JP2844064B2 - Photographic film cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic film cartridge capable of unwinding and winding a roll-shaped film housed in a cartridge.

[0002]

2. Description of the Related Art As a 35 mm film cartridge, a commercially available patrone is most commonly used. As is well known, this patrone is wound in a so-called "bull winding" state on a spool in which the film is built. Therefore, the film cannot be unwound even when the spool is rotated, so that the film is kept in a state where the leading end thereof always projects from the film entrance of the cartridge and can be easily pulled out.

[0003]

Accordingly, since the telemping material attached to the film entrance is required to have a light-blocking effect and a braking action for suppressing the movement of the film, it is necessary to strongly press the film, and therefore, the drawing resistance of the film is reduced. May be increased, or a flaw may be caused by adhesion of a foreign substance or the like.

A cartridge in which these points are improved and the leading end of the film is housed in a cartridge has already been disclosed in Japanese Patent Application Laid-Open Nos. 3-116136 and 4-237.
No. 043 has been disclosed.

However, in the former case, a light-shielding member for opening and closing the film entrance is provided at the film entrance, but since the spool can be rotated even when the film entrance is closed by the light-shielding member, the film entrance and exit are provided. If the spool is rotated in the film unwinding direction with the cartridge closed, film breakage will occur inside the cartridge, and even if the film entrance is opened and the spool is rotated in the film unwinding direction, the leading end of the film will come out of the film entrance. There is a risk of an accident that the vehicle will not come out. On the other hand, with respect to the latter, the telemping material used for light shielding unwinds, which may result in resistance to the movement of the film at the time of winding, and also may cause the above-mentioned scratches.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photographic film cartridge having a high reliability while solving and improving these points and improving the safety of light-tightness.

[0007]

The object of the present invention is to provide a cartridge having a light-shielding member rotatable between a first position for closing the film entrance and a second position for opening the film entrance at the film entrance. In a photographic film cartridge in which the light-shielding member is set to the second position and the spool around which the film is wound is rotated in the film unwinding direction so that the leading end of the film is unwound from the entrance, the light-shielding member is moved to the first position. In some cases, the light-shielding member includes a rotation preventing unit for preventing the light-shielding member from rotating from the first position to the second position,
A second position of the light blocking member from the first position is
The rotation of the spool is prevented while the rotation to the position is prevented, and the rotation of the light blocking member from the first position to the second position and the prevention of the rotation of the spool are released. When the light-shielding member is rotated from the first position to the second position to open the film entrance, the film is bent and transported by the inner wall of the cartridge body on the back side of the film and the light-shielding member on the film front side. A photographic film cartridge characterized by forming a passage; and
The rotation preventing means is provided with a release member provided on the camera so that the light blocking member can be rotationally moved from the first position to the second position when the cartridge is loaded in the camera. 3. The system is released.
The photographic film cartridge according to the above item is achieved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a photographic film cartridge (A).

The cartridge (A) 10 has a film F
Is wound around a spool 11, and the film entrance 13 is closed by an axial light-shielding member 12 having a semicircular cross section to keep the film F in a light-tight state.

When the cartridge (A) 10 is loaded in a target camera and the light shielding member 12 is turned to be switched to the open position (second position), the film entrance 13 is opened.
Is opened and the spool 11 is driven and rotated, whereby the film F can be unwound and wound.

After the film (F) has been wound, the cartridge (A) 10 rotates the light shielding member 12 to return to the closed position (first position), and again keeps the film F in a light-tight state. Is taken out of the camera.

The light shielding member 12 is formed in a semicircular cross section 12A having a chevron-shaped projection 14 as shown in FIG. 2 (a) showing an AA cross section at a portion corresponding to the width of the film entrance 13 of the cartridge body. When the switch is switched to the open position by the rotation, the protrusion 14 of the light shielding member 12 located on the film front side projects between the inner wall of the cartridge body on the film rear side as shown in FIG. A bent film path is formed so that the film is transported in a bent state.

Therefore, the film F receives an appropriate frictional resistance when passing through the film entrance 13 and the resistance becomes a tension applied to the film F when the film F is wound on the cartridge (A) 10. It is wound in close contact with the spool 11 to be wound tightly.

FIG. 3 shows a projection 15 on the film passage itself.
Is provided, and shows an example in which a bent film passage is formed regardless of the rotation of the semicircular cross section 12B,
Also in this case, tension can be applied to the film F to be wound as in the previous embodiment.

FIGS. 4 (a) and 4 (b) show a cross section taken along the line BB in FIG. 2 (b) and a cross section taken along the line CC in FIG. 3 (b), respectively. When cut, each of the protrusions 14
By limiting the range in which the films 15 and 15 are formed so as to correspond to the cut width of the film, the front end of the film F can be easily passed during unwinding.

As a means for eliminating the frictional resistance of the film F at the time of unwinding, a light-shielding member 12 having a semicircular cross section 12C partially cut as shown in FIG. It is also possible to adopt a method of switching and using three stages of the closed position shown, the unwinding position shown in FIG. 5B, and the winding position shown in FIG. 5C.

In the present invention, in order to ensure light-tightness, a circle having a hole 110A connected to the spool 11 and the light-shielding member 12, respectively, is provided on the outer surface of the cartridge (A) 10 as shown in FIG. Pin 12 on plate 110 and tip
An elastic stop lever 120 having 0A is provided as a rotation preventing means. When the cartridge (A) 10 is alone, as shown in FIG. The rotation of the light shielding member 12, which is in the closed position by engagement, to the open position is prevented, thereby preventing the opening of the film entrance 13 and the rotation of the spool 11.

After the cartridge (A) 10 is loaded into the camera, the stop lever 120 is retracted by pressing a pin P which is a release member on the camera side, and the stop lever 120 is retracted.
A is released from engagement with the hole 110A of the disk 110. As a result, the light-shielding member 12 is turned to the position shown in FIG. 6B by the rotation of the camera-side key K1 which becomes rotatable, and the film entrance 13 is opened.

On the other hand, the spool 11 is also in a rotatable state, and the film F is unwound and wound through the camera-side key K2.

If the purpose is simply to wind the film F in a close-wound state, as shown in FIG.
1 and a concave and convex surface R2 corresponding to the concave and convex surface R1 is also formed and placed in the passage of the film of the cartridge (A) 10. At the end of the winding of the film F, the front end of the film F is set to the camera side. When the tension is lost by detaching from the hoisting member, a method of applying tension to the film F by the frictional force generated between the uneven surfaces R1 and R2 can be adopted.

By providing the irregular surfaces R1 and R2 with directionality, the resistance of the film F applied during unwinding can be extremely reduced.

[0022]

According to the present invention, a highly reliable photographic film cartridge can be provided while improving the light-tightness.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a cartridge (A) of the present invention.

FIG. 2 is a sectional view of a main part of the cartridge (A) (part 1).

FIG. 3 is a sectional view of a main part of the cartridge (A) (part 2).

FIG. 4 is a sectional view of an essential part of FIGS. 2 and 3;

FIG. 5 is a sectional view of a main part of the cartridge (A) (part 3).

FIG. 6 is an external perspective view of a main part of the cartridge (A).

FIG. 7 is a sectional view of a main part of the cartridge (A) (part 4).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cartridge (A) 11 Spool 12 Light shielding member 13 Film entrance 14, 15 Projection

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-181141 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03C 3/00

Claims (2)

(57) [Claims] 1. A film entrance and exit of a cartridge body,
A light shielding member rotatable between a first position for closing the film entrance and a second position for opening the film entrance, and rotating the spool around which the film is wound in the film unwinding direction with the light shielding member as the second position. In this way, in the photographic film cartridge in which the leading end of the film is unwound from the entrance, when the light shielding member is at the first position, the rotation of the light shielding member from the first position to the second position is prevented. A rotation preventing unit configured to prevent rotation of the spool while the rotation of the light blocking member from the first position to the second position is prevented by the rotation preventing unit. The rotation of the light shielding member from the first position to the second position and the inhibition of the rotation of the spool are released, and the light shielding member is moved to the first position.
When the film is rotated from the position to the second position and the film entrance is opened, a passage through which the film is bent and transported is formed by the inner wall of the cartridge body on the back side of the film and the light shielding member on the front side of the film. Photographic film cartridge. 2. The camera according to claim 1, wherein the light blocking member is provided on the camera so that the light blocking member can be rotated from a first position to a second position when the cartridge is loaded in the camera. The photographic film cartridge according to claim 2, wherein the blocking state is released by a member.