JP3100810B2 - 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 apparatus for a camera, and more particularly to an exposure screen switching apparatus in which a light shielding plate for defining an exposure screen is rotatably provided in a dark box.

[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. In this panoramic camera, for example, Japanese Patent Application No.
As proposed in Japanese Patent No. 153710, there is a method in which an exposure screen is switched between a full size and a panorama size even during the shooting of one film.

The exposure screen switching mechanism according to the above-mentioned application has a structure in which a pair of light-shielding plates are provided up and down inside a dark box so that the light-shielding plates are retracted from a photographing optical path in a falling state. 24mm x 36mm
Exposure is performed in full size (aspect ratio 1.5),
In the upright state, the light-shielding plate is in a panoramic position in which the light-shielding plate enters the shooting path, so that exposure is performed with a panorama size of 13 mm × 36 mm (aspect ratio 2.8).

In the background of the present lab industry, a photographic film in which a full-size frame and a panorama-size frame are mixed in a single film (hereinafter, referred to as a "film") is provided as a background of providing a large number of such cameras which can be switched midway. The mixed film is referred to as a "combined film.") It is distinguished from a photo film consisting of only full-size frames, and each frame size of the mixed film is automatically detected and a verification is performed to mark the print type. This is because a photographic print system has been established in which full-size frames and panorama-size frames are separately and efficiently printed without changing the print magnification or the size of the mask.

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 has a built-in exposure screen switching mechanism, and 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.

[0006] It is desired that the production cost of the film unit be lower than that of a compact camera, and most parts are formed of a plastic material. Therefore, for example, when a pair of bearings are formed in a dark box in order to rotatably support a pair of rotation shafts provided at both ends of a light shielding plate, in order to reduce the manufacturing cost of a mold, It is desirable to make the bearing part of the through hole.

[0007]

However, when a through-hole is formed in the dark box, even when the turning shaft of the light-shielding plate is fitted in the through-hole, a small amount of light from the small gap between them passes through the inside of the dark box. There is a risk of entering. Therefore, if the bearing portion is formed as a non-through hole, it is necessary to provide a core slidably movable between the non-through hole portion and a position to be retracted from the male die side due to the structure of the mold. Therefore, in this case, the mold itself becomes complicated, and the movement of the core must be controlled with high accuracy, the production cost of the mold is increased, and the production cost of the film unit is increased unequivocally. There is a disadvantage.

The present invention has been made to solve such a problem, and it is an exposure screen switching method that maintains the most important light-shielding property due to the nature of the dark box and reduces the manufacturing cost of the dark box. It is intended to provide a device.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a bearing hole for supporting a rotating shaft of a light shielding plate in a dark box is a through hole, and the rotating shaft is A cylindrical projection is integrally formed outside the dark box so as to surround the through hole in order to block light entering the dark box from the gap between the through hole and the through hole. According to this, since the bearing hole of the dark box is formed as a through hole, a mold can be manufactured at low cost, and a cylindrical projection is formed integrally with the dark box outside the dark box so as to surround the through hole. It is possible to block light that enters the dark box from the gap between the moving shaft and the through hole.

According to the second aspect of the present invention, a structure in which the through hole of the dark box is closed from the outside by one of the outer walls of the patrone chamber in which the patrone is loaded and the film roll chamber for storing the film in a roll form. It is what it was.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Film unit 2 with lens shown in FIG.
(Hereinafter, referred to as a "film unit"), by sliding the operation knob 3 for switching the screen size, the photographing can be performed by selecting the screen size of the film to either the full size or the panorama size. . The film unit 2 has a configuration in which a unit main body is wrapped in an outer case 4. The outer case 4 includes a photographing lens 5, a shutter button 6, an operation knob 3, a strobe switch 7, a winding knob 8, a finder 9, Charge completion lamp confirmation window 1
An opening is provided for exposing the number 0, the number-of-photographs display window 11, the strobe light emission window 12, and the like.

As shown in FIGS. 1, 3 and 4, the unit main body has a rear cover 15 on the back of a main body 14 and a strobe unit 16 and a mechanical unit 17 on the front, which are detachably mounted. A front cover 18 is detachably attached so as to cover the upper, front, and both side surfaces. The mechanical unit 17 includes an exposure screen switching mechanism 19 and the photographing lens 5.
And an exposure applying mechanism 20 having

An exposure frame 21 is integrally formed on the optical axis 5a of the main body base 14, and a patrone chamber 22 and a film roll chamber 23 are integrally formed on both sides of the exposure frame 21. Patrone room 22 and film roll room 23
International Standards (ISO: 1007-19)
The film 24 with a 135-type patrone specified in (1979 version) is loaded, and is housed in a light-tight manner with the rear cover 15.

The exposure frame 21 is formed to have a size slightly larger than the full size, and has a shape curved together with the film supporting surface 25 provided on the rear surface so as to be convex toward the rear side with respect to the film feeding direction. It has become. The rear cover 15 facing the film support surface 25 is formed with a film regulating surface 26 that is curved in the same manner as the film support surface 25. The mechanical unit 17 is removably attached to the front surface of the exposure frame 21 by nail coupling or the like.

The strobe unit 16 is provided with a strobe light emitting section 27, a battery 28, an X contact 29, and the like.
By pressing the elastic strobe switch 7 formed integrally with the front cover 18, the circuit of the strobe board 16 a is closed via the contact plate 30, and charging of the main capacitor 31 is started. When the charging of the main capacitor 31 is completed, the charging completion lamp 32 blinks, and when the X contact 29 is turned on in conjunction with the operation of the shutter blade, a trigger signal is transmitted. When this trigger signal is obtained, strobe light is emitted from the strobe light emitting unit 27 through the strobe light emitting window 12.

An operation plate 35 and a cover plate 36 are detachably incorporated in the front cover 18. On the front cover 18, in addition to the finder objective window 37 and the strobe light emission window 12, the shutter button 6 and the like are integrally formed. On the front surface of the finder objective window 37, an operation plate 35 is incorporated so as to be slidable along the film feeding direction. The operation plate 35 is integrally provided with a panoramic visual field frame 38 and the operation knob 3. The panoramic field frame 38 is formed to have a size that defines the field of view of the finder 9 with the same aspect ratio as the panoramic size. Further, the cover plate 36 is integrally provided with a full-size field frame 40 defining the same aspect ratio as the full size on the finder optical axis 39 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 configured such that the operation knob 3 is provided with an elongated hole opening 41.
The slide operation within the panoramic view frame 3
8 is slidably mounted between a panoramic photographing position located on the finder optical axis 39 and a full size position retracted from the panoramic photographing position. At these positions, the notches 42, 43 provided at the lower portions on both sides are click-coupled to the elastic click claws 44, 45 provided integrally with the front cover 18. The operation panel 35 is provided with an exposure screen switching mechanism 19 to be described later in connection with the movement to these positions.
Are integrally provided with a cam 46 for linking.
In addition, in order to reduce the amount of movement of the operation plate 35, the edge 47 at one end of the operation plate 35 has a cross-sectional shape cut out so as not to block the finder visual field range at the full size position.

The mechanical unit 17 is, as shown in FIG.
The exposure screen switching mechanism 19 and the exposure applying mechanism 20 are incorporated in a dark box 50 for guiding only the subject light transmitted through the photographing lens 5 to the exposure frame 21. On the upper surface of the dark box 50, two shafts 51 and 52 and a bearing opening 53 are integrally formed. The shaft 51 has a shutter drive lever 5
4 and the number-of-images display plate 55 are rotatably inserted, and are finally stopped by the retaining ring 56. A spring 57 and a locking lever 58 are rotatably inserted into the shaft 52, and are finally stopped by a retaining ring 59. These shafts 51, 52
Has a length slightly protruding from the retaining rings 56 and 59.

The rotating member 60 is inserted into the bearing opening 53. The rotation member 60 has a winding stop cam 60a at a central portion thereof.
Shutter charge cam 60b, shaft 60 projecting downward
c and the one-tooth gear 60d protruding upward are integrally formed. The shaft 60c is engaged with a driven sprocket 61 arranged in the dark box 50, and the rotation of the driven sprocket 61 is transmitted. The one-tooth gear 60a meshes with teeth 55a formed on the outer periphery of the number-of-photographs display plate 55. The driven sprocket 61 rotates once when the film winding operation of the film winding knob 8 rotates the core of the cartridge 24b and the film 24a is transported by the length of one frame.

One end 57a of the spring 57 is engaged with the other end 54b of the shutter drive lever 54, and biases the shutter drive lever 54 counterclockwise about the shaft 51.
The other end 57b of the spring 57 is engaged with the falling piece 58b of the locking lever 58 to urge the locking lever 58 clockwise about the shaft 52. Shutter charge cam 60b
One end 54a of the shutter drive lever 54 is in contact with this, and the rotation of the sprocket causes the shutter drive lever 54 to rotate clockwise against the bias of the spring 57.

A groove 60e is formed on the outer circumference of the stopping cam 60a. When the film is fed by one frame, the claw 58a of the locking lever 58 is fitted into the groove 60e, and the driven sprocket 61 The rotation is locked, and the winding of the film 24a is prevented. Lock lever 5
The engaging lever 58 slightly rotates clockwise because the claw portion 58a of FIG. 8 fits into the groove 60e. By this rotation, the ridge 58 c of the locking lever 58 is moved to the shutter driving lever 54.
Of the shutter drive lever 5
4 is held at the charge position. At this time, the locking lever 5
8 is engaged with the outer periphery of the hoisting knob 8,
Prevent the hoisting operation. The driven sprocket 61
One rotation causes the one-tooth gear 60d to change
Is advanced by one division.

The pressing operation of the shutter button 6 causes the locking lever 58 to rotate counterclockwise about the shaft 52. With this rotation, the projection 58c of the locking lever 58 is disengaged from the rising piece 54c of the shutter driving lever 54, and the shutter driving lever 54 rotates counterclockwise around the shaft 51 by the bias of the spring 57, and The kicking arm 54d of the shutter blade 6 is described in detail later.
Kick 4 off.

On the front surface of the dark box 50, an axis 63 is formed in parallel with the optical axis 5a. A shutter blade 64 having a crank shape is rotatably mounted on the shaft 63. The shutter blade 64 rotates between a position where the opening 50a provided on the optical axis 5a is shielded by the bias of the spring 65 and a position where the shutter driving lever 54 retreats from the opening 50a by kicking.

A shutter cover 66 is mounted on the front surface of the shutter blade 64, and the shutter blade 64 is connected to the optical axis 5a.
Swinging in the direction of. In the shutter cover 66, a stop aperture 66a is formed on the optical axis 5a, and a lens barrel 66b is integrally formed so as to surround the stop aperture 66a. A rear lens 67 and a front lens 68 constituting the photographing lens 5 and a spacer 69 interposed therebetween are inserted into the lens barrel 66b, and a lens cover 70 is finally covered.

On the upper right side of the dark box 50, a concave holding frame 7 is provided.
1 are integrally formed. An inverted Galilean finder lens comprising an objective lens 72 and an eyepiece 73 is removably inserted into the holding frame 71, and a top plate 74 is put on the top. The top plate 74 is for pressing the objective lens 72 and the eyepiece 73 against the holding frame 71. Note that these finder lenses are arranged between the objective window 37 of the front cover 18 and the eyepiece window 75 of the rear cover 15.

As shown in FIG. 6, the top plate 74 is made of a transparent plastic material, and is integrally provided with a hole 75, an arc wall 77, and a convex lens 79. The shaft 51 is engaged with the hole 75, and the arc wall 77 is slidably contacted with the outer circumference of the winding cam 60a to rotatably support the rotating member 60. Thereby, the shaft 51 and the rotating member 60
Are supported at predetermined intervals. Convex lens 79
Is arranged above the number display displayed on the upper surface of the number-of-photographs display plate 55, and allows the number display recognized from the number-of-photographs display window 11 to be enlarged and visually recognized.

FIG. 7 shows a main part of the exposure screen switching mechanism 19. The exposure screen switching mechanism 19 is roughly divided into the intermediate lever 8.
0, torsion spring 81, crank lever 82, spring 83,
And upper and lower light shielding plates 84 and 85. The intermediate lever 80 is provided rotatably about a shaft 86 implanted on the upper surface of the top plate 74. This intermediate lever 80
Is a projection 80a that slides on the cam 46 of the operation plate 35;
Lower protruding piece 8 that engages with pin 82a of crank lever 82
The protrusion 80a is urged by the torsion spring 81 in the direction in which the protrusion 80a contacts the cam 46 (clockwise direction shown in the figure).

The crank lever 82 has a pin 82a at one end for engaging with the downwardly projecting piece 80b, and a bearing 8 at the other end.
2b are provided respectively. This bearing portion 82b is
The upper light shielding plate 83 is pivotally supported via a bearing opening 89 provided in the dark box 50, and the upper light shielding plate 83 and the crank lever 82 are connected by a press-fit pin 85.

The lower part of the dark box 50 has a curved shape following the contour of the battery 28. The dark box 50 has a front surface and a rear surface along the optical axis 5a for guiding the subject light incident from the photographing lens 5 to the exposure frame 21. , An opening 87 for passing the subject light,
88 are provided. The dark box 50 has the optical axis 5
The bearing opening 89 and the bearing holes 90 to 92, which are through holes, are integrally formed on both side surfaces sandwiching a. The bearing opening 89 and the bearing hole 90 are formed in the upper light shielding plate 83, the bearing hole 91, and the bearing hole 91, respectively. Reference numeral 92 indicates the center of rotation of the lower light shielding plate 84.

On the outside of the dark box 50 in which the bearing holes 90 to 92 are formed, cylindrical projections 90a, 91a, 92a (see FIG. 5) are integrally formed so as to surround the bearing holes 90 to 92. Have been. Tube projections 90a, 91
a. Reference numeral 92a reliably blocks light that enters the interior of the dark box 50 from gaps between the bearing holes 90 to 92 and the shaft portions 83b, 84c, 84d of the upper and lower light shielding plates 83, 84 described later. Dark box 5 further provided with bearing holes 90 to 92
0, a pair of stoppers 93, 9 for positioning the upper and lower light shielding plates 83, 84 at the panoramic position.
4 are provided integrally.

The upper light shielding plate 83 is provided with shaft portions 8 on both front sides.
3a and 83b are provided integrally, and the rear edge 83c has the same curved shape as the film support surface 25. Notches are provided between the shaft portions 83a and 83b, and the shaft portions 83a and 83b are elastically deformed to form the bearing holes 8a and 83b.
9, 90 snap-fit. Further, between the notch and the edge 83c, a shielding wall 83d for blocking extra light incident from the notch is integrally formed. 8 and 9 show the surface of the upper light shielding plate 83 facing the optical axis 5a.
As shown in FIG. 7, in order to prevent internal reflection, a plurality of sawtooth-shaped light-shielding grooves 83f are integrally formed along the film feeding direction.

The upper light shielding plate 83 has a connecting pin 83e for transmitting the rotation of the crank lever 82 to the lower light shielding plate 84.
Is provided. The projecting piece 84a of the lower light shielding plate 84 abuts on the connecting pin 83e. Then, the projecting piece 84a is brought into contact with the connecting pin 83e by the spring 95,
That is, the upper and lower light shielding plates 83 and 84 are biased toward the full size position defining the full size in the exposure frame 21. The projecting piece 84a is provided with a slit 84b for absorbing the pressure received from the connecting pin 83e. Further, inside the dark box 50, a light-shielding frame 96 for preventing flare during normal photographing is attached.

The lower light shielding plate 84 is provided with shaft portions 84c and 84d on both sides on the front end side. Shaft 84
Notches c and 84d have respective cutouts formed therein, and are elastically deformed and snap-coupled to bearing holes 91 and 92. The lower light shielding plate 84 is connected to the upper light shielding plate 8.
In conjunction with the rotation of 3, the camera rotates between a panoramic position protruding into the photographing optical path and a full size position retracted downward from the panoramic position.

The lower light shielding plate 84 has a curved shape along the bottom surface of the dark box 50 in order to reliably prevent flare due to internal reflection, and has a cross-sectional shape in which the edge 84e is bent upward in an L-shape. Has become. The edge 84e has the same curved shape as the film support surface 25 along the horizontal direction. Further, a pair of bag-shaped blocking walls 84f are integrally formed with the shaft portions 84c and 84d, respectively, to block extraneous light entering the film surface from the cutout portions. In FIG. 10, the exposure applying mechanism 20 is omitted to prevent the drawing from being complicated.

Next, the operation of the above embodiment will be described. The film unit 2 is provided in a form stored in a moisture-proof bag. When the film unit 2 is taken out of the moisture-proof bag, the screen size for exposing the film 24a by the upper and lower light shielding plates 83 and 84 is adjusted as shown in FIG. It is in a state where the panorama size is defined. Therefore, when the user looks directly through the eyepiece window 75, the viewfinder viewing range of the panoramic viewing frame 38 of the operation plate 35 is similar to the panorama size.

When taking a picture, first, the film winding operation is performed by turning the winding knob 8. The film 24a is transported in conjunction with the film winding operation, and the driven sprocket 61 rotates counterclockwise in FIG. 6 in conjunction with the transport of the film. Driven sprocket 6
With the rotation of 1, the shutter charge cam 60b rotates the shutter drive lever 54 clockwise. When the film is advanced one frame, the claw 58a of the locking lever 58
Fits into the groove 60e, the rotation of the driven sprocket 61 is prevented, and the winding of the film 24a is prevented. At this time, the locking lever 58 slightly rotates clockwise, and the protrusion 58 c of the locking lever 58 is moved to the shutter driving lever 54.
Of the shutter drive lever 5
4 is held at the charge position. Then, one rotation of the driven sprocket 61 causes the one-tooth gear 60d to advance the number-of-photographs display plate 55 by one scale. When looking through the number-of-photographs display window 11, the number display is enlarged and visible by the convex lens 79 of the top plate 74, so that it is very easy to see.

After the completion of the winding operation, the photographer moves the eyepiece window 7
While performing peep framing from 5, the strobe switch 7 is pressed. By this pressing operation, the power of the battery 28 is supplied to the circuit of the strobe unit 16, and the high voltage is charged in the main capacitor 31. Main capacitor 3
When the charging of 1 is completed, the charging lamp 32 blinks. After confirming this blinking, shooting is performed.

The photographing is performed by pressing the shutter button 6. With this operation, the shutter button 6 presses the falling piece 58b of the locking lever 58, and the locking lever 5
8 rotates counterclockwise. The rotation of the locking lever 58 releases the engagement between the ridge 58 c and the rising piece 54 c, and the shutter driving lever 54 is rotated counterclockwise by the bias of the spring 57. During the rotation of the shutter drive lever 54, the kicking arm 54d of the shutter drive lever 54
Kick off This kicking causes the shutter blade 64 to swing once and twice around the shaft 63. During this one-time double swing, the shutter blade 64 turns on the X contact 29. The strobe light is emitted from the strobe light emitting unit 27 when the X contact 29 is turned on.

The subject light illuminated by the strobe light passes through the photographing lens 5 and is shielded by the upper and lower light shielding plates 83 and 84.
The film 24a is exposed on a panoramic-size screen. At this time, the cylindrical projections 90a, 91a, 9 of the dark box 50
2a reliably blocks light that enters the interior of the dark box 50 from gaps between the bearing holes 90 to 92 and the shaft portions 83b, 84c, 84d of the upper and lower light shielding plates 83, 84. A plurality of sawtooth-shaped light-shielding grooves 83f are provided on the surface of the upper light-shielding plate 83 facing the optical axis 5a along the film feeding direction, and the surface of the lower light-shielding plate 84 has a deep section. Due to the shape, internal reflection is prevented.

When photographing is performed on a full-size exposure screen, the operation knob 3 is slid along the right direction in FIG. 7 to connect the notch 43 of the operation plate 35 with the click claw 45 of the front cover 18. Cancel. When these couplings are released, the torsion spring 81 urges the intermediate lever 80 clockwise, so that the operation plate 35 smoothly moves rightward. When the notch 42 engages with the click claw 44, the finder optical axis 39 is set.
, The panoramic size field frame 38 is retracted.
At this time, the photographer is given a click feeling to recognize that the size of the exposure screen has been switched.

The movement of the operation plate 35 causes the intermediate lever 80 to move.
Is rotated clockwise about the shaft 86 by the bias of the spring 81. In conjunction with this rotation, the crank lever 82 rotates counterclockwise about the bearing 82b. In conjunction with this rotation, the upper light shielding plate 83 rotates counterclockwise around the shafts 83a and 83b, and the lower light shielding plate 84 is urged by the spring 95.
Also rotates clockwise about the shafts 84c and 84d. As a result, the upper and lower light shielding plates 83 and 84 are in a state where the screen size is defined to be the full size inside the exposure frame 21, as shown in FIG.

Thereafter, after performing the film winding operation in the same manner as described above, framing is performed by looking through the eyepiece window 75. The finder viewing range at this time is defined in the full size viewing frame 40 as a viewing range corresponding to the full size. Exposure is performed by pressing the shutter button 6 in the same manner as described above.

As described above, the photographing is performed while the operation knob 3 is selectively operated to one of the full-size photographing position and the panoramic photographing position. Then, when the photographing of all the frames is completed, the film unit 2 is submitted to the developing laboratory as it is. At the developing station, the cartridge 24b containing the exposed film 24a is taken out. At this time, if a display indicating that the film is a mixed film is given to the patrone 24b, the work at the developing laboratory becomes simple.

The patrone 24b taken out is developed by a film processor and then inspected with a notcher / puncher for frame size and the like. In this test, a notch is applied to a full size frame to distinguish it from a panorama size frame. At this time, the panorama size frame is about 13 ×
Since the rectangular size is 36 mm, the process is performed while detecting the frame size. Then, the verified negative film is set on the scanner, where the image of the notched frame, that is, the image of only the full size frame is read,
The correction amount of each frame for obtaining an appropriate exposure amount at the time of printing is calculated. The correction data is written on the LSI card in association with the frame number. When the work on the scanner is completed, the negative film together with the LSI card is set in the printer processor. Here, print processing is continuously performed on only full-size frames, and a print photograph of 89 × 127 mm is obtained.

Next, the negative film is set again in the scanner together with the LSI card, and only a panorama-sized frame is read to calculate a correction amount for obtaining an appropriate exposure amount. Then, the negative film together with the LSI card is set in the printer processor, and only the panorama size frames are continuously printed. This allows 89 ×
A print photograph having a size of 254 mm is obtained.
At this time, the print magnification of the printer and the sizes of the printing paper and the paper 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 photo and the negative film are returned to the user. Then, the empty film unit 2 is collected at the factory and recycled.

In the above embodiment, the cylindrical projections 90a. 91a, 9
2a is formed integrally with the dark box, and the light entering the dark box through the gaps between the shaft portions 83b, 84c, 84d of the upper and lower light shielding plates 83, 84 and the bearing holes 90 to 91 is cut off. The invention is not limited to this, and the bearing holes 90 and 92 may be closed from the outside by the outer wall of the patrone storage chamber 22 as shown in FIG.

In this case, as shown in FIG. 11, a projecting surface 22a for closing the bearing holes 90 and 92 is integrally formed on the outer wall of the patrone storage chamber 22, and the projecting surface 22a is formed as shown in FIG. The projecting rib 50b engaging with the outer periphery is
It is desirable to form them integrally with each other so as to form a labyrinth structure by fitting them. According to this, since the outside of the bearing holes 90 and 92 is closed by the protruding surface 22a and the protruding surface 22a and the protruding rib 50b are fitted by the labyrinth structure, it is possible to reliably shield the light. . Further, since the number of parts is not increased, cost reduction can be achieved. The bearing hole 91 may be closed by the outer wall of the film roll chamber 23.

[0048]

As described in detail above, according to the first aspect of the present invention, since the bearing hole of the dark box is formed as a through hole, a mold can be manufactured at low cost and the mold is formed so as to surround the through hole. Since the cylindrical projection is integrally formed outside the dark box, it is possible to reliably block light that enters the dark box from the gap between the rotation shaft and the through hole. Claim 2
In the described invention, since the through-hole of the dark box is closed from the outside by one of the outer walls of the patrone chamber and the film roll chamber, the light-shielding property of the dark box is maintained by using conventional parts, so that the film unit is used. Cost can be reduced.

[Brief description of the drawings]

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

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

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

FIG. 4 is an exploded perspective view showing a front cover unit of the film unit with a lens.

FIG. 5 is an exploded perspective view of the mechanical unit.

FIG. 6 is a schematic explanatory view showing a main part of the mechanical unit.

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

FIG. 8 is an explanatory diagram showing a state of a panoramic position of upper and lower light shielding plates.

FIG. 9 is an explanatory diagram illustrating a state of a full size position of the upper and lower light shielding plates.

FIG. 10 is a cross-sectional view of a film unit with a lens showing an embodiment in which a bearing hole is closed by a patrone storage chamber.

FIG. 11 is a perspective view of a main part of the cartridge storage chamber shown in FIG.

FIG. 12 is a perspective view of the dark box shown in FIG.

[Explanation of symbols]

 17 Mechanical base 22a Projecting surface 50b Projecting rib 83 Upper light shielding plate 84 Lower light shielding plate 90-92 Bearing hole 90a, 91a, 92a Cylindrical projection

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 17/28 G03C 3/00 G03B 17/04

Claims (2)

(57) [Claims] 1. An exposure screen switching device for a camera, comprising: a light-shielding plate which is rotatably provided in a dark box formed so as to surround a photographing optical path and changes a screen size in a width direction of a photographic film. A bearing hole for supporting the rotating shaft in the dark box is a through hole, and outside of the dark box so as to surround the through hole in order to block light entering the dark box from a gap between the rotating shaft and the through hole. An exposure screen switching device for a camera, wherein a tubular projection is integrally formed on the exposure screen. 2. A dark box provided to surround a photographic optical path between a patrone chamber in which a patrone is loaded and a film roll chamber for accommodating a film in a roll form, and a dark box provided rotatably in the dark box. An exposure screen switching device for a camera, comprising: a light-shielding plate for changing a screen size in a width direction of a photo film; a bearing hole for supporting a rotation axis of the light-shielding plate in a dark box; And at least a patrone chamber to block light from entering the dark box from the gap between the through hole and
An exposure screen switching device for a camera, wherein a through hole is closed by one of the outer walls of a film roll chamber.