JP2597685Y2 - Lens shutter camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens shutter camera, and more particularly, to a mounting structure of a sector blade for blocking an optical path. 2. Description of the Related Art As is well known, in a lens shutter camera, a plurality of sector blades for interrupting an optical path are sometimes moved synchronously by shuttering to expose a film. Are in a state in which the base is only supported by the fulcrum pin, so that they come into contact with each other, and the resistance associated with the opening / closing operation is very unstable. Further, in the conventional lens shutter, since the shutter charge spring is charged by winding the film, the stored charge of the shutter charge spring is large. Was less likely. Recently, attempts have been made to control the shuttering and the sector blades by switching the direction of rotation of the DC motor without using the above-described shutter charge spring. Compared to the force of the charge spring, the rotation torque is small, and the rotation speed is also affected by the magnitude of the load resistance. Therefore, when driven by a DC motor, a stable small friction resistance of the sector blade is required. . However, as described above, the conventional sector blade support structure of the lens shutter has a large frictional resistance and is unstable, so that it has been difficult to obtain a DC motor driven lens shutter having various advantages. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described structural problems of the conventional lens shutter, and has been proposed to stably reduce the frictional resistance of the sector blade. Lens shutter with DC motor drive
The purpose is to provide a camera. SUMMARY OF THE INVENTION The present invention, which achieves the above object, comprises a pair of base members having a shutter opening,
A lens shutter / camera that is disposed between the pair of base members and incorporates a plurality of sector blades that open and close the shutter opening by being rotated in a plane substantially parallel to the pair of base members. The pair of pedestals that rotatably support each of the sector blades are opposed to each other so that the height of each of the sector blades from one base member of the pair of base members is different. Along with each provided by integral molding, each fulcrum pin which is inserted into a fulcrum hole provided in each of the sector blades and serves as a fulcrum of rotation of each sector blade is provided by integral molding on one of the pair of base members,
A recess for receiving the tip of each of the fulcrum pins of each of the sector blades is provided in the other of the pair of base members by integral molding, and each of the fulcrum pins is supported by a driving member for moving the plurality of sector blades. A lens shutter camera is characterized in that the sector opening is opened and closed by rotating the sector blade. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG. 7 is a front view of an autofocus camera according to the present invention having a program shutter. The camera has a photographic lens barrel B provided in front of a camera body A. A focus unit for measuring a focal length to a subject is provided at an upper part. That is, the focus unit is well known structure, light to calculate the distance from the reflection angle of the light emitting module D ₁ and its infrared light irradiated by the first stage depression of the release button C infrared light on the subject to the subject comprises a module D _2, the position of the focus lens 1 will be described later, it is adjusted according to the focal length calculated by the light-receiving module D _2. An AE photometric element E for detecting the light value of the subject is arranged between the light emitting module D ₁ and the light receiving module D ₂ described above,
When the release button C is depressed by the first step, the AE photometric element E sends the light value of the subject to the CPU, and rotates the shutter control motor 2 (to be described later) forward and backward at the shutter speed calculated by the CPU. Then, the sector blades 3A, 3B, 3C are opened and closed. FIG. 3 is a sectional view of the photographing lens barrel B described above. The photographing lens barrel B has a large-diameter first lens barrel member 4 and a first lens barrel member 4 which are concentrically positioned with respect to the lens optical axis α of the focus lens 1 forming a part of the photographing lens.
Comprises a small-diameter second lens barrel member 5 assembled inside
The outside of the first lens barrel member 4 is covered with a decorative tube 6 formed at the tip of the exposure window 6a. Then, the above-mentioned first lens barrel member 4
A disk-shaped first base 8 is fixed to a base portion by a fixing screw 7 shown in FIG. 6, and a shutter base 10 having a shutter opening 9 formed in the center portion with respect to the first base 8 is shown in FIG. Are fixed by mounting screws 11 shown in FIG. An arc-shaped second base 13 is fixed to the distal end surface of the first lens barrel member 4 by a fixing screw 12. A lens holding frame 14 that holds the focus lens 1 that can move in the direction of the lens optical axis α is disposed inside the second lens barrel member 5. The lens holding frame 14 is provided with the feed screw rod 1 shown in FIG.
5 moves in the length direction of the feed screw rod 15 by the feed screw rod 15 held by the integrated base portion 14a held in the gear 5 and sent in the length direction by the drive of the focus control motor 17 via the reduction gear train 16. Is done. The reduction gear train 16 rotates a barrier opening / closing ring 19 for controlling opening / closing of a barrier member 18 located at the exposure window 6a. That is, the barrier member 18 is rotatably supported on the first lens barrel member 4 by the barrier fulcrum shaft 20 in FIG. 3, and the vertical movement arm 22 extending from the opening / closing gear 21 for rotating the barrier member 18 includes: The barrier opening / closing ring 19 faces the movement trajectory of the opening / closing projection 19a. Therefore, the barrier member 18 is opened in the run-in section of the focus control motor 17 for performing automatic focusing, and is closed again when the film winding after photographing is completed. The first lens barrel member 4 is provided with a shutter control motor 2 constituted by a reversible DC motor.
The shutter ring 23 that opens and closes A, 3B, and 3C is rotated. That is, the drive shaft pinion 24 of the shutter control motor 2 is engaged with the large-diameter teeth 25a of the first reduction gear 25, as shown in FIGS.
Are meshed with the large-diameter teeth 26a of the second reduction gear 26, and the small-diameter teeth 26b of the second reduction gear 26
, The shutter ring 23 is rotated in a predetermined direction at a reduced speed according to the direction of application of the DC voltage to the power supply terminal of the shutter control motor 2. As shown in FIG. 3, the sector blade 3
A, 3B, and 3C are accommodated in a flat mounting space formed between the first base 8 and the shutter base 10 so as not to contact each other. That is, these sector blades 3A, 3B, and 3C have fulcrum holes 3a that are loosely fitted to fulcrum pins 27 integrally formed on the surface of the first base 8 at equal pitches in the circumferential direction of the shutter opening 9. doing. The periphery of these fulcrum holes 3a, that is, the base 3b, is formed on the shutter base 10 in opposition to the first base side pedestal 28A formed around each fulcrum pin 27 and these first base side pedestals 28A. It is interposed in the gap formed between the shutter base side pedestal 28B. In other words, these gaps have dimensions corresponding to the thicknesses of the sector blades 3A, 3B, 3C, and each of the first base pedestal 28A and the shutter base pedestal 28B has a sector blade 3A, 3B, 3C.
Since the height H is different for each sector, each sector blade 3
A, 3B, and 3C are guaranteed to be parallel to each other. In addition,
The fulcrum pin 27 also functions as a positioning member when the base 10 and the base 8 are assembled. Further, the clearance between the openings of the base 8 and the base 10 is maintained for three blades. Further, each of the sector blades 3A, 3
Each of B and 3C has an elongated hole 3c into which a ring pin 29 protruding from the shutter ring 23 can be inserted, as shown in FIGS. These long holes 3c
As shown in FIG. 2, the pinhole forming portion 3d that crosses the lens optical axis α when the shutter is opened and closed and the fulcrum pin 27
Are extended in the direction of a line segment X connecting. Since the lens shutter according to the illustrated embodiment has the above-described structure, the sector blades 3A, 3B, 3C are opened and closed by applying a forward or reverse DC voltage to the power supply terminal of the shutter control motor 2. it can. The shutter operation will be described in detail. The light value of the subject is measured by the AE photometric element E, and the light value is an integral value of the opening area and the opening time of the sector blades 3A, 3B, 3C. Feather 3A,
The opening and closing times of 3B and 3C are determined by the CPU based on the light value values. In other words, when the light value is high, the sector blade 3
Before A, 3B and 3C are not completely opened to the state shown in FIG. 8, the shutter ring 23 is stopped, and the sector blades 3A, 3B and 3C are rapidly closed by application of a reverse voltage to the shutter control motor 2. . When the light value of the subject is low, the application of the positive voltage to the shutter control motor 2 is stopped after the sector blades 3A, 3B, 3C are opened to the fully open state in FIG. The stop time is monitored by the CPU, and after a lapse of a predetermined time, a reverse voltage is applied to the shutter control motor 2 to close the sector blades 3A, 3B, 3C. The stop operation of the shutter control motor 2 in the open state is a remarkable advantage when the shutter is operated in a so-called "valve" operation, and since the shutter control motor 2 does not consume power while the shutter is open, it is mounted on the camera. Battery power can be effectively consumed. In the lens shutter shown in the figure, since the sector blades 3A, 3B and 3C are driven by a DC motor, the rotation speed of the sector blades 3A, 3B and 3C, that is, the sector blades 3A, 3B and 3C depends on the load on the shutter control motor 2. Although the opening time tends to change, the sector blades 3A, 3B,
Since the load of 3C is very small and in a stable state, the rotation speed of the shutter control motor 2 and, at the very least, the exposure time are stable. That is, the main load on the shutter control motor 2 is the light weight of the sector blades 3A, 3B, 3C.
The inertia of each of the sector blades 3A, 3B, and 3C, as described above.
A, 3B, 3C are parallel to each other by being sandwiched between a first base pedestal 28A and a shutter base pedestal 28B having different heights H, and the pedestals for these sector blades 3A, 3B, 3C. Since the frictional resistance is very small, the rotation speed of the shutter control motor 2 is in a range that can be sufficiently adjusted only by adjusting the applied voltage for each camera. Therefore, an exposure amount corresponding to the program shutter speed can be obtained by adjusting the power supply voltage applied to the shutter control motor 2. Further, as described above, the sector blade 3
Since the fulcrum pins 27, the long holes 3c, and the pinhole forming portions 3d of A, 3B, and 3C are located on one line segment X,
A high shutter speed can be realized. That is, FIG. 9 shows a state immediately before the sector blades 3A, 3B, 3C are opened. In this state, the pinhole forming portions 3d of the sector blades 3A, 3B, 3C coincide with the lens optical axis α. Is done. Therefore, the ring pin 29 in this state
Is a tangential direction of a circle centering on the fulcrum pin 27 of each sector blade 3A, 3B, 3C and having a diameter from the fulcrum pin 27 to the ring pin 29. Thereby, the shutter opening 9 can be quickly opened and closed. For this reason, a so-called "sharp" shutter can be provided, and a higher shutter speed can be obtained with the same light value value. As is apparent from the above description, according to the present invention, each sector blade is different from each other so that the height of each sector blade from one base member of the pair of base members is different. A pair of pedestals rotatably supported are provided facing each other by integral molding on each of the pair of base members, and are inserted into fulcrum holes provided in each sector blade to serve as fulcrums for rotation of each sector blade. Each fulcrum pin is provided on one of the pair of base members by integral molding, and a recess for receiving the tip of each fulcrum pin of each sector blade is provided on the other of the pair of base members by integral molding, and the plurality of sector blades are rotated. The opening and closing of the shutter opening is performed by rotating each sector blade with each fulcrum pin as a fulcrum by a driving member for the rotation of the sector blade. In addition to reducing frictional resistance, the occurrence of shutter abnormalities due to collisions and catches between sector blades is suppressed, and the rotation of each sector blade with each fulcrum pin as a fulcrum by a drive member for rotating a plurality of sector blades is performed. Obtain a lens shutter / camera that can realize a lens shutter / camera that moves reliably and stably with a simple configuration, and that can use, for example, a DC motor with a small rotating torque as its driving member. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view taken along the line II of FIG. FIG. 2 is a plan view of a sector blade. FIG. 3 is an enlarged cross section taken along line IV-IV in FIG. 7; FIG. 4 is a sectional view taken along the line VV of FIG. 3; FIG. 5 is a sectional view taken along the line VI-VI in FIG. 4; FIG. 6 is a sectional view taken along the line VII-VII in FIG. FIG. 7 is a front view of the autofocus camera according to the present invention. FIG. 8 is a view similar to FIG. 1 with a shutter fully opened. FIG. 9 is a view similar to FIG. 1 immediately before the shutter is opened; FIG. 10 is a view similar to FIG. 1 in a shutter half-open state; [Description of Signs] α lens optical axis 2 shutter control motors 3A, 3B, 3C sector blade 3b base 8 first base 10 shutter base 23 shutter ring 27 fulcrum pin 28A first base side pedestal 28B shutter base side pedestal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 9/10 G03B 9/22

Claims (1)

(57) [Rules for requesting registration of utility model] A pair of base members each having a shutter opening formed thereon, and a plurality of base members disposed between the pair of base members, the plurality of base members being configured to open and close the shutter opening by being rotated in a plane substantially parallel to the pair of base members. In a lens shutter camera incorporating sector blades, a pair of base blades each rotatably supporting each sector blade so that the height of each sector blade from one base member of the pair of base members is different. The pedestals are opposed to each other and integrally formed on each of the pair of base members, and each fulcrum pin which is inserted into a fulcrum hole provided on each of the sector blades and serves as a fulcrum for the rotation of each sector blade is provided. Provided by integral molding on one of the pair of base members,
A recess for receiving the tip of each of the fulcrum pins of each of the sector blades is provided in the other of the pair of base members by integral molding, and each of the fulcrum pins is supported by a driving member for moving the plurality of sector blades. A lens shutter camera, wherein the sector blade is rotated to open and close the shutter opening.