JP3398208B2 - Film feed control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film feeding control device for detecting the perforations formed on a photographic film and controlling the feeding of the film.

[0002]

2. Description of the Related Art Currently, various photographic films are used. For general photography, a spool is rotatably provided inside the cartridge body, and the end portion of a 35 mm wide strip-shaped photographic film is attached to the spool. 135 fixed and wrapped
The type of photo film patrone is the most popular.
Recently, U.S. Pat.
As known from Japanese Patent No. 846418, and Japanese Patent Application Laid-Open No. 3-37645 by the present applicant, in the unused state, all of the photographic film is stored in the main body of the cartridge and the photographic film is rotated by rotating the spool. A photo film patrone that has the function of sending it out of the patrone body has been proposed. In each of these photographic film cartridges, the edge of the strip-shaped photographic film is
A perforation for feeding control is formed corresponding to each shooting frame. Therefore, in a camera using such a photographic film, the number of passing perforations may be counted, and the feeding of the photographic film may be stopped when the counted value reaches a predetermined value.

For example, in the film feeding control device described in Japanese Patent Application No. 5-258716, an electric motor for feeding the film is provided, and perforation corresponding to the next frame is detected within a predetermined time. Depending on whether or not to do so, the photographable portion and the end portion of the photographic film are discriminated. This film feeding control device is premised on that the feeding speed of the photographic film is always constant, and when the feeding reaches the end of the photographic film, the motor continues to rotate until a predetermined time elapses. The motor will be stopped later.

[0004]

However, the rotation speed of the motor tends to fluctuate due to changes in conditions such as the voltage of the power supply battery and the ambient temperature, and in practice, it is difficult to always keep the feeding speed of the photographic film constant. Is. Therefore, it is difficult to set the predetermined time to an appropriate value in the film feeding control device described above. For example, if the predetermined time is set to a relatively long time, the photo film is pulled out to the final end and the motor load is increased. Will increase. On the other hand, if the predetermined time is set to a short time, there is a problem that it is not possible to accurately determine whether or not it is the final end of the photo film.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a film feeding control apparatus capable of controlling the feeding stop at the film end portion without increasing the motor load. To aim.

[0006]

In order to achieve the above object, a film feeding control device of the present invention comprises pulse signal generating means for generating a pulse signal in synchronization with rotation of a motor,
Photographic film on the basis of the number of pulse signals generated by the pulse signal generating means while being fed first predetermined length feeding, each
Arithmetic means is provided for calculating the specified number of pulse signals generated during the feeding of the second predetermined length, which is longer than the interval length between shooting frames, and all the perforations corresponding to the exposed shooting frames are provided.
The rotation of the motor is stopped when the number of pulse signals output from the pulse signal generating means reaches the specified number calculated by the calculating means after the detection of the rotation is completed. The first predetermined length is preferably the length of the perforation in the film feeding direction . Further, the specified number of pulse signals should be recalculated each time the photographic film is fed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of a camera provided with the film feeding control device of the present invention. The camera body 10 is provided with a cartridge chamber 11 and a film roll chamber 12. The cartridge main body 13 in the cartridge chamber 11
And the film roll chamber 12 is provided with a take-up spool 15 for taking up the photographic film 14 pulled out from the cartridge body 13. An aperture 16 is formed between the patrone chamber 11 and the film roll chamber 12 to determine the exposure range for the photographic film 14 and cooperate with a film pressure plate 18 elastically attached to the back cover 17 to form the photographic film 14 Are positioned in the optical axis direction.

As shown in FIG. 3, the end of the photographic film 14 is fixed to a spool shaft 19 rotatably housed in the cartridge body 13. A pair of perforations 20a and 20b are formed on one side edge of the photographic film 14 so as to correspond to the shooting frames 14a, 14b, ..., 14 _END defined by the aperture 16. The perforations 20a and 20b are
It is formed at the tip and rear ends of each photographic frame 14a~14 _END. Further, a perforation 20c is provided at a position further apart from the perforation 20a on the front end side of the first shooting frame 14a by a distance L ₂ toward the front end. This perforation 20c is used for control when setting the photographing frame 14a on the aperture 16. Also, each perforation 20a
A length L ₁ in the feeding direction of ˜20 c, and a shooting frame 14 a
Each interval length L ₂ of up to 14 _END is standardized for each type of photographic film.

FIG. 1 shows a film feeding control apparatus of the present invention. The take-up spool 15 is rotated by driving a motor 22 incorporated therein. Motor 22
Is connected to a microcomputer 25 via a motor driver 23, and its drive and rotation direction are controlled. The rotation of the motor 22 is transmitted via the drive transmission device 26 to the fork 27 that engages with the spool shaft 19. The drive transmission device 26 is the microcomputer 2
Controlled by the signal from the motor 5, the motor 22 and the take-up spool 15 and the fork 27 are linked and released. The motor 22 is driven in the normal direction when the photo film 14 is wound on the take-up spool 15, and the cartridge main body 13 is driven.
When it is rewound inward, it is driven in reverse.

A sensor 30 for detecting the perforations 20a to 20c of the photographic film 14 is provided near the end of the aperture 16 on the take-up spool 15 side. The sensor 30 is, for example, an LED that emits infrared light.
And a phototransistor for receiving the reflected light, and outputs a signal of a level corresponding to the amount of the reflected light. The output signal of the sensor 30 is converted into a perforation signal by the perforation signal generator 31, and then sent to the perforation counter 32 via the microcomputer 25. The perforation signal generator 31 is at a high level when the film surface of the photographic film 14 faces the sensor 30, and the perforations 20a to 20a.
When either c is facing each other, a low level perforation signal is output. The perforation counter 32 sets the count value to “1” at the rising and falling edges of the perforation signal.
Step forward. Further, the count value of the perforation counter 32 is reset by a signal from the microcomputer 25 and becomes "0" when the rotation of the motor 22 is stopped.

A gear 33 meshes with the rotating shaft of the motor 22 and rotates as the motor 22 rotates. Gear 3
On the rotary shaft of No. 3, an encoder plate 34 having slits radially formed at a constant pitch on a disk is connected and rotates integrally with the gear 33. An encode sensor 35 is arranged near the encode plate 34. A pulse generator 36 is connected to the encode sensor 35, and the pulse generator 36 generates a pulse signal every time the encode sensor 35 detects a slit of the encode plate 34. Further, since the encoder plate 34 is rotating with the rotation of the motor 22, the pulse signal is generated every time the motor 22 rotates by a certain angle. The pulse signal generated by the pulse generator 36 is sent to the pulse counter 36 via the microcomputer 25, and the number thereof is counted.

The microcomputer 25 includes a photo file.
From the pulse generator 36 while the rum 14 is fed for a fixed length
An arithmetic unit 37 for calculating the number of generated pulse signals,
ROM storing programs, film feeding programs, etc.
39, L of photo film 14 ₁, L₂Standard data such as
RAMs 40 for storing are respectively connected. In addition,
The standard data of Photo Film 14 is Photo Film Patro.
When loading the camera into the camera, from the cartridge main body 13
Read via barcode.

The operation of the film feeding control device constructed as described above will be described with reference to FIGS.
When the cartridge main body 13 is loaded into the cartridge chamber 11 and the back cover 17 is closed, a loading completion signal is input to the microcomputer 25. The microcomputer 25 reads the standard data of the photographic film 14 from the cartridge main body 13 and stores it in the RAM 40, switches the drive transmission device 26 to the film winding transmission system, and connects the motor 22 with the take-up spool 15 and the fork 27. To do. Thereafter, the microcomputer 25 sets the first photographed frame 14a of the photographic film 14 as a frame.

The film set operation of the film is performed according to the sequence shown in FIG. Microcomputer 2
First, the motor 5 drives the motor 22 in the normal direction via the motor driver 23 to rotate the take-up spool 15 in the winding direction and the fork 27 in the film feeding direction. By rotating the fork 27, the photographic film 14 is sent out from the cartridge body 13. Further, the encoder plate 34 rotates with the rotation of the motor 22, and every time the encode sensor 35 detects a slit formed in the encode plate 34, a pulse signal is emitted from the pulse generator 36. At this time, since the encode plate 34 rotates integrally with the motor 22, the pulse signal is generated every time the motor 22 rotates by a certain angle. When the photo film 14 sent out from the cartridge body 13 reaches the sensor 30 and the output signal from the perforation signal generator 31 rises from low level to high level, the microcomputer 25
Activates the perforation counter 32.

When the photographic film 14 is fed forward and the edge portion of the perforation 20c on the front end side faces the sensor 30, the perforation signal output from the perforation signal generator 31 is output as shown in FIG. 6 (a). It falls from the high level to the low level, and the count value of the perforation counter 32 becomes "1". At this timing, the microcomputer 25 operates the pulse counter 37 and counts the number of pulse signals emitted from the pulse generator 36. Then, when the edge portion on the rear end side of the perforation 20c faces the sensor 30 and the perforation signal rises from the low level to the high level, the count value of the perforation counter 32 is advanced by 1 and becomes "2". At this timing, the microcomputer 25 stops the operation of the pulse counter 37.

Next, the microcomputer 25 sets the prescribed pulse signal number P _S according to the sequence shown in FIG. First, the microcomputer 25 reads the count value P ₁ from the pulse counter 37,
From 0 to the length L ₁ of each perforation 20a-20c
And the frame interval length L ₂ of the shooting frames 14a to 14 _END are read out and sent to the arithmetic unit 38. After that, the microcomputer 25 once resets the pulse counter 37 to set the count value to "0".

The arithmetic unit 38 obtains the number P ₂ of pulse signals generated from the pulse generator 36 while the photographic film 14 is fed by the frame interval length L ₂ . The pulse signal is
Since it is generated every time the motor 22 rotates by a certain angle,
The number of occurrences is proportional to the feeding length of the photographic film 14 regardless of the rotation speed of the motor 22. The count value P ₁ read from the pulse counter 37 is the number of pulse signals generated while the photographic film 14 is fed by the length L _{1 of the} perforation 20c, as shown in FIG. Therefore, the number of pulse signals P ₂ generated while the frame interval length L _{2 is} fed can be calculated by the formula P ₂ = P ₁ × (L ₂ / L ₁ ).

Next, the arithmetic unit 38 calculates the number of specified pulse signals P _S generated while the photographic film 14 is fed by the specified length L _S shown in FIG. The specified length L _S is the length of the monitoring area for determining the feeding position of the photo film 14, and the frame interval length is set so that the perforation 20a on the leading end side of the next shooting frame is included in this monitoring area. The length is set to about ₂ to 3 times L ₂ . Therefore, the ratio “L _S / L ₂ ” of the specified length L _S and the frame interval length L ₂
Is defined as N, the specified pulse signal number P _S can be calculated by the equation P _S = P ₂ × N.

When the prescribed number of pulse signals P _S is set, the microcomputer 25 operates the pulse counter 37 to restart counting the number of pulse signals. The count value of the pulse counter 37 is the specified pulse signal number P _S.
Before the above, when the edge portion on the tip side of the perforation 20a faces the sensor 30 and the count value of the perforation counter 32 becomes "3", the microcomputer 25 stops the rotation of the motor 22 at this timing. . As a result, the feeding of the photo film 14 is stopped, and the first photo frame 14a is set on the aperture 16 to be ready for photo shooting. At the same time when the motor 22 is stopped, the operation of the pulse counter 37 and the perforation counter 32 is stopped, and the respective count values are reset to “0”.

After this, photographing is performed, and when the exposure completion signal is sent to the microcomputer 25, the microcomputer 25 performs the frame setting operation again in the same manner as the first frame 15a to be photographed. First, the number P ₁ of pulse signals generated while the perforation 20b of the exposed frame is passing through the sensor 30 is counted, and the photographic film 14 feeds the prescribed length L _S based on the number P ₁ of pulse signals. The specified pulse signal number P _S generated during the operation is calculated. Since the specified length L _S is set to be longer than the frame interval length L _2, when there is an unexposed frame, as shown in FIG. 6A, the pulse generator 36
Until the number of pulse signals emitted from the device reaches the specified number of pulse signals P _S
a faces the sensor 30. As a result, the perforation signal changes from the high level to the low bell, and the count value of the perforation counter 32 becomes "3". Therefore, if the microcomputer 25 stops the rotation of the motor 22 at this timing, a new unexposed exposure is made. The shooting frame of is set in the aperture 16 and the shooting is ready again.

On the other hand, when the count value of the perforation counter 32 does not become "3" even when the number of pulse signals generated from the pulse generator 36 reaches the specified number of pulse signals P _S ,
As shown in FIG. 6B, the exposure of the last frame 14 _END has been completed, and the unexposed frames have already disappeared. Therefore, the microcomputer 25
It is judged that the feeding of the photographic film 14 has reached the end portion, and the rotation of the motor 22 is stopped to stop the normal feeding of the photographic film 14.

As described above, since the encode plate 34 rotates integrally with the motor 22, the pulse signal is generated every time the motor 22 rotates by a certain angle. For this reason,
When the winding amount of the photo film 14 of the take-up spool 15 increases and the diameter thereof increases, the feeding amount of the photo film 14 also increases while the motor 22 rotates by a certain angle. Therefore, the photo film 14 has a specified length L. _The number of pulse signals generated during _S- feed is reduced. However, the specified pulse signal number P
_{Since S} is calculated based on the number of pulse signals P ₁ counted immediately before that, the specified length L _S does not fluctuate due to the influence of the winding thickness of the take-up spool 15, and is always maintained at a constant length. Be drunk Therefore, the last shooting frame 14
_{At the time when} the PER perforation 20b has passed and the prescribed length L _S has been fed, the photo film 14 is surely supplied.
Stop control is started, and it is not pulled out to the final end of the photo film 14.

The microcomputer 25 includes a motor 22
When the rotation of the motor 22 is stopped, the drive transmission device 26 is switched to the film rewinding transmission system, the connection between the motor 22 and the take-up spool 15 is released, and the motor 22 and the fork 27 are released.
Work with. Thereafter, the microcomputer 25 drives the motor 22 in the reverse direction via the motor driver 23,
The fork 27 is rotated in the film rewinding direction for a predetermined time. By the rotation of the fork 27, the exposed photographic film 14 is rewound into the cartridge main body 13.

In the above embodiment, each time the paper is fed,
Based on the counted pulse signal number P ₁ , the frame interval length L ₂
The number of pulse signals P ₂ corresponding to
_The specified pulse signal number P _S is calculated by multiplying ₂ by N, but since the perforation length L ₁ and the frame interval length L ₂ are known, “M> L ₂ / L ₁ ”. The M value may be calculated in advance and the M value may be directly added to the count value P ₁ of the pulse signal.

[0025]

As described above, according to the film feeding control apparatus of the present invention, the number of pulse signals generated while the photographic film is fed by the predetermined length longer than the frame interval length is the specified number. Since it becomes possible to stop the rotation of the motor when it becomes low, it is possible to accurately control the stop of the feeding at the end portion of the photographic film without increasing the motor load. Moreover, since the prescribed number of pulse signals is reset every time one frame of the photographic film is fed, this predetermined length is always a fixed length without being influenced by the winding thickness of the take-up spool.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a film feeding control device of the present invention.

FIG. 2 is a schematic view showing an example of a camera provided with the film feeding control device of the present invention.

FIG. 3 is an explanatory diagram showing a configuration of the photographic film shown in FIG.

FIG. 4 is a flowchart showing a sequence of a frame setting operation by the film feeding control device shown in FIG.

FIG. 5 is a flowchart showing a setting sequence of a prescribed pulse signal number.

FIG. 6 is a timing chart showing the relationship between the feeding position of the photographic film and the generation timing of each signal.
Shows the case where there is an unexposed frame, and (b) shows the case where the end portion is reached.

[Explanation of symbols]

14 Photo film 20a, 20b, 20c Perforation 22 motor 25 microcomputer 30 sensors 31 Perfor signal generator 32 perforation counter 33 gears 34 Encoding board 35 Encoding sensor 36 pulse generator 37 pulse counter 38 Operation part

Claims (3)

(57) [Claims] 1. A motor for feeding a photographic film is provided,
In a film feeding control device for feeding and controlling a photographic film while detecting perforations formed corresponding to each frame, a pulse signal generating means for generating a pulse signal in synchronization with rotation of the motor, and a photographic film. Is fed for a first predetermined length, and is fed for a second predetermined length which is longer than the interval length between the shooting frames based on the number of pulse signals generated by the pulse signal generating means. a calculation means for calculating a defined number of pulse signals generated during that provided, against the exposed photographic frame
The rotation of the motor is stopped when the number of pulse signals output from the pulse signal generating means reaches the specified number calculated by the calculating means after the detection of all the corresponding perforations is completed. A film feeding control device. 2. The film feeding control device according to claim 1, wherein the first predetermined length is a length of perforation in a film feeding direction. 3. The specified number of pulse signals is calculated each time a photographic film is fed.
2. The film feeding control device described in 2 .