JPS6113728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic film winding device, and more particularly to an automatic film winding device of the type that winds the leading end of the film around a spool using only frictional force.

This type of automatic winder has a mechanism that when you open the camera back cover and load a film cartridge,
Place the tip of the film that is slightly protruding from the cartridge (in many cases, it is also the narrow tip) on the sprocket, then close the camera back and perform the normal film winding operation to wind the film onto the spool. There is something that does that. That is, the film with the perforation of the narrow end portion engaged with the pawl on one side of the sprocket is fed to the spool side by the rotation of the sprocket based on the film winding operation, and the narrow end portion of the film is fed into the spool side by rotation of the sprocket based on the film winding operation. A frictional force is generated between the film and the spool outer circumferential surface when the film contacts the spool outer circumferential surface, and this frictional force causes the leading end of the film to be wound around the spool. Of course, in this case, the outer circumferential surface of the spool is formed of a high friction generating material such as rubber, and a guide means is used to forcibly guide the leading end of the film to the outer circumferential surface of the spool.

Therefore, the shape and dimensions of the thin end portion of commercially available films, especially 35 abrasion perforated films, and the film pull-out load, which are of great concern to this type of automatic film winding device, are unique to each manufacturer's product. As a result of experiments, it has been found that the difference caused by this characteristic has a subtle effect on the automatic winding operation of the film, that is, on the winding condition of the film.

Now, regarding the winding condition of the film, when winding the narrow end of the film around the spool, the side edge of the film should be placed on a straight trajectory (hereinafter referred to as ideal) determined by the rail position of the exposed opening and the position of the sprocket pawl. The film is fed in such a way that it advances along the ideal linear trajectory (called a linear trajectory), and the film is fed so that the end face of the film stack wound around the spool is always located on the ideal linear trajectory regardless of the amount of winding, and the film is placed on the outer peripheral surface of the spool. It is desirable to wrap tightly. This is not just a requirement for automatic film winders, but is a general principle for winding film onto a spool. However, when we actually feed the narrow end of the film toward the spool by rotating the sprocket, we find that the end of the film deviates from the ideal linear trajectory described above, that is, when the film is loaded into the camera, In the normal case where the narrow portion is formed on the lower part of the film, a phenomenon occurs in which the film is fed somewhat diagonally upward.

When this phenomenon occurs, on the one hand, the most extreme corner of the narrow film tip that goes around the spool gets wedged into the subsequent perforation;
At this point, a "loose winding phenomenon" occurs in which a ring ring with a diameter much larger than the spool diameter is formed, and on the other hand, even if the thin end of the film is wound around the spool, This results in the "bamboo shoot phenomenon" in which the narrow part winds around the spool in a spiral like the surface of a bamboo shoot.

If a "loose winding phenomenon" occurs, there will be an accident in which the outer periphery of the film comes into pressure contact with the inner wall of the film chamber when the film is wound to a certain diameter, making further winding impossible. When rewinding the film, the operating force becomes extremely heavy, and as a result, in some cases, the film may be cut. When the "bamboo shoot phenomenon" occurs, the film may be cut during the winding stage. Accidents in which the film is forced to be biased to one side, resulting in a "stretched state" that not only makes it impossible to wind the film in the future, but also breaks the perforation, and the operation when rewinding the film. If the force is too heavy and the film is cut, the phenomenon described above will occur.

In order to prevent these phenomena from occurring, a roller means is installed around the film winding member to press the narrow end portion of the film against its outer circumferential surface in order to advance the narrow end portion of the film appropriately. Sometimes. However, if the pressing roller means is simply provided, the leading edge of the film that has gone around the film winding member will be located inside the following film section at this roller position, that is, between the outer circumferential surface of the film winding member and the inner surface of the succeeding film section. When entering the space between the two, the following defects occur.

That is, the leading edge of the film is fed by the feeding action of a sprocket, etc., and after passing the roller means, the leading edge of the film is moved forward by the frictional force exerted by the outer peripheral surface of the film winding member, and is guided by the inner wall surface of the winding chamber to wind the film. If the pressing force of the roller means is strong, friction will occur between the leading edge of the film and the following film portion when the leading edge of the film is sandwiched between the roller and the outer peripheral surface of the winding member. This is a phenomenon in which the film loops, which are partially overlapped due to the force, continue to advance with the current loop diameter, resulting in a so-called "loose winding" state.

The present invention has been made for the purpose of preventing this undesirable phenomenon, and its novel feature is that the advancing force of the leading end of the film toward the superimposed position is strengthened, so that the outer circumferential surface of the film winding member is The reason is that the tensile action of the film tip is increased.

Another feature of the present invention is that one end portion of the film winding member is made larger than the other portion so that one side edge of the narrow end portion of the film can be overlapped therewith; Of the at least two pressing members, the pressing member that comes into contact with the film first is used to prevent the leading end of the film from being displaced in the direction opposite to the large diameter portion of the film winding member during the film feeding operation. That's what I did.

Hereinafter, details of the present invention will be explained with reference to embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of an auto-loading 35mm camera to which the present invention has been applied. In the figure, numeral 1 is the photographing lens, 2 is the camera body, and 3 is a hinge 3a provided on the right side that opens the camera to one side. 4 indicates the sprocket. The narrow end portion A of the film wound on the film cartridge stored in the cartridge chamber 5 is passed through the space between the exposure window 6 and the pressure plate 7 into the take-up chamber 8 by a fixed length by the sprocket 4. The film is fed out and wound into an automatic film winding device located in the winding chamber 8.

The automatic film winding device includes a cylindrical film winding member 9 rotatably supported by the camera body 2, and two pressing means for pressing the narrow end portion A of the film against the circumferential surface of the film winding member 9. 10,
11.

As shown in FIG. 2, the film winding member 9 includes an inner cylinder 12 made of a rigid material such as metal and having a cylindrical shape and having a flange 12a.
The inner cylinder 12 is provided with an outer cylinder 13 made of a high friction elastic material such as neoprene or butadiene rubber and having a hardness of about 40 to 50 degrees, which is in close contact with the outer periphery of the inner cylinder 12.

According to the present invention, the flange 12 of the outer cylinder 13
The outer diameter of the end portion 13a closer to a is set to be larger than the outer diameter of the other portion 13b (for example, a diameter difference of about 0.2 to 0.4 mm). Specifically, due to this different diameter,
A double-sided adhesive tape 14 of a constant thickness is wrapped around the outer surface of one end of the inner cylinder 12, and a rubber cylinder, that is, an outer cylinder 13 of uniform thickness, is wrapped around the outer surfaces of the inner cylinder 12 and the double-sided adhesive tape 14. Preferably, the width B of the large diameter end portion 13a is smaller than the distance L from the side edge of the narrow end portion of the film to the far side of the corresponding perforation a. Further, in order to partially make the film winding member 9 different in diameter, in addition to the above-described structure, as shown in FIG. The outer circumferential surface of the inner cylinder 12 may be covered with an outer cylinder 13A having a uniform thickness and made of an elastic material. Further, as shown in FIG. 5, the film winding member 9 is provided with an outer tube made of an elastic material having a large diameter portion on the outer circumferential surface at one end and having partially different thicknesses. Cylinder 1
3B or as shown in Figure 6,
After covering the outer surface of the inner cylinder 12C with a uniform outer circumferential surface with an outer cylinder 13C having a uniform thickness, the structure is further modified such that a tape 13D made of a high friction material is wrapped around a part of the outer cylinder 13C. be able to.

The film winding member 9 is rotationally driven by a DC motor 14 inserted concentrically into the inner cylinder 12. That is, a pinion 15 on the output shaft of the DC motor 14 is meshed with a gear on a shaft 16 rotatably installed in the camera body 2. And the axis 16
The driving gear 18 loosely fitted on the top is meshed with the internal teeth 19 of the inner cylinder 12, and rotational torque is transmitted to the driving gear 18 from the friction plate 20 of the shaft 16, so that the film winding member 9 is rotationally driven at a reduced speed. It goes without saying that the inner cylinder 12 and the outer shell structure of the motor 14 may be integrally constructed.

On the other hand, as shown in FIG. 3, the film overlapping pressing means 10, which is located in the take-up chamber 8 and whose base is pivoted to the camera body 2 by a shaft 21, is urged in the direction of the arrow by a spring 22. At its tip, there is a metal shaft 23.
A roller 24 cut out integrally with the roller 24 is supported.
The position of the roller 24 with respect to the film width is as follows:
It is set to be located outward from the perforation position on both sides of the film. In this case, the lower roller 24 is the film winding member 9
Theoretically, the winding member 9 will be in a state of partial contact with the large diameter portion of the winding member 9, but there is no problem in practice. A downward guide portion 25 protrudes from the guide curved surface 10a of the pressing means 10 to engage with the upper edge of the narrow end portion A of the film and push it toward the large diameter portion 13a. Regarding the function and structure of this downward guide part 25, please refer to the application filed in 1973-
Since it is described in detail in the specification of No. 116344, the details will be omitted here. Further, the film receiving pressing means 11 whose base is pivotally supported by a shaft 26 installed on the back cover 3 is biased in the direction of the arrow by a spring 27, and a rotatable metal shaft 28 is mounted on the tip end of the film receiving pressing means 11. A rubber roller 29 supported by is provided. In this case, the rubber roller 29 and the film winding member 9
The point of contact with the roller 24 of the film superimposing pressing means 10 is set near the point where the leading end of the film fed by the sprocket 4 first contacts the outer peripheral surface of the film winding member 9 in a natural state, and The point of contact with the outer circumferential surface of the film winding member is set such that the leading edge of the film, which is oriented by the inner wall surface of the winding chamber 8 and the guide curved surface of the film overlapping pressing means 10, easily faces the outer circumferential surface of the film winding member 9. It is preferable to set the position. However, the present invention is not limited thereto.

The forces of the respective springs 22 and 27 are set so that the pressing force of the film superimposing pressing means 10 is greater than the pressing force of the film receiving pressing means 11.

Here, although it may seem redundant, the film overlapping pressing means 10 and the film receiving pressing means 11 will be briefly explained. First, regarding the latter receiving pressing means 11, when there is no film, only the rubber roller 29 comes into pressure contact with the outer peripheral surface of the film winding member 9 and becomes the actual pressing member.
The plate member rotatably supports the metal shaft 28 that holds the roller 29 at both ends, and its inner surface 11
A serves as a guide curved surface for the narrow end portion A of the film. Therefore, the narrow end portion A of the film fed by the sprocket 4 follows this guide curved surface 11a.
The film is forced to be guided to the outer circumferential surface of the film winding member 9, and the outer circumferential surface and the rubber roller 29
It will be caught between. Similarly, in the former film stacking pressing means 10, the roller 24 serves as the actual pressing member, and the inner surface of the plate member that rotatably supports the roller 24 serves as the guide curved surface 10a. Therefore, as the film advances, the narrow end portion A of the film is guided by the inner wall surface of the winding chamber 8 and when it reaches the pressing means for superimposition, the guiding curved surface 10a causes the leading end of the narrow end portion A of the film to be wound again. The film is guided to the outer peripheral surface of the removing member 9, and the narrow end portion of the film is sandwiched between the roller 24 and the outer peripheral surface. At this time, due to the function of the downward guide portion 25 which is in contact with the upper edge of the narrow end portion A of the film in the drawing, the narrow end portion of the film moves along the ideal linear trajectory or in a direction of movement slightly diagonally downward. 24 and the outer peripheral surface of the film winding member. Regarding the relationship between the sprocket 4 and the film winding member 9, they are interlocked by an appropriate gear train means (not shown), and the rotation ratio thereof is determined by the circumferential speed of the sprocket 4 (film feed amount). It is preferable to set the ratio between the rotation speed and the circumferential speed of the film winding member 9 (the amount of film winding in the first rotation) to be 1:1.3 to 2.0.

Now, since the illustrated embodiment has the above-described configuration, the narrow end portion A of the film sandwiched between the roller 24 of the film superimposing pressing means 10 and the outer circumferential surface of the film winding member 9, as described above. The leading edge of the film continues to advance while receiving a stronger pressing force from the roller 24, and the leading edge of the film continues to move forward while receiving a stronger pressing force from the roller 24, and the film portion (still narrow portion) that is stretched between the sprocket 4 and the film winding member 9 continues to advance. ), and is guided by the inner surface of the film to reach the point of contact between the rubber roller 29 of the receiving pressing means 11 and the outer peripheral surface of the film winding member. At this time, since the above-described restricting action of the downward guide section 25 is activated, there is no risk that the leading edge of the film will enter the perforation of the following film section, and there is no risk of the film progressing in a so-called bamboo shoot shape. Further, since the pressing force applied to the roller 24 of the film superimposing pressing means 10 is greater than the pressing force of the rubber roller 29 of the receiving pressing means 11, the film winding member 9
The leading edge of the narrow end portion A of the film that has gone around the film enters between the succeeding film portion and the film winding member 9 while overcoming the pressing action of the receiving rubber roller 29.

Therefore, the circumferential speed of the film winding member 9 is greater than the circumferential speed of the sprocket 4, and the friction generating force on the outer circumferential surface of the film winding member is larger than the receiving rubber easer 2.
Because the force that generates friction between the film surfaces at position 9 is greater than that, the advancing speed of the inner film portion (the most extreme portion of the narrow tip portion) that is in direct contact with the outer circumferential surface of the film winding member is greater than that. The feeding speed becomes higher than the feeding speed of the succeeding film portion located therein, so that the narrow end portion A of the film that is circulating around the film winding member 9 gradually comes into close contact with the outer circumferential surface of the winding member 9. . In other words, they become tightly wound. In this case, since the outer diameter of one end portion 13a of the film winding member 9 (for example, about four times worn from the end) is slightly larger than the outer diameter of the other portion 13b, the leading end of the film is narrowed in the process of being tightly wound. Since the portion A tends to be displaced toward the large diameter portion 13a as in the case of a normal medium-thick pulley, the end face of the narrow portion A at the tip of the film that is wound together with the presence of the flange 12a is as described above. It will be located on an ideal straight trajectory. Therefore, the so-called "bamboo shoot phenomenon" can be completely avoided. still,
In the illustrated embodiment, the rubber roller 29 of the receiving side pressing means 11 is set near the upper edge of the narrow end portion A of the film (approximately in the center of the entire width of the film); This is convenient for bringing the lower end portion into contact with the large diameter portion 13a without any force, and is also effective in preventing the occurrence of the bamboo shoot phenomenon, but this does not mean that it is necessary to do so. For example, it is also possible to provide rubber rollers 29 at both ends like the rollers 24 of the superimposing pressing means 10.

Now, after the narrow end portion A of the film is tightly wound around the film winding member 9, the film is sequentially rolled one frame at a time while being regulated by the amount of rotation of the sprocket 4, as in the case of normal film winding. It is wound around the outer periphery of the winding member 9.
At this time, the difference in circumferential speed between the sprocket 4 and the film winding member 9 is corrected by the sliding action of the friction plate 20, but it may be corrected by other means. In the illustrated embodiment, a sprocket is used to feed the film, but if a film without perforation is used, a friction roller means may be used. Therefore, even if the camera back is closed after the camera is pulled out to the position of the pressing means for accepting the film, and the narrow end portion is automatically wound by simply rotating the film winding member, the camera back can still be closed. If you do not need the automatic winding system, install a receiving pressure means on the camera body side, and with the back cover open, feed the film tip into the film winding member side with your fingertips until the film tip is fine. The back cover may be closed after confirming that the width portion is wrapped around the film winding member.

As described above, when the present invention is used, it becomes easy for the leading end of the film to enter the film overlapping position, and the winding action of the leading end of the film by the outer peripheral surface of the film winding member is reliably performed, resulting in a tightly wound state. It produces the effect of becoming.

Note that the distance between the two pressing members may be any value as long as the leading edge of the film that has gone around the film winding member naturally moves toward the film overlapping position.
It can be said that it is desirable that both are provided closer to each other. Additionally, it should be noted that the presence of the downward guide portion is not necessarily required in the present invention.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a 35-year-old camera to which the present invention has been applied, Figure 2 is an enlarged sectional view of the main parts of the same camera, and Figure 3 is an enlarged sectional view of the main parts of the same camera.
The figure shows an exploded perspective view of the automatic film winding device, and FIGS. 4 to 6 show modified examples of the film winding member. 2 is the camera body, 3 is the camera back cover, 4 is the sprocket, 8 is the winding chamber, 9 is the film winding member,
10 is a pressing means for overlapping the film; 11 is a pressing means for receiving the film; 12, 12A, 12B, 12
C are all inner cylinders, 13, 13A, 13B, 13
C is the outer cylinder, A is the thin end of the film, 1
3D is the tape, 13a is the large diameter part.

Claims (1)

[Scope of Claims] 1. In an automatic film winding device of a type in which the leading end of the film is wound onto a film take-up spool by frictional force, a winding region of the narrow end of the film of the film winding spool and a film The diameter of the portion near the side end is larger than that of the other portion, and a pressing member for receiving the film that can be displaced in the radial direction of the take-up spool is pressed with a predetermined pressure against the tip of the film corresponding to the take-up area. A close film winding device, characterized in that the film is transferred in a state where the leading end of the film is in contact with both the large diameter portion and the small diameter portion due to the pressing force of the film receiving pressing member. 2. The film tight winding device according to claim 1, wherein the film receiving pressing member is positioned so as to be able to come into contact with the film near the notch edge of the narrow end portion of the film. 3. The film receiving pressing member has a roller shape and is provided at each free end of a swinging guide member so as to guide the leading edge of the advancing film to the outer peripheral surface of the film winding member. The film tight winding device according to item 1 or 2. 4. The film tight winding device according to claim 1, wherein the film receiving pressing member is provided on the back cover of the camera. 5. The film tight winding device according to claim 1 or 3, wherein the pressing force of the other pressing member is greater than the pressing force of the film receiving pressing member. 6. The close film winding device according to claim 1, wherein the large diameter portion of the film winding member has a diameter difference of about 0.2 to 0.4 mm compared to other portions.