JPS5941172B2 - Film guide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film guide device for a still camera using roll film.

In recent years, when cameras are driven by an electric drive device, the film travels at a high speed, and the speed changes rapidly. Problems such as damage to the film, stability and flatness of the film in the photographing aperture have started to occur.

For example, as seen in conventional still cameras, a guide plate is pressure-contacted to the film regulation rail (outer rail) to form a tunnel-like film path, and this method regulates the film. When the running speed of the film increases, there are problems not only with the stability of the film's position in the running direction but also with the flatness of the photographing aperture, making it difficult to obtain uniformly stable images. There was a drawback. That is, during high-speed continuous drive, even if the film drive mechanism stops, the film supply side members continue to move due to inertia, resulting in excess film being supplied, causing sag at the photographing aperture, or causing the shutter to sag. The drawback was that the film did not stand still during operation, making it difficult to obtain good photographs.
Furthermore, there was a fear that the film surface would be damaged due to contact with the guide plate. In addition, in the case of so-called lateral pressure type film guiding devices such as those found in cine cameras, etc., the film is regulated by pressing the side edges of the film, so the flat surface of the film located at the photographing opening is The drawback was that it was not possible to maintain good quality. The present invention solves the various drawbacks of conventional film guiding devices as described above, and provides a new film guiding device that can always produce good images even when driven at a fairly high speed. The feature is that the film is ejected by an elastic means to a film guide device having a film guide plate that constantly forms a film path in cooperation with an aperture frame member having an aperture for photographing. The present invention is intended to stabilize the regulation of the position of the film located in the photographing aperture by providing a film pressing means for pressing a part of the film onto the aperture frame member. Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

First, FIGS. 1 to 3 are diagrams showing the structure of a conventional film guide device in a still camera and its operating state. A film guide plate 1 is connected to a camera (not shown) via a leaf spring 2. The guide plate 1 is attached to the back cover, and when the back cover is closed, the guide plate 1 is pressed against the film regulation rail 4a of the frame plate 4, which is an opening frame member having an opening for photographing, by the action of the leaf spring 2. Since there is a step slightly larger than the thickness of the film 6 between the regulating rail 4a and the inner rail 4b that regulates the focal plane of the frame plate 4, the film is A passage 7 was formed, and the film 6 was configured to run through this gap, but in the film guide device configured in this way, when the camera was driven continuously at high speed, the film 6 For example, the film was curved as shown in FIG. 2 6a and FIG. 3 6b and 6c, and therefore, the flatness of the film located in the photographing aperture 5 could not be maintained well. Next, an embodiment in which the film guide device of the present invention is applied to a still camera will be described.

FIG. 4 is a perspective view showing the structure of the film guide device, and FIGS. 5 and 6 show its operating state. A square hole 1a is bored in the film guide plate 1, and a pressing piece 8a of the film pressing means 8 is inserted into the square hole 1a, and the film pressing means 8 is elastically pushed by the arm 2a of the leaf spring 2. Therefore, when the back cover of the camera (not shown) is closed, the guide plate 1 is pressed against the regulation rail 4a by the action of the leaf spring 2, so as to form the passage 7 for the film 6 together with the inner rail 4b as described above. However, at this time, since the film pressing means 8 is also elastically urged by the arm 2a of the leaf spring 2, the pressing piece 8a presses against the film 6.
A part of the inner rail 4b is pressed against the inner rail 4b. Therefore, curvature at the opening of the film 6 during continuous high-speed driving as seen in conventional film guiding devices is prevented. Note that 3 is a stud for connecting the guide plate 1 and the leaf spring 2. In addition, in FIG. 4, the spring pressure of the arm 2a of the leaf spring 2 acting on the film pressing piece 8a may be designed to a level that does not significantly affect the running of the film.

As described above, the film guiding device according to the present invention has a simple structure in which a film pressing means is provided in a conventional device, and extremely beneficial effects can be obtained.

That is, in the apparatus of the present invention, a part of the film is pressed against the opening frame member having the opening for photographing by the film pressing means, so that the guide only forms a gap as a conventional film path. The stability and flatness of the film at the photographic aperture are maintained extremely well compared to other devices, and therefore, no matter what speed the camera is driven at, a uniform and stable image can always be taken. You will be able to get it. In addition, the problem of damage to the film surface due to contact with the film guide plate has been solved by crimping the outside of the effective shooting area of the film, and furthermore, the problem of film settling during manual or high-speed electric winding in still cameras has been solved. This also solves problems such as temporal variations.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of main parts of a conventionally formed film guide device in a still camera, Figs. 2 and 3 are sectional views showing its operating state, and Fig. 4 shows a film guide device of the present invention in a still camera. FIGS. 5 and 6 are sectional views showing the main parts of an embodiment configured to be applied to a camera, and FIGS. 5 and 6 showing the operating state thereof. 1... Film guide plate, 2... Leaf spring, 2a... Arm of plate spring 2, 3... Stud, 4... ... Opening frame member, 4a ... Film regulation rail (outer rail), 4b ... Film guide rail (inner rail), 5 ... Shooting opening, 6° ... Film, 7 ... Interval as film passage, 8 ... Film pressing means.

Claims (1)

[Claims] 1. A film regulation rail is provided on the outside of the film guide rails arranged on both sides of the photographing aperture, and a film guide plate is pressed against the film regulation rail to allow the film to pass between the film guide rail and the film guide plate. In a roll film guide device that forms a gap and feeds the film without contacting the film guide plate using the gap, a pressing member supported by an elastic member is provided on the film guide plate,
The pressing member presses the vicinity of each end along the film feeding direction of the film frame facing the photographing opening to each of the film guide rails, so that the film is pushed into the plane formed by the film guide plate. A roll film guiding device characterized by holding a roll film.