JP2001013563A - Film feeder for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of suppressing an influence of a static mark, etc., due to static electricity. SOLUTION: The film feeder is provided with driving means 1, 14, 15 and 16 for feeding a film, film feeding detecting means 11, 12, 13 and 17 for detecting the film feeding and a control means 19 for controlling the driving means based on the detection information from the film feeding detecting means and controlling the drive of the film. In this case, the control means 19 is provided with a humidity detecting means 21, and a film driving device is varied based on the humidity detection result so as to change the film feeding velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film feeder for a camera.

[0002]

2. Description of the Related Art In recent years, the automation of cameras has advanced, and most cameras automatically perform film feeding operations such as loading and rewinding and rewinding after filming.

A major problem in automation of a conventional film feeding operation is how to feed the film with high accuracy.
In particular, many proposals have been made regarding correction for temperature changes. This is a problem in the control of the automatic film feeder, and the driving state of the film is detected optically and electrically.

In many cases, a photo interrupter is turned on / off by a light-shielding member that repeats light-shielding and non-light-shielding in conjunction with the rotation of a film moving sprocket or the like, and the number of pulses generated thereby is detected in accordance with the amount of movement. Alternatively, a method is employed in which a change in light-shielding properties of a hole and a non-hole in perforation of a film is detected by an optical / electrical detector including a light emitting element and a light receiving element.

[0005] For example, in Japanese Patent Application Laid-Open No. 2-256038,
By obtaining a photoelectric conversion signal using the optical characteristic difference between the perforated and non-perforated portions of the film, that is, light transmittance or reflectance, the threshold level is calculated from the maximum value and the minimum value, A proposal has been disclosed in which a drive value of a film winding motor is controlled by comparing a detected value with a threshold level.

Further, in this case, the threshold level is variably set for each film to be used at the stage of film auto-loading or pre-winding so as to absorb the difference between the detection levels of various films and avoid erroneous detection. In addition, the control is performed so as to cope with a temperature change by correcting the threshold level based on the detected value of the ambient temperature.

Further, Japanese Patent Application Laid-Open No. 4-50827 proposes that the ambient temperature is detected for the deceleration curve of the film winding motor and the correction by the temperature change is performed in more detail.

On the other hand, Japanese Patent Application Laid-Open No. 6-75279 describes that a more appropriate film feeding operation is performed by performing control correction based on humidity.

[0009]

However, the above-mentioned prior art relates to a method for realizing film feeding with high accuracy, and in particular, shows a disclosed example in which the purpose is to correct for changes in ambient temperature or humidity. However, it is well known that there is another major problem with humidity. It is a static mark,
Or, due to a phenomenon called electrostatic fogging, when a film is wound up or rewound, point-like, tree-like, or feather-like reflections occur due to static electricity charging / discharging due to friction between the film and the patrone or the pressure plate. This is a phenomenon that can occur. This is a phenomenon caused by static electricity, and it is needless to say that the influence of humidity is great.

Conventionally, the phenomenon of reflection due to static electricity and adhesion of dust have been regarded as problems. However, recording of high-level information on the transparent magnetic layer of the film has become possible, and reading / writing errors of magnetic information have been reduced. The importance of responding to is also becoming important. For example, Japanese Patent Application Laid-Open No. Hei 7-181630 proposes to use a conductive material or an antistatic agent in order to reduce the surface resistivity of the resin material of the film cartridge or the pressure plate, and to electrically ground the pressure plate. It has been disclosed.

Japanese Patent Application Laid-Open No. HEI 6-175297 discloses a proposal in which static electricity generated in a photographic film in a patrone is leaked to the outside by imparting conductivity to patrone internal parts.

The above is a proposal to eliminate static electricity by taking measures against the material of each component. The measures have not been taken to take measures to take the camera operation aggressively. There was a problem that sufficient measures were not taken.

In view of the above, the present invention provides a film feeder for a camera capable of actively preventing an electrostatic discharge phenomenon and protecting recording of an important film by changing a film driving speed based on a result of detection of ambient humidity. It is intended to provide a device.

[0014]

According to a first aspect of the present invention, there is provided a driving mechanism for feeding a film, a film feed detecting means for detecting a feed of the film, A film feeder for a camera having a control means for controlling the driving means based on the detection information from the film feed detection means and controlling the film drive, wherein the control means has a humidity detection means, and the humidity detection result A film feeder for a camera, wherein the film drive speed is varied based on

According to this configuration, the electrostatic discharge phenomenon can be prevented by actively changing the camera operation.

A specific configuration for realizing the object of the invention according to the present application is as described in claim 2, in the camera film feeder according to claim 1, it is determined that the humidity is low based on the humidity detection result. In the case, there is a film feeder for a camera characterized in that the film drive speed is lower than usual.

According to this structure, when the ambient humidity is low and the air is dry, an electrostatic discharge phenomenon is likely to occur. Therefore, by reducing the film feeding speed, it is possible to prevent the electrostatic discharge phenomenon from occurring. Can be.

Another specific configuration for realizing the object of the present invention according to the present invention is that, in the film feeder for a camera according to the second aspect, it is determined that the humidity is low based on the humidity detection result. The film drive speed of the camera is variable depending on the material of the feeding system.

According to this configuration, the speed is set lower than the normal speed when the humidity is low and in a dry state. For example, when the material of the feeding system that comes into contact with the film is nonmetallic, the speed is set to the lowest speed. In the case of a metal system, the normal speed is set to a speed higher than that but lower than the normal speed,
By selecting and setting from three kinds of setting values of two kinds of low speeds, it is possible to take measures to prevent the electrostatic discharge phenomenon including the consideration of the humidity and the material of the feeding system.

Another specific structure for realizing the object of the invention according to the present application is as described in claim 4, wherein the film feeder for a camera according to claim 2 determines that the humidity is low based on the result of humidity detection. The criterion to be determined is made variable depending on the material of the feeding system.

According to this configuration, the threshold value for judging whether the humidity is low depending on whether the material of the film feeding system is metallic or nonmetallic, for example, is high when the material of the feeding system is nonmetallic. Set the threshold value to a lower humidity value for metal-based materials and set the threshold to a lower humidity value so that the drying state is faster than that for non-metallic materials so that the humidity value is set and the low-speed operation is switched as soon as the drying condition occurs. By setting the threshold value variably so as to switch to a slower speed than in the case of a non-metallic system, it is possible to take measures to prevent the electrostatic discharge phenomenon.

According to another specific configuration for realizing the object of the invention according to the present invention, a film driving device for changing the speed in the film feeder for a camera according to the first aspect is provided. The operation is a film rewinding operation of the camera, which is a rewinding operation at the end of or in the middle of all film shooting.

According to this configuration, it is possible to prevent the occurrence of a discharge phenomenon due to static electricity during the film rewinding operation.

According to another specific configuration for realizing the object of the invention according to the present application, a film driving device for changing the speed in the film feeding apparatus for a camera according to the first aspect is provided. The operation is a film winding operation up to the photographing start position after the film is loaded.

According to this configuration, during the winding up to the cue frame when the film can be reloaded while the film is being photographed, an adverse effect on the image of the photographed frame, magnetic recording, and the like due to the occurrence of the electrostatic discharge phenomenon during winding. Can be avoided.

According to another specific structure for realizing the object of the invention according to the present application, in the film feeder for a camera according to the first aspect of the present invention, the film driving device is capable of changing the speed. The operation is a winding and rewinding operation at the end of each frame photographing, which is provided in the film feeding device of the camera.

According to this configuration, it is possible to prevent adverse effects due to the occurrence of an electrostatic discharge phenomenon during winding and rewinding at the end of each frame shooting.

Another specific configuration for realizing the object of the invention according to the present application is as described in claim 8 in the film feeder for a camera according to claim 3 or 4, wherein The feeding system is a film feeding device for a camera, which is a rail surface or a pressure plate.

According to this configuration, it is possible to suppress the occurrence of the electrostatic discharge phenomenon by changing the feeding speed or the threshold value for judging low humidity depending on whether the film feeding rail and the pressure plate are metallic or nonmetallic. it can.

According to another specific configuration for realizing the object of the invention according to the present invention, in the film feeding apparatus for a camera according to the seventh aspect, winding at the end of each frame shooting is performed. A camera characterized in that when the count value of the film moving amount driven by the motor speed changed by the humidity measurement value reaches a preset number of braking pulses, the motor is braked until winding is stopped. Film feeder.

According to this configuration, the link between the motor speed changed by the humidity measurement value and the steady control such as the winding and rewinding of the camera operation is executed without any trouble, and the camera operation by the changed motor speed is performed. Works smoothly.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing a main part of a film feeding device for a camera according to a first embodiment of the present invention. FIG. 2 is a flowchart of the operation of the film feeding apparatus shown in FIG.

In FIG. 1, reference numeral 1 denotes a motor as a drive source;
Reference numeral 2 denotes a pinion gear fixed to the rotating shaft of the motor 1, 3 denotes a sun gear connected to the pinion gear 2 via a speed reduction mechanism (not shown), 4 denotes a planetary gear that meshes with the sun gear 3, and 5 denotes a sun gear 3 and a planet. A planetary arm rotatably connected to a gear 4.
It constitutes a known planetary mechanism that can revolve around a.

Reference numeral 6 denotes a hoisting gear arranged to mesh with the planetary gear 4, and 7 denotes a spool gear meshing with the hoisting gear 6, which is held coaxially with the spool 8 so as to be integrally rotatable. The spool 8 is a known spool that winds the film by winding the film 14 around its outer periphery.

Reference numeral 9 denotes a rewind gear, which is arranged to be able to mesh with the planetary gear 4 and connected to the patrone gear 10 via a connecting mechanism (not shown). Patrone gear 10
Are configured to engage with the film cartridge 15 and transmit the rotation thereof to the cartridge.

Reference numeral 11 denotes a film detecting roller, which is configured to rotate about a shaft 11a in conjunction with the movement of the film, and a pulse plate 12 having a radial light and dark pattern is fixed to the tip of the shaft. I have. Reference numeral 13 denotes a photo interrupter, which is arranged so that the pulse plate 12 is located between the opposing light emitting and receiving elements. The light / dark pattern of the pulse plate 12 is configured to detect a film feed with a very fine pitch.

Reference numeral 16 denotes a drive circuit for controlling the driving and braking of the motor 1, 17 denotes a detection circuit for detecting the film feed using the photo interrupter 13, 18 denotes a storage device such as an EEPROM, and 19 denotes various operations of the camera. Control CPU,
Reference numeral 20 denotes a temperature detecting device using a temperature compensating resistor or the like.

Reference numeral 21 denotes a humidity detecting device using a humidity sensor. Humidity sensors mainly use moisture-sensitive films made of moisture-sensitive materials such as polymers and ceramics, and measure changes in their own impedance due to moisture absorption and changes in the electrical capacitance of a pair of electrodes sandwiching the moisture-sensitive film. The humidity is thus detected. A small unit that is integrated with a peripheral circuit and that directly reads humidity with an analog voltage output is commercially available.

Next, the film winding and rewinding operations will be described with reference to FIG. The release operation of the camera is started by the release operation, and when the exposure operation ends, the film winding operation starts (S101). First,
A humidity measurement operation is performed by the CPU 19 and the humidity detection device 21 (S102). The process of S102 detects the humidity at the time of the winding operation. However, temperature information by the temperature detecting device 20 is also required depending on whether the humidity is the absolute humidity or the relative humidity.

The current dry state is determined using the result of the measured humidity operation (S103). If the dry state is determined, the speed setting of the winding operation is set to a low speed (S10).
4) If it is determined that it is not dry, the normal speed is set (S105).

The driving circuit 16 starts the rotation of the motor 1 in the winding direction (S106), and the driving force is transmitted to the sun gear 3 and transmitted to the spool 8 via the planetary gear 4, the winding gear 6, and the spool gear 7, and Is started.

The amount of movement of the film is detected by the detection circuit 17 as a pulse output of the photo interrupter 13,
The PU 19 performs a count (S107), and starts a tension timer (S108). The count value of the film movement amount detection pulse in this case is stored in the storage device 18 in advance.
As soon as the braking pulse A stored in step S10 is reached, the braking operation of the motor 1 is performed by the drive circuit 16 (S10).
9), (S110). The counting of the pulse output is continued even during the braking operation, and is performed until the film winding operation stops. The stop of the film winding operation is determined (S111).
The stop may be determined when a predetermined time elapses from the start of braking (timer value) by the timer, or when the detection pulse interval of the film movement amount becomes equal to or longer than a predetermined time, the stop may be performed.

If it is confirmed that the winding is stopped, the pulse count and the tension timer are terminated (S112), and the winding operation is terminated (S113).

Next, the automatic rewinding operation will be described. The pulse interval detected by the film movement amount detection circuit 17 is compared with a predetermined timer (stretch timer) (S114). Perform rewind. First, the tension timer is terminated (S115), and the driving circuit 16 drives the motor 1 in the rewinding direction (S116). This driving force is transmitted to the sun gear 3, and the planetary gear 4 revolves clockwise by a known planetary mechanism (FIG. 1), and meshes with the rewind gear 9. Thereby, the patrone gear 10 rotates, and the film patrone is rotated in the rewinding direction to rewind the film.

During the rewinding, when it is detected that the pulse interval is longer than a predetermined rewinding end timer (stretch), it is determined that the rewinding is completed by detecting the completion of the rewinding (S117). The pulse count is also terminated (S118), and the rewind operation is terminated (S119).

As described above, according to the first embodiment,
The film feed speed is set to be variable according to the detected value of the ambient humidity, and in a state where the occurrence of static electricity is expected to dry out, the feed speed is reduced to reduce the effect, and the film is wound up.
The rewinding is performed at the low speed, and the braking pulse A
Since the braking operation, the rewinding operation, and the like are performed, it is possible to take a countermeasure against the electrostatic discharge phenomenon that actively steps into the camera operation. This makes it possible to protect the recording of both the photographed image and the magnetically recorded information.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
The embodiment will be described with reference to the drawings. FIG. 3 is a flowchart of the operation of the film feeder for a camera according to the second embodiment of the present invention. FIG. 4 is a subroutine of the feeding speed setting process shown in FIG.

In the previous embodiment, a simplified flow of performing a low-speed feeding operation if the humidity is low is adopted. However, the feeding system such as a rail surface or a pressure plate may be made of a metal or a non-metal. In the second embodiment, the processing is performed in accordance with the material of the feeding system, because the influence of humidity may be different from the above and the countermeasures should be taken into account.

FIG. 3 shows S102 to S1 in FIG.
05 is the “feeding speed setting” process of S202, and the other processing flow is S101 in S201.
And S106 to S119 are exactly the same processing flows as S203 to S216, and the duplicate description will be omitted. Also,
FIG. 1 is used as a common diagram.

As a second embodiment, a flowchart shown in FIG. 4 showing a subroutine of the "feed speed setting" process of S202 in FIG. 3 as a process different from that in FIG. 2 will be described. "When the feed speed setting subroutine is called (S
301) First, a humidity measurement operation is performed by the CPU 19 and the humidity detection device 21 (S302). The current dry state is determined using the result of the humidity measurement operation (303). If the dry state is determined, then the material of the feeding system is determined (S).
304).

Here, different feeding speeds are set for each of metal (S305) and non-metal (S306). For example, when the rail surface or the pressure plate is made of non-metal, the charging voltage of static electricity is also increased, and it is considered that the influence of the discharge phenomenon is increased. Therefore, in the case of a non-metal system, the speed is set lower than that of the metal system. . If it is determined in step S304 that the sheet is not in the dry state, the normal feeding speed is set (S304).
307). As described above, the optimum feeding speed is selected from the three types, the "feeding speed setting" subroutine ends (S308), and the process returns to the process after the start of winding power supply (S203).

(Third Embodiment) Next, a third embodiment of the present invention will be described.
The embodiment will be described with reference to the drawings. FIG. 5 is a flowchart showing a subroutine of a feed speed setting process of the camera according to the third embodiment of the present invention. In the third embodiment, the threshold value itself is changed according to the material of the feeding system to switch the criterion for determining the dry state. Note that the flowchart of FIG. 3 is common to the previous embodiment, and is also used in the third embodiment. FIG.
Are also used as common diagrams.

When the "feed speed setting" subroutine is called (S401), first, the CPU 19 and the humidity detecting device 2 are started.
1 performs a humidity measurement operation (S402). Subsequently, the material of the feeding system is determined (S403), and the material is determined to be metal (S40).
4) A different judgment threshold is set depending on whether it is non-metal (S405). In this case, for example, in the case of a non-metallic feeding system, the threshold value is set to a high humidity value, that is, a “threshold value” that quickly switches to a low speed before the drying state progresses. . As described above, the current dry state is determined using the “threshold” in consideration of the material of the feeding system (S406),
If it is determined that the sheet is in the dry state, the low feeding speed is set (S40).
7) If not in a dry state, a normal feeding speed is set (S408). As described above, the optimum feeding speed is selected based on the material of the feeding system and the dry state, the "feeding speed setting" subroutine is terminated (S409), and the process after the start of winding energization (S203) in FIG. Return.

As described above, in each embodiment of the present invention,
Although the feeding operation with variable speed, that is, the film feeding operation, has been described as the winding and rewinding operation at the end of each frame shooting, however, the film driving operation with variable speed requires the beginning of the frame to be used. Needless to say, a rewinding operation during shooting of one film, which enables unwinding, and a winding operation to a shooting start position after loading the film may be included.

[0055]

As described above, according to the present invention,
In film feeders for cameras with humidity detection means, variable film drive speeds based on humidity detection results can actively prevent electrostatic discharge phenomena and protect important film recordings. Has the effect of becoming

Also, taking into account the material of the feeding system, the effect of preventing the discharge phenomenon of static electricity, maintaining the operability as much as possible, and providing a comfortable environment for the photographer can be obtained. is there.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a film feeding device of a camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart of an operation of the film feeding apparatus shown in FIG.

FIG. 3 is a flowchart of an operation of a film feeder for a camera according to a second embodiment of the present invention.

FIG. 4 is a subroutine of a feeding speed setting process shown in FIG. 3;

FIG. 5 is a subroutine of a feed speed setting process according to a third embodiment of the present invention.

[Description of Signs] 1 Motor 2 Pinion Gear 3 Sun Gear 4 Planetary Gear 5 Planetary Arm 6 Winding Gear 7 Spool Gear 8 Spool 9 Rewind Gear 10 Patrone Gear 11 Film Detection Roller 12 Pulse Plate 13 Photointerrupter 14 Film 15 Patrone 16 Drive Circuit 17 Detection circuit 18 Storage device 19 CPU 20 Temperature detection device 21 Humidity detection device

Claims (9)

[Claims] A film feed detecting means for detecting a film feed; a control means for controlling the film driving by controlling the drive means based on detection information from the film feed detecting means; The film feeder for a camera according to claim 1, wherein the controller has a humidity detector, and varies a film driving speed based on a result of the humidity detection. 2. A film feeder for a camera according to claim 1, wherein when it is determined that the humidity is low based on a result of the humidity detection, the film drive speed is set lower than usual. . 3. A film feeder for a camera according to claim 2, wherein the film drive speed when the humidity is determined to be low based on the humidity detection result is variable depending on the material of the feed system. Feeding device. 4. A film feeder for a camera according to claim 2, wherein a criterion for judging low humidity based on a result of humidity detection is variable depending on a material of a feed system. 5. A film feeding apparatus for a camera according to claim 1, wherein the film driving operation for changing the speed is a rewinding operation at the end of all film shootings or in the middle. apparatus. 6. A film feeding apparatus for a camera according to claim 1, wherein the film driving operation for changing the speed is a winding operation to a shooting start position after loading the film. apparatus. 7. A film feeding apparatus for a camera according to claim 1, wherein the film driving operation for changing the speed is a winding and rewinding operation at the end of each frame shooting. apparatus. 8. A film feeding apparatus for a camera according to claim 3, wherein the feeding system whose material is to be determined is a rail surface or a pressure plate. 9. The film feeding apparatus according to claim 7, wherein at the time of film winding at the end of each frame shooting,
When the count value of the amount of film movement driven by the motor speed changed by the humidity measurement value reaches a preset number of braking pulses, the motor film is subjected to motor braking until winding is stopped. Feeding device.