JPH0572610A - Camera using a film with magnetic storage - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to always reproduce accurate information regardless of the type of film without using a complicated circuit configuration. A discriminating means 6 for discriminating a film type, and a feeding speed varying means 101 for varying a film feeding speed by the film feeding means 51, 103 according to the film type discriminated by the discriminating means. The film feeding speed of the film feeding means is changed according to the type of the film discriminated by the discriminating means so that the level of the signal reproduced by the magnetic head 4 is constant during the film feeding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for reproducing information written in a magnetic storage unit provided in a film during film feeding, and for amplifying an analog signal reproduced by the magnetic head. An amplifier circuit, an A / D converter circuit for converting an analog signal from the amplifier circuit into a digital signal,
The present invention relates to an improvement of a camera using a film with a magnetic storage unit, which is provided with a film feeding means for feeding a film.

[0002]

2. Description of the Related Art In recent years, a film having a magnetic storage unit is used, and photographing information such as shutter speed, aperture value, date, title, etc. is written in the magnetic storage unit by a magnetic head.
A camera that reads out the photographing information as needed is proposed in US Pat. No. 4,864,332 and the like.

By the way, the density of the magnetic layer of the magnetic recording portion varies depending on the type of film. With respect to the difference between negative films and reversal films, reversal films, which require more transparency, were required to have a magnetic layer having a density much lower than that of the negative film.

[0004]

Therefore, when the amplification level of the analog signal amplifier of the magnetic reproduction circuit is set to an amplification level suitable for negative film reproduction, and when the information is reproduced from the magnetic memory section of the reversal film. However, since the reproduction level is low, a signal that does not reach the digital conversion level is generated, resulting in an information read error.

On the other hand, when the amplification level of the amplifier for amplifying the analog signal is set to the amplification level suitable for the reversal film, the amplitude level becomes too large when the information is reproduced from the magnetic storage section of the negative film. Then, the saturation region of the amplifier is reached, and a waveform different from the original signal is output from the amplifier.

In order to solve the above-mentioned point, a method of discriminating the kind of film and varying the amplification degree of the amplifier according to the result can be considered, but in such a case, the circuit configuration becomes complicated. turn into.

In view of the above points, an object of the present invention is to provide a camera using a film with a magnetic storage unit, which can always reproduce accurate information regardless of the type of film without using a complicated circuit structure. It is to be.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a discriminating means for discriminating the type of film, and a feeding means for varying the film feeding speed of the film feeding means according to the type of the film discriminated by the discriminating means. The speed varying means is provided.

[0009]

The feeding speed varying means changes the film feeding speed by the film feeding means according to the type of the film discriminated by the discriminating means, and keeps the level of the signal reproduced by the magnetic head constant during the film feeding. I am trying to.

[0010]

1 to 4 are views showing a mechanical structure in a first embodiment of the present invention, and FIG. 1 is a perspective view showing a main part of a camera.

In FIG. 1, 1 is a film cartridge, 2 is a film provided with a magnetic memory (magnetic track) T, and 3 is a perforation (P1, P2) of the film 2.
And the like), and the photosensor 4 for feeding the film at a fixed length is in sliding contact with the magnetic track T of the film 2,
A magnetic head 5 for writing or reading information is located at a position facing the magnetic head 4 with the film 2 interposed therebetween.
The pad has a function of pressing the film 2 against the magnetic head 4.

Reference numeral 6 denotes a film type determination switch mounted on a camera body (not shown). For example, a film cartridge 1 for storing a reversal film has a cutout portion 1a as shown in FIG. Assuming that the film cartridge does not exist in the film, and the film cartridge having the cutout portion 1a is loaded in the camera, the contact piece 6a is inserted into the cutout portion 1a, so that the contact piece 6a and the contact piece 6b are electrically connected. If the film type discriminating switch 6 is turned off and the film cartridge 1 having no notch 1a is loaded into the camera, the contact piece 6a is deformed by the film cartridge 1 and the contact piece 6a The contact piece 6b becomes conductive and the film type discrimination switch 6 is turned on.

Reference numeral G denotes a film feeding mechanism for transmitting the output of the film feeding motor 1 to the fork 70, the details of which will be described later with reference to FIG. 57 is a film winding spool.

The film cartridge 1 used in this embodiment has the following structure proposed in US Pat. No. 4,834,306.

That is, the film passing slit and one end of the film 2 fixed to the supply spool and wound on the supply spool, and the film 2 which is arranged coaxially with the supply spool and expands in the radial direction of the outermost periphery of the film. Film 2 regulated by the regulatory department
The pressing member (not shown) that prevents the outermost periphery of the film from substantially contacting the inner wall of the film cartridge, and a part of the pressing member are deformed so that the outermost peripheral portion of the film is prevented from being restricted in the radial direction of the pressing member. The fork 70 is provided with a releasing portion (not shown) for continuously releasing and a guiding portion (not shown) for guiding the portion of the film 2 released from the regulation to the film passage slit.
The supply of a supply spool (not shown) engaged in the direction of extruding the film 2 prevents the slippage between the outer periphery of the film 2 and the pressing member due to the expansion of the outermost circumference due to the loosening of the film 2 caused by the rotation of the film 2. The driving force is applied to enable the film 2 to be extruded from the film cartridge 1.

The film 2 is extruded from the inside of the film cartridge 1 by a film feeding mechanism which will be described later, and then the film winding spool 57 of the camera is formed by a known means.
It is wound up and sent.

2 to 4 are views showing a concrete configuration example of the film feeding mechanism G. As shown in FIG.

In these figures, reference numeral 51 is a film feeding motor, which is normally rotated (in the direction of arrow B in FIG. 3) when the film is wound, and is rotated in the reverse direction (direction of arrow C in FIG. 4) when the film is rewound. Reference numeral 52 is a pinion gear fixed to the rotation shaft of the motor 51. Reference numeral 53 denotes a first sun gear, which meshes with the pinion gear 52. 54 is a first planetary gear that meshes with the first sun gear 53. 55
Connects the first sun gear 53 and the first planetary gear 54, and rotatably holds the first planetary gear 54 while generating frictional force between the first sun gear 53 and the first planetary gear 54. It is a first connecting lever that revolves around the first planetary gear 54 about the first sun gear 53 as the center of rotation when the first sun gear 53 rotates. The first sun gear 53, the first planetary gear 54, and the first connecting lever 5
5 constitutes a known planetary gear mechanism. Reference numeral 56 is a spool gear which meshes with the first planetary gear 4 only when the film feeding motor 51 is rotated in the normal direction. Reference numeral 57 is a film winding spool that is fixed to the spool gear 56 and moves integrally.

Reference numeral 58 denotes a first idler gear which is always meshed with the first sun gear 53, 59 is a large gear portion 59a and a small gear portion 59b, and the large gear portion 59a is a first idle gear which meshes with the first idler gear 58. Two-stage gear, 60 is the first
A second idler gear that meshes with the small gear portion 59b of the two-stage gear 59, 61 is a third idler gear that meshes with the second idler gear 60, 62 is a second sun gear that meshes with the third idler gear 61, and 63 is It is a second planetary gear that meshes with the second sun gear 62. 64 is the third
This planetary gear is engaged with the second sun gear, like the second planetary gear 13. Reference numeral 65 connects the second sun gear 62, the second planetary gear 63 and the third planetary gear 64 with arm portions 65a and 65b, respectively, and holds each planetary gear rotatably while generating frictional force. The second planetary gear 63 and the third planetary gear 64 revolve around the second sun gear 62 as a rotation center by the rotation of the second sun gear 62. .. The second sun gear 62 and the second and third planetary gears 63, 64
A known planetary gear mechanism is configured by the second connecting lever 65 and the second connecting lever 65.

Reference numeral 66 is a fourth idler gear, which is a second idler gear of the second connecting lever 65 when the film feeding motor 51 is rotated in the forward direction.
When the motor 51 rotates in the reverse direction, it engages with the second planetary gear 63 and does not engage with the third planetary gear 64 by rotating the sun gear 62 in the left direction about the right side of the second connecting lever 65. This is a gear that meshes with the third planetary gear 63 and does not mesh with the second planetary gear 63 by rotating in the direction. 67 has a large gear portion 67a and a small gear portion 67b, the large gear portion 67a has a second two-stage gear that meshes with the fourth idler 66, and 68 has a large gear portion 68a and a small gear portion 68b. Part 6
Reference numeral 8a denotes a third two-stage gear that meshes with the small gear portion 67b of the second two-stage gear 67, 69 denotes a fork gear that meshes with the small gear portion 68b of the third two-stage gear 68, and 70 denotes the fork. A fork which rotates integrally with the gear 66, thereby rotating a supply spool (not shown) in the film cartridge 1 to extrude and wind the film 2 from the inside of the cartridge 1. ..

Reference numeral 71 is a stopper provided on the camera body (not shown) for regulating the position of the first connecting lever 55 in the leftward rotation direction.

In the above structure, after the film cartridge 1 is loaded in the cartridge chamber (not shown), the film feeding motor 51 (pinion gear 52) is shown in FIG.
Is rotated in the direction of arrow B (normally rotated), the first sun gear 53 is rotated clockwise, and the action of the first connecting lever 55 causes the first planetary gear 54 to rotate. Revolves clockwise around the first sun gear 53 as a center of rotation, and then meshes with the spool gear 56, the driving force of the film feeding motor 51 is transmitted to the spool gear 6, and the film take-up spool. -Le 57 will rotate clockwise.

Further, the driving force is supplied to the first two-stage gear 59, the second idler gear 60, through the idler gear 58 which is another gear meshing with the first sun gear 53.
It is transmitted to the second sun gear 62 via the third idler gear 61. Therefore, since the second sun gear rotates counterclockwise, the action of the second connecting lever 65 causes the second planet gear 63 and the third planet gear 64 to rotate about the second sun gear. It revolves counterclockwise and eventually the second planetary gear 63 comes into mesh with the fourth idler gear 66. As a result, the driving force in the B direction of the film feeding motor 51 is transmitted to the fourth idler gear 66 as a counterclockwise driving force, and further, the second two-stage gear 67 and the third two-stage gear 68. Is transmitted to the fork gear 69 via
The forks 70 rotate clockwise.

Here, the gear ratio of the gear train is constructed as follows.

The peripheral speed of the film winding spool 57 is set to "V1", and the fork 70 is used to form the film cartridge 1.
When the speed of the film 2 extruded from the film is “V2”,
There is a relationship of “V1> V2”.

When the film 2 is extruded from the film cartridge 1 by the clockwise rotation of the fork 70, the end of the film is moved by a known means (a claw provided on the film winding spool 57). The perforation P of the film 2 is hooked, or the film 2 is pressed against the film take-up spool 57 provided on the camera body side. It is wound around the winding spool 57.
After that, the film 27 is wound only by the rotation of the film winding spool 57 by the film feeding motor 51, for the reason described below.

Due to the relationship of "V1>V2", when the film 2 is wound around the film winding spool 57, the film winding spool 57 interposes the film 2 on the fork gear 69 and the third gear. The second planetary gear 6 is transmitted in the order of the step gear 68, the second two-step gear 67, and the fourth idler gear 66.
4th idler gear 66 than the clockwise rotation speed of 3
The counterclockwise rotation speed of is faster, but at this time, the fourth idler gear 66 bounces off the second planetary gear 63,
This is because the second planetary gear 63 and the fourth idler gear 66 are disengaged from each other for a moment, and the difference in speed is absorbed.

Next, the operation of rewinding the film will be described.

This operation will be described with reference to FIG. 4. When the film feeding motor 51 is rotated in the direction of arrow C, the first connecting lever 55 and the first planetary gear 54 become the first sun gear 5.
It revolves counterclockwise around the rotation center 3 until the end portion 55a of the first connecting lever 55 contacts the stopper 71. Therefore, the first planetary gear 54 and the spool gear 56
The engagement with is released.

At this time, the second sun gear 62 rotates clockwise, so that the second planetary gear 63 and the third planetary gear 64 are actuated by the second connecting lever 65. The gear 62 revolves clockwise around the rotation center,
The idler gear 66 and the second planetary gear 63 are disengaged from each other, and instead, the fourth idler gear 66 and the third planetary gear 64 are engaged with each other. Therefore, the fork gear 69 rotates counterclockwise, and the fork 70 rotates the supply spool (not shown) in the film cartridge 1 in the reverse direction so that the film 2 is wound into the cartridge 1. Go

FIG. 5 is a circuit block diagram of a camera according to the first embodiment of the present invention.

In FIG. 5, reference numeral 101 is a control circuit configured by a microcomputer or the like for controlling various operations of the camera, 102 is an AF / AE control circuit for controlling the focusing of the photographing lens and the operation of the exposure control shutter, 103 is a film feeding motor for driving the film feeding motor 51.
A driver circuit, 104 is a magnetic head drive circuit for driving the magnetic head 4 to perform an information writing operation, 105
Is a release switch. When this switch is turned on, the camera is released. Reference numeral 106 is a cartridge loading switch which is turned on when the film cartridge 1 is loaded in the camera, and 107 is a back lid switch which is turned on when the back lid is closed. Both of these switches 106 and 107 are turned on. Thereby, the control circuit 101 drives the film feeding motor driver circuit 103 to start the cueing of the first frame of the film 2.

A magnetic reproducing circuit 108 detects the magnetic information written on the magnetic track T of the film 2 through the magnetic head 4, amplifies it as an analog signal and then digitally converts it into information for the control circuit 101. And
A signal amplifier 108a that detects the output from the magnetic head 4 and amplifies the analog signal thereof, and an A / D converter 108 that converts the analog signal amplified here into a digital signal.
b.

Here, the control circuit 101, as shown in FIG. 6, is a "full energization mode" in which the film feeding motor 51 is always energized, and the film feeding mode is shown in FIG. -A film feeding mode can be selected by either of two types of "pulse energization mode" in which a pulsed signal is repeated to the motor 51 within a minute time.
A motor 5 for feeding a film via a driver circuit 103.
1 is driven, but it is better to drive the film feeding motor 51 in the "full energization mode" than to drive it in the "pulse energization mode". Since the output of 51 is large, the film feeding speed is naturally high.

The "pulse energizing mode" is used as the "energizing mode" for changing the output value of the film feeding motor 51.
The method of changing the ratio of energization and de-energization, that is, the duty may be changed.

Next, the operation of the control circuit 101 will be described with reference to the flowchart of FIG.

When the power switch of the camera is turned on, the operation from step 100 is started. "Step 100" Cartridge loading switch 106
And the back cover switch 107 are both turned on, and if both are turned on, it is determined that the film cartridge 1 is loaded in the camera, and the process proceeds to step 101. [Step 101] It is determined whether or not the film type determination switch 6 shown in FIG. 1 is turned on. If it is turned on, it means that the film cartridge 1 does not have the cutout portion 1a. Is a negative film, the process proceeds to step 102. If the film type determination switch 6 is not turned on, it means that the film cartridge 1 has the cutout portion 1a.
Is a reversal film, so step 10
Go to 3. "Step 102" The film feeding motor 51 is set to be driven by the "pulse energizing mode" through the film feeding motor driver circuit 103. In this case, the film feeding speed becomes slow. "Step 103" The film feeding motor 51 is set to be driven in the "full energization mode" via the film feeding motor driver circuit 103. In this case, the film feeding speed becomes faster than that of the negative film. [Step 104] An operation of driving the film feeding motor driver circuit 103 to locate the first frame of the film 2 at the aperture position by the film feeding motor 51.
That is, the film idling operation is started. At this time, the film feeding motor 51 is operated in the step 1 depending on the type of the film 2.
It is driven by the energization mode set in 02 or step 103. [Step 105] During the idling operation of the film 2, the magnetic head 4 is driven through the magnetic head drive circuit 104, and the film sensitivity and the number of film frames pre-written on the magnetic track T included in the film 2, Read and store film information such as film type (negative or positive).

At this time, as described above, the film feeding motor 51 is driven by the "pulse energizing mode" when the film 2 is a negative film, that is, a film having a high magnetic layer density. The feeding speed is slow, and when the film 2 is a reversal film, that is, a film having a low magnetic layer density, it is driven by the "full energization mode" so that the feeding speed of the film is high. Therefore, as a result, the level of the reproduction signal from the magnetic head 4 input to the signal amplifier 108a in the magnetic reproduction circuit 108 becomes the same level in both the negative film and the reversal film. This means that the amplification factor of the signal amplifier 108a may be kept constant, and it is not necessary to change the amplification factor by using a complicated circuit. The analog signal amplified by the signal amplifier 108a is no different from the original signal output by the magnetic head 4, and this signal has a known circuit configuration A.
Is converted into a digital signal by the / D converter 108b,
The control circuit 101 takes in this signal. "Step 106" Here, it is known that the first frame has been cued (for example, by detecting the film feed amount by the encoder, the motor energization time, and the perforation P). When it is discriminated that it is detected by, the process proceeds to step 107. "Step 107" The film feeding motor 51 is stopped via the film feeding motor driver circuit 103,
Stop film winding. "Step 108" The state of the release switch 105 is discriminated. If the release switch 105 is on, it is determined that release has been performed and the process proceeds to step 109. [Step 109] The AF / AE control circuit 102 is driven to perform a shooting operation such as an exposure operation by focusing the shooting lens and opening / closing a shutter. "Step 110" The number of film frames read out in step 105 or the number of film frames preset by a known means is compared with the number of frames currently photographed to determine whether or not there are remaining film frames. To do. As a result, if there are remaining frames, the process proceeds to step 111, and if there are no remaining frames, the process proceeds to step 115. "Step 111" The film feeding motor 51 is driven through the film feeding motor driver circuit 103 to start winding one frame of the next frame.

In this case, the film feeding motor 51 uses the energizing motor determined in step 102 or step 103.
It is designed to be driven by a car. [Step 112] During the winding of the next frame of the film 2, the magnetic head 4 is driven through the magnetic head drive circuit 104, and the photographing information, for example, the shutter speed and the aperture value is transferred to the magnetic track T corresponding to the photographing frame of the film 2. , Write information such as the date of shooting, or magnetic reproduction circuit 10
The information written on the film 2 is read by driving the magnetic head 4. [Step 113] It is determined whether or not the winding of the next frame of the film 2 is completed. If completed, the process proceeds to step 114, and if not completed, the process returns to step 111. [Step 114] The film feeding motor 51 is stopped through the film feeding motor driver circuit 103 to stop the winding of the film 2, and then the step 1
Return to 08.

If it is determined in step 110 that there is no remaining frame of the film 2, the process proceeds to step 115 as described above. [Step 115] The film feeding motor 51 is driven in the film rewinding direction through the film feeding motor driver circuit 103 to start rewinding the film 2 to the film cartridge 1. At this time, since the magnetic head 4 is not writing or reading information, the drive mode of the film feeding motor 51 is "full energization mode".
Or "pulse energization mode". [Step 116] It is determined whether or not the rewinding of the film 2 into the film cartridge 1 is completed, and if completed, the process proceeds to step 117. If not completed, the process returns to step 115. "Step 117" A series of operations of the camera is ended.

FIG. 9 is a circuit block diagram of a camera according to the second embodiment of the present invention, and the same parts as those in the first embodiment are designated by the same reference numerals.

In this embodiment, the voltages for driving the film feeding motor 51 are "E1, E2 (E1 <E
2) ”, and the film type determination switch 6 is O
In the case of N, that is, when the film 2 is a negative film, "E
The film feeding motor 51 is driven by the voltage "1", and when the film type discrimination switch 6 is not turned on, that is, when the film 2 is a reversal film, the voltage "E2" is used for the film feeding motor. Drive 51, film 2
It tries to change the feeding speed of.

In FIG. 9, reference numeral 109 is a DC / DC converter, and assuming that the voltage of the power supply 110 is E, the above "E
Two types of voltage, "1" and "E2" are generated (however, E1 <E
2) In accordance with a control signal from the control circuit 101, the voltage "E1" or "E2" is supplied to the film feeding motor driver circuit 103 to drive the film feeding motor 51. ..

The control circuit 101 reads the information from the magnetic track T of the film 2 by the magnetic head 4, and when the film 2 is a reversal film, the DC /
Instructing the DC converter 109 to supply the voltage "E2" to the film feeding motor driver circuit 103,
If film 2 is a negative film, "E2"
Instruct to supply the voltage. Therefore, as a result, the level of the signal when the output from the magnetic head 4 is input to the signal amplifier 108a becomes the same.

FIG. 10 is a circuit block diagram showing a third embodiment of the present invention, in which the same parts as those in the first and second embodiments are designated by the same reference numerals.

In this embodiment, it is assumed that the user inputs the identification of the type of the film 2 manually, and in FIG. 10, 7 is the film type setting operation switch, which is well known. It consists of a contact piece and a pattern substrate. When the user operates the film 2 to be a negative film, the film type setting switch 7 is turned on, and when the user operates the film to be a reversal film, the film type is changed. The setting switch 7 is supposed to be turned off.

Next, the control circuit 101 in this configuration.
The operation will be described with reference to the flowchart of FIG. Note that FIG. 11 shows a portion different from FIG.

When the power switch of the camera is turned on, the operation from step 99 is started. [Step 99] It is determined whether or not the film type setting switch 7 is operated by the user, and the process proceeds to step 99 by determining that the operation has been performed. "Step 100" Cartridge loading switch 106
And the back cover switch 107 are both turned on, and if both are turned on, it is determined that the film cartridge 1 is loaded in the camera, and the process proceeds to step 101. [Step 101-1] It is determined whether or not the film type setting switch 7 shown in FIG. 10 is turned on. If it is turned on, the film 2 loaded at this time is a negative film. Go to. When the film type determination switch 7 is OFF, the loaded film 2 is a reversal film,
Go to step 103. "Step 102" The film feeding motor 51 is set to be driven by the "pulse energizing mode" through the film feeding motor driver circuit 103. In this case, the film feeding speed becomes slow. "Step 103" The film feeding motor 51 is set to be driven in the "full energization mode" via the film feeding motor driver circuit 103. In this case, the film feeding speed becomes faster than that of the negative film. [Step 104] An operation of driving the film feeding motor driver circuit 103 to locate the first frame of the film 2 to the aperture position by the film feeding motor 51.
That is, the film idling operation is started. At this time, the film feeding motor 51 is operated in the step 1 depending on the type of the film 2.
It is driven by the energization mode set in 02 or step 103.

After that, the same operation as that after step 105 in FIG. 8 is performed.

According to each of the above embodiments, the type of the film 2 is discriminated and the film feeding speed is changed based on the discrimination, so that the level of the signal reproduced by the magnetic head 4 is a negative film. Even if there is a reversal film, the reversal film also becomes constant, so that the amplification factor of the signal amplifier 108a in the magnetic reproduction circuit 108 should be kept constant, and a complicated circuit is always used for accurate reproduction of information. This has the effect of eliminating the need to change the amplification factor.

[0051]

As described above, according to the present invention,
A discriminating means for discriminating the type of film and a feeding speed varying means for varying the film feeding speed by the film feeding means according to the type of the film discriminated by the discriminating means are provided, and the discriminating means makes the discrimination. The film feeding speed by the film feeding means is changed according to the type of film,
The level of the signal reproduced by the magnetic head during film feeding is kept constant. Therefore, it is possible to always reproduce accurate information regardless of the type of film without using a complicated circuit configuration.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a gear train of the film feeding mechanism of FIG.

FIG. 3 is a plan view showing an arrangement of gears at the time of film winding of the film feeding mechanism of FIG.

FIG. 4 is a plan view showing an arrangement of gears at the time of film rewinding of the film feeding mechanism of FIG.

FIG. 5 is a circuit block diagram of the camera of the first embodiment of the present invention.

FIG. 6 is a diagram showing an example of an energization mode for the film feeding motor according to the first embodiment of the present invention.

FIG. 7 is a diagram showing another example of the energization mode for the film feeding motor in the first embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the control circuit of FIG.

FIG. 9 is a circuit block diagram of a camera according to a second embodiment of the present invention.

FIG. 10 is a circuit block diagram of a camera according to a third embodiment of the present invention.

11 is a flowchart showing a main part of the operation of the control circuit of FIG.

[Explanation of sign]

 4 Magnetic Head 6 Film Type Discriminating Switch 7 Film Type Setting Switch 51 Film Feeding Motor 101 Control Circuit 103 Film Feeding Motor Driver Circuit 104 Magnetic Head Driving Circuit 108 Magnetic Reproducing Circuit 108a Signal Amplifier 108b A / D Converter

Claims (1)

[Claims] 1. A magnetic head for reproducing information written in a magnetic storage unit provided in a film during film feeding, an amplifier circuit for amplifying an analog signal reproduced by the magnetic head, and Discrimination for discriminating the type of film in a camera using a film with a magnetic storage unit, which is equipped with an A / D conversion circuit for converting an analog signal from an amplifier circuit into a digital signal and a film feeding means for feeding the film. A film with a magnetic storage section is provided, which is provided with a means and a feeding speed varying means for varying the film feeding speed of the film feeding means according to the type of film judged by the judging means. camera.