JPH11327027A - Film unit with lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily modify a metallic mold in a short term even when the surface of a pressing plate is required to be worked according to the accuracy of the metallic mold, the piling error of respective parts and a surface shape when an unexposed film is previously loaded in a manufacturing process. SOLUTION: This film unit with a lens is provided with a back cover 3 covering the film F and internal members from the back part, a unit main body 1 having a picture frame 1a forming a photographic picture frame at the film F and the pressing plate 4 forming a prescribed gap for regulating the film F at the position of a photographing lens L in the optical axis direction together with rail surfaces 1b and 1c formed at the periphery of the frame 1a. Then, the plate 4 and the cover 3 are separately formed and the plate 4 is fixed to the cover 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film unit with a lens provided with a pressure plate for forming a predetermined gap for restricting a film at a position in the optical axis direction of a photographic lens together with a rail surface provided around a screen frame of a unit body. About.

[0002]

2. Description of the Related Art In a film unit with a lens,
A screen frame for forming a photographing screen on the film is provided in the unit body, and rail surfaces are provided above and below the screen frame in parallel with the film feeding direction. The film is held at a predetermined position in the optical axis direction by a gap formed by a rail surface and a pressure plate integrally formed with the rear cover, that is, a tunnel. With this tunnel, the film is accurately held at the focus position of the taking lens, and a large resistance is not applied when the film is fed.

In a film unit with a lens,
Because there is no need for an opening for the user to insert and remove the film like a normal camera, and to manufacture at low cost,
The pressure plate is molded integrally with the rear cover.

In a normal camera, the pressure plate and the back cover are separate bodies, and the back cover for holding the pressure plate can be opened and closed to insert and remove the film. Therefore, the position of the pressure plate varies from camera to camera. It is hard to be fixed. Therefore, the main body is provided with a first rail surface and a second rail surface having a step, and a third rail surface and a fourth rail surface having a step, and a leaf spring or the like is arranged between the pressure plate and the back cover. To the higher first and fourth rail surfaces to form a pressure plate and a tunnel between the second and third rail surfaces.

[0005]

When the pressure plate is molded integrally with the rear cover, the position of the pressure plate may be shifted in the direction of the optical axis of the photographing lens due to the accuracy of the mold and the stacking error of each part. If the pressure plate is located in a direction away from the two rail surfaces, the amount of tunneling increases, the film position shift increases, the focus position deviates, and the resolution of the photograph decreases. Also, when the pressure plate is located in the direction approaching the rail surface, the tunnel amount decreases, and the film is sandwiched, and the film winding becomes heavy.

Further, even if the position of the pressure plate is accurately molded,
If the surface shape of the surface in contact with the film is bad, the film may be damaged during film feeding.

When the above problem occurs, it is necessary to correct the mold, but in this case, it is very difficult to correct the mold, and in some cases, the mold may be newly manufactured. . In such a case, of course, the development period becomes longer, and the cost for repairing the mold also increases significantly.

The present invention has been made in view of such a problem, and it is an object of the present invention to propose a film unit with a lens that can easily repair a mold of a pressure plate as needed.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to provide a lens-fitted film unit in which an unexposed film is loaded in advance in a manufacturing process, a rear cover for covering the film and internal members from behind, and a photographing screen on the film. A unit body having a screen frame to be formed, and a pressure plate that forms a predetermined gap that regulates the film at a position in the optical axis direction of the photographing lens together with a rail surface provided around the screen frame, and the pressure plate The problem is solved by a film unit with a lens, wherein the rear cover is formed separately and the pressure plate is fixed to the rear cover.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a film unit with a lens according to the present invention will be described with reference to FIGS.

FIG. 1 is a longitudinal sectional view of a film unit with a lens, and FIG. 2 is a perspective view of a rear cover and a pressure plate.

In FIG. 1, L is a photographing lens, and F is a film. In the film unit with a lens, an unexposed film F is previously loaded in the manufacturing process. The subject light forms an image on the film F by the photographing lens L, and a photographing screen is formed by the screen frame 1a in the unit main body 1. Reference numeral 2 denotes a front cover that covers the internal member from the front, and reference numeral 3 denotes a rear cover that covers the internal member and the film F from behind. A pressure plate 4 formed separately is fixed to the rear cover 3, and a film F is formed in a gap between the rail surfaces 1b and 1c of the unit body 1 and the pressure plate surface 4a of the pressure plate 4, that is, a tunnel.
Is regulated and held in the optical axis direction. Therefore, if each component is formed as designed, the tunnel amount is formed to be, for example, about 0.07 mm larger than the thickness of the film F, and the film F is shifted in the optical axis direction of the taking lens L within this range. There is no problem in focusing, and the film can be fed smoothly.

Means for fixing the pressure plate 4 to the rear cover 3 include bonding, ultrasonic welding, press fitting, and the like.

However, the position of the pressure plate surface 4a of the pressure plate 4 may be located rearward or forward depending on the accuracy of the mold or the stacking error of each component. In such a case, only the press plate 4 having a simple shape needs to be repaired, and the repair cost of the mold can be reduced in a short period of time.

Since the taking lens L is formed of one or two plastic lenses in order to manufacture the camera at low cost, the film F is moved in the feeding direction to correct the spherical aberration of the taking lens L. The screen frame 1a and the pressure plate 4 are formed so as to be curved in the feeding direction of the film F so as to be positioned in a curved manner. Therefore, the positioning of the pressure plate 4 is important not only in the direction of the optical axis but also in the direction perpendicular to the optical axis.

To this end, a recess 3a is provided in the rear cover 3 for sinking the pressure plate 4, or a rib 3b is provided on the periphery to form a step, and the pressure plate 4 is attached to the rear cover 3 by the outer periphery of the pressure plate 4 and the step. A form in which positioning is performed with respect to this is conceivable.

Also, a boss 3c is erected on the rear cover 3 to
The pressure plate 4 may be positioned with respect to the rear cover 3 by being inserted into the through hole 4 b or the non-through hole provided in the pressure plate 4.

Further, conversely, a non-through hole may be provided in the rear cover 3 and a boss standing upright on the back surface of the pressure plate 4 may be inserted to position the pressure plate 4 with respect to the rear cover 3.

In order to reduce the frictional force at the time of feeding the film F, it is desirable to provide a plurality of ribs parallel to the film feeding direction on the pressure plate surface 4a.

[0020]

According to the film unit with the lens of the first aspect, since the pressure plate is separate from the rear cover, it is necessary to correct the pressure plate surface according to the mold accuracy, the stacking error of each part, and the surface shape. The mold can be easily modified in a short period of time, and the cost does not increase. According to the film unit with the lens of the second to fourth aspects, the pressure plate can be positioned with respect to the rear cover.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a film unit with a lens.

FIG. 2 is a perspective view of a rear cover and a pressure plate.

[Explanation of symbols]

 L Shooting lens F Film 1 Unit body 1a Screen frame 1b, 1c Rail surface 3 Rear cover 4 Pressure plate 4a Pressure plate surface

Claims (4)

[Claims] 1. A film unit with a lens in which an unexposed film has been loaded in a manufacturing process in advance, wherein a unit body having a rear cover for covering the film and an internal member from behind, and a screen frame for forming a photographing screen on the film. And a pressure plate that forms a predetermined gap that regulates the film at a position in the optical axis direction of the photographing lens together with a rail surface provided around the screen frame, wherein the pressure plate and the rear cover are formed separately. A film unit with a lens formed, and wherein the pressure plate is fixed to the rear cover. 2. The film unit with a lens according to claim 1, wherein the pressure plate is positioned with respect to the rear cover by regulating the outer periphery of the pressure plate by a step provided on the rear cover. . 3. The pressure plate is positioned with respect to the rear cover by inserting a boss erected on the rear cover into a through hole or a non-through hole provided in the pressure plate. The film unit with a lens according to 1. 4. The pressure plate according to claim 1, wherein the pressure plate is positioned with respect to the rear cover by inserting a boss standing on the pressure plate into a non-through hole provided in the rear cover. Film unit with lens.