JPS60221733A - Electromagnetically operated feather shutter for camera - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens shutter for a photographic camera, in which the shutter blades are rotated by an electromagnetic force against the force of a spring means, thereby It is set in a first position to allow light to pass through for exposure of the photosensitive material. The shutter further includes an armature made of a "soft" magnetic material and arranged rotatably about the optical axis.

This shutter is particularly suitable for use in photographic cameras employed in microscopic systems.

[1st row 1F The use of electromagnets or permanent magnets to operate shutters and apertures is discouraged. German Patent Application No. 2017467 (Prontor) describes a diaphragm vane guide ring rotatable around the optical axis, which is actuated by a compact individual attraction magnet via a lever system. It is.

This technical solution contains many drawbacks. In order to keep frictional losses and unavoidable vibrations as low as possible, various components are required, which makes the structure bulky and complex.

U.S. Pat. No. 2,861,506 describes self-adjusting means for a diaphragm in which the necessary force is provided by the magnetic field of a permanent magnet or an electromagnet. This device is bulky based on the shape and dimensions of the driving and driven parts, and even if it uses a large number of magnetic poles, it is unsuitable for use as a photographic shutter that requires an ultra-high shutter time. It is.

German Patent No. 2,738,824 describes an electromagnetically actuated shutter in which a pair of magnet coils are combined via permanent magnets to a vane actuating ring to actuate it.

German Patent No. 2,853,232 describes an electrically driven system using a centrally located toroidal coil in order to better extract the electrical energy and increase the magnetic and mechanical efficiency.

All of the above-mentioned devices have the following features in common, which are clearly disadvantageous as will be described later.

In order to obtain a suitable operating mode for this vane shutter, it is necessary to combine permanent magnets with "soft" magnetic iron and coils, or to employ electromagnetic coils of considerable bulk.

Moreover, the use of different elastic members and stops and the different diameters of the moving parts make the device non-symmetrical, which requires different stable mounting members.

However, if these components are placed in different locations near the axis of rotation, they will involve different forces transverse to the optical axis, which is particularly disadvantageous and can lead to significant drawbacks.

is still One of the objects of the invention is to eliminate the above-mentioned drawbacks.

Another object of the invention is to provide a compact and simple shutter for use in microphotographic equipment.

Another object of the invention is to provide an electromagnetically actuated vane shutter which has significantly fewer moving components and which does not use permanent magnets and which allows for economical manufacture.

Another object of the invention is to provide an electromagnetic vane shutter which, due to its shape, ensures an optimum flow of the magnetic flux of the electromagnetic coil in which it is used from the pole piece to each pole of the armature. It is to be.

Yet another object of the invention is to provide a means for substantially eliminating the effects of stray magnetic fields on each shutter blade in an electromagnetic shutter.

These and other objects are realized in an electromagnetically actuated vane shutter that includes an armature of 9' soft magnetic material symmetrically about the optical axis.

The armature used in the present invention for configuration I of the invention has a magnetic pole "protrusion".
has an outwardly extending annular shape, and this armature 17- is fixed to a vane actuating ring having a similar shape but made of non-magnetic material. This blade actuation ring is provided with several means for actuating the shutter blades. An annular magnetic field ring is provided coaxially and radially adjacent to the armature, and has a magnetic pole piece that encloses the armature and extends from its inner surface in a direction opposite to the magnetic pole toward the optical axis. are doing. The same number of pole pieces and poles are provided on the annular magnetic field ring and on the armature, respectively.

Preferably, the pole pieces are radial protrusions about twice the width of the pole and are each surrounded by a coil for energizing each pole piece. A portion of each pole piece protrusion projects beyond each pole to the armature itself and is provided with an abutment surface for the face of each adjacent pole.

The abutment surfaces of the magnetic pole pieces and the abutment surfaces of the corresponding magnetic poles are □ parallel to each other when they substantially contact each other.

Preferably, means are provided to prevent the abutting surfaces from "sticking" to each other.

Advantageously, each pole piece tapers towards the light.

Advantageously, a protective ring is provided between each blade of the shutter and the armature to eliminate the influence of stray magnetic fields on the shutter blades, the material of this protective ring being selected from soft magnetic iron. It is better.

Furthermore, some means are provided for returning each shutter blade to its original position after the electromagnetic actuation has ended and the exposure operation has been completed.

The configuration of the electromagnetically actuated vane shutter provided by the invention makes it possible to use an even number of electromagnetic coils of significantly smaller volume. These coils are coupled in parallel or in series such that the magnetic polarity of adjacent pole pieces varies between positive and negative. That is, the annular magnetic field ring, the pole piece, and each electromagnetic coil used to rotate the armature by each magnetic pole are magnetically optimally combined, so that the armature made of this soft magnetic material has a technically favorable symmetrical shape. Moreover, it can be formed in a closed shape. Furthermore, the annular magnetic field ring having the magnetic core and pole pieces is completely closed and symmetrical for magnetic feedback.

The stepped embodiment of each magnetic pole of the armature and of the pole piece provides an optimized course of the magnetic field lines and thus a very rapid actuation of the diaphragm shutter. The transverse thrust and longitudinal feed, each applied by a corresponding magnetic field, simultaneously impart a rotational moment to the armature.

All magnetic force components resulting from the excitation of the coils and which do not contribute to the rotational moment of the armature are compensated by the symmetrical magnetic circuit coupling and arrangement of this all-magnetic drive system. There is no frictional force in the armature bearing provided by magnetic forces.

It is a further advantage that in the device according to the invention the magnetic flux is directed substantially in a plane parallel to the plane defined by the shutter blades. Residual stray magnetic fields are removed by the previously described guard ring of soft magnetic material.

BRIEF DESCRIPTION OF THE DRAWINGS In order to make the invention easier to understand, it will be explained in more detail below by way of example with reference to the accompanying drawings, which schematically show embodiments of shutters according to the invention.

Support 1 The electromagnetically actuated shutter shown in FIG. 1 consists of a cylindrical housing 1 having a base plate or rear plate 1'. A cylindrical shaft or socket 2 is attached to the base plate 1' in a central portion of the base plate symmetrically around an axis X--X which forms the optical axis of the shutter. The inside of this cylindrical shaft 2 has an opening 2'' for the optical path. The wall 1'' of the cylindrical housing and the wall 2' of the cylindrical shaft are arranged coaxially with the optical axis X-X at a distance of This allows insertion of various constituent members to be described later. An annular magnetic field ring 5 is provided to fit into the housing 1 coaxially with the axis
’ is fixed.

Fixing screws are omitted for simplicity. This annular magnetic field ring 5 has four protrusions 111.172.173.17
4, which are provided on the inner surface of the annular magnetic field ring 5 at regular intervals and extend radially inward toward the optical axis XX. These projections 171.172
．． 113 , 114 are respectively surrounded by electromagnetic coils or wires 181 , 182 , 183 and 184 , respectively, which are electrically coupled to a power source 185 via conductors 186 .

The visible portions of each of the protrusions 171, 172, 173, 174 have opposite shapes and form pole pieces.

An annular armature 11 is mounted on the cylindrical shaft 2 with an inner surface 11
′ is arranged coaxially with the optical axis ×−×.

Protruding magnetic poles 12 are arranged on the outer peripheral surface t of the armature 11, and the number and symmetry of these magnetic poles are the same as the number and symmetry of the pole pieces 171, 172, 173, and 174.

The gap between the armature 11 and the annular field ring 5 allows rotation of the former within the latter. Pole piece 171.172.
173 and 174 each has a contact surface or a stop surface (1
7' are shown), and these surfaces serve, in addition to magnetic attraction, to restrain the movement of each pole 12.

The annular armature 11 is composed of a circular first ring 10 (not shown), the armature 11 itself, and a shutter blade actuating ring 9 with a plurality of pins 13, the line of which is connected to the light It extends parallel to the axis X--X and is used to move the shutter blade 14.

A return spring 15 is connected at one end to the armature 11 and at the other end to the cylindrical housing 1, the details of which are not shown. The annular shutter blade mounting is such that the member 7 is provided in the cylindrical housing 1 coaxially with and in close contact with the shutter blade actuating ring 9, at a distance defined by the spacer 4 with respect to the base plate 1'. ing.

The annular mounting element 7 consists of a magnetic protection ring 6 adjacent to the armature 11 and the mounting element 7 itself, which is slightly wider in the radial direction than this protection ring 6. For mounting, member 7 is provided with slots 13'' (only one of which is shown);
This includes pins 1 in respective slots 13' provided in each of the vanes 14 (only four are shown).
3 is allowed to enter. Each vane is rotatably arranged via a respective stud 14' fixed to the annular mounting member 7.

Furthermore, a perforation 3' is provided in the member 7 and the protective ring 6, in which each of the previously mentioned configurations is provided in the cylindrical housing 1, which is closed by a cover plate 8. A screw 3 used for fixing the member can be inserted.

Next, the operation of this electromagnetically actuated shutter will be explained with reference to FIG. 1 and FIGS. 2 and 3, in which the same numerals indicate the same or corresponding parts.

2 and 3 are front views of the shutter shown in FIG. 1, with cover plate 8 removed.

In FIG. 2 the shutter is shown in its initial position, ie the light path (shutter) is closed by the blades 14. Each magnetic pole 12 contacts a stopper 16 that limits the range of rotation of the armature 11 in one direction (counterclockwise direction).

Switch 20 is open, so coil 18 is not energized by power supply 185. Annular magnetic field ring 5 and pole piece 111.172.173.17
Since the material of 4 is a soft magnetic material, no magnetic force is applied, so each magnetic pole 12 has a pole piece 111, 112 .
173 and 174 are not attracted.

The return spring 15 is also in the "relaxed" position.

A shutter is opened by closing switch 20, which energizes each coil 181, 182, 183, 184 that is series coupled to power supply 185.

This creates a magnetic field and the armature 11
are adjacent pole pieces 111 .
By being attracted to 112, 113 and 114,
rotated in a clockwise direction.

The armature 11 thus pivots on the cylindrical shaft 2 until each pole 12 abuts against the contact surface (only 17' is shown) of the respective pole piece 171 to 114.

The movement of each vane 14 is brought about by the armature 11 via a pin 13 and a stud 14', i.e. the light path blocking part of each vane 14 is rotated around said stud 14' to space the light path 2''. At the same time, the return spring 15 is tensioned.The optical path 2'' is opened to expose the photosensitive material (not shown) for the required time. After this exposure, power supply 185 is disconnected from electromagnetic coil 18 by actuation of switch 20, thereby extinguishing the magnetic field.

The armature 11 is rotated back by the return spring 15, so that the platform shutter blade 14 is rotated back to the closed" position.

In FIGS. 1 and 3, the shutter is shown in the "open" condition.

In order to explain the excellent effects peculiar to the shutter device according to the present invention, FIG. . Power supply 18 by switch 20
5 is coupled to each electromagnetic coil 18 connected in series. Parallel connection is also possible.

The armature 11 and the annular magnetic field ring 5 are pole pieces 17
1 to 174, made of soft magnetic or non-coercive material, which is A kadell+5chen
Verein Huette E, V, Berli
“Huette” No. 28 published in 1955 by n.
ed., page 289, lines 5 to 10, the material is such that the hysteresis curve loop approximately becomes a single curve.

Under the action of each energized coil 181 to 184, N and S poles are formed alternately at the pole pieces 111 to 174 and in parts of the iron cores 171' to 174', not shown, and each The magnetic field line FL is 4
Two closed loops L1, L2, La.

L4, these loops act only in the same direction (only part of which is shown by the dotted line) and never in opposite directions (pole piece 1
71 to 174 and magnetic poles 121 to 124), however, in the annular magnetic field ring 5, the lines of magnetic force of the loop L1 are opposite to those of the loop L2, and those of the loop La are opposite to those of the loop L4.

At the beginning of the rotational movement of the armature 11 relative to the annular magnetic field ring 5, there are magnetic poles 121 to 124 and a pole piece.
Between each of 171 to 174 there is a magnetic flux flow (not shown), similar to that between the stator and rotor of an electric motor, for example. Due to the force exerted by this magnetic flux, the armature 11 is absorbed in the direction indicated by the arrow. The tangential direction component of the magnetic force acting on this armature 11 is the magnetic pole 121 to 1.
24 decreases at an equal rate as it approaches the tangential plane of the corresponding pole pieces 171 to 174. At the same time, the radial surfaces of the pole pieces 171 to 174 (abutment surfaces 1 in FIG.
1') and the opposite radial surfaces of the corresponding magnetic poles 121 to 124 are reduced so that the pole pieces 171 to 174 act as attractive magnets and their attractive force is reduced between them. increases with decreasing air gap. Therefore, changes in the magnetic force occur in a virtually continuous course for the entire shutter operation process. The resulting stray magnetic fields are suppressed by the inclined surfaces of the pole pieces 171 to 174 on the opposite side from the radial surface (17').

Furthermore, magnetic forces that would inhibit the operation of each shutter blade due to magnetic adhesion are removed by the shielding effect of the protective ring 6, which collects residual stray magnetic fields due to its soft magnetic properties. .

The armature 11 rests on a vane actuation ring 9 made of non-magnetic material (such as aluminum), so that each bottle 13 does not come into contact with this soft-magnetic armature 11.

The present invention is not limited to the specific examples described above.

Pole pieces 171-174 may have any other suitable shape, and the respective mating poles 11 may also have respective matching IC shapes, such as those shown in FIG. 5, for example.

It is also possible to attach each coil 181 to 184 to any other suitable part of the annular magnetic field ring 5.

The number of coils, pole pieces, and magnetic poles is also arbitrary, provided that each of them must satisfy the condition of 2n (n is an appropriate integer).

Additionally, switch 10 may be configured as any suitable switching means ranging from a manual switch to a computer-controlled timing circuit.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of an example of an electromagnetically actuated shutter according to the present invention, and FIGS. 2 and 3 are partially cutaway front views of the shutter in FIG. 1 in the "closed" and "open" states, respectively. 4 shows the state of magnetic flux flow inside the armature and annular magnetic field ring of this electromagnetically actuated shutter, and FIG. 5 shows another specific example of the pole piece. 1...Housing 2...Socket 1'...Base plate 1'', 2'...Wall 2''...Opening 3'...Drilling 4...Spacer 5...Magnetic field ring 5' ...Protrusion 6...Protection ring 7...Blade attachment is member 8...Cover plate 9...Blade operating ring 11...Armature 12.121.122.123.124...Magnetic pole 13
...Pin 13'13'' ...Slot 14...
・Blade 14'...Stud 15...Return spring
16... Stopper 17'... Contact surface 18.181.182.183.184... Coil 2
0...Switch +71.172.173.174...Pole piece 185
Conflict - Power supply Ll, L2, La, L4...Magnetic field line procedure Neil
Official document (spontaneous) January 30, 1985 Title Heb Karl Zeis Jena 6 Subject of amendment Drawing procedure amendment document May 23, 1985 Commissioner of the Patent Office Electromagnetic operation for cameras Type-blade shutter Nationality: German Democratic Republic 6, Subject of amendment: Ming*si 7, Contents of amendment

Claims (4)

[Claims] (1) An electromagnetically actuated vane shutter for use in a camera mounted on a microscope, among others, comprising: a rear surface, a cylindrical housing wall, and a housing mounted on the rear surface in a spaced apart and concentric relationship with the housing wall; a cylindrical shutter housing surrounding the optical axis, the housing having a socket having a wall located at the rear surface thereof, the socket being configured to allow light to pass through the rear surface of the socket; an annular armature seated for rotation through its inner surface, the armature having a plurality of magnetic poles on its outer surface; an annular magnetic field ring fixed to said housing and enclosing said armature; This annular magnetic field ring has an even number of magnetic pole pieces protruding toward the optical axis, each of which is provided with a magnetic coil, and the number of these pole pieces and the number of magnetic poles are equal to 2n. (however, n=1.2.3...), each of the above-mentioned pole pieces is combined with one of the magnetic poles adjacent to it, and the above-mentioned pole piece and the above-mentioned the magnetic poles each have abutment surfaces that are parallel to each other when substantial contact is reached, the pole pieces having a wedge-like shape directed toward the optical axis, and means for exciting the magnetic coil; a plurality of shutter blades operatively coupled to said armature and used to open and close a light path, provided that each abutment surface of said pole piece defines a first end position of said armature as said armature rotates; , means for determining a second end position for each magnetic pole of said armature as they rotate; means for returning said armature to said second end position, provided that said annular magnetic field ring is in a state in which said magnet coil is energized; said blade shutter, said blade shutter serving to rotate said armature to said first end position when in said blade shutter, and comprising means for protecting said shutter blades against electromagnetic fields. (2) The blade shutter according to claim 1, wherein the material of the armature and the annular magnetic field ring is selected from soft magnetic materials. (3) The blade shutter according to claim 2, wherein the means for rotating each shutter blade is a circular ring inserted between the shutter blade and the armature, and the ring is made of a soft magnetic material. . (4) The vane according to claim 3, wherein the means for exciting each magnet coil includes a conducting wire connecting the coil and a power source, and a switch means for connecting and disconnecting the power source and the magnet coil. Shitotsuta-0