JP2756312B2 - Optical means operation setting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an optical device operation setting device for setting an optical device such as a photographic lens at a desired position.

2. Description of the Related Art Conventionally, as an operating device of a camera for moving and stopping an optical member, a helicoid provided on the outer periphery of a taking lens barrel is helicoid-coupled to a lens frame, and the taking lens barrel is connected to a spring or a motor. The photographic lens barrel is moved in the direction of the optical axis by the rotational driving of the photographic lens barrel. The configuration was such that it was engaged and held at the focal position.

As another method, a photographing lens barrel is held on a lens frame by a support bar that slidably holds in the optical axis direction, and the photographing lens barrel is driven by a cam ring having a lift amount in the optical axis direction. In this case, the focusing operation is performed.

However, in the former case, high dimensional accuracy is required for parts due to the presence of helicoids in the photographing lens barrel and lens frame. In some cases, it is necessary to use metal helicoids, which increases costs. Had become.

In the latter conventional lens, a slight play is required between the taking lens barrel and the support bar in order to hold the taking lens barrel slidably in the optical axis direction. The tilt of the lens barrel causes a tilt of the photographing lens optical system and adversely affects the optical performance. Therefore, in order to minimize the inclination of the lens barrel due to the backlash, the above-mentioned object has been achieved by increasing the fitting length between the support bar and the taking lens barrel. This has the disadvantage of increasing the size of the device.

In addition, in any of the above configurations, in general, the focusing point is evaluated at a position that falls within the permissible circle of confusion, and the locking claw is inserted into the locked tooth that conforms to the value. The focus position of the lens barrel is controlled. For this reason, there is a drawback that a photograph taken at the very end of the circle of allowable confusion cannot be greatly enlarged in consideration of the effect of blurring due to defocus during printing.

[Object of the Invention] The present invention has been made in view of the above circumstances, and generates a driving force acting on the optical means in a non-contact manner in the optical axis direction of the optical means to move the optical means in the optical axis direction. Driving means for moving, moving means for moving integrally with the optical means, and holding means for holding the optical means while holding the optical means while the optical means is moved to a desired position by the driving means And a driving unit that generates a driving force acting on the optical unit in a non-contact manner in the optical axis direction of the optical unit to move the optical unit in the optical axis direction, a fixing unit, and the optical unit. And holding means for holding the optical means while holding the optical means in a state where the optical means is moved to a desired position by the driving means. Light that can be set with high precision in the position It is intended to provide a learning device operation setting device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view of an automatic focusing apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a photographing lens barrel, 2 denotes a photographing lens as an optical member, and 3 denotes a photographing lens parallel to the optical axis. None, a held member as an interlocking member fixed to the taking lens barrel 1. The downwardly projecting portion 3a in FIG. 1 of the held member 3 is a holding portion of the holding members 4 and 5 as holding means.
It is pinched or released as required by 4a and 5a. The holding members 4 and 5 are fixed to the screw portion 5b of the holding member 5 through mounting holes (not shown) through the through holes 4b of the holding member 4 to constitute a holding mechanism as a whole. An implanting pin for positioning is arranged below the holding member 4 in the figure, and the pin is fitted into a fitting hole 5c of the holding member 5. An eccentric pin 6 is rotatably supported in the other through hole 4c of the holding member 4 so that a downwardly projecting pin of the eccentric pin 6 is fitted into a fitting hole 5d of the holding member 5. . When the eccentric pin 6 is rotated, the holding member 4 rotates about the downward projecting pin fitted in the fitting hole 5c of the holding member 5 described above. As a result, the amount of clearance between the holding portions 4a and 5a changes, so that the holding member 3 can be held with an appropriate pressurization during assembly, and the photographing lens barrel can be stably held. At this time, the pressurization is generated by the elastic force of the neck 4f of the holding member 4.

A laminated piezoelectric element 7 indicated by a dashed line in FIG. 1 is fixed to the concave portion 4d of the holding member 4. Laminated piezoelectric element 7
As is well known, is an actuator whose dimension in the longitudinal direction changes when a voltage is applied between the electrodes (extends in the longitudinal direction when a voltage is applied). When a voltage is applied to the laminated piezoelectric element, the holding member 4 receives the extension by the wall 4e, and as a result, the holding portion 4a rotates around the neck 4f in the direction of the arrow in FIG. As a result, the clearance between the holding portions 4a and 5a increases, and the holding of the held member 3 is released.
And can move freely in the optical axis direction of the lens.

Reference numeral 9 denotes a voice coil unit which is fixed to the mounting portion 1b of the photographing lens barrel 1 and has a coil 10 wound around a coil winding portion and inserted into an opening 11a of a yoke 11. A permanent magnet is disposed in the camera, and the magnetic force of the permanent magnet acts on the current flowing through the coil 10 provided in the voice coil unit to move the photographing lens barrel upward in FIG. It constitutes driving means.

Reference numeral 12 denotes a base plate on which the holding member 5, the yoke 11, and the guide bar 8 are mounted, and 13 denotes an upper base plate. 14 is located between the taking lens barrel 1 and the upper base plate 13 with the upper part 3b of the held member 3 in the drawing and the guide bar 8 as guide rods at the time of assembly, and the taking lens barrel 1 is attached to the upper base plate 13 in the drawing. Is a spring for urging downward.

 Next, the operation of the above configuration will be described.

First, in the initial state, no voltage is applied to the multilayer piezoelectric element 7, and the longitudinal dimension of the element 7 is reduced. The holding part 4a of the holding member 4 holds the held member 3 with a certain pressurization between the holding part 4a and the holding part 5a as described above. Therefore, the photographing lens barrel 1 is located at the lower end in FIG. 1 in the initial state, and the held member 3 is stably held by the holding members 4 and 5.

Next, when a voltage is applied to the multilayer piezoelectric element 7, the dimensions of the element change as described above, and as a result, the holding state of the holding member is released. At this time, the taking lens barrel 1
Is movable in the optical axis direction by being guided by the guide bar 8, but maintains the initial state due to the urging force of the spring 14.

From this state, the coil 10 is energized in the direction in which the lens barrel 1 moves so as to drive the photographing lens barrel to a focal point by a focus adjustment signal obtained by a known method.
By this energization, the photographic lens barrel 1 starts to move upward in FIG. 1, but in order to measure the amount of protrusion of the barrel, the light receiving element array 15 as shown in FIG. The light receiving element array 15 is attached to the holding portion 1c (see FIG. 1) of the tube 1 and moves in the vertical direction in FIG. In FIG. 2, reference numeral 16 denotes an infrared light emitting diode, and 17 denotes a front surface of the infrared light emitting diode, and a horizontal slit is formed at a central portion thereof. 9 is a slit sheet for projecting onto the elements of the element array 15. The infrared light emitting diode 16 and the slit sheet 17 are mounted on a holder 18 and fixed to the base plate 12 shown in FIG.

With the configuration described above, the position of the taking lens barrel is measured, and the amount of power to the coil 10 is controlled while comparing this value with the target value. When the shooting lens barrel reaches a target value, the lower biasing force of the spring 14 and the upper drive of the barrel by energizing the coil are balanced, and the shooting lens barrel is in a parallel state at the in-focus position. keep.

When the above state is reached, when the voltage application to the multilayer piezoelectric element 7 is stopped and both electrodes of the element 7 are short-circuited, the dimension in the longitudinal direction is reduced. The member 3 is held by being rotated clockwise in FIG. 1 around the neck 4f by force to reduce the clearance between the holding portions 4a and 5a.

With the above movement, the taking lens barrel 1 is stably held at the focal point. At this time, the holding force of the holding member is adjusted so that the holding force of the holding portion is stronger than the downward urging force of the spring 14 of the shooting lens barrel, so that the shooting lens barrel 1 is shown in FIG. It is kept stable without slipping downward.

Thus, the focusing operation of the present apparatus is completed, and then the sequence shifts to a known exposure operation. When the exposure operation is completed, the photographing lens barrel is returned to the initial position by the downward biasing force of the spring 14 by energizing and short-circuiting the multilayer piezoelectric element 7, and then the holding members 4, 5 are again returned. As a result, the held portion is held, thereby returning to the initial state.

Thereafter, the camera winds up the influence film by a known method, and the preparation for the next photographing is completed.

FIG. 3 is a plan view of a main part of an automatic focusing apparatus according to another embodiment of the present invention. Reference numeral 19 denotes a holding member fixed to the base plate 1 shown in FIG. 1, which corresponds to the holding member 5. Reference numeral 20 denotes another holding member which is made of a ferromagnetic material and is rotatably supported about a shaft 20a by a pin 12a provided on the base plate. This is a holding member 4 in the first embodiment. Is equivalent to The held portion 3 fixed to the photographic lens barrel 1 is held between the holding portion 20 and the holding portions 20b and 19a of the holding member 19 by the action of the spring 21. Reference numeral 22 denotes an electromagnet, which is a coil prior to the focusing operation.
By energizing 22a, the attracted portion 20c of the holding member 20 is attracted to the distal end portion 22b of the electromagnet 22 against the urging force of the spring 21 so that the shaft 20a of the holding member 20 is rotated about the center of the timepiece in the figure. Then, the holding member 3 is released by holding the holding member 3 by the urging force of the spring 21 by turning off the coil 22a simultaneously with the end of the focusing operation.

Configurations other than those described above are the same as those of the first embodiment, and thus description thereof will be omitted.

FIG. 4 is a plan view of a main part of an automatic focusing apparatus according to a third embodiment of the present invention. Reference numeral 23 denotes a well-known bimorph type piezoelectric element, the end 23a of which is fixed to the base plate 12, and the other end 23b.
Is engaged with the engaged portion 1d of the taking lens barrel 1 and energizes the bimorph type piezoelectric element 23, so that the taking lens barrel 1 is driven in the optical axis direction by the driving force of the piezoelectric element 23, The movement in the direction perpendicular to the paper of the figure is enabled. In the present embodiment, since the configuration other than the above is the same as that of the embodiment of FIG. 1, the description thereof is omitted.

In the above embodiment, the held member 3 moves integrally with the photographing lens, and the holding members 4 and 5 are fixed to the base plate. However, the present invention can be applied even if these are reversed. Needless to say.

In the above embodiment, the holding of the photographic lens barrel is released by applying a driving force. However, it is also possible to adopt a configuration in which the photographic lens barrel is held by applying a driving force. Good.

Further, although the above embodiment shows a case where the present invention is applied to an automatic focusing apparatus, it goes without saying that the present invention can be applied to an actuator for other optical members as well.

[Correspondence between the Invention and the Embodiment] In the above embodiment, the voice coil unit 9, the coil 10, and the yoke 11 are used as the driving means of the present invention,
The holding member 4, the moving means of the present invention, or the fixing means,
5, 19 and 20 correspond to the holding means of the present invention, respectively.

[Effects of the Invention] As described above, according to the present invention, the optical unit can be set at a desired position with high accuracy with a simple configuration.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an automatic focusing apparatus according to a first embodiment of the present invention, and FIG. 2 is a sensor unit for measuring the amount of protrusion of a taking lens barrel 1 according to the embodiment of the present invention. FIG. 3 is an exploded perspective view, FIG. 3 is a top view of a main part of an automatic focus adjusting device showing a second embodiment of the present invention, and FIG. 4 is a top view of a main part of the automatic focus adjusting device showing a third embodiment of the present invention. FIG. 1 is a taking lens barrel 2 is a taking lens 3 is a held member 4, 5, 19, and 20 is a holding member 6 is an eccentric pin 7 is a laminated piezoelectric element 8 is a guide bar 9 is a voice coil unit 10 is a coil 11 Yoke 12 Base plate 13 Upper base plate 14 Spring 15 Light receiving element array 16 Infrared light emitting diode 17 Slit sheet 18 Holder 21 Spring 22 Electromagnet 23 Bimorph type piezoelectric element

Claims (2)

(57) [Claims] 1. A driving means for generating a driving force acting on the optical means in a non-contact manner in the optical axis direction of the optical means to move the optical means in the optical axis direction, and a movement moving integrally with the optical means. And a holding means for holding the moving means while holding the moving means in a state where the moving means is moved to a desired position by the driving means. 2. A driving unit for generating a driving force acting on the optical unit in a non-contact manner in the optical axis direction of the optical unit to move the optical unit in the optical axis direction, a fixing unit, and the optical unit. Holding means for holding the optical means while holding the optical means in a state where the optical means has been moved to a desired position by the driving means. .