JPH07159938A - Film unit with lens - Google Patents

Abstract

PURPOSE:To prevent the occurrence of flare and to obtain a clearly printed photograph. CONSTITUTION:When a control lever 3 is switched between a panoramic photographing position and a standard photographing position, upper and lower light shielding plates 83 and 84 are rotated between a panoramic position where an exposure screen is demarcated to a panoramic size and a retreat position retreated outside from a luminous flux which is made incident in an exposure frame 21 thereafer. Behind the exposure frame 21, a curved film supporting surface is formed so as to project into the rear side, and circular-arcuate shielding walls 83f and 84g projecting into a photographing optical axis are integrally formed on opposed two faces of the upper and lower mask plates 83 and 84 in order to prevent the occurrence of flare with reference to the curved exposure screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens-fitted film unit, and more particularly to a lens-fitted film unit having a built-in exposure screen switching mechanism for switching exposure screens.

[0002]

2. Description of the Related Art Recently, the horizontal side of a print is 2 times larger than the vertical side.
A panoramic camera is provided to create a wide panoramic print by changing the ratio to more than double. In this panoramic camera, for example, Japanese Patent Application No.
As proposed in Japanese Patent No. 153710, there is a method in which the exposure screen is switched between the full size and the panorama size even during the shooting of one film.

In the background of the large number of such cameras that can be switched in the middle, in the current laboratory industry, a photographic film (hereinafter, "full-size frame" and "panorama size frame") is mixed in one film. It is called "mixed film"), and it is distinguished from a photo film with only full-size frames, the size of each frame of the mixed film is automatically detected, and the mark of the print type is verified. This is because a photographic printing system has been established that efficiently prints full-size frames and panorama-sized frames separately without changing the print magnification and mask size one by one.

Therefore, an exposure screen switching mechanism is also provided in an inexpensive lens-equipped film unit (hereinafter referred to as "film unit") using a fixed-focus plastic lens proposed in Japanese Examined Patent Publication (Kokoku) No. 2-332615. It is desired that the exposure screen be switched between the full size and the panorama size while shooting one film so that shooting can be performed.

In this film unit, a combination of at most two lenses is used as a photographic optical system in order to achieve low cost, and in order to avoid image deterioration due to various aberrations as much as possible, The film surface is curved at the image plane. Along with this, the opening edge of the flare prevention frame that cuts the light that goes out of the shooting screen out of the light passing through the shooting lens is formed in a convex arc shape toward the inside, making it clear on a full-size exposure screen. It is devised to form an image of various subjects (Japanese Patent Application No. 4-1245).
21).

[0006]

However, in the case of incorporating the exposure screen switching mechanism in the film unit, a pair of shading plates are provided between the flare prevention frame and the exposure frame between the inside and outside of the photographing optical path. Since it is arranged so that it can be inserted and removed, there is a drawback that a part of the light that has passed through the flare prevention frame is reflected on the inner surface of the light shielding plate and is incident on the exposure screen as flare light. Especially in the exposure screen defined in full size,
Since the width in the vertical direction is longer than the panorama size, flare may be noticeable.

The present invention has been made in order to solve such a problem, and has a lens which has a built-in exposure screen switching mechanism to prevent flare from occurring and to obtain a clear print photograph. It is intended to provide an attached film unit.

[0008]

In order to achieve the above object, in the present invention, an exposure frame provided on the front surface of a film surface curved so as to be convex on the back side, and the exposure frame on the film surface. And a width in the vertical direction on the film surface so as to have a second aspect ratio different from the first aspect ratio so as to define a first exposure screen having a first aspect ratio. A pair of upper and lower light-shielding plates that are movable between an insertion position that is inserted into the front surface of the exposure frame to define a narrowed second exposure screen, and at least one of the upper and lower light-shielding plates faces the other. Is formed in a circular arc shape that is convex toward the photographing optical axis.

[0009]

The flare preventing frame may have a rectangular shape when the film surface is a flat surface, but when the film surface is curved so as to be convex toward the back side, the flare preventing effect is simply obtained with a rectangular frame. I can't expect. Therefore, the opposing surfaces of the upper and lower light shielding plates are formed in a convex arc shape toward the photographing optical axis to prevent flare. In the invention according to claim 2, a groove is formed on the arcuate surface of the upper and lower light shielding plates. According to this, the light reflected by the arc-shaped surfaces of the upper and lower light shielding plates and entering the exposure screen can be blocked.

[0010]

EXAMPLE A lens-fitted film unit 2 shown in FIG.
(Hereinafter, referred to as a "film unit".) Has a structure in which the unit body 1 is wrapped in an outer case 4, and the outer case 4 includes a taking lens 5, a shutter button 6, an operating lever 3, and a winding knob. 8, an opening for exposing the viewfinder objective window 9, the number-of-photographs display window 11, and the like to the outside. Operation lever 3 provided on the front
Is operated when switching the exposure screen between full size (24 × 36 mm; aspect ratio 1: 2) and panorama size (13 × 36 mm; aspect ratio 1: 2.8). “Standard shooting position”) and the position moved to the right in the slot 41 (hereinafter, referred to as “standard shooting position”).
This is called the "panoramic shooting position". ) Is operated between.
When the operation lever 3 is operated to the standard shooting position, the exposure screen is switched to the full size, and the viewfinder view range is similar to the full size aspect ratio (hereinafter,
This is referred to as the "standard visual field range". ). Further, when the panorama shooting position is operated, the exposure screen is switched to the panorama size, and the viewfinder field range is switched to a field range similar to the aspect ratio of the panorama size (hereinafter, referred to as “panoramic field range”).

As shown in FIGS. 3, 4, and 5, the unit main body comprises a main body base 14, a rear cover 15, a mechanical unit 17, and a front cover unit 18. The body base 14 has an international standard (ISO: 1007-19
The photographic film cartridge 24 of 135 type specified in 1979 edition) is loaded. Further, a mechanical unit 17 is detachably attached to the front surface of the main body base 14. The mechanical unit 17 is composed of a mechanical base 50 integrally formed with a dark box 50a, an exposure screen switching mechanism 19, an exposure applying mechanism having a photographing lens 5, a film winding mechanism, and the like, which are integrated. The rear cover 16 is
It is detachably attached to the back of the main body base 15 to shield the main body base 14 from light. The front cover unit 18 is detachably attached to the front surface of the main body base portion 15.

The photographic film cartridge 24 comprises a photographic film 24a and a cartridge 24b for accommodating the photographic film 24a in a light-tight manner. This Patrone 24b
Is a spool 24c in which the end of the photo film a is fixed.
When the spool 24c is rotated, the exposed photographic film 24a is wound around the outer periphery of the spool 24c. A cartridge storage chamber 22 for storing the cartridge 24b and a film storage chamber 23 for storing a roll of the unexposed photographic film 24a pulled out from the cartridge 24b are integrally formed in the main body base 14. The exposure frame 21 is provided between the cartridge storage chamber 22 and the film storage chamber 23.
Is located there, and a full-size exposure opening 21a is formed therein.

The back surface of the exposure frame 21 is a film support surface 25.
The film support surface 25 has a curved shape that is convex toward the back side along the film feeding direction in order to improve the distortion of the taking lens 5. The center of this curvature is the optical axis 5 of the taking lens 5.
The curvature has a radius of 100 mm on a. Also,
The inner surface of the rear cover 15 forms a curved film regulation surface 26 corresponding to the film support surface 25. And
A dark box 50a is detachably attached to the exposure opening 21a by nail coupling or the like, and the subject light transmitted through the taking lens 5 is guided. A finder eyepiece window 27 is integrally provided on the rear cover 15.

The front cover unit 18 includes an operation plate 35,
It is composed of a cover plate 36 and a front cover 34 in which these are detachably incorporated. In addition to the viewfinder objective window 37, the shutter button 6 and the like are integrally formed on the front cover 34. On the front of the viewfinder objective window 37,
The operation plate 35 is incorporated so as to be slidable along the film feeding direction. On the operation plate 35, the panoramic view frame 3
8 and the operation knob 3 are integrally provided. The panoramic field frame 38 is formed with a size that defines the viewfinder field range to have the same aspect ratio as the panoramic size. Further, the cover plate 36 is integrally provided with a full-size visual field frame 40 on the finder optical axis 39 that defines the same aspect ratio as the full-size, and a long hole opening 41 for movably exposing the operation knob 3 to the outside. It is provided in.

The operation plate 35 is provided with the operation knob 3 with an elongated hole opening 41.
By operating the slide inside, the panoramic view frame 3
8 is slidably incorporated between a panoramic photographing position located on the finder optical axis 39 and a standard photographing position retracted from the panoramic photographing position. At these positions, the notches 42 and 43 provided on the lower portions of both sides and the elastic click claws 44 and 45 integrally provided on the front cover 34 are click-coupled. The operation plate 35 is integrally provided with a cam 46 for interlocking with an exposure screen switching mechanism 19 which will be described later when the operation plate 35 moves to these positions. The edge 47 at one end of the operation plate 35 has a cross-sectional shape that is cut out so as not to block the viewfinder field range at the standard photographing position.

As shown in detail in FIG. 6, the mechanical base 50a has two shafts 51 and 52 and a bearing opening 5 on the upper left side.
3 and 3 are integrally formed. A shutter drive lever 54 and a number-of-photos display plate 55 are rotatably inserted into the shaft 51, and finally a retaining ring 56 prevents the shutter drive lever 54 and the number-of-images display plate 55 from coming off. Also, axis 5
A spring 57 and a locking lever 58 are rotatably inserted into the shaft 2, and finally a retaining ring 59 prevents the spring 57 from coming off. Bearing opening 5
A cam member 60 is inserted into the unit 3. A one-tooth gear 60a is integrally provided on the upper side of the cam member 60, and meshes with a tooth 55a formed on the outer periphery of the photograph number display plate 55. The lower side of the cam member 60 has a driven sprocket 61.
Engage with.

As is well known, when the film winding operation of the winding knob 8 is performed, the winding core of the cartridge 24b is rotated and the film 24a is transferred. This film 2
The driven sprocket 61 is included in the perforation 4b.
Teeth are in mesh. Therefore, the driven sprocket 61 rotates in association with the film transfer, and the cam member 60 also rotates in accordance with this rotation. Rotation of the cam member 60 moves the shutter drive lever 54 to the charge position via the locking lever 58. When the driven sprocket 61 makes one rotation, the one end 58a of the locking lever 58 engages with the outer circumference of the winding knob 8 to prevent the winding operation. At this time, the number-of-photographed display plate 55 rotates by one scale.

When the shutter button 6 is operated, the shutter drive lever 54 is slightly rotated counterclockwise by the bias of the spring 57. During this slight rotation, the kick-off portion 54a of the shutter drive lever 54 kicks off the shutter blade 63 described later. A shaft 62 is formed on the front surface of the mechanical base 50 in parallel with the optical axis 5a. A shutter blade 63 having a crank shape is rotatably attached to the shaft 62. The shutter blades 63 rotate between a position where the shutter 64 is biased by the spring 64 to block the shutter opening 50b provided on the optical axis 5a and a position where the shutter driving lever 54 kicks the shutter opening 50b away from the shutter opening 50b.

A shutter cover 64 is attached to the front surface of the shutter blade 63 to prevent it from swinging in the direction of the optical axis 5a. The shutter cover 64 has an optical axis 5a.
A diaphragm opening 64a is formed on the upper side, and a lens barrel 64b is integrally formed so as to surround the diaphragm opening 64a. This lens barrel 6
4b includes a rear lens 65 and a front lens 66 that form the taking lens 5, and a spacer 67 that is sandwiched between them.
And are inserted, and finally the lens cover 68 is covered.

Since the focal length of the photographing lens 5 is a type in which the exposure screen can be switched between the panorama size and the full size on the way, a wide-angle effect can be obtained in the panoramic photographing.
Further, in order to obtain a standard angle of view in the case of normal photography, the length is set to 32 mm and the F number is set to 10.5.
The rear lens 65 is a biconvex spherical plastic lens and the front lens 66 is a front aspherical convex meniscus plastic lens in order to set the focal length to 32 mm in the two-lens taking lens 5.

The reason for mounting a lens having a large F number is to use a pan focus that focuses on a short-distance subject to a long-distance subject without using the focusing function. It is preferable that the focal length (f) of the taking lens of the film unit that switches the exposure screen between the panoramic size and the full size is 28 ≦ f ≦ 33 mm. Further, although the taking lens 5 is composed of two plastic lenses, a single lens plastic lens can be used. In this case, 28 ≦ f ≦ 33 mm
In order to satisfy the focal length of, it is necessary to mold with a two-sided aspherical surface.

A concave holding frame 71 is integrally formed on the upper right side of the mechanical base 50. In this holding frame 71,
Grooves for positioning the objective lens 72 and the eyepiece lens 73 are formed respectively, and an inverted Galilean finder lens including the objective lens 72 and the eyepiece lens 73 is detachably inserted into these grooves. These finder lenses 72 and 73 are used for the objective window 3 of the front cover 34.
7 and the eyepiece window of the rear cover 15 are arranged.

FIG. 7 shows a main part of the exposure screen switching mechanism 19. The exposure screen switching mechanism 19 is roughly classified into an intermediate lever 8
0, torsion spring 81, crank lever 82, spring 95,
And upper and lower light shielding plates 83 and 84. The intermediate lever 80 is rotatably provided around a shaft 86 that is planted on the upper surface of the top plate 74. This intermediate lever 80
Is a projection 80a that is in sliding contact with the cam 46 of the operation plate 35,
Lower protruding piece 8 that engages with pin 82a of crank lever 82
0b and 0b are integrally formed of a hard plastic material, and the torsion spring 81 urges the protrusion 80a in a direction in which the projection 80a abuts the cam 46 (clockwise direction in the figure). When the operation plate 35 is operated from the standard photographing position to the panoramic photographing position, the cam 46 of the operation plate 35 is operated.
However, in detail, there are a retracted position where the upper and lower light shielding plates 83 and 84 of the exposure screen switching mechanism 19 which will be described later are retracted from the front surface of the exposure opening 21a and a panoramic position which enters the front surface of the exposure opening 21a and defines a panorama size exposure screen. The shape is such that the intermediate lever 80 is rotated more than the amount of movement between them.

The crank lever 82 is made of an elastic plastic material and has a pin 82a at one end 82c.
However, bearing portions 82b are integrally provided on the other end portion 82d. The bearing portion 82b pivotally supports the upper light shielding plate 83 through a bearing opening 89 provided in the dark box 50a, and the upper light shielding plate 83 and the crank lever 82 are integrally connected by a press-fitting pin 85. The pin 82a hits the lower projecting piece 80b along the direction in which the intermediate lever 80 rotates when the operation plate 35 is slid from the standard shooting position to the panoramic shooting position. The one end portion 82c provided with the pin 82a absorbs the movement amount of the intermediate lever 80 which is moved more than the movement amount of the pair of light shielding plates 83 and 84 between the retracted position and the panoramic position. The shape is narrower than the other end portion 82d.

The lower portion of the dark box 50a has an arc shape, and the subject light incident from the taking lens 5 is exposed through the exposure opening 21.
In order to guide the light to a, openings 87 and 88 for passing the subject light are provided on the front surface and the back surface along the optical axis 5a, respectively. In the dark box 50, bearing openings 89 and bearing holes 90 to 92, which are through holes, are integrally formed on both side surfaces sandwiching the optical axis 5a, and these bearing openings 89 and bearing holes 90 are formed on the upper light shielding plate 83. And bearing holes 91, 92
Is the center of rotation of the lower light shielding plate 84.

On the outside of the dark box 50a in which these bearing holes 90-92 are formed, cylindrical projections 90a, 91a, 92a (see FIG. 6) are integrally formed so as to surround these bearing holes 90-92. Has been done. Cylindrical protrusions 90a, 91
The a and 92a surely block the light that is about to enter the dark box 50a through the gaps between the bearing holes 90 to 92 and the shaft portions 83b, 84c and 84d of the upper and lower light shielding plates 83 and 84 which will be described in detail later. . Further, a pair of stoppers 9 for positioning the upper and lower light shielding plates 83 and 84 at the panoramic position are provided on the left and right side surfaces inside the dark box 50a having the bearing holes 90 to 92.
3, 94 are integrally provided. Further, inside the dark box 50a, a light-shielding frame 96 for preventing flare during standard photography is attached. This shading frame 9
As shown in FIG. 8, 6 is the edge four sides 96a to 96d of the opening.
Are formed in a circular arc shape that is convex toward the optical axis 5a.

The upper light-shielding plate 83 is made of an elastic plastic material, and has shaft portions 83a on both front sides.
83b are provided integrally with each other, and the rear edge 83c has the same curved shape as the film supporting surface 25. The shaft portions 83a and 83b are provided with notches between them, and are elastically deformed so that the bearing holes 89 and 90 are formed.
Is snap-coupled to. Further, between the cutout portion and the edge 83c, a shield wall 83d for blocking extra light incident from the cutout portion is integrally formed.

Further, the upper light shielding plate 83 is provided with a connecting pin 83e for transmitting the rotation of the crank lever 82 to the lower light shielding plate 84. The projecting piece 84a of the lower light-shielding plate 84 contacts the connecting pin 83e. Then, the projecting piece 84a is connected to the connecting pin 8 by the tension coil spring 95.
The upper and lower light-shielding plates 83 and 84 are urged toward the retracted position, that is, in the direction of contacting the 3e. The spring 95 is arranged inside the dark box 50a outside the linear range connecting the light shielding frame 96 and the exposure opening 21a, which contributes to compactness (see FIG. 5).

The lower light-shielding plate 84 is formed of an elastic plastic material, and shaft portions 84c and 84d are integrally provided on both sides of the front end side, and the above-mentioned projecting piece 84a is integrally formed therein. . The shaft portions 84d and 84d have notches formed inside thereof, respectively, and are elastically deformed to be snap-connected to the bearing holes 91 and 92. Then, the lower light-shielding plate 84 rotates in conjunction with the rotation of the upper light-shielding plate 83 between the panoramic position protruding into the photographing optical path and the retracted position retracted downward from the panoramic position.

Further, the lower light shielding plate 84 has a curved shape along the bottom surface of the dark box 50a in order to surely prevent flare due to internal reflection, and a cross section in which an edge 84e is bent upward in an L shape. It has a shape. This edge 8
4e has the same curved shape as the film supporting surface 25 along the horizontal direction. Further, the shaft portions 84c and 84d
In this case, a pair of bag-shaped blocking walls 84f are integrally formed so as to block extra light that enters the film surface from the cutout portions. Note that, in FIG. 7, the exposure applying mechanism 20, the film winding mechanism, and the like are omitted in order to prevent the drawing from being complicated.

As shown in FIG. 9, the upper and lower light shielding plates 83, 84
The shield walls 83f and 84g are integrally formed on the opposite surfaces. These shielding walls 83f and 84g are
In order to cut flare light that passes through the light shielding frame 96 and causes flare, a cross section cut along the film feeding direction is formed in an arc shape convex toward the optical axis 5a. The shielding walls 83f and 84g are provided when the upper and lower light shielding plates 83 and 84 are in the retracted position during standard photography.
The tops of f and 84g are formed on the upper and lower light-shielding plates 83 and 84 so as to come into contact with the light flux that goes into the full-size exposure screen, and when the upper and lower light-shielding plates 83 and 84 are at the retracted position, the panoramic size exposure screen is displayed. It is in a state of being retracted from the light flux that goes inward. Further, as shown in FIGS. 10 and 11, a plurality of V-shaped grooves are formed on the inner surfaces of the shielding walls 83f and 84g along the film feeding direction to block the light reflected here. There is.

Next, the operation of the above embodiment will be described. The film unit 2 is provided in the form of being housed in a moisture-proof bag, and the state where the film unit 2 is taken out from the moisture-proof bag is that the operation plate 35 is in the panoramic photographing position, as shown in FIG. A pair of shading plates 83 and 84 define a panoramic size in front of the exposure opening 21a. Moreover, the operation plate 3
The cam 46 of No. 5 moves the intermediate lever 8 more than the moving amount of the pair of light shielding plates 83, 84 between the retracted position and the panoramic position.
The crank lever 8
One end portion 82c of No. 2 bends to absorb an excessive amount of movement beyond the allowance of play of each component. Therefore, the upper light shielding plate 83
Is in a panoramic position in which the stopper 93 is surely abutted. Further, the connecting pin 83e of the upper light shielding plate 83
Thus, the protruding piece 84a is overstroked, and this overstroke is absorbed by the bending of the protruding piece 84e, and the lower light-shielding plate 84 is accurately positioned in a panoramic position where it abuts the stopper 94.

When taking a picture, first, the winding knob 8 is turned to perform a film winding operation. The film 24a is transferred in synchronization with this film winding operation,
When the transfer of the frames is completed, the film winding stopping mechanism is activated, the operation of the winding knob 8 is locked, and the shutter mechanism is charged.

After the completion of the winding operation, the photographer takes the eyepiece window 2
When the peeping framing is performed from 7, the panoramic field of view is limited by the panoramic field of view frame 38 of the operation plate 35. Photographing is performed by pressing the shutter button 6. By this operation, the shutter mechanism operates and the shutter blades 63 open and close one by one. The subject light that has passed through the taking lens 5 during this one-time double opening and closing passes through the light-shielding frame 96 and is exposed on the film 24a with a panorama size exposure screen defined by the upper and lower light-shielding plates 83 and 84. At this time, dark box 5
The light that wraps around the upper and lower shield plates 83 and 84 inside 0a can be blocked by the shield wall 83d and the shield piece 84f.

When shooting with a full-size exposure screen, the operation knob 3 is slid along the right direction in FIG. 4, and the notch 43 of the operation plate 35 and the click claw 45 of the front cover 18 are connected. To cancel. When these connections are released, the torsion spring 81 urges the intermediate lever 80 clockwise, so that the operation plate 35 moves smoothly toward the standard photographing position. Then, the cutout 42 is engaged with the click claw 44 by the final pushing operation. This allows the panoramic size field frame 3 from the finder optical axis 39.
8 is in a retracted state. At this time, the photographer is given a click feeling to recognize that the size of the exposure screen has been switched.

As shown in FIG. 7, the movement of the operation plate 35 causes the intermediate lever 80 to rotate clockwise about the shaft 86 by the bias of the spring 81. In conjunction with this rotation, the crank lever 82 rotates counterclockwise around the bearing 82b. In association with this rotation, the upper light shielding plate 83 has the shaft 83a,
It rotates counterclockwise around 83b, and the lower light-shielding plate 84 also rotates clockwise around the shafts 84c and 84d by the bias of the spring 95. As a result, the upper and lower light shielding plates 83 and 84 contact the inner wall of the dark box 50a, and are in the retracted position retracted from the exposure opening 21a, as shown in FIG. 1B.

Thereafter, after the film winding operation is performed in the same manner as described above, the framing is performed by looking through the eyepiece window 27. The finder visual field range at this time is limited to the standard visual field range by the full-size visual field frame 37. Then, the photographing lens 5 is pressed by pressing the shutter button 6.
The photographing light that has passed through the
The film 24a is exposed with a full size screen defined by a. At this time, the light flux passing through the light-shielding frame 96 toward the outside of the exposure screen is cut by the shield walls 83f and 84g, and the surfaces of the shield walls 83f and 84g are V-shaped grooves, and are reflected here. The light that goes into the exposure screen can also be cut. Furthermore, since the shielding walls 83f and 84g are formed in a convex arc shape toward the optical axis 5a with respect to the exposure screen of the film 24a which is curved so as to be convex on the back side, the four corners of the exposure screen are surrounded. This has the effect of minimizing the decrease in the amount of light in the area.

In this way, photographing is performed while the operation knob 3 is selected and operated at either the standard photographing position or the panoramic photographing position. Then, when the photographing of all the frames is completed, the film unit 2 is submitted to the photo lab as it is. At the developing station, the cartridge 24b containing the exposed film 24a is taken out. At this time, if the display indicating that the film is a mixed film is provided on the cartridge 24b, the work at the developing place is simplified.

The taken-out cartridge 24b is developed by a film processor, and the size of each frame of the photographic film 24a is detected by a frame size detector. The size data of each frame is written in the LSI card in association with the frame number together with the correction data of each frame for obtaining an appropriate exposure amount at the time of printing. Then, the negative film together with the LSI card is set in the printer processor. This printer processor continuously prints only full-size frames for 89 x
A 127 mm print photograph was obtained, and then only the panorama size frames were printed, and 89 x 2
A printed photograph with a size of 54 mm is obtained. The obtained print photograph is recorded as a clear image without flare.

When printing from full size to panorama size frames, the print magnification of the printer and
The sizes of the printing paper and the paper mask are changed. The print magnification for expanding a full-size frame to photographic paper is about 3.5 times, and the print magnification for expanding a panoramic-size frame to photographic paper is about 7 times. After performing the printing process in this manner, the print photograph and the negative film are returned to the user. Then, the empty film unit 2 is collected in the factory and recycled.

[0041]

As described in detail above, according to the present invention, with respect to the film surface curved so as to be convex on the back side, the opposite surfaces of the upper and lower light shielding plates are projected toward the photographing optical axis. Since it is formed in a simple arc shape, flare is prevented from occurring and a clear print photograph can be obtained. Moreover, it is possible to prevent a decrease in the amount of light in the peripheral portion of the exposure screen. Furthermore, in another invention, since the grooves are provided on the arcuate surfaces of the upper and lower light shielding plates, it is possible to block the light reflected here.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of an exposure screen switching mechanism of the present invention, (A) showing a state of a panoramic photographing position, and (B).
Indicates the state of the standard photographing position.

FIG. 2 is a perspective view showing the outer appearance of a lens-fitted film unit.

FIG. 3 is an exploded perspective view showing a main part of a lens-fitted film unit.

FIG. 4 is an exploded perspective view showing a front cover unit.

FIG. 5 is a cross-sectional view of a lens-fitted film unit.

FIG. 6 is an exploded perspective view of a mechanical unit.

FIG. 7 is an exploded perspective view showing an exposure screen switching mechanism.

FIG. 8 is an explanatory diagram of a light-shielding frame as seen from the photographing lens side.

FIG. 9 is an explanatory view of the upper and lower light shielding plates viewed from the side of the photographing lens during standard photographing.

FIG. 10 is a perspective view showing an upper light shielding plate, with a part cut away.

FIG. 11 is a perspective view showing a lower light shielding plate, a part of which is cut away.

[Explanation of Codes] 3 Operation knob 21a Exposure opening 35 Operation plate 38 Panoramic field frame 83 Upper light-shielding plate 83f, 84g Shielding wall 84 Lower light-shielding plate 93, 94 Stopper 95 Spring 96 Light-shielding frame

Claims (2)

[Claims] 1. An exposure frame provided on the front surface of a film surface curved so as to be convex toward the back surface, and an exposure frame for defining a first exposure screen having a first aspect ratio on the film surface by the exposure frame. On the front surface of the exposure frame in order to define a second exposure screen in which the width in the vertical direction is narrowed so as to have a second aspect ratio different from the first aspect ratio on the film surface and the retracted position retracted from the front surface of the frame. A pair of upper and lower light shielding plates that are movable between the inserted and inserted positions are provided, and at least one of the upper and lower light shielding plates is formed in a circular arc shape whose surface facing the other is convex toward the photographing optical axis. A film unit with a lens that is characterized. 2. The lens-fitted film unit according to claim 1, wherein a groove extending in a direction orthogonal to a photographing optical axis is formed on the surface formed in an arc shape.