JP4131758B2 - Camera iris mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diaphragm mechanism that adjusts the amount of exposure light of a camera.
[0002]
[Background]
As is well known, as a diaphragm mechanism of a camera, a main opening is formed at the center of a base plate, and a plurality of diaphragm plates that can be moved synchronously around the main opening are arranged. A mechanism for forming a diaphragm aperture having a necessary aperture area between the diaphragm plates by interfering with each other, or a plurality of diaphragm apertures having different apertures are formed on the surface of one diaphragm plate that can interfere with the main aperture. A so-called turret-type diaphragm mechanism is known in which one of the diaphragm apertures coincides with the main aperture by moving the diaphragm plate.
[0003]
[Problems to be solved by the invention]
By the way, in the former diaphragm mechanism provided with a plurality of diaphragm plates that are synchronously moved, the shape and the aperture area of the diaphragm aperture change depending on the rotation posture of each diaphragm plate. Because it is difficult, it is not suitable for digital cameras with a small minimum aperture value.
In this type of diaphragm mechanism, it is necessary to precisely synchronize a plurality of diaphragm plates, and the synchronization mechanism requires processing accuracy and the number of parts is high, so a high-grade camera that requires multistage arbitrary diaphragms. Although it can be used, it is not suitable for a simple camera.
[0004]
In the latter turret type diaphragm mechanism in which a large number of diaphragm apertures having different areas (different aperture diameters) are formed on one diaphragm plate, one of a plurality of diaphragm apertures aligned in a certain direction is used as the main diaphragm aperture. Since the aperture plate is moved in an arc to match the aperture, the outer diameter of the base plate on which the aperture plate is mounted becomes larger, the camera barrel becomes larger, and this is an obstacle to downsizing the camera. Yes.
Of course, even in this turret type diaphragm mechanism, the center of the diaphragm aperture to be interfered needs to be exactly coincident with the center of the main aperture, so that it is necessary to maintain the positioning accuracy of an arbitrary stop position of the diaphragm plate.
[0005]
An object of the present invention is to reduce the size of a conventional camera with a relatively simple structure, an accurate aperture value, and not requiring high processing accuracy in view of the problems of the conventional camera aperture mechanism as described above. In order to obtain an aperture mechanism suitable for a camera.
[0006]
[Means for Solving the Problems]
To this end, the present invention includes a main opening the formed base plate you pass the exposure light in the center, the base plate between the mask portion and the driven portion to form an aperture of different diameters Two diaphragm plates rotatably supported on a common support shaft provided on the two, and two springs biasing the diaphragm plates in opposite directions so as to retract each diaphragm plate from the main opening, Two stoppers which are provided on the base plate and stop at their initial positions where the rotation of the diaphragm plates by the urging force of the spring is retracted from the main opening, and a drive pin which can be reciprocally rotated. And when each of the diaphragm blades is in the initial position, the drive pin is brought into a non-contact state between the two driven portions, and the drive pin is selectively rotated in either direction. The driven part is brought into contact with any one of the driven parts. It said aperture plate has to make and a, and actuating means for matching said main opening the aperture of the narrowed plate is pivoted against the biasing force of the spring.
[0007]
In this case, the the aperture of each diaphragm plate, the amount of exposure light passing through said main opening, may be an optical filter is arranged to restrict the wavelength.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
In the drawings, sign-1 is a base plate that are provided in the lens barrel 2, the central portion of the base plate 1, that have main opening 3 is formed.
[0009]
On the surface of the base plate 1 is provided with the support shaft 4, the support shaft 4, the entire "V" pair of diaphragm plates 5A formed in shaped bent portion of the 5B freely respectively Ru Tei is supported in a state capable of rotating. Each of these diaphragm plates 5A, 5B are provided on the base plate 1 of the locking pin 6A, the return spring 7A which spanned between 6B, have been biased in opposite directions by 7B, the base plate 1 of the surface was stopper pin 8A, Ru Tei locked respectively engaged by 8B.
[0010]
Each of the diaphragm plates 5A and 5B described above includes a mask portion 5a having an area larger than the opening area of the main opening 3 at one end thereof , and the mask portion 5a is provided with a stopper pin 8A corresponding to each of the diaphragm plates 5A and 5B. , 8B, the position indicated by the solid line in FIG.
Further, the diaphragm plate 5A, aperture 9A having different diameters at the center of the mask portion 5a of 5B, because 9B is Ru are formed respectively Tei, these aperture 9A, when 9B is matched to the main opening 3, exposure light is the aperture 9A of going out through the main opening 3, is restricted to the opening diameter of 9B, so that the aperture stop is narrowed.
[0011]
Both the diaphragm plates 5A and 5B are provided with follower portions 5b on the opposite side to the mask portion 5a. As shown in an enlarged view in FIG. 2, these follower portions 5b are formed by the respective diaphragm plates 5A and 5B. When in the initial positions locked by the stopper pins 8A and 8B, they are in a substantially parallel state with the interval L maintained.
While the drive pin 12 provided at the distal end of the actuating arm 11 of the rotary solenoid 10 between these driven portion 5b is that located, the distance L between the outer diameter of the drive pin 12 is two follower 5b It is intended to keep the drive pin 12 in a non-contact state with respect to both driven parts 5b when the diaphragm plates 5A and 5B are in the initial position.
This is intended to start the rotation operation of the corresponding diaphragm plates 5A and 5B after the operation arm 11 starts to rotate. By adopting such a configuration, each diaphragm plate 5A, and ensuring correct initial position of 5B, aperture plate 5A, it is possible to eliminate as much as possible the influence of the machining accuracy of 5B or the like.
[0012]
The rotary solenoid 10 provided on the outer peripheral portion of the base plate 1 is provided with a drive pin 12 at the distal end portion of the operating arm 11 fixed to the output shaft 10a, and the driving pin of the operating arm 11 that is rotated in the left-right direction. both stop plate 5A at 12, there is so also causing interference 5B selectively to the main opening 3, in the present invention, it is possible to use other forms of actuators instead of the rotary solenoid 10.
[0013]
In the illustrated embodiment, a diaphragm mechanism using a pair of diaphragm plates 5A and 5B is shown, but the number of diaphragm plates 5A and 5B is arbitrary, and the present invention is a mask portion of diaphragm plates 5A and 5B. Instead of the diaphragm apertures 9A and 9B having different diameters formed in 5a, an optical filter that restricts the light amount and wavelength of the exposure light passing through the main aperture 3 can be attached.
[0014]
Since the diaphragm mechanism of the camera according to the illustrated embodiment has the above-described structure, in the normal state, the diaphragm plates 5A and 5B are urged by the return springs 7A and 7B and are locked by the stopper pins 8A and 8B, respectively. 1, the mask portion 5a of each diaphragm plate 5A, 5B is in a position retracted from the main opening 3, and the opening area of the main opening 3 is in the fully open diaphragm state of the exposure light.
[0015]
Next, as shown in FIG. 3, when the operating arm 11 of the rotary solenoid 10 is rotated counterclockwise by the command signal, the drive pin 12 is moved to the aperture plate 5A after the operation arm 11 starts rotating. contact the follower 5b, since the rotated clockwise to the stop plate 5A about the support shaft 4, aperture 9A of the diaphragm plate 5A is matched to the main opening 3, the exposure light going out through the main opening 3 so that is limited to the diameter of the aperture stop 9A.
In this case, in the structure of the illustrated embodiment, the rotating end smell of actuating arm 11 Te, since diaphragm plate 5A is as hardly rotate around the support shaft 4, the influence of the rotation error of the operating arm 11 There is an advantage that the center of the aperture opening 9A of the aperture plate 5A can be made coincident with the center of the main aperture 3 without receiving the above.
[0016]
Further, as shown in FIG. 4, when the actuating arm 11 of the rotary solenoid 10 is rotated in the clockwise direction by the command signal, as in the case of FIG. 3, the driving after the start rotation of the actuating arm 11 pin 12 comes into contact with the follower 5b of the diaphragm plate 5B, but in this case, then, since is rotated counterclockwise to the stop plate 5B about the support shaft 4, the minimum diaphragm plate 5B of the opening area aperture Ri opening 9B is matched to the main opening 3, so that the exposure light going out through the main opening 3 is limited to the diameter of the aperture stop 9B of.
[0017]
【The invention's effect】
As is apparent from the above description, according to the first aspect of the present invention, it is possible to obtain a simple camera aperture mechanism that is small in size and has a small number of parts and does not require processing accuracy. Further, when a rotary solenoid that is relatively easy to control is used as the operating means , not only can the diaphragm plate be operated accurately, but also a structure that is stable against external vibration and the like.
In the invention described in claim 2 , there is an effect that a simple optical filter loading device can be obtained.
[Brief description of the drawings]
FIG. 1 is a plan view of a diaphragm mechanism according to the present invention.
FIG. 2 is an enlarged plan view of a main part of the diaphragm mechanism.
FIG. 3 is a plan view of the aperture mechanism in a first aperture state.
FIG. 4 is a plan view of the diaphragm mechanism in a second diaphragm state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base plate 2 Lens barrel 3 Main opening 4 Support shaft 5A, 5B Diaphragm plate 5a Mask part 5b Drive part 6A, 6B Locking pin 7A, 7B Return spring 8A, 8B Stopper pin 9A, 9B Aperture opening 10 Rotary solenoid 11 Actuation Arm 12 drive pin

Claims (2)

An exposure light in the center portion to form a main opening you pass bedplate, pivoting on a common support shaft provided in the base plate between the mask portion and the driven portion to form an aperture of different diameters Two diaphragm plates supported freely, two springs biasing the diaphragm plates in opposite directions so as to retract each diaphragm plate from the main opening, and the springs provided on the base plate The stop blades are stopped at their initial positions retracted from the main opening due to the urging force of the main aperture, and there are drive pins capable of reciprocating rotation. When in the position, the drive pin is brought into a non-contact state between the two driven parts, and the drive pin is selectively rotated in either direction to contact one of the driven parts. The diaphragm plate having the driven portion is biased by the spring. Camera aperture mechanism, wherein Rukoto the narrowed opening of the narrowed plate is rotated features, and actuating means for matching said main opening against. Wherein the aperture of the stop plate, the camera of the diaphragm mechanism according to claim 1 amount of exposure light, an optical filter for limiting a wavelength characterized that you have been arranged to pass through said main opening.

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