cam member  60  forming a part of the press mechanism  46 . 
         [0036]    The press mechanism  46  includes the first cam member  60 , a second cam member  61 , and a press member  62 . The first cam member  60  is attached to the inner peripheral surface of the boss  11   a  while being rotatable but axially non-movable. The second cam member  61  is configured to axially move in conjunction with rotation of the first cam member  60 . The press member  62  is configured to axially move in conjunction with the second cam member  61 . The first cam member  60  is a two-tier (large and small tier) tubular member configured to rotate in conjunction with pivot of the brake operating lever  45 . Further, the first cam member  60  includes a tilt cam on the base-end surface of the large-diameter portion thereof. The second cam member  61  is a tubular member. The second cam member is attached to the inner peripheral surface of the boss  11   a  while being non-rotatable but axially movable. The second cam member  61  includes a tilt cam on the outer peripheral side end surface thereof opposed to the first cam member  60 . The tilt cam of the second cam member  61  is configured to be engaged with the tilt cam of the first cam member  60 . When the above two tilt cams are relatively rotated, rotary movement of the first cam member  60  is converted into axial linear movement of the second cam member  61 . The second cam member  61  is thereby axially moved. The inner peripheral surface of the second cam member  61  is screwed onto the press member  62 . The relative axial positional relation can be thereby adjusted between the second cam member  61  and the press member  62 . In other words, drag force can be adjusted depending on the position of the brake operating lever  45 . 
         [0037]    As illustrated in  FIGS. 2 and 3 , the attachment board  10   a  is attached and fixed to the inside of the first side plate  10  of the reel unit  1 . The control unit  73  (see  FIG. 7 ), which is configured to execute a variety of controls, is attached to the attachment board  10   a.  As illustrated in  FIG. 7 , the control unit  73  is electrically connected to the spool sensor  71 , the spool counter  72 , the torque sensor  75 , the temperature sensor  76 , a communication unit  74 , the operating unit  77 , the storage unit  78 , the display unit  79 , the board temperature sensor  69 , and other input/output units. 
         [0038]    The control unit  73  includes a microcomputer including a variety of components, such as a CPU, a RAM, a ROM, and an I/O interface, which are disposed on the attachment board  10   a.  The control unit  73  is configured to execute a variety of control operations based on a control program preliminarily stored in the storage unit  78 . For example, the control operations include a communication control processing for the communication unit  74 , a display control processing for the display unit  79 , a control processing of calculating the terminal tackle water depth information (i.e., fishing line length) and the release speed of the fishing line based on the data detected by the spool sensor  71  and the spool counter  72 , and a control processing of calculating a corrected torque by correcting a detected torque based on the torque data detected by the torque sensor  75  and the temperature data detected by the temperature sensor  76  and the board temperature sensor  69 . The storage unit  78  is formed by a nonvolatile memory such as an EEPROM, and preliminarily stores a variety of data such as the map data to be used for calculating the fishing line length. 
         [0039]    The spool sensor  71  includes two lead switches aligned back and forth. The lead switches detect two magnets attached to a magnet wheel. The spool counter  72  counts the detection pulses emitted by the lead switches. The number of rotations of the reel can be thereby detected. Further, the rotational direction of the spool  3  can be detected based on which of the reel switches emits the detection pulse earlier. 
         [0040]    The spool counter  72  is configured to count the number of times that the spool sensor  71  is turned on and off. The rotational position data regarding the number of spool rotations can be obtained from the counted value. The spool counter  72  is configured to reduce the counted value when the spool  3  rotates in the forward direction (i.e., in the fishing line release direction). On the other hand, the spool counter  72  is configured to increase the counted value when the spool  3  rotates in the reverse direction. 
         [0041]    As illustrated in  FIGS. 2 to 4 , the torque sensor  75  is a magnetostrictive sensor including the magentostrictive element  75   a  and the detection coil  75   b.  The magnetostrictive element  75   a  is attached onto the tubular member  2   a.  The tubular member  2   a  is herein attached onto the outer periphery of the spool shaft  2  while being disposed between the ratchet wheel  50  of the anti-reverse mechanism  9  and the friction disc  26  of the lever drag mechanism  7 . On the other hand, the detection coil  75   b  is held by the holder case  75   c.  The holder case  75   c  is herein attached and fixed to the attachment board  10   a  while being disposed on the surrounding of the magnetostrictive element  75   a.  For example, the magnetostrictive element  75   a  includes a soft magnetic member made of amorphous alloy foil. The magnetostrictive element  75   a  is wound about and fixed to the spool shaft  2  at a predetermined interval. The magnetostrictive element  75   a  includes grooves on the surface thereof. The grooves are slanted at different angles for producing magnetic anisotropy. The detection coil  75   b  has a cylindrical shape for enclosing the magnetostrictive element  75   a.  The self-inductance of the detection coil  75   b  varies in response to variation in the magnetic permeability of the magnetostrictive element  75   a  due to the torsion of the spool shaft  2 . The detection coil  75   b  is connected to the control unit  73  (see  FIG. 7 ). The detected torque, detected by the detection coil  75   b,  is transmitted to the control unit  73 . Further, two sensors, forming the temperature sensor  76 , are disposed on the both sides of the detection coil  75   b  in the axial direction. The temperature sensor  76  detects the temperature of the detection coil  75   b.    
         [0042]    As illustrated in  FIGS. 3 and 4 , the temperature sensor  76  is a thermistor attached to the detection coil  75   b  in a contactable state. The temperature sensor  76  includes a first temperature sensor  76   a  and a second temperature sensor  76   b.  The first temperature sensor  76   a  is disposed on the left side of the detection coil  75   b , whereas the second temperature sensor  76   b  is disposed on the right side of the detection coil  75   b.  The first and second temperature sensors  76   a  and  76   b,  together with the detection coil  75   b,  are held by the holder case  75   c  attached and fixed to the attachment board  10   a.  The first and second temperature sensors  76   a  and  76   b  are connected to the control unit  73  (see  FIG. 7 ). The temperatures of the detection coil  75   b,  detected by the first and second temperature sensors  76   a  and  76   b,  are transmitted to the control unit  73 . 
         [0043]    The board temperature sensor  69  (see  FIG. 7 ) is a sensor for detecting the temperature of a sensor board where a sensor circuit connected to both the torque sensor  75  and the temperature sensor  76  is attached. The board temperature sensor  69  is disposed on the sensor board of the attachment board  10   a.  The board temperature sensor  69  is connected to the control unit  73  (see  FIG. 7 ). The temperature of the sensor board, detected by the board temperature sensor  69 , is transmitted to the control unit  73 . 
         [0044]    The control unit  73  is configured to execute a variety of controls for the display unit  79 , the communication unit  74 , and the like. The control unit  73  is also configured to execute a water depth calculation processing of calculating the terminal tackle water depth information. In the water depth calculation processing, the number of rotations of the spool  3  is converted into the terminal tackle water depth information by matching the number of rotations of the spool  3  counted by the spool counter  72  with the map data stored in the storage unit  78 . The thus-obtained terminal tackle water depth information is transmitted to the display unit  79  and the communication unit  74  as numerical information. 
         [0045]    Further, the control unit  73  is configured to execute a rotation speed calculation processing of calculating the rotation speed of the spool  3 . In the rotation speed calculation processing, the rotation speed of the spool  3  per a unit time is calculated based on the number of rotations of the spool  3  counted by the spool counter  72  and the time information obtained from an internal clock of the control unit  73 . The thus-obtained rotation speed information of the spool  3  is transmitted to the display unit  79  and the communication unit  74  as numerical information. 
         [0046]    Yet further, the control unit  73  is configured to execute a detected tension correction calculation output processing of calculating and outputting a corrected tension by converting the detected torque of the spool shaft  2  detected by the torque sensor  75  into a calculated tension, and then correcting the calculated tension in accordance with both the temperature of the detection coil  75   b  detected by the temperature sensor  76  and the temperature of the sensor board detected by the board temperature sensor  69 . In the detected tension correction calculation output processing, the detected torque of the spool shaft  2  is converted into a calculated torque based on the diameters, frictions and the like of the spool  3  and the lever drag mechanism  7 . Further, the calculated torque is corrected in accordance with the winding diameter of the fishing line for calculating the corrected tension. The detected tension correction calculation output processing will be hereinafter specifically explained with reference to a control flowchart represented in  FIG. 8 . 
         [0047]    First, the power is on when the operating unit  77  is kept pressed for a predetermined period of time. The initial setting is executed in Step S 1 . In the initial setting of Step  51 , a variety of variables and flags are reset and the initial screen is displayed on the display unit  79 . 
         [0048]    Next in Step S 2 , the torque of the spool shaft  2  is detected. In Step S 2 , the detected torque detected by the torque sensor  75  is stored in the storage unit  78 . The processing proceeds to Step S 3 . 
         [0049]    In Step S 3 , the temperature of the detection coil  75   b  is detected by the temperature sensor  76 . In Step S 3 , the temperature of the detection coil  75   b,  detected by the temperature sensor  76 , is stored in the storage unit  78 . The processing proceeds to Step S 4 . 
         [0050]    In Step S 4 , the temperature of the sensor board is detected by the board temperature sensor  69 . In Step S 4 , the temperature of the sensor board, detected by the board temperature sensor  69 , is stored in the storage unit  78 . The processing proceeds to Step S 5 . 
         [0051]    In Step S 5 , the detected torque of the spool shaft  2 , which has been detected by the torque sensor  75 , is converted into a calculated tension. The calculated tension is then corrected in accordance with both the temperature of the detection coil  75   b  detected by the temperature sensor  76  and the temperature of the sensor board detected by the board temperature sensor  69  for calculating a corrected tension. Specifically, the winding diameter of the fishing line wound about the spool  3  is firstly calculated based on a predetermined relational table preliminarily stored in the storage unit  78  and the number of rotations of the spool  3  detected by the spool counter  72 . The predetermined relational table herein indicates the relation between the winding diameter of the fishing line wound about the spool  3  and the number of rotations of the spool  3 . Next, another predetermined relational table preliminarily stored in the storage unit  78  is read out thereof, and the detected torque detected by the torque sensor  75  is converted into a corrected torque based on the read-out relational table. The predetermined relational table herein indicates the relation between the corrected torque detected by the torque sensor  75  and both the temperature of the detection coil  75   b  detected by the temperature sensor  76  and the temperature of the sensor board detected by the board temperature sensor  69 . Subsequently, a corrected tension is calculated based on the above-calculated winding diameter of the fishing line wound about the spool  3  and the above-converted corrected torque. The corrected tension calculated in Step S 5  is stored in the storage unit  78 . The processing proceeds to Step S 6 . 
         [0052]    In Step S 6 , the corrected tension stored in the storage unit  78  is read out thereof and is outputted to the display unit  79  and the communication unit  74  as numerical information. Accordingly, the corrected tension is displayed not only on the display unit  79  but also on a display unit  85  of a fishing information display device  80  through the communication between the communication unit  74  and a communication unit  86  of the fishing information display device  80 . 
         [0053]    As illustrated in an enlarged view of  FIG. 5 , the display unit  79  is a segment LCD (liquid crystal display) sequentially including a fishing line length display area  79   a,  a torque display area  79   b  and a speed display area  79   c  from front to rear thereof (i.e., from top to bottom in  FIG. 5 ). The fishing line length display area  79   a  displays the terminal tackle water depth information (i.e., fishing line length). The torque display area  79   b  displays the tension applied on the fishing line (i.e., corrected torque). The speed display area  79   c  displays the release speed of the terminal tackle or the like. Specifically, the fishing line length display area  79   a  is an area for displaying the terminal tackle water depth information (i.e., fishing line length), and displays “120.0” indicating a fishing line length of 120.0 m in the example of  FIG. 5 . The torque display area  79   b  is an area for displaying the tension applied on the fishing line (i.e., corrected torque), and displays both a character of “T” indicating tension and “15.0” indicating a corrected torque of 15.0 kg in the example of  FIG. 5 . The speed display area  79   c  is an area for displaying the release speed of the terminal tackle (i.e., rotation speed of the spool  3 ), and displays both a character of “S” indicating speed and “10.0” indicating a speed of 10.0 km/h in the example of  FIG. 5 . 
         [0054]    The operating unit  77  is a roughly oval push-type button for switching back and forth the display settings of the display unit  79  and resetting the display content. Further, the display settings of the display unit  79  can be switched back and forth by an operating unit  84  disposed in the fishing information display device  80  (see  FIGS. 6 and 7 ) provided separately from the fishing reel  100  as an external device. The fishing information display device  80  will be described below The communication unit  74  (see  FIG. 7 ) disposed in the fishing reel  100  and the communication unit  86  (see  FIG. 7 ) disposed in the fishing information display device  80  are electrically connected to each other through the wireless communication. As illustrated in  FIG. 7 , the fishing information display device  80  is configured to cause the communication unit  86  to receive the terminal tackle water depth information obtained by the fishing reel  100  and the information of a school of fish obtained by a fish finder  90  and cause the display unit  85  to display the information received by the communication unit  86 . 
         [0055]    As illustrated in  FIG. 7 , the communication unit  74  is allowed to send/receive a variety of information to/from the communication unit  86  of the fishing information display device  80  provided separately from the fishing reel  100  as an external device. The communication unit  74  is allowed to send the terminal tackle water depth information, the rotation speed information of the spool  3  and the information of the tension applied on the fishing line to the communication unit  86  of the fishing information display device  80 . 
         [0056]    As illustrated in  FIG. 7 , the fishing information display device  80  is allowed to display as echo images the information obtained from the fish finder  90 , i.e., the water depth of the floor in a fishing ground and a shelf position indicating the position of a school of fish. The fish finder  90  will be described below. Further, the fishing information display device  80  is allowed to display the terminal tackle water depth information obtained from the fishing reel  100  together with the above information displayed as echo images, i.e., the water depth of the floor in a fishing ground and the shelf position. 
         [0057]    As illustrated in  FIGS. 6 and 7 , the fishing information display device  80  includes a body member  81 , the communication unit  86 , the display unit  85 , and the operating unit  84 . The body member  81  is a portrait-oriented member with a shape of a roughly rectangular cuboid. The communication unit  86  is disposed in the inside of the body member  81 . The display unit  85  includes an LCD attached to the body member  81 . The operating unit  84  includes a plurality of operating buttons disposed below the display unit  85  in  FIG. 6 . 
         [0058]    As illustrated in  FIG. 7 , the fishing information display device  80  includes a control unit  83  in the inside thereof. The control unit  83  is configured to execute a variety of controls. The control unit  83  includes a microcomputer including a variety of components, such as a CPU, a RAM, a ROM, and an I/O interface, disposed in the body member  81 . Based on the control program, the control unit  83  is configured to execute a variety of controls including: a display control of causing the display unit  85  to display the information obtained from the fishing reel  100  and the fish finder  90 ; and a control of causing the communication unit  86  to execute a variety of operations such as transmissions of a variety of command information to the fishing reel  100 . Further, the control unit  83  is connected to a variety of switches of the operating unit  84 , the display unit  85 , the communication unit  86  and other input/output units, as illustrated in  FIG. 8 . 
         [0059]    The operating unit  84  is a switch for executing a variety of controls such as a display control of the display unit  85 . As illustrated in  FIG. 6 , the operating unit  84  includes four buttons horizontally aligned below the display unit  85 . From left to right in  FIG. 6 , the buttons correspond to switches with the functions of “decision”, “cancellation (going-back)”, “up” and “down”. A variety of settings is executed by operating the operating unit  84 . The operating unit  84  is allowed to execute controls in the fishing reel  100  as well as controls in the fishing information display device  80 . 
         [0060]    The display unit  85  is a dot matrix LCD such as a color TFT (thin film transistor) LCD. The display unit  85  is allowed to display the information allowed to be displayed by the display unit  79  of the fishing reel  100 , such as the water depth information, the tension applied on the fishing line, and the release speed of the terminal tackle. Further, the display unit  85  is allowed to display a variety of information to be obtained from the fish finder  90 . As illustrated in  FIG. 6 , the display unit  85  is a dot matrix LCD including a fishing line length display area  85   a,  a torque display area  85   b,  and a speed display area  85   c  from top to bottom thereon in this order. The fishing line length display area  85   a  displays the terminal tackle water depth information (i.e., fishing line length). The torque display area  85   b  displays the tension applied on the fishing line (i.e., corrected torque). The speed display area  85   c  displays the release speed of the terminal tackle or the like. Specifically, the fishing line length display area  85   a  is an area for displaying the terminal tackle water depth information (i.e., fishing line length), and displays “120.0” indicating a fishing line length of 120.0 m in the example of  FIG. 6 . The torque display area  85   b  is an area for displaying the tension applied on the fishing line (i.e., corrected torque), and displays a character of “T” indicating tension and “15.0” indicating a corrected torque of 15.0 kg in the example of  FIG. 6 . The speed display area  85   c  is an area for displaying the release speed of the terminal tackle (i.e., rotation speed of the spool  3 ), and displays a character of “S” indicating speed and “10.0” indicating a speed of 10.0 km/h in the example of  FIG. 6 . 
         [0061]    As illustrated in  FIG. 7 , the communication unit  86  is allowed to send/receive a variety of information to/from the communication unit  74  of the fishing reel  100  and a communication unit of the fish finder  90  through the wireless communication. The communication unit  86  receives a variety of information, such as the terminal tackle water depth data, the rotation speed information of the spool  3 , the information of the tension applied on the fishing line, from the communication unit  74  of the fishing reel  100 , and sends a variety of command information to the communication unit  74  of the fishing reel  100 . Further, the communication unit  86  is allowed to communicate with the communication unit of the fish finder  90  and thereby receives the information of the water depth of the floor in a fishing ground, the position of a school of fish, and the like from the communication unit of the fish finder  90 . 
         [0062]    The fish finder  90  is a device for collecting the information indicating a shelf position of fish, a condition of a school of fish and a moving direction of a school of fish. As illustrated in  FIG. 7 , the fish finder  90  includes the communication unit for transmitting the information of a school of fish to the communication unit  86  of the fishing information display device  80  through the wireless communication. It is noted that the other components of the fish finder  90  are identical to those of the well-known fish finders. Therefore, a detailed explanation will be omitted for the other components of the fish finder  90 . 
         [0063]    According to the thus-configured fishing reel  100 , the detected torque detected by the torque sensor  75  is configured to be corrected for obtaining a corrected torque in accordance with both the temperature of the detection coil  75   b  detected by the temperature sensor  76  and the temperature of the sensor board detected by the board temperature sensor  69 . An angler is thereby allowed to precisely grasp the tension applied on the fishing line even when the temperature of the detection coil  75   b  and the temperature of the sensor board are increased. 
       OTHER EXEMPLARY EMBODIMENTS 
       [0064]    (a) In the aforementioned exemplary embodiment, the fishing information display device  80  is provided separately from the fishing reel  100  as an external device and the display unit  85  of the fishing information display device  80  is configured to display the tension applied on the fishing line. However, only the display unit  79  of the fishing reel  100  can be configured to display the tension applied on the fishing line. In this case, an angler is allowed to grasp the tension applied on the fishing line only by providing the angler with the fishing reel  100  without providing the angler with the fishing information display device  80  and the fish finder  90 . 
         [0065]    (b) In the aforementioned exemplary embodiment, the torque sensor  75  includes the magnetostrictive element  75   a  and the detection coil  75   b.  The magnetostrictive element  75   a  is attached onto the tubular member  2   a  that is attached onto the outer periphery of the spool shaft  2  while being disposed between the ratchet wheel  50  of the anti-reverse mechanism  9  and the friction disc  26  of the lever drag mechanism  7 . The detection coil  75   b  is held by the holder case  75   c  that is attached and fixed to the attachment board  10   a  while being disposed in the surrounding of the magnetostrictive element  75   a.  However, the arrangement of the torque sensor  75  is not be necessarily limited to the above. 
         [0066]    (c) In the aforementioned exemplary embodiment, the temperature sensor  76  includes the first temperature sensor  76   a  and the second temperature sensor  76   b.  The first temperature sensor  76   a  is disposed on the left side of the detection coil  75   b , whereas the second temperature sensor  76   b  is disposed on the right side of the detection coil  75   b.  The arrangement and the number of sensors included in the temperature sensor  76  is not be necessarily limited to the above. 
         [0067]    (d) In the aforementioned exemplary embodiment, the display unit  85  of the single fishing information display device  80  is configured to display the information of the single fishing reel  100 , such as the terminal tackle water depth information (i.e., fishing line length), the tension applied on the fishing line (i.e., corrected torque) and the release speed of the terminal tackle. As illustrated in  FIGS. 9 and 10 , however, the display unit  85  of the single fishing information display device  80  can be configured to display the information obtained from a plurality of the fishing reels  100 , such as the water depth information of a plurality of the terminal tackles (fishing line lengths), the tensions applied on a plurality of the fishing lines (i.e., corrected torques) and the release speeds of a plurality of the terminal tackles. 
         [0068]    As illustrated in  FIG. 9 , the fishing information display device  80  includes the body member  81 , the communication unit  86 , the display unit  85 , and the operating unit  84 . The body member  81  is a landscape-oriented member with a shape of a roughly rectangular cuboid. The communication unit  86  is disposed in the inside of the body member  81 . The display unit  85  includes a touch panel LCD disposed in the center part of the surface of the body member  81 . The operating unit  84  includes a touch panel  84   a  and a power switch  84   b.  The touch panel  84   a  is disposed on the surface of the display unit  85 . The power switch  84   b  is a push-type switch disposed lateral to the display unit  85 . The touch panel  84   a  is allowed to execute an operation of switching back and forth the display settings of the display units  79  of the plural fishing reels  100 . The power switch  84   b  is allowed to turn on and off the screen displayed on the display unit  85 . The fishing information display device  80  is embedded with a global positioning system (GPS) module (not illustrated in the figures). The fishing information display device  80  is allowed to cause the display unit  85  to display a variety of information from the GPS through a switching operation of the touch panel  84   a.  The fishing information display device  80  is attached to an arm-like attachment base  87 . Specifically, the both lateral portions of the body member  81  are detachably and pivotably attached thereto. The display unit  85  is allowed to be positioned at an arbitrary angle in response to the front and rear pivots of the body member  81 . Further, the fishing information display device  80  includes an information input/output port (e.g., USB (universal serial bus) input/output port) connectable to the information input/output ports of the personal computers (not illustrated in the figures). For example, it is possible to input a variety of log information of the fishing reel  100  stored in the storage unit of the fishing information display device  80 , such as the terminal tackle water depth information (i.e., fishing line length), the tension applied on the fishing line (i.e., corrected torque) and the release speed of the terminal tackle, into a storage unit of a personal computer through a USB input/output port of the personal computer using a USB memory. It is subsequently possible to cause a display unit of the personal computer to display the various log information of the fishing reel  100 , such as the terminal tackle water depth information (i.e., fishing line length), the tension applied on the fishing line (i.e., corrected torque) and the release speed of the terminal tackle. 
         [0069]    As illustrated in  FIG. 10 , the display unit  85  of the single fishing information display device  80  is configured to display the information of six fishing reels  100  on the 3×2 matrix fields thereon, such as the water depth information of six terminal tackles (i.e., fishing line lengths), the tensions applied on six fishing lines (corrected torques) and the release speeds of the six terminal tackles. In the example of  FIG. 10 , three fishing reels  100  are connected to the single fishing information display device  80 . The display unit  85  of the single fishing information display device  80  is configured to display the information of the three fishing reels  100 , such as the water depth information of three terminal tackles (i.e., fishing line lengths), the tensions applied on three fishing lines (i.e., corrected torque) and the release speed of the three terminal tackles. 
         [0070]    As illustrated in  FIG. 10 , the display unit  85  is a dot matrix LCD including the 3×2 fields (referred to as first to sixth fields from the left top to right bottom), each of which includes the fishing line length display area  85   a,  the torque display area  85   b  and the speed display area  85   c  from top to bottom thereon. The fishing line length display area  85   a  displays the terminal tackle water depth information (i.e., fishing line length). The torque display area  85   b  displays the tension applied on the fishing line (i.e., corrected torque). The speed display area  85   c  displays the release speed of the terminal tackle or the like. The fishing line length display area  85   a  in the first field is an area for displaying the terminal tackle water depth information (i.e., fishing line length), and displays characters of “DISTANCE” and “120.0 m” indicating a fishing line length of 120.0 m in the example of  FIG. 10 . The torque display area  85   b  in the first field is an area for displaying the torque applied on the fishing line (i.e., corrected torque), and displays characters of “LINE TENSION” and “15.0 kg” indicating a corrected torque of 15.0 kg in the example of  FIG. 10 . The speed display area  85   c  in the first field is an area for displaying the release speed of the terminal tackle (i.e., rotation speed of the spool  3 ), and displays characters of “LINE SPEED” and “10.0 km/h” indicating a release speed of 10.0 km/h in the example of  FIG. 10 . In this case, the display unit  85  of the single fishing information display device  80  is allowed to display the information obtained from the plural fishing reels  100 , such as the water depth information of the plural terminal tackles (i.e., fishing line lengths), the tensions applied on the plural fishing lines (i.e., corrected torques) and the release speeds of the plural terminal tackles. Therefore, an angler is allowed to timely grasp the current fishing conditions such as the information regarding whether or not fish are caught and the pulling levels of fish only by watching the information of the plural fishing reels  100  on the display unit  85  of the single fishing information display device  80 . 
         [0071]    (e) In the aforementioned exemplary embodiment, the board temperature sensor  69  is provided for detecting the temperature of the sensor board of the attachment board  10   a,  and the detected torque detected by the torque sensor  75  is corrected for obtaining a corrected torque in accordance with the temperature of the detection coil  75   b  detected by the temperature sensor  76  and the temperature of the sensor board detected by the board temperature sensor  69 . However, the detected torque detected by the torque sensor  75  can be configured to be corrected for obtaining a corrected torque only in accordance with the temperature of the detection coil  75   b  detected by the temperature sensor  76  without providing the board temperature sensor  69 . 
       General Interpretation of Terms 
       [0072]    In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
         [0073]    While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.