JPH04116539A - Camera using film with magnetic storage part - Google Patents

Abstract

PURPOSE:To execute high-density recording within a prescribed range while avoiding expensive and complicated constitution by providing a count means and a correction value calculation means which calculates a correction value based on a counted feeding time and a predicted feeding time and outputs it to a prediction and calculation means as the correction value of the predicted time of a next photographing frame. CONSTITUTION:The count means 105 which counts the actual feeding time of the photographing frame fed at a speed corresponding to the predicted feeding time obtained by the prediction and calculation means 101A is provided. Besides, the correction value calculation means 101B which calculates the correction value based on the feeding time counted by the count means 105 and the predicted feeding time and outputs it to the prediction and calculation means 101A as the correction value of the predicted time of the next photographing frame is provided. Then, the feeding time of the next photographing frame is decided by comparing the feeding time predicted by the prediction and calculation means 101A, the actual required feeding time and the information of a power supply voltage, besides. Thus, the high-density recording is executed within the prescribed range while the constitution is prevented from becoming expensive and complicated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to an improvement in a camera using a film with a magnetic storage section, which is equipped with a magnetic head for writing information into a magnetic storage section provided on the film.

(Background of the Invention) Conventional devices that magnetically record information can record at appropriate density by feeding the magnetic recording medium at a constant speed or by detecting the speed of the magnetic recording medium with an encoder. was possible.

On the other hand, in the case of cameras, as described in U.S. Pat. No. 4,864,332, etc., there are cameras that use a magnetic head to record photographic information such as shutter speed and aperture value in a magnetic storage section provided on the film. Proposed.

However, in cameras such as those proposed above, the length of information that can be recorded on the film per frame is finite, and although it is necessary to ensure that the information per frame does not exceed this length, constant speed feed is almost impossible. However, in order to realize the above-mentioned functions, the camera must be equipped with an encoder having an expensive and complicated configuration.

There is also a method that detects the power supply voltage of the camera and uses duty drive to feed the film based on this, trying to keep the feeding speed as constant as possible, but even if this method is adopted, many This was insufficient when attempting to record information at high density.

(Objective of the Invention) An object of the present invention is to solve the above-mentioned problems and to provide a magnetic memory unit that can perform high-density recording within a predetermined range while preventing an expensive and complicated configuration. An object of the present invention is to provide a camera using film.

(Features of the Invention) In order to achieve the above object, the present invention provides a film feeding time for each frame after shooting based on the winding time between each frame during film feeding until at least reaching the frame to be shot. a prediction calculation means for predicting and calculating the prediction calculation means; a counting means for counting the actual feeding time of the shooting frame fed at a speed according to the predicted feeding time determined by the prediction calculation means; and a correction value calculation means for calculating a correction value based on the feeding time counted by the user and the predicted feeding time, and outputting the correction value to the prediction calculation means as a correction value for the predicted time of the next shooting frame. Further, a prediction calculation means predicts and calculates the film feeding time of each frame after shooting based on at least the winding time between each frame during film feeding until reaching the frame to be shot, and the prediction calculation means A counting means for counting the actual feeding time of the photographic frame fed at a speed according to the calculated predicted feeding time, and a voltage detecting means for detecting the state of the power supply voltage during operation of the counting means. , calculating a correction value based on the feeding time counted by the counting means, the predicted feeding time, and the respective information from the voltage detecting means, and using this as a correction value for the predicted time of the next shooting frame. The correction value calculation means outputs to the prediction calculation means, and by comparing the feeding time predicted by the prediction calculation means with the actually required feeding time and power supply voltage information, it is possible to determine the next time. The present invention is characterized in that the feeding time of the photographic frame is determined.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, and its operation will be explained below using the flowchart shown in FIG. In this embodiment, a so-called prewind camera is assumed, in which the entire film is wound once and then the film is rewound frame by frame while taking pictures.

The control means 101 first determines whether or not the back cover is closed in step 201, and when it determines that the back cover is closed, the control means 101 proceeds to step 202, assuming that the film cartridge is loaded in the camera, and drives the film feeding means 104. Then, winding of the film provided with the magnetic storage section is started. Next, in steps 203 and 204, the frame number detection means 102 and counting means 105 detect the number of the frame detected by the frame position detection means (not shown).
The current frame number and the time required to wind up one frame are detected from the information from the information, and these pieces of information are stored in the storage means 103 in a corresponding manner. In the next step 205, it is determined whether winding of all films (total number of sheets) has been completed or not.
That is, it is determined whether or not the briwind has ended, and if it has not ended, the same operation is repeated thereafter, and after confirming the end, the process proceeds to step 206.

In step 206, the state of the switch SWI, which is turned on by the first stroke of the release button, is determined, and when it is determined that it has been turned on, the process proceeds to step 207208, where a photometering means and a distance measuring means (not shown) are respectively operated to perform photometry. and obtain distance measurement information. Next, in step 209, the switch s is turned on by the second stroke of the release button.
The state of w2 is determined. Then, the switch SW2 is turned on.
If it is determined that this has been done, the process proceeds to step 210, where known lens control and shutter control, that is, focus adjustment and exposure operations on the film surface are performed.

In the next step 211, the calculation means 101A in the control means 101 detects the current shooting frame number from the information from the frame number detection means 102, and the film feeding time (main time) suitable for this shooting frame number is detected. In the embodiment, since a rewind system is assumed, a prediction calculation of the rewind time is performed. Although the details will be described later, the calculation means 101A performs the steps 203 and 204.
In the step, the feeding speed for the frame after photographing is predicted and calculated from each piece of information stored in the storage means 103 and further from power supply voltage information to be described later.

In the next step 212, the feeding time estimated in step 211 is corrected using the correction value calculated by the correction value calculation means 101B in step 220 after the feeding of the previous photographic frame is completed. Arithmetic means 101A
(Since there is no correction value or the reliability of the correction value is low for the first photographed frame and several frames after the first photographed frame, the correction value is set to rOJ.) In step 213, the correction value is set to rOJ. The writing frequency is determined based on the feeding time.For the first photographed frame and several frames after the first photographed frame, for the reasons mentioned above, the writing frequency is set to a relatively high value to ensure reliable writing. ), next step 2
Similarly, at step 14, the film feeding means 104 is commanded to feed the film at a speed according to the corrected feeding time. Then, in step 215, the magnetic head 106 is driven to write various photographic information such as shutter speed, aperture value, photographing date, and comments to the magnetic storage section of the film.

In the next step 216, it is determined whether or not the feeding of the photographic frame has ended. When it is determined that the feeding has ended, the process proceeds to step 217, in which the film feeding means 104 is commanded to stop feeding the film.

Next, in step 218, the count value of the counting means 105 which counts the time from the start to the end of feeding of the photographic frame, that is, the time actually required for feeding the photographic frame is stored in the storage means 103. In step 219, the voltage detection means 107 is operated to obtain current power supply voltage information, and this is stored in the storage means 103.In the next step 220, the correction value calculation means 101B is
Based on the feeding time predicted and calculated in step 211 and the actually required feeding time and power supply voltage information stored in steps 218 and 219, predictive calculation is performed for the next shooting frame. A correction value for the feeding time to be calculated is calculated and stored in the storage means 103.

Next, in step 221, it is determined whether the film has finished or not.
In other words, it is determined whether or not the photographing of all the pieces has been completed. If not, the process returns to step 206 and the same operation is repeated. Also, if the photographing of all the pieces has been completed, the Start winding all the films into the film cartridge.

As described above, the feeding time of the next photographic frame predicted from the winding time information of each frame stored in the storage means 103 at the time of film winding is calculated based on the predicted time of the current photographic frame and this predicted time. Since the determination is made based on the actual feeding time of the current shooting frame and information on the power supply voltage at that time, it is possible to maintain the feeding time within a predetermined range without using an encoder with an expensive and complicated configuration. It becomes possible to perform high-density information recording.

FIG. 3 is a view from the back of the camera that makes it possible to realize the above embodiment, with the back cover removed.

In Figure 3, 1 is the camera body, 2 is the viewfinder, and 3
4 is a film cartridge chamber, and 4 is a fork for driving the spool in the film cartridge to rewind the film. 5 is a film aperture, 6 is a magnetic head, and 7 is a film winding spool, which is driven when winding the film.

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

In FIG. 4, 51 is a photometry circuit that measures the brightness of an object to be photographed, and 52 is a distance measurement circuit that measures the distance to the object. A microcomputer (hereinafter referred to as microcomputer) 53 controls various circuits, and has a timer, ROM, RAM, etc. inside. Reference numeral 54 indicates a switch (hereinafter referred to as SWI) for starting photometry/distance measurement which is turned ON by the first stroke of the release button of the camera (not shown), and 55 indicates ONL by the second stroke of the release button to start the release operation. switch (hereinafter referred to as SW2)
It is. 56 is a camera back switch (not shown);
Turns on in conjunction with opening and closing of the back cover.

Turn off. 57 is a switch (not shown) for detecting the presence or absence of a film cartridge. 58 reads the number of films and film type (for example, manufacturer, universal/negative, film sensitivity, etc. (this determines the type of film base and emulsion and predicts the film pulling and winding force) from the DX code provided on the film cartridge. This is a DX code reading circuit.

Reference numeral 59 denotes a motor control circuit for controlling a film feeding motor (not shown), and the film is wound up by forward rotation of the motor and rewound by reverse rotation. 60 is a shutter control circuit for controlling exposure to the film; 61 is a lens control circuit for controlling the position of the photographing lens so that the subject is in focus; 62 is a circuit for controlling the magnetic head 6 shown in FIG. This is a head control circuit that records and reads various information into and from the provided magnetic storage section. Reference numeral 63 denotes a frame position detection circuit for detecting each frame (one frame) on the film, and there is a method for detecting perforations or a method for detecting the amount of film travel.

Reference numeral 64 denotes a temperature detection circuit, which is configured independently in this embodiment, but can also be used as the photometry circuit 51. 65 is a voltage detection circuit that detects the battery voltage, performs A/D conversion, and transmits the information to the microcomputer 53.

FIG. 5(a) is a graph showing changes in film winding time (ie, changes in feeding time) during briwinding.

The film is wound by the film take-up spool 7, and the winding time per frame increases as the spool diameter apparently increases as the film is wound onto the film take-up spool 7. As shown in Fig. 5(a), the winding time t is reduced, but on the other hand, as the spool diameter increases, the load increases.
The speed does not simply depend on the ratio of the spool diameter; it is l/1 (
part B).

In the case of the briwind method as in this example, it is better to record the winding time for all pieces during briwind.
This information is useful when feeding (rewinding) the film. just,
It is possible to predict and correct load fluctuations due to the number of turns.

FIG. 5(b) is a diagram in which the time between photographed frames during rewinding is predicted using the information in FIG. 5(a).

In the rewinding direction, the film is wound around the spool in the film cartridge, so initially the rewinding time t
' takes time, and the winding diameter increases as the number of shooting frames (frame number) advances, and the rewinding time t' becomes shorter.On the other hand, the load increases just like when winding, so the rewinding time is monotonous. t' does not decrease (part B').

Therefore, it becomes possible to perform correction using the information shown in FIG. 5(a) stored at the time of briwind. That is, Fig. 5(a)
The prediction in FIG. 5(b) is that the film take-up spool 7
This is possible by determining the ratio between the rotation speed and diameter of the spool and the rotation speed and diameter of the spool in the film cartridge. In other words, the initial velocity at the beginning of winding around each spool is determined, and then the slope is determined by using the ratio of the respective spool diameters to determine the rate of change in the apparent spool diameter due to film thickness. Finally, the portion where the linear change does not occur (portion B) is corrected using the raw data shown in FIG. 5(a). Note that the slope of the portion B can also be predicted by predicting and correcting the load fluctuation based on the remaining amount of film and the amount of winding.

An example of the calculation formula according to the above explanation is shown below.

In FIG. 5(a), N: total number of sheets, M: frame number of the part (A-B) where the winding time does not change linearly,
to = first winding time, A: slope between (N-M),
B is the slope between (M and 1). Further, n in the following formula means the frame being fed.

tn=to-A (N-n),', (N≧
n≧M)tn:to A(NM) B(M
n), ", (M≧n≧1) Next, the diameter of the film take-up spool 7 is Dl, its rotational speed at no load is vl, the spool diameter of the film cartridge is D2, and its rotational speed at no load. Let be v2.

In Fig. 5(b), t□ = D2 / DI X V2 / VI
tOA' ” A X D 1/D 2B' =
B
n≧1) t n = t o -A' (M -1)
−B′(n−M),” (N≧n≧M) is expected.

It is quite conceivable that the correction term for the above approximate formula will increase by taking into account the film type, temperature, and power supply voltage state, and this will enable appropriate information to be recorded. As described below, the feeding time is predicted taking these into consideration.

Furthermore, it is also effective to create a predictive formula that takes into account actual data such as the characteristics of the film feed motor used in the camera and the gear train.

6(a) and 6(b) are operational flowcharts of the microcomputer 53 shown in FIG. 4, which has the function of performing the above-mentioned predictive calculation.

"Step 1" It is determined whether the back cover is closed based on the state of the back cover switch 56. If it is not closed, step 1 is repeated, and if it is closed, the process proceeds to step 2.

"Step 2" It is determined whether the film cartridge is loaded in the film cartridge chamber 3 based on the state of the switch 57. If the film cartridge is not loaded, the process returns to step 1, and if it is loaded, the process proceeds to step 3.

"Step 3" A film feeding motor (not shown) is rotated normally via the motor control circuit 59 to start winding the film.

Step 4J The DX code reading circuit 58 is driven to read the number of films (total number of films) and film type from the DX code provided in the film cartridge.As a reading method, reading from the film by the magnetic head 6 may be considered. This embodiment assumes a method of reading the DX code on the surface of the film cartridge as described above.

"Step 5" Here, the number of films read in step 4 (total number) is set.

"Step 6" Here, set the film type (manufacturer reversal/negative, film sensitivity) read in step 4.

"Step 7" It is determined whether one frame has been detected by the frame position detection circuit 63 which detects the position of a frame from perforations or the like. If not detected, step 7 is repeated, and if detected, the process proceeds to step 8.

"Step 8" The winding time required to wind one frame is read from the timing of the frame position detected in step 7 above using an internal timer, and is stored in the RAM in the microcomputer 53.

"Step 9" In order to know which frame the above winding time information corresponds to, a frame number is also stored in the RAM in correspondence with the above information.

Although this embodiment assumes a camera using the pre-wind method as described above, the present invention is also effective in the case of a camera that does not use this method (hereinafter referred to as a normal wind method) as described below. Yes, in this case, only the data at the time of film feed is stored as the winding time equivalent to a frame unit, and the feeding time of each frame after shooting (
This will be used to predict feeding speed).

"Step IOJ Temperature detection circuit 6 detects the temperature inside the camera.
4, measure the temperature, input this temperature information, and store it in the RAM.
memorize it internally.

"Step 11" The voltage detection circuit 65 is operated to measure the power supply voltage, and this power supply voltage information is input and stored in the RAM.

"Step 12" It is determined whether the prewind has been performed up to the number of films set in step 5. If the prewind has not been completed, the process returns to step 7, and if the prewind has ended, the process proceeds to step 13.

"Step 13" Switch SWI enters standby state.

Then, when the switch SW1 is turned on, the process proceeds to step 14.

"Step 14" The photometric circuit 51 is operated and the subject brightness information obtained here is input.

"Step 15" The distance measuring circuit 52 is operated and the object distance information obtained here is input.

"Step 16" Determine the state of switch SW2 and turn O
If N, proceed to step 18 in FIG. 6(b), and OF
If it remains F, the process advances to step 17.

"Step 17" Here, the state of the switch SWl is determined again, and if it remains ON, the process returns to step 16 and the switch SWl is turned on.
If it is FF, the process returns to step 13.

"Step 18" The lens control circuit 61 is controlled based on the object distance information (distance measurement information) obtained in step 15, and the photographic lens is focused.

"Step 19" The shutter control circuit 60 is controlled based on the subject brightness information (photometry information) obtained in step 14, and an exposure operation is performed on the film surface.

"Step 20" In order to know the temperature inside the camera at this point, the temperature detection circuit 64 is operated, and the obtained temperature information is input.

Step 21J: In order to know the state of the power supply voltage at this point, the voltage detection circuit 65 is operated, and the obtained power supply voltage information is input.

"Step 22" The winding time between one frame in step 8 and the winding time for one frame in step 9 are used to know the inclination that appeared in the prediction formula explained using FIG. 5(b) and the first winding time. In addition to the frame number, we also consider the number of films in step 5, the type of film in step 6, the temperature in step 10, the power supply voltage in step 11, the temperature in step 20, and the power supply voltage in step 21. Predicting the feeding time of the frame after shooting is performed.

"Step 23" The predicted feeding time is corrected using the correction value stored in step 31, which will be described later. Note that during the first few frames, the correction value is set to rOJ for the reason mentioned above.

"Step 24" Based on the result of step 23 above, the write frequency f for recording information to the magnetic storage section is determined.

"Step 25" The film feeding motor is reversed via the motor control circuit 59 at a speed according to the corrected feeding time to start rewinding the film.

"Step 26" The magnetic head 6 is actually driven via the I\rad control circuit 62 to write the various kinds of photographic information mentioned above onto the magnetic memory provided in the film being fed.

"Step 27" It is determined whether or not the frame position has been detected by the frame position detection circuit 63. If detected, the process proceeds to step 28.

"Step 28" Drive of the film feeding motor is prohibited via the motor control circuit 59, and rewinding of the film is stopped.

"Step 29" Here, the actual time required to rewind the photographic frame is stored.

"Step 30" The power supply voltage, temperature, and frame number at this time are memorized.

"Step 31J: Analyze the difference between the feeding time predicted in step 22 and the actual feeding time stored in step 29, and take into account the information in step 30, and then In step 22, a correction value for the predicted feeding speed is determined for the captured frame, and this correction value is stored.

"Step 32" Current frame number and step 5
It is determined from the number of films in step 1 whether all the frames have been photographed. If not, the process returns to step 13 and the same operation is repeated, and if it has been completed, the process proceeds to step 33.

``Status 33'' The film feeding motor is reversed via the motor control circuit 59, and all the film is wound into the film cartridge.

"Step 34" It is determined whether or not there is a film cartridge in the film cartridge chamber 3 based on the state of the switch 57, and when there is no film cartridge, the process returns to step 1 in FIG. 6(a).

FIG. 7 shows an example of changes in the winding time t due to temperature changes.

As the temperature rises, the winding time tends to become faster due to a reduction in the film winding load, a reduction in the friction of the gear train, and an increase in the efficiency of the power source battery, while at a lower temperature, the winding time tends to become slower. Therefore, in the step 22, the feeding speed obtained under other conditions is predicted by the temperature based on the ratio when the normal temperature is set to "1".

FIG. 8 shows changes in the winding time t due to changes in the power supply voltage.

It is well known that the higher the power supply voltage, the faster the rotation of the film feeding motor becomes, and the shorter the winding time t becomes. In step 22, in addition to the correction for this, since the camera in this embodiment uses a briwind system, power is continuously consumed during winding, and a voltage drop occurs as the winding progresses. When shooting a single frame, the power must be restored, so we take this into consideration when making corrections.

FIG. 9 is a plot of the difference in the average winding time depending on the number of films (total number of films).

If all information is stored during pre-winding as shown in Figure 5(a), the impact will be small, but if no information is stored during pre-winding or if the normal winding method is used, the load will increase as the amount of winding increases. By using this number of films as one of the correction factors in step 22, it is possible to predict the feeding speed more accurately. Become. Furthermore, when the diameter of the spool in the film cartridge changes depending on the number of films, such as when shooting 12 or 24 films, this information is essential for predicting the feeding speed.

In addition, in this embodiment, the load fluctuation caused by the winding amount and the remaining amount is included as a correction factor, but since these relationships depend on the total number of films, from this point of view, the number of films is important information. It would be one.

FIG. 10 is a plot of the difference in the average winding time t when the film type, for example, manufacturer reversal/negative, film sensitivity, etc., is classified into A-H.

If the camera has information about the average film type in this way, it becomes possible to predict the feeding speed corresponding to various types of film, but in step 22, taking this into account, the film type information is I am using it.

Furthermore, it is also possible to correct the fact that changes due to temperature differ depending on the type of film. That is, it is possible to handle corrections other than changes in the apparent spool diameter.

FIG. 11 is a flow chart showing the operation of the main parts in another embodiment of the present invention, and
Steps 20 to 25 in Figure (b) are partially modified. Note that the same step number indicates a part that performs the same operation, so the details are omitted here.

After step 20, the process proceeds to step 24, where the film starts to rewind, and then proceeds to step 21, where the power supply voltage is measured, and in the next step 31, the change in the power supply voltage measured in step 21 is approximately It is determined whether the voltage has become constant (stable) or not, and if it is not constant, the process returns to step 21 and the power supply voltage is measured again. If it is determined in step 31 that the power supply voltage is constant, the process proceeds to step 22, where the feeding speed is predicted and calculated as described above. A writing frequency f for information recording is determined, and in step 25 the magnetic head 6 is actually driven to start writing information.

FIG. 12 is a diagram explaining the reason for performing the determination as described in step 31 of FIG. 11 above.

A necessary condition for writing information in step 25 in FIG. 6(a) is that the motor current is at or after time t2 in FIG. 12. Time t1 to t2 in FIG. 12 is the start-up time of the film feeding motor, and at this time, a large amount of current is flowing through the motor, so the power supply voltage is extremely low, so information is written at time t2. The subsequent steps are appropriate, and in order to achieve this, the determination flow of step 31 is provided.

FIGS. 13 and 14 show another embodiment of the present invention. In this embodiment, a camera using a normal wind system, which winds the camera each time a photograph is taken, is used as an example, instead of the above-described pre-wind system. ing.

In the case of this method, the winding time (feeding speed) of the frame after shooting is determined by the apparent change in the diameter of the film winding spool 7, using the winding time between each frame when the film is not fed as shown in FIG. The prediction is made and the film is wound. At this time, the latter part (Figure 5 (
The correction in part B' of b) may be performed using information such as the number of films of one type.

FIG. 14 shows a main flowchart related to the import of the various information shown in FIG. 13.

In step 41, film feed is started, and in the next step 42, the frame position is detected by perforation detection, and once the frame position is determined, step 43
Then, the winding time between perforations (between frames) is memorized. At the same time, in step 44, the power supply voltage is stored. In the next step 45, it is determined whether or not the film feeding up to the first frame of the film has been completed. If it has not been completed, the process returns to step 42. If it has been completed, it is assumed that the first frame has been reached and the process proceeds to step 46. , completes film feeding. Then proceed to step 47 and turn on the SWI.
enters standby state.

According to this embodiment, in a pre-wind camera, the winding time of each frame during pre-winding and the pre-stored information on the spool diameters of the film take-up spool and the spools in the film cassette are used to determine the time required for each frame after shooting. In order to predict the film feeding speed of a frame (see Figures 5(a) - 5(b)), in a normal wind camera, the frame after shooting is calculated based on the winding time of each frame during film feeding. The film feeding speed is predicted and the film feeding is performed based on this, and the feeding time of the next shooting frame predicted as described above is compared with the predicted time of the current shooting frame. Since the determination is made based on the actual required feeding time of the current photographic frame fed according to this predicted time and the power supply voltage information at this time, an encoder with an expensive and complicated configuration is required. It becomes possible to record high-density information within a predetermined range without using it.

In addition, the feeding time determined by predictive calculations is corrected based on the number of films, film type, temperature, etc., so not only changes in the apparent spool diameter but also
It is also possible to predict changes in the load of the film pull-out force, resulting in higher accuracy.

(Effects of the Invention) As explained above, according to the present invention, the film feeding time of each frame after shooting is determined based on the winding time between each frame during film feeding until at least reaching the frame to be shot. a prediction calculation means for predicting and calculating the prediction calculation means; a counting means for counting the actual feeding time of the shooting frame fed at a speed according to the predicted feeding time determined by the prediction calculation means; and a correction value calculation means for calculating a correction value based on the feeding time counted by the user and the predicted feeding time, and outputting the correction value to the prediction calculation means as a correction value for the predicted time of the next shooting frame. Further, a prediction calculation means predicts and calculates the film feeding time of each frame after shooting based on at least the winding time between each frame during film feeding until reaching the frame to be shot, and the prediction calculation means A counting means for counting the actual feeding time of the photographic frame fed at a speed according to the calculated predicted feeding time, and a voltage detecting means for detecting the state of the power supply voltage during operation of the counting means. , calculating a correction value based on the feeding time counted by the counting means, the predicted feeding time, and the respective information from the voltage detecting means, and using this as a correction value for the predicted time of the next shooting frame. The correction value calculation means outputs to the prediction calculation means, and by comparing the feeding time predicted by the prediction calculation means with the actually required feeding time and power supply voltage information, it is possible to determine the next time. Since the feeding time of the shooting frames is determined, it is possible to perform high-density recording within a predetermined range while preventing an expensive and complicated configuration.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, Fig. 2 is a flowchart showing its operation, and Fig. 3 is a rear view of a camera for realizing the embodiment of Figs. 1 and 2. , FIG. 4 is a block diagram showing the same configuration, and FIG. 5 (
Similarly, Figure 5(b) shows the apparent spool during film rewinding, which can be predicted from Figure 5(a). A diagram showing the feeding time varying with changes,
Figures 6 (a) and (b) are flowcharts showing the operation of the microcomputer shown in Figure 4, Figure 7 is a diagram showing the relationship between temperature changes and winding time, and Figure 8 is the relationship between power supply voltage status and winding time. 9 is a diagram showing the relationship between the number of various films and their average winding time, FIG. 10 is a diagram showing the relationship between film type and winding time, and FIG. 11 is a diagram showing the relationship between the number of various films and the average winding time. FIG. 12 is a flowchart showing the operation of the main parts in the embodiment, and FIG. 12 is a diagram to help explain the operation.
FIG. 3 is a diagram showing the feeding time that varies with apparent changes in the spool during film winding in another embodiment of the present invention, and FIG. 14 is a flowchart showing the main part of the operation. 1...Camera body, 6...Magnetic head, 7...Film winding spool, 53...
... Microcomputer, 59 ... Motor control circuit, 6
3... Frame position detection circuit, 101...
...control means, l0IA... calculation means, loI
B... Correction value calculation means, 102... Frame number detection means, 103... Storage means,
104...Film feeding means, 105...
...Counting means, 106...Magnetic head, 1
07... Voltage detection means.

Claims (2)

[Claims] (1) In a camera that uses a film with a magnetic memory unit that is equipped with a magnetic head that writes information to the magnetic memory unit of the film while the film is being fed, the film is fed at least until the frame to be photographed is reached. a prediction calculating means for predicting the film feeding time of each frame after shooting based on the winding time between each frame; and feeding at a speed according to the predicted feeding time determined by the predictive calculating means. a counting means for counting the actual feeding time of the photographed frame; a correction value is calculated based on the feeding time counted by the counting means and the predicted feeding time; A camera using a film with a magnetic storage unit, characterized in that a correction value calculation means is provided for outputting a correction value for the predicted time to the prediction calculation means. (2) In a camera that uses a film with a magnetic memory unit that is equipped with a magnetic head that writes information to the magnetic memory unit of the film while the film is being fed, the film is fed at least until the frame to be photographed is reached. a prediction calculating means for predicting the film feeding time of each frame after shooting based on the winding time between each frame; and feeding at a speed according to the predicted feeding time determined by the predictive calculating means. a counting means for counting the actual feeding time of the captured photographic frame; a voltage detecting means for detecting the state of the power supply voltage during operation of the counting means; and a feeding time counted by the counting means and the predicted feeding time. A correction value calculation means is provided for calculating a correction value based on the feeding time and the respective information from the voltage detection means, and outputting the correction value to the prediction calculation means as a correction value for the predicted time of the next shooting frame. A camera using a film with a magnetic memory section, characterized by: