JP3152784B2 - Camera exposure screen switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure screen switching device used for a camera or the like.

[0002]

2. Description of the Related Art Recently, the horizontal side of a print is two times longer than the vertical side.
A panoramic camera for creating a wide panoramic print by changing the ratio more than twice as long has been provided. Some panoramic cameras switch the exposure screen between full size and panoramic size even during the shooting of one film, such as “Cardia Mini Everyday OP” (product name) sold by the present applicant. There is something that can be done. Such a camera that can be switched in the middle has a full size of 24 mm x 36 mm (aspect ratio 1.5), which regulates the exposure range for the film in conjunction with the operation of an operation unit provided outside. And an exposure screen switching mechanism for inserting a flat mask from above and below the full size exposure frame and switching the exposure screen to a panoramic size regulated to 13 mm × 36 mm (aspect ratio 2.8). .

[0003] The background of providing a large number of cameras that can be switched midway is that in the current lab industry, a photographic film in which a full-size frame and a panorama-size frame are mixed in one film (hereinafter, "mixed"). The film is distinguished from a photo film consisting of only full-size frames, and the size of each frame of the mixed film is automatically detected and a verification is made to mark the print type. This is because a photographic printing system has been established which can efficiently print full-size frames and panoramic-size frames separately without changing the print magnification or mask size.

[0004] Therefore, an inexpensive film unit with a lens (hereinafter, referred to as a "film unit") proposed in Japanese Patent Publication No. 2-32615 or the like incorporates an exposure screen switching mechanism and has a single unit. It has been desired that the exposure screen can be switched between the full size and the panorama size during the filming so that the filming can be performed.

Incidentally, a plastic lens is used as a photographing lens in the film unit in order to mass-produce it at low cost. Since the lens configuration is reduced to one or two, correction of spherical aberration, curvature of field, astigmatism, distortion, and the like is required. As the correction, in addition to making the shape of the photographing lens aspherical, the various aberrations are corrected in a well-balanced manner by curving the film surface. For this reason, the film unit also has a curved film surface to reduce the influence of distortion and the like, thereby ensuring a good focus state at the periphery of the screen.

[0006]

In consideration of incorporating an exposure screen switching mechanism into such a film unit, a mechanism for simply inserting a flat mask from above and below the exposure screen because the film surface is curved. In such a case, a gap is generated between the film surface and the mask, and the upper and lower contour lines of the screen are exposed in a curved shape. Such a barrel-type exposure screen has a drawback that it is difficult to test it as a panorama-size frame with the current photo print system.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. An exposure screen defined by upper and lower masks on a curved film surface is formed such that the upper and lower lines of the outline are straight lines. An exposure screen switching device for a camera, which is configured to expose a subject.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a rectangular exposure frame provided on the front surface of a photographic film surface curved so as to be convex on the back side, and Two masks which are provided in the optical path so as to be able to freely enter and exit, and narrow a width of a screen defined by the exposure frame in a direction perpendicular to a film feeding direction to define a screen having an aspect ratio different from the screen. A mask plate when the mask plate enters the photographing optical path, so that the gap between these opposing edges and the photographic film surface is constant.
It is formed in a curved shape along the curved photographic film surface.

According to this, the size of the screen exposed on the photographic film is reduced by the width of the screen defined by the exposure frame and the width of this screen in the direction perpendicular to the film feeding direction by using two mask plates. The screen is switched to a screen having an aspect ratio different from that of the screen. When entering the shooting optical path,
Since these two mask plates have a curved shape along the curved photographic film surface such that the gap between these edges and the photographic film surface is substantially constant, a screen defined by the two mask plates Of the contour lines along the film feeding direction are linearly exposed on the curved photographic film surface. At this time, it is preferable to make the edges of the two mask plates as close as possible to the photographic film surface.

[0010] According to the second aspect of the present invention, the exposure screen
Is always defined by a mask plate.

[0011]

FIG. 2 shows the appearance of a film unit with a lens 10 having a built-in exposure switching mechanism 17. As shown in FIG.
The film unit 10 is provided with an operation lever 11 operated when a panoramic print is intended.
The illustrated operation lever 11 is in a state of a normal photographing position where normal photographing is performed, and when performing panoramic photographing from this state, the operation lever 11 is depressed to operate the state of the panoramic photographing position.

As shown in FIG. 3, the film unit 10
Is a main body 15 in which a 135-type film 14 with a patrone specified by the International Standard ISO 1007-1979 is loaded, and a patrone is attached to the back of the main body 15 to be attached thereto. Rear cover 16 for accommodating the attached film 14 in a light-tight manner, an exposure screen switching unit 17 attached to the main body 15, and an exposure unit 2 attached to the front of the exposure screen switching unit 17.
1 and a front cover 22 attached to the front surface of the main body 15, which are detachably attached.

The exposure unit 21 incorporates a film wrapping mechanism, a shutter mechanism, a photographic lens 23, and the like. The front cover 22 has a transparent finder 2
5 are provided integrally. On the outer surface of the patrone 14b, a display unit 14c for displaying that a photo film in which a full size frame and a panorama size frame are mixed is stored is provided.

As shown in FIG. 4, an exposure frame 28 having a full size (aspect ratio 1.5) is provided between a patrone chamber 26 and a film roll chamber 27 in the main body 15.
Is provided. The exposure frame 28 has a shape that is curved along the film feeding direction together with the film support surface 29 provided on the back surface. On the inner surface of the rear cover 16, a film regulating surface 30 which is curved in the same shape as the film supporting surface 29 is formed.

FIGS. 5, 6 and 7 show the exposure screen switching unit 17. FIG. The operation lever 11, the rack plate 35, the holding claws 36, and the sector gear 37 are attached to the outer surface 33a of the base 33. The operation lever 11 is fixed so as to be movable in the vertical direction. The rack plate 35 is movably fixed in the up-down direction between the base 33 and the operation lever 11, and the sector gear 37 meshes with a gear portion 35a provided on the rack plate 35. Operation lever 11 and rack plate 3
The springs 39 and 40 are hung on 5 and 5, respectively. One spring 39 urges the rack plate 35 upward with respect to the base 33, and the other spring 40 urges the operation lever 11 downward with respect to the rack plate 35. In FIG. 5, the springs 39 and 40 are omitted to prevent the drawing from being complicated.

The holding claw 36 is rotatably fixed in a state where the holding claw 36 is urged in a left turning direction by a torsion spring 41. The holding claw 36 is integrally provided with a tip claw 36a and a release claw 36b. The tip claw 36a is connected to the operation lever 11
The notch 35 of the rack plate 35 is
b, and holds the operation lever 11 at the panoramic position. When the operation lever 11 is pulled up, the projection 11 a provided on the operation lever 11 is
b, and the engagement between the tip claw 36a and the notch 35b is released.

Between the back surface 33b of the base 33 and the outer surface 43a of the left plate 43, there is provided a slide plate 44 movable in the optical axis direction of the taking lens 23, and a rotary lever interlocked with the rotation of the sector gear 37. 45 are provided. The tip of the rotation lever 45 is engaged with the slide plate 44, and moves the slide plate 44 in conjunction with the rotation of the sector gear 37. The dark box 47 has an opening 47 for guiding the subject light passing through the photographing lens 23 to the exposure frame 28.
a, 47b are formed. On the left side of the dark box 47,
The left side plate 43 is fitted therein, and the main body upper and lower mask plates 50 and 51 are built therein.

On both ends of the upper and lower mask plates 50 and 51, shafts 50a, 50b, 51a and 51b are provided, and connecting portions 50c and 51c are provided at positions separated from one of the rotating shafts 50b and 51b by a predetermined distance. Each is provided. Axis 50a,
50b, 51a and 51b are bearing portions 47c provided inside the dark box 47 and the left side plate 43 along the film feeding direction.
The upper and lower mask plates 50 and 51 are rotatably supported by being fitted into 43b, 47d and 43c, respectively.

The connecting portions 50c and 51c are engaged with the slide plate 44 via the guide grooves 43d and 43e of the left side plate 43, and the main body is guided by the guide grooves 43d and 43e by the movement of the slide plate 44. The upper and lower mask plates 50 and 51 are rotated. As a result, the upper and lower mask plates 50 and 51 of the main body are retracted from the photographing light incident on the exposure frame 28 by the movement of the connecting portions 50c and 51c, and the film is fed on the screen defined by the exposure frame 28. It rotates between a panorama position defining a panorama size in which the width orthogonal to the direction is narrowed, and is normally urged toward the retreat position by torsion springs 52 and 53.

When the panorama position enters the photographing optical path, the upper and lower mask plates 50 and 51 are so arranged that the gap between the opposing edges 50d and 51d and the surface of the photographic film 14a is constant. , Curved photo film 14
It has a curved shape along the plane a. These edges 50d and 51d are formed parallel to the film feeding direction when viewed from the front on the photographic lens side.

The exposure screen switching unit 17 includes a finder upper / lower mask that controls the view range according to the full size of the viewfinder 25 from above and below and switches the view range according to the panorama size according to the operation of the operation lever 11. 11b and 56 are provided. The finder upper mask 11b is provided integrally with the operation lever 11,
In conjunction with the movement of the operation lever 11, the viewfinder 25 is cut through a notch 25a (see FIG. 9) of the viewfinder 25.
Move between the inside and outside of the building.

The finder lower mask 56 is provided on the upper surface of the dark box 47 so as to be rotatable about an axis along the film feeding direction, and is in a retracted position where it is always retracted downward from the finder 25 by the torsion spring 57. Is being urged towards. The finder lower mask 56 is provided with a hitting plate 58 with which the pressing plate 11c of the operation lever 11 is engaged. The finder lower mask 56 is provided with the finder 25 through the opening 25b of the finder 25 in conjunction with the pressing operation of the operation lever 11. Go inside.

Next, the operation of the above embodiment will be described. The panorama shooting position of the operation lever 11 of the film unit 10 is in an initial state. In this state, as shown in FIG. 8A, the tip claw 36a is engaged with the notch 35b, and the operation lever 11 is held in a state where it enters the contour of the film unit 10. Also, as shown in FIG.
Inside the dark box 47, the upper and lower mask plates 50 and 51 are in a panoramic position. Further, inside the finder 25, the finder upper mask 11b
However, the lower viewfinder mask 56 is exposed below.

When taking a picture, first, the winding knob 59 is turned to charge the shutter. After the shutter charge is completed, the photographer performs peeping framing from the viewfinder eyepiece window 60. At this time, since the view range of the viewfinder 25 is a panoramic view range in which the width along the film feeding direction is narrowed by the viewfinder upper and lower masks 11b and 56, mistakes in the switching operation can be prevented.

When the shutter button 61 is operated, the shutter of the exposure unit 21 opens and closes, and the subject light transmitted through the taking lens 23 enters the film 14a in the exposure frame 28. At this time, since the upper and lower mask plates 50 and 51 are in the panoramic position, the upper and lower mask plates 50 and 51 are vignetted by the upper and lower mask plates 50 and 51, and the film 14 is turned off.
The screen size exposed to a is the panorama size.

As shown in FIG. 1, the exposure screen 62 of panoramic size has a curved shape along the surface of the photographic film 14a in which the upper and lower mask plates 50 and 51 are curved. The line 63 along the film feeding direction A is linearly exposed. Also, if the upper and lower mask plates 50 and 51 are arranged close to the surface of the photographic film 14a, blurred images generated by light diffraction and the like are reduced, and the edge 63 of the exposure screen 62 is sharply exposed. become. 28a shown in FIG.
2 shows a full-size exposure screen defined by an exposure frame 28.

When performing normal photographing, the operation lever 11
Pull up. By this pulling operation, FIG.
As shown in (B), the protrusion 11a contacts the release claw 36b and urges the holding claw 36 to turn left. By the rotation of the holding claw 36, the engagement between the tip claw 36a and the notch 35b is released, and the rack plate 35 is moved upward by the bias of the spring 39, as shown in FIG. Rack plate 3
In conjunction with the movement of 5, the rotation lever 45 rotates counterclockwise via the sector gear 37. The slide plate 44 is moved forward in conjunction with the rotation of the rotation lever 45, and the movement of the slide plate 44 causes the upper and lower mask plates 50 and 51 to be
It is rotated to the retracted position, and is in the state shown by the two-dot chain line in FIG. Also, on the finder inside the finder 25,
The lower masks 11b and 56 are retracted upward and downward (indicated by a two-dot chain line in the figure).

When photographing is performed in this state, the photographing lens 23
Of the subject light that has passed through, the subject light incident on the exposure frame 28 is exposed to the film 14a by the upper and lower mask plates 50 and 51 without vignetting. As described above, the photographing is performed while selecting one of the normal photographing and the panoramic photographing. When the photographing of all frames is completed, the film unit 10 is submitted to the developing laboratory as it is.
At the photo lab, a patrone 1 containing the exposed film
Remove 4b. At this time, the display unit 14 is displayed on the patrone 14b.
Since c is applied, it can be easily recognized that the stored exposed photographic film 14a is a mixed film.

The sorted cartridges 14b are tested after being subjected to development processing. In this test, a panorama-size frame is marked to distinguish it from a full-size frame. At this time, since the panorama-sized exposure screen has a predetermined rectangular shape, the verification can be performed reliably. In the printing process, first, only the full-size frame is printed, and then, only the panorama-sized frame is printed. At this time, the print magnification of the printer and the size of the mask are changed. The print magnification from a full-size frame to photographic paper is about 3.5 times, and the print magnification from a panorama-size frame to photographic paper is about 7 times. After performing the printing process as described above, the print photograph and the film negative are returned to the user. Then, the empty film unit 10 is collected and recycled at the factory without being returned to the user.

In the above embodiment, the upper and lower mask plates 5
The exposure screen defined by 0 and 51 is only the panorama size, but the present invention is not limited to this, and the exposure screen may be defined by the upper and lower mask plates 50 and 51 for the film size. The embodiment shown in FIG. 10 is an example in which two screens of a full size and a panoramic size are constituted by the upper and lower mask plates 71 and 72 of the main body. The upper and lower mask plates 71 and 72 are provided with these edges 71a,
72a always constitutes two opposite sides of the screen size. Edges 7 of these upper and lower mask plates 71, 72
FIGS. 11A and 1A show plan views from the top.
11B, and in a front view from the photographing lens 23 side, as shown in FIG. 11B, the surfaces facing each other are curved so as to be convex.

These upper and lower mask plates 71, 72
Is a point P at which an optical path 73 (solid line in the figure) passing through the principal point O of the photographing lens 23 and the central edge 71a of the upper mask 71 shown in FIG. 12 enters the surface 14d of the photographic film 14a.
2 and a point P1 at which an optical path 74 (dotted line in the drawing) passing through the principal point O of the taking lens 23 and the edge 71a 'at the end of the upper body mask 71 enters the surface 14d of the photographic film 14a with respect to the optical axis. If the screen size is determined so as to be the same height, a line along the film feeding direction among the contour lines of the exposure screen is exposed in a straight line. In the case of this embodiment,
The exposure screen 70 needs to be formed larger than the full size. A mechanism for moving the upper and lower mask plates 71 and 72 between the panorama position and the full size position is shown in FIG.
Needless to say, the same mechanism as that shown in FIG. 7 can be used.

In each of the above embodiments, the exposure screen switching mechanism 1
7, the switching screen size is a full size and a panoramic size. However, the present invention is not limited to this, and the high definition size (aspect ratio 1.46), cinema size (aspect ratio 2.30), square size Any of size (aspect ratio 1.0) and the like may be used.

[0033]

As described above in detail, according to the first aspect of the present invention, the two mask plates are curved so that the gap between the edge defining the screen and the photographic film surface is constant. Since the curved shape is formed along the photographic film surface, the line in the film feeding direction among the contour lines of the screen exposed on the photographic film surface curved with respect to the film feeding direction can be exposed in a straight line. With the current photo print system, it can be reliably verified as a panorama-sized frame.

According to the second aspect of the invention, two opposite sides of the screen size to be switched are always constituted by two mask plates, so that the amount of rotation of the upper and lower mask plates of the main body can be reduced. In addition, since these evacuation spaces are not required, there is an effect that the size can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a main part of an exposure frame switching mechanism.

FIG. 2 is a perspective view showing an appearance of a film unit with a lens.

FIG. 3 is an exploded perspective view of the film unit with a lens.

FIG. 4 is a cross-sectional view of the film unit with a lens.

FIG. 5 is a perspective view showing an exposure screen switching mechanism.

FIG. 6 is an exploded perspective view showing a part of an exposure screen switching mechanism.

FIG. 7 is an exploded perspective view showing another part of the exposure screen switching mechanism.

FIGS. 8A, 8B, and 8C are explanatory diagrams of the operation of an exposure screen switching mechanism.

FIG. 9 is a longitudinal sectional view of a film unit with a lens.

FIG. 10 is a sectional view of a main part showing an embodiment in which two screen sizes are defined by the upper and lower mask plates of the main body.

11A is a plan view schematically showing the upper and lower mask plates shown in FIG. 10; FIG. 11B is a front view schematically showing the upper and lower mask plates shown in FIG. 10;

FIG. 12 is an explanatory diagram of the embodiment shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 Film unit with lens 11 Operation lever 17 Exposure screen switching unit 14a Film 23 Photo lens 28, 70 Exposure frame 50, 71 Upper body mask plate 51, 72 Lower body mask plate

Claims (2)

(57) [Claims] A rectangular exposure frame provided on a front surface of a photographic film surface which is curved so as to protrude rearward with respect to a film feeding direction, and a rectangular exposure frame provided so as to freely enter and exit a photographic optical path. Two mask plates for narrowing the width of a prescribed screen in a direction orthogonal to the film feeding direction to define a screen having an aspect ratio different from the screen, and when the mask enters the photographing optical path. The exposure screen of a camera, wherein the mask plate is formed in a curved shape along the curved photographic film surface such that a gap between these opposed edges and the photographic film surface is constant. Switching device. 2. A screen-size film feeder movably provided in a photographing optical path incident on a photographic film surface curved so as to project rearward with respect to the film feed direction, and exposed to the photographic film. In an exposure screen switching device for a camera having two mask plates that change the width in a direction perpendicular to the direction, two opposite sides of the screen size are always defined by edges of the two mask plates. ,Previous
When entering the optical path, the mask plate
The gap between the opposing edges of the
So that the curvature along the curved photographic film surface
Exposure screen of camera characterized by being formed in shape
Switching device.