JPH09269541A - Camera and film use controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of troubles such as double exposure etc., by deciding a noise state and changing the control operation of a control means. SOLUTION: The output of a comparator 27 in a magnetic reproduction circuit 36 is taken into through the terminal CMPIN of a control circuit 19, and the variation number of pulses of the terminal CMPIN is counted for a specified time. The output of the comparator 27 is repeatedly inverted from low to high, or from high to low in accordance with the noise whose level exceeds a reference one, and the number of inversion times is counted. Besides, when the noise amount is large, the power source of the magnetic reproduction circuit 36 is turned off. By setting a terminal RON low, a semiconductor SW 37 is turned off, and then, the power supply to the magnetic reproduction circuit 36 is stopped. A data disk is set at a halfway exposure position again. An alarm display is given by a display circuit. Besides, an alarm is given by buzzing by a buzzer circuit for a prescribed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a device such as a camera which can automatically reuse a film of a partially used film cartridge from an unused frame position.

[0002]

2. Description of the Related Art Conventionally, a camera capable of magnetic recording on a film has been known. Also, on the cartridge of this film, there is provided an index indicating the exposure state of the film in the cartridge, that is, whether the film is unexposed film, fully exposed film, or partially exposed film. By using the information from the index and the magnetic recording information on the film recorded for the exposed film, when the film cartridge that has been exposed halfway is loaded into the camera, it will reach the top position of the unexposed frame. A camera that performs automatic winding has been proposed.

[0003]

In the above conventional example,
The cue of the leading position of the unexposed frame is performed by magnetically reproducing the magnetic recording information written on the film and determining whether the frame is an unexposed frame or an exposed frame. Since the density of the magnetic layer on the film is thin, the magnetic reproducing circuit reproduces the signal with a circuit having a large amplification degree and discriminates the signal.

In the case of such a magnetic reproduction method, the influence of magnetic noise coming into the camera from the surroundings cannot be ignored, and when the magnetic head picks up the noise during magnetic reproduction, it is written on the film itself. It is difficult to distinguish it from a magnetic signal, and it may be erroneously determined whether it is an unexposed frame or an exposed frame. Therefore, there is a possibility that an accident may occur in which the frame is exposed again although it has already been exposed once.

A first object of the present invention is to provide a camera or a cartridge use control device for preventing an accident such as double exposure because an unused frame position of a film cannot be accurately determined due to noise. It is what

A second object of the present invention is to provide, in addition to the first object, a camera or a cartridge use control device which enables the above determination to be appropriately performed according to the type of film. .

A third object of the present invention is to provide a camera or a power supply device in which power is not wasted.

[0008]

In order to achieve the above first object, the present invention provides a first judging means for judging the position of an unused frame of a film, and a judgment result of the first judging means. The control means for controlling the film so that it can be used from the unused frame position, the second determination means for determining the state of noise acting on the first determination means, and the second determination A camera or a cartridge use control device having a changing unit for changing the control operation of the control unit according to the determination result of the unit.

In order to achieve the above-mentioned second object, the present invention uses a film as a judgment criterion of the second judging means for judging whether or not the noise acting on the first judging means is within an allowable range. It is a camera or a cartridge use control device that is changed according to the type.

In order to achieve the third object, the present invention comprises a magnetic information reading circuit for reading magnetic information on a film, and a judging means for judging the state of noise acting on the magnetic information reading circuit. A switch means for stopping the supply of power to the magnetic information reading circuit when the first judging means determines that the noise acting on the magnetic information reading circuit is not within an allowable range. Alternatively, it is a power supply device.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an internal structure of a main part of a camera according to an embodiment of the present invention.

In FIG. 1, 1 is a taking lens, 2 is a lens actuator for driving the taking lens, and a lens encoder for generating a position signal, 3 is a lens shutter, 4 is a photometric sensor for AE, and 5 is a photometric sensor 4. A lens for determining the light receiving angle, 6 is a block including a distance measuring sensor 6a and a finder, which will be described later, and 7 is a signal and information for detecting one frame of the film F which detects perforations P1 and P2 of the film, which will be described later. A photoreflector for generating a signal of the end timing, 8 is a film feeding motor arranged in a spool, 9 is a gear train for performing deceleration and switching between winding and rewinding, and 10 is a rewinding fork.

C is a film cartridge containing a film F, F is the above-mentioned film having a magnetic recording portion (magnetic track T) on the base side, and P1 and P2 are the perforations corresponding to the photographing screen A. , H are magnetic heads for writing information to or reading information from the magnetic tracks T on the film F. Reference numeral 11 denotes a pad for pressing the film F against the magnetic head H. The pad 11 has a concave portion at the center for improving the adhesion of the head gap between the film F and the magnetic head. Reference numeral 12 is a pad advance / retreat control mechanism that presses the pad 11 against the magnetic head H with the film F sandwiched by a predetermined pressure only when the film is fed, 16 is a release button, and 17 is photometric according to the first stroke of the release button 16. , Switch (SW1) for starting distance measurement, 18
Is a switch (SW2) for starting a shutter release and film feeding sequence in accordance with the second stroke of the release button 16.

FIG. 2 is a circuit block diagram of the main part of the camera.

In FIG. 2, reference numeral 19 denotes a control circuit for controlling various operations of the camera. In the camera, 20 is a well-known clock circuit, which is usually composed of a one-chip microcomputer. A RAM for recording shooting information such as shutter speed, 23 is a read / write circuit shown in FIG. 4, and 22 is a motor driver for driving the film feeding motor 8. 30 is a switch for determining that the cartridge C has been loaded in the camera, 31 is a rewind start switch, 32 is a display circuit composed of an LCD or the like,
Reference numeral 33 is a buzzer circuit, and 34 is data of a data disk 35 (information such as film type ISO is shown in a bar code data format on the data disk 35) attached to the lower surface of the film cartridge. The DD detection circuit is, specifically, a circuit that reads out the black-and-white light and dark pattern on the disk by a photo reflector in accordance with the rotation of the data disk 35. Further, by determining the stop position of the data on the data disk 35, the film F in the cartridge C is
However, it is possible to know whether it is an unexposed film, a fully exposed film, an intermediately exposed film, or a developed film.

Next, an example of concrete display contents of the display circuit 32 is shown in FIG. FIG. 11A shows a state in which all the LCD segments are lit, including the ISO display segment ISOSG, the shutter time segment display TUDS,
A segment AVDS of an aperture value display, a segment FRCDS of a frame counter display, a segment BTSG indicating a battery state, an FLSG indicating a cartridge state,
It is composed of a segment group EXDS for displaying the level of exposure correction.

FIG. 3 is a diagram showing the relationship among the film F, the photo reflector 17 and the magnetic head H.
FIG. 3 is a view of the film F as viewed from the opposite side of the taking lens 1.

In FIG. 3, Aa is a shooting screen for which shooting has already been performed, Ab is a shooting screen for which shooting is to be performed at the aperture position, and Ac is a shooting screen for shooting subsequent to the shooting screen Ab. T is a magnetic recording layer provided on the film F as described above. Sa is an area where the magnetic head H has written the shooting information such as shutter time and the shooting date when the imaged screen Aa is wound up, and Sb is an area where the magnetic head H will write the information. X is an arrow indicating the winding direction of the film F.

FIG. 4 shows the write / read circuit 23 of FIG.
It is a figure which shows the detail of. In FIG. 4, reference numeral 36 denotes a read circuit, that is, a block of a reproduction circuit. 24 is a differential amplifier, 25 is an amplifier, 26 is a film circuit, 27 is a Schmitt comparator, 28 is a constant current circuit for writing,
Reference numeral 37 is a semiconductor switch for controlling the power supply.

Here, the magnetic reproduction signal from the magnetic head H is obtained by the differential amplifier 24 as an output of the difference between its inputs, and is greatly amplified by the amplifier 25. Then, by passing through the filter circuit 25, the band is limited (in this case, fc in the figure corresponds to the cutoff frequency), and the signal-to-noise ratio is improved.

Next, the Schmitt is input to the comparator 27, which outputs "H" when it becomes higher than a predetermined level and outputs "L" when it is lower than the predetermined level, which is input to the control circuit 19.

Explaining this with reference to FIG. 5, the reproduction waveform of the magnetic circuit accompanying the movement of the film is as the output of the filter 26 with respect to a certain reference level as shown in FIG.
A pulse-like change is made to the High side. When this output enters the comparator, it has a pulse waveform as shown in FIG. This is input to the control circuit 19, and the time until the next High edge is measured based on the Low active edge, and converted into a digital signal according to the magnitude of the time. In FIG. 5, it is determined to be 0.1.1. In other words, this is equivalent to determining the phase of the pulse waveform.

By converting into a digital signal in this manner, the magnetically recorded data of the film, for example, the exposure value, the shutter speed or aperture value, the photographing date, the hour and minute, etc. can be discriminated.

The above waveform example of FIG. 5 is an example when the film is driven and the exogenous noise level is small, but when the noise level becomes large (assuming that the film is not moving at this time), , The waveform is as shown in FIG. As shown in FIG. 6, when the waveform of the noise level becomes large, the output of the comparator 27 changes without permission because the film originally does not move, so there should be no signal (that is, no signal change). Become. That is, the signal changes each time the noise level exceeds the High level and Low level of the comparator 27.

Next, the overall operation of the above configuration will be described with reference to the flow chart of the control circuit 19 shown in FIG.

First, step (hereinafter abbreviated as "S") 1
Then, it is determined whether or not the cartridge C is loaded in the camera by the switch 30, and if it is loaded, S10
At 2, the data information of the data disk 35 is read. For example, by rotating the film cartridge in a direction opposite to the winding direction, the data of the exposure state of the film (unexposed, full exposure, halfway exposed, developed) is determined based on the position of the starting point of the data. Read,
The film type (negative, positive) data and the ISO sensitivity of the film are read.

In step S103, it is determined whether the film type is negative or positive in the information of the data disc used in this routine.

In step S104, it is determined from the exposure state data of the film in step S102 whether or not the intermediate exposure film is loaded. If the intermediate exposure film is loaded, the power source of the magnetic reproducing circuit 36 is turned on in step S105. Turn on. The semiconductor switch 37 is turned on by supplying a high output from the RON terminal of the control circuit 19 to the semiconductor switch 37 shown in FIG. 4, thereby supplying power to the magnetic reproducing circuit 36.

Next, in S106, it is determined whether or not the static noise amount of the magnetic reproducing circuit is large. This is made into a subroutine, and is specifically expressed by the flowchart of FIG.

In FIG. 8, S201, first, the output of the comparator 27 in the magnetic reproducing circuit 36 of FIG.
Captured at the CMP IN terminal of
Count the number of pulse changes at the IN terminal. FIG. 6 shows an example of the waveform at this time. In FIG. 6, when Ta indicates a predetermined time and the noise amount is large, the output of the filter 26 in the magnetic reproducing circuit 36 is V _COMPH, V _COMPL Hi as shown in FIG.
Occasionally, noise that exceeds the standard level of gh and Low comes in. In response to noise that exceeds this reference level, the output of the comparator 27 is Low → High, High →
The inversion of Low is repeated and the number of times of this inversion is counted. In FIG. 6, ten inversions are observed during this Ta period. In addition, this inversion cycle is irregular because it may be caused by noise.

Next, in S202, if the film is a negative film based on the negative and positive information determined in S103 of FIG.
At 203, the previous count number is compared with the predetermined value A. If it is larger than the predetermined value A, the process proceeds to S204, and the amount of noise is larger than the allowable amount of noise, that is, the amount of noise is so large that it cannot be guaranteed that the position of the unexposed frame is accurately determined by reading the magnetic information of the film (hereinafter, This is abbreviated as a large noise amount), and if it is smaller than the predetermined value A, the process proceeds to S206, and it is smaller than the allowable noise amount, that is, the magnetic information of the film is read, and the position of the unexposed frame is accurately determined. It is determined that the noise amount is a small amount (hereinafter, this is abbreviated as a small noise amount).

When there is usually no noise, the count number is substantially equal to φ, and the determination of the small noise amount in S206 is made.

If it is a positive film in S202,
In S205, the count number is compared with the predetermined value B.

When it is larger than the predetermined value B, the process proceeds to S204, and it is determined that the noise amount is large, and when it is smaller than the predetermined value B, S20.
It proceeds to 6 and determines that the noise amount is small.

The predetermined values A and B usually have a relation of A> B. Because the density of the magnetic layer of the film can be higher in the negative film than in the positive film, the magnetic output is higher in the negative film during reproduction, so even if the noise level is a little higher, the magnetic data signal Is highly likely to be read accurately. Conversely, for a positive film, this means that the allowable amount of noise becomes smaller.

After the noise amount magnitude determination routine of FIG.
If the amount of noise is large at 106, the magnetic reproducing circuit 36 is powered off at S107. Contrary to S105, the RON terminal in FIG. 4 is set to Low to turn off the semiconductor SW 37 and stop the power supply to the magnetic reproducing circuit 36. Then, in S108, the data disk 35
To the halfway exposure position.

This means that the motor 8 is rotated in the same direction as the reading direction of the data disk 35, that is, in the direction opposite to the winding (rewinding direction), and the relationship between the data stop position and the reference position indicates intermediate exposure. It is done by controlling the position.

Then, in S109, the display circuit 32 displays a warning. An example of this display is shown in FIG. FIG.
In 1 (C), the LCD TV segment TVDS and a noise-like display are displayed as shown in the figure, and the cartridge mark FL
A warning is given by blinking SG. In addition, the display FRCDS of the film counter is a “−−” mark.

Further, in S109, the buzzer circuit 33
Then, a buzzer sounds for a predetermined time to give a warning.

In S110, it is determined whether the cartridge C has been taken out from the camera by the photographer by the switch 30, and if it is taken out, the process returns to S101.

On the other hand, if it is determined in S106 that the amount of noise is not large, the magnetic reproducing circuit 36 reproduces the magnetic data written in each frame of the film in S111 while the exposed frame and unexposed frame are being reproduced. The film is wound up to the leading position of the unexposed frame.

As a method of discriminating the magnetic data of the exposed and unexposed frames, since the exposed frame has data such as shutter speed at the time of photographing, aperture value, photographing date and time, the output of the comparator 27 as shown in FIG. Changes according to certain rules. Further, since this kind of data has not been written in the unexposed frame, the output of the filter 26 continues to remain at a constant φ level, so that the comparator 27 does not change at all.

From the state of this pulse change, it is possible to discriminate between exposed and unexposed. In addition, as a display, FIG.
The same display as the display is performed, but the number of wound frames is displayed only for the frame counter number.

Next, in S112, the magnetic reproducing circuit 36 is powered off. This is performed similarly to S107. Then, it goes to the routine of S115 for photographing.

On the other hand, if it is determined in S104 that the film is not an intermediately exposed film, it is determined in S113 whether or not the film is an unexposed film. If it is determined in S113 that the film is not the entire unexposed film, that is, it is the fully exposed film or the developed film. Therefore, in S123, the data disk 35 is reset. This is achieved by performing stop control at the positions corresponding to the reference position of the data disk 35, that is, all exposed and developed, as in S108.

Then, in S110, the process waits until the cartridge is taken out.

On the other hand, if the film is all unexposed film in S113, the film is wound up to the first frame in S114 to prepare for photographing, and the display circuit 32 displays FIG. 11 (B). At this time, the display of the shutter speed and the aperture value indicate values set according to the exposure mode of the camera and the like. In addition, the frame counter displays "1".

Next, in S115, SW1 is determined,
If SW1 is pressed, the photometric sensor 4 performs photometry at S116 to determine the shutter speed and the aperture value, which are exposure control parameters, and the range sensor 6
The distance is measured by a, the subject distance is calculated, and the focus is adjusted by driving the lens to the lens focus position by the actuator and the lens encoder 2.

If SW2 is turned on in S117, exposure control is performed in S118. This is the previous S11
When the shutter speed obtained in 6 is reached, the lens shutter 3 is controlled based on the aperture value. After this exposure control, the motor driver 22 winds up one frame of the film F in S119, and the magnetic data is recorded on the film F by the magnetic head H in accordance with the movement of the film accompanying the winding operation. This is performed through the constant current circuit 28. At this time, the pad 11 and the pad moving mechanism 12 shown in FIG.
The control is performed so that the magnetic head H, the film F, and the pad 11 are in a good contact state. The write magnetic data includes a shutter speed and an aperture value at the time of photographing, a photographing date, a time and a minute.

After the winding operation is completed, it is determined in S120 whether there are any remaining frames. If there are no remaining frames, S121
, The film is rewound by the motor driver 22.

After this rewinding operation is completed, the position of the data disk 35 is set to the position where all exposure is completed in S122. Then, in S110, the process waits until the cartridge C is taken out from the camera.

If there are remaining frames in S120, S11
Then, the procedure returns to 5 to move to the next shooting sequence.

On the other hand, if SW2 is not turned on in S117, the process also returns to S115 and SW1 is set in S115.
If is not turned on, it is determined in S124 whether or not the rewind switch 31 is turned on. If it is turned on, the motor driver 22 rewinds the film F in S125. In S126, since the film is rewound during the use of the film, the data disk 35 is set at the mid-exposure position. Then, the process proceeds to S110.

Next, a second embodiment of the present invention will be described. The present embodiment shows another example of the large noise amount determination routine of S106 of the above embodiment.

FIG. 9 is a flowchart showing this modified example. In FIG. 9, in step S301, the FIN P for a predetermined time is set.
-P value calculation is performed. This is the filter circuit 2b in FIG.
Is output to the control circuit 19 as an analog input FIN, the analog output is A / D converted, the number of samples of the A / D data is input during a predetermined time, and the A / D converted value P-P value (peak-to-
peak), that is, (MAX-MIN) is calculated.

Then, in S303 and S304, the predetermined amount P
A and PB values are compared according to negative and positive. When it is larger than the predetermined amount, it is determined that the noise amount is large in S304, and when it is smaller, it is determined that the noise amount is small in S306.

In this example, the P-P value of the analog value is calculated. However, as in the case of FIG. 8, when the noise becomes large, the P-P value also becomes large, and when the film is negative or positive, it is also the same. The negative film has a larger allowable amount, and its PP value can be increased. That is, PA> PB.

According to this embodiment, an analog FI is used.
By calculating the N, P-P values, higher-precision control can be performed as compared with the embodiment of FIG. 8 in which digital determination is performed.

Next, a third embodiment of the present invention will be described. In this embodiment, the RMS value is adopted as the noise amount determination routine of S106 of the first embodiment.

This routine will be described below with reference to the flowchart of FIG.

At S401, FIN RMS during the predetermined time
As in the case of FIG. 9, the value calculation means that the analog input of the FIN is A / D converted for a predetermined time, and its RMS value (root-me) is calculated.
an-square) is calculated, and the effective value of noise is calculated.

This effective value RMS value is set to a predetermined value RA, RB in S403 and S405 according to the negative or positive of the film.
If it is larger than that value, it is determined that the noise amount is large in S404, and if it is smaller, it is determined that the noise amount is small in S406.

In this case as well, RA> RB as before.

According to the present embodiment, the analog FI
The calculation of N and RMS values is more reliable than the previous PP values. That is, in the PP value, a large PP value may occasionally appear, but the RMS value shows a relatively stable value, and thus more stable control can be performed.

Next, a fourth embodiment of the present invention will be described with reference to the flowchart of FIG.

In each of the above embodiments, the noise amount is discriminated only once, and if the result is that the noise amount is large, the cartridge C is set to the initial state without any further processing. In the embodiment, even if it is determined that the noise amount is large once, the determination is repeated a plurality of times thereafter, and if it is determined that the noise amount is small, the unexposed frame is cueed.

In FIG. 12, the same steps as those in FIG. 7 are designated by the same reference numerals. In FIG. 12, after a warning is displayed once in S109, a predetermined time is waited in S130, and in S131, a large amount of noise is determined again as in the routine of S106. Here, if the amount of noise is large, it is determined in S132 whether or not this determination has been performed a predetermined number of times, and if it has not reached the predetermined number of times, the process returns to S130 and the determination is performed again. If it is determined in S131 that the noise amount is small during the predetermined number of times, the process proceeds to S111, and the winding routine for finding the unexposed frame is performed.

According to the present embodiment, since the noise amount determination is performed a plurality of times, for example, even if the noise is once determined to be large and displayed, the photographer moves to an environment with less noise. By doing so, it is determined again that the noise is small, and the usability is improved.

Next, a fifth embodiment of the present invention will be described with reference to the flowchart of FIG.

In this embodiment, when the noise amount is large, the noise amount can be displayed.

In FIG. 13, the same steps as those in FIG. 12 are designated by the same reference numerals. In FIG. 13, in S109,
The display circuit 32 gives a warning display as shown in FIG. This is the noise amount, the count number obtained in S201 of FIG. 8 or FINP-P obtained in S301 of FIG.
The value or the FINRMS value obtained in S401 of FIG. 10 is normalized based on a predetermined amount, and the level is displayed using the display segment and EXDS.

In addition, in order to update the display even during execution of the noise amount determination routine of a predetermined number of times, the process in FIG.
The warning display 4 is displayed. This updates the level display for the noise amount executed in the routine of S131.

By displaying the amount of noise in this way, the photographer can grasp the current amount of noise, and by moving the place, for example, it is possible to wind up in the middle in an environment with less noise. Therefore, it is very easy to use.

In addition, although the level display is performed as the noise amount display of the present embodiment, it is also possible to use the display segment of the frame counter to display the numerical value.

(Correspondence between the Invention and the Embodiment) In the above embodiment, the magnetic reproducing circuit 36 is used as the first judging means of the present invention or the magnetic information reading circuit, and the motor driver 22 is used.
Is the control means of the present invention, and the control circuit 19 is the second judging means and changing means or the judging means of the present invention, and the display circuit 3
2 and the buzzer circuit 33 correspond to the display means of the present invention, the DD detection circuit 34 corresponds to the third determination means of the present invention, and the semiconductor switch 37 corresponds to the switch means of the present invention.

The above is the correspondence relationship between each configuration of the present invention and each configuration of the embodiment, but the present invention is not limited to the configuration of these embodiments, and the functions shown in the claims, It goes without saying that any structure may be used as long as the functions of the structure of the embodiment can be achieved.

For example, the warning display in S109 of FIG. 7 may be an LCD display or another lamp or LED display.

In the above embodiment, the data reading for determining the noise amount is performed during the routine of S106, but this data and the determination may be executed in advance. For example, it may be inserted between S101 and S102. Of course, the power supply control of the magnetic reproducing circuit 36 can be included here.

In the fourth embodiment, the noise amount determination is repeated a predetermined number of times until it is determined that the "noise amount is small". The present invention can be applied even if the noise amount determination is repeated a predetermined number of times regardless of whether or not the determination result is comprehensively determined to give the final result of the noise amount determination.

Further, in the above embodiment, when the "noise amount is large" is discriminated, the winding to the unexposed frame position is not carried out. Is prohibited, or the film is rolled up to the unexposed frame position, but a warning is issued not to guarantee that it is really the unexposed frame position. The present invention can be applied to any type of control that changes the control according to "amount of noise", such as setting a circuit for determining the position of the exposure frame to a state in which it can cope with noise.

The present invention is not limited to the case where a partially used film can be reused from the position of an unexposed frame, but the first frame can be discriminated even for a film that has not been used at all. It can be widely applied as long as it can determine the position of the film.

The present invention can also be applied to a method of recording or reading information on a film by a method other than magnetic such as optical.

The present invention can also be applied to image recording media other than films.

The present invention can also be applied to a cartridge of a type other than the cartridge described in the above-mentioned embodiments and a cartridge having an image recording medium other than a film.

Further, in the present invention, the one-frame feeding of the film can be applied whether it is by winding or rewinding (so-called prewind type).

Further, the present invention may be made by combining the above-described embodiments and modified examples or their technical elements as needed.

The present invention also relates to various types of cameras such as single-lens reflex cameras, lens shutter cameras, video cameras,
Further, the present invention can be applied to optical devices and other devices other than cameras, devices applied to the cameras, optical devices, and other devices, or elements constituting these devices.

[0089]

As described above, according to the present invention,
The present invention can be provided by a camera or a cartridge use control device that prevents an accident such as double exposure from occurring because the unused frame position of the film cannot be accurately determined by noise.

Further, according to the present invention, it is possible to provide a camera or a cartridge use control device which enables the above determination to be appropriately performed according to the type of film.

Further, according to the present invention, it is possible to provide a camera or a power supply device that prevents power from being wasted.

[Brief description of drawings]

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

FIG. 2 is a circuit block diagram of a main part of the camera shown in FIG.

FIG. 3 is a layout diagram showing a positional relationship between a photo reflector and a magnetic head with respect to a film of the camera of FIG.

FIG. 4 is a detailed diagram of the write / read circuit 23 of FIG.

5 is a signal waveform diagram of the circuit of FIG.

6 is a signal waveform diagram when the circuit of FIG. 4 has a large amount of noise.

7 is a flowchart of a control circuit 19 shown in FIG.

8 is a flowchart of the noise amount determination step of FIG.

FIG. 9 is a flowchart showing another example of the noise amount determination step of FIG. 7 according to the second embodiment of the present invention.

FIG. 10 is a flowchart showing yet another example of the noise amount determination step of FIG. 7 according to the third embodiment of the present invention.

11 is a diagram showing a display example of the display circuit 32 of FIG.

FIG. 12 is a flowchart showing a modification of the flowchart of FIG. 2 according to the fourth embodiment of the present invention.

FIG. 13 is a flowchart showing a modification of the flowchart of FIG. 12 according to the fifth embodiment of the present invention.

FIG. 14 is a diagram showing a display example of the display circuit 32 of FIG. 2 according to the fifth embodiment of the present invention.

[Explanation of symbols]

 C film cartridge H magnetic head DD data disk 19 control circuit 22 motor driver 23 read / write circuit 32 display circuit 33 buzzer circuit 34 DD detection circuit 36 magnetic reproduction circuit 37 semiconductor switch

Claims (26)

[Claims] 1. A first judging means for judging the position of an unused frame of a film, and a control for controlling the film so that the film can be used from the unused frame position according to the judgment result of the first judging means. Means, second determining means for determining the state of noise acting on the first determining means, and for changing the control operation of the control means according to the determination result of the second determining means. A camera having a changing unit. 2. The camera according to claim 1, wherein the first determination means has a magnetic information reading means for determining magnetic information on the film. 3. The camera according to claim 1, wherein the first determination means has a magnetic head for determining magnetic information on the film. 4. The control means has a film feeding means for feeding the film to an unused frame position according to the judgment result of the first judging means. Camera. 5. The second determining means determines the state of the noise based on the number of times the noise is equal to or more than a predetermined value used for the first determining means within a predetermined time. The camera according to any one of 5 above. 6. The second judging means has a converting means for converting the noise acting on the first judging means to a predetermined value or more into a pulse, and the number of pulses pulse-converted by the converting means within a predetermined time. The camera according to claim 1, wherein the state of the noise is determined by the method. 7. The method according to claim 1, wherein the second determination unit determines the state of the noise based on a peak value of noise that acts on the first determination unit. camera. 8. The method according to claim 1, wherein the second determination unit determines the state of the noise based on an execution value of the noise that acts on the first determination unit. camera. 9. The method according to claim 1, wherein the second determination means determines whether or not the noise acting on the first determination means is within an allowable range. The camera described in. 10. The second determining means changes the criterion for determining whether or not the noise acting on the first determining means is within an allowable range according to the type of film. The camera according to claim 9. 11. The second judging means determines whether the noise acting on the first judging means is within an allowable range according to whether the film is a negative film or a positive film. The camera according to claim 9, wherein the camera is changed. 12. The second determination means determines the determination result by determining a predetermined number of times whether or not the noise acting on the first determination means is within an allowable range. The camera according to any one of claims 1 to 11, which is characterized. 13. The first determining means repeatedly determines whether or not the noise acting on the first determining means is within an allowable range.
11. The camera according to any one of 11. 14. The second judging means judges whether or not the noise acting on the first judging means is in an allowable range, and if the noise is in an unacceptable range, the second judging means again determines. The camera according to any one of claims 1 to 11, wherein it is determined whether or not the noise acting on the first determination means is within an allowable range. 15. The second determining means determines whether or not the noise acting on the first determining means is in an allowable range, and determines that the noise is in an unacceptable range. 12. The method according to claim 1, wherein it is determined whether or not the noise acting on the first determination means is within a tolerable range a predetermined number of times until it is determined to be within an acceptable range. The camera described in. 16. The second determination means determines whether or not the noise acting on the first determination means is within a range acceptable for the first determination means. Item 9. The camera according to any one of Items 1 to 8. 17. The changing means feeds the film between unused frame positions in response to the second judging means judging that the noise acting on the first judging means is not within an allowable range. The camera according to claim 1, wherein the operation of the control unit is restricted. 18. The camera according to claim 1, further comprising a display unit that displays according to the determination result of the second determination unit. 19. The camera according to claim 1, further comprising a display unit that displays a noise amount according to the determination result of the second determination unit. 20. A third determination means for determining whether or not the film is partially used, based on an index of the cartridge, wherein the third determination means determines that the film is partially used. 20. The camera according to claim 1, wherein the changing unit operates according to a result. 21. The first determination means responds to a determination result of the second determination means.
The camera according to any one of 20. 22. The first determining means stops the operation in response to the second determining means determining that the noise acting on the first determining means is not within an allowable range. The camera according to any one of claims 1 to 20, which is characterized. 23. The power supply to the first judging means is stopped in response to the second judging means judging that the noise acting on the first judging means is not within an allowable range. 21. The camera according to claim 1, further comprising a switch means. 24. A magnetic information reading circuit for reading magnetic information of a film, a judging means for judging a state of noise acting on the magnetic information reading circuit, and the first judging means for reading the magnetic information. And a switch means for stopping the supply of power to the magnetic information reading circuit when it is determined that the noise acting on the circuit is not within an allowable range. 25. First judging means for judging the unused frame position of the film, and control for controlling the film so that the film can be used from the unused frame position according to the judgment result of the first judging means. Means, second determining means for determining the state of noise acting on the first determining means, and for changing the control operation of the control means according to the determination result of the second determining means. A film use control device comprising: a changing unit. 26. A magnetic information reading circuit for reading magnetic information of a film, a judging means for judging a state of noise acting on the magnetic information reading circuit, and the first judging means for reading the magnetic information. And a switch means for stopping the supply of power to the magnetic information reading circuit when it is determined that the noise acting on the circuit is not within an allowable range.