JPH02254431A - Camera with aperture diameter regulating device - Google Patents

Abstract

PURPOSE:To constantly and properly set the diaphragm diameter of a lens system and to make the use of a complicated and high-performance lens unnecessary by controlling the displacement quantity of an operating lever by a regulating cam in response to a focal distance change. CONSTITUTION:Before an exposing operation, a zooming operation is performed in response to an object distance and a movable barrel member is moved to a set position. The regulating cam 22 is interlocked with the motion, moved and guided into the displacement locus of the operating lever 3 by prescribed quantity. At the next stage, an electromagnetic actuator 1 is started for the exposing operation and the lever 3 is interlocked with the operation of the actuator, displaced from a rest position in a normal direction along the prescribed displacement locus and abuts on the cam 22. Hereby the displacement quantity in the normal direction is regulated. Resultantly the opening operation of blades 14 and 15 is also stopped and their possible maximum opening amount is decided. Through a series of these actions, the diaphragm diameter of the lens system is controlled in response to the focal distance change accompanied with a zooming position.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an automatic focusing function (hereinafter referred to as AF), a mechanism (hereinafter referred to as AF) that automatically controls the exposure aperture and exposure time of a shutter.
The present invention relates to a compact camera equipped with functions such as AE (hereinafter referred to as AE) and zooming according to the subject distance (hereinafter referred to as zoom), and particularly relates to regulation of the aperture diameter of the shutter.

[Prior Art] In the above-mentioned type of compact camera, a drive device capable of generating driving torque in both forward and reverse directions, such as a moving magnet type electromagnetic actuator or a stepping motor, has been used to continuously open and close the shutter blade. AE was performed by transmitting the driving torque to the blades via the actuating mechanism. In addition to the AE mechanism, it was equipped with a zooming mechanism for zooming.

[Problem that the invention seeks to solve]

However, in conventional cameras equipped with zoom lens systems with lens shutters, a system is adopted in which the aperture diameter of the lens system remains constant regardless of changes in focal length due to zooming, which eliminates the need for complicated aperture diameter regulation. I've lost it. However, the aperture value (F value) is F - aperture diameter/
Since it is determined by the focal length, in the case of a lens with a large zoom ratio, if the aperture diameter is constant, the F value will change between the short focal length side and the long focal length side. For this reason, in order to obtain a lens that is bright even on the long focal length side, which is a recent trend in the market, that is, has a small F value, the short focal length side has a so-called large aperture, which tends to be inferior in terms of image quality. It has become. This reduces the degree of freedom in lens design, and in order to ensure performance, it is necessary to increase the number of lenses and to have shapes and dimensional precision that are not suitable for mass production, which has a negative impact on the ability to make cameras smaller and lower in cost. Also, if you do not use a high-performance lens system,
Also, since the aperture diameter cannot be adjusted according to changes in focal length,
Due to the above-mentioned reasons, there was a problem in that it was difficult to obtain photographic images of a certain quality or higher.

The present invention aims to solve the problems of the conventional example by using a simple method.
The purpose of the present invention is to provide a compact camera that can adjust the aperture diameter according to changes in focal length using a mechanism that allows the aperture diameter to be adjusted according to changes in focal length.

[Means for solving problems]

The camera device to which the present invention is applied includes a movable blade member that opens and closes the lens system to determine the exposure aperture and exposure time, and a movable blade member that engages with the blade member and is displaced in both forward and reverse directions along a predetermined trajectory. By doing so, the blade member is provided with an operating mechanism for opening the blade member when the blade member is displaced in the forward direction and closing the blade member when the blade member is displaced in the reverse direction. A drive mechanism that generates bidirectional torque in a switchable manner is engaged with the actuation mechanism in order to displace the actuation mechanism in both forward and reverse directions. The vane member and the actuation mechanism are mounted on a substrate having an opening.

Further, a cylindrical member is disposed around the substrate, which is interlocked with at least a portion of the lens system and is movable as the focal length changes due to zooming. The camera device according to the present invention is further characterized in that it is fixed to the cylindrical member, and as it moves, it enters the displacement locus of the actuating mechanism and regulates the amount of forward displacement thereof, thereby reaching the maximum opening actuation amount of the blade member. It includes a regulating member for determining the

[For production]

According to the present invention, first, prior to exposure, a zooming operation is performed in accordance with the subject distance, and the movable barrel member is moved to a set position. Along with this movement, the regulating member also moves,
It enters into the displacement locus of the actuating mechanism by a predetermined amount.

Next, the drive mechanism is started for the exposure operation, and in conjunction with this, the operating mechanism is displaced in the forward direction from the rest position along a predetermined displacement trajectory, but eventually comes into contact with the regulating member and the amount of forward displacement is regulated. Ru. As a result, the opening operation of the blade member is also stopped, and the maximum opening operation amount is determined. Through this series of actions, the aperture diameter of the lens system can be controlled in accordance with changes in focal length due to zooming. Generally, the smaller the focal length is, the smaller the maximum opening operation is controlled, and the amount is determined by the performance of the lens system.

〔Example〕

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an exploded perspective view of the shutter section and its surroundings that perform AE among the components of the camera device according to the present invention. As shown in the figure, the drive mechanism is composed of, for example, an electromagnetic actuator 1, and a drive bin 2 is attached to the lower surface of the actuator 1, which is displaced along a predetermined trajectory with a predetermined torque in both forward and reverse directions as shown by the arrow. There is. The actuation mechanism consists of an actuation lever 3, which has a shaft hole 4 and an elongated length 5 that engages with the drive pin 2. Further, °C operating pins 6 and 7 are installed on the lower surface of the operating lever 3 at a distance from the shaft hole 4. The actuating lever 3 swings along a predetermined locus in both forward and reverse directions about the shaft hole 4 in accordance with the displacement of the drive bin 2.

The substrate 8 has at its center an opening 9 for a lens system and escape holes IO and 11 for allowing the operating pins 6 and 7 to escape to the lower surface side. Further, on the upper surface of the substrate 8, there is provided a shaft pin 12 for engaging and supporting the shaft hole 4 (!) of the operating lever 3. On the lower surface side of the substrate 8, a pair of blades 14 and 15 (not shown) are provided. ) is arranged.The blade 14 is provided with a shaft hole 16 and an elongated hole 17.The blade 14 is rotatably mounted on the substrate 8 through the shaft hole 16, and is rotatably mounted on the substrate 8 through the shaft hole 16. The blade 14 is engaged with the operating pin 7. The swing of the operating lever 3 causes the blade 14 to move in both opening and closing directions relative to the opening 9, thereby performing shuttering.

Now, the regulating member that regulates the displacement of the operating lever 3 is constituted by a regulating cam 22 arranged around the base plate 8, and the regulating cam 22 has an inclined cam surface 23 that can come into contact with the contact point 21 of the operating lever 3. has. The regulating cam 22 is fixed along the axial direction of the inner surface of a movable cylindrical member (not shown), and moves as shown by the arrow in unison with the axial movement of the movable cylindrical member. As a result, the cam surface 23 of the regulating cam 22 enters the displacement locus drawn by the contact point 21 of the actuating lever 3 in accordance with the amount of movement thereof.

FIG. 2 is a plan view of the shutter section and its surroundings as seen from the bottom surface of the board after the parts shown in FIG. 1 are assembled, and shows the aperture in a fully open state, and FIG. 3 similarly shows the aperture in a fully open state. Second
As shown in the figure, a pair of blades 14 and 15 rotatably supported on a common shaft pin 24 provided on the base plate 8 are attached to the center of the base plate by actuating pins 7 and 6 fixed to the actuating lever 3, respectively. They are held in the rest position in an overlapping state, and the opening 9 is fully closed. Further, the actuating lever 3, which is pivotally supported around the shaft pin 12, is also held at the rest position in the extreme clockwise direction in the drawing by the drive pin 2 of the actuator 1. Furthermore, the drive pin 2 of the actuator tacho is also placed in the extreme clockwise rest position in the drawing.

In this state, the regulating cam 22 fixed to the dJ cylinder member 25 disposed around the periphery of the board 8 is placed in a predetermined position according to the axial movement of the movable cylinder member 25 during zooming, and its cam surface 23 is placed on the board 8. The contact point 21 of the operating lever 3 enters the notch 20 provided at the peripheral end of the
Compare with. As a result, the cam surface 23 enters into the displacement locus of the contact point 21, and the distance between the cam surface 23 and the contact point 21 of the actuating lever 3 in the rest position defines the amount of forward displacement of the actuating lever 3. becomes. The amount of penetration of the zoom plane 23 is naturally set in accordance with the change in focal length due to zooming.

FIG. 3 is a plan view of the pair of blades 14 and 15 moved from the rest position shown in FIG. 2 to the fully open position. As shown in the figure, by actuating the actuating lever 3 in a counterclockwise or forward direction from its rest position, the pair of blades 1
4 and 15 move in opposite directions and in a direction away from the opening 9, using the common shaft pin 24 as a fulcrum, to fully open the opening 9. The blades 14 and 15 are actuated via actuating pins 7 and 6 inserted into elongated holes provided in these blades.

The actuating lever 3 is swung counterclockwise, that is, in the forward direction, along a predetermined locus by the driving pin 2 of the actuator 1 about the shaft pin 12. At this time, the drive bin 2 is also displaced counterclockwise, ie, in the forward direction, along a predetermined trajectory from its rest position.

By the way, in the case shown in FIG. 3, the cam surface 23 of the regulating cam 22 is set so as to come into contact with the contact point 21 of the actuating lever 3 and regulate it when the apex vanes 14 and 15 reach the fully open position. has been done. Therefore, in this case, the aperture diameter of the lens system is controlled to match the full aperture diameter of the shutter in accordance with the change in focal length due to zooming.

However, when the aperture diameter of the lens system is further reduced in accordance with a change in focal length, the movable cylinder member 25 is moved further in the axial direction, and as a result, the inclined cam surface 23 of the regulating cam 22 is moved deeper. Contact point 2I of actuation lever 3
enters into the displacement trajectory of.

As a result, the cam surface 23 approaches the contact point 21 of the operating lever 3 in the rest position, and the amount of forward displacement of the operating lever 3 decreases. As a result, the blades 14 and 15 touch the contact point 21 of the operating lever 3 and the cam surface 2 of the regulating cam 22 before reaching the full position.
3, the opening is stopped by contact with the shutter 3, and it is possible to obtain the desired amount of opening operation and the desired maximum opening diameter of the shutter.

FIG. 4 is a developed cross-sectional view showing the main parts of the camera device according to the present invention, and shows part of the AF mechanism, AE mechanism, and zoom mechanism. The lens system includes a lens group 26 on the object side (only a portion shown), a second lens group 27 in the middle, and a third lens group 28 on the film side (only a negative portion shown). Front frame 29
and the rear frame 30 are guided by zoom guides 31 that are spaced apart from each other. A front lens barrel 32 and a rear lens barrel 33 that hold the second lens group 27 are arranged between the front frame 29 and the rear frame 30, and are movable in the optical axis direction with respect to the front and rear frames 29 and 30. There is.

The AF mechanism includes an AF stepping motor 34 fixed to the front frame 29, an AF cam 37 arranged in the rear frame 30 and driven by the stepping motor 34 via a pinion gear 35 and a transmission gear 36, and front and rear lens barrels 32 and 33. An AF pin 38 passes through and is fixed to the front lens barrel 32 and abuts the AF cam 37, and an AF pin 38 is fixed along the axial direction between the front and rear frames 29 and 30 to prevent the front and rear lens barrels 32 and 33 from moving in the axial direction. AF guide 39 to guide and front and rear lens barrels 3
2 and 33 toward the rear frame 30.

Next, the zoom mechanism includes a member (not shown) for moving the lens group 2B and/or the third lens group 28 along the axial direction and changing the focal length of the lens system by manual or automatic zooming operation. the aforementioned movable cylinder member, that is, the zoom ring 25, which moves linearly in the axial direction in accordance with the operation of the member;
It is composed of the above-mentioned regulating cam 22 fixed to or integrated with the zoom ring 25.

Finally, the AE mechanism is comprised of the above-mentioned electromagnetic moving actuator 1 mounted on the rear frame 30, the above-mentioned operating lever 3 and a pair of blades 14 and 15, each disposed on the base plate 8.

Next, referring to FIG. 4, the operations of the camera device according to the present invention will be explained in the order of AF, zoom, and AE.

In the AF operation, the distance to the object is first measured by a distance measuring means (not shown) in the camera body, and signal pulses corresponding to a predetermined number of stages suitable for the distance are supplied from the drive control circuit to the AF stepping motor 34. AP stepping motor 34
rotates, outputs torque, and rotates the AF cam 37 via the pinion 35 and transmission gear 36. Note that the initial rest position of the AF cam 37 is set to top dead center or bottom dead center depending on the specifications of the camera. AF according to the rotation of the AF cam 37
The pin 38 is pushed up, and the front lens barrel 32, which moves together with the threaded portion of the AF pin 38, moves forward along the AF guide 39. At this time, the rear lens barrel 33 also moves at the same time. However, the front frame 29 and the rear frame 30 do not move in the axial direction. What moves are the front and rear lens barrels 32 and 3.
3 and blades 14 and 15, etc. Also, the front and rear lens barrels 32
．． In order to accurately control the amount of axial forward movement of the lens barrels 32, 33, the lens barrels 32, 33 are always biased rearward by a spring member 40. In the case of a compact camera, the maximum movement amount of the second lens group 27 for AF mentioned above is from 2 to 311 degrees.
The distance is about 1 m, and this maximum amount of movement is divided into several tens of steps to perform fine focus adjustment.

Next is the zoom operation, but first the external zoom operation member (
(not shown) according to the subject distance.
Alternatively, the third lens group 28 is moved along the axis to set a desired focal length. In response to this operation, the zoom ring 25 moves in the axial direction, and the cam surface 23 of the adjustment cam 22 fixed thereto enters the displacement locus of the contact point 21 of the operating lever 3 by a predetermined amount.

Finally, AE operation is performed. In response to desired exposure amount information and exposure time information sent from an exposure control circuit (not shown), the electromagnetic actuator 1 is started and the drive pin 2 is moved forward from its rest position. Accordingly, the operating lever 3 is also moved in the forward direction from its rest position along a predetermined trajectory.

As a result, the blades 14,15 are actuated and exposure begins.

Eventually, the contact point 21 of the actuating lever 3 comes into contact with the cam surface 23 of the regulating cam 22, and its forward movement is restricted, and the blades 14,
15 is held at the maximum opening position. After the exposure is completed, the output torque of the actuator 1 is switched in the opposite direction, the drive pin 2 moves in the opposite direction, and in conjunction with this, the operating lever 3 also returns to the rest position, completing the camera operation. It goes without saying that depending on the amount of exposure, the amount of movement of the actuating lever 3 may not reach the maximum aperture, and therefore the actuating lever 3 may return to the rest position without coming into contact with the regulating cam 22.

〔Effect of the invention〕

As described above, according to the present invention, the amount of displacement of the actuating lever driven by the electromagnetic actuator can be easily controlled by the regulating cam according to changes in the focal length, so the aperture diameter of the lens system can always be appropriately set, and therefore There is no need to use a complicated and high-performance lens system as in the past.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the lens shutter section of a camera device according to the present invention, FIG. 2 is a plan view showing the lens shutter section shown in FIG. 1 in a fully closed state, and FIG. 3 is a diagram showing the same fully open state. , and FIG. 4 are developed cross-sectional views along the optical axis of essential parts of the camera device according to the present invention. 1... Actuator, 2... Drive bin, 3...
... Operating lever 8... Board, It, 15... Vane, 24... Common shaft pin, Applicant Co., Ltd. 6.7... Operating pin, 9... Opening, 22 ...Regulation cam, 25...Zoom ring. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A blade member that opens and closes the lens system in order to determine the exposure aperture and exposure time, and a blade member that engages with the blade member and is displaced in both forward and reverse directions along a predetermined trajectory. an operating mechanism for opening the vane member when displaced in the forward direction and closing and closing the vane member when displaced in the reverse direction; a drive mechanism that switches and generates a directional torque; a substrate member for holding the blade member and the actuating mechanism; and a substrate member disposed around the substrate member and interlocked with at least a part of the lens system to adjust the focal length. In a camera device having a cylindrical member that is movable with a cylindrical member, the blade member is fixed to the cylindrical member, and as the cylindrical member moves, it enters the displacement locus of the actuating mechanism and regulates the amount of forward displacement thereof, thereby increasing the maximum opening actuation amount of the blade member. A camera device characterized by including a regulating member for determining. 2. Claim 1, wherein the drive mechanism comprises an electromagnetic actuator that can be switched and continuously generates forward and reverse bidirectional torque.
Camera device described in. 3. The camera device according to claim 1, wherein the operating mechanism includes an operating lever that swings forward and backward along a predetermined trajectory. 4. The cylinder member consists of a zoom ring that moves linearly in the axial direction of the lens system, the regulating member consists of a cam surface member that extends along the inner axial direction of the zoom ring, and the cam surface member 4. A camera device according to claim 3, which acts directly on the camera.