JPH10104709A - Magnetic reproducing device for photographic film and camera provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the S/N ratio of a reproducing signal by arranging a noise canceling magnetic head and a reproducing magnetic head side by side, in parallel with the rotary shaft of a motor. SOLUTION: A magnetic head unit 16 is provided with the reproducing magnetic head HR and the noise canceling magnetic head H. which are disposed in parallel with the axial direction of the rotation of the motor 8 (the width direction of a film 1), when it is shown in an assembled state. A reproducing coil 24 and a noise canceling coil 34 are connected to develop voltages in directions opposite to luminous fluxes in the same direction (in the direction of A in the figure) which pass through cores on which the coils are wound respectively and the bobbin temtinals 25 and 35 of the respective coils 24 and 34 are connected to the input terminal of a reproducing amplifier 61. Therefore, when magnetic information is not reproduced by the reproducing magnetic head HR, noise voltages appgaring in the reproducing coil 24 and the canceling coil 34 are canceled in the reproducing amplifier 61, so that the output of the amplifier 61 becomes zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing apparatus for a photographic film having a magnetic head for reproducing a signal magnetically recorded on the photographic film.

[0002]

2. Description of the Related Art A photographic film having a magnetic layer on the film base side has been proposed in the prior art, and is disclosed in U.S. Pat.
No. 8,075 proposes a camera that magnetically records information such as a photographing date, a photographing time, and photographing conditions for each photographing frame for each photographing frame of the film. Also, when the film is once rewound in the middle of photographing and the photographing from the unexposed frame is started again, the information recorded on the magnetic layer is reproduced as photographed information and moved to the photographing position of the unexposed frame. There is also disclosed a camera having a function of performing positioning (hereinafter, referred to as an unexposed film cueing function).

[0003] Such a camera has been proposed in, for example, Japanese Patent Laid-Open No. 6-95234.
A recording magnetic head for recording photographed information on the magnetic layer and a reproducing magnetic head for reproducing photographed information from the magnetic layer are provided.

A camera is provided with a motor for feeding a photographic film. However, there is a problem that a magnetic field generated by the motor causes an induction noise in a reproducing magnetic head.

Therefore, for example, Japanese Patent Application Laid-Open No. Hei 4-22937 focuses on the fact that the strength of a magnetic field generated from a motor decreases in a specific direction about the motor rotation axis, and the reproducing magnetic head is moved in this direction. S / N of playback signal
Cameras that improve the ratio have been proposed.

However, even if the reproducing magnetic head is arranged in a place where the motor magnetic field is weak, the influence of the motor magnetic field is not completely eliminated, so that it is not easy to sufficiently increase the S / N ratio of the reproduced signal.

Japanese Patent Application Laid-Open No. Hei 7-128724 discloses a noise detecting magnetic head which has a configuration similar to a reproducing magnetic head and outputs only a noise signal generated by a motor magnetic field. By subtracting the output signal of the magnetic head for noise detection from the output signal of the magnetic head for reproduction, a noise component included in the output signal of the magnetic head for reproduction is canceled, and the S / N ratio of the reproduced signal is further improved. Cameras have been proposed.

[0008]

However, in the camera proposed in Japanese Patent Laid-Open No. 7-128724, the strength of the motor magnetic field penetrating the reproducing magnetic head and the motor magnetic field penetrating the noise detecting magnetic head are also reduced. If the strength differs greatly, the noise component contained in the output signal of the reproducing magnetic head cannot be completely canceled,
The S / N ratio of the reproduced signal cannot be improved.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic reproducing apparatus for a photographic film capable of almost completely canceling a noise component in an output signal of a reproducing magnetic head, and a camera provided with the magnetic reproducing apparatus. And

[0010]

According to the present invention, a magnetic head for reproducing a magnetic signal from a photographic film and a motor (for example, a motor for driving a film feed) are provided. In a magnetic reproducing apparatus for a photographic film having a noise detecting means for detecting electromagnetic noise, the magnetic head and the noise detecting means are arranged in parallel with a rotation axis of a motor.

As described above, the strength of the magnetic field generated by the motor decreases in a specific direction about the motor rotation axis, but is substantially constant in a direction parallel to the motor rotation axis. Focusing on this point, the present invention makes the magnetic head, noise detecting means, and the motor magnetic field strength affecting these substantially parallel by arranging the magnetic head and noise detecting means in parallel with the rotation axis of the motor, and includes them in the output signal of the magnetic head. Thus, the influence of the motor magnetic field can be almost completely canceled.

Here, the noise detection means has substantially the same configuration as the magnetic head, and a signal substantially the same as the noise component signal included in the output signal of the magnetic head is output from the noise detection means, thereby simplifying the noise canceling circuit. It is desirable to be able to configure it. When the magnetic head has a recording coil for magnetically recording a signal (that is, when the magnetic head is used for both recording and reproduction), the noise detection means having the same configuration as the magnetic head is used. It is desirable to provide a dummy coil corresponding to the recording coil.

Further, it is preferable that the magnetic head and the noise detecting means are housed in one magnetic shielding case so that the motor magnetic field acting on the magnetic head and the noise detecting means are equivalent.

As a method of arranging the magnetic head and the noise detecting means, the magnetic head is arranged at a position facing a magnetic recording portion (a magnetic track on which a signal is recorded by a recording magnetic head), and then the noise is detected. By disposing the means at a position not facing the film or at a position facing a portion other than the magnetic recording portion of the film, it is possible to prevent the signal of the magnetic recording portion from being reproduced by the noise detecting device. Is desirable. Also, as in the latter case, by causing the noise detection means to face a portion of the film other than the magnetic recording portion (part of the magnetic layer), it is possible to cancel noise due to defects in the magnetic layer itself.

Further, in the present invention, as another arrangement method of the magnetic head and the noise detection means, they are arranged so as to face each other with a film interposed therebetween.

That is, a motor magnetic field of the same strength passing through the opposing portion between the magnetic head and the noise detecting means affects the magnetic head and the noise detecting means so that the motor included in the output signal of the magnetic head can be used. The effect of the magnetic field can be canceled more completely as compared with the case of the above-described parallel arrangement with the motor rotation shaft.

It is desirable that the magnetic head and the noise detecting means are housed in a magnetic shielding case, respectively, so that the motor magnetic fields acting on the magnetic head and the noise detecting means are equivalent.

According to the present invention, by providing such a magnetic reproducing apparatus for photographic film, it is possible to realize a camera which can accurately magnetically reproduce photographed information and the like from photographic film without being affected by noise caused by a motor magnetic field. I have.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a configuration of a camera according to a first embodiment of the present invention. In this figure, reference numeral 1 denotes a photographic film having a magnetic layer on the base surface side.
2 and is exposed to an aperture position behind the optical axis and receives exposure.

The cartridge 2 has an in-cartridge spool 5 which engages with the spool driver 4 of the camera when loaded into the camera. The spool driver 4 is provided with a motor 8 ( When the output shaft is driven to rotate in the direction of arrow A by a pinion gear 9), the spool 5 in the cartridge also rotates in the same direction, and the film outlet 6 of the cartridge 2 is rotated.
Extrudes the film 1.

When the leading end of the film 1 is guided by the guide rollers 10 and 11 and reaches the take-up spool 7 of the camera, the film 1 is thereafter rotated by the motor 8 in the direction of arrow B. Is wound up in the direction of arrow C.

When the take-up spool 7 is driven by the motor 8, transmission of the motor driving force to the spool driver 4 is not performed by switching operation of a known driving force transmission mechanism having a one-way clutch or the like. If the motor 8 is driven in the direction opposite to the direction of winding, the switching operation of the driving force transmission mechanism rotates the spool driver 4 in the direction opposite to the direction of pushing, and the film 1 is rewound to the cartridge 2. .

The output shaft of the motor 8 according to the present embodiment extends in the axial direction of the take-up spool 7. Furthermore, the output shaft of the motor 8 extends in the width direction of the film 1 wound by the winding spool 7.

Reference numeral 13 denotes a guide plate which is in contact with the base surface of the portion of the film 1 located at the aperture position to ensure the flatness of the film portion. Film feeding direction (film longitudinal direction) 2 above the guide plate 13
Photoreflectors 14 and 15 are attached to the three locations. The photoreflectors 14 and 15 output a detection signal of the perforation P of the film 1 while the film 1 is being fed. The detection signal is sent to a control device (not shown) of the camera, and the control device controls the operation of the motor 8 based on the detection signal to perform positioning of the film 1 of the film 1 with respect to the aperture position.

A magnetic head unit 16 which is in sliding contact with the magnetic layer of the film 1 is attached to the lower side of the guide member 13 on the side of the take-up spool 7 (ie, on the side of the motor 8).

In the figure, F indicates the photographing frame of the film 1, and O indicates the center of the photographing frame F (the photographing center of the photographing lens 12). When photographing (exposure) ends for each photographing frame F, the motor 8 is energized, and the film 1 is fed in the direction of arrow C by one frame. At this time, the magnetic head unit 16 magnetically records the photographing information (date, time, title, photographing data, etc.) corresponding to each photographing frame F on the film 1, and records a magnetic track on the film 1. A recording section T is formed.

When the film cartridge 2 in which the film which has been photographed halfway is rewound is loaded in the camera, the motor 8 is energized to push out the film 1 by the spool driver 4 and take up the subsequent take-up spool. 7, the film 1 is continuously drawn in the direction of arrow C.

At this time, the magnetic head unit 16 reproduces the photographing information recorded on the magnetic track T, and the control circuit of the camera determines whether each frame has been photographed in order from the first frame F based on the reproduced information. Determine whether or not.
When an unphotographed frame is detected, an operation of setting the frame F to the aperture position is performed.
The camera stops operating. The magnetic reproduction by the magnetic head unit 16 is performed while the motor 8 is energized and is rotating.

By the way, in the present camera, the motor 8 and the magnetic head unit 16 are arranged very close for miniaturization. Therefore, a large induced voltage due to the magnetic field generated from the motor 8 is superimposed on the reproduction output of the magnetic head unit 16 as noise (electromagnetic noise), which may cause a deterioration in the S / N ratio of the reproduction signal.

Here, N ₁ , N shown by chain lines in FIG.
₂ qualitatively indicates the magnitude of the magnetic field generated by the motor 8. The magnetic field has a direction in which the strength is maximum as indicated by an arrow D and a direction in which the intensity is minimum as indicated by an arrow E, around the rotation axis of the motor 8. In each direction, the strength of the magnetic field is substantially constant in the axial direction of the motor 8 (in the figure, N ₁ and N _1
2 has the same shape). For this reason, in the present embodiment, the magnetic head unit 16 which dislikes noise is arranged in the direction of arrow E with respect to the motor 8.

However, even if the magnetic head unit 16 is arranged in the direction of arrow E, the effect of the motor magnetic field is not completely eliminated. Therefore, in this embodiment, as shown in FIG. A magnetic head for cancellation is provided.

FIG. 2A shows the appearance of the magnetic head unit 16, and FIG. 2B shows the internal structure of the magnetic head unit 16.

The magnetic head unit 16 includes a reproducing magnetic head H _R and a noise canceling magnetic head H _C arranged in the axial direction of the motor 8 (in the width direction of the film 1) in the case of the assembled state shown in FIG. have. These magnetic heads are covered by a shield case 41 made of a material having high magnetic permeability such as permalloy in order to suppress intrusion of external noise.

Two openings are formed in a sliding contact surface 41a with the film 1 in the shield case 41.
A reproduction channel C _R and a noise cancellation channel C _C are formed by the core head portion of each magnetic head exposed from these openings. And these core head portion for being exposed to the outside, the magnetic head H _C magnetic head H _R and noise canceling reproduction would affected by the motor magnetic field.

Since the two magnetic heads H _R and H _C are arranged in the axial direction of the motor 8 in the same direction, the direction and strength of the motor magnetic field passing through the two magnetic heads H _R and H _C are as follows. A mounting plate 42 for mounting the magnetic head unit 16 on the guide member 13 is fixed to the shield case 41 on the side opposite to the sliding surface 41a. A screw hole 42a for using a screw or the like at the time of mounting is formed.

The reproducing magnetic head H _R comprises a pair of cores 21 and 22 opposed to each other in the longitudinal direction of the film, a reproducing bobbin 23 and a recording bobbin 27 attached to the cores 21 and 22, and a reproducing bobbin. 23, a reproducing coil 24 wound around a recording bobbin 27, and reproducing bobbin terminals 25 and 26 for transmitting a voltage generated in the reproducing coil 24 to the outside. And recording bobbin terminals 29 and 30 for transmitting the voltage generated in the recording coil 28 to the outside.

On the other hand, the noise canceling magnetic head H _C
Has the same configuration as the magnetic head H _R for reproduction. That is, the cores 31 and 32, bobbins 33 and 37, coils 34 and 38, and bobbin terminals 35 and 36 (two more terminals (not shown)) are formed. , Length, number of turns of coils 34, 38 to be wound,
Elements that determine the characteristics of the reproduction output, such as the wire diameter, are also the same.

The noise canceling magnetic head H _C
It is provided with the same dummy coil 38 and the recording coil 28 of the reproducing magnetic head H _R on. Therefore, it does not also cause a slight characteristic difference between shared with going on a magnetic head for reproducing H _R and the magnetic head H _C for noise cancellation between the recording and reproducing. Moreover, as described above, the noise canceling magnetic head H _C and the reproducing magnetic head H _R
Are housed in the same shield case 41.

[0039] Thus, when subjected to motor field of the same intensity, it is possible to generate the exact same induced voltage in a reproducing magnetic head H _R and noise magnetic head cancellations H _C.

FIG. 3 shows a cross section taken along line III-III in FIG. 1 in a state where the magnetic head 16 is attached to the camera. Reference numeral 51 denotes a camera body, and outer rails 51a, 51a are provided above and below the camera body 51,
Inner rails 51b, 51b are formed. The outer rails 51a are connected to the film sliding surface 13 of the guide member 13.
By contacting a, a tunnel through which the film 1 passes is formed. The inner rails 51b, 51b ensure the flatness of the film 1 by sandwiching the upper and lower portions of the film 1 in the tunnel with the film sliding surface 13a.

Reference numeral 51c denotes an opening of the photographing aperture. The magnetic head unit 16 is arranged at a position where the reproducing channel C _R faces the magnetic track T of the film 1 shown in FIG. 1 and the noise canceling channel C _C faces the lower outer rail 51a. 52 is a pad made of an elastic member. The pad 52 is attached to the tip of a lever 53. When the lever 53 is urged in the direction of the film 1 by a spring 54, the lower part of the film 1 is pushed, and the magnetic track T of the film 1 is moved to the reproduction channel C _R. Press

[0042] Figure 4, each coil of the reproducing magnetic head H _R and noise canceling magnetic head H _C 24,28,3
4, 38 electrical connections are shown. The recording coil 28 (bobbin terminals 29, ₃₎ in the reproducing magnetic head H _R
0) is connected to a magnetic recording circuit 62 of the camera, and performs magnetic recording on the film 1 according to a signal from the magnetic recording circuit 62 to form a magnetic track T.

The dummy coil 38 of the magnetic head H _C for noise cancellation is in a disconnected form the apparatus. This is because, as described above, the dummy coil 38 is provided to completely equalize the characteristics of the two magnetic heads H _R and H _C , and the connection with the device makes the characteristics of the noise canceling magnetic head H _C subtle. This is because there is a risk of changing to

On the other hand, the reproducing coil 24 and the noise canceling coil 34 are connected so as to generate a reverse voltage with respect to a magnetic flux in the same direction (direction A in the drawing) passing through the wound core. And each coil 24, 34
Output terminals (bobbin terminals 25 and 35) of the reproducing amplifier 61
Is connected to the input terminal of Then, as described above, the reproducing cores 21 and 22 and the noise canceling core 3
The magnetic fluxes of the same direction and strength (density) generated from the motor 8 pass through 1 and 32.

Therefore, when magnetic information is not reproduced by the reproducing magnetic head H _R, the noise voltage generated in the reproducing coil 24 and the canceling coil 34
Is cancelled in the reproduction amplifier 61, and the output of the reproduction amplifier 61 becomes zero. Therefore, if information is reproduced from the magnetic track T by the reproducing magnetic head H _R , the noise voltage component in the reproducing voltage generated in the reproducing coil 24 is completely canceled, and the reproducing amplifier 6
It is possible to output an information signal having an extremely high S / N ratio in which only the information voltage in the reproduction voltage of the reproduction coil 24 is amplified from 1.

[0046] In the present embodiment, a position facing the channel C _C for noise canceling out rail 51a, i.e. are arranged at positions not facing the film, which the film 1 is meandering in feeding it allows for noise cancellation channel C _C is in contact with the magnetic track T, in order to prevent the magnetic signals recorded on the magnetic track T from being reproduced from the channel C _C for noise cancellation.

(Second Embodiment) FIG. 5 shows a camera according to a second embodiment of the present invention. This embodiment is different from the first embodiment in the arrangement of the magnetic head unit 61. However, the reproducing magnetic head H _R in the magnetic head unit 61 is different from the first embodiment.
Since the configuration of the noise canceling magnetic head H _C itself and the configuration of the camera are the same as those of the first embodiment, common elements are denoted by the same reference numerals as those of the first embodiment and will not be described.

In this embodiment, the magnetic head unit 61
And the reproduction channel C _R is the magnetic track T of the film 1.
And the noise canceling channel C _C is located at a position distant from the reproduction channel C _{R in} the axial direction of the motor 8 and the photographing frame F of the film 1 (but on the base surface side)
It is arranged at the position facing to. That is, with respect to the magnetic head 16 of the first embodiment, the vertical positions of the reproduction channel C _R and the noise cancellation channel C _C are reversed.

[0049] Then, in this embodiment, the electrical connection of the reproducing magnetic head H _R and noise each coil cancel magnetic head H _C (not shown) is the same as the first embodiment shown in FIG. 4 is there.

Therefore, also in this embodiment, the magnetic flux of the same direction and strength (density) generated from the motor 8 passes through the reproducing core and the noise canceling core, and the noise voltage generated in the reproducing coil is reduced. The noise voltage generated in the canceling coil is canceled. Therefore, if information is reproduced from the magnetic track T by the reproducing magnetic head H _R , the noise voltage in the reproducing voltage generated in the reproducing coil is completely canceled, and only the information voltage in the reproducing voltage is amplified. An information signal having an extremely high S / N ratio can be output.

In the present embodiment, the noise canceling channel C _C is arranged at a position facing the photographing frame F of the film 1, that is, at a position somewhat distant from the magnetic track T in the film width direction. As in the first embodiment, when the film 1 meanders during feeding, the noise canceling channel C _C comes into contact with the magnetic track T, and the magnetic signal recorded on the magnetic track T is transferred to the noise canceling channel C. _This is to prevent playback from _C.

[0052] Meanwhile, unlike the first embodiment, it is arranged in sliding contact position channel C _C for noise cancellation in the magnetic layer of the film 1. Thus, in addition to the noise caused by the motor magnetic field, and sliding noise caused by the sliding of the core and the magnetic layer of the reproducing channel C _R, a similar noise canceling noise generated when there is a minute defect in the magnetic layer There is an advantage that these other noises generated in the channel C _C and generated in the reproduction channel C _R can be canceled.

[0053] However, in this embodiment, not be pressed against the channel C _C unit for noise cancellation by pressing the film 1 by the pad. Therefore, the shooting frame F
There is no possibility of scratch due to sliding contact with the channel C _C for noise cancellation within.

(Third Embodiment) FIG. 6 shows a camera according to a third embodiment of the present invention. In the present embodiment, the reproducing magnetic head unit (the reproducing magnetic head H _R
Is covered with a shield cover 71 at a position where the reproduction channel C _R faces the magnetic track T of the film 1, and the noise canceling magnetic head unit (the noise canceling magnetic head H _C is covered with the shield cover). ) 72 is disposed at a position facing the magnetic head unit for reproduction with the film 1 interposed therebetween. That is, disposed at a position facing each other with a magnetic head H _C magnetic head H _R and noise canceling reproduction across the film 1. The configuration of the two magnetic heads H _R and H _C themselves is the same as that of the first embodiment (however, the reference numerals for each component are different).

Magnetic head unit 7 for noise cancellation
Numeral 2 is fixed to the front end of the mounting plate 73. When the mounting plate 73 is urged in the direction of the film 1 by the spring 74, the noise canceling magnetic head unit 72 is pressed against the film 1, and The magnetic track T is configured to be pressed against the reproducing head unit 71. In other words, the reproduction channel C _R and the noise cancellation channel C _C are arranged at very close positions separated by the thickness of the film 1. This arrangement includes a reproducing magnetic head H _R and a noise canceling magnetic head H
_This can be said to be an ideal arrangement in making the direction and intensity of the motor magnetic field penetrating into _C and the same.

Since the configuration of the camera other than the above is the same as that of the first embodiment, common elements are denoted by the same reference numerals as in the first embodiment, and description thereof will be omitted.

[0057] Then, in this embodiment, the electrical connection of the reproducing magnetic head H _R and noise each coil cancel magnetic head H _C (not shown) is as shown in FIG.

The recording coil 88 (bobbin terminals 89 and 90) of the reproducing magnetic head H _R is connected to the magnetic recording circuit 62 of the camera, and performs magnetic recording on the film 1 in accordance with a signal from the magnetic recording circuit 62. The magnetic track T
To form

[0059] The dummy coil 98 of the magnetic head H _C for noise cancellation is in a disconnected form the apparatus. This is similar to the first embodiment in order not subtly alter the properties of the magnetic head H _C for noise cancellation.

Reproducing magnetic head H_RReproduction coil 84
And magnetic head H for noise cancellation _CNoise canceling
Coil 94 is a core wound around each.
In the same direction (N direction in the drawing)
The coils 84, 9 are connected to generate pressure.
The output terminals (bobbin terminals 85 and 95) of the reproduction amplifier 6
1 input terminal. And as mentioned above
The reproducing cores 81 and 82 and the noise canceling core 9
1, 92 have the same direction and strength
(Density) magnetic flux passes.

[0061] Therefore, when not performing the reproduction of the magnetic information by the magnetic head H _R for reproduction, the noise voltage and cancellation coil 94 generated in the reproduction coil 84
Is cancelled in the reproduction amplifier 61, and the output of the reproduction amplifier 61 becomes zero. Therefore, if information is reproduced from the magnetic track T by the reproducing magnetic head H _R , the noise voltage component in the reproducing voltage generated in the reproducing coil 84 is completely canceled, and the reproducing amplifier 6
It is possible to output an information signal having an extremely high S / N ratio in which only the information voltage in the reproduction voltage of the reproduction coil 84 is amplified from 1.

Further, in this embodiment, the distance between the reproduction channel C _R and the noise cancellation channel C _C is shorter than in the first and second embodiments. Therefore, the penetration of the motor magnetic field into both channels can be made equal, and a higher S / N ratio can be obtained by more complete noise cancellation.

Although a camera has been described in each of the above embodiments, the present invention may reduce the S / N ratio of a magnetic reproduction signal due to noise from a motor or the like, and may reduce the noise source to reduce the size of the apparatus. Can be applied to a device other than a camera that needs to be disposed near a reproducing magnetic head.

[0064]

As described above, the present invention focuses on the fact that the intensity of the magnetic field generated by the motor is substantially constant in the direction parallel to the motor rotation axis, and the magnetic head and the noise detecting means are connected to the motor. Are arranged in parallel to the rotation axis. Therefore, according to the present invention, the intensity of the motor magnetic field affecting the magnetic head and the noise detecting means can be made substantially the same, and the influence of the motor magnetic field included in the output signal of the magnetic head can be almost completely reduced. Can be canceled.
Therefore, it is possible to obtain a reproduced signal having a higher S / N ratio than before.

If the noise detecting means has substantially the same configuration as that of the magnetic head, it is possible to output from the noise detecting means a signal substantially the same as the noise component signal contained in the output signal of the magnetic head. The cancellation circuit can be easily configured. Furthermore, if the magnetic head and the noise detecting means are accommodated in the same magnetic shielding case, the motor magnetic field acting on these magnetic heads and the noise detecting means can be made equivalent, and the noise canceling circuit can be simplified. Can be configured.

Further, after the magnetic head is disposed at a position facing the magnetic recording section, the noise detecting means is disposed at a position not facing the film, or at a position facing the portion other than the magnetic recording section of the film. If this is done, it is possible to prevent the signal from the magnetic recording section from being reproduced by the noise detecting means, thereby preventing the S / N ratio of the reproduced signal from the magnetic head from being lowered. In addition, by causing the noise detecting means to face a portion of the film other than the magnetic recording portion (part of the magnetic layer), noise due to a defect in the magnetic layer itself can be canceled.

Further, in the present invention, the magnetic head and the noise detecting means are arranged to face each other with the film interposed therebetween. Therefore, according to the present invention, it is possible to cause a motor magnetic field of the same strength passing through the opposing portion between the magnetic head and the noise detecting means to affect the magnetic head and the noise detecting means, The influence of the motor magnetic field included in the output signal can be canceled more completely as compared with the case of the above-described parallel arrangement with the motor rotation axis.

In this case, the noise canceling circuit can be simplified if the noise detecting means has substantially the same configuration as the magnetic head, or if the magnetic head and the noise detecting means are respectively housed in a magnetic shielding case. Can be configured.

According to the invention of the present application, by providing such a magnetic reproducing apparatus for a photographic film, it is possible to realize a camera which can accurately magnetically reproduce photographed information and the like from a photographic film without being affected by noise due to a motor magnetic field. Can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a camera according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a magnetic head unit in the camera of the first embodiment.

FIG. 3 is a cross-sectional view of the camera according to the first embodiment.

FIG. 4 is an electrical connection diagram of a magnetic head unit of the camera according to the first embodiment.

FIG. 5 is a sectional view of a camera according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a camera according to a third embodiment of the present invention.

FIG. 7 is an electrical connection diagram of a magnetic head unit of the camera according to the third embodiment.

[Explanation of symbols]

1 photographic film 3 camera 8 motor 13 guide members 14, 15 photo-reflector 16 magnetic head unit 51 camera body 71 reproducing magnetic head unit 72 for noise cancellation magnetic head unit H _R reproducing magnetic head H _C noise canceling magnetic head

Claims (13)

[Claims] 1. A magnetic reproducing apparatus for a photographic film, comprising: a magnetic head for performing magnetic reproduction from a photographic film; and a noise detecting means for detecting electromagnetic noise generated from a motor, wherein the magnetic head and the noise detecting means are: A magnetic reproducing apparatus for a photographic film, wherein the magnetic reproducing apparatus is arranged in parallel with a rotation axis of the motor. 2. The magnetic reproducing apparatus for a photographic film according to claim 1, wherein the motor drives the film to be fed. 3. The apparatus according to claim 1, wherein the magnetic head is disposed at a position facing the magnetic recording portion of the film, and the noise detecting means is disposed at a position not facing the film. Magnetic reproduction device for photographic film. 4. The apparatus according to claim 1, wherein the magnetic head is disposed at a position facing the magnetic recording section, and the noise detecting means is disposed at a position facing a portion of the film other than the magnetic recording section. A magnetic reproduction apparatus for a photographic film according to claim 1. 5. The magnetic reproducing apparatus for a photographic film according to claim 1, wherein said noise detecting means has substantially the same configuration as said magnetic head. 6. The magnetic head has a recording coil for recording a signal on the magnetic recording section, and the noise detecting means has a dummy coil corresponding to the recording coil. The magnetic reproducing apparatus for a photographic film according to claim 5, wherein 7. The magnetic reproducing apparatus for a photographic film according to claim 1, wherein said magnetic head and said noise detecting means are housed in one magnetic shielding case. 8. A magnetic reproducing apparatus for a photographic film, comprising: a magnetic head for reproducing a magnetic signal from a photographic film; and noise detecting means for detecting an electromagnetic noise generated from a motor, wherein the magnetic head and the noise detecting means are provided. A magnetic reproducing apparatus for a photographic film, wherein the magnetic reproducing apparatus is arranged to face the film. 9. The photographic film magnetic reproducing apparatus according to claim 8, wherein the motor drives the film to be fed. 10. The magnetic head according to claim 8, wherein the noise detecting means has substantially the same configuration as the magnetic head.
4. The magnetic reproduction device for a photographic film according to claim 1. 11. The magnetic head has a recording coil for recording a signal on the magnetic recording section, and the noise detecting means has a dummy coil corresponding to the recording coil. The magnetic reproducing apparatus for a photographic film according to claim 10. 12. The magnetic reproducing apparatus for a photographic film according to claim 8, wherein said magnetic head and said noise detecting means are respectively housed in a magnetic shielding case. 13. A camera comprising the magnetic reproduction apparatus for a photographic film according to claim 1.