JPH08328106A - Camera - Google Patents

Abstract

PURPOSE: To prevent the erroneous operation of a camera resulted from the erroneous detection by noise. CONSTITUTION: This camera has a control means 31 for driving regenerating means 10, 37 in the state where a film part having no information recorded thereon passes the positions of the regenerating means 10, 37 and canceling the judgment result for having been exposed or not exposed by a judging means 31 when the information quantity obtained at that time is larger than a predetermined prescribed information quantity, so that a significant influence by noise is judged to cancel the judgment result for exposed or not exposed, when the regenerated information quantity obtained in the regenerating drive of the film part having no information recorded thereon is larger than the prescribed information quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a reproducing means for reproducing information recorded in each frame of a film, and whether or not each frame has been exposed, based on the amount of information reproduced by the reproducing means. The present invention relates to an improvement of a camera provided with a discriminating means for discriminating.

[0002]

2. Description of the Related Art Conventionally, when a film taken halfway is reloaded into a camera, it is detected by a magnetic head whether or not shooting information is recorded in a magnetic recording portion of the film, and whether or not the film has been exposed. Various cameras have been proposed that can detect the position of the unexposed frame and detect the cue of the unexposed frame.

In this type of camera, Japanese Patent Laid-Open No. 5-34
In No. 7174, in order to detect whether it has been exposed,
The reproduction information amount of each frame is compared with a predetermined value, and when the difference is smaller than the predetermined value, it is assumed that the reproduction of the information for judging whether or not the exposure is completed can be properly performed. The playback operation was made to continue.

In the proposed camera, the amount of information recorded in each frame is compared with the amount of information in the previous frame, and when the difference is smaller than a predetermined value, it is determined that the frame has been exposed. It was

[0005]

However, in the conventional example of the above-mentioned Japanese Patent Laid-Open No. 5-347174, the reproduction information amount is compared with a predetermined value as described above, and each frame on the film is exposed. Since it is configured to determine whether or not it is, it is possible to prevent malfunction due to an increase in the amount of information due to quantitative external noise, but when reproducing at the film portion (film leading end) without magnetic recording. When the reproduction signal is output due to noise or when the reproduction signal is output due to sudden noise during reproduction, it is not possible to properly determine whether or not exposure has been performed, and there is a problem such as multiple exposure. Was there.

(Object of the Invention) An object of the present invention is to provide a camera capable of preventing a malfunction of the camera due to an erroneous detection due to noise.

[0007]

In order to achieve the above object, the present invention according to claim 1 drives the reproducing means in a state where a film portion on which no information is recorded passes, and at this time, the reproducing means. If the amount of information obtained by is larger than the predetermined amount of information determined in advance, control means for invalidating the determination result of whether the exposure has been completed by the determination means is provided to reproduce the unrecorded film portion. If the reproduction information amount obtained at the time of performing is larger than the predetermined information amount, it is determined that the influence of noise is large and the determination result of whether or not the exposure is completed is invalidated.

In order to achieve the above object, the present invention according to claim 2 compares whether the difference between the reproduced information amount of the previous frame and the reproduced information amount of the current frame is within a predetermined range, When it is out of the range, a control means is provided for invalidating the determination result of whether or not the exposure has been completed by the determination means, and the difference between the reproduction information amount of the previous frame and the reproduction information amount of the current frame is not within the predetermined range. In this case, the result of the determination as to whether or not the exposure has been completed is invalidated, assuming that the effect of the sudden noise is large.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

1 to 5 are views relating to a camera according to an embodiment of the present invention, and FIG. 1 is a perspective view showing a main structure of the camera.

In FIG. 1, 1 is a film, 2 (2a,
2b, 2c ...) Perforations provided in the film 1, 3 is a magnetic recording unit provided in the film 1, 4 is a film cartridge, and 5 is a movable light-shielding window opening / closing drive unit of the film cartridge 4. Reference numeral 6 denotes a film exposure status display section for displaying the status of the film 1 stored in the film cartridge 4 as "exposed" or "unexposed", which is displayed in a black and white pattern (details will be described later with reference to FIG. 3). To). Reference numeral 7 denotes a movable light-shielding window of the film cartridge 4, which is driven by the movable light-shielding window opening / closing drive unit 6 to open and close. Reference numeral 8 denotes a spool shaft of the film cartridge 4, and the spool shaft 8 rotates in a direction in which the film 1 is rewound into the film cartridge 4, whereby the film 1 is wound into the film cartridge 4. Reference numeral 9 denotes a display window of the film cartridge 4, through which the state of the film exposure state display section 6 is detected by the detection means described later.

Reference numeral 10 is a magnetic head for recording and reproducing information on the magnetic recording section 3 provided on the film 1. 11
Is a pad which is arranged so as to face the magnetic head 10 and sandwiches the film 1 with a predetermined force. The force generated by the pad 11 and the magnetic head 10 causes the magnetic head 10 to move to the magnetic recording portion 3 on the film 1. It is in close contact. 12, 13
Is a photo-reflector, and the film exposure state display section 6
It forms the detection means of the state of. Reference numeral 15 denotes a movable light-shielding window opening / closing member, which rotates to open / close the movable light-shielding window 7 via the movable light-shielding window opening / closing drive unit 5. Reference numeral 16 denotes a joint portion on the movable light shielding window opening / closing member 15 to the movable light shielding window opening / closing drive unit 5. Reference numeral 17 denotes an electrode member on the movable light-shielding window opening / closing member 15, and rotation of the movable light-shielding window opening / closing member 15 brings the movable light-shielding window opening / closing detection switches 18 and 19 into a conductive state and a non-conductive state (in this case, the movable light-shielding window 7). By the opening of
It becomes conductive). Reference numeral 20 denotes a gear unit, which drives the movable light shielding window opening / closing member 15 via the gear 22 by the driving force of the movable light shielding window opening / closing motor 21. Reference numerals 23 and 24 denote film cartridge presence / absence detection switches, which are turned on when the film cartridge 4 is inserted into a film cartridge chamber in the camera body (not shown).

Reference numeral 25 denotes a film rewinding joint member,
By this rotation, the film 1 can be rewound into the film cartridge 4. A gear unit 26 transmits the driving force of the film feeding motor 27 to the film rewinding joining member 25 and a film winding member (not shown) via the gear 28. Reference numerals 29 and 30 denote photoreflectors provided on the film 1 for detecting perforations (2a, 2b, 2c ...).

In the above structure, when the film is wound, the driving force of the film feeding motor 27 is transmitted to the rewinding joint member 25 and the film winding member (not shown) through the gear unit 26, and the rewinding joint is carried out. The combination member 25 rotates in the direction of pushing the film 1 out of the film cartridge 4, and the film winding member (not shown) rotates in the direction of winding the film 1. As a result, the film 1 is pushed out of the film cartridge 4 and wound up on the film winding member (not shown), and then the extrusion force generated by the rewinding joint member 25 is taken up by the film winding member. When the force becomes dominant, the planetary gear in the gear unit 26 is disengaged and the driving force of the rewinding joint member 25 is lost. Therefore, it is possible to reduce the feeding load of the film feeding motor 27 when winding the film.

When the film 1 is rewound, the film feeding motor 27 is rotated in the reverse direction, and the rewinding joint member 25 is rotated in the direction in which the film 1 is wound into the film cartridge 4 so that the film 1 is rewound. It can be wound into the cartridge 4.

Next, the function of the photo reflectors 29 and 30 at the time of film feeding will be described.

The film 1 is moved, and the photo reflector 2 is moved.
When the perforation 2 passes in front of 9, a signal is generated in the photo reflector 29, and in response thereto, a signal having a recording frequency according to the moving speed of the film 1 is applied to the magnetic head 10 to perform magnetic recording. . Next, when the perforation 2 passes in front of the photo reflector 30 and a signal is generated in the photo reflector 30, the control circuit, which will be described later, causes the film feeding motor 27 to be energized in a time-division manner, and the film 1 is stopped. It will be slowed down for ease.
Then, when the next perforation 2 again passes through the position of the photo reflector 29, the both electrodes of the film feeding motor 27 are set to the GND potential at this moment, the brake is applied, and the film 1 is stopped.

FIG. 2 is a diagram showing a state in which magnetic information is recorded on the film 1 by the magnetic head 10.

In FIG. 2, 14a to 14e are exposed portions on the film 1, and 14a to 14c are exposed frames.
Reference numerals 4d to 14e denote unexposed frames, respectively. The other parts are as described above.

FIG. 3 is a view showing each state of the film exposure state display section 6 provided in the film cartridge 4.

3A shows the film exposure state display section 6 in the "unexposed" state, FIG. 3B shows the "all frame exposed" state, and FIG. 3C shows the "partial exposed" state. 3D shows the "developed" state, which is detected by the photo reflectors 12 and 13 not shown here, and is transmitted to the control circuit described later.

FIG. 4 is a block diagram showing the electrical construction of the above camera, and the same parts as in FIG. 1 are designated by the same reference numerals.

In FIG. 4, 31 is a control circuit for performing sequence control of the entire camera, 32 is auto focus control (AE), automatic exposure amount control (AE), shutter control (S).
H) and other control circuits, 33 is a display unit such as an LCD, 34 is a sounding body, 35 and 36 are driver circuits for driving the movable light-shielding window opening / closing motor 21, and the film feeding motor 27, and 37 is the magnetic head. The magnetic recording / reproducing unit drives 10 to record information or reproduce information.

SW1 is a switch that is turned on by a first stroke of a release button (not shown), SW2 is a switch that is turned on by a second stroke of a release button (not shown), and SW3 is a rewind used when rewinding the film midway. It is a switch. SW4 and SW5 are switches used forcibly taking out the film, and these switches SW
By turning on both SW4 and SW5, it is possible to shoot from a predetermined frame (unexposed frame position) of the reloaded forcible intermediate take-out film. SW6 is a movable light-shielding window opening / closing detection switch corresponding to the movable light-shielding window opening / closing detection switches 18 and 19, SW7 is a film cartridge presence / absence detection switch corresponding to the film cartridge presence / absence detection switch,
SW8 is a cartridge chamber lid close detection switch.

Next, the camera (control circuit 31) having the above structure
The operation will be described with reference to the flowchart of FIG.

In the flow charts of FIGS. 5 and 6, the film exposure state display section 6 displays an EI (Exposure Indicator).
, "All exposed" is E (Exposed), "Developed" is Pr
(Procced), “Partially exposed” is Pa (Partially expose)
They are abbreviated as d). The movable light-shielding window 7 is L
It is abbreviated as L (Ligh Lock).

When the camera is powered on, step S
In step S102 via 101, it is determined whether the cartridge chamber cover is closed or not by the cartridge chamber cover close detection switch S.
It is detected from the state of W8. If the cartridge chamber cover is open, the process stays in this step, and the process proceeds to step S103 by detecting the closing of the cartridge chamber cover. Then, in this step S103, the presence / absence of the film cartridge 4 is detected from the state of the film cartridge presence / absence detection switch SW7. If there is not, the process returns to step S102 to repeat the same operation. If there is the film cartridge 4, the process proceeds to step S104.

In the next step S104, the state of the film exposure state display portion 6 of the film cartridge 4 (see FIG. 3) is detected by the photo reflectors 12 and 13. As a result, if it is detected that the film is fully exposed, that is, "all frame exposed" or "developed", the process proceeds to step S119, and if "unexposed" is detected, step S105. If it is detected that "partially exposed", the process proceeds to step S127.

First, the operation when the process proceeds to step S105 assuming that "unexposed" is detected will be described.

In step S105, the driver circuit 35 drives the motor 21 for opening and closing the movable light-shielding window, and the film cartridge 4 is driven through the movable light-shielding window opening-closing member 15.
The movable light-shielding window opening / closing drive unit 5 is rotated to start the opening operation of the movable light-shielding window 7. When the movable light-shielding window opening / closing detection switch SW6 becomes conductive, the movable light-shielding window opening / closing motor 21 is stopped. As a result, the movable light-shielding window 7 is opened, and the spool shaft 8 of the film cartridge 4 can be rotated. Therefore, this time, the control circuit 31 is the driver circuit 3
The film feeding motor 27 is driven by 6 to rotate the rewinding joint member 25 to start extruding the film 1 from the inside of the film cartridge 4.

In the next step S106, the film exposure state display section 6 rotates in association with the film feeding, but various information recorded in a black-and-white pattern on the surface thereof, that is, the exposed film defining frame is exposed. Information such as number, film sensitivity (ISO), and film type is read by the photo reflectors 12 and 13.

Next steps S107 to S10
Up to 9, while monitoring the output signals of the photo reflectors 29 and 30 for detecting the perforation 2,
The value of K indicating the number of frames to be photographed is set to “0”, and the film 1 is set to the first
When the feeding of the frames is completed, the number of frames is set to "1".

In step S110, it is detected whether or not the release button (not shown) is pressed and the switch 1SW1 is turned on. If not, the process remains in this step until it is turned on. After that, when the switch SW1 is turned on, the process proceeds to step S111, the known photometry and distance measurement operations are performed using the control circuit 32, and the autofocus control is performed based on the obtained distance measurement information.

In the next step S112, it is further detected whether or not the release button is pushed and the switch SW2 is turned on. If it is not turned on, the above step S112 is performed.
Returning to 111, the same operation is repeated. After that, when the switch SW2 is turned on, the process proceeds to step S113, and the control circuit 32 is used again to control the opening / closing of the shutter based on the photometric information obtained by the photometric operation. And
In step S114, the film feeding motor 27 is driven through the driver circuit 36 to wind one frame of film. At this time, the recording frequency is determined based on the output of the photo reflector 29 for perforation detection, and the magnetic head 10 is driven to record the photographing information such as the date and the shutter speed in the magnetic storage unit 3 provided on the film 1. To do.

Next, in step S115, the state of the intermediate take-out switch SW3 is checked, and if it is turned on, the step of FIG.
Proceeding to 148, the film feeding motor 27 is reversely rotated through the driver circuit 36 to start rewinding of the film,
When the photoreflector 29 for perforation detection does not generate a signal, the driving of the film feeding motor 27 is stopped. And the next step S
At 118, after a certain time after the signal from the photoreflector 29 for perforation detection is stopped, the film feeding motor 27 is driven and controlled again according to the signals from the photoreflectors 12 and 13, and the film exposure state display section is displayed. The rotation position of 6 is adjusted to the state of "partially exposed" [state of FIG. 3 (c)]. Then, step S15
At 0, the movable light-shielding window opening / closing motor 21 is driven through the driver circuit 35 to close the movable light-shielding window 7, and the series of operations is ended in the next step S151.

If the midway take-out switch SW3 is OFF in step S115, the flow advances to step S116 to check whether the number K of photographed frames has reached the specified number of photographed frames (photographing frames). If not, the process returns to step S109, and the value of the number of shooting frames K is set to "+
1 ". Then, the operations after step S110 described above are performed.

Thereafter, when it is detected in step S116 that the number K of photographed frames has reached the specified number of frames,
In step S117, the film feeding motor 27 is rotated in the reverse direction via the driver circuit 36 to start film rewinding, and no signal is generated from the photoreflector 29 for perforation detection. The driving of the motor 27 is stopped.

In the next step S118, the film feeding motor 27 is driven again in response to the signals from the photoreflectors 12 and 13 after a lapse of a certain time after the signal from the photoreflector 29 for detecting the perforations disappears. Then, the rotational position of the film exposure state display section 6 is adjusted to the "exposed" state [state of FIG. 3 (b)]. Then, in step S150, the movable light-shielding window opening / closing motor 21 is driven through the driver circuit 35 to close the movable light-shielding window 7, and in the next step S151, a series of operations ends.

Next, the case where it is detected in step S104 that the state of the film exposure state display section 6 is "exposed" or "developed" will be described.

In this case, the process proceeds from step S104 to step S119, and the open / closed state of the movable light-shielding window 7 is detected from the state of the movable light-shielding window open / closed detection switch SW6. As a result, if the movable light-shielding window 7 is closed, the process proceeds to step S123, and if it is open, the process proceeds to step S120.

In step S120, the spool shaft 8 may rotate and the position of the film exposure state display portion 6 may change, and if exposure has been completed, the movable light-shielding window 7 may be moved.
Since the light is exposed in the open state, the film exposure state of the film cartridge 4 is displayed on the display unit 33 such as an LCD to inform the camera user. And step S
At 121, the film feeding motor 27 is driven and controlled in accordance with the signals from the photo reflectors 12 and 13, and the film exposure state display section 6 is adjusted to the original state.
At 122, the movable light-shielding window 7 is closed. After that, the process proceeds to step S123, in which the movable light-shielding window 7 is in the closed state, so that the present film exposure state is displayed (when this step is reached through step S120, this display is continuously performed. The display unit 33 displays that the film cartridge can be taken out.

Next, in step S124, the state of the forced halfway film use switch SW4 is detected,
If it is OFF, the process proceeds to step S151 in FIG. 6 to end the series of operations.

On the other hand, when the forced mid-take-out film use switch SW4 is ON, step S12 in FIG.
Go to 5.

In such a case, for example, when a "partially exposed" film cartridge is loaded but the film exposure state display section 6 detects "all frame exposed", it is used only halfway. When it is desired to start photographing from the unexposed frame position of the film which has not been performed, and when such a use is desired, the forced intermediate take-out film use switch SW5 is also turned on as described in the next step.
It is possible by doing (using a double switch configuration).

In step S125, the state of the forcible intermediate take-out film use switch SW5 is detected this time, and if it is OFF, the film exposure state display section 6 indicates "all frame exposed" or "developed" In addition to displaying on the display unit 33 that the instruction to start the exposure state check operation of each frame on 1 has been instructed,
A sound is emitted by the sounding body 34 to notify.

When it is detected in step S125 that the forced take-out film use switch SW5 is turned on by looking at the above display, the process proceeds to step S127, and the following operations are executed. Even if it is determined in step S104 that "partially exposed", the process proceeds to step S127, and the same operation as described below is executed.

In step S127, the driver circuit 35 drives the movable light-shielding window opening / closing motor 21 to open the movable light-shielding window 7. This allows the film cartridge 4
Since the spool shaft 8 can be rotated, the next step S
At 128, the driver circuit 36 drives the film feeding motor 27 to rotate the rewinding joint member 25 to start pushing the film 1 out of the film cartridge 4. Then, in the next step S129, the film exposure state display section 6 rotates in association with the film feeding, but various information recorded in a black-and-white pattern on the surface thereof (the number of film-definable frames that can be exposed, Information on film sensitivity, film type, etc.)
Read by 2 and 13.

In step S136, when the leading edge of the film 1 being fed passes the position of the magnetic head 10, the magnetic head 10 is pressed against the film 1 and the magnetic recording section 3 starts reproducing information. Then, the reproduced output is amplified, converted into a digital signal, and taken into the control circuit 31. At this time, since there is no magnetic information at the leading end of the film 1, the noise generated in the film feeding motor 27 or the like is reproduced by the magnetic head 10. Since this is an operation for detecting the amount of noise other than the original magnetic information, since no magnetic recording is made at the leading end of the film 1 as described above, the magnetic head 10 is not always pressed against the film. There is no need.

In the next step S130, the amount of information reproduced in the portion where the magnetic information does not exist is set to NO,
The NO is compared with a predetermined value ΔNO.

Here, since NO is the amount of information reproduced in the portion where magnetic information does not exist, the amount of information that is the reproduction output is originally "0". However, when affected by external noise or the like, the information amount NO is not "0". If the reproduced information amount NO is "0" or less than a certain predetermined amount, that is, if the noise is small, the position of the unexposed frame can be detected, but the noise amount is large and the information amount NO is more than a predetermined amount. If so, there is a great possibility that the reproduction output of the magnetic information that should be originally detected cannot be detected, and as a result, multiple exposure due to false detection or missing (judging that an unexposed frame is already exposed and skipped). Can occur.

Therefore, as a result of the above comparison, the information amount NO reproduced in the portion where the magnetic information does not exist is predetermined Δ.
When NO or more (NO ≧ ΔNO), the process proceeds from step S131 to step S147, and a reproduction error display or warning is performed using the display unit 33 and the sounding body 35. Then, after that, in the same manner as described above, in step S148, the film feeding motor 27 is driven to rewind the film 1, and in the next step S149, the film feeding motor 2 is rewound.
7 and the photo reflectors 12 and 13 to set the original film exposure state display portion 6 to "partially exposed", and step S
At 150, the movable light-shielding window 7 is closed, and step S15 is performed.
At 1, the series of operations ends.

When it is determined in step S131 that the information amount NO reproduced in the portion where the magnetic information does not exist is less than the predetermined ΔNO (NO <ΔNO).
Proceeds from step S131 to step S132.

In step S132, predetermined values ΔN1 and ΔN2 are used, and a value N1 for discriminating that the frame (frame) is an "unexposed frame" below that value is set by N1 = N0 + ΔN1. If the value is equal to or more than that value, the value N2 for determining that the frame is “exposed” is set by N2 = N0 + ΔN2. Note that “N2> N1”.

Then, in the next step S133,
The number of frames K to be photographed is set to "0", and in the subsequent step S134, the film feeding motor 27 feeds one frame of the film 1 and at the same time, "1" is added to the number of frames K to be photographed.
The magnetic reproduction information amount of K frames during film feeding is N.

In the next step S135, the magnetic reproduction information amount N of the K frame is compared with the value N2 for discriminating "exposed", and if "N≥N2", the K frame is "exposed". If it is determined that there is, go to step S136,
If “N <N2”, there is a possibility that the K frame is “unexposed”, and therefore the process proceeds to step S141.

In step S136, the difference SN (= previous frame N-current frame N) between the magnetic reproduction information amount of the previous frame (previous frame N) and the magnetic reproduction information amount of the current frame (current frame N) is detected. Here, even when “N ≧ N2” is determined in the above step S135, for example, when external noise is received during the magnetic reproduction, the magnetic reproduction information amount N is the unexposed frame in the unrecorded state. However, there is a possibility that this relationship will be established and "exposed". On the other hand, if the exposed frame receives an abnormal increase or strong noise, the magnetic reproduction information amount N may decrease. , Cause false detection.

Therefore, in step S136, the difference SN between the magnetic reproduction information amount of the previous frame (previous frame N) and the magnetic reproduction information amount of the current frame (current frame N) is within the predetermined range of -XN and XN. If it is out of the range, it is determined that the magnetic reproduction information cannot be detected reliably due to the influence of external noise and the like, and the process proceeds to step S147, and the reproduction error display is performed using the display unit 33 as described above. And the warning is given using the sounding body 34. And the next step S
In 148, the film feeding motor 27 is driven to rewind the film, and in the subsequent step S149, the film feeding motor 27 and the photo reflector 1
2 and 13 are used to set the film state display portion 6 to the original "partially exposed". Further, in step S150,
The movable light-shielding window 7 is closed, and in step S151, a series of operations ends.

On the other hand, in step S136, the difference SN between the magnetically reproduced information amount of the previous frame (previous frame N) and the magnetically reproduced information amount of the current frame (current frame N) is within the predetermined range of -XN and XN. If it is determined that step S137
In step S129, the number of film frames specified in step S129 is compared with the current number K of frames to be photographed to determine whether K is the last frame. If the K frame is the last, the above step S
When it is determined in step 104 that "partially exposed" has been reached and this step is reached, in this case, it means "all frames have been exposed", which is a contradiction. Therefore, in the next step S147, a reproduction error is displayed on the display unit 33 in order to inform that the condition of the step S136 is cleared due to an erroneous detection due to some factor, and the sound generator 3
4 generates a warning sound. Further, when this step has been passed through the above steps S124 and S125, it is possible that all frames have been exposed, so that "all frames have been exposed" is displayed.

Thereafter, similar to the above, in step S148, the film feeding motor 27 is driven to rewind the film, and in the following step S149, the film feeding motor 27 and the photo reflectors 12 and 13 are used. The film state display portion 6 is adjusted to the original "partially exposed", "all frames exposed" or "developed", and step S15 is performed.
At 0, the movable light-shielding window 7 is closed, and at step S151, a series of operations ends.

Next, a case will be described in which it is determined in step 135 that the K frame may be "unexposed".

In this case (when "N <N2"), step S
The process proceeds from 135 to step S141, and the magnetic reproduction information amount N of the K-1 frame and the value N for determining the above "exposed"
2 is compared, for example, when K = 1, the information amount N of K = 0
However, in this case, when the relationship of “N <N2” is established, it can be determined that the K−1 frame (first frame) is “unexposed”, and therefore the process proceeds to step S147, and here, in step S104, “partial exposure” is performed. Even if it is determined that "completed", "all frames have been exposed" or "developed", the first frame is "unexposed", which is inconsistent. Therefore, it is conceivable that dust or the like has adhered to the surface of the magnetic head 10. Therefore, an error is displayed on the display unit 33 and a warning is issued by the sounding body 34.

In step S141, K
When the relationship of "N≥N2" holds for the -1 frame, the process proceeds to step S142, the film 1 is fed so as to return by one frame, and K frames are reproduced again. This is because if the K-1 frame is reproduced again, it can be checked whether the reproduction information amount has decreased due to dust or the like.

Then, in the next step S143,
The reproduction information amount N for the second time with respect to the K frame is compared with the above-described value N2 for determining "exposed". As a result, "N
If ≧ N2, it can be determined that the K frame is “exposed”, and therefore the process proceeds to step S137 described above, and the same operation is performed thereafter.

On the other hand, in step S143, "N
If "N2", there is a possibility that the K frame is "unexposed", so the flow advances to step S144 to compare the reproduction information amount N for the second time of the K frame with the value N1 for determining "unexposed frame". . As a result, if “N ≧ N1”, the K frame is determined to be “unexposed” and the process proceeds to step S139. Then, in this step S139, the film feeding motor 27 is driven to control the feeding of the film 1, and the K frame is adjusted to a position where photography can be performed. Then step 1
At 40, the display unit 33 displays that resetting of the half-taken-out film cartridge is completed. As a result, the preparation for photographing is completed, so that the above-described step S1 in FIG.
Then, the process goes to 10 to enter the ON standby state of the switch SW1.

Further, as a result of comparing the reproduction information of the K frame for the second time in step S144, "N>N1"
If so, the process proceeds to step S145, the film 1 is fed so as to return by one frame, and the third K frame is reproduced. Then, the process proceeds to step S146, and the reproduction information amount N for the third time and the above-mentioned "unexposed" with respect to the K frame.
The value N1 for determining is compared. As a result, “N ≧ N
If "1", it can be determined that the K frame is "unexposed", so the process proceeds to step S139 described above. If "N <N1", the K frame can be determined that "exposed", the process proceeds to step S137 described above. Perform the same operation.

According to the present embodiment, the magnetic head 1 is the film portion (film front end portion) where magnetic information is not recorded.
When the magnetic head 10 passes through the position of 0, the magnetic head 10 is set in a reproducible state, and if the reproduced information amount obtained at that time is larger than a predetermined information amount, subsequent information reproduction is invalidated. (Step S128 of FIG. 6 → S1
29 → S130 → S131 → S147 ...), and erroneous determination of “exposed” and “unexposed” can be prevented.

Further, it is compared whether the difference between the magnetic reproduction information amount of the previous frame and the magnetic reproduction information amount of the current frame is within a predetermined range. Since it is determined that the information cannot be detected and the subsequent information reproduction is invalidated (steps S136 → S147 in FIG. 6), erroneous determination of “exposed” and “unexposed” is prevented. I can do it now.

Further, as described above, when the subsequent information reproduction is invalidated, the display unit 33 is used to display the reproduction error and the sounding body 34 is used to give the warning. The user can be clearly notified of this.

(Correspondence between Invention and Embodiment) In this embodiment, step S131 or step S1 of the control circuit 31 is performed.
The part that executes the operation of 36 corresponds to the determining means of the present invention, and the part of the control circuit 31 that executes the operation of S131 → S147 or steps S136 → S147 corresponds to the controlling means of the present invention.

The magnetic head 10 and the magnetic recording / reproducing section 37 correspond to the reproducing means of the present invention.

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

[0072]

As described above, according to the present invention,
If the reproduction information amount obtained when reproducing the unrecorded film portion is larger than the predetermined information amount, it is determined that the influence of noise is large and the determination result of whether or not the film is exposed is invalidated. ing.

Further, according to the present invention, when the difference between the reproduction information amount of the previous frame and the reproduction information amount of the current frame is not within the predetermined range, it is considered that the influence of the sudden noise is large and the exposure is performed. The determination result of whether or not it is completed is invalidated.

Therefore, it is possible to prevent the malfunction of the camera due to the false detection due to the noise.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a state in which magnetic information is recorded on a film by a magnetic head in the camera of FIG.

FIG. 3 is a diagram showing each state of a film exposure state display section provided in the film cartridge of FIG.

FIG. 4 is a block diagram showing an electrical configuration of the camera of FIG.

5 is a flowchart showing a part of the operation of the camera of FIG.

FIG. 6 is a flowchart showing a continuation of the operation of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 film 10 magnetic head 12,13 photo reflector 27 film feeding motor 31 control circuit 33 display section 34 sounding body 37 magnetic recording / reproducing section

Claims (3)

[Claims] 1. A reproducing means for reproducing the information recorded in each frame of the film, and a judging means for judging whether or not each frame is exposed based on the amount of information reproduced by the reproducing means. In the provided camera, the reproducing means is driven in a state where a film portion on which no information is recorded passes, and when the amount of information obtained by the reproducing means is larger than a predetermined amount of information determined in advance, The camera is provided with a control means for invalidating the discrimination result by the discrimination means. 2. A reproducing means for reproducing the information recorded in each frame of the film, and a judging means for judging whether or not each frame has been exposed based on the amount of information reproduced by the reproducing means. In the provided camera, it is compared whether the difference between the reproduction information amount of the previous frame and the reproduction information amount of the current frame is within a predetermined range. If the difference is out of the range, the determination result by the determination means is invalidated. A camera provided with a control means. 3. The camera according to claim 1, further comprising an informing unit for informing that the determination result of the determination unit is invalidated by the control unit.