JP2941019B2 - Camera using film with magnetic storage - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a camera using a film with a magnetic storage unit provided with a magnetic head for writing information to a magnetic storage unit provided on the film.

BACKGROUND OF THE INVENTION Conventional magnetic information recording devices perform recording at an appropriate density by feeding a magnetic recording medium at a constant speed or detecting the speed of the magnetic recording medium by an encoder. Was possible.

On the other hand, as described in U.S. Pat.No. 4,864,332 and the like, a camera capable of recording shooting information such as a shutter speed and an aperture value in a magnetic storage unit provided on a film using a magnetic head is known. Proposed.

However, in the cameras of the above proposals, etc., the length of information that can be recorded per frame of film is limited,
The information per frame must not exceed the length, but in the camera where constant speed feed is almost impossible,
In order to realize the above, there is a disadvantage that an encoder having an expensive and complicated configuration must be provided.

In addition, there is a system that detects the power supply voltage of the camera and feeds the film by the duty drive based on this, and tries to keep the feeding speed as constant as possible. However, it was insufficient when trying to record the information at a high density.

(Object of the Invention) An object of the present invention is to provide a magnetic storage unit capable of performing high-density recording within a predetermined range while solving the above-mentioned problems and preventing an expensive and complicated structure. It is to provide a camera using a film.

(Features of the Invention) In order to achieve the above object, the present invention provides a magnetic head for writing information to a magnetic storage unit provided on a film during film feeding, and a frame for detecting information on a frame number. In a camera using a film with a magnetic storage unit provided with a number detecting means, time detecting means for detecting information on a feeding time between frames during film feeding until reaching a first photographing frame; Storage means for storing the information detected by the means, and information on the frame number detected by the frame number detection means from the information from the storage means to the magnetic storage unit of the frame fed after shooting. Frequency determining means for determining the information writing frequency.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, and its operation will be described below with reference to a flowchart shown in FIG. In the present embodiment, a so-called pre-wind camera is used in which the film is wound up once and the image is taken back while being rewound frame by frame.

The control means 101 first determines whether or not the back lid has been closed in step 201, and when it is determined that the back lid has been closed, proceeds to step 202 assuming that the film cartridge has been loaded into the camera, and drives the film feeding means 104. Then, winding of the film provided with the magnetic storage unit is started. Next step
At 203 and 204, the current frame number and the time required to wind up one frame are detected from information from the frame number detecting means 102 and the timer 101B for detecting the number of the frame detected by the frame position detecting means (not shown). Is stored in the storage unit 103 in association with the information. The storage means 103 stores a film take-up spool (a film feed spool for feeding a film until a frame to be shot) and a spool in a cartridge (a film feed spool for a frame after shooting). The spool diameter is stored. In the next step 205, it is determined whether or not the winding of all the films (total number) has been completed.
That is, it is determined whether or not the prewind has been completed, and if not, the same operation is repeated thereafter. Thereafter, the process proceeds to step 206 by confirming the end.

In step 206, the first stroke of the release button
The state of the switch SW1 to be N is determined, and when it is determined that the switch SW1 is turned on, the process proceeds to steps 207 and 208, where the light measuring means and the distance measuring means (not shown) are operated to obtain light measuring and distance measuring information. Next, at step 209, the state of the switch SW2 which is turned on by the second stroke of the release button is determined. If it is determined that the switch SW2 has been turned on, the process proceeds to step 210, where known lens control and shutter control, that is, focus adjustment and film surface exposure operation are performed.

In the next step 211, the arithmetic means 101A in the control means 101
, The current photographing frame number is detected from the information from the frame number detecting means 102, and the film feeding speed suitable for this photographing frame number (the rewind speed is assumed in this embodiment because the prewind system is assumed). ) Is performed. Although the details will be described later, the arithmetic means 101A calculates the information stored in the storage means 103 in the steps 203 and 204 and the change in the apparent film take-up spool diameter (as the winding proceeds, the spool diameter increases, Based on the apparent change in the diameter of the spool in the film cartridge (this is performed based on the diameter of each spool), the feeding speed for the frame after photographing is predicted and calculated based on the assumed (higher feeding speed).

In the next step 212, the control means 101 instructs the film feeding means 104 to feed the film according to the predicted calculated feeding speed. In step 213 the magnetic head
The 105 is driven, and a shutter frequency, an aperture value, a shooting date, a comment, etc. are taken into the magnetic storage unit of the film being fed as described above at the writing frequency determined based on the film feeding speed. Write information.

In the next step 214, it is determined whether or not the feeding of the photographic frame has been completed. When it is determined that the feeding has been completed, the process proceeds to step 215, where a command to stop the film feeding is issued to the film feeding means 104. Next, in step 216, it is determined whether or not the film has been completed, that is, whether or not shooting of all frames has been completed. If not, the process returns to step 206, and the same operation is repeated. When the photographing of all the frames is completed, the operation of winding all the films into the film cartridge is started as is well known.

As described above, based on the winding time information of each frame stored in the storage means 103 at the time of film winding and the apparent change in the spool diameter in the patrone assumed from the apparent change in the film winding spool diameter, Since the feeding speed is estimated and calculated, high-density information recording can be performed within a predetermined range without using an expensive and complicated encoder.

FIG. 3 is a diagram in which a camera capable of realizing the above-described embodiment is written from the back with a back cover removed.

In FIG. 3, 1 is a camera body, 2 is a finder,
Reference numeral 3 denotes a film cartridge chamber, and reference numeral 4 denotes a fork, which drives a spool in the film cartridge to rewind the film. Reference numeral 5 denotes a film aperture, 6 denotes a magnetic head, and 7 denotes a film take-up spool, which is driven when winding the film.

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

In FIG. 4, reference numeral 51 denotes a photometric circuit for measuring the brightness of the subject to be photographed, and 52, a distance measuring circuit for measuring the distance to the subject. Reference numeral 53 denotes a microcomputer for controlling various circuits (hereinafter, referred to as a microcomputer).
It has RAM and the like. 54 is a switch for starting photometry and distance measurement (hereinafter referred to as SW1) which is turned on by a first stroke of a release button (not shown) of a camera, and 55 is a switch for starting a release operation by being turned on by a second stroke of the release button. (Hereinafter referred to as SW2). Reference numeral 56 denotes a camera back cover switch (not shown), which is turned on and off in response to opening and closing of the back cover.
I do. A switch 57 detects the presence or absence of a film cartridge (not shown). 58 included in the film patrone
This is a DX code reading circuit that reads the number of films and the type of film (for example, manufacturer, reversal / negative, film sensitivity, etc. (these are used to determine the type of film base and emulsion to predict film withdrawal and winding forces) from the DX code).

Reference numeral 59 denotes a motor control circuit for controlling a film feeding motor (not shown). The film is wound up by forward rotation of the motor and rewound by reverse rotation. Numeral 60 denotes a shutter control circuit for controlling exposure to the film, numeral 61 denotes a lens control circuit for controlling the position of the taking lens so that the subject is in focus, and numeral 62 denotes a film which controls the magnetic head 6 shown in FIG. This is a head control circuit for recording and reading various information to and from a magnetic storage unit provided. 63 is 1 on the film
This is a frame position detection circuit that detects one frame (one frame per frame), and includes a method of detecting perforation or a method of detecting a film traveling amount. Reference numeral 64 denotes a temperature detection circuit, which is configured independently in the present embodiment, but can be used also as the photometry circuit 51. A voltage detection circuit 65 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 the film winding time during prewinding (ie, changes in the feeding speed).

The film is wound up by the film take-up spool 7, but the winding time per frame becomes apparently larger as the film is wound on the film take-up spool 7, so that the winding speed becomes faster. As shown in FIG. 5A, the winding time t is reduced. On the other hand, if the spool diameter is large, the load increases, so that the spool diameter does not simply increase (Section B).

In the case of the prewind system as in the present embodiment, recording the winding time for all frames at the time of prewind is more effective information at the time of film feeding (rewinding). However, load fluctuations due to the number of turns can be predicted and corrected.

FIG. 5 (b) is a diagram in which the time between photographing frames at the time of rewinding is predicted using the information of FIG. 5 (a).

In the rewinding direction, since the film is wound around the spool in the film cartridge, the rewinding time t 'takes a long time at first, and as the photographing frame (frame number) advances, the winding diameter increases, and the rewinding time t 'Becomes shorter. On the other hand, since the load increases as in the winding, the rewinding time t 'does not decrease monotonously (part B').

Therefore, it is possible to make correction using the information of FIG. 5A stored at the time of prewind. That is, the predictions shown in FIGS. 5 (a) and 5 (b) can be made by calculating the ratio between the rotation speed and diameter of the film take-up spool 7 and the rotation speed and diameter of the spool in the film cartridge. That is, the initial speed at which winding starts around each spool is obtained, and then the ratio of the apparent spool diameter due to the film thickness is obtained using the ratio of each spool diameter to obtain the inclination. Finally, the part (part B) which is not changed linearly is corrected by the raw data shown in FIG. 5 (a). The inclination of the portion B can also be predicted by predicting and correcting the load fluctuation from the remaining amount and the winding amount of the film.

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

In FIG. 5 (a), N: the total number, M: the frame number of the portion (A → B) where the winding time is not a linear change,
t ₀ : initial winding time, A: slope between (N to M), B (M
傾 き 1). Further, n in the following equation means a frame being fed.

_{tn = t 0 -A (N-} n) ∴ (N ≧ N ≧ M) tn = t 0 -A (N-M) -B (M-n) ∴ (M ≧ n ≧
1) Next, the diameter of the film take-up spool 7 D _1, the rotation speed at no load v _1, the spool diameter of the film cartridge D _2, the rotation speed of the unloaded and v _2.

In FIG. 5B, t ₀ ′ = D ₂ / D ₁ × v ₂ / v ₁ × t ₀ A ′ = A × D ₁ / D ₂ B ′ = B × D ₁ / D ₂ , and tn ′ _{= t 0 '-A' (n} -1) ∴ (M ≧ n ≧ 1) tn '= t 0' -A '(M-1) -B' (n-M) ∴
(N ≧ n ≧ M).

In the above approximation, it is sufficiently considered that the correction term increases by taking into account the film type, the temperature, and the state of the power supply voltage, so that appropriate information can be recorded. In consideration of these, as described below, the feed speed is predicted.

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

FIGS. 6A and 6B are operation flowcharts of the microcomputer 53 shown in FIG. 4 having a function of performing the above-described prediction calculation.

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

"Step 2" Whether the film cartridge is loaded in the film cartridge chamber 3 is determined 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] The film feed motor (not shown) is rotated forward through the motor control circuit 59 to start film winding.

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

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

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

"Step 7" It is determined whether or not one frame has been detected by the frame position detection circuit 63 which detects the position of the frame from perforation or the like. If not detected, Step 7 is repeated.

[Step 8] The winding time required to wind up one frame from the timing of the frame position detected in Step 7 is read from the internal timer, and RA in the microcomputer 53 is read.
Remember in M.

[Step 9] In order to know what frame the winding time information is, the frame number is also stored in the RAM in association with the information.

In this embodiment, a pre-wind camera is assumed as described above. However, in the case of a camera other than the pre-wind camera (hereinafter referred to as a normal wind camera), the present invention is effective as described below. In this case, only the data at the time of film idle feeding is stored as a winding time corresponding to a frame unit, and is used for predicting the feeding speed of each frame after photographing.

[Step 10] The temperature in the camera is measured by operating the temperature detection circuit 64, and this temperature information is input and stored in the RAM.

[Step 11] The power supply voltage is measured by operating the voltage detection circuit 65, and the power supply voltage information is input and stored in the RAM.

[Step 12] It is determined whether or not prewinding has been performed up to the number of films set in step 5, and if not completed, the process returns to step 7;

[Step 13] The switch SW1 enters a standby state. When the switch SW1 is turned on, the process proceeds to step 14.

[Step 14] The photometric circuit 51 is operated to input the subject luminance information obtained here.

[Step 15] The distance measuring circuit 52 is operated to input the subject distance information obtained here.

"Step 16" The state of the switch SW2 is determined. If the switch SW2 is ON, the process proceeds to step 18 in FIG. 6B, and if the switch SW2 remains OFF, the process proceeds to step 17.

[Step 17] Here, the state of the switch SW1 is determined again. If the switch SW1 remains ON, the process returns to step 16, and if the switch SW1 is OFF, the process returns to step 13.

[Step 18] Based on the subject distance information (distance measurement information) obtained in Step 15, the lens control circuit 61 is controlled to focus the photographing lens.

"Step 19" The shutter control circuit 60 is controlled based on the subject luminance information (photometric information) obtained in Step 14,
The film surface is exposed.

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

[Step 21] The voltage detection circuit 65 is operated to know the state of the power supply voltage at this time, and the obtained power supply voltage information is input.

"Step 22" The winding time between one frame in Step 8 and the frame number in Step 9 for knowing the inclination and the initial winding time expressed in the prediction formula described with reference to FIG. In addition, taking into account 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, Of the feed speed of the frame.

[Step 23] A write frequency f for recording information on the magnetic storage unit is determined based on the result of Step 22 described above.

[Step 24] The film feed motor is reversed via the motor control circuit 59 at the feed speed determined by the above-described prediction calculation, and rewinding of the film is started.

[Step 25] The magnetic head 6 is actually driven via the head control circuit 62, and the various kinds of photographing information described above are written on the magnetic storage provided in the film being fed.

"Step 26" It is determined whether or not the frame position is detected by the frame position detection circuit 63, and the flow proceeds to step 27 when the frame position is detected.

[Step 27] The drive of the film feed motor is prohibited via the motor control circuit 59, and the rewinding of the film is stopped.

[Step 28] It is determined from the current frame number and the number of films in step 5 whether or not shooting for all frames has been completed. If not completed, the process returns to step 13 and the same operation is repeated thereafter. Goes to step 29.

[Step 29] The film feed motor is reversed through the motor control circuit 59, and the entire film is wound into the film cartridge.

[Step 30] From the state of the switch 57, it is determined whether or not the film cartridge is in the film cartridge room 3, and
When it disappears, the process returns to step 1 of FIG.

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

When the temperature increases, the winding time tends to be shorter due to a decrease in film winding load, a reduction in gear train friction, an increase in the efficiency of a power supply battery, and the like, and at a lower temperature, the winding time tends to be slower. Therefore, in the step 22, the feeding speed obtained under other conditions or the like is estimated by the temperature and the ratio when the normal temperature is set to "1".

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

It is well known that the higher the power supply voltage, the faster the rotation of the film feed motor and the shorter the winding time t. In step 22, in addition to the correction based on this, in addition to the fact that the camera in this embodiment is of a pre-wind type, continuous power consumption is performed at the time of winding, and a voltage drop occurs according to the winding. Since the power supply is restored in the shooting of one frame, correction is made in consideration of this fact.

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

The effect is small when all information is stored during prewinding as shown in FIG. 5 (a). However, in the case where no information is stored during prewinding or in the case of the normal winding method, the load increases as the winding amount increases. By using this number of films as one of the correction terms in step 22, it is possible to more accurately predict the feeding speed because of the increase in the drawing force when the film cartridge is tightly packed in the film cartridge. . Further, when the spool diameter in the film cartridge changes according to the number of films, such as taking 12 or 24 images, it is indispensable information for predicting the feeding speed.

Further, in the present embodiment, the load variation caused by the winding amount and the remaining amount is included as a correction term. However, since these relationships depend on the total number of films, the number of films is important information from this point as well. It will be one.

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

Since the camera has information on the average film type in this manner, it is possible to predict the feeding speed corresponding to various types of films. Used.

Further, it is possible to correct that the change due to the temperature varies depending on the type of the film. That is, it is possible to cope with a correction other than the apparent change in the spool diameter.

FIG. 11 is a flowchart showing the operation of the main part in another embodiment of the present invention.
Steps 20 to 25 in FIG. 9B are partially modified. Note that the same step number is a part that performs the same operation, and thus the details are omitted here.

After step 20, the process proceeds to step 24, in which rewinding of the film is started, and then the process proceeds to step 21 to measure the power supply voltage.In the next step 31, the change in the power supply voltage measured in step 21 is substantially It is determined whether or not the power supply voltage has become constant (stable). If the power supply voltage 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, in which the feed speed prediction calculation is performed as described above, and in the next step 23, information is recorded by the magnetic head 6 based on the above information. The write frequency f is determined, and in step 25, the magnetic head 6 is actually driven to start writing information.

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

The recording of the information performed in step 25 of FIG.
It is a necessary condition is the time of time t ₂ after the motor current of FIG. 12. 12th time t ₁ ~t ₂ in figure when the rise of the film feeding motor, and a large amount of current flows to this Sai該motor, thus the writing because the supply voltage is extremely low information time t ₂ later always becomes proper, is provided with a determination flow of the step 31 in order to achieve this.

FIG. 13 is a flowchart showing the operation of the main part in another embodiment of the present invention. In this embodiment, the time and temperature actually required for the feeding with respect to the expected feeding time are shown.
The power supply voltage and the frame number are stored to correct the feeding time (feeding speed) of the next photographing frame. The step shown in FIG.
The part between 27 and step 28 is partially deformed. Note that the same step numbers as those in FIG. 6 (b) denote the parts performing the same operations, and thus the details thereof are omitted here.

After stopping the film rewinding in step 27, the process proceeds to step 27-1, where the time actually required for rewinding is stored. In the next step 27-2, the power supply voltage, temperature, and frame number at this time are stored. In a step 27-3, the difference between the feeding time predicted in the step 22 and the feeding time stored in the step 27-1 is analyzed.
After taking into account the information stored in -2, a correction value of the feeding speed predicted in step 22 in the next shooting frame is obtained, and this correction value is stored.

FIG. 14 and FIG. 15 show still another embodiment of the present invention. In this embodiment, not a pre-wind system described above, but a camera of a no-pre-wind system which winds up for each ordinary photographing. An example.

In the case of this system, the winding time (feeding speed) of the frame after photographing due to a change in the diameter of the apparent film take-up spool 7 is determined by using the winding time between the frames during the film idle feeding shown in FIG. And the film is wound up. At this time, the correction in the latter half (the portion B 'in FIG. 5B) may be performed based on information such as the number of films and the type.

FIG. 15 shows a main flowchart relating to the import of various information shown in FIG.

In step 41, the idle film feed is started. In the next step 42, the frame position is detected by perforation detection. When the frame position is determined, the process proceeds to step 43, where the winding time between perforations (between frames) is stored. At the same time, the power supply voltage is stored in step 44. In the next step 45, it is determined whether or not the film idle feeding up to the first frame of the film has been completed. If not completed, the process returns to step 42. If completed, the process proceeds to step 46 on the assumption that the first frame has been reached. Then, the empty film feed is ended.
Then, the process proceeds to a step 47, wherein a standby state for turning on the SW1 is entered.

In each of the above embodiments, in the pre-wind camera, the pre-winding time of each frame and the pre-stored information of the spool diameter of each of the film take-up spool and the spool in the film cartridge are stored in advance. The film feed speed of the frame is predicted and calculated (FIG. 5 (a) → FIG. 5 (b)). In a normal wind type camera, the film feed speed after photographing is determined from the winding time of each frame during the film idle feed. Since the film feeding speed of the frame is estimated and calculated, and the film feeding is performed based on this, it is possible to write information to the magnetic storage unit provided in the film at a high density within a predetermined range. In addition, the encoder for detecting the amount of movement of the film can be omitted from this fact. The simplification can be achieved.

In addition, since the feeding speed determined by the prediction calculation is corrected based on the number of films, film type, temperature, power supply voltage, etc., not only changes in the apparent spool diameter but also load fluctuations in the film pulling force. Etc. can also be predicted, and more accurate results can be obtained.

(Effects of the Invention) As described above, according to the present invention, the information about the feeding time between frames and the information about the frame number during the film feeding until reaching the first shooting frame and the information about the frame number are used. Since the frequency of writing information to the magnetic storage unit of the transmitted frame is determined, it is possible to perform high-density recording within a predetermined range while preventing an expensive and complicated configuration. Become.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing the operation thereof, and FIG. 3 is a rear view of a camera for realizing the embodiments of FIGS. , FIG. 4 is a block diagram showing the same configuration, FIG. 5 (a) is a diagram showing the feed speed which varies with an apparent spool change during film winding, and FIG. 5 (a) is a diagram showing the feeding speed which fluctuates with an apparent spool change at the time of film rewind which can be predicted from FIG. 5 (a). FIGS. 6 (a) and 6 (b) are flowcharts showing the operation of the microcomputer shown in FIG. , FIG. 7 is a diagram showing the relationship between the temperature change and the winding time, FIG. 8 is a diagram showing the relationship between the power supply voltage state and the winding time, and FIG. Fig. 10 shows the relationship between film types and winding Diagram showing the relation between between, Fig. 11 is a flowchart showing the operation of the main part according to another embodiment of the present invention, Figure 12 is a diagram for aid in the description,
FIG. 13 is a flow chart showing the operation of the main part in another embodiment of the present invention, and FIG. 14 is a feeding speed fluctuating with an apparent spool change at the time of film winding in still another embodiment of the present invention. FIG. 15 is a flowchart showing a main part of the operation. 1 camera body, 6 magnetic head, 7 film take-up spool, 53 microcomputer, 59 motor control circuit, 63 frame position detection circuit, 101 control means, 1
01A: arithmetic means, 101B: timer, 102: frame number detecting means, 103: storage means, 104: film feeding means, 105: magnetic head.

Claims (1)

(57) [Claims] 1. A film with a magnetic storage unit, comprising: a magnetic head for writing information to a magnetic storage unit provided on the film during the feeding of the film; and a frame number detecting means for detecting information on a frame number. In a camera using, during film feeding until the first photographing frame is reached, time detecting means for detecting information on a feeding time between frames, and storage for storing the information detected by the time detecting means Means for determining, from the information from the storage means and the information on the frame number detected by the frame number detection means, a writing frequency of the information to be written to the magnetic storage unit of the frame fed after photographing; and A camera using a film with a magnetic storage unit, comprising: