JPH0125938Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is applicable to cameras equipped with an autoloading device, especially an autoloading type in which the leading edge of the film advances in the winding chamber in an idle state away from the reel. Relating to a camera equipped with a device.

(Prior Art) In recent years, with the spread of cameras, ease of operation has been required, and various autoloading devices have been proposed.

Not only in autoloading, but in general when winding film in a camera, problems include properly engaging the perforations of the film with the pawls of the sprocket and tightly winding the film around the take-up reel. In other words, the film has a tendency to curl while being stored in the cartridge, and even if the perforation is placed correctly on the sprocket pawl during loading, the film always tends to lift up due to curling. If an unexpected force is applied when holding the film and winding it, or if the film does not advance smoothly and becomes loose, the film may lift up and cause the perforation and sprocket pawl to engage. It may come off and cause a winding failure.

As a countermeasure for this, even in devices where the sprocket is driven, the feed speed of the take-up reel is generally set to be slightly faster than the feed speed of the sprocket, so that the leading edge of the film is accurately fixed to the take-up reel. If it is, the tip of the film will be pulled against the sprocket,
This tension prevents the film from lifting up and maintains engagement with the sprocket.

However, if the leading edge of the film is not fixed well and moves away from the take-up reel and moves freely in the winding chamber, the leading edge of the film that has gone around once inside the winding chamber will move around the winding reel. Even if it is able to enter between the peripheral surface and the succeeding part of the film, it remains loose relative to the take-up reel and the subsequent winding proceeds, resulting in so-called bull winding, where the film cannot be wound midway through. In some cases, even though the leading edge of the film goes around the winding chamber once and stops when it hits the following film, the following film is fed, and eventually A phenomenon that winding becomes impossible easily occurs.

In this way, film loading is a tedious task not only for beginners, but also often leads to failures.Therefore, an autoloading device was developed to ensure reliable film winding with simple operations. It is what was done. Many autoloading devices follow the conventional approach and emphasize the above two conditions for winding, namely, engagement between the perforation and sprocket pawl, and tight winding on the take-up reel. The aim was to achieve this more reliably and automatically than by humans.

Autoloading devices based on this idea take great care to feed the film while keeping the leading edge of the film in close contact with the take-up reel.

That is, the first embodiment of Special Publication No. 42-21851,
In Utility Model Publication No. 47-25540, an engaging pawl is provided on the take-up reel and engaged with the perforation. This type of thing, once engaged,
As long as the back tension is acting on the film, it will not come off. However, during loading, it is necessary to engage the perforation with the reel pawl, or a structure to ensure this engagement is essential.

Needless to say, it is easier to operate a film that does not have an engaging claw on the take-up reel and simply places the leading end of the film on the reel and closes the back cover. Even in a type of film transport system that utilizes the frictional force between the reel circumferential surface and the film, attempts have been made to guide the leading edge of the film in close contact with the take-up reel from the start of the winding operation. Kosho 42-3491
No., Special Publication No. 1972-3645, Utility Publication No. 50-37786, etc.).
For this purpose, the member for pressing the leading end of the film against the reel must be arranged around the entire circumference of the take-up reel with as few gaps as possible, resulting in a complicated structure and increased costs. Further, even when the back cover is opened, the take-up reel is not completely exposed, making it difficult to place the leading end of the film on the take-up reel.

Furthermore, there are examples in which the leading edge of the film is only minimally restrained in the winding chamber, and most of the film is allowed to freely advance into the winding chamber. One example is Utility Model Publication No. 51-276, which is used in micro readers and the like, in which the film is fed by a capstan and a pinch roller, and there is no need to consider engagement with a sprocket. In addition, this type of film also requires a special means for attaching the leading end of the film to the take-up reel, but the specific structure thereof is unknown. Jitsukō 1975−
In No. 36828, it is not possible to take up the slack in the film at the beginning of winding and ensure the engagement with the sprocket, and it is necessary to use a lever to press the film into engagement in advance to prevent it from lifting up. Further, the structure for absorbing the sagging generated on the film in the winding chamber is unknown.

(Problems to be solved by this invention) This invention, for example, simply places the leading end of the film on the take-up reel and closes the back cover, and then the film perflation and sprocket are connected by the subsequent winding operation. The object is to obtain an autoloading device that can realize both engagement and tight winding on a reel, and to obtain a camera that is low in cost and easy to use.

(Means for solving the problem) The camera autoloading device of the present invention is
a sprocket; a film take-up reel that rotates at a fixed position provided within the film take-up chamber;
A guide member for guiding the film from the sprocket toward the film take-up reel, and a pressing roller provided on the guide member to elastically press the guided film against the take-up reel. , a first pressing means attached to the back cover; an inner wall of the film winding chamber in which the leading end of the film fed out by the pressing roller of the first pressing means and the take-up reel moves in an idle state; a space formed by the circumferential surface of the take-up reel;
a guide member that directs the film that has moved in an idle state toward the take-up reel; and a guide member provided on the guide member to elastically press the guided film against the take-up reel; a pressing roller located near the pressing roller of the first pressing means on the take-up reel so as to feed the leading end of the film between the film being pressed by the roller and the take-up reel; A second pressing means attached to the main body;

A rubber material is preferably disposed on the circumferential surface of the film take-up reel, and the film guide member may be a spring plate member.

Furthermore, the pressing force is set so that the pressing force of the second pressing means is greater than the pressing force of the first pressing means.

(Function) In this invention, the idea is changed from the conventional one, and a reel with a surface that has a suitably large frictional force with the film is used, and the first pressing means is used at the point where the leading edge of the film first contacts the take-up reel. A tension force is generated by the frictional force caused by pressing, absorbing the initial loosening of the film and applying tension to the film to ensure engagement with the sprocket. However, after passing the first pressing means, the leading end of the film is released, and the leading end of the film is allowed to advance through the winding chamber in a free play state without any restraint. Naturally, when the leading edge of the film hits the trailing part after almost one turn, the film has a large amount of slack in the part away from the take-up reel, that is, in the take-up chamber, a condition that was previously thought to never occur. It's getting old. However, if the leading end of the film is fed between the succeeding portion of the film and the take-up reel, a pulling force is applied to the leading end of the film due to the frictional force between the film surface and the reel surface. The succeeding part of the film is subject to tension in the opposite direction to the advancing direction due to the feeding speed being regulated by the sprocket or resistance when being pulled out from the cartridge, but since the friction between the films is relatively small, the first As a result, slippage occurs between the films in the pressing means of the film, and the leading edge of the film is fed at almost the original feed speed of the take-up reel, which is faster than the trailing part of the film. As a result, the film that is loose in the take-up chamber is quickly wound up, and its Looseness is absorbed and tight winding is achieved.

In this case, in order for the leading edge of the film to slightly push up the first pressing means by the thickness of the film and enter between the succeeding part and the take-up reel,
A second pressing means placed near the entry point is required, and in order to push up against the pressing force of the first pressing means, the pressing force must be greater than that of the first pressing means. is preferred.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

In the figure, 1 is a camera body, 2 is a sprocket, and 3 is a back cover held by a hinge 3a. 4
A film winding reel rotates at a fixed position in a film winding chamber, and a reel rubber 4a is attached to the outer surface of the reel to increase frictional force with the film. Further, a motor (not shown) is built into the central axis of the film take-up reel 4, and rotates the take-up reel in the direction of the arrow. Film lifting prevention rollers 5 and 6 are arranged on the left and right sides of the sprocket 2, respectively, and press the film toward the sprocket so that the perforation of the film can easily come into contact with the sprocket.

Reference numeral 7 denotes a first pressing means provided on the back cover, which is composed of a film guide member 7b and a film guide roller 7a provided at the tip thereof. It is rotatably attached to the film take-up reel 6a, and is constantly biased in four directions.
The roller 7a at the tip thereof is always elastically pressed against the reel rubber 4a near the top of the take-up reel 4 in the figure with the back cover closed. The guide member 7b may be a spring plate. The film guiding portion 7b can reliably guide the leading end of the film to the pressing roller 7a and to the film winding chamber even if the leading end of the film is placed only up to the sprocket.

A second pressing means 8 is rotatably supported by a shaft 8b inside the camera body 1, and like the first pressing means, a guide member 8c and a pressing roller 8a provided at the tip end of the guiding member 8c are used to roll the film. It is urged toward the take-up reel 4 side, and the roller 8a at the tip of the film is pushed toward the film tip 9.
is elastically pressed by the reel rubber 4a near the portion where it enters under the first film guide roller 7. The film guide portion 8c of the second pressing means has a gentle curve and guides the leading end of the film onto the film take-up reel 4.

Further, the pressing force of the pressing roller 8a of the second pressing means 8 is set to be larger than the pressing force of the pressing roller of the first pressing means.

The autoloading device of this embodiment operates as follows.

When the photographer opens the camera back, the sprocket 2 and film take-up reel 4 are completely exposed.
When the back cover is closed, the film leading end 9 placed over the completely exposed sprocket 2 and the film take-up reel 4 by the photographer is moved to the first film guide roller. 7, the reel rubber 4 on the film take-up reel 4 is
Pressure is applied to a. In this state, when the film is wound, that is, the motor in the film take-up reel 4 is driven to rotate the film take-up reel 4 and the sprocket 2, the leading edge of the film is moved by the pressing force of the first film guide roller 7. The resulting frictional force with the film take-up reel 4 causes the film to be pulled by the take-up reel 4 and rapidly fed to the film take-up reel chamber, absorbing slack in the film due to curling, etc., and tightening the film and sprocket. ensure engagement with. At this time, the film is held down by the anti-float rollers 5 and 6 and is more securely engaged with the sprocket 2 (first feeding speed).

When the film is tightly engaged with the sprocket and the above-mentioned slack is removed, a tension in the opposite direction to the feeding direction acts on the film, and the film feeding speed decreases to the normal winding speed (second feeding speed). .
Thereafter, the leading end portion 9 of the film advances in the film take-up reel chamber in an idle state and is guided onto the film take-up reel 4 along the film guide portion 8c of the second film guide roller 8. Then, due to the frictional force between the second film guide roller 8 and the film take-up reel 4, the first film guide roller 7 is slightly pushed up and enters between the film and the film take-up reel 4. Then, the tension in the opposite direction is not acting on the leading end of the film due to the slack in the take-up reel chamber, so the take-up reel 4
The leading edge of the film is suddenly wound into the lower layer of the following film due to the speed of the take-up reel itself, causing slippage between the film and the succeeding part of the film. (Third feeding speed).

As a result, the slack in the film winding chamber is quickly absorbed, and the leading end is reliably pressed by the succeeding film, completing the film winding. Thereafter, due to the action of the tension in the opposite direction, the winding speed returns to the normal winding speed (fourth feeding speed).

In this embodiment, in order to prevent scratches etc. from occurring on the film, the tip of the pressing member is preferably a roller, and the guiding member is a curved spring plate. It can also serve as a member, allowing for a simpler structure. Furthermore, if the first pressing member is provided on the back cover, the sprocket and take-up reel will be exposed to the photographer when loading film, making it extremely easy to place the leading end of the film onto the take-up reel. becomes. After placing it, close the back cover and the first
The pressing member can reliably press the film onto the take-up reel.

(Effects of the invention) As described above, the invention of the present invention differs from the conventional concept by providing a tensioning function of the film tip to ensure engagement with the sprocket during film winding, and a tension function for tight winding. For example, after loading a film in which the back cover is closed simply by placing the leading edge of the film on the take-up reel, at the start of winding (first feeding speed stage), The first pressing means has the role of applying tension to the film to ensure engagement between the sprocket and the perforation, and has a structure that does not take into account tight winding on the take-up reel. When the film is loosened due to the film not being tightly wound, the leading edge of the film that has freely progressed in the winding chamber rotates approximately once, and the second pressing means causes the film to come loose between the winding reel and the following part of the film. From the time when the leading edge of the film enters the film at a higher speed than the trailing part by utilizing the difference in the feeding speed between the trailing part of the film and the take-up reel (third feeding speed stage) ) This is an attempt to absorb the slack, and as a result, it was possible to obtain a camera equipped with an autoloading device that operates reliably with a simple configuration in which pressing members are placed in two locations. It is.

Since the first pressing member was provided on the back cover,
When loading the film, the sprocket and take-up reel are exposed to the photographer, making it extremely easy to place the leading edge of the film from the sprocket onto the take-up reel, and the first feed at the start of winding. Hoisting at the feed speed can be ensured.

[Brief explanation of drawings]

The figure is a sectional view of the vicinity of the film winding chamber of a camera showing one embodiment of the present invention. 1: Camera body, 2: Sprocket, 3: Back cover, 4: Film take-up reel, 4a: Reel rubber, 5, 6: Film lifting prevention roller, 7: First
Film guide roller, 8: second film guide roller, 9: film leading end.

Claims (1)

[Claims for Utility Model Registration] 1. A sprocket; A film take-up reel provided in a film take-up chamber that rotates at a fixed position; A guide member that guides the film from the sprocket to the film take-up reel;
a first pressing means attached to the back cover, the first pressing means having a pressing roller provided on the guide member so as to elastically press the guided film against the take-up reel; a space formed by the inner wall of the film winding chamber and the circumferential surface of the take-up reel, in which the leading end of the film sent out by the pressure roller and the take-up reel moves with play; a guide member for directing the film toward the take-up reel; and a guide member provided on the guide member so as to elastically press the guided film against the take-up reel, the guide member being pressed by a pressing roller of the first pressing means. a pressing roller located near the pressing roller of the first pressing means on the take-up reel so as to send the leading end of the film between the film and the take-up reel; 2
A camera equipped with an autoloading device, characterized in that it has a pressing means; 2. A camera equipped with an autoloading device according to claim 1, characterized in that a rubber material is arranged on the circumferential surface of the film take-up reel. 3. A camera equipped with an autoloading device according to claim 1, wherein the film guide member is a spring plate member. 4 The pressing force of the first pressing means is greater than the pressing force of the second pressing means.
2. A camera equipped with an autoloading device according to claim 1, wherein the pressing force of the pressing means is set to be greater than the pressing force of the pressing means.