JP2002244177A - Diaphragm-switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To insert a diaphragm plate between lenses and to make a diaphragm surely switchable. SOLUTION: A diaphragm opening 76 is formed at the diaphragm plate 54 and is fitted freely movably between a small a diaphragm position where the diaphragm opening 76 is inserted to a photographing optical axis and a large diaphragm position, where the diaphragm opening 76 is made to retreat. The photographing lens 5, consisting of the first lens 65 and the second lens 66, is held in a lens holder 62 of a lens barrel section 53 by pinching a spacer 63 and a flare stopper 67 between the lenses and is retained by a lens retaining plate 69. When there is the diaphragm plate 54 in the small diaphragm position, the front end of the diaphragm plate 54 is inserted into a notched part 68a of the spacer 68, and the diaphragm opening 76 is located at the center of the photographing optical axis. The lens-holding plate 69, attached to the lens barrel section 53, hermetically closes the inside of the lens barrel section 53, thereby preventing advancing of sand grains or the like between the diaphragm plate 54 and the photographing lens 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm switching device used for a film unit with a lens, for example.

[0002]

2. Description of the Related Art A film unit with a lens is known as a simple camera of a single use type in which a photographic film is pre-loaded. In this film unit with a lens, the cost is reduced thoroughly and the structure of the device itself is simplified. For this reason, in a film unit with a lens, a so-called kicking-type shutter device that opens and closes a shutter by kicking a shutter blade having a single configuration spring-biased to a closed position in an opening direction is used. As an exposure adjusting mechanism to be added to a film unit with a lens having such a shutter device, an aperture plate having a small aperture opening is provided separately from the shutter blades, and the aperture plate is moved according to the photometric value. Incorporation of an aperture switching device that performs aperture switching is being considered.

This diaphragm plate is movably mounted between a position where the small aperture opening is inserted on the optical path and a position where it is retracted out of the optical path. The diaphragm plate is driven by a solenoid or the like to stop the diaphragm. Is switched. The solenoid is incorporated so as to operate according to a detected value of the amount of light of a subject started by a shutter button operation. This makes it possible to adjust the exposure with a simple structure.

On the other hand, in a film unit with a lens,
Due to the necessity of the cost reduction described above, the configuration of the photographing lens is also very simple, and is generally 1
A lens having two groups and two lenses is mainly used because it is composed of two lenses and is recently advantageous for aberration correction. Such a two-group two-lens imaging lens is held by a substantially cylindrical lens holder formed in front of an aperture stop having a constant diameter. In order to determine the relative positions of the two lenses,
On the surface where the lenses face each other, an annular rib is formed on one of the lenses, and the rib is brought into contact with the other lens to perform positioning in the optical axis direction.

[0005]

When the above-described diaphragm switching mechanism is combined with a lens-fitted film unit incorporating a two-group two-lens photographing lens, a small diaphragm opening is formed due to the structure around the lens holder. It is desirable to insert the formed aperture plate between the two lenses and arrange the small aperture in front of the open aperture from the viewpoint of realizing high image quality and achieving compactness. However, since the two lenses are positioned by contacting each other as described above, it is difficult to provide a space for inserting the diaphragm plate.

In addition, when the film unit is used on a sandy beach, foreign matters such as sand particles enter the inside of the film unit with the lens and enter the space between the diaphragm plate and the lens. In such a case, there is a concern that the diaphragm plate stops in the middle of the movement and covers the optical path, so that appropriate photographing cannot be performed.

An object of the present invention is to provide a lens-fitted film unit having a structure in which a diaphragm plate can be inserted between lenses and capable of reliably switching the diaphragm.

[0008]

In order to achieve the above object, according to the present invention, an aperture plate is moved in a plane perpendicular to an optical axis between two lenses constituting a taking lens, and Aperture switching is performed between a small aperture position where a small-diameter aperture opening formed on the plate is located on the imaging optical path and a large aperture position where the aperture opening is retracted from the imaging optical path. And a spacer that keeps the distance between these lenses constant is provided. When the diaphragm is switched, the diaphragm plate is moved so as to pass through a space surrounded by the spacer and the two lenses. I have. The diaphragm plate is moved to the small diaphragm position by the bias of the spring. When the diaphragm plate is at the small diaphragm position, the diaphragm plate or a member integrally fixed to the diaphragm plate is provided so as to protrude on the movement path. It is positioned in contact with the contact member.

According to a third aspect of the present invention, there is provided an aperture switching device for a camera, wherein an optical path is restricted between one of the lenses and the spacer to suppress the occurrence of flare. A flare stopper for positioning the plate in the optical axis direction is provided, and the tip of the diaphragm plate at the large diaphragm position is kept within the outer shape of the flare stopper.

According to a fourth aspect of the present invention, there is provided an aperture switching mechanism for a camera, wherein the photographing lens, the spacer, and the flare stopper are held on a lens barrel having a shaft that rotatably supports the aperture plate. A photographic lens is pressed into the lens holder by integrally forming a lens holder having a shape and mounting a lens pressing plate so as to cover the front side of the lens barrel, and regardless of the switching position of the aperture, An aperture plate is housed between the lens barrel and the lens holding plate.

[0011]

FIG. 1 is a perspective view showing the external appearance of the front of a lens-fitted film unit 2 embodying the present invention. The film unit 2 with a lens includes a unit main body 3 in which various photographing mechanisms are incorporated, and an exterior label sheet 4 partially covering the unit main body 3. On the front surface of the unit body 3, a photographing lens 5,
An objective-side finder window 6, a strobe light emitting unit 7, a strobe charge changeover switch 8, a photometric device 9, and the like are provided. On the upper surface of the unit body 3, a release button 11,
A counter window 12 for displaying the number of remaining photographable frames and a light guide 13 for strobe charging display are formed. Further, on the back side of the unit body 3, a winding knob 14,
The viewfinder window and the like on the eyepiece side are exposed.

As shown in FIG. 2, the unit body 3 includes a body base 19 into which the exposure device 16 and the strobe device 17 are incorporated, a front cover 20 attached to cover the front and back of the body base 19, and a rear cover. 21. The front cover 20 is formed with an opening for exposing the photographing lens 5, the object-side finder window 6, the strobe light emitting unit 7, the strobe charge switch 8, the photometric device 9, and the like.

The rear cover 21 covers the rear surface of the main body base 19, and forms a film passage between the rear cover 21 and the main body base 19 from the film roll chamber 23 through the back of the aperture to the cartridge storage chamber 22. The photographic film 24 is stored from the film roll chamber 23 into the film cartridge 25 loaded in the cartridge storage chamber 22 through the film passage. Further, bottom covers 21a and 21b are formed at the bottom of the rear cover 21, and the cartridge storage chamber 22 is formed by these bottom covers 21a and 21b.
And the bottom of the film roll chamber 23 is closed light-tight. The bottom cover 21a of the cartridge storage chamber 22 is openable and closable, and also functions as a take-out cover for taking out a film cartridge 25 containing all the photographed films 24 already taken.

A cartridge chamber 22 and a film roll chamber 23 are integrally formed on the left and right sides of the main body base 19, and an exposure device 16 is provided between them. Further, between the exposure device 16 and the film roll chamber 23,
The strobe device 17 is attached by nail coupling. In the cartridge chamber 22 and the film roll chamber 23, a film cartridge 25 and a film roll 24a, which is a roll of the photographic film 24, are loaded. A winding knob 1 is provided above the cartridge chamber 22.
4 is rotatably disposed, and a shaft member provided integrally therewith is engaged with a spool of a film cartridge 25 stored in the cartridge chamber 22. By rotating the winding knob 14 in the counterclockwise direction in the figure, the photographed photo film 24 is wound into the film cartridge 25.

The strobe device 17 is a unit formed by assembling a strobe light emitting unit 7, a main capacitor 31, a battery 32, a synchro switch 33, an aperture control mechanism 34, and the like on a circuit board 30. Flash charging switch 8
Is slid upward, the metal contact piece 35 provided on the circuit board 30 is turned on, and the main capacitor 3 is turned on.
1 is started. The strobe device 17 includes a shutter blade 3 that rotates when a shutter mechanism is operated.
The synchro switch 33 is short-circuited by the sixth pressing piece 36c (see FIG. 3), and emits strobe light. When the strobe charging switch 8 is slid upward, a part of the light guide 13 projects from the unit body 3.

The aperture control mechanism 34 includes a photometric switch 38,
Aperture switching lever 39, solenoid 40, stopper 4
1 and a photometric device 9. Of these, the components other than the photometric device 9 are assembled to the holding member 42 together with the sync switch 33, and the circuit board 30
Attached to.

As shown in detail in FIG. 3, the aperture switching lever 39 is disposed so that its longitudinal direction is orthogonal to the photographing optical axis, and a projection 39 which contacts an aperture lever 44 described later.
a, a locked projection 39b locked by a charge lever 45 (see FIG. 5) described later, and a fitting hole 39c. The fitting hole 39c is rotatably fitted to a rotating shaft 33a formed integrally with the synchro switch 33. The aperture switching lever 39 has a fitting hole 39c fitted to the rotating shaft 33a and is attached to the sync switch 33, and the sync switch 33 is attached to the holding member. Further, a retaining member 47 is attached to the tip of the rotating shaft 33a to prevent the aperture switching lever 39 from coming off the rotating shaft 33a. Further, a spring 48 is attached to the aperture switching lever 39, and the aperture switching lever 39 is urged clockwise in the drawing by the spring 48, and the projection 37a presses the aperture lever 44 by the bias of the spring 48. The spring 48 is set so as to have a larger biasing force than a spring 49 described later that biases the diaphragm lever 44, and rotates the diaphragm lever 44 counterclockwise in the drawing against the biasing force of the spring 49. Let it.

A stopper 41 is disposed below the distal end of the aperture switching lever 39. The stopper 41 has a fitting hole 41a and a protrusion 41 protruding upward from the fitting hole 41a.
b and a fitting portion 41c arranged in parallel with the center direction of the fitting hole 41a. The fitting portion 41c includes a stopper 41
Is rotatably fitted to a movable iron core 40a of a solenoid 40 disposed behind the solenoid. The stopper 41 has a fitting hole 41a.
Are rotatably fitted to a shaft portion (not shown) formed on the holding member 42, and the fitting portion 41c is fitted to the movable iron core 40a. , Is rotatably mounted between a rotation preventing position where the tip of the projection 41b protrudes and a blocking releasing position where the protrusion 41b retreats from the track.

The solenoid 40 includes a movable iron core 40a, a coil 40b, and a holding frame 40c for holding the coil 40b.
And a spring 40d. The holding frame 40c is a holding member 4
2 is held by the holding member 42 by being locked by a locking portion (not shown) formed on the second member 2. The movable iron core 40a is slidably mounted inside the coil 40b,
d urges the coil 40b to project downward. The solenoid 40 is of a type that generates a magnetic force for attracting the movable iron core 40a by energizing the coil 40b, and energizing the coil 40b is performed via a control circuit by a photometric value of the photometric device 9. Only when the photometric value of the light quantity of the subject by the photometric device 9 is smaller than the set value, the coil 40b is energized and the movable iron core 40a is drawn into the coil 40b.

The photometric device 9 comprises a light receiving element 50, a light receiving element case 51, and a protector 52. The light receiving element case 51 houses the light receiving element 50 and
And only a part of the light receiving surface formed on the front surface of the light receiving element 50 is exposed to the outside from the light guide opening 51a formed on the front surface. The light receiving element 50 is mounted on the circuit board 30.
When the photometric switch 40 is turned on, the light quantity of the subject is measured. Protector 5 made of transparent resin
Reference numeral 2 is attached to the front side of the light guide opening 51a to protect the light receiving element 50 and the light receiving element case 51.

The exposure device 16 is provided substantially at the center of the main body base 19. The aperture switching device according to the present invention includes a photographing lens 5 and a lens barrel 5 incorporated in the exposure device 16.
3, an aperture plate 54, a shutter mechanism 55, and the like, and the above-described aperture control mechanism 34. Further, the exposure device 16 incorporates a film unwinding mechanism, a counter mechanism for displaying the number of remaining photographable frames, a finder, and the like. On the front surface of the dark box 56, a shutter blade 36,
The lens barrel 53 is attached in this order.

As shown in FIG. 3, the shutter blade 36 is
It is composed of one sector blade, and is attached to a pin 56a provided in the dark box 56 so as to be rotatable. The shutter blade 36 is normally held at a closed position where the blade portion 36a closes the shutter opening 58 by the urging of a spring 57, and is attached by a shutter lever 59 (described later) that operates in conjunction with the pressing of the release button 11 during shooting. The tip of the portion 36b is kicked off and pivots to an open position (clockwise in the drawing) to open the shutter opening 58. Thereafter, the shutter blade 36 returns to the closed position by the urging of the spring 57, but during the rotation of the shutter blade 36, the shutter opening 5 is closed.
7 is opened to perform exposure. Also, the shutter blade 36
Is formed with a pressing piece 36c for pressing a synchro switch 33 provided in the flash device 17. When the shutter blade 36 reaches a fully open position where the shutter opening 58 is fully opened, the pressing piece 36c turns on the synchro switch 33.

The lens barrel 53 has a substantially plate-shaped base plate 60 that covers the front side of the dark box 56, an opening 61 that is disposed substantially at the center of the base plate 60, and that serves as an open stop. A substantially cylindrical lens holder 62 integrally formed in the front, a substantially rectangular frame-shaped projection 63 formed to surround the lens holder 62,
A rotation shaft 64 is provided to protrude forward from the base plate portion 60 and to which the aperture lever 44 is rotatably fitted. The photographing lens 5 held by the lens holder 62 includes two lenses, a first lens 65 and a second lens 66. As the first lens 65, a large-aperture lens having a convex surface on the object side is used, and as the second lens 66,
A small-diameter lens whose image surface side is convex is used.

As shown in the sectional view of the main part of FIG. 4, the lens holder 62 includes a first lens 65, a flare stopper 67, and a flare stopper 67 from the object side to the image plane side along the optical axis direction of the taking lens 5. The spacer 68 and the second lens 66 are held in this order. The spacer 68 has a horseshoe shape, and is interposed between the first lens 65 and the second lens 66 together with the flare stopper 67 so as to be 2 in the optical axis direction.
Positioning is performed so that the distance between the lenses is kept constant. Then, the diaphragm plate 54 moves so as to pass through a gap formed at an interval from the front end to the rear end of the spacer 68.

On the front side of the lens barrel 53, a lens pressing plate 69 is attached. The lens holding plate 69 is a front wall 70 that covers the front side of the taking lens 5.
And a lens opening 71 formed in the front wall 70 and exposing the photographing lens 5, and formed in a substantially rectangular frame shape that is continuous from the front wall 70 to the rear and covers the outside of the protrusion 63, and is slightly larger. The wall portion 72, an annular rib 73 formed slightly larger than the lens opening 71 on the inner surface side of the front wall 70, and a locking claw 60 a formed at the upper and lower ends of the base plate portion 60. Locking hole 74, which engages with a pin 60 b formed in the base plate portion 60.
Consists of The rib 73 is located on the outer peripheral portion 65 a of the first lens 65.
The photographing lens 5, together with the flare stopper 67 and the spacer 68, is sandwiched and held between the lens holding plate 69 and the lens barrel 53. The lens holding plate 69 has a locking hole 74
Is locked to the locking claw 60a, and the engaging hole 75 is engaged with the pin 60b, so that the mounting hole 75 is attached to the lens barrel 53, and the wall portion 72 is covered on the outside of the protruding portion 63. Thus, the inside of the lens barrel 53 is sealed.

The spacer 68 has a notch 68 a corresponding to the shape of the outer periphery of the distal end portion of the aperture plate 54, which will be described later, and an outer peripheral surface 68 having an outer diameter corresponding to the inner peripheral surface of the lens holder 62.
b, and a projection 68c inserted into the slit 62a of the lens holder 62. The protrusions 68c are formed at two locations so as to protrude from the outer peripheral surface 68b.
By inserting the convex portion 68c into the slit 62a of the lens holder 62, the spacer 68 is positioned inside the lens holder 62 without rotating around the photographing optical axis. Notch portions 62b and 63a are also formed in a part of the lens holder 62 and the protruding portion 63. The aperture plate 54 enters through the notch 63 a of the protruding portion 63, and most of the diaphragm plate 54 is housed inside the lens barrel 53. Further, the tip of the aperture plate 54 enters the lens holder 62 from the cutout portion 62b of the lens holder 62, and the aperture is switched.

The flare stopper 67 restricts the optical path of the off-axis light beam to suppress the occurrence of flare, and the diaphragm plate 5 which has entered the lens holder 62 from the notch 62b.
4 is in sliding contact with the front surface. Thus, the positioning of the diaphragm plate 54 in the optical axis direction is performed.

The first lens 65 is formed with a convex portion 65b so as to protrude from a substantially disk-shaped outer peripheral surface. Since the convex portion 65b is fitted into the cutout portion 62b of the lens holder 62, the first lens 65 is positioned so as not to rotate around the optical axis. The second lens 66 has an annular rib 6 on the outer periphery of the lens surface 66a on the object side.
6b are integrally formed. The rib 66b comes into contact with the rear surface of the aperture plate 54 that has entered the lens holder 62 from the cutout portion 62b. Thereby, the positioning of the diaphragm plate 54 in the optical axis direction is performed.

The aperture plate 54 is formed in a substantially L shape.
An opening 61 formed in the lens barrel 53 is provided at the tip thereof.
A stop aperture 76 having a smaller diameter than that is formed. The distal end of the diaphragm plate 54 is inserted into a gap formed between the first lens 65 and the second lens 66 by the spacer 68.

The aperture lever 44 includes a shaft member 44a, a mounting portion 44b, and a contact portion 44c. The aperture lever 44 has a fitting hole (not shown) formed through the shaft member 44 a rotatably fitted to a rotating shaft 64 formed in the lens barrel 53. A diaphragm plate 54 is fixed to the mounting portion 44b. The contact portion 44c protrudes upward from the rear end of the shaft member 44a, and contacts the aperture switching lever 39 described above. A spring 49 is attached to the aperture lever 44. By the urging of the spring 49, the diaphragm plate 54 fixed integrally with the diaphragm lever 44 rotates clockwise in the drawing, and its tip is inserted into the gap formed by the spacer 68. The aperture lever 44 rotated by the bias of the spring 49 has an upper edge (see FIG. 8) of the mounting portion 44b.
The protruding portion 63 abuts on and is received by a protruding portion 63 b provided integrally with the protruding portion 63. As a result, the diaphragm plate 54 moves the diaphragm aperture 76
Is positioned so as to be at the center of the photographing optical axis. The member that receives the urging force of the spring 49 and positions the diaphragm plate 54 includes the protrusion 6 provided integrally with the protrusion 63 described above.
The member is not limited to 3b, and may be provided on any member around the aperture lever 44 as long as it is arranged to protrude on the rotation path of the aperture lever 44. Also, the aperture plate 54 and the aperture lever 44 are formed integrally, and the aperture plate 54 itself is
3b.

As will be described below, the position of the diaphragm plate 54 is moved by energizing the coil 40b of the solenoid 40. When the power supply to the coil 40b is cut off, the movable iron core 40a
It is projected below the coil 40b by the bias of 0d,
At this time, the stopper 41 attached to the movable iron core 40a is at a rotation preventing position for preventing the rotation of the aperture switching lever 39. The aperture switching lever 39 whose rotation has been prevented by the stopper 41 is in a state where the urging by the spring 48 is stopped, and the projection 39 a does not press the aperture lever 44. The aperture plate 54, which is stopped being urged by the aperture switching lever 39, is at the small aperture position where the aperture aperture 76 is inserted into the photographing optical axis by the urging of the spring 49.

When the coil 40b is energized, the movable iron core 40a moves upward by the attraction force from the coil 40b. At this time, the stopper 41 rotates from the rotation inhibition position to the inhibition release position in conjunction with the movement of the movable iron core 40a. The stop switching lever 39, for which the inhibition of the rotation by the stopper 41 has been released, presses the stop lever 44 by the bias of the spring 48. Then, the aperture switching lever 39
The aperture plate 54 urged by the above rotates from the small aperture position described above to a large aperture position where the aperture opening 76 is retracted from the photographing optical axis. Thus, the solenoid 40 is used as a drive source for rotating the stopper 41. Although the diaphragm plate 54 moves while slidingly contacting the flare stopper 67 as described above, even when the diaphragm plate 54 rotates to the large diaphragm position, the tip end of the diaphragm plate 54 is positioned inside the outer shape of the flare stopper. The stop plate 54 and the flare stopper 67 are always in contact with each other to perform positioning in the optical axis direction, and to position the stop plate 54 so as to move in a plane perpendicular to the optical axis. Thereby, it is possible to smoothly move without interfering with the surrounding parts such as the lens barrel 53 and the lens pressing plate 69.

As shown in FIG. 5, the shutter mechanism 55 is installed above the dark box 56. The shutter mechanism includes a winding stop lever 82, a shutter lever 59, a delay lever 84, a charge lever 45, a cam 85, a governor mechanism 86
Consists of The cam 85 is provided with a disk 87 and a semi-disk-shaped first cam 88 and a second cam 89 below the disk 87. The locking piece 82a of the winding stop lever 82 is
Notch 87a for locking the lock. The hook 59b of the shutter lever 59 contacts the outer periphery of the first cam 88. The second cam 89 is formed at a predetermined interval from the first cam 88, and a shoulder 84 d of the delay lever 84 abuts on the outer periphery of the second cam 89. The cam 85 is inserted into a boss 90 formed in the dark box 56, and the lowermost end of the shaft portion 85 a is engaged with the engagement hole 92 of the sprocket 92.
a. When the photographed photo film 24 is stored in the cartridge 25, the sprocket 92 engages with the perforations formed on the photo film 24, rotates counterclockwise in the drawing, and the cam 85 also rotates. At the same time, the counter plate for displaying the remaining number rotates.

The shutter lever 59 is rotatably attached to a pin 94 provided in the dark box 56. The shutter lever 58 includes a kicking arm 59 a for kicking off the tip of the shutter blade 36, a hook 59 b abutting on the first cam 88 of the cam 85, and a projection 59 c locked on the delay lever 84. Further, a torsion spring 95 is provided above the shutter lever 59, and the torsion spring 95 causes the shutter lever 5 to move.
9 is urged counterclockwise in the figure.

The locking lever 82 includes a locking claw 82a, a projection 82b, a release portion 82c, and a locking portion 82d, and is rotatably attached to a shaft 97 provided in the dark box 56. The torsion spring 98 is
Is attached and urged clockwise in the figure. The protrusion 82b of the stop lever 82 is arranged so as to abut on the locking piece 84c of the delay lever 84. Locking claw 82a
Is provided to enter the notch 87a of the cam 85. When the winding stop lever 82 rotates clockwise in the figure, the winding stop 82d engages with a groove formed on the outer peripheral portion of the winding knob 14 to lock the rotation of the winding knob 14. When the release button 11 is pressed, the release portion 82 c presses the pressing piece 1 formed below the release button 11.
1a, and rotates counterclockwise in the figure.

The delay lever 84 is rotatably attached to a shaft 96 formed on the upper part of the dark box 56, and constitutes a delay mechanism together with the governor mechanism 86. The delay lever 84 has a gear 84a at one end.
The gear 84a is a switch gear 100 of the governor mechanism 86.
And are engaged. In the vicinity of the gear 84a, a pin 8
4b is formed. The delay lever 84 is urged counterclockwise in the figure by a torsion spring 99 attached to the pin 84b. On the upper surface of the delay lever 84, a locking piece 84c is formed. The locking piece 84c locks with the projection 82b of the winding stop lever 82. The shoulder 84d abuts on the second cam 89 of the cam 85.

The governor mechanism 86 includes a switch gear 100 and an ankle 101, and is disposed above the dark box 56, respectively. The rotation speed of the switch gear 100 is adjusted by the pallet 101. As described above, the switch gear 100 is engaged with the gear 84a of the delay lever 84, and follows the rotation of the delay lever 84. Accordingly, the governor mechanism 86 is connected to the delay lever 84.
It operates as a speed control mechanism for adjusting the rotation speed of the motor. As shown in FIG. 6, a fan-shaped pressing rib 100a is formed below the switch gear 100.
The charge lever 45 pressed by the rotation of 0a rotates clockwise in the drawing. Further, a pin 100b is formed on the upper portion of the switch gear 100.
Is rotated, the light measuring switch 38 is brought into contact, and the light measuring switch 38 is turned on. The governor mechanism 86 delays kicking of the shutter blades 36 by the shutter lever 58, during which time photometry is performed by the photometric device 9, and switching of the aperture plate 54 is reliably performed.

The charge lever 45 is formed in a substantially L shape, and has an arm portion 45a and a locking projection 45b formed on the upper surface thereof. A torsion spring 103 is attached to the charge lever 45 and is urged counterclockwise in the figure.
The arm portion 45a protrudes above the charge lever 45, and has a contact surface 45c at a tip portion thereof and a pressed portion 45 at a lower end portion thereof.
d is formed. The contact surface 45c is a switchgear 1
The charging lever 45 is urged in the counterclockwise direction in the figure by the urging of the torsion spring 103 as described above.
Comes into contact with the switch gear 100 and the rotation stops. The pressed portion 45d is a pressing rib 100a of the switch gear 100.
, The charge lever 45 is moved to the torsion spring 1
Rotate clockwise in the figure against the bias of 03. The locking projection 45b locks the locked projection 39b of the aperture switching lever 39 to hold the aperture switching lever 39.

A shutter mechanism using the above-described delay lever and governor mechanism is disclosed in Japanese Patent Application No. Hei 11 (1999) -118.
It is the same as that described in No. 31354, and its function is also the same.

Next, the operation of the present embodiment will be described. FIG.
Shows a shutter mechanism after shutter release. 6 and 7, the ankle 101 of the governor mechanism 86, various springs, and the like are omitted in order to prevent the drawings from being complicated. The winding stop lever 82 is urged clockwise in the figure by a torsion spring 98, but since the projection 82b and the locking piece 84c of the delay lever 84 abut, the winding stop 82d is It is held at an initial position outside the groove 14a formed in the outer peripheral portion. On the other hand, the charge lever 45 is
03, the contact surface 45c is in contact with the side surface of the switch gear 100, and its rotation is stopped. At this time, charge lever 4
5 is located away from the locked projection 39b of the aperture switching lever 39.

When the cam 85 rotates as the photographic film 24 is wound up, the second cam 89 is moved to the delay lever 84.
Is pressed. As a result, the delay lever 84 starts rotating clockwise. Then, as shown in FIG. 7, when the delay lever 84 rotates a predetermined amount, the engagement between the locking piece 84c of the delay lever 84 and the projection 82b of the locking lever 82 is released, and the locking lever 82 is rotated clockwise. Rotate a predetermined amount. Then, when the winding of the photo film 24 for one frame is completed, the locking claw 82a enters the notch 87a formed in the disk 87 of the cam 85.
At the same time, the winding stopper 82d enters the groove 14a formed on the outer peripheral portion of the winding knob 14, and the winding knob 14
Is prevented from rotating. Further, the delay lever 84 tries to rotate counterclockwise by the bias of the spring 99,
The rotation of the locking lever 82 is stopped by the locking between the projection 82b of the winding stop lever 82 and the locking piece 84c.

On the other hand, when the delay lever 84 rotates clockwise in the figure, the switch gear 100 starts to rotate counterclockwise in the figure following the rotation. When the switch gear 100 rotates a predetermined amount, the pressing rib 100a presses the pressed portion 45d of the charge lever 45, and the charge lever 45
Is rotated clockwise in the figure. Then, as shown in FIG. 7, when the shutter is charged, the pressing rib 10
The pressed portion 45d abuts on the outer peripheral surface of Oa, and the charge lever 45 is held. At this time, the charge lever 45
The locking projection 45b locks the locked projection 39b of the aperture switching lever 39 to stop the rotation of the aperture switching lever 39. The aperture switching lever 39 locked by the locking projection 45b of the charge lever 45 is located at a position separated from the aperture lever 44 as shown in FIG. As a result, the diaphragm plate 54 does not receive the bias from the diaphragm switching lever 39 but receives only the bias from the spring 49, and the mounting portion 44 b of the diaphragm lever 44 comes into contact with the convex portion 63 b of the protrusion 63. , The aperture opening 76 is at the small aperture position where it is inserted into the photographing optical axis.

When the release button 11 is pressed with the shutter charged, the pressing piece 11a formed below the release button 11 presses the release portion 82c of the stop lever 82. Thereby, the winding stop lever 82
Rotates counterclockwise in the figure against the bias of the spring 98.
Then, the locking between the locking piece 84c of the delay lever 84 and the projection 82b of the winding stop lever 82 is released. The delay lever 84 rotates counterclockwise by the bias of the spring 99. This rotation causes the switchgear 1 of the governor mechanism 86 to rotate.
01 rotates, the pin 100b comes into contact with the photometry switch 38, and the photometry device 9 performs photometry of the subject image.
The presence or absence of energization of the solenoid 40 is determined by the photometric value of the photometric device 9.

When the delay lever 84 rotates counterclockwise, the pressing rib 100a deviates from the rotation path of the pressed portion 45d of the charge lever 45, and the charge lever 45 rotates counterclockwise in FIG. I do. Thereby, the locking projection 45b of the charge lever 45
The engagement between the stop switch 39 and the locked projection 39b of the aperture switching lever 39 is released, and the aperture switching lever 39 rotates clockwise in FIG. At this time, when the photometric value by the photometric device 9 is larger than a predetermined value, the power supply to the solenoid 40 is cut off, and the stopper 41 is at the rotation preventing position. The aperture switching lever 39, which has been unlocked by the locking projection 45b, slightly rotates clockwise in the figure, and is thereafter prevented from rotating by the stopper 41, as shown in FIG. Since the aperture switching lever 39 whose rotation has been prevented by the stopper 41 does not press the aperture lever 44,
The aperture plate 54 remains at the small aperture position.

When the photometric value is smaller than the predetermined value, the solenoid 40 is energized, and the stopper 41 rotates from the rotation inhibition position to the inhibition release position as shown in FIG. The stop switching lever 39 from which the inhibition of the rotation by the stopper 41 is released presses the stop lever 44, and rotates the stop plate 54 from the small stop position to the large stop position as shown in FIG. At this time, even when foreign matter such as sand enters the film unit with lens 2 on a sandy beach or the like, the lens barrel 53 and the lens pressing plate 69 hermetically seal the inside and accommodate the diaphragm plate 54. Therefore, it is possible to prevent sand or the like from entering between the taking lens 5 and the aperture plate 54. Thereby, the position of the diaphragm plate 54 can be reliably switched.

On the other hand, after the switching of the diaphragm plate 54, the end of the delay lever 86 whose rotation speed has been adjusted by the governor mechanism 86 and the projection 59 of the shutter lever 59
The shutter lever 59 is rotated in the counterclockwise direction in the drawing, and the shutter blade 36 is kicked off by the kicking arm 59a. Thus, the exposure to the photographic film 24 is performed in a state where the aperture plate 54 is held at the large aperture position or the small aperture position. At this time, when the diaphragm plate 54 is at the small diaphragm position, the tip of the diaphragm plate 54 is inserted into the notch 68a of the spacer 68, and is positioned and held so that the diaphragm opening 76 is at the center of the photographing optical axis. Therefore, it is possible to take a picture with an appropriate exposure amount.

In the above-described first embodiment, the driving of the solenoid is controlled in accordance with the amount of light of the subject, and the diaphragm plate 54 is driven by the bias of the spring, so that the diaphragm is moved between the small diaphragm position and the large diaphragm position. Although an aperture control mechanism for moving the plate is incorporated, the present invention is not limited to this. For example, the aperture control mechanism is linked to a manual operation of a strobe charge switch 8 as proposed in Japanese Patent Application No. 2000-280538. Then, the position of the aperture plate may be moved to hold the aperture plate at the small aperture position during normal shooting, and an aperture control mechanism that moves the aperture plate to the large aperture position during flash shooting may be combined. The aperture changeover switch for selecting and operating the large aperture position from outside may be provided independently, and may be interlocked with the manual operation of this switch.

In the first embodiment, a small aperture opening having a smaller diameter than the aperture opening formed in the lens holder is provided on the aperture plate, and the first position where the small aperture aperture is inserted on the photographing optical path. And a second position in which the small aperture opening is retracted from the imaging optical path shape. However, the aperture plate is provided with two large and small aperture openings, and the second aperture is inserted into the imaging optical path. It is also possible to adopt a method of switching between the position 1 and the second position where the large stop aperture is inserted on the photographing optical path.

Further, in the first embodiment, the shape of the spacer 68 is formed in a horseshoe shape. However, the present invention is not limited to this, and the spacer 68 is fixed between the first lens 65 and the second lens 66. The aperture plate 54 that moves in a plane perpendicular to the optical axis direction when switching the aperture is formed by a first lens 65 and a second lens 6 that are formed by spacers.
6 as long as it does not hinder the movement of the diaphragm plate 54 so that it can pass through the gap with the diaphragm 6, for example, it may be an arc shape that conforms to at least a part of the shape of the diaphragm plate 54.
Alternatively, each component may be composed of two separate components.

In the above example, the present invention has been described as an example in which the present invention is applied to a film unit with a lens. However, the present invention may be applied to a compact camera or the like. Although the 135 type cartridge has been described as the photo film, other types may be used. For example, an IX240 type cartridge may be used.

[0051]

As described above in detail, the aperture switching device for a camera according to the present invention includes a spacer which is sandwiched between two lenses constituting a taking lens and keeps the distance between these lenses constant. When switching the aperture,
Since the diaphragm plate is moved so as to pass through the gap between the two lenses formed by the spacer, the diaphragm plate can be inserted between the lenses, and the position of the diaphragm plate can be reliably switched. it can. Further, the diaphragm plate is moved to the small diaphragm position by the bias of the spring. When the diaphragm plate is in the small diaphragm position, the diaphragm plate or a member fixed integrally with the diaphragm plate is provided with a contact provided so as to protrude on the movement path. Since it is positioned in contact with the member, it can be positioned so that the center of the aperture opening does not deviate from the optical axis of the taking lens.

In the aperture switching device for a camera according to the present invention, the optical path is restricted between one of the lenses and the spacer to suppress the occurrence of flare. A flare stopper for positioning in the axial direction is provided, and the tip of the diaphragm plate at the large diaphragm position is kept within the outer shape of the flare stopper, so that the diaphragm plate moves in a plane perpendicular to the optical axis, and Does not interfere with

According to a fourth aspect of the present invention, the camera has a substantially cylindrical shape in which a photographing lens, a spacer, and a flare stopper are held on a lens barrel having a shaft that rotatably supports an aperture plate. Form the lens holder integrally,
By mounting the lens holding plate so as to cover the front side of the lens barrel, the taking lens is pressed into the lens holder, and the aperture plate is connected to the lens barrel and the lens holding plate regardless of the aperture switching position. Since it is stored between the aperture plates, it is possible to prevent sand particles and the like from entering between the aperture plate and the lens, so that the aperture can be switched reliably.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a film unit with a lens.

FIG. 2 is an exploded perspective view of the film unit with a lens.

FIG. 3 is an exploded perspective view of the exposure apparatus.

FIG. 4 is a sectional view of a main part of the exposure apparatus.

FIG. 5 is an exploded perspective view showing a configuration of a shutter mechanism.

FIG. 6 is a schematic view showing a main part of a shutter mechanism, showing a state immediately after a shutter release.

FIG. 7 is a schematic diagram showing a main part of the shutter mechanism, showing a state where a delay lever and a charge lever are charged.

FIG. 8 is a schematic diagram showing a main part of an aperture control mechanism, showing a state in which a charge lever is charged.

9 shows a state where the subject is bright after the state of FIG.

FIG. 10 shows a state where the subject is dark after the state of FIG.

FIG. 11 shows a state where exposure is performed on the photographic film after the state of FIG. 10;

[Explanation of symbols]

 2 Film unit with lens 5 Photographing lens 8 Strobe 9 Photometer 16 Exposure device 34 Aperture control mechanism 36 Shutter blade 53 Lens barrel 62 Lens holder 65 First lens 66 Second lens 67 Flare stopper 68 Spacer 69 Lens holder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03B 17/04 G03B 17/04 G03C 3/00 575 G03C 3/00 575C 575F

Claims (4)

[Claims] An aperture plate is moved in a plane perpendicular to an optical axis between two lenses constituting a photographic lens, and a small-diameter aperture formed in the aperture plate is positioned on a photographic optical path. An aperture switching device for a camera that performs aperture switching between an aperture position and a large aperture position in which the aperture opening is retracted from a shooting optical path, wherein the lens is sandwiched between the two lenses, and the distance between these lenses is reduced. An aperture switching device for a camera, comprising: a spacer for keeping the aperture constant; and when the aperture is switched, the aperture plate is moved so as to pass through a gap between the two lenses formed by the spacer. . 2. The diaphragm plate is moved to a small diaphragm position by the bias of a spring. When the diaphragm plate is at the small diaphragm position, the diaphragm plate or a member fixed integrally with the diaphragm plate is provided on a moving path provided on the moving path. 2. A diaphragm switching device for a camera according to claim 1, wherein said diaphragm switching device is positioned in contact with said member. 3. A flare stopper is provided between one of the lenses and the spacer to restrict the optical path to suppress the occurrence of flare and to slide in contact with the diaphragm plate to position the diaphragm plate in the optical axis direction. 3. An aperture switching device for a camera according to claim 2, wherein the tip of the aperture plate at the large aperture position is kept within the outer shape of said flare stopper. 4. A substantially cylindrical lens holder for holding the photographing lens, spacer, and flare stopper is integrally formed on a lens barrel portion provided with a shaft rotatably supporting the diaphragm plate. By mounting a lens holding plate so as to cover the front side of the lens barrel, the taking lens is pressed into the lens holder, and regardless of the aperture switching position, the aperture plate is connected to the lens barrel and the lens barrel. The aperture switching device for a camera according to claim 3, wherein the aperture switching device is housed between the lens holding plate and the lens.