JPS61286827A - Variable focus camera equipped with lens barrier - Google Patents

Abstract

PURPOSE:To realize compact constitution, to make the quantity of projection from a camera body small, and to eliminate the probability that adverse influence is exerted upon a photographic optical device and a shutter device when an external force is applied by fixing a main optical system and the shutter unit on the base plate of a barrier unit independently. CONSTITUTION:A photographic lens consists of the main optical system 1 and a subordinate optical system 2 and a holding frame 3 which holds the main optical frame 1 is fixed to a shutter ground plate 5 which holds a stop shutter 4. This shutter ground plate 5 is fitted to the surface of the base plate 6 which is movable in the direction of an optical axis with a small screw 7. The barrier unit 8 is provided on the surface of the base plate 6 while sandwiched between an external cylinder 9 and the base plate 6 and the barrier unit 8 and external cylinder 9 are fixed on the base plate 6 with a small screw 10. Consequently, an external force applied to the front ring of the barrier unit and the external cylinder is never transmitted directly to the shutter unit and main optical system, and consequently there is no possibility that shutter accuracy and optical performance deteriorate.

Description

DETAILED DESCRIPTION OF THE INVENTION In particular, the present invention relates to the structure of a lens barrel portion of a variable focus camera equipped with a lens barrier.

[Background of the invention]

In a so-called variable focus camera, the focal length of the photographic lens is changed by moving the main optical system of the photographic lens forward along the optical axis beyond the distance adjustment range and inserting a sub-optical system on the optical axis. A system in which a shutter serving as an aperture is provided on the optical axis between the main optical system and the sub optical system is already known, for example, as disclosed in Japanese Patent Application Laid-open No. 19926/1983. However, in this known variable focus camera, a shutter base plate that holds the shutter device is added on the rear base plate that holds the sub-optical system drive mechanism for inserting the sub-optical system onto the photographing optical axis. On top of the shutter base plate, an autofocus mechanism that moves out the main optical system for distance adjustment and a magnet holder equipped with a shutter magnet are attached, and the front base plate is screwed onto the magnet and holder. It was stopped and on the front board.

A cover that encloses all drive mechanisms from the sub-optical system to the main optical system is provided to protrude from the camera body. In cases where the lens barrel is constructed by stacking each device one after another in this way, one
For example, there are disadvantages in that the base plate is likely to deform, resulting in deterioration of the viscosity of the base plate, and dimensional deviations are likely to occur in the optical axis direction.

Furthermore, since the cover is formed in a size that includes even the sub-optical system holding frame located at a retracted position outside the photographing optical path, there is a drawback that the outer diameter of the lens barrel portion becomes extremely large.

On the other hand, in a variable focus camera, the amount of photographed images becomes large. However, the external shape of the lens barrel that protrudes from the camera body is important when considering appearance, handling, etc.

It is desirable that it be as small as possible. Therefore, we installed a base plate that can be moved along the optical axis, and placed it on the back side of the base plate.

A sub-optical system drive device that is displaced at right angles to the optical axis and requires a relatively large space is installed together with the sub-optical system, and a shutter that also serves as an aperture, a main optical system, and a lens barrier that handles the front surface of the main optical system are installed. The lens barrel is constructed by surrounding the shutter, which is provided on the front side of the base plate and also serves as an aperture, to the lens barrier with a cylindrical outer tube, leaving the sub optical system and the base plate, and only that lens barrel can switch the focal length. If the camera is made to protrude from the camera body during the process, the camera can be made smaller and easier to handle.

However, in the above-mentioned structure, if the components are stacked one after another, as in the prior art example, it is difficult to achieve precision, and the structure is weak against external forces.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks of conventional cameras, and although it has a built-in lens barrier, it is compact, has a small amount of protrusion from the camera body, and can be easily moved even when external forces are applied to the photographic optical system and shutter device. It is an object of the present invention to provide a variable focus camera having a lens barrel part that does not have a negative effect on the camera.

[Summary of the Invention] In order to achieve the above object, the present invention includes a sub-optical system on the back side of a base plate that is movable along the photographing optical axis, and an optical system that inserts and removes the sub-optical system from the photographing optical axis l. In addition to providing a switching mechanism, the main optical system, shutter unit, and barrier uni-soto that can be opened and closed to cover the front of the main optical system are placed on the front side of one board.
When the outer cylinder covering the main optical system, shutter unit, and barrier unit is attached to the surface of the base plate, the barrier unit is fixed on the base plate independently of the main optical system and shutter unit. The technical point is to configure the system as follows.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a sectional view of a camera according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the configuration of the lens barrel portion in FIG. 1, showing a state in which the main optical system is extended and the sub optical system is inserted in the direction of the photographing optical axis.

In Figure 1, the photographic lenses are main optical system 1 and sub optical system 2.
A main optical system holding frame 3 that holds the main optical system 1 is fixed to a shutter base plate 5 that holds a shutter 4 that also serves as an aperture. Further, this shutter base plate 5 is attached to the surface of a base plate 6 that can move forward and backward in the optical axis direction with machine screws 7. Furthermore, a barrier unit 8 is provided on the surface of the base plate 6 so as to be sandwiched between the outer cylinder 9 and the base plate 6. Front 118 installed at predetermined intervals on
A lens barrier 8 that is openable and closable between B and 1
C, each has a protrusion 8 at the tip of the three legs 8a.
b, and the protrusions 8b are formed into five protrusions so as to fit into notch grooves 6b provided on the side surfaces of the three posts 6a formed to protrude from the surface of the base plate 60, as shown in FIG. ing.

An escape groove 5a is provided on the shutter ivy base plate 5 at a portion corresponding to the post 6 & of the single plate 6. There is. Further, the outer shape of the shutter base plate 5 is formed into a circular shape that is slightly smaller than the inner diameter of the cylindrical outer tube 9 (second
(see figure).

The sub-optical system 2 is held by a sub-optical system holding frame 11 that is swingably provided along the back surface of the base plate 6, as shown in FIG.

It is driven by a sub-optical system switching mechanism 12 driven by a reversible motor M provided on the back surface of the base plate 6.

When the main optical system 1 is moved in the optical axis direction beyond the distance adjustment range, the sub optical system 2 is inserted on the photographing optical axis or is moved to a retracted position outside the optical axis shown by the two-dot chain line in Fig. 3. It is configured to be displaced up to Furthermore, the base plate 6 is connected to the base plate 6 in the optical axis direction via a feeding mechanism 13 driven by a motor M.
A companion feed screw shaft 14 passes through the second shaft, and a guide shaft 15,16 for guiding its forward and backward movement also passes through the second shaft.
As shown in the figure, they penetrate through each of them. The small feed screw shaft 1
4 and guide shafts 15 and 16 are both fixedly installed between the camera body 17 and the dark box 18 shown in FIG. The outer periphery of the outer cylinder 9, which is movable in the optical axis direction together with the one plate 6, is fitted with a dark box 18 fixed to the camera body 17, and the outer periphery of the camera body 17 and the dark box 18 is surrounded by an outer cover 19. covered with.

Since the embodiment shown in FIG. It is placed on the surface of the base plate 5 so as not to come into contact with the bosses 6a of 6, and is attached to the base plate 5 with machine screws 7. A main optical system holding frame 3Fi that holds the main optical system 1 is fixedly attached to the main optical system base plate 5 thereof.

In that case, the central cylindrical portion of the shaft base plate 5 to which the main optical system holding frame 3 is attached is thick in the optical axis direction.

Therefore, there is no risk that the shutter base plate 5 will be deformed.

The installation of the main optical system 1 does not affect the accuracy of the optical system.

Next, the rear i8A, the front ring 8B and the lens barrier 8Ct-
A barrier uni soto 8 including the barrier uni soto 8 is attached to the base plate 6. At this time, the legs 8a of the rear ring 8A do not touch the shaft/lid base plate 5 and the main optical system holding frame 3 at all. Therefore, even if an external force is applied to the barrier unit 8, there is no fear that the shutter accuracy will be disturbed. Also, the end of the leg 8a of the rear layer 8A is connected to the boss 6a of the base plate 6.

The leg 8a is inserted into the notch groove 6b provided in the post 6a on the base plate 6.
This is done by inserting the protrusion 8b provided at the tip without any play. Then, attach the outer cylinder 9 to the barrier unit 8.
The assembly work on the front side of the base plate 6 is completed by covering the outer periphery of the base plate 6 and fixing it to the base plate 6 with machine screws 10. When this barrier unit 8 is fixed to the base plate 6, the outer circumferential surface of the leg 8a fits into the inner circumferential surface of the outer tube 9, so the movement of the leg 8a in the radial direction about the optical axis is controlled by the outer tube 9. suppressed.

Further, the movement of the barrier unit 8 in the optical axis direction is caused by the front edge 9a of the outer tube 9 pressing down on the front section 8B.

This is suppressed by the tip of the leg 8a coming into pressure contact with the end surface of the boss 6a. Therefore, no special screws or the like are required to fix the barrier unit 80 to the base plate 6.

Assembly work can be done quickly and easily.

On the other hand, optical system drive devices 12 and 13 including a sub-optical system holding frame that holds two sub-optical systems and a reversible motor M require a large space.

It is attached to the back surface of the base plate 6. Therefore, these assembly operations can be performed independently of the installation of the main optical system 1, the shutter unit including the shutter 9 and the shutter plate 5, and the barrier unit/soto 8, etc., which are provided on the front side of one plate. It is possible to increase the level of ability.

In the above embodiment, the movement of the base plate lO in the optical axis direction and the swinging of the sub-optical system holding frame 11 are performed by a reversible motor, but the base plate can be moved manually. The sub optical system may be configured to be inserted into and removed from the original axis in conjunction with this movement.

The optical system switching mechanism for inserting and removing the optical system on the optical axis is provided on the back side of the base plate, and the shutter unit and barrier unit provided inside the outer cylinder are each independently fixed directly on the base plate, so the barrier The forward force of the unit and the external force applied to the outer cylinder are not directly transmitted to the shutter unit and the main optical system.

Therefore, there is no fear that shutter accuracy or optical performance will be disrupted. In addition, the barrier unit is fixed to the base plate at the same time as the outer cylinder is fixed, and since the outer cylinder does not enclose the sub-optical system holding frame, the external cylinder can be small and compact, and assembly can be quick and easy. It has the advantage of being easy.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of the present invention, Figure 2 is an exploded perspective view showing the configuration of the lens barrel section in Figure 1, and Figure 3 is a view of the base plate in Figure 1 from the back side. FIG. [Explanation of symbols of main parts] 1...Main optical system, 2...Sub-optical system. 3...Main optical system holding frame. 6... Base plate-6a... Boss. 9...Outer tube, 11.Old...Sub-optical system holding frame. 12...Optical system switching mechanism.

Claims (3)

[Claims] (1) A camera with a photographing optical system whose focal length can be changed by advancing the main optical system along the photographing optical axis and inserting the sub optical system onto the photographing optical axis from a retracted position outside the photographing optical axis. The sub-optical system and an optical system switching mechanism for inserting and removing the sub-optical system on the photographing optical axis are provided on the back side of the base plate movable along the photographing optical axis, and the surface of the base plate is The main optical system and the shutter unit, an openable and closable barrier unit that covers the front surface of the main optical system, and an outer cylinder that covers the outer periphery of the main optical system, the shutter unit, and the barrier unit are disposed on the side. . A variable focus camera equipped with a lens barrier, wherein the barrier unit and the outer tube are configured such that the main optical system and the shutter unit are each independently fixed on the base plate. (2) The barrier unit includes a lens barrier 8C, a front ring 8B, and a rear ring 8A that sandwich the lens barrier 8C, and the rear ring 8A is connected to the base plate 8 through a plurality of legs 8a extending in the optical axis direction. A variable focus camera equipped with a lens barrier according to claim 1, characterized in that the camera is configured to be directly connected to a lens barrier. (3) A patent characterized in that the barrier unit (8) is configured to be fixed to the base plate (6) at the same time when the outer cylinder (9) is attached to the base plate (6). A variable focus camera comprising the lens barrier according to claim 1 or 2.