JPH0682900A - Camera - Google Patents

Abstract

PURPOSE:To inform a user whether a proper exposure is obtained or not with the sensitivity of a newly loaded film by providing a means recording the fact that a film under use is rewound in the midst, because of improper conditions for an exposure. CONSTITUTION:When a film cartridge is loaded, the film information of film sensitivity, etc., recorded on the magnetic track of the film F is read by a magnetic head H. The film information is transferred to a control circuit 27 via a head amplifier 22, a buffer 23 and a decoder 24. The control circuit 27 stores the fact that the film under use is rewound in the midst, judges whether the newly loaded film has proper film sensitivity for photographing or not in comparison with the film used the last time and displays the state of the judgement on the display unit of the camera, so that the user of the camera is informed whether the exchanged film is suitable for photographing or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention drives a magnetic head during film feeding by film feeding means after the end of photographing,
The present invention relates to an improvement in a camera using a film with a magnetic storage unit, which is provided with a writing instruction means for performing overwriting of film information previously written in the magnetic storage unit of the photographed frame.

[0002]

2. Description of the Related Art In recent years, a film having a magnetic storage unit has been used, and information such as year, month, date of the day, shutter time, aperture value, etc. is written in the magnetic storage unit by a magnetic head.
A camera capable of reading out the information as necessary, and reading the information such as the ISO and the number of specified frames of a film written from the beginning is a U.S. Pat. No. 4,864,332.
It has been proposed in the issue. Regarding the detailed recording method of this magnetic information, etc., in WO90-04204, a different ID (IDENTIFICAT) is used for each magnetic information.
ION), and WO90-04225 discloses examples in which there is an end mark after the data.

Further, the information such as ISO and the specified number of film frames which is written from the beginning is overwritten with photographing information such as shutter speed and aperture value and date information after photographing with a camera. At the time, instead of writing in the entire area (in the magnetic storage section) for one frame, by writing in a certain limited range and leaving the original information in other areas, the film shot halfway can be rewound, and the film can be rewound. When the camera is loaded again into the camera and used, the camera counts the amount of original information (for example, the number of certain fixed markers) when reading the information on the film to determine whether it is an exposed frame or an unexposed frame. The applicant of the present application has already applied for a camera that determines and brings the unexposed frame to the aperture position (Japanese Patent Application No. 2-297828).
Has been done.

[0004]

However, in the above-mentioned camera, when the film being used is rewound in the case of unsuitable photographing such as overexposure or underexposure, when a new film is loaded, the loaded film is Sensitivity
Since there was no function to judge whether proper exposure could be obtained under the same shooting conditions as the previous time, even if I accidentally loaded a film with inappropriate sensitivity under the same conditions as the previous time, I could not know this. There wasn't.

The present invention has been made in order to solve such a conventional problem, and when the film in use is in an inappropriate exposure condition, the film is rewound midway in order to obtain proper exposure. An object of the present invention is to provide a camera capable of informing a user, when a film is loaded, whether or not a proper exposure can be obtained with the sensitivity of the loaded film.

[0006]

In order to achieve the above object, the camera of the present invention comprises a magnetic head for writing and reading information to and from a magnetic recording section provided on a film and a film feeding for feeding the film. Means for driving the magnetic head while the film is being fed by the film feeding means after the completion of photographing, and writing the camera information on the film information previously written in the magnetic memory portion of the photographed frame. Means and a means for judging whether or not the loaded exposure is properly performed, and a camera capable of rewinding the film halfway, in which the newly loaded film is the same as the last time. It is provided with means for making a judgment as to whether or not an appropriate exposure can be obtained in the photographing state and notifying the result.

[0007]

According to the present invention, the newly loaded film is photographed by the means for storing the overexposed or underexposed state at the time of photographing, and for storing the fact that the film in use is rewound midway. It is now possible to judge whether or not the film has the proper film sensitivity by comparing it with the film used last time, and the judged condition is displayed on the camera display. It tells you if the film is suitable for shooting.

[0008]

1 to 5 show a first embodiment of the present invention.

FIG. 1 is a perspective view showing a main configuration of a camera of the present invention. In FIG. 1, 1 is a taking lens, 2 is a lens actuator for driving the taking lens 1, and a lens encoder for generating a lens position signal. 3 is a lens shutter, 4 is a photometric sensor for AE, 5 is the photometric sensor 4
A lens for determining the light receiving angle of the film F, a block 6 including a distance measuring sensor and a finder, and a photo 7 for detecting the perforations P ₁ and P ₂ of the film F and generating a signal for indexing one frame of the film F. A reflector, 8 is a film feeding motor arranged in the spool, 9 is a gear train for decelerating and switching between winding and rewinding, and 10 is a rewinding fork.

C is a film cartridge which stores the film with the front end of the film exposed, F is the above-mentioned film having a magnetic storage section (magnetic track T) on the base side, and P ₁ and P ₂ are images. The above-mentioned perforation corresponding to the screen A, H is a magnetic head for writing information to or reading information from the magnetic track T on the film F. Reference numeral 11 denotes a pad that presses the film F against the magnetic head H, and has a concave portion at the center for increasing the adhesion between the film F and the head gap. Reference numeral 12 denotes 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.
Reference numeral 16 is a release button, 17 is a switch (SW1) for starting photometry and distance measurement, 18 is a switch (SW2) for opening a shutter and starting a film feeding sequence,
Reference numeral 20 is a rewind switch for rewinding on the way.

FIG. 2 is a circuit block diagram of a camera of a portion according to the present invention, and the same portions as those in FIG. 1 are designated by the same reference numerals.

In FIG. 2, 19 is a back cover switch for detecting the closing of the back cover, 21 is an ID detection circuit for detecting the ID sentinel in the film information, 22 is a head amplifier for the magnetic head H, and 23 is a buffer. 24 is a decoder, 25
Is an encoder, 26 is a buffer, 27 is a control circuit configured by a microcomputer or the like for performing sequence control of each circuit, 28 is a motor driver for driving the film feeding motor 8, 29 is a display unit including a display circuit and a display element. Is.

The operation of the control circuit 27 will be described below with reference to the flow chart of FIG. The camera of the present embodiment assumes a so-called prewind system in which the film F is once wound up and the film is rewound for each frame.

When the film cartridge C is loaded into the camera, the back cover is closed, and the back cover switch 19 is turned on,
Proceeding from step 101 to step 102, the film feeding motor 8 is driven via the motor driver 28 to start the winding of all the films F. And step 10
3, during film winding, film information such as film sensitivity, specified number of frames, film type, etc. recorded on the magnetic track T of the film F as a string of data characters starting from the ID sentinel (information head signal) is magnetically recorded. Read with the head H.

The read film information is amplified by the head amplifier 22 and A / D converted, and then the buffer 23.
To the control circuit 27. Then, the decoder 24 decodes it and transfers it to the control circuit 27.

In step 103, the ID
The detection circuit 21 continues to detect the N-bit ID sentinel (for example, “10000000”) of the film information, and the control circuit 27 inputs and counts this detection output.

In step 104, the film information read in step 103 is displayed on the display unit 29 (see FIG. 5). In FIG. 5, 30 is a display element such as a liquid crystal display panel, 31 is a film sensitivity display, 32 is a film number display, and 33 is a film type display.

Next, it is determined whether the flag MRIF is 1 (step 105). If the flag MRIF is 1, it is determined that the film was rewound midway last time, and the process proceeds to step 106. If the flag MRIF is not 1, it is determined that the film was not rewound midway last time, and the process proceeds to step 111.

When the film is rewound last time,
It is determined whether the flag OVF is 1 (step 10).
6). If the flag OVF is 1, it is determined that the previous shooting condition is overexposure, and the process proceeds to step 110, where the sensitivity of the film loaded this time and the sensitivity of the film used last time are compared to determine the film loaded this time. If the sensitivity of is lower than the previously used film sensitivity, step 11
If the sensitivity of the film loaded this time is not lower than the sensitivity of the film used last time, the process proceeds to step 109. Then, the ISO display 31 displayed on the display element 30 is blinked to inform that the sensitivity of the loaded film is inappropriate (step 109).

If the flag OVF is not 1 at step 106, the routine proceeds to step 107, where it is judged if the flag UDF is 1. If the flag UDF is 1, it is determined that the previous photometric operation is underexposure, and the process proceeds to step 108. If the flag UDF is not 1, it is determined that the previous photometric operation is the proper exposure state, and step 11
Go to 1. In step 108, the sensitivity of the film loaded this time is compared with the sensitivity of the film used last time. If the sensitivity of the film loaded this time is higher than the film sensitivity used last time, the process proceeds to step 111, and the sensitivity of the film loaded this time. If is not higher than the previously used film sensitivity, the process proceeds to step 109, the ISO display 31 displayed on the display element 30 is blinked, and the sensitivity of the loaded film is notified (step 10).
9).

Further, the number of ID sentinels of the film information is compared with a predetermined number (for example, 8) which is a threshold value for determining whether or not the frame is "exposed" (step 111), and the frame is "exposed". When it is determined that (number of ID sentinals ≤
(Predetermined number) proceeds to step 112, and if the frame is not “exposed” (ID sentinel number> predetermined number), step 1
Proceed to 14. If it is an exposed frame, the film feeding motor 8 is prohibited from being driven, and the film winding is stopped (step 112).

Next, the film feeding motor 8 is driven in the reverse direction to rewind one frame, and the unexposed frame is located at the aperture position of the camera (step 113). "Exposed"
If it is not a frame, the number of frames fed is counted from the output of the photo reflector 7, and it is judged whether or not the number of specified frames read previously is reached. When it is judged that the number has been reached, the process proceeds to step 115 to feed the film. The drive of the feed motor 8 is prohibited and the film winding is stopped. In step 116, it is determined whether or not midway rewinding is performed from the state of the rewind switch 20, and if midway rewinding is instructed, the process proceeds to step 117, the flag MRIF is set to 1, and the process proceeds to step 133. .

If it is determined in step 116 that no midway rewinding instruction has been issued, the process proceeds to step 118.

In step 118, the switch SW
It is determined whether or not 1 is ON, and when it is determined to be ON, the process proceeds to step 119, and each operation of photometry and distance measurement is performed. In the next step 120, the shutter speed, aperture value and the like obtained by the photometry and distance measurement operations are converted into camera information and transferred to the encoder 25.

The encoder 25 encodes the transferred camera information, and the buffer 26 stores the coded information.

Then, a flag OVF indicating overexposure
And a flag UDF indicating underexposure is set to 0 (step 121).

Next, the photometric value (BV) and the film sensitivity (S
When the calculated exposure amount (EV = BV + SV) calculated from V) and the maximum control value (EVcmax) of the camera are compared, and it is determined that overexposure has occurred (EV> EVcmax)
Goes to step 125, and if not overexposed, goes to step 123.

In step 123, the calculated exposure amount (E
V) and the minimum control value (EVcmin) of the camera are compared, and it is determined that underexposure (EV <EVc)
min) proceeds to step 124, and proceeds to step 126 if not underexposed. If it is underexposure, the flag UDF indicating underexposure is set to 1 (step 124) and the process proceeds to step 126. In the case of overexposure, the flag OVF indicating overexposure is set to 1 (step 125) and the process proceeds to step 126.

In the next step 126, it is determined whether or not the switch SW2 is turned on. If it is determined that the switch SW2 is turned on, the process proceeds to step 127, and a known exposure operation is performed. If it is OFF, the process returns to step 116.

That is, the control circuit 27 inputs the lens position signal from the lens encoder 2b via the lens actuator 2a, and the photographing lens 1 comes to a position corresponding to the distance measurement information obtained in step 119, whereby the lens actuator 2a To stop the driving of the taking lens 1, that is, the focus operation. At approximately the same time, the shutter 3 is opened and closed for the time determined by the photometric calculation in step 119 (step 127).

In step 128, the rewinding of the photographed frame (one frame rewinding) is started. And step 129
In the process of rewinding the film, head amplifier 2
The camera information stored in the buffer 26 via the 2 is sent to the magnetic track T of the film F on the magnetic track T of the film F, and an N-bit ID sentinel different from the ID sentinel of the film information (for example, “00000000”).
Write in the form of a sequence of data characters beginning with. In step 130, it is judged from the output of the photo reflector 7 whether or not the rewinding of the photographing frame is completed, and if it is judged that the rewinding of the photographing frame is completed, the process proceeds to step 131, in which the film F is not exposed. It is determined whether or not there is a piece (whether or not there is a remaining piece), and if there is, a step 116
Return to. When it is determined in step 131 that there is no remaining frame on the film F, the flag MRIF is set to O in step 132, and the process proceeds to step 133 until the continuous output from the photo reflector 7 is stopped.
That is, the rewinding of the film F is continued until the leading edge of the film passes the position of the photo reflector 7. As a result, only the leading edge of the film is not wound into the film cartridge C. The film cartridge at this time is
As long as the film tip can be pushed out of the cartridge by the rotation of the fork 10, the film rewinding may be continued until the film tip is housed in the cartridge.

Although not described above, the pad 11 is moved in and out of the pad F only when the film F is moving.
Is pressed by the magnetic head H to read out magnetic information,
Writing is becoming more reliable.

6 and 7 are flow charts showing the second embodiment of the present invention.

The flowcharts of FIGS. 6 and 7 are different from the flowcharts of FIGS. 3 and 4 in that instead of using a flag for storing overexposure and underexposure, a register is used to store the overexposure amount and the underexposure amount. It is something that is done.

In the flowcharts of FIGS. 6 and 7, the flow of the part different from the flowcharts of FIGS. 3 and 4 will be described below.

6 and 7, steps 150 to 1
54 corresponds to steps 105 to 110 in FIG. Further, in FIG. 6, steps 160 to 164 correspond to steps 121 to 124 in FIG.

First, it is determined whether the flag MRIF is 1 (step 150). If the flag MRIF is 1, it is determined that the film was rewound midway, and the process proceeds to step 151. If the flag MRIF is not 1, it is determined that the film has not been rewound previously, and the process proceeds to step 111.

Next, it is judged whether or not the value of the register REXP is larger than 0 (step 151). If it is larger than 0, it is judged that the previous photographing condition is overexposure, and the routine proceeds to step 154. When the value of the register REXP is 0 or less, the process proceeds to step 152, and it is determined whether the value of the register REXP is less than 0 (step 152). When the value is less than 0, it is determined that the previous photographing condition is underexposure. Go to step 153. Also, register REXP
If the value of 0 is 0 or more, the previous shooting condition is proper exposure, so the process proceeds to step 111.

Whether the difference between the sensitivity of the film used last time and the sensitivity of the film loaded this time is less than or equal to the value of REXP indicating the underexposure amount, that is, the sensitivity of the film loaded this time is
It is higher than the film sensitivity used last time, and the difference in sensitivity has a difference in sensitivity that should compensate for the underexposure amount. It is judged whether proper exposure can be obtained (step 153), and it is determined that proper exposure can be obtained with the film loaded this time. If yes, go to step 111. If the film loaded this time has insufficient sensitivity and it is determined that proper exposure cannot be obtained, step 1
Proceed to 55.

When the value of the register REXP is larger than 0, whether the sensitivity difference of the film used last time is more than the value of REXP indicating the overexposure amount, that is, the sensitivity of the film loaded this time is the film sensitivity used last time. The sensitivity difference is lower, and it is determined whether proper exposure can be obtained because there is a sensitivity difference that should compensate for the overexposure amount (step 15).
4) If it is determined that proper exposure can be obtained with the film loaded this time, proceed to step 111, and if it is determined that proper exposure cannot be obtained with the film loaded this time, proceed to step 155, and display element The ISO display 31 displayed on 30 is blinked to notify that the sensitivity of the loaded film is inappropriate (step 15).
5).

Next, steps 160 to 164 will be described.

In step 160, the value of the register REXP is set to 0. The register REXP is a register for storing the amount of overexposure or underexposure. When the amount of overexposure, the amount of overexposure is stored as a positive value, and when underexposure is stored, the amount of underexposure is stored as a negative value. When the exposure is appropriate, 0 is stored.

Then, the calculated exposure amount (EV = BV + S) calculated from the photometric value (BV) and the film sensitivity (SV).
V) and the maximum control value (EVcmax) of the camera are compared to determine whether overexposure has occurred (step 161). If it is determined that overexposure (EV> EVcmax), the process proceeds to step 164, and if not overexposure, the process proceeds to step 162. Then, the above-mentioned calculated exposure amount (EV = BV + SV) is compared with the minimum control value (EVcmin) of the camera, and underexposure (EV <
EVcmin) is determined (step 16).
2). If it is determined that the exposure is underexposure, step 1
When it is determined that the exposure is not underexposure, it is determined that the exposure is appropriate, and the process proceeds to step 125.

When it is determined that the exposure is underexposure, the difference EV-EVcmin between the above-described calculated exposure amount (EV) and the minimum control value (EVcmin) of the camera is stored in the register REXP as the underexposure amount. At this time EV <EVcmi
Since n, EV-EVcmin <0.

At step 164, the calculated exposure amount (EV) and the maximum control value (EVcm) of the camera are stored in the register REXP.
The difference of ax), EV-EVcmax, is stored as the overexposure amount. At this time, EV> EVcmax, so
EV-EVcmax> 0.

[0046]

As described above, according to the present invention, when a film in use is rewound midway and a new film is loaded thereafter, the previous shooting is overexposure or undershooting. It is judged whether or not it was in a state, and it is judged whether the newly loaded film is a film with appropriate sensitivity under the same shooting conditions as the last time,
Since this is displayed on the display, it becomes possible to inform the user of the camera whether or not a film having a sensitivity suitable for photographing is loaded.

[Brief description of drawings]

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

FIG. 2 is a circuit block diagram of a portion of the camera according to the present invention.

FIG. 3 is a flowchart showing an operation of the circuit shown in FIG.

FIG. 4 is a flowchart showing an operation of the circuit shown in FIG.

FIG. 5 is a diagram showing a state displayed on a display device.

FIG. 6 is a diagram showing a state of the second exemplary embodiment of the present invention.

FIG. 7 is a diagram showing a state of the second exemplary embodiment of the present invention.

[Explanation of symbols]

 7 Photo Reflector 8 Film Feed Motor 20 Rewind Switch 21 ID Detection Circuit 27 Control Circuit 28 Motor Driver 29 Display H Magnetic Head F Film with Magnetic Storage T Magnetic Storage (Magnetic Track)

Claims (1)

[Claims] 1. A magnetic head for writing / reading information to / from a magnetic recording portion provided on a film, a film feeding means for feeding the film, and a magnetic film feeding means for feeding the film after completion of filming by the film feeding means. Drive the head,
A writing means for overwriting the camera information on the film information previously written in the magnetic memory portion of the photographed frame, a means for judging whether the loaded exposure is properly performed, and A camera capable of rewinding, judges whether or not the newly loaded film can obtain an appropriate exposure in the same shooting condition as the previous time, and informs the result. A camera provided with means.