Patent Publication Number: US-2002012537-A1

Title: Magnetic recording information reading device

Description:
[0001] This application is based on patent application No. 10-96925 filed in Japan, the contents of which is hereby incorporated by reference. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] The present invention relates to a magnetic recording information reading device and particularly to a magnetic recording information reading device suitable for a device of using a film cartridge capable of magnetically recording information on a film.  
       [0004] 2. Prior Art  
       [0005] A film used in a camera referred to as APS (Advanced Photo System) is installed with a magnetic recording portion on the film and the magnetic recording portion can be recorded with various information, for example, date and time of photographing and so on in photographing respective frames by a camera mounted with a write head. Information such as information of date and time of photographing and so on recorded on a magnetic recording portion is read in developing or printing the film and can be used for printing the information of date and time of photographing and the like on photographic paper along with picture image.  
       [0006] In the meantime, in a camera mounted with a write head, various information in photographing are recorded on a magnetically recording portion mentioned above in respect of exposed frames and therefore, no magnetic recording information is provided to unexposed frames.  
       [0007] By utilizing such a situation, according to a camera mounted with a read head, even when film cartridges are interchanged and reloaded in the midway of photographing operation, photographing can be restarted from a frame successive to a final exposed frame. That is, in the case in which a film is rewound to a cartridge under a state where photographing operation has been carried out only in respect of a portion of frames on the film, the cartridge is unloaded from the camera and is interchanged by other cartridge to thereby continue photographing operation and thereafter, the previous cartridge is again reloaded to the camera, after initial load (operation of winding the film to the first frame when the cartridge is loaded to the camera) has been finished, the film is wound up while detecting presence or absence of information of the magnetic recording portion by the read head and the film is wound up until a frame not recorded with the magnetic recording information is detected, then the first unexposed frame can be set to a photographing frame position.  
       [0008] In a camera mounted with a write head, it is adjusted such that an angle (azimuth angle) made by a magnetism change boundary line of a magnetic recording portion recorded in feeding a film and a center line of a gap of the head becomes within a predetermined angle (for example, ±0.85).  
       [0009] In the meantime, in reading magnetic recording information by a read head, information recorded in a magnetic recording portion is read by presence or absence of a change in output signal which is caused when a magnetism change boundary line passes through on a gap of the read head in feeding a film and in that case, in respect of an angle made by a center line of the gap of the read head and the magnetism change boundary line, it is preferable that the both are in parallel with each other and when there is an angular difference therebetween, there causes a drawback in which an output from the read head is reduced.  
       [0010] In order to prevent the drawback, two pins are implanted on a plate attached to a write/read head and the pins are pressed to end faces of a film whereby a relative position between the head and the end faces of the film is stabilized and the angle made by the center line of the gap of the head and the magnetism change boundary line of the magnetic recording portion is made to fall within a predetermined angle.  
       [0011] However, according to a camera mounted with a write only head, information recorded on a magnetic recording portion is not read and accordingly, there is a case in which the angle (azimuth angle) made by a magnetism change boundary line of the magnetic recording portion and the center line of a gap of the head is not set strictly within a predetermined angle. When the magnetic recording information on a film recorded by such a camera is read by other camera or a read head of other device, there is a possibility in which the magnetic recording information cannot accurately be read such as an output signal level is lowered and the output signal is concealed by the magnetic noise or the like.  
       [0012] Further, the level of an output signal caused when a magnetism change boundary line of the magnetic recording portion passes through a gap of a read head in feeding a film, is dependent on the film feed speed, the faster the feed speed, the larger becomes the output signal and accordingly, when the film feed speed is fast, a sufficient level of the output signal can be taken out even when the azimuth angle is more or less deviated from an allowable value.  
       [0013] Accordingly, in order to firmly read information recorded in the magnetic recording portion, it is preferable to accelerate the film feed speed and to provide a film edge guide mechanism for guiding end faces of a film such that the angle (azimuth angle) made by the center line of a gap of a read head and a magnetism change boundary line of the magnetic recording portion falls in a predetermined angular range.  
       [0014] However, in order to accelerate the film feed speed, a large-sized motor needs to use and in providing the film edge guide mechanism, the camera becomes large-sized in any case, resulting in a drawback of increasing the fabrication cost. SUMMARY OF THE INVENTION  
       [0015] It is an principal object of the invention to provide a magnetic recording information reading device capable of reading information magnetically recorded on a film.  
       [0016] It is another object of the invention to provide a magnetic recording information reading device capable of reading recorded information with further certainty by moving a magnetic head placed on a magnetic recording portion at a speed faster than speed of transferring a film.  
       [0017] It is another object of the invention to provide a magnetic recording information reading device having a moving mechanism for moving a magnetic head placed on a magnetic recording portion at a speed faster than the speed of transferring a film.  
       [0018] It is another object of the invention to provide a novel camera having a recorded information reading device capable of moving a magnetic head placed on a magnetic recording portion at a speed faster than the speed of transferring a photographic film in a camera using the photographic film having the magnetic recording portion.  
       [0019] Other objects of the invention will become apparent from a detailed explanation of the invention in reference to attached drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0020]FIG. 1 is a drawing for explaining a film cartridge for APS loaded in a camera, a spool, a film and a position of a magnetic recording portion thereof and a constitution related thereto;  
     [0021]FIG. 2 is a drawing for explaining the constitution of an inner portion of a rear face of the camera according to the first embodiment;  
     [0022]FIG. 3 is a perspective view for explaining a mechanism of driving a cam according to the first embodiment;  
     [0023]FIG. 4 is a drawing for explaining the constitution of an inner portion of a rear face of a camera according to a second embodiment;  
     [0024]FIG. 5 is a perspective view for explaining a mechanism of driving a cam according to the second embodiment;  
     [0025]FIG. 6 is a plane view for explaining other example of a shape of a cam;  
     [0026]FIG. 7 is a drawing for explaining the constitution of an inner portion of a rear face of a camera according to a third embodiment;  
     [0027]FIG. 8 is a drawing for explaining the constitution of an inner portion of a rear face of a camera according to a fourth embodiment;  
     [0028]FIG. 9 is block diagram for explaining the constitution of a control circuit of a magnetic recording information reading device; and  
     [0029]FIG. 10 is a flowchart for explaining control operation of a control mechanism of a camera for searching a first unexposed frame and setting it at a photographing position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0030] An explanation will be given of embodiments of the invention as follows.  
     [0031] First, an explanation will be given of a position of a magnetic recording portion formed on a film used in APS and the constitution related thereto which is used in a first through a fourth embodiment explained below.  
     [0032]FIG. 1 is a view showing a cartridge, a spool, a film and a position of a magnetic recording portion thereof as well as the constitution related thereto in a state in which a film cartridge for APS is loaded at inside of a camera and a front end of the film is wound up to the spool.  
     [0033] In FIG. 1, numeral  101  designates a film cartridge and numeral  102  designates a spool arranged on the side of the camera for winding up the film. The film F is provided with the magnetic recording portion M below a region P coated with a photosensitive material. Further, notation Fp designates perforations for transferring the film, and transfer of the film can be controlled by detecting presence or absence of the perforations by photo-reflectors  103 . Further, numeral  105  designates a magnetic head for writing/reading information to and from the magnetic recording portion M and numeral  106  designates a pad for pressing the magnetic recording portion M of the film F to the magnetic head  105 .  
     [0034] First Embodiment  
     [0035]FIG. 2 is a view for explaining a first embodiment of the invention and is a view showing the constitution of an inner portion of a rear face of the camera. In FIG. 2, numeral  1  designates a camera body, numeral  2  designates a press plate for pressing the film to a picture frame from a rear side to maintain it in a plane state, numeral  3  designates a cartridge chamber for containing the film cartridge and numeral  4  designates the spool for winding up the film.  
     [0036] In the press plate  2 , a pivoting plate  6  is pivotably supported around a shaft  6   a  and is urged to pivot in the clockwise direction by a spring  7 . Further, the press plate  2  is installed with a pin  2   a  for locking the pivoting plate  6  urged by the spring  7 .  
     [0037] Further, in the press plate  2 , a cam  8  is supported rotatably around a shaft  8   a  and the cam  8  is constituted to rotate in an arrow a direction (clockwise direction) by a drive mechanism, mentioned later. The cam  8  is provided with a cam face in a shape of circular arcs eccentric from the shaft  8   a  and each of the cam faces is provided with a high cam position  8   b  remote from the shaft  8   a  and a low cam position  8   c  adjacent to the shaft  8   a  and the cam face of the cam  8  is arranged at a position in contact with a stepped portion  6   c  of the pivoting plate  6 .  
     [0038] By the constitution, when the cam  8  is rotated in the arrow a direction (clockwise direction), the pivoting plate  6  is pivoted in the counter clockwise direction since the stepped portion  6   c  of the pivoting plate  6  is pressed in the left direction of FIG. 2 by the cam  8  and when the cam  8  is rotated and the stepped portion  6   c  of the pivoting plate  6  passes through the high cam position  8   b , the pivoting plate  6  is pivoted rapidly in the clockwise direction by urge force of the spring  7  until the stepped portion  6   c  is brought into contact with the low cam position  8   c  and accordingly, the pivoting plate  6  is rocked in the left and right direction around the shaft  6   a.    
     [0039] A hole  6   b  is formed in the pivoting plate  6  and the magnetic head  105  is attached at the center of the hole  6   b  at a position opposed to the magnetic recording portion of the film, and the magnetic recording portion of the film is constituted to be able to magnetically record information and read the magnetically recorded information.  
     [0040] In the above-described constitution, when the cam  8  is rotated while winding up the film by the spool  4  in initial loading operation, the pivoting plate  6  is rocked around the shaft  6   a  and is reciprocated by a very small distance substantially in parallel with the direction of transferring the film. When the pivoting plate  6  is pivoted in the clockwise direction by the urge force of the spring  7 , the magnetic head  105  on the pivoting plate  6  is driven in a direction reverse to the direction of transferring the film and accordingly, the speed of moving the film relative to the magnetic head  105  becomes faster than the speed of transferring the film. Further, the magnetic head  105  on the pivoting plate  6  is constituted to move on the same plane.  
     [0041] When the urge force of the spring  7  is adjusted and the speed of moving the magnetic head  105  by the urge force of the spring is set to a speed equivalent to or more than the speed of transferring the film, the speed of moving the film relative to the magnetic head  105  becomes twice as much as the speed of transferring the film or more and output signal generated in the magnetic head becomes larger than in the case in which the magnetic head is fixed.  
     [0042] For example, when the magnetic head is fixed, even when the magnetic recording information can be read at a normal film transferring speed, in the case where the film transferring speed is lowered by lowering power source voltage, lowering environmental temperature or the like, there is a case in which the magnetically recorded information cannot be read. In contrast thereto, when the speed of moving the film is twice as much as or more of the film transferring speed, even when the film transferring speed is lowered, the speed of moving the film relative to the magnetic head can be maintained to a degree of a normal case and the magnetic recording information can firmly be read.  
     [0043] In this case, whether the film transferring speed is equal to or more than a predetermined speed capable of reading the magnetic recording information may be determined directly or from power source voltage, temperature or the like and the magnetic head may be driven by rocking the pivoting plate and the speed of moving the film in respect of the magnetic head may be accelerated only when it is difficult to read the magnetic recording information.  
     [0044] Further, when an angle of rocking the pivoting plate is made equal to or more than ±0.85, there causes a case in which the azimuth angle which is an angle of intersection of the magnetic recording portion on the film and the center line of a gap of the magnetic head becomes zero degree (0°) and accordingly, an optimum value of the azimuth angle is necessarily produced when the magnetic head is reciprocated to rock at least once during a time period in which the magnetic recording portion on the film passes above the magnetic head and accordingly, there can be determined whether the magnetic recording information is present on the frame.  
     [0045] Next, an explanation will be given of a mechanism of driving the cam. Although a film transfer motor, a transferred film, a motor other than the film transfer motor (for example, a mirror drive motor) or the like is conceivable as a drive source of the cam, an explanation will be given of a mechanism of driving the cam by a film transfer motor in this embodiment.  
     [0046]FIG. 3 is a perspective view for explaining a drive mechanism of a cam. In FIG. 3, numeral  11  designates a motor incorporating a speed reduction mechanism constituted by a plurality of gears including gear  12 , not illustrated, and is constituted to drive the spool  4  by reducing speed of rotation of a rotor shaft of the motor.  
     [0047] A gear  13   a  is a spur gear in mesh with a gear  12  which is one of a gear train and the gear  13   a  is coaxially and integrally fixed with a bevel gear  13   b . The bevel gear  13   b  is in mesh with a bevel gear  14   a  which is orthogonally intersected therewith and a gear train is constituted to drive a spur gear  17  via a spur gear  14   b  integrally fixed to the bevel gear  14   a  and intermediary spur gears  15  and  16 . The spur gear  17  is coaxially and integrally attached with the cam  8  and rotational power separated from the gear  12  in mesh with the gear train of the motor  11  is transmitted to the cam  8  via the spur gear  13   a , the bevel gear  13   b , the bevel gear  14   a , the spur gear  14   b , the intermediary spur gears  15  and  16  and the spur gear  17  to thereby rotate the cam  8  in an arrow a (clockwise direction) of FIG. 3.  
     [0048] Further, although not illustrated, in respect of dividing to allocate the rotational power to the gear  13   a  in the motor  11 , there are (1) a method of dividing it from a midway of a gear train for driving the spool and (2) a method of dividing it from a midway of the gear train for driving the spool in initial loading. According to the method (1), the structure is simplified and is advantageous when the magnetic head is exclusive for reading. Further, according to the method (2), the gear  13   a  needs to constitute to become in mesh with the gear train only in initial loading and the structure becomes complicated, however, in the case in which the magnetic head is both for reading and writing, when rotation of the cam  8  is stopped to fix such that the magnetic head is set to a predetermined position, the azimuth angle in writing can be set to a predetermined value.  
     [0049] Further, although in explaining the operation of the constitution shown by FIG. 2, the explanation has been given of an example in which the magnetic recording information is read at initial loading, the magnetic recording information can also be read in rewinding the film. In this case, the direction of exerting the urge force of the spring  7  may be set to be reverse to the direction shown by FIG. 2 and division of power from the motor  11  to the cam  8  may be constituted such that power dividing is carried out in driving to rewind the film spool.  
     [0050] Further, other than reading the magnetic recording information in initial loading, the magnetic recording information can be constituted to read also in rewinding the film. In this case, the direction of exerting the urge force of the spring  7  may be set such that the magnetic head is moved in the direction reverse to the direction of transferring the film when there is carried out operation at a slower speed of the speed for transferring the film in initial loading and the speed for transferring the film in rewinding the film.  
     [0051] Second Embodiment  
     [0052]FIG. 4 is a view for explaining a second embodiment of the invention and is a view showing the constitution of an inner portion of a rear face of a camera. In FIG. 4, numeral  21  designates a camera body, numeral  22  designates a press plate for pressing the film from a rear face side to a picture frame to maintain a plane state, numeral  23  designates a cartridge chamber for containing a film cartridge and numeral  24  designates a spool for winding up the film.  
     [0053] A slide plate  26  is supported by the press plate  22  slidably in the left and right direction and is pulled and urged by a spring  27  in the right direction of FIG. 4. Further, notation  26   b  designates holes for guiding the slide plate  26  in the sliding direction, notation  22   a  designates pins implanted to the press plate  22  and by fitting the holes  26   b  to the pins  22   a , the slide plate  26  is only slidable in the left and right direction, and stays unmoved in the up and down direction by being restricted thereby. Further, the press plate  22  is installed with a stop pin  22   b  and movement of the slide plate  26  in the right direction is restricted.  
     [0054] Further, a cam  28  is supported by the press plate  22  rotatably around a shaft  28   a  and the cam  28  is constituted to rotate in an arrow a direction (clockwise direction) by a drive source, not illustrated, for example, a drive source divided from the motor  11 . The cam  28  is provided with a constitution similar to that of the cam  8  explained in the first embodiment, installed with the cam face in a shape of circular arcs eccentric from the shaft  28   a , provided with a high cam position  28   b  remote from the shaft  28   a  and a low cam position  28   c  adjacent to the shaft  28   a  and the cam  28  is arranged at a position in contact with a stepped portion  26   c  of the slide plate  26 .  
     [0055] By the constitution, when the cam  28  is rotated in the arrow a direction (clockwise direction), the stepped portion  26   c  of the slide plate  26  is pushed by the cam  28  in the left direction of FIG. 4 and therefore, the slide plate  26  is pushed in the left direction of FIG. 4 and when the cam  28  is rotated and the stepped portion  26   c  of the slide plate  26  passes through the high cam position  28   b , the slide plate  26  is rapidly slid in an arrow b direction (right direction of FIG. 4) until the stepped portion  26   c  is brought into contact with the low cam position  28   c  by the urge force of the spring  27 .  
     [0056] A hole  26   d  is formed in the slide plate  26  and the magnetic head  105  is attached to its center at a position opposed to the magnetic recording portion of the film and is constituted to be able to magnetically record information to the magnetic recording portion of the film and read magnetically recorded information.  
     [0057] In the above-described constitution, in the case in which the cam  28  is rotated when the film is being wound up by the spool  24  in initial loading, the slid plate  26  is reciprocated by a very small distance in parallel with the left and right direction of FIG. 4, that is, in a direction of transferring the film. When the slide plate  26  is moved in the arrow b direction (right direction of FIG. 4) by the urge force of the spring  27 , the magnetic head  105  on the slide plate  26  is driven in a direction reverse to the direction of transferring the film and accordingly, the speed of moving the film relative to the magnetic head  105  becomes faster than the speed of transferring the film.  
     [0058] When the urge force of the spring  27  is adjusted and the speed of moving the magnetic head  105  by the urge force of the spring is set to be a speed equivalent to or more than the speed of transferring the film, the speed of moving the film relative to the magnetic head  105  becomes twice or more of the speed of transferring the film and output signal generated in the magnetic head becomes larger than in the case in which the magnetic head is fixed.  
     [0059] For example, in the case in which the magnetic head is fixed, although the magnetic recording information is constituted to be able to read at a normal speed of transferring the film, when the power source voltage is lowered or the speed of transferring the film is lowered by lowering of environmental temperature or the like, there is a case in which the magnetic recording information cannot be read. In contrast thereto, when the speed of moving the film relative to the magnetic head is twice or more of the speed of transferring the film, even when the speed of transferring the film is lowered, the speed of moving the film relative to the magnetic head can be maintained to a degree of the normal case and the magnetic recording information can firmly be read.  
     [0060] In this case, whether the speed of transferring the film is equal to or more than a predetermined speed capable of firmly reading the magnetic recording information may be determined directly or from power source voltage or temperature and only when reading is determined to be difficult, the magnetic head may be driven by reciprocating the slide plate in the left and right direction and the speed of moving the film relative to the magnetic head may be accelerated.  
     [0061] According to the constitution, the slide plate, that is, the magnetic head is constituted to reciprocate in the left and right direction and accordingly, the azimuth angle that is an angle of intersection of the magnetic recording portion above the film and the center line of a gap of the magnetic head is maintained to substantially a constant value. Accordingly, when driving of the cam  28  is stopped in writing the information to the magnetic recording portion, the azimuth angle can be maintained at a constant value regardless of the rotational angular position of the cam  28  and the rotational angular position of the cam  28  needs not to investigate.  
     [0062] Next, an explanation will be given of a drive mechanism of the cam. As a drive source of the cam, although there is conceivable a film feed motor, a film to be fed, a motor other than the film feed motor (for example, mirror drive motor) or the like, in this case, an explanation will be given of a drive mechanism of the cam with a film to be fed as a drive source.  
     [0063]FIG. 5 is a perspective view of essential portions f or explaining the constitution of a drive mechanism of the cam with the film as a drive source. The press plate  22  is rotatably attached with a film roller  29   a  rotated by movement of the film by being brought into frictional contact with the film F and the film roller  29   a  is attached with a bevel gear  29   b  coaxially fixed thereto. Further, the cam  28  is fixed with a bevel gear  28   d  coaxially therewith and the bevel gear  28   d  is in mesh with the bevel gear  29   b.    
     [0064] In the meantime, on the side of the camera body, there is arranged a pad  30  for pressing the film F to the roller  29   a  at a position opposed to the roller  29   a  and the pad  30  is urged to the roller  29   a  by a spring  31 .  
     [0065] In the above-described constitution, when the film F travels in a direction of winding up the film F (arrow f direction) the roller  29   a  which is brought into frictional contact with the film F and the bevel gear  29   b  are rotated, the cam  28  is rotated in the arrow a direction (clockwise direction) of FIG. 4 and FIG. 5 via the bevel gear  28   d  and accordingly, the slide plate  26  can be reciprocated in the arrow b direction and a direction opposed thereto (left and right direction).  
     [0066] When the film F travels in the direction of rewinding, the cam  28  is rotated in the counter clockwise direction of FIG. 4 and FIG. 5 and as is apparent from the constitutions shown by FIG. 4 and FIG. 5, in rotating the cam  28 , the stepped portion  26   c  of the slide plate  26  is engaged with the cam face  28   c  and rotation of the cam  28  is blocked. Therefore, in rewinding the film F, the pad  30  is escaped and the film F is constituted to prohibit from being pressed to the roller  29   a . Although the mechanism of escaping the pad  30  is not illustrated here, the pad  30  may be driven by a rewind switch mechanism of the film F.  
     [0067] Further, when the shape of the cam  28  is constituted by that of a cam  28   s  in an elliptic shape as shown by FIG. 6, the slide plate  26  can be reciprocated in the left and right direction of FIG. 6 in either of cases of rotating the cam  28   s  in the clockwise direction and rotating it in the counter clockwise direction and the escape mechanism of the pad  30  mentioned above is not needed. Incidentally, in this constitution, when the slide plate  26  is moved in the right direction of FIG. 6, the speed of moving the slide plate  26  is restricted by the cam  28   s  even with traction by the spring  27 . By constituting the shape of the cam by that of the cam  28   s  in an elliptic shape as shown by FIG. 6, the magnetic recording information can be read in either of a case of initial loading and a case of rewinding the film.  
     [0068] Third Embodiment  
     [0069]FIG. 7 is a view for explaining a third embodiment of the invention and is a view showing the constitution of an inner portion of a rear face of a camera. In FIG. 7, numeral  41  designates a camera body, numeral  42  designates a press plate for pressing the film from a rear face side to a picture frame to maintain the film in a plane state, numeral  43  designates a cartridge chamber for containing a film cartridge and numeral  44  designates a spool for winding up the film.  
     [0070] A pivoting plate  46  is supported by the press plate  42  pivotably around a shaft  46   a  and is urged to pivot in the clockwise direction by a spring  47 . Further, the press plate  42  is installed with a pin  42   a  for locking the pivoting plate  46  urged by the spring  47 .  
     [0071] A hole  46   b  is formed in the pivoting plate  46  and the magnetic head  105  is attached to its center at a position opposed to the magnetic recording portion of the film and is constituted to be able to magnetically record information to the magnetically recording portion of the film and read magnetically recorded information.  
     [0072] Further, one end  48   a  of a wire  48  made of a shape memory alloy is attached to the pivoting plate  46  and other end  48   b  of the wire  48  is fixed to the press plate  42 . The wire  48  made of a shape memory alloy is previously memorized with a predetermined contraction shape in this case.  
     [0073] The pivoting plate  46  is urged to pivot in the clockwise direction by the spring  47  and therefore, the wire  48  made of a shape memory alloy is elongated in a normal state, however, when the wire  48  is heated to predetermined temperature by generating heat by resistance of the wire per se by flowing electric current in the wire  48 , the wire  48  is contracted to recover to the memorized shape and accordingly, the pivoting plate is pivoted in the counter clockwise direction against the urge force of the spring  47 . When electric current to the wire  48  is cut off, the wire is cooled and accordingly, the pivoting plate  46  again recovers to the position shown by FIG. 7 by being pivoted in the clockwise direction by the spring  47 .  
     [0074] In the above-described constitution, in the case in which the film is being wound up by the spool  44 , when supplying and cutting off of electric current is repeated in the wire  48  made of a shape memory alloy, the pivoting plate  46  is pivoted around the shaft  46   a  and is reciprocated by a very small distance substantially in parallel with the direction of feeding the film. In this case, when the pivoting plate  46  is pivoted in the clockwise direction by the urge force of the spring  47 , the magnetic head  105  on the pivoting plate  46  is driven in a direction reverse to the direction of feeding the film and accordingly, the speed of moving the film relative to the magnetic head  105  becomes faster than the speed of feeding the film.  
     [0075] When the urge force of the spring  47  is adjusted and the speed of moving the magnetic head  105  by the urge force of the spring is set to be a speed equivalent to or more than the speed of feeding the film, the speed of moving the film relative to the magnetic head  105  becomes twice or more of the speed of feeding the film, output signal generated in the magnetic head becomes larger than in the case in which the magnetic head is fixed, even when the speed of feeding the film is lowered, the speed of moving the film relative to the magnetic head can be maintained to a degree of the normal case and the magnetic recording information can firmly be read.  
     [0076] Further, when the pivoting angle of the pivoting plate is set to be equal to or more than±0.85°, there causes a case in which the azimuth angle which is an angle of intersection of the magnetic recording region on the film and the center line of a gap of the magnetic head becomes zero degree (0°) and accordingly, an optimum value of the azimuth angle is necessarily caused when the magnetic head is reciprocated at least once during a time period in which the magnetic recording region on the film passes through above the magnetic head and therefore, whether the magnetic recording information is present or not in the frame can be determined quite similar to the case of the first embodiment.  
     [0077] Further, although the urge force of the spring  47  is utilized for driving the slide plate  46  in a direction reverse to the direction of winding the film in FIG. 7, when the drive speed by heating/cooling the wire  48  made of a shape memory alloy is faster than the drive speed by the urge force of the spring  47 , drive by the wire made of a shape memory alloy may be constituted to utilize in the driving operation in the direction reverse to the direction of winding up the film. There is adopted driving means of a faster one of the drive speed by utilizing either of the driving operation by the urge force of the spring and the driving operation by the wire made of a shape memory alloy in driving the pivoting plate in a direction reverse to the direction of winding up the film.  
     [0078] Although in the above-described explanation, an example of reading the magnetic recording information in initial loading has been shown, the magnetic recording information can also be read in rewinding the film, further, similar to the first and the second embodiments, the magnetic-recording information may be read both in initial loading and rewinding the film.  
     [0079] According to the constitution, a cam for driving the magnetic head and a mechanism of rotating the cam are not needed as in the first embodiment and the second embodiment and accordingly, the constitution can be simplified and when the wire made of a shape memory alloy is arranged linearly as shown by FIG. 7, no special space is particularly needed.  
     [0080] Fourth Embodiment  
     [0081] According to a fourth embodiment, operation of driving a pivoting plate by a wire made of a shape memory alloy explained in the third embodiment mentioned above is applied to driving a slide plate explained in the second embodiment.  
     [0082]FIG. 8 is view for explaining the fourth embodiment and is a view showing the constitution of an inner portion of a rear face of a camera. In FIG. 8, numeral  51  designates a camera body, numeral  52  designates a press plate for pressing a film from a rear face side to a picture frame to maintain the film in a plane state, numeral  53  designates a cartridge chamber for containing a film cartridge and numeral  54  designates a spool for winding up the film.  
     [0083] A slide plate  56  is supported by the press plate  52  slidably in the left and right direction and is pulled and urged in an arrow b direction (right direction of FIG. 8) by a spring  57 . Further, notation  56   b  designates holes for guiding the slide plate  56  in the sliding direction and numeral  52   a  designates pins implanted to the press plate  52  and by fitting the pins  52   a  into the holes  56   b  mentioned above, the slide plate  56  is slidable in the left and right direction, and stays unmoved in the up and down direction by being restricted thereby. Further, the press plate  52  is installed with a lock pin  52   b  to restrict movement of the slide plate  56  in the right direction.  
     [0084] A hole  56   d  is formed in the slide plate  56  and the magnetic head  105  is attached to its center at a position opposed to the magnetic recording portion of the film and is constituted to be able to magnetically record information to the magnetic recording portion of the film and read magnetically recorded information.  
     [0085] Further, one end  58   a  of a wire  58  made of a shape memory alloy is attached to the slide plate  56  and other end  58   b  of the wire  58  is fixed to the press plate  52 . The wire  58  made of a shape memory alloy is previously memorized with a predetermined contraction shape in this case.  
     [0086] The slide plate  56  is urged to slide in the arrow b direction (right direction of FIG. 8) by a spring  57  and accordingly, the wire  58  made of a shape memory alloy is elongated in the normal state, however, when electric current is flowed in the wire  58  and the wire  58  is heated to a predetermined temperature by generating heat by resistance of the wire per se, the wire  58  is recovered to contract to the memorized shape and accordingly, the slide plate  56  is slid in a direction opposed to the arrow b (left direction of FIG. 8) against the urge force of the spring  57 . When electric current to the wire  58  is cut off, the wire is cooled and therefore, the wire  58  is again slid to the arrow b direction (right direction of FIG. 8) by the spring  57  and is returned to a position shown by FIG. 8.  
     [0087] In the above-described constitution, in the case in which the film is being wound up by the spool  54 , when conduction and cutting off of electric current is repeated at the wire  58  made of a shape memory alloy, the slide plate  56  is reciprocated by a very small distance in parallel with the arrow b direction and the direction opposed thereto (left and right direction), that is, the direction of transferring the film. At this occasion, when the slide plate  56  is slid in the arrow b direction (right direction of FIG. 8) by the urge force of the spring  57 , the magnetic head  105  on the slide plate  56  is driven in the direction reverse to the direction of feeding the film and accordingly, the speed of moving the film relative to the magnetic head  55  becomes faster than the speed of feeding the film.  
     [0088] When the urge force of the spring  57  is adjusted and the speed of moving the magnetic head  105  by the urge force of the spring is set to be a speed equivalent to or more than the speed of feeding the film, the speed of moving the film relative to the magnetic head  105  becomes twice or more of the speed of feeding the film, output signal generated in the magnetic head becomes larger than in the case in which the magnetic head is fixed, even when the speed of feeding the film is lowered, the speed of moving the film relative to the magnetic head can be maintained to a degree of the normal case and the magnetic recording information can firmly be read.  
     [0089] Further, according to the constitution, similar to the case of the third embodiment mentioned above, a cam for driving the magnetic head and a mechanism for rotating the cam are not needed and accordingly, the constitution can be simplified, further, when the wire made of a shape memory alloy is arranged linearly above the press plate as shown by FIG. 8, no special space is particularly needed.  
     [0090] Further, similar to the second embodiment mentioned above, according to the constitution, the slide plate, that is, the magnetic head is reciprocated in the left and right direction and accordingly, the azimuth angle which is an angle of intersection of the magnetic recording region on the film and the center line of a gap of the magnetic head, can be maintained to a substantially constant value.  
     [0091]FIG. 9 is a block diagram for explaining the constitution of a control circuit of a magnetic recording information reading device which is applicable to those of the first and the second embodiments mentioned above. In FIG. 9, a constitution added with a constitution of a portion indicated by a chain line is applicable to those of the third and the fourth embodiments.  
     [0092] A control circuit  60  is constituted by CPU (Central Processing Unit)  61 , a motor  11 , a magnetic head  105  and a photo-reflector  103  which are connected to input/output ports of CPU  61 . The control circuit  60  according to the third and the fourth embodiments is constituted to connect the wire  48  (third embodiment) or  58  (fourth embodiment) made of a shape memory alloy via a heating control unit  65  for supplying electric power to the wire made of a shape memory alloy. The motor  11  is used in transferring the film F and driving the cam drive mechanism for driving the pivoting plate  6 .  
     [0093] Next, an explanation will be given of an outline of the operation. When a switch, not illustrated, is made ON, control operation by CPU  61  is started. When loading of a film cartridge is detected, the film is wound up by the motor  11  and initial loading is started.  
     [0094] Perforations of the film are detected by the photo-reflector  103  and transfer of the film is controlled.  
     [0095] Simultaneously therewith, according to the first and the second embodiments, the pivoting plate  6  or the slide plate  26  is driven by the cam drive mechanism and movement of the magnetic head  105  is started. According to the third and the fourth embodiments supplying and cutting off of electric power is started at the wire  48  or  58  made of a shape memory alloy via the heating control unit  65 , the pivoting plate  46  or the slide plate  56  is driven and movement of the magnetic head  105  is started.  
     [0096] The magnetic recording information on the film is read by the magnetic head  105  and based on the recorded information, control of transfer of the film, stop at a photographing position and so on is carried out.  
     [0097]FIG. 10 is a flowchart for explaining control operation of the control circuit  60  for searching an initial unexposed frame and setting it at a photographing position when a film cartridge which has been photographed until a midway thereof is reloaded in a camera according to the first through the fourth embodiments explained above.  
     [0098] First, the operation awaits for loading of the film cartridge to a cartridge chamber of the camera (step P 11 ) and starts initial loading when it is loaded (step P 12 ). During a procedure of winding a film in the initial loading, the operation starts to drive a magnetic head, that is, pivot or reciprocate the magnetic head (step P 13 ) and searches an information item recorded on the magnetic recording portion in correspondence with respective frames on the film (step P 14 ).  
     [0099] When the recorded information is discovered, the operation determines whether the recorded information is of a final frame or not (step P 15 ). When the recorded information is not of the final frame, continues winding up the film (step P 25 ) and returns to step P 14 . When the recorded information is of the final frame by determination at step P 14 , it signifies that all the frames of the film cartridge have been photographed and accordingly, the operation stops to drive the magnetic head (step P 16 ) and stops winding up the film (step P 17 ). Further, the operation starts rewinding the film and awaits for finish of the rewinding operation (steps P 18  and P 19 ). When the rewinding operation has been finished, ejects the film cartridge (step P 20 ) and finishes the processing.  
     [0100] When it is determined that there is no recorded information in the magnetic recording portion by the judgement at P 14 , the frame is determined to be an initial unexposed frame and accordingly, the operation stops driving the magnetic head (step P 21 ), stores a number of the unexposed frame, rewinds the frame by one frame or more (step P 22 ), winds up the film (step P 23 ) until the frame having the unexposed frame number reaches the photographing position (step P 23 ), sets the unexposed first frame at the photographing position (step P 24 ) and returns to an exposure control routine, not illustrated.  
     [0101] Although according to the above-described explanation, when it is determined that there is no recorded information at the magnetic recording portion by determination at step P 14 , driving of the magnetic head is stopped at steps P 21  and P 22 , the unexposed frame number is stored and the film is rewound by one frame or more, presence or absence of the recorded information at the magnetic recording portion may be determined by driving the magnetic head even in rewinding the film, the determination may be compared with a result of determination at step P 14 , when results of both determination coincide with each other, the film may be wound up until the frame having the unexposed frame number reaches the photographing position and when the results of determination do not coincide with each other, the operation may return to step P 12  and may start driving again the magnetic head in the procedure of winding up the film and may determine presence or absence of information at the magnetic recording portion. Thereby, an error in reading the recorded information can be prevented. Further, when the results of both determination mentioned above do not coincide with each other, alarm may be displayed.  
     [0102] According to the embodiments of the invention explained above, an explanation has been given by an example in which the invention is applied to a magnetic recording information reading device of a camera using the film cartridge for APS. However, the invention is not limited to such a magnetic recording information reading device of a camera but is naturally applicable to other device utilizing magnetic information on a film having a magnetic recording portion, that is, a magnetic recording information reading device of, for example, a photo player, a film scanner or the like.  
     [0103] As has been explained, according to the invention, in a magnetic recording information reading device using a film cartridge capable of magnetically recording information on a film, by reciprocating a read head for reading magnetic recording information recorded on a magnetic recording portion by a small distance in parallel with a direction of transferring the film, a speed of the magnetic recording portion passing through the read head is accelerated and a level of a signal outputted from the read head is increased.  
     [0104] Thereby, the speed of the magnetic recording portion passing through the read head can be accelerated without accelerating the speed of transferring the film, even when an angle (azimuth angle) between a magnetism change boundary line of the magnetic recording portion and the center line of a gap of the head is not strictly set within a predetermined angle, an output signal having a sufficient level is obtained from the read head and the magnetic recording information can be read easily and firmly.  
     [0105] Further, it is not necessary to use a film guide mechanism for strictly setting the angle (azimuth angle) made by the magnetism change boundary line of the magnetic recording portion and the center line of a gap of the head within a predetermined angle, a large-sized motor for accelerating the speed of transferring the film and the like and the device can be arranged in small size and light weight.