Camera shutter device with double-arm lever

Abstract

The invention relates to a camera shutter device comprising an optical opening (1) and an electromagnetic drive (2) fixed relative to the optical opening, having a linearly guided moving part, which is fixedly connected in one piece with a first shutter blade (3) to a unit (23). The unit (23) is connected to a drive end (4.1) of a double-armed lever (4) rotatable about an axis of rotation (4.0). A counterweight (5) is present at a driven end (4.2) of the lever (4). A second gravitational force (F2) acting on the counterweight (5) causes a second torque (M2) about the axis of rotation (4.0) of the lever (4), a first gravitational force (F1) acting on the unit (23) causes a first torque (M1), the second torque acting against the first torque.

Description

TECHNICAL FIELD

[0001] The present invention relates to a shutter device for camera modules, for example IR camera modules, in particular for various types of photographic and thermographic instruments, as well as for instruments for measuring the imaging quality of lenses and for calibrating image sensors, which uses electromagnetic forces for opening and closing, as generally referred to in patent document DE 2707175 A1. BACKGROUND

[0002] Shutter devices are used in cameras and optical sensors, which interrupt the light path if necessary. The main challenge in constructing such shutter devices is that the camera modules are increasingly miniaturized, while the requirements for heat generation, positioning time, service life, operating temperature, costs, etc. are increasing. Existing solutions include iris, focal plane shutter or pivot or guide shutter leaves driven electromagnetically or by a motor.

[0003] In infrared or thermographic applications, it is necessary to perform a so-called "Dark Frame Calibration" within certain time intervals to correct certain detector parameters that often drift over time during camera operation. At this point, the shutter device is closed and the resulting dark image is used to correct the offset. In radiometric cameras, such a shutter device can also be used as a temperature reference to improve the measurement accuracy.

[0004] Patent document DE 1447470 A discloses an electromagnetically actuated shutter mechanism, in which there is a certain time interval between the opening pulse and the closing pulse. The shutter element is braked at a certain position by a stop. After the impact, it vibrates due to the remaining kinetic energy. Since the vibrations are transmitted to the sensor, this can lead to errors in the exposure time or to image blurring.

[0005] Patent document CN 202748581 U discloses a shutter device for a camera module, comprising a frame, two shutter leaves, a permanent magnet, a spring, two linear slide structures, an electromagnet and a light transmission area. The two shutter leaves each have two slide tubes, which guide the two shutter leaves between two positions on two linear slide structures arranged parallel to each other, wherein the linear slide structures are configured as guide cylinders. The slide tubes on the shutter leaves are permanent magnets. The electromagnets are each arranged centrally on the guide cylinders and are designed as permanent magnets that attract or repel the slide tubes depending on the polarity, against the force of the compression spring arranged around the guide cylinder. In the de-energized state, the shutter leaves are in a first position, in which they expose the light transmission area and rest against the frame, which acts as a stop. In a second position, the shutter leaves close the light transmission area and slightly overlap each other. The slide tubes rest against the electromagnets under the influence of the magnetic force. Here, the same problem exists, namely that vibrations occur at the end of the shutter element movement.

[0006] A disadvantage of many camera shutter devices of the prior art, in which the shutter blades are moved into two positions by magnetic forces, is that the permanent magnets or ferromagnetic bodies are acted upon by the magnetic field in such a way that their mass is accelerated, and the shutter blades connected thereto are moved directly or indirectly, usually without damping, into the two positions. The shutter blades can bounce back from the end position and unintentionally partially open or close the light beam path again.

[0007] Patent document DE 2642601 C2 discloses an electromagnetically actuated shutter mechanism in which the shutter element opens the exposure opening by an opening pulse and closes the exposure opening by a closing pulse. Here, the impact shock at the reversal point of the shutter element is avoided, since the opening pulse partially overlaps the closing pulse, as a result of which the shutter element releases most of its kinetic energy before it reaches the reversal point.

[0008] Patent document DE 3017893 A1 discloses a camera shutter device having two shutter blades, which are each connected to a linearly guided moving part of an electromagnetic drive by a pivotally arranged connecting member. The shutter blades and their associated moving parts are moved symmetrically in opposite directions about the axis of the pivotally arranged connecting rod. In the case of an axis which is oriented essentially horizontally, the torque on the connecting rod axis, which is generated by the weight of the moving parts, counteracts the torque generated by the weight of the shutter blades. This makes it possible for the respective shutter blade to be moved between the open and closed positions with a relatively small force, since the torques are complementary. Any influences on the stopping of the shutter blades in the two positions are kept to a minimum.

[0009] In the embodiments of the above-mentioned patent document DE 3017893 A1, a double rocker is provided as a guide for the shutter blades, wherein the rocker arms are provided with pins which engage in first slot holes formed at the driven end of the pivotally arranged connecting rod. Second slot holes are formed at the other, driven end of the pivotally arranged connecting rod, and pins present at the moving parts of the magnetic drive engage in these second slot holes. The magnetic force-guided moving parts of the drive and the shutter blades are linearly guided parallel to one another.

[0010] Patent document US 4,171,987 A discloses an electromagnetically operated shutter having two shutter blades. The shutter blades are symmetrically arranged on both sides of the exposure opening and are arranged to be movable in opposite directions along a common linear axis, which is coupled by a connecting rod. The free ends of the shutter blades are each configured as an electromagnetic linear drive. One drive is used to open the shutter, and one drive is used to close the shutter, so that the movement of the shutter blades is also slowed down.

[0011] However, in the de-energized state, the shutter position cannot be determined.

[0012] The patent document GB 2235541 A discloses an electromagnetically operated camera shutter with two shutter blades. Both shutter blades are arranged pivotable about a fulcrum and are connected at a common mounting point to a spring-loaded return lever which is in turn connected to an electromagnetic linear drive. The shutter is opened by means of the electromagnetic linear drive against the spring force of the return lever. A counterweight of the return lever serves to compensate the gravitational force acting on the return lever when operating the shutter. This ensures that the shutter can be operated independently of the position of the camera.

[0013] The above patent document DE 2707175 A1 discloses a camera shutter device comprising an optical opening and an electromagnetic drive fixed relative to the optical opening. A shutter blade is attached to a linear guide part and is movable into an open position exposing the optical opening and into a closed position covering the optical opening. A double-armed lever pivotable about a fulcrum is connected to the linear guide part by means of a drive end and is provided at a driven end with a counterweight. The counterweight generates a torque about the axis of rotation which counteracts the torque caused by the gravitational force. The above shutter device has the disadvantage, inter alia, that a separate motor drive is required for moving both shutter blades. The shutter device is also not stable in the de-energized state, i.e. a jolt or vibration acting in the direction of movement can cause the shutter blades to move out of their respective positions. SUMMARY

[0014] It is an object of the present application to propose a camera shutter device which can be designed more compactly.

[0015] In order to achieve the above object, the present application provides a camera shutter device comprising an optical opening and an electromagnetic drive fixed relative to the optical opening, a first shutter blade and a double-armed lever.

[0016] The electromagnetic drive has a linearly guided movable part.

[0017] The first shutter blade is movable into an open position exposing the optical opening and into a closed position covering the optical opening.

[0018] The double-armed lever is divided by a fulcrum into a drive end and a driven end and is pivotable about the fulcrum within a range of pivot angles. The fulcrum is arranged on a rotation axis fixed relative to the optical opening, and the drive end is connected to the movable part.

[0019] The first shutter blade is fixedly connected as an integral unit to the movable part, and a counterweight is present at the driven end of the double-armed lever. A first torque about the rotation axis caused by a first gravitational force acting on the unit counteracts a second torque about the rotation axis caused by a second gravitational force acting on the counterweight.

[0020] Since the first shutter blade is fixedly connected to the movable part and forms a unit therewith, a counterweight is provided at the drive end of the double-armed lever, a second gravitational force acting on the counterweight causes a second torque about the axis of rotation, which counteracts the first torque caused by the first gravitational force acting on the unit.

[0021] The application focuses on the fact that the camera shutter device has a first permanent magnet having at least one magnetic face and is fixedly arranged in association with the counterweight within a pivoting angle range, so that the counterweight is held in the open position and the closed position by the magnetic force of the first permanent magnet, or there are a first permanent magnet and a second permanent magnet, each having at least one magnetic face. These permanent magnets are associated with the counterweight so that the counterweight is held in the open position and the closed position by the magnetic force of the first permanent magnet or the second permanent magnet.

[0022] In particular, the counterweight is made of ferromagnetic material, and one of the at least one magnetic face is arranged opposite one of two different surface portions of the outer periphery surface of the counterweight in the open position and the closed position.

[0023] Advantageously, the counterweight is made of ferromagnetic material, and there are at least two magnetic faces, wherein one of the at least two magnetic faces is arranged opposite a surface portion of the inner periphery surface of the counterweight in the open position, and the other of the at least two magnetic faces is arranged opposite another surface portion of the inner periphery surface of the counterweight in the closed position.

[0024] Alternatively, advantageously, the first permanent magnet is attached to the counterweight, and a ferromagnetic armature is arranged within the pivoting angle range, having two end faces facing the counterweight, wherein one of the at least one magnetic face is arranged opposite one of the two end faces in the open position and opposite the other of the two end faces in the closed position.

[0025] In particular, the counterweight is made of ferromagnetic material, and the first permanent magnet and the second permanent magnet are arranged opposite each other outside the pivoting angle range. In the open position, one of the at least one magnetic face of the first permanent magnet is arranged opposite a surface portion of the outer periphery surface of the counterweight, and in the closed position, one of the at least one magnetic face of the second permanent magnet is arranged opposite another surface portion of the outer periphery surface of the counterweight.

[0026] Advantageously, the associated magnetic face and the associated surface portion each mutually enclose a gap in the open position and the closed position, which gap is narrower than any distance of the counterweight to the first permanent magnet or the second permanent magnet during movement between the open position and the closed position.

[0027] The counterweight can advantageously comprise a second shutter blade.

[0028] Advantageously, the second shutter blade is fixedly connected to a linearly guided link, which link forms the counterweight together with the second shutter blade and is rotatably arranged at the drive end of the double-armed lever.

[0029] Advantageously, the electromagnetic drive is a lifting magnet with a coil and a ferromagnetic or permanent magnet armature core, wherein the armature core is attached to the plunger representing the movable part.

[0030] The ratio of the stroke length of the electromagnetic drive to the total length of the camera shutter device in the direction of the stroke length is advantageously greater than 1:2.

[0031] To this end, the coil has a coil former and advantageously at least a two-phase winding, whereby the plunger movement is caused by an attractive force and a repulsive force acting locally in the direction of the stroke length in succession.

[0032] It is particularly advantageous if the coil former represents a linear slide guide for the plunger.

[0033] It is also advantageous if there is a ferromagnetic enclosure surrounding the coil, whereby the magnetic flux generated inside the coil is increased and the stray field generated around the coil is reduced.

[0034] The camera shutter device described in the above-mentioned patent document DE 3017893 A1 is apparently based on the idea of at least partially compensating the weight acting on the movable part of the electric drive unit by a weight acting on the shutter blade. To this end, the movable part and the shutter blade are connected to each other by means of a connecting rod which is arranged pivotable about a fulcrum. The fulcrum is located between two pins on the shutter blade or the movable part, each of which is guided in a slot formed in the connecting rod.

[0035] The present invention is based on the recognition that a camera shutter device can be made more compact and more stable if the shutter blade is directly fixedly connected to the movable part of the electromagnetic drive. A counteracting torque is generated with a counterweight which can also comprise a second shutter blade, thereby allowing a single electromechanical drive to drive one shutter blade as well as two shutter blades. BRIEF DESCRIPTION OF DRAWINGS

[0036] Embodiments of the present invention will be described in the following with reference to the accompanying drawings. In the drawings:

[0037] Figure 1a and Figure 1b a first embodiment of a camera shutter device with a shutter blade is shown, in which a counterweight is pivotable between a first permanent magnet and a second permanent magnet;

[0038] Figure 2a and Figure 2b a second embodiment is shown, in which a counterweight is pivotable relative to a first permanent magnet;

[0039] Figure 3a and Figure 3b a third embodiment is shown, in which a counterweight is pivotable about a first permanent magnet;

[0040] Figure 4a and Figure 4bA fourth embodiment is shown, in which the first permanent magnet is fixedly connected to the counterweight and is pivotable relative to the ferromagnetic armature;

[0041] Figure 5a and Figure 5b A fifth embodiment is shown with two shutter blades.

[0042] Figure 6 A detail view with a lifting magnet and a first shutter blade is shown in an exploded view. DETAILED DESCRIPTION

[0043] In each embodiment, the camera shutter device according to the application comprises an optical opening 1, an electromagnetic drive 2 fixed relative to the optical opening 1 and having a linearly guided movable part, and a first shutter blade 3 forming a unit 23 fixedly connected to the movable part.

[0044] The shutter blade 3 is movable into an open position (see Fig. 1) exposing the optical opening 1 and into a closed position (see Fig. 2) covering the optical opening 1. Furthermore, there is a double-armed lever 4, which is divided at a fulcrum P into a drive end 4.1 and a driven end 4.2 and is pivotable about the fulcrum P within a pivot angle range α. The fulcrum P is arranged on a rotation axis 4.0 fixed relative to the optical opening 1. The drive end 4.1 of the double-armed lever 4 is connected to the movable part by a pivot formed by a pin inserted into a slot hole, and the driven end 4.2 of the double-armed lever 4 is provided with a counterweight 5. Figure 1a and Figure 2a ) and into a closed position (see Figs. 2 and 3) covering the optical opening 1. Furthermore, there is a double-armed lever 4, which is divided at a fulcrum P into a drive end 4.1 and a driven end 4.2 and is pivotable about the fulcrum P within a pivot angle range α. The fulcrum P is arranged on a rotation axis 4.0 fixed relative to the optical opening 1. The drive end 4.1 of the double-armed lever 4 is connected to the movable part by a pivot formed by a pin inserted into a slot hole, and the driven end 4.2 of the double-armed lever 4 is provided with a counterweight 5. Figure 1b and Figure 2b ) and into a closed position (see Figs. 2 and 3) covering the optical opening 1. Furthermore, there is a double-armed lever 4, which is divided at a fulcrum P into a drive end 4.1 and a driven end 4.2 and is pivotable about the fulcrum P within a pivot angle range α. The fulcrum P is arranged on a rotation axis 4.0 fixed relative to the optical opening 1. The drive end 4.1 of the double-armed lever 4 is connected to the movable part by a pivot formed by a pin inserted into a slot hole, and the driven end 4.2 of the double-armed lever 4 is provided with a counterweight 5.

[0045] A first gravitational force Fl acts on the unit 23, mainly determined by the mass of the plunger 8.2 and the first shutter blade 3, and a second gravitational force F2 acts on the counterweight 5, determined by its mass.

[0046] The first gravitational force Fl causes a first torque Ml about the rotation axis 4.0, and the second gravitational force F2 causes a second torque M2 about the rotation axis 4.0, the first torque Ml acting against the second torque M2. The first torque Ml and the second torque M2 are not necessarily constant and of the same size in the open position, in the closed position and during movement between these two positions, but always act in opposite rotational directions and largely compensate each other.

[0047] The optical opening 1 can be an area free of physical constraints through which the radiation impinges on the detector. It can also be an aperture opening or a detector receiving surface. It can be of any shape, for example circular or, as shown in the following embodiments, preferably rectangular. Only the shape of the first shutter blade 3 or the second shutter blade 7 must be adapted to the second embodiment.

[0048] An implementation of a camera shutter device with only a single-piece shutter (hence only a first shutter blade 3) is advantageous for using the camera shutter device for offset adjustment (non-uniformity-correction, NUC) in IR cameras (especially infrared thermal cameras), where the key point is that the shutter briefly closes the optical opening 1 during at least one imaging cycle and has a temperature on its surface that is as precise and uniform as possible. In the case of a two-piece shutter (hence a first shutter blade 3 and a second shutter blade 7), there are inevitably different relative positions within the device with respect to the existing heat source or radiator, and the temperature difference that arises between the first shutter blade 3 and the second shutter blade 7 may make the shutter less suitable for offset adjustment.

[0049] Nevertheless, the implementation with the first shutter blade 3 and the second shutter blade 7 would still be beneficial for other applications.

[0050] For the camera shutter mechanism, which has only the first shutter blade 3 or both the first shutter blade 3 and the second shutter blade 7 as components of the counterweight 5, it is advantageous that the counterweight 5 is equipped with a first permanent magnet 6.1 or a first permanent magnet 6.1 and a second permanent magnet 6.2, so that the counterweight 5 can be held in the open and closed positions by magnetic force when the electromagnetic actuator 2 is de-energized.

[0051] The first permanent magnet 6.1 and the second permanent magnet 6.2 each have at least one magnetic surface 14. For the purposes of this specification, the magnetic surface 14 should be understood as a surface having at least one magnetic pole.

[0052] In the following five embodiments, four implementations are described with reference to the accompanying drawings, each having only a first shutter blade 3 and one implementation having a second shutter blade 7.

[0053] According to such Figure 1a As shown, it is in the open position and as Figure 1b In the first embodiment shown in the closed position, the camera shutter device has only the first shutter blade 3.

[0054] The counterweight 5 is made of ferromagnetic material and has a first permanent magnet 6.1 and a second permanent magnet 6.2, which hold the counterweight 5 in the open or closed position when the electromagnetic actuator 2 is de-energized. Advantageously, the first permanent magnet 6.1 and the second permanent magnet 6.2 are two identical bar magnets with the same holding force and axis of symmetry, and they are aligned parallel to each other in a straight line.

[0055] The counterweight 5 is in the form of a disk, with its center lying on a straight line in both the open and closed positions. The magnetic surface 14 facing the counterweight 5 (here, for example, contains the north or south pole of the first permanent magnet 6.1 or the second permanent magnet 6.2) is typically planar or advantageously a cylindrical cross-section with a radius slightly larger than that of the counterweight 5.

[0056] Advantageously, the first permanent magnet 6.1 and the second permanent magnet 6.2 do not serve as stopper as such, but there is a gap 12 between the counterweight 5 and the first permanent magnet 6.1 or the second permanent magnet 6.2 in the open position and in the closed position. The gap 12 is advantageous to limit the holding force, in particular to prevent wear of the magnetic faces 14. The gap 12 is narrower than any distance of the counterweight 5 from the first permanent magnet 6.1 or the second permanent magnet 6.2 during the movement between the open position and the closed position.

[0057] This statement advantageously also applies to the other embodiments described below.

[0058] Advantageously, the range of pivot angles a is limited by the stroke length or by a mechanical stopper, for example, the active part or the double-armed lever 4 hits. Here, the electromagnetic drive 2 is implemented by a lifting magnet 8 with a coil 8.1 and a ferromagnetic or permanent magnet armature core 8.2.1, which is attached to a plunger 8.2, which here represents the active part of the electromagnetic drive 2.

[0059] The coil 8.1 has a coil carrier 8.1.1, which not only serves as a carrier for the winding 8.1.2, but advantageously also as a sliding guide 10 for the plunger 8.2, as shown in Figure 6 For this purpose, it is lengthened beyond the length provided for accommodating the winding 8.1.2 and is slotted along the lengthened portion. The plunger 8.2, which is fixedly connected to the first shutter blade 3, can slide in the coil carrier 8.1.1. There is no need for any additional components to guide the plunger 8.2.

[0060] The first shutter blade 3, which is fixedly connected to the plunger 8.2, is linearly guided in the direction specified by the movement direction of the armature core 8.2.1 between the open position and the closed position, while the double-armed lever 4 is pivoted about the fixed pivot point P in the range of pivot angles a. The movement of the armature core 8.2.1 takes place over a stroke length, which advantageously is greater than half the overall length of the camera shutter device. The overall length is the maximum extension of the camera shutter device in the movement direction of the armature core 8.2.1. The connection of the double-armed lever 4 to the unit 23 is established with a pin-and-slot connection. As a result, the distance between the point of action of the first gravitational force Fl and the pivot point P changes during the movement, and thus the length of the first lever arm rl also changes, which in turn changes the first torque Ml. The length of the second lever arm r2 remains constant. In addition, both torques Ml, M2 change with the angles Φ1, Φ2. The first torque Ml and the second torque M2 do not necessarily change equally.

[0061] Since the moving part, in this first embodiment the plunger 8.2, is directly connected to the first shutter blade 3, the movement of the armature core 8.2.1 is transmitted with a transmission ratio of 1 : 1. In order to be able to determine a length on the coil former 8.1.1 which is shorter than the movement range of the plunger 8.2 to receive the winding 8.1.2, the winding 8.1.2 is designed as at least a two-phase winding. It can consist of at least two bipolar single windings which are arranged one after the other on the coil former 8.1.1 or of a pair of single windings whose halves are wound in opposite directions. The time- and phase-shifted actuation results in a relatively longer stroke length compared to a coil with only the same length of a single winding. A longer stroke length also occurs when using a permanent-magnetic armature core 8.2.1 and alternatingly using attractive and repulsive forces by reversing the magnetic field direction of the coil 8.1. In the case of a bipolar single winding, the current flows in the reverse direction, in the case of a pair of single windings, one half winding or the other half winding is alternately energized.

[0062] Advantageously, the coil 8.1 is partially or completely surrounded by a ferromagnetic envelope 11, which increases the magnetic flux occurring inside the coil 8.1 and reduces the stray field occurring around the coil 8.1.

[0063] As Figure 2a shown in the open position and as Figure 2a shown in the closed position, the second embodiment differs from the modified first embodiment or implementation described above in that only the first permanent magnet 6.1 is arranged relative to the counterweight 5 and the geometry of the counterweight 5. Here, the counterweight 5 is shaped like a segment of a disc, the outer circumference of which has two planar sections which are at an angle of less than 180° to one another, one of which is in parallel opposition to the same magnetic face 14 of the first permanent magnet 6.1 in the open position or in the closed position. For this purpose, the first permanent magnet 6.1 is arranged within the range of the pivot angle α. Here, the magnetic face 14 is planar.

[0064] As Figure 3a shown in the open position and as Figure 3b shown in the closed position, the third embodiment differs from the second embodiment in the geometry of the counterweight 5. Here, the counterweight 5 is shaped like a spanner, the inner circumference of which exhibits two planar regions. These have the same gap 12 of the same thickness and the same width, each in opposition to one of the planar magnetic faces 14 in the open position or in the closed position. The first permanent magnet 6.1 is arranged within the range of the pivot angle α and within the counterweight 5.

[0065] According to a fourth embodiment, as Figure 4a shown in the open position and as Figure 4b shown in the closed position, the first permanent magnet 6.1 is fixedly attached to the counterweight 5 within the range of the pivot angle α and is oriented radially relative to the fulcrum P, so that the counterweight 5 itself does not have to be made of ferromagnetic material in this case.

[0066] Within the pivot angle range a there is also statically fixedly arranged a ferromagnetic armature 13, which has two flat end faces 13.1 facing the pivot points P. In the open position and in the closed position one of the end faces 13.1 is opposite the same magnetic face 14 and forms the same gap 12.

[0067] In the embodiment, surface portions of the magnetic faces 14, of the end faces 13.1 or of the inner or outer circumferential surface of the weight 5 are described as planar, they can also have other surface shapes, for example cylindrical, conical or spherical portions. It is known to the person skilled in the art that the specific magnetic force course during the movement over the pivot angle range a can be influenced purposefully by the design of the magnetic faces 14.

[0068] According to a fifth embodiment as shown in Figure 5a and Figure 5b the weight 5 comprises a second shutter blade 7. The embodiment differs from the first embodiment only in the design of the weight 5.

[0069] In the first embodiment the weight 5, which is fixedly connected to the driven end 4.2 of the double-arm lever 4 and which in turn moves on a circular path, here moves linearly and orthogonally to the rotation axis 4.0 like the unit 23. For this purpose, it is connected to the driving end 4.1 of the double-arm lever 4 by a pin-slot connection and to the driven end 4.2 of the double-arm lever 4 by a pin-slot connection in a rotationally supported manner, whereby the length of the second lever arm r2 is also changed in the course of the movement. Advantageously, the second shutter blade 7 is fastened to the connecting rod 9, similar to the connection of the first shutter blade 3 to the plunger 8.2. The connecting rod 9 is made of a ferromagnetic material and can therefore be held by the first permanent magnet 6.1 or the second permanent magnet 6.2. Like the plunger 8.2, the connecting rod 9 has a pin which is guided in a slot hole formed in the double-arm lever 4.

[0070] For the linear guidance of the connecting rod 9, a sliding guide 10 is provided. With only one electromagnetic drive 2 the first shutter blade 3 and the second shutter blade 7 are moved simultaneously in opposite directions.

[0071] In particular, the advantageous embodiment of the camera shutter device with only the first shutter blade 3 is significantly more compact compared to the prior art. Advantageously, the holding force is exerted by the first permanent magnet 6.1 and the second permanent magnet 6.2 in the direction of movement of the first shutter blade 3 in the position covering the optical opening 1 or in the position exposing the optical opening 1, ensuring that the first shutter blade 3 remains in a stable position even when an impact or a vibration is acting on the camera shutter device in the direction of movement.

[0072] List of reference signs

[0073] 1 optical opening

[0074] 2 electromagnetic drive

[0075] 3 first shutter blade

[0076] 23 unit

[0077] 4 double-arm lever

[0078] 4.0 rotation axis

[0079] 4.1 drive end

[0080] 4.2 driven end

[0081] 5 counterweight

[0082] 6.1 first permanent magnet

[0083] 6.2 second permanent magnet

[0084] 7 second shutter blade

[0085] 8 lifting magnet

[0086] 8.1 coil

[0087] 8.1.1 coil former

[0088] 8.1 winding

[0089] 8.2 plunger

[0090] 8.2.1 armature core

[0091] 9 connecting rod

[0092] 10 sliding guide

[0093] 11 housing

[0094] 12 gap

[0095] 13 armature

[0096] 13.1 armature end face

[0097] 14 magnetic face

[0098] P pivot point

[0099] a range of swivel angles

[0100] M1 first torque

[0101] M2 second torque

[0102] F1 first gravitational force

[0103] F2 second gravitational force

[0104] Φ1 first angle

[0105] Φ2 second angle

[0106] r1 first lever arm

[0107] r2 second lever arm

Claims

1. A camera shutter device, comprising: Optical opening (1); An electromagnetic actuator (2) is fixed relative to the optical opening (1) and has a linearly guided moving part; The first shutter blade (3) can be moved to an open position that exposes the optical opening (1) and can be moved to a closed position that covers the optical opening (1); And a double-arm lever (4), which is divided into a driving end (4.1) and a driven end (4.2) with a fulcrum (P) and can pivot about the fulcrum (P) within a pivot angle range (α), wherein the fulcrum (P) is arranged on a rotation axis (4.0) fixed relative to the optical opening (1), and the driving end (4.1) is connected to the movable component, wherein the first shutter blade (3) is fixedly connected to the movable component as an integral unit (23), and there is a counterweight (5) at the driven end (4.2) of the double-arm lever (4), wherein a first gravity (F1) acting on the unit (23) causes a first torque (M1), and a second gravity (F2) acting on the counterweight (5) causes a second torque (M2) about the rotation axis (4.0), and the second torque (M2) reacts on the first torque (M1). Its features are, A first permanent magnet (6.1) having at least one magnetic surface (14) is fixedly arranged in association with the counterweight (5) within the pivot angle range (α), thereby holding the counterweight (5) in the open and closed positions by the magnetic force of the first permanent magnet (6.1); or There are a first permanent magnet (6.1) and a second permanent magnet (6.2) each having at least one magnetic surface (14), which are arranged in association with the counterweight (5) to hold the counterweight (5) in the open position by the magnetic force of the first permanent magnet (6.1) and to hold the counterweight (5) in the closed position by the magnetic force of the second permanent magnet (6.2).

2. The camera shutter device according to claim 1, characterized in that, If only the first permanent magnet (6.1) is present, the counterweight (5) is made of ferromagnetic material, and one of the at least one magnetic surface (14) is arranged opposite to one of two different surface portions of the outer peripheral surface of the counterweight (5) in both the open and closed positions.

3. The camera shutter device according to claim 1, characterized in that, If only the first permanent magnet (6.1) exists, the counterweight (5) is made of ferromagnetic material and has at least two magnetic surfaces (14), wherein one of the at least two magnetic surfaces (14) is arranged opposite to a surface portion of the inner circumferential surface of the counterweight (5) in the open position, and the other of the at least two magnetic surfaces (14) is arranged opposite to another surface portion of the inner circumferential surface of the counterweight (5) in the closed position.

4. The camera shutter device according to claim 1, characterized in that, If only the first permanent magnet (6.1) exists, then the first permanent magnet (6.1) is attached to the counterweight (5), and a ferromagnetic armature (13) is arranged within the pivot angle range (α), having two end faces facing the counterweight (5). 13.1), wherein one of the at least one magnetic surface (14) is arranged opposite to one of the two end faces (13.1) in the open position and opposite to the other of the two end faces (13.1) in the closed position.

5. The camera shutter device according to claim 1, characterized in that, If the first permanent magnet (6.1) and the second permanent magnet (6.2) are present, the counterweight (5) is made of ferromagnetic material, and the first permanent magnet (6.1) and the second permanent magnet (6.2) are arranged opposite to each other outside the pivot angle range (α), and at least one of the magnetic surfaces (14) of the first permanent magnet (6.1) is arranged opposite to a surface portion of the outer peripheral surface of the counterweight (5) in the open position, and at least one of the magnetic surfaces (14) of the second permanent magnet (6.2) is arranged opposite to another surface portion of the outer peripheral surface of the counterweight (5) in the closed position.

6. The camera shutter device according to any one of claims 2, 3, 4 or 5, characterized in that, The surface portions of the associated magnetic surface (14) and the associated counterweight (5) or the associated end face (13.1) each form a gap (12) between the open position and the closed position, and the gap (12) is narrower than any distance from the counterweight (5) to the first permanent magnet (6.1) or the second permanent magnet (6.2) during movement between the open position and the closed position.

7. The camera shutter device according to any one of claims 1-5, characterized in that, The counterweight (5) includes a second shutter blade (7).

8. The camera shutter device according to claim 7, characterized in that, The second shutter blade (7) is fixedly connected to the linearly guided connecting rod (9), and the connecting rod (9) and the second shutter blade (7) together form the counterweight (5) and are rotatably placed at the driven end (4.2) of the double-arm lever (4).

9. The camera shutter device according to claim 1, characterized in that, The electromagnetic actuator (2) is a lifting magnet (8) having a coil (8.1) and a ferromagnetic or permanent magnet armature core (8.2.1) attached to a plunger (8.2), wherein the plunger (8.2) represents the moving part.

10. The camera shutter device according to claim 1, characterized in that, The ratio of the stroke length of the electromagnetic actuator (2) to the total length of the camera shutter device in the stroke length direction is greater than 1:

2.

11. The camera shutter device according to claim 9, characterized in that, The coil (8.1) has a coil frame (8.1.1) and a winding (8.1.2) having at least two phases.

12. The camera shutter device according to claim 11, characterized in that, The coil holder (8.1.1) represents the linear sliding guide (10) of the plunger (8.2).

13. The camera shutter device according to claim 9, characterized in that, There is a ferromagnetic enclosure (11) surrounding the coil (8.1), thereby increasing the magnetic flux generated inside the coil (8.1) and reducing the stray field generated around the coil (8.1).

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