JPH0572611A - Camera using film with magnetic storage part - Google Patents

Abstract

PURPOSE:To accurately reproduce information from the 1st frame to the last frame of a film. CONSTITUTION:Frame number discriminating means 101 and 109 for discriminating whether or not the number of photographic frames of the film attains a specified number, and revolving speed varying means 101 and 103 for varying the revolving speed of a motor 51 for feeding the film in accordance with the discrimination by the means 101 and 109 are provided, and the revolving speed of the motor for feeding the film is varied according to whether or not the number of the photographic frames of the film attains the specified number, so that a film feeding speed is made constant without depending on the number of the photographic frames.

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 in a camera using a film with a magnetic storage unit, which is provided with a film feeding motor 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, a film winding spur of a camera
As the film is wound around the film, the diameter of the film winding spool gradually increases, and the film feeding speed increases. That is, the film feeding speed is different between the first frame and the last frame.

[0004]

When information is read by the magnetic head during film feeding, the magnitude of the signal level detected by the magnetic head is proportional to the film feeding speed. In other words, the film feeding speed of the first frame is relatively slow,
The level of the signal detected by the magnetic head is low, and the film feeding speed becomes higher toward the final frame, so that the signal level detected by the magnetic head becomes higher. Therefore, if the amplification circuit that amplifies the analog signal detected by the magnetic head is set to an amplification level suitable for the last frame of the film, the detection signal level at the time of reproduction at the first frame of the film is low, and the digital conversion is performed. There is a risk that a signal that does not reach the level is generated, resulting in an information reading error. Further, when the amplification level of the amplifier for amplifying the analog signal is set to the amplification level suitable for the first frame, and when the information is reproduced from the magnetic memory section of the last frame, the amplitude level becomes too large, so that the amplification circuit described above. Of the original signal, a waveform different from the original signal is output from the amplifier.

In view of the above points, an object of the present invention is to provide a camera using a film with a magnetic memory unit capable of reproducing information accurately from the first frame to the last frame of the film. is there.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a frame number discriminating means for discriminating whether or not the number of photographed frames of a film has reached a predetermined frame number, and film feeding according to the discrimination of the frame number discriminating means. Rotational speed varying means for varying the rotational speed of the motor is provided.

[0007]

The rotating speed changing means changes the rotating speed of the film feeding motor according to whether or not the number of filmed frames has reached a predetermined number, and the film feeding speed becomes the number of filmed frames. I try to keep it constant.

[0008]

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 having 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 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 the film 2 having one end fixed to the supply spool and wound around the supply spool, and the film 2 which is arranged coaxially with the supply spool and spreads 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 inside 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 when the film is wound (in the direction of arrow B in FIG. 3), and is reversely rotated (in the 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 that is constantly meshed with the first sun gear 53, 59 is a large gear portion 59a and a small gear portion 59b, and a large gear portion 59a is a first idle gear that 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 normally rotated.
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 denotes a stopper provided on a 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”.

As the film 2 is extruded from the film cartridge 1 by the clockwise rotation of the fork 70, the leading 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 in the clockwise direction, 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.

Reference numeral 109 is a counting circuit for counting the number of times the camera is released, 110 is a frame number display for displaying the number of frames to be photographed, such as a liquid crystal display, and 111 is the frame number display 1
It is a display driver circuit for driving 10 to count up or count down.

As shown in FIGS. 6 (a) (b) (c), the control circuit 101 repeats "energization and non-energization" at a predetermined ratio within a very short time, that is, the duty control. Then, the film feeding motor 51 is driven to change the rotation speed of the film feeding motor 51. Needless to say, the rotation speed of the film feeding motor 51 becomes higher as the ratio of the time for energizing becomes longer as shown in FIG. 6 (a) → (b) → (c).

Therefore, in this embodiment, the beginning of the film 2 being wound on the film winding spool 57 of the camera, that is, the first frame, is fed with the film as shown in FIG. 6 (a). The energizing time to the sending motor 51 is made longer than the non-energizing time, and the diameter becomes larger as the film photographing progresses and the amount of the film 2 wound around the film winding spool 57 increases. Therefore, as shown in FIG. 6 (b) → (c), the ratio of the energized time to the non-energized time is gradually reduced.

The diameter of the film winding spool 57 is
D, thickness of film 2 is d, pitch of one frame is L, fill
The film tip is wrapped around the film winding spool 57 once.
If the aperture position is set to the first frame when
Film 2 when winding up to n frames around the take-up spool 57
The total length Fn of the film is Rn = (n-1) L + Dπ, and the total film length Fm up to the mth round is= {(D-2d) m + dm (m + 1)} π, and the number of laps of the nth frameCan be represented by Therefore, the inner winding diameter D of the nth frame
n can be expressed by Dn = D + f (m) × 2 × d (where f (m) is the decimal point of m.
Function to discard). Therefore, as an example of this, D = 10 m
m, d = 0.14 mm, L = 38 mm
Inserting it, the inner winding diameter D1 of the first frame → "10.28 mm" The inner winding diameter D of the 20th frame 20 → "19.13 mm" The inner winding diameter of the 36th frame is D36 → "30.60 mm".

Further, the number of rotations of the film feeding motor 51 is set to be Nn = N1 (D / Dn) when the first frame is "N1".

In the above example, the 20th frame → “0.537 × N1”, the 36th frame → “0.336 × N1”.

As a result, when the winding diameter of the film winding spool 57 of the film 2 is small, the output of the film feeding motor 51 is large, that is, the rotation speed is high and the film winding spool of the film 2 is small. As the winding diameter of the reel 57 increases, the output of the film feeding motor 51 decreases, that is, the number of rotations decreases. As a result, the feeding speed of the film 2 is always constant, and the information reading error occurs. −
Will not occur.

Next, the operation of the control circuit 101 will be described according 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] 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 driven by the duty control as shown in FIG. 6 (a) as described above, and its output, that is, the rotation speed of the film feeding motor 51. Is high. [Step 102] During the idling operation of the film 2, the magnetic head 4 is driven via the magnetic head drive circuit 104, and the film sensitivity and the number of film frames pre-written on the magnetic track T provided in the film 2 are recorded. Read and store film information such as film type (negative or positive). "Step 103" Here, it is known means that the cueing of the first frame has been completed (for example, by detecting the film feed amount by the encoder, motor energization time, detection of perforation P, etc.). When it is determined that the detection has been performed, the process proceeds to step 104. "Step 104" The film feeding motor 51 is stopped via the film feeding motor driver circuit 103,
Stop film winding. [Step 105] The frame number indicator 111 is driven through the frame number indicator driver circuit 110 to display the first frame. "Step 106" The state of the release switch 105 is discriminated. "Step 107" The counting circuit 109 is caused to count the number of releases for the film 2 currently in use. [Step 108] 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 the shutter. "Step 109" The number of film frames read out in step 102 and the number of film frames preset by a known means are compared with the number of frames currently photographed to determine whether there are remaining film frames. To do. As a result, if there are remaining frames, the process proceeds to step 110, and if there are no remaining frames, the process proceeds to step 115. [Step 110] 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 is based on the number of releases stored in the counting circuit 109, that is, the film winding spool 5 as described above.
The duty drive is performed based on the winding diameter of 7.
Therefore, the film is fed at a substantially constant speed regardless of the number of frames photographed. [Step 111] 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.

At this time, since the film feeding speed is constant regardless of the number of frames as described above, when the information is read, as a result, the signal amplifier 1 in the magnetic reproducing circuit 108 is read.
The level of the reproduction signal from the magnetic head 4 input to 08a is the same for both the first and last frames. This means that the amplification factor of the signal amplifier 108a may be kept constant, and the occurrence of read error can be prevented without changing 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 is an A / D converter 1 having a known circuit configuration.
It is converted into a digital signal by 08b, and the control circuit 10
1 captures this signal. [Step 112] 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 113. If not completed, the process returns to step 110. "Step 113" The film feeding motor 51 is stopped via the film feeding motor driver circuit 103 to stop the winding of the film 2, and then the step 1
Proceed to 14. "Step 114" The frame number display driver circuit 110 is instructed to count up the frame number.

If it is determined in step 109 that there are no remaining frames on 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 duty driving of the film feeding motor 51 is as shown in FIG.
It may be any one of (a), (b) and (c). [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. 8 is a circuit block diagram of a camera according to the second embodiment of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals.

In FIG. 8, reference numeral 112 denotes a DC / DC converter, which has voltages E to E1, E2 and E of the power source 113.
For example, four kinds of voltages of 3 and E4 are generated (E1 <E2
<E3 <E4), a voltage for causing the film feeding motor driver circuit 103 to drive the film feeding motor 51 by using any one of the voltages E1, E2, E3, E4 in accordance with an instruction signal from the control circuit 101. Supply as.

The control circuit 101 outputs "E4" from the first frame to the 10th frame, "E3" from the 11th frame to the 20th frame, and the 21st frame from the 21st frame, for example. "E2" until the 30th frame, "E1" after the 31st frame
In this way, the supply voltage is changed depending on the number of frames to be photographed to change the number of rotations of the film feeding motor 51, and as a result, the supply speed of the film 2 is constant regardless of the number of frames.
The signal level when the output of the magnetic head 4 is input to the signal amplifier 108a is the same.

According to each of the above-mentioned embodiments, the number of frames of the film 2 is discriminated (in the embodiment, it is discriminated by the number of releases), and the film feeding motor 51 is set to a different duty based on this.
Since the number of revolutions is made constant by driving or varying the supply voltage depending on the tee ratio, the film feeding speed is made constant even if the winding diameter of the film winding spool 57 changes. The level of the signal reproduced by the magnetic head 4 is constant irrespective of the number of frames, so that a read error can be prevented without changing the amplification factor of the signal amplifier 108a in the magnetic reproduction circuit 108.

(Modification) According to the present embodiment, a counting circuit 109 for counting the number of releases is provided in order to know the number of filmed frames, and the film feeding motor 51 is provided in accordance with the count content. Are driven at different duty ratios or the supply voltage is varied to keep the number of revolutions constant, but the invention is not limited to this. For example, the film winding spool 57 and one contact piece. Are in contact with
When the tenth frame is wound around the film winding spool 57, the contact piece is electrically connected to the other contact piece to be turned on.
And a second switch, etc., which is turned on by connecting one contact piece to the other contact piece by winding the 20th frame around the film winding spool 57, and depending on the state of this switch. The film feeding motor 51 may be driven at different duty ratios or the supply voltage may be varied to keep the rotation speed constant.

[0048]

As described above, according to the present invention,
A frame number discriminating means for discriminating whether or not the number of photographed frames of the film has reached a predetermined frame number, and a rotational speed variable for varying the rotational speed of the film feeding motor according to the discrimination by the frame number discriminating means. A means is provided to change the rotation speed of the film feeding motor according to whether or not the number of filmed frames has reached a predetermined number, so that the film feeding speed becomes constant regardless of the number of filmed frames. I am trying. Therefore, it is possible to accurately reproduce information from the first frame to the last frame of the film.

[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 duty control of the film feeding motor in the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the control circuit of FIG.

FIG. 8 is a circuit block diagram of a camera according to a second embodiment of the present invention.

[Explanation of sign]

 4 magnetic head 51 film feeding motor 101 control circuit 103 film feeding motor driver circuit 104 magnetic head drive circuit 108 magnetic reproduction circuit 108a signal amplifier 108b A / D converter 109 count circuit

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 In a camera using a film with a magnetic storage unit, which comprises an A / D conversion circuit for converting an analog signal from an amplifier circuit into a digital signal and a film feeding motor for feeding the film, A frame number discriminating means for discriminating whether or not the number of photographed frames has reached a predetermined frame number, and a rotational speed varying means for varying the rotational speed of the film feeding motor according to the discrimination by the frame number discriminating means. A camera using a film with a magnetic storage section, which is provided with.